Analysis of the compound Inflammable Gases. 281 



have more than once experienced, with considerable danger 

 from the bursting of the glass tubes. It was desirable, there- 

 fore, to employ a process not liable to these objections ; and 

 after many alterations of the apparatus, contrived with this 

 view, I at length fixed upon one, which I shall now proceed 

 to describe. 



The principal parts of the apparatus are two glass cylinders, 

 or air receivers*, bb and oo (PI .VI.), of which the larger one 

 is intended to contain oxygen gas, and the smaller one, the 

 inflammable gas submitted to experiment. They are con- 

 nected by a bent glass tube s s, thediameter of which should 

 not be less than -j^ of an inch, to the upper extremity of 

 which is cemented an iron burner, t, the orifice of which 

 is about -J-q- of an inch, while to the lower end a socket is 

 fixed, on which may be occasionally screwed the cock r. 

 The receiver o o is contained in a larger glass jar n n, and is 

 closed at the top by a brass cap p, and stop cock q. The 

 oxygen gas receiver is, also, closed by a brass cap e and 

 cocky, the lower orifice of which is tapped internally, for 

 the purpose of receiving a small screw at the end of the 

 copper wire g. This wire is in two parts, each of which 

 ■screws into a moveable socket, connecting the two ; and, by 

 this contrivance, the wire may be lengthened or shortened, 

 at pleasure. To prepare the apparatus for use, the receiver 

 oo is partly filled with the combustible gas ; and is secured 

 by wedges of cork vv, in the jar nn, the level of the water 

 in the latter being regulated by opening the cock x or z. 

 The bent pipe ss, with its cock r, is screwed upon the top 

 of the receiver, and partly immersed in the water of a pneu- 

 matic cistern, aa, so that the orifice of the burner may rise 

 a few inches above the surface of the water. The receiver b k 

 detached from the situation in which it is represented in the 

 drawing, is then exhausted "by an air pump ; and, being 

 filled with oxygen gas, is transferred (its mouth being closed 

 during the act of removal with a piece of leather) to the 

 cistern c, and quickly inverted over the burner /. By a 



* I am indebted to Mr. H. Creighton, of Soho, not o»ly for a drawing of 

 the apparatus, but for much valuable assistance in the performance of the ex- 

 periments-. 



little 



