MisceUanies. 365 



afterward with nitric acid, (to remove a portion of peroxide of mer- 

 cury which was deposited,) washing, drying and weighing, I obtained 

 19 grains sulphate of baryta. Now 19 grains sulphate of baryta con- 

 tain 6.44 grs. sulphuric acid, and the white powder submitted to 

 experiment consisted of sulphuric acid, 6. 44 grs. ■\- peroxide of 

 mercury, 23.56 grs. =30 grs. We have, therefore, the proportion 



23.56 : 6.44: :216 : 59.04 

 where 216 represents the atom of peroxide of mercury, and 59.04 

 the quantity of sulphuric acid that would combine with it to produce 

 the compound under examination. If the numbers I obtained had 

 been 6.48 and 23.52, the proportion would have been 



23.52 : 6.48: :216 : 60 

 and the last term would precisely represent 1 J atom of sulphuric 

 acid. The hastiness of my experiment would account for a much 

 greater discrepancy. 



This sesqui sulphate has no very interesting properties. It ap- 

 pears to be insoluble, but is easily decomposed even by cold water. 



It is usually said that the action of water upon the white bi-per- 

 sulphate of mercury consists in the resolution of it into the yellow, 

 insoluble, neutral sulphate, and a soluble super-sulphate. Yet, upon 

 evaporating the liquid thus obtained, I observed the deposition of a 

 white substance resembling, in its external characters, the bi-per-sul- 

 phate ; while the supernatant liquid had those of free sulphuric acid. 



I decomposed 37 grs. of the bi-sulphate by adding hot water to it ; 

 there resulted 29.75 grs. of turpeth mineral, whence 7.25 grs. (or 

 about \ of the whole,) must have been dissolved. These 29.75 

 grs. of the yellow sulphate contain, acid, 4.654- peroxide mercury 

 25.10; and since 37 grs. of bi-sulphate of mercury, consist of acid, 

 10-{- peroxide of mercury 27, the solution must contain acid (10 — 

 4.65 = ) 5.35 grs. + peroxide (27 — 25.10=) 1.9 gr. Wherefore, 

 if these bodies be united to form a super-sulphate of mercury, it 

 must be the inconceivable one of 15^ atoms of acid -\- 1 atom of base ! 

 That these theoretical quantities actually exist in the solution, I as- 

 certained by experiment. Is it not probable, that when water acts 

 on the bi-per-sulphate of mercury, a small portion of the salt is dis- 

 solved while the rest loses just half its acid ? 



