Table of the ductility and malleability of Metals.
| Metals ductile and malleable in alphabetical order. | Brittle metals in alphabetical order. | Metals in the order of their wire-drawing ductility. | Metals in the order of their laminable ductility. |
|---|---|---|---|
| Cadmium. | Antimony. | Gold. | Gold. |
| Copper. | Arsenic. | Silver. | Silver. |
| Gold. | Bismuth. | Platinum. | Copper. |
| Iron. | Cerium. ? | Iron. | Tin. |
| Iridium. | Chromium. | Copper. | Platinum. |
| Lead. | Cobalt. | Zinc. | Lead. |
| Magnesium. | Columbium. ? | Tin. | Zinc. |
| Mercury. | Iridium. | Lead. | Iron. |
| Nickel. | Manganese. | Nickel. | Nickel. |
| Osmium. | Molybdenum. | Palladium. ? | Palladium. ? |
| Palladium. | Osmium. | Cadmium. ? | Cadmium. ? |
| Platinum. | Rhodium. | ||
| Potassium. | Tellurium. | ||
| Silver. | Titanium. | ||
| Sodium. | Tungsten. | ||
| Tin. | Uranium. | ||
| Zinc. |
There appears to be therefore a real difference between ductility and malleability; for the metals which draw into the finest wire are not those which afford the thinnest leaves under the hammer or in the rolling press. Of this fact iron affords a good illustration. Among the metals permanent in the air, 17 are ductile and 16 are brittle. But the most ductile cannot be wire-drawn or laminated to any considerable extent without being annealed from time to time during the progress of the extension, or rather, the sliding of the particles alongside of each other, so as to loosen their lateral cohesion.
DUNGING, in calico-printing, is the application of a bath of cowdung, diffused through hot water, to cotton goods in a particular stage of the manufacture. Dunging and scouring are commonly alternated, and are two of the most important steps in the process. The operation of dunging has for its objects:—
1. To determine the entire combination of the aluminous sub-salts with the stuffs, by separating almost all the acetic acid which was not volatilized in the stove-drying of the mordant.
2. To dissolve and carry off from the cloth a portion of the thickening matters.
3. To separate from the cloth the part of the mordant that is uncombined, and merely mixed mechanically with the gum or starch.
4. To prevent, by the peculiar action of the dung, the uncombined mordant, as well as the acetic acid with which the bath is apt to get loaded, from affecting the blank parts of the cloth, or being injurious to the mordant.
The aluminous base or mordant on the cloth, more or less neutralized by the dunging, is next subjected to the dash-wheel or fulling mill, where by the stream of water the remainder of the thickening and other impurities are washed away.
No very exact analysis has been made of cowdung. Morin’s, which is the most recent and elaborate, is as follows:—