H. Charlton Bastian

“ If Bacteria fail to multiply in a suitable fluid, and under suitable conditions, we have the best proof that can be obtained of their death.
Having made many experiments with solutions of ammonic tartrate and sodic phosphate, I have almost invariably observed that such solutions—when exposed to the air without having been boiled—become turbid in the course of a few days owing to the presence of myriads of Bacteria and Vibriones, with some Torulæ. These organisms seem to appear and multiply in such a solution almost as readily as they do in an organic infusion. ”

“ We should have no longer to do with the members of a stable species, which had been reproducing its like through countless geologic ages anterior to the advent of man upon the earth. Indeed, in order to reconcile such a possibility with the seemingly contradictory fact of the known extreme changeability of these lower forms of life, we hear only vague hints thrown out about our imperfect knowledge of the “limits within which species may vary.” ”

“ M. Pasteur may, moreover, be reminded that when he resorts to the supposition of Bacteria possessing “germs” which are indistinguishable, he is again resorting to hypothesis rather than to fact, in order to prove the truth of the particular doctrine of fermentation which he advocates. Bacteria are known to reproduce and multiply only by a process of fission; each of the parts into which they divide being nothing more than a part of the original Bacterium, and therefore endowed with similar properties of resisting heat, desiccation, and other agencies. ”

“ Whilst we do know something about the ability which most organisms possess of reproducing similar organisms, we cannot possibly say, from direct observation, that every organism which exists has had a similar mode of origin, because the cases in which organisms may have originated de novo are the very cases in which their mode of origin must elude our actual observation. ”

“ And, also, even if it had been always efficacious—the reason adduced could not hold good, in the face of my other experiments, which had shown that a development of life might go on in cases where the air, which had been similarly driven out, was subsequently, in place of being filtered, prevented from gaining access to the fluid.
If germs derived from the air are the sole causes of putrefaction, then, surely, deprivation from air ought to be just as efficacious as any process of filtration of air—more especially when the filtration or the deprivation have a common starting point. ”

“ To suppose that actual germs of Bacteria and of Torulæ are uniformly distributed throughout the tissues of higher organisms, is to harbour a hypothesis which would appear to many to be devoid of all probability—more especially when the heterogenetic mode of origin of larger and higher organisms is a matter of absolute certainty. ”

“ Believing that the air is the source of germs from which Life is first developed in infusions, he thinks that what rapidly enters at first, on the cessation of ebullition, has its germs destroyed by contact with the almost boiling liquid; whilst the air which enters subsequently, and more slowly, is supposed to deposit its germs in the various flexures of the tubes, so that none are able to reach the fluid itself. ”

“ The living matter which is no longer able to exist round a single centre, re-arranges itself around two centres,—as a result of which, fission occurs. It seems only natural, therefore, that whilst this active work of molecular re-arrangement is going on, those other molecular movements which occasion the actual locomotion of the organism from place to place, should be more or less interfered with. ”

“ The finding of visible germs in the atmosphere can, therefore, only have an indirect bearing upon the solution of the problem. Since it can be shown that some visible spores and ova exist in the atmosphere, this affords a certain amount of warrant for the supposition that invisible, living, reproductive particles may also exist—more especially if the existence of an amount of organic matter, which is ordinarily invisible, can be revealed in the air, by the agency of the electric beam, or by any other means. ”

“ Yet, without a shadow of proof, without even an attempt to prove it, the air was for a time represented to be a mere stirabout, thick with invisible germs. The briefest reflection, however, upon the probabilities of the case, should have sufficed to suggest a totally different interpretation. The surface of the earth is clothed with living things of all kinds, animal and vegetal, which are not only continually throwing off organic particles and fragments during their life, but are constantly undergoing processes of decay and molecular disintegration after their death. ”

“ It becomes obvious, then, that in doubtful cases we ought not to rely very strongly upon the character of their movements, as evidence of the death of Bacteria—although these may frequently be of so extensive a nature as to render it not at all doubtful whether the Bacteria which display them are living. In the experiments which I am about to relate, we shall be able to pronounce that the Bacteria are living or dead, by reference to the continuance or cessation of their most essentially vital characteristic. ”

