22 INQUIRIES RESPECTING FLUORIC ACID. 



A nonconduc- The mass did not conduct electricity, and none of its 

 parts could be separated, so as to examine as to this pro- 

 perty. 



Action on wa- When a portion of it was thrown into water, it effer- 

 vesced violently, and the gas evolved had some resem- 

 blance in smell to phosphuretted hidrogen, and was inflam- 

 mable. 



Heated in con- When a part of the mass was heated in contact with air, 

 tact with air, . , , , '. . 



it burnt slowly, lost its brown colour, and became a white 



saline mass. 

 and in ox:gen. When heated in oxigen gas in a retort of plate glass, it 

 absorbed a portion of oxigen, but burnt with difficulty, and 

 required to be heated nearly to redness ; and the light gi- 

 ven out was similar to that produced by the combustion of 

 liver of sulphur. 



Examination The water which had acted upon a portion of it was exa- 

 of the water, . . 



mined; a number of chocolate coloured particles floated in 



it. When the. solid matter was separated by the filter, the 

 fluid was found to contain fluate of potash, and potash, 

 and of the re- The solid residuum was heated in a small glass retort in oxi- 

 siduura. g en g as . j t burnt before it had attained a red heat, and be- 



came white. In this process oxigen was absorbed, and acid 

 matter produced. The remainder possessed the properties 

 of the substance formed from fluoric acid gas holding sili- 

 ceous earth in solution, by the action of water. 

 Experiments In experiments made upon the combustion of quantities 

 tHi^not^de- 11 " °^ P otass ' um equal to from six to eleven grains, the portion 

 eisive as to the of matter separable from the water has amounted to a very 

 pure basis. sma |] p ar t of a grain only ; and operating upon so minute a 

 scale; I have not been able to gain fully decided evidence, 

 that the inflammable part of it is the pure basis of the fluo- 

 ric acid; but with respect to the decomposition of this body 

 by potassium, and the existence of its basis at leas! combin- 

 ed with a smaller proportion of oxigen in the solid product 

 generated, and the regeneration of the acid by the ignition 

 of the product in oxigen gas, it is scarcely possible to en- 

 tertain a doubt. 

 D«coTipo'ition The decomposition of the fluoric aeid by potassium seems 



ofthf fi ''" ric analogous to that of the acids of sulphur and phosphorus, 

 acid an ilogous " . J . r r 



to that ox the In neither of these cases is the pure basis, or even the basis 



in 



