306 Prof. Horsford on the Permeability of Metals to Mercury. 
to give, in the following paper, the results at which I have 
arrived.* 
Experiments with Lead.—The bars employed by me, witha 
few exceptions for specified purposes were cast in paper moulds 
surrounded by sand, of a diameter varying but slightly from -0U6 
m., aud of variable lengths to suit the objects of experiment. 
The following inquiries were submitted to experiment. 
I. Has the bar saturated with lead increased specific gravity ? 
Bars of lead, after standing in a cup of mercury until they had 
become saturated with the latter metal, were taken ont and care- 
fully scraped to remove the surface coat, and the specific gravity 
ascertained in the usual manner. ‘The following determinations 
d 
” were made, 
Sp. gr. of lead. Sp. gr. of lead and mercury. 
11-431 ug tes ae 
11:405 Sdrawn bars. 11-426 
11-407 rag ee ee 
11-415 
11-414 average. 
11-421 average. 
11-423 
11:405< cast bar. 11-464 cast bar. 
11-387 : 
11-405 % 
They seem to indicate increased specific gravity. 
The irregularity of these results led to au experiment to ascer- 
tain if there might be cavities in the bar. The specific gravity 
of mercury being greater than that of lead, as 13°575 (Fahren- 
heit) is to 13-445 (Berzelius), a bar containing cavities would 
have when saturated with merenry a higher specific gravity than 
a bar without cavities, similarly saturated, 
‘The following are the weights before and after being saturated 
with mercury. a 
Increased to” 
I. 46342 gr.oflead. 2. , ‘ 46730 gr. 
If. 48403 « “ es cc (SO 
Ill. 62051 « ae : , a 63153 “ 
: Increase, 
I. 00888 grammes. 
If. 00787 ¢“ 
ILI. 0-1 102 “ 
The result was unsatisfactory, nearly equal weights of lead 
had apparently absorbed weights of mercury differing from each 
other by a hundred per cent. — 
~ # I met with the first exhibition of the experiment of Prof Henry in the labora- 
tory of Prof. Ten Eyck of Aiteayod a 
