RECENT WORK IN AGRICULTURAL SCIENCE. 



AGRICULTURAL CHEMISTRY— AGROTECHNY. 



In reg-ard to the constitution of albumin, K. Chodat {Ahs. in Chcm. Ztg., 

 36 (1912), No. 52, p. JiSl). — ^.1 special reaction is described which is supposed 

 to be characteristic of the a-aminocarboxylic acids of the fatty series, peptids, 

 simple or complex peptid chains, polj^peptids, peptones, albumoses, and soluble 

 proteins. The method is as follows : A purified tyrosinase is allowed to act upon 

 a phenol; i. e., p-creosol, pyrocatechol, etc., in the presence of equimolecular or 

 multiple quantities of an amino acid, a peptid, or a polypeptid. The reaction is 

 indicated by a red coloration which changes to a violet green and finally to a 

 blue having marked red dichroisms, and is very sensitive. 



The following among other substances were studied: Glycocoll, d- and 

 1-alanin, d-valin, d- and 1-leucin, phenylglycin, d- and 1-tyrosin, d- and 1-phenyl- 

 alanin, arginin, and cystin. Anthranilis acid does not react, but with trypto- 

 phan and pyrrolidincarboxylic acid a stronger coloration is obtained. Peptones 

 and albumoses give a marl^ed coloration which becomes stronger as peptoniza- 

 tion proceeds. The color is also marked in the case of albumins, pure globulins, 

 nucleo-globulins, and other proteins. The reaction will also show a change 

 in the condensation or alteration in the composition of the original protein. 

 As the reaction is specific for amino acids, it determines without going any 

 further the presence of NH2- and COOII-groups. 



A preliminary note on the coagulation of proteins by ultraviolet light, 

 W. T. BoviE (Science, n. ser., 37 (1913), No. 9JfO, pp. 2//, 25).— In order to gain 

 insight into the action of ultraviolet light on living cells, tests were conducted 

 with ordinary egg albumin, crystallized egg albumin prepared according to the 

 Hopkins and Pinkus method, egg albumin (Hopkins and Pinkus) dialyzed 

 against tap water, and ox serum. 



In all instances the albumin was more or less coagulated, and in the case of 

 the egg albumins the coagulum produced was insoluble in alcohol, hot or cold 

 water, and dilute acids, but soluble in dilute alkalis. In these respects it cor- 

 responded to the coagulum produced by heat alone. 



New Investigations in regard to our knowledge of fats, R. Limprich (Neue 

 Vntcrsuchimgcn zur Kenntnis der Fette. Inaug. Diss., Univ. Miinster, 1912, 

 pp. 89, figs. 9). — The first part of this work embraces a study of methods for 

 determining the presence of beef or mutton tallow in lard. It describes a new 

 method for this purpose, and gives the results of a study of the Polenske method 

 and its theoretical foundations. 



The second part deals with heptadecylic acid and triheptadecylene, the former 

 having been previously found by other investigators to be present in lard in the 

 form of a glycerid. An attempt was made to prepare the heptadecylic acid syn- 

 thetically and to compare it with the compound occurring in lard. 



The third part of the dissertation gives the results of some feeding experi- 

 ments with carp, with special reference to the influence of the fat given in the 

 food on the body fat of the animals. 

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