296 ANNUAL OF SCIENTIFIC DISCOVERY. 



This alloy, it is stated, is very beautiful, resembles gold in many respects, 

 and may be used in a pure condition, or as a base for gold plating. Its cost 

 is about eighty cents per pound, and yet its appearance is such that it would 

 readily be taken for gold by most casual observers. 



In France a law has already been passed to prevent frauds, by compelling 

 under severe penalties for neglect, all manufacturers of "oreide " to stamp 

 the word upon the articles produced. 



Castings made of oreide are cleansed with an ordinary pickle of sulphuric 

 acid and water to remove the oxide. The zinc may be replaced with tin. 

 but it makes the alloy more brittle. 



The manufacture of oreide has been recently commenced at Waterbury, ' 

 Conn. 







NEW ALLOY OF SILVER. 



A new alloy, applicable for many purposes in place of silver, has recently 

 been brought out in Paris. It is composed of silver, copper, and punned 

 nickel, which metals may be combined in any suitable proportions ; as 

 silver, twenty parts ; nickel, from twenty-five to thirty-one parts ; and the 

 rest up to one hundred parts in copper. An alloy is thus produced, con- 

 taining twenty per cent, of silver, and constituting silver of the third degree 

 of fineness, thus reversing the proportions of the ordinary compositions of 

 the second degree. The copper employed must be the purest obtainable, 

 and the nickel should be purified by some suitable process. 



ON THE ORIGIN OF "CLAY STONES. 



The following is an abstract of a discussion which recently took place in 

 the Boston Society of Natural History, on the origin of the concretions 

 found in clay, and familiarly known as " clay stones : ' 



Dr. C. T. Jackson considered the crystallizing force of the carbonate of 

 lime to be the cause of the concretionary structure and form of these bodies, 

 the foreign substances occasionally formed within them, serving as nuclei 

 around which this semi-crystallization took place, the carbonate of lime ag- 

 gregating and carrying with it the inert particles of clay, the spheroidal form 

 being that which would result from this action when the force was not ade- 

 quate to the production of crystals. He illustrated this view by reference to 

 the spheroidal structure of hyallitc and of various hydrous silicates, which 

 form from a gelatinous paste, in which there is not sufficient freedom of 

 motion to allow of the formation of perfect crystals. In case there were a 

 larger proportion of carbonate of lime in solution as a bicarbonate, the crys- 

 talline forms would become more perfect, as in the well-known crystalline 

 sand alone of Fontainbleau, in Avhieh grains of silicious sand are forced into 

 the form of calcareous spar by the energetic segregation of the crystallizing 

 carbonate of lime ; the sand being inert matter which was forced by the cal- 

 careous salt to enter into the crystalline form of the spar. 



Similar illustrations were adduced from chemical experiments and ob- 

 servations in which spheroidal forms result, and also in which foreign bodies 



