335 
cillium. At the same date the open tubes @’ and 0’, contain- 
ing boiled solution, were free from microzymes, but contained 
numerous torula cells and mycelium. c¢ and d were not 
examined until the 4th of January, at which time both 
liquids were perfectly clear and contained no organic forms 
of any description. 
VIII.—October 5.—T wo test glasses were placed side by 
side on a shelf under a glass shade, one of which, marked a, 
contained unboiled Pasteur’s solution, the other, marked 3, 
boiled solution. On October 10 glass a was turbid, and was 
found on microscopical examination to be teeming with 
bacteria; a thick whitish scum had formed on its surface. 
Glass 6 was perfectly clear; there were, however, great 
numbers of torula cells on its surface, but no bacteria. On 
October 12 6 exhibited numerous tufts of penicillium, but 
the liquid still remained lmpid and free from bacteria; five 
days later similar tufts appeared on the surface of a. 
In the last two experiments it is seen that fungi (torula 
and penicillium) appeared in unboiled solutions whether they 
were exposed or not, but much more abundantly when they 
were exposed than when they were protected; and that in 
boiled solutions the growth of penicillium was somewhat 
more luxuriant than in unboiled under similar circumstances 
of exposure. Microzymes did not appear in the boiled liquids 
under any circumstances, but were quite as numerous in the 
tube d (Obs. VII), which remained closed for many months, 
as in any other of the same series. From these facts it seemed 
clear, not merely that the conditions of origin and growth of 
microzymes and fungi are considerably different, but that as 
regards the former the germinal matter from which they 
spring does not exist in ordinary air. The experiments to be 
next related, however, showed that it would have been wrong 
to have inferred from these facts that the boiling of a liquid 
is of itself sufficient to prevent the development in it of these 
organisms, or that their complete absence in the tubes of the 
second series of Observation VII (a’, 0’, c’, d’) was exclusively 
attributable to this condition. 
1X.—October 25.—A solution (A) according to Pasteur’s 
formula, was prepared in the same manner as before, with 
the exception that water distilled on the same day in the 
laboratory was used instead of the ordinary distilled water, 
great care being taken to prevent its contamination. At the 
same time another solution (B) was made with the same 
water, of materials which had been previously heated in the 
hot-air bath to 110°C. Eight glasses were at the same time 
prepared, of which four, marked severally with the odd num- 
