I. SALT SPRINGS.
IN the United States, salt springs are very numerous. They sometimes
flow naturally, but are generally formed by sinking wells in those
places where salt is known to exist, as in marshes, salt licks, and
other similar places. The country on the Arkansas river furnishes some
salt; it differs however, from most other places in the United States,
by existing in pools, and forming incrustations on the soil of plains
and prairies. There is no salt obtained in Arkansas by boring, the
usual mode of procuring it in other localities. There are numerous salt
springs in Missouri; the working of many of them, however, has been
suspended or relinquished, on account of the reduced price of salt.
Large quantities of the article are still made at Boon’s Lick, and near
St. Genevieve and Herculaneum.
Salt springs are worked at Sciota; the quantity yielded, however, is
comparatively small. There are no salt-works on the Tennessee river;
but on the Holston, one of its tributaries, are extensive salt springs,
situated near Abingdon, Virginia, and known by the name of King’s and
Preston’s salt-works. These springs yield a considerable quantity of
salt. Preston’s works have been rendered less productive, by being
diluted by a spring of fresh water flowing into the midst of the salt.
Salt springs are very numerous in Kentucky, Ohio, and Virginia. Springs
holding salt in solution are common in various parts of the bituminous
coal region of Pennsylvania. They are generally weak near the surface,
but deep springs, disclosed by boring, are often strong. One of these,
which contains as much salt as the ordinary water of Salina, was
discovered by boring, about twenty miles from Montrose, bordering on
the state of New-York. The most considerable saline springs are on
the banks of the Conemaugh and Kiskeminitas, about thirty miles east
of Pittsburg. These rivers for many miles wind through rocky ravines,
bordered by hills of three and four hundred feet in height, that rise
with steep acclivities, presenting mural precipices of grey sand-stone,
in places jutting over the road and torrent. Large quantities of salt
are made at these springs.
In the town of Salina, in the state of New-York, about one hundred
and thirty miles west of Albany, are situated the most extensive works
in the United States for the manufacture of salt from natural brine.
The indications of that substance along the margin of Onondaga Lake
are supposed to have been similar to those found on the salt licks,
so common in the interior of the country, and the knowledge of their
existence was derived from the aborigines.
‘One of the earliest settlers in the county of Onondaga,’ says a
writer in Silliman’s Journal, ‘has informed me, that to procure salt
for his family, about forty years since, he, with an Indian guide in
a canoe, descended a small river that discharges into the lake at its
south-eastern termination, along the shore of which he passed, a short
distance to the right, and, ascending a rivulet (now Mud Creek) a few
rods, arrived at the spring or natural discharge of salt water, which
was obtained by lowering to the bottom, then four or five feet beneath
the surface of the fresh water of the lake, an iron vessel, which,
filling instantly with the heavier fluid, was drawn up and the brine
poured out. In this way, he got enough to make on the spot, by boiling,
and without any separation of the earthy impurities that were held with
the salt in solution, a small quantity of brownish colored and very
impure salt. Since that time other springs have been discovered at
various and almost opposite points on the shores of the lake, and many
wells have been sunk to procure brine for the manufactories at the
villages of Liverpool, Salina, Syracuse, and Geddesburg. The wells
did not exceed eighteen feet in depth, and in the strength of the
water which they respectively afforded there was great difference,
which varied much with the seasons, with this remarkable circumstance,
that it sometimes diminished fifteen to twenty per cent., and in some
instances, one third, as the adjoining lands, on the advance of summer,
became drained; and the lake, which in the spring overflowed the wells,
had subsided six or eight feet.’ The salt springs of Salina are found
on the margin of an extensive marsh.[22]
II. MINERAL SPRINGS.
The mineral springs in the state of New York, in excellence and
variety, are unsurpassed in any part of the world. The most famous are
called by the general name of the _Saratoga_ and _Ballston Springs_,
and are embraced in an extent of about twelve miles in the county
of Saratoga. The first spring discovered in the neighborhood of
Ballston stands on a flat. It formerly flowed out of a common barrel,
sunk around it, without any other protection from the invasion of
cattle, who often slacked their thirst in its fountain. Afterwards the
liberality of the citizens was displayed in a marble curb and flagging,
and a handsome iron railing. The curb and flagging were finally removed,
leaving the railing, which still serves the purposes of ornament and
protection. The spring flows now, probably from the place where it
originally issued, some feet below the surrounding surface, which has
been elevated by additions of earth, for the purpose of improving the
road in which it stands.
