general and inorganic chemistry. - ACS Publications

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ABSTRACTS : GENERAL AND TXORGANIC CHEMISTRY.

I?R

ABSTRACTS. --

GENERAL AND INORGANIC CHEMISTRY. Incompleteness of Combustioil in Gaseous Explosioiis. H. B. DIXONand H. W. SMITH. When a misture of hydrogen and oxygen, in the propnrtions in which they combine to form water, was exploded in a leaden tube 100 metres long and 9 m. m. in diameter, there remained an esplosive residue. Even with a slight excess of osygen the hydrogen was not completely burned. From investigation, it appears that although the amount of burface exposed to the gases, has some iqfluence on the amount uihurnt, the influence is not very great, and that the incompleteness of the combustion is therefore not due to the cooling action of thc surface of the vessel. The capacity of the above mentioned lead tube was 8100 c. c. and the volume of unconsumed gas varied from 100 c. c. to 250 c. c. Nearly one per cent. of the original detonating gas remained unbnrnt. (Clmn. Y e w s . , 59, 6.5.) W. P. M.

Coloratioii of a Coal Fire By Conimoii Salt. K o ~ ~ r .Leoxis ARl),

The blue flame produced, so different from the well-known sodium flame coloration, has been considered as perhaps due to :i union of chlorine with the carbon and hydrogen of the fuel, with formation of compounds such as chloroform and tetrachloride of carbon. This supposition is pretty well borne out by the following facts : 1. The blue flame is not produced when sodium chloride is projected on to a red-hot platinum capsule. 2. The coloration is produced equally well by potassium chloride, and less readily by the chlorides of bnrinm, calcium niid ammoni urn. 3. The coloration is not produced by sodium carbonate, phosphate or sulphate. 4. Chloroform, carbon tetrachloride and ethylene dichloride, when thrown into a coal fire, produce blue colorations similar t o that produced by sodium chloride. (Chem. iVe?cs.59, 16). IV. 1’. M.

ANALYTICAL CHEMISTRY. Decoinposition of Yickel and Cobalt. The Clwtiicnl -1-ews piilllislics the following portion of a letter from Proff. Kriiss : '* I have in fitct succeeded iii splittiiig up nickel and c+obalt,each into two parts, and both these metals have one component in common. In coiicert with my colleague. I sciit a brief notice on this subject to the Bericlife. which will ilppear iii I3crlin 011 Monday next, Blst inst, The matter communicated in this short memoir has been intentionally kept very scanty, and I h a w given as little room as possible to speculation $or fear of being led to assertions which I might perhaps soon have to withdrm. Meantime, I have fully confirmed our first observations, and we have now about ten different methods by which we can resolve these bodies, Iiitlierto regarded as elementary. each into two parts. TVe shall soon give a full report on our results, but iii tlic me;tntime I may inform you, as a curious fact, that we h a w succreded i n obtainin yree,i socalled nickel salts from red cobalt salts and the cobrless salts of the substance which accompanies both nietals, and further, in transforming some green nickel salts into red cob:tlt salts ;md other components. '(This may perhaps sound alchemical, but i t cannot be denied. As for the spectra of the three components of cobalt find nickel. we have not as yet, with the ordinary experimental arrangements. observed any characteristic lines. This is doubtless the rewon why hitherto no spectral lines have been found common to pure cobalt and nickel." (Chevn. News. 59, 35.) M.P. Jr.

Analytical Examiliation of Water for Twhiiical Piirposes. A. H. ALLEN. Determination of hardness by titration with ,soap solution is utterly misleading. Although acting more slowly than CaO, still MgO does not possess greater hardening power ; a statement contrary to Wanklyn, who claims that the hardening power of CaO is to that of MgO is as 2 is to 3. If by "hardness" of water is meant its soap destroying power, thcn 110 dilution of hard watei-s should Irc made previous tn ntltlition of the sonil wliition. inas-

