39 



wire so made serves for musical instruments, Sec. A wire 

 one tenth of an inch in diameter will support 270 pounds 

 weight. 



Silver, by being dissolved in nitric acid, and precipitated 

 with mercury, will form the likeness of a tree, and is then 

 called Arbor Dianae. — If precipitated from the nitric acid 

 by lime water, the precipitate dried, and washed with a 

 solution of pure ammoniac, has a dangerous fulminating 

 property ; and on the slightest touch, or friction, will explode 

 most violently, exceeding the force of gunpowder. The 

 nitrate of silver stains animal substances a deep black, „and 

 has been used to blacken human hair; but it is extremely 

 dangerous, owing to its corrosive property. 



