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HP f %-J f ; * T ' . / - ^ , 
IV. ^ Letter from Mr. Stephen Gray to Dr. 
Mortimer, Seer. <%. S. containing a farther 
Account of his Experiments concerning Elec- 
tricity. 
Charter-Houfe , June yth, 1734. 
SIR, 
S INCE myIaft(N° 4ii)whereinlgavean Account 
of my Experiments, lhe wing Water will be attraded 
by Eledrick Bodies, and that it may have anEleftrick 
Vertue communicated to it, fo as to attrad foiid ones, 
I have been upon another Enquiry ; Whether there 
might not be a Way found to make this Property of 
Eledrical Attradion more permanent in Bodies ? How 
far I have fucceeded in this Attempt, will appear by the 
Experiments I have made on the feveral Bodies menti- 
oned in the following Catalogue; and as they were all 
of them prepared after the fame manner, excepting 
Numb. 18 and 19, which (hall be deferibed afterwards, 
a general Defcription of the Method of preparing 
and preferving them in a State of Attradion, may 
fuffice. 
The Bodies on which the Experiments were made, 
were Rofin both black and white, Stone-Pitch, Shell 
or Gum-Lac, Bees-Wax, and Sulphur. I procured 
three Iron Ladles of feveral Sizes, in which I melted 
thefe Subftances, making ufe of that which I thought 
mod convenient for the Quantity I defigned to melt. 
When any of thefe Bodies were melted, they were 
P p taken 
