Modern Doctrine of Spontaneous Generation.
Althougli Strauss greatly exaggerates when he says that men of science in our day are unanimous in supporting the doctrine of spontaneous genei'ation, it is undoubtedly true that a large class of naturalists, especially on the continent of Europe, are in favour of that doctrine. Professor Huxley, in his discourse on the " Physi- cal Basis of Life," lends to it the whole Aveight of his authority. He does not indeed expressly teach that dead matter becomes active without being subject to the influence of previous living matter ; but his whole paper is designed to show that life is the result of the peculiar arrangement of the molecules of matter. His doctrine is that " the matter of life is composed of ordinary matter, differing from it only in the manner in which its atoms are aggregated."'- "If the properties of water," he says, "may be properly said to result from the nature and disposition of its com- ponent molecules, 1 can find no intelligible ground for refusing to say that the properties of protoplasm result from the nature and disposition of its molecules." ^ In his address before the British Association, he says that if he could look back far enough into the past he should expect to see " the evolution of living protoplasm from not living matter." And although that address is devoted to showing that spontaneous generation, or Abiogenesis, as it is called, lias never been proved, he says, " I must carefully guard myself against the supposition that I intend to suggest that no such thing as Abiogenesis has ever taken place in the past or ever will take place in the future. With organic chemistry, molecular physics, and physiology yet in their infancy, and every day making pro- digious strides, I think it would be the height of presumption for any man to say that the conditions under which matter assumes the properties we call ' vital,' may not some day be artificially brought together."^ All this supposes that life is the product of physical causes ; that all that is requisite for its production is " to bring together" the necessary conditions.
Mr. Mivart, while opposing Mr. Darwin's theory, not only maintains that the doctrine of evolution is " far from any necessary opposition to the most orthodox theology," but adds that " the same may be said of spontaneous generation." * As chemista have
1 Lay Sermons and Addresses, London, 1870, p. 144.
2 Jbid. p. 151.
8 Athenceum, September 17, 1870, p. 376.
* Genesis of Species, by St. George Mivart, F. R. S. p. 26$.
6 PART II. Ch. I. — ORIGIN OF MAN.
succeeded in producing urea, which is an animal product, he thinks it not unreasonable that they may produce a fish.
But while there is a class of naturahsts who maintain the doctrine of spontaneous generation, the great body even of those who are the most advanced admit that omne vivum ex vivo, so far as science yet knows, is an established law of nature. To demonstrate this is the object of Professor Huxley's important address just referred to, delivered before the British Association in September, 1870. Two hundred years ago, he tells us, it was commonly taken for granted that the insects which made their appearance in decaying animal and vegetable substances were spontaneously produced. Redi, however, an Italian naturalist, about the middle of the seven- teenth century, proved that if such decaying matter were protected by a piece of gauze admitting the air but excluding flies, no such insects made their appearance. " Thus, the hypothesis that living matter always arises by the agency of preexisting living matter, took definite shape ; and had henceforward a right to be con- sidered and a claim to be refuted, in each particular case, before the production of living matter in any other way could be admitted by careful reasoners." ^ This conclusion has been more and more definitely settled by all the investigations and experiments which have been prosecuted from that day to this. It has been proved that even the infusorial animalcules, which the most powerful micro- scopes are necessary to detect, never make their appearance when all preexisting living germs have been carefully excluded. These experiments, prosecuted on the very verge of nonentity, having for their subject-matter things so minute as to render it doubtful whether they were anything or nothing, and still more uncertain whether they were living or dead, are reviewed in chronological order by Professor Huxley, and the conclusion to which they lead fully established.^ This is confirmed by daily experience. Meat, vegetables, and fruits are preserved to the extent of hundreds of tons every year. "The matters to be preserved are well" boiled in a tin case provided with a small hole, and this hole is soldered up when all the air in the case has been replaced by steam. By this method they may be kept for years, without putrefying, fer- menting, or getting mouldy. Now this is not because oxygen is excluded, inasmuch as it is now proved that free oxygen is not necessary for either fermentation or putrefaction. It is not because
1 AtkeiKBum, September 17, 1870, p. 374.
* What Dr. Charlton Bastian, who contested the conclusions of Professor Huxley, took to Jm .living organisms, turned out to be nothing but minute follicles of glass.