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THE

AMERICAN
JOURNAL OF SCIENCE.

Kpitrorn: EDWARD S. DANA.

ASSOCIATE EDITORS

' Proressors GEORGE L. GOODALE, JOHN TROWBRIDGE,

W. G. FARLOW anp WM. M. DAVIS, or Camsrince,

Proressors ADDISON E. VERRILL, HORACE L. WELLS,
LOUIS V. PIRSSON, HERBERT E. GREGORY
AND HORACE S. UHLER, or New Haven,

Proressor HENRY S. WILLIAMS, or IrHaca,
Proressorn JOSEPH S. AMES, or Battimmore,
Me. J. S. DILLER, or Wasuinerton.

FOURTH SERIES
VOL. XXXITI—[ WHOLE NUMBER, CLXXXIIT].

WITH THREE PLATES.

NEW HAVEN, CONNECTICUT.
OOF Me?

223346

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; ; + a eae
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THE TUTTLE, MOREHOUSE & TAYLOR COMPANY
NEW HAVEN. :

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=% é 4
cid ; fecal
— Cee

CONTENTS TO VOLUME XXXIII.

INGvacaes 1938.

Page
Art. I.—Physiography of Newfoundland ; by W. H. Twen-
EeepEI ee eee ese ee et as ee Le Safe ei 1
Il.—Hydrocarbon Found in the Diamond and Carbonado
District of Bahia, Brazil ; by J. C. BRaNNER._-. .----- 25
II.—Hydrolysis of Esters of Substituted Fatty Acids ; by
Riper ser EUGHIE, © 0 22.5 oe eee eos Soe e a eee Se 27
~TV.—Relations of Missouri River Less Mantle and in
Prmiconert.: by Cult. Kevise 2 S222 2 lok 32
V.—Crystallized Turquoise from Virginia ; by W. T. Scuat-
IIS Sk Sed See ge SE eS ig eee ee a 1)
VI.—Crescentic Fractures of Glacial Origin; by F. H.
epmEnes ay epeepe ae 2 8S eek Le ee 41
VII.—Heat of Formation of Titanium Dioxide ; by W. G.
SLES TEAR: co)" Ss Shean Cope ai eC 45
VIII.—Composition of Nephelite ; by N. L. Bowzn_-_._--- 49
IX.—Baddeleyite from Montana ; by A. F. Rocrrs ------- 54

Chemistry and Physics—Uranium Hexafluoride, Rurr and HEINZELMANN :
Atomic Weight of Extra-terrestrial Iron, BAXTER and THORVALDsSOoN, 57.—
Compounds of Ammonia and Water, Smits and Postma: Quantitative
Determination of Fluorine as Calcium Fluoride, Starck and THORIN :
Volumetric Determination of Antimony in Alloys, G. S. Jamison, 58.—
Radio-activity of the Diirkheim Mineral Waters, EBLER and FELLNER :
Bulletin of the Bureau of Standards, 59.—Annual Tables of Constants and
Numerical Data, Chemical, Physical and Technological, 60.—The Sun,
©. G. ABBot: Physical Optics, R. W. Woop: Illumination, its Distribu-
tion and Measurement, A. P. TRorrER, 61.—Kometen und Elektronen,
A. RIGHI, 62.

Geology and Mineralogy—Publications of the Geological Survey of the
United States, 62.—U. S. Bureau of Mines, 63— Geological Survey of New
Jersey: Geological Survey of Alabama: Data of Geochemistry, F. W.
CLARKE, 64.—American Permian Vertebrates, S. W. WILLISTON :, Analyses
of Stone Meteorites, O. C. FARRINGTON, 60. —Mineralogy of Pennsylvania :
Praktikum der experimentellen Mineralogie, E. SOMMERFELDT: Uraninite
from German East Africa: Production of Platinum in 1910, 67.—Les
Syenites Nepheliniques de l’Archipel de Los et leur Mineraux, A. Lacroix,
68.—Potash in the United States, H. S. Gate, 69.

Miscellaneous Scientific Intelligence—Heredity in Relation to Evolution and
Animal Breeding, W. E. CastLE: Animal Intelligence, Experimental
Studies, E. L. THORNDIKE: Parasitic Amcebe of Man, C. F. Craic, 70.—
Inland Lakes of Wisconsin: A Laboratory Guide ‘in Bacteriology, P. G.
HeINEMAN: Annual Report of the Board of Regents of the Smithsonian
institution : Twenty-seventh Annual Report of the Bureau of American
Ethnology: Appleton’s Scientific Primers, 71.

Obituary—JOSEPH DALTON HOOKER: GEORGE DAVISON: WILLIAM SUTHER-
LAND: GIORGIO SPEZIA.

lV CONTENTS.

Number 194.

Page
ArT. X.—Study of Some American Fossil Cycads —Part
VI. On the Smaller Flower-Buds of Cycadeoidea ; by

G: JR. WikLAND (8.280) ee ee 73
XJ.—Occurrence of Coral Reefs in the Triassic of North

America >. by J.P. SMITH 3 J 62 eee 92
xa? ay adovidian Outlier at Hyde Manor in ave Ver-

mont ; by T..N. Dari 2 3) ele ee ee
XIII. ENG olor. Effect of Isomorphous Mixture; by H. L.

WSDL 2. 2-25 525225... ee ee 103
XIV.—Lorandite from the Rambler Mine, Wy oming ; 5 by:

A. HORogERS .. 22.25... 2. see 105

XV.—Rate of Decay of Different Sizes of Nuclei, Deter-
mined by Aid of the Coronas of Cloudy Condensation ;
by C2 Baris 22S Be Sees ek eos 107

X VI.—Displacement Interferometer Adapted for High Tem-
perature Measurement, Adiabatic Transformations of a

Gas, ete: 5: by C. DARUS 2-22) 225. 442 2 - 109
X VII.—Unconformity at the Base of the Chattanooga Shale

in Kentucky; by E. M. KInpLE .-.-.22..... 22 eee
XVIII.—Suggestion for Mineral Nomenclature; by H. S.

WASHINGTON 22 0 3a 20 ee 137
XIX.—Optical Resolution of the Saturnian Ring ; by D

TPOpp 424 2.88.5. bree ee ee 152

Chemistry and Physics—Canadium, an Alleged New Hiement of the Platinum
Group, A. G. Frencu: Alleged Complexity of Tellurium, Harcourt and
BakER, 155.—New Quantitative Separation of Iron from Manganese, J. A.
SANCHEZ: Famous Chemists, E. RoBerts, 156.—Quantitative Chemical
Analysis, CLowES and CoLEMAN: Photometric Paddle-Wheels, J. R.
MitneE: Text-Book of Physics, L. B. Spinney, 157.—Tables of Physical
and Chemical Constants and some Mathematical Functions, G. W. C.
Kaye and T. H. Lapy: Electrochemische Umformer, J. ZACHARIAS, 108.
—Neue Welt der Fliissigen Kristalle, O. LEHmMaAnn, 109.

Geology and Natural History—Thirty-second Annual Report of the United
States Geological Survey, G. O. SmitH, 159.—Granites of Connecticut, T.
N. Dae and H. E. Grecory, 160.—The Mount McKinley Region, Alaska:
Bulletin of the Seismological. Society of America, 161.—Atlas Photo-
graphique des Formes du. Relief Terrestre, J. BRUNHES, EK. CHaix, HE. DE
MartTONNE: New Zealand Botanical Notes, B. C. Aston, 168. —Fungous
Diseases of Plants, B. M. DucGar: Practical Botany, J. "Y. BERGEN “and
O. W. CaLDweELL: A Practical Course in Botany, E. F. ANDREws, 164.

Miscellaneous Scientific Intelligence—Report of the Secretary of the Smith-
sonian Institution, 165.—Report of the Librarian of Congress and Report
of the Superintendent of the Library Building, 166.—Das Schicksal der
Planeten, $. ARRHENIUS: The Capture Theory of Cosmical Evolution, T.
J. J. See, 167.—The Teaching of Geometry, D. E. Smita: The Hindu-
Arabic Numerals, D. E. Smiru and L. C. Karpinsxy, 168.

Obituary—C,. EK. Dutton.

CONTENTS. V

Number 195.

Page
Arr. XX.—Mineral Sulphides of Iron; by E. T. ALien,
J. L. Crensnaw, and J. Jounston ; with Crystallo-
Srapmienouuidy, by W.S. LARSEN _2--2252 2-5. 22 Syste 169

XXI.—Some Relations between Gravity Anomalies and the
Geologic Formations in the United States ; by W. BowrE 237

XXI.—Association of Native Gold with Sillimanite ; by T.

1s. VE JSST O90 ies REN BOIL, ERS See era te ea ane een a ale | each neal 241
X XIII.—Hecker’s Remarks on Ocean Gr avity Observations ;
pra tae NSE AUUEUI UR rh Gales) ahgeer ee tS BES ph el eh a 245

XXIV.—Relations of the Degree of Metamorphism to Geo-
logical Structure and to Acid Igneous Intrusion in the
Narragansett Basin, Rhode Island; by F. H. Lanrx__- 249

XXV.—IImenite Rocks near St. Urbain, Quebec; A New
Occurrence of Rutile and Sapphirine ; by C. H. WarREN 263

Chemistry and Physics—Quantitative Determination of Manganese, Rarkow
and Tiscokow: A Pernitride of Carbon, G. DarzEns, ° 278, — Portland
Cement, E. JANEcKE: Annual Report of the International Committee on
Atomic Weights for 1912.—Hydrates of Sodium Carbonate, WEGSCHEIDER :
Canadium : Intrinsic Brightness of the Starlit Sky, C. Faspry, 280.—Mag-
netische Spektren der 6-Strahlen des Radiums, 281.—Production of Char-
acteristic Réntgen Radiations, R. WHIDDINGTON, 282.—Weitere Messungen
tiber Wellenlangennormale im EKisenspektrum, EVERSHEIM, 283.—The Sun’s

_Energy-Spectrum and Temperature, C. G. ABBot, 284.—College Physics,
J. O. Reep and K. E. Gutue, 285.

