Rodolfo Amedeo Lanciani.

The American journal of science and arts online

. (page 63 of 109)
Online LibraryRodolfo Amedeo LancianiThe American journal of science and arts → online text (page 63 of 109)
Font size
QR-code for this ebook

Shepard, Sr.

1. A new variety {species ?) of Oolumbite,

The Columbites of New England deserve a closer examina-
tion than they have yet received. Those of New Hampshire,
Massachusetts and Connecticut may embrace at least two, per-
haps three, mineralogical species. A new locality, recently
opened at Haddam (Conn.), has certainly disclosed a variety so
diflferent from the productions of the old one on the farm of Mr.
Brainard, as to have led to doubts among collectors whether it
fairly belongs to the Columbite group.

For my first knowledge of the new variety, I am indebted to
several of my pupils who visited Haddam during the past year ;
and particularly to Mr. Charles H. Ames of the Senior class in
Amherst College, who has furnished me with several dozen
specimens, mostly isolated crystals, from one ounce in weight,
d!ownward. to that of a few grams. They all occur at a
single repository, contiguous to the center of the villj^e, and
directly in rear of the house of Mr. Nathaniel Cook, the well
known collector and dealer in Haddam minerals. The locality
was opened by explorers for porcelain stone ; but the feldspar

E roving too ferruginous, being of a somewhat flesh-red color,
as lea to an abandonment of the enterprise. Although this
discovery is a recent one, it is not unlikely that specimens from
the same spot had previously found their way mto cabinets ;
and maj thus have led to some of the discrepancies existing in
the various descriptions of the Connecticut columbites.

The general aspect of the crystals is rather peculiar. Instead
of flattened prisms, they are nearly all square and often,
through imperfection, decidedly rhombic. With the common

Digitized by VjOOQ IC

0. U. Shepard, Sr. — Mtneralogicai (hntrOmtions. 91

goniometer, many of them give angles nearly as oblique as
pyroxene. Nevertheless, when more carefdlly studied by means
of the reflective goniometer, accompanied by observations on
the fiwes replacing the lateral prismatic edges, no essential dis-
tinction of form can be made out between these crystals and
those of columbite or of tantalita They are all strictly isomor-
phous. An unimportant, though striking peculiarity is ob-
served in these crystals, proceeding from the unusual develop-
ment of the octahedral faces, whereby they possess a four-
sided pyramidal summit at one, or each extremity. Very rarely
are traces of the terminal plane visible ; and when seen, the
eye or the common goniometer would always report it as
slightly wanting in verticality. Its smoothness is insufficient
for measuring its position witn the reflective goniometer.

The feces of the crystals t^re wanting in that high luster so
frequent in those from other localities. In luster, color and
even in general shape, they resemble on first inspection, the
average specimens of Elba yenites nearly as much as they do
the ordinary Haddam columbite, — the chief exception being,
that the narrow faces about the prismatic edges are bright

No pavonine tints are seen m the present variety. Their
absence is so marked, not only on natural planes but also on
fractured surfeces, as to affora a ready and almost sure criterion
for distinguishing specimens of this locality from those obtained
at the old one of Brainards, where every crystal and almost
every fragment displays the blue or yellowish tarnish.

The color of the fracture is perfectly black approaching
pitchy. It is more firm, and less prone to crumble than the
ordinary columbite. The fracture is occasionally small con-
choidaL No distinction in hardness can be made out It is
nevertheless more easily ground to a fine powder than the
usual mineral; and, when perfectly powdered, presents an
almost black color, while columbite is only brownish black.
This distinction is so marked, as to be recognized by candle

But the most remarkable distinction resides in its lower
specific gravity, which may be said to be strictly unifomL
Eight examples (varying in weight from 2 to 16 grams) gave
6*31 as the averaga Three of these gave respectively, 5*82,
5 '34 and 5*35; while four specimens of columoite from the
Brainard locality gave 602, 6-08, 610 and 619,— the average
being 6-086.

