FUNCTIONS OF THE SYMPATHETIC SYSTEM. 527 



by different individuals, or by the same individual at different times. 

 The Cerebellum, in the Sleep-waking state, seems to be frequently in a 

 condition of peculiar activity ; a remarkable power of balancing and 

 combining the movements of the body, being often exhibited. 



925. On the other hand, there may be an undue exaltation or a per- 

 version of mental activity, without any affection of the sensorial appa- 

 ratus. This is well seen, for example, in the first stage of Alcoholic 

 excitement, and in that of Mania, Phrenitis, and other disorders in 

 which the Cerebral Hemispheres are especially affected. Frequently, 

 as in the case of Alcohol, Opium, Haschish, &c., we may directly attri- 

 bute the morbid action of the Cerebrum to the presence of a poison in 

 the blood which permeates it ; and there is strong reason to believe that 

 many other forms of delirium are partly due to a perverted state of that 

 fluid. On the other hand, there can be no doubt that an extreme 

 depression of intellectual power, as well as of the emotional state, is 

 often to be attributed to a depravation of the blood ; a slight accumula- 

 tion of bile being very prone to occasion this state in some individuals, 

 and an entire change being effected by a mild dose of mercurial prepa- 

 rations, which, by eliminating the bile, restores the circulating fluid to 

 its proper purity. And it may be fairly suspected, that the foul atmo- 

 sphere in the midst of which a large class of our population habitually 

 lives, has the effect, by keeping their blood charged with noxious mat- 

 ters, of so perverting the actions of the brain, that neither the intellec- 

 tual powers nor the moral sense can be duly exercised ; and thus it may 

 be anticipated that Sanitary Reform will largely benefit* not merely the 

 corporeal but the mental and moral health of those, whose position is at 

 present one of fearful degradation from the want of it. 



8. Functions of the Sympathetic System. 



926. The Cerebro-Spinal apparatus, of which the several parts have 

 now been described, is not the only system of ganglia and nerve-trunks, 

 that is contained within the body of a Vertebrated animal. There is 

 another system, having its own set of centres, and its own distribution 

 of branches, characterized also by a peculiarity in the nature of the 

 nervous fibres of which its trunks are composed, and communicating at 

 numerous points with the preceding. It will be remembered that, in 

 front of the vertebral column, there is a series of ganglia on each side ; 

 communicating, on the one hand, with the spinal nerves, as they issue 

 from the vertebral canal ; and also connecting themselves with the two 

 large Semilunar ganglia, which lie amidst the abdominal viscera ; as well 

 as with a series of ganglia, that is found near the base of the heart. In 

 the head, also, there are numerous scattered ganglia, which evidently 

 belong to the same system ; having several communications with the 

 cephalic nerves ; and being also connected with the chain of ganglia in 

 the neck. The branches proceeding from this series of ganglia are dis- 

 tributed, not to the skin and muscles (like those of the cerebro-spinal 

 system), but to the organs of digestion and secretion, to the heart and 

 lungs, and particularly to the walls of the blood-vessels, on which they 

 form a plexus whose branches probably accompany their minutest rami- 



