374 STUDIES ON FERMENTATION. 



Composition of the gas : — Per cent. 



Oxygen . . . . . . . . . . 18'25 



Nitrogen 81-57 



The formula which we deduced above (§ II.) allows us to 

 conclude that at the temperature of 8° C. (46'4° F.), which was 

 the temperature at which the wort was saturated before the 

 analysis given above, the quantity of oxygen in solution in the 

 120 c.c. (4-2 fl. oz.) of wort was 0'84 c.c. (0-051 cub. in.). 



At the moment when the flask was closed, the total volume 

 of oxygen, calculated to zero and 760 mm. (30 in.) pressure, 

 was 44-73 c.c. (2-729 cub. in.). 



At the moment when the analysis was finished, the volume 

 of oxygen was calculated to the same conditions of temperature 

 and pressure, 38"86 c.c. (2-355 cub. in.) ; 5-87 c.c. (0-374 cub. 

 in.) has, therefore, disappeared. Now, as there is 0-84 c.c. 

 (0-051 cub. in.) in solution, there has, consequently, been an 

 absorption, by combination with 120 c.c. of wort, of 5-03 c.c. 

 (0-32 cub. in.) of oxygen, or 41-7 c.c. per litre (ll'G cub. ins. 

 per gallon). 



Second Experiment. — In a similar experiment, in which, how- 

 ever, the flask was kept for five days at a rigorously constant 

 temperature of 55° C. (131° F.), day and night, and in which 

 the supernatant air was not shaken up with the wort, we 

 found — 



Volume of gas analyzed . . 28-5 



After treatment with potash . . . . 28-3 



„ „ „ pyrogallol . . . . 23-0 



Oxygen . . . . . . . . 5*3 



Composition of the gas : — Per cent. 



Oxygen . . . . . . . . . . 18*6 



Nitroo-en . 81'4 



