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by the aberrations arifing from the different refrangi-' 
bility of the rays of light j thefe objed -glades confid- 
ing of two menifcus lens's, with water between them. 
Mr. John Dollond, who is an excellent analyd and 
optician, has examined the faid theorem, and has 
difcovered a midake in it, which arifes by affuming 
an hypothecs contrary to the edablifhed % principles 
of optics ; and, in confequence of this, M*r. Dollond 
has lent me the inclofed letter, which contains the 
difcovery of the faid midake, and a demondration 
of it. 
In order to ad in the mod candid manner with 
Mr. Euler, I have propofed to Mr. Dollond to write 
to him, fhewing him the midake, and defiring to 
know his reafons for that hypothefis j and therefore I 
defire, that this letter of Mr. Dollond’s to me may- 
be kept amongd the Society’s papers, till Mr. Euler 
has had a fufilcient time to anfwer Mr. Dollond’s 
letter to him. I am, 
S I R, 
Surrey-ftreet, April 9, 
* 75 2, Your mod humble fervant, 
James Short. 
II. 
