This luminous judgment, it must be noted, was written by a man of acknowledged purity of life, who admired Mirabeau in early life not when he was a statesman, but when he was only a struggling literary man.
Photography is based on chemical action induced by luminous rays; apart from this practical application there are many other cases in which actinic rays occasion chemical actions; these are treated in the article Photochemistry.
Bernard Shaw, though concerned mainly with the social philosophy of the Ring, gives a luminous account of Wagner's mastery of musical movement.
According to the best determinations the value of elm does not exceed 1.8X Io', and T is of the order of Io 15 second, the period of luminous vibrations; hence OM/M must always be less than 109 H, and therefore the strongest fields yet reached experimentally, which fall considerably short of Io %, could not change the magnetic moment M by as much as a ten-thousandth part.
In many cases the subject of examination is a luminous line of uniform intensity, the various points of which are to be treated as independent sources of light.