new books - ACS Publications


new books - ACS Publicationspubs.acs.org/doi/pdf/10.1021/j150248a011It is very interesting to note, p. 175, that “in g...

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NEW BOOKS A Comprehensive Treatise on Inorganic and Theoretical Chemistry. Bt/ J.W . Mellor. Vol. 8.26x17 cm, p p . xflOO4. Nezo YorL and London: Longmans, Green and Po., 1924. Price: $20.00. This volume deals with boron, aluminum, gallium, indium, thallium, scandium, cerium, and the rare earth metals, and an instalment on carbon. I t was new to the reviewer that boron was first called boracium by Humphry Davy and that he afterwards suggested changing the name to boron in order to emphasize the analogy with carbon, p.3. Under these circumstances there seems to be no justification in clinging to glucinum in preference to beryllium. The uses of borax are given on p. 7 j. “Borax and boric acid have an extraordinary number of applications in different industries. They are used as constituents in making enamels for iron, and other metals; in the manufacture of pottery glazes; in making glass, artificial gems and strass; and in the manufacture of pigments for glass painting. Borax is used in making Guignet’s green. It is employed in the tannery, and in the currying shops for dissolving dirt and blood from skins and thus ensuring a more rapid liming. It is used for cutting oils and fats used in stuffing leather and in bleaching and mordanting leather. I t is used in the laundry in washing and starching; it helps to give linen a high gloss. Many commercial starches contain borax; and borax is also used in making some soaps. Borax is used as a wood preservative against dry rot, and on account of its antiseptic qualities it is introduced in cosmetics, mouth-washes, tooth-powders, and salves. It is used as a constituent of powders for killing insects, etc. It is employed as a preservation for meats, fish and other food-stuffs. A varnish for stuffing hats is made from borax and shellac. A mixture of casein and borax is a substitute for gum and it is moisture-proof. The paper mills use borax in making a kind of parchment, and borax is used in making sizes and coatings for glazed papers and playing cards. Borax is used as a stiffeningagent for the wicks of stearin candles; and it is also used in calicoprinting. On account of the solvent action of fused borax on metal oxides, it is used for keeping a clear surface in the welding and brazing of metals. It is also used as a flux in many other operations; and in blowpipe analysis. Borax is employed in making manganese borate to be used as a drying agent for oils”. I t is claimed that the Parthians used aluminum sulphate to make their wooden turrets fireproof, p. 148. Aluminum is apparently the ideal substance for sounding-boards, p. 180. “Aluminum differs from all other metals in the absence of the comparatively continuous and uniform higher partial tones which give in other metals the tone-color called metallic; and further that it possesses an elasticity capable of synthetic vibration uniformly through a wide range of tone-pitch, which renders it superior in this respect to wood”. The uses of aluminum are given on p. 2 2 3 . Chromium oxide is given, p. 263, as the coloring matter of the ruby; but there is no discussion why the color should be red. The suggestion has been made that the blue of the sapphire is due to an unspecified but different oxide of chromium. This does not seem probable in view of the very different behavior of the ruby and the sapphire to radium emanation and to ultraviolet light. On p. 264 we read that. “according to Rankin and Merwin, alumina occurs in two distinrt forms: a-alumina is the ordinary crystalline variety represented by corundum; and 0-alumina, which is formed in small quantities in hexagonal crystals often in groups of overlapping triangular plates when pure alumina is melted and cooled slowly. The presence of magnesia (say 0.j percent) assists the transformation of a-to 0-alumina, whereas the presence of lime or silica facilitates the formation of the a- variety. It has not been possible to convert 0-alumina to a-alumina by holding the former a t temperatures above or below the meltingpoint, and it is therefore suspected that (%alumina is monotropic with respect to a-alumina”. This last conclusion does not follow and is probably unsound. Air-dried alumina shows marked selective adsorption of air, the gas adsorbed being 41 % nitrogen and j 9 % carbon dioxide with no oxygen, p. 269. If the alumina is dried a t I IO’, the composition of the adsorbed gas is 83y0nitrogen and 19% oxygen with no carbon dioxide, p . 269.