much as the water is not diluted when used ; on the other hand, if (‘hardness ” represents tlie calcium and magnesinm c.ompoiinds prcscnt in the water, thcb soap test is too crude for me. For determination of *‘ magnesian hardness ” Wanklpn suggests tlie addition of ammonium oxalate powder. filtration and subsequent titration of the filtrate with standard soap soliition. The author finds tliat such procedure does not answer, as tlie presence of the itnimonium salt (other salts of tliealkalies acting in a similar manner) lias a most marked effect npon the result, the indicated hardness of it magnesiaii water to which an oxalate has been added, being found to vary with the amount of oxalate employed. The author holds tliat the day of Clai’k’s soap test has gone by, and that chemists shonld turn to more accurate mcthods. Concerning the combination of basic and acid radicals the author believes that magnesium chloride shonld appear in the analysis to the fnll extent corresponding t o the chlorine mid magnesium present, on accoiint of the tendency of mibgnesium chloride to decompose. 011 evaporating its solution, with formation of free HC1. Xaters containing much Mg(‘l$ corrode the boiler at the water line. Tlie addition of K H 4 ( ’ lwill prevent the decom~~osition referred to. and, from esperieiicie with sed wtiter, XaCl appears to act tlie same mity. All the calciiim, over iLlld nbove that reqnired to form (wbonate, shonld be expressed tts CaSO,, 011 account of the prominenee that sl~onldbe given to the tendency of the m;Lter to form boiler scale. ( J . floc. Chenr. l i d , 7, Y.G.) TV. 1’. 11.

Estiniatioii of Caiistic Alkali I) N. (‘arbonates. L E ~ N A RDoiiei

iii

Preseiicc of Alkalilie

The method is a kind of inverted “Nessler ” test. A solution is prepttred of the donble potassium and mercury iodide, and a known amount of ammonium chloride is added. Alkaline carbonates give no rcaction with this reagent, but a caustic alkali. when added in sufficient quantity to break np all the KH4(‘l. present will give the nsual ‘L Nessler ” coloration. Tlie ready solubility of the well-known brown precipitate in a solntion of NH,Cl, prevents any formation of color before the wliolc of the Fr‘IE,Cl. has becn broken up into free ammonia. IVitll a

standard solution snch as the abovc, and also n standard solutio11 of caustic alkali, the proccss for quantitative purposes is apparent. For use as a quantitative test for caustic alkali the reagent may be quickly made by taking a small qiiaiitity of H g U 2 solution, ad4ing solution of KI until red precipitate just redissolves and then adding a drol’ of KI14(’l solntion. ( J . SOC.Chen?.Jnd. 7, 829.) \Ir. P. N.

New Test for ‘L’annic Acid. S. Cf. R A I ~ O X . .lmmonium cliloridc mixed with ammonia, produces in solutions of tannic acid a white precipitate which rapidly becomes reddish brown on exposure to the! air. With gitllic acid no precipitate falls bnt the liquid becomes red. In working with dilute solutions of tannic acid it is b c t t e ~to add the ammonia mixture slowly. so that it may float on top. The white precipitate may then be casily seen a t the line of separation of the two liquids. IT. I’. 31. (ClLt?V?.*Tt??OS. 59, 5 2 , )

Estimation of Cflgcerine in Soaps, Leys and Concentrated Glycerine. OTTO HXHXETL A valuable paper not suitable for abstraction. (J floc. C‘hew. IT. P. 31. Id.,8, 4.) Testing of Lard for Cotton Seed Oil aiid Reef Stearine. .TOHX P ~ ~ ~ r s o s .

Forty drops of the melted lard are placed in a test tube and dissolved in 10 c. c. ether. Two c. c. alcoholic8 solntion Ag NO, (1 of the salt to 11)O alcohol) are added. T h e tube and its contents are left to stand five or six hours away from the light. If present. cotton seed oil will reduce the silver and imparts a maroon color to the solution. By compxring the depths of color with those produced by lards containing k n o w n amounts of cotton seed oil, the quantity present in the sample is estimated. When searching for beef stearine, prepare an ethereal solution of the lard as above, plug the tube loosely with cotton wool and allow crystals to form by spontaneous evaporation. Under the

microscope the beef stearine crystals form curved tufts somewhat of the shape of the short tail of it horse. with terminals pointed and hair-like. Lard carystds are usually foiind in oblong plates, occasionally radiated, and liave oblique terminals. (J. ~Soc. Clwnj. w. P. AI. Iltd., 8, 30. ) ___.

