Nervous System. 



THE Nervous System consists of a series of connected central organs, called 

 collectively, the cerebro-spinal centre or axis, of the ganglia, and of the nerves. 



The cerebro-spinal portion of the nervous system includes the brain and spinal 

 cord, with the nerves connected with them, and the ganglia seated upon these 

 nerves. It was distinguished, by Bichat, as the nervous system of animal life. 

 It includes those nervous organs in and through which the several functions- of 

 the mind are more immediately connected ; the nerves of the senses, and those 

 relating to volition and common sensation, are connected with it, as well as those 

 concerned in many nervous actions, with which the mind has no connection. 



The ganglionic or sympathetic system consists of a double chain of ganglia 

 connected by nervous cords, situate along the spinal column; and from which 

 nerves with ganglia developed upon them proceed to the viscera in the thoracic, 

 abdominal and pelvic cavities. It was distinguished, by Bichat, as the nervous 

 system of organic life. This system is less immediately connected with the mind, 

 appearing to be more closely concerned than the cerebro-spinal system with the 

 processes of organic life. 



The several organs of the nervous system are composed of two different 

 substances, which differ from each other in density, color, in their minute struc- 

 ture, and in their chemical composition. They are called the vesicular nervous 

 matter and the fibrous nervous matter. The former is often called the gray or 

 cineritious substance ; and the latter, the white or medullary. 



The fibrous nervous matter is most extensively diffused throughout the body. 

 It forms a large portion of the nervous centres, either alone, or mixed with 

 vesicular matter ; and is the principal constituent of the nerves which connect 

 them with the various tissues and organs. 



The vesicular nervous matter is usually known by its soft consistence, and dark 

 reddish-gray color ; it is generally collected into masses intermingled with the 

 fibrous structure, in various parts of the brain and spinal cord, and in the several 

 ganglia. 



Chemical Composition. The following analysis by Lassaigne represents the 

 relative proportion of the different constituents composing the gray and white 

 matter of the brain : 



Gray. White 



Water 85.2 . 73.0 



Albuminous matter . . . 7.5 . 9.9 



Colorless fat . . . . 1.0 . 13.9 



Red fat 3.7 . 0.9 



Osmazome and lactates . . 1.4 . 1.0 



Phosphates . . . . 1.2 . 1.3 



100.0 100.0 



It appears from this analysis that the cerebral substance consists of albumen, 

 dissolved in water, combined with fatty matters and salts. The fatty matters, 

 according to Fremy, consist of cerebric acid, which is most abundant, cholesterin, 

 oleophosphoric acid, and olein, margarin, and traces of their acids. The same 

 analyst states, that the fat contained in the brain is confined almost exclusively to 

 the white substance, and that its color becomes lost when the fatty matters are 

 removed. According to Vauquelin, the cord contains a larger proportion of fat 



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