116 BISMUTH. ARSENIC. 



BISMUTH. 



Bismuth is found native, and also combined with 

 sulphur and arsenic. 



It is of a reddish white colour, brittle, and easily 

 fusible. It is not quite so hard as copper. It 

 is not oxidated by water; it tarnishes in the air, 

 but does not undergo any other change. Kept 

 melted in an open vessel, its surface becomes 

 covered with a dark grey pellicle, which is renewed 

 till the whole is converted into oxide. 



The oxide of bismuth is a yellow powder. When 

 strongly heated it melts and becomes darker 

 coloured. 



Bismuth dissolved in the nitric acid, affords a 

 white powder, if water be added to the solution. 

 This is the magistry of bismuth, or pearl white, which 

 has been used as a cosmetic, but very improperly, 

 as it is apt to turn black by sulphuretted hydrogen. 



Bismuth dissolved by the acetic acid forms a 

 sympathetic ink. The characters written with it 

 are invisible, until they are exposed to sulphuretted 

 hydrogen, when they appear black. 



Bismuth alloys with all the metals, and has the 

 property of giving them great fusibility. If eight 

 parts of bismuth, five of lead, and three of tin be 

 fused together, they form what is called the fusible 

 metal, which melts in boiling water. On this ac- 

 count bismuth enters into the composition of some 

 of the soft solders. 



It has also the property of rendering gold ex- 

 tremely brittle. 



ARSENIC. 



Arsenic, the poisonous effects of which are so 

 well known, is a metallic substance, sometimes 