“ Just as the life of one of the cells of a higher organism may continue for some time after the death of the organism itself, so, in accordance with this latter view, may one of the particles of such a cell be supposed to continue to live after even cell-life is impossible.
Now, to many persons, the latter seems to be a much simpler hypothesis than the former, and one, moreover, which is more in accordance with known facts. People’s views, however, on this subject are likely to be much influenced by their notions as to the possibility of Bacteria arising by a process of Archebiosis. ”

“ The third mode of origin is what is called Heterogenesis; whilst the first and second modes are the representatives of more familiar processes, included under the head of Homogenesis. Thus, in accordance with the first view, Bacteria may be regarded as low organisms having a distinct individuality of their own and multiplying by a process of fission—thus affording instances of what I propose to term direct Homogenesis. ”

“ Without the aid of elaborate experiments, however, the evidence which the microscope can supply is capable of leading us to the conclusion that such search for atmospheric Bacteria germs, was comparatively useless. If it can be shown that Bacteria can arise in a fluid independently of visible germs, then, obviously, any inquiries as to the nature of the visible contents of the atmosphere, can have only a very indirect bearing upon the question as to the mode of origin of these organisms. ”

“ If fluids in vacuo (in hermetically-sealed flasks) , which were clear at first, have gradually become turbid; and if on microscopical examination this turbidity is found to be almost wholly due to the presence of Bacteria or other organisms, then it would be sheer trifling gravely to discuss whether the organisms were living or dead, on the strength of the mere activity or languor of the movements which they may be seen to display. Can dead organisms multiply in a closed flask to such an extent as to make an originally clear fluid become quite turbid in the course of two or three days? ”

“ There is an utter absence of light, an absence of free oxygen, and also an absence of that diminished pressure which my experiments seem to show is favourable to the promotion of many kinds of fermentative change. So that if fermentation does not take place in a closed flask which is full of a boiled infusion of hay,91 it may be owing to the fact that there is no space for the residual gases, and that undue pressure retards many fermentative changes. ”

“ Heterogenetic Mode of Origin of Bacteria and of Torulæ.
It has been long known that Bacteria and Torulæ are frequently to be found within vegetable cells, taken even from the central parts of plants, whenever these are in a sickly condition or are actually dying. They are apt to exist also within epithelial cells taken from the inside of the mouth; and the frequency and abundance with which such organisms are met with in these cells, is almost in direct proportion to the malnutrition and lack of vital power in the individual who is the subject of observation. ”

“ Every-day experience convinces them of the truth of this. They merely affirm that the intervention of vital action is not essential: they look upon fermentation as a purely chemical process, and believe that even in those cases where fermentation is initiated by living organisms (such as beer-yeast) , these—although living—act chemically upon the matter which undergoes fermentation. ”

“ Our whole point of view, in fact, concerning such fungi as are seen to develop through Leptothrix forms from Bacteria must be entirely altered, if it is once conceded that Bacteria may arise de novo. Such simple Mucedineæ would then have to be regarded as mere upstart organisms only a few removes from dead matter, and—in view of the greater molecular mobility of living matter—capable of being modified in shape and form even more than the most changeable crystals under the influence of altering “conditions.” ”

“ That the Bacteria which reproduce should be in a comparatively quiescent condition, seems not difficult to understand. Such rudimentary organisms do not appear to possess cilia or other locomotory appendages: their movements are, therefore, in all probability dependent upon the mere molecular changes which are taking place within them, and upon which their life and nutrition depend. The process of fission must, however, be considered as the result of a new effort at equilibrium, which has, perhaps, been necessitated by molecular changes that have occurred during a preceding period of growth. ”

“ Seeing however, that we are able, with the aid of the microscope alone, to demonstrate that Bacteria and Torulæ can develop in situations where no visible germs had previously existed, it is useless, as I have said before—so far as the question of their mode of origin is concerned—to search the atmosphere to ascertain what visible germs it may contain. If some Bacteria and Torulæ arise from germs at all, it must be from germs which are invisible to us. ”

