44 SHELLFISH CONTAMINATION FROM SEWAGE-POLLUTED WATERS. 
work, therefore, the ability to demonstrate clearly the presence of a specific sewage 
organism such as B, coli is an invaluable aid in determining the question of punty or 
pollution.”’ 
Fuller * concludes his work on oysters from the Narragansett Bay 
by saying: 
The results obtained in these experiments indicate that B. coli is not marecenat 
found in sea water or in common edible shellfish, and that the presence ot this organism 
in oysters, clams, mussels, and similar shellfish is an indication of sewage pollution. 
VITALITY OF BACILLUS COLI AND BACILLUS TYPHOSUS IN SEWAGE- 
POLLUTED WATER AND IN SHELLFISH. 
The results obtained by different investigators on this point vary 
somewhat according to the conditions under which the experiments 
were conducted: the vital fact, however, is that B. coli, B. typhosus, 
and other organisms do survive sufficiently long, under favorable 
conditions, in sewage-polluted waters to transmit disease when such 
water is eougumnel eacthes directly, or indirectly by such a medium 
as shellfish. 
Savage °° says: 
Owing to the enormous difficulties inherent to the isolation of the typhoid bacillus 
from bacteriologically complex substances such as highly polluted tidal mud it would 
be rash to draw sweeping deductions from negative results, but * * * it seems 
justifiable to infer that typhoid bacilli can survive in polluted muds for at least two 
weeks, and this fairly readily, but that after about two weeks they may rapidly de- 
crease, although they may, and probably do, persist under favorable conditions for 
some little longer, but in vastly diminished numbers. Experiment (3) seems to 
definitely show that they may survive for at least three weeks. 
McNaught *” concludes that “‘the duration of life of B. coli in 
unsterilized water varied greatly in waters from different sources. 
The purer the water the longer did B. coli survive in it.”” He further 
Says: 
In unsterilized sewage B. coli only survived for three weeks, while it survived over 
eight months in the same sewage sterilized. After six months’ growth in sterilized 
water and eight months’ growth in sterilized sewage B. coli retained all its original 
characters except that possibly its power of indol production was weakened. 
The Lancet,” in reviewing some experiments and observations 
on the vitality of B. typhosus in oysters made by Klein, says: 
The actual results detailed in the report, though valuable, are not particularly novel. 
They definitely settle the question as to whether the Bacillus typhosus will live in the 
oysters. Itis demonstrated that there is destruction of the Bacillus typhosus-both in 
the body of the oyster and in sea water; that an oyster infected with large numbers of 
typhoid bacilli ‘‘cleans” itself in about from 9 to 12 days when placed in clean water 
which is frequently changed; and that oysters kept in the dry state, though capable 
of destroying the bacillus, yet remain polluted for a much vonget period than oun 
placed in constantly arene clean water. 
The investigations of Dr. Buchan show that typhoid bacilli sur- 
vived in mussels for at least 26 days where the organisms were found 
abundantly; he concludes by saying: ‘“‘This experiment emphasizes 
