76 OF THE SYSTEM OF DeS CARTES.

the contradictions and absurdities which attendthis hypothesis. For if these imaginary vortices,earned the planets from west to east, by meansof their particular circulations, the comets,which traverse those spaces in all manner of di-rections, from east to west, and from north tosouth, could never move according to any de-terminate law, as they would be constantly im-peded and turned out of their course by so manycontrary and opposite motions.

And besides, if it should be allowed, that thecomets had never actually passed from east towest, and from north to south, yet nothingwould be gained by this concestion. For it iswell known, that whilst a comet is passingthrough the neighbourhood of Mars, Jupiter, orSaturn, it moves considerably swifter than eitherof those planets; and therefore cannot be carriedround by the fame bed of fluid matter, whichis supposed to carry round these planets.

It has likewise been demonstrated by Newton,and others, that let the nature of these vorticesbe what it may, yet the circulations of theplanets, in such a fluid, would never agree withthe known laws of their motion, established byall the later astronomers, from repeated obser-vations. But, admitting for a moment thatthis system of whirlpools was' compatible withthe phænomena of nature, and the laws of me-chanics,