166 HUMAN PHYSIOLOGY 



vation. Death occurs when a little more than one-half of 

 the body weight has been lost. 



Besides the loss of material, starvation causes the following 

 results: The activity of the heart decreases, the number of beats 

 is lessened. General weakness sets in (psychical depression). 

 The body temperature remains the same except just before death, 

 when it falls considerably. The indol and aromatic oxyacids of 

 the urine formed by putrefaction in the intestine disappear, but 

 phenylsulphuric acid is excreted with the urine till death sets in. 



(b) Partial inanition. If only some constituents of food 

 necessary for life are given, or if all the constituents are 

 given but in insufficient quantities, death by starvation is but 

 delayed. 



1. Lack of water in the food causes death more speedily 

 than lack of all food. This is evidently due to the fact that, 

 for the normal course of metabolism, a definite proportion 

 must exist between the water and the solid constituents of 

 the body. Besides this, dry food is very soon refused, so 

 that lack of water is finally followed by absolute starvation. 



2. Salt-hunger. If no salts are present in the food, the 

 excretion of salts steadily decreases and the excretion of 

 sodium chloride soon ceases altogether even at a time when 

 the body still contains considerable quantities of it. Potas- 

 sium and calcium phosphates are, however, continually 

 excreted. By eating organic foods the excretion of calcium 

 phosphate is somewhat decreased, because the salt, derived 

 from the breaking down of the tissue, can be utilized in the 

 regeneration of the tissues. Still a part of the salts is con- 

 tinually lost, and since, for the maintenance of life, a certain 

 proportion must exist between the salts and the organic 

 constituents of the body, death finally sets in. Death is 

 preceded by weakness and paralysis. 



3. Lack of all organic constituents in the food. If no 

 organic foodstuffs are given, the animal being supplied only 

 with water and salts, death by starvation occurs. The 

 phenomena of metabolism are practically the same as in 

 absolute inanition, the organism consumes its own body 



