In Modern Sunlight (Murray, 7s. 6d.) Mr. Leonard V. Dodds
tells us of all kinds of curious and important uses to which artificial rays may be pid todiscover, for instance; the impu- rities in paint ; to reproduce the almost-vanished marks of
fossils on rocks ; and, more marvelloui still, to photograph writing on parchment which has been erased and written over ; to test the freshness of eggs ; to sterilize water ; and to improve the health of animals. Mr. Dodds declares that when
pigs were experimented' u-pon, they' crinie of their own accord and lay down under the iiiercury-vapour lamp! The irradia- tion hens has greatly improved their 'egg-laying qualities.
Even bees, under this stimulus, have been known to hum in their hive as if the mid-day sun were shining, and to build many more cells than in a non-treated hive under otherwise exactly similar .conditions. Racehorses have long been treated with ultra-violet rays. But Mr. Dodds is even more interesting in his' description Of what this' new branch Of science may do for litimair heir* : We have here a. guide to heliotherapy in all its aspects, suitable for the general reader as Well as those more
specially interested in the subject.
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