934 Mr, Scanlan on the irtcidental Formation of the [Nov , 



Article II. 



Incidental Formation of the Compound of Hyponitrous and Snl' 

 phuric Acids, lately examined by Dr, Henri/. By Mr. Scanlan. 



(To the Editors of the Annals of Fhilosophy.) 



GENTLEMEN, Laboratory^ Shaw-street, Sept. 16, 1826. 



A FEW days since, while preparing nitric acid, from one atom 

 nitre, and two atoms oil of vitriol, sp. gr. 1*812, a compound 

 was formed, which I believe to be the same as that found in 

 the Manchester vitriol chamber, and examined by Dr. Henry. 



The distillation was performed in a cast-iron pot, with a stone- 

 ware head and connecting pipe, to which was adapted a glass 

 receiver. When about nine-tenths of the acid had distilled over 

 in a continuous stream,* the receiver was changed ; it now began 

 to drop very slowly, and was quite green ;t the fire was then 

 urged, and suddenly the receiver became lined with a white 

 substance, which, at first, I mistook for the boiling over of the 

 fused bisulphate of potash — an accident which has more than 

 once occurred with me ; but on examining more closely, I found 

 the substance to be translucent and crystaUine, resembling ice, 

 as it forms on the pane of a window, and I observed, when it 

 came in contact with the liquid acid, it effervesced violently, and 

 the acid did not become muddy. 



Although I could not collect enough of, the substance to 

 prove its identity with that described by Dr. Henry, yet, I think, 

 there is little doubt that they are the same. A small portion 

 crystallized in the bent tube, connecting the receiver with a 

 Woulfe's bottle ; when distilled water was introduced into this 

 tube, nitrous gas was evolved, the instant the water came in 

 contact with the substance, with brisk eflfervescence, first 

 becoming blue-green at the point of contact; and the resulting 

 solution, which was transparent and colourless, abundantly pre- 

 cipitated solution of nitrate of barytes. 



I conceive that the production of this compound, in the pre- 

 sent instance, can only be accounted for, by supposing that 

 when the nitric acid had distilled over, the atom of sulphuric 

 acid, constituting a bisulphate, began to act upon the iron, pro- 

 ducing sulphurous acid gas, which, coming in contact with 

 nitrous acid, in the atmosphere of the apparatus, gave rise to 

 this substance. The production of sulphurous acid gas would 

 also account for the boiling over before-mentioned ; for I find 

 bisulphate of potash to fuse quietly in a glass retort, and to bear 



• Sp.gr. 1*455 did not disturb solution of nitrate of barytes. 

 -)- Sp.gr. 1*237 contained a good deal of sulphuric acid. 



