For it very rarely otherwise happens, than that theories, that are grounded but upon few and obvious experiments, are subject to be contradicted by s… - Robert Boyle

Those distinct substances, which concretes generally either afford, or are made up of, may, without very much inconvenience, be called the elements or principles of them.

And of universal nature, the notion I would offer, should be something like this. Nature is the aggregate of the bodies, that make up the world, in its present state, considered as a principle, by virtue whereof, they act and suffer, according to the laws of motion, prescribed by the author of things.

As for silver, I never could see any degree of fire make it part with any of its three principles. ...But admitting, that some parts of the silver were driven away by the violence of the fire, what proof is there, that it was either the salt, the sulphur, or the mercury of the metal, and not rather a part of it homogeneous to what remained? for besides that the silver, that was left, seemed not sensibly altered, which probably would have appeared, had so much of any one of its principles been separated from it.