Geology and Mineralogy—Geology of the Lake Superior Region, C. R. Van
Hise and C. K. Lerru, 286.—Elastic-Rebound Theory of Earthquakes, H.
F, Rep, 287.—La Sismologie moderne, Comte de MONTESSUS DE BALLORE :
Periodic Variations of Glaciers: Interpretation of Peneplains, E. C.
ANDREWS, 288.— Australia in its Physiographic and Economic Aspects, G.
TAYLOR: Canada, Department of Mines, 289.—The present distribution
and origin of ‘‘ Coal Balls,” M. C. Stoprs and D. M. 8. Watson, 290.—
Early Paleozoic Bryozoa of the Baltic Provinces, R. S. BASSLER: Fossil
Fish remains of the Cretaceous of New Jersey, H. W. Fowiter: Types of
Ore Deposits, H. F. Barn, 292.—Brief Notices of some Recently Described
Minerals, 293.

Miscellaneous Scientific Intelligence—Fourth Report of tho Wellcome Tropi-
cal Research Laboratories, A. BaLrour, 294.—Einfihrung in die Mykol-
ogie, A. Kossowicz: Pr inciples of Human N utrition, W. ei ORDAN, 290.
Ostwald’s Klassiker der exacten Wissenschaften, 296.

Obituary—G. J. Brusa: J. Lister: C.G. WHEELER: J. B. E. BoRNET, 296.

v1 CONTENTS.

Number 196.

Art. XX VI.—Discovery of Pre-Historic Human Remains
near Cuzco, Peru; by H. Bineuam, Director of the Yale
Peruvian Expedition. (With Plates I and II) -._...--

XX VII.—Geologic Relations of the Cuzco Remains; by
L- BOWMAN. ooo 35202 2 ee

XXVIII.—Report on the Remains of Man and of Lower
Animals from the Vicinity of Cuzco, Peru; by G. F.
WUATON 2. Soo) eee Oe ees ea ee a

ee a er rey

XXIX.—Estimation of Lead, Nickel, and Zine by Precipita-
tion as Oxalates and Titration with Potassium Perman-
ganate 5 by Hud, WARD 22..." 295 220 ee

XX X.—Description of the Skulls of Diadectes lentus and
Animasaurus carinatus ; by E. C. Casr and 8. W. Wit-
LISTON | 00 Dee 2 ee a eo G2

XX XI.—New Volumetric Method for the Determination of
Mercury ; by GS. JAMIESON ~-2 2.2...) oe

XX XII.—Volumetric Method for the Determination of
Hydrazine ; by G. 8. JAMIESON 22 2222_22 3. 35= eee

XX XIII.—Relations of the Degree of Metamorphism to Geo-
logical Structure and to Acid Igneous Intrusion in the
Narragansett Basin, Rhode Island ; by F. H. Lanus_--

Page

297

306

325

304

oo04

Chemistry and Physics—Separation of Titanium from Niobium, Tantalum,

Thorium, and Zirconium, J. H. MuLLER: Cementite, RurF and GERSTEN,
373.—Use of Sulphur Monochloride for Decomposing Certain Minerals,
W. B. Hicks: Determination of Water, ZeREwITINoFF, 374.—Reduction
of Vanadic Acid ian Concentrated Sulphuric Acid Solution, Carn and
HostTEtTER : Die Zersetzung von Stickstoffdioxyd im elektrischen Glimm-
strom, J. ZENNEOK, 375.— Mechanism of the Semi-permeable Membrane,
and a New Method of Determining Osmotic Pressure, F. T. Trouton,
3/¢7.—Note on the Monatomicity of Neon, Krypton and Xenon, Sir W.
Ramsay, 378.—Modern Microscopy, M. I. Cross and M. J. Cote: Labo-
ratory Problems in Physics, F. T. Jones and R. R. Tatnaty, 879.—
Storage Batteries, H. W. Morse: A Laboratory Manual of Physics and
Applied Electricity, 580.—Die Bearbeitung des Glases auf dem Blase-
tische, D. Dsakonow and W. LERMANTOFF, 381.

Geology—West Virginia Geological Survey: Wirt, Roane, and Calhoun

Counties, R. V. Hennen, 381.—Geological Survey of New Jersey: State
of the Ice in the Arctic Seas : Wisconsin Geological and Natural His-
tory Survey, 882.—Annual Progress Report of the Geological Survey of
West Australia for the year 1910: Uses of Peat, C. A. Davis, 383.

Miscellaneous Scientific Intelligence—Carnegie Institution of Washington

Year Book No. 10, 1911: Publications of the Carnegie Institution, 384,—
Elements of the Differential and Integral Calculus, W. A. GRANVILLE:
Theory and Practice of Technical Writing, S. C. EARLE: Publications
of the Harvard College Observatory: Publications of the Allegheny
Observatory of the University of Pittsburgh, 386.

Obiluary—C. E. Durron, 387: T. H. Monrcommry, Jr.: J. B. SmirH: R. 8.

TaRR, 388.

CONTENTS. Vil

Number 197.

Page

CHroOnrcelaAnvaiswoRuse.. With a Portrait: 2 222.202.2225. °389
Arr. XXXIV.—Life of the Connecticut Trias; by R. 8S.

Uorameaatan Sot Dp RE Aaa SE EGY on) a Ree a ee Pg ie or ANG aan Maes |

XXX V.—Oxalate-Permanganate Process for the Determina:
tion of Copper Associated with Cadmium, Arsenic, Iron,
Gupeadns ya tigi WARD 3928 9 ou2 005.0 el 493

XXXVI. arn Solution in Minerals. Ii.—The Chemical
Composition of Analcite; by H. W. Foote and W. M.

DADLEY, 61s. eats a pee Be ea a eee en en EFS)
XXXVII.—Chemical Composition of Nephelite ; : by H. W.

Boomscand: VW. MM. BRADLEY 279s) 2°. b ee a 439
XXX VIII.— Description of a new Genus and Species of

igaleechinoides | by Ax VOESSONG 2220022 oe 442

XXIV.—Relations of the Degree of Metamorphism to Geo-
logical Structure and to Acid Igneous Intrusion in the Nar-
ragansett Basin, Rhode Island; by F. H. Langer. Pt. IIL 447

XX XIX.—One Phase of Microseismic Motion; by J. E.

JEMTRIBARGR cs 5s OWN AANA eS ee eae emer 8
XL.—Microseisms Caused by Frost Action; by J. E. Bur-
EPAONGKS oe a8 Se eee es cre os ke eye ois an, LEA

XLI.—Dahllite (Podolite) from ‘Tonopah, ‘Nevada; Vele-
kerite, a New Basic Calcium Phosphate ; Remarks on
the Chemical Composition of Apatite and Phosphate
Rock; by A. F. Rogers ; with Analyses by G. E.
JE GYSTUNEEA “x a8 hae Sere A EM Sena amt ise OED ta A ee 445
XLIT.—Distribution of the Active Deposit of Radium in an
Hlectric Field; by E. M. Wetuiscu and H. L. Bronson 483

SCIENTIFIC INTELLIGENCE.

Chemistry and Physics—Melting-point of Spodumene, ENDELL and RIEKE:
Detection of Nitric Acid in the Presence of Nitrous Acid, Smn and Dey,
499,—Chemical Constitution of Ilmenite, W. Mancuot: Determination of
Alkalies in Silicates, E. MAkinun : Dictionary of Applied Chemistry, 500.
— Properties of the Rays Producing Aurora Borealis, L. VeGarp : Pressure
of a Blow, B. Hopkinson, 501.—Photographic Study of Vortex Rings in
Liquids, KE. F. Nortarup, 504.—Note on Nevil Maskelyne’s Article, ‘‘ On
the Trisection of an Angle,” H. 8S. UHuER, 506.

Geology—Publications of the United States Geological Survey, 507. —Cambro-
Ordovician Boundary in British Columbia with description of fossils,
C. D. Watcort, 508.—Sardinian Cambrian Genus Olenopsis in America,
C. D. Waucott: Middle Cambrian Branchiopoda, Malacostraca, Trilobita,
and Merostomata, C. D. Watcortt, 509.—Strophomena and other fossils
from Cincinnatian and Mohawkian horizons, A. F. Forrstr: Arnheim
formation within the areas traversed by the Cincinnati geanticline, A. F.
ForrstE : Paleontologia Universalis: Petrographic Methods, 511. — Methods
of Petrographic-Microscopic Research, F. EK. Wriaut: The Soil Solution ;
the nutrient medium for plant growth, F. K. Cammron, 512.

