INTRODUCTION. XXXV11 



Tongue ; The Nose is insensible to odours ; And the 

 Touch becomes obtuse. Fatigued by the continued ex- 

 ercise of perception, of imagination, and of memory, 

 the brain has to recruit its strength, by a state of com- 

 plete inactivity for some time. The muscles, relaxed 

 by fatigue, are incapable of farther contraction, till they 

 have been permitted to rest; hence the necessary inter- 

 mission, in every individual, of locomotion and of voice. 

 This intermission of action is sometimes extended to 

 all the organs of animal life at the same time ; on other 

 occasions, only a part of them is affected by it. It is 

 in this way that the brain frequently continues in the 

 active exercise of thought, while the senses, as well as 

 the powers of locomotion and of voice are suspended. 



In addition to the foregoing views, it has also been 

 suggested by Bichat, that another striking difference 

 between organic and animal life, is found in the epoch 

 and mode of their origin. Organic life exists from the 

 first moments of conception ; but animal life does not 

 commence till after birth, when exterior objects are es- 

 tablished in a certain relation with the individual. It 

 is more than probable, that the function of the Eye, the 

 Ear, the Tongue, and the Nose, does not exist in such 

 manner as to communicate their several sensations in 

 the foetus; and that the enjoyment of a sort of indistinct 

 sense of touch, arising from its striking against the pa- 

 rietes of the womb, is the only circumstance which can 

 give the latter any idea of its existence; it is, however, 

 doubtful whether it has even a consciousness on that 

 point. The organic life, on the contrary, of a fetus, 

 though not so complicated as afterwards is still re- 

 markable for the promptitude and vigour of some of its 

 functions, particularly of assimilation; and in a very 

 short time after birth, all the organs which it employs 

 reach their highest degree of perfection, and thus pre- 

 VOL. I. 4 



