WAT 
WAT 
W A T 
88fr 
turn the centre wheel round once in an hour: 
the spiaclle of this projects through the lower 
plate (fig. 8), anti has a tube fitted on it, 
which is square at the top, and carries the 
minute hand ; the other end of this tube has 
a pinion of 12 teeth on it, which turns the 
minute wheel s, (figs. 8 and 18) of 48, and its 
pinion of 1 6 , which moves the hour wheel t, 
•of 48 teeth: the spindle of this is a tube 
which is put over the tube of the minute 
hand, and has the hour hand fixed on it to in- 
dicate the time upon the dial-plate. 
Watch, striking, one which, besides the 
common watch-work for measuring time, 
has a clock part for striking the hours, so that, 
.properly speaking, they are pocket-clocks. 
See Clock. 
Watch, repeating, one that by only pull- 
ing a string, pushing in a pin, &c. repeats 
the hour, quarter, or minute, at any time of 
the day or night. 
Watches made by artificers are to have 
the makers’ names, under the penalty of 20/. 
9 and 10 W. III. c. 28. 
WATCHING. See Medicine. 
WATER was universally considered as a 
■simple elementary substance, till the chemists 
of the present age proved, by experiments, 
the substance of which has been stated in a 
preceding article (see Chemistry), that it 
•is in reality a compound body. Its prin- 
ciples have been ascertained both by com- 
position and decomposition ; and one hun- 
dred paits of water are found to consist of 
eighty-five parts of oxygen, and fifteen of hy- 
drogen, with a certain portion of caloric. 
This very useful and necessary fluid pre- 
sents itself to our notice in three distinct 
forms, namely, in its liquid state, in the state 
of vapour or steam, and, lastly, in its frozen 
«tate. See Freezing, Evaporation, 
Eteam, &c. 
Water, when fluid, is not in its most simple 
state; for its fluidity depends on a certain 
quantity of caloric, which enters into com- 
£>ination with it, and insinuating itself be- 
tween the particles of the water, renders 
them capable of moving in all directions. 
We are supplied with water either from 
the atmosphere, whence it descends in the 
form of rain, hail, or snow, or from the earth, 
Which Sends it forth in springs and rivulets. 
In the former case, the watery exhalations 
■drawn from the sea, and the surface of the 
earth by the sun’s heat, form clouds, whose 
particles being afterwards condensed, fall 
iback again in showers. In the latter, the 
-water which falls on the tops of mountains, 
'•and other lofty situations, penetrates the 
earth, and, after passing downwards, breaks 
forth at some fissure or aperture at a distance 
from its source. 
Water, common. Good water is as 
transparent as crystal, and entirely colourless. 
It lias no smell, and scarcely any taste ; and 
in general the lighter it is, so much the bet- 
ter. If we compare the different waters which 
are used for the common purposes of life with 
each other, and judge of them by tin: above 
standard, we shall find them to differ con- 
siderably from each other, according to the 
circumstances of their situation. 'These wa- 
ters may be reduced under four heads, name- 
ly, 1. Rain water; 2. Spring and river water; 
i. Well water; 4. Lake water. 
1. Rain water, unless when near a town, 
or when collected at the commencement of 
the rain, possesses the properties of good wa- 
ter in perfection, and is as free from foreign 
ingredients as any native water whatever. 
1 lie substances which it holds in solution are 
air, carbonic acid, carbonat of lime, and, ac- 
cording to Bergman, it yields some traces of 
nitric acid, and a little muriat of lime. The 
quantity of air in good water does not exceed 
-aV-h °t the bulk. One hundred cubic inches 
of water contain generally about one cubic 
inch ot carbonic acid gas. It is to the pre- 
sence of these two elastic fluids that water 
owes its taste, and many of the good effects 
which it produces on animals and vegetables. 
Hence the vapidness of newly-boiled water 
from which these gases are expelled. Snow 
water, when newly melted, is also destitute of 
gaseous bodies. Hence the reason that fish 
cannot live in it, as Carradori has ascertain- 
ed. Hassenfratz, indeed, has endeavoured 
to prove, that snow water holds oxygen gas 
in solution; but in all probability the water 
which he examined had absorbed air from the 
atmosphere. 
The quantity of muriat of lime contained 
in rain water must be exceedingly minute ; 
as Morveau has ascertained that rain water 
may be rendered sufficiently pure for che- 
mical purposes by dropping into it a little 
barytic water, and then exposing it for some 
time to the atmosphere, and allowing the 
precipitate formed to deposit. According to 
that very accurate philosopher, the rain water 
which drops from the roofs of houses, after it 
has rained for some time, contains only a 
little sulphat of lime, which it has dissolved as 
it trickled over the slates. 
