RECENT WORK IN AGRICULTURAL SCIENCE. 



CHEMISTRY. 



A hydrolytic derivative of the globulin edestin and its relation to "Weyl's 

 albuminate and the histon group, T. B. Osborne {ConnccticiU State Sta. Rpt. 

 1900, pt. 4, PP- 388-399). — A continuation of work previously reported (E. S. R., 12, 

 p. 512) on the proteids. The action of water or very dilute solutions of acids converts 

 the globuUn edestin into a substance insoluble in saline solutions of moderate con- 

 centration. This derivative of edestin is formed by hydrolysis and is the same 

 substance as that designated "albuminate" by Weyl, which is the first product of 

 the hydrolitic changes leading to the formation of so-called acid albumin. This 

 substance the author terms edestan, and it is of the same composition, as determined 

 by analysis, as that of edestin, from which it is formed. Edestan forms salts with 

 hydrochloric acid, possessing an acid reaction; it is insoluble in water, less soluble 

 in potassium hydrate than edestin, and insoluble in all except very strong ammonia 

 solutions. The aqueous solution of edestan chlorid, when concentrated, has an acid 

 reaction, and is precipitated by neutralization, the precipitate being soluble in strong 

 ammonia. It gives a precipitate with nitric acid, which dissolves on warming and 

 reappears on cooling; a precipitate with ovalbumen solutions, with the alkaloidal 

 reagents, and with mercuric chlorid.- These reactions agree closely with those given 

 by Kossel as characteristic of histons. With the true histons, however, edestan has 

 little in common. 



The basic character of the protein molecule and the reactions of edestin 

 ■with definite quantities of acids and alkalis, T. B. Osborne {Connecticut State 

 Sta. apt. 1900, pt. 4, PP- 399-441)- — From a large number of experiments the author 

 draws the following conclusions: The proteins are basic bodies, and with acids form 

 true salts. For example, the preparations of native proteins usually obtained from 

 slightly acid or neutral solutions are salts of the basic protein substance. The acid 

 of these salts can be separated from the proteins insoluble in water by neutralizing 

 with potassium or sodium hydrate. The acid may then be identified by filtering, 

 evaporating, and analyzing the alkali salt obtained. Preparations of edestin made 

 in the usual way partake of the nature of the salts from which they are crystallized. 

 Those obtained from, sodium chlorid solutions dissolve to a considerable extent in 

 washing, the soluble portion being twice as acid as that undissolved. From the 

 reaction of the insoluble portion edestin must form salts corresponding to a mono- and 

 a bi- chlorid. The crystals of edestin and its different salts are isomorphous, the small 

 amount of combined acid not being able to effect a change in crystalline form. 



The action of acids upon edestin is treated at some length. Ten times as much 

 sulphuric acid as of hydrochloric acid is required to dissolve a given quantity of 

 edestin, while the latter dissolves more nearly the calculated quantity than acetic 

 acid. Phosphoric acid reacts with edestin as a mono-basic acid, and nitric acid forms 

 a salt which corresponds to the bi-chlorid. Edestin is dissolved in centinormal potas- 

 sium, or sodium hydrate solution, in an amount closely proportioned to 1 molecule 



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