Its powder, strongly heated in an open platinum crucible,
lost only -02 p. c. in weight, but changed in color, by several
shades, to a brownish black.

Alone before the blow-pij)e, small firagments had their edges
decidedly rounded by rasion. Treated in powder in small

Digitized by VjOOQ IC

92 C. U, Shepardf Sr. — Mineralogical Oontributums.

quantity, in tlie outer flame with borax on platinum wire, a
clear, pale yellow globule (while hot) with feint tinge of brown,
was obtained, which on cooling became almost colorless. In
the interior flame, no change took place, except that of greater
paleness in the globules. The addition of nitre produced the
reaction for manganese.

The columbite powder from Brainards' gave similar results,
with the diflference, of deeper tints to the glass.

With microcosmic salt, the behavior was similar, excepting
when the mineral was added in excess ; a brownish red globule
was then afforded.

Heated with carbonate of soda on charcoal, it yielded, in
common with the columbite, minute granules of tin-
It is feebly, if at all, attacked by nydrochloric acid ; but is
perfectly decomposed by heated sulphuric acid The action is
evinced almost unmediately, — the mixture becoming first jel-
lowish, then greenish yellow, and finally deep yeUow, which
by the affusion of water turns white. The Haddam columbite,
on the other hand, is only imperfectly decomposed by the same
treatment Both minerals, however, are speedilj decomposed
by fusion with bisulphate of potash,* but with a marked
difference in the aspect of the fused mass ; the new variety yields
a honey yellow, transparent glass, while the columbite gives
one whicn is grayish white and opaqua

A portion of the white insoluble residue (after decomposition
of mineral with sulphuric acid) on being treated on tinroil with
hydrochloric acid, instantly produced a deep Prussian blue
liquid and precipitata On dilution with water, the color grew
paler; and, in half an hour, even the sediment had nearly
changed to a grayish blue.

Another portion of the above moist powder was treated with
dilute sulphuric acid and a strip of zinc. The metal was
instantly coated by a dark blue precipitate, which after two
hours also changed to ash-gray.

The original sulphuric acid solution, slightly diluted with
water, after separation from the insoluble white precipitate, was
boiled; whereupon a considerable white precipitate of the
metallic acid, (or acids,) was thrown down. This on being
heated was of a faint yellow color, and nearly white after
cooling. It tinged borax pale citron yellow while hot, but
left it colorless on cooling; and gave similar results with
microcosmic salt

A portion of the metallic acids was fiised with caustic soda
in a silver crucible. The mass obtained was dissolved in
water ; and through the solution a stream of carbonic acid was

* This easy decomposition, which is the most strikiiig in the new varietj, points
also to the oomparatiye absence of tantalic acid.

Digitized by VjOOQ IC

C. U. Shepard, Sr. — Mineralogical CcmtnJmtions. 98

conducted to complete saturation, producing no precipitate,
whereby the absence of tantalic acid was inferred.*

Analysis, the decomposition being eflfected by fusion with
potash, gave the composition as follows :

Metallic acids 78-30

Protoxyd of Iron 13'86

Protoxyd of Manganese 1'12

Tin only in traces.


In two processes for the metallic acids, one by the decom-
position of the mineral by sulphuric acid, the other by potash,
an exact agreement in specific gravity was found, viz. : 4-06 ;
fix)m which, perhaps, it may be just also to infer the absence of
tantalic acid, whose densitv when pure, though varying some-
what according to its mod.e of preparation, averages folly one-
third higher than the present result

Hermann distinguishes three varieties of columbite, viz. :
(1) with gravity above 5*9, (2) with gravity 5*5 to 5*9, and (3)
with gravity 54; but it is very doubtful whether an example
of the mineral under notice has ever fallen into his hands, as
this locality is of recent discovery. In conclusion, it may be
added that minute coatings of uranochre were observed in
patches and specks upon a few of the crystals; though no
evidence of the presence of uranium was afforded in the
mineral itself

