Chemistry and Physics. 321 
flask. The Florence flask filled with w ater is heated a pet beneath 
by a Bunsen burner, and water entering through the stop cock 
from the glass bottle is raised to the boiling point. The bubbles 
of steam rise in the vertical tube and the alternations of heating in 
the flask and changes of level of the water in the vertical tube 
cause steam and water to issue with violence from the vertical tube. 
The tube conveying the cold water to the Florence flask should be 
curved at its lower end to prevent the cold water from striking 
the hot base of the flask, and the vertical tube should be flush 
with the bottom of the cork which closes the Florence flask.— 
ie der Physik und Chemie, No. 1, 1882, pp. 173-175. 3. 7. 
. Electrical resistance of Gases. —E. Epuunp in this er 
reviews the segs of previous experimenters, especially thee of 
Becquerel and Hittorf. Since it is known that gases differ from 
solid and fluid rere? in not conducting electricity wie the elee- 
neous fnieimess n. Edlun anew that his unitarian theory o 
electricity is borne out by the behavior of gas in respect to elec- 
trical conduction.—Ann. der Physik und ‘Chemie, No. 1, 1882, 
pp- 165-171. 3 x 
3. Dielectric pete in Electrolytes. — The phenomenon 
of sieotsion! conduction through electrolytes has lately been the 
8 
ductors of electricity. Among these rabacabces were benzo 
light benzine, heavy benzine, petroleum, olive oil, solution of 
chloride of iron in benzol, and ether. The results of his investiga- 
tion confirm the views of Faraday and Maxwell in regard to elec- 
trical action in a dielectric. Dielectric ee exists not 
only in insulators but also in conductors, the dielectric con- 
stants of electrolytes are of the same order i proutieas as those 
of true dielectrics.—Ann. der Physik und Chemie, No. 1, aig 
pp. 94-111. 
Change of temperature due to extension and soiaiaseton: of 
metallic wires.—In works on thermo-dynamics the expression 
5 (273+) aP., 
=— ee is given for the change of temperature which 
results from mechanical strains in wires produced by extension 
and subsequent contraction. In this expression, 
