CHEMICAL COMPOSITION OF THE HUMAN BODY. 1 



I. INORGANIC PROXIMATE PRINCIPLES. 



SUBSTANCE. WHERE FOUND. 



Oxygen ........................... Lungs and blood. 



Hydrogen ........................ Stomach and intestines. 



Nitrogen ....................... ,. Blood and intestines. 



Carbonic anhydride ............ Expired air of lungs. 



Carburetted hydrogen ) T , . . , . 



OIL. LI. j i. j ? ... Lungs and intestines. 



Sulphuretted hydrogen / 



Water ............................ Found in all solids and fluids. 



Sodium chloride ............... In all fluids and solids except enamel. 



Potassium chloride ............ In muscles, liver, saliva, gastric juice, etc. 



Ammonium chloride .......... Gastric juice, saliva, tears, urine. 



Calcium chloride ............... Bones, teeth, urine. 



Calcium carbonate ............. Bones, teeth, cartilage, internal ear, blood. 



Calcium phosphate " 



- I" -1 ** * -lids of the body. 

 Potassium phosphate } 

 Sodium sulphate ) TT . , 



Potassium sulphate. j "' Universal, except milk, bile and gastric juice. 



Sodium carbonate \ ^, 



Potassium carbonate } - Blood ' bones > ^P^ urlne ' etc ' 



Magnesium carbonate ........ Blood and sebaceous matter. 



The inorganic principles enter and leave the body under their own 

 form. Water is an essential constituent of all the tissues of the body, 

 constituting about 70 per cent, of the entire body weight. It is introduced 

 into the body in the form of drink and as a constituent of all kinds of 

 food. The average quantity consumed daily is about four pints. While 

 in the body, water acts as a general solvent, gives pliability to various 

 tissues, and promotes the passage of inorganic and organic matters through 

 animal membranes. It also promotes chemical changes which are essen- 

 tial to absorption and assimilation of food and the elimination of products 

 of waste. It is probable that water is also formed within the body by the 

 union of oxygen with the surplus hydrogen of the food. It is eliminated 

 by the skin, lungs and kidneys. 



Sodium chloride is present in all the solids and fluids of the body, with 

 the exception of enamel. It regulates osmotic action, holds the albuminous 

 principles of the blood in solution, and preserves the form and consistence 

 of blood corpuscles and the cellular elements of the tissues, by regulating 

 the amount of water entering into their composition. 



Calcium phosphate is the most abundant of all the inorganic principles 

 with the exception of water, and is present to a great extent in bone, teeth, 

 muscles and milk. It gives the requisite consistency and solidity to the 