2. Unknown mineral {microlite f) in Haddam columbite.

This mineral I suspect to be new. It has never Mien under
my notice imtil found among the productions of a recent blast-

* The following reaotions were obtained in testing a solution of the above oom-
poond of soda yrVSb. the metallio add; with protonitrate of mercury, a curdj, dense
precipitate of a pale yellowish white, which after fifteen minutes assumed a green
tint: with oorrosive sublimate, no precipitate, but by slight evaporation, it thick-
ene4 u^d by drying, still farther, a red-brown ozychlorid of mercury was deposit-
ed ; sulphate of soda gave no precipitate, but sulphate of potash a feeble one after
a little standing; ferrocyanid of potassium, no change at first, but a pale yellowish
one afterwards; phosphoric add rendered the solution feebly opaline at the end of
two hours: cyanid of potassium produced immecUatelv a thick, white predpitate;
infasion of nut-gaUs no eflfeot until a drop of hydrochloric add was added, when a
thidc, orange-red predpitate appeared ; nitric add gave an abundant predpitate
that did not dissolve by heating ; hydrochloric acidproduced a voluminous pre-
o^itate; a portion of the solution was evaporated to ^th its bulk, whereby a por^
tion of ibB salt was thrown down, whidi was redissolved, with exception of a uint
opaUnity in the liquid ; nitrate of sOver added to this last solution produced an
abundant pale yellow predpitate that was redissolved by boiling, a few drops of
ammonia changed its color to brown, a larger quantity dissolved it entirely, and by
drying in porcelain, it became first brown, than black. The foregoing reactions are
those heretofore supposed to belong to the soda salts of niobium, or odumbiiun :
but it is probable that they may be shared to some extent by those of the aDiea
metal, ifanenium.

Digitized by VjOOQ IC

94 C. U. Shepard, Sr, — Mirwrdlogieal Coninbutiona,

ing of the columlate at the Brainard loealitj. It occurs very
sparingly (for the most part requiring the use of the microscope
for its detection), occupying the sides of open crevices in large
crystals of columbite, and also between the surfiices of these
crystals and feldspar. At first, I was led to suspect them
to be cassiterite ; but blow-pipe examination with * soda on
charcoal only afforded minute traces of tin- The high ada-
mantine lustre next suggested zircon and tungsten. The color
was intermediate between that of wohlerite and monazite ; but
a closer examination showed a wide divergence in other proper-
ties fix)m either of these speciea

Apparency equilateral triangular planes were detected ; and
finally portions of both pyramids, which leave little doubt that
the form is that of the regular octahedron, especially as two of
the solid angles were each similarly replaced by four planes,
resting on the octahedral fisujea To verify this conjecture of
a cubic primary, will require the breakmg up of the only
specimens I possess of the crystals, which for the present I
defer in the hope of obtaining other examplea The hardness
is 5' to 6 '5. Brittle, firacture conchoidal, semi-transparent to
translucent Luster of fiiucture, resinous ; that of surface of
crystals, adamantina Streak yellowish white.

Before the blow-pipe, infdsibla AAer long heating, it loses
its brown tint, and while still hot, assumes a feeUe citron
yellow color, which becomes paler on cooling, when it is seen
to have lost much of its luster, and is also less translucent
With microcosmic salt in the outer flame, it slowly dissolves
into a perfectly colorless, transparent glass ; but in the interior
flame, it becomes, while warm, slightly milky with a tinge of
blue. An intermittent flame produced the same transparency
and tinge of blua Long contmued heatii^ produced no trace
of brown, violet, amethyst or yellow. The addition of tin
gjive a bluish white semi-opaque pearl

