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LXXXVI. Intelligence and Miscellaneous Articles. 



ON CHLOROAZOTIC ACID. 



M BAUDRIMONT remarks, that Mr. Edmund Davy published 

 • his researches on aqua regia in 1831, and concluded from 

 them, that what he terms chloronitrous acid is composed of equal 

 volumes of chlorine and nitric oxide gases, which combine without 

 alteration of volume. 



According to M. Baudrimont, the presence of [uncombined] 

 chlorine in the product obtained by Mr. Davy prevented the product 

 from being properly examined, and he therefore undertook fresh re- 

 searches on the subject. 



In order to prepare the active product [chloroazotic acid] of aqua 

 regia, M. Baudrimont mixed three parts, by weight, of nitric acid, 

 of specific gravity about 1'3 14, with five parts of hydrochloric acid, 

 of specific gravity 1*156; this mixture yields a colourless liquid, 

 which after an uncertain time becomes red, according to the tempe- 

 rature of the air and the intensity of the light to which it is exposed. 

 If, however, the mixture be heated, it becomes red at about 187° 

 Fahr., and yields vapour of the same colour ; the temperature gra- 

 dually increases to nearly 230° Fahr., and then remains so invariably 

 during the whole time of the operation. 



If the product of the distillation be received in a vessel properly 

 cooled, a red liquid is obtained ; but if the neck of the retort be 

 simply passed into a receiver, a red vapour is formed which does 

 not condense, and a colourless liquid is condensed. 



This experiment shows that this distillation yields two distinct 

 products — a red vapour which is very volatile, and a colourless pro- 

 duct which is more fixed. It shows also that the temperature of 

 230° Fahr. does not indicate a boiling-point, but a fixed point of 

 decomposition. By adopting the requisite arrangements, the red 

 vapour may be condensed in tubes in the state of a red liquid, which 

 boils at a very low temperature ; it can be preserved only in tubes 

 hermetically sealed. This is what the author terms chloroazotic 

 acid ; the properties of which are as follows : — 



At a sufficiently low temperature it is a red limpid liquid, sur- 

 mounted with vapour of the same colour ; its boiling-point is about 

 20° Fahr. ; from this it follows that it is gaseous at ordinaiy tem- 

 peratures. In the state of gas it is red, and possesses a suffocating 

 odour, analogous to that of chlorine, but still differs considerably 

 from it. 



The extreme volatility of chloroazotic acid presented almost in- 

 surmountable difficulties to the determination of its principal pro- 

 perties. 



The elements of chloroazotic acid reduced to volumes, and the 

 volumes multiplied by the corresponding specific gravities, give the 

 following results : — 



2 P2 