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“According to E. Stern, in 1913, about 3300 tons of monazite were consumed annually in producing the 300 tons of thorium nitrate used in making incandescent mantles; about 315 million mantles were made in that year. About IOO tons of ceria were obtained as a by-product. Of this, about 3 tons were used in making gas mantles; zoo tons in making pyrophoric alloys; and 300 tons of cerium fluoride in impregnating arc-light carbons. A mixture of 100 grms. of thorium nitrate; 0.8 to 0.1 grm. cerium nitrate; 0 . 2 - 0 . 5 grni. beryllium nitrate; and 0.10to 0.25 grm. of magnesium nitrate is employed for impregnating the mantles. Mantles for high-pressure gas may have 2.8 per cent. of ceria. For stamping the mantles before burning off, a solution containing didymium nitrate is used. d little yttria earth, along with t,horia and zirconia, is employed in making the filaments for Nernst’s lamps. The pyrophoric alloys are used in the manufacture of modern automat,icgas lighters, petrol lighters, cigarette lighters, for indicating the path of projectiles in the so-called tracer shells and tracer bullets, etc. Here, the ‘flint and steel’ of our forefathers is revived; the steel is replaced by the so-called pyrophoric alloys. I t has been known for a long time that metals other than steel give pyrophoric sparks when struck. Thus, G. Chesneau observed that sparks can be detached from uranium by friction with hard steel, and these sparks instantly ignite mixtures of methane and air, and alcohol, benzene, or light petroleum poured on cotton. The estimated temperature is over 1000’. The sparks detached from steel have not so high a temperature since they ignite none of these gases and vapours. The term pyrophoric alloy is applied to those brittle metals or alloys which, when struck with hard steel, furnish a shower of small particles which are heated sufficiently to allow them to ignite. The cerium family of metals also gives sparks, but the metals are too soft to be useful. C. A. von Welsbach found that cerium, or mischmetall, when alloyed with iron, cobalt, or nickel, becomes brittle enough to enable the alloys to be employed for the purpose,” p. 610. “The oxidation of cerous t>oceric oxide takes place more rapidly in the presence of alkali hydroxides, but in the presence of alkali carbonate a still higher oxide is produced. The oxidation to the peroxide in the presence of air occurs only with cerous hydroxide and not ceric hydroxide. The ready oxidation of cerous hydroxide renders it a strong reducing agent, for, as W. Biltz and G. A. Barbieri showed, it reduced cupric to cuprous salts; mercuric to mercurous salts, etc. This reducing action of the cerous salts distinguishes them from the salts of all the ot,her rarc earths, and shows that in this respect they are more nearly allied to the manganese salts,” p. 628. “The colloidal solutions of ceric hydroxide, made by the dialysis of a solution of ceric ammonium sulphate, change in a marked manner with time, the ageing being accompanied by a diminution in viscosity, a gradual loss of the faculty of gelatinization, and by a diminution in the sensitiveness towards electrolytes. The change is irreversible, and is accelerated by t)he rise of temperature. It is supposed that the ageing is due to the gradual dehydration of the sol particles. The ageing of ceric hydroxide sols is very largely modified under the influence of p- or 7-rays from radium. The first effect consists in an accelerated rate of diminution of t,he viscosity, but this effect is succeeded by a second, in which the viscosity of the sol increases to a value very large in comparison with t’hat of the freshly dialyzed sol. The progress of the second stage is not dependent on the continued exposure of the sol to the action of the active rays, for if the exposure be made intermittent, it is found that the course of the viscosity-time curve is quite unchanged. A further curious effect is observed when the source of the radiation is removed before t’heend of the first stage in the ageing process. Under these circumstances, the second stage in the ageing process sets in, and the viscosity of the sol increases very considerably, attains a maximum value, and subsequently decreases almost CZPrapidly as it increased before the attainment of the maximum. The jelly obtained when the radiation is allowed to act sufficiently long appears to be perfectly stable. Similar changes in the visooeity are produced by the addition of electrolytes, although the effects are not readily distinguishable. The ageing of sols is supposed to be due to the gradual formation of larger colloidal particles by a process of aggregation, but it is probable that the effects described by the authors are connected with changes in the degree of hydration. It is probable that ceric hydroxide and other metallic hydroxide sols are highly hydrated, and in this way differ from hydrophobic colloids, such as the metallic and the sulphide sols. Under the in-

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fluence of electrolytes or p- or y-rays, the electrical charge of t’hecolloidal particles is neutralized, and this is accompanied by a diminution in the degree of hydration, and results infa lowering of the viscosity, gradual when the sol is subjected to p- or y-rays and immediate when an electrolyte is added. The increase in viscosity in the second state of the ageing process is then due to the aggregation of the electrically neutral particles, a process which takes place with a velocity comparable with that of crystallization and similar processes. The attainment of a maximum viscosity and the subsequent fall which is observed when the added electrolyte is very small in quantity or the time of exposure to the rays is comparatively brief is explained by assuming that this peptization is due to the action of the electrically charged colloid particles which are enclosed by the jelly resulting from the aggregation of the electrically neutral particles. I n support of this view, it has been found that ceric hydroxide jelly may be readily peptized by the addition of the corresponding sol,” p. 633. There is an interesting case of selective wetting in connection with diamond mining, p, 716. The heavier portions of the diamantiferous gravel “fall through a grating and are conveyed to percussion or shaking tables smeared with greases. The diamonds adhere to the grease, and the other constituents flow as tailings over the end of the percussion tables. The tailings may be dribbled on to a second shaking table; and the reject from this may be examined and any diamonds picked out. The grease is scraped froni the tables, and is placed in a pot which is immersed in a cauldron of boiling water. The grease is recovered to be used again, and the diamonds are then examined on a sorting table, where the true diamonds are separated from pyrites, barytes, etc., by hand-picking.” “The diamond is used as a gem-stone; for bearings, etc., in watches, electric meters, and scientific instr!iments; for testing the scratching hardness of minerals, etc.; for cutting glass; drilling glass and pottery; and as a powder, in cutting diamonds, drilling rock,-for which purpose carbonado is preferred because it has no tendency to cleavage, etc. Graphite is used in making refractory goods---e.g. bricks, crucibles-when the crystalline or flaky variety is preferred. -% mixture of plastic clay with 50 to 75 per cent of Cingalese graphite is moulded, dried, and fired in muffles in a reducing atm. I t is used as a resistor in electric furnaces--e.g. kryptol is a mixt,ure of graphite, carborundum, and clay so compounded as to give a granular mass; but graphite alone gives as good or even better results. Graphite is used in the manufacture of lead pencils. -% mixture of graphite and clay, very carefully graded and washed, is moulded by expression, fired, and fitted into the wooden casing. Graphite-particularly the colloidal form-is used as a lubricant with or without tallow, grease, palm oil, etc. Graphite is used in the foundry as a facing for moulds; in making paints, particularly for coating iron surfaces; in electrotyping; for commutator brushes; in making battery plates; as a polishing medium-e.g. for gunpowder-in making stove polish; as a preventive of boiler scale; etc. Amorphous graphite, and charcoal are used for decolorizing sugar, fats, glycerol, etc. ; in the filtration and disinfection of liquids; for the separation and recovery of gases and vapours; the purification of gases; the storage of gases; as a catalyst in many reactions; in the production of high vacua; as an absorbent in gas masks for noxious gases, and in the removal of industrial stenches. The charcoal mask was recommended by J. Stenhouse in 1854. Charcoal is used as a constituent of some explosives; as a depilatory in the tannery; in making crucibles; battery plates; in the manufacture of indian ink, printers’ ink, black paints; etc. The manufacture of carbon electrodes for electric furnaces and arc lighting is one of the most important branches of the carbon industry, and is growing rapidly as electric furnaces are increasingly applied in the metallurgical industries. As experience in the manufacture of carbon electrodes grows, the specifications as to purity, electrical resistance, hardness, and density become more and more stringent. Carbon electrodes were used by H. Davy about 1 8 ~ 6 .Carbon filaments are employed in incandescent electric lamps. The light emitted by a hot body increases rapidly with rise of temp. A platinum wire heated by the electric current gives a good light, but this metal melts a t too low a temp. to render it satisfactory. Carbon filaments mere then tried and they gave better results, but they had a comparatively short life. Improvements in the manufacture of the filaments considerably increased the length of t,heir practical life. The useful life of a carbon filament lamp depends more on the

