EXPERIMENT STATION RECORD. 



Vol. XXVII. Abstract Number. - No. 6. 



RECENT WORK IN AGRICULTURAL SCIENCE. 



AGRICULTUEAL CHEMISTRY— AGROTECHNY. 



Studies in protein hydrolysis, F. W. Foreman {Jour. Agr. Sci., Jf (1912), 

 No. J/, pp. Jf30-Jf33). — As a result of this research it was found that by using 

 dry salts for esterification, in place of the ^aterj' sirup which is usually 

 employed, a great saving of time and trouble may be effected in the early stages 

 of the process, and furthermore that a very satisfactory esterification may be 

 obtained. This is due to the fact that alcohol when used will prevent the 

 reverse effect of the small amount of water produced. The complete removal of 

 water from such a sirup is prevented by the presence of an excess of free 

 hydrochloric acid, and the removal of the esterification water may therefore be 

 more efficiently secured when an alcoholic solution containing the ester hydro- 

 chlorids alone, as in the author's process, is evaporated. 



It is further claimed for this process that owing to the solubility of the ester 

 hydrochlorids in chloroform and the freedom of their solution from hydro- 

 chloric acid the presence of a small quantity of anhydrous baryta, without the 

 addition of water, will efficiently liberate the esters fi'om their hydrochlorids. 

 The yields obtained are as high as those obtained by the older methods. 



In regard to the investig'ation of proteins with the formol-titrametric 

 method, F. Obeemayek and 11. Wilhelm (BiocJiem. Ztschr., 38 (1911), No. 3-Jt, 

 pp. S31-3J,3; abs. in ZcntU. Expi. Med., 1 (1912), No. J,, pp. 157, 158; ZentM. 

 Biochem. u. Biophys., 13 (1912), No. 1-2, p. 6). — It was noted that when adding 

 a neutral solution of formaldehyde to an aqueous solution of a protein which 

 reacted neutral to litmus, a sti'ong acid reaction developed. According to this, 

 the amino acids and ammonia are not the only substances which can be deter- 

 mined by the Sorenson method. 



The tests were conducted with carefully purified proteins which gave a nega- 

 tive reaction with Nessler's reagent and only a faint brown tinge with the 

 quinone test for amino acids. The results bring out the fact that the method 

 will yield constants for certain classes of proteins, which are more or less 

 characteristic. If the value found for total nitrogen by the Kjeldahl method 

 is divided by the value obtained in the formaldehyde titration a figure is 

 obtained which the authors term the amino index of the protein in question. 



It was found that the amino index of globulin is greater than that of albumin. 

 Globulin from horse serum had an index of 20 while albumin from the same 

 source had one of 13. The figures for the proteins from the different mammalia 

 were found to differ only slightly among themselves. 



Following proteolysis in cheese with the formol-titrametric method, O. 

 Gratz (Ztschr. Vntersuch. Nalir. u. Genussnttl., 23 (1912), No. 8, pp. 879-384).— 

 The course of proteolysis was followed in Emmental, Limburg, Edam, Camem- 



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