408 Scientifie Intelligence. 
in adjusting the compensation of a pendulum. It is however first 
mentioned in print in Prof. Bache’s reports on Weights and Meas- 
ures for 1846 and 1848, and ced described and figured in ee re- 
port for 1856. It is referred t as having been us ised t mpare 
oe 
1 na new ‘Ac id o of Sulphur.—Some years ago Schonbein no- 
ticed that when an aqueous solution of sulphurous acid is acted upon 
by zinc for a few moments, it becomes yellow in color, and acquires 
the property of decolorizing energetically mena of indigo and 
litmus. He supposed ozone to be in some way formed, and to 
act as the bleaching agent. This interesting nha has been 
recently studied by ScutrzenpercEr, who argued that since the 
indigo and litmus solutions, thus bleached, regained their color on 
exposure to the air, the décolorization must be due to a reduction 
rather than to an oxydation ; and since the liquid possessed 
activity even after separation from the zine, the effect could n 
be due to a simultaneous action of the acid and zinc, but vin 
result from the production of some new and energetic reducing 
body, which it would be possible to isolate. His pre griweil 
h ee 
of a titred potassic permanganate solution is one and a half times 
that of the sulphurous acid solution, b < utting in the zinc; 
5th, that the zinc may be replaced by ee eat or by 
magnesium with the same results ; and ‘eth, that no h drogen is 
oe Petes ie ai Me ala eis ee ae o 
apo ne te ORE et ee Ene Me eR rs Wa: Sh) a SACRE eee SG Re el en ee ee ee ee 
