ARTIFICIAL ICRS—COOLING LIQUORS.

1G9

hands, and monopolized the trade, by farming it out. Thesefarmers raised the price from lime to time; but at lengththeir parsimony, and the prodigal extravagance of the courtrequired such large supplies of each to support it, that thepeople generally disused it; which caused so great a fluc-tuation in the value of the article, that governmentagain rendered the trade free: the expense again becamemoderate, except after mild winters and in exceeding warmsummers. 15

The utility of tenacious salts had not, as yet, been dis-covered to cool liquors ; but it has since been found thatsaltpetre mixed in a certain proportion with water, canproduce the same effects as an admixture of either snow orice. It is not now questioned, but it is a properly commonto other salts, as well as saltpetre, to produce this effect.This valuable discovery was made in the beginning of thesixteenth century.

B. Villafranca, a Spanish physician, resident in Rome ,about 1550, was retained by numerous of the nobility andgreat people of that capital; he informs us, that about, andbefore that period, wines cooled by this means were drankat the tables of all the great, in that voluptuous city. Alsoobserving, he was the first who had made the fact public ;which, he notices, was originally occasioned by .having per-ceived that saltw'ater in summer was much colder than freshwater. According to his directions, illustrated by a figure, theliquor must be put into a globular vessel, or bottle, with along neck, for the sake of holding, and for the motionnecessary to be produced; then water must be put into alarger vessel, and the long necked bottle held in the water,whilst saltpetre is thrown into the outer vessel ; the formermust then be put in strong motion, moving it round upon itsaxis whilst the salt is dissolving. Villafranca thinks theweight of the saltpetre necessary for the operation, shouldbe equal to one fourth or fifth part of the weight of wateremployed, which will all erystalize, and may be employedseveral times in the same manner; the mode he proposes toexplain upon the principles at Aristotle , and affords his noblepatrons directions howto use it, and so preserve their health.

An Appulian physician also, Marcus Antonius Zitnara,likewise speaks of it in his book of Problems, often pub-lished with those of Aristotle . The problem of Zimara,alluded to, runs thus: Problema 102. Quasivit dominatiovestra (Joannes Castriota Ferraitdiiue dux) propter quod

‘3 Diet, de Com. article Glace.