102 ACIDOSIS, ACETON^EMIA, 



blood is much reduced by the increase of diacetic 

 and especially of /3-oxybutyric acids in the plasma. 

 This condition is called " acidosis." It would 

 perhaps be going too far to say that absolutely 

 unlimited quantities of /3-oxybutyric acid may be 

 formed and tolerated if sufficient alkali is supplied 

 to neutralize it ; there is a point beyond which even 

 sodium /3-oxybutyrate becomes toxic ; and by keeping 

 the urine alkaline, although we may greatly delay, 

 we do not altogether prevent the onset of diabetic 

 coma. 



The body is able for a long time to defend itself 

 against the increased production of diacetic and 

 /3-oxybutyric acids, by furnishing enough alkali to 

 neutralize them more or less completely. First, 

 the reserves of sodium and potassium are called upon, 

 but the main defence is the production of large 

 quantities of ammonia. In normal metabolism the 

 proteins of the tissues split off their effete nitrogen 

 in the form of ammonium salts (carbonate, carbamate, 

 etc.), and these are converted into urea by the liver. 

 When diacetic and /3-oxybutyric acids are present, 

 these unite with the ammonia, and it escapes con- 

 version into urea ; consequently there will be an 

 increase of ammonia nitrogen in the urine (as am- 

 monium diacetate and ammonium /3-oxybutyrate). At 

 length, however, the production of the acids becomes 

 so excessive that the supply of ammonia from the 

 tissues fails to keep up with them. Then the normal 

 alkalinity of the blood falls, and dyspnoea, collapse, 

 and coma begin to appear. 