It approaches most nearly to the microlite, but differs fixjm it
in the aosence of all cleavages as well as in luster and in its
behavior before the blow-pipe. Its mode of occurrence and
properties lead to the suspicion of its being chiefly, if not
wholly, composed of (me of the metallic acids of the oolumbium

Soup. The microlite, though occurring within a few yards of
e columbite at Ohesterflela and in the same ledge of granite,
was never seen associated with this spedies, but invariably pre-
sents itsdf either in the albite or crystals of tourmaline, wnile
the present mineral at Haddam occurs solely in, or upon, the

8. Nev) localUy of jBismuihme cmd Bismutite in Bcddam,

About thirty years since I pointed out the existence of botb
these species and a third bismuthic minenO, tiie bismucone, as

Digitized by VjOOQ IC

C U. Shepardj Sr. — Mineralogioal ChntribiLiiona. 96

existinff together in small quantity, associated with chiysoberyl,
yellow beryl, columbite, garnet and a zircon mineral which I
afterwards called calyptolite. Mr. Ames has lately procured
for me large crystalnne masses of bismuthine, more or less
coated by bismutite, from a quarryman who had discovered
them on the iolite hill, situated about one mile to the southwest
of the meeting-house. They had apparently formed a narrow
seam in the common orthoclase granite, which had been opened
with a view to working as a porcelain-feldspar quarry. One of
the specimens weighs about half a pound; and constitutes a
deeply striated or channeled crystal The mineral was supposed
to be molybdenite. Examined before the blow-pipe, it affords
no indications either of tellurium or selenium.

^ On the metallic acid in Mtcrolite.

It having been suggested by Prof Brush, from blow-pipe
experiments* and the mgher percentage of the metallic acia m
this mineral, that it is the tantalic instead of the columbic, I
made the following experiments upon two small crystals whose
weight together was 0*360 gram. It was decomposed by
fusion with bisulphate of potash, cold water dissolved the mass,
which afterwards deposited a white granular precipitate, the
clear supernatant liquid not showing even an opaline tendency
on ebulition. The white precipitate after ignition gave 72-80
p. c. for the metallic acid. It evinced scarcely the slightest
yellow tint when hot ; and when cold, was perfectly white.

A portion of it gave with microcosmic salt, a perfectly clear
glass, which showed only a faint yellowish tince while hot
The addition of sulphate of iron produced a blood red tint
when heated in the inner flame; on cooling, it changed to
dirty yellow. With borax, it dissolves almost without color,
being only a faint greenish yellow ; but the globule inclines to
opacity. No tinge of violet or pink is visible.

Fused with soda, the metallic acid afforded a bluish gray
mass. The excess of alkali being removed by cold water, the
addition of more water took up the residuum. A portion of
this solution on being acidulated with hydrochloric acid, and
afterwards treated with solution of nutgalls, gave a very yellow
orange precipitate, quite different from that produced by colum-
bic acia, which when contrasted therewith was seen to have a
deep reddish tintf as compared with columbic acid.

The chief portion of the sodio solution was then super-
aatorated with carbonic acid, and gave rise to a dedded

* Daim'8 Mineralogj, p. 614.

f Thefe wae a want of oorrospondenoe also in tbe leaotiaiB of tiie metallic acid
and soda compound, with nitrate of diver, nitrate of BierooTy, oonosive eobfimate
and ferrocyanid of potassium.

Digitized by VjOOQ IC

98 dU. Shepard, Sr. — Mineralogtcal Con^ribtUions.

precipitata From the forgoing results, it would seem little
doubt remains that microlite is a tantalate rather than a colum-
bate of lima

5. Bedondtte.

I have examined still farther the hydrous phosphate of
alumina and iron described by me in a previous number of
this Journal (voL xlvii, p. 338), as occurring so abundantly in
the island of Eedonda, W. L, and am now of the opinion that
it constitutes a species distinct from barrandite, from which it
differs in several particulars, and essentially in specific gravity.
Barrandite has gr. =2-576. Redondite gives gr.=2'019, which
may be presumed to be a little too high, as the three examples
used in the determination were found on analysis to give 8*8
p. c. of silica.

