AGRICULTURAL CHEMISTRY AGROTECHNY. 715 



on a course of lectures given on alcoholic fermentation at London University 

 and tlie Royal Institution during 1909-10, including zymase and its properties ; 

 tlie function of phosphates in alcoholic fermentation; the coenzym of yeast 

 juice; action of some inhibiting and accelerating agents on the enzyms of yeast 

 juice ; the by-products of alcoholic fermentation ; the chemical changes involved 

 in fermentation; and the mechanism of fermentation. An extensive bibliog- 

 raphy embracing 272 titles is appended. 



In reg-ard to the constitution of proteins, with special reference to C. 

 Reichard's merciiry salt reaction, G. Rottke (Vntersitchimgeii iiber die Eon- 

 stitution des Eiweisses unter Berucksichtigung von C. Rcichards Quecksilhersals- 

 Reaktionen. Inaug. Diss., Univ. Bern, 1910, pp. 39). — Proteins have reducing 

 groups in their molecule for the mercury salts. Amino acids were found to be 

 capable of reducing mercurous nitrate and ammonium molybdate. Glucose pos- 

 sesses the same properties. It was not possible with the reagents used to de- 

 termine whether it was the amino acids or a hexose in the molecule which 

 brought about the reduction. 



Some tests were also made with mercuric chlorid but with negative results. 

 The protein preparations tested were blood albumin, alkali albuminate, globu- 

 lin, blood fibrin, casein, peptohe, peptone and albumin gelatin, etc. 



Investigation by means of the dilatometer on the heat coagulation and 

 solution of albumin, T. Gayda (Biochem. Ztschr., 39 (1912), No. 5-6, pp, 400- 

 409, fig. 1; abs. in Jour. Chem. Sac. [London], 102 (1912), No. 595, I, p. 399).— 

 It is shown that the thermal expansion of pure albumin is greater than that of 

 water. 



" The volume changes taking place when the temperature is very slowly 

 raised during coagulation are very small. Below the coagulation temperature, 

 the x'ate of increase of volume change is greater and remains so while the clot 

 is forming, but falls to a slower rate of increase as the albumin reaches the 

 stage of complete coagulation. During the solution of albumin a contraction 

 of volume takes place. This is possibly due to a true solution of the water in 

 the substance of the colloidal particles." 



Specific rotation of fructose, B. Tollens (Ztschr. Ver. Deut. Zuckerindus., 

 1912, No. 674, II, PP- 360, 361; ahs. in Chem. Ztg., 36 (1912), No. 42, Repert., 

 p. 217). — A revision of the work of Winter and Herzfeld (1S8S), in which 

 marked variations in ao = — 71 to — 77° were i-eported, is shown to rest on an 

 error in calculation. It is claimed that Winter's figures should be ao — — 92.22 

 and —106.14° and Herzfeld's, Hd — —93.59°. These figures agree very well 

 with those generally considered correct. 



The quantitative determination of saccharose in various foods and condi- 

 ments, A. JOLLES (Abs. in Chem. Ztg., 36 (1912), No. 115, p. 1100).— The detec- 

 tion of saccharose, when other sugars are present, by the method recommended 

 by the author (E. S. R., 25,p. SOG) has the disadvantage that the reducing sugars 

 in decinormal alkali solutions must not exceed 2 per cent, because with the 

 usual decolorizing methods filtrates are obtained which can only be polarized 

 with difficulty. Some tests have now shown that 10 per cent solutions of 

 reducing sugars treated with one-fifth-normal alkali solution after 24 hours at 

 37° C. lose their optical activity. Very dark solutions are also obtained. 



Using the principles pointed out by Neuberg and Ishida (E. S. R., 27, p. 714) 

 for obtaining colorless filtrates, the method has been modified as follows : A 

 measured volume of the fluid to be examined, which has been treated with 

 one-fifth-normal alkali at 37* C, is neutralized with dilute acetic acid, and a 

 50 per cent solution of mercuric acetate is added until a precipitate is no longer 

 produced. The total volume of the fluid and precipitate is then noted. To an 

 aliquot of the filtrate from this mixture a 25 per cent phosphotungstic acid 



