176 ANNUAL OF SCIENTIFIC DISCOVERY. 



A NEW SILVER ALLOY. 



M. De Ruolz and De Fontenay, of France, have lately obtained, after 

 several years' experiments, a new alloy, which may be very useful for 

 small coin and for many industrial uses. It is composed of one-third 

 silver, twenty-five to thirty per cent, of nickel, and from thirty-seven to 

 fifty per cent, of copper. Its inventors propose to call it tiers-argent, or 

 tri-silver. Its preparation is said to be a triumph of metallurgical science. 

 The three metals, when simply melted together, form a compound 

 which is not homogeneous ; and, to make the compound perfect, its 

 inventors have been compelled to use phosphorus and certain solvents 

 which they have not yet specified. The alloy thus obtained is at first 

 very brittle ; it cannot be hammered or drawn, and lacks those prop- 

 erties which are essential in malleable metals. But after the pbos- 

 phorus is eliminated, the alloy perfectly resembles a simple metal, 

 and possesses, in a very high degree, the qualities to which the 

 precious metals owe their superiority. In color it resembles platinum, 

 and is susceptible of a very high polish. It possesses extreme hard- 

 ness and tenacity. It is ductile, malleable, very easily fused, emits 

 when struck a beautiful sound, is not affected by exposure to the 

 atmosphere, or to any but the most powerful reagents. It is without 

 odor. Its specific gravity is a little less than that of silver. An alloy 

 possessing these properties must be very useful to gold and silver 

 smiths. It can be supplied at a price forty per cent, less than silver, 

 and its greater hardness will give it a marked superiority. It may 

 also serve as a substitute for gold-plated or silver-plated articles, 

 which are now so common on account of their cheapness, but which 

 will not bear replating more than a few times, and which are, in the 

 long run, sometimes more expensive than the pure metal. The new 

 alloy, however, will be most useful for small coin. Its preparation 

 and coinage are so difficult that the coin made of it cannot easily be 

 counterfeited. Its hardness would render it more durable than silver ; 

 and thus the expense of re-coining, and the heavy loss arising from 

 the wearing of our silver coinage, would be greatly diminished. 

 London Chemical News. 



SILVER TEST. 



Silver coins, jewelry, or any other rich alloy, when moistened with 

 a solution of chromic acid, or a mixture of bichromate of potassa and 

 sulphuric acid, become covered with a red purple spot of bichromate 

 of silver. This spot does not occur on poor alloys or metals imitating 

 silver. Paris Cosmos. 



NITROGEN AND IRON. 



Nitrogen is the most sluggish of all metalloids, or non-metallic 

 elements ; and while oxygen displays the most surprising affinity for 

 nearly all the substances we know, nitrogen scarcely combines directly 

 with any, and its combinations must be effected by circuitous routes. 

 Even carbon and hydrogen, for which it has a decided affinity, since 

 with the former it constitutes cyanogen, and with the latter ammonia, 



