336 
bers 1, 3, 1’, and 3’, were washed and dried with a towel. 
The remainder, numbered 2, 4, 2’, and 4’, were immersed for 
some time in a vessel of boiling water and then dried as 
before. The two solutions were then distributed in these 
glasses as follows:—In 1 and 2 solution A unboiled; in 3 and 
4 the same solution after previous boiling; in 1’ and 2 solu- 
tion B unboiled ; in 3’ and 4’ the same after boiling. Glasses 
1, 2, 1’, and 2’ were placed under one shade, and the other 
four glasses under another. On November 1, tufts of peni- 
cillium were obvious on 1, 2, 1’, and 2’, and were beginning 
to appear on the rest. The liquids were examined micro- 
scopically at this date and again on November 8, when the 
tufts had increased in size. All contained torula cells and 
mycelium, but microzymes were found only in 1, 3, I’, and 
2’. Thus it appeared that neither the boiling of the liquids, 
nor of the glasses, nor the superheating of the materials, had 
exercised any appreciable influence in preventing the develop- 
ment of microzymes. It was still more remarkable that in 
glass 2, which contained unboiled solution, none of these 
organisms could be discovered. 
These facts, apparently so contradictory, were explained 
by subsequent experiments. 
X.—November 11.—Pasteur’s solution was prepared with 
ordinary distilled water obtained from Messrs. Hopkin and 
Williams, and distributed in five glasses designated by num- 
bers, the conditions being as follows:—1, a clean test glass, 
taken from the shelf, was filled without further cleansing 
with solution which had not been subjected to heat; 2,a 
similar glass, previously rinsed with distilled water, was filled 
with the same liquid; 3, a glass just before heated to 200° C. 
was also filled in like manner. The other two glasses (4and 
5) were charged with boiled liquid, the method used being to 
boil the solution in a test tube for a few minutes, then to cool 
it rapidly by dipping it in a stream of cold water, and transfer 
it at once to the experimental glass. Glass 4 was merely 
rinsed with distilled water; 5 was previously heated to 200° C, 
The results were as follows :—On November 20, torula cells 
were found on the surface of all the liquids. On the 26th, 
bacteria had appeared in immense numbers in 1, 2, and 4, so 
that the liquid was milky. In 3 it was apparently clear, but 
was found on microscopical examination to contain bacteria. 
Subsequently it also became opalescent. At the same date 
all the glasses showed tufts of penicillium; those on 3 and 5 
were more advanced than the rest, and had become greenish 
from the development of heads of spores. At this time, and 
on all subsequent occasions, the liquid in 5 was found to be 
