121 
specific Gravity , and comparative IVear of Gold. 
The rough end of the bar, next the mouth of the mould, was 
cut off, and then three pieces were taken, viz. one from the 
upper extremity, another from the middle, and a third from the 
bottom. 
The specific gravity of these three pieces was ascertained; 
and they were then assayed by Mr. Bingley, his Majesty's 
Assay Master at the Mint, who reported them as follows. 
Specific gravity. 
Quality by assay. 
i. Top - 
18,141 
1 Better than standard, 3|- carat grs.* 
1 =210 Troy grains. 
i. Middle - 
i 7>°43 
r Worse than standard, j.1 carat grs. 
1 =105 Troy grains. 
Bottom 
16,689 
r Worse than standard, 3^ carat grs. 
1 =225 Troy grains. 
This experiment therefore proved, that as the upper extre- 
mity, or No. 1, was superior in specific gravity to the middle 
of the bar, or No. 2, so this last was superior to the bottom, or 
lower extremity, No. 3 ; in like manner, the quality of the gold 
was much better in No. 1 than in No. 2 ; and this also consi- 
derably surpassed the quality of the last, or No. 3. 
But it was still uncertain, supposing the alloy to have been 
perfectly mixed, whether it would readily become partly sepa- 
rated from the gold, so as to leave the mass thus of different 
qualities. 
To determine this, the next experiment was made. 
MDCCCIII. 
* One carat grain is equal to 60 Troy grains. 
R 
