ON MIXED GASES. 269 



XIII. 



Obfervations on Mr. Gough's tvoo Letters on Mixed Gajcs,^ 



To Mr. NICHOLSON. 

 SIR, 



iVjiY reply to Mr. Gough's ftri6lures being chargeable, it lntrodu£lIo«« 

 feems, with acrimony and ridicule, and with having but few 

 arguments, and thofe in appearance negligently conduced, 

 (though the laft charge requires a whole letter to make it 

 good) ; I propofe, in what follows, to avoid the two former 

 of thefe as much as may be, and to be as careful as poflible in 

 conducting my arguments ; fo, that if they appear to Mr. G. 

 deftitute of that logical precifion which charaderifes his, he 

 may afcribe it to ray inability, and not to any want of iacli- 

 nation. 



The accuracy of Mr. G.'s demonftration in the former let- Obfervations on 

 ter, depends upon that of three phyfical data : IJl, The fpe- J^t'tefo^ mixed 

 cific gravity of azotic gas ; 2d, The fpecific gravity of oxi- gaffes, 

 genous gas ; and, Sd, The quantity of oxigen in a given vo- 

 lume of atmofpheric air. If any one of thefe be wrong, it 

 may prove fatal to his demon ftration : now it unfortunately 

 happens that all three are wrong, and that, when corrected, 

 they prove the very reverfe of his propofition ; namely, that 

 atmofpherical air is a mechanical mixture of oxigenous and 

 azotic gafes. 



Mr. G.'s data are, 



Sp. gravity of azotic gas, .985 



oxigenous gas, 1,103 



Quant, of oxigen in atmo- 



fphere, per cent, in bulk, 22-25-28, uncertain which. 

 The true, or at leaft the moft approximate numbers, are, 

 Sp. gravity of azotic gas, - ,966 



oxigenous gas, 1 . 1 27 



Quant, of oxig. in atmofphere, 

 j^er cc«^ in bulk, - - 21 



Then, per Mr. G.'s theorem, 21 x 1,127 = 23.667 

 and 79 X .966 = 76.314 



99.981 

 • Seepages 107, 160, of the prefcnt Vol. 



The 