Miscellaneous Scientific Intelligence—National Academy of Sciences, 513.—
Sixth Annual Report Carnegie Foundation for the Advancement of Teach-
ing: Report of Superintendent of the Coast and Geodetic Survey, O. H.
Titrmann, 514,--Bulletin of the Bureau of Standards, 515.

Obituary—R. S. Tarr, 515: A.L. RotcH: O. Rpynoups, 516.

Vill CONTENTS.

Number 198.

Page
Art. XLITI.—Nitrogen Thermometer Scale from 300° to
630°, with a Direct Determinatton of the Boiling Point

of Sulphur; by A. L.. Day and BK. B. Sosman 2) See 517

XLIV.—Note on the Standard Scale of Temperatures be-
tween 200° and 1100°; by L. H. Apams and J. Joun-
STON ~~ -- 6-4 --e eee ee ee ee

XLV.—Note on Measurements of Radio-activity by Means
of Alpha Rays; by W. R. Barss 202250257 eee 546

XLVI.—The Binary System: Na,Al,8i,0, (Nephelite, Car-
negieite)—CaAl,8i,O, (Anorthite); by N. L. BowEn_.. 551

XLVII.—New Occurrence of Carnotite; by E. T. Wuerry 574

XLVIIL—Age of the Cleveland Shale of Ohio; by H. P.
CUSHING 22 2e..4 5. OL Cee ee 581

SCIENTIFIC INTELLIGENCE.

Chemistry and Physics—Ultra-filtration in Chemical Analysis, DORFURT and
GALECKI: Magnesia Rods as a Substitute for Platinum Wire, E. Wapz-
KIND, 585.—Combustion of Carbon Monoxide, WimLanpD: Purity of Com-
mercial Metals, F. Myxius, 586.—Effect of Temperature upon Radio-active
Disintegration, A. S. RUSSELL, 087.—Das Magnetische Spektrum der {-
Strahlen des Thoriums, von BAEYER, Haun, and Meritner, 588.—Applied
Physics for Secondary Schools, V. D. Hawkins: Die Messung vertikaler
Luftstromungen, P. LupEwic, 589.—Teaching of Physics for Purposes of
General Education, C. R. Mann: Uber Zerfallprozesse in der Natur, —
C. ENGLER, 590.

Geology—Evolution of the Vertebrates and their Kin, W. PatTen, 590.—
Die Wirbeltiere : eine Ubersicht tiber die fossilen und lebenden Formen,
O. JAEKEL; American Permian Vertebrates, S. W. WuIxL.iston, 592.—
Maryland Geological Survey: Method of Removing Tests from Fossils,
S. 8S. Buckman, 095.—Virginia Geological Survey : West Virginia Geolog-
ical Survey, 594.—Wisconsin Geological and Natural History Survey :
Building Stones and Clays, E. C. Eckert: Mineralogy, F. H. Harton, 595.

Miscellaneous Scientific Intelligence—Annals of the Association of American
Geographers, R. E. Dopgz: Annual Report of the Director of the Field
Museum of Natural History, 596.—Science Reports of the Tohoku Imperial
University, Sendai, Japan: Fourth Report of,the Wellcome Tropical Re-
search Laboratory, 597.--Life and Love of the Insect, J. H. FABRE:
Evolution of Animal Intelligence, S. J. Ho~mgs, 598.

Obituary—P. N. LEBepEW: A. TOPLER: E, Divers: G. Borup, 598.
INDEX TO VOLUME XXXIII, 599-604.

ibrary, Bureau of Peet | by }

eer ae JANUARY, 1912.

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Art. ].—Physiography of Newfoundland ; by Wiiuram H.

TWENHOFEL.

INTRODUCTION.

Onty isolated references to the physiography of Newfound-
land occur in the various papers that have been published
relating to its geology, while almost nothing has been written
on the physiography from the modern standpoint. To obtain
some idea of the surface, and its history, the writer, while
assisting in a study of the Cambro-Ordovician section of the
west and northwest coasts,* made such notes on the physi-
ography as time and opportunity permitted, and as these and
the conclusions based upon them may be of value, it has been
thought best to publish them. Only the west and northwest
coasts have been seen and data relating to other areas have
been derived from earlier writers, and in this connection the
map by Mr. James P. Howley, Director of the Geological
Survey of Newfoundland, has been of great assistance. The
complete absence of topographic maps and the lack of detailed
facts relating to the geology of much of Newfoundland,
requires that many of the statements be couched in general
terms.

In treating the subject the major physiographic features are
described, and as the Newfoundland surface is to a large degree
controlled by rock and structure, these are shown in so far as
necessary for interpretation. The chief factors concerned in

* For the opportunity of assisting in this interesting work, undertaken in
the summer of 1910, the writer is indebted to Professor Schuchert, for whom
he acted as assistant, and Doctor Charles D. Walcott ; the work being done
under the auspices of the Peabody Museum of Yale University and the

Smithsonian Institution. The writer is further indebted to Professors
Schuchert and Barrell for having read the paper.

Am, Jour. Scl.—FourtTH SEerRies, Vou. X XXIII, No. 193.—January, 1912.
il

+

x

2 W. H. Twenhofel—Physiography of Newfoundland.

Fie. 1.
NEWFOUNDLAND.

Fic. 1. Map of Newfoundland from Rev. M. Harvey’s Text Book of
Newfoundland History (1890). The northern tributaries of the Humber
should extend farther to the north and west.

td

W. H. Twenhofel—Physiography of Newfoundland. 3

the production of the surface are examined and the conclusion
is reached that the uplands of Newfoundland are the remnants
left by dissection of a once almost perfect peneplain. Finally,
the relation of the western settlements to the coastal physiog-
raphy is briefly stated and a few notes are added on the
physiography of the Belle Isle coast of Labrador.

GENERAL OUTLINE OF THE ISLAND.

The general outline of Newfoundland is very irregular, the

coast being diversified by many bays and headlands, with the
result that its length is tripled if not quadrupled. Tor descrip-
tive purposes the island may be divided into three parts: (1)
the main body elongated east and west along the parallel of
48° 30’, terminating on the west in the Long Range Mountains ;
(2) the northern peninsula, formed for the most part of the
Long Range mountains and the foreland to the west ; and (3)
the peninsula of Avalon on the southeast, almost cut off from
the rest of the island by Trinity and Placentia Bays. Possibly
a fourth part may be considered as made by the peninsula
lying between Placentia Bay and Fortune Bay farther to the
west; of which St. Pierre and Great and Little Miquelon
Islands may be considered the extension.
_ Thoroughly land-locked harbors, extending, in the case of
many, miles into the land, are common features, some of them,
ten to fifteen miles from the sea, having depths of water in
their middle portions not permitting the anchorage of ordinary
vessels.

CHARACTER OF THE Rocks.

The variations of the rocks in texture, hardness, and solu-
bility have been important factors of physiographic control in
the development of the Newfoundland surface, and their
regional distribution is as follows :

The northern peninsula of Newfoundland consists of an
interlor axis formed of metamorphic and igneous crystalline
rocks of Laurentian or undetermined age (Howley, Map of
Newfoundland). The axis is bordered on the northwest, from
Cape Norman to Table Point, by a belt of limestones, gen-
erally magnesian, which begin in the Lower Cambrian and.
extend to about the middle of the Ordovician, having in some
places a width of twenty miles and upward. South from
Table Point to the Bay of Islands the belt is continued by thick
beds of fine-grained shale to coarse sandstone and the coarsest
of limestone conglomerate, in which blocks of interstratified
limestone and shale with lengths exceeding 250 feet are not
uncommon. The bold and rugged coast between Bonne Bay
and the north end of Port au Port Bay is composed of basic

x

4 W. H. Twenhofel—Physiography of Newfoundland.

igneous rocks, probably intrusive in the sediments. Where
these terminate, the limestones, shales, and conglomerates of
the north reappear, repeating the sequence but in a reverse
direction. From St. George Bay to the southwest corner of the
island the rocks are of Carboniferous age, consisting of gypsum,
thin coal beds, shale, sandstone, conglomerate, and limestone.

On the east side of the northern peninsula the section, begin-
ning in the pre-Cambrian and extending into the Silurian, con-
sists of alternating zones of limestones, slates, sandstones, and
conglomerates,* the belt varying in width from nothing at the
south to ten miles and upward at the north.

On the southeastern peninsula the youngest strata are of
Cambrian time, consisting of conglomerates, shales, and lime-
stones.+ Beneath is the Avalonian series - (Pr oterozoic) of
slates, sandstones, quartzites, and conglomerates.

The interior 1s underlain by more or less alternating bands
of Paleozoic and Huronian sediments of varied character,
Laurentian crystallines, and great masses of post- -Ordovician
intrusives, consisting of granite, diorite, and trap.§

It is readily seen from this brief description of the rocks
that they vary widely, which in consequence leads to decided
variations in topographic expression.

STRUCTURE OF NEWFOUNDLAND.

No factor has made a more decided impress on Newfound-
land topogr aphy than that of structure, which in its broader
outlines is as follows:

On the coasts of the northern peninsula the beds depart
little from the horizontal, Logan| stating that ‘fin the great
northern peninsula of Newfoundland, instead of undulations,
great lines of fracture and dislocations are observed while the
strata are but little tilted ” and only locally does the dip rise
to high angles. On the northern half of the west coast the
beds are generally inclined southwestward and the inclination
may rise to as high as 30°, while on the opposite side the dip
varies around 20° and is south of east.44 On the east side the
faults, with trends approximately parallel to the Long Range,
have displacements exceeding 1000 feet and usually the
western blocks have been elevated.** On the west side faults
strike inland from Hawke Harbor,t+ Table Point, and Port-
land Head,t+ the displacement at Table Point being known

* Murray, Can. Geol. Surv., 1869.

