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remarkable thing is this—these same germs or similar germs of - 
equally simple structure, still exist at the present day. What is 
their past history? What is their future destiny? Go almost 
anywhere, we find them in the atmosphere, mixed up with more 
or less of dust and other extremely small particles of matter. 
The dust is easily explained. It comes from the wear and tear, 
as also from the decomposition, of all the various substances, 
organic or inorganic, existing upon the globe. The motes we see 
in a sunbeam are specimens of this dust; and it is observable 
that wherever this dust exists, there also we find the above 
microscopic germs, the harbingers—or first forms—of life, waiting, 
as it were, to take a higher grade of existence according as 
circumstances favour such development or not. The dust in the 
air spoken of above is most abundant (as might be expected) in 
large towns ; in the open country it is much reduced in quantity ; 
it is still further diminished by the sea shore, where it lies open 
landwards and away from houses, and in the midst of a wide 
ocean it scarcely exists at all. And all this may be said in like 
manner of the microscopic germs of life. In fact the dust and 
the germs go together.* 
These microscopic germs are the microbes of Pasteur, that 
distinguished French experimentalist of whom we have heard so 
much lately, and who has proved them to be the source of so 
many of our infectious diseases as well as accidental maladies. 
They are inconceivably minute. Huxley says that if one of 
them measured only the thousandth part of an inch, it would be 
a giant among its fellows.t The writer of the article Atom, in 
the “Encyclopedia Britannica” before alluded to, says, “That 
* The above remarks on dust are grounded on experimental 
researches made by an observer, and published ; but I am unable to 
refer to the original authority. 
+ Letter to the Lord Mayor on Pasteur’s researches. See Jature, 
vol. xl., p. 225, 
