Page:A Practical Treatise on Brewing (4th ed.).djvu/238

222 We learn from the researches of Beckerel, by what feeble electrical forces great chemical results may be produced. Slight electrical polarity, produced by the temperature of a piece of metal being higher at one end than at the other, is sufficient to excite certain chemical actions. From these facts, we may imagine the great power those alterations in the electrical states of the earth and air, which are constantly occurring in connection with meteorological changes, must have on chemical processes.

Mr. Weekes, of Sandwich, has kept a register of the electrical changes of the atmosphere for the last three years, which may be seen in the Transactions of the London Electrical Society. The instrument he uses for ascertaining these changes, is a wire for collecting the atmospherical electricity, extended between two elevated points, and connected with them by non-conductors. From the centre of this atmospherical wire, another wire extends to the electroscope, by which the power and appearance of the electricity collected by the former are manifested. To give an idea of the quantity thus collected, I shall simply give Mr. Weekes' report for 9th May 1841, as per the register for that