+ Walcott, 10th Ann. Rep., U.S. Geol. Surv., p. 554, 1890.

t Walcott, Bull. Geol. Soc. America, x, pp. 219-220, 1898.

§ Murray and Howley, Geol. Surv. Newfoundland, 1881.

| Logan, Can. Geol. Surv., Appendix to paper by A. Murray, p. 40, 1865.

*| Murray, Can. Geol. Surv.. pp. 9-44, 1869.

** Logan, Ibid., pp. 872-876, 1863.

+t Logan, Ibid., pp. 292, 877, 1863.

W. H. Twenhofel—Physiography of Newfoundland. 5

to be greater than 1000 feet. In every case the eastern mass
has been elevated and at Table Point this block has been
shoved to the north (relatively), as shown by the bending of
the beds on the downthrown mass. The trend is parallel to
the Long Range.

At Bonne Bay and the Bay of Islands of the west coast, the
beds are in great confusion through fracturing, faulting, and
folding. Many of the folds are closed and overturned and to
add to the complexities of structure, great masses of basic
rocks are intruded into the midst of the sediments. At the
former locality, however, the original texture is not greatly
modified, for many of the fossils are still present. At the
Bay of Islands the forces were of greater magnitude, changing
the shales to slates and the limestones to marbles—a change
attended by the complete obliteration of all organic remains. —

From Port au Port Bay to the southwest corner the strata
in places are quite highly disturbed. The dip shows many
variations, faulting is not uncommon, and there has been much
intrusion of basic igneous rock.*

In respect to the other parts of Newfoundland, Murrayt
states that the Avalon peninsula and “ probably the whole
island . . . seems to be ranged in an alternation of great anti-
clinal and synclinal lines, independent of innumerable minor
folds, which present throughout a remarkable degree of paral-
lelism, pointing generally about N.N.E. and 8.8.W. from the
true meridian, corresponding with the marked indentations of
the coast as well as the topographical features of the interior.”
A. great fault “intersects the island diagonally from shore to
shore, running in an almost straight line from near the entrance
of the Little Codroy River to White Bay.”{ This fault gives
off a branch northeast of Bay St. George which courses
through Grand Lake to Hall Bay, the southwest arm of Notre
Dame Bay.§

It is readily seen from this brief description that Newfound-
land structure is extremely varied and should be an important
factor of surface control.

Mason FEATURES OF THE TOPOGRAPHY.

General surface.—There is no more striking feature in the
topography of Newfoundland than the marked parallelism of
the peninsulas, reéntrants, lakes, rivers, ridges, and outcrops,
which in nearly every case approximate a direction about N.
28° K. Some of the most prominent of the examples are St.
.* Murray and Howley, Geol. Surv. Newfoundland, 1873, 1874; Map of
Newfoundland, 1904.

t Murray and Howley, Geol. Surv. Newfoundland, p. 139, 1868.

{ Murray and Howley, Ibid., p. 90, 1866.
$ Murray and Howley, Ibid., pp. 380-382, 1873.

6 W. H. Twenhofel—Physiography of Newfoundland.

Mary’s Bay, continued northeastwardly by Conception Bay;
Placentia and Trinity Bays, and Fortune and Bonavista Bays,
similarly aligned ; the west and northwest coast, offset and
broken at St. Geor ge, but still essentially parallel ; the east
coast of the northern peninsula; the coast of the Avalon
peninsula; the intrusive masses, the outcrop of the sedimen-
taries ; the Long Range; the course of the Humber River;
ao and Red Indian sree: and Glover Island in Grand
Lake.

In general, the surface slopes southeastward. The average
elevation of the west coast is about 2000 feet, the northern
portion approximating 2100 feet or less, which rises to 2300 -
near the middle and decreases to 1700 feet near Cape Ray. On
the east side of the northern peninsula there do not appear to
be any elevations greater than 1200 feet. Along the south
coast the height decreases from 1700 feet at Table Mountain
to about 1350 feet north of Fortune Bay, and on the peninsula
of Avalon the highest point is 1100 feet. An axis of some-
what higher elevations extends from the neighborhood of the
Bay of Islands through the middle of the Avalon peninsula
from which the peaks decrease in height northeastward and
southwestward, but are about equal for any particular locality.
These figures of altitude, though significant, do not emphasize
the real facts, as they are taken from conspicuous elevations
rising above the average highland surface. The decrease in
elevation of the highlands southeastward is fairly systematic,
averaging a little less than 10 feet to the mile, and two planes
placed on the western upland and meeting along a line extend-
ing from the Bay of Islands to the Avalon peninsula, if given
the average slope of the surface, would very nearly coincide
with the summits of the aver age highlands of Newfoundland ;
and if projected beneath the sea they would rest on, or slightly
above, the immediate sea bottom off the east coast. Through
this plane would project numerous conical peaks 100 to 400
feet high, usually formed of igneous rocks. On the west coast
the regular ity and hor izontality of the sky line is striking, but
on the east greater irregularity appears to exist, the country
being more dissected.

The Long Range—The Long Range, situated along the
entire west coast, with an average elevation of 2000 feet, is the
highest range of mountains in Newfoundland. At St. George
Bay, where the Codroy—White Bay fault strikes into the land,
it is broken and offset to the southeast. Its greatest elevation
is in the Lewis Hills, about halfway between the Bay of Islands
and St. George Bay, where 2700 feet is reached, an elevation
purely local and exceeding by nearly 400 feet the height of
any other portion of the range. The range faces the west

W. H. Twenhofel—Physiography of Newfoundland. 7

with an almost vertical front, in some places
reaching the sea; but usually with an inter-
vening foreland. To one approaching New-
foundland from Sidney to Port aux Basques,
the most impressive feature is the high flat-
topped upland, here rising almost vertically
from the sea—the southern extremity of the
Long Range. If Newfoundland be observed
from the Labrador side, one feature will
attract and maintain the attention: the flat-
topped upland, standing boldly and promi-
nently in view with a low plain on either
side, widest toward Cape Norman way—the
northern extremity of the Long Range. The
sky line of the Long Range is strikingly hori-
zontal and the appearance of an equal height
in all its parts is not a fiction resulting from a
distant view, for it remains the same near as
well as far, while a very cursory study of
Howley’s map confirms the evidence of direct
observation. At many points in this range
are ‘table mountains.” Suchis that forming
its terminus on the southwest and rising to an
elevation of 1700 feet. Here for fully fifty
miles parallel to the railroad, which follows
the west coast, 1s the steep western front, ris-
ing like a wall, little cut up by erosion and
with the top of the wall reaching to one level.
On the west side of the railroad, opposite this
table mountain, is the triangular block of the
Anguille Mountains, built upon the older
Paleozoic sediments and rising to a height of
1832 feet, more than 100 feet higher than the
mountain to the east. The name of Table
Mountain might with justice be applied to
this block. At the Bay of Islandsis Mount
Blomidon, 2125 feet high, with a table top, in
the central portion of which isa lake. Table
Mountain at Bonne Bay, 2336 feet high, is
almost as flat on its summit as a western
prairie, the surface rising gently from the
margin toward the middle. It has been thor-
oughly shattered by the movements to which
it has been subjected, favoring the formation
of angular gravel through sun and frost action,
and were it not for a mantle of such gravel a

Fic. 2.

The lowest line is drawn at sea level, the middle at the

top of the timber on the foreland (250' +), and the upper the summit level of the Long Range (2000’). Drawn from a photograph

The north is on the left.

Fie. 2. The Long Range opposite Cow Head. Length 7-10 miles.

by Charles Schuchert, the vertical being multiplied by 2.

“

6 eee weonhofel—Physiageaphy of Newfoundland.

bicycle could be ridden with ease on the top of the mountain,
a surface stated to have a length of six miles parallel to the
coast and four miles in the opposite direction. Its sides are very
steep and there are few places where it may be ascended
except with difficulty. The summit is almost bare of vegeta-
tion and that present consists of dwarfed plants occurring in a
few wet places or shallow bogs. The plane of this Bonne Bay

iG:

Fic. 8. Table Mountain, Bonne Bay, 2336 feet high. Photograph by
Charles Schuchert.

“table” truneates the rock of all the systems in the region, no
matter what their structure or character, the elevations rising to,
or almost to, its level and there stopping either as peaks,
ridges, or ‘ tables.”

The Long Range scarp with its elevated valleys.—The slope
of the surface of Newfoundland rises toward the west till the
summit of the Long Range is reached, where an abrupt drop
of between 1500 and 2000 feet takes place. The line of west-
ward-facing cliffs, for the most part composed of crystalline
rocks, is almost a straight one, but is broken and offset to the
southeast at St. George Bay, south of which it continues in the
same direction as a straight line. West of the cliff face the
rocks are almost wholly sedimentary and, in general, do not

W. H. Twenhofel—Physiography of Newfoundland. 9

depart greatly from a horizontal attitude; the general dip is
away from the cliff face, but at some localities, as the St. John
Mountains and St. George Bay, the beds dip toward the cliff.*
In most places, the beds if projected towards the mountains
with the dip they have at the sea, would abut against the cliff
face; but it is very probable that at its base the strata have an
entirely different attitude. Such is the case at Bonne Bay and
the Bay of Islands, and Murray} found similar conditions
about St. George, where at the foot of the mountains the beds
“are usually very highly tilted, inclining in the opposite direc-
tion (away from the mountains) or vertical.”

