EXPERIMENT VII.
The strong Spirit of Sal Armoniac made without Quick Lime operates also more easily and strongly upon the Brass than Spi∣rit of Urine. An Experiment having been made after the same manner as we just be∣fore related, the same Phoenomen was not only observed for Colour, but also that the same Mercury, which was plac'd according to the precedent Experiment, descended, although very slowly, for two or three days in the seal'd side, until it appear'd to be the fourth part of an Inch lower than it was; and probably the descent of Quick-Silver wou'd be greater if the Glass had not been touched, by which the compleating of the Experiment was hindred. The Event whereof, nevertheless, seem'd sufficiently to declare, that the Spring of the Air inclosed in the Concavity of the Glass, and mixing with that which is contained in the open side of the Pipe where the Mercury was, was weak in respect to that which was en∣closed, where it could have no Communica∣tion, since the Quick-Silver hindreth it on one side, and the Glass that was seal'd Her∣metically, on the other.