86 BACTERIA IN DAILY LIFE 



sunshine plays any part in the predisposition of 

 animal life to infection. 



Now sunshine has long been credited with 

 possessing therapeutic powers, and, indeed, tra- 

 ditions of cures effected by the ancients by 

 means of insolation have been treasured up and 

 handed down to the present day. Even as late 

 as the beginning of the present century we may 

 read of a French physician seriously recording 

 his claim to have cured a dropsical patient within 

 two weeks by placing him daily for several hours 

 in the sunshine, and many medical journals of 

 recent years contain communications on the bene- 

 ficial results derived from the use of sunshine 

 in the treatment of various diseases. It seems 

 curious, therefore, that whilst so much has been 

 done to test the action of light on disease 

 microbes in artificial surroundings, such as are 

 to be found in laboratory experiments, hardly 

 any investigations have been made to try and 

 define more precisely how sunshine may affect 

 their pathogenic action within the animal system. 

 Dr. Masella's researches, undertaken with the 

 express object of, if possible, elucidating this 

 question, are therefore of special interest and 

 importance. 



The first series of experiments was carried 

 out to ascertain whether exposure to sunshine 