Erosion has done extremely little to destroy or modify this
precipitous westward-facing scarp, its integrity being well pre-
served. In but afew places like the Bay of Islands and St.
George Bay has a large river cut its way to the sea or pushed
its head far beyond the mountain face; but many small valleys
have been cunt in the upper portion of the wall at elevations
varying with the region, but averaging one-half to two-thirds
the height of the cliff. Most of them flare out near their
heads and flow on levels having a lesser gradient than lower
down in their courses and nearly all of them appear to head in
a wall. At Bonne Bay, where some of these valleys were
studied in detail, they present a profile similar to that which
follows (fig. 3). The upper level is flat-floored, quite wide, in
a few cases one-half mile or more, and at an elevation of about
1200 feet above the sea, or about 900 to 1000 feet below the
top of the Table Mountain wall. At Bonne Bay and the Bay
of Islands many of the lower elevations rise to about the level of
these upper valleys, where they, while not flat-topped, show an
older topography on their summits, and at least one table
mountain, that at Port au Port, rises to a level slightly less.

Their width is out of all proportion to the small streams
flowing in them, which move slowly from one to another of
the ponds and lakes commonly present. Lower down in their
courses they become a series of rapids and cataracts, enclosed
in steep-walled narrow gorges, the descent of which, actual
experience teaches is not only difficult but dangerous.

At Bonne Bay the upper valley level affords an easy route
ot travel from that place to Trout River, a fishing settlement
about ten miles farther south on the coast. This route, after
the ascent to the upper level has been made, is a really excel-
lent one for vehicles, and the only one that is at all practicable
(see fig. 4).

*The dip at the St. John Mountains was judged from the deck of a

schooner, but appears so plain that it can hardly be questioned.
+ Murray, Geol. Surv. Newfoundland, p. 88, 1866.

10 «OW. A. Twenhofel—Physiography of Newfoundland.

Foreland of the Long Range.—Along the northern and
western sides of the island, the Long Range is fringed by a
foreland of greater or less width. It is widest along the Strait
of Belle Isle, approaching twenty miles, but decreases to about
ten miles at Port Sanders and holds this width nearly to Bonne
Bay. From Bonne Bay to Port au Port Bay the Long Range
reaches the sea and the foreland vanishes, but reappears at St.

Pies

Top of highlands

Fic. 4. Profiles of valleys and upland at Bonne Bay. (Diagrammatic.)

George Bay, where both shore and Long Range are offset to
the southeast.

The surface of this lower level gives to the observer a
decided impression of flatness. Near the sea it is carved into
wide and narrow terraces, making the elevation immediate to the
shore quite variable, the average being about 75 feet. Inland,
elevations rise above 150 feet with many much higher, there
being at least three very high blocks of sediments,—Anguille
Mountains, St. John Mountains, and Portland Head. Many
parts are also low, and it is said that tidal waters go nearly to
the mountains at Paul Inlet, Parson’s Pond and Portland Creek,
at each of which the shores are very low. There also appear
to be places where the land is higher on the shore than in the
backland, Mr. Thomas House, a fisherman at Table Point,
stating that the rear of the foreland in that locality is a marsh
considerably lower than is the shore. The presence of glacial
strize at many localities fixes the time of the carving of the
surface as pre-glacial.

Uplands of the east and central parts.—Of the east and
central parts the writer has no first-hand knowledge, but a
study of the published maps and sections and the literature
shows that the surface consists of a series of parallel valleys
lying in the softer sediments, separated by flat-topped ridges

W. H. Twenhofel—Physiography of Newfoundland. 11

on which rise local elevations. Professor Schuchert, who
visited this part of the island after the writer had left for home,
states that “what we saw [on the west] was confirmed in the
eastern part of the island and the interior, although the physio-
graphic aspect is a very different one. One sees no such
foreland as we saw in western Newfoundland. The nearer one
is to the coast the more fiord-like it is” ;* but even here a
section published by Walcott in 1899,¢ extending from Signal
Hill, St. John’s Harbor, to Portugal Cove, Conception Bay,
shows well preserved flat-topped hills. 3

On the granite hills of the interior, where crossed by the
railroad, “the surface is not a plane; but a gently undulatory
one with pointed conical residual hills standing several hun-
dred feet higher,”t a description, judging from the reports of
Murray and Howley, apparently applicable to most of the inte-
rior upland.

Murray states that two great depressions extend across the
island, one from St. George Bay through the Humber Valley
and Deer Lake to White Bay, the other from St. George Bay
through Grand Lake to Hall Bay, their location coinciding with
the two great faults described by him.

Liwers and lakes.—The rivers and lakes of Newfoundland
are in no respect striking or peculiar with the exception of the
Humber and its tributaries. In general, the rivers flow north-
east or southwest, parallel to the ridges, along the outcrops of
the sedimentary formations. The lakes have their greatest
elongation in the same direction. Near the shore the general
aspect of the rivers is that of youth, falls and rapids being met
with at nearly every turn, with lakes in many places inter-
rupting the course of rapid flow. In the interior the rivers
flow in wide, sediment-cloaked valleys, carved in the softer
sediments, most of them consisting of chains of lakes separated
by intervals of rapid water.

The Humber River with its tributaries, however, more than
atones for whatever simplicity is exhibited by its fellows. It
has two main branches, one rising far to the south, about twelve
miles from the head of St. George Bay, the other about nine
miles from the head of White Bay, at an elevation of less than
700 feet. The former flows for about fifty miles in a north-
northeast direction, where it meets the latter, which has followed
a south-southwest course for more than twenty miles. After
the junction the united stream flows almost due west for about
ten miles, where another tributary enters from the north-north-
east which has two branches; one believed to head less than

* Schuchert, Personal letter dated October 3, 1910.

+ Walcott, Bull. Geol. Soc. America, x, p. 221, fig. 6, 1899.
¢t Schuchert, Note book, August 26, 1910.

12) W. HH. Twenhofel—Physiography of Newfoundland.

five miles from the bottom of a western reéntrant from White
Bay, while the other has its source about twelve miles from the
head of Deer arm of Bonne Bay. Briefly stated, the Humber
in two of its tributaries rises less than a dozen miles from the
eastern sea at elevations less than 700 feet, with two other
tributaries rising but twelve miles from the sea into which it

iGo:

~ } G,
2M 23 y
S,
Ly fy
| Fr
4

Fic. 5. The Humber drainage. The Long Range lies between the upper
river and the coast. 1. Bay of Islands; 2. Bonne Bay; 8. White Bay; 4. St.
George Bay. Reduced with some omissions from Howley’s map of New-
foundland.

empties, flows entirely across the southern end of the northern
peninsula, and then ina steep V-shaped gorge dashes through
a mountain range which gradually rises toward the sea and
reaches a height of over 2000 feet where the waters of the
Humber join with those of the Gulf. In this course the river
flows across nearly every character of rock possessed by the
island and across such structural features as faults, folds, and
igneous contacts. That it is an antecedent river can hardly be
questioned.

Peninsulas and bays.—The coast of Newfoundland is
diversified by extremely deep bays and bold headlands which
on the south and north coasts are elongated in the direction of
the structural features already outlined; but on the west and

W. H. Twenhofel—Physiography of Newfoundland. 13

northwest coasts large bays are not. prominent and are rather
irreeular in their shape and alignment.

Among the large peninsulas of the west coast those of Port
au Choix, Cow Head, and Port au Port are the most irregular,
the last having a long northern prolongation which finds its
continuation in the submerged Long Ledge, afew miles beyond.
Each of these headlands is connected with the mainland by a
low and narrow neck of accumulated sands and muds which
an elevation of the sea-level of but about 25 feet would sub-
merge, converting the peninsula into an island.

The more important bays of the west and northwest coasts
are Bonne, St. George, and St. Barbe Bays, the Bay of Islands,
and the double reéntrant made by Port Sanders and Hawke
Harbor. With the exception of St. George Bay, each of these
extends far into the land with deep waters almost to the head.
The Bay of Islands and Bonne Bay branch just a short dis-
tance from the sea, and then each branch extends back into
the land for many miles.. Across the mouth of the former
there is a string of high islands which are formed of the same
kind of rock as exists on each side of the bay. Port au Choix
Bay may also be mentioned; not because of its size, but by
reason of its narrow entrance and the enormous depth of water
within a stone’s throw of the shore.

Islands.— Along the coasts of Newfoundland there are many
islands, of which only those of the west coast have been seen
and to which the remarks that follow alone apply. Those
about the western extremity of Belle Isle Strait are very low
and of most extravagant shapes. In the broad indentation
extending from St. Barbe Bay to Port au Choix there is a suc-
cession of low islands and long peninsulas, one of which, Point
Ferolle, divides the indentation into almost equal parts. The
islands of the northern part are separated from the mainland,
here low, by very shallow water. The southern embayment
contains sixteen islands, of which the largest is St. John.
Deep water les between this group and the mainland, here
formed of the St. John Mountains, an outlier of the Long
Range. South from Port au Choix islands are uncommon, if
those at the mouth of the Bay of Islands be excepted.

