RECENT WORK IN AGRICULTURAL SCIENCE. 



AGRICULTUEAL CHEMISTRY— AGROTECHNY. 



The color reactions of the proteins (egg albumen), I. C. Reichaed (Pharm. 

 7A(j., 55 (1910), Nos. 16, pp. 158-160; 17, pp. 167, 168).— A study of the color 

 reactions produced with desiccated and powdered egg albumen and various re- 

 agents, among them sulphuric, acetic, hydrochloric, fuming hydrochloric, nitric, 

 trichloracetic, amidoacetic, molybdic, sulphanilic, picric, titanic, iodic, vanadic, 

 and metaphosphoric acids, ammonium hei)tomolybdate, potassium hydrate, 

 copper sulphate, silver chlorid. vanillin, urea, and phenylhydrazin. 



Proteids in the seeds of Pinus koraiensis, K. Yoshimura {/Aschr. Unter.surh. 

 Nahr. u. Genussmtl., 19 {1910), No. 5, pp. 2.57-260) .—A proximate analysis of 

 these pine nuts is reported, as well as determinations of the proportion of his- 

 tidin, arginin, and lysin. 



Some contributions to our knowledge of stachyose, C. Neuberg and S. 

 Lachmann {Blochcm. Ztschr., 2.', (1910), Nos. 1-2, pp. 171-177) .—The authors 

 have perfected a method for extracting and purifying stachyose, the resulting 

 product having all the characteristics of the tetrasaccharid isolated by Schulze, 

 Planta, and Winterstein. When stachyose was treated with emulsin for a 

 period of 3 months no substance having the characteristics of 5-galactose was 

 found, though reducing substances were formed. With yeast maltase after a 

 period of 3 days the stachyose solution showed evidences of a right-handed 

 rotation, and eventually yielded a substance having the characteristics of 

 dextrose and an osazon with the characteristics of the trisaccharid manuio- 

 triose. Kefirlactase also produced a phenyl osazon. 



Contribution to our knowledge of the nitrogen-free extract substances 

 in foods and feeding stuffs, J. Konig and W. Sutthoff (Zfschr. Untersiidi. 

 Nahr. u. Genussmtl., 19 (1910), No. .J, pp. 177-189). — Previously noted from 

 another source (E. S. R., 22, p. 111). 



The influence of acids and alkalis on the activity of invertase, C. S. Hud- 

 son and H. S. Paine (U. 8. Dept. Agr., Bur. Chem. Circ. 55, pp. 7, figs. 2). — 

 "Acids and alkalis are found to affect the purified enzym invertase in two 

 ways; in small concentrations they influence its activity but do not per- 

 manently destroy it, in lai-ger concentrations they accomplish its destruction. 

 The destruction by acid at 30° C. reaches a barely noticeable rate at 0.01 normal 

 acidity and increases rapidly with the acidity until it becomes almost instan- 

 taneous at 0.0.5 normal. The rate of destruction follows the formula for uni- 

 molecular reactions. The alkaline destruction begins a little below 0.01 normal 

 and is almost instantaneous at 0.045 normal. The activity of invertase in acid 

 solutions, which are not strong enough to destroy the enzym, was measured for 

 hydrochloric, hydrobromic, nitric, phosphoric, sulphuric, boric, oxalic, tartaric, 

 citric, and acetic acids; the activity depends almost entirely on the concentra- 

 tion of hydrogen ions in the acid solution and the various acids thus show 

 typical differences which correspond with their recognized degrees of dissocia- 

 tion. The activity of invertase is zero in alkaline solutions, rises to a maximum 

 in very weakly acid ones, and decreases with stronger acidity." 

 110 



