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XXIX. Account of fome Experiments in Electricity. In a 
Let er from Mr. William Swift to the Rev. Dr. King,. 
F. R . S. 
EING encouraged by the attention the Royal So- 
ciety did me laffc year to give to the account of fome 
electrical experiments I had made, which you were fo 
good as to prefent to them, I take the liberty to beg their 
indulgence again, and hope you will be pleafed to lay 
before them fome new improvements I have made in my 
eleClrical apparatus. X fhall efteem myfelf very happy if 
what I have done is worthy the farther attention of that 
moft learned and refpeCtable body. 
One particular addition X have made to the apparatus 
confifts in what I call an anti-conduClor : it is exaCtly like 
the prime conductor, but it is fixed to the cufhion of the 
machine, and confequently, when the cylinder is put in 
motion, the anti-conduCtor is charged negatively, that is,, 
the eleCtric matter is diminifhed therein in the fame pro- 
Read April 29, 1779^. 
S I 
Greenwich, 
April 28, 1779. 
portions 