+ . e

c _ _

INDUSTRIAL CHEMISTRY. A Sew Alkali Process. W. IV. ST;\\ ~:I,E\. llefurriiig to the nianp tittempts that liitve h e 1 1 made to tlecomSO,, by means of slaked lime, the autlior states that it occurred to him that, probahly a t the nioment of formation of 3 %KO, a reverse ac%ioii takes plme, niid that if some body mere present wliicli could combine with tlie Xa HO at the moment of formation, better results could be obtained. L'pon agitating tt mixtnre of Ka2 SO, solution ancl slaked lime and gradually adding cresol thereto. an dniost complete decomposition of the sulphate into sodiiim cresylate wits obtained with a precipitation of Cit SO4. 'I'hc sodium cwsylate remaining in solution inay I)c rcildily tleconiposed b y I I I ~ ~ L I Iof S ('Og (fuel or limekiln b vases) forming Sit,( ' 0 3in soliitiou ;tnd libcrating the cresol, which will float on tlie sui.fauc~its an oily liquid, and may be again employed for aiiotlier lot of Sa,SO,. The paper is a full one aud gives some figures as to (lost, compiired with other processes. ( J . Sot.. Chelii. Id.,7, 80s.) €.' M. ~ X J WS n ,

w.

Natural A p e r i w t Hitter Watws. ()woH I ~ N E H . I t is doubtful if it Irw geiier:tlly known by the medical profession that these waters, coming usually from very shallow wells fluctuate in strength almost from day to day. Hy varying the mcdhod of collection, two samples of very tlifft.i*entstrengths may be L' k en a t the same time. as tlie stronger water tend to collect at the bottom of thv well. In tho sitnic brand of water, bought a t different times in the liondon ~ j i i ~ k ( 'tlw t, i~iithor fount1 tlici following amoniit of l l g SO, : 1st sample- - - - .- - .- - - - .- - - -:?li,% parts per 10000. .!d - - - - - - - - - - - - - - - - 304.s0 * ' " *(,4tzaZyst, 14, 36.) P. &I. & '

w.

A S(bw l'roctw for Obtaioiiig A i i i i i i o i i i i i n i C'iilorid~~ fiwtii t h t b Sitrot~eiiof Coal, ('oke, ('iiitler.; aiitl Organic Matter geiic~i*slly. -1Y D I ~ E I VFI{ES(ir. \\-lien nitrogenous organic matter is biir~ieilwith it limited snp1)ly of air. in presence of sulphurous acid, steam and csoninion salt, t h e author believes reaction takes place accaording to tlicb following q u 'I' t '1011 : .!sit('1 11, ~ 0+ n,i r ~( + c' + K, =.:KI E, C'I + s a zso, + ti( ) p . 'I'lic 1ircsc.ncc of S11,t'l about the mouths of coal mines. wliere tires 1 i ; i r i b i t i t r t d . may be t h u b esplainc~rl, thc witclrs of collieries frc~quciitlyuuiitaiiiiiig iiotablc quitntitii~sof stilt. 1,itboratory exjwinicnty iverv made witli coal, coal cinders, sliales, sewage sludge atkc, seaweed. vtc., in every case NH,CI was obtained. The author docs not consider the proccss as yet developrd to a maniifactiiring stage, bnt believes that it will be ultimately o ~ i eof the iniliortant soiirces of ammonia. ( J . Soc. ('hem. Iud., 7, 7 ~ 7 . ) \I1'..M.

REGULARMEETIXO, Dec. Yth, 1888. Prof. TV. P. Mason in the chair. The minutes of the preceding meeting were read and approved. Election of officers for the ensning year being next in order, the chair appointed Messrs. Mnnsell and Kent as tellers. The following officers were elected :

