342 PHYSIOLOGY AND HEALTH. 



any thing which crowds the brain, the organ suffers. A sud- 

 den effusion of water, or pressure of bone from fracture of 

 the skull, or blood from apoplexy, immediately suspends its 

 action, and then its functions, and those of the voluntary 

 organs and the mind, are suspended ; torpor and heaviness 

 overwhelm the whole system. In other cases, where a tumor 

 grows, or water is effused very slowly, the skull may expand, 

 and still leave room for the brain ; but in most of these in- 

 stances, however slow their progress, the brain, sooner or 

 later, suffers, from the pressure, and then the physical and 

 mental powers are impaired or suspended. 



785. Sir Astley Cooper relates a remarkable instance of 

 a man whose skull was broken on a British man-of-war, in 

 June, 1799, in the Mediterranean Sea. He was found in a 

 state of insensibility, and incapable of voluntary motion, arid 

 he remained in this condition till May, 1800, when he was 

 carried to St. Thomas's Hospital, in London. There the sur- 

 geon found a piece of bone forced in, and pressing upon the 

 brain. When he removed this bone, the man recovered his 

 sensibility, and was soon restored to health and activity, after 

 having -lived nearly a year in a state of unconsciousness.* 



786. The brain is subject to the law of growth and decay 

 of its atoms. It requires nourishment of new particles and 

 removal of the old, as well as all the other organs. It 

 is therefore provided v/ith an apparatus for nutrition and 

 absorption, and arteries that bring the new blood, and 

 veins that carry off the old blood and the wasted particles 

 of matter. It seems to require more blood for its nourish- 

 ment, and for the supply of its waste, than other organs of 

 the same size, for it receives a much greater proportion than 

 any other part of the body. The human brain receives from 

 one fifteenth to one tenth of all the blood that flows in the 

 body, and yet it weighs only about one fortieth of the whole 

 frame. Its arteries, being a part of the general circulatory 

 system, beat in the same manner and with the same frequen- 

 cy as the arteries of the wrist. 



* Lectures on Surgery, Vol. I. p. 233. 



