34 
The following table gives the data in brief upon the subject: 
Effect of direct sunlight upon the tubercle bacillus. 
Author. 
Conditions. 
Koch, 1890. 
Tubercle bacilli. 
Not killed. 
Killed. 
Few minutes 
to several 
hours. 
Feltz, 1890 
Ransome and Delepine, 1894. . 
Migneco, 1895. 
Tuberculoussputum in road dust exposed 
to sun. 
Pure culture dried on paper in thin lay- 
ers. 
Tuberculous sputum on linen and wool- 
en cloth. 
About 140 
days. 
'-Gardiner, 1898 
Tuberculous sputum on: 
12f hours. 
24 to 30 hours: 
virulence di- 
minishes in 
10 to 15 hours. 
Sand . 
Stone. 
Wood 
Mitchell and Crouch, 1900 ; Tuberculous sputum placed upon ster- 
ilized soil. 
If hours 
2 hours 5 min- 
utes 
24 hours (local- 
ized tuber- 
culosis). 
35 hours; viru- 
lence dimin- 
ished after 
20 hours. 
45 hours. 
Tousset, 1900 
-Annett, 1903 
■Cadeac, 1905 
Twitchell, 1905 
Hi Donna, 1907 
Koch, 1890 
Hansome and Delepine, 1894 . 
Tuberculous sputum, exposed to dust 
and sunlight. 
Dried muco-purulent sputum in small 
masses about size of one expectoration. 
Tuberculous sputum on a board 
Tuberculous sputum on glass plates ex- 
posed to artificial light. 
Tuberculous sputum exposed to direct 
sun rays. 
Pure cultures 
Cultures of tubercle bacilli exposed to 
dispersed daylight near window. 
Pure culturers dried on paper in thin lay- 
ers, exposed to air and light. 
Same exposed to sunlight 
2 to 24 hours. 
24 hours 
1 hour. . 
fi days . . 
4 hours. 
48 hours. 
24 hours. 
48 hours. 
7 hours. 
8 days. 
5 to 7 days. 
4 days. 
12f hours. 
THE TUBERCLE BACILLUS IN WATER. 
'The tubercle bacillus may probably live and remain virulent in 
■water for several months. We have indications of this in the work 
‘of Straus and Dubarry, 1899; Muscliold, 1900; Galtier, 1889; Chan- 
vfcemesse and Widal, 1888; and Cadeac and Malet, 1888. 
Since the danger of ingesting the tubercle bacillus is now well 
‘established, its presence in drinking water assumes a special sig- 
nificance. Tuberculous cattle, as well as tuberculous individuals, 
discharge large numbers of tubercle bacilli in their dejecta. Sewage- 
polluted water used for drinking purposes may, therefore,, harbor 
clangers other than the intestinal order of diseases, such as typhoid, 
-cholera, etc. Dixon found acid-fast organisms morphologically re- 
sembling the tubercle bacillus in the sewage from hospitals in 
Philadelphia. Sedgwick and MacNutt, a 1908, have examined the 
.theorem first enunciated by Hiram F. Mills and others, but first 
definitely formulated and published by Allen Hazen, that “for 
® Sedgwick, W. T., and. MacNutt, Scott: Typhoid fever and the purification of 
public water supplies. Science, vol. 27, Aug. 14, 1908, p. 215. 
