VOL. XXXIX.3 PHILOSOPHICAL TRANSACTIONS. fj 



A Chemical Experiment, serving to illustrate the Phenomenon of the Inflammable 

 Air shown by Sir James Lowther, Bart, as described in Phil. Trans. N" 429. 

 Bi/ Mr. John Maud. N° 442, p. 282. 



Sir James Lowther made an experiment on some air which he collected 

 out of a coal-mine, and brought in bladders, close tied, by sea to town; the 

 effects of which was, that the air being pressed out of the bladder through 

 the small orifice of a tobacco-pipe, would catch fire from a lighted candle, and 

 burn like an inflammable spirit, till it was all consumed. 



On considering that the cause was only a great quantity of sulphureous 

 vapours fluctuating in that air, Mr. M. was naturally induced to make an essay, 

 by an artificial mixture, to produce the like eflfect. It is very well known (he 

 observes) to every one versed in chemical affairs, that most metals emit great 

 quantities of sulphureous vapours, during the effervescence they undergo, in 

 their solutions in their respective menstrua, or solvents. Of these fumes, iron 

 emits a great quantity while it is dissolving in oil of vitriol, which are very in- . 

 flammable, and not easily to be condensed. These fumes Mr. Maud collected 

 into a bladder with the desired success, and having produced before the Royal 

 Society two bladders of this fictitious air, at the same time that Sir James 

 Lowther made trial of his, they both exhibited the same phasnomena. A par 

 ticular account of the preparation made use of is as follows. 



Mr. Maud took jij of oil of vitriol, and mixed it with jviij of common 

 water, which he put into a glass with a flat bottom, about 10 inches wide, and 

 3 deep, with a long neck ; to this he added jij of iron filings : there instantly 

 arose a great heat, with a violent ebullition, and the iron was wrought upon 

 very fast, with a copious exhalation of fumes. To the end of the neck of the 

 glass he luted a bladder, void of air, the neck of the bladder being fastened to 

 a tobacco-pipe ; the fumes arising from the dissolving metal soon puffed up the 

 bladder to its full extent, when that being taken away, the neck of it being first 

 tied close with a string, he applied another in the same manner : thus may be 

 got as many bladders full as you please, while the effervescence lasts. Two of 

 these bladders were tried before the Society, and exhibited a flame like those of 

 Sir James Lowther's, very like in the smell, though somewhat different in the 

 colour of the flame. After Mr. M. had pressed part of the air out of the blad- 

 der, by drawing back the hand, the flame was sucked into the bladder, which 

 set on fire what inflammable air remained all at once, and went off like a gun, 

 with a great explosion. 



It is worthy of notice in this experiment, that all the air which filled the 



