Prof. Sclioenbein on the Discoveiy ()f Gun-CoUon. 9 



acid mixture, rapidly absorbs oxygen, when exposed to a low 

 temperature; and there is formed, besides iodic acid, the 

 compounds to which Millon has lately drawn attention. After 

 the reaction a li(|uid remains, which, diluted with water, gives 

 an abundant disengagement of deutoxide of nitrogen and 

 liberates iodine. 



My experiments on ozone having shown that this body, 

 whicfi I consider to be a distinct peroxide of hydrogen, forms, 

 as well as chlorine, at the ordinary temperature, a peculiar 

 compound with olefiant gas, without apparently oxidizing in 

 the least either the hydrogen or the carbon of this gas, I had 

 the idea that it would not be impossible that certain organic 

 matters, exposed to a low temperature, would likewise form 

 compounds, either with the peroxide of hydrogen alone, which, 

 on my hypothesis, occurs in a state of combination or of mix- 

 ture in the acid mixture, or with NO4. It was this conjecture, 

 doubtless very singular in the eyes of chemists, which princi- 

 pally led me to commence experiments with common sugar. 



I made a mixture of one part (volume) of nitric acid, of 1*5 

 spec, grav., and two parts of sulphuric acid of 1'85, at the 

 temperature of 36° F. ; I then added some finely powdered 

 sugar, so as to form a very fluid paste. I stirred the whole, and, 

 at the end of a few minutes, the saccharine substance formed 

 itself into a viscous mass entirely separated from the acid 

 liquid, without any disengagement of gas. This pasty mass 

 was washed with boiling water, until this last no longer exer- 

 cised any acid reaction ; after which I deprived it, as much as 

 possible, at a low temperature, of the water it still contained. 

 The substance now possessed the following properties: — Ex- 

 posed to a low temperature, it is compact and brittle ; at a 

 moderate temperature, it may be moulded like jalap resin, 

 which gives it a beautiful silky lustre. It is semi-fluid at the 

 temperature of boiling water ; at a higher temperature, it 

 gives off red vapours ; heated still more, it suddenly defla- 

 grates with violence, without leaving any perceptible residue. 

 It is almost insipid and colourless, transparent like the resins, 

 almost insoluble in water, but easily soluble in the essential 

 oils, in aether and concentrated nitric acid, and in most cases 

 it acts in general like the resins in a chemical and physical 

 point of view : thus friction renders it very electro-negative. 

 I will add, that the acid mixture, by means of which this resi- 

 nous body was obtained, has an extremely marked bitter taste. 



I wished to make experiments also with other organic sub- 

 stances ; and I soon discovered, one after another, all those 

 about which there has been so much said of late, especially in 

 the Academy of Paris. All this passed in December 1845, 



