John Almon.

The American journal of science and arts online

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848 /. P. Coeke, Jr., on determining am&uni of

by the apparatus represented in the acoompanying figore whicky
although it may appear complicated at nrst sight, is really a
simple combination of parts, which are &miliar in every labora-
tory.

To the sides of a common copper water bath are attached
three tubes as is shown in the figure. The tube on the left con-
nects with a Mariotte's flask by which the water is maintained
at a constant level in the bath. The upper tube on the right
connects with a carbonic acid gas generator, while the lower
tube (connected with Che sink by a rubber hose), serves simply
as an overflow for the water. Cfn the cover of the water-bath
close to the rim is a depressed circular groove, which receives
the lip of an inverted glass tunnel. When the apparatus is in



use this eroove is kept full of water by the spray from the boil-
ing liquid and thus forms a perfect water joint ; but in order to
secure this result the bath must be kept nearly full of water
and holes for the ready escape of the steam and spray should
be provided in the copper rings, which cover the bath and
adapt it for vessels of various sizes. It is evident that, by this
simple modification of the ordinary water-bath, we can keep
our assay surrounded by an atmosphere of steam or of carbonic
acid, as may be desirable, during the whole process of diges-
tion, and that too for an indefinite period. Moreover while
watching the process through the glass we can either pour in
fresh quantities of the solvent, or we can stir up the material,
in the vessel within, introducing a tube-tunnd or stirrer through
the spout of the covering tunnel.

After the above descnption the method of making .the iron
assay will be readily understood. A small amount of the finely



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Protoxyd of Iron in Silicates. 349

pulverized mineral (firom one-half a gram to a gram) is weighed
out in a large platinum crucible. Upon this we pour a mixture
of dilute sulphuric acid (sp. gr. 1*5) with as little hydrofluoric
acid as experience may show is required to dissolve* the mineral
stirring up the material with a platinum spatula. The crucible
is next transferred to the water bath, the covering tunnel put in
place, water poured into the groove, the interior filled with car-
bonic acid from the generator and the gas lamp lighted. As soon
as the water boils, the connection with the generator is closed, and
if the water level has been properly adjusted, the apparatus will
take care of itself, the groove will be kept full of water and the
interior of the tunnel full of steam. If the materials cake on the
bottom of the crucible, — as is not unfrequently the case when a
large amount of insoluble sulphate is formed, — ^the lamp may be
removed, the apparatus again filled with carbonic acid, and the
contents of the crucible stirred up as above described. A stout
platinum wire about two inches long, cemented before the blow-
pipe to the end of a glass tube, makes an excellent stirring rod,
and after using it any adhering material can easily be washed back
into the crucible by airecting the jet from the wash bottle down the
throat of the covering tunnel. The lamp may then be replaced,
the current of carbonio'acid interrupted and the process of diges-
tion continued. When the decomposition is complete the cur-
rent of carbonic acid gas is reestablished, the lamp extinguished
and the air tube of the Mariotte's flask raised until its lower end
is above the level of the overflow. A slow current of water is
thus caused to flow through the bath, which soon cools down
the whole apparatus. The crucible may now be removed, its
contents washed into a beaker glass and the solution diluted
with pure water until the volume is about 500 cTm.*, when the
amount of protoxyd of iron present can be determined with
a solution oi permanganate of potassa in the usual way. The
total amount of iron present being subsequently determined, the
relative proportion of the two oxyds is of course well known.
In order to show the afccuracy of the method and also to prove
that the presence of hydrofluoric acid does not exert any ap-
preciable influence on the permanganate solution we subjoin
the following results.

The strength of the solution of permanganate was tested with
the double sulphate of ammonia and iron. In each case 14
grams of the salt were accurately weighed out and dissolved in
about 500 cTml* of water. To the first two portions sulphuric
acid was alone added while to the last two there was also added
a very large amojj||w)f hydrofluoric, acid, four or five times as

* If the mineral contaiiis lead, baryta, stroatia or eTen lime in any considerable
quantity, complete solution cannot of course be obtained, but this is unimportant so
Umg as thi» mmeral is wholly decomposed.



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850 /. P. Cooke, Jr.^ on determining amount, etc.

much as would be required in any mineral analysis. The re-
sults were

No. 1, 1*4 grams iron salt required 26*85 &m7 permaDganate.

