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Dichroscopes for microscope stage and ocular

Published online by Cambridge University Press:  14 March 2018

A. T. J. Dollar
A. T. J. Dollar*
Affiliation:
Department of Geology, University of Glasgow
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Extract

The optical accessories here described are two dichroscopes to facilitate microscopical comparisons by eye between the hues and intensities of axial absorption colours shown by thin slices, crushed fragments, or detrital grains of transparent coloured doubly-refracting crystals. Their chief applications lie in microscopic mineralogy and petrology, but they can be of service, also, in chemistry and allied subjects.

The aims of the accessories are two in number. They provide: (i) simple microscopic means for viewing simultaneously any pair of distinct hues, intensities of hue, or combinations of these variables, which result from differential absorption of white light; and (ii) a convenient method for detecting small differences between any pair of hues, intensities, or both, in terms of immediate ocular comparison between two sets of small symmetrically-shaped coloured images which alternate, and meet in straight boundaries.

Type
Research Article
Information
Mineralogical magazine and journal of the Mineralogical Society , Volume 29 , Issue 209 , June 1950 , pp. 163 - 172
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1950

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