604 PHILOSOPHICAL TRANSACTIONS. [ANNO 1800. 



tarding the velocity of their fluids. It is however necessary to examine these 

 subjects more accurately*. 



p. s. The Maucauco which Mr. John Symmons lately possessed, was sufficiently 

 quick in the movements of its head to snap a person's finger, when touched in- 

 cautiously; and the motion of its jaw, when chewing, was not slower than in other 

 animals. A Maucauco of the same species, kept among the wild beasts in the 

 Tower, was very apt to bite those who, calculating the movements of its head by 

 those of its limbs, approached within the length of its neck : the chewing of this 

 animal was similar to that of a cat. 



VII. Outlines of Experiments and Inquiries respecting Sound and Light. By Thos. 



Young, M. D., F. R. S. p. 106. 



It has long been my intention to lay before the r. s. a few observations on the 

 subject of sound ; and I have endeavoured to collect as much information, and to 

 make as many experiments, connected with this inquiry, as circumstances enabled 

 me to do; but the further I have proceeded, the more widely the prospect of what 

 lay before me has been extended ; and as I find that the investigation, in all its mag- 

 nitude, will occupy the leisure hours of some years, or perhaps of a life, I am de- 

 termined, in the mean time, lest any unforeseen circumstances should prevent my 

 continuing the pursuit, to submit to the Society some conclusions which I have al- 

 ready formed from the results of various experiments. Their subjects are, 1. The 

 measurement of the quantity of air discharged through an aperture. 2. The de- 

 termination of the direction and velocity of a stream of air proceeding from an 

 orifice. 3. Ocular evidence of the nature of sound. 4. The velocity of sound. 

 5. Sonorous cavities. 6. The degree of divergence of sound. 7« The decay of 

 sound. 8. The harmonic sounds of pipes. Q. The vibrations of different elastic 

 fluids. 10. The analogy between light and sound. 11. The coalescence of mu- 

 sical sounds. 12. The frequency of vibrations constituting a given note. 13. The 

 vibrations of chords. 14. The vibrations of rods and plates. 15. The human 

 voice. l6. The temparement of musical intervals. 



1 . Of the quantity of air discharged through an aperture. — A piece of bladder 

 was tied over the end of the tube of a large glass funnel, and punctured with a 

 hot needle. The funnel was inverted in a vessel of water; and a gage, with a 

 graduated glass tube, was so placed as to measure the pressure occasioned by the 

 different levels of the surfaces of the water. As the air escaped through the 

 puncture, it was supplied by a phial of known dimensions, at equal intervals of 

 time; and according to the frequency of this supply, the average height of the 

 gage was such as is expressed in the first table. It appears, that the quantity of 

 air discharged by a given aperture, was nearly in the subduplicate ratio of the 



* There is a rete mirabie in the genus bos, and in some of the cervi which I have seen j but of these 

 and the other pecora a fuller description will be given in a future paper. — Orig. 



