EFFECTS OF CERTAIN DRUGS AND POISONS 733 

 If the normal -" rat * (~^) rema * n3 undisturbed the condi- 



tion is one of compensated acidosis, but should the respiratory center fail 

 to remove the relatively excessive carbon dioxid present when bicarbonate 

 has been lost the acidosis is said to be uncompensated. 



Since excess of carbon dioxid gas in the blood may occasionally in- 

 crease the numerator of the ratio without disturbing the denominator a 

 true acidosis without change in the bicarbonate level is possible. 



Next to carbonic acid and sodium bicarbonate the acid and alkaline 

 phosphates of the corpuscles and tissues assist in maintaining the neutrality 



of the blood. The normal =^ J* 4 ratio in the blood plasma is given as 



^ by Michaelis and Garmendia. 



Besides these defenses and the ammonia regulation (see "Acids"), a 

 factor of possible significance in maintaining the neutrality 'is lactic acid. 

 MacLeod and Knapp observed that this acid may appear in the urine, 

 after alkali injections in animals, in amounts sufficient to account for 

 five or six per cent of the alkali given.. 



Acids. Walter in 1877 appears first to have shown that acids dimin- 

 ish the carbon dioxid content of the blood by displacing the "weaker" 

 acid, H 2 C0 3 . Kraus and many others showed later that acids diminish 

 the total or titratable alkalinity. Walter pointed out the differences be- 

 tween herbivora and carnivora with respect to their manner of regulating 

 against acids. While the former to accomplish this must surrender their 

 fixed alkali from the tissues, 3 the carnivora are able to deflect ammonia 

 from the protein metabolism (at the expense of urea formation) for pur- 

 poses of neutralization. Recently Loeffler has shown that acids inhibit 

 somewhat the formation of urea by the perfusion of the liver in vitro with 

 ammonium salts. 



Thus an augmented - ratio in the urine has become a significant 



guide to acidosis. 



The term "acidosis" may be understood in its broadest sense to in- 

 clude all those disturbances of the acid-base equilibrium in which there 



occurs either an actual increase in the P h (i. e, in the TT/^\ ra ^io) of 



the blood, or, as is far more frequent, a decrease in the alkali reserve, or 

 both. The appearance of the acetone bodies, as in diabetes, merely indi- 

 cates one form of acidosis, sometimes designated as "ketosis." 



L. J. Henderson and Palmer (6), as well as Hanzlik and Collins, have 

 shown that acid sodium phosphate increases the urine acidity, although 



* But Hart and Nelson have found a certain degree of ammonia regulation in cattle. 



