12 Effects of Oxygen and other Gases 



stance, and to produce direct debility, insensibility, and loss of 

 voluntary power in the second, involuntary action continuing 

 indefinitely. 



6. The invasion of the symptoms from breathing oxygen 

 does not generally occur in less time than about an hour ; and 

 the sensibility of the animal is not uniformly affected at the 

 same period. 



7. The invasion of the symptoms seems to depend much 

 upon the size, strength, and age of the animal employed. 



8. Death is ultimately the constant result of breathing oxy- 

 gen, pure or in excess. 



9. If the motion of the diaphragm has not entirely ceased 

 more than about two or three minutes, animation may be 

 restored by atmospheric inflation of the lungs ; and, as the 

 blood acquires free access to common air, the functions of the 

 brain are renewed. 



10. The contractility of the heart and intestinal canal is 

 retained long after the functions of the brain have ceased, or 

 when sensibility, voluntary motion, and the action of the 

 diaphragm, no longer exist. 



11. Animals, having breathed oxygen during a certain time, 

 circulate no venous blood in any part of the body ; the whole 

 mass throughout being of the brightest, transparent, arterial 

 colour. 



12. Animal heat is kept up, during the whole period of 

 immersion in oxygen, above the ordinary temperature of the 

 surrounding media, though apparently a few degrees lower 

 than the usual degree of the animal. 



13. Quick coagulation of the blood takes place, after death^ 

 from the respiration of oxygen. 



Such are the facts indicated by the experiments and obser- 

 vations which I have made upon oxygen, at different periods ; 

 and which appear to suggest some important reflections relative 

 to the physiological and pathological relations of animal life to 

 the principal component of the atmosphere surrounding our 

 globe ; while they tend, also, to place the respiration of pure 

 oxygen in a point of view that may, perhaps, be considered, in 

 some respects, novel and interesting to science. 



Encouraged by the novelty and constancy of my resultS| 



