Buchner has paid special attention to the effect of antiseptics on the course of fermentation by yeast-juice [Buchner and Rapp, 1897; 1898, 2, 3; 1899, 1; Buchner and Antoni, 1905, 1; Buchner and Hoffmann, 1907; Buchner, E. and H., and Hahn, 1903, pp. 169-205; see also Albert, 1899, 2; Gromoff and Grigorieff, 1904; Duchaček, 1909] in order (1) to obtain evidence as to the possibility of the active agent in yeast-juice consisting of fragments of protoplasm and not of a soluble enzyme, and (2) also to provide a safe method of avoiding contamination, by the growth of bacteria or yeasts, of the liquids used which were often kept at 25° for several days. The results of these experiments are briefly summarised in the following table, in which the effect of each substance on the total fermentation produced is noted:-- Substance. Effect on Total Fermentation. Concentrated solution of glycerol Slight diminution " " " sugar " increase Toluene (to saturation or excess) Less than 10 per cent. diminution Chloroform 0·5 per cent. Slight increase " 0·8 per cent. (saturation) No change " Large excess (17 per cent.) 64 per cent. diminution Chloral hydrate 0·7 per cent. Increase up to 27 per cent. " 3·5-5·4 per cent. Completely destroyed Phenol 0·1 per cent. No change " 0·5 " 40 per cent. diminution " 1·2 " Completely destroyed Thymol 1 " Slight diminution " 5 " Marked " Benzoic acid 0·1 " 7 per cent. diminution " 0·25 " 26 " " Salicylic acid 0·1 " 10 " " " 0·27 " 35 " " Formaldehyde 0·12 " 20 " " " 0·24 " 30-60 " " Acetone 6 " 20 " " " 14 " 80 " " Alcohol 6 " 0-20 " " " 14 " 75 " " Sodium fluoride 0·5 " 90 " " " 2 " Almost completely destroyed Ammonium fluoride 0·55 per cent. Completely destroyed Sodium azoimide, NaN{3}, 0·36 per cent. Slight diminution " " 0·71 " Marked " Quinine hydrochloride 1 " Slight increase Ozone 10·4-34·8 milligrams per 20 c.c. Marked diminution Hydrocyanic acid 1·2 per cent. Completely destroyed [p037]