different substances which it holds in solution, is one of the most
difficult and complicated operations that is known in this branch of
science; and one that exercises, in a peculiar degree, both the skill
and industry of the operator. The difficulty arises not only from the
diversity of the bodies which occur, but from the very minute quantities
of some of them.
These bodies are discovered by an addition to the water of certain
substances, the consequence of which is some change in its appearance,
and this change indicates the presence or absence of the bodies
suspected.
The substances thus employed are very numerous, and have the name of
_tests_. The methods of ascertaining the exact proportion of each of
these ingredients are much too complicated to require a place in the
present work.
Water cannot be obtained in any state of perfect purity except by the
artificial process of distillation.
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ORDER I.—COMMON WATER.
274. _RAIN WATER is considered to be next in purity to distilled water,
from its having undergone a natural distillation. Its foreign contents
vary according to the state of the air through which it falls. Hence,
for instance, when it passes through the atmosphere of a smoky town, it
becomes impure: and when collected in towns, it frequently acquires a
small quantity of sulphat of lime (192), and calcareous matter from the
mortar and plaster of the houses._
This water is always very soft; and is, consequently, well calculated
for the dissolving of soap, in washing and other processes. It is also
peculiarly adapted to the solution of alimentary or colouring matter, in
the preparation of food and dyeing, and is accordingly used to great
extent for these purposes. By the addition of a small quantity of a
solution of barytes (195), it may be rendered sufficiently pure for all
chemical uses.
If rain water be long kept, especially in hot climates, it acquires a
disagreeable smell, and becomes putrid, and full of animalculæ.
275. _ICE and SNOW WATER are equal to rain water in purity; and the air
having been expelled from them during the process of freezing, they are
consequently devoid of air when first melted._
Ice and snow, in their natural state, are highly important to mankind.
It is a general law of nature that all bodies become more dense and
heavy by exposure to cold; but the freezing of water is an exception to
this law, and for a purpose of extreme benefit to mankind. By this
ordination it is that ice always rises to the surface of the water, and
thus preserves from the effects of the surrounding cold, a vast body of
heat in the fluid beneath; and is itself ready to receive its own
accustomed quantity upon the first change of the atmosphere. The
expansion of water, in freezing, is owing to its assuming a crystallized
form; and this expansion is often so great that glass bottles, filled
with water, are burst by it.
During the intense cold of winter, snow, which is of a soft and spongy
texture, is considered of great utility in preventing the immediate
access of the atmospheric air to the ground; it has doubtless been
designed by Providence as a garment to protect the incipient vegetation,
at that inclement season, from injury.
The inhabitants of all the extreme northern parts of the world use
thawed snow for their constant beverage during winter; and the vast
masses of ice which float in the polar seas afford an abundant supply of
fresh water to the navigators of those dreary regions. Snow water has,
however, long lain under the imputation of occasioning those
extraordinary swellings in the neck, which deform the inhabitants of
some of the alpine valleys of Switzerland; but this opinion is not
supported by any well─authenticated facts. Indeed it is rendered quite
improbable by the frequency of this disease in the island of Sumatra,
where ice and snow are never seen: and by its being quite unknown in
Chili and Thibet, though the rivers of these countries are chiefly
supplied by the melting of the snows.
276. _SPRING WATER is nothing more than rain water, which having
gradually filtered through the earth, collects at the bottom of
declivities, and there makes its way to the surface._
_It is obvious that spring water must be nearly as various in its
contents as the substances through which it flows._
Ordinary springs pass insensibly into mineral springs, according as
their foreign contents become more abundant; but it has not unfrequently
happened that waters have acquired great medical reputation from their
purity only. Although by far the greater number of springs are cold,
some are hot, or at least are of a temperature which, at all times,
exceeds that of summer heat: and this warmth is so little influenced by
the state of the atmosphere, that it is nearly the same both in summer
and winter.
