* 
‘from the heavens. 
1803.] 
mens of the ftones analyfed by Mr. How- 
ard, brought from Benares, in the Eat 
Indies; from Yorkthire, in England ; 
from Sienna, in Italy; and from Bohe. 
mia; to which he has joined thofe which 
fell in France in the year 1739, at Bar- 
botan, near Roqueton, and io the year 
1790, at Creon, a paifh of Juliac. He 
has remarked, as well as Mr. Howard, 
that thefe ttones refamble each other fo ex- 
actly, that it is almoft impoffible to diftin- 
guith them, Different: analyfes have con- 
vinced him, thar they all contain the fame 
principles ; namely, filex, magnefia, iron, 
nickel, and fulphur. Thefe refults, con- 
formable to thofe which Mr. Howard had 
already obtained, and to the work in which 
M. Ciladni, wel) known by his fine ex- 
periments on the vibration of furfaces, 
has collected all the recitals which have 
been made on the fall of thefe ftones, con- 
cur to render it probable that thzir origin 
is exterior to our globe; for hitherto no fi- 
milar {tones have been found in its in- 
terior. 
The reading of this interefting memoir 
has givenrife to a difcuffion, the refults of 
which merit infertion here, as they prefent 
additional motives for the colleéting, dif- 
cufing, and appreciating the different 
teftimonies agreeably to which the ftones 
here treated of are fuppofed to have fallen 
In faét, when a phe- 
nomenon is announced, if we are able to 
certify by a complete enumeration of the 
different phyfical agents, that none of 
them are able to produce it, the abfolute 
impoflibility of fuch a phenomenon will 
evidently retult, and by confequence the 
falfity of fuch announcement. 
When, on the contrary, we find a 
caufe which eltablifhes the poffivility of 
it, provided that found logic does not al- 
low us to attribute the fame exclufively to 
that caufe, it becomes us at the fame 
time to fubftiture doubt for abfolute ne- 
gation, and to ufe all poffible means to af- 
certain the fact, fecing that it is not re- 
pugnant to the general laws, of nature. 
Chemitts would at this day be very 
much embarraff<d to find in the atmo- 
{phere the component parts which they 
have dilcovered by analyfation in the 
fiones reprefented to have fallen from 
Heaven, and of courfe would be naturally 
inclined to rejeét fuch ftatements as. ab- 
furd. But Citizen Laplace has here fug- 
gelted an explication, which he offers, not 
as the only one that may be given of the 
fact, and not with a view to prove tlie 
Proceedings of Learned Societies. 
307 
exiftence of if, but merely that we may 
not too haftily rejeét the fame as abfurd ; 
and that we may, at leaf, fufpend our 
judgment, until time fhall procure more 
decifive authorities. 
A very limole caiculation fuffices to 
fhew, that a bedy projected from the 
moon requires only a velocily nearly quin- 
tuple to that of a twenty-four pound 
ball, difcharges with a portion of pow- 
per equal to one half ot its weight, to 
arrive at a diftance where the attraction 
of that fatellite is reduced to the fame in- 
tenhiiy as that of the earth. That point 
being paffed, the body, as being then 
within the ipnere of activity of our globe, 
mult neceflarily fall upen its furface. The 
appearance of very confiderable. volca- 
noes perceivable on the difk of the moon, 
render fuch a difcharge or projection not 
improbable; but, independently of the 
eruptions, which may be more or lefs fre- 
quent, it will not frequently happen that 
the direction of the projectile force will 
be that which the combined movemenis of 
the moon and of the earth require, in or- 
der that a moveable body difcharged from 
the former planet may reach the other. 
The atmofphere of the moon, the 
very exiftence of which is called in 
queftion by feveral aftronomers, is, at 
leaft, fo rare, and comprehends fo {mall 
an extent, that it can only oppofe a very 
feeble refiftance to the bodies that move 
within its region. It is not the fame 
with our terreftrial atmofphere ; it reduces 
almof& to the tenth part of its length the 
greateft range of a piece of artillery ; and 
the refiftance which it oppofes to rapid 
movements is fuch, that for a body dif- 
_charged from Vefuvius, for example, to 
be able to arrive in France, it would re- 
quire a velocity of projection infinitely 
more confiderable than that which would 
carry alunar body tq the limits of the 
{phere of aétivity of that ftar. 
There is no reafon, therefore, to ima- 
gine that ftones, falling at an immenfe 
diftance from terreftrial volcanoes, can 
be the product of the eruptions of thofe 
mountains ; and mineralogy equally mili- 
tates againft fuch an explication ; for none 
of the volcanic products hitherto known 
has any identity with the ftones prefumed 
to have fallen trom the fky. 
a 
ROYAL SOCIETY OF LONDON. 
“ASTRONOMY aud MATHEMATICS. 
q R. HERSCHEL, in his excellent 
paper entitled * 4 Catalogue of 500 
new 
