Tribo-electricity and friction. III.—Solid elements and textiles

Abstract

1. No systematic investigation on this subject has yet been attempted. The efforts made to group these materials in a series according to the charges generated when they are rubbed two at a time are of uncertain value because of (1) impurities of substance and surface, (2) indeterminate initial surface strains. Moreover, the general practice has been to rub the solids when held, one in each hand. A more reliable method is to mount the bodies in a mechanism which ensures that the same parts of them come into contact at each fresh stroke. In the present research, the elements, mostly metals, are those specified in the preceding paper. The textiles are made and cleansed as described in an earlier paper. Silk, cotton and linen in our experience behave reliably when fully cleaned. The other great textile material, wool, is more oily and cannot be readily cleansed; so is less trustworthy. We therefore at present confine ourselves to one animal and one vegetable textile, choosing the pure samples of silk and cotton specified in the above paper. Also filter paper, another convenient fabric, is used after being boiled in several lots of distilled water. As the silk and cotton are treated with boiling chloroform, we tried exhausting the filter paper in this solvent to see if such treatment affected the cellulose in any way; but no effect on the properties of the paper could be found.