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vaporization than on the melting point of the carbon. Different kinds of carbon have different vapor pressures. The graphitized filaments have the longer life,” p. 833. While we have no direct method of determining the molecular weight of graphite or diamond, “Sernst’s observations on the specific heat of the diamond fit formulas deduced on the assumption that the molecule of the solid is monatomic; while the specific heat of graphite fits better the assumption that the molecule is polyatomic, C,, whrre n is greater than unity.” P. 839. “According to NI. Tanret, if a mixture of solutions of chloral hydrate, CCla.CH(OH)z, and of potassium permangante be made alkaline, say with potassium hydroxide, gas is evolved, the liquid becomes discoloured, and sesquioxide of manganese is precipitated. If several grams of chloral hydrate be acted upon, and the temperature not raised above 40°, the reaction will last for some hours; then on filtering the liquid the filtrate will be found to contain chloride, carbonate, and formate of potassium. The gas evolved is carbon monoxide. The reaction occurs equally well with very dilute solutions, and even if borax be substituted for potassium hydroxide. This decomposition leads to a theory to account for the action of chloral hydrate upon the animal system; it is suggested that when this substance is taken into the circulation, it is submitted to oxidizing agencies; the alkalinity of the serum determines its decomposition; the carbon monoxide displaces the oxygen from the arterial blood, and produces an effect similar to that resulting from poisoning by carbon monoxide. The lowering of the temperature of the body and the prolonged action of the chloral hydrate, owing to slow decomposition, tend to make this theory more tenable than the assumption of its conversion into chloroform. The slow decomposition of chloral by an oxidizing agent also explains the continuity of its action as a hypnotic, which would not be the case if it were transformed into chloroform,” p. 913. T i l d e r D. Bancroft Chemistry in the Twentieth Century. Edited by E. F . Armstrong. 2 6 x 2 0 cm; pp. ix+ 281. New York: l h e Macmillan Co., 19S4. Price: $5.25. The aim of this volume is to present to the reader, by means of a series of monographs, a statement of the present position of chemical science in Great Britain. There is an introduction by the editor, E. Frankland Armstrong, and the individual papers are: the rBle of chemistry in physical science, by J. I. 0. Masson; the structure of the atom, by E. N. daC. Andrade; crystallography, by T. V. Barker; X-ray analysis of crystals, by Sir William Bragg; the rare gases of the atmosphere, by M. W. Travers; the chemistry of carbon compounds, by J. F. Thorpe; milestones in organic chemistry, by H. E. Armstrong; the chemistry of colloids, by William Clayton; catalysis, by T. P. Hilditch; the fats and oils, by John Allen; the sugars and carbohydrates, by J. C. Irvine; cellulose, by C. F. Cross; colour in nature, by Reginald Furness; coal-tar colours, by E. A. Bearder; syntheses in the terpene series, by G. G. Henderson and Alexander Robertson; the alkaloids, by F. L. Pyman and T. A. Henry; the nitrogenous constituents of the living cell, by R. H. A. Plimmer; biochemistry and fermentation, by Arthur Harden; chemistry in agriculture, by H. J. Page; alloys, by C. H. Desch; pottery and refractories, by Joseph Burton; explosives, by Sir Robert Robertson; the chemistry of photography, by Walter Clark. On p. 17 the editor says that perhaps some day the chemist may even succeed in having a loaf of bread delivered to the customer wrapped in clean paper. That stage has been reached to some extent in this country. On p. 24 we read that “the foremost aim of physical science today may be taken as the discovery of a fundamental unit of matter; of a fundamental unit (if there be one) of action or energy; and ultimately, of the cause-and-effect connection between these two units. Although we do not a t all presume to determine the deeper exploration of the future, it seems justifiable for us now to say that the first of these units is nearly in our grasp, the second is apparently drawing within range; but the definite capture of both involves that of the third, which is no nearer than the horizon.” “An objection to the theory that the mass of all nuclei is due to protons immediately occurs”namely, that the atomic weight of hydrogen is not I , but 1,0077, in terms of oxygen as 16. This has been met by arguments which lead to speculations of the first importance. The

