. Elements of modern chemistry . a=§^Sgo g2 ^ S J? ?? S S ?? *:: 3 ^ ^ 2 ?> ? i ?? o §>§> « fl 3J I S • • • • I 8> • j 1^..^^ 3 „f-Q-^|- g ??^^ s?f ^ ? i a I a S ^i a?^i ? a •i a g t .2 g 3 5 • r i — s S .2 I § -3 n .2 a fl .2~- 3 2!r23Ss-?•3 aS 2 :irt>a-^S§J SSoS<^ GENERAL PROPERTIES OF METALS. 235 metal will solidify first next to tlie walls of the vessel and ontlie surface, where it is most cooled. If, in a little while, thecrust which covers the still liquid metal be pierced, and thelatter be poured out, the whole of the interior of the vesselwill be found c
. Elements of modern chemistry . a=§^Sgo g2 ^ S J? ?? S S ?? *:: 3 ^ ^ 2 ?> ? i ?? o §>§> « fl 3J I S • • • • I 8> • j 1^..^^ 3 „f-Q-^|- g ??^^ s?f ^ ? i a I a S ^i a?^i ? a •i a g t .2 g 3 5 • r i — s S .2 I § -3 n .2 a fl .2~- 3 2!r23Ss-?•3 aS 2 :irt>a-^S§J SSoS<^ GENERAL PROPERTIES OF METALS. 235 metal will solidify first next to tlie walls of the vessel and ontlie surface, where it is most cooled. If, in a little while, thecrust which covers the still liquid metal be pierced, and thelatter be poured out, the whole of the interior of the vesselwill be found covered with magnificent crystals, arranged inhopper-like pyramids, and presenting brilliant, rainbow-likecolors. Other metals, such as copper, lead, antimony, tin, silver, andgold, may be crystallized under certain conditions. Some ofthe metals are found crystallized in nature. Those metals which may be beaten or rolled into thin laminse*are said to be malleable. AA (Fig. 90) represent two steel. Fig. 90. rollers capable of moving on their axes in opposite plate of metal engaged between them will be drawn in, andthe rolled sheet will pass out on the other side with a uniformthickness equal to the distance between the two rollers. Bydiminishing this distance more and more by means of thescrews BB, the sheet may gradually be reduced in thickness. Metals which may be drawn out into wires are said to beductile. The wire-drawing machine is represented in It consists of a steel plate, //, firmly fixed in the up-rights CC, which are themselves solidly attached to a plate is pierced with a series of holes regularly decreasingin diameter. The wire is drawn from the bobbin-A, throughthe holes and around the cylinder B, which is moved by power. That a metal may be drawn into fine wires, it is necessarythat it shall offer a certain resistance to rupture. This is calledthe tenacity of the metal. It is measured by suspending weights 23
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Keywords: ., bookcentury1800, bookdecade18, booksubjectchemistry, bookyear1887
