MISCELLANEOUS METHODS AND APPARATUS. 



73 



samples, a and 6, could be compared and notation made of marked dis- 

 crepancies, if any existed. Theoretically both samples should have 

 dried to essentially the same weight. 



Fig. 1. — Drying oven. 



The walls and doors of this oven are of asbestos board and the shelves are of strong wire mesh. 

 A rose burner in the air intake at the bottom furnishes the heat; the temperature of the oven 

 is indicated by a thermometer at the side. Ventilation is secured by a fan placed in the exit 

 pipe above the oven. 



METHODS OF ANALYSIS. 



URINE. 



Observations on the urine were confined to the crude observations of 

 specific gravity with a standard spindle and to the exact determination 

 of nitrogen by the Kjeldahl process. The Laboratory is well supplied 

 with automatic pipettes, digestive apparatus, and stills for the most 

 rapid work. The 1,000 or more urine analyses involved in this 

 research were made exclusively under the supervision of Miss Elizabeth 

 B. Babcock, and were carried out with extraordinary fidelity, rapidity, 

 and accuracy. In this work she was assisted by Miss Marion L. Baker 

 and Mr. Harry Silverman. 



