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254 MECHANICAL DENTISTRY AND METALLURGY.
ing- to Faraday. lOO parts of steel alloyed with one of plat-
inum is dissolved with effervescence in dilute sulphuric acid
too weak to act with perceptible energy on common steel.
It is offered in explanation of this fact that the steel is ren-
dered positive by the presence of platinum.
Fusible Metals.—A series of alloys, usually known as
fusible metals, consist chiefly of lead, tin, bismuth, and
cadmium. The several metals are fused in a crucible under
a layer of charcoal and stirred thoroughly before pouring.
A very small percentage of mercury is sometimes added just
before pouring- to further lower the fusing point. By the
union of these metals in certain proportions alloys may be
obtained which will fuse below the boiling point of water
tin and bismuth, for instance—both having low melting
points, form alloys which melt at a considerably lower tem-
perature than either of the metals separately. The formulas
of a few of the well known fusible metals are as follows
Newton's Alloy. Rose's Alloy.
Fusing Point 202° F. Parts. Fusing Point 175° F. Parts.
Bismuth 8 Bismuth 8
Tin 8 Tin 3
Lead 5 Lead 8
Wood's Alloy. LiPOvviTZ Alloy.
Fusing Point 160° F. Parts. Fusing Point 145° F. Parts.
Bismuth Bismuth
5 15
Tin 2 Tin 4
Lead 4 Lead 8
Cadmium 2 Cadmium 3
SOLDERS AND SOLDERING.
Solders are fusible alloys used for joining or binding
together two or more metallic surfaces or joints. These
alloys must necessarily l)e more fusible than the metals to
be united, and should have a strong affinity for theuL These
alloys are made in the same manner as other alloys, that is,
254 MECHANICAL DENTISTRY AND METALLURGY.
ing- to Faraday. lOO parts of steel alloyed with one of plat-
inum is dissolved with effervescence in dilute sulphuric acid
too weak to act with perceptible energy on common steel.
It is offered in explanation of this fact that the steel is ren-
dered positive by the presence of platinum.
Fusible Metals.—A series of alloys, usually known as
fusible metals, consist chiefly of lead, tin, bismuth, and
cadmium. The several metals are fused in a crucible under
a layer of charcoal and stirred thoroughly before pouring.
A very small percentage of mercury is sometimes added just
before pouring- to further lower the fusing point. By the
union of these metals in certain proportions alloys may be
obtained which will fuse below the boiling point of water
tin and bismuth, for instance—both having low melting
points, form alloys which melt at a considerably lower tem-
perature than either of the metals separately. The formulas
of a few of the well known fusible metals are as follows
Newton's Alloy. Rose's Alloy.
Fusing Point 202° F. Parts. Fusing Point 175° F. Parts.
Bismuth 8 Bismuth 8
Tin 8 Tin 3
Lead 5 Lead 8
Wood's Alloy. LiPOvviTZ Alloy.
Fusing Point 160° F. Parts. Fusing Point 145° F. Parts.
Bismuth Bismuth
5 15
Tin 2 Tin 4
Lead 4 Lead 8
Cadmium 2 Cadmium 3
SOLDERS AND SOLDERING.
Solders are fusible alloys used for joining or binding
together two or more metallic surfaces or joints. These
alloys must necessarily l)e more fusible than the metals to
be united, and should have a strong affinity for theuL These
alloys are made in the same manner as other alloys, that is,
