

ALIMENTARY TRACT AS AN EXCRETORY SYSTEM. 313 



apparently limited to the region of the alimentary tract be- 

 yond the stomach. 



The following experiments will serve to illustrate the fore- 

 going. As strontium tends to be stored in certain tissues of 

 the body and is only eliminated slowly, the dejecta of the 

 animals experimented upon have to be studied for several 

 days. A dog weighing 6 kilos received a number of subcu- 

 taneous strontium acetate injections, the total amount of 

 strontium injected being 0.543 gm. The urine and faeces 

 were collected separately for 21 days. The total urine con- 

 tained an unweighable trace of strontium. The total faeces 

 contained 0.0998 gm. of this element. 



At times, however, a much larger percentage of the injected 

 strontium can be recovered. A dog weighing 14 kilos was 

 given 0.28 gm. strontium (in the form of the acetate) sub- 

 cutaneously. At no time for 17 days subsequently could 

 strontium be detected in the urine. From the faeces 0.237 

 gm. were recovered during this period. 1 



In a series of experiments which Professor MENDEL 2 has 

 communicated to me by letter, he has been able to show that 

 barium behaves not unlike strontium. If barium chloride is 

 introduced into the body even in other ways than through 

 the mouth, it is eliminated almost exclusively by the intes- 

 tinal tract. After the first twenty-four or forty-eight hours 

 the urine shows no signs of containing the element barium, 

 even though the faeces contain the substance for days after- 

 ward. Barium tends to be stored in the body even more 

 readily than strontium and so is eliminated more slowly. 



Rubidium belongs in the class with sodium, and like this 

 leaves the body chiefly through the kidneys. To a certain 

 extent, however, rubidium also is eliminated through the 

 intestinal tract. 



1 MENDEL and THACHER: American Journal of Physiology, 1904, XI 

 p. 14. 



2 Personal letter dated New Haven, Connecticut, July 23, 1905. 



