752 Experiments 



The next day, all are dead except the myriapods. 

 Experiment CCCXV. June 23. 



Silkworm cocoons, sent by M. Raulin, from Alais, all of the same 

 day. 



A. 12 are placed in an open bell-jar. 



B. 6 in the cylindrical glass apparatus, at 5 superoxygenated 

 atmospheres. 



C. (By some mistake, probably of the proof-reader, the conditions 

 in C were not given; the pressure was probably much higher than in 

 B. Translator.) 



The air was changed every other day. 

 July 8. A. All have emerged. 



B. No motion. 



C. All dead; the skin of the chrysalises is not separable; they evi- 

 dently were killed very soon. 



So the formidable influence of compressed oxygen is felt by in- 

 vertebrate animals as well as those belonging to the higher types. 



The animals which in the simultaneous experiments first felt the 

 fatal effects of oxygen were the flies; after them the bees and the 

 butterflies; then the dragon flies and the fleas; considerably later, 

 the ants and the coleoptera (longicorn and carabic) . The woodlice, 

 and especially the arachnids (spiders, acaridae) and the myriapods 

 (centipedes, geophiles) are much more resistant. Then come the 

 earthworms and the snails, at least for length of life, if not for 

 lethal concentration. 



The great importance of this kind of research is to show that 

 death from excess of oxygen does not depend upon a mechanism 

 peculiar to animals with red corpuscles, but is a general fact. There 

 is present a profound modification in the metabolism of the tissues. 

 We should note that these animals never seemed excited; on the 

 contrary, they quickly become motionless and fixed in some corner 

 of the apparatus, and die without showing any convulsion. 



As a type of aquatic animal to be studied, I generally used young 

 eels, called "de la montee", the hearts of which one can easily see 

 beating. 



Experiment CCCXV I. April 1. Small eels "de la montee", trans- 

 parent, temperature 15°. 



A. 5 are placed in a well-corked test tube; 



B. At three o'clock, 5 are placed in the cylindrical apparatus and 

 raised to 11 atmospheres of an air with 50% of oxygen. Oxygen ten- 

 sion 550, corresponding to about 26 atmospheres of air. 



In the evening at 7:30, nothing particular apparent. 

 April 2, 1 o'clock. A: in good condition. 



B: dead, stiff, not transparent, and not contractile when stimu- 

 lated electrically. 



