1918.] AGRICULTURAL CHEMISTRY AGROTECHNY. 803 



precipitating with acetone, redissolving in water, and repreoipilating with 

 alcolaol. The optimum action of papain was found to be at pH=10"'. Papain 

 seems to act like urease, invertase, and lipase in forming an intermediary 

 compound which is broiven up into cleavage products and liberates the enzym. 

 The quantitative relations of the enzym, hydrocyanic acid, and protein lend 

 support to the view tliat there is a ternary compound formed which then breaks 

 down. Hdyrocyanic acid may be recovered almost quantitatively from diges- 

 tion mixtures, indicating that it is not utilized in the reaction of fermentation 

 but tliat It can renew proteolysis in papain digests that are almost in equilib- 

 rium. 



Studies on enzym action. — XVI, The formation of ester-hydrolyzing sub- 

 stances by the action of alkali on proteins, Florence Hulton-Frankel {Jour. 

 Biol. Chein., 32 (1917), No. 3, pp. SOS-JfOT ; abs. in Chem. Ahs., 12 (1918), No. S, 

 p. 281). — The present investigation was undertaken to determine whether the 

 activity of the ester-hydrolyzing substances follows the general laws of enzym 

 action and to what extent they are specific in their action. The proteins used 

 were casein, gelatin, and dried egg al)}umin. The esters used were of a liigh 

 grade of purity and were in most cases redistilled after drying over sodium 

 carbonate. The factors studied were the influence of concentration of alkali 

 used and duration of action, of hydrogen ion concentration on the activity of 

 alkali-treated proteins, of temperature of standing on the action of alkali on 

 protein, the lipolytic activity of a papain digestion mixture of casein, and the 

 effect of boiling on the lipolytically active substance. 



It was found that proteins when treated with alkali yield substances which 

 have the power to accelerate hydrolysis of esters. For casein, gelatin, and egg 

 albumin, 3 N alkali seemed to produce solutions of the highest activity. These 

 solutions showed greater activity at a concentration of the hydrogen ions less 

 than 10''' N. or they were more active in a slightly alkaline solution. The time 

 and temperature at which the alkali stood in contact with the protein did not 

 affect the activity of the solution except where the temperature was above 

 S0° C. The solution obtained by hydrolyzing the protein by acid instead of 

 alkali did not possess ester-hydrolyzing properties. 



Polarimetry (U. S. Dept. Com., Bur. Standards Circ. 44 U918), 2. cd., rev. 

 and cnl., pp. 196, pis. 2, figs. IS). — This is a revised and enlarged edition of the 

 circular issued in 1914. It contains chapters on absolute measurement in cir- 

 cular degrees, saccharimeters, temperature corrections and control, polari- 

 scope tubes, cover glasses, flasks, thermometers, weights, optical activity in 

 organic compounds, testing of raw sugar, polarimetric analysis of other sugars, 

 estimation of reducing substances, the preparation of pure sugars, general in- 

 structions to applicants for tests, etc. In the appendixes 43 pages of addi- 

 tional data have been added comprising 10 tables, the results of recent polari- 

 metric researches, a consideration of the polarization of low-grade products, 

 a resumg of the work of the International Commission for Uniform Methods 

 of Sugar Analysis, and amendments to the U. S. Treasury Department sugar 

 regulations. 



An improved automatic pipette-washing device, A. V. Fulleb (Jour. Indus, 

 and Engin. Chem., 10 (1918), No. 4, p. 297, fig. 1). — This is a modification of the 

 device previously noted (E. S. R., 38, p. 203), the improvements being greater 

 capacity, smaller table space occupied, lower first cost, and cleaning of both 

 outside and inside pipettes. 



A new method of extracting the soil solution, C. B. Lipman (Univ. Cat. 

 Pubs. Agr. Set., 3 (1918), No. 7, pp. 131-134; abs. in Chem. Abs., 12 (1918), No. 

 10, p. 1094)- — By means of a special form of pressure tube the author has 

 succeeded in obtaining from soils the soil solution as it exists in thin films 



