*No. LIII.--Ammonic Acetate Solution* after twenty-four hours was faintly opalescent, and in forty-eight hours showed a very slight bluish tint. In seventy-two hours it was in the same state, and, on microscopical examination, the fluid showed no distinct _Bacteria_ or other living things, though there were a number of very minute particles distributed, singly or in small groups, throughout the fluid. On the thirteenth day there was no change in appearance, except that the sediment had somewhat increased in amount. Still, no _Bacteria_ could be found in the fluid or the sediment,--only the above-mentioned particles, and a few somewhat larger, which resembled very minute _Torulæ_. Amongst the sediment, however, there were two or three very small mycelial tufts of a developing fungus. *No. LIV.--Ammonic Oxalate Solution.*--On the eighth day the fluid showed a very faint opalescence, though there was a well-marked, greyish, flocculent deposit, which was found to be composed of an aggregation of colourless and blackish granules, of a multitude of minute crystalline particles (mostly diamond-shaped), and some rounded or ovoidal, thick-walled, spore-like bodies; amongst which, and enveloped in part by them, were several mycelial tufts of a fungus. A number of minute _Bacteria_ were found distributed throughout the fluid, and also a quantity of minute star-like bodies (crystalline), about 1/12000 in diameter. *No. LV.--Ammonic Carbonate Solution.*--On the eighth day the fluid showed a very faint opalescence, and a slight deposit, which was found to be composed principally of amorphous granules. Distributed through the fluid were some small and sluggish _Bacteria_, though no other organisms were seen. *No. LVI.--Ammonic Tartrate Solution.*--After twenty-four hours the fluid showed the faintest opalescence, and in forty-eight hours there was a slight bluish-white turbidity. In seventy-two hours the turbidity was well marked, and there was a very thin pellicle on the surface. When examined microscopically the fluid was found to contain multitudes of very active _Bacteria_, and the pellicle was also composed of an aggregation of _Bacteria_. On the thirteenth day the opacity had somewhat increased; there was also a well-marked pellicle, and an obvious deposit. The pellicle was found to be composed of _Bacteria_, and in the fluid there were multitudes of medium-size _Bacteria_ and _Vibriones_, with here and there a small _Torula_ cell.[71]