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BENJ. PIKE S, JR., DESCRIPTIVE CATALOGUE. 



suspended just above the lower edge of the inner vessel. 

 Hydrogen will now be generated, and rising in the inner 

 vessel, expel the acid till it is below the surface of the zinc, 

 when no more hydrogen is formed. To procure a light, 

 turn the stop-cock, and the hydrogen will pass out in a very 

 minute stream upon the platina ; this will become red hot, 

 and the hydrogen jet be inflamed a match or candle may 

 then be lighted by it. As the gas burns, the pressure is 

 removed, the water again sinks, acts upon the zinc, and 

 forms gas a second time, and so on till the whole is consum- 

 ed. This instrument is sure and quick in its action, and is 

 extremely valuable as a blow-pipe for chemical analysis, 

 and when made large particularly for working in glass. 



Price, $2.00 ; $3.00 ; $4.00. 



Fig. 539. 



Hydrogen Gas Generator. (Fig. 

 539.) This represents nearly the 

 same apparatus as the last, of a larger 

 construction, producing and contain- 

 ing a greater quantity of gas, and 

 particularly useful in chemical expe- 

 riments where a supply of hydrogen 

 is required. On the top of the plate 

 there is a stop-cock of the usual size 

 of the cocks in chemical apparatus, 

 having a brass jet for burning the 

 gas. Price, $4.00 and $6.00. 



Hydrogen Gas Pistol (Fig. 540.) 

 This consists of a vessel in the form 

 of a double cone, soldered together, 

 and having a neck at one end about 

 one inch in diameter ; on the surface 

 of the opposite cone, is a small hole. 

 Fill the vessel with hydrogen gas, 

 and apply the flame of a candle 

 to the small hole, the hydrogen 

 will take fire and burn with a pecu- 

 liar flame, and from its lightness 

 will occupy the upper parts of 

 the vessel, and the air pressing in below will mix with the 

 gas. Invert the vessel slowly, and the mixture will explode 

 with a loud report. Price, 38 cts. 



