The Chemical Constituents of the Organism,. 21 



The preponderance of potassium over sodium salts is 

 here most marked, and Bunge considers that when a rela- 

 tion of from 4 to 6 equivalents of potassium to one equivalent 

 of sodium is obtained in a diet no addition of sodium 

 chloride is necessary ; but where the proportion of potas- 

 sium is higher than this the animal instinctively seeks for 

 sodium, for the reason that the effect of potassium salts in 

 the blood is to withdraw sodium salts from the system. 



I should be sorry to deny the stimulant to the palate which 

 common salt may afford the herbivora, but so far as horses 

 are concerned, and I think the same argument must apply 

 to cattle, I am perfectly clear on the point that no addition 

 of common salt to the ordinary diet is absolutely necessary, 

 and that the food furnishes ample sodium, for the secretions, 

 as shown by my inquiry into the amount excreted by the 

 urine during rest and work, and the quantity excreted by 

 the sweat. 



From the little we know of the character of the saline 

 secretions in the horse, we are prepared to find that the 

 preponderance of potassium over sodium, in both the urine 

 and the sweat, can only be accounted for by the excess of 

 potassium salts supplied by the food. 



Calcium forms the largest mineral deposit in the body ; 

 it is taken in by means of the food. Bunge states that it 

 is probable that the lime salts required for the growth of 

 bone in young animals are contained in some organic com- 



