CHEMICAL APPARATUS. 

 Fig. 535. 



85 



Compound Blow-pipe and Pneumatic Cistern. (Fig. 536, 

 next page.) The compound blow-pipe with pneumatic cis- 

 tern combined, consists of a stout oblong cistern having two 

 gas holders in the form of square boxes ; the one for hydro- 

 gen being the largest. The gas holders are confined in their 

 places by being slid under projections on the sides of the 

 cistern, so that they cannot rise when filled with gas, and 



