ss. - - 
349 
for that medium, and if it be permitted to represent dis- 
persion by developing the velocity ; of the transmission of 
phase in a series of the form 
] Qr\? 2n\4 / 
= Mo — mi ({) + (=) — &e., (A) 
then the velocity wherewith light of this colour conquers 
darkness, in this dispersive medium, by the spreading of 
vibration into parts which were not vibrating before, is some- 
what less me being represented by this other series 
—'SM, (= sve + 5m, (#)'- &e. (BY 
For other details of this inquiry it is necessary to refer 
to the memoir itself, which will be published in the Trans- 
actions of the Academy, and will be found to contain many 
other investigations respecting vibrating systems, with ap- 
plications to the theory of light. 
The two golden torques found at Tara, and exhibited 
on a former occasion by Mr. Petrie (see Procrrpines, 
p- 274), having been purchased from Messrs. West by sub- 
scription, they were this evening presented to the Acotnny 
by Mr. Petrie, in the name of the subscribers. 
It was Resotvep—That the Subscription List be printed* 
in the Procreepines; and that the marked thanks of the 
Academy be given to those gentlemen, who, not being mem- 
bers thereof, joined in the subscription. 
* It will be found under the head of Donations. 
