216 THE PHILOSOPHY 



merit they receive. An ox is fix times heavier than a man ; 

 but the brain of an ox weighs not above a fourth part of 

 that of a man. On this fuppolltion, an ox's brain muft fe- 

 Crete twenty-four times more nouriOimcnt than a portion 

 equal to it of the human brain. In two years an ox acquires 

 his full fize. His brain muft, of courfe, be fiippofed to tranf- 

 mit daily through the nerves two or three pounds of fiefh, 

 bones, &c. But the much larger brain of a man does not, 

 in an equal time, add to his body a fiftieth part of that 

 weight. 



< In monfters, fays the DosSlor, « I have found the limbs 



* very plump, though the brain was very fmall. Nay, in 

 ' fome monfters, the head has been wanting, yet the limbs 



* were as large and perfe<St as common. In other monfters 

 *■ with one head and two bodies, I have found that the brain 

 « furnifhed the nerves of the head and fpinal marrow on the 



< right ftde of the monfter ; yet the left fpinal marrow, at the 



< top of which there was only a fmall medullary knob, about 



< the fize of a large pea, was as perfect as the right one •, and 

 « that body, and its limbs, Vv'cre as large, and as well nourilh- 

 « ed, as thofe on the right ftde. On the other hand, where 

 « there were two heads of the ordinary ftze, and only one 



* body, the limbs were not remarkable for their ftze. 



< "VVe fee that organs, of which the nerves are (o fmall 



< that we cannot trace them by difteclion, as the bones, the 

 « placenta, &c. grow as quickly as the other organs, in which 



< the nerves are lar^e and numerous. 



o 



< A year after I had cut acrofs the fciatic nerve of a living 



< frog, I could not perceive that limb fmaller than the other •, 



< yet it continued to be infenfible and motionlefs. Nay, 

 ' when I had broken the bones of the infenfthle limb, or 

 « wounded the Ikin and ftefti, I found that the callus formed, 

 ^ and the wounds healed, as readily as if the nerve had been 

 « entire. The event was the fame after dividing, tranfverfe- 



