ArTIcLeE IV. 
Action of Sulphurous Acid on Hyponitric Acid (peroxide of nitro- 
gen) ; crystals of the leaden chamber ; theory of the formation 
of Sulphuric Acid. By M. F. Dexa Provostaye, Professor 
in the College of Louis-le-Grand*. 
[From the Annales de Chimie et de Physique, t. 73. 
NotwitTHsTANDIN G the numerous investigations which 
have been made to elucidate the theory of the formation of sul- 
phuric acid, chemists are by no means agreed respecting it. The 
principal difficulty appearing to exist in the study of the interme- 
diate products, these have been made the subject of a special 
examination by MM. Clement and Desormes, by Gay-Lussac, 
Henry, Berzelius, Bussy, and Gaultier de Claubryt. The same 
products form likewise the subject of the present memoir. It 
will therefore be necessary to revert briefly to the results of 
anterior researches ; results, some of which are incontrovertibly 
established, and others which are not altogether satisfactory. 
At the time of publication of the memoir of MM. Clement and 
Desormes{, the combinations of oxygen with nitrogen were im- 
perfectly known. The importance of their function in the 
formation of sulphuric acid was amply demonstrated by these 
chemists ; but they erred in regarding the crystalline compound 
which is produced in this case as composed of sulphuric acid 
and nitric oxide. When decomposed by a small quantity of 
water in an atmosphere of carbonic acid, it gave rise to red va- 
pours; a fact irreconcilable with that hypothesis. It is to 
Gay-Lussac that we are indebted for this important experiment 
(1816). That illustrious chemist arrived at the conclusion, that 
the crystals in question contained sulphuric acid, united to the 
acid existing in the nitrites. This conclusion was a necessary 
one; for at that time no other degree of oxidation of nitrogen, 
but nitrous acid, was known between nitric oxide and nitric acid. 
Further, this constituent of the crystals was considered identical 
* Translated by Mr. E. A. Parnell. 
_ t To these may be added a recent paper by Adolph Rose, on the Combina- 
tion of the Hydrate of Sulphuric Acid with Nitric Oxide, a translation of 
which appeared in the Philosophical Magazine for February, 1841, p.81.—Ep. 
$ Annales de Chimie, t. 59. 1805. 
VOL. III. PART IX. F 
