Scientific Intelligence. “966 
* 
SCIENTIFIC INTELLIGENCE: 
I. CHEMISTRY. | 
1, On the Electrical Conductibility of certain bodies; by Ev. Bre- 
QuEREL, (Comptes Rendus, March 1846.)—It has been shown that the 
coefficients representing the relative conductibility of different substan- 
ces, do not answer for different degrees of temperature ; thus at 32° 
Pahr,, silver conducts about 57 times more readily than mercury, while 
at 212° Fahr. the comparative conductibility of these two metals is as 44 
to 1; the same amount of heat creating a much greater relative resist- 
-8nce in the silver than in the mercury. From the author’s experiments 
the following table has been constructed. 
| 
|Londucting power compared with that of silver at|Conducting power at 212° 
3 32° Pahr. -_.|Fahr. compared with that of] 
AL 82° Pabrs yat212°Fahr.| silver at 212° Fahr. 
re silver, (annealed) 100°. | 71-316— (Silver, - 100° | 
* copper, “ 1-517| 64-919 |Copper, - 91-030 
gold, eee? 60| 48-489 67-992 
mium, 24:579| 17:506 (Zi : 24-673) 
Cy : 
24-063} 1'7-°596 Cadmium, ~ 24-547 
. ' . « 
* 
' . ’ 4 ‘ a ‘ 
7-933, 6688 |Le 
1-739}. 15749 |Mercury, 
Shee J. Lawrence Smits. 
: 2 Liberation of Electricity by the bursting of a Bladder ; (Chem- 
ist; April, 1846,)—Mr. J. Dupréy has shown that in the well known ex- 
Periment of bursting a bladder stretched over the mouth of a vessel, by 
the alr pump, electricity is always liberated, and that it is of a positive 
character. _ It is shown by passing a brass rod through the side of the 
_Fecelver, into which it is cemented, the inner end seertag a 
we b, the outer being connected with an electroscope. 
3. Appreciation of the Force of . Magnets; by M. DE Haupar, 
( "Institut, No, 647, May 27, 1846.)—M. de Haldat has contrived a 
Means of ascertaining the force of magnets, based on the influence ex- 
erted at a distance from a needle. The apparatus is extremely simple ; 
FF consists of a rule two to'three meters long and three to four decime- 
8 ters in width, subdivided into centimeters, and divided into two equal 
Parts by a longitudinal line. A delicate needle twelve to fifteen cen- 
‘Meters in length, is fixed on a pivot on the meridian line; and a point 
. * of copper is adapted to it, to indicate by its coincidence with the ex- 
7 . 
