140 Sezéentific Intelligence. 
SCIENTIFIC INTELLIGENCE. 
I, CHEMISTRY AND PHYSICS. 
stance was again subjected to pressure, this time for only a few 
‘days. third measurement of specific gravity was then made. 
Thus lead, whose density before pressing was 11°350 at 14°, had 
a specific gravity of 11°501 at 14° after the first pressing, and of 
11-492 at 16°, after the second. Antimony was 6°675 at 16° 
before, and 6°733 at 15° and 6-740 at 16° after pressing. Zinc, — 
7°142 at 16°, was 7°153 at 16° and 7°150 at 16° after it was pressed. 
Potassium sulphate, 2°653 at 21°, was 2°651 at 22° and 2°656 at 
22°, after the pressure. Potassium alum, 1°758 at 21°, became 
1°756 at 16°5° and 1°750 at 16°5°. Potassium chloride, 1°980 at 
22°, became 2-071 at 22° and 2-068 at 21°, after pressure. It will - 
be noticed that after the first pressing, the density of some of © 
th 
not fundamental. Moreov is permanence of y oR 
t incompressibility of the materials, since their volume 
continually di hed as the pressure incre pis 
the pressure however, the original volume was completely resumed; 
the elasticity of these solids being as perfect as that of liquids an¢ 
ases. Some time ago the author had shown that bodies oper : 
