AGRICULTURAL CHEMISTRY AGROTECHNY. 505 



The mechanism of the arrest of diastatic activity by filtration, M. Hol- 

 DEKER (Compt. Rend. Acad. Sci. [Paris], 155 (1912), No. 4, pp. 318, 819).— In 

 some preAious work it was shown that if a solution of diastase was filtered 

 through a Chamberlaud bougie F a filtrate was obtained which was active if 

 the diastase solution was rendered alkaline before filtration. On the other 

 hand, solutions neutral or acid to methyl orange yielded inactive filtrates. 



It has now been found that if white of egg or peptone is added to the diastase 

 solution before filtering, almost all of the diastase goes through the filter even 

 when it is in an acid solution. If the albumin, etc., is passed through the filter 

 before tlie diastase solution, the same result is obtained. 



The mechanism of the process can probably be explained by a fixation of the 

 albumin on the porcelain of the filter. 



The saccharification of malt by its own diastase, H. Van Laee (Bui. Soc. 

 Chilli. Belg., 26" (1912), No. 5, pp, 223-226). — The diastase present in malt was 

 found to act directly upon the starch in accordance with Ostwald's definition 

 of a catalyzer. 



Action of emulsin on gentiopicrin in solution in neutral organic liquids, 

 E. BouRQUELOT and M. Bridel (Compt. Rend. Acad. Sci. [Paris], 15-'f (1912), 

 No. 19, pp. 1259-1261; abs. in Jour. Chem. Soc. [London], 102 (1912), No. 

 597, I, p. 593). — The decomposition of gentiopicrin or salicin by emulsin takes 

 place by simple contact because the hydrolysis goes on in a solution in which 

 emulsin is insoluble. It is shown, however, that gentiopicrin is not hydrolyzed 

 by emulsin suspended in dry acetone, but that the hydrolysis may take place 

 slowly in an acetone containing 10 per cent of water. The amount of hydrol- 

 ysis increases as the water is increased, and is complete in 37 days when 40 

 per cent of water is added. Similarly, no hydrolysis takes place in a dry 

 solution of ethyl acetate. "Hydrolysis also takes place when solutions made 

 by macerating emulsin in acetone containing at least 50 per cent of water are 

 used, but not with liquids prepared by macerating emulsin in wet ethyl acetate." 



A synthetic action of emulsin, E. Bouequelot and M. Bridel (Compt. 

 Rend. Acad. Sci. [Paris], 151t (1912), No. 21, pp. 1315-1318; Jour. Pharm. et 

 Chim., 1. ser., 5 (1912), No. 12, pp. 569-513; abs. in Jour. Chem. Soc. [London], 

 102 (1912), No. 591, I, p 592).— With the object of demonstrating the synthe- 

 tic action of enzyms, the authors have submitted an alcoholic solution of dex- 

 trose and saligeniu to the action of emulsin. The course of the action was 

 followed by means of the polarimeter, the final readings of which corresponded 

 with that deduced for the quantity of salicin expected. Attempts to isolate 

 salicin from the reaction product were unsuccessful. In its place a noncrystal- 

 line substance, [aln —80.02°, was obtained, which scarcely reduced Fehling's 

 solution, and was rapidly hydrolyzed by emulsin. It is possibly ^-ethyl 

 glucosid." 



New synthesis of glucosid alcohols with the aid of emulsin, E. Boue- 

 quelot and M. Bridel (Compt. Rend. Acad. Sci. [Paris], 155 (1912). No. 1, pp. 

 ^31-fi39). — This continuation of the above work deals with the synthesis of 

 j3-butyl glucosid, j8-isobutyl glucosid, and /S-allyl glucosid. 



Reversibility of enzym action. — Influence of the dilution of ethyl alcohol 

 on the synthetic action of emulsin in this medium, E. Bouequelot and M. 

 Bridel (Compt. Rend. Acad. Sci. [Paris], 155 (1912), No. 4, pp. 319-322; abs. 

 in Jour. Soc. Chem. Indus., 31 (1912), No. 16, p. 800; Jour. Chem-. Soc. [London], 

 102 (1912), No. 601, I, p. 928). — Experiments were made with mixtures of 

 equivalent amounts of p-ethyl glucosid and dextrose with 85 per cent alcohol 

 in separate flasks. To each of the mixtures there was added the same amount 



