184 Mr. Hatchett’s Experiments on the various Alloys , 
Table XIV. ( continued.) 
Experiment 1. 
Experiment 11. 
Experiment in. 
Experiment iv. 
Revolutions. 
I 1880. 
Whiting. 
Revolutions. 
880. 
Sand. 
Revolutions. 
660. 
Filings of 
Standard gold. 
Revolutions, 
404 - 
Filings of Iron. 
Quality of the pieces 
of gold. 
Loss. 
Loss,' 
Loss. 
Loss. 
Gold made stand- 
ard by equal 1 
parts of fine and | 
dollar copper J 
Grains. 
0)20 ) 1,40 
1,20 J r 
Grains. 
Grains. 
°’ 4 ° ) 0,90 
0,5° / 
Grains. 
37,80 1 55*20 
27,40 / “ 
Gold of 1 8 carats | 
O O 
d d 
9 ' 
11,90 j 
^ 20,90 
0 
TO 
d 
0 0 
w N 
0 6 
10,20 
10,90 j 
j> 21,10 
Standard silver 
i,8o } z ’ 8 ° 
9,80 1 
10,40 j 
> 20,20 
SS } 1,60 
11.40 1 
16.40 J 
► 27,80 
Fine copper - ^ 
O O 
N U 
O O 
O 
■$- 
O 
7,20 1 
9>6o / 
16,80 
> 0,20 
0,20 J 
12,60 "j 
- 25,60 
When the whole of the preceding experiments, made with the 
three different machines, are viewed and compared, their general 
results appear to be as follows. 
1st. That when equal friction, assisted by a moderate pres- 
sure, takes place between pieces of coin which are in each series 
of a similar quality, then, abrasion is most commonly produced 
in an inverse ratio to the degree of ductility. 
sdly. That the contrary effect happens, when pieces of dif- 
ferent qualities rub against each other ; for then, the more duc- 
tile metal is worn by that which is harder.* 
* Some experiments were made at Paris, in 1790, upon pure and upon alloyed silver, 
the results of which appear to be nearly the same as those of the present experiments 
upon gold. These experiments upon silver are concisely mentioned as follows. <f L’ob- 
«* jection la plus forte contre l’usage des metaux purs dans les monnoies, est la crainte 
<f qu’elles ne s’usent plus vite. Mais la durete que l’alliage leur communique. 