No. 2, •* " " •* " 26-36 " "

No. 8, ** " •* " " 26-4 " "

No. 4, " " ** " " 26-45 " "

From a specimen of yerv dark green actinolite treated as
above described we obtained in three determinations the follow-
ing results.

No. 1, 0*6918 grains of mineral required 14*1 c m.* permanganate.
No. 2, 0-6640 u i, a u |3.g u u

No. 8, 0*8910 « •* «« ** 18*2 " «

The per centage composition deduced from this is

Per cent of FeO.
No. 1, 19-86.

No. 2, 19*95.

No. 3, 19*89.

In order to test still further the efficiency of our apparatus we
have several times dissolved 2 decigrams of iron in dilute sul-
phuric acid and heated the solution in the bath for more than
twelve hours without its undergoing the slightest oxydation.

It is of course essential in this process that both the sulphuric
and hydrofluoric acids should be perfectly pure and whollv free
from any oxydizing or reducing agents. There is no difficulty
in obtaining from the manufacturers pure sulphuric acid, but un-
fortunately the commercial hydrofluoric acid is apt to be very
impure and must be carefully purified by repeated distillation
berore it is used in this process. The apparatus here described
will also be found very useful in the ordinary iron assays and is
also applicable in a large number of analvtical processes, where
it is necessary that the assay should not be exposed to the air.
Of course in such cases a glass beaker would take the place of
the platinum crucible, as is shown in the figure. Lastly, this
method of heating in an atmosphere of steam will be found very
convenient in the many cases where it it is desirable to prevent
the evaporation of water during the process. The presence of
the steam moreover, prevents to a great degree the escape of the
volatile acids ; so that in the process above described, tne glass
covering tunnel is not perceptibly corroded unless the hydro-
fluoric acid used is very strong.

Cambridge, June 22d, 1867. ^



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Parks of Colorado. 3!^1



Abt. XXXVII.— rAg Parka of Oolorador

[Thc "^ San Luis Park " of Colorado, in which the Rio Grande del
Norte takes its rise, has recently been described by an anonymous
writer, reported on ffood authority to be Hon. Mr. Gilpin, late Governor
of Colorado. This description is so graphic and minute, and exhibits so
good an acquaintence with a region which has been but little investiga-
ted, that we are led to reprint it from the ephemeral pages in which it
has appeared. — Eds.]

The San Luis Park — The San Luis park is readily entered at
the extreme north through the Poncno pass, penetrating the
Cordillera from the Arkansas river. This park, of elliptical
form and immense dimensions, is enveloped between the Cordil-
lera and Sierra Mimbres. It has its extreme northern point be-
tween these two Sierras, where they separate by a sharp angle
and diverge: the former to the southeasty the latter to the south-
west. The latitude of the Poncho pass is 88° 80', the longitude
106°. It is one hundred and twenty-five miles southwest from
Denver, and thirty-seven miles due west from Canyon City.

Emerging from the Poncho pass, the waters begin to gather
and form the San Luis river. This flows to the south through
a valley of great beauty, which rapidly widens to the right and
left On the east flank the Cordillera ascends abruptly and
continuously, without any foot hills, to a sharp, snowy summit;
on the west, foot hills and secondary mountains, rising one
above the other, entangle the whole space to the Sierra Mimbres.

The Sawatch river has its source on the inner (eastern) flank
of the Sierra Mimbres, about sixty miles south of its angle of
divergence from the Cordilleras, and by a course nearly east
converges toward the lower San Luis river. It enters upon the
park by a similar valley. These two valleys expand into one
another around this mass of foot hills, fusing into the open park,
whose center is here occupied by the San Luis lake, into which
the two rivers converge and discharge their waters.

The San Luis lake, extending south from the point of the foot
hills, occupies the center of the park for sixty miles, forming a
bowl without any outlet to its waters. It is encircled by im-
mense saturated savannas of luxuriant grass. Its water surface
expands over this savanna during the season of the melting
snows upon the Sierras and shrinks when the season of evapo-
ration returns. From the flanks of the Cordillera on the east,
at intervals of six or eight miles asunder, and at verv equal dis-
tances, fourteen streams, other than the San Luis, descend and
converge into the San Luis lake. The belt of sloping plain be-
tween the mountains and the lake, traversed by so many paral-
lel streams, bordered by meadows and groves of cottonwood



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852 Parks of Colorado.

trees, has from this feature the name " Los Alamosos." It is
sixty miles !h length and twenty wide. On the opposite (west-
ern) side, from the flank of the Sierra Mimbres, similar streams,
known as the Sawatch, the Carnero, and the Gareta, descend
from the west into the lake.

