14 HUMAN PHYSIOLOGY. 



cause starch an ! albumen to be transformed into sugar and albuminose 

 respectively. Different albumens possess varying proportions of water, 

 which they lose when subjected to desiccation, becoming solid ; but upon 

 exposure to moisture they again absorb water, regaining their original con- 

 dition they are hygroscopic. Another property is that of coagulation, 

 which takes place under certain conditions: e.g., the presence of mineral 

 acids, heat, alcohol, etc. 



After death the albuminous compounds undergo putrefactive changes, 

 giving rise to -carburetted and sulphuretted hydrogen and other gases. 



Albumen exists in the blood, lymph, chyle, constituting the pabulum of 

 the tissues; it is coagulated by heat, mineral acids and alcohol. 



Peptones are found in the stomach from the digestion of albuminous 

 principles of the food ; they are coagulated by tannic acid, chlorine, acetate 

 of lead, and characterized by great diffusibility, which permits them to 

 pass through animal membranes with facility. 



Fibrin can be obtained from freshly drawn blood by whipping ; it also 

 coagulates spontaneously, and when examined microscopically exhibits a 

 lilamentous structure. 



Casein is the albuminous principle of milk. 



Ostein constitutes the organic basis of bone, with which are mingled the 

 salts of lime. 



Myosin is found in muscles, protagon in brain, pepsin, pancreatin and 

 salivin, in the digestive fluids. 



Mucin, chondrin, elastin, keratin and globulin, are found in mucus, 

 cartilage, elastic tissues, hair, nails, and red corpuscles, respectively. 



As the properties of the compounds formed by the union of elements are 

 the resultants of the properties of the elements themselves, it follows that 

 the ternary substances, sugais, starches and fats, possess a great inertia and 

 a notable instability; while in the more complex albuminous compounds, 

 in which sulphur and phosphorus are united to the four chief elements, 

 molecular mobility, resulting in isomerism, exists in a high degree. As 

 these compounds are unstable, of a great molecular mobility, they are well 

 fitted to take part in the composition of organic bodies, in which there is 

 a continual movement of composition and decomposition. 



IV. PRINCIPLES OF WASTE. 



Urea, Xanthin, Sodium, 1 



Creatin, Tyrosin, Potassium, | 



Creatinin, Hippuric Acid, Ammonium, 



Cholesterin, Calcium Oxalate, Calcium, 



