ON THE 'NATURE OF CERTAIN EOD1ES. ]Q^ 



On fluoric acid gas no such effect was occasioned. This ^ ut not f rcm 

 fact, at first view, might be supposed to show that the hi- fluoric acid 

 drogen evolved by the action of potassium upon fluoric acid 

 gas is owing to water in actual combination with it, like 

 that in muriatic acid gas, and which may be essential to its 

 elastic state ; but it is more probable, from the smallness of 

 the quantity, and from the difference of the quantity in dif- 

 ferent cases, that the moisture is merely in that state of dif- 

 fusion or solution in which it exists in gasses in general; 

 though from the disposition of water to be deposited in this 

 acid gas in the form of an acid solution, it must be either 

 less in quantity, or in a less free state, so as to require for 

 its exhibition much mo e delicate hygrometnca! tests. 



The facts advanced in this Lecture afford no new argu- No farther 

 ments in favour of an idea, to which I referred in my last P r0 °* of hldm " 

 communication to the Society, that of hidrogen being a common prin- 

 common principle in all inflammable bodies; and except cl P' e °f lnflam- 

 in instances which are still under investigation, and concern- 

 ing which no precise conclusions can as yet be drawn, the 

 generalization of Lavoisier happily applies to the explana- 

 tion of all the new phenomena. 



In proportion as progress is made towards the knowledge Sulpliurand 

 of pure combustible bases, so in proportion is the number of P llos P' 10r u s 

 me ;.l lie substances increased; and it is probable, that sulphur tain metallic 

 and phosphorus, could they be perfectly deprived of oxi- bast;s ' 

 gen, would belong to this class of bodies. Possibly their 

 pure elementary matter may be procured by distillation, at 

 a high heat, from metallic alloys, in which they have been 

 acted upon by sodium or potassium. I hope soon to be able 

 to try this experiment. 



As our inquiries at present stand, the great general divi- Perhaps allbe- 



sion of natural bodies is into matter which is, or may be dus ' exce P t 



,1 ii- i • i -.i i ,i oxigen metal- 



supposed to be, metallic, and oxigen ; but till the problem ] 1C . 



concerning the nature of nitrogen is fully solved, all syte- 



matic arrangements made upon this idea must be regarded 



as premature. 



IV. 



