156 EXPERIMENTS ON VARIOUS ALLOYS OF GOLD. 



penfate the additional expence of the filver required for half ©f 

 the alloy; and, indeed, any extraordinary addition of filver 

 appears to be the lefs neceffary, as there is commonly fome 

 filver in the gold which is fent to the Mint, which, being 

 reckoned as part of the alloy, contributes to produce thofe be- 

 neficial effedts which refult when filver is purpofely added. 



From a general view of the prefent experiments, there does 

 not appear to be any very great or remarkable difference in 

 the comparative wear of the three kinds of ftandard gold, all 

 of which fuffer abrafion flowly, and with much difficulty ; and 

 (as it has been already obferved) the difference of wear between 

 Extraordinary the two lafl; mentioned, is certainly but inconfiderable. For 

 lofs fuftained by thefe reafons, and from the confideration of every other circum- 



ourgold coin not . .Z ,ri-i 



imputable to fair "^"^^> ^^ mult be evident, that the extraordmary lols which 

 wear. the gold coin of this kingdom is ftated to have fuftained within 



a certain limited time, cannot, with even a ftiadow of proba- 

 bility, be attributed to any important defefl in the compofition 

 or quality of the ftandard gold ; and all that can be faid upon 

 this fubjed is, that fome portion of this lofs may have "been 

 caufed by the rough impreffion and milled edge now in ufe, 

 by which each piece of coin ads, and is acted upon by the 

 others, in the manner of a file. 



The lofs thus occafioned cannot however be confiderable ; for 

 the quality of the prefent ftandard gold is certainly that which 

 is well adapted to refift abrafion, efpecially in the cafe of the 

 fri6iion of coin againft coin ; and this is ftrongly corroborated 

 by the obfervations of bankers and others, who are in the babit 

 of fending or receiving large quantities of gold coin from any 

 confiderable diftance. When a number of guineas, rather 

 loofely packed, have been long fliaken together by the motion 

 of a coach or other carriage, the effeds of fridion are obferved 

 chiefly to fall upon only a few of the pieces. But it is not a little 

 remarkable, that although thefe are often reduced nearly or 

 quite to the ftate of plain pieces of metal or blanks, ^j^i, upon 

 being weighed, they are found to have fuftained little or no 

 lofs; and from this it appears, that the impreffions have been 

 obliterated, not by an adual abrafion of the metal, but by the 

 depreffion of the prominent parts, which have been forced into 

 the mafs, and become reduced to a level with the ground of the 

 coin. Pieces of hard gold would not fo eafily fuffer by depref- 

 4 fion : 