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hypothesis to be justified is that packing the protons close together to form heavier nuclei, the size of which is but little larger than their own, leads to a slight loss of mass. The electromagnetic theory of mass does, in fact, indicate such loss, since the inertia of an electric charge depends upon the space in which it is concentrated, but the problem arises as to what has become of the mass. On all older theories mass is indestructible, but according to Einstein’s theory of the equivalence of mass and energy a loss of mass can be compensated by a release of an amount of energy which calculation shows to be very large. I n fact, it follows from the theory that if four protons, which when separated have a total mass 4.0308, should combine to form a helium nucleus, 5 x 10-6 ergs of energy would be set free. This may not sound very much, but it is equivalent to saying that if a gram-molecule of helium could be made out of the necessary hydrogen atoms 7 X ~ o l calories l would be set loose, or some hundred million times as much heat as is produced by the burning of an equal weight of coal. To put the matter in an engineering form, one ounce of helium in the course of formation from hydrogen should yield a million horse power for seven hours. This exceeds the transformations dreamt of by the alchemists; but, so far, we cannot see our way to making hydrogen nuclei stick together with the cement of two electrons. Perhaps we shall one day get, with great difficulty, a few atoms of helium so to form, which will satisfy the man of science; perhaps we shall get a controlled rate of formation in appreciable quantities, which will satisfy the engineer; perhaps we shall get an uncontrolled and cumulative rate of formation which will destroy the experimenter, and satisfy certain religious sects who object to experiments as impious; or will destroy the world and satisfy nobody. This is merc speculation, but one can scarcely refrain from speculation a t the thought of these enormous supplies of energy associated with so small a weight of matter. I n any case nuclear chemistry, which is at its very beginning, is bound to furnish sensational results,” p. 49 When discussing crystallography, Barker says, p. 73, that “in a series of investigations, in collaboration with Miss F. Isaac, it was shown, by measuring the refractive index of the solution in contact with the crystal, that there are two degree of supersaturation, the metastable and the labile. ,4 solution in the former condition will not crystallize spontaneously, however violently stirred, but will quietly deposit material on any crystals that happen t o have been introduced. A solution in the labile state, on the other hand, immediately liberates a shower of crystals on shaking, the result being a sharp drop in the refractive index.” I n regard to the Lodge-Cottrell process, Clayton says, p. 133, that “owing to the rapidly alternating polarity of the particles, they clump together to form flakes or drops, as the case may be, and these clumps are heavy enough to settle out provided the gas velocity is sufficiently low.” This is not a t all what happens. A direct current is used and the particles are carried to the larger electrode. It, is very misleading for Hilditch to say in regard t o contact catalysis, p. 137, that “according to one view, the chemical combination of two substances in presence of a specific third material is due to the condensation of the two former a t the surface of the third, resulting in a highly concentrated surface layer of each of the interactants.” This seems to imply that the high concentration is the important thing. It is very interesting to note, p. 1 7 5 , that “in general the distribution of pigments in flowers coincides exactly with that of oxydases. The oxydases, it is true, are more widely distributed than are the chromogens; but the distribution is in conformity with the oxydasechromogen hypothesis, as will be illustrated by several typical examples, culled from the many available. The flowers of P r i m u l a sznensis and of Dianthus barbatus (Sweet William) show most epidermal oxydase in the most deeply coloured varities, less in the less deeply coloured, and none a t all in the white varieties. The white flowers of certain P r i m u l a sinensis, P i s u m sativum, and Lathyrus odoratus have all been shown to contain oxydases, and the white colour is attributed to the absence of chromogen. In the Mont Blanc Star, the distribution of oxydase again parallels that of pigment. One flower had irregular magentaflaked petals with one exception, this particular petal being of a uniform magenta colour. The latter petal gave a well-marked oxydase reaction, the magenta patches on the others demonstrated a fair reaction, whilst the white portions did not respond to the test. Similarly, Sweet Williams were grown in full-coloured, white, and almost white varieties, the latter showing rosy dots or lines. The fully-colored flowers responded definitely to the tests for the pres-

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ence of oxydases, whilst the white flowers also gave a definite but limited reaction-the white colour being probably due, as explained above, to the absence of chromogen. The white flowers with rosy dots showed oxydases only in the part,s of the petals corresponding to the pigmented dotb.” “There is one aspect of the importance of the industry which is deserving of mention. h few years ago the manufacture of artificial silk from cellulose acetate became a commercial proposition and its production on an industrial scale commenced. Very grave obstacles were encountered, however, which were gradually overcome and ultimately an excellent saleable material was evolved. It was then found that, unlike the other varieties of art,ificial silk, this new one was not susceptible to the usual dyeing processes and, indeed, that it could not be dyed by any known process so as to yield shades of a useful degree of fastness. Without a suitable method of dyeing it was clear that the new fibre could have but a very limited utility, and consequently a great deal of attention was directed to the problem with the result that very praiseworthy progress has been made. If the problem has not yet been completely solved it’is a t least now possible to dye cellulose acetate silk in practically any hue required, and there is little danger of the young industry being stunted from difficulties in this direction,” p. 182. “In recent) years very striking results have been obtained in the study of the effect on plant growth of small quantities of elements other than those known to be essential. Bertrand and MazB, in France, have studied this subject extensively, and they conclude that in small doses manganese, zinc, fluorine, and iodine produce definite increase in growth in water cultures; in this country, similar results have been obtained with manganese by Dr. Brenchley in water cultures; but in field trials the results were negative, probably owing to the presence of sufficient manganese in t,he soil already. Silicates also appea8rto have a beneficial effect. This is especially noticeable on the phosphate-starved plots a t R,othamsted; Hall and Morrison conclude that silicates act by causing an increased assimilation of phosphoric acid by the plant. The view has also been advanced, however, that silicates are able to replace phosphates to a certain extent in the plant. This problem is now under investigation a t Rothamsted. Voelcker has carried out a long series of pot experiments as Woburn on a variety of inorganic substances. These were all toxic above a certain concentration, but in some cases there was evidence of a st’imulatingeffect when the concentration is low. This appears to be the case with salts of lithium and with borates. The study of the action of the latter has recently been again taken up at Rothamsted, with very striking results. I t has been found that in water or sand culture certain leguminous plants, such as the broad bean, are quite unable t,o make satisfactory growth or to flower and set seed if they are entirely deprived of boron. The most, minute trace of boric acid ( I part in 2 . 5 million parts, or even less) suffices, however, to bring about normal healthy growth; moreover, a plant which is almost i n eztremis from lack of boron can be cured and started into healthy growth by the addition of a quantity of boron of the above order. Similar results have been obtained with other leguminous plants such as runner beans and red clover, but in the case of a cereal crop such as barley the effect is not produced. I t is a t present impossible to say what part these minute traces of boron play in the growth of the plant, nor is there any evidence that plants grown in the field ever suffer from lack of boron, which j s present in traces in most soils. Results of this sort do, however, suggest the possibility that the deterioration of soil continually receiving only artificial fertilisers may be due to the gradual removal from the soil of some element which is beneficial to the crop in minimal amounts, and which is present in dung,” p. 228. “Before leaving the consideration of the physical properties of the soil, mention may be made of the striking results that have recently been obtained a t Rothamsted in the study of the effect of farmyard manure and of chalk on the mechanical properties of the soil. Practical men have long known that both these materials exerted a beneficial effect on the tilth and ease of cultivation of heavy soils. Quantitative expression is given to this fact by measurements which have been made, by means of the dynamometer, of the power consumption in ploughing land which has been dunged or chalked. I t has been found that if the draw-bar pull exerted in ploughing unmanured land on the Rothamsted farm be represented by 100,

