C 2 75 ] 
ventricle, and the extravasation covering the ft (lure in 
the aorta, exadtly marked, as they appeared to. 
My Lord, 
Your Lord (hip’s 
molt obedient 
and moft; humble fervant, 
Frank Nicholls. 
LI I. Of the Irregular Hies in the planetary 
Motions , caufed by the mutual Attraction 
of the Planets : In a Letter to Charles 
Morton, M. D. Secretary to the Royal 
Society , by Charles Walmefley, F. R. S. 
and Me?nber of the Royal Academy of Sci- 
ences at Berlin, and of the Injlitute at Bo- 
logna. 
S I R, 
Read Dec. 10, TT~Mnding that the influence, which the 
1761. JjH primary planets have upon one an- 
other, to difturb mutually their motions, had been 
but little considered, I thought it a fubjedt worthy of 
examination. The force of the fun, to disturb the 
moon’s motion, flows from the general principle of 
gravitation , and has been fully ascertained, both by 
theory and obfervation ; and it follows, from the 
N n 2 fame 
