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X. Chemical Expcrimcvts on Mercury. By Messrs, 

 Braamcamp and SiauEiRA-OLiVA, of Portitgai*. 



J. HESE experiments have for llicir objects: l.To ascertain 

 the action of pho,sj<horous acid, of phosphites, and of phos- 

 phorus, on the oxides and salts of mercury : 2. The analy- 

 sis of some mercurial salts, by means of phosphorous acid : 

 3. To ascertain the action uf hyperoxygenated muriatic 

 acid on red oxide of mercury, 



1 . Of the Action of Phosphorous Acid upon the Oxides of 

 Mercury. 



Having placed 10 grammes of red oxide in contact with 

 phosphorous acid a little concentrated, the colour of the 

 oxide was ch'anged into a gray. On boiling this mixture, 

 we saw, in a few instants, runinua; globules appear, which 

 led us to suppose that the phosphorous acid had passed into 

 the state of phosphoric acid, by con)bining with the oxy- 

 gen of the oxide of mercury ; and also that perhaps the 

 phosphoric acid, as it formed, had dissolved some portion 

 of the oxide of mercury. To ascertain this point, 'we fil- 

 tered and treated the liquor by sulphurized hydrogen : to 

 our great astonishment, this reagent afforded but extremely 

 slight indications of the presence of mercury. The resi- 

 duum that remained on the filter, after having been well 

 washed and dried, gave us nine grammes of mercury. 

 Hence we concluded that the red oxide of mercury contains 

 nearly ten per cent, of its weight of oxygen. 



The result of this experiment points out new means for 

 analysing the oxides of mercury, which appear to us pre- 

 ferable to sublimation, which is less expeditious, and is at- 

 tended, besides, with the inconvenience of not giving ac- 

 curately the quantity of mercury reduced to the metallic 

 state, either because bv accident if may be volatilized, or 

 adhere so closely to the vessels employed in the operation 

 that the whole cannot be detached. 



We hoped also to be able, by means of this acid, to ana- 

 lyse the salts of mercury, by adding to theni potash to de- 

 compose them at the same time that thephosphoric acid 

 should reduce the axide into running mercury ; but the re- 

 sults were not sstisfactorv. Having tried, this process on 

 10 grammes of oxi-muriate of mercury, we obtained only 

 66 of running mercury, instead of 73, which we ought to 



• From Aimales de Chimic, vol. }iv. 



have 



