ANATOMY AND PHYSIOLOGY OF NERVOUS SYSTEM. 

 NARCOTICS. 



709 



Meyer and Overton have arrived at the conclusion that anaesthesia 

 caused by the solution of the lipoid (fatty) constituents of the 

 ills by the absorbed anaesthetic. All the substances which dissolve 

 its are anaesthetics if they enter the cell, and anaesthetic power is 

 >roportional to this factor. The quick recovery which ensues when 

 ic anaesthetic substances are removed shows that the lipoids are not 

 :en out of the cell, but merely dissolved within the cell. Wright 

 ids that anaesthetics produce a disappearance of Nissl corpuscles and 

 shrinkage of the nerve-cells after prolonged anaesthesia by either 

 chloroform or ether. 



Bromides and opium produce sleep by depressing the excitability 

 >f the cortex cells of the cerebrum. 



CEREBRO=SPINAL FLUID. 



The cerebro-spinal fluid is like a lymph-fluid. It is only in the 

 mllest part a transudate, and as such is modified through the specific 

 jcretion of the capillaries of the brain. It is chiefly a specific pro- 

 luct of the brain. It has been shown that this fluid contains 20 to 

 10 per cent, of potash salts and only 15 per cent, of soda salts, and 

 ie brain has also an excess of potash compared with sodium. Spina 

 lieves that the cerebro-spinal fluid comes either from its blood- 

 vessels or the brain-substance, and not only from its choroid plexus, 

 tt differs from the blood-plasma in containing only 0.2 per cent, of 

 ilbumin, whilst blood contains 7 per cent, and lymph 4.5 per cent, of 

 ilbumin. Cerebro-spinal fluid does not contain, like the blood, an 

 igglutinin (it has no globucidal action on foreign blood), nor an 

 ilexin. 



According to Allihin, it contains 0.0461 per cent, of glucose, 

 ).221 per cent, of proteid, 0.2794 per cent, of organic material, 

 ).813 per cent, of inorganic, 98.886 per cent, of water; peptones and 

 albumoses were not present, and the proteid seemed to be a globulin. 

 The cerebro-spinal fluid of diseased brains contains poisonous 

 taterial, which results from a disintegration of nervous tissues. In 

 meral paralysis of the insane, Halliburton and Mott found a nucleo- 

 )roteid in the cerebro-spinal fluid. It is a nucleo-proteid, which, 

 rhen injected into the circulation, can cause intravascular clotting, 

 'he cerebro-spinal fluid and the blood also contain choline, which 

 lepresses the heart. Donath injected choline into the sensori-motor 

 involution and produced convulsive attacks. Choline is also found 

 other diseases of the central nervous system, 