The phosphoric acid was determined on the same specimens
by the molybdate of ammonia process; and amounted to
40192 p. a But as the silica (8*8 p. c.) was obviously acci-
dental, the proportion of phosphoric acid in the pure mineral
will stand at 4407 p. c. The water is 24*73 p. c

6. PhospJiortc acid in the Diaspore of Chester, Mass.

Heermann having found phosphoric acid in the diaspores of
several localities, I thought it worth while to analyze a good
crystal of this mineral from Chester. It was semi-transparent
and of a rich hair-brown color with a faint tin^e of violet
Sp. gr.=3'343. The phosphoric acid was determmed by the
molybdate of ammoma. I obtained

Water, 16-80

Phosphoric acid, 0-32

Protoxyds iron, with traces of man^nese 0*38

Alumina not determined ; but by dmerence...83*50


7. ThePelham Vermiculitet

It occurred to me as possibly interesting to make some
chemical examination of this rather curious exfoliating mica,
described by Mr. Adams in a late number of this journal (vol
xlix, p. 271). It is very abundant, and to the eye apparently
as homogeneous as other softened micas.

It loses on an average 7 p. a of water by ignition. By diges-
tion in hot aqua regia, half its weight comes^ into solution,
leaving behind 50 p. c. of minute, colorless scales, closelj
resembling niargario acid. They are so remarkable for their
uniformity oi size, freedom from color, and pearly luster, as
scarcely to suggest their inorganic composition. Under the
microscope, however, they very nearly give the distinct lateral

Digitized by VjOOQ IC

0. C. Marsh on a new speciea of Ocmalfrom New Jersey. 97

cleavage lines of mica ; nor have they the perfect elasticity of
a true mica. They show no tendency to ferther exfoliation
when heated ; before the blow-pipe they melt with difficulty
on the edges into a colorless glass. Prof DesCloizeaux was
kind enough to examine some of these scales optically ; and
found them to be uniaxial, from whence it is probable that
they belong to the species biotite.

The solution in aqua regia afforded the following result in
reference to 100 parts of the dissolved material

Alumina 1400

Magnesia 13-68

Peroxydof iron 3200

Silica 24-00

No search was made for alkalies ; but from the result obtained
it is apparent that the magnesia in part explains the use made
by the farmers of this material for a fertilizer, as described by
Mr. Adams.

The point, however, which most interested me was the dis-
covery thus accidentally made of the cause of the worm-like
exfoliation in the mineral, viz : from the coatinff of the mica
scales with a hydrated, argillaceous mixture, wnich probably
owes its origin to the decomposition of some other species of the
micaceous or chloritic fiunily. In subjecting a fra^ent of the
vermiculite of Millbury, Mass., to a similar action of aqua regia,
the result was an abundance of brilliant green scales, probably
belonmig to the species ripidolite. It may therefore be sug-
gested, that many earthy species of minerals (silicates) will under
analogous treatment be found to be less homogeneous than has
been supposed.

Amherst^ Maj 7, 1870.

Abt. Xm. — Notice of a new Species of Gaviaijrom the Eocene
of New Jersey ; by Professor 0. C. Mjlbsh, of Y ale OoUega

The Museum of Tale College has recently received some
interesting reptilian remains from the Eocene ^reensand of New
Jersey, which indicate a new species of Gbvial, considerably
smaller than any Crocodilian neretofore discovered. These
specimens, which were found together, and are evidently parts
of the same skeleton, consist of various fingments of the skull,
and ten vertebrae. The codssification of the neural arches of
the vertebrae, and the almost entire obliteration in some of them
of the sutures, would imply that the individual, although
diminutive, was nearly or quite mature.
Ail Joub. Scl—Ssoond Sbbibs, Vou L, No. 148.— July, 187a

Digitized by VjOOQ IC

98 0, C. Marsh on a new species of Oavialfrom New Jersey.

