658 
EDITORIAL OBSERVATIONS. 
flask was then again hermetically sealed by means of the 
blow-pipe. Many flasks were prepared in this way, and in 
every case, after standing in a warm situation for twenty- 
four to thirty-six hours, vegetation appeared in the same 
manner as if the contents of the flask were exposed to the 
open air; but the mould, or mucedines, appeared first in the 
little tubes carrying the cotton, which was often thus filled to 
its extremities. The organic growths which appeared were 
the same as in flasks exposed to the open air,—viz., of infu¬ 
soria, bacterium ; of mucedines, the penicilium , ascophora , asper- 
cjillus , and some others. When calcined asbestos alone was 
introduced no vegetation appeared. 
c *It was thus demonstrated that amongst the dust suspended 
in ordinary air there are always organized corpuscles, and 
that these powders when mixed with a suitable liquid, in an 
atmosphere of itself inactive, give origin to bacteria and muce¬ 
dines such as are furnished by the same liquid in the open air. 
“ Pasteur confirmed these results by another method. 
Similar quantities of the same fermentable liquid were intro¬ 
duced into a series of flasks in all respects alike. The necks 
of the flasks were all drawn out over the flame of a lamp, and 
bent into a variety of different forms, but the tubular neck of 
each flask was left with an opening one twenty-fifth of an 
inch or more in diameter. In some of the flasks the liquid 
was boiled for several minutes, but three or four were not 
heated to the boiling point. All the flasks were then set 
away in a quiet place, free from currents of air. After 
twenty-four or forty-eight hours, according to the tempera¬ 
ture, the flasks in which the liquid was not boiled after being 
put into them (although all the liquid had been boiled before 
it was put into the flasks) were found to be troubled and 
covered little by little with mucor. The liquid which had 
been boiled in the flasks remained limpid, not only for days, 
but even for entire months, although all the flasks were left 
open. There can be no doubt that the curves and sinuous 
forms of the necks served to secure the contained fluid from 
the fall of germs. 
6 ‘ The common air entered these flasks as they were cooling, 
but so slowly during the gradual cooling of the hot liquid, 
that the germs were either destroyed by the heat or were 
deposited in the curvatures of the narrow necks of the flasks, 
so that no viable germs reached the liquid. When the neck 
of one of these flasks was broken off, and the remaining por¬ 
tion placed vertical, in a day or two the liquid became 
mouldy or filled with bacteria. This method, which so well 
explains the preceding, and which can be so readily practised 
