178 
PROFESSOR TYNDALL ON THE DEPORTMENT AND VITAL 
continuous series of experiments extending over periods of boiling varying from one to 
six hours. Up to three hours the infusion resisted sterilization ; but when, the periods 
of boiling were prolonged to four, five, and six hours respectively, all the bulbs became 
permanently barren. The liquid continued in the highest degree transparent, and in 
colour a brilliant orange-brown. 
Experiments intended to determine the limit of resistance of cucumber-infusion were 
made on the 24th of February. Nine pipette-bulbs were then charged, plugged, her- 
metically sealed, and subjected to the boiling temperature for the following times : — 
1st bulb ...... 
. . . 15 minutes. 
2nd „ ...... 
... 30 
5? 
3rd „ ...... 
... 45 
59 
4th „ 
... 60 
55 
5th „ ...... 
... 120 
59 
6th ,; . 
o 
oo 
rH 
95 
7th „ ...... 
... 240 
99 
8th „ 
... 300 
59 
9th „ 
... 360 
95 
After boiling and cooling they had as usual their ends broken off by a file. The result 
here was that at the 5th bulb, which corresponded to a boiling for two hours, the life- 
development suddenly ceased. All the tubes boiled from three to six hours inclusive 
were completely sterilized. 
The infusion in this case had been diluted by an accident, so that its specific gravity 
was hardly above that of distilled water. On the 28th of February, therefore, a fresh 
infusion having a specific gravity of 1006 was prepared, and introduced into a series of 
bulbs exactly as in last experiment. The bulbs were exposed to the boiling temperature 
for the following times : — 
1st bulb .... 
2nd „ 
. . . . . 30 „ 
3rd „ . . . . , 
45 „ 
4th „ 
. . . . . 60 „ 
5th ,, . . . . , 
. .... 120 „ 
6th „ .... 
. .... 180 „ 
7th „ . . . . , 
240 „ 
8th „ . . . . , 
300 „ 
9th „ 
360 „ 
The result here was that at the 6th bulb, which corresponded to three hours’ boiling, 
the life-development suddenly ceased. All the bulbs boiled from 15 minutes to 180 
minutes inclusive proved fruitful ; while from 240 minutes to 360 inclusive all were 
completely sterilized. As in the case of the turnip-infusion, the cucumber subjected to 
long periods of boiling assumed an orange-brown tinge. 
