334 HENRY A. MATTILL AND HELEN I. MATTILL 



carbonic acid as such by the lungs does not involve a permanent with- 

 drawal of alkali from the body, and by virtue of the peculiar ability of 

 the kidney only a portion of the alkali used to neutralize phosphoric acid 

 is lost. The inorganic sulphates of the urine, on the other hand, represent 

 a complete loss to the body of the alkalies required in their formation. 

 The presence of bicarbonate and of phosphates in the blood in optimum 

 concentration is the basis for the delicate mechanism of neutrality regula- 

 tion which Henderson has so fundamentally conceived. Because of this 

 mechanism assisted by the acid-alkali exchanges between the plasma and 

 the erythrocytes as well as the tissues (Collip; Haggard and Henderson 

 (6) ; Henderson and Haggard), an overproduction of acid, even though 

 it is considerable, does not change the hydrogen-ion concentration of the 

 blood (Sonne and Jarlov) ; the alkali reserve, as measured by the carbon 

 dioxid capacity, is decreased (Van Slyke and Cullen) and urinary acidity 

 and ammonia are increased. The character of the food influences these 

 relations, foods high in protein and, therefore, containing a preponderance 

 of acid-forming elements decrease the alkali reserve and increase urinary 

 acidity and ammonia, those containing a preponderance of base-forming 

 elements (vegetables, fruits), decrease the latter two and increase the 

 former (Kastle; Forbes(a) ; Sherman and Gettler; Hasselbalch; Blather- 

 wick; McClendon, et cd.}. 



Prolonged administration of acids or of acid-forming foods tends to 

 deprive the organism of alkalies. Thus acidosis produced in children by 

 an acid-forming diet caused a loss of Ca and Mg (Sawyer, Baumann and 

 Stevens), and in observations on animals with experimental acidosis the 

 alkaline phosphates, especially the potassium phosphate of the muscles, 

 and the calcium carbonate of the bones were the first major reserves drawn 

 upon after the bicarbonates of body fluids (Goto(c)). McCollum(a) (/) 

 found that rats could grow and be maintained for fairly long periods 

 on acid-forming and also on base-forming rations though reproduc- 

 tion was usually not successful. Lamb and Eward determined that 

 the addition of sulphuric acid to the ration of swine did not inter- 

 fere with growth but prevented reproduction. Of the ingested sul- 

 phuric acid only 61 per cent was neutralized by ammonia, and their 

 conclusion (that there was no marked loss of calcium) is, according to 

 Forbes, not justified. To what extent these reserves are called into action 

 in daily dietary fluctuations in man cannot be stated ; in the experiment 

 of Sherman and Gettler the substitution of isodynamic quantities of rice 

 in place of potato in an otherwise constant diet caused an increase in 

 urinary acidity and ammonia, but the combined increase in both could 

 account for only about two thirds of the acid involved. They suggest 

 that most of the excess might be accounted for by a change in the balance 

 of acid and base-forming substances in the feces, but unfortunately they 

 were unable to make a complete study of the feces. It is significant that 



