I find by experiments with the purified ferments that their action is very slow compared with the bate itself. Two portions of the same skin were taken: one of them was treated with a 1 per cent. solution of pepsin acidified with 0·2 per cent. of hydrochloric acid, the other in a bate liquor of dog’s dung; both at a temperature of 40° C. (104° F.). At the end of one hour, the skin in the pepsin solution was considerably “fallen,” but that in the manure solution was bated nearly away, i.e. the greater part of it was dissolved. A 1 per cent. solution of pancreatin (Merck’s) was found to act far more rapidly than pepsin. At 40° C. in a neutral solution the skin fell rapidly, and the action continued even in the cold. In this experiment it was found that in 15 hours the liquid was swarming with minute bacteria. In order to guard against the influence of bacteria a similar experiment, at the suggestion of Mr. H. R. Procter, of the Yorkshire College, Leeds, was tried with the addition to the pancreatic solution of 1·5 per cent. of chloroform; this prevents the development of bacteria, while it does not interfere with the action of the pancreatin. The skin was reduced as before, but in neither case had it the peculiar touch of a “puered” skin, nor were the characteristics of the leather the same. II. NOTES ON THE CONSTITUTION AND MODE OF ACTION OF THE DUNG BATE IN LEATHER MANUFACTURE. Read before the Nottingham section of the Society of Chemical Industry, Oct. 26, 1898. In a paper read before the Society of Chemical Industry (J.S.C.I., 1894, 219), the author gave an outline of the bating process as far as he had then investigated it. Further researches have shown that, although the views then put forward must be somewhat modified, in the main they are correct. In 1895–96 a series of experiments was undertaken with a view of ascertaining how much of the reducing action of the bate was due to: (1) the chemical constituents; (2) the bacteria; (3) the digestive ferments and enzymes. The puer used was dog dung obtained freshly every week from hunting kennels. It contained on an average: water, 85 per cent.; organic matter, 10 per cent.; mineral matter, 5 per cent.; about 3 per cent. of the organic is soluble and about 1 per cent. of the mineral matter. According to Gamgee (Phys. Chem. 2), a dog fed on flesh diet excretes from 27 to 40 grm. of fæces in 24 hours, of which 12·9 grm. are solids. On a bread diet the amount of fæces is much more. An ultimate analysis gave the following results:-- ---------------+------------+---------- | Bread Diet | Meat Diet ---------------+------------+---------- C | 47·39 | 43·44 H | 6·59 | 6·47 N | 2·92 | 6·50 O | 36·08 | 13·58 Mineral matter | 7·02 | 30·01 ---------------+------------+----------