THE PHAEMACEUTICAL JOURNAL. 
SECOND SERIES. 
VOL. VIII.—No. III.—SEPTEMBER, 1866 . 
WHAT IS IN THE WATER? 
There has probably never been a time when so much attention was directed 
to the quality of the water used for domestic purposes as there is at present. 
Effects have been ascribed to impurities in the water we drink, which, if 
credited, could not fail to create some alarm, and to raise many doubts with 
reference to the wholesomeness of this essential constituent of our food. 
When a fatal epidemic occurs, men begin to inquire into the probable causes 
of the visitation; and the air, the water, the food, the habits of life, of those 
who suffer are severally brought under review, in the hope of finding the 
source of the evil, by the removal of which relief might be obtained, or a re¬ 
currence of the malady prevented. At one time epidemics were chiefly 
ascribed to atmospheric influences, and the chemist was appealed to for the 
determination of the abnormal conditions of the air, from which diseases might 
be supposed to arise. The chemical composition of the air was known; the 
importance of its oxygen was universally admitted ; the ill effects of carbonic 
acid and other gases, when present in excess, was obvious; these were all 
estimated and noted; analysis was carried to its utmost practicable extent; yet 
it cannot be said that any complete or satisfactory insight into the atmo¬ 
spheric causes of disease have thus been obtained. No one doubts that what 
we call “ pure air ” is essential to the maintenance of a healthy condition in 
those who constantly breathe it. But what is pure air ? If it be a mere 
mixture of nitrogen and oxygen with a little carbonic acid and the vapour of 
water, where is it to be found ? The atmosphere in which we live is some¬ 
thing more than atmospheric air as determined by chemical analysis, and as 
usually represented in works on chemistry. Some portions of all the volatile 
matters that are exposed on the surface of the earth are converted into vapour 
and mixed with the atmosphere, and in addition to this there are innumerable 
beings, both animal and vegetable, whose living organisms are diffused through 
the air we breathe. The purest atmospheric air contains all these, and the 
most impure, or at least the most unhealthy, hardly differs in anything that 
the chemist can estimate or identify. There are situations where typhus 
fever or ague prevails, and a blue mist has recently been described which is 
said to be in some way connected with cholera, but nothing certain or definite 
is known of the particular conditions of the atmosphere that induces or favours 
any one of these diseases. So completely has chemical analysis failed to 
detect in air the sources of disease, that nobody now ever thinks of sending a 
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