506 Scientific Iniellugence. 
SCIENTIFIC INTELLIGENCE. 
I, CHEMISTRY AND PuHysics. 
1. e Specific Heats of Zirconium, Silicon and Boron.— 
W. G. Mei and E. 8. Dana have determined with great care, 
in Bunsen’s laboratory, the A ota heats of zirconium, of silicon 
and of boron, with av o fix the atomic weight of zirconium 
mm consequently the Iormule of zirconia. Although this earth 
forms salts with acids, yet Marignac’s discovery of the isomor- 
phism of zirconium fluoride with the fluorides of silicon, of titan- 
ium and of tin, has resulted in giving the formula ZrO, to zirconia, 
instead of ZrO or Zr 20,. The specific heat determinations were 
made with the original ice-calorimeter of Bunsen.* In order to 
bec ome familiar with the use of the apparatus, some preliminary 
experiments were made with chemicall par cast et and with 
c sos silicon. The constants of the aratus were 
9 3 Tepresenting Passo yt Ae in aiiaond of t the scale 
on "he instrument the quantity of heat evolved by one gram of 
water, platinum and the cine used, when cooled from 1° to 0° C. 
ese values were as follows: W,,==14°657 ; ; Wp=0°4692; Wy= 
2°7657. The results of the Pillai experiments are given in 
the following table 
Silver, Silicon, Silicon. 
Weight of eae poate G, 41415 10011 10011 
Weight of glass case-..--.-- Gg, 0 0-2014 02014 
Weight of platinum ee este Gg, 0 04374 0°437 4 
wo a of Gxptiecd ceses t 99°3° 99°45° 99°45 
Duration of experiment.... M, —M, ‘ 40’ 20’ 45 
Scale motion before expt., Be +0°02 +0-236 +0°169 
ry ? 
t 
“ “ after “ vd : +0163 +0°327 +0°151 
Oscillation of seale-----... Q—Q,, 3275 3176 este: 
rected movement_-___.__ z, 33116 3°23 324° 
Bh ck oi ces bdcs 8, 0-05494 0716995 0°1704 
The value thus found for the specific heat of silver, 0°0549, agrees 
very well with that obtained by Bunsen, 0°0559, and is less than 
that given by Regnault, 0°0570, For silicon, different oe 
gave Regnault values varying between 0°166 and 0°180. order 
to ascertain the purity of their specimen, which consisted of large 
_ gow (14-20-1710) 2-429 for its atomic heat; thus con- 
le oD he deviation of this element, even when pure, from the 
law of Dulong and Petit. 
‘* This ASE III, i, 172, 271, 348, 1874. 
