Evening star. [volume] (Washington, D.C.) 1854-1972, 1885-10-21
CITY AND DISTRICT.
THE DISTRICT CHEMISTS WORK.
Operations I'm His Laboratory During
the Past Year.
THE PURITY AND PORTABILITY OF THE CITY's
WATER SUPPLY-TESTS APPLIED TO THE
NEUTRALITY-SUSPICIOUS. MADE OF PAVE
MENTS AND CEMENTS.

THE PURITY AND PORTABILITY OF THE CITY'S
WATER sUPPLY-TEsTs APPLIED TO THE
NEUTRALITY-SUSPICIOUS. MADE OF PAVE
MENTS AND CEMENTS
The annual report of Prof. E. ]. De Smedt,
chemist Of the District of Columbia, which was
submitted to-day to the Engineer Commits
sloner, gives an interesting account OF the
operations of his office for the last fiscal year
For the health Office of the District there We're
made 90 analyses for the purpose of determin-
Ing the innocuous or injurious qualities of the
articles ana yzed and their usefulness and in
huence in sanitary point of view. These
analyses comprised 80 of water, II of milk, of
butter, 2 of me- at 2 of vinegar and of coffee.
-Four samples of water were found unfit for
drinking purposes; 4 OF milk were found to be
t auniterated with water: 2 of butter adult
CURED strength, and one OF coffee adulterated
with roots.
THE CITY'S WATER SUPPLY.
During the months OF May and June, 1885"
the report says, considerable excitement was
created in regard to the purity OF the water sup
ply of this city. Twenty-three analyses were
made at the time by several prominent chem
lists of the different departments of the govern
tlon OF the samples were taken direct from the
fotomac river, some from the different lakes
ana reservoirs, and others from the water pipes
in the city. The conclusion we arrived at was
that the water supply of this city, like all river
water, is of variable quality, owing to climatic
Influences, but that it is, nevertheless. good,
potable water, and of a healthy character This
SUBJECT has been treated in my former annual
reports. The following statement will show
water supply:
appearance, turbld.
Hardness, degrees.
Solid residue 81 milligrammes per liter
parts per million,
Organic and volatile, 80. miligrammes.
Mineral matter, GA. millgrammes.
ammonia mi liur
A!Dumlnoid ammonia, O.OS millgrammes.
Nitrites slight traces.
NltrateS Oh milligrammeS.
Chlorine, 4. milligrammes
oxygen required O42 milligrammes.
Microscopic examination, good.
opinion, good potable water.
In regard TO the fiSh-ike OdOr which has been
detected in our water supply, all scientific au-
thorites agree in attributing it to the formation
OF microscopic algR, such as cOnferraScese Oscil-
latorise. and protO-cocci, but there is no evil
dence 10 warrant suspicion that this water
health of those who drink it. The formation of
these algfe and likewise the fish-like Odor has
this summer, been quite general all over the
United States. 1t is also renarked periodical
ly, more or less, in other parts OF the world I
was unable to experiment on the algae found
IN our reservoirs, owing to the fact that they
cure specimens.
MICROSCOPIC EXAMINATIONS.
The methods have adopted in the examine
ton and analyses of water have been fully de-
scribed by me in the report of the Health off,
Ger, D. c.. for the year 1850. Still l deem it
proper to say few words in regard to the eX-
animation of water by the aid of the micro
scope, without which the analysis would be in
complete, notwithstanding its use is often
neglected by the analyst. Inasmuch as it is the
character rather than the quantity of the organic
matter found, by which we Judge the quality of
water in sanitary point of view, we are neces-
sarily obliged to go into the most minute de-
tails connected with the subject matter. and
here it is that the microscope becomes indis-
.nl,l Ia xyr,fx.,v
information which enables us to determine the
nature of the organic matter referred to. The
cOrpuscules visible under the microscope are
sand, clay, chalk, &c. The vegetable debris
consists of leaves fbers, etc. Animal debris
arises principally from insects The living Or
ganisms found in water consist of vibrians
bacierie, alg:e, dfatolnaceA, iatusori@, eggs OF
tanise, of aScaridas, and a multitude of micro
scopic organisms which are generally found in
ploy are a solution of iodine, which gives q
blue color to the amylaceous cells; second, a So
luton of carmine in glycerine and alcohol,
which cOlOrS red the vegetable cells; third, the
violet methylene, which colors the batteries
Now, inasmuch as it is sometimes difficult to
ascertain the putrescibility of water by the
most direct microscopic examination only,
also make use of the method adopted by DIR.
