III. On the optical phenomena of certain crystals

Abstract

Some time ago I had the honour to communicate to the Royal Society an account of my invention of the polarizing microscope. This instrument possesses so great a power of developing the internal structure of transparent bodies, even in their mi­nutest visible particles, that I feel confident the employment of it will lead to many new and interesting results. At present I mean to confine myself to the description of a phenomenon which shows strikingly the beautiful order and regularity with which nature disposes the fabric of some of her minutest visible works. The object I speak of is a kind of minute crystallization which may be obtained in peculiar circumstances, and I doubt not, in many different ways; but the manner in which it has presented itself to my observation is as follows.