and Water used for General Purposes. 
143 
on boilings fell from 17f degrees to 4 dcgi'ees, and that of No. 2 
from 16^ to 3^ degrees. 
The lime and other saline constituents do not interfere with 
their use as a beverage. Both were perfectly wholesome and, 
indeed, choice drinking-waters, for they contained, practically 
speaking, merely traces of organic matter, and that of a kind 
which appears to be incapable of undergoing putrefactive de- 
composition ; and their clearness, freedom from colour, and 
brilliancy, were unexceptionable. 
Deep chalk well-water generally has a uniform temperature 
throughout the year of 50° to 52° Fahr., and thus possesses a 
desirable coolness which recommends it for drinking purposes. 
The only and obvious objection to chalk spring-water is its 
hardness, which, when the water is first drawn, is generally from 
16 to nearly 18 degrees. A portion of the carbonate of lime, 
which occasions the hardness, is deposited from the water, when 
exposed to the atmosphere, with facility, from the escape of car- 
bonic acid gas, and thus by simple storage in reservoirs or tanks 
for a few davs the water becomes much softer. 
The good quality and abundance of the water from the chalk 
have been proved in every case, and it has been found suitable 
for town use, as at Gravesend, Folkestone, Dover, Brighton, 
Lewes, Portsmouth, Deal, Canterbury, Arundel, and Win- 
chester. 
When hard waters are used in steam-boilers they rapidly pro- 
duce a stone-like incrustation or fur, which interferes with the 
economic generation of steam, and if not removed from time 
to time may become the cause of boiler explosions. Boiler 
incrustations produced from hard water consist principally of 
carbonate and sulphate of lime, as the following analysis, which 
I made some years ago, will show : — 
Composition of a Boiler Incrustation. 
Grains. 
Water of combination <and organic matter .. .. 4 "59 
Oxide of iron and alumina ".oS 
Phosphoric acid '58 
Carbonate of lime 71 "06 
Sulphate of lime 12 " 75 
Lime in a state of silicate 1 • 56 
Magnesia 3-23 
Soluble silica 5 " 70 
100-00 
Various plans have been recommended for preventing the 
formation of boiler deposits, to which reference will be made in 
a subsequent page of this paper, in discussing the means of 
effecting the purification of natural waters. 
