308 BULLETIN No. 161 [November, 



"It is worthy of notice that it is maintained from the surgical side that 

 since the nitration of the water, the number of cases of bone and joint tu- 

 berculosis has diminished extraordinarily. Further observations should 

 tell whether a causal connection really exists here. At any rate such a 

 possibility cannot be excluded, since of course the sputa and the bowel dis- 

 charges of all the tuberculous reach the Elbe thru the sewers; and tubercle 

 bacilli, just as well as typhoid bacilli, could have been carried thence in 

 the water to the people." (Page 300). 



Sedgwick and MacNutt find, by comparing the number of 

 deaths from pulmonary tuberculosis for a period of five years just 

 previous to water-supply purification with the five-year period just 

 following, a decrease of 12 percent at Lawrence, Massachusetts, 

 and a decrease of 14 percent at Lowell. "Tho it is certain that this 

 decrease is not wholly due to the better water supply r yet when 

 compared with Manchester, Massachusetts, a city with a fair water 

 supply, which supply had not been changed during this ten-year 

 period, it is seen that the percentage of decrease in deaths from 

 tuberculosis at Lowell and at Lawrence is much more marked than 

 at Manchester. That drinking water has been and is still, in places, 

 a source of tuberculous infection is probable. 



IN FOOD ^ e f rec l uenc y with which tubercle bacilli occur in 



AND SOIL market milk and butter is indicated by a tabular 



review of the literature upon this subject given 

 in our previous publication (Briscoe and MacNeal, Bulletin 149 

 of this station). In 1233 samples of butter tubercle bacilli were 

 found 163 times (13.2 percent); in 7397 samples of market milk 

 they were found 502 times (6.8 percent). This frequency, to- 

 gether with the length of time that these germs are known to live 

 in butter, indicates that this is an important source of infection 

 for man, especially Children. In soil and foul material they are 

 known to live for a great length of time, and are there dangerous 

 to farm animals. 



A brief summary of the literature on the life of tubercle bacilli 

 in water and in other material is given in Table 7. 



