CHEMICAL COMPOSITION OF TEE BODY. $1 



oxygen ; some contain nitrogen also. There a' 3 three chief 

 kinds of them, viz. : albumens^ fats, and carbohydrates. 



Albuminous or proteid substances. These are by far 

 the most characteristic organic compounds existing in the - 

 body ; /they are only known as obtained from living beings, 

 having never yet been artificially constructed in the labor- 

 atory-) a good example is found in the white of an egg, 

 which consists chiefly of albumen dissolved in water. All 

 the tissues of the body which have any marked physiolog- 

 ical property contain some albuminous substance, only 

 such things as hairs, nails, and teeth being devoid of 

 them. All albuminous bodies contain nitrogen, carbon, 

 hydrogen, and oxygen ; most of them sulphur and phos- 

 phorus in addition. The more important ones found in 

 the body are, (1) Serum albumen, which is very like egg 

 albumen, and is found dissolved in the blood ; (2) Fibrin, 

 which forms in blood when it clots ; (3) Myosin, found in 

 the muscles and " setting" or coagulating after death, when 

 it causes the death stiffening ; (4) Casein, found in milk, 

 and forming the main bulk of cheese. 



Fats belong to the organic compounds in the body 

 which contain no nitrogen ; they consist solely of carbon, , 

 hydrogen, and oxygen. The chief fats in the body are 

 palmatin, stearin, and olein; by proper treatment each 

 can be split up into glycerine and a fatty acid ; palmitic, 

 stearic, or oleic acid as the case may be. 



What is found in addition in some of them ? How many chief 

 varieties of organic compounds are there in the body ? Name them. 



Give another name for albuminous substances. Can they be made 

 artificially ? Give an example of an albumen. What elements do 

 albumens contain ? Name the more important albumens of the body. 

 Where are they found ? 



What elements do fats contain ? Name the chief fats of tne body. 

 Into what may they be decomposed ? 



