Lectures on Education delivered at the Royal Institution of Great Britain, London, 1855, published in "What Knowledge is of Most Worth", The Westminster Review (July 1859) volume CXLI, p. 1-23, at p. 19 http://books.google.com/books?id=5NQ6AQAAMAAJ&pg=RA1-PA19
Kontext: The current opinion that science and poetry are opposed is a delusion. … Think you that a drop of water, which to the vulgar eye is but a drop of water, loses any thing in the eye of the physicist who knows that its elements are held together by a force which, if suddenly liberated, would produce a flash of lightning? Think you that what is carelessly looked upon by the uninitiated as a mere snow-flake does not suggest higher associations to one who has seen through a microscope the wondrously varied and elegant forms of snow-crystals? Think you that the rounded rock marked with parallel scratches calls up as much poetry in an ignorant mind as in the mind of a geologist, who knows that over this rock a glacier slid a million years ago? The truth is, that those who have never entered upon scientific pursuits know not a tithe of the poetry by which they are surrounded.