CHEMICAL COMPOSITION OF THE HUMAN BODY. 13 



elements entering into their composition, but with the carbon and hydrogen 

 increased and the oxygen diminished in amount; 3d, fatty acids; 4th, alco-- 

 hols. 



SUGARS. C. O. H. 



Glycogen, or Liver sugar. 

 Lactose, or Milk sugar. 

 Glucose, or Grape sugar. 

 Inosite, or Muscle sugar. 



Sugar is found in many of the tissues and fluids of the body ; e.g., liver, 

 milk, placenta, blood, muscles, etc. The varieties of sugar are soluble in 

 water, assume the crystalline form upon evaporation, and are converted 

 into alcohol and carbonic acid by fermentation. Sugar is derived from the 

 food, converted, in the alimentary canal, into glucose, absorbed by the veins 

 of the portal system, and then stored up in the liver, under the form of 

 glycogen. When the system requires sugar, it is again returned to the cir- 

 culation, and plays its part in the nutritive processes of the body. It is 

 finally oxidized, and thus contributes to the formation of heat. It is finally 

 eliminated under the form of carbonic acid and water. There is no experi- 

 mental proof that sugar contributes directly to the formation of fat in the 

 animal body. 



NEUTRAL FATS. C. O. H. 



Palmitin. 



Stearin. 



Olein. 



The Neutral fats, when combined in proper proportions, constitute a 

 large part of the fatty tissue of the body; they are soluble in ether, chloro- 

 form and hot alcohol; insoluble in cold alcohol and water, and liquefy at 

 a high temperature; when a neutral fat is subjected to a high temperature 

 in the presence of water and an alkali, it is decomposed, with the assimi- 

 lation of the elements of water, into a fatty acid and glycerine. The fatty 

 acid combines with the alkali and forms an oleate, palmitate or stearate, 

 according to the fat used. A similar decomposition of the neutral fats is 

 said to take place in the small intestine during digestion. When thoroughly 

 mixed with pancreatic juice, the fats are reduced to a condition of emulsion, 

 a state in which the fat is minutely subdivided and the small globules held 

 in suspension. 



FATTY ACIDS. C. O. H. 



Palmitic acid. Propionic acid. 



Stearic acid. Butyric acid. 



Oleic acid. . Caproic acid. 



