258 
Experiments on 
t Monthly Microscopical 
Journal, Nov. 1, 1869. 
cells that have been found in the mimeroTis infusions that have been 
made in the investigations of this so-called "Spontaneous Genera- 
tion ; " for although I have studied fungi for at least twenty years, 
I have never found them so abundant as to fill the atmosphere so 
completely with sporules as some would have us believe, and that 
at all seasons of the year, and in every condition,! in the still atmo- 
sphere of a room equally with that in the open air. 
The extreme difficulty of destroying life I have found in every 
experiment, for neither baking nor boiling will destroy it; these 
may change the form and outward condition of the things operated 
on, but you cannot drive life entirely out of it by either of these 
processes. 
The greatest heat that has been applied to experiments of this 
kind is 200° centigrade, or 500° Fahrenheit, and even then, says 
M. Pouchet, animalcules and fungi are developed. " Neither calcined 
air, sulphuric acid, liquor potassse, gun-cotton, nor a boiling tempe- 
rature have prevented the production of infusoria, or destroy the 
supposed germs in the air or infusion."* 
If we take the case of sareina ventricuU, as found not unfre- 
quently in the human stomach, and also the vegetable sporules 
found in the kidneys ; the temperature of the stomach averages 
about 98°. Again, take plants, such as ulva thermalis and others, 
which live in the hot springs. But it may be said that these 
plants are adapted to places in which they are found, and it is 
consequently natural to them. Be it so. But still it shows 
us that a heated medium is not antagonistic to vegetable life. 
M. Pasteur says, that the boiling temperature, that is, 100° centi- 
grade, does not prevent the growth of the germs in the atmosphere ; 
but, he says, that 130° centigrade always destroys their vitality. 
This, it will be observed, is directly opposed to the experiments 
instituted by M. Pouchet, as before stated, that the temperature of 
the infusions may be raised to 200° centigrade, and yet animalcules 
and fungi are developed. 
There is one very remarkable thing to be observed in all the 
experiments that I have prosecuted, and that is this, that all 
the larger and stronger plants, if I may call them so, have 
sprung from the oil-globules. This^may be said to be in favour of 
M. Pasteur's argument, that the germs are admitted with the atmo- ^ 
sphere ; and as the oil, being lighter, generally floats on the surface 
of the infusion, the germs are first brought into contact with it; 
and finding a proper and rich medium in which to vegetate, they 
rapidly spring into life, the result of which we see in our micro- 
scopic examinations of the infusions. This, although it appears so 
favourable to M. Pasteur's hypothesis, is not true in the main ; for 
I have carefully examined other parts of the infusions, and particu- 
* Dr. Hughes Bennett, in ' Popular Science Review,' January, 1869. 
