132 



BEPOKT — 1887. 



and it was, indeed, becaase of such an indication tliat the investigation 

 was undertaken. The animals hitherto experimented on were cats and 

 rabbits. The method emploj^ed was as follows : — 



The animal was confined in a large cage, supplied with a double 

 bottom of zinc. The false bottom was perforated, allowing the passage 

 of urine, but retaining the fEBces. At one end of the real bottom a tube 

 conducted into a receiver, where the urine was collected. The urine was 

 collected once in twenty-four hours, and was usually quite clear and free 

 from foreign admixture. In order to simplify the experiment and avoid 

 as far as possible variations due to different quantities of food, the animal 

 was fed on a stated quantity of porridge, made of a weighed quantity of 

 meal, and there was added a measured quantity of milk. The animal was 

 in all cases kept for a week or more on the regulation diet before the 

 observations began, until the urine, in regard to total quantity and to 

 constitution, became steady. Variations were thus easily observed, and 

 the risk of error in assigning the cause much diminished. 



After the urine had become steady, and a record of the quantity and 

 amount of nitrogen present had been taken for a number of days, atropine 

 ■was injected hypodermically and its effects on the urine observed. The 

 total nitrogen was estimated by the method of Knop and Hiifner, a large 

 number of estimations of urea by the method of Liebig having led to its 

 abandonment. 



Some of the results are given in tabular form as obtained from the 

 cat. They are a fair sample of the results obtained in every one of a 

 large number of observations on the cat. 



The first table gives the results of two consecutive experiments on the 

 same cat. 



Table l.— Cat. 



The table shows that after the injection of atropine the total quantity 

 of urine falls and the total N. rises : this is more marked with the larger 

 dose of atropine. The increased elimination of N. occurs in spite of 

 a lessened consumption of food. In two or three days after the injection 



