TYPHOID 175 



very probable that the number present rapidly diminishes 

 in milk which is kept. 



It has been proved that the typhoid bacillus will live in 

 sterile milk which is curdled by the addition of bacillus 

 lactis. 



It will also live in milk which has turned sour at the 

 temperature of the room in which it is kept. 



These latter results indicate that it is quite possible for 

 the typhoid bacillus to exist in curd cheeses. 



Conveyance by Vegetation. — Enteric fever has been known 

 to be conveyed by vegetables grown on sewage farms, and 

 also by watercress grown in sewage-polluted streams. 



Conveyance by Shell-fish. — Oysters, mussels, etc., which 

 have come from water contaminated by drainage may be 

 a source of infection. Foote has recently been carrying out 

 a series of interesting investigations on the vitality of 

 typhoid bacilli when inoculated into oysters. For the first 

 fourteen days after introduction the typhoid bacilli multi- 

 plied, but after some time a steady decline in the number 

 of microbes took place. Thirty days after the bacilli were 

 first introduced into the oyster their presence was still 

 demonstrable, they having been preserved in the stomach of 

 the oyster, where they retained their vitality unimpaired. 



In some experiments the water containing the oyster was 

 infected with the bacilli, and it was found that they actually 

 lived longer in the body of the oyster than they did in the 

 water containing the latter, which seems to distinctly point 

 to the possibility of contracting typhoid through the con- 

 sumption of the bivalve. 



Conveyance by Dust. — It is improbable that the soil in 

 this country is a great factor in the conveyance of typhoid, 

 but the soil in India seems to give peculiar facilities for 

 the spread of the disease, and to play a somewhat different 

 role to what it does in England. The soil for the great 