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that exerted in ploughing dunged land was 78-82, while for chalked land the figure was 8j. This represents a n appreciable saving in power, and in cost of cultivation,” p. 230. ‘‘The shortage of farmyard manure arises, not from any shortage of straw, but from a shortage of animals, caused in no small degree by the replacement of the horse by mechanical traction. Earlier work a t Rothamsted by Hutchinson on the breakdown of cellulose in the soil and on the relation of carbohydrate material to nitrogen fixation and nitrate assimilation led Hutchinson and Richards to study the conditions under which straw could be caused to rot down. As a result of this work they found that by treating wet straw with a certain amount of combined nitrogen and maintaining the reaction of the mixture faintly alkaline it was possible to convert the straw into a product which had all the outward appearance of farmyard manure and was of very similar composition. Field trials gave very promising results, and the process was patented. The commercial development of the process is now in the hands of the AigriculturalDevelopment Company, a non-profit-making syndicate which owes its origin to the public-spirited action of Lord Elveden, who had already given considerable support to the earlier work on which the process is based. The process has now been further improved in several respects, and a number of large-scale trials have taken place in various parts of the world. In this country, straw is the raw material to which the process would ordinarily be applied; but many other waste plant products from outlying parts of the Empire have been tested and successfully converted into synthetic farmyard manure in the laboratory.. The further development of this process promises to be of great value to agriculture both in this country and overseas,” p. 240. TVilder D . Rancivfl

The Story of Early Chemistry. By John Maxson Stillman. 22x15 em; p p . xiiiJr666. New York: D. Appleton and Company, 1924. Price: 04.00. Professor Stillman died just before the first proofs of this book were received from the printers and the volume has been seen through the press by his colleague Professor Young. No one who had the privilege of knowing Stillman, no matter for how short a time, ever forgot him. Young says in the foreword that “there was something in Stillman’s art as a teacher that almost invariably commanded the respect, admiration, and devotion of his pupils. . . . If it is to be explained a t all, I think it was due to a fine power of his, of keenly discerning the deeper spiritual characteristics and mental traitsof eachof those with whom he came into contact, and thus of subtly distinguishing between individuals and meeting each on his own ground. . . “It was out of Professor Stillman’s labors as a teacher that ‘The Story of Early Chemistry’ was born and grew to what it is. For much of his life he had given increasing attention to the history of chemistry, and for many years taught the subject to small classes. Gradually covering new ground and extending his knowledge of the field, he finally gained a breadth of view which he felt might justify some contributions to the literature of the subject.” The book deals with chemistry up to the death of Lavoisier; in other words, through the beginning of modern chemistry. The chapters are entitled: the practical chemistry of the ancients; the earlieit chemical manuscripts; theories of the ancients of matter and its changes; the early alchemists; chemical knowledge in the Middle Ages; chemistry in the thirteenth century; chemistry of the fourteenth and fifteenth centuries; the progressive sixteenth century; chemical currents in the sixteenth century; chemistry of the seventeenth century; the eighteenth century-rise and fall of the phlogiston theory; the development of pneumatic chemistry in the eighteenth century; early ideas of chemical affinity; Lavoisier and the chemical revolution. “There has been much speculation as to the sources whence the ancient Egyptians obtained the tin for their bronzes. X o nearby sources have been discovered. Geologic evidence is to the effect that tin occurred in Persia, and it may have been from this region that the earliest supplies came. It is also possible that sources of tinstone from farther south on the African continent may have been drawn upon, but any evidence t o that effect is also lacking.

