156' Mr . Hatchett’s Experiments on the various Alloys , 
Table III. ( continued .) 
Quality. 
Weight be- 
fore friction. 
Weight after 
friction. 
Loss. 
O * 1 
Grains. 
Grains. 
Grains. 
51. Gold with iron and copper 
136,50 
129,30 
7,20 
52. Gold with tin and copper 
136,70 
129 
7»70 
53. Gold with tin and copper 
139,20 
13340 | 
i 5.8° 
54. Gold of 18 carats 
i 25,30 
125,50* 
1 - 
The different pieces mentioned in the foregoing Table, are 
enumerated according to the order of their arrangement in the 
apparatus ; and it is proper to observe, that the pieces of copper. 
Nos. 13 and 14, as well as the piece of gold made standard by 
copper, No. 17, and the piece of copper No. 18, were worn so 
thin during the experiment, that they were taken out after 
114520 revolutions; but all the other pieces sustained twice 
that number, or 229040 revolutions. 
When the preceding experiment was terminated, it was ob- 
served, that, 
No. 15, or standard silver, was coated slightly by the copper 
No. 16. 
That, No. 19, or gold made standard by copper, was coated 
by the standard silver No. 20. 
That, No. 28, or standard silver, was slightly coated by the 
geld of 23 car. 3! grs. or No. 27. 
That, part of No. 31, or gold of 23 car. 3^ grs. adhered to 
the gold made standard by copper, or No. 32 ; and, that the gold 
alloyed by an equal proportion of copper, No. 38, was slightly 
coated by the gold made standard by snver, No. 37. But, to avoid 
repetition, it appears proper that other observations should be 
deferred, until the following experiment has been described, 
* Increased in weight 0,20. 
