fiJCPERIMENTS ON VARIOUS ALLOYS OF GOLD. ] q\ 



(he unftamped pieces 92,8 grs. ftamped, 95,6 grs. No. 2, 

 tinftamped, 63,5 grs. ftamped, 60,1 grs. No. 3, undamped, 

 12 grs. flamped, 11,7 grs. No. 4, unftamped, 18 grs. ftamped, 

 19,2 grs. No. 5, unftamped, 13 grs. ftamped 12,1 grs, Tiie 

 total weight of the unftamped pieces, before friiSinn, was 

 13701,3 grs. Their total lofs, 199,3: the weight of the 

 llamped, 13679,5; the lofs 198,7. 



All the pieces appeared to have fuffered more on the edges Edges worn 

 than on the faces ; and thofe which were ftamped had the imi- '"°'^' 

 preflion more or lefs obliterated or flattened, in proportion to 

 their refpei^ive degree of duflility, or to the lofs which 

 according to the refult of this experiment, they had rela- 

 tively fuftained. 



The different pieces, after the experimenl, had a curious ^ raifed bead 

 appearance ; for^ on the edges, which were become round " ' 



and polidied, a fraall regular raifed bead or moulding was 

 formed, which furrounded each face, like a frame ; and both the faces con- 

 faces were become more or lefs concave. ^^''^' 



The original diameter of the pieces was alfo diminidied. The diameter 

 nearly according to their different degrees of dudility, and ac- <^'i^'nifhed. 

 cording to the lofs which they had experienced in confeqiience 

 ©f the operation. 



The meafure of the diameters of the pieces, after the ex- 

 periment, was. 



Gold 23 car. 3|grs. eight-tenths of an inch and ^. 



Gold alloyed with filver, nine-tenths of an inch. 



The others varied little from nine-tenths and -JL ; which 

 was lefs, by about -^-^ of an inch, than the original diameter 

 of the pieces ; and it was evident, that the pieces of fine 

 gold, and thofe confifting of gold alloyed with filver, being 

 the moft du61ile, had fufiered the greateft lofs, and were raoft 

 diniiniflied in diameter. Upon the whole, therefore, this ex- 

 periment appears to corroborate what has been afterted con- 

 cerning the former, viz. that foft or du6lile gold fuffers the 

 greateft lofs, when expofed to friclion in conta6l with gold 

 which is comparatively harder. Thefe experiments for afcer- 

 taining the effects arifing from the fridion of coin againft coin 

 being gone through, another feries was commenced with the 

 apparatus. No. 3, by means of which various pieces were ex- Apparatus, 

 pofed to the adion of certain powders and filings of metals, ^o* 3* 

 which were feparately fprinkled upon the horizontal table. 



The 



