599 
The minimum for the springs in Virginia showing otherwise no 
signs of pollution was 2 parts per 1,000,000; the maximum 20. 
In regard to the total number of bacteria per 1 cubic centimeter it 
may be stated that it was not large as a rule and in many cases it 
ran low. In the water from wells in Maryland pronounced good on 
r sanitary survey and which showed no evidence of pollution other- 
, wise, the number ran from 10 to about 500 per cubic centimeter, 
except in 2 cases where the numbers were 1,580 and 2,900, respec- 
tively. 
In the Maryland wells which were above suspicion the numbers ran 
from 15 to 320. 
In the Virginia wells which were above suspicion the number of 
bacteria per 1 cubic centimeter ran from 0 to 510. In the Virginia 
springs which were above suspicion the numbers ran from 0 to 120, 
except in 1 case where the number ran up to 8,900. 
The presence or absence of B. coli in the water of dairies is perhaps 
of special significance. By some the presence of this organism in 
water is interpreted to signify that the water is polluted with human 
feces and that if this is true typhoid feces may gain access. The 
presence of the B. coli is thus regarded by some as sufficient ground 
for condemning and closing the source of supply in such cases. It is 
true that there are others who are more reserved in their opinion of 
the significance of the B. coli in water and others again who are 
inclined to deny any such significance. It is not the purpose of the 
present paper to discuss the relative merits of any of these views, 
but to merely state what would appear to be the significance 
of the presence of B. coli in the water supply of the dairies under 
examination. 
The occurrence of B. coli in some of the wells with apparently tight 
coping and cover, driven through rock, would seem difficult to 
account for. One case in particular seems remarkable. Well No. 
24 of the Virginia dairies seems peculiarly well situated as regards 
likelihood of pollution of any kind, and 2 chemical examinations made 
about three months apart failed to show any indication of pollution. 
It is situated on the summit of a high hill several hundred yards from 
and 60 or 75 feet above the barnyard, and still farther and higher 
above any dwelling house. The surroundings are all clean. The 
ground is rock and the pump is placed on a high coping which is 
apparently tight. Yet the bacteriological examination showed high 
bacteria count on two examinations, too many in jV cubic centi- 
meter to count in one case and 800 per 1 cubic centimeter in the other. 
B. coli was detected on both occasions. Other examples are not 
wanting in which similar results were obtained. The probability of 
pollution with human feces in all such cases seems very remote if not 
