78 



BEiNJ. PIKE S, JR., DESCRIPTIVE CATALOGUE. 



Fig. 527. 



Flexible Gas Bags (Fig. 5^2 7.) 

 Gas bags made of India rubber 

 cloth are very convenient for hold- 

 ing gases ; they are made of vari- 

 ous sizes, from one foot to two 

 feet in diameter. One is repre- 

 sented in the cut, having a large 

 stop-cock and mouth-piece, as used 

 for inhaling nitrous oxide gas. 

 Price, 12-inch, - - - $1.50. 

 " 15-inch, - - - $2.00. 

 " 18-inch, - - - $2.50. 

 " 24-inch, - - $3.50. 



" with large stop -cock 



and mouth-piece, - $4.00. 

 " large gas bags for com- 

 pound blow-pipes, oxygen 

 microscopes, &c., holding 

 from 5 to 40 gallons, 



$4.00 to $20.00. 



The Gas Holder. (Fig. 528, next page.) This consists 

 of a body, or reservoir, closed at top and bottom, which 

 may hold about eight gallons. Above this, and supported 

 by four legs, is a cistern, open at the top, and connected 

 with the body by two cocks ; the larger of which (the 

 centre one) has a pipe running down to very near the 

 bottom, so that when the gas holder is but partly filled with 

 gas, none cnn possibly escape by this cock. The other 

 cock, which is between the cistern and body, merely con- 

 nects the two vessels, and if left open the gas would rapidly 

 escape through it. Another cock is attached near the top, 

 on the side of the body, to draw off the gas when wanted for 

 use, and near the bottom is a short thick tube, to which is 

 fitted a cork or screw. To use the gas holder : tighten the 

 screw on the end of the short tube at bottom, then open all 

 three cocks at top, and fill the whole with water, by pour- 

 ing a requisite quantity into the cistern. Now close all 

 three of the upper cocks, and open the screw at the bottom. 

 The water within will not flow out, although this hole is 

 open. Into this hole the beak of the retort is to be fixed, 

 as the gas rises from it the water will pour out below. The 

 quantity which may be contained in the gas holder from 



