Pasteur on Spontaneous Generation. 3 
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 tube carrying the cotton which was often thus 
filled to its extremities. ‘he organic growths which appeared, 
were the same as in flasks exposed to the open air, viz: of infu- 
soria, bacter’tum, of mucedines the penzeilium, ascophora, aspergillus 
and some others. When calcined asbestos alone was introduced 
no vegetation appeared. . 
It was thus demonstrated that among 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 Mucedines such as are 
furnished by the same liquid in the open air. 
asteur confirmed these results by another method. Similar 
quantities of the same fermentable liquid were introduced 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 24 or 48 hours, according to the temperature, 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. 
€ common air entered these flasks as they were cooling, but 
so slowly during the gradual cooling of the bot liquid, that the 
