CILY WELLS: 547 
large body of water which is not used for drinking-purposes, and thus 
dono harm. | If, however, there are wells in the neighbourhood, the 
chances are in favour oi the contents of the cesspools and of the wells 
becoming mixed. The larger the number of cesspools and of wells, 
the greater the danger of. such a result. In a city not provided with 
sewers, therefore, the conditions are such as to lead almost certainly 
to contamination of the water of surface-wells with the contents of 
the cesspools. Besides this, there is the danger of contamination 
from ‘surface-drainage, which cannot be avoided. The water which 
falls upon the ground, whether the ground be paved or not, sinks to 
a considerable extent below the ‘surface, carrying with it such 
impurities as may be present. Such surface-water in cities, it is safe 
to.say, is always contaminated. Someof it is sure to find its Way into 
the wells. : 
This, latter. source of contamination is common to all cities, 
whether they are provided with sewers or not. While, however, the 
city which is. provided. with sewers is not. subjected ‘to exactly the 
same kind of danger as that first referred to above, the.cases do. not 
present as much. difference as might at first be supposed. The 
sewers are generally. leaky, and the soil in their vicinity becomes 
saturated with sewage. Thus they may contribute to the contamina- 
tion of the well-waters. Of course, the danger of such contamination 
is not. so great as when there are no sewers, but still it is quite 
sufficient to justify the condemnation of the surface-wells. 
The waters of city wells havefrequently been studied by chemists 
and biologists, and the results invariably show that contamination is 
the rule. In Brooklyn, N.Y., there were, in 1882, three hundred and 
sixteen wells. Chemical examination showed, & that, of this whole 
number, but seventeen furnished water fit for human consumption.” 
Similar results have been reached in an examination of the water of 
the wells of Baltimore, where a few years ago there were between one 
and two hundred in use. The contamination of some of the waters 
examined was such as to show that very close connection must exist 
between the wells and cesspools. The testimony of all who have given 
special attention to the subject of the water of city wells is unanswer- 
able: Not only does a consideration of the surrounding circumstances 
lead us to suspect that the water must be contaminated, but.the most 
careful examinations, by those most capable of making the examina- 
tions, have shown that actually, and almost invariably, the water is 
badly contaminated. 
Jt is an unfortunate fact, that, though the waters of city wells are 
generally impure, their external properties do not always reveal the 
impurity. Sometimes they do; and then it requires but a very slight 
hint as to the cause of the properties, to stop the further use of the 
water. Thus, for example, some years ago there was a spring in 
Baltimore, which, owing to its peculiar taste and odor, was regarded 
asa mineral spring. It was therefore fenced in, and covered, and 
generally treated like others of the class known as ‘ mineral springs.’ 
It was afterwards found that very close connection existed between it 
and a neighbouring cesspool; and the cause of the taste and odor 
which had given the water its reputation was thus revealed. It need 
not be added that the water ceased to be popular. More frequently 
‘these well-waters are clear, and without taste and odor, and, comine 
