PNEUMATO-CHEMICAL APPARATUS. 13 



The shelf, with the lamp and the ring having the 

 retort in it, are now to be adjusted by moving them 

 up or down, until the lamp is at a convenient 

 height below the retort, the neck of whicli rests 

 upon the edge of the cistern, and the end of its 

 neck opens in the funnel under the jar standing 

 upon the shelf. The lamp must now be lighted, 

 and as soon as the substances in the retort act upon 

 each other sufficiently, the gas will begin to be dis- 

 engaged, and will ascend through the hole in the 

 shelf into the vessel, B, and displace the water witli 

 which it had been filled. When all the water is 

 displaced, the receiver is full of the gas which was 

 disengaged from the retort, and may be preserved 

 in it by keeping its mouth always under the water 

 in the cistern. 



This gas may be transferred from the vessel, B, 

 into any other vessel, in the following manner : fill 

 the vessel into which the gas is to be transferred, 

 with the fluid in the trough, and place it on the 

 shelf as before directed, over one of the holes. 

 -Then take the vessel, B, and keeping its mouth still 

 under the fluid, bring it under the hole on which 

 .the vessel is placed, then depressing its bottom, 

 and elevating its mouth, so as to bring it more to a 

 horizontal position, the gas in it will escape and 

 rise up through the hole on which the other vessel 

 has been placed, and will fill it by displacing the 

 fluid. In this manner any gas may be formed, or 

 transferred from one vessel to another. 



The cistern for the water may be made of wood, 

 in the manner of a tub, and hooped round, which 

 may or may not be painted inside and out. But it 

 will be much more elegant if made of sheet-iron, 

 tinned, and japanned of a brown or chocolate co- 

 lour. The ornaments, if any, may be of brass, or 



