3 



Biological Chemistry. 



amount of substance to be 

 combusted (usually about 0'2 

 grm.) is introduced into the 

 long tube behind the platinum 

 star in a porcelain boat, or 

 (in the case of a liquid) in a 

 glass bulb, which is intro- 

 duced into a tube, one end of 

 which is drawn out into a cap- 

 illary which fits into a wider 

 tube which passes through 

 the cork (see Fig. 11). The 

 last-named tube is connected 

 with a specially constructed 

 apparatus, interpolated be- 

 tween it and the drying 

 tower, the object of which is 

 to divide the oxygen current 

 into two streams. The smaller 

 stream passes through the cap- 

 illary, and comes into direct 

 contact with the substance, 

 whereas the greater stream 

 passes on the outside of the 

 tube into which the substance 

 has been inserted, and mixes 

 with the products of combus- 

 tion. The water formed is 

 collected in the U tube E, 

 and the carbon dioxide in the 

 vessels F, containing soda- 

 lime, and G, containing in the 

 first limb soda-lime and in 

 the second calcium chloride 



