Page:Philosophical Transactions - Volume 004.djvu/176

 quantity of Brine it affords. Thus they have a rich Brine in their chief Pit atMidle-wich, which yields a full fourth part of Salt, like the rich Burgundian Springs, mentioned in Kircher's Mundus Subterraneus; yet this is so thrifty of its Brine, that the Inhabitants are limited to their proportions out of it, and their quantity is supply'd out of Pitts that afford a weaker Brine. Our, Pitt at Nantwich yields but a sixth part; but then 'tis so plentiful a Spring, that, whereas they seldome Wall, that is, make Salt, in above 6. Houses at a time, and there are or should be about 50. Wich-houses in the Town; this Pitt is Judged sufficient to supply them all: And this advantage would accrew over and above, that such quick Use of the Pitt extreamly strengthens the Brine, perhaps to a degree little less than that of Middle-wich Pitt: For, I have tryed it myself, that a quart of Brine, when the Pitt hath been drawn off 3. or 4. days first, to supply 5. or 6. Wich-houses, hath yielded an Ounce and an halfe more of Salt, than at another time, when it hath had a rest of a week or thereabout. But I conclude, that the nearest conjecture, to be made of the strength of this Brine, is, to yield one pound of Salt for six pounds of Brine; as I have severall times tryed without any operation that might obscure the working: By which proportion you sie, that six Tuns of Brine yield one tun of Salt: which may be built upon; though in their ordinary way of working they make such variety of Additions, that 'tis impossible for any to be confident of the Product.

To adde some particulars, concerning this point; I shall tell you, that March 8. 1668. I weighed two pounds of distilled water in a narrow-mouthed Glass-bottle, that I might make an exact marks for a quart. This Bottle, being fil'd with our Brine to the very same mark, weigh'd (besides the tare of the Bottle) two pounds three ounces and five drachmes. This was taken up, when the Wich-houses but began to work, so that the Pitt was but little drawn. I fill'd up the Bottle with the same Brine, and it weighed just three drachms more. This Brine, boyled away without any addition or clarification, made five ounces and two drachmes of Salt. Five days after, when the Pitt had been drawn all that while for the working of the Wich-houses, vid. March. 13, the same Bottle, fill'd to the Quart-mark