172 PHYSICAL CHEMISTRY 



sorbed to a surface, the anesthetic adsorbed to the same surface, 

 and its concentration increased above that in the interior of the 

 solution. Meyerhof (1914 a) attempted to make a model to 

 show this difference. He found that the activity of an invertase 

 solution is not altered by adsorption to colloidal ferric hydrate 

 (dyalized iron). If the same concentration of anesthetic is added 

 to the invertase solution and the invertase iron suspension, the 

 activity of the latter is reduced more than the former, but the 

 difference is very small, not nearly so great as between the inver- 

 tase inside and outside the cell. 



The question as to whether the cells of the body would use 

 more oxygen if they were more liberally supplied with it is very 

 important. Paul Bert (1878) found that animals died in oxygen 

 under pressure, but this phenomenon has never been thoroughly 

 analyzed. Anaerobes and facultative anaerobes may live in- 

 definitely and many other organisms may live for a time without 

 oxygen. Infusoria may live from five to twenty days without 

 oxygen (Putter, 1911). The development of Fundulus eggs may 

 be suspended by withholding oxygen and commence again when it 

 is readmitted. Henze (1910) found that sea anemones use more 

 oxygen the greater its concentration in the sea water. When 

 protein is eaten the mammal uses more oxygen than when a 

 carbohydrate of the same calorific value is eaten. One explana- 

 tion of this might be that the protein gives rise to acid substances 

 in the blood which stimulate the respiratory center and cause 

 more oxygen to be brought to the tissues. 



Heat Production 



The heat produced by burning fats and carbohydrates in the 

 body is the same as that obtained in burning them in the bomb 

 calorimeter, 3.74 Cal. per gram of monosaccharide, 3.95 for di- 

 saccharide and about 9.5 for ordinary animal or vegetable fat. 

 But the heat produced by protein is 5.7 in the calorimeter and 

 only 4.5 in the body. The difference is that the protein is not 

 completely burned in the body, being excreted as urea, uric acid, 

 NH 3 and other incompletely oxidized products. 



While heat production and loss in man is so regulated from 

 the heat center in the brain that the temperature of the body, 

 to within an inch of the surface, seldom varies more than a de- 



