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- V. &art of a Letter from Monjieur Claud. 
Jofeph GeofFroy, F. R. S. to David Hartley, 
M . A. F. R. S. containing his Method of 
making Soap-lees and Hard Soap, for Me- 
dicinal Ufes. 
SIR , RartSy July 23.1741. N. S. 
Read April x. "*0 make the Lye, I take, for 
I7+2 ‘ Inftance, of the beft calcined 
Lime, that has been the lead expofed to the Air, y ib r 
of good Salt of Kali or Glafs-wort of Alicanty pul- 
verized, and pafTcd through a fine Sieve, 10 lb* I di- 
vide the Lime and the Salt of Glafs-wort (called in 
England Barillia) into two equal Parts ; then I put 
the Lime, broken into Pieces not bigger than an 
Egg, into new ftone Pans, and cover it with as much 
Salt of Glafs-wort as is defigned for each Pan. I pour 
afterwards on thefe feveral Mixtures hot Water by 
little and little, to give Time to the Lime to open 
itfelf, till it turns into a fort of Meal, which will 
happen after I have poured Three half Pints * into 
each Pan. I then add to it the reft of the Water that 
is required, ftirringthis Mixture with a Stick of white 
Wood ; when there are Eighteen or Nineteen Quarts 
of Water in each Pan, there is enough for diffolving 
the Salts. In this State the Pans are left for Twelve 
or Fifteen Hours 5 after which this Lye is filtrated 
* 
The Paris Pirn is near a Quart En&lijb. 
through 