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“The Greek name ‘kassiteros’ is allied to the more ancient names for tin among Assyrians, Acadians and Babylonians. The Sumerians in Southern Babylonia (Shinar), evidently possessed a knowledge of tin as a constituent of bronze ab early as about 3000 B. C., and i t is not impossible that this region was the earliest source of tin for Egypt and the Mediterranean countries. Just when the sources of tin in Britain became available to the ancient world about the Mediterranean is difficult to determine. References in ancient authors, however, make evident that certainly by the fifth century B. C. tin was received from that region. The price of the metal was lowered and the uses of bronze much expanded by the opening up to trade of the rich deposits of the British Islands,” p. 4. On p. 48 we read that the ‘ammoniacal’ salt of Dioscorides is not, as was sometimes supposed, our sal-ammoniac; but was common salt from Egypt in the vicinity of the temple of Ammon. Our word ammonia is apparently a corruption of Armenia, p. 245. The v i e w of Dioscorides on wine and beer would have delighted the modern prohibitionist, p. 5 5 . “Fermented liquors, wines, meads and beer were known in all countries from the most ancient times. Their use a t the time of Dioscorides and Pliny wa6 extensive and excessive. They naturally entered largely into medicine. I t is worthy of note that Dioscorides ascribes injurious action to their continual use, and advises they be used only as occasional stimulants. The effect of new mine in accelerating the pulse may be avoided, he says, by adding water and boiling until this is again evaporated. That the reason for this lies in the elimination or reduction of the alchool content was beyond the understanding of the time. “Beer, from grain, especially barley, he considers as especially deleterious, as it bloats, promotes obesity, attacks the kidneys through its diuretic properties, and irritates the nervous system and the brain.” Stillman does not attempt to settle the dispute whether the Greeks did or did not get their theories of the nature of matter from the philosophers of India, p. 104. “These two nations developed the most consistent and logical theories, strangely parallel indeed in their development. Scholars are not agreed upon the question as to whether the development of the philosophy of nature in the two ancient civilizations has been entirely independent. Certain it is that, up to the present time, no historical evidence has been discovered which indicates any direct contact of Hindu and Greek thought, though it is not thereby rendered impossible nor even improbable that through Persian mediation Hindu concepts may have found their way to Greek thinkers, if only in the form of imperfect and incomplete suggestions. Scholars differ on this probability.” Stillman points out, p. 127, how far Aristotle’s method of developing a theory was removed from the inductive methods of modern science, and on p. 144 we read that the inductive method of modern science is not the method of Plato. The reviewer believes that modern science talks about the inductive method but uses the deductive method. Stillman tells us, p. 279 that “so far as present knowledge authorizes we may assume that Geber was a European chemist, probably a Spaniard, who wrote largely from his own experience as a practical chemist and metallurgist, and that his theoretical views upon alchemy were those of the thirteenth century, which were largely the result of Arabian development. S o Arabian originals are known which might have been translated by him nor which present so advanced a knowledge of chemical processes. On the other hand he makes no claim to originality, and seems to have endeavored to give a clear description of the practice of his time.” He also thinks well of Paracelsus, p. 3 2 3 . “Much more important than any specific chemical advances due to Paracelsus was his influence in attracting the attention of physicians and chemists to the importance of chemistry in the development of medicine in connection with his campaign against the blind worship of traditional authorities. In his life-long and intense struggle against the conservatism of the medicinal faculties and profession, he constantly emphasized the duties of the physicians to depend upon experiment and independent observation rather than on the dogmatic medicine of Galen and Avioenna, and emphasized the great value of new medicine derived from the development of chemistry.

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“He possessed a breadth of view as to the field of chemistry and its possibilities, and stimulated chemists to seek a more important field for their activities than the search for gold making or the philosopher’s stone. Not that he disbelieved in the possibility or reality of transmutation. On the contrary it received full attention and credence from him in his chemical philosophy.” The reviewer was much pleased to learn the origin of the word gas, p. 323. “The term gas a s a generalization for aerial fluids was first suggested by van Helmont (1577-1644)~ himself very familiar with the works of Paracelsus and to some extent a champion of his views. He tells us that he derives this word from the Greek chaos, and it is more than probable that it ’(vas the use of the word by Paracelsus in this sense that suggested the word gas to van Helmont.” Of interest also is van Helmont’s experiment, p. 382, in which a willow tree gained one hundred and sixty-four pounds when grown in a weighed amount of earth which remained unchanged. Since the pot was supplied only with rain water or distilled water, van Helmont concluded that one hundred and sixty-four pounds of willow tree had been produced from pure water. “If we recall that a t that time there was no knowledge or suspicion of the presence of carbon dioxide or of nitrogen compounds in the atmosphere, and that nothing was known of their relation to vegetation, and again if we consider the large number of substances obtained by the distillation of wood, me cannot regard van Helmont’s conclusion as anything but a reasonable deduction from the facts as he knew them. Furthermore, his conclusion was confirmed from certain facts of which he knew but had not personally experimented upon. Such was the often repeated account of certain springs which have the power of converting wood or charcoal into stone, a process usually interpreted a t that time as a kind of transmutation. As charcoal is producible from water alone, and as charcoal can be changed to stone, this proved to van Helmont that the stone also is materially water. Also the fact that fishes spend their lives in the mater and obtain their development by things occurring in the water is interpreted by van Helmont to mean that they, like his willow tree, are also ultimately produced from water.” We wish that Professor Stillman could have been spared to writes more books for us; but this one is a fitting close to a busy and well-spent life. Wilder D. Bancroft

The Simple Carbohydrates and the Glucosides. B y E. Frankland Armstrong. Fourth edition. 26x16 cm; p p . x i f Z 9 3 . New Y o r k and London, 1924. Price: $5.00. I n the preface the author says that “a natural period in the history of chemical discovery, especially in the sugar group, was brought to a close through the death of Emil Fischer in 1919. This monograph is very largely a record of his monumental work. . . . I t is remarkable that just a t the close of Fischer’s activity, the outlook suddenly became widened by the disclosure, both in his laboratory and by Irvine in that built by Purdie at St. Andrews, of a form of hexose molecule other than the isodynamic, stereoisomeric alpha and beta forms. The new form, gamma glucose, is characterised by its relative instability and the readiness with which it undergoes oxidation. “That a discovery of so refined a character, so long delayed, would rapidly find practical application was scarcely to have been expected; there is, however, reason to think that it may prove to be of primary importance in connection with the fell disease, diabetes.” The subject is presented under the headings: introduction; glucose; stereoisomerismisomeric change-structure; the chemical properties of glucose and the hexoses; the hexoses pentoses, and carbohydrate alcohols; the disaccharides; hydrolysis and synthesis; the polysaccharides; the relation between configuration and biological behaviour ; the natural glucosides; the synthetic glucosides; the function of carbohydrates and glucosides in plants. The a- and 0- methyl glucosides, p. 12, and the a- and (3- glucoses, p. 40, are striking cases of slowly interconvertible liquid modifications. The glucoses are especially interesting because, p. 41, “a solution of glucose containing a and P forms can be made to give wholly a- or wholly P-glucose on concentration, according to the temperature a t which crystallisa-

