GENERAL CONSIDERATIONS. 



3. Internal Struct che and Vital Phenomena of Man. ooo 



Investigations in reference to the corporeal nature of man are carried on 

 under two points of view, one liaving respect to his anatom}^, the other to 

 his physiology. By anatomy^ is to be understood the structure of the ani- 

 mal machine, with the form and constitution of the individual parts ; while 

 -physiology^ on the other hand, seeks to cxj)lain the office or function which 

 each part of the system plays in the animal economy. 



Human Anatomy is divisible, in the first place, into General and Special« 

 General Anatomy treats of the minute individual components of the body ; 

 their varieties of structure, their peculiarities, and their mode of combina- 

 tion ; it stands in very close connexion with the chemistry of the human 

 body. Special Anatomy refers to the indi vidual organs, teaching their forms, 

 magnitudes, positions, and connexions with the other parts of the body. 



4. Constituents and Elementary Tissue of the Human Body. 



The human body consists of solid, liquid, and gaseous substances, so 

 intimately united as to be only separable by artificial means. All solid 

 particles, for instance, are penetrated b}' liquid, and these contain gaseous 

 in solution. In addition to these, there are cavities in various portions of 

 the body, more or less moistened or filled with collections of liquid matter, 

 not to speak of the gases contained in the lungs, the intestinal canal, &c. 



The liquids of, the human body constitute its principal mass, amounting 

 to nearly four fifths of the entire weight. They consist in part of a watery 

 matter, generally distributed throughout the body, and containing a little 

 albumen and a few salts in solution ; partly of nutritious juices, as the 

 blood, the lymph, and the chyle ; and partly of secretions, which are sepa- 

 rated from the blood to be entii'cly thrown ofi", or else used for some special 

 purpose. Thus we have serous liquids in the cellular tissue, in various closed 

 cavities, in the chambers of the eye, and in the inner ear : albuminous are 

 found in the synovial membranes and the vitreous humor of the eye : fats 

 occur in the cellular tissue and in the marrow of bones : coloring matters in 

 the blood, the muscles, and under the skin of certain races. 



All the components of the body may be reduced to fifteen elementary 

 constituents, which, however, are not peculiar to it. These are oxj-gen, 

 hydrogen, nitrogen, carbon, sulphur, phosphorus, sodium, chlorine, fluorine, 

 potassium, calcium, magnesium, manganese, silicon, and ii'on. 



Some principal organic combinations of these elements in the human 

 body are as follows : tears ; saliva ; crystallin, in the crystalline lens ; biliary 

 resin, biliary sugar (bilin), taurine, bilifulvin, Cholesterin, dyslysin, &c., in 

 the bile; uric acid and urea in the urine; caseiue, whey, butter, sujgar of 

 milk, and lactic acid, in milk ; mucus ; horn, in the epidermis, hair, and 

 nails ; Jibri)ie in the blood, lymph, chyle, and muscles ; albumen in serum, 

 in the substance of the brain and nerves, in the muscles, the synovia, the 



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