LOUIS PASTEUR.* PROFESSOR TYNDALL, in concluding his Introduction to this
work, which has been translated from the French by Lady Claud Hamilton, remarks :—" The task expected of me is now accomplished, and the reader is here presented with a record, in which the verities of science are endowed with the interest of romance ;" but not with the romance of a human life, as the biographer takes us scarcely further into the home of the great investigator than into his laboratory. In truth, one learns little of himself beyond the fact of his birth from humble parentage, some scant information as to his early struggles and successes ; and later, of his marriage with the daughter of the Rector of the Academy. On the morning of this event, important generally to mortals less scientifically gifted, Pasteur was found in his laboratory quite absorbed in some engaging chemical experiment, and apparently lost to the interesting event of the day. However, his devoted son-in-law, who gives this record to the world, adds, for the satisfaction of domestic devotees,—" If Pasteur was thus guilty of an absent-mindedness worthy of La Fontaine, he proved as a husband so different from La Fontaine, that Madame Pasteur, when reminded of this lapse of memory, receives the reminder with an indulgent smile."
Until his recent startling experiments in hydrophobia, Pasteur was but little known to the English general public, so that this work, describing step by step his more striking discoveries and progress, will be of interest to those whose intelligent curiosity on the subject has been awakened by his late investigations. Beginning with the study of molecular physics, his researches were already of considerable promise, when quite by chance his attention was diverted into another direction, and he was led to consider the phenomena of fermentation. Until then there had been various more or less erroneous explanations of this remarkable process, but no one had traced it to its true cause—the action of a living organism. "It matters little," says he, "whether the progress of science makes of this vibrio a plant or an animal ; it is a living organism endowed with motion which is a ferment, and which lives without air." Cagniard-Latour in France, and Schwann in Germany, had, however, attributed the ferment process of yeast to a like cause, and had suggested that all other fermentation was probably also intimately connected with the growth of some similar fungus ; but as the hypothesis was not verified by any proof, it remained nothing more than an idea. To Pasteur—who sees no place for science in the realm of supposition—it was given to trace and prove the actual dependence of all fermentation on the presence of an organism, and consequently the necessary existence of that organism in the midst of such process. Following up this subject, Pasteur went on to the study of acetification, the further action whereby the wine produced by fermentation is converted into vinegar. This he showed to depend on a tiny fungus, the mycoderma aceti, which, feeding upon the albnminoid matters in the wine, " fixes " atmospheric oxygen, and leads to the acetic transformation. A vegetable worker in the cause of temperance one might justly call this busy little fungus ; unfortunately for its efforts, if happily for those whose sympathies lie in the opposite direction, M. Pasteur has shown that a temperature of 60° Centigrade suffices to destroy its vitality and check its operations. Vinegar exposed to the air not only deteriorates on account of its loss of acidity, but also gets to contain "little eel-like organisms, very curious when viewed with a strong magnifier. Their bodies are so transparent that their internal organs can be easily distinguished. These eel-like creatures multiply with extraordinary rapidity. Certainly there is not a single barrel of vinegar manufactured by the New Orleans system which does not contain them in alarming numbers." These were looked upon as necessary to the manufacture, and their presence, therefore, was welcomed, and their gyrations inspected with as much complacent satisfaction as if the medium in which they sported were an aquarium and not intended to be taken into the stomach, until it was shown that the existence of the vinegareel is quite unnecessary and even objectionable. It is satisfactory to know that Pasteur's process insists on cleanliness, and that if this be scrupulously attended to, the vinegar-eel is suppressed.
"Spontaneous generation" next claimed "the Professor's" attention, and when one considers the quaint and curious views held on the subject, one concludes that the time had arrived when something more scientific should be said concerning it. " All dry bodies," said Aristotle, " which become damp, and all damp bodies which are dried, engender animal life." In truth, a most exquisitely impartial antithesis of action ! Van Helmont, a celebrated alchemist, who wrote in the time of Louis XIV., informs us that " the smells which rise from the bottom of morasses produce frogs, slugs, leeches, grasses, and other things." He then goes on to state that by placing dirty rags and corn in a vessel, one can readily produce a pot of mice. This phenomenon he states gravely he has himself witnessed, and adds,---" The mice are born full-grown ; there are both male and female. To reproduce the species it suffices but to pair them." As the eyes of the world opened wider to fact, it became necessary to reduce the magnitude of the fallacy, and so it was announced that this remarkable performance could not possibly take place on a scale so large, but was confined to organisations not visible to the eye, and therefore not subjected to the criticism of sneering sceptics. Pasteur, however, was not satisfied that this unforeseen responsibility should rest with his infinitesimal pets, and from a series of experiments came to the conclusion that microscopic organisms cannot come into the world without germs or without parents like themselves. " Spontaneous generation," he says, "is a chimera." Air, water, earth, animal and vegetable matter, all contain eggs and spores which, under suitable conditions, give rise to living organisms ; but whence this element of life the great professor does not say. The problem is still unsolved, though its -elements may have been reduced to their lowest terms. He came now to the Germ-theory of disease, which was then being investigated with much zeal. His discoveries, Professor Tyndall tells us, had been frequently referred to as bearing upon the subject, though he himself kept clear for a long time ofthis special field of inquiry. He was not a physician, and he did not feel called on to trench upon the physician's domain. With the somewhat biassed mind of kinship M. Radot here deals not quite justly with the investigators who had preceded Pasteur in this research. Koch had previously connected the parasite (discovered in 1850 by Davaine and Bayer) with disease, had, indeed, developed this aspect of the germ-theory with which Pasteur is more generally credited. The latter certainly elaborated it, and to him we owe a great deal of our knowledge on the subject.
