John Almon.

The American journal of science and arts online

. (page 24 of 102)
Online LibraryJohn AlmonThe American journal of science and arts → online text (page 24 of 102)
Font size
QR-code for this ebook


This gives carbon 62*98 per cent THe calculated quantity is
681« per cent

The substance is therefore hydrated terpin or crystallized
turpentine camphor C3,Hj^04-f-2aq. Perhaps we should say
it is one of the terpins, since, according to Berthelot, the differ-
ent oils of turpentine, on hydration, yield crystals of different
degrees of solubility.

The formation of this substance in the buried tree presents
no difficulties, since we know on the authority of Dumas, Deville
and others, that oil of turpentine in contact with water, combines
with the latter in absence of acids or other powerful agents of
chemical change.

Prof. Brewer, who is familiar with the timber of California, is
of the opinion that the wood to which the crystals were attached
is that of a pitch pine, Pinus ponderosa.

This appears to be the first recorded instance of the occur-
rence of crystallized terpin, native.

November, 1S66.

* Mr. Blake has measured and figured both the native and artificial crystals and
has in reserve some other valuable observations which it is to be hoped he wiU
•bofftly pablish.-Hk w. j.



Digitized by



Google



SOS J. M, Blake on natural Hydrated Terpin.



Abt. XXIII. — On the crystallization of natural Hydrated Terpin
from California ; by John M. Blake.

Some crystals, from a buried pitch-pine log, were handed me
for.examination by Prof. S. W. Johnson, of the Sheffield Scien-
tific School

A comparison of these crystals with terpin of artificial prep-
aration leaves no doubt that the natural substance is hydrated
turpentine camphor. The natural and artificial crystals agree
closely in their angles, and have the same cleavage. The posi-
tion and separation of the optical axes is alike in both, and ex-
periment shows that the two substances are supercrystallizable.

Certain observations made at first, suggested that the two spe-
cimens mi^ht not be absolutely identical, but rather isomeric hy-
drates, sucn as were supposea by Berthelot to result from iso-
meric oils, derived from the same or different trees. Thus, hemi-
hedrism constantly occurred on the natural crystals, which has
not been observed on the artificial. The proportional develop-
ment of the planes was strikingly difierent. The two specimens
manifested opposite pyro-electric characters, in so far that the
free-growing extremities of the natural crystals were antilogue
poles, (developed negative electricity on heating,) while those of
the artificial crystals, first examined, were the reverse, or ana-
logue poles.

On farther investigation, these points of difference disappeared.
By recrystallizing from alcohol and other solvents, much varia-
tion was produced in the planes. The peculiar development of
the natural crystals was not indeed reproduced on the artificial,
but the attachment of the latter to the support by the analogue
pole, as with the natural crvstals, was obtained. On recrystal-
lizing from alcohol, natural terpin lost its hemihedral charac-
ter, and in case of crystals grown radiating from a support, pre-
sented the analogue pole to the solution, like the artificial sub-
fitaace when deposited from the same solvent. Crystals of each,
when free-growing in alcoholic solution, had the same develop-
ment of the planes, and with each there was the same percepti-
ble difference in the proportions of the planes at the two ends of
a crystal, by which the poles could be distinguished ; bat no
corresponding difference could be detected in the angles of these
terminal planes.



Digitized by



Google



T. S, HufU on the objects and method of Mineralogy. 208



Art. XXIV. — On the Olyjecis and Method of Mineralogy ; by
T. Sterry Hunt, F.R.S.

(Road before the American Academj of Sciences, Jan. 8, 1867).

MiN£RALOGY, as popularly understood, holds an anomalous
position among the natural sciences, and is by many regarded
as having no claims to be regarded as a distinct science, but as
constituting a branch of chemistry. This secondary place is dis-
puted by some mineralogists, who have endeavored to base a
natural-history classification upon such characters as the crys-
talline form, hardness, and specific gravity of minerals. In sys-
tems of this kind, however, like those of Mohs and his followers,
only such species as occur ready formed in nature are compre*
hended, and the great number of artificial species, often closely
related to native minerals, are excluded. It may moreover be
said in objection to these naturalists, that, in its wider sense, the
chemical history of bodies takes into consideration all those char-
• acters upon which the so-called natural systems of classification
are based. In order to understand clearly the question before
us, we must first consider what are the real objects, and what
the provinces, respectively, of mineralogy, and of chemistry.

