262 On the Taidenc^ of 



sible quantity of acid gas, as appeared from 

 agitating lime water in it. In three hours it 

 had the acid gas in great plenty, instantly 

 making lime water milky. After this it was 

 repeatedly removed in the space of half an 

 hour, and never failed to exhibit signs of the 

 acid gas. Things remaining just the same, the 

 upper phial was filled with the different gases 

 mentioned above repeatedly, and in half an 

 hour there was always found acid sufficient to 

 make the phial ~ filled with lime water quite 

 milky. There was not any perceptible dif- 

 ference whatever gas was in the upper phial.* 



SECOND CLASS. 



HYDROGENOUS GAS, 



with Atmospheric Air and Oxygenous Gas. 



1 . Two 6 ounce phials were connected by 

 the tube of a tobacco pipe, 3 inches long, the 

 upper containing hydrogenous gas, the lower 

 atmospheric air : after standing two hours, the 

 lower phial was examined ; the mixed gases it 

 contained made six explosions in a small 

 phial. The gas in the upper also exploded. 



* The small tube of 10 inches was (hen used and a 

 phial of common air ; in one hour much acid gas had 

 come through, as appeared by lime vvaler. 



