298 NATDUE ANP DECOMPOSITION OF THE FIXtB AtKALIS. 



a globule of mercury was placed near a olobule of the pe- 

 cular substance, it W3,3 not possible to detect a difference 

 by the eye. 

 But its fli iciity At 60" Fahrenheit it is however only imperfectly fluid, 

 imptrfect be- foi- it does not readily run into a ylobule, when its shape is 

 "^ ' altered ; at 70° it becomes more fluid ; and at 100° its fluidity 

 is perfect, so that difl'erent g'lobules may be easily made to 

 Af 50° soft and vuu into one. At 50" Fahrenheit it becomes a soft and uiaU 

 rualleable. leable solid, which has the lustre of polished silver ; aqd at 

 about the freezing point of water it becomes harder and 

 At g2'> brittle, brittle, and when broken in frag^ments, exhibits a crystal- 

 lized textu-e, which in the microscope seems composed ©f 

 beautiful facets of a perfect whiteness and hij^h m- tallid 

 splendour. 

 Distilled with- To be converted into vapour, it requires -a temperature 

 out ctenge. approachitig that of the red heat; and when the experi- 

 ment is conducted under proper circumstances, it is found 

 unaltered after distillation. 

 A perfect con- ^^ '^^ ** perfect conductor of electricity. When a spark 

 ductoi of dec- from the Voltaic battery of 100 of 6 inches is taken upon a 

 *f»=ity> large globule in the atmosphere, the lio-ht is green, and 



combustion takes place at the point of contact only. When 

 a small globule is used, it is completely dissipated with ex- 

 plosion, accompanied by a most vivid flame, into alkaline 

 fumes. 

 3tA of heat. It is 8n excellent conductor of heat. 



!t> -specilic Resembling the metals in all these sensible properties, it 



gravity ,is however remarkably difl'erent from any of them in speci- 



fic gravity; I found that it rose to the surface of naphtha 

 distilled from petroleum, and of which the specific gravity 

 was '861 ; and it did not sink in double distilled naphtha, 

 the specitic gravity of which was abo it '77°, that of water 

 being considered as 1. The small quantities in which it is 

 produced by the highest electrical powers, rendered it very 

 difticultto determine this quality with minute precision. I 

 endeavoured to gain approximations on the subject by com- 

 paring the weights of perfectly equal globules of the basis 

 of potash and mercury. I used the very delicate balance of 

 the Royal Institution, which when loaded with the quanti- 

 ties I employed, and of which the mercury never exceeded 



ten 



