14 
Proceedings of the Royal Irish Academy. 
the Pasteur-Pouchet controversy about spontaneous generation, a com- 
parison of these results with what those inquirers have obtained can 
hardly fail to be of some interest. 
Former observers, I find, have recognised in the dust subsiding from 
the air spores of fungi, lichens, algje, and mosses, the detritus of the 
soil, fine fragments of vegetable and animal fabrics accidentally 
difi'used ; the dried, but vital, bodies of infusoria ; and the eggs of the 
lower members of the animal kingdom. Besides these, in cities, they 
have observed fragments of the products of manufactures, with the 
spores of fungi, mixed with particles of carbon or soot, the ova of 
lower animals being few. 
M. Pouchet declares that the air everywhere is naturally fecund, 
but that usually it nowhere contains ova or spores. However, he 
qualifies this by observing, that the atmosphere may be the vehicle of 
such objects ; yet he adds — " I have experimented on the air taken 
from open sea, between Corsica and Sicily, and on other specimens 
gathered, in perfectly calm weather, in the midst of the Ionian Sea; I 
have also taken air of the summit of Etna, and from the depths of the 
recesses of the caverns of Caumont, near Rouen ; and none of my ex- 
periments [on the fecundity of the air] have been stricken with 
sterility. Nevertheless, in analysing this air by the aeroscope or other- 
wise, no egg of infusoria or other seed was found in it.'"^ 
And again, he says, There are so few seeds or germs in the air, 
that even in places where plenty should be found they are only met 
with exceptionally. M. Musset, who has been long engaged in re- 
searches on fungi, whose laboratory is quite filled with them, informed 
me recently that he never yet has been able to meet with spores there." 
Whilst, by employing three kinds of tests, M. Pouchet found it 
difficult to discover an ovum or a spore in a hundred cubic yards of 
air, he asserts that with a decimetre of the same air he could at will 
produce thousands of animalcules and plants. In the atmosphere of 
French towns he observed particles of starch in three states — first, in 
a normal condition ; secondly, panified ; and, thirdly, having a blue 
colour. He asks whether the iodine recognised in the atmosphere by 
M. Chatin may not have thus coloured it ? Starch granules he has 
found frequently. Soot and fragments of clothing are also common. 
As by a chance there occur in the atmosphere wandering seeds or 
germs, the corpses of animalculee, and even some live individuals, he 
considers it but natural that here and there eggs and spores may be 
seen. But their number is so scanty that they must be taken as 
absolutely null, in the controversy and experiments having reference to 
spontaneous generation. Having been contemporaneously with, but in- 
dependently of, Messrs. Joly and Ch. Musset, the first to examine 
snow for the purposes of atmospheric micrography, he found it enor- 
mously charged with detritus of various kinds, with soot, with normal 
* " Nouvelles Experiences sur la Generation Spontanee et la Resistance vitale, par 
F. A Pouchet." Paris, 1864. 
