Third Set of Experiments (XXII.–XXX.).
a. Fluid exposed to Air in a Flask with a short Open Neck.
No. XXII.—Urine in twenty-four hours showed no change; though in forty-six hours the turbidity was well marked.[56] Examined microscopically it was found to contain an abundance of Bacteria.
b. Fluid in contact with Ordinary Air and its Particles; Neck of Flask Sealed after the Fluid had become Cold.
No. XXIII.—Urine in eighteen hours showed a distinct pellicle, though there was not much general turbidity. During the next few days the old pellicle fell to the bottom, and a new one formed.
c. Fluid in a Bent Neck Flask, having Eight acute Flexures.
No. XXIV.—Urine in forty-eight hours showed no change. After twelve days there was still no general turbidity, though there was a slight flocculent deposit of an uncertain nature. Two days afterwards the flask was broken, when the odour of the fluid was still found to resemble that of fresh urine, and its re-action was acid. The flocculi were made up of granular aggregations, in the midst of which were a few bodies closely resembling Torulæ, though they were somewhat doubtful in nature. Neither Bacteria nor Vibriones could be found. The flask, having a short open neck, was then replaced in the warm bath. In sixteen hours the whole fluid had become turbid; it was also slightly fœtid; and on microscopical examination it was found to be swarming with Bacteria, Vibriones, and Leptothrix.
No. XXV.—Turnip Infusion + 1/2 gr. of Cheese in forty-eight hours showed no change, though in seventy-two hours there was a well-marked pellicle, in which some bubbles of gas were engaged. After ninety-six hours the neck of the flask was broken; the fluid was found to be fœtid, and it had an acid re-action. On microscopical examination, a portion of the pellicle was seen to consist of multitudes of Bacteria, Vibriones, and jointed Leptothrix filaments.
No. XXVI.—Simple Turnip Infusion remained clear, and showed no appreciable change for seven days. On the eighth day a slight general turbidity of the fluid was noticed. On the ninth, the turbidity was rather more marked, though there was no trace of a pellicle; the neck of the flask having been broken, the fluid was found to be odourless and very faintly acid. On microscopical examination, multitudes of languid Bacteria of medium size were found, and also short monilated chains with from two to ten segments. There were no Vibriones, Leptothrix or Torulæ.[57]
e. Fluid (in vacuo) in a Flask, Sealed during Ebullition.
No. XXVII.—Healthy Urine after twenty-four hours showed no change. After eleven days there was still no apparent change, though on the thirteenth a slight amount of flocculent sediment was noticed. This deposit increased in amount, very slowly, during the next fortnight; though afterwards the fluid seemed to undergo no further change, and did not become generally turbid.[58]
No. XXVIII.—Healthy Urine ( 1/3) and Filtered Turnip Infusion ( 2/3) after forty-eight hours showed a very slight turbidity, which, however, became quite marked in another twenty-four hours.
No. XXIX.—Albuminous Urine ( 1/3) and filtered Turnip Infusion ( 2/3) after twenty-four hours, showed a slight turbidity, which became much more marked in forty-eight hours; whilst in seventy-two hours there was a considerable deposit at the bottom of the flask.
No. XXX.—Simple Turnip Infusion showed no change in forty-eight hours, though in seventy-two hours there was well-marked turbidity. The turbidity and sediment continued to increase for several days, and both were most marked on the tenth day, when the flask was opened. There was an outrush of gas, having an extremely fœtid odour. The fluid had an acid re-action, and when examined microscopically, multitudes of Bacteria, Vibriones and Leptothrix filaments were found—the movements of the Bacteria being very languid.