( 839 )
Num. 134.
PHILOSOPHICAL
TRANSACTIONS.
April 23. 1677.
The CONTENTS.
A Letter of Dr. Wallis, concerning a new Musical Discovery. An Improvement of the Bononian Stone, shining in the dark. Extract of a Letter out of Scotland, concerning a man of a strange Imitating nature; as also of several human calculus's, of an unusual bigness. Mr. Leewenhoecks Letter, giving some account of the manner of his observing so vast a number of live Insects in several sorts of water, as was said in the next foregoing Tract. A Continuation of the Hortulan and Rural Advertisements, formerly promised. A Letter of Monsieur Hevelius, delivering his observations, made for several years together, concerning three New Stars. An Account of two Books: I. Traité de la PERCUSSION on CHOQ des CORPS; par Monsieur Mariotte, de l'Academie des Sciences, à Paris. II. Johanni Trithemii STEGANOGRAPHIA, vindicata, reserata, & illustrata: Auth. Wolfgango Ernesto Heidel, Wormatiensi.
Dr. Wallis's Letter to the Publisher, concerning a new Musical Discovery; written from Oxford, March 14. 16767.
SIR,
I have thought fit to give you notice of a discovery that hath been made here, (about three years since, or more) which I suppose may not be unacceptable to those of the Royal Society, who are Musical and Mathematical. 'Tis this; whereas it hath been long since observed, that, if a Viol string, or Lute firing, be touched with the Bow or Hand, another string on the same or another Instrument not far from it, (if an Unison to it,or
