AND THEORY OF THE HEAVENS. 99 



as unusual objects of terror, they have been regarded by 

 the common people as foretelling imaginary fates. The 

 astronomers, who give more attention to the laws of 

 their movements than to the strangeness of their form, 

 observe a second characteristic which distinguishes the 

 comets from the planets, namely, that they are not con- 

 fined like the latter to the zone of the zodiac, but revolve 

 freely in all quarters of the heavens. This peculiarity 

 has the same cause as their eccentricity. If the planets 

 have their orbits included within the narrow region of 

 the zodiac, it is because the elementary matter near 

 about the sun obtains circular movements which at every 

 revolution have tended to intersect the plane of relation, 

 and do not allow the body once formed to deviate from 

 this plane to which all the matter presses from both sides. 

 Hence the primitive matter in the regions of space far 

 away from the centre and which is feebly moved by attrac- 

 tion, cannot attain to free circular revolution; and from 

 this very cause, which produces the eccentricity, it is not 

 able to accumulate at that distance at the plane of the 

 relation of all the planetary movements, or so as to main- 

 tain the bodies formed there specially in this track. 

 Rather will the scattered primitive matter, since it is not 

 limited to a particular region as is the case with the 

 inferior planets, form itself into heavenly bodies as easily 

 on one side as on the other, and just as frequently far 

 from the common plane of relation as near to it. Hence 

 the comets will come to us without restriction from all 

 quarters ; yet those whose first place of formation was not 

 removed far beyond the orbits of the planets will show 

 less deviation from the limit of their paths, as well as less 

 eccentricity. This lawless freedom of the comets in regard 