The water of almost every spring is of such nature that it will not
dissolve, but curdles, soap; and cannot be used for dressing several
kinds of food. Water of this description is denominated _hard_, a
property owing to the great proportion of earthy salts which it holds in
solution, and which, at the same time, are not in such abundance as to
impair its taste. The most common of these salts is selenite, or sulphat
of lime (192), and chalk, or carbonat of lime (140); when it contains
only the latter, the water is easily rendered soft by boiling, which
expels the excess of carbonic acid (26), and thus causes the chalk to be
precipitated. Hence originates the earthy crust or _fur_ in such tea
kettles as have had hard water several times boiled in them.
The water of deep wells is for the most part much harder than that of
springs which overflow their channels.
277. _RIVER WATER is a mixture of spring and rain water, which, from
much agitation, and by long exposure to the air, in the course of its
channel, becomes, in general, tolerably soft and free from earthy
salts._
For washing, and other purposes of domestic economy, river water, from
its softness and purity, is not only preferable to spring water, but
also serves for many uses to which the latter cannot be at all applied.
As a beverage, however, it is in general vapid and unpleasant.
The waters of some rivers, particularly where the beds, over which they
flow, are sandy or stony, are remarkably pure. This is the case with
several of those in Switzerland, Wales, Scotland, and the northern
counties of England. The river Seine has great repute in France on this
account: it has been found, on accurate examination, even more pure than
Bristol water.
That of the river Thames, impregnated as it would appear to be with
putrid remains, is soft and good, when taken up at low water; and, after
rest and filtration, is found to contain but a small portion of any
thing either noxious or unpleasant. It is preferred, by mariners, to
most other water for sea store; but it soon becomes putrid, and
undergoes a remarkable spontaneous change. When, after having been kept
a month or two, a cask is opened, a quantity of inflammable air escapes,
and the water is black and nauseous. If, in this state, it be racked off
into large earthen vessels (oil jars it is said are commonly used for
the purpose), and exposed to the air, it gradually deposits a portion of
black slimy mud, and becomes perfectly clear, sweet, and fit for use.
278. _STAGNANT WATER contains greater impurities than any other. In
ponds and marshes particularly, it is filled with the remains of animal
and vegetable matters, which are there undergoing a gradual
decomposition._
_The water of lakes is not, in general, so much contaminated as this;
but from the same cause, it frequently has a slimy appearance, a
brownish colour, and an unpleasant taste._
From the putrefying contents of stagnant water, nutriment is afforded to
various living plants and insects which there supply the place of those
that perish. Its taste is vapid, unpleasant, and wholly destitute of
that agreeable freshness which is found in spring water. It is, however,
generally soft, and, by filtration, it may be freed from many of its
impurities.
The air which issues from marshes and stagnant pools is extremely
noxious, and is the cause of agues and other distressing complaints, to
such persons as reside in the neighbourhood of them or are much exposed
to them; and the injurious effects of such air have also been considered
to extend to the internal use of these waters.
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ORDER II.—SEA WATER.
279. _SEA WATER is a very heterogeneous compound, not only containing a
considerable portion of saline substances, but holding also suspended in
it an infinite number of minute animal and vegetable particles, to the
gradual putrefaction of which its peculiarly nauseous and bitter taste,
at the surface, is in some measure to be attributed._
_The average quantity of salt in sea water is estimated to amount to
about one─thirtieth part of its weight. It likewise contains a certain
portion of muriat of magnesia, sulphat of magnesia or Epsom salts (199),
and a small quantity of sulphat of lime (192). Sea water, taken from a
great depth, has not the bitterness which the water of the surface has:
it is only saline._
No natural waters, if we except certain brine springs and salt lakes,
are so saline as those of the ocean; and the latter differ, in this
respect, in different parts of the world. At the tropic, the sea is in
general more salt than it is at the poles, a wise ordination to preserve
it, in those climates, from the great tendency to putrefaction: and, at
a considerable depth, it is always found more salt than at the surface.
The water of the Baltic is much less salt than that of the Atlantic; and
it is a remarkable circumstance, that its saline contents are increased
by a west wind, but still more so by a gale from the north west.