Of the three great divisions, or kingdoms of nature, the clas-
sification of the vegetable gives rise to systematic botany, that
of the animal to zoology, and that of the mineral to mineralogy,
which has for its subject the natural history of all the forms of
unorganized matter. The relations of these to gravity, cohe-
sion, light, electricity, and magnetism, belong to the domain of
physics; while chemistry treats of their relations to each other,
and of their transformations under the influences of heat, light,
and electricity. Chemistry is thus to mineralogy what biology
is to organography ; and the abstract sciences, physics and chem-
istry, must precede, and form the basis of the concrete science,
mineralogy. Many species are chiefly distinguished by their
chemical activities, ana hence chemical characters must be greatly
dci^nded upon in mineralogical classification.

Chemical change implies disorganization, and all so-called
chemical species are inorganic, that is to say unorganized, and
hence. really belong to the mineral kingdom. In this extended
sense, mineralogy takes in not only the few metals, oxyds, sul-
phids, silicates, and other salts, which are found in nature, but
also all those which are the products of the chemist's skill. It
embraces not only the few native resins and hydrocarbons, but
all the bodies of the carbon series made known by the researches
of modern chemistry.

The primary object of a natural classification, it must be re-



Digitized by



Google



304 T. iSi. Hunt on the objects and method of Mineralogy.

membered, is not like that of an artificial system, to serve the
purpose of determining species, or the convenience of the ski-
dent, but so to arrange boaies in genera, orders, and species as to
satisfy most thoroughly natural affinities. Such a cmssification
in mineralogy will be based upon a consideration of all the phys-
ical and chemical relations of bodies, and will enable us to see
that the various properties of a species are not so many arbi-
trary signs, but the necessary results of its constitution, it will
give for the mineral kingdom what the labors of great natural-
ists have already nearly attained for the vegetable and animal
kingdoms.

Oken saw the necessity of thus enlarging the bounds of min-
eralogy, and in his Physiophilosophy, attempted a mineralogical
classification ; but it is based on fanciful and false analogies, with
but little reference either to physical or chemical characters, and
in the present state of our knowledge is valueless, except as an
effort in the right direction, and an attempt to give to mineral-
ogy a natural system. With similar views as to the scope of
the science, and with far higher and juster conceptions of its
method, Stallo, in his Philosophy of Nature, has touched the
questions before us, and has attempted to show the significance
of the relations of the metals to cohesion, gravity, light, and elec-
tricity, but has gone no farther.

In approaching this great problem of classification, we have
to examine— first, the physical condition and relations of each
species, considered with relation to gravity, cohesion, light, elec-
tricity, and magnetism ; secondly, the chemical history of the
species; in which are to be considered its nature, as elemental or
compound, its chemical relations to other species, and these rela-
tions as modified by physical conditions and forces. The quan-
titative relation of one mineral (chemical) species to another, is
its equivalent weight, and the chemical species, until it attains
to individualitynn the crystal, is essentially quantitative.

It is from all the above data, which woula include the whole
physical and chemical history of inorganic bodies, that a nat-
ural system of mineralogical classification is to be built up.
Their application may be illustrated by a few points drawn from
the history of certain natural families.

The variable relations to space of the empirical equivalents of
non-gaseous species, or in other words, the varying equivalent
volume, (obtained by dividing their empirical equivalent weights
by the specific gravity,) shows that there exist in different spe-
cies very unlike degrees of condensation. At the same time we
are led to the conclusion that the molecular constitution of gems,
spars, and ores, is such that those bodies must be represented by
formulas not less complex, and with equivalent weights far more



Digitized by



Google



T. & Hunt on the objects and meihod of Mineralogy, 205

elevated than those usually assigned to the poljcyanids, the
alkaloids, and the proximate principles of plants. To similar
ooDclusions, conduce also the researches on the specific heat of
compounds.

