Experiment replication - Gould 1684 (Johns Hopkins University, Baltimore, USA, 6/6/2022)

Replication in laboratory of an experiment reported by William Gould, “An Account of the increase of weight in oyl of vitriol expos’d to the air,” Philosophical Transactions 14(156): 496–506 (1684):

“On the ninth of No[vember] 1683. Three drams of oyl of vitriol so far dephlegm’d as to burn or corrode a strong packthred assunder, was expos’d to the air in a marmalade glass of three inches diameter, and plac’t in a nice pair of scales, in a room where no fire nor sun came; its increase for 7 natural days divided by less portions of time was according to the following table [...] upon the view of the whole diary of almost two months; it appear’d, the increase was more in a moist, rainy, misty, and snowy, but less in a frofty, clear, and dry seafon, as also was more in a cold than in a warm air” (pp. 497 & segg.)

“All these circumstances which relate to the quantity will also influence very much the time of the encrease, the last thing to be consider’d in the experiment; but I shall only mention that which makes the most peculiar and principal variation in this point, and tis the proportion of the surface to the the liquor. For I find the greater or less the surface is, the quicker or slower the encrease [...] I expos’d in the same room and to the same temper of the air (as near as I could guess) three drams of the same oyl of vitriol in an open flat glass one inch broad, being only 2/3 of the diameter of that glass us’d at first with the like quantity. The result was this; that whereas the other surface of three inches diameter gain’d (as in the table) near nineteen grains the first six hours, this less surface gained a very little perceivable more then two grains in the same space of time” (pp. 503-504).

The (potential) significance of this experiment for the debate on mineral generation lies also in the fact that it is mentioned by J.F. Henckel, Pyritologia (1721, Engl. transl. 1757): “Dr. Gould, of Oxford, has observed, that oil of vitriol does, by means of the air, encrease in weight, having, for that purpose, exposed a highly dephlegmated oil in an open wide glass, and weighed it accurately every day. In the space of fifty seven days three drachms of oil of vitriol came to nine drachms thirdy grains. The first day the oil increased one drachm and eight grains, afterwards, from day to day, still less, nay, the last day, scarce half a grain. This succeeds in moist foggy weather better than in dry, also in a wide than narrow vessel” (Henckel 1757, p. 374).

Date: June 6, 2022

Place: Johns Hopkins University, Baltimore (MD), US

Project and Funding Source: Horizon 2020 – MGA MSCA-IF – Grant agreement No. 101019781 – SOUNDEPTH

Work Package: 4