*No. XXXI.--Healthy Urine* remained in the warm bath for twenty-eight days without undergoing the least change. *No. XXXII.--Simple Turnip Infusion* remained in the warm bath for twenty-eight days without undergoing any appreciable change.[59] On breaking the neck of the flask, the fluid was found to be quite odourless. With its neck quite open, the flask was replaced in the water-bath. During the first forty-eight hours it underwent no apparent change, though at the end of seventy-two hours a slight general turbidity was noticeable, and an examination of a drop of the fluid (still odourless), showed a number of minute but very active _Bacteria_.[60] [59] Experiment No. 8, recorded in ‘Nature,’ 1870, No. 36, p. 194, may be compared with this and No. XXXIII. [60] This experiment should be compared with Nos. XVIII. and XXXIII. It seems to show that if some fermentable fluids can be kept for a time under conditions in which they will not ferment, the constitution of the fluid, instead of remaining the same, undergoes a slow alteration by which it is rendered absolutely less fermentable, even when exposed to the most favouring influences. _c. Fluid in a Bent-Neck Flask, having Eight acute Flexures._ *No. XXXIII.--Simple Turnip Infusion* showed no change after eight days’ immersion in the warm bath. After _eleven_ days, the fluid being still clear, the tube was broken just beyond the second bending from the bulb, and then the flask was re-immersed in the bath. After three days’ exposure, the fluid being still clear, it was boiled in the flask for one minute, when it was noticed that the steam was quite odourless. The flask was then replaced in the water-bath, where it remained for twenty-two days (still with the neck open and broken just beyond its second bending) without showing any change.[61] It was then submitted to examination; the fluid was found to be devoid of all odour, it had a slightly bitter taste, and its re-action was very faintly acid. On microscopical examination no living things were found; there were no _Bacteria_, no _Vibriones_, and no _Torulæ_, only some mere granules, a small amount of amorphous matter, and a few fibres.[62] [61] After this experiment had been completed, a fresh-filtered infusion of turnip was placed in the same flask (having the neck open just beyond its second bending), and after having been boiled for a few minutes it was immersed in the same water-bath. This fluid became turbid in thirty-six hours, and was then found to contain multitudes of _Bacteria_; and the characteristic odour of the turnip infusion was still appreciable.