176 



mena of combustion, while the silicon was deposited or left in combi- 

 nation with potassium and its fluoride. 



Lately he had resorted with success to a much simpler process, by 

 which the evolution of silicon or boron might be made easy to any 

 person possessing a sufficiently large mercurial reservoir. 



A bell glass, over mercury, was filled with fluo-silicic acid, and by 

 means of a bent wire, a cage of wire gauze, containing a suitable 

 quantity of potassium, was introduced through the mercury into the 

 cavity of the bell, and supported in a position nearly in the centre of it. 

 A knob of iron was made at the end of the rod, so recurved as 

 to reach the cage with ease. The knob, having been heated nearly 

 white hot, was passed through the mercury, so as to touch the cage, 

 and cause the combustion of the potassium and evolution of the silicon. 

 Of this, much remains attached to the cage, in combination with the 

 fluoride of potassium, from which the silicon may be separated by wash- 

 ing in cold water and digestion in nitric acid. 



Dr. Hare exhibited a specimen of the silicon obtained by the 

 means above described, weighing seventeen grains. 



Dr. Hare made some observations on certain products from 

 the formation of hyponitrous or nitric ether, and its decompo- 

 sition by various agents, one of which he exhibited to the 

 Society. 



This was an extremely acrid liquid, obtained from the last ethereal 

 products of the distillation of hyponitrite of soda, with equivalent 

 measures of alcohol, sulphuric acid and water. The products thus 

 procured, being agitated with green sulphate of iron, until no further 

 portion was absorbed, the aggregate was washed with hydric ether. 

 The resulting ethereal solution, being separated by a funnel and the 

 finger, was subjected to the air in an open vessel. The hydric ether 

 soon evaporating, the residue was the acrid liquid in question, which 

 might be inferred to be a peculiar ether. Its boiling point did not ap- 

 pear to be inferior to that of water. It was soluble in ether and 

 alcohol, but insoluble in water. Caustic potash appeared to cause its 

 decomposition. 



As Dr. Hare had elsewhere stated, the effects of this liquid upon 

 the organs of taste and smell, resembled those of mustard or horse- 

 radish: upon the eyes its influence was equally distressing. Dr. 

 Hare believed this acrid principle might always be generated at the 

 close of the process for obtaining sweet spirits of nitre by distilling 