Presideitt,

C. F. CHAKDLER. Vice-Preside&, A. A. BRENEJIAN, T. S. HUNT, C. E. MUNROE,

A. C. HALE, TV. P. MASON, J. W. MALLET.

Correspoitcliwg flecretary, M. ALSBERG. Recording Secretary, D. TVOODNAN. Trenszirer, J. H. STEBBIXS, JR. Librarian, WJI. RUPP. Czcrators, TV. H. KENT, F. VANDERPOEL, A. H. SABIN. Comnzittee o n Papers aittl Pzcblicatiom, A. C. HALE, A. A. BRENEJIAX, J. F. GEISLER. Contniittee oit ,Voini?aations, M. LEAL, R. TV. XOORE, A. EIJIER, T. D. O’CONXOR. A. I?. HALLOCK, Directors, M. ALSBERG, J. H. STEBBINS, JR., TJ. H. FRIEDBURG, M. E. WALDSTEIN, T. D. O’CONNOR,

D. WOODJIAN, TVJL RUPP, H. ENDEJIANN, C. F. CHANDLER, W. H. KENT.

I t was moved by 1)r. Friedbnrg. that tile names of Mendelejeff, Jdliiig and Ki.kuli3, be added to the list of Honorary Members of the Society. Carried. The followiug papers were then read by title : “Fatal Poiboning by Carbon Jlonoxide.” By I’rof. IT. P. Blasos. * ( 011a Xew JIethod for Conimercial Aiialysis of Indigo.” By F. A. O ~ e s . Communicated by A. H. SABIN. (‘On a Jlodificatioii of Guimingham’s Blast Lamp.” By A. 1%.

S.1urs. The secretary

IVRS

directed to cast one ballot for the election of

ROBERTW. HALL.riiiversity Building, K. Y., and C’. T. POXE1%. D., 2 G G I-Inlsey street, Kewark, S. J . Xr. L. E. Mvfioz DEL lfONT6 was proposed for membership. The meeting was then adjourned.

ROY.

T. D. O’(’ON?\’OR, liecording Secretary.

A BST R A CTS:

GENERAL AND INORGANIC CHEMISTRY. Deconipositioii of Potassiiiiii Chlorate by Heat in Prerence of' MiiO,. H. IICLEOI). The first action is : 0 MnO, + 2KC10, = K,RIn,O, C'I, + 0,. Afterwards by further heating : K,JIII,U, = K,RlnO, MiiU, + Os. The third stage is not so clear ; it is rery improbable that the maiigawte is transformed into permanganate I Jtlie ~ osygen from the chlorate. It is more likely that it is acted on I J more ~ chlorine p p l u c e d by tlie action of the U n o , on fresh chlorate, thus : K211n0, I- C1, = t?KC'l+ MnO, i 0,. If the chlorine produced by tlie actioii of the MnU, directly 011 the KC'IO, is thus absorbed by the manganate, it fully esplaiiis tlic very small quantity of chlorine that is evolved. Cliloriiie is certainly evolved as soon as the actioii commences. The author finds that the MnO, cannot, as has been stated, be eshausted by use ; it enters into chemical reaction and is reprodnctd IY. P. 11. (.I. C ' I ~ P W . Soc., 5 5 , 184.)

+

+

011a Sew Acid of Tiii. K.S I ' R I S ( i . Tlie author has fonnd a combination of the formula €I2 Sn, Oi, of the type of disulplinric wid, H, S, U,, or dichromic acid, H, Cr, C)?. A solution of stannous chloride Sn GI,, in L: solution slightly acidulatecl with H C'1 is treated with an excess of piire barium binoxide : the tin oxide remains in a colloidal state, sliicl is scparated from the barinm chloride by dialysis. The solntion free of Bn C1, is evaporated on the water bath ; the resalt is a ivliite maw the analyses of which gives Calculated forH,

Sn

6;.33

H, 0 0

27.16

6.40

6 7.40 q5.14 '!7.46

Sill 0:

188

ABSTRACTS : O R G A S I C CHENISTRY.

These determinations lead to the conclusion of the existence of the compound Sn 0,, capable of remaining in combination with The author wnter a t 100° to form 2Sn0,, H,O or H,Sn,O; expects to study the mechanism of the transformations by the bnrinni binoxide. (Bri2. Soc. C'him., 51, 189.) M.L.

Analysis of Waters of the Yellowstoiie National Park. E'. A. GOOCHASD J. E. WHITFIELD. This excellent paper, from Bulletin qf t h e i 7,S. Geoloyicul S w vey, Yo. 47, is printed in full in the C'hemicnl ,Yews, beginning with 59-113. A full account is given of the analytical methods employed. w.P. 11.

