TRANSACTIONS OK THE SECTIONS.. 33 



CHEMISTRY. 



Extracts from a Letter addressed hy Dr. Hare, of Philadelphia, to the- 

 Chemical Section of the British Association for the Advancement of 

 Science. 



" Since July last, when I had the honour of addressing you through 

 your venerable and distinguished president Dr. Dalton, I have made 

 some additional observations and attained some farther results, of 

 which a brief notice may, I trust, be deemed worthy of attention. 



" I have, by improvements in my process for fusing platina, suc- 

 ceeded in reducing twenty-five ounces of that metal to a state so liquid, 

 that the containing cavity not being sufficiently capacious, about two 

 ounces overflowed it, leaving a mass of twenty three ounces. I repeat, 

 that I see no difficulty in extending the power of my apparatus to the 

 fusion of much larger masses. 



" When nitric acid (or sulphuric acid and a nitrate) is employed tO' 

 generate ether by reaction with alcohol, there must be an excess of 

 two atoms of oxygen for each atom of the hyponitrous acid which en- 

 ters into combination. This excess involves not only the consumption 

 of a large proportion of alcohol, but also gives rise to several acids and 

 to some volatile and acrid liquids. 



" It occurred to me, that for the production of pure hyponitrous 

 ether, a hyponitrite should be used. The result has fully realized my 

 expectations. 



" By subjecting hyponitrite of potash or soda to alcohol and diluted 

 sulphuric acid, I have obtained a species of ether which differs from 

 that usually known as nitrous, or nitric ether, in being sweeter to the 

 taste, more bland to the smell, and in being more volatile. It boils 

 below 65° F., and produces by its spontaneous evaporation a tempera- 

 ture of 15". On contact with the finger or tongue, it hisses as water 

 does with red-hot iron. After being made to boil, if allowed to stand 

 for some time at a temperature below its boiling point, ebullition may 

 be renewed in it apparently at a temperature lower than that at which 

 it had ceased. Possibly this apparent ebullition arises from the partial 

 resolution of the liquid into an aeriform etherial fluid, which escapes 

 both during the distillation of the liquid ether and after it has ceased, 

 even at a temperature below freezing. This aeriform product has been 

 found partially condensible by pressure into a yellow liquid, which 

 when allowed to escape into the mouth or nose, pi'oduced an impression 

 like that of the liquid ether. I conjecture that it consists of nitric ox- 

 ide, so directed to a portion of the liquid ether as to prevent the wonted 

 reaction of this gas with atmospheric oxygen. Hence it does not pro- 

 duce red fumes on being mingled with air. 



" Towards the close of the ordinary process for the evolution of 

 sweet spirits of nitre, a volatile acrid liquid is ci'eated, which affects 

 the eyes and nose like mustard or horse-radish. It is probable, however. 



