( o fas will hereafter appear) therefore I fhall treat of Thefe a little. By the word Earth I do not mean that pure and fimple Element, whereof the Philo- fophers fay all mixed fublunary Bodies are compofed. Neither do I mean that which is fo grofs as it remains mixed # with Metal, Vitriol, or other Juices. But I mean fuch an earthy Subfiance as neither melts in the Fire, nor diffolves in the Water, as Metals and Juices do, nor is fo compacted or hard as are Stones. Some report Arijiotlc to have been of Opi nion, that the pure elementary Earth was void of Colour. Strabo affirms it to be white, becaufe Afhes are of that Colour ; but the Miner may reft fecure, that, dig he ne ver fo deep, he fhall not meet with any fuch pure Element of Earth to make new Experi ments by, becaufe it is not in the World, by Reaibn of the perpetual Mixture of tire Ele ments one with the other. The Colour of the pureft Earth that hath been' found, Cardona would have to be a very dark Grey : In the other forts of Earth we fee how rich Nature hath adorned the World with Variety of Colours, crufed by difference of Exhalation, as ‘Tbeoprajius fays, or by difference of Heat, as Arijhtle fays, and both truly : For if under Earth, that hath notit’s natural and proper Colour, there be found Metals, it is certain, that the Exha lations from thofe Metals hath difcoloured the Ground ; and if there be no Metal found there, then the Difcolouring proceeds from the con-