Near this spring, in boring about six or eight years ago, an excellent
mineral fountain was discovered at a considerable depth beneath the
surface. Its qualities are said to be superior to those of the spring
already mentioned, and, by many, its waters are preferred to any other
in the village.
The _United States’ Spring_ is situated at the east end of the
village. Near this fountain, a large and commodious bathing-house has
been erected, to which, not only the waters of this, but of a number
of other adjacent springs, are tributary, for the purpose of bathing.
Between the springs already mentioned, there was discovered in the
summer of 1817, a mineral spring, called the Washington Fountain. This
latter spring rose on the margin of the creek in front of the factory
building; it flowed through a curb twenty-eight feet in length, sunk
to the depth of twenty-three feet, and was liberated at the top in the
form of a beautiful _jet d’eau_; but the spring disappeared in 1821.
Numerous attempts have since been made to recover it, but they have
proved fruitless. The principal ingredients of these waters consist
of muriate of soda, carbonate of soda, carbonate of lime, carbonate
of magnesia, and carbonate of iron; all of which, in a greater or less
degree, enter into the composition of the waters, both here and at
Saratoga.
The justly celebrated springs of Saratoga are about six miles
north-east of Ballston Spa. They are situated on the border of a
valley, which bounds the village on the east, and form the continuation
of a series of springs which first appear in Ballston about twelve
miles to the south, and extend easterly in a semicircular line to the
Quaker village. In the immediate neighborhood are about a dozen springs,
the most celebrated of which are the Congress, the High Rock, the Flat
Rock, the Hamilton, the Washington, the Columbian and the President. A
cluster, known by the name of the Ten Springs, is found at the distance
of a mile to the eastward.
The _Congress Spring_ is situated at the south end of the village. It
was first discovered about thirty years since, issuing from a crevice
in the rock, a few feet from its present location. Here it flowed for
a number of years, until an attempt to improve the surface around it
produced an accidental obstruction of its waters, which afterwards made
their appearance at the place where they now flow. It is inclosed by
a tube sunk into the earth to the distance of twelve or fourteen feet,
which secures it from the water of the stream, adjoining to which it
is situated. Besides a handsome inclosure and platform for promenading,
the proprietor has thrown an awning over the spring for the convenience
of visitors.
The _High Rock_ is situated on the west side of the valley, skirting
the east side of the village, about half a mile north of the Congress.
The rock inclosing this spring is in the shape of a cone, nine feet
in diameter at its base, and five feet in height. It seems to have
been formed by a concretion of particles thrown up by the water, which
formerly flowed over its summit, through an aperture of about twelve
inches in diameter, regularly diverging from the top of the cone to its
base. This spring was visited in the year 1767 by Sir William Johnson,
but was known long before by the Indians, who were first led to it,
either by accident or by the frequent footsteps of beasts, attracted
thither by the saline properties of the water. A building was erected
near the spot previous to the revolutionary war, afterwards abandoned,
and again resumed; since which, the usefulness of the water has, from
time to time, occasioned frequent settlements within its vicinity.
The water now rises within two feet of the summit, and a common notion
prevails that it has found a passage through a fissure of the rock,
occasioned by the fall of a tree; since which event, it has ceased to
flow over its brink.
Between the Red spring in the upper village, and the Washington in
the south part of the lower village, are situated most of the other
mineral springs in which this place abounds. At three of the principal
springs, the Hamilton, Monroe and Washington, large and convenient
bathing-houses have been erected, which are the constant resort for
pleasure as well as health, during the warm season.
The mineral waters, both at Ballston and Saratoga, are supposed to be
the product of the same great laboratory, and they all possess nearly
the same properties, varying only as to the quantity of the different
articles held in solution. They are denominated acidulous saline and
acidulous chalybeate. Of the former, are the Congress, (which holds
the first rank,) the Hamilton, High Rock, and President, at Saratoga;
and of the latter, are the Columbian, Flat Rock, and Washington,
at Saratoga, and the Old Spring and United States, at Ballston. The
waters contain muriate of soda, hydriodate of soda, carbonate of soda,
carbonate of lime, carbonate of magnesia, oxide of iron, and some of
them a minute quantity of silica alumina. Large quantities of carbonic
acid gas are also contained in the waters, giving to them a sparkling
and lively appearance. The Congress, in particular, the moment it is
dipped, contains nearly one half more than its bulk of gas; a quantity
unprecedented in any natural waters elsewhere discovered.
