
THERMAL DEATH-POINTS TY? 
per ounce. The addition was made in the propor- 
tion of two minims of the spore-containing liquid 
to each ounce of the urine; and with this well- 
shaken mixture nine bulb-tubes were charged 
After their necks had been drawn out in the blow- 
pipe flame, the fluid in each of them was boiled over 
the flame for rather less than one minute, when the 
vessel was hermetically sealed. An interval of 
nearly a minute having been allowed to elapse (so 
as not to crack the heated tip), each closed vessel 
was inverted and plunged into a can of boiling 
water, where it was allowed to remain for twenty 
minutes. 
Subsequently all the tubes were placed together 
in an incubator at 122° F., and with them a control 
experiment, consisting of a small flask plugged with 
cotton wool, in which some of the same urine had 
been boiled alone for twenty minutes, and to which 
two drops of the original spore-containing mixture 
(not previously dried or heated), were added when 
the urine had cooled. This latter operation was 
effected by removing the cotton-wool plug for an 
instant, allowing the spore-containing fluid to drop 
into the urine, and then carefully replacing the plug, 
after the manner so often adopted by Professor (now 
Lord) Lister. | 
_ The results of these experiments were as follows : 
In sixteen hours the fluid in the control-tube was 
notably turbid, and at the expiration of twenty-four 
hours a thin scum of Bacilli had formed on its surface. 
The fluids in the other nine tubes all remained quite 
1 Quart. Journl. of Microsc. Science, 1873, p. 384. 
