SCIENTIFIC SUMMARY. 
531 
mercury appeared to be a binary compound. Iron does not appear to 
lose any of its magnetic virtue in consequence of its combination with 
mercury. Its amalgamation has the effect of making it negative with 
respect to iron in the electro-chemical series. The affinity between 
mercury and iron is so feeble that the amalgam is speedily decomposed 
when left undisturbed, and almost immediately when agitated. The 
application of a pressure of fifty tons to the square inch drives out so 
much mercury as to leave only 30 per cent, of it in the resulting button. 
Amalgam of Copper. By precipitating copper on mercury electro- 
lytically, a mass of crystals is gradually formed. After a certain time 
the crystals begin to get fringed with pink, indicating uncombined copper. 
In this state the amalgam is found to be nearly a binary compound. On 
applying strong pressure to an amalgam containing excess of mercury, 
the latter is driven off, leaving a hard mass composed of equivalents of the 
metals ; if, however, the pressure be continued for a long time, the result- 
ing amalgam contains more than one equivalent of copper, indicating a 
partial decomposition. 
The author gave an account of his experiments with amalgams of 
silver, platinum, lead, zinc, and tin. In the case of the latter amalgam, 
long-continued pressure drives off nearly the whole of the mercury, 
indicating in a striking manner the efficacy of mechanical means to 
overcome feeble chemical affinities. 
A new Fusible Alloy. — Dr. Wood, who has investigated many of the 
alloys, has just published a description of a new and interesting fusible 
alloy. “ In the American Journal of Science and Art for September, 
1860,” Dr. Wood says, “will be found a notice of the cadmium allo3 r , dis- 
covered by me, consisting of from one to two parts of cadmium, two parts 
of tin, four parts of lead, and from seven to eight parts of bismuth, and 
so exceedingly fusible as to melt below the temperature of 160° Fahr. A 
brief description of another alloy, similar in character and scarcely less 
remarkable, is herewith submitted ; it consists of cadmium, one part ; 
lead, six parts ; bismuth, seven parts. This alloy melts at about 180° 
Fahr., being nearly midway between the melting-point of the old fusible 
metal, consisting of the three metals, tin, lead, and bismuth, and that of 
the alloy first mentioned, consisting of the four metals, cadmium, tin, lead, 
and bismuth. It is remarkable, as exhibiting the liquefying property of 
cadmium in certain combinations ; also in the fact that, while the mean 
melting-point of the constituents composing it is much higher than that of 
those composing the old fusible metal, it melts at a much lower tempera- 
ture, being more fusible than any other alloy yet known consisting of but 
three metals. It has a clear, brilliant, metallic lustre, that does not readily 
tarnish. Its colour is a bright bluish grey, resembling platinum ; when 
cast, its free surface presents a white frosted appearance. It is very flexible 
in thin plates, and breaks with a hackly fracture ; but when thicker bars 
are broken, the fracture is smooth, resembling that of tempered steel. It 
is malleable, but not perfectly so. Its hardness is about the same as 
bismuth, and about the same as an alloy of two parts of lead and one part 
of tin or coarse solder, which it more nearly resembles in other respects. 
It may be that more approved methods of measuring temperature will give 
