RECENT WORK IN AGRICULTURAL SCIENCE. 



CHEMISTRY. 



On Ritthausen's classification of the plant proteids, D. Prianisitnikov 

 (Landw. Vers. Stat., 60 {1904), No. 1-2, )>}>. 15-27).— A consideration of available 

 experimental data led to the conclusion that Ritthausen's classification of proteids 

 needs some modification. 



The author divides the proteid group into water-soluble proteids .(plant albumen ), 

 proteids insoluble in wafer but soluble in hydrochloric acid (plant globulin), proteids 

 soluble in 70 to 80 per cent alcohol and precipitated with a small quantity of sodium 

 chlorid, for instance, gliadin, and proteids (rich in P 2 O ft ) insoluble in the above- 

 named reagents, but capable of being extracted with alkalis and precipitated with 

 acids, for instance, gluten casein. In addition the plants contain proteids of smaller 

 molecular weight (peptones and albumoses), which may be regarded as intermediary 

 products of hydrolysis, and also bodies (for instance, nucleins) with molecular weight 

 higher than proteids. 



The author believes that legumin and congluten should not be regarded as plant 

 caseins, but as belonging to a special group of plant globulins. 



On the action of 4 per cent sulphuric acid on legumin, D. Prianisitnikov 

 {Landw. Vers. Stat., GO {1904), No. 1-2, pp. 27-40, fig. 1).— According to the author's 

 experiments 4 per cent sulphuric acid when warmed with legumin causes a marked 

 reaction. It quickly acts upon the legumin and changes it into compounds which 

 are not precipitated with copper oxid. The author considers it probable that dilute 

 acid causes a cleavage of the proteid molecule with the formation of amido acids. 

 The other cleavage products are spoken of. 



The occurrence of hexone bases in the tubers of potatoes ( Solan um tube- 

 rosum) and the dahlia (Dahlia variabilis), E. Schulze {Landw. Vers. Stat., 59 

 {1904), No. 5-6, pp. 331-343). — The investigations reported led to the conclusion that 

 histidin and lysin are contained in the juice of potato tubers, and that arginin was 

 present in these tubers and also in dahlias. According to the author, these facts 

 furnish additional reasons for believing that the juice of roots and tubers contains a 

 mixture of crystallizable nitrogenous compounds, which in composition closely 

 resemble that present in etiolated germinating plants. 



The molecular weight of glycogen, Mine. Z. Gatin-Gruzewska [Arch. Physiol. 

 [Pfluger], 103 {1904), No. 5-6, pp. 282-286) . — The results of cryoscopic investiga- 

 tions, in the author's opinion, showed that the ordinarily accepted data for the 

 molecular weight of glycogen are not trustworthy. The subject is discussed from 

 the standpoint of physical chemistry. 



Determination of phosphoric acid by the weight of the molybdic precipi- 

 tate, S. Brushlinski (Zhur. Oputtn. Agron. [Jour. Expt. Landw.~\, 4 {1903), No. 5, 

 pp. 525-527). — The author made 10 determinations of phosphoric acid by the Lorenz 

 method of direct weighing of the molybdic precipitate obtained by means of a 

 molybdic solution containing sulphuric acid and nitric acid, modifying the method 

 by using the ordinary nitric-acid solution. Very accurate results on solutions of 

 known composition were obtained. — p. fireman. 



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