IOWA ACADEMY OF SCIEXCES. 93 



111 comparing the results of the second analysis with the 

 first analysis, it will be noticed that the amount of nitro- 

 gen as nitrates, has increased from 24 parts to 40 parts per 

 million, while the albuminoid ammonia has decreased. 



These results indicate that the nitrogen in the organic 

 matter which was present in the water has been changed 

 during the process of nitrification into nitric acid. This 

 change has probably taken place during the passage of the 

 water through soil in which the conditions w^ere favorable 

 for the nitrifying process. 



When inquiries were made regarding the use of this 

 well, the claim was made by the owner that it was not 

 used, but that a deeper w^ell, which was near the shallow 

 well, furnished the water. It was discovered, however, on 

 visiting the place one morning, that a bucket of water was 

 being pumped from this well for drinking purposes, and 

 w^as supplied to a number of men working on the railroad 

 near the place. The deep well proved to have a very lim- 

 ited supply of water when tested; and it was then claimed 

 that the shallow well water was used only for washing out 

 the milk cans, etc. A case of typhoid fever had occurred 

 in the family of the farmer during the summer, and on 

 tracing the case it was found, that this case and the epi- 

 demic were closely related when consideration w^as given 

 to the time necessary for the development of the disease 

 The number of cases were from forty-five to fifty, and almost 

 the entire number of patients came from those who used 

 the milk furnished by the farm with the contaminated 

 well. It was also found on investigation by the physician 

 that a number of the laborers on the railroad had devel- 

 oped cases of typhoid fever. The conclusion naturally 

 reached is, that the well was contaminated from 

 some source, and at the time at which the case of typhoid 

 fever was in progress in the family of the farmer, contained 

 the typhoid germ. The use of this water for washing milk 

 cans without boiling, transmitted the germ to the milk, 

 and by the milk to the digestive system of the persons 

 using the milk. 



