Part 28 (1/2)

Our author takes up the question of the possibility of causing yeast to grow in sweetened water, to which a salt of ammonia and some yeast-ash have been added--a fact which is evidently incompatible with his theory that a ferment is always an albuminous substance on its way to decomposition In this case the albuminous substance does not exist; we have only the mineral substances which will serve to produce it We know that Liebig regarded yeast, and, generally speaking, any ferenous, albuminous substance which, in the saing about certain chemical decompositions He connected fermentation with the easy decoined that the pheno manner: ”The albuminous substance on its way to deco to certain other bodies that same state of mobility by which its own atoh its contact with other bodies it i into other co failed to perceive that the fer to do with the fermentation

This theory dates back as far as 1843 In 1846 Messrs Boutron and Fremy, in a Memoir on lactic fermentation, published in the Annales de Chimie et de Physique, strained the conclusions deducible from it to a most unjustifiable extent They asserted that one and the sao various modifications in contact with air, so as to become successively alcoholic, lactic, butyric, and other fer more convenient than purely hypothetical theories, theories which are not the necessary consequences of facts; when fresh facts which cannot be reconciled with the original hypothesis are discovered, new hypotheses can be tacked on to the old ones This is exactly what Liebig and Fremy have done, each in his turn, under the pressure of our studies, coanis's theory of 1843, together with the additions which Boutron and he had made to it in 1846; in other words, he abandoned the idea of albu ferments, to take up another idea, that albuminous substances in contact with air are peculiarly adapted to undergo organization into new beings--that is, the living ferments which we had discovered--and that the ferin

This theory of heanism ord for word the antiquated opinion of TurpinThe public, especially a certain section of the public did not go very deeply into an examination of the subject It was the period when the doctrine of spontaneous generation was being discussed with anism, which was the only novelty in M Freht that M Fremy had really discovered the solution of the question of the day It is true that it was rather difficult to understand the process by which an albu cell This difficulty was solved by M Fremy, who declared that it was the result of soanic impulse” [Footnote: FREMY, Comptes rendus de l'Acade, who, as well as M Fre the nature of fer, 1870, already cited):

”There seeanish it alone that an albuar are enabled to unite and form this particular combination, this unstable form under which alone, as a coar Should the row, the bond which unites the constituent parts of the cellular contents is loosened, and it is through theabout a disarrangear into ht easily believe that the translator for the Annales has e

Whether we take this new form of the theory or the old one, neither can be reconciled at all with the development of yeast and fermentation in a saccharine mineral medium, for in the latter experiment fermentation is correlative to the life of the fer on between the ferment and its food-matters, since all the carbon assien from ammonia and phosphorus from the phosphates in solution And even all said, what purpose can be served by the gratuitous hypothesis of contact-action or co is thus a fundamental one; indeed, it is its possibility that constitutes the ht say, ”but it is the motion of life and of nutrition which constitutes your experiment, and this is the coh, Liebig does endeavour, as a matter of fact, to say this, but he does so timidly and incidentally: ”From a chely abandon, a VITAL ACTION is a phenomenon of motion, and, in this double sense of LIFE M Pasteur's theory agrees with e 6)” This is true

Elsewhere Liebig says:

”It is possible that the only correlation between the physiological act and the pheno cell, of the substance which, by soous to that by which edalin, anic ical act, in this vieould be necessary for the production of this substance, but would have nothing else to do with the ferain, we have no objection to raise

Liebig, however, does not dwell upon these considerations, which he , because he is well aware that, as far as the defence of his theory is concerned, they would be mere evasions If he had insisted on them, or based his opposition solely upon them, our ansould have been simply this: ”If you do not admit with us that fermentation is correlated with the life and nutrition of the fer, let us examine, if you will, the actual cause of fermentation;--this is a second question, quite distinct froiven to questions of ever increasing subtlety, approaching nearer and nearer towards the very essence of phenoether the question of how living, organized beings act in deco fermentable substances, ill be found to fall out once more on your hypothesis of co to our ideas, the actual cause of ferht, in most cases, in the fact of life without air, which is the characteristic ofthinks of the experination of a saccharine reatly at variance with histhe question [Footnote: See our Memoir of 1860 (Annales de Chi, especially pp 69 and 70, where the details of the experiment will be found)] After deep consideration he pronounces this experi, however, was not one to reject a fact without grave reasons for doing so, or with the sole object of evading a troublesome discussion ”I have repeated this experireatest possible care, and have obtained the saards the formation and increase of the ferment” It was, however, the formation and increase of the ferment that constituted the point of the experiment Our discussion was, therefore, distinctly li denied that the ferment was capable of development in a saccharine mineral medium, whilst we asserted that this development did actually take place, and was co before the Paris Academy of Sciences in a Note, in which we offered to prepare in a mineral medium, in the presence of a coht of fer could reasonably demand [Footnote: PASTEUR, Comptes rendus de l'Academie des Sciences, vol lxxiii, p 1419