August smith (reyue d'hygiene ct de police
sanitaire tom V, No. 81 which is as follows:
Dissolve grammes OF pure gelatine with 2
centigrammeS OF phosphate OF soda in 100
grammes of pure distilled water. then add
fresh albumel. and heat the whole to 1000 for
the purpose of Qualification, then filter.
Twenty-Five c. c. of this solution is mixed with
25 c. c. of the water to be examined: the tubes,
when filled, are kept for few minutes in a
water bath at plus $50 centigrade, in order that
assimilation may be perfected; the tube is then
days in a warm place heated to about plus 300
to $50 centigrade. When the water which is
added to the .gelatine solution is per-
fectiy pure (boiled distilled water) the
liquid under examination remains almost
intact, but when, the contrary the
water is impure the living organisms are as so
nfarc # aafin xyni
gelatine and give 1t the appearance of oily glob-
ules, proportional in quantity to the ratio of
the second day some white points are visible.
On the third day the little globules appear in
much greater number. A turbid division is
now remarked at the surface, and the micro
scope shows the presence of a multitude of bac-
terra On the fourth and fifth days this turbid
division becomes greater and the gelatine be-
comes liquid, beginning at the upper division,
and this change is effected more rapidly in pro-
portion to the impurity of the water. When the
water is infectious the upper part is liquefied,
and becomes milky and putrid at the expira-
ton OF As hours.
The above process is very valuable for the
purpose of determining the relative purity or
impurity of water.
COUNTING THE MICROBES
I have also adopted in doubtful cases the
method pursued by DIR. Koch, which is based
on the same principle as that described above,
but with this difference, that the examination
is made with a certain number of drops, or a
fraction of a drop, of water, and the number of
colonies of microbes are counted in a given
space. Knowing the volume of water mixed
with the geiatine, we can readily calculate the
number of micro germs susceptible of develop
ment in a centimeter cube of water, and thus
arrive at the result"
For assistance at the inquests of the coronera
four Genealogical analyses were made during
the year. In two OF the cases poison was de-
tected and its presence demonstrated. In the
remaining two cases no poison was found. Six
analyses were made for the Metropolitan police9
In three of the cases under examination poison
was found. The fourth case was one of adulter-
alton OF food. In the remaining two cases no
poison was discovered.
AT the request of District Commissioner West
atmospheric analyses were made at the Ban
neker, Twining and AnalOstan school buildings,
and the result proved these buildings to be well
ventilated, the quality OF the atmospheric air
being good.
Two analyses of giant powder (nitrogly cerine),
six of rocks from the reservoir tunnel shafts,
and seven OF water from different springs in the
new reservoir. were made at the request of
Capt. Symons, corps of engineers U. s. A. The
seven samples of water were all found to be
good, pure, potable water.
EXAMINING PAvEMENTS AND DEMENT'S.
A large part Of the report is devoted to setting
forth the results of tests and analyses made OF
asphalt pavenents and cements for the engi-
neer department.. Prof. De Smedt says he has,
as In preceding years, made daily analyses Of
the asphalt pavement laid in the District The
average percentage of asphalt cement in 1856
samples was: Chemically pure asphalt 800
commercial, 13.SOE carbonate OF lime, 900:
granite stone dust 700; sand, 1890. The
average composition OF asphalt block Is: As