Offsetting of the west coast.—The west coast of Newfound-
land shows at four localities,—Point Ferolle, Port au Choix,
Table Point, and St. George Bay,—rather striking offsettings,
or inland sags of the coast. At each of these places the shore
makes a very abrupt bend in an easterly direction, southward
from which it continues parallel to the original coastal line.
The three northern offsets are parallel to each other, with a
southeasterly trend ; but the St. George Bay offset trends almost
due east and finds its continuation inland in the valley of St.

14. W. H. Twenhofel—Physiography of Newfoundland.

George River, an almost straight line. The Table Point sag
has a thousand-foot fault at its back, Logan has described a fault
at the back of the Port au Choix offset, while numerous faults
are known about St. George Bay, at the back of which is the
great displacement described by Murray. Of Point Ferolle
nothing is known.

EVIDENCE OF UPLIFT.

In shaping the surface of Newfoundland, relative elevation
has been an extremely important factor, and the evidence for
this is given in the paragraphs that follow.

Youthful aspect of the streams.—The rivers of the west
coast present a rather striking aspect of youth. Except where
the mouths are drowned, all that were seen consist in their
lower courses of a series of rapids and falls and flow as a rule
in steep-walled gorges. Inland the waters move more slowly,
but the numerous lakes with rapid waters between, as described
by Murray and Howley, prove the immaturity of drainage.

Terraces.—From the Straits of Belle Isle to the southwest
corner of the island, systems of terraces rise like giant staircases

Fig. 6.

Fic. 6. Elevated terraces cut in igneous rock at Beverly Head, north of
the Bay of Islands. The uppermost is about 400 feet, the lowest about 20
feet, the very marked one about 75 feet. Photograph by Charles Schuchert.

from the sea. The lowest of these is less than a dozen feet
above high water, the highest observed rises above 400 feet.
Finely preserved examples of a 25-foot terrace, backed by a 26-
foot cliff, exist on the islands north of the Port au Choix penin-
sula, on the peninsula itself, and at numerous places south
therefrom to the Bay of Islands, particularly in the islands at

W. H. Twenhofel—Phystography of Newfoundland. 15

the mouth. The flat-topped “ barrens” of the foreland rising
to elevations of about 75 feet or less, are remnants of terraces
that are devoid of trees by reason of theirswampiness. Around
Mall Bay south of Hawke Harbor, three beautifully preserved
terraces occur at elevations of about 15, 25, and 40 feet, while
still higher may be seen remnants of others, and at Romaine
River, near Port au Port, there are five, the highest about 70
feet above the sea.

In the interior, terraces exist around Grand and Deer Lakes,
there being at least three at the former at about 5, 15, and 60
feet above lake level, which is 255 feet above the sea ; and in
the Humber gorge there are also at least three.* There seems
no reason for doubting that these inland terraces can be readily
correlated with those of the shore.

Barrier beaches.—At several places barriers extend along
the sides of shore slopes like windrows of hay in a meadow.
Two places in particular where such are rather marked are
Current Island, south of St. Barbe Bay, where there are eight,
the highest being between 20 and 25 feet above sea-level, and
each elevated about 2 to 3 feet above the other ; and at Trap-
per Cove, south of Hawke Harbor, where there are six, with
the highest about 20 feet above sea-level, with about 3 feet ver-
tically between one and the next above. These barriers are
bare of vegetation and are composed of fresh rock derived from
the limestone of the coast, and have, moreover, been there a
number of years, appearing to have been formed by successive
relative elevations and not by a succession of storms, each of
less magnitude than the preceding, as at the latter point they
are in a protected place and in the former on the land side of
the island.

Delta deposits.—At the mouth of almost every stream on the
_ west coast there is a flat-topped alluvial deposit with the upper sur-
face now standing at an elevation of 60 to 75 feet. The depos-
its consist of coarse and fine alluvium, the particles rounded, and
derived in most cases from the neighboring elevations. They
cannot be interpreted as other than delta deposits formed at a
time when the strand-line stood relatively higher by-at least 60
feet. At many places on each side of the delta flat a terrace
continues the level, winding in and out of the reéntrants of the
coast (see view 4).

Marine shells.— Mya arenaria was observed in clays and
sand at two localities on the west coast of Newfoundland,—the
modern seachff on the west side of Port Sanders and in the
cliffs of glacial materia] five or six miles south of Hawke Har-
bor, being in each case but a few feet above high-tide level.
Rock surfaces riddled by lithodomous shells exist at many

* Schuchert, Note book, September 4, 1910.

16 W. Hl. Twenhofel—Physiography of Newfoundland.

points on the west coast of Newfoundland to elevations as great
as 75 feet, and at Bell Burns Cove, just south of Table Point,
Mr. Thomas House stated that in digging a well* on the edge
of the marsh, about one-half mile from the shore and 40-50
feet above high tide, he had passed through a bed of “clams.”

Rica

Fic. 7. Trout River, south of Bonne Bay. The 60-75 foot elevated beach
and delta are shown with the elevated peneplain in the background. The
houses stand on the lowest terrace. Photograph by Charles Schuchert.

Constructions.—No evidence based on human constructions
was seen, nor did anyone appear to have any information lead-
ing to any conclusions. It is, however, stated by Dalyt that
along the coasts of Labrador and Newfoundland the fish stages
have had to be lengthened again and again, while among the
shoals new passages have had to be sought due to the shoaling
of the old.

EVIDENCE OF SUBMERGENCE.

Drowned gorges.—St. Barbe Bay, Port Sanders, Bonne Bay,
and the Bay of Islands are drowned gorges, the submerged
lower courses of once swiftly flowing mountain streams. Each
shows all the characters of ariver system,—St. Barbe with three
main branches and some smaller ones, Port Sanders with two
main arms and each with smaller ones, Bonne Bay with three
branching arms, and the Bay of Islands with an equal number,
each of which fingers out near its head. Each branch of an

* The inhabitants of some of the villages on the west coast migrate annu-

ally to the woods on the edge of the marsh fronting the Long Range in order

to escape the winds, hence the well.
+ Daly, Bull. Mus. Comp. Zool., xxxviii, p. 261, 1902.

W. H. Twenhofel—Physiography of Newfoundland. 17

arm receives its tributary, a remnant of a dismembered river
system. At Bonne Bay and the Bay of Islands the mountains
tower over the water with elevations of 2000 feet a mile from
the shore, and cliffs rise from the water’s edge to nearly a
thousand feet, while im the bays the slope descends precipi-
tously from a shallow shelf, where ships may anchor, to depths
greater than 700 feet.* The other bays do not have such
high margins, though almost equally precipitous, nor do they
descend so deep; but depths of 500 feet are not exceptional.

Low islands.—Attention has been called to the numerous
low islands on that portion of the coast extending from Belle
Isle Strait to Port au Choix. North of St. Barbe Bay these are
quite low, many barely rising above the surface of the water,
yet with relatively deep water on their inland sides. South
from St. Barbe Bay the islands are a little higher and the coast
line of the north, if projected south, would rest on the surface of
the outer islands and again touch the mainland at Point Rich,
the outer extremity of the Port au Choix peninsula. The fore-
land almost ceases to exist on this portion of the coast, but in
its place appear numerous islands with passages between them
and the mainland of sufficient depth to float large steamers.
The islands are thought to represent the submerged foreland.
Between the Bay of Islands and Port au Port the general
line of the coast is continued by the submerged Long Ledge
and Long Point and the outer margin of the peninsula. The
enclosed waters are, in general, quite shallow. An exception
is a long narrow trough of 20 fathoms depth that very closely
follows the mainshore. This bay with its low islands and sub-
merged ledges is also thought to be a part of the submerged
foreland.

Submerged folds off the Avalon peninsula.—That the east
side of Newfoundland is in a drowned condition appears
equally certain. Nearly every river in its lower course enters
ina deep bay and the headlands rise precipitously from the
water’s edge. The parallelism of the peninsulas and bays on
this portion of the coast is one of its remarkable features; but
equally striking is the submerged topography immediate to the
shore with peninsulas essentially similar to those above the
water and bays little different from those of the present coast.

EFFECTS OF GLACIATION.

Along the west coasts erratics are quite common and deposits
of till and bowlders exist at several places in considerable thick-

* A part of this depth may be due to glacial overdeepening. How much,
however, there are no means of determining, but it is to be noted that the
water is more shallow at the entrances than in the interior of the bays. The
channels, however, could readily have been filled by the currents that drift
along the coast.

Am. Jour. Sci.—FourtH Smries, Vout. X XXIII, No. 193.—January, 1912.
2

18 W. H. Twenhofel—Physiography of Newfoundland.

nesses, notably in the cliffs about ten miles south of Hawke
Harbor. In the interior, along the line of the railroad, glacial
debris appears to be more abundant, the mountain slopes being
cloaked with material, morainic in character.*

Strize were seen at numerous localities, generally with a direc-
tion closely approximating the trend of the valleys of the place
in question. Their presence was noted on top of Table Moun-
tain, at Bonne Bay, in the elevated valleys, and numerous
places on the foreland.

The upper system of valleys in the Long Range are decid-
edly U-shaped while the flared-out heads of some of them
strongly resemble the descriptions given of cirques, which resem-
blance is intensified by the lakes and ponds found in these val-
leys and held in rock basins. Nearly every one of the valleys
shows by the polished rock surfaces that at one time it was
filled with the ice, and their precipitous margins are no doubt,
in part, due to its work. The surface at many points has a
rounded aspect, seen to good advantage near the mouth of the
Bay of Islands in the foothills of Mount Blomidon, and to the
work of ice may perhaps be ascribed, in part, the gouging out
of the deep bays existing around the entire coast although those
of the west side are decidedly canyon-like.