1871] We were bolder than we should, perhaps, have been in 1860; the reason was that our knowledge of the subject had been strengthened by ten years of renewed research Liebig did not accept our proposal, nor did he even reply to our Note Up to the time of his death, which took place on April 18th, 1873, he wrote nothingmade a remarkable admission: ”My late friend Pelouze,” he says, ”had coo certain results of M Pasteur's researches on fermentation I told him that just then I was not disposed to alter my opinion on the cause of fermentation, and that if it were possible, by means of a liquors, industry would soon avail itself of the fact, and that I would wait to see if it did so; up to the present tie in the manufacture of yeast ”We do not knohat M Pelouze's reply was; but it is not difficult to conceive so sagacious an observer re to his illustrious friend that the possibility of deriving pecuniary advantage from the wide application of a new scientific fact had never been regarded as the criterion of the exactness of that fact We could prove, uished practical men, notably by that of M Pezeyre, director of distilleries, that upon this point also Liebig was mistaken]

When we published, in 1860, the details of the experith the difficulties of conducting it successfully, and the possible causes of failure

We called attention particularly to the fact that saccharine mineral media are much more suited for the nutrition of bacteria, lactic ferment, and other lowly forms, than they are to that of yeast, and in consequence readily becorowth of ger in the atrowth of alcoholic ferments, especially at the commencement of the experiments, is because of the unsuitableness of those media for the life of yeast The latter may, nevertheless, foranized forinal mineral medium by the albu to peruse, in our Me to fermentation by means of albumens--that of the blood for example, from which, we may mention incidentally, ere led to infer the existence of several distinct albumens in the serum, a conclusion which, since then, has been confirmed by various observers, notably by M

Bechamp Now, in his experiments on fermentation in sweetened water, with yeast-ash and a salt of a had failed to avoid those difficulties which are entailed by the spontaneous growth of other organisms than yeast

Moreover, it is possible that, to have established the certainty of this result, Liebig should have had recourse to a closer es in his Memoir he seems to have adopted We have little doubt that his pupils could tell us that Liebig did not even employ that instrument without which any exact study of ferh impossible We ourselves, for the reasons, mentioned, did not obtain a si did In that particular experiave in our Memoir of 1860, we obtained lactic and alcoholic ferether; an appreciable quantity of lactic acid foration of the lactic and alcoholic ferar re

This, however, in no way detracted from the correctness of the conclusion which we deduced froht even be said that, froeneral and philosophical point of viehich is the only one of interest here--the result was doubly satisfactory, inasmuch as we demonstrated that mineral media were adapted to the sianized ferments instead of only one

The fortuitous association of different feren of the cells of the alcoholic and lactic feren in the ammoniacal salts, and that all the carbon of those ferar, since, in the ar was the only substance that contained carbon Liebig carefully abstained fro this fact, which would have been fatal to the very groundwork of his criticisrave contradiction by arguing that we had never obtained a simple alcoholic ferer upon the subject of the difficulties which the propagation of yeast in a saccharine mineral ress of our studies has imparted to the question an aspect very different from that which it formerly wore; it was this circu before the Academy of Sciences in 1871, to prepare, in a saccharine mineral medium, in the presence of a commission to be appointed by our opponent, any quantity of ferht require, and to effect the ferar whatsoever

Our knowledge of the facts detailed in the preceding chapter concerning pure ferments, and their manipulation in the presence of pure air, enables us coard those causes of embarrasseranisms different in character from the ferments introduced by the air or from the sides of vessels, or even by the ferment itself

Let us once more take one of our double-necked flasks, which ill suppose is capable of containing three or four litres (six to eight pints)

Let us put into it the following:

Pure distilled water

Sugar candy200 grarararararains)

Let us boil the anisms that may exist in the air or liquid or on the sides of the flask, and then per placed, by way of extra precaution a small quantity of asbestos in the end of the fine curved tube Let us next introduce a trace of ferh the other neck, which, as we have described, is terlass stopper

Here are the details of such an experiment:--

On December 9th, 1873, ed some pure ferment--saccharomyces pastorianus Froht hours after ination,aalmost continuously from the bottom, indication that at this point the fer days, several patches of froth appeared on the surface of the liquid We left the flask undisturbed in the oven, at a terees F) On April 24, 1874, we tested soht tube, to see if it still contained any sugar We found that it contained less than two grarammes (42 oz Troy) had already disappeared Some time afterwards the fermentation came to an end; we carried on the experiment, nevertheless, until April 18, 1875