The few portions of the ekxill preserved are sufficiently char-
acteristic to show that the animal had an elongated muzzle, and
that the upper and posterior parte of the head were of the gavial
tjrpa The form oi the parietal bone indicates, moreover, that
the temporal apertures were large, and near together, with their
adjoining sides nearly vertical The quadrates are elongate,
unusuaUy straight on the inner side, and their condylar sur-
feces deeply and obliquely notched. The pneumatic foramen^
on the upper surface of the quadrate near the inner edge, is
verjr large, and characteristic. The teeth of this specimen were
unK)rtunately not secured

The vertebrae are well preserved, and present marked char-
acters. The articular cup is transversely oval in the cervicals
and anterior dorsals, and has its upper mai^n depressed in the

Posterior dorsals. The hypapophyses are simple and elongate,
'he neural canal of the cervical and anterior dorsal series is
transverse, and sub-rectangular in outline, and the floor unusu-
allv broad and flat In the posterior dors^ the canal, although
still transverse, becomes less rectangular, with the broader por-
tion above.

The principal dimensions of the tenth, or first dorsal, tCTtebra
are as follows : —

Length of centrum, - - - - 15* lineR
Transverse diameter of cup, - - - 8*76 "

Vertical diameter of cup, - - - 7* "

Width of neural canal, m front, - - 6* "

Height of neural canal, in front, - - 8*50 "

The species here described may perhaps prove to be generi-
cally identical with the one namea by the writer Thecachampsa
Sqiumkensis, which is the only Crocoaiiian hitherto found in the
Eocene of New Jersey. The genus Thecachampsa^ however, as
proposed by Prof Cope, cannot vet be r^arded as a vaHd one,
since the concentric structure oi the dentine, on which it was
founded,* is not a character of generic importance ; for it occurs
in various other Crocodilians, and also in some of the Cetacea.
The present remains, therefore, may be placed provisionally in
the genus Cfavtaiis, and the species be called Qavialis minor.
It may readily be distinguishea from Thecachampsa Sjuankensis,
aside fix>m its greatly inferior size, by the posterior dorsal
vertebrflB, which have the cup and neural canal transverse,
instead of vertical, and especially by having the bodies of these
vertebrflB proportionally more elongate, and witiiout Ae
remarkable constriction, which is one of the most striking
characters of the latter speciei^.

* Prooeedings Philadelphia Acad. Nat Sdenoes, 1867, p. 143.

Digitized by VjOOQ IC

0. Loew on Bydrogenium-amalgam. 99

The present specimens indicate that the animal to which they
belonged was quite slender, and about six feet in lengtL They
were found by Hugh Hurley, Esq., in the Eocene ffreensand
of Shark River, Monmouth county. New Jersey, and by him
presented to the Museum of Yale College.

New Haven, Conn., June 10th, 1870. ,

Art. XIV. — On Hydrogenium-amatgam ; by O. LoEW, of the
Collie of the City of New York.*

When zinc-amalgam is shaken with water, a slow decompo-
sition of the latter takes place, recognized by the formation of
flocculi ol hydrated oxyd of zinc, and the evolution of small
bubbles of hydrogen on allowing the mixture to stand for a
time. This decomposition of water by zinc is intensified when
a small quantity oi bichlorid of platinum is present ; a spongy *
body then being formed on the surfi^e of the zinc-amalgam.
This body I have found to be an alloy of hydrogenium and

In order to obtain the hydrogenium-amalgam on a larger scale,
zinc-amalgam containing a few per cents of zincf is shaken
thoroughly with about an equal volume of a solution of bi-
chlorid of platinum containing about 10 per cent of the chlorid,

Online LibraryRodolfo Amedeo LancianiThe American journal of science and arts → online text (page 63 of 109)