The record-union., 1894-03-14
DELICACY AND DANGER OF
WATER ANALYSIS.


As our Trustees are wrestling with the
question of water analysis, some idea of
the views held by scientists on that SUBJ
ject should be of interest.
Perhaps they are fairly embodied in
the recent address on that subject before
the Rensselaer, Polytechnic Institute,
Troy, N. Y, by Professor w. P. Mason,
one of the most skilled analysts, and re-
produced in the Engineering NeaCs and
the Sanitdrian.
may be said to be. as based on long ex-
perience and thousands of experiments:
l. A water analysis is not really an analy-
sis, but a series of experiments under
taken to assist the judgment in determin-
ing the potability of the supply. 2. A
chemical analysis is not complete or in
telligible without the chemist is ac-
quainted with the surroundings of the
spot from which the sample is drawn. 1t
will be recalled that Mr. Rising, the State
Analyst, has made the same claim in his
letter to the Trustees.
For instance, salt in large quantity in
water is suspicious because it suggests
infiltration OF sewage. But quantity of
salt that would condemn water in a shall
low we'll in one place, would be unob-
jectionable in a deep well in another
place. So it is concluded (3) that his
tory of the water and its surroundings is
essential to the honest chemist TO enable
him to interpret all the items of the
analysis.
Not long ago water from Florida was
sent to the institute laboratory. 1t was
found to contain LIS parts of free ammo
MIA per million. This points to contami-
nation from animal sources. But it was
learned from the history" that the
water was derived from melting artificial
ice made by the ammonia process. and
this fact saved the water from condemn
alton.
Again a., the analyst should know Of
the depth from which the water is taken,
its relation to large streams, to sewage
lines, contact with organic waste, tenn
perature at dates of sampling, etc. If
contamination is suspected. samples
above and below the suspect line should
be taken of the suggested intake. Pro-
fessor Mason then goes on to say:
AS Nichols has well said: 1T is great mis-
take to suppose that the proper way to con-
suit a chemist is 10 send a sample of water in
sealed vessel with no hint to its source
On the contrary, the chemist should know as
much as possible as to the hint and source of
the water, and if possible should take the
samples himself" In taking samples for so
important a matter as town supply, the
chemist should unqueStiOnably personally
superintend their collection, but for individ-
ual outlying waters printed instructions have
TO be frequently depended upon.
We summarize the instructions issued
by the Rensselaer, Laboratory: Use glass
stoppered bottles; not less than two gall
Ions should be sent; the bottle must be
perfectly clean, rinsed with the water
sampled and all foreign matter removed
the neck of the bottle must not be secured
or wiped with the finger or with any
cloth. After thorough rinsing it must be
filed to over1owing to displace all air
and then completely emptied. Never
seal with cork, if a glass stopper can be
had, but if a cork is used it must be new
and not sealed with wax.
Bear in mind throughout that water analy-
sis deals with material present in very mi
mute quantity, and that the least carelessness
in collecting the samples must V1tiate the re-
suits. Give the date of taking the sample
and full description as possible of the
soil through which the water flows, together
with the immediate sources of possible con-
tamination.
Reason justifies all these precautions;
it does not need chemist to understand
them and why they should be observed
It would be well for the Trustees to know
in sending the new supply" sample of
Sacramento water to Analyst Rising. If
not, can the board afford to risk so much
upon an analysis that may not give true
results? How was the water taken !?
How was the bottle cleansed? How was
it stoppered? How was it handled? /?
What information of environment was
given to the analyst? Was the lift of the
water perfectly free from pump impuri-
ties, and was every precaution taken to
prevent the sample being contaminated
by any contact with the hands, old corks,
machinery, wax, surface soil. etc.?