EFFECTS OF A COMPLETE DEPRIVATION OF AIR. 35 



portance of this process. The existence of the vital force, and the performance 

 of the functions of the organs and apparatus of the system, are incompatible with 

 the sudden arrest of the chemical changes and metamorphoses of the elements of 

 the solids and fluids. If, however, the process of oxidation be slowly stopped, by 

 a gradual diminution of the temperature of cold-blooded animals, the existence of 

 the vital force is not destroyed, although all the vital, physical, and mechanical 

 functions are suspended. 



Hydrogen Gas. 



A Yellow-bellied Terrapin {Emys serrate), which had been placed in a large 

 receiver of hydrogen gas, died in ten hours. 



The blood-corpuscles from all parts of the body presented an altered appearance, 

 similar, in many instances, to that produced by carbonic acid gas. The simple 

 exclusion of the oxygen of the atmosphere, by a harmless gas, produced remark- 

 able alterations in the shape of the corpuscles. 



The urine contained grape sugar. 



Fig. 6 represents the appearance of the blood-corpuscles of this Emys serrata, 

 after it had been confined in hydrogen gas for ten hours. 



Fig. 6. 



Blood-corpuscles of a Yellow-bellied Terrapin (Emys serrala) which had been destroyed in hydrogen gas. 



Complete Deprivation of Air. 



Ligatures were passed around the tracheas of Yellow-bellied Terrapins (Emys 

 serrata) and Salt-water Terrapins (Emi/s terrapin), which had been deprived of 

 food and drink for several weeks, and then transferred to tubs of water, and abund- 

 antly supplied with vegetable food. The access of air to the lungs was thus com- 

 pletely cut off. 



These Chelonians gave signs of muscular contractility for twelve to twenty 

 hours. In one instance, the stomach and intestines became greatly distended with 

 gas, which consisted partly of carbonic acid. 



