408 J. D. Dana on Spontaneous Generation. 
lish the theory of spontaneous generation, or prove that the 
germs of these beings were not previously deposited in the or 
ganic matters employed. But, in fact, whilst animalcules a 
when the ordinary air has access, without this access under the 
precautions mentioned they do not appear. 
6. Note on Spontaneous Generation, by James D. Dana. 
1. There is a well-known principle in the system of nature oe 
deserves to be considered in this connection. The principle1s $ 
fully sustained by all research both in chemistry and zoology, 
cluding the important experiments above mentioned, that : 
may well carry with it great weight, and quiet both apprenela 
and expectation on this subject. It is this:—The forces m 
and inorganic nature act in opposite directions, the former up: 
ward, the latter downward. renils 
The vital force, in the organic substances it forms, @ h 
through vegetable and animal life to an exalted height orn 
scale of compounds at an extreme remove from saturation se 
oxygen; inorganic force descends towards the saturated . 
The former reaches a point which from its very elevation 'S si 
of great instability ; the latter tends towards one of Pp asl 
bility. There is hence a counterpart or cyclical relation betw’ 
the two great lines of action in nature. sree 
some readers of these remarks may not be familiar W 
chemistry, a further word of explanation is added. o 
__ When an element unites with its full allowance of OXY oh it. 
determined by its affinities, it is in a sense saturated wr aes 
nce the attraction of the elements for oxygen 18 aes’ oe 
versal and, in general, the strongest in nature, the, oxy! 
ns eae eee : 
; 
2 