Some philosophers have endeavoured, but to little purpose, to account,
from second causes, for the saltiness of the ocean. Dr. Halley persuaded
himself that it might have been gradually acquired, in very minute
portions, by a deposit of salt washed down from the land by rivers, and
that, as it could not be carried off by evaporation, instead of being
diminished, it must be constantly increasing. But this idea of salting
the sea with fresh water, is, to say the least of it, somewhat absurd,
more particularly as it presumes that the sea was originally
unimpregnated with salt. Had this been the case, the putrefaction of the
immense mass of animal and vegetable substances which it gradually
contained, would, in a short time, have proved fatal to the whole
inhabitants of the earth.
The temperature of the sea, although it must necessarily vary in the
different seasons, is much more uniform than that of any inland water
exposed to the atmosphere. This is, in a great measure, attributable to
its vast body of water, and the perpetual agitation to which it is
exposed.
Sea water, when congealed by frost, is found to reject all, or nearly
all, its saline particles; and consequently, when thawed, its ice yields
water so fresh that it may be drunk without unpleasantness. The freezing
of sea water is not unfrequently practised in the northern parts of the
world, with a view to lessen the trouble and expense of extracting salt
from it, for domestic and other uses (202). Salt water may likewise be
rendered fresh and palatable by distillation, a mode which is now very
generally practised at sea.
The sea shore has of late become so much frequented by invalids, for the
purpose of bathing, that there is scarcely a fishing village, on the
whole extent of our coast, but which is provided with some accommodation
for bathers. As a cold bath, sea water is employed, with advantage, in
all those cases of debility for which cold bathing has, in general, been
recommended. It is also used as an external application in tumours and
some other complaints; and, taken internally, as a remedy in various
disorders.
It is to sea water that we are chiefly indebted for the salt which we
use at table, and for all the purposes of domestic economy (202). From
this water is also obtained those salts used in medicine, called
Glauber’s (203) and Epsom salts (199).
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ORDER III.—MINERAL WATERS.
1. THE MORE SIMPLE COLD WATERS.
280. _MALVERN WATER is a simple cold water, perfectly bright and
pellucid: it has an agreeable, and somewhat pungent flavour; but, in
other respects, it does not differ in taste from pure and good soft
water._
_It contains carbonic acid (26), and a very small portion of earth,
either lime or magnesia; but, the carbonic acid perhaps excepted, the
foreign bodies are less in quantity than those even of our common spring
water._
The spring from which this water principally issues is denominated the
Holy Well: and is situated high up the hill, about midway between the
villages of Great and Little Malvern, in Worcestershire.
Both as an external and internal application, the waters of Malvern have
been considered beneficial in many obstinate complaints. It is a
singular circumstance respecting them that, notwithstanding their
apparent purity, if they be exposed to the air in an open vessel, they
will soon acquire a fetid and unpleasant smell.
Malvern is principally frequented during the summer season.[5]
Footnote 5:
Adjoining to Great Malvern, and a little higher up the hill, there is
a very light and pleasant _chalybeate water_.
2. THE MORE SIMPLE WARM WATERS.
281. _BRISTOL HOT─WELL WATER is pure, warm, and slightly acidulated,
clear, sparkling, and agreeable to the palate, but without any very
decided taste. It is also destitute of smell. When poured into a glass
it sends forth numerous air─bubbles. The heat of this spring is very
moderate, the average_ _being about 74° of Fahrenheit’s thermometer; and
this heat does not sensibly vary during summer or winter._
_The foreign contents of the hot─well water are muriat of magnesia,
common salt, Glauber’s salt, sulphat of lime (192), and chalk: but these
are in extremely small quantity. It also contains at the rate of about
thirty cubic inches of carbonic acid gas, or fixed air (26), in every
gallon._
This water springs from the bottom of the southern extremity of St.
Vincent’s rock, a lofty cliff of limestone situated on the north bank of
the river Avon, and about a mile below the city of Bristol. And,
although it is considerably higher than the river, it is so far affected
by the spring tides as to become, thereby, in some degree turbid. The
discharge of water amounts to about forty gallons in a minute.
