THE THREE HALOS.
Take a saturated solution of alum, and, having spread a few drops of it over a plate of glass, it will rapidly crystallize. When this plate is held between the observer and the sun or a lamp-flame, with the eye very close to the smooth side of the glass plate, there will be seen three beautiful halos of light at different distances from the luminous body. The smallest, which is the innermost circle, is the whitest, the second is larger and more colored, with its blue rays extending outward, and the third is very large and highly colored.
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