The " attenuation of virus," that process by which disease introduced into an animal and cultivated, as it were, through successive generations, furnishes finally a virus as well able as the more virulent form to exhaust the pabulum which exists in the blood for disease to live upon,—this was Pasteur's most remarkable work. As a scientific fact, it is interesting to learn that such a process leads to such results ; but so far as the practical utility of the thing is concerned, there is much difference of opinion. The immediate effects, in the case of splenic fever (which was the disease to which Pasteur chiefly directed his attention), appear to be satisfactory, the non-vaccinated animals succumbing at once to inoculation of virulent virus, while those vaccinated are said to suffer hardly at all; but later on it was found (according to Professor Koch and the Sanitary Commission appointed in 1881 by the Hungarian Government for the purpose of testing the prophylactic value of brute vaccination) that the constitution of these vaccinated animals had so deteriorated as to render them peculiarly liable "to be carried off by pneumonia, catarrh, distoma, strongylus, and pericarditis." Such inoculations, after all, are but a clumsy substitute for prevention ; and who knows but that the very disease we attempt to elude may not be Nature's band-maid, whereby, by weeding out the frail, she secures the survival of the fittest? Animals bred and reared under domestic (which
means more or less unnatural) conditions, tend to deteriorate in stamina, to become strumons, tuberculous, and subject to various inflammatory diseases ; and it is more than likely that the careful preservation of such creatures until they are ready to kill, will gradually succeed in producing a race of sickly valetudinarians. How much better might it not have been to allow disease to carry off their ailing ancestry, and thereby secure a healthy stock.
Pasteur would have been wise to content himself with a careful observance of demonstrable fact, leaving the application to more practical minds. As an observer he was valuable; but his lately-developed tendency to trespass on the domain of the physician has been by no means successful. In his investigations on rabies he brought to bear on it his theory of inoculation, and thereupon conceived the notion that "vaccination " with an attenuated virus might be practised as a specific against hydrophobia. But he lost sight of the troth—evident to commoner minds—that true hydrophobia is, after all, not so large a fact in the world as to necessitate or justify so dangerous a means of prevention. For if one eliminates its hysterical dissimulators, it is so rare as to count for almost nothing in man, while amongst dogs it is probable that the best means are to be found in guarding them carefully against it. The subject is still under observation ; but, so far, it seems likely that nothing practical will be discovered. It is not improbable that the inoculation with rabies acts chiefly as a counter-irritant (a tolerably severe one when, as happens, the skull is trephined and the virus introduced into the brain), and that a vaccination with calf-lymph, or the introduction of any other irritant, would lead to equally good results. M. Pasteur knows, probably, more of the microscopic appearances of disease than of its actual bearings; or he might find in the effect of a simple blister on furious delirium, an action not very dissimilar or much less remarkable than that of inoculation of rabies virus on the hydrophobic.
This subject leads ns naturally to that of vivisection, as with Pasteur we are in the presence of one of its most able practitioners; and it is interesting to find that of his discoveries those which are of the most unquestionable value were made without the use of this means. From a careful study of his labours, it appears that the really useful aid he has given to science has not resulted from the scalpel and vivisecting-board. The parasitic theory of disease might have been equally well proven by examining the secretions or a drop of the blood of infected animals. We are told that a long course of vivisection has not hardened M. Pasteur's heart, for M. Radot assures us that Pasteur is nothing if not a man of sentiment ; but he hastens to give us a very strange proof of it by the following illustra tions :—
" In the basement of his laboratory in the Rue d'Ulm [he writes], a whole population of animals is retained under experiment. Isolated in round cages, which impart some sense of security, are the rabid dogs, some'attacked with furious madness biting their bars, devouring hay, uttering doleful howls, which those who have once heard can never forget ; others carrying the germ of this terrible disease, still fawning with a humble look of tenderness, as if imploring attention. Hens and chickens pass their heads through the wooden bars of their coops. From time to time a cock from the bottom of his den crows a gloomy dawn.' Rabbits eat peaceably, while little families of guinea-pigs cluster together, and at the least alarm utter a frightened cry. All these animals are destined to be shortly inoculated. Each morning a round of inspection is made in this little hospital of condemned animals. The dead are taken out, carried to one of the upper rooms, and placed on the dissecting-boards."
In another place,—" Take," cries Pasteur, with enthusiasm, "take the limb of an animal and crush it in a mortar; let there be diffused in this limb as much blood, or any other normal or abnormal liquid as you please. Take care only that the akin of the limb is neither torn nor laid open," d-c. We confess that we have not yet arrived at that pitch of scientific ardour, where the curious sympathy between animal and animal is lost in such zeal as this. It would be rather a good thing, however, to keep these details out of books intended for the laity, as there is still apathetic element left in the unlearned, and their number is legion. After all, one would have thought better of the French investigator if he had not been led by the egotism of learned curiosity to dissect and crush the quivering limbs of living animals for the greater glorification of his art. It seems but a pitiful evolution of faculty—this scientific callousness to suffering. And certainly it has a way of misleading its votaries, so that, whatever their previous promise, once plunged into the whirlpool of vivisection, their best energies are absorbed to be cast-np presently as wrecks and debris from the sea of knowledge.
Previous page
