CHAP. XIII.
Of the causes of actual heat, and medicinal virtue in Mineral Waters, divers opinions of others rejected.
NOW I come to shew how our mineral waters receive both their actual heat, and their virtues. I joyn them together, because they depend upon one and the same cause, unless they be juices which will readily dissolve in wa∣ter, without the help of heat: other minerals will not, or very hardly.
This actual heat of waters hath troubled all those that have written of them, and many opinions have been held of the causes of them. Some attribute it to wind or air, or exhala∣tions included in the bowels of the earth, which either by their own nature, or by their violent motion, and agitation, and attrition upon rocks and narrow passages, do gather heat, and impart it to our waters. Of their own nature these ex∣halations cannot be so hot, as to make our water hot, especially seeing in their passage among cold rocks, it would be much allaied, having no sup∣ply