Doctor Steel, in his geological report of the county of Saratoga,
published a few years since, remarks, that ‘the temperature of the
water in all these wells is about the same, ranging from forty-eight
to fifty-two degrees on Fahrenheit’s scale; and they suffer no sensible
alteration from any variation in the temperature of the atmosphere;
neither do the variations of the seasons appear to have much effect
on the quantity of water produced.
‘The waters are remarkably limpid, and when first dipped sparkle with
all the life of good champaigne. The saline waters bear bottling very
well, particularly the Congress, immense quantities of which are put up
in this way and transported to various parts of the world; not, however,
without a considerable loss of its gaseous property, which renders its
taste much more insipid than when drank at the well. The chalybeate
water is likewise put up in bottles for transportation, but a very
trifling loss of its gas produces an immediate precipitation of its
iron; and hence this water when it has been bottled for some time,
frequently becomes turbid, and finally loses every trace of iron; this
substance fixing itself to the walls of the bottle.
‘The most prominent and perceptible effects of these waters, when
taken into the stomach, are _cathartic_, _diuretic_, and _tonic_. They
are much used in a great variety of complaints; but the diseases in
which they are most efficacious, are, jaundice and bilious affections
generally, dyspepsia, habitual costiveness, hypochondriacal complaints,
depraved appetite, calculous and nephritic complaints, phagedenic or
ill-conditioned ulcers, cutaneous eruptions, chronic rheumatism, some
species or states of gout, some species of dropsy, scrofula, paralysis,
scorbutic affections and old scorbutic ulcers, amenorrhea, dysmenorrhea,
and chlorosis. In phthisis, and indeed all other pulmonary affections
arising from primary diseases of the lungs, the waters are manifestly
injurious, and evidently tend to increase the violence of the disease.
‘Much interest has been excited on the subject of the source of
these singular waters; but no researches have as yet unfolded the
mystery. The large proportion of common salt found among their
constituent properties, may be accounted for without much difficulty;
all the salt springs of Europe, as well as those of America, being
found in geological situations exactly corresponding to these. But
the production of the unexampled quantity of carbonic acid gas, the
medium through which the other articles are held in solution, is yet,
and probably will remain, a subject of mere speculation. The low and
regular temperature of the water seems to forbid the idea, that it is
the effect of subterranean heat, as many have supposed, and the total
absence of any mineral acid, excepting the muriatic, which is combined
with soda, does away the possibility of its being the effect of any
combination of that kind. Its production is therefore truly
unaccountable.’[23]
At Albany, in the summer of 1826, in boring for pure water for a
brewery, a mineral spring was accidentally opened. The sensible
qualities of this water have a great resemblance to those of the
Congress Spring at Saratoga, but those who are acquainted with it,
think it by no means so stimulating. Its temperature is uniformly
from fifty-one to fifty-two degrees of Fahrenheit, at all seasons
of the year; its specific gravity, when taken with great care, and
after repeated trials, was found to be as one thousand and ten to one
thousand. The taste of the water is purely saline, somewhat pungent,
and not at all disagreeable; it has no sensible chalybeate taste, and
no perceptible smell, which could lead to the suspicion of its holding
sulphuretted hydrogen gas in solution.
_New Lebanon Spring_ is situated in Columbia county, New-York about
twenty-four miles south-east of Albany. It is a very remarkable
fountain, issuing from a high hill. The water boils up in a space of
ten feet wide by three and a half deep, and is so perfectly clear that
the smallest objects may be seen at the bottom of the spring. Much
gas issues from the pebbles and sand, and keeps the water in constant
and pleasing agitation. The fountain is very copious, and more than
eighteen barrels of water are discharged in a minute. This supply is
not only sufficient to furnish the baths abundantly, but turns the
wheels of several mills. The quantity of water does not perceptibly
vary at any season; its temperature is uniformly seventy-three degrees
of Fahrenheit. The water is without taste or odor, is very soft, is
used for all culinary and domestic purposes, and differs but little
from pure mountain water, except in its remarkable temperature. It is
found very useful in salt rheums, and other cutaneous affections; it
augments the appetite, and sometimes acts as a cathartic. For those who
wish to enjoy fine rural scenery, bold, picturesque, and beautiful, and
such advantages to health as this copious fountain presents, nothing
can be better in its kind than New Lebanon.
The _Bedford Springs_ rise near a romantic and frequented village
of that name, situated among the mountains in the southern part of
Pennsylvania. They rise from a limestone rock at the base of a hill.
