Prof. Horsfordon the Permeability of Metals to Mercury. 311 
could not be ascertained. It is evident nevertheless from this 
experiment and those detailed yore inquiry (11), that the prog- 
ress of mercury is so slow after having penetrated some 0-150 to 
0200 mm. of mere length, that length influences more than ver- 
tical height. From the results of the first and second series of 
experimeuts, arose naturally the inquiry, 
VII. Does the mercury saturated with lead flow through 
leaden bars ? 
The following experiments were made. 
Ist. Two syphon- shaped bars were placed in mercury that had 
once run through lead. In three days drops fell from both. 
ercury it which lead had been standing for months, and 
which was viscid from the presence of crystallized amalgam, 
was taken, and two bar syphons, one saturated with mercury 
and the other pure, were placed in it. In due time the amalgam 
fell from both. 
3d. Three syphons of nearly equal length were placed in 
cup of mercury. In due time the amalgam dropped from al. 
In a few days the cup was emptied. As it ran through it was 
received into a second cup, from which when the first was emp- 
tied, it pee poured back, to run through a second umes and a 
third, and so on. 
The atealeae thus ran through some twelve or mare times. 
It was saturated when it first came through, for it had every fa- 
cility for acquiring the largest measure of lead i could hold. In 
this condition it ran repeatedly through the bar 
The quantity of liquid amalgam Sauiament and there accu- 
mulated in the cup, at each end of the bar, crystallized amalgam. 
he mercury had evidently evaporate 
Bars brittle when first withdrawn from the mercury in time 
recovered their tenacity, and apparently, with the loss of mercury 
Yy evaporation. This led to analyses in answer to the inquiry, 
hat is the constitution of the bar saturated with mer- 
cury when in contact dies the mercury, and also after long exr- 
Posure to the atmosphere 
An analysis of the Cea bar—the lead determined as sul- 
Phate* and the mereury as sulphide, gave of 
* An analysis of the saturated bar, by a ing under a mixture of carbonate of 
Soda, cyanid of potassium and sand, gav 
Le 
ab os ‘ ‘ 2 i 96°53 
Mercury, - - - - - . - B47 
100°00 
Another gave of 
Lead, - - - - - 94°25 
Mercury, - a ae - Ss - 676 
10006 
ig aloe tias if the loss by vaporization nove ee emtraced ‘eer 
eury, it included some of the lead in 