There probably exists between the true equivalent weights of
non-gaseous species, and their densities, a relation as simple as
that between the equivalent weights of gaseous species ana their
specific gravities, ^he gas, or vapor of a volatile body consti-
tutes a species distinct from the same body in its liquid or solid
state ; the chemical formula of the latter being some multiple
of the first, and the liquid and solid species themselves, often
constituting two distinct species, of different equivalent weights.
In the case of analogous volatile compounds, as the hydrocar*
bons and their derivatives, the equivalent weights of the liquid
or solid species approximate to a constant quantity, so that the
densities of those species, in the case of homologous or related
alcohols, acids, ethers and glycerids, are subject to no great vari-
ation. These non-gaseous species are generated by the chemical
union, or identification, of a number of volumes or equivalents
of the gaseous species, which varies inversely with the density
of these species. It follows from this, that the equivalent weights
of the liquid and solid alcohols and fats must be so high as to
be a common measure of the vapor-equivalents of all the bodies
belonging to these series. The empirical formula, CiwHuoCia,
which is the lowest one representing the tristearic glycerid, ordi-
nary stearine, is probably fer from representing the true equiv-
alent weight of this fat in its liquid or solid state; and if it should
hereafter be found that its density corresponds to six times the
above formula, it would follow that liquid acetic acid, whose
density differs but slightly from that of fused stearine, must have
a formula and an equivalent weight about one hundred times
that which we deduce from the density of acetic acid vapor,

Starting from these high equivalent weights of liquid and
solid hydrocarbonaceous species, and their correspondingly com-
plex formulas, we become prepared to admit that other orders
of mineral species, such as oxyds, silicates, carbonates, and kuI-
phids, have formulas and equivalent weights corresponding to
their still higher densities, and we proceed to apply to these bod-
ies the laws of substitution, homology, and pofymerism, which
have so long been recognized in the chemical study of the mem-
bers of the hydrocarbon series. The formulas thus deduced
for the native silicates and carbon-spars show that these poly-
basic salts may contain many atoms of different bases, and their
frequentlv complex and varying eonstitution is thus rendered
intelligible. In the application of the principle of chemical ho-
Am. Joub. Sol— Sioond Sbrdbb, Vol. XLIII, No. laa—HiBCH, 1867.
37



Digitized by



Google



206 T. S. Hunt on the objeelt and nteihod of Mineralogy,

mology, we find a ready and natural explanation of those vari-
ations, within certain limits, occasionally met with in the compo-
sition of certain crystalline silicates, salphids, etc., from which
some have conjectured the existence of a deviation from the law
of definite proportions, in what is only an expression of that law
in a higher form.

The principle of ^lymerism is exemplified in related mineral
species, such as meionite and zoisite, dipyr»and jadeite, horn-
blende and pyroxene, calcite and aragonite, opal and quartz, in
the zircons of different densities, and in the various forms of
titanic acid and of carbon, whose relations become at once intel-
ligible if we adopt for these species high equivalent weights and
complex molecules. The hardness of these isomeric or allotro-
pic species, and their indifference to chemical reagents, increases
with their condensation, or in other words, varies inversely as
their empirical equivalent volumes ; so that we here find a direct
relation oetween chemical and physical propertiea

It is in these high chemical equivalents of the species, and in
certain ingenious, but arbitrary assumptions of numbers, that is to
be found an explanation of the results obtained by Play£siir and
Joule, in comparing the volumes of various solid species with
that of ice; whose constitution they assume to be represented by
HO, instead of a high multiple of this formula. The recent in-
genious but fallacious speculations of Dr. Macvicar, who has
arbitrarily assumed comparativelv high equivalent weights for
mineral species, and has then endeavored, by conjectures as to
the architecture of crystalline molecules, to establish relations
between his complex formulas and the regular solids of geom-
etry, are curious, out unsuccessful attempts to solve some of the
problems whose significance I have here endeavored to set forth.
I am convinced that no geometrical groupings of atoms, such as
are imagined by Macvicar, and by Oaudin, can ever give us an
insight into the way in which nature builds up her units, by
interpenetration and identification, and not juxtaposition of the
chemical elements.