The water is pleasant and cold, and without any perceptible odor;
the iron, lime, and magnesia, with which it is impregnated, render it
useful in chronic and cutaneous disorders. Mineral springs abound among
the mountains in the central parts of Virginia. The _Yellow Springs_,
near the falls of the Little Miami, in Ohio, are esteemed for their
medicinal properties; the water is a strong chalybeate. The country
about them possesses much attraction in point of scenery, and is
unusually salubrious.
Florida is remarkable for the large number of its springs; a substratum
of soft and cavernous stone appearing to extend over the whole country,
admitting the courses of subterraneous brooks, which burst out at
frequent intervals in the form of springs. The most remarkable of these
is the fountain of Walkulla river, twelve miles from Tallahassee. It is
so large as to be navigable by boats directly below its sources. About
a mile from its head-waters the channel becomes choked with weeds, but
suddenly breaks on our view in the shape of a circular lake, that has
been sounded with a line of two hundred and fifty fathoms. It is clear
as crystal, and has the cerulean tinge which mark the waters of the
gulf. This hue is attributed to the presence of the sulphuret of lime.
‘To a person placed in a skiff,’ says Mr. Flint, ‘in the centre
of this splendid fountain basin, the appearance of the mild azure
vault above, and the transparent depth below, on which the floating
clouds and the blue concave above are painted, and repeated with an
indescribable softness, create a kind of pleasing dizziness, and a
novel train of sensations, among which the most distinguishable is a
feeling, as if suspended between two firmaments. The impression only
ceases, when the boat approaches the edge of the basin near enough to
enable you to perceive the outlines of the neighboring trees pictured
on the margin of the basin. It has been asserted, that limestone
water, in its utmost purity, has less refractive powers for light, than
freestone water. The water of this vast spring, even in this sultry
climate, has a coldness almost like ice-water. The water, probably
from the pressure of the sulphuret of lime, is slightly nauseous to
the taste. Beautiful hammock lands rise from the northern acclivity of
this basin. It was the site of the English factory in former days. Here
resided the famous Ambrister. The force, which throws up this vast mass
of waters from its subterranean fountains, may be imagined, when we
see this pellucid water swelling up from the depths, as though it were
a cauldron of boiling water. It is twelve miles from St. Marks, and
twenty from the ocean.’
III. BURNING SPRINGS.
Burning springs, or springs of water charged with inflammable gas,
are found in many places in the western part of the state of New-York,
chiefly near Canandaigua Lake. Their positions are known by little
hillocks of a dark bituminous mould, through which an inflammable
gas escapes to the surface. The following description is taken from
a Canandaigua Journal.
‘These springs are found in Bristol, Middlesex, and Canandaigua. The
former are situated in a ravine on the west side of Bristol Hollow,
about half a mile from the north Presbyterian meeting-house. The ravine
is formed in clay slate, and a small brook runs through it. The gas
rises through fissures of the slate, from both the margin and the
bed of the brook. Where it rises through the water, it is formed into
bubbles, and flashes only when the flame is applied; but where it rises
directly from the rock, it burns with a steady and beautiful flame,
which continues until extinguished by storms, or by design.
‘The springs in Middlesex are situated from one to two miles
south-westerly from the village of Rushville, along a tract of nearly
a mile in length, partly at the bottom of the valley called Federal
Hollow, and partly at an elevation of forty or fifty feet on the south
side of it.
‘The latter have been discovered within a few years, in a field which
had been long cleared, and are very numerous. Their places are known
by little hillocks of a few feet in diameter, and a few inches high,
formed of a dark bituminous mould, which seems principally to have been
deposited by the gas, and through which it finds its way to the surface,
in one or more currents. These currents of gas may be set on fire, and
will burn with a steady flame. In winter they form openings through
the snow, and being set on fire, exhibit the novel and interesting
phenomenon of a steady and lively flame in contact with nothing
but snow. In very cold weather, it is said, tubes of ice are formed
round these currents of gas, (probably from the freezing of the water
contained in it,) which sometimes rises to the height of two or three
feet, the gas issuing from their tops; the whole, when lighted in a
still evening, presenting an appearance even more beautiful than the
former.
‘Experiments made with the gas seem to prove, that it consists
principally of a mixture of the light and heavy carburetted hydrogen
gases, the former having greatly the preponderance; and that it
contains a small proportion of carbonic acid gas. It seems also to hold
a little oily or bituminous matter in solution. It burns with a lambent,
yellowish flame, scarcely inclining to red, with small scintillations
of a bright red at its base. It has the odor of pitcoal. It produces
no smoke, but deposits, while burning, a small quantity of bituminous
lampblack. It is remarkable that the hillocks, through which the
gas rises, are totally destitute of vegetation. Whether the gas is
directly deleterious to vegetable life, or indirectly, by interrupting
the contact of the air of the atmosphere, it is certain that no plant
can sustain life within the circle of its influence.
