Further Expetiments about Freezing. By Mr. Desmasters. Communicated by Dr. Musgrave

III. Further Experiments about Freezing. By Mr. Desmasters. Communicated by Dr. Musgrave. In the Account given Numb. 245. p. 384. concerning the Expansion of Water by Freezing, the Water then made use of in these Tryals, was, a sort of rough Pump-Water; which, according to what Tryals have been made with it, does, upon the effusion of Oyl of Tartar per deliquium, immediately turn milky and turbid: and considering the Ice made of this Water was a sort of very rarefied white Ice, I was thereby inclined to try whether River Water, which would readily mix with Oyl of Tartar without the least precipitation, would upon freezing be expanded to the height of the Pump-Water, above-mentioned. In order to which, I filled a Glass Tube, of almost an Inch Diameter, with River-Water to the height of Six Inches (as I had done in the former Tryal) and putting it to freeze in a Mixture of Snow and Salt, it gained but \( \frac{1}{4} \) of an Inch after it was frozen, whereas the Pump-Water got \( \frac{7}{4} \) of an Inch. I observed that while the River-Water was freezing, Bubbles rose from the bottom of the Tube much at the same rate as in the freezing of Pump-Water. I likewise took boyled Pump-Water, and having filled a Tube with it to the height of Six Inches, and let it to freeze as before, it rose hardly to \( \frac{6}{4} \) of an Inch above the Mark; when as the same Water un-boyld rose \( \frac{7}{4} \).