None of the above points are presented as new, though they
arc all, I believe, original with myself, and have been, from time
to time brought forward, and maintained, with numerous illus-
trations, chiefiy in the American Journal of Science, since March,
1858, when my paper on the Theorv of Chemical Changes and
Equivalent Volumes, was there put)li8hed. I have, however,
thought it well to present these views in a connected form, as
exemplifying my notion of some of the principles which must
form the basis of a true mineralogical classification.



Digitized by



Google



C. Abbe on the Rtpsold Portable Circle. 907



Art. XXV.— 7%e Sepsold Portable Vertical Circle; by
Cleyelakd Abbe.

The progress of practical astronomy in the United States
has already been distinguished by the suggestion of quite new
ideas, as well as by improvements upon methods and instru-
ments in use in Europe. It seems that a part of our national
mission is to give a full and free development to whatever of
good can be transplanted here from abroad ; it is therefore un-
pardonable in us to neglect any opportunity of acquainting our-
selves with the results of the experience of the astronomers of
the Eastern hemisphere. The history of the brilliant life of
F. G. W. Struve, to whom the world is indebted for the observa-
tories of Dorpat and Poulkova, is doubtless familiar to all. The
school of practical astronomv and geodesy that grew up under
him at these two places, and is now officially establishea at the
Central Obstjrvatory for the benefit of the Imperial Military
Academy and other departments of the government, has, by the
extent of the astronomical and geodesicul works executed, made
its influence felt far beyond the dominions of the Russian Czar.
A residence of nearly two years at this Observatory has im-
pressed the writer most deeply with the correctness of that gen-
eral opinion, which for years has instinctively pointed to this
magnificent institution as the head-quarters of the practical as-
tronomy of the present day.

Nffhe extent of the territory of the United States, and the oft-
i^urring demand for accurate topographical maps, will increase
tfc interest with which we study the levels, barometers, base ap-
paratus, universal instruments, vertical circles, prime vertical and
extra-meridional transits, with which the Russian astronomers
have sought tO'^meet the demands made upon them. With them,
as with us, celerity is of equal importance with accuracy. The
extent of their territory must forbid them, as that of ours does
us, from contemplating a minute triangulation of its entire super-
ficies — such as the smaller and more densely populated territo-
ries of the British Isles and the central European states both
allowed and demanded. Our national government has rightly
apprehended the importance of having the most accurate charts
possible to be made of our extended Eastern and Western bor-
ders; of similar importance is the survey of our inland fresh-
water lakes, now in the hands of the engineers of the War De*
partment; of great value also is the accurate survey of inter-
national boundary lines, — but the general survey and mapping
of the interior presents a problem not dissimilar from that which
is being solved by the Russian geographers for their own land.

It was early sei^n that if astronomicaJ determinations of relaiive



Digitized by



Google



206 C. Abbe on the Repsold Portable Circle.

position could be made accurate to within one or two seconds of
arc, the central points of reference being referred with much

S eater accuracy to each other and to a very few zero points,
en would these relative positions, as derived from aeftronomical
observations combined with an accurate knowledge of the fig-
ure of that portion of the earth's surface covered by these sta-
tions, suffice as groundwork for supplying the present wants of
geographers and topographers. Inspired by tne magnitude of
the work, and support^ by an interested military government,
Struve and Tenner, co-working with the Norwegian and Swedish
governments, carried out the astronomical and geodetical work
recorded in the " Arc du M^ridien de 25^ 20' entre le Danube
et la mdr Glaciale" — at present under the authority of O. Struve
and General Baeyer, co-working with Gneat Britain and Bel-
gium ; the field operations connected with the measurement of
the arc of longitude between Yalentia and Orsk are being rap-
idly pushed forward and will be finished in the summer of the
present year. These two great works, and the similar ones that
may be expected to follow in future years, when the surveys of
the ihimense regions of Asiatic Russia come to be connected
with the survevs now being carried on by the British govern-
ment, furnish the necessary determination of the figure of the
earth for that portion of the globe : they find their counterparts
in the geodetic astronomic works in progress or already executed
upon our Atlantic and Pacific sea-board, which will afford us de-
terminations of arcs of latitude between the parallels of 26^ and
48^ north, and ought to be extended to the measurement of
arcs of longitude of 60° on our northern, and 40° on our south-
ern boundaries, or possibly one of 45° between Washington and
San Francisco. Up to the present decade it must be conceded
that the attention of geodesists has been perhaps too exclusively
directed to the measurements of degrees of latitude ; it is now
become important to determine also arcs of longitude, and the
present European international undertaking is one worthy of
emulation. It is indeed with peculiar pleasure that we notice
the comparatively slight expense that would attend the junction
of the present and proposed triangulations of the lake survey
and of the coast survey, by a triangulation W)m Buffalo to Al-
bany, leading thereby to the measurement of an arc of 18° on
the parallel of 42° north between Chicago and the extremity of
Cape Cod. At some future time the junction of the northwest
end of Lake Superior and Cape Breton will become equally feas-
ible, whence will result an arc of 33° on the parallel of 46° north.
By the junction of the coast survey operations on the gulf of
Mexico with the Pacific coast, taking advantage of the labors
performed by the Mexican Boundary Survey we may be led to
an arc of 33° on the parallel of 81° north, and the continuation



