The wonder of chemistry

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Ammonlum Hydroxide Does Not Exlst TOthe Editor: John T. Yoke's note, "Ammonium Hydroxide Does Not Exist" [1989,66,310], underscores the fact that the nonexistence of NHaOH needs to be brought to the attention of a new eeneration of chemical educators and students. For -~ morelthan three decades I have distributed John B. Davis's excellent article on this subiect. "Ammonia and 'Ammonium Hydroxide7" 1195.3, 30, 51i], as a handout to my students everv semester with onlv moderate success. Therefore I r e cently supplemented this handout with Michael Laing's article "There Is No Such Thinr as NH,OH" ISpcctrurn 1988, 26(4), 111. One of the reasons that the latebohn F.~ a x t e r , Jr., and I advocated the use of "Hydrated Cations in the General Chemistry Course" [1981,58,349] was to avoid the necessity of the use of NH40H or NH3 + Hz0 in equations for the precipitation of gelatinous metal hydroxides by the action of aqueous ammonia on solutions containing hydrated metal cations such as A1(Hz0)s3+, M g ( H ~ 0 ) 6 ~ + , Cr(H20)s3+,Zn(Hg0)a2+,etc. Yoke is correct in advocatine that laboratorv s u o ~ l v houses stop labeling their bottle'"ammonium hy&oxi'de". This mislabeling and the unfortunate use of this term even in some recently published laboratory manuals and textbooks by authors who should know better only confuse students and encourage them to cling to an obsolete nonexistent com~ound.Until the millenium arrives, however, I appeal t o - m y s t u d e n t s ' self-purported worldly wise sophistication. "Who among you", I ask, "in this post-Watergate, Iran-Contra generation, would be so naive as to believe in the existence of ammonium hydroxide, NH40H, merely because these words and this formula appear in raised glass letters on a reagent bottle?" ~

George 6. Kauffman California State University, Fresno Fresno. CA 93740

Enzymes at the Frontier (1822-1833) To the Editor: In reference to Alan Mellors' statement that i t is not known what happened to the sample (not samples) of Alexis St. Martin's gastric juice sent by William Beaumont to Jons Jacob Berzelius in Stockholm 11990,67,194-1951, Berzelius did indeed receive the sample. He refers to i t extensively in the Animal Chemistry volume of his celebrated Textbook of Chemistry ( I ) . I t is amusing t o quote here an excerpt (2), taken from Friedrich Wohler's classical German translation of Berzelius's text: I recciwd a small hattle of this gastric juice through Pn~fersor Silliman in Nt.w Hawn. Before it reached Stockholm rt had been en route for 5 monchs in the hot summer of 1831 nnd hence it was not to be considered unchanged and suitable for an exact analysis. It was a clear, yellowish liquid without the slightest smell, and gave a strong red color to litmus paper .. . [Various analytical results follow here, some commented on in ref 3.1 . .. A part of this gastric juice, after being stored for 2 years, remained without any sign of putrefaction. Berzelius's detailed treatment of human and animal gastric digestion admirably summarizes the state of knowledge on this topic a t the time. His work with Alexis St. Martin's gastric iuice did not remain unknown: the results were of some considerable importance. Thus, referring to the above Dassaee. the first head of the first American laboratorv of physi&gicnl chemistry ( 4 ) ,at the very institute that ~ e $ a min Sillimnn had helped to found, stated (3):

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534

Journal of Chemical Education

.. .the analysis of human gastric juice made by Berzelius, in 1834, showed that the secretion contains very little solid matter (1.26 per cent.), thus calling attention to the fact that the digestive oower of this fluid is out of all .nroDortion to the amount of .oeosin. . . .. . a n d ronrequently pavmg the way h r a general apprreintwn of the peculiar nature of the dominant hady, i t , the pppsin.

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I t mav be mentioned that,. long- before Beaumont, starting in fact as early as 1798, fistulous patients had already been the subjects of studies of human digestion (5). Literature Cited 1. Rerzeliur, J. J. Lehrbuch der Chemie. 3rd ed.; transl. by F. WOhler: Arnold: Dresden, 1840: Vol.9. pp 209-2L1.321-322. 2. Fliedmsnn, H.C. Enz3rner (Benchmark Papera in Biochemistry Vol. 1): Hutchinson RoP.: S t ~ ~ ~ d s h u1981: r g , pp 19-20.96. 3. Chitlenden. R. H. On D i ~ s s t i u eProieolysir: Tuttle. Morehouse & Taylor: New Haven, 1895; p 5. a. chittenden.R. H. he oeueloprnen!o i ~ h y s i o l o g i c dchrmirtry i n the u n i t e d stotar: ChemicslCstalog Company: NeuYork. 1930:p33. 6. Number8.R. L.J.Hizt.Bio.I979,12. 113-136.

Herbert C. Frledmann Department of Biochemistry and Molecular Biology The University of Chicago 920 East 58th St. Chicago, IL 60637

The Wonder of Chemistry To the Editor: I t is not often that one is moved to tears, as I was recently, by reading an article in this Journal. Ole Bostrup and Ellen Hirbel's article on "Chemistry and the Mentally Retarded Child" was both creative and compassionate (J. Chem. Educ. 1989,66,827-8). Indeed, we could do well by including more of "the wonder of chemistry" in our regular courses for all students, especially in high school and college general chemistry. The loss of "wonder" from and the rise of the "abstract" in these courses has long taken its toll, and is no doubt a major factor in the declining interest in science among the young. Utility is also important, as Stephen J. Hawkes pointed out in the same journal issue (Provocative Opinion, J. Chem. Educ. 1989,66,831-2). Students do seem to he more willing to learn what is perceived to be useful, rather than useless. Nevertheless, let us not go overboard on utility as a criterion for what to include in the general chemistry course. Leave room for beauty and wonder, too. Harold Hart Michlgan State University East Lansing. MI 46824

Inductive Effect To the Editor: Kolb and Kolb have a useful demonstration 11989, 66, 10341 on the "Inductive Effect on Acid Strength of Carboxylic Acids". Calder and Barton argued [1971, 48, 338-3401 that an entroov effect redom mi nates in these cases. As Kenneth Kolb wrbte in a private communication (I abbreviate) "The ~ o i nist a good one but no basic oreanic text has oicked up on-it." Let ;s here ask textbook &ers to consiier the implications of all the data. Ronald L. Rlch Carolina State University Department of Chemical Enigneering North

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