( ioj8 ) 
Kowupon this Experiment finding that ;;i9 Silk-Balls 
would make one Pound and one Ounce of fine Silk. I was 
<3efirous to know what quantity of Silk might be expe(fted 
from the Worms Hatched from one Ounce of Eggs. 
Of which to obtain the Knowledge^ I made ufe of the 
following Method; by often weighing and telling 1 found 
that one hundred Eggs weighed b^ut one Grain, fo that if 
one Grain contains loo, a Scruple mutt contain 2000, and 
a Dram 6ooo, and an Ounce at 8 Drams to the Ounce, mutt 
contain 48000 Eggs. Now if every Egg hatch a Worm, 
and every Worm makes a Silk-Ball, there mutt be from one 
Ounce 48000 Silk-Balls,- and if Balls will make one 
Pound and one Ounce of fine Silk, ( v;hich by Experience 
I found they did) then 48C00 Silk-Balls will make 15- 
Pounds and 6 Ounces of Avtrdupois Weight in fine Silk, or 
i8 Pounds and eight Ounces of Troy Weight, which is 
very confiderable. And in the fame Proportion one Pound 
of Silk Worms Eggs, will produce Worms fuflicient to make 
above 180 Pounds of Silk. But allowing for Cafualties, and 
fuppofing but 12 Pound of fineSilk made from theWorms and 
their Silk-Balls produced from an Ounce of Silk Worms Eggs ; 
it will be found much to exceed molt Countries, according 
to Augufiino Gallo's Computation ; For he fayeth, that in the 
Southern parts of France, viz. Languedsic and Trovettce, they 
make but 7 or 8 Pound of Silk from Silk Worms hatched 
from an Ounce of b'ggs ; and inBrefcia in Italy, but 8, 9, 
or 10 Pound of Silk from an Ounce; only in Calabria, where 
the Silk Worms and their Eggs are larger, they make 11 or 
12 Pounds of Silk from an Ounce of Eggs ,- which ftill doth 
not exceed, nay hardly comes up to, what we make in Eng., 
land. 
As to the Charge and Expences of making the aforefaid 
quantity of Silk in England, different from that of other 
Places, I fliall be able to give you a more particular Ac- 
count in my next Experimental Obfervations. 
1 have only this to add, that Experience hath taught me 
how to hatch Silk Worms twice in a Year, fo as to have two 
good Crops of Silk in one Year. And that the Mulberry 
Trees will have Leaves in England twice in a Year, without 
prejudice to either Tree or Fruit, is'moft certainly true. 
But more in my next. 
II. V IRC 
