12 DAIRY ANALYSIS 



weight of milk taken and multiplied by 100 gives the 



percentage of total solids. 



(Babcock's method) The basin may be loosely packed with 



ignited asbestos, if 

 great accuracy is 

 required ; (Stokes' 

 method) if speed is 

 wanted, a few drops 

 of a 10 per cent, so- 

 lution of acetic acid 

 in alcohol, or (Revis* 

 method) an equal 

 volume of acetone, 

 may be added, and 

 FIG. 8. Water-bath. the time of drying 



canthenbe curtailed. 

 Estimation of Ash. The total solids are ignited 



in a muffle furnace (Fig. 10), which should not be 



allowed to become hotter than a dull red heat ; to 



facilitate burning, upstand- 

 ing portions of the ash may 



be broken down by touch- 

 ing with a platinum wire ; 



when all the carbon is 



burnt away the basin is 



cooled in a desiccator and 



weighed. The ignition may 



be performed over a Bun- 

 sen burner (Fig. n), the 



point of the flame of which 



should barely be allowed 



to touch the bottom of 



the basin, or an Argand 



burner may be used; the FIG. 9 .-Water-oven. 



basin should be covered 



with a platinum lid. It is very important not to heat 



the ash to too high a temperature. 

 Estimation of Soluble and Insoluble Ash. 



Fill the basin with hot water and filter through a 



