( 1087) ^mb.6u 
PHILOSOPHICAL 
TRANSACTIONS. 
July 1 8. 1670* 
The CONTENTS. 
A Letter of DoBor^ohnV^dMhtoKohtxt Boyle Efqt^ cm» 
eerning the faid DoStors Ejjay ef Teaching a perfon Dumb 
and Deaf to (peak) and to underftand a Language 5 to* 
get her with the fuccefs thereof^ made apparent to his Ma-- 
jefly^ the Royal Society ^ and the Vniverpy of Oxford « 
A Relation concerning the Sal-Gernme-Mines in Poland, 
deep 200 Fathoms, the way of making Vinegar in 
France, An Accompt of fome Books : 1, MECHANIC A 
five De MO TV TrailatHs Geometrims PARS 
CVNDA, inquaDe CENTRO GRAVlTAtlS 
Ejufque CALCVLO, Johanne Wallis S.Th.D^ 
^ Geometric Prof, Saviliano, &c, Ih EXE RC I TA- - 
T I ONES MECHANICAL, Alexandri Marchettf. 
IIL The Natural Hijiory of NlTER, by William Clark. 
A Letter 0/ Dr. John Wall is to Robert ^oyU Efcj^ cencermng 
the faid DoElo/s Ejjay of Teaching a ferfon Dumb and Deaf to 
fj>eak^. W f(? Underftand a Language ^ together with the faccefs 
thereof: Which Letter though written many years fince ^ was but 
lately obtain d to he infer ted here, it being efleemed very well worth ' 
to be freferv'd and commmicatedfor PMick^ Vfe. 
I Did acquaint you a while fince , That (befide the 
confideration of , which I had in hand,) 
1 had undertaken another Talk , ( almoft as hard as to 
make Mr. underftand ReafoOj ) to Teach a per- 
P fon 
