T. S. Hunt—Celestial Chemistry. 129 
cowpletes his Hypothesis of the Universe, adds: “ Perhaps the 
whole frame of nature may be ceed but various Ost TC 
the Creator, and ever since, by the power of nature, which, by 
virtue of the command ‘increase and multiply,’ became a com- 
plete imitator of the copy set her by the great Laren 
Thus, perhaps may all things be originated from ether 
If now we look’to the third book of the Principia, we shall 
find in eames 41 the remarkable chemical argument by 
which Newton was led to regard the interstellary ores as 
peng “the material principle of life” and ‘the food of 
planets.” Considering the exhalations from the tails of matiot 
he supposes that the vapors thus derived, being rarified, dilated, 
and spread through the whole heavens, are by gravity brought 
atmosphere, so important, though small in amount, he then 
Supposed might come from the tails of comets.* 
his appeared in the first edition of the Principia, in 1687. 
It was not until later that the conception of exhalations from 
p 
e may learn from the Optics. Thus, in the first edition of this 
— in Query 11, the sun and fixed stars are spoken of as 
“Vapor enim in ihe tae illis ioe perpetud rarescit, “ iar gs << 
ots fit ut cauda omnis ad extremitatem superiorem latior udm 
pita cometae. Ka Rare rarefa singe pepe perpetud tatu aiitandl =e 
i 
: lin fri 
ba philosophantur) decurrant ie fontes et flumina : sic ad phate tionem ma- 
um 
t humo m u 
et vaporibus ng ones aeahgp liquoris per vegetationem et putrefactionem 
cousumitur et in Ter Shee convertita Y continud — et refici it. 
Nam vegetabilia Sibi te Nagano t, dein magn ex parte in Ter- 
ram aridam per sotbetactiaiis aunt et limus ex isaac putrefactis perpetud 
decidit. Hine moles Terrae aridae indies es ur, et liqnores, nisi aliunde augmen- 
tum sumerent, perpetud decresere deberent, ac tandem deficere. Porro suspicor 
ase gew hae ian qui aéris nostri pars mini i "est, s ed subtillissima et sehen et ad 
omnium sae requiritur, ex cometis — venire.”— Newton, Principia, 
lib. IIL prop. Xt 
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