That glaciers covered the western side of the island to the
highest summits is certain and the same was probably true in
respect to the other parts of Newfoundland. The direction of
the striz on the western foreland leads to the conclusion that
the ice movement was controlled by the topography, which is
in harmony with the belief that ‘‘ Newfoundland seems to have
been a separate area of glaciation. ’’+

ORIGIN OF THE SURFACE F'RATURES.

Parallel features.—The presence of great structural lines
with a northeastwardly trend finds expression on the surface
in control of erosion resulting im parallel ridges and valleys
having the same direction as the fold and faults, the softer
beds and zones of weakness having been eroded out.

Upland surface.—The accordance of the summit levels of
the highlands, the systematic decrease of the elevations east-
ward, the presence of well preserved flat-topped mountains at
many localities with the projected plane of their summits trun-
cating all kinds of structure and rock, the course of the Hum-
ber River with its source less than a score of miles from the
eastern shore at an elevation of less than 700 feet and its mouth
on the opposite side of a mountain range 2000 feet high: these

* Schuchert, Note book, August and September, 1910.
+Chamberlin and Salisbury, Earth History, vol. iii, p. 336, 1907.

W. H. Twenhofel—Physiography of Newfoundland. 19

are considered evidence of the present dissection, but one
time perfection of a peneplain, a plain of erosion of remark-
able perfection extending over the whole of Newfoundland.*
If the valleys were filled to the level of the average mountain
summits the resulting plain would be strikingly perfect, would
be 2000 feet high on its western border and pass beneath the
sea on its eastern with an elevation of about 700 feet at the
shore. This slope probably represents the tilting that has
occurred with uplift, which, however, does not appear to have
been a simple warping uplift, but by different blocks acting as
units, of which the Long Range is perhaps the most conspicu-
ous. On this ancient plain the rivers were free to wander
where they would, structure and texture of rock being mini-
mized as factors of stream control. They probably crossed
the site of the present mountain ranges and, when the land
arose, each stream struggled to maintain its position. The
Humber alone carved its way through the rising Long Range
blocks and by developing northern and southern tributaries
took from other western streams their sources, but thus pre-
served their waters for the western sea.

Attempts to fix the time of the close of the cycle of erosion in
which this peneplain was carved meet with difficuity. The
latest rocks involved in the folding that probably initiated the
erosion cycle are of Pennsylvanian age and the upper wide and
flat-floored valleys are pre-glacial.

In the eastern United States throughout the Appalachians,
the existence of an extensive peneplain, completed before the
end of Cretaceous time, is now universally admitted and with
this base level that of Newfoundland is tentatively correlated,
and the period of development and close of the cycle assumed
to be the same. |

Elevated valleys.—These valleys, situated at altitudes of
from 800 to 1200 feet, were probably carved during a period
of temporary stability when the land was lower by an amount
almost equal to their present elevation. The evidences of an
older topography at this level are so evident that any possi-
bility of ascribing them wholly to the work of ice is eliminated
and to the work of this agent can merely be assigned their
U-shape and greater width. Except that they are pre-glacial
their time of origin cannot at present be determined in New-
foundland, but the observations of numerous workers in many
parts of the Appalachians have proven the development of a
partial peneplain during Tertiary time and these elevated val-
leys were perhaps a part of that level. There are not sufficient

* Without discussion the writer assumes that this plain owes its origin to

subaérial erosion and not marine, considering that the numerous conical
residuals and the extensive area support the assumption.

20 W. H. Twenhofel—Physiography of Newfoundland.

data to discuss the occurrence of this level in other parts of
Newfoundland.

Scarp of the Long Range und the foreland.—These two
features seem to be causally related in their method of origin
and so are considered together. The absence of detailed facts
relating to the sediments along the entire base of the cliff
renders any conclusion merely tentative. The facts at present
known to the writer suggest an origin for each in two possible
ways, one far more plausible than the other. These are dis-
cussed in succeeding paragraphs.

(1) It may be assumed that the foreland is a plain resulting
from marine erosion. The presence of terraces up to 400 feet
shows that at one time sea waters covered such portions as are
below this elevation. These waters were, however, post-glacial
while the foreland’s surface existed in pre-glacial time. The
general limitation of the foreland to the sediments and _ its
absence when the crystallines are reached favor the idea of its
produetion by marine erosion, which is not supported, however,
by the fact that at least three large blocks of the sediments—
Anguille Mountains, St. John Mountains, and Portland Head—
are left standing on the plain and reach the sea. Its extreme
variability in width and almost total absence where the line of
cliff reaches the sea, no matter of what kind of rock it be com-
posed, and the steepness and well preserved character of the
cliff face in view of the great age required on the assumption
of marine erosion render the hypothesis untenable.*

(2) It may be assumed that the scarp is a fault face along
which the present Long Range has been elevated. The facts
practically proving this idea are: the localization of numerous
intrusions along the foot of its southern extension, its remark-
able integrity, the actual presence of great faulting near its
base at several widely removed localities, and the upturning of
the beds where these have been observed at the base of the
cliff. The horizontality of the beds, except in the immediate
vicinity of the intrusive masses, and their occasional dip
toward the mountains find in this idea a ready explanation.
On this idea the elevated blocks on the foreland and its varia-
tion in altitude are merely due to differential subsidence and
elevation, while the bays of St. George and St. John are
masses in which the depression was somewhat greater than
the rest of the surface, the straight northern coast of St. George
being the bounding fault of this bay, which, continued inland,
fixed the course of the St. George River. The upper portion
of the cliff face, that in which the elevated valleys have been

* This hypothesis permits the assumption that the Long Range may be

anticlinal in character. A search for data supporting this assumption
yielded negative results.

We 1 wenhofel—Physiography of Newfoundland. 21

carved, is the older, while the lower portion may be immediately
pre-glacial or even younger, thus explaining its well preserved
character. This hypothesis gives to the foreland surface and
that of the upraised peneplain a community of origin—both
formed when the land was a peneplain and since separated by
the faulting up of the Long Range.

PuysioGRaPpuHic Hisrory.

The present physiography probably took its birth at the

close of the period of folding in which the Pennsylvanian
sediments were the latest involved. Then was initiated that
cycle of erosion resulting in the peneplain, the numerous rem-
nants of which are so well preserved on the flat-topped uplands
of the west coast. On the lowland thus created, made almost
perfect by the end of the Cretaceous, the rivers, free to wander,
ploughed their channels across the site of the present moun-
tains. The close of Cretaceoustime is thought to have witnessed
the uplift of the highlands of the west coast to an amount
equal to about 800 feet, in which movement it is not believed
that the foreland participated to a great extent. That it was
below the wide upper valleys appears certain, otherwise they
should be found engraved on its surface. This uplift inaugu-
rated a new cycle in which these valleys were carved and the
rivers once more became adjusted to the structure and assumed
their northeast-southwest alignment. before the completion
of this cycle it was interrupted by renewed uplift; but suffi-
cient time had elapsed to bring the topography well on the
way toward maturity. When the movement had reached com-
pletion, the highlands of the west coast stood about 600 feet
above their present altitude, this figure being derived from
the depth of the drowned valleys:* and the distance between
their summits and the surface of the foreland was increased by
an average of about 1000 feet, the latter not participating to a
great extent in the elevation. To what extent the east side was
affected is not known but that it once was much higher appears
certain. Following the elevation the deeply submerged val-
leys of the west coast were cut. The striking U-shape of
the upper valleys and the presence of strize on the foreland
fix the time of uplift as pre-glacial.
- Glacial time saw the island under a sheet of ice and then
were developed the U-shapes to the upper valleys and the
flaring out of the small valleys cut in the cliff face. The
topography was softened by the chiseling exerted by the ice
on its salients, and many rock basins—the beds of existing
lakes—were carved.

*Tt is possible that a part of this depth may be due to ice cutting below
sea-level, although more than 100 feet has been allowed.

22 W. H. Twenhofel—Physiography of Newfoundland.

Champlain submergence brought a loss of about 1000 feet
in the relative elevation of the west coast (the depth of the
drowning of the valleys plus the elevation of the highest
terrace) and an equivalent amount is assumed for the east.
Since that time the island has experienced relative uplift,
intermittent in its nature, to an amount equal on the west
coast to at least 400 feet. On the east coast the elevation has
been differential in character, Daly* stating that the altitude
of the highest beach (507 feet on Signal Hill, St. John)
decreases northward.

RELATION OF SETTLEMENTS TO COASTAL PHYSIOGRAPHY.

An extremely close relation exists between the location of
the settlements of the west coast and the coastal physiography.
The larger settlements owe their existence to the presence of a
land-locked harbor, and unless two such harbors are very close
together a rather large settlement may be looked for in every
one entered. Fish, alluvial deposits, and coves have been the
conditioning factors in the location of the smaller settlements
north of St. George, a protected cove in which small boats can
find refuge and alluvial deposits on which a garden can be
made. Most of the streams of the western coast have ancient
deltas bordering one side or other of their entrances to the sea,
and these places have invariably proved attractive to the settlers
as places in which to locate their houses; so that the relation
of hut to cove is exceedingly intimate, and one on rounding a
headland expects to find a “livier’s” homet and rarely is he
disappointed, the size of the settlement being correlated with
the extent of the cultivatable ground, the protection afforded
by the cove, and the excellence of the fishing.

