CHEMICAL APPARATUS. 



tory or difficultly fusible substances. The cut represents the 

 apparatus complete. A and E (fig. 1) is the safe apparatus, 

 a section of which is seen in fig. 2, and through which the 

 gas must pass from the gasometer, through the stop-cock C, 

 G is a transferring bladder, screwed to the stop-cock, H, by 

 which the gasometer is charged by an assistant during its 

 action, and such a quantity of gas supplied as to keep up a 

 flame for any requisite time. Between the gasometer and 

 the charging bladder a valve is placed, to prevent a return 

 of the gas. I, a wood or pasteboard cap, so contrived as to 

 unite lightness with strength ; this is attached by four 

 strings, K, to wires, which passing through holes, L L, in 

 the table of the instrument, are fixed to M, a movable 

 press-board below. When the requisite pressure or weight 

 is placed on M, the cap, 1, is drawn down horizontally and 

 equally on the gasometer, D ; upon which the gas (this is 

 oxygen and hydrogen mixed together in the proportion of 

 one part of the former to two of the latter) is forced through 

 the water-tube, B, the safety apparatus, A, and out of the 

 jet, C, at the end of which it is burned. In fig. 2, the gas 

 enters B, passes through the water at D, then through a 

 series of wire gauzes at E, and afterwards out at the jet. 



Price, $18.00. 



Hydrogen Lamp. (Fig. 538.) Fi s- 53S - 



The hydrogen lamp consists of a 

 glass vessel, into which a smaller 

 one with open bottom, and having 

 a small neck, is inverted ; the 

 neck being cemented into the 

 socket of a brass plate covering 

 the outer vessel. On the top of 

 the plate is a stop-cock, with 

 spring and lever to open at the 

 side, to throw the hydrogen when 

 made, on some spongy platina sup- 

 ported in a small box in front of 

 the jet. 



To charge the instrument, the 

 outer vessel is nearly filled with 

 water, previously mixed with one- 

 tenth the quantity of sulphuric acid ; a piece of zinc is sup- 

 ported on a brass rod fixed to the centre of the plate, and 



