The fact revealed by M. Pasteur, that _some_ fluids remain unchanged for an indefinite period, after having been boiled in flasks, with long and bent necks, is easily explicable in accordance with the physical theory of fermentation, and now that it has been thoroughly proved that _other_ fluids--submitted to precisely similar conditions--do nevertheless undergo fermentation, this fresh fact is just as completely adverse to the explanations and views of M. Pasteur, as it is thoroughly harmonious with the doctrines of Baron Liebig. The fluids which are capable of being preserved--generally not presenting a high degree of fermentability--do not undergo change, _at ordinary atmospheric pressure_, after having been boiled, unless they are brought into contact either with some pre-existing living things or with some unaltered organic particles from the atmosphere. Neither of these, however, can gain access to the fluid, in such a vessel; because all the air which enters, after the first inrush into the still almost boiling fluid, has to pass, more or less slowly, through the numerous flexures of the narrow neck of the flask and the two or three strata of fluid which always remain therein. Some of the fluids which do not undergo change in these bent-neck vessels are, however, by no means notable for possessing a low degree of fermentability. This is the case, for instance, with infusions of turnip, which, under other conditions, have been found to be most prone to undergo fermentation. And, I have found in several cases in which such an infusion had been exposed in a bent-neck vessel, and had remained unchanged for twelve or fourteen days (even though subjected to a temperature of 85°–95° F.), that if the neck of the flask were then broken shortly above the bulb, the solution would still continue without alteration for a week, ten days, a fortnight, or even more--although freely exposed to the air, and therefore to the access of any living germs which might be floating about in the atmosphere.[83] [83] See notes on pp. 73 and 79. It was not that these fluids were incapable of being inoculated, or that they were unsuitable for the development of the lower forms of life, as was shown by their subsequent fate, and by the fact that they can always speedily be made to become turbid if they are really inoculated with living _Bacteria_. Almost similar facts in opposition to the prevalent Panspermic views have been noted by Professor Cantoni (Rend. del R. Istit. Lombardo, Novembre, 1869). He found (as I have also frequently found) that when fluids had been subjected to the influence of high temperatures, and had subsequently remained sterile in closed flasks, they might be freely exposed to the air for one or two weeks, or more, without becoming turbid--although at any time a general turbidity could be speedily induced, by introducing a few living _Bacteria_ into the fluid.