i8o Joliii Bruce MacCallinn, M. D. 



scribed by Loeb^. The antagonism which has been shown by 

 Loeb to exist between the actions of many sodium salts on the 

 one hand, and calcium and magnesium salts on the other was 

 further illustrated by these experiments. 



It seemed possible then in the light of these facts that the activ- 

 ities of the kidney might be controlled in the same way as those 

 of the intestine. Since it is well known that many sodium salts 

 have a distinct diuretic action, it seemed conceivable that calcium 

 or magnesium might act as an antidiuretic. In order to decide 

 this point I have made a series of experiments in which I have 

 found that the relation of many of the salts to the activity of the 

 kidneys is similar to that which they bear to the glandular activity 

 of the intestine. 



METHODS. 



The following experiments were carried out mainly on rabbits; 

 a few dogs also were used. In all cases morphine was given 

 as an anaesthetic. The rabbits received 3-5 cc. 1% solution of 

 morphine hydrochlorate subcutaneously ; the dogs in addition 

 to this dose of morphine were given ether when necessary. 



The urine was collected by catheterising the ureters or by tying 

 a cannula in the bladder. The latter method was employed in 

 all cases except those in which it was necessary to observe the dif- 

 ference between the amounts secreted by the two kidneys. In 

 placing a cannula in the bladder a small incision was made in the 

 abdominal wall. The bladder, which usually contains a consid- 

 erable quantity of urine, was then lifted out of the body cavity, 

 and the abdominal wall sewed up around the neck of the bladder 

 so that the intestines could not be forced out. A purse-string su- 

 ture was then made in the fundus of the bladder and an incision 

 made in the bladder wall within the suture. In this way the urine 

 could be removed, and the cannula securely tied in. Care was 

 taken to allow no urine to collect in the bladder, so that the meas- 

 urements given in the tables represent all the urine that was se- 

 creted during each period. The simple catheterisation of the 

 bladder through the urethra may be easily performed in rabbits, 



1 Loeb, J. — Festschrift fiir Fick, 1899; Archiv. fiir die gesammte Physiologic. 

 1902, XCI, p. 248. 



