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followed you, having witnessed the details of this great prin 
ciple and calculated the different circumstances with the 
utmost accuracy. All the attempts in giving a plausible 
explanation of the phenomenon in question have generally 
conveyed this opinion, that the molecules of bodies, as well as 
those of ordinary matter, are liable to Newton’s attraction, 
and, consequently, must be separated from each other by 
spaces infinitely larger than they occupied before ; then, they 
must keep their distances from each other by virtue of laws, 
if not identical, at least analogous with those which govern 
the celestial bodies and maintain in fixed boundaries the 
distances between the planets and the stars, which determine 
their course. 
“ Such were the ideas I had, when addressing a letter on 
this subject to the celebrated and most learned Sir John 
Herschel, when President of the Royal Astronomical Society, 
the most distinguished man of our time for his philosophical 
genius and his wise and judicious manner of treating sciences, 
well known to me through the connection I have had with 
him. 
“We are indebted, sir, there is not a doubt, to the solid 
and enlightened spirit that characterises the English learned, 
for the development made in your country on this interesting 
question, which occupies the most learned men in the world. 
I have endeavoured to engage, by numerous papers, the 
attention of the members of the French Academy of Sciences, 
my colleagues, upon this important subject, but without avail. 
But I take the liberty of asking you to communicate this 
letter to the members of the Institution of which you are a 
member, and, should I obtain its publication, I hope my 
studies will be known by all your learned colleagues, and 
contribute to enlighten the opinion of those who pursue this 
branch of science. 
“The letter I addressed, on the 2nd of April, 1824, to 
Sir John Herschel has been translated into English, and was 
sent to Sir David Brewster, who inserted it, on the 24th of 
