ON FLUOR 



SECTION V. EFFECTS OF ACIDS ON FLUOR. 



I poured 2 oz. of concentrated vitriolic acid upon 

 the same quantity of fluor, which had been previously 

 powdered in a glass mortar, and then put into a retort, to 

 which a receiver was adapted, and the juncture well closed 

 with grey blotting paper. A gentle fire was then applied ; 

 the mass began immediately to effervesce and swell ; invisible 

 vapours penetrated everywhere through the joining of the 

 vessels ; and, towards the end of the process, white vapours 

 rose, and formed a white matter on the whole internal 

 surface of the receiver. The lute was so much corroded as 

 to be quite friable between the fingers, but its colour was 

 unchanged. The mass remaining in the retort was as hard 

 as stone, and could not be taken out without breaking the 

 vessel. 



SECTION VI. 



The process (Sec. v.) was repeated exactly in the same 

 manner, excepting only that a quantity of distilled water 

 was put into the receiver before the operation. When the 

 mass began to grow warm and to swell, a vapour rose, 

 which was condensed upon the surface of the water in the 

 receiver, and formed just in the centre of it, immediately 

 under the mouth of the retort, a white round spot. This 

 spot continually increased till it at last occupied the whole 

 surface of the water, forming a pretty thick crust, which 

 prevented the communication of the water with the new 

 vapours that came over ; I therefore gently agitated the 

 receiver, upon which this crust burst and fell to the bottom, 

 and soon after a new crust like the former was produced. 



