Excretion of Phosphorus and Calcium. 273 



animals (rabbits), so that very large doses of acid, for instance, 

 had to be given to obtain effects marked enough to study analytic- 

 ally. Repeated doses of 75 c.c, .9 per cent. HC1 given to the 

 rabbits of 1.5 kg. is very considerable and in the experiments of 

 Fitz, Alsberg and Henderson usually finally resulted in death of 

 the animal. Under such conditions, secondary results due to 

 the large amount of acid must have complicated the picture. 



This paper is an attempt to formulate the relation of acid 

 base equilibrium to the urinary and fecal Ca and P excretion in 

 normal adult man on a uniform mixed diet in which the greater 

 portion of P and Ca are given in an easily available form. Three 

 experiments were done on the effect of administration of HC1 and 

 NaHCOs, the one recorded here showing the effect of base and 

 acid successively on the same diet. Previous to the days recorded 

 in the tables, tfie subject had been on the diet for four days. The 

 assumption is made that he was in calcium and phosphorus equili- 

 brium, which is verified by the totals shown in the second table. 

 The experiment was divided into three periods: normal, basic and 

 acid. The P H of the urine in the normal period was 5.7 to 5.9 and 

 the effect of administration of base and acid is seen clearly. The 

 acidity (titrated according to Folin) runs parallel to this. The 

 ammonia nitrogen shows clearly t?he well known effect of acid and 

 base administration. The urinary P and Ca are progressively 

 diminished by the NaHCOs and progressively increased by the 

 acid. 



Now on turning to the second table, which gives figures for 

 urine and feces for periods constituting the last three days of the 

 periods as given in the first table, we find that the total Ca and 

 total P excreted in each period is constant. It is hardly to be 

 expected that either loss or storage should occur under these 

 conditions, sufficient to be discernible in a three day period. A 

 dose of acid comparable to 75 c.c. of .9 per cent. HC1 for a rabbit 

 would undoubtedly produce a negative Ca balance. It may be 

 noted that the C0 2 combining power of the blood during the entire 

 experiment remained within the range of normal. In the alkaline 

 period it rose to 77.7 and in the acid period went down to 69. 

 Normal was 74. 



