ON THE COMPOUNDS OF SULPHUR AND OXYGEN. 93 



The firft of thefe is fuppofed to contain a minimum, the third 

 a maximum of oxygen. Of thefe three the conRituents of 

 the laft only have been afcertained with precifion. It will be 

 proper to begin with it, as the knowledge of its compofition 

 may be of fervice in afcertaining the conftituents of the reft. 



I. Of Sulphuric Acid, 



This acid has been lately analyfed with precillon by Sulphuric acid, 

 Thenard and Chenevix. I have repeated their experiments ^^|"J[[j^^^^°'' ^* 

 with care, and have obtained for the mean refult 39 per cent, ©xygen. 

 of oxygen, which is only one half per cent, greater than the 

 refult obtained by Mr. Chenevix. This difference in the pre- 

 fent ftate of analyfis may be accounted altogether infignificant. 

 I ftiall confider fulphuric acid, then, as compofed of 



61 fulphur 



39 oxygen 



100 



II. Of Sulphurous Acid. 



Moft of the properties of this Acid have been long known Sulphurous acid. 

 to chemifts ; but no experiments have been made to afcertain 

 the proportion of its component parts. Before I proceed to 

 relate the refult of mine, it may be worth while to defcribe a 

 few of the properties of Sulphurous Acid, which have not hi- 

 therto been flaled with precifion, 



1. Fifty-three rqeafures of fulphurous acid gas were intro- Waterateo'ab- 

 duced into a graduated tube ftanding over mercury, and one i "rh^ °t"% 

 meafure of water was thrown up. In five minutes 20 mea- its weight of fuU 

 fares of gas were abforbed, and in 24- hours the abforption?*^"'""^ S^'' 

 amounted to 33 meafiires. No farther abforption took place 

 in three days more ; but on introducing the tube into water, 

 the whole gas difappeared, except a fmall globule, which did 

 not exceed 1-lOth of a meafure. During this experiment the 

 thermometer at the time of obfervation deviated very little 

 from 61°, and the barometer ofcillated from 29.55 to 29,77. 

 Water then, at the temperature of 61'', abforbs 33 times its 

 bulk of this gas. Now, if with Lavofier, we fuppofe a cubic 

 inch of gas to weigh 0.63 grs. a cubic inch of water will ab- 

 forb 19.79 grains of fulphurous acid, and 100 parts of water 

 will abforb 8.21 parts by weight. ^ 



' 2;. A current 



