WATER, WATER ANALYSIS, AND THE MICROSCOPE. 285 
directors knew that they had taken every care in sinking the well, 
and also that no sewage matter could possibly come near it. They 
felt convinced that the water was not so bad as B and C had 
reported it. Nothing daunted, and thinking that in the multitude 
of counsellors there is wisdom, they called in the aid of chemist D. 
He considered the water quite fit for all domestic purposes. D 
also wrote a letter, saying that, as far as chemical analysis could 
determine, the water from the well was fit to drink, and that it was 
not necessary either to boil or filter it previously to use. Chemist 
C had previously said that none of this water should be used with- 
out filtering. From this report the directors gained courage. 
Still they were between two opinions, and to settle the question a 
sample of the water was sent to E. The report was: ‘The quanti- 
ties of free and albumenoid ammonia contained in this water are 
very small, and in this respect the water may be pronounced to be 
very pure.’ A letter was also sent, with this remark in it: ‘I am 
glad that the results are so favourable. The waters are, indeed, 
unusually pure, but somewhat too hard.’” 
These instances could be multiplied to an almost unlimited 
extent were it necessary to do so, but quite enough has been said 
to show that even from the same samples chemical reports may 
differ, and that the reports of most chemists upon the subject of 
drinking water are not, as a rule, trustworthy. 
In the August number of Zhe Wineteenth Century there is a 
paper on “Cholera and Water Supply,” by Dr. Percy Frankland, 
in which the words “chemical analysis” so frequently recur as to 
give the uninitiated the idea that the results of the processes admit 
of easy, definite, and decisive interpretation: this is not so, the 
balance of evidence being directly contrary to any such proposition. 
We venture to say that if a gallon of the purest water were mixed 
with 50 grains of salt and a few drops of the white of an egg, and 
sent to a chemist for analysis, he would, most probably, certify the 
water as dangerous to drink, and state that it contained so-and-so 
many grains of sewage matter. Again, if a few grains of either of 
the nitrates of sodium or potassium be added to a gallon of water, 
and dealt with as above, the chemist would probably regard their 
presence as indicative of “previous sewage contamination,” and 
record his opinion in the usual way. 
Perhaps the most important paragraph in the article before us is 
the following :— 
“The subject of domestic filtration is one which, in a town with 
a water-supply like that of London, possesses peculiar interest, and 
is of no little importance. Most people imagine that by once 
going to the expense of a filter they have secured for themselves a 
safeguard which will endure throughout all time without further 
trouble. No mistake could be greater, for without preserving 
