EDITORIAL OBSERVATIONS. 
657 
particles remained undissolved and had all the characteristics 
of the spores of ordinary mucedines, which are known to resist 
the solvent properties of concentrated sulphuric acid. [It is 
worthy of notice, that certain minute fungi are capable of 
decomposing a solution of sulphuric acid. A few years 
since, a little mould developed in the solution of sulphate of 
copper, used for electrotyping in the department of the 
U. S. Coast Survey at Washington, proved an intolerable 
nuisance. It decomposed the salt, assimilating the sulphuric 
acid, and rejecting the copper which was deposited around 
its threads in a metallic form. From this it appears that 
sulphuric acid does not prevent, but may rather assist the 
growth of certain fungi.— Tr.~\ 
(i To determine the action of atmospheric air, and of atmo¬ 
spheric dust upon fermentation, putrefaction and the appear¬ 
ance of organization, Pasteur adopted the following methods : 
“ A flask was about half filled with a fluid consisting of 
water containing in solution about ten per cent, of sugar and 
from two to seven parts in a thousand of the scum of beer. 
The neck of the flask was drawn out in the flame of a lamp 
and attached to a platinum tube, one twenty-fifth of an inch 
in diameter, which was then heated to redness. The fluid 
was boiled for two or three minutes to expel all air from the 
flask, when it was allowed to cool very gradually, and as it 
cooled the air which entered the flask was calcined, and all 
organic germs it contained were destroyed by passing through 
the red-hot platinum tube. When the flask had thus cooled 
to the temperature of the surrounding air, the neck was her¬ 
metically sealed. The flask was then removed to an oven, 
and kept at a temperature of 80° or 90° Fahr. for an indefi¬ 
nite period, without producing any organisms or undergoing 
any change whatever. 
“ To test the influence of atmospheric dust upon a fluid thus 
hermetically sealed, Pasteur placed a pledget of cotton or 
asbestos in a small tube, and caused a current of common 
air to pass through it by means of an aspirator. This small 
tube containing the cotton or asbestos, loaded with atmo¬ 
spheric dust, was then transferred to a larger T-shaped tube, 
one end of which was connected by india-rubber with the 
sealed flask, another end was connected with a platinum 
tube heated to redness, and the third being connected with 
an aspirator, the apparatus was easily charged with calcined 
air, and all the common air was expelled. The neck of the flask 
was then broken within the T-shaped tube, and the small 
tube containing the atmospheric dust was passed into 
the flask, with access only of calcined air. The neck of the 
xxxv. 42 
