374 ON THE DECOMPOSITION OP THE ^|pTl». 



boiling, through a jmall orifice in the end corresponding ta 



the receiver, which was hermetically sealed when the tube 



contained nothing but the rapour of naphtha, and the 



amalgam. 



Part of the I found immediately, that the mercury rose pure by dis- 



mercury easily tillation from the amalgam, and it was very easy to separate 



distilled off, . r-. 1- .. i-x- , ; ... 



a part of it; but to obtain a complete decomposition was 



very difficult, 

 but the whole ^^"^ ^^^^ nearly a red heat was required, and at a red heat 

 oply with great the bases of the earths instantly acted upon the glass, and 

 '^^ ^' became oxigenated. When the tube was large in proportion 



to the quantity of amalgam, the vapour of the naphtha fur- 

 nished oxigen sufficient to destroy part of the bases : and 

 when a small tube was employed, it was difficult to heat the 

 part used as a retort sufficient to drive off the whole of the 

 mercury from the basis, without raising too highly the tem- 

 perature of the part serving for the receiver, so as to burst 

 the tube*. 



^ j^j j^lj In consequence of these difficulties, in a multitude of tru 



als, I obtained only a very few successful results, and in no 

 case could I be absolutely certain, that there was not a mi- 

 nute portion f mere ury still in combination with the me- 

 tals of the o rths. 

 Base of bary- I" *^® ^®^*' ^csult that I obtained from the distillation of 

 tes. the amalgam of barytes, the residuum appeared as a white 



metal of the colour of silver. It was fixed at all common 



•temperatures, but became fluid Hr heat below redness, and 

 did not rise in vapour when heated to redness, in a tube of 

 plate glass, but acted violently npon the glass, producing a 

 black mass, which seemed to contain barytes, and a fixed 

 alkaline basis, in the first degree of oxigenation f , 



When 



* When the quantity of the amalgam was about fifty or sixty 



grains, I found that the tube could not be conveniently less than 



one sixth of an inch in diameter, and of the capacity of about 



half a cubic inch. 



, . j- From this fact, compared with other facts that haye been 



earths probably stated, p. 369, it may be conjectured, that the basis of barj'tes has 



the most pow- a higher affinity for oxigen than sodium ; and hence probably the 



erful means of ^^^^ ^^ ^jj^ earths will be more powerful instruments for detecting 



detecting oxi- . ., .u i r ^.i n i- ■ . "° 



g .„ oxigen, than the bases of the alkahs. 



*" ■ J have 



