The Alcoholic Ferment of Yeast-juace. 301 
| Time Free phosphate as Mg,P,07 | Total phosphate as Mg»P,O, 
| in hours. per 10 c.c. per 10 c.c. 
gramme. gramme. 
5°5 0-021 0 266 
18-0 0 093 0 ‘269 
66 ‘0 | 0. 133 
138°0 | 0°175 
426 °O 0-226 0-273 
the original juice, was 0°266—0°133=0°133 gramme, it follows that at least 
0'205—0:133=0:072 gramme of this has been derived from the hexose- 
phosphate produced during the initial period from the added phosphate. 
Even in the absence of added phosphate a gradual production of free 
phosphate occurs when yeast-juice is incubated at 25°. In the absence of 
glucose, when the fermentation is very small, the increase in the amount of 
free phosphate is comparatively rapid, whereas, in the presence of glucose, the 
fermentation lasts for a considerable period, and the appearance of free 
phosphate is delayed, since it continually enters into fresh combination as 
rapidly as it is formed. 
Examples of this are the following. The various materials were digested 
at 25° with toluene for the time shown, and were then boiled and filtered and 
the free phosphate estimated. 
Experi- a oe Time Free phosphate as 
Gi. PS PSESS ING ee siat of digestion. Mie PLOMGEE! 25 ©€.c. 
days. gramme. 
12 (a) Yeast-juice alone .................006 O 0 +128 
b ‘ Ma ate Fete Na Leer 2 0-284 
(c) : i Ok cee oe ane 10 0-283 
(d) Yeast-juice + glucose ................4 2 0 +123 
(e) , A ee eee ee 10 0 °255 
13 (@) Neast-juice‘alone ......22....a0s0.6s0: 0 0 024 
(d) ei a tie ee Pee satis | 1 0-053 
(c) i Ay Ne eae § cere ge cn : 2 0 063 
(d) 5 oP nudes ee ate se te tse) ale 4 0 069 
(e) Yeast-juice + glucose ..............0065 1 0-011 
i aM Dt et benders | 2 0 025 
(9) 55 me etn oe aCe 4 0-051 
hours. 
14 (a) Yeast-juice + glucose + phosphate 1°25 0-063 
(0°276 gramme per 25 c.c.) 
re 6 ob 46 ‘0 0°138 
(c) A is a 96-0 0 °387 
(d) ” ” ” 168 -0 0 °453 
(e) ” ” ” 240 -O 0 -489 
(f) ” ” » 336 -0 0 501 
(9) ” 9 29 456 -O 0 °523 
