Lord Monboddo, the Scotch judge, who was a pioneer in regard to many modern ideas, had already in the eighteenth century realized the hygienic value of “air-baths,” and he invented that now familiar name.  “Lord Monboddo,” says Boswell, in 1777 (Life of Johnson, edited by Hill, vol. iii, p. 168) “told me that he awaked every morning at four, and then for his health got up and walked in his room naked, with the window open, which he called taking an air-bath.”  It is said also, I know not on what authority, that he made his beautiful daughters take an air-bath naked on the terrace every morning.  Another distinguished man of the same century, Benjamin Franklin, used sometimes to work naked in his study on hygienic grounds, and, it is recorded, once affrighted a servant-girl by opening the door in an absent-minded moment, thus unattired.

Rikli seems to have been the apostle of air-baths and sun-baths regarded as a systematic method.  He established light-and air-baths over half a century ago at Trieste and elsewhere in Austria.  His motto was:  “Light, Truth, and Freedom are the motive forces towards the highest development of physical and moral health.”  Man is not a fish, he declared; light and air are the first conditions of a highly organized life.  Solaria for the treatment of a number of different disordered conditions are now commonly established, and most systems of natural therapeutics attach prime importance to light and air, while in medicine generally it is beginning to be recognized that such influences can by no means be neglected.  Dr. Fernand Sandoz, in his Introduction a la Therapeutique Naturiste par les agents Physiques et Dietetiques (1907) sets forth such methods comprehensively.  In Germany sun-baths have become widely common; thus Lenkei (in a paper summarized in British Medical Journal, Oct. 31, 1908) prescribes them with much benefit in tuberculosis, rheumatic conditions, obesity, anaemia, neurasthenia, etc.  He considers that their peculiar value lies in the action of light.  Professor J.N.  Hyde, of Chicago, even believes ("Light-Hunger in the Production of Psoriasis,” British Medical Journal, Oct. 6, 1906), that psoriasis is caused by deficiency of sunlight, and is best cured by the application of light.  This belief, which has not, however, been generally accepted in its unqualified form, he ingeniously supports by the fact that psoriasis tends to appear on the most exposed parts of the body, which may be held to naturally receive and require the maximum of light, and by the absence of the disease in hot countries and among negroes.

The hygienic value of nakedness is indicated by the robust health of the savages throughout the world who go naked.  The vigor of the Irish, also, has been connected with the fact that (as Fynes Moryson’s Itinerary shows) both sexes, even among persons of high social class, were accustomed to go naked except for a mantle,