154 On the Composition and Properties of Drinking-Water, 
jellow-coloured, and turned dark on exposure to a strong heat 
in a platinum dish. The residue amounted to 218*26 grains 
per gallon, and in it I found by direct determinations : — 
Grains. 
Oxidisable organic matter 2 ■ 68 
Oxide of iron and alumina "OS 
Phosphoric acid "17 
Lime 39-82 
Magnesia 15 '49 
Sulphuric acid 82-34 
Nitric acid 10 '50 
Chlorine 27-52 
Soluble silica 1-82 
Alkalies and carbonic acid, not determined separately. 
The water further contained in the gallon : — 
Actual (saline) ammonia - 126 
Organic (albuminoid) ammonia - 126 
According to these analytical data the composition of the 
water may be represented as follows : — 
An imperial gallon contained : — 
Grains. 
Oxidisable organic matter 2-68 
Oxide of iron alumina -95 
Phos[)horic acid - 17 
Sulphate of lime 96-71 
Sulphate of magnesia Si" 83 
iSI itrate of magnesia 13-93 
Sidphate of soda 3-96 
Chloride of sodium 45-35 
Alkaline carbonates 17-86 
Soluble silica 1-82 
Total solid constituents per gallon .. .. 218-26 
Actual (saline) ammonia - 126 
Organic (albuminoid) ammonia • 126 
A cursory inspection of these results will show that the water 
was impregnated with no less than 218 grains of earthy and 
saline matters per gallon, comprising nearly 100 grains of sulphate 
of lime, about 45 grains of common salt, much sulphate of mag- 
nesia, a considerable proportion of nitrate of magnesia, and other 
saline compounds. Besides the saline and earthy impurities 
which were present in abnormally large proportions, the water 
was contaminated with much unoxidised organic matter. The 
occurrence in the water of nitrates, and much more saline and 
all)umin()id ammonia than is ever found in good drinking-water, 
clearly showed that the organic impurities were derived from 
animal refuse-matters. Unquestionably the water was charged 
with a large proportion of injurious organic impurities, - and 
much contaminated with saline and earthy compounds, which 
