339 
On March 18 the surface of the liquid in the first bulb was 
crowded with a dense crust of penicillium; in the last bulb 
there were no tufts, and the liquid was still entirely free from 
microzymes. ‘The result shows in a most striking manner 
not only that ordinary air is entirely free from living micro- 
zymes, but that the activity of the development of penicil- 
lium is in proportion to the degree of exposure. 
XIV.—March 2.—A test tube, containing Pasteur’s solu- 
tion, in which there were immense numbers of microzymes 
and torula cells (penicillium), was plugged with cotton wool, 
boiled for a few minutes, and placed, still plugged, in a rack, 
where it remained for some time. The hquid which, at the 
time of boiling, was quite opalescent, gradually became clear, 
from the subsidence of the organisms it had contained. It 
remained perfectly clear and free from organic forms until 
the 18th of March. The plug of cotton wool was then re- 
moved, soon after which tufts of penicillium appeared on its 
surface; but up to the present time (March 81) the liquid is 
entirely free from microzymes. 
Srction II.—Distribution of the Germial Matter of 
Microzymes in ordinary Water. 
Having thus found in a number of cases that either contact 
with surfaces which had not been superheated, or the admix- 
ture of water which had not been boiled, was the exclusive 
cause of the growth of microzymes in the experimental 
liquid, it was not necessary to go far in order to arrive at the 
inference that water is the primary source from which the 
germinal particles of bacteria are derived, whenever they 
seem to originate spontaneously in organic solutions. To 
prove this is a number of experiments were made with 
different varieties of water in ordinary use, in order in the 
first place to confirm the observations already made, and to 
ascertain whether all waters possess the properties in ques- 
tion in a like degree. 
XV.—January 2, 1871.—A number of eprouvettes of the 
form shown in the margin were placed in the hot-air oven 
and heated to 200°C. They were then filled with Pasteur’s 
solution made with ordinary distilled water, under the fol- 
lowing conditions :—a. Solution not subject to heat. 0. Solu- 
tion introduced boiling, which was then allowed to cool; 
immediately after, a single drop of cold distilled water was 
added to it. c. The same as 4, with the exception that water 
from the tap was used instead of distilled water. d. The 
eprouvette was filled with boiled solution, as in 6 and e, b 
VOL. XI.—NEW SER. Z 