ORGANIC CHEMISTRY. Starch Iodide. SEYFERT. l'feiffer and Tollens have decided that the formula of starch is C 2 4 H , , 0 , 0 , and that of the iodide (C24H400,0)~I,, containing 22.865 per cent. I. On this basis it is proposed to determine starch by dissolving one grm. in water, cooling, adding 50 C.C. of iodine solution, 20 C.C. concentrateh HC1, and diluting to 500 C.C. After vigorous shaking, the starch iodide is allowed to settle, and in an aliquot portion of the clear liquid the excess of iodine present is determined by hyposulphite. The iodine solution contains 12 or 13 gms. I per litre, with sufficient KI to effect solution. The amount of iodine absorbed by the starch, multiplied by 4.37, gives the amount of starch present. (Dingl. Jour., 271, 189.)

E. T.V. On Dioxethyl Acetone. E. GRI>IAUXand L. LEFEVRP. Theory indicates the existence of two isomeric derivatives of glycerine by loss of hydrogen, glyceric aldehyde and dioxacetone. The first has been obtained by one of t,he authors by the oxidation of glycerine by platinum black, and he has shown that it is a true fermentable sugar ; the authors in trying to obtain dioxacetone have obtained its dioxyethyl derivative.

CH, OC, H6-CO-CH,

OC, H,.

ABSTRACTS : ORGANIC CHEJIIYTKY.

189

The paper concludes with the preparation of dioxethylacetone by the use of ethoxaceto-ethoxacetic ether, and descriptions of dioxethylacetone ; the latter strongly reduces cupro-potassic solub1. L. tions, etc., etc. ( B d . SOC. Chiw., 51, l., 15.)

Reduction of Cupric Salts by Sugars, M. MOUKET. A solution of saccharose, saturated a t ordinary temperatures, precipitates metallic copper if sulphate of this metal be added, after a few minutes boiling. Invertion precedes as the solution acts strongly afterwards on the cnpro potassic solution. Lactose and dextrose act similarly, but more slowly. The reduction takes place a t any temperature, being slower a t low temperatures. Cupro-potassic solution is entirely reduced by concentrate solution of sugar, a t ebullition; there is production of the yellow cuprous oxide, changing after ebullition to red anhydrous oxide ; with dextrose a i d lactose the red oxide appears a t once. There is always transformation, after long ebullition, of the oxide into metallic copper, etc., etc. ( B d . SOC.C % i m , 61, 2-88.) M. L.

Manufacture of Iodoform. H. SL-ILLOTS and H. RASKAVD. The purpose of the authors was to manufacture iodoform with acetone and to transform all the iodine in iodoform. Basing themselves on the theory that the sodium hydrate transforms the iodine into hypoiodite, which subsequently acts on the acetone, the authors have thought of employing a hypochlorite added t o an iodide. If, as they say, they take 1 mol. acetone -555, and 3 potass. iodide -495, there is, after action of sodium hypochlorite in slight excess, 1 mol. of iodoform formed = 394. The reaction is represented by : KI+K C10, =K Cl+K I 0, C,H, 0 , + 3 ( K 10,)=C2 HI,+K C , H, 0,+2(KH02)*. The authors have by this process manufactured iodoform on a large scale from the ashes of sea weed. (Bul. SOC.Chiuz.,51,

1Y-4.)

* (0-8.)

Coiiipositioii of l i l k . 1’. VIETH. During the year lSSS there were 12,6$2 samples of milk taken from the railway churns for analysis in the ituthor’s laboratory. The results are as follows : Specific Gravity.

1888.

.January - - - - - - - - - - 1.0:3.?5 Pebruary - - - .- - - - - 1.0325 March- - - - - - - - - - - - 1 . 0 3 5 .lpril - - - - - - - - - - -1.0324 May - - - - - - - - - . - - - - 1.0324 .June - - - - - - - - .- - - -1.0324 .July - - - - - - - ..- - - - 1.03’?0 August - - - - - - - .- - -1.031!) September - - - - - - - - 1.032? October - - - - - - - - - 1.0X.i November - .- - - - . - 1.0322 December- - - - .- - - 1.0:??1

__

~

Yearly average- .1,0:323 :1n azyst, 14, 6.9.

