The chief works of Benedict de Spinoza,
translated from the latin by R.H.M. Elwes,
London, George Bell and sons,

Introduction : a short treatise on the rainbow

Skill in polishing lenses gave him sufficient money for his scanty needs, and he acquired a reputation as an optician before he became known as a philosopher. It was in this capacity that he was consulted by Leibnitz.
His only contribution to the science was a short treatise on the rainbow, printed posthumously in 1687.
This was long regarded as lost, but has, in our own time, been recovered and reprinted by Dr. Van Vloten.

Chap. VI. Of Miracles: His bow in the cloud

In Genesis ix. 13, God tells Noah that He will set His bow in the cloud;
this action of God's is but another way of expressing the refraction and reflection which the rays of the sun are subjected to in drops of water.

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