Critiques and addresses / by Thomas Huxley.

  • Huxley, Thomas Henry, 1825-1895.
Date:
1873
Catalogue details

Licence: Public Domain Mark

Credit: Critiques and addresses / by Thomas Huxley. Source: Wellcome Collection.

    99/344 (page 79)
    yeast, rests upon an unassailable foandation ; and the inquiry into the exact nature of the substance which possesses such a wonderful chemical influence becomes profoundly interesting. The first step towards the solution of this problem was made two centuries ago by the patient and pains taking Dutch naturalist, Leeuwenhoek, who in the year 1680 wrote thus :— Ssepissime examinavi fermentum cerevisiae, semperque hoc ex globulis per materiam pellucidam fluitantibus, quam cerevisiam esse censui, constare observavi: vidi etiam evidentissime, unumquemque hujus ferment! globulum denuo ex sex distinctia globullis constare, accurate eidem quantitate et formoe, cui globulis sanguinis nostri, respondentibus. Verum tails mihi de horum origine et formatione conceptus for- mabam ; globulis nempe ex quibus farina Tritici, Hordei, AvensD, Fagotritici, se constat aquas calore dissolvi et aquae commisceri; hac, vero aqua, quam cerevisiam vocare licet, refrigescente, multos ex minimis particulis in cerevisia coadunari, et hoc pacto efficere particu- lam sive globulum, quse sexta pars est globuli fsecis, et iterum sex ex hisce globulis conjungi.1 Thus Leeuwenhoek discovered that yeast consists of globules floating in a fluid; but he thought that they were merely the starchy particles of the grain from which the wort was made, re-arranged. He discovered the fact that yeast had a definite structure, but not the meaning of the fact. A century and a half elapsed, and the in vestigation of yeast was recommenced almost simulta neously by Cagniard de la Tour in France, and by Schwann andKlitzing in Germany. The French observer was the first to publish his results; and the subject received at his hands and at those of his colleague, the o * botanist Turpin, full and satisfactory investigation. The main conclusions at which they arrived are these. The globular, or oval, corpuscles which float so thickly in 1 Leeuwenhoek, Arcana NaturaeDetecta. Ed. Nov., 1721.