[ 47 ° ] 
The firft Diamonds I had the Opportunity of feeing 
weigh’d, were two very large ones from the Brafils y 
which were fumifhed by Mr. Chace , a Merchant in 
Auftinfriers : The fpecific Gravities of thefe were 
found to be much greater than the heavied of Mr. 
Boyles , the one being to an equal Bulk of Water 
as 35 1 8, and the other as 3521 to 1000, and the Diffe- 
rence between them lefs than the one-thoufandth Part. 
There were two fmaller Brafil Diamonds weigh'd at 
the fame time, which indeed were not quite fo heavy 
as the former, the lighted being but as 3501, the other 
as 3511 ; but, as thefe were of the fame kind, and 
comparatively fmall, I judged this Difference could 
not be much depended on. Having therefore an Op- 
portunity fome time fmce of a large Parcel of Eaft- 
India Diamonds, I chofe out 10, which, both in 
Shape and Colour, and every other refpedt, were as 
different from each other as poffible. Thefe being 
weigh’d in the fame Scales and Water as the former, 
the lighted proved to be as 351^, and the heavied 
as 3525 ; the very near Agreement of thefe lad with 
each other, and with the former, tho’ weigh’d at 
about eight Months Didance, makes it highly pro- 
bable, that fo great a Difference as appears from the 
Place above-cited, and Mr. Boyle's Table, is not to 
be found in any Diamonds whatfoever, much lefs 
fo great a Difference as appears between the lighted 
of his and the heavied of mine, being above J of 
the Whole. 
I had never made any Experiments myfelf, by 
which I could form a Judgment, how much of the 
Difference between thefe and former Trials might 
arife from the different Tempers and Qualities of the 
7 Waters 
