778 Experiments 



April 10. The young tadpoles are moving in A and B; some are 

 free in A. 



April 20. All dead in C and D; the tadpoles are alive and free 

 in A and B. 



May 1. Same. 



May 4. As neither water nor air was changed, there was begin- 

 ning to be a little putrefaction in the eggs of A and B; however the 

 tadpoles are still alive. 



May 10. All dead; foul odor in A; a little less in B; no odor of 

 putrefaction, but a sort of fishy smell in C and D. 



Experiment CCCXLVI. April 13. Tadpoles. 



A, free air. 



B, 5 atmospheres of air. 

 April 20. All alive. 



May 1. A, living; B, dead. 



Experiment CCCXLVII. June 26. Carp and larvae of midges in 

 great number, in water with algae. 



A, under bell full of air. 



B, under bell full of air with 85% of oxygen. 



July 5. The animals in B are less lively than those in A; the 

 algae look sick. 



July 11. All, algae, carp, larvae, dead in B; on the contrary, all 

 are quite alive in A, the air of which still contains all its oxygen. 



Experiment CCCXLVIII. October 4. Larvae of mosquitoes, in 

 great numbers, in water. 



A, under a bell full of ordinary air. 



B, under a bell full of air with 52% of oxygen. 



C, under a bell full of air with 62% of oxygen. 



D, under a bell full of air with 89% of oxygen. 

 November 8. All the larvae are alive under the different bells; 



in A, a great many are transformed, none in B, C, D. 



The experiments which have just been reported were made on 

 vertebrates (fish, tadpoles, and frog eggs) and on invertebrates 

 (chrysalises, larvae of aquatic insects, little aquatic crustaceans) ; 

 they gave similar results, and this fact permits one, I think, to de- 

 duce generalized conclusions. 



To me, they seem first to prove that compression to 4 or 5 

 atmospheres, or, to speak more exactly, oxygen at a tension of 80 

 and above, has a fatal effect on animals, which is apparent in a few 

 days on cold-blooded animals, and which, of course, would give 

 fatal results much more rapidly in warm-blooded animals. 



The second conclusion to be drawn from the experiments is 

 that increase in the oxygen tension above its normal value in ordi- 

 nary air seemed to bring no advantage, far from it. When any 

 difference is noticeable, it is in favor of normal air; life persists 



