"Experiments on Charcoal. 155 



cock A, and open the two cocks 1 and 2, and the gas will 

 aicend into the receiver, while the water will take its place in 

 the gas-holder. The jubilances to be experimented upon 

 ihould be mounted with wires patting through corks covered, 

 with wetted leather, like the watch-fpring S, or the defla- 

 grating pan D, in which the mbftances intended to be ex- 

 pofed to the action of the gas mutt be ignited. 



It is not here neccflary to enter into a particular account 

 of each procels, as they are in general well known even to 

 the young experimentalift. It may be neceflary, however,- 

 to add as a caution — that, after the deflagration, the gas-holder, 

 and receiver mould be removed into an open place or under 

 the chimney, that the acid gas, or any other injurious air, 

 may be fufficiently changed before the receiver is again ex- 

 baufted by the mouth. 



When the blowpipe is ufed it mould with its elaftic pipe 

 be fcrewed on to the cock Ck; the ciftern mould be kept 

 full by reverfmg a large receiver of water over it, or any other 

 fimple method, and the cock 2, only opened for the admiffion 

 of water. 



Bladders mounted with cocks may be filled with gas by 

 firft emptying them of atmofpheric air, then fcrcwing them 

 to the cock Ck, filling the ciftern with water, and opening 

 the cock 2. In all thefe inftances the quantity ufed may be 

 afcertained from the regifter, which has a fcale of pints or 

 cubic inches attached to it. 



The numerous experiments in which the gafes, particularly 

 oxygen, are ufed, will, I conceive, be a fufficient apology for 

 troubling the readers of your valuable and interefting Maga- 

 zine with this trifle, which I have really found ufeful in the 

 laboratory. 



XXVII. 'Experiments on Charcoal. By Clement and 



Desormes. 



[Concluded from p. 73.] 

 SECOND METHOD. 



Acllon of the Sulphur. 



H 



AD we begun our labour as we have related, we mould 

 probably have been fatisfied with the proofs before efiablifhed^ 

 that there exifts no hydrogen in charcoal ; and we mould 

 not have had recourfe to the acliofl. of fulphur. But an ex- 

 periment having made known to^is a .particular combination 

 of charcoal and fulphur, wc refolvcd to continue our labours'. 



We 



