152 On the Composition and Properties of Drinking-Water, 
family, and suspicion having been raised with regard to the 
purity of the drinking-water used by that family, two samples 
were sent to me for examination. One of the samples was 
decidedly yellow-coloured, the second nearly colourless. On 
evaporation to dryness they left respectively, per imperial 
gallon : — 
~ " No. 2. 
Solid residue 
No. 1. 
Grains. 
70-11 
Grains. 
70-84 
In the residue I found, by direct determination : — 
Oxidisable organic matter 
Oxide of iron and alumina and phosphoric) 
acid J 
Magnesia . . 
Sulphuric acid 
Nitric acid .. 
Alkalies and carbonic acid, not determined spparately. 
Soluble silica 1-12 
The two waters further contained in the gallon 
Actual (saline) ammonia •014 
Organic (albiuninoid) ammonia . . . . - 021 
23 
1 
56 
28 
98 
19 
91 
14 
79 
3 
98 .. 
6 
15 
9 
13 
12 
16 
5 
77 
14 
10 
35 .. 
12 
40 
1-40 
•039 
•058 
According to these analytical data the composition of these 
two waters may be expressed as follows. An imperial gallon 
contained : — 
No. 1. 
Grains. 
-23 
28 
Oxidisable organic matter 
Oxide of iron and alumina and phosphoric) 
acid I 
Carbonate of lime 24 ' 14 
Sulphate of lime 15-52 
Carbonate of magnesia 3-86 
Nitrate of magnesia 7*91 
Chloride of sodium 17-05 
Alkaline carbonates 
Soluble silica 1-12 
Total solid constituents (dried at 130° C.) 70-11 
Actual (saline) ammonia -014 
Organic (albuniinoid) ammonia -021 
No. 2. 
Grains. 
1-56 
11 
20 
12 
20 
1 
1 
98 
21 
67 
81 
19 
44 
58 
40 
84 
093 
058 
In explanation of the preceding analytical results I would 
observe : — 
1. The total amount of solid matter is much larger in both 
samples than in good drinking-waters. 
2. Both contain more actual and organic ammonia than ought 
to occur in wholesome water. 