“ So that even where obvious cracks occur, and the vacuum is altogether impaired by the consequent inrush of air, such air does not necessarily carry with it germs of Bacteria—which have been supposed to be universally diffused, and capable of passing through cracks so minute as to be invisible. These results, important as they are, have not at all surprised me, because one may frequently find a previously boiled solution of the kind under consideration, remaining free from turbidity for two weeks or more, although the neck of the flask has been merely covered by a loose paper-cap (see p. 30) . ”

“ Now, if Pasteur’s theory of fermentation, and the prevalent notions concerning the universal distribution of “germs” throughout the atmosphere were true, it might be expected that the fluid in B would always rapidly change; that that in A would always remain pure; and that the fluid in C would, similarly, undergo no alteration. The facts, however, are quite the reverse: if a strong turnip infusion be employed, the fluid in A will almost always remain unchanged; that in B will sometimes rapidly change, and at other times will remain quite pure ”

“ It is, however, no easy matter definitely to prove or to disprove the possession of this property by organisms so minute as Bacteria, and therefore so difficult to identify. If dried Bacteria are added to a drop of a suitable solution—similar to that in which they had been bred—it soon becomes quite impossible to distinguish those which have been added from those which arise in the fluid. ”

“ The actual reproductive elements of these living things are extremely small in bulk, when compared with the other parts which are not reproductive, and although Bacteria and Torulæ do exist abundantly, and do materially help to bring about some of the decay in question, yet their bulk, also, is extremely small in comparison with the amount of organic matter itself that is continually undergoing disintegration of a dry kind, in which Bacteria and Torulæ take no part. ”

“ The question of the mode of origin of Living Matter, is inextricably mixed up with another problem as to the cause of fermentation and putrefaction. M. Pasteur’s labours were, at first, undertaken in order to solve the latter difficulty—to decide, in fact, between two rival hypotheses. It was held, on the one hand, that many ferments were mere dead nitrogenous substances, and that fermentation was a purely chemical process, for the initiation of which the action of living organisms was not necessary ”

“ I have, I hope, shown that it is perfectly easy to teach children, from the very first, to distinguish true history alike from legend and from wilful invention, and also to understand the nature of historical authorities, and to weigh one statement against another. ”

“ Huxley says he has never seen putrefaction or fermentation occur after certain organic fluids have been boiled for ten or fifteen minutes, if a good plug of cotton-wool has been inserted into the neck of the flask in which they are contained whilst ebullition is going on, and has, subsequently, been allowed to remain in the same situation. Using other or perhaps stronger fluids, however, I have found that such a method of proceeding is by no means adequate to stop the growth and development of organisms. ”

“ Both processes are really alike inexplicable—both products are similarly the results of the operation of inscrutable natural laws, and what seem to be inherent molecular affinities. The properties of living matter, just as much as the properties of crystalline matter, are dependent upon the number, kind, and mode of collocation of the atoms and molecules entering into its composition. There is no more reason for a belief in the existence of a special “vital force,” than there is for a similar belief in the existence of a special “crystalline force.” ”

“ More especially is there room for doubt on this subject when, as I have found, the result of the experiment can be, within certain limits, predicated beforehand, according to the nature of the fluid employed. If all organisms proceed from pre-existing germs, and these can be filtered from the air by a certain mechanical contrivance, then, if it be alleged that it is on account of such filtration that certain boiled fluids do not change, all fluids placed under these conditions ought, on this theory, to be similarly preserved. ”

“ When, however, it is also ascertained that provisions which have been subjected to the long-continued influence of heat, do not undergo change in closed vessels, if all air has been expelled from the very small space above the level of the provisions; though many organic infusions will putrefy if they occupy only one half, or less, of a hermetically closed vessel from which all air has been similarly expelled by ebullition of its fluid contents, it is impossible that the same explanation can hold good. ”

“ It does not seem to me that the presumed permanence of a very changeable organism is consistent with, or rendered more explicable by, the supposition that some representatives of the species have constantly been undergoing progressive modifications which have been successively perpetuated by inheritance, in the shape of distinct specific forms. ”

“ Hence we have a fluid which is eminently suitable for testing the vital resistance of Bacteria,—one which, although quite capable of nourishing and favouring their reproduction, does not appear capable of evolving them, when, after previous ebullition, it is enclosed in a hermetically sealed flask from which all air has been expelled. ”