268 EXAMINATION FOR ARSENIC 



This bulb serves to collect the particles of liquid which 

 are thrown up from the contents of the bottle, and 



Fig. 41. 



which drop down again into the latter, from the ob- 

 liquely cut end of the tube. The other end of this 

 tube is connected, by means of a cork, with the tube 

 d, about 6 inches long, which is filled with fused pure 

 chloride of calcium, free from powder, destined to re- 

 tain the moisture. In the opposite end of the tube d, 

 is fixed, air-tight, another tube e, made of glass free 

 from lead, 12 inches long, and at most J-% inch in in- 

 ternal diameter. It should be made of rather thick 

 glass, and somewhat drawn out at the end. It must 

 be observed that the funnel-tube d is indispensably 

 necessary. If a two-necked bottle cannot be procured, 

 one with a single neck must be provided with a cork 

 bored with two holes. >._ . 



A better form of apparatus than the one just de- 

 scribed is shown in Fig. 42, which differs from it in 

 having the large tube filled with asbestus to prevent 

 impurities being carried over mechanically by the cur- 

 rent of gas. 



Several ounces of granulated zinc are introduced 



