328 Scventific Intelligence. 
SCIEN-TIFIC INTELLIGENCE: 
I. Puystcs. 
1. Changes of volume produced by Electricity. a sums 
up his results and those of other observers as follows: 1. Solid 
case of fat oils. 3. Quincke has not observed any change of 
volume in gases submitted to electrical oo If a change 
takes place it must be smaller than sygy-oa-—a7 Of the volume 
of air submitted to examination. 4. The change of volume is 
n 
glass, which is a better conductor of electricity. Upon the dis- 
densers the glass resumes its original volume ; this resumption is 
Po eal yne a in . case of flint glass, but slower with Thiringian 
glass. 5. ength of a cylindrical condenser alters at the 
same time that its volume ch 6. The changes in volume 
e 
the condenser. 7, These changes are appronn ftely: a ortional 
to the square of the ratio of the difference of pot Spee ge 
thickness. These changes are different in different Seietuiibes 
8. After the discharge _ br coatings of the condenser a residual 
change of volume and length is observed. This effect is very 
small with flint glass, greater with Thiringian glass, and appears 
to ea upon the electric polarization of the mass of the glass. 
changes in ee and length do not arise from an 
t 
result. 15. By means of yards es einem dilated ass 
shows no electric double refraction. 16. The results of Dr. gle 
on positive and negative electrical double refraction depend on 
the manner in which the index of refraction in different substances 
changes with the density and the volume under electrical influ- 
