74 of the system of Des Cartes.

of nature, which is not to be expected evenfrom the labour of ages.

The method which he has taken to establishthe existence and attributes of the Deity, merelyfrom any abstract notions which we can form ofsuch a being, independent of his works, is alsovery improper and unsatisfactory. And themaking of truth and falshood, right and wrong,to be dependent on his will only, tends toweaken all science and confound its principles.

Whilst he supposes extension to constitute theessence of matter, he neglects solidity, and theinertia by which it resists any change in its stateof motion or rest, which principally distinguishesbody from space ; and, for that reason, the doc-trine of an universal plenum, deduced fromthis definition, is founded upon false principles.

That there is such a thing as a vacuum innature, or a space void of body, may be de-monstrated from a thousand experiments. Bymeans of the air-pump, we can so far exhaustthe air from a glafs-receiver, that a guinea anda feather, being let fall together, from the topof the vessel, shall both descend equally swift,and come to the bottom at the same time:which evidently strews, that the air being takenaway, there remains no other matter sufficientto cause any sensible resistance, or that in theleast impedes or obstructs their passage.

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