146 MEMORANDA. 
We conclude our notice with an account of some experi- 
ments made by M. Pouchet wita air collected on Mont Blane 
by Dr. Kolb. ‘T'wo vessels containing air, obtained at a 
height of 4810 métres, were opened under the surface of a 
decoction of common clover, which had been boiled for an 
hour, and was still at almost the boiling-point. The rising 
of the liquid in the vessels showed that they had been 
hermetically closed, the air which they contained having 
preserved all its rarefaction. After having recorked the 
flasks in the hot liquid, the necks were put into mercury 
heated for an hour to 160°. The third day the decoction, 
which occupied about a third of the vessels, became clouded, 
and it was evident that Jnfusoria had been produced. Viewed 
under the microscope, the decoction was found to be filled 
with living monads of a size intermediate between Monas lens 
and Monas corpusculum, with Spiri/lum, and with Bacterium. 
Some Amebe immobiles were also observed. A flask of air 
obtained on the summit of the Buet, at a height of 3166 
métres, and partly filled with the same liquid, gave abso- 
lutely analogous results. In some centimétres of air 
obtained on Monte Rosa, monads and vibrios have also been 
produced. These experiments on the air of Mont Blanc, and 
some other of the higher peaks of the Alps, go to prove, as 
remarked by M. Pouchet, contrary to the assertion of M. 
Pasteur, that whatever be the place or height whence it is 
obtained, it is uniformly capable of producing living animal- 
cules. M. Pouchet remarks that, at all these considerable 
latitudes, the air is almost entirely deprived of organic 
corpuscles. The examination both of air and snow proves it. 
Neither ova nor spores can be discovered. Thus it would 
seem that the question concerning the high air is at present 
undecided. We need, however, scarcely remark that the 
experimentum crucis alluded to by M. Pasteur is the real 
point of the controversy, and one, moreover, which renders 
journeys to distant mountain ranges unnecessary. Can M. 
Pouchet reply toit? It is simple—it requires no elaboration ; 
the comparative skill of the experimenter, therefore, need no 
longer be any element in the inquiry. It is here that 
M. Pouchet must silence M. Pasteur, or in his turn hold his 
peace.—Regder, Dec. 12. 
Anatomy of Helix aspersa—In your numbers for January, 
1863, and October, 1861, I observed two excellent papers by 
Dr. Lawson on the anatomy of Limax maximus and Helix 
aspersa. 
