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and because it can be done only at certain times, I have most commonlymade the Experiment with Sphit of Vinus, or Verdigrtase, which it rheHighest Vtnegar in the World ; Wich this the Cold will be most Sensible totheToUch, and most conspituous on the Weather Glass. For by this Mix-ture I have in the Summer made a Weathtr Glass to Descend below the Tem-perament of Cold Fountain-water, 6 Indes at least, which brought it sonear the Freezing Mark that it scarce wanted half an Inch. But at thefame time the Liquor Swells and takes up more room than bcfore, and wil!not be contained in Shallow Veflels. In this Experiment we have famethings very Rare, that a great and violent motion of two Diflenting Li-quor,--, shouid be Io lar from producing Heat as to produce a notable degrecof Cold, and that too with aconsidcrable£xpj»/to»of their parts. Here wemight Instance in an apposite and as unexpected an Experiment, where anEffect contrary to our common Observation happenj, and that is thus; IFyou Mix with Oyl of Vitriol a quantity of Water, a great Heat will followwithout an Expansion of thesc Liquors, whereas Heat does conllantly produceit in Wine, Water, and most Fluid and Solid Bodies: For here it ratber Shrinktand Condenses , as you may see by making the Experiment in a Glast witha long Neck and sctting your Mark as soon as you make your Mixture.Both thesc Instances may a litt le puzile theC arttfian Hypotbefis to account for,tho’ I am far from thinking they are able to destroy it. But to proceed withour Experiments, aster I had sufficiently fatisfy’d the Worthy Spectators,that the produced degree of Cold was very confiderable, I then poured inscme fev/ Drops of another Liquor, that soon altered the Temper of ourCold Mixture, and in two or three Minute« brought ic to a warmth be«yond that of the Ambient Air, though it was a very warm Sun (hining Day,in July.

To apply the Experiment. In the Cold Fit of an Ague we have osten aStrong and Quick Vulse, which argues an EbuHitton ftho’ I dare not call itan Effervescence) and Quick Motion of the Bleod, and the Pains of theHead and other Parts may be due to too great Di st fest or Extension of theVeflels, which depends on the Expansum of the Boyling Humours. In thisArtisicial tho’ Cold Mixture we observe, a mighty Commotion and HighE bullit ion and Expansum of the Liquor. In the Blood and other Juices of theBody we constantly discover great Quantities of Volatile Salts, and some-rimes either from an Infected Air, or bad Dyet, and from scverai otherCausis, Sour Juices may be derived to the Bhod, which may so act upon thoseVolatile Salts, the Blood fo much abounds with, asto give a notable Sense ofCold. It is no new thing for us to meet with Patients, that have throwoupon their Stomaeh and Beweis (which are the great EmunBories of theBlood) very Sour Lkjuors, soch as whsn they happen to fall upon theTeeth will Corrode those Hard Parts. Thus in our Experiment ’tis plain, that aforreign Acid meeting with a Volatile Seit drawn from the Blood, does pro-duce a Cold Effeti-, andsince we knowno Liquors but a Mixture of this kindthat gives soch a ColdVhanomertm, it feenw not unreafonable to believe thatthe Cold Fit of an Ague may be due to soch a Mixture.

As to the hcaUsctnee, made ia our Mixture, I (hould have told c u, that it

was