178 



DETERMINATION OF ASH OF BLOOD. 



[BOOK i. 



in dry air, it is then placed on the balance and weighed. The 

 weight having been noted, the crucible is again heated to 110 for some 



FIG. 31. Hoi-AiR OVEN WITH BDNSEN'S BEGULATOR. 



time, and again weighed as before, the process being repeated until 

 two successive weighings give the same result. 



FIG. 32. AN EXSICCATOR. 

 A bell- jar 6, with ground rim, fits 

 air-tight over the plate a. c is a vessel 

 containing sulphuric acid or phosphoric 

 anhydride, d is a tray with circular holes 

 for crucibles and capsules. 



FIG. 33. 



A SMALL EXSICCATOR, SUITABLE 



FOR A CRUCIBLE. 



