116 ILLINOIS STATE DAIRYMEN'S ASSOCIATION 



to read just for a minute the results of some experiments. I 

 think it will be of interest to you and these experiments are 

 outlined in the weekly news letter of the U. S. Department of 

 Agriculture in volume 316: 



SUNSHINE AS A GBRMICIDB. 



Weekly Department of Agriculture News Letter Vol. 3^ No. 16. 



Tests Show That Germs of Disease Can Not Survive 



When Exposed to the Sun. 



Sunshine is an amazingly potent germicide for the farm 

 housekeeper and in the dairy and stables. The practice of ex- 

 posing cooking and other utensils used in connection with food 

 to direct sunlight makes use of this fact, although comparatively 

 few appreciate exactly the work done by the sun in this regard. 

 Probably only those who are acquainted with tests which have 

 actually been made realize how quickly sunshine kills disease 

 germs exfosed to it. Hence the following tests may be generally 

 instructive and interesting. 



A pasty, creamy mass of tuberculosis material, which was 

 proved to contain uncountable numbers of virulent tubercle bac- 

 illi, was obtained from a tuberculous cow and spread in thin 

 smooth translucent layers on sheets of glass, pieces of wood, 

 and strips of muslin. Some of the sheets of glass, pieces of wood 

 and strips of muslin were then placed outdoors on a moderately 

 warm, clear, calm' day where the sun could shine on them, and 

 an equal number were placed in a dark room. After 15 minutes' 

 exposure to the sun, the tuberculous material on the glass, wood, 

 and muslin still contained large numbers of living, virulent tub- 

 ercle bacilli, which were proved to be fully capable of causing 

 tuberculosis but after 30 minutes exposure to the sun no liviiig 

 tubercle bacilli could be found; every test that could be made 

 proved that they were all dead. 



Similar tests with quite large opaque masses of tuberculosis 

 material, larger and denser than any tuberculous person is apt 

 to expectorate, proved that the bacilli in such masses on glass 

 are still alive after 4, but entirely dead in less than 8 hours, and 



