DE. A. MATTHIESSEN ON THE SPECIEIC GEAVITT OE ALLOTS. 
179 
where they did not agree amongst themselves to O'l per cent, of the value, a + will be 
placed by the alloy, and the value there given is the mean of a number of experiments 
(generally six or more)*. 
Table I. 
Specific gravity found. 
Metal, 
1st Deter- 
mination. 
T. 
2nd Deter- 
mination 
re-fused. 
T. 
3rd Deter- 
mination 
re-fused. 
T. 
Mean of 
Determined by 
Spec. gray. 
T. 
Antimony ... 
6-715 
13-6 
6-713 
14-4 
6-710 
15-0 
6-713 
14-3 
A. Matthiessen. 
Tin 
7-293 
11-5 
7-295 
12-8 
7-294 
14-0 
7-294 
12-8 
A. Matthiessen. 
Cadmium 
8-655 
10-0 
8-657 
10-2 
8-654 
11-2 
8-655 
10-5 
A. Matthiessen. 
Bismuth 
9-823 
12-0 
9-824 
12-4 
9-823 
12-4 
9-823 
12-3 
Dr. M. Holzmann. 
Silver t 
10-468 
13-2 
Dr. M. Holzmann. 
Lead 
11-374 
13-0 
11-380 
16-5 
11-376 
11-0 
11-376 
13-5 
Dr. M. Holzmann. 
Mercury 
13-575 
14-0 
13-569 
14-7 
13-574 
14-8 
13-573 
14-5 
Dr. M. Holzmann. 
Gold 
19-261 
10-0 
19-269 
15-5 
19-264 
12-8 
19-265 
12-8 
A. Matthiessen. 
Table II. gives the mean of the three determinations made with the alloys, the mean 
of the temperatures (T.), and the specific gravity calculated from the first of the follow- 
ing formulae : — 
A + Aj 
( 1 -) 
where 
71S + WjSj 
9 
S= 
As + A] Si 
A + Ai ’ 
S=the specific gravity of the alloy, 
V and Vi = the volumes of the metals, taking 
n and Wi = the numbers of the equivalents of the metals, and 
A and Ai = their respective weights. 
s and §1 — their specific gra\ities. 
( 2 .) 
( 3 .) 
* Those alloys which are underlined have been made twice, as it was supposed these must have an error 
in the weighing out of the metals, as they do not agree with the calculated values. The values, however, 
were found to be correct. 
t No concordant results could be obtained with this metal. Experiments were made with it after having 
been fused under borax, chloride of sodium, charcoal, in hydrogen. The above value is the mean of a 
number of determinations which varied between 10’424 and lO'Sll. 
Some specimens of not quite pure silver were lent me by Mr. Ph. "Woeslet, who prepared them as 
follows ; — 
The silver was made as hot as possible, and well-stirred with a stick of charcoal before pouring. The 
mould was a steel one, forming a bar of about 25 millims. square and about 300 millims. high. The bar 
weighed about 2y kilogrammes. The top of it, when cold, showed a funnel-shaped depression, and the 
soundest part of it was about two-thirds down, and from this different pieces were cut, which gave very good 
results. The values obtained were 10'504, 16°'7 ; 10’505, 17°'2 ; 10‘502, 19°'2. A second bar gave similar 
numbers ; they were 10-500, 24°-5 ; 10-496, 24°-8 ; 10-492, 25°-0. 
2b2 
