HEAT UPON LIVING MATTER. 147 
very small numbers when raised to the temperature 
of 135°, whilst all perished at 140°. The larve reared 
from these eggs all died, as those of the silk-worm 
and Elm-moth had done, as soon as the temperature 
of the water rose to 1084°. Other adult larve of the 
same species with which experiment was subse- 
quently made perished at the same heat. 
In addition, Spallanzani experimented with certain 
aquatic organisms, though he was unable to discover 
their eggs, and consequently was unable to make 
experiments as to their power of resisting heat. 
Thus he found that Leeches perished at 111°, and 
the Nematoids known as “Vinegar Eels” at 113°. 
Other aquatic Worms were killed at 111°, whilst 
Water Fleas died at 107°. 
So far, therefore, Spallanzani’s results were most 
uniform : the different kinds of eggs were killed by 
mere momentary exposure to a temperature of about 
140° F,, whilst the animals to which they were related 
perished at or about 110°. 
The Abbé next turned his attention to the power 
possessed by plants and their seeds of resisting the 
action of heated water. These observations were 
conducted in the same manner, though only the roots 
of the plants were immersed in the water whilst its 
‘heat was being raised. The plants with which ex- 
periment had been made were afterwards carefully 
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