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tion takes place. The a form, which is then the less soluble, is that obtained at lower temperatures; but, above 98’, the 6 form, being the less soluble a t the higher temperature, alone separates.” I t is a pity that we have no diagrams for this equi1;brium. The interconversion of glucose, fructose, and mannose in presence of dilute alkali, p. j6, is another case of the same type. On p. 50 is an interesting paragraph. “From the biological point of view, the fact that glucose exists in solution not as a single substance but as an equilibrated mixture of stereoisomeric butylene oxide forms, readily convertible into one another, is of fundamental and far-reaching importance. If one of the stereoisomerides is preferentially metabolised in the plant or animal, in the course of either synthetic or analytic processes, the possibility of controlling the equilibrium in the one or other direct,ion, so as to increase or limit the supply of this form, places a very delicate directive mechanism at the disposal of the organism. This question is undoubtedly one which demands the close attention of physiologists.” “The ketose sugars without exception are decomposed when their aqueous solutions are exposed in quartz tubes to sunlight. Carbon monoxide is evolved and the corresponding alcohol containing one carbon atom less is formed. The aldose sugars are practically unaffected under these conditions. Exposure of the ketoses to the ultra-violet light from a mercury lamp brings about the same decomposition, but other actions also take place involving the formation of hydrogen, methane, formaldehyde and non-volatile acids. The aldoses are decomposed in a similar manner to the ketoses by ultra-violet rays but are less susceptible to attack,’’ p. 57. “The combination O.C.O.C.0 determines the extraordinary instability of sucrose in presence of acids as compared with that of maltose, lactose, etc. The amylene oxide ring> in contrast to the butylene oxide ring, opens by the agency of very weak acids thus disturbing the glucosidic linking which then undergoes hydrolytic cleavage. The initial condition of the fructose formed is transient as it rapidly passes to the stable butylene oxide form,” p. 123. “Today’s knowledge enables it to be stated that the active forms of sugar in metabolism are not the stable butylene oxide forms but the 2 ring forms, whatever they may be, under acid and neutral conditions and the open ring enolic form or even the very closely allied aldehyde or ketone itself when the reaction is alkaline. The effect of the addition of an aldehyde to a fermenting mixture of yeast juice and glucose in presence of a suitable amount of phosphate is greatly to diminish the time required for the attainment of the maximum rate of fermentation: it is considered that the aldehyde acts as an acceptor for hydrogen, a conclusion supported by the fact that methylene blue produces a similar effect. I n an ordinary fermentation of glucose it is probable that hydrolysis of hexose phosphate results in the formation of fructose which in its turn yields a hydrogen acceptor and assists the increase in the rate of fermentation. Acetaldehyde and methylene blue are something like j o times as eflective as fructose in accelerating the fermentation of glucose. I n the presence of acetaldehyde fructose is fermented more rapidly than glucose. “In view of the preceding there can be little doubt that one function of phosphoric acid in the plant is in some way to modify the sugar as in fermentation. Probably the intermediate product of the hydrolysis of glucose phosphate is */-glucose,” p. 176. The saponins “are soluble in water, giving clear solutions which froth strongly on agitation, form emulsions with oils or resins, prevent the deposition of finely divided precipitates, and occlude electrolytes and also many soluble dyestuffs. The saponin of soapwort, for example, in its colloidal form gives a blue adsorption compound with iodine, although the crystallisable constituent does not,” p. 216. “The recognition of the potent effect of the constituents of glucosides in acting as stimuli and starters of active metabolism may be of importance in studying the nutrition of animals. I t is well known that the herbage of one pasture may have the power of fattening an animal whereas similar grass on an adjoining field, though equally readily consumed by the animal, fails to bring it into condition for the market. “This is especially the case in Romney hlarsh, where one field mill fatten six or eight 01’ more sheep to the acre whereas an adjoining field will do little more than keep the sheep in

