20 THE AMERICAN MONTHLY [Jan., 



that they should be lying in this place at just the period 

 when the typhoid germs were swept by the currents or 

 eddies from the sewer over the oyster bed, and such a 

 condition, even though there might be continued cases of 

 typhoid in the course of the sewer, would doubtless not 

 by any means be a constant one. Oysters as a rule are 

 said to open their shells on flood tide rather than ebb 

 tide, and this would, of course, make it more difficult for 

 them to be contaminated by sewage from sewers above 

 them on the creek. While this would by no means make 

 impossible the chances of contamination it would cer- 

 tainly render it less. It is not to be supposed, therefore, 

 that the oysters deposited in the creek for fattening 

 would all, or indeed many of them, become contaminated 

 by the typhoid material, but that only exceptional con- 

 ditions would produce the result. Where a private 

 sewer containing typhoid excreta opens in the vicinity 

 of such an oyster bed the danger must certainly be con- 

 siderable. Where the typhoid material is mixed in the 

 city sewers with the large amount of sewage, and issub- 

 quently diffused through a considerable body of salt 

 water when the sewer empties into the sea, the danger 

 of oyster contamination must be considerably less. But 

 there must be danger to public health from oysters fat- 

 tened in any fresh water in the vicinity of sewage. 

 Doubtless many cases of mysterious typhoid have been 

 due to such a cause. To trace these cases is a matter of 

 extreme difficulty. The peculiar conditions which have 

 occurred here have been such, however, as to bring the 

 matter into clear light, and to throw with certainty blame 

 of typhoid distribution upon a source which has for 

 some time been suspected but not demonstrated. That 

 the practice of fattening oysters in the mouth of rivers 

 and in the vicinity of sewers is dangerous to the public 

 health is beyond question shown by the combination of 

 conditions which have attended the typhoid at Wesleyan. 



