Russel Wallace : Alfred Russell Wallace (sic)
Dr. Bastian also criticises many of the experiments of Pasteur, and the arguments founded on them. He maintains that the corpuscles found by the latter to exist in the atmosphere, and which "resemble" spores of fungi, have never been proved to be such; and even if they were so proved, it would not account for the constant occurrence of Bacteria and other low organisms, whose "germs" are quite unknown, and which there seems no reason to believe could retain their vitality in a dry state [[p. 179]] in the atmosphere. The fact that vessels with bent necks or with plugs of cotton-wool do not produce organisms, while other vessels not so protected produce them in abundance, is shown, by numerous experiments, not to be universal. The evidence now adduced is held to prove that a variety of conditions hitherto not attended to affect the result, such as temperature, the strength of the solution, and especially the presence of particles of organic matter, other than "germs," derived from the atmosphere. A summary is given of sixty-five comparative experiments, which are believed to show, among other things, that the non-production of Bacteria, &c., in infusions and other suitable liquids, is so common an occurrence that the negative experiments of Pasteur and others have no weight as compared with the positive results obtained by a considerable number of observers, to whom the author refers, as well as by himself.
Some of these comparative experiments are very suggestive. Hay infusion, for instance, exposed to air, produced abundance of Bacteria in forty-eight hours, and these had increased considerably in sixty-eight hours. A similar infusion, sealed up after the fluid had become cold, behaved in a similar manner. The same in a flask with neck two feet long and having eight acute flexures, remained unchanged for twelve days. A similar infusion, hermetically sealed during ebullition, on the other hand, showed turbidity in forty-eight hours, which subsequently increased, and Bacteria, Vibriones, Leptothrix, and Torulæ were found in abundance. Here, then, whatever inference may be drawn from the first three experiments is entirely negatived by the fourth. Other experiments show that ammonia-tartrate solution sealed in vacuo at a temperature of 90° F. produced in eighty-four hours abundance of Bacteria; while the same solution, if boiled at 212° F. and exposed to the air in flasks covered with paper caps, remained quite clear for nine days; yet as soon as it was inoculated with living Bacteria, they increased rapidly and produced turbidity. These, and a number of other equally suggestive experiments, indicate that the conditions favourable to the origin and to the increase of these low forms are not always identical. Both are very complex, and we cannot avoid the conclusion that the advocates of the universal germ theory have been somewhat hasty in founding their doctrine upon insufficient data, for the most part of a negative character.
We have here, undoubtedly, an important addition to the experimental evidence by which alone the question can be decided, and we are glad to observe the unprejudiced and philosophical spirit with which Dr. Bastian discusses this most interesting and important problem.