There is another spring at _Clifton_, on the summit of the same hill,
from the bottom of which the waters of the hot─well issues. This is
called the _Sion spring_, and is one or two degrees colder, but, in
other respects, it very nearly resembles the water of the hot─well.
Its discovery was somewhat remarkable. A Mr. Morgan, an attorney of
Bristol, having erected a house near the spot, sunk a well for the
supply of his family with water. The workmen had proceeded to the depth
of nearly 240 feet without success, when they were suddenly alarmed by
the gushing forth of such an abundance of water that they were compelled
to retreat with precipitation. The proprietor was so far disappointed of
his hopes as to find that this was a spring of warm instead of cold
water. But the circumstance induced him to erect an engine to raise the
water for medicinal purposes; and, since that period, a pump room and
bathing houses have been prepared for the accommodation of visitors.
The water of each of these springs, besides being used medicinally in
pulmonary consumptions and other complaints, is employed very
extensively at table, and for all domestic purposes. It is remarkable
for softness and purity; and, from its quality of continuing untainted
for a great length of time, even in hot climates, is a valuable water
for long voyages, and is accordingly exported in considerable quantities
to distant parts.
The season of general resort to Clifton and the hot─wells is from about
the middle of April to the end of October.
282. _MATLOCK WATER is a simple warm water, which, in its sensible
properties, exclusive of its temperature, which is only about 66° of
Fahrenheit, is scarcely different from good spring water. It is
beautifully clear, and exhales no steam, except in very cold weather._
The medicinal virtues of this water have chiefly been ascribed to its
temperature. Its supply is very copious, and from several different
sources. Though recommended in some internal complaints, it is
principally employed as a bath; and, in this respect, it forms a medium
betwixt the waters of Bath or Buxton and those of the generality of cold
baths.
Matlock, which is a beautifully romantic village, situated in a hilly
part of Derbyshire, and at the distance of 143 miles north of London,
was first brought into public notice about the year 1698, shortly after
which period the first bath was erected. It is chiefly frequented from
the month of May to that of October; or, if the weather continue fine,
till near the beginning of November.
283. _BUXTON WATER is a simple warm water, which contains so little
foreign matter, as scarcely to be distinguishable from common spring
water heated to the same temperature. It has neither smell nor taste;
and, though it sparkles a little in the glass, when first drawn, this is
not apparently more than what is observable in the water of many common
springs._
_Its temperature, in the bath called the Gentleman’s bath, is invariably
82°._
Buxton has been celebrated, for its warm springs, nearly two centuries
and a half. As early as the year 1572 a treatise on their virtues was
published: this states them to have been at that time much resorted to
by persons from all the adjacent counties. The water is employed both
externally and internally, and to great extent. Its principal value, as
a bath, arises from its very copious supply, its purity, and its high
temperature. The sensation which is felt from bathing in it is
considered to be such as would be experienced from any bath heated to
the highest temperature which is compatible with giving some sensation
of cold when the body is first plunged into it. This water is also used
as an internal medicine; and is frequently used by the inhabitants as
their common beverage, and for such domestic purposes as its hardness
will admit.
There are several springs and several distinct baths; but the original
and most ancient of them is called St. Ann’s Well, and is enclosed in an
elegant stone building. These waters are frequented by persons afflicted
with the rheumatism, gout, diseases of the alimentary organs, and
kidneys, and various other complaints: and the chief influx of company
is during the summer and autumnal months.
The situation of Buxton is in a narrow and funnel─shaped valley,
surrounded by wild, bleak, and dreary mountains, in the midst of the
county of Derby, and about 160 miles north of London.
