803 
COMRT. 
of it contain the or!g;inal text, and others Zoroaster’s second thoughts 
sn})joined, for explaining more fully his doctrine. These were occa- 
sioned by the opposition of adversaries, and unforeseen circumstances 
which occurred during the fabrication of the imposture. 
About three hundred \earsago, when the old Persian language had 
become antiquated and little understood, one of the destours, or high 
priests among the Persecs, composed the Sadda, whicli is a cojopcu- 
diuni, in the vulgar or modern Persic tongue, of those parts of the 
Zend that relate to religion, or a kind of code of canons and precepts 
drawn from the theological writings of Zoroaster, seiving as an au- 
thoritative rule of faith and practice for his followers. This Sadda 
is written, in alow kind of Persic verse, and, as Dr. Hyde informs 
us, ii is /mjiorwm malowm farrago, having many good and pious 
things, and others very superstitious aud trihing. 
Comet. 
A heavenly body, in the planetary region, appearing suddenly, and 
again disappearing ; and, during the time of its appearance, movicjg 
ti) rough its proper orbit like a planet. The orbits of comets are 
ellipsesi, having one of their foci in the centre of the sun ; and being 
very long and eccentric, they become invisible when in that part most 
remote from the sun. Comets, popularly called blazing stars, arc 
distinguished from other stars by a long train or tail of light, always 
opposite to the sun ; hence ai^ises a popular division of comets into 
three kinds, bearded, tailed, and haired comets ; though the division 
rather relates to the different circumstances of the same comet, than 
t’j the phenomena of several. Thus when the comet is eastward of 
the sun, and moves from it, the comet is said to be bearded, harba- 
because the light marches before it. When the light is westward 
of the sun, the comet is said to be tailed, because the train follows. 
When the comet and th^suu are diametrically opposite, the earth being 
betw'een them, the train is hid beliind the body of the comet, excepting 
a iittle that appears around it, iu form of a border of hair, hence 
called crinitas. 
According to Sir Isaac Newton, the tail of a comet is a very thin 
vapour, emitted by the liead or nucleus of the comet ignited by its 
neighbourhood to the sun, aud this vapour is furnished by the atmo- 
sphere of the comet. The vapours of cornets being thus dilated, rarefied, 
and diffused, may probably, by means of their own gravity, be attracted 
down to the planets, .and become intermingled with their atmospheres. 
For the conservation of the water and moisture of the planets, comets 
seem absolutely requisite, from whose condensed vapours and exha- 
lations all tliat moisture which is spent in vegetation and putrefac- 
tion, and turned into dry earth, may be resupplied and recruited ; 
for all vegetablesincrease wholly from duids, and turn by putrefaction 
into earth. Hence the quantity of dry earth must continyally increase, 
and the moisture of the globe decrease, and at last be quite evapora- 
ted, if it have not a continual supply. And I suspect, adds Sir Isaac, 
that the spirit w hich makes ihe finest, snbt lest, and best part of our 
air, and which is absoiuiely requisite for the life and being of all 
things, comes principally from the comets. 