Digitized by



Google



C. Abbe an the Rspsold PmrtAle Circle. 209

westward of the survey of the lakes, or rather the completion
of the labors of N. W. boundary survey should lead to the deter-
mination of an arc of 65 to 60 degrees of longitude — ^the largest
probably that will ever be measured on this continent In for-
mer years the difficulties in the way of accurate longitude deter-
minations may well have prevented such undertakings as those
here suggested, — but at present the telegraph and chronograph
and the use of accurate extra-meridional transits have undoubt-
edly removed those obstacles; as regards latitudes, it is probable
that the Bepeold portable vertical circle will lon^ simce for
measurement of vertical angles. It is, however, imperatively
necessary in determinations of lobgitude, that not only the obser-
vers be exchanged, but also with them their transits, their relay
batteries, chronometers and chronographs, and all apparatus used
at either end

The quadrangular area of the United States (whose natural
nucleus is probably found in St Louis or Omaha City — even as
for the present state of population Cincinnati may lie regarded
as a central point), offers the same variety of hills and mountains;
plains and plateaus as is found in Bussia, and by its. extent re-
quires that the curvature of its surface be determined independ-
ently of the investigations made in the eastern hemisphere.
Until this is done, the topographical surveys made by the land
commissioners and surveyors of the Federal government, and by
the several states, ought to be considered as plane table sheets
whose fundamental points (the secondary points of a triangula-
tion), can only be properly fixed by geodetic and astronomic
measurements.

The accurate, convenient, speedy and economical determina-
tion of the positions of as many of these secondary stations as are
needed for topographical maps that do not pretend to a pedantic
accuracy is the present problem; — and assuming that the coast
survey will give us a sufficient knowledge of the curvature of
our portion of North America, we shall arrive at a solution of
our present problem by selecting central or primary astronom-
ical stations at convenient points — for instance, one to three in
each of the states east of the Mississippi, and traversed by sev-
eral railroads or navigable rivers. The astronomical latitude of
these primary points, and their longitudes relative to each other
and to the zero point — Washington Observatory — are to be de-
termined with all attainable accuracy. Expeditions starting from
one such point (and consisting of one observer, one vertical cir-
cle, five to twenty-five chronometers, including one non- and one
over-compensated, one barometer, &c.), visiting in the course of
five to twenty-five days five, ten, twenty secondary stations, and
returning to the same or another primary station, will be able to
famish the relative position of all the secondary points visited



Digitized by



Google



ft 10 C Abbe on the Resold Portable Circle.

to within two seconds of arc ; or to be more definite, to within
0"'5 in latitude and O'l in longitude, and to give equally ap-
proximate determinations of the relative vertical heights. That
this is practically done bv the Russian geodesists (the first expe-
dition dates 1846), and that in our own easily traversed country
it can be better done than in theirs, is sufficient reason for call-
ing attention to the work of Colonel Smyssloif, mentioned below,
where ** are fully detailed the different astronomico-geographical
methods of determining position, which, by the influence of the
Poulkova Observatory, have been introduced into the geodetic



Online LibraryJohn AlmonThe American journal of science and arts → online text (page 24 of 102)