CONSTITUTION OF MIXED GASES. g| 



the martial parte of fulphur, the fpecific gravity, drawn from 

 his experiment, was certainly to be preferred in my calcula- 

 tion to any other. This refiduum was called by me azote, 

 probably becaufe Mr. Kirwan called it phlogifiicated air : 

 but it was evidently confidered as a compound in the etTar 

 alluded to by Mr. Dalton ; and certainly the advocate for a 

 multiplicity of co-exiftent atmofpheres will not controvert the 

 fuppofition. The remaining objections made by my opponent to 

 the paper in queftion, are levelled at my ignorance, not at 

 my conclufions ; they (hail therefore be. paffed over in filence. 

 In the mean time, Mr. D. perhaps will not take it amifs if I 

 requeft him to repeat his calculations with the fpecific gravity 

 of ovigenous gas when properly corrected, and to try what 

 will be the variation of the eudiometer, either on the data of 

 Mr. Davy or M. Lavoifier. 



Permit me, Mr. Nicholfon, to conclude this part of my A new inftra*. 

 fubjecl by obferving, that an inftrument of great ufe in P ne »- ^"J "j 00 " 1 * 

 matics might be conftrucled on the principles of your hy dro- 

 it atic weighing machine. The body of it fhould be of glafs, 

 furnithed with proper floppies and flop-cocks, fo that it might 

 beeafdy exhaufted and replenifhed. The preceding is but an 

 imperfect fketch of an inftrument, the mechanifm of which I 

 refign to your pen and pencil, fhould the idea appear worth 

 purfuing. 



Mr. Dallon's tinctures on my lad letter afcribe to me very A mifreprefen- 

 fingular opinions; but he neglects to point out the paragraph ^!° n pointc<l1 

 where the grounds of this charge maybe found; a charge 

 which infinuates, that, according to my notions of things, a 

 veffel containing a cubic foot of one gas cannot receive an 

 equal bulk of a different kind : Here indeed he accufes me 

 of grofs ignorance ; for there are but few who do not know 

 that fermenting liquors increafe the denfity of the gafes, which 

 occupy part of the clofe veffels containing them. In reality, 

 the charge is fo perfectly groundlefs, that, had it been made 

 by almoft any other perfon, I would not have hefitated to have 

 pronounced my accufer guilty of mifreprefentation to conceal 

 his want of argument, and to fecure the prejudices of the 

 fuperficial reader in his own favour. He may court the ad- 

 miration of fuch ; I do not defire their applaufes. 



Mr. Dalton fpeaks with confidence of what he calls his im- Mr.D.'s impor- 

 por.tant argument, i, e. his affertion, that equal quantities of ^nt argument 



vapour all. 



