Harvard classics . lot n° 3 à l'aide du flacon C (Fig. 4), holding 4.7Liters (8yi pints), et équipé d'habitude la uplike flacons à col à deux,avec l'objet de libérer l'thefermentable foreigngerms de liquide, en la faisant bouillir à beginwith, afin de nous faire travailler dans des conditions onour. ofpurity Le volume de l'eau de levure (contenant 5  %, ofsugar) n'était que de 200. (7 fl.oz.), et par conséquent, en prenant en compte de la capacité des theflask, mais il s'est formé une couche très fine en bas. Surle jour après l'imprégnation le dépôt de levure a été alreadyconsiderable, et quarante-huit heures afterwa

• Contributeur: The Reading Room / Alamy Banque D'Images
• ID de l’image: 2ANAY7A
• Taille du fichier: 7,1 MB (214,5 KB Téléchargement compressé)
• Autorisations: Modèle - non | Propriété - non
• Dimensions: 1364 x 1832 px | 23,1 x 31 cm | 9,1 x 12,2 inches | 150dpi

Informations supplémentaires

Cette image appartient au domaine public, ce qui signifie que le droit d’auteur a expiré ou que le titulaire du droit d’auteur a renoncé à ses droits. Les frais facturés par Alamy couvrent l’accès à la copie haute résolution de l’image.

Cette image peut avoir des imperfections car il s’agit d’une image historique ou de reportage.

Harvard classics . third lot by means ofthe flask C (Fig. 4), holding 4.7litres (8yi pints), and fitted uplike the usual two-necked flasks, with the object of freeing thefermentable liquid from foreigngerms, by boiling it to beginwith, so that we might carry onour work under conditions ofpurity. The volume of yeast-water (containing 5 per cent, ofsugar) was only 200 cc. (7 fl.oz.), and consequently, taking in-to account the capacity of theflask, it formed but a very thin layer at the bottom. Onthe day after impregnation the deposit of yeast was alreadyconsiderable, and forty-eight hours afterwards the fer-mentation was completed. On the third day we collectedthe yeast after having analyzed the gas contained inthe flask. This analysis was easily accomplished by plac-ing the flask in a hot-water bath, whilst the end of thecurved tube was plunged under a cylinder of mercury. Thegas contained 41.4 per cent, of carbonic acid, and, after theabsorption, the remaining air contained:— Oxygen 19.7 Nitrogen 80.3. Fig. 4 100.0 Taking into consideration the volume of this flask, thisshows a minimum of 50 cc. (3.05 cub. in.) of oxygen to THEORY OF FERMENTATION 303 have been absorbed by the yeast. The liquid contained nomore sugar, and the weight of the yeast, dried at a tem-perature of ioo° C (2120 R), was 0.44 grammes. Theratio between the weights of yeast and sugar is *j^* « ^-^ *.On this occasion, where we had increased the quantity ofoxygen held in solution, so as to yield itself for assimilationat the beginning and during the earlier developments of theyeast, we found instead of the previous ratio of fa that of The next experiment was to increase the proportion ofoxygen to a still greater extent, by rendering the diffusionof gas a more easy matter than in a flask, the air in whichis in a state of perfect quiescence. Such a state of mattershinders the supply of oxygen, inasmuch as the carbonicacid, as soon as it is liberated, at once forms an immovablelayer on the surface

Recherche dans la banque de photos par tags

• bookcentury1900
• bookdecade1910
• bookpublishernewyo
• bookyear1910