The conflaent streams thus converging into the San Luis lake
are nineteen in number. The area thus occupied by this isola-
ted lake and drained into it by its converging affluents, forming
distinctly the northern section of the park, and being one-third
of its whole surface, is classified unaer the gener^ name of
" Eincon."

Advancing onward to the south, along the west edge of the
plains, ten miles from the Gareta, the Bio del Norte issues
from its mountain gorge. Its source is in the perpetual snows
of the peaks of San Juan, the local name given to this stupen-
dous culmination of the Sierra Mimbres. The Del Norte flows
from its extreme source due east one hundred and fifty miles,
and having reached the longitudinal middle of the park turns
abruptly south, and bisecting the park for perhaps one hundred
and nfty mile?, passed beyond its rim in its course to the Gulf
of Mexico. All the streams descending firom the enveloping
Sierras (other than the Alamosos) converge into it their tribu-
tary waters. On the west come in successively the Pintada, the
Bio del Gata, the Bio de la Gara, the Conejos, the San Antonio,
and the Pieda. These streams, six or eight miles asunder, pa-
rallel, equidistant, fed by the snows of the Sierra Mimbres, have
abundant waters, very fertile areas of land, and are all of the
very highest order of beauty.

Advancing again from the Bincon, at the eastern edge of the
plain along the base of the Cordillera, the prodigious oonical
mass of the Sierra Blanca protrudes like a vast hemisphere into
the plain and blocks the vision to the direct south. The road
describes the arc of a semi-circle around its base for thirty miles,
and reaches Fort Garland.

In the immediate vicinity of Fort Garland, the three large
streams, the Yuta, Sangre de Christo, and the Trenchera, de-
scend from the Cordillera, converge, unite a few miles west, and
blending themselves in the Trenchera, flow west twenty-four
miles into the Bio del Norte. The line of the snowy Cordillera,
hidden behind the bulk of the Sierra Blanca, here a^in reveals
itself pursuing its regular south-southeast course and direction.
Fourteen miles south is reached the town of San Luis, upon the
Calebra river ; seventeen miles further is the town of Costilla,
upon the Costilla river ; fifteen miles further the town of Bito
Colorado is reached; eighteen miles onward is the Arroyo
Hondo ; (between these is the San Cristova ;) from the Arroyo
Hondo to Taos is fourteen miles ; twenty miles beyond Taos is



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Parks of Colorado. 853

the mountain chain whose circle toward the west forms the
southern mountain barrier which encloses the San Luis park in
that direction.

The San Luis park is then an immense elliptical bowl, the
bed of a primeval sea which has been drained; its bottom,
smooth as a water sur&ce and concave, is 9,400 square miles in
area. It is watered bj thirty-five mountain streams, which, de-
scending from the encircling crests of snow, converge, nine-
teen into the San Luis lake, the rest into the Bio del Norte.
An extraordinary symmetry of configuration is its prominent
feature. The scenery, everywhere sublime, has the everchang-
ing variety of the kaleidoscope. Entirely around the edge of
the plain, and closing the junction of the plain with the moun-
tain foot, runs a smooth glacis, exactly resembling the sea beach,
which accompanies the conjunction of the land with the ocean.
From this beach rise continuously all around the horizon the
great mountains, elevating their heads above the line of per-

Setual snow. On the eastern side the escarpment of the Cor-
illera rises rapidly, and is abrupt ; on the western side the
crest of the Sierra Mimbres is more remote, having the inter-
val filled with ridges, lessening in altitude as they descend to
the plain of the park. This continuous shelving flank of the
Sierras, completing a perfect amphitheater, has a superficial area
equal to that of the level plain which it envelops, and gives to
the whole enclosure within the encircling band of snow an area
of 18,000 square miles. At an elevation of five or six thousand
feet above the plain a level line upon the mountain wall marks
the cessation of arborsence, above which naked granite and
snow alone are seen. To one who ascends to this elevation at
any point, the whole interior of this prodigious amphitheatre
is scanned by the eve and swept in at a single glance. Aided
by a glass, the smallest objects scattered over the immense ellip-
tical area beneath are discernible through the limpid, brilliant,
and translucent atmosphere. Two facts impress themselves up-
on the senses: the ^neot symmetry of configuration in nature
and the intense varietv in the forms and splendor of the land-
scape. The colors of the sky and atmosphere are intensely
vivid and gorgeous; the dissolving tints of light and shade are
forever interchanging ; they are as infinite as are the altering
angles of the solar rays in their diurnal circuit.

