STUDIES ON FERMENTATIOX. 377 



The analyses showed that the worts in the three flasks con- 

 tained : — 



Flask A, oxygen in combination, per litre 20 c.c. 

 „ B, „ „ „ 21-4 c.c. 



„ C, „ „ „ 16-8 c.c. 



Several facts may be deduced from these experiments : the 

 shaking up of the wort with air has a marked effect on the 

 absorption ; a very appreciable absorption immediately follows 

 the shaking up of the wort when warm ; whereas, in the case 

 of cold wort that has remained undisturbed, the absorption 

 takes place slowly. 



The results of the preceding experiments plainly show that 

 the wort, which is very hot when it comes on to the coolers, 

 where it remains for several hours, must absorb an ap- 

 preciable quantity of oxygen by combination ; but these same 

 experiments teach us nothing definite concerning the volume of 

 oxygen that is actually absorbed. We can only gather from 

 the remark which concludes the third experiment given above, 

 that the total quantity of oxygen absorbed by the wort in 

 Tourtel's brewery, during the time that it remains on the 

 coolers, must be less than 17 c.c. per litre (4-7 cubic inches 

 per gallon), inasmuch as the coloration effected by combined 

 oxygen in the proportion of 17 c.c. per litre was considerably 

 greater than that of the wort taken from the backs in the 

 brewery. 



If we knew the curve of cooling on the Tourtonville coolers 

 we might easily, in experiments conducted in our laboratory, 

 assimilate the conditions of our experiments to those of the 

 oxidation of the wort in the brewery, by exposing wort in con- 

 tact with air in closed flasks to temperatures varying according 

 to the indications of the curve in question. For this purpose, 

 we induced M. Calmettes to study the process of cooling upon 

 the coolers at Tantonville. In Fig. 84 the figures found in one 

 of that gentleman's experiments are given. 