Fat.

‘Torn1 Yolid*.

F.11.

12.97

2.79 ::.31

9. lh‘

2.73 if. tjS :;. 69 ::.69 3.?6 3. a0 :1.94 :;.s9 4.0:;

!).17 !!.13 !). 13 I). 14

13.00

12.90 1’?.S1 l.?.f$? l?.d3 12.S2 1?.84 13.06 13.09 1:j.I s 1 :Lo1

-_

1 ?.!U

S o i ~ d . I,,):

!).

!).Oti

:;,!I1

:;.s1

19

!I. 04 9.12 ! J . 2G !Ll5 9.10

!),

w. 1’.

13

?if.

T On a Diquiiioleic Base. A I . ~ R (:OJ.SOS.

The author expresses the opinion that quinine is the hydride of a base resulting from the union of 3 niols. of quinoleine, an opin-

ion not destroyed by the results of the osidation of quinine made ‘I’o try to throw some light on the constitution of quinine the author has had in view the formation of a cliquinoleic base of known constitution and the comparison of its reaction with quinine. He describes this base and the mode of obtaining a diquinoleic base, which is diosethylized, and seemingiy a derivative of oxydiphenylene. This biise has the form IJY 11. Skraup.

The aiitlior describes its properties :nul concl~icles,from its mode of formation and the composition of its chloroplatinate, that there is no doubt abont its molecnlar weight nor the position occnpied by the qninoleic hydrogen. (Bid. SOC.U i i u t . , [3J 1, 16.9.) 11. I;.

Ggniiieiiiie Acid. DAW)

~~OOPEIL

This acid is prepared from a plant (Cr'yr)iae/un xyZmtr*e) the leaves of which have the peculiar property of destroying the power of the tongue to appreciate the taste of sweet substances. It is a brittle, black, resinons substance, of a greenish color when powdered and is best prepared from the leaf (where it esists as a potassium salt) by treating the aqueons solntion of the alcoholic extract with a mineral acid, washing the precipitate and drying in a cnrrent of hot air over a desiccator. The formula is H(CS,l15,0, ,). (Chcsi. -Yews, 59, 1.59.) P. 11.

w.

Traiisforiiiatioii of Terpileiiol iiito a Menthenol. (2. 130C('HARDAT and J.

LAFOST.

The authors have prepared terpileiiol di-iodhydratc, C, 11, 2111, by the action of iodhydric acid or terpine C,,,H 1 6 3H, 0,. The principal product is a body isomeric if not identical with menthol-iodhydric ether, C2,, H, ,I. The body obtained and described by the anthors has a composition identical with that obtained by Oppenheim by the action of II C1 011 the weiathol C , , 33," 0,. From this esperinieiit the natnral menthol ought to be allied to the teqiiIeuo2 series. This menthol 13, 0, having with terpilenol, C , , 13, O,, relations comparltble to those which connect allylic alcohol, C, H, O,, to propylic nlcohol, C,;11, O,.* (BnZ. 31. I,. SOC.Chinz., 51, S o , 6 8.)

192

ABSTRACTS : AKALTTICAL CHEMISTRY.

ANALYTICAL CHEBAISTRY. Deteriiiiiiatioii of h’itric Acid. H. WILFARTH. This method is a modification of Schlijsing’s, based on the decomposition of nitrates by an acid solution of ferrous chloride. T h e liberated nitric oxide is collected snd oxidized in an alkaline solution of hydrogen peroxide and the nitric acid formed determined by the amount of alkali thus neutralized. The entire operation for determining the nitric acid by this method may be accomplished within 30 minutes when the apparatus .is in working order. The working of the apparatus can only be understood with the aid of the diagram. ( Z t s c h ~n~inl. . Ciieiiz., 27, 441.) J. F. G.