‘It is well known that this gas is found abundantly in coal mines; and
being accidentally set on fire, mixed as it is in those mines with the
air of the atmosphere, has many times caused terrible and destructive
explosions. The writer cannot learn that it has ever been known to be
generated in the earth, except in the presence of coal; and hence the
inference is strong that it proceeds from coal.’
There is a burning spring much resorted to by travellers, at the
distance of about two miles from Niagara Falls. At Dunkirk, on Lake
Erie, there are marshy spots which emit gas, that has been used for
lighting some of the houses in the village.
IV. WARM AND HOT SPRINGS.
The _Warm Springs_ of Arkansas territory are among the most interesting
curiosities of the country. They are in great numbers. One of them
emits a vast quantity of water. The ordinary temperature is that of
boiling water. When the season is dry, and the volume of water emitted
somewhat diminished, the temperature of the water increases. The waters
are remarkably limpid and pure; and are used by the people, who resort
there for health, for culinary purposes. They have been analyzed,
and exhibit no mineral properties beyond common spring water. Their
efficacy then, for they are undoubtedly efficacious to many invalids,
that resort there, results from the shade of adjacent mountains, and
from the cool and oxygenated mountain breeze; the conveniences of warm
and tepid bathing; the novelty of fresh and mountain scenery; and the
necessity of temperance, imposed by the poverty of the country, and
the difficulty of procuring supplies. The cases in which the waters are
supposed to be efficacious, are those of rheumatic affection, general
debility, dyspepsia, and cutaneous complaints. The common supposition,
that they are injurious in pulmonary complaints, seems to be wholly
unfounded. It is a great and increasing resort for invalids from the
lower country, Arkansas, and the different adjoining regions. During
the spring floods of the Washita, a steam-boat can approach within
thirty miles of them. At no great distance from them is a strong
sulphur spring, remarkable for its coldness. In the wild and mountain
scenery of this lonely region, there is much of grandeur and novelty,
to fix the curiosity of the lover of nature.
The _Warm Springs_ near Green Valley, in Virginia, are used for bathing,
and are esteemed valuable in rheumatic complaints. The temperature of
these springs is about ninety-six degrees, and sufficient water issues
from them to turn a mill. The _Bath_, or _Hot Spring_, is about five
miles distant. The stream is small, but the temperature is much greater
than that of the Warm Springs, being one hundred and twelve degrees.
These springs flow into the Jackson, a source of the James river.
The Warm Springs of Buncome county, in North Carolina, are found upon
the margin of a river called the French Broad, about thirty-two miles
from Ashville, and five and a half miles from the Tennessee line.
Several springs have already been discovered, at various distances from
each other, within the extent of a mile. They are generally so near the
bank, that in moderate freshets the river enters them, and it is said
that at a particular spot in the bed of the stream, about ten yards
from the usual bank, there is a constant jet of warm water. The depth
of the river varies from ten to fifteen feet, and in some places it is
even shoaler. The supply of water in all of them is very abundant.
‘The original proprietor of these springs,’ says a writer in the
Journal of Science, ‘informed me, that he supposed the first discovery
of them to have been made about forty years since, at which time this
part of the country was altogether uninhabited, and the persons who
resorted to the waters, had to encamp in their vicinity. He has been
personally acquainted with them, for upwards of twenty years, and made
the first and lowest establishment for bathing, near to a ferry, which
is opposite to his residence. Mr. Nelson further states, that he has
known sundry cases of palsy, rheumatism, and cutaneous affections, &c.
greatly benefited by the internal and external use of the waters. The
large establishment, and the one that is now principally visited, is
seated about half a mile higher up the river, and has at the present
time two large baths, whose temperature at the boils of the springs
is one hundred and four degrees of Fahrenheit; but at the surface the
temperature of the old bath, which is very near to the river, is one
hundred degrees, while that of the new, which is higher up the bank, is
but ninety-four degrees. I was informed that this temperature was much
increased when there was a considerable swell in the river, but I had
no opportunity of witnessing the fact.
