[118] H. K. Procter, “Text Book of Tanning,” 1885, p. 18.
[119] See Procter, “Text Book of Tanning,” pp. 8 and 21.
[120] Since the above was written, Severin (Centr.-Bl. iii. [2], 628) has described seven other species of bacteria, isolated from horse dung; for the description and property of these the original memoir must be consulted. Popp and Becker, German Patent 86,335, 28, describe fourteen species which they isolated from dog and pigeon dung, of which three have considerable bating action on skins, and which form the subject of the patent. Some of these are probably identical with organisms in the above list.
[121] Centr.-Bl. ii. [1], 97.
[122] J.S.C.I., 1894, March 31, 218–221.
[123] See Gamgee, Phys. Chem. 2.
[124] Ann. de Micrograph, ii. [6], March 20, 1896.
[125] I did not consider it necessary to purify the enzymes, the object being to examine the action of the bacterial products apart from the living organisms.
[126] Reprinted from the Journal of the Society of Chemical Industry, November 30, 1899, No. 11, vol. xviii.
[127] 10 Jahresber. d. Deutsch. Gerberschule zu Freiberg, 1898–99: Beiträge zur Kentniss der wissenschaftlichen Grundlagen der Gerberei, p. 32.