Bleaching by Eleetrioity.--Dobbie and Hutcheson have experimented upon bleaching by the aid of electrolysis. For this purpose the stuff is dipped into sea water and then passed through hot rolls which are connected with the poles of a galvanic battery. In order to decompose the hypochloride which is thus formed, the cloth is drawn through diluted acid and fully bleached.--Dingler's Journal, Oct., '82.
Gravity
Barometer. --Maseart has invented a barometer in which the variations of weight are shown and measured by the changes of height in a column of mercury, which is in equilibrium with the pressure of a mass of gas. The instrument has been tested under shocks of every kind to which it would be exposed in traveling in Paris, Hamburg, Stockholm, Drontheim, and TromsS. It was found to be readily transportable, and its precision did not appear t~ be inferior to that of the pendulum. It requires no other observation than that of the temperature and the level of the mercury, and the preparation can be made in less than an hour in a hotel chamber.--