Plate, arrangement of lenses for viewing crystals by [John Frederick William Herschel] Plate V containing figure 6 which shows a diagram of an arrangement of lenses used for viewing crystals. Subject: Physics Published in Philosophical Transactions as 'On the action of crystallized bodies on homogeneous light, and on the causes of the deviation from Newton's scale in the tints which many of them develope on exposure to a polarised ray'. Read 23 December 1819. [1819]