I know in nothing indeed where there is a greater Intercourse and Sympathy; and a considerable Illustration of which may be made by the following Experiment. If any one in the Spring-time, when the Sun is approaching nearer to us, digs up a Piece of Earth, and after Infusion and Filtration, evaporates the Liquor, he will find at the Bottom of the Vessel a Sixth Part of Salt more than at any other Time of the Year, from the same Quantity of Earth managed after the same Manner; the nitrous Salt for many Reasons not arising in so great a Quantity for the Exigencies of Nature, at any other Times; whence I conceive it manifestly to prove, that there is such an Efflux of this Salt as before suggested, and a Kind of Sublimation of it into the Air, and that this saline Spirit hath a Sort of Sympathy with the superior Heat. But that we may not use more Arguments than are necessary to prove the Energy of this Principle, every one who is doubtful herein may observe, that not only Plants are produced and nourished by its subtle and luxuriant Insinuation into their Fibres, but that also from the same aerial Spirit the Life of Animals, and even the humane Species is preserved. And I cannot see any Difficulty in the Opinion, that the best Temperature of the Blood and animal Juices, the Renewal of wasted Spirits, the Restauration of Strength, and the good and healthful Constitution of the Viscera, Members, and whole Body, is maintained by the Assistance of this nitro-aerial Spirit. Nor does any Thing appear more congruous to Reason, than that from the same Cause does the Racy Spirit of the Blood arise, as it is not derivable from any other; nor is it my single Opinion, that from the same Principle it derives its Colour; but as there are no Arguments even objected to this Doctrine, it is needless to imploy more Time in its Vindication. BUT further, it may happen that this nitro-aerial Spirit may various Ways be changed in its Properties; that is, either with Regard to its proliffick Influences, (if it may be so expressed) or, which much oftner happens, in its accidental and adventitious Impurities.