290 Mr, J. Taylor's Lectures on Metallurgy. 



metal vvoiked on; and combining in some degree with it, makes 

 a perfect joint. 



Tin alloyed with lead makes a solder for lead and tin. 

 Zinc and a little copper 1^ ^^^ ^ ^^,^^g^ 



called spelter j 



Brass for iron. 



8th. From the aflinity of the metals for other substances, 

 and the ease widi which they combine chemically with them, 

 we derive a great number of substances most important to 

 the arts, to medicine, and almost every purpose of life. 



With oxygen the metals readily unite, and the metallic ap- 

 pearance and properties are lost, and a class of substances 

 formed which were at one time called calces, but are now more 

 appropriately denominated oxides. 



Iron with oxygen forms rust. 



Lead "- forms lidiarge, red-lead, & massicot. 



Copper forms scales and red oxide. 



Mercury forms substances which are import- 

 ant in medicine ; such as precipitate 

 per se, red precipitate. 



Tin Enamel or glaze. Putty powder used 



in polishing. Black oxide is the ore. 



Antimony gives oxides used in medicine. 



Arsenic tlie poisonous state of this metal. 



Manganese is principally useful from the large quantity of 

 oxygen combined with it in its most common form. 



The metals very readily also unite with sulphur, and form 

 many useful compounds. 



Mercury gives a beautiful pigment called cinnabar or ver- 

 milion. 



Antimony gives some important medicines. 



Bismuth gives a cosmetic, pearl white, or blaiic de fard. 



Carbon forms an important compound with iron in the ar- 

 ticle of steel; and Plumbago is also a small proportion of 

 iron with a large proportion of carbon. 



The beautiful art of enamel-painting, with the colours given 

 to our porcelain and glass, are to be referi'ed to the combina- 

 tions which take place between the metallic oxides and sili- 

 ceous earth in a state of vitrification. 



Some of the oxides act powerfully as a flux in promoting 

 the fusion of silicejus earth when it is converted into glass; 

 and those of lead and arsenic (but particularly the former) are 

 much employed in the manufacture of flint glass, and commu- 

 nicate no colour to it. 



Other metallic oxides, however, combine thus with silex, 



imparting 



