MEBCURY SULPHITES AND OXYGENOUS SALTS. 103 



Here it will be seen that in the sulphonate, the ethyl is directly united 

 to the sulphur, and the potassium only by the intervention of an atom 

 of oxygen. Whether these sulphonates are true organic sulphites, and 

 whether, therefore, inorganic sulphites are similarly constituted, or 

 have their base wholly in oxylic union, has long been uncertain, 

 although now the opinion most generally held is that sulphites have 

 half- their metal directly united to sulphur, thus, Mg^-^SO^-, and not, 

 Mg=02=S0. This opinion has been based, however, wholly upon 

 evidence afforded by organic bodies, and it seemed to us desirable that 

 evidence from the inorganic sulphites themselves should be sought for, 

 by examining the mercury, silver, and copper sulphites. Hence, the 

 reason of our working upon mercury sulphites. We have also done a 

 little upon silver sulphite, already pretty well known, but have not yet 

 examined copper sulphites. 



Mercury sulphites, we found, had been but very imperfectly 

 studied. Several had been described, but we were soon convinced 

 that of these only one really existed. To this, however, we succeeded 

 in adding two new ones in the separate state, besides one which we 

 only got in dilute aqueous solution. Yet after all, most remarkable to 

 state, we could get neither the normal mercuric sulphite, Hg SO3, nor 

 the mercurous sulphite, Hg.2 SO3, but only a basic salt ; an acid salt ; a 

 mixed salt, partly mercurous, partly mercuric; and another mixed salt, 

 partly hypomercurous, partly mercuric. Besides these, there are 

 double sulphites, one of which, sodium mercuric sulphite, we have 

 examined more fully than had been done before. 



The evidence afforded by the mercury sulphites, and by silver 

 sulphite, as to the constitution of sulphites, proved even greater than 

 we had expected. They are not decomposed by dilute nitric or sul- 

 phuric acid, and in this they resemble the chlorides and cyanides of 

 these metals, instead of their oxygen, (or rather oxylic), salts, while in 



