1912} 



FATE OF TUBERCLE BACILLI OUTSIDE THE ANIMAL BODY 



289 



i. e., one cent per 1000 gallons. This indicates a feasible system of 

 supplying a city with a good, potable water from a contaminated 

 source. Years ago it was suggested by Marshall Ward that the dis- 

 infection of cow sheds might well be done with electric lights. 

 Tho this was thought fanatical at the time, it may be feasible with 

 such light as the present powerful mercury vapor lamp produces. 

 Why cannot the "toning up" effect that is to be felt in a room 

 which has been exposed to the sunlight thruout the day be in a 

 way brought about by exposing to one of these powerful mercury 

 vapor lamps, for a few hours in the evening, such rooms as have 

 no access to the sun, at the same time securing the great benefit 

 that comes from disinfection by its powerful beams? 



For further discussion of this most interesting subject we refer 

 our readers to the recent numbers of the periodicals, more espe- 

 cially the chemical and engineering journals. The following table 

 gives a brief review of the results found in the literature upon the 

 action of sunlight on bacteria. 



TABLE 1 ACTION OF SUNLIGHT UPON BACTERIA 



