Prof. Horsford on the Permeability of Metalsto Mercury. 317 
Summary of Results. 
Ist. The specific gravity of lead is increased by saturation with 
mercury. 
2d. The velocity of mercury diminishes, as the length of the 
saturated bar increases—and in a kind of geometrical ratio. 
. The progress is more rapid in cast than in drawn lead. 
4th. The total height to which the mercury attains is greater 
in cast than in drawn lea 
5th. Gravity facilitates the flow of mercury from above down- 
ard , 
6th. The mercury, which passes through a syphon-shaped bar 
of lead, contains Jead in solution. ‘ 
7th. This lead is derived from the interior of the bar. 
8th. After the transmission of a certain amount of mercury, 
and the return of this mercury to be passed again, the amount 
transmitted in a given time attains a maximum. 
9th. The amount passed in a given time with a given length 
of the shorter leg of the syphon, is dependent on the absorbing 
surface exposed to the mercury. » 
The syphon action is limited by the same law that de- 
termines the height or length of bar, through which mercury . 
will pass. 
llth. Mercury saturated with lead passes through leaden bars. 
_ 12th. The saturated bar is eminently brittle. 
13th. the saturated bar contains— 
3°55 per cent of mercury. 
96-45. * ad. 
14th. The bar saturated with, and afterwards withdrawn from 
the mercury, in seven months lost by atmospheric diffusion— 
2:75 per cent. of mercury. 
Leaving only 80 “ “ in the bar. 
15th. In this condition the bar had nearly recovered its origi- 
nal texture. 
16th. After the loss of a certain amount by diffusion, the sur- 
face becomes coated with crystalline amalgam, and the diffusion 
ceases, “ 
17th. The liquid amalgam contains 2°52 per cent. of lead. 
18th. The saturated bar long in contact with mercury assumes 
4 Crystalline texture and cracks open 
19th. After crystallization commences the progress of the mer- 
cury is impeded. 
20th. The specific gravity of tin is increased by saturation 
with mercury. oe : 
Ist. The saturated bar soon opens by numerous fissures, pre- 
senting crystalline angles and surfaces. ee PO a 
22d. The specific gravity of the HF tents amalgam is greater 
th mercury. — 
than that of the bar merely saturated wi 
