II. OUTLINES
OF EXPERIMENTS AND INQUIRIES RESPECTING
SOUND AND LIGHT.
• r
BY THOMAS YOUNG, M.D F.R.S.
IN A LETTER TO EDWARD WHITAKER GRAY, M.D. SEC. R.S.
DEAR SIR,
| t has long been my intention to lay beforetin; Royal Society a lew observations on thesubject of sound ; and I have endeavoured tocollect as much information, and to make asmany experiments, connected with this in-quiry, as circumstances enabled me to do ;but the further 1 have proceeded, the morewidely the prospect of what lay before mehas been extended ; and, as 1 lind that theinvestigation, in all its magnitude, will oc-cupy the leisure hours of some years, or per-haps of a life, 1 am determined, in the meantime, iest any unforeseen circumstancesshould prevent my continuing the pursuit, tosubmit to the Society some conclusionswhich 1 have already formed from the resultsof various experiments. Their subjects are,J.The measurement of the quantity of un-discharged through an aperture. 11. The de-termination of the direction and velocity of astream of air proceeding from an oritice.
III. Ocular evidence of the nature of sound.
IV. The velocity of sound. V. Sonorous ca-vities. VI. The degree of divergence ofsound. VII. The decay of sound. VIII. Theharmonic sounds of pipes. IX. The vibra-tions of different elastic fluids. X. The ana-logy between light and sound. XL Thecoalescence of musical sounds. XII.'I hefrequency of vibrations constituting a givennote. Xlll. The vibrations of chords. XIV.T he vibrations of rods and plates, Thehuman voice. XVI. The temperament ofmusical intervals.
I. Of the Quantity of Air discharged throughan Aperture.
A piece of bladder was tied over the endof the tube of a large glass funnel, andpunctured with a bot needle. The funnelwas inverted in a vessel of witter; and a gage,with a graduated glass tube, was so-placedas to measure the pressure occasioned by thedifferent levels of the surfaces of the water.