Benjamin Franklin stated he was in the habit of rising every morning and reading or writing in his chamber without any clothes on for one half to one hour, according to the season, so as to get the benefit of a cold air bath. In this practice he was followed by Thoreau. As long ago as 1835, sun baths were successfully prescribed for rickets and scrofula. Dowries and Blunt in 1876 proved that sun- light killed bacteria.















