The London, Edinburgh and Dublin philosophical magazine and journal of science . chis founded on the principle of Lichtenbergs figures), showedthat the two slices were in fact absolutely homogeneous; for thecrystal having been heated, and, while cooling, dusted overwith the proper mixture, showed one of the two surfaces per-fectly yellow, the other perfectly red. The method employed in experimenting on the conductivityfor heat has been adapted from one used by F. Weberf forliquids. A thermoelectric junction, fixed in a copper cylinder, * Wied. Ann. xx. p. 592 (1883). t F. Weber, Wied. Ann. x.
The London, Edinburgh and Dublin philosophical magazine and journal of science . chis founded on the principle of Lichtenbergs figures), showedthat the two slices were in fact absolutely homogeneous; for thecrystal having been heated, and, while cooling, dusted overwith the proper mixture, showed one of the two surfaces per-fectly yellow, the other perfectly red. The method employed in experimenting on the conductivityfor heat has been adapted from one used by F. Weberf forliquids. A thermoelectric junction, fixed in a copper cylinder, * Wied. Ann. xx. p. 592 (1883). t F. Weber, Wied. Ann. x. p. 103 (1880). of Tourmaline for Heat. 429 rests on the tourmaline plate. Both the junction and the p]ateare allowed to acquire the temperature of the room; the undersurface of the slice is then cooled to 0° C. by bringing it incontact with a smooth surface of ice, and the change of tem-perature is read off on the scale of a delicate mirror-galvano-meter. The galvanometer (fig. 1, G) used by me was one ofsmall resistance, with an astatic needle and a powerful damper. Fig.
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Keywords: ., bookcentury1800, bookdecade1840, bookidlondon, booksubjectscience
