388 



PHYSIOLOGICAL CHEMISTRY. 



of a 10 per cent solution of barium chloride, adding the solution 

 slowly, drop by drop. Allow the precipitated solution to stand 2 

 hours and filter while cold. Ignite, weigh and calculate according 

 to directions given under Total Sulphates, p. 384. 



Compute the quantity of sulphur, expressed as SO 3 or S, present 

 in the twenty-four hour urine specimen. 



FIG. 124. 



BERTHELOT-ATWATER BOMB CALORIMETER. (CROSS-SECTION OF APPARATUS AS READY 



FOR USE.) 



A, Steel cup or bomb proper ; C, collar of steel ; G, opening through which oxygen 

 is forced into the bomb ; H and I', insulated wires which serve to conduct an electric 

 current for igniting the substance which is held in the small capsule ; L, a stirrer 

 which serves to keep the water surrounding the bomb in motion and insures the 

 equalization of temperature ; P, a delicate thermometer which shows the rise in 

 temperature of the water surrounding the bomb. 



