106 JOURNAL OF THE 



price of the ordinary apparatus is a serious objection to its use, 

 or where one is at a distance from the supply stores and hence 

 forced to make use of some substitute for the store- bought article. 

 The figure at the end of this Journal will show the form of 

 the ap|)aratus. B B are two tubes (about 8 x J inch) which can 

 easily be gotten in the form in the diagram by taking a single 

 tube of double the length mentioned, giving it the desired bend 

 and then scratching and breaking in the middle. A stout piece of 

 rubber tubing unites these at A. This tubing is by means of a 

 cork-borer perforated in the centre between the tubes B. Into 

 this opening a tube C is inserted, bent at right-angles at P and 

 with its end enlarged to prevent leaking. It is not necessary to 

 bend at right-angles for some kinds of supports, but the opening 

 in the rubber A may be directly on top and the tube C let right 

 into it. D is a funnel with stop-cock fastened to C by the rub- 

 ber connection A. Into the tubes B wires F F (best of plati- 

 num, with flattened ends, though copper will answer) are placed, 

 reaching nearly to the bend and coming out under the rubber 

 connections O O, passing a short way down the outside, wound 

 round the tube two or three times and ending in loops to which 

 the battery wires may be attached. The tubes B B are connected 

 with jet pieces by means of rubber tubing, and can be tightly closed 

 by pinch-cocks. All rubber connections must be tightly wound 

 with w ire to prevent leakage. The gases produced can be exam- 

 ined at the jets, or a delivery tube attached, running under a 

 test-tube which is placed in a pneumatic trough. As a support 

 the ordinary iron retort-stand may be used, fastening the tubes 

 with wnres. It is better, however, to have a board, blackened or 

 covered with black paper, and nailed to a block so as to stand 

 upright. The tubes B B can be fastened to this by wires going 

 through gimlet-holes. The funnel D can rest in a hole or slit 

 cut in a thin strip tacked across the top of the board. 