On the Use of Hydrogeii Peroxide for the Determination of the Jietals of the Iroii Family. A. CARNOT. CI&niui~.-The action of chromic acid on peroxide hydrogen has long been known to have been first indicated by Barroswil ; M. Mossin has shown that it is due to a combination of chromic acid a i d of HO,(Cr O,HO,). The author has found that after the peroxide has acted the chromic acid is reduced as chromium sesquioside, a i d a corresponding quantity of peroxide has been destroyed. This phenomenon is employed by the author to determine hydrogen peroxide by means of a standard solution of bichromate, but better for the determination of chromic acid or a chromate. The peroxide employed is poured drop by drop in the slightly acid chromate solution till the blue color is no longer produced ; asimilar operation is performed with a chromate of known strength (bichromate). It is well not to act on more than 200 or 300 grms-of chromic, acid. (Bzdl. SOC.Chim., 1, 275.) 31. L.

[.‘I

On the Use of Peroxide of Hydrogen for the Determination of Metals of the Iron Family. lst, Chromiiim ; 2d, Manganese ; 3d, Iroii. A. CARNOT. Chronzium.-If hydrogen peroxide reduces chromic acid in a cold and acid oxide solution, it peroxidizes chromium, on the contrary, in a, hot and alkaline or arnnioniacal solution. On this is

ABSTRACTS

: ANALYTICAL CHEJLISTRT.

193

based the gravimetric determination of chromium ; the chromium will be peroxidized in an ammoniacal solution and then, when oxidized, liberated as chromic acid by the peroxide method, or any other. The same reagent can be employed for gravimetric analysis, the chromate formed will be separated from the oxides thrown down by NH, or its carbonate. The chromate left is then reduced by the peroxide in the acid solution, and the excess of peroxide boiled off. T o be sure of its entire destruction H,S is passed into the hot solution j the chromium oxide is then thrown down by KH,. Another way is to add to the solution just reduced by the hydrogen peroxide, sodium phosphate and then sodium acetate and ammonia and boil 10 or 15 minutes. Under these conditions there is obtained the precipitate of hydrated chromium oxide, the formation of which under these circumstancep has already been indicated by the author. (C.R.,93, 154.) Manganese.-In an ammoniacal solution of a manganous salt hydrogen peroxide precipitates a brown manganese oxide, but the precipitate retains the other bases, and it is necessary to reprecipitate several times to secure good results. The volumetric process, on the contrary, is reliable ; the author has assured himself that the conipositioii of the precipitated oxide is constant and is represented by Mn,O, or BMnO,MnO), whether the foreign metals be calcium, baryum, zinc or iron. The available oxygen is then calculated volumetrically with oxalic acid, snlphuric acid and standard permanganate, the manganese being calculated on the basis of 5 equivalents of available oxygen corresponding to G equivalents of manganese.

I m e - 1 ~ peroxidized in the cold and in a n acid solution by H,O, better than by any other peroxidizing agent. (BziII. Soc. M. L. Cliim. [3] 1, 877.)

Deteriiiinatioii of Lithium by the Pluorides. A. CAHNOT. The author has found that lithium fluoride is very sparingly oluble in cold mater, and much less so in a solution of animoniums fluoride. The author indicates the purification of this reagent. The solution of the alkaline earths is evaporated to a few c. c. in

a tared platinum capsule : uninionium fluoride is added w i t h xn excess of ammonin. A gelatinous precipitat,e ,j formefi i v h ich is complete after a day : ;t portion of the l i q i i i d is clecante~lon n very small filter, a n d replaced by a few c. (...of amnioiiincitl amrnoiiiiim fluoride. stirrer1 with the platinum spatula, m d left to stand ; this treatment is repeitted several times : finally there yemains only ;dl the lithium impregnatell only with 2$ H, nnd ammonium fluoride. -111 volatile nxitter is ewporatecl off. the axh of filter is added, is treated with 13, SO, :tail calcinctl to obtain neutral lithium sulphate. The results must' be corrected for the st~lnbilit~y in .washing solutions (30-50 c. c.) increasing results by 1 mg. of lithium for every 7 c. c. of ~vashwaters:. The resnlts, ;weording t o the autr170r, 1, A'/).) are very satisfactory. ( B N ! .Sm. (.'Ai/,/.[I:] 31. I,.

I)eterniiiiatioii of Ash. F. A. The author calls attention to the suggestion of I