t 

 28 INTRODUCTION. 



of these changes, and consider ourselves fortunate in under- 

 standing a few of the laws which regulate them. As exam- 

 ples of principles of this class we may cite musculine, os- 

 teine, fibrin, albumen, and caseine. 



INORGANIC PRINCIPLES. 



The number of principles of this class, now well estab- 

 lished as existing in the human body, is twenty-one. 1 All 

 substances which at any time exist in the body are proximate 

 principles ; but some are found in small quantities, are not 

 always present, and apparently have no very important func- 

 tion. These will be passed over rapidly, as well as those 

 which are so intimately connected with some important func- 

 tion as to render their full consideration in connection with 

 that function indispensable. The following is a list of the 

 inorganic principles, excluding those which are excrementi- 

 tious, and one or two which are not yet well established : 



Table of Inorganic Principles. 



Proximate Principle. Where Found. 



f Oxygen. Lungs and Blood. 



^ I Hydrogen. Gases of Stomach and Colon. 



-| Nitrogen. Lungs, Intestinal Gases, and Blood. 



^ Carburetted Hydrogen. Lungs (expired air), Intestines. 



^Sulphuretted Hydrogen. Lungs (expired air), Intestines. 



Water. Universal. 



Chloride of Sodium. Universal, except the enamel. 



Chloride of Potassium. Muscles, Liver, Milk, Chyle, Blood, Mu- 



cus, Saliva, Bile, Gastric Juice, Ce- 

 phalo-rachidian Fluid, and Urine. 



1 Robin and Verdeil give twenty-nine ; but of these, three (acid phosphate of 

 soda, acid phosphate of lime, arid ammonio-magnesian phosphate) are found only 

 in the urine, and may be considered as coming under the head of excrements, 

 with carbonic acid, which is one of the most important excretions ; one (bicar- 

 bonate of lime) is abnormal ; one (bicarbonate of potassa) is found only in cer- 

 tain of the inferior animals ; and two (carbonate and bicarbonate of ammonia) 

 are doubtful. 