The average elevation of the plain above the sea level is
6,400 feet. The highest peaks have an altitude 16,000 feet
above the sea. In the serrated rim of the park, as seen firom
the plain, projected against the canopy, are discernable seventeen
peaks, at very equal distance one from another. Each one dif-
fers from all the rest in some peculiarity of shape and position.
Each one identifies itself by some striking beauty. From the



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S54 Park$ of Colorado.

snows of each one descends some considerable riyer, as well
within the park as oatward down the external mountain bank.

We recognize, therefore, in the San Luis Park an immense
elliptical basin enyeloping the sources of the Rio Bravo del
Norte. It is isolated in the heart of the continent, twelve hund-
red miles from the sea. It is morticed, as it were, into the midst
of the vast mountain bulk, where, rising gradually from the
oceans, the highest altitude and amplitude of the continent is
attained. This park spreads it plain from 86^ to SS** 30', and
is bisected by the 106th meridian. Its greatest leogth is 210
miles ; its greatest width is 100 ; its aggregate approximate area
is 18,000 sjjuare miles.

Such being the geographical position, altitude, and peculiar
unique configuration, these features suggest the inquiry into
parallel peculiarities of meteorology, geology, physical structure,
agriculture, mineralogy, and the economy of lalior.

The American people have heretofore developed their social
system exclusively on the borders of the two oceans, and within
the maritime valleys of moderate altitude, having navigation
and an atmosphere influenced by the sea. To them, then, the
contrast is complete in every feature, in these high and remote
altitudes beyond all influence of the ocean, and specially conti-
nental.

There is an identity between the " Valley or Park of the
City of Mexico " and the San Luis park which ought to be here
mentioned. They are similar, twin basins of the great plateau,
classifying together and alike in the physical structure of the
continent. Mexico is in latitude 20^, longitude 99"^, and at
7,500 of altitude. The width of the continent is here 675 miles
(from ocean to ocean,) and the divergence of the Cordilleras is
275 miles, which is here the width of the plateau. At the 39**
the continent expands to a width of 8,500 miles between the
oceans ; the Cordilleras have diverged 1,200 miles asunder, and
the plateau has widened the same dimensions. In harmony
with this great expansion of the continent are all the details of
its interior structure. The " Park of the City of Mexico " is but
one-tenth in size and grandeur as compared and contrasted with
the San Luis park. Of identical anatomy, the former is a pigmy,
the latter a giant The similtude as component parts of the
mountain anatomy is in all respects absolute, as is also true of
the other parks, which occupy longitudinally the center of the
State of uolorado.

Meteorology. — The atmospheric condition of the San Luis
park, like its scenery, is one of constant brilliancy, both by day
and night, obeying steady laws, yet alternating with a kind of
playfully methodical fickleness. There are no prolonged vernal
or autumnal seasons. Summer and winter divide the year.






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Parks of Colorado. 355

Both are characterized by mildness of temperature. After the
autumnal equinox the snows begin to accumulate upon the
mountains. After the vernal equinox they dissolve. The for-
mation of light clouds upon the crest of the Sierras is incessant.
The meridian sun retains its vitalizing heat around the year ;
at midnight prevails a corresponding tonic coolness. The clouds
are wafked away by the steady atmospheric currents coming
from the west. They rarely interrupt the sunshine, but refract-
ing his rays, imbue the canopy with a shining silver light, at
once intense and brilliant. The atmosphere and climate are es-
sentially continental, being uninterruptedly salubrious, brilliant,
and tonic.

