Page 310
EXPERIMENT III.
THE 12th of March, Eight Ounces of Out∣landish Vitriol calcin'd to a Redness, be∣ing put into a broad and flat Metalline Vessel; and into another Vessel smaller than the other, we put 2 Ounces of Colcothar, so that the Su∣perficies of the latter, was larger, in respect of it's Quantity than the Superficies of the other. June 25. We weigh'd these Powders, and found that the 8 Ounces had gain'd a Drachm and 16 Grains, and the 2 Ounces had gain'd as much within a Grain. Then the Powders being put into the same Vessels, August the 4th, the smal∣ler Quantity weigh'd 26 Grains more than it did in June. Whence it appears, that different Cir∣cumstances cause notable Disparities in the In∣crease of Weight.