a considerable retardation of growth, over half as much as ten times the amount in one hundredth of one per cent, and about one fifth as much as the retardation caused by one hundred times as much alcohol, one tenth of one per cent. That is to say, we find a truly physiological curve, of practically the same form as that obtained from the fatigue of a muscle fiber or a nerve cell. This is not so remarkable, since in all such experiments we are touching, in final analysis, the vital activities of living cells, and in muscle or nerve one of the prime factors in causation of fatigue is accumulation of the waste products of active metabolism.
In the right-hand diagram in Fig. 1 and in Fig. 2 the same fact is expressed as a race—a competitive effort—in which the culture containing no alcohol is seen to win, the others falling behind. In general, retardation of growth is directly proportional to amount of alcohol. This is the unmistakable result of the entire series of experiments, fifteen in number. In Fig. 2, however, it may be noted that the cultures containing one per cent have grown somewhat better than those of 0·1 and 0·01 per cent. This is clearly due to difficulties in uniformly "seeding" the cultures, and when these were overcome perfectly consistent results, as seen in Fig. 1, were obtained.[1]
Too great caution can not be used in interpreting the above results. While the physiology of the yeast cell and that of the cells of the human body may be at ground similar, in certain particulars they may be widely different. The yeast cell has not the power to oxidize alcohol. The cells of the body, or some of them at least, are most certainly able to bring about this reaction. Furthermore, if we had experimented with Mycoderma aceti—the normal food of which alcohol seems to be—we should have doubtless obtained a diametrically opposite result.
On the other hand, ethyl alcohol is found in minute quantities in the fresh tissues of man and animals where no alcohol has been given as a constant normal constituent. It has been distilled off from the brain, muscle, and liver.[2] Whether it exists as a food in process of transformation or as a waste product, as in case of the yeast cell; whether it is a waste product from the activity of
- ↑ S. cerevisiœ, obtained in pure culture from Fleischmann's compressed yeast, was used throughout these experiments. The chief difficulty encountered consisted in breaking up the large clusters, composed of hundreds of torulæ, so as to get a uniform seeding suspension. This was finally done by churning the culture from which it was desired to seed with a wad of sterilized absorbent cotton. The liquid squeezed out of the cotton contained only single torulæ. The seeding was always done from fresh stock solution—i, e., it was free from alcohol.
- ↑ Rajewski. Pflüger's Archiv, Bd. ii, S. 122. Hoppe-Seyler. Handbuch der chermischen Analyse, Berlin, 1893, S. 40 and 41.
