AGRICULTURAL CHEMISTRY — AGROTECHNY. Ill 



Reducing' power of sugars (monosaccharids), and its bearing on the defi- 

 nition of these substances, N. Schoorl {Chcm. Wcckhh, 9 {1912), No. 35, 

 pp. 706-711; ahs. in Jour. Chem. Soc. [London], 102 {1912), No. 600, I, p. 750).— 

 The introduction of a nonoxidized carbon atom between the CO- and CH(OH)- 

 pronps in a compound contninhig the group .CO.CII(On). diminishes the re- 

 ducing power materially toward weak alkaline copper solutions. Ttie author 

 maintains that the term " sugar " should include all substances containing the 

 group .CO.cn (OH)., whether tliey are polyhydric alcohols or not. 



Studies in regard to plant colloids. — I, Swelling of the starch solution 

 in the presence of crystalloids, M. Samec {KoUoklchcm. BriUcftc, 3 {1911), 

 No. 3-4, pp. 123-160, figs. 7). — The presence of a crystalloid seems to change 

 the swelling of starch granules in lower concentration th:in was usually sup- 

 posed. This is apparently due to the anions, and the cations have only a quan- 

 titative influence upon the action exerted by the anions. The influence of the 

 inorganic and organic ciystalloids, glucose, urea, chloral hydrate, glycerin, 

 etc., upon the swelling process of starch and gelatin with few exceptions is 

 identical. 



The stimulation of swelling for the ions investigated is a periodic function 

 of the atomic weight of the respective element. Classification according to the 

 nature and intensity of the swelling process leads to the figures obtained by 

 Pnuli and Hofmeister. The swelling induced by certain salts was found to be 

 reversed with an increase in temperature. Salts yielding Oil on cleavage in 

 medium concentrations seem to induce swelling. 



Acids do not show as great a sensitiveness toward starch as salts. The 

 same conditions for swelling hold for acids as for salts, and, in addition, the 

 condition of the solution (sohate) is modified by the respective acid. Bases 

 stimulate the swelling in highly dilute solutions, and in the lowest concentra- 

 tions alkali hydroxids show the greatest influence in this direction. The curve 

 (swelling) of most salts points to the formation of ion-adsorption compounds 

 with starch, while the swelling produced by alkali hydroxids can be explained 

 in the light of Pauli's theory of ion hydration. The influence which other 

 crystalloids exert upon starch appears also to be due to lyotrop activities. 



On the starch of glutinous rice and its hydrolysis by diastase, Y. Tanaka 

 {Jour. Indus, and Engln. Chcm., If. {1912), No. 12, p. 918). — This presents 

 corrections of an article previously noted (E. S. R., 28, p. 407). 



Investigations in regard to the formation of enzyms. — VII, About the 

 development of certain yeasts in various nutrient solutions, II. Euler and 

 B. Palm {Hoppe-Scyler's Ztschr. Physiol Chcm., SI {1912), No. 1-2, pp. 59-70, 

 figs. 6). — The results show that the quantitative multiplication of cells of 

 Saccharoinyccs cCrcvisicc (beer yeast), /Sf. apieiilatus. and iS. marxianus in a 

 solution of an unfermentable disaccharid and fermentable hexose proceeds in 

 the snme manner. Apparently yeasts contain hydrolyziug enzyms for certain 

 disaccharids, the fermentation of which can not be determined by existing 

 methods. 



The nutrient solution in addition to the sugar was composed of 0.25 gm. of 

 magnesium sulphate, 5 gm. of orthomonopotassium sulphate, and 4.5 gm. of 

 asparagin and water to make 1 liter. The sugars studied were saccharose, 

 glucose, galactose, and lactose. 



»Sf. thcrmantitonum was also tested in this regard but with negative results. 



Formation of alkali by enzyms, C. Neuberg {Ahs. in ZentN. Physiol., 26 

 {1912), No. 16, pp. 715-717). —The fermentation of the potassium salt of pyro- 

 racemic acid with yeast or yeast juice, prepared by von Lebedew's methods, 

 resulted in the formation of carbon dioxid acetaldehyde and potassium car- 



