April 2, 1894,] THE TROPICAL AGRICULTURIST. 
^55 
CEYLON MANUAL OF CHEMI- 
CAL ANALYSES. 
A HANDBOOK OF ANALVSKS CONNECTED WITH THE 
INDUSTRIES AND PUBLIC HEALTH OF CEYLON FOR 
PLANTERS, COMMERCIAL MEN, AGRICULTURAL 
STUPEJITS, AND MEMBERS OF LOCAL BOARDS. 
By M. COCHRAN, m.a., f.c.s. 
( Continued from page 588. ) 
CHAPTER X. 
WATER. 
Classification of waters— standards of pur- 
ity FOR POTABLE WATER— CEYLON SPRING 
WATERS- HOT MINERAL SPRING WATERS FROM 
BTRAITS SETTLEMENTS— RAIN WATER — WATERS 
FROM STREAMS— COLOMBO TOWN WATER FIL- 
TERED AND UNFILTERED— AVERAGE COMPOSI- 
TION OF COLOMBO WATER SUPPLY — WATER 
FROM VARIOUS DEPTHS OF LABUGAMA RESER- 
VOIR— KANDY PUBLIC WATER SUPPLY — COM- 
PARI.SON OF COLOMBO, KANDY AND ENGLISH 
WATER SUPPLIES— COLOMBO DRAINAGE WATER 
—STANDARD ANALYSIS OF SEWAGE. 
The Royal Commissiou on water supply of 1869 
classed unpolluted natural waters in respect of 
their freedom from the most objectionable impur- 
ity in potable water, viz,, organic matter, in the 
following order : — 
1st. Spring water. 
2nd. Deep well water. 
3rd. Rain water. 
4th. Upland .surface water. 
In respect of wholesomeness, palatability, and 
general htness for drinking, the following, accord- 
ing to Dr. Frankland, was the classitication of 
waters in order of excellence that was adopted : — 
1 1. Spring water. 
Wholesome. -| 2. Deep well water. 
Is. Upland surface water. 
1. Pure and Wholesome Water. 
Suspicious. 
Stored rain water. 
Surface water from cultiyated 
land. 
f6. River water to which sewage 
Pangerous. \ gains success. 
\J. Shallow well water. 
When analysing waters witli a view to pro- 
nounce upon their htness for drinking or cooking 
purposes, it is necessary to have some standard 
of purity, by which to interpret the analytical 
results obtained. Many such standards kave 
been proposed from time to time, and, though 
none of them will apply in every case, so as to 
dispense with the necessity on the part of the 
analyst for the exercise of his own judgment 
after taking local circumstances into account, the 
value of a good general standard of purity is uu-. 
questionable. Of the different standards proposed, 
none will l)e found more useful for the guidance 
of the analyst or of sanitary authorities, than 
the four-fold classilication given in the seventh 
edition of farkes' PracticsJ Hygiene, the more 
important featurea of which I here reproduce. 
83 
Character or Constituejits. 
Physical characters 
Colourless or 
bluish tint, trans- 
parent, sparkling 
and well aerated, 
no sediment visi- 
ble to the naked 
eye, no smell, 
taste palatable. 
Chemical Constituents. 
Grains per gallon. 
1 Chlorine in chlorides under 
2 Solids in solution ,, 
,, volatile ,, 
N.B. — The solids on inciner- 
ation should scarcely 
blacken 
3 Ammonia, free or saline 
under 
Ammonia, albuminoid under 
4 Nitric Acid No, , 
in nitrates 
Nitrous acid No, , 
in nitrites 
5 Oxygen absorbed by organic 
matter in 15 mins. by per- 
manganate and acid (gjSO ® F 
(27 ®C.) under 1 
Do in 4 hours at 
80 »F. (27 = C.) under 
6 Hardness, total ,, 
,, fixed ,, 
7 Phosphoric acid in phosphates 
Sulphuric acid in sulphates 
8 Heavy metals ... 
9 Hydrogen sulphide, Alka- 
line sulphide ... 
1-O000<x 
5-00006 
1-00006 
0-0014 
0-0035 
I 0 0226 
Microscopic characters 
^nil. 
0-OlOOc 
0 0350c 
6»-0 
2«-0 
tracea 
traces 
nil 
nil 
- Mineral mat- 
ter ; vegetable 
forms with en- 
dochrome ; large 
animal forms ; no 
organic debris. 
Remarks.— Turbifiity, due to very fine mineral 
matter, is sometimes associated with pure waters: 
thus, minutely divided, calcium sulphate will not 
subside in distilled water. 
a This may be exceeded if from a purely mineral 
source. 
b The solids may be exceeded in chalk waters 
where they are mostly calcium carbonate. 
c The oxygen absorbed may be exceeded in 
peat or upland surface waters. 
A water such as the above nx&y generally bo 
used with conlidenee, in the ab.scnre of any 
history of jwssible polhition, or of any recent 
and jippreciable change in the amount of the 
organic constituents. 
