SERIES XI. 



THE EFFECT OF SALICYLIC ACID AND SODIUM SALICYLATE UPON 

 THE NITROGENOUS ELEMENTS OF THE URINE. 



PRELIMINARY 



STUDY FOR THE DETERMINATION OF THE RATION AND 

 METHODS OF ANALYSIS. 



Before entering upon the special study respecting- the influence of 

 salicylic acid and salicylates upon the excretion and composition of 

 the urine, a preliminary experiment was conducted to determine the 

 kind of ration best suited to this particular investigation and also for 

 the purpose of comparing the two most promising methods, namely, 

 the Morner-Sjoqvist and the Braunstein methods," for the determina- 

 tion of urea. It will also be noted that analyses were made of the 

 daily samples and of a composite sample made by mixing aliquot portions 

 of the dail} T samples. These samples were composited each day and 

 preserved until the end of the period bj the addition of chloroform 

 and thymol, the object in view being to determine whether any mate- 

 rial change took place in the samples upon standing. 



THE RATION. 



For the purposes of this preliminary investigation three men were 

 placed on a definite diet for a limited time, the character of the ration 

 being unchanged throughout the series of observations, as shown in 

 Table I. 



TABLE I. Daily ration, showing amount of food and quantity of nitrogen ingested in the 

 preliminary experiment, Series XL 



a See p. 722 for description of methods. 



706 



