J. Wyman on living organisms in heated water. 165 
perature of which does not exceed 100° C. during the baking ;* 
while in the crust, the temperature which exceeds 200° C. (392° 
F.) destroyed the vitality of the Ordiwm.”+ ere are here two 
conditions of the bread recognized; the moist interior which 
destroys the spores at 212° F., and the dry exterior which does 
80 at 892° F. Mention has also been made of the germination 
of seeds taken from the raspberry jam, as proof that these had 
resisted the action of boiling water. But in none of these cases 
have we seen any evidence adduced to show that they had 
really been boiled. We have not been able to find a single 
instance in which seeds or spores or infusoria, excepting only 
Vibrios, Bacteriums and Monads, thoroughly moistened before 
~ the °° ane. have resisted the prolonged action of boiling 
Water. 
The organisms which we have most commonly met with in 
our experiments in flasks, in fact almost the only ones, when the 
boiling was prolonged, are Vibrios, Bacter‘ums and Monads. The 
first and second are without doubt plants allied to the Alga; the 
nature of Monads is more obscure. They are all among the 
lowest of living organisms. Leaving out of consideration cil- 
lated infusoria which perish more easily, our inquiry now is, 
al what temperature, or after how long an exposure to the 
boiling water are the Vibrios, Bacieriums and Monads killed, and 
by what signs can we know that they are dead?—This question is 
4 difficult one to answer. : : : 
he usual signs of life manifested by the infusoria found in 
the flasks are the following: Ist, locomotion in nearly all of the 
Species; 2d, growth and reproduction; 3d, their reaction on the 
“urounding fluid, producing fermentation or putrefaction. The 
Second and third are so intimately associated that the presence 
of one’ is almost a certain indication of the other. If a clear 
°rganic solution ferments, or becomes turbid, it may be safely 
inferred that living infusoria are present; nevertheless the cor- 
mcttess of this inference must be tested with the microscope. 
The absence of either of the above signs alone cannot be consid- 
‘red as a proof of death, and under certain circumstances 
-J"8 of life may cease, but the infursoria = still be alive. If 
pl *xample, they are developed in a sealed flask, as soon as the 
“ganic matter convertible into infusoria is exhausted their ac- 
Lvity ceases, and they remain dormant for months; we have 
Wg ing the in loaves 
; baking in th for the purpose of destroying the spores 
Mite, wid not for thoes going into the oven for the ficet Gans: 
{ Precis de Chim. Indust. Paris, 1859, t. i, p 160. os 
The assertion that infusoria i 
Water, 
unier, 
