Ammonium lactate, prepared in a similar way, had an almost identical action on the skin, but was more effective in removing the last traces of lime.
Ammonium butyrate, prepared as above, removed lime, but instead of a reducing action it appeared to plump the skin slightly.
Action of Bile.
Amongst other compounds in the dung which might have some action on skin were the bile salts and bile colouring matters. (For a full description of these, see Gamgee, Phys. Chem. ii.)
Experiments were made with ox bile, 25 c.c. being diluted with 250 c.c. of water. Pieces of sheep grain previously washed in water were digested in this solution at 37° C. for 1–4 hours. The bile had no reducing action on the skin and in fact hardened it, at the same time staining it a dirty yellowish brown, the colour differing from that of the colouring matter of dung (hydrobilirubin). Even after continued standing there was little or no development of bacteria, the bile appearing to have an antiseptic action.
Action of Bacteria.
Having ascertained the action of the chief chemical constituents of the dung, that of the bacteria was next examined. In the first experiment, eliminating all but bacterial action, a tube of nutrient gelatin was inoculated from an active bate. In two days the gelatin had liquefied along the needle track.
The culture was now transferred to the following solution:—
| Gelatin | 4 | grm. |
| Dextrose | 4 | " |
| K2HPO4 | 1 | ·0 " |
| MgSO4 | 0 | ·2 " |
| NaCl | 0 | ·4 " |
| Water | 2000 c.c. | |