3. HOT CARBONATED CHALYBEATE WATER.
284. _BATH WATER is a hot carbonated chalybeate. When first drawn, it
appears clear and colourless, nor does it afford any signs of briskness
or effervescence. The temperature of the water drawn from the King’s
Bath, which is that usually employed for drinking, is 116° of
Fahrenheit, and that of the Cross Bath is 112°. No odour whatever is
perceptible from a glass of fresh water; but from a large body of it the
nose is affected by a slight degree of pungency. When the water is hot
from the pump, it fills the mouth with a strong chalybeate impression
without any pungency, and accompanied with scarcely any kind of saline
taste; and, what is remarkable, as soon as the water cools, the
chalybeate taste is entirely lost, and nothing but an extremely slight
saline sensation remains upon the palate._
_The foreign contents of Bath water are sulphat of lime (192), chalk,
Glauber’s salt (203), and common salt; together with a very small
portion of oxide of iron (21), yet sufficient to give iron mould stains
to the linen of the bathers. The water curdles soap, and is so hard as
to be unfit for many domestic purposes._
The city of Bath has been celebrated for its hot springs even from the
time of the Romans. These are of higher temperature than any within the
British dominions; and indeed are the only natural waters which we
possess that are at all hot to the touch, the other thermal waters being
of heat below the animal temperature.
There are three principal sources of these waters, called the King’s
Bath, the Cross Bath, and the Hot Bath; and they differ slightly in
their properties. The springs arise within a short distance of each
other, at the lower part of the city; and yield so copious a supply that
all the large reservoirs used for bathing are filled every evening with
water fresh from their respective fountains.
The application of the water externally is either general or local. The
latter consists in pumping it for a considerable time on the part
affected. This is called _dry pumping_, because in it only one part of
the body is wetted, whilst the rest is kept dry; and in many cases, it
is found an excellent remedy.
The diseases for which these waters are resorted to are very numerous,
and are amongst the most important and difficult to be cured that come
under medical treatment.
4. HOT ALKALINE SULPHUREOUS WATER.
285. _AIX─LA─CHAPELLE or AKEN WATER, is an alkaline sulphureous water,
much hotter than that of any of the springs in England, varying in
temperature in the different baths from 112° to 143°. It has a saline,
bitterish, and somewhat alkaline taste; and its smell precisely
resembles, but is greatly more powerful than, that of Harrowgate water
(299)._
_It contains a small quantity of chalk, common salt, and carbonat of
soda (201), the latter of which renders it soapy to the touch. But the
most striking feature in this water is_ _the unusual quantity of sulphur
which it contains; and which is so extremely volatile on the application
of heat, that none of it is left in the residuum after evaporation. In
this water there is also a considerable portion of carbonic acid._
The city of Aix─la─Chapelle is in the circle of Westphalia, betwixt the
rivers Meuse and Rhine, about seventy miles east of Brussels, and in a
rich and fertile country. Its waters have been in great medical repute,
and have attracted a numerous concourse of visitants for many centuries
past. Their reputation was so well established, even in the time of
Charlemagne, that he frequently resided at Aix: and he is said to have
been so much delighted in the use of the waters as to have sometimes
even held his levee at the baths.
In this city, and in the small territory that belongs to it, there are
several sources of hot water. Of these the principal spring is enclosed
in a stone cistern, which is vaulted and almost conical at the top, and
the parts of which are connected with the utmost care, to prevent the
vapour from escaping. From this spring the water flows, in a copious
stream, into several spacious and elegant baths, in the different parts
of the city, distinguished by the names of the Emperor’s Bath, the
Nobles’ Bath, the Poor’s Bath, and other appellations. In most of these
there is every necessary apparatus for bathing by immersion, for vapour
bathing, and for pumping on any particular parts of the body.
The water rises, with great quickness, from the springs, and sends forth
bubbles of air, which burst with a slight noise when they reach the
surface. It is at first perfectly colourless and pellucid, and emits a
large portion of steam, and with it a strong sulphureous smell, which is
perceptible at a great distance.
Its temperature is so high, that, in the large baths, it requires to
stand from fifteen to eighteen hours before it is sufficiently cooled
for tepid bathing; and it is one of the few natural springs which are
hot enough to be employed as a vapour bath without the addition of
artificial heat. On standing to cool, it gradually loses its clearness,
acquires a milky hue, and deposits an earthy sediment, which is entirely
calcareous. At the same time it loses its offensive smell, and, when
cold, has scarcely any odour.