[ 4i7 ] 
Received February 8, 1770. 
XXXIV .* Difficulties in the Newtonian Theory 
of Light , confdered and removed , by the 
Rev. S. Horfley, LL. B. F. R. S . 
Read Dec. 20, R. Franklin, in a letter to a corre- 
1//0 * fpondent at New-York, the 23d 
of that valuable collection with which the public was 
obliged in the latter end of the year 1768, propofes 
fome objections to the Newtonian theory of light. His 
words are thefe. “ I am much in the dark about 
«« light. I am not fatisfied with the doCtrine that 
“ fuppofes particles of matter called light, continual- 
“ ly driven off from the fun’s furface with a fwiftnefs 
“ fo prodigious. Muft not the fmalleft particle con- 
“ ceivable have, with fuch a motion, a force exceed- 
“ ing that of a twenty-four pounder difcharged from 
“ a cannon ? Muft not the fun diminifh exceedingly 
“ by fuch a wafte of matter, and the planets recede 
u to greater diftances by the leftened attraction ? Yet 
“ thefe particles with this amazing motion will not 
“ drive before them, or remove, the leaft and lighteft 
tc dull they meet with : and the fun, for aught we 
“ know, continues of his antient dimenfions, and his 
“ attendants move in their antient orbits.” Dr. 
Vol. LX. H h h Franklin’s 