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a growing condition. Hall and Russell, who investigated this difference in 1912, found that the floral type in the two fields was constant but that a leafy habit of growth obtained in the fattening field and a stemmy habit in the poorer fields. The ordinary methods of chemical analysis failed to reveal any difference either in the herbage or the soils. Since this date much evidence has accumulated in favour of the importance of quality as well as of.quantity in animal feeding and the subject is one of the greatest importance to agriculturalists. “Subtle differences between the grasses of these two fields have hitherto defied detection, but it is not impossible that the presence or absence of certain glucosides or similar constituents may have some bearing on the difference,” p. 230. Three changes take place simultaneously in the potato tuber during storage : “starch is being transformed into sugar, sugar into starch and also by the procees of respiration into carbon dioxide. A decrease in the temperature hinders all three reactions but it has least effect on the formation of sugar from starch. Accordingly, when the potato is stored at oo sugar is formed till the amount increases to 3 per cent. At - I O all enzyme action ceases. ht+3” there is still formation of sugar but the enzymes acting to destroy it tend to keep the amount down to 0.5 per cent. *4t 4-6’ the rate of formation of sugar from starch and that of the reverse change are equal; above this temperature the formation of starch predominates. I n consequence no sugar js stored and any sugar previously present is destroyed,” p. 237. “In the case of plants which are killed by frost it is supposed that as a result of the removal of the water as ice the concentration of the cell fluid becomes such that the soluble proteins are precipitated from solution. This salting out of the proteins is prevented by the presence of non-electrolytes such as sugar: Lidforss, to whom this explanation is due, has shown that the leaves of winter plants are free from starch but contain much sugar. The warm days of early spring bring about the regeneration of starch and partial disappearance of sugar; in consequence the cell is but ill protected against the effects of a subsequent frost,” p. 238. “During ripening, the skin of the banana changes from green to yellow, deep brown, and finally black; the fruit is then fully ripe. This change is due to an oxydase acting on some aromatic substance liberated from a glucoside. The black colour is quickly produced when a yellow banana skin is disintegrated by mincing or when the entire skin is exposed to the vapour of some hormone. Under natural conditions the stimulus which leads to blackening is given from within the fruit by the liberation of the characteristic ester of the banana, which acts as a powerful hormone. I n the case of mojt fruits, it would seem that the final appearance which is associated with ripeness is conditioned by st,imulus from within rather than by any envjronmental influence,” p. 239, FVilder D. Bancroft The Corrosion of Metals. By Ulick R. Evans. Z Z X 1 6 cnz; p p . xi+%?IZ. Yew York and London: Longmans, Green and Co., 1924: PTice: $6.00. The author is a firm believer in the electrochemical theory of corrosion, though he prefers to call it the newer electrochemical theory, p. 9. Ry this he merely means that he is laying more stress on differences of oxygen concentration and less on differences of metal surface than Cushman and Walker did. He also emphasizes the fact that direct oxidation at higher temperatures is quite differenttheoretically from oxidation at ordinary temperatures in presence of moisture, p. 12. I t is rather a pity, p. 36, that he prefers to discuss the anodic corrosion of zinc in a chloride solution as due to the discharge of chlorine which then reacts with the zinc. It is true that, he makes clear that this is not what happens; but it is usually safer to state things as they are. One wonders whether the difference in rate of going passive of pure, rolled nickel anodes and impure, cast anodes is really only a matter of current density, p. 48. The author brings out clearly, p. 62, that over-voltage may easily overbalance the effects due to heterogeneity. “The corrosion of zinc was not aided by contact with compact cadmium or compact lead (metals with high overpotential values); but was accelerated by contact, with dark spongy lead. Cadmium, which mas itself almost unaffected by hydro-

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chloric acid, liberated hydrogen when brought into contact with nickel or iron. Iron gave off hydrogen slowly by itself, but much more quickly in contact with nickel; contact with copper or lead was not found to have any appreciable effect. Sickel, lead, and tin, as already explained, only liberate hydrogen when in contact with black platinum, and even then only extremely slowly. . . . “Although impurities of low overpotential value usually increase corrosion by acids , those having high values may actually diminish it. Amalgamated zinc, for instance, is practically unattacked by dilute sulphuric acid owing to the high overpotential of mercury, although it evolves hydrogen readily if touched with copper; amalgamated iron withstands the effect of fifteen percent sulphuric acid for a day or two, but the protective effect may vanish quite suddenly, probably because the mercury gathers itself spontaneously into globules. The presence of arsenic in dilute sulphuric acid reduces greatly the corrosion of iron by that acid, probably owing to the high overpotential of the arsenic deposited on the metal. Arsenic fails to protect iron against corrosion by an acid solution of ferric chloride (an oxidizing agent which corrodes without the evolution of hydrogen), nor does amalgamation protect zinc from the same reagent.” “Whilst heterogeneous structure on a coarse scale certainly affords a condition favourable to corrosion, a fine duplex structure, such as is present in alloys or impure metals, does not necessarily lead to rapid attack. Here the anodic product (a soluble salt of the metal) and the cathodic product (alkali) are produced so close together that the insoluble precipitate is formed almost in contact with the surface, and may produce a ‘blanket’ over it. Furthermore, if the alkali from the cathodic areas gains direct access to the anodic areas it may produce passivity there; the whole surface may thus become ‘equipotential’ and corrosioncurrents may cease to flow altogether. Consequently an article consisting of a large piece of the metal A in mechanical union with a large piece of the metal B will behave differently from a similar article constructed wholly of an alloy consisting of a mosaic of A and B. Murray has found that the so-called ‘double fagoted iron’ (consisting of alternate layers of wrought iron and mild steel) rusts quicker in damp air than simple mild steel; microscopic examination has shown that rusting commences where the pearlite areas of the steel touch the ferrite areas of the pure iron. But within the steel itself, pearlite and ferrite are in contact, and yet along these lines of contact no special corrosion can be observed,” p. 70. There is an excellent discussion, pp. 72-82, of corrosion due to differential aeration. The effect of stirring on the corrosion of copper is taken up on p. 103 and, on p. 105, we find McKay’s work on the different behavior of stagnant and moving solutions. Since nearly everybody is apparently willing to accept the electrochemical theory of corrosion when properly worded, it is time for those interested in the subject to get together and to devise methods for studying the behavior of protecting films and for developing an accelerated test. These two problems are not taken up in this book because they are the unsolved ones. The reviewer is quite confident that the accelerated test of the future will be an electrolytic one; but he recognizes fully the immense amount of work to be done before any such test can be accepted as absolutely satisfactory. A’zlder D.Bancroft

What Industry Owes to Chemical Science. Bu Richard B. Pilcher and Frank Butler-Jones. Second edition, rewised and enlarged. 19 X1.3 cm; p p . xof158. N e w York: D. Van Nostrand C o m p a n y , 1984. Price: 83.00. Thc first edition was reviewed over five years ago (23,660). The new edition differs but slightly from the old one, and the titles of the chapters are the same in the two editions. The chief value of the book is that it gives numberless examples of industrial applications and the teacher can choose from these the ones which will be helpful to him. Wilder D.Bancroft

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