from The Century Dictionary.
- noun A glass plate with a band, or usually a series of bands, of very finely ruled lines, used in testing the resolving power of microscopic objectives, particularly of high powers.
- noun In ceramics, a piece of pottery upon which the vitrifiable colors are tried before being used on the pieces to be decorated, usually a plate with the different colors painted on its rim.
Sorry, no etymologies found.
With this illuminator Möller's balsam test-plate is resolved with ease, with suitable objectives.
No. 628: "O summer time! you who give good opportunities for rendezvous by drying the small ditches and covering the trees with a dense abundance of leaves! you test-plate of the gold of love-happiness, you must not fade away yet for a long time."