1020] AGRICULTURAL CHEMISTRY — AGROTECHNY. Ill 



Tlic oriftin of tlu' huiiiin fornu'd by the acid hydrolysis of proteins — 



V, U. A. (.JoKTNKK and U. E. Holm {Jour. Aiitir. Vltcin. .s'oc, .'i^ (1920), No. Jf, pp. 

 82J-827). — To further confirm the conclusion, noted above, that the blacli 

 insoluble huinin formed in protein hydrolysis is due to trytophan in the presence 

 of an aldehyde, 15 pure amino aciils were mixed in various proportums and 

 boiled with 20 per cent HCl, botli in the presence and in the absence of 

 formaldehyde. 



The only experiment which yielded any insoluble humin nitrogen was that 

 ill which both trJ^)tophan and aldehyde were present. The nitrogen secured 

 ill that fracticm amounted to 95.5 per cent of the tryptophan nitrogen which 

 had been added. This is thought to afford conclusive proof that the black 

 insoluble humin is derived from tryptophan, and when the proper amount 

 of aldehyde is present is a quantitative measure of the tryptoplian present. 



The evidence pre.sented in an earlier paper (E. S. R., 38, p. 201) that soluble 

 humin is derivetl from ty rosin was confirmed, for only those hydrolysates 

 which contained both tyrosin and aldehyde yielded appreciable amounts of 

 soluble humin. On account of the solultility of humin it can not, however, 

 1k' usetl as a quantitative measurement of the tyrosin. 



>.'o evidence was secured in these experiments as to the nature of the 

 jihosphotungstic acid humin. When both tryptophan and formaldehyde were 

 I (resent in the proportions necessary for the maximum formation of insoluble 

 humin there was less deamination than when either the aldehyde or tryp- 

 tophan was absent. Cystin was not readily deaminized. 



The food of the small sea herring and ammonia and aniins as end prod- 

 ucts of its deconii)osition, F. C. Wkhkr and .1. B. Wilson (Jour. Amer. Chcm. 

 Hoc, 42 (J920), No. 4, pp. 8^1-8^9). — This paper reports the results obtained in 

 the chemical study of the herrings used in the sardine industry of Maine and 

 of their feed, continuing the investigation previously noted (E. S. R., 40, p. 411) 

 and supplementing the bacteriological studies of Obst (E. S. R., 40, p. ,555). 



Ammonia and amins were found in appreciable quantities in the different 

 forms of herring feed (copepods and schizopods) which had undergone decom- 

 position, in culture media in which the bacteria BaciUioi tvalfisehra ii.ich hr<i ml 

 and lUiciUus B., conmionly found associated with tlie feed, were grown, and 

 ill the contents of the digestive tract of "belly-blown" "feedy" fish. Skatol 

 and indol were also identified in the culture media in wMch the bacteria had 

 grown. 



The results indicate that the decomposition of the feed is due to the action 

 of the two bacteria which are always found associated with the feed, and is 

 responsible for the bursting of the bellies of " feedy " fish and the occasional 

 .swelling and spoilage of canned sardines. 



On amino-acids. — II, Hydro\yglutamic acid, H. D. Dakin (Bioclicm. 

 Jour., IS (1919), No. 4, pp. 398-J,29) .—In continuation of the investigation pre- 

 viously noted (E. S. R., 40, p. 611). the re.sults are reported of a further study 

 of the new animo acid /3-hydroxyglutamic acid, together with experiments 

 on its synthesis and that of allied substances. 



Although considerable difliculty was experienced in synthesizing the inactive 

 acid the synthesis was finally effected with glutamic acid as a starting point. 

 The intermediat«! steps in the synthesis and the methods which proved unsuc- 

 cessful are outlined. The acid has been isolated from gliadin and glutenin 

 by the method used in its isolation from caseinogen. 



*' When administered to a diabetic (phloridzinised) dog /3-hydroxyglutamic 

 acid yields 55 to 60 per cent of its weight as glucose, apparently three of its 

 five carbon atoms being concerned in glucose formation. In this it resembles 



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