353 



Chemical Apparatus. 



Apparatus for showing some of the distinguishing prop 

 ties of carbonic acid gas. 



er- 



Having introduced into 

 the three necked bottle, 

 represented in this figure, 

 one or two ounces of car- 

 bonate of ammonia, add 

 about half as much deep 

 orange colored nitric acid, 

 an active effervescence 

 will ensue, arising from the 

 expulsion of the carbonic 

 acid from the ammonia, 

 by the stronger affinity of 

 the nitric acid. At the 

 same time sufficient fume 

 will be generated to make 

 it evident, how far the ves- 

 sels are occupied by the 

 gas, to the exclusion of 

 atmospheric air. 



The movements of the 

 carbonic acid gas will thus 

 be recognized, as ascen- 

 ding to the upper vessel, 

 it will fill, and finally overflow this vessel, through the crev- 

 ice, between the brim and cover. 



The cover being removed, a lighted candle will cease to 

 burn, when lowered into the fume, indicating the space oc- 

 cupied by the gas. This space will comprise the whole cavity 

 of the vessel, so long as the aperture, A, is closed ; but, on 

 removing the cock from this aperture, the gas will flow out, 

 and the stream marked by the accompanying fume, will be 

 seen descending towards the table, and will extinguish the 

 flame of a candle if made to encounter it ; or, it may be re- 

 ceived into a mug, so as to arrest the combustion of a taper 

 introduced into it, or upon which the contents of the mug 

 may be poured. 



Under these circumstances, a taper will burn any where 

 within the vessel, V, if it be not below the aperture, A, above 

 which the gas is not now seen to extend itself. But if one 

 of the orifices of the bottle be opened, the carbonic acid 

 will be found entirely to desert the upper vessel. 



