740 HENKY G. BAKBOUK 



Boracic Acid and Borax. Boracic acid and borax are respectively 

 weakly acid and alkaline in reaction. Moderate doses of either do not 

 effect the metabolism, but Chittenden and Gies(fe) found that large quanti- 

 ties (5 to 10 grams per day for dogs) increase the urinary nitrogen; a 

 dose of 4 to 8 grams in man retards the absorption of proteins and fats. 



Under borax the body weight often falls, which has been attributed 

 to augmented fat destruction by Kost and by Rubiier(i), who found a cor- 

 responding increase in the carbon dioxid elimination. Boracic acid is said 

 to be the least harmful of the food preservatives. 



IV. Oxygen and Asphyxiants 



Breathing undiluted oxygen produces no very significant effects, but 

 when the supply of oxygen has been deficient asphyxial symptoms are 

 promptly removed by inhalation. Lavoisier and Seguin in 1789 estab- 

 lished the fact that pure oxygen under ordinary conditions does not Affect 

 the metabolism. Long continued exposure to atmospheres rich in oxygen 

 produces pneumonia. (Karsner.) 



Oxygen Deficiency. Haldane has described the acute effects of 

 atmospheres low in oxygen. Chronic oxygen-lack as seen in anemias, etc., 

 causes considerable tissue destruction (Frankel), fatty degeneration and 

 acidosis, often with increased ammonia excretion. A. Loewy found amino- 

 acids in the urine. Mansfeld attributes the increased protein metabolism 

 to thyroid influence, for it fails to occur in the partial asphyxia of thyroi- 

 dectomized dogs. In anemias with the hemoglobin as low as 20 per cent, 

 Dubois has observed a marked augmentation cff the total metabolism. 



Exposure to rarified air, as first shown by \ 7 iault, increases the hemo- 

 globin content. This is preceded by a relative hemoglobinemia (Dallwig, 

 Kolls and Loevenhart). This blood concentration probably induces the 

 fever of "mountain sickness" in which the temperature, according to 

 Caspari and Loewy, sometimes attains 42 C. Such a temperature favors 

 the free dissociation of oxygen, tiding over the period of preparation of 

 better oxygen-transporting facilities. Douglas, Haldane, Henderson and 

 Schneider at an elevation of 4,290 meters, found the hemoglobin some- 

 times increased to 150 per cent. Some evidence of "secretion" of oxygen 

 into the pulmonary capillaries was found. 



The total metabolism, in similar investigations by "Wendt and by 

 Durig and Ziinz was found increased, while there were evidences of a 

 diminished protein catabolism. 



Asphyxial Glycosuria. Araki(d) and others have shown that simple 

 asphyxia and other conditions associated with oxygen-lack cause an excre- 

 tion in the urine of both glucose and lactic acid, the latter being regarded 

 as a result of imperfect combustion. The glycosuria, like those produced 