2. 'The water of springs is nothing else than 
rain water, which, gradually filtring through 
the earth, collects at the bottom of declivities, 
and makes its way to the surface. It is there- 
fore equally pure with rain water, provided it 
does not meet with some soluble body or 
other in its passage through the soil. But as 
this is almost always the case, we generally 
find, even in the purest spring water, a little 
carbonat of lime and common salt, besides 
the usual proportion of air and carbonic acid 
gas. Sometimes also it contains muriat of 
lime or a little carbonat of soda. Bergman 
found the springs about Upsal, which are 
reckoned exceedingly pure, to contain the 
following foreign bodies : 
E Oxygen g is, .5. Common salt, 
2. Carbonic acid, 6. Sulphat of potass, 
3. Carbonat of lime, 7. Carbonat of soda, 
4. Silica, 8. Muriat of lime. 
The whoie of these ingredients amounted 
at an average to 0.00004 parts ; and the pro- 
portion of each of the solid bodies was as fol- 
lows : 
Carbonat of lime 5.0 Muriat of lime 0.5 
Common salt 3.0 Sulphat of potass 0.25 
Silica - - 0.5 Carbonat of soda 0.25 
River waters may be considered as merely 
a collection of spring and rain water, and 
therefore are usually possessed of a degree of 
purity at least equal to these. Indeed, when 
their motion is rapid, and their bed siliceous 
sand, they are generally purer than spring 
water; depositing during their motion everv 
thing which was merely mechanically sus"* 
pended, and retaining nothing more than the 
usual proportion of air and carbonic acid gas, 
10 
1 and a very minute quantity of carbonated 
lime and common salt. \Y lien their bed is 
clayey, they are usually opal-coloured, i«- ! 
consequence of the particles of clay which 
they hold in suspension. 
3. By well water is meant the water which 
is obtained by digging deep pits, which is not 
in sufficient quantity to overflow the mouth 
of the well, but which may be obtained in 
abundance by pumping. It is essentially the 
same with spring water, being derived from 
the very same source ; but it is more liable 
to be impregnated with foreign bodies from 
the soil, in consequence of its stagnation or : : 
slow filtration. Hence the reason that well 
water is often of that kind which is distin- 
guished by the name of hard water, because ! 
it does not dissolve soap, and cannot be used 
for dressing several kinds of food. 'These 
properties are owing to the great proportion 
of earthy salts which it holds in solution. 
The most common of these salts is sulphat of 
lime. 'These earthy salts have the property 
of decomposing common soap: their acid 
unites with the alkali of the soap, while the 
earthy basis forms with the oil a soap not 
soluble in water, which envelopes the soap 
and gives it a greasy feel. These water* 
may be in general cured by dropping into 
them an alkaline carbonat. Mr. Sennebier 
has shewn that well water usually contains a 
greater proportion of carbonic acid gas than 
spring or river water. 
4. The water of lakes is merely a collec- 
tion of rain water, spring water, and river 
water, and of course contains precisely thb 
same heterogeneous salts : but it is seldom 
so transparent as river water, being usually 
contaminated with the remains of animal and 
vegetable bodies which have undergone pu- 
trefaction in it. For as lake water is often 
nearly stagnant, it does not oppose the pu- 
trefaction of these bodies, but rather pro- 
motes it; whereas in river water, which is 
constantly in motion, no putrefaction takes 
place. Hence the reason of the slimy ap- 
pearance and the brownish colour which 
often distinguish lake water. 
Marsh water contains a still greater pro- 
portion of animal and vegetable remains than 
lake water, because it is altogether stagnant. 
Moss water is strongly impregnated with 
those vegetable bodies which constitute 
mosses, and usually also contains iron. 
Waters, mineral. All waters which are 
distinguished from common water by a pe- 
culiar smell, taste, colour, &c. and which in 
consequence ot these properties cannot be 
applied to the purposes of domestic economy, 
have been distinguished by the appellation of 
mineral waters. These occur more or less 
frequently in different parts of the earth, con- 
stituting wells, springs, or fountains ; some- 
times of the temperature of the soil through 
which they pass, sometimes warm, and "in 
some cases even at the boiling temperature. 
Many of these mineral springs attracted the 
attention of mankind in the earliest ages, and 
were resorted to by those who laboured under 
diseases, and employed by them either ex- 
ternally or internally as a medicine. Bint it 
was not till towards the end of the 17th cen- 
tury that any attempt was made to detec t the 
ingredients of widen these waters were (com- 
posed, or to discover the substances to which 
they owed their properties. 
