604 VITAL OFFICE OF 



ternal world, and to enjoy whatever is beautiful 

 or excellent in the universe. For the same rea- 

 son, birds die much sooner after decapitation or 

 the privation of oxygen, than mammalia, and the 

 latter than cold-blooded animals. In other words, 

 it is because arterial blood is more essential to the 

 vitality of the brain than to any of the other 

 organs, that it dies in a few moments when de- 

 prived of that fluid, or when the latter is no longer 

 arterialized by respiration ;* whereas the contrac- 



* For example, when the smaller birds are deprived of oxygen, 

 or the vessels that supply the brain with blood are divided, they 

 become insensible in 40 seconds. When insects are smeared 

 over with varnish, so as to prevent respiration, they die almost 

 immediately, as shown by the experiments of Treviranus ; the 

 more active mammalia in about one minute, whereas in man, 

 sensibility remains for about one minute and a half, after the 

 process of breathing has been arrested by exposure to mephitic 

 gases, strangulation from hanging or drowning, as found by the 

 experiments of Goodwyn and Bichat. But when reptiles and 

 fishes are deprived of oxygen, or the great vessels are divided, 

 they often maintain a low degree of vitality for several hours, and, 

 even for several days when the energy of their functions has 

 been diminished by external cold. We also learn from the re- 

 searches of Legallois and Edwards, that puppies, kittens, and 

 other mammalia that are born with the eyes closed, (and in 

 which the function of respiration is so imperfect as to resemble 

 that of cold-blooded animals,) may be resuscitated after remain- 

 ing above half an hour under water. The rationale of which is, 

 that in proportion to the vital energy of animals, is the rapidity 

 of its expenditure in maintaining their activity, and the necessity 

 of its renewal by respiration, which is therefore less essential to 

 mammalia than to insects and birds, and still less essential to the 

 imperfect vitality of cold-blooded animals. 