The flanks of the great mountains, bathed by the embrace of
these irrigating clouds, are clad with dense forests of pine, fir,
spruce, hemlock, aspen, oak, cedar, pinon, and a variety of smaller
fruit trees and shruos, which protect the sources of springs and
running rivulets. Amon^ the forests alternate mountain mead-
ows of luxuriant and nutritious grasses. The ascending clouds,
rarely condensed, furnish little irrigation at the depressed eleva-
tion of the plains, which are destitute of timber, but clothed
in grass. Tnese delicate grasses, growing; rapidly during the
annual melting of the snows, cure into hay as the aridity of
the atmosphere returns. They form perennial pastures, and
supply the winter food of the aboriginal cattle, everywhere indi-
genous and abundant

An infinite variety in temper and temperature is suggested as
flowing from close juxtaposition of extreme altitudes and de-
pressions ; permanent snows, running rivers, and the concentric
courses of the mountains and rivers. Storms of rain and wind
are neither frequent nor lasting. The air is uniformlv dry, hav-
ing a racy freshness and exhilarating taste. A soothing seren-
ity is the prevailing impression upon those who live perpetually
exposed to the seasons. Mud is never anywhere or at any time
seen. Moderation and concord appear to result from the pres-
ence and contact of elements so various.

The critical conclusions to which a rigid study of nature
brings the scrutinizing mind are the reverse of first impressions.
The multitudinous variety of nature adjusts itself with a deli-
cate harmony which brings into healthy action all the industrial
energies. There is no use for the practice of professional
pharmacy. Chronic health and longevity characterize animal
life. The envelope of cloud-compelling peaks, the seclusion
from the oceans, tne rarity of the air inhaled, and the absence of
humidity disinfect the earth, the water, and the atmosphere of ex-
exhalations and miasmas. Health, sound and uninterrupted, stim-
ulate and sustain a high tone of mental and physical eneryg.
All of these are banished, as it were, by the perpetual brilliancy



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356 Parks of Colorado.

and salabrity of the atmosphere and landscape, whose unfail- {

ing beauty and tonic taste stimolate and invite the physical j

and mental energies to perpetual activity. ']

Oeohgy and Minerals. — As a geological basin, the San Luis

!)ark is in the highest degree interesting and remarkable. It is
bund to contain, intermingled and in order, a complete epitome
of all the elements of which geological science and research
take note. Its intra-mural locality l^tween the primeval crests
of the Cordillera, on the east, and the Sierra Mimbres, (here
called the " San Juan,'') on the west, multiplies this variety in-
definitely. These primary Sierras, separated by the park, fece
one another in full sight, as they rear their flanks from the op-
posite edges of the concave plain. The successive periods and
stupendous forces which have expended themselves to produce
what is in sight, and then subsided to an eternal rest, each par-
ticularly manifest itself. The comb of the Sierra presents the
prodigious plates of prijneval porphyry driven up, as the sub-
soil of a furrow, from the lowest terrestrial crust and protruding
their vertical edges toward the sky.

This summit yielding to the corroding forces, presents a
wedge toward the canopy ; is arranged in peaks resembling the
teeth of a saw ; is above all arborescence, and is either clad in
perpetual snow, or is bald rock.

Against this is lapped perpendicularly the second stratum,
less by many thousand feet in altitude, its top forming a brim or
benolL This bench, being the rended edge of the erupted stra-
tum, softer than the first and receiving the debris from above,
has a deep, fertile soil, a luxuriant alpine vegetation, forests of
fir and aspen, and is the highest region of arl^^resence and vege-
table growth.

This is the region of rocks where the metals, especially gold
and silver, abound in crevices charged and infused with the
richest ores. It is from hence that the gold of the gulches is
disintegrated and descends. Here are springs of water and
and the sources of rivers. The timber is excellent and the past-
ures of various grasses luxuriant and inexaustible. Swept by
ascending currents of vapor, irrigation is constant. This ele-
vated bench is a permanent characteristic of the mountain flank,
continuous as the continent itself; a coUossal staircase whose
steps are themselves of mountain magnitude. It is here, at
these surfaces of contact of the erupteid plates of the lowest
terrestrial crust, that the thread of the "gold belt " is revealed
and found. From this thread, as from a core outward, the pre-
cious metals taper in quantity and become diluted in the irar
mensity of the rocks, as a hill of rock salt disappears to the eye,
dissolved in the immensity of the ocean.

The top of this continuous bench is undulating, broad, and



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Pmrki of Colorado. 857

oocafiionally crossed by transverse ridges and the chasms of water-
courses. The fix)nt nank of this bench forms the stupendous
escarpment of the mountains, everywhere lofty and precipitous.
It is cut through by innumerable streams, up whose gorges ac-
cess to the upper regions is attained, and the internal contents,



Online LibraryJohn AlmonThe American journal of science and arts → online text (page 92 of 102)