‘A smaller stream of water, which is usually limpid and shallow, comes
into the French Broad on its southern side, and separates the first
bathing establishment from that which is now used. The stream affords
the conveniences of a saw, and grist-mill, within a very short distance
of the establishment, and without the necessity of a mill-pond. The
whole are situated in a beautiful and romantic spot upon a large flat,
contiguous to the water, and embosomed in lofty mountains, among which
the river winds, while the valley in this spot appears not to exceed a
mile in width, and is much narrower in all others, both above and below.
‘These mountains seem to consist principally of rocks, of which a
considerable proportion in the immediate vicinity are compact limestone,
both blue and gray. About six miles above the springs there is said to
be a vein of the sulphate of barytes, a specimen of which was given me;
and in the vicinity of the ferry below, there is a cavern of limestone,
which may be penetrated with convenience for thirty yards, and from
the roof of which stalactites are pendant. Near to this cave there is
another, containing a large quantity of yellow ochre.
‘There are said to be mines of cobalt, copper, and iron in the
neighboring mountains, but these are lofty and not very accessible. I
found that there was, from the local circumstances of the establishment,
considerable humidity during the mornings and evenings, and a pretty
high temperature for several hours of the day. There were also sudden
and frequent thunder showers, but these were generally of short
duration. These meteorological observations will perhaps lead to the
conclusion, that this watering-place would not be advisable for persons
laboring under pulmonic or dropsical affections, and I did not learn
that any such had been benefited by their residence.
‘Persons using these waters, are in the habit of drinking from three
to four quarts in a day, and also of bathing twice. They generally
remain in the bath from a half hour to an hour, and find it so pleasant
they are loth to leave it. It was stated to me by a very respectable
gentleman, who has resorted to this watering-place for several summers
past, that after drinking the water freely for several days, it
generally had a brisk cathartic effect for a day or two, and after that
produced no sensible result. This gentleman is afflicted with chronic
rheumatism, and has always obtained decided relief from the long
continued use of the waters, both internally and externally. Upon the
record book of the establishment there are sundry interesting cases
of benefit, imparted to persons laboring under rheumatism, palsy, or
loss of motion from other causes. I am inclined to believe that long
continued bathing in water of such an elevated and constant temperature,
must produce some effect in such cases as have been alluded to,
independent of the mineral ingredients, and, conjoined with them, it
will probably be more efficacious. The healthy, cheap, and plentiful
country, in which the Buncome Springs are situated, the novel and
mountainous scenery and variety of company, present many attractions
to the invalid, the idler, and the curious.’
GENERAL REMARKS ON SPRINGS.
The most common ingredient of mineral and medicinal springs,
is iron under a variety of forms. But they also often contain
magnesia, glauber salt, carbonic acid gas, and other substances,
which, from their combinations, give great diversity to the waters.
Springs impregnated with sulphur are also common in the vicinity
of volcanoes, and in countries subject to earthquakes. They are
usually warm, and the heat is sometimes accompanied by a violent
ebullition which frequently projects the water to a great height.
Iceland, the Azores, and various other places, afford striking
examples of this kind. The celebrated fountain called the _Geyser_,
in the first of these islands, often propels its contents the
height of one hundred feet, and sometimes to double that height.
There are also springs which are inflammable without being hot.
This generally arises from a quantity of inflammable gas, or
oily matter, which floats on the surface of the water; as in the
instance of a brook in the vicinity of _Bergerac_, in the south
of France, the surface of which may be set on fire by a lighted
straw. Others, being mixed with bitumen, which often floats on the
surface, will easily take fire, as at _Baku_, and other places in
Persia.
The waters of some springs and lakes have a petrifying, and
others an incrusting quality. The former is impregnated with
extremely fine silicious particles, which penetrate the pores of
the substances immersed in them, and change their nature. This
property is possessed by Lough Neagh. The Danube and the Pregel
have also the same quality, but in a less degree. The waters
which possess the incrusting property operate in a more rapid and
manifest manner, by depositing the earthy particles they hold in
solution, on the surfaces of bodies submitted to their action.
This effect is produced by both hot and cold springs, particularly
by the former. The matter deposited is usually calcareous, but in
the instance of the Great Geyser it is silicious.
Waters holding salt in solution, or muriated waters, as they
are commonly called, are perhaps the most common of all; but
they are rarely found in a state of purity. Among the Uralian
and Carpathian mountains, they are frequent, and in general in
the zone comprised between the parallels fifty and thirty north
latitude. More to the north they are rarely found; farther toward
the south crystallized salt is abundant in certain regions, as in
the great desert of Africa; but we find only a few salt springs
there.