Note on LABRADOR.

About two weeks were spent on the coast of Labrador, and
here on the western end of the Strait of Belle Isle were
observed elevated beaches in a magnificent state of preserva-
tion, at least eight being seen at one locality, the highest of
which was 350 feet above high tide. No careful measurements
of slope were made, but the general impression is that they
slope to the east, an impression supported by observation made
with a hand clinometer. Some of the elevated beaches are
covered with myriads of rounded bowlders exactly similar to
those of the present shore, only the water being needed to com-
plete the picture of a modern beach from which, however,
shells would be lacking, as none was seen in these old beaches.

* Daly, Bull. Mus. Comp. Zool., xxxviii, p. 259, 1902.
+ The name ‘‘livier” is used on the west coast for an inhabitant of a village.

W. H. Twenhofel—Physiography of Newfoundland. 28

Above the terraces the Cambrian sandstones and limestones
rise to about one level, presenting a flat-topped upper surface
which truncates the structure.

A trip was made westward along the coast to Brador Bay,
the site of the ancient French settlement of New Brest, to
examine the contact between the Cambrian and the gneiss. It
was not found, having been completely eroded out by a river

Fie. 8.

Fic. 8. Elevated beaches cut in the Lower Cambrian sandstones and lime-
stones, Blane Sablon, Labrador. Photograph by Charles Schuchert.

which follows it back into the country, forming a lowland
between the Cambrian strata and the crystallines. Inquiry
along the coast elicited the information that this depression
exists almost everywhere between the Cambrian and _ the
eneiss. If this be correct, then the Cambrian strata form a
cuesta and the line of contact with the Laurentians an inner
lowland.

CoNCLUSIONS.

(1) The physiography of Newfoundland owes most of its
detail to the structure and texture of the rock which have local-
ized erosion along the zones of the softer sediments and frac-

24 W. H. Twenhofel—Physiography of Newfoundland.

ture. Still other detail is due to variations in the position of
the strand-line and the work of ice.

(2) The extensive distribution of wide flat-topped uplands
with local elevations of a few hundred feet, and the horizon-
tality of the summit levels truncating an exceedingly complex
structure, show the former presence of a plain at this level,
assumed to be a plain of subaérial erosion completed in Cre-
taceous time and correlated with a similar plain in the Appa-
lachians.

(3) The presence of faulting of great magnitude, the up-
turning of the beds at the foot of the western face of the Long
Range, the extreme straightness of this face, and the elevation
on the foreland of large blocks of sediments no different from
those contiguous, render untenable the hypothesis that the cliff
face and the foreland are due to marine erosion, and practi-
cally prove that the Long Range owes its origin to the faulting
upward of this block from the foreland’s level.

(4) Wide elevated fiat-floored valleys along the western
face of the Long Range are thought to have been formed in
an uncompleted cycle of erosion interrupted by renewed uplift
of the Long Range in pre-Glacial time.

J.C. Branner—Hydrocarbon Found in Braz. 25

Art. I].—A Hydrocarbon Found in the Diamond and Car-
bonado District of Bahia, Braz; by J. OC. BRanner.

Amone the minerals obtained by me in the diamond wash-
ings of Bahia was one known among the miners as “gelo”—
ice. The only specimen I have seen was originally about the
size of a man’s fist, but upon drying it crumbled into angular
lumps about as large as peas. It is jet black and opaque; it
has a conchoidal fracture, a hardness of 2°2, a specific gravity
of 1:51, and is very friable.

The following note was sent me by my Brazilian friend Dr.
Alencar Lima of Bahia in regard to this hydrocarbon: ‘“ This
specimer is from the Caetano Martins diamond washings at
Chique-Chique, State of Bahia. The diamond miners call it
‘velo’ (ice). It is found in the beds below the diamond-bear-
ing gravels, and it occurs in big pieces, sometimes nearly as
large as a man’s head. It is solid only so long as it retains its
natural moisture, for as soon as it dries it becomes friable in
proportion as it dries out. While it is moist it yields a black
inky substance, but once dry it does not absorb moisture again.”

I have had an analysis made of this material with the fol-
lowing results:

Analysis of a Hydrocarbon from the Diamond-bearing Gravels
- at Chique- Chique, State of Bahia, Brazil.

L. R. Lenox, analyst.

Nec ie tona tine tee Dh Bes wR ONE By ee 19°43%
Volatile combustible matter ____ __.. Seno A
axedecanbom.e2 pte en ee cA OSO6
J CAS, Si I eA Ee ean a 5:07
100-034

The ash is mainly alumina with a little silica, calcium, and
magnesium.
Tested for solubility it was found to be:

INSOLUBLE IN SOLUBLE IN
Cold water Concentrated sulphuric acid
Hot water (to a dark brown liquid)
Alcohol Nitric acid
Kther (to a dark brown liquid)
Petroleum ether Strong potassium hydroxide
Chloroform (to a dark brown solution)
Benzene

Carbon disulphide
Hydrochloric acid

26 J. C. Branner— Hydrocarbon Found in Brazil.

Professor F. J. Rogers of the Physics Department of Stan-
ford University kindly tested the conductivity of this material,
but, owing to the small size of the fragments and to its fria-
bility, no absolute measure of its conductivity could be made.
The general conclusion was reached, however, that it has a low
conductivity, about like that of bituminous coal. As an insu-
lator it is not as good as elaterite, Cuban asphaltum, or alber-
tite.

When I first heard of this hydrocarbon I thought it possible
that it might be genetically related to the diamonds and ear-
bonados of the region in which it was found. But the size
and occurrence of these lumps in recent gravels do not bear
out such a theory.

Attempts to obtain specimens of this material from other
localities disclosed the fact that the term “‘gelo” is also applied
to material other than hydrocarbon. For example, Mr. Arthur
R. Turney of Cachorros has sent me several specimens of what
is called “gelo” at the diamond washings at Mosquitos, a few
miles south of the city of Lengoes. The materials from near
Lengoes, however, are simply hard beds of various thicknesses
in the recent gravels. They are made up of sands and water-
worn pebbles firmly cemented. They contain no lime and
very little iron, and it is therefore inferred that the cementing
matter is silica.

Stanford University, California.

W. A. Drushel— Hydrolysis of Esters in Fatty Acids. 27

Art. III.— On the Hydrolysis of Esters of Substituted Fatty
Acids ; by W. A. DrusuHet.

[Contribution from the Kent Chemical Laboratory of Yale Univ.—cexxviii. ]
2. Hthyl Cyanacetate.

Wuen hydrogen is replaced by halogens in fatty acids the
strength of the acids is increased and greater stability of the
esters of such substituted acids than of the esters of unsubstituted
acetic acid toward the hydrolytic action of water in the presence
of a strong catalyzing acid, may be expected. It was shown in
a previous paper* from this laboratory that the methyl, ethyl,
propyl and isobutyl esters of chlor and brom substituted acetic
acids have smaller velocities of hydrolysis in the presence of
hydrochloric and hydrobromic acids than the corresponding
esters of unsubstituted acetic acid. These results are in accord
with the theory that a substance most readily undergoes hydrol-
ysis if it is formed by the combination of a weak acid and a
weak base.t

In view of the results obtained from the esters of halogen
substituted acetic acids it seemed desirable to make a further
study of the rates of hydrolysis of esters of substituted acids.
Cyanacetic acid being more strongly dissociated than the mono-
halogen substituted acetic acids, it is to be expected that ethyl
cyanacetate would be even more stable than the ethyl esters of
these acids. However the great difference in the rates of
hydrolysis of ethyl cyanacetate and ethyl chloracetate under the
same conditions of temperature and concentration of ester and
catalyzing acid, recorded in Table I, can scarcely be explained
on this theory alone. The dissociation constants of acetic
acid, chloracetic acid and cyanacetic acid are in the ratio
1: 86: 205, and the velocity constants of the ethyl esters of
these acids taken in the same order have a mean ratio, caleu-
lated from Table I, of 65 :4:2:1. The rate of hydrolysis of
ethyl cyanacetate is lower than would be expected from a com-
parison of the dissociation constants of the acids and the rates
of hydrolysis of ethyl acetate and ethyl chloracetate.

Preparation of Hsters.—The ethyl cyanacetate used in the
hydrolysis experiments recorded in this paper was prepared
from recrystallized monochloracetic acid by the method of
Phelps and Tillotson.t Five hundred cubic centimeters of
the crude ester were fractioned under diminished pressure and
200°™* of the pure ester boiling at 953°C. at a pressure of 12™™
were obtained. The ethyl monochloracetate was prepared by
boiling for six hours with a reflux condenser a mixture of 100

* This Journal, xxx, 72. + Nernst, Theoretical Chemistry, p. 521.
tIbid., xxvi, 267.

28 W. A. Drushel—Hydrolysis of Esters in Fatty Acids.

grm. of recrystallized monochloracetic acid and 800°™* of abso-
lute ethyl alcohol containing 1°25 per cent of dry hydrochlorie
acid gas. The crude ester was separated from the excess of
alcohol by fractional distillation and purified by the method of
Phelps and Eddy.*

Hydrolysis in Decinormal Hydrochloric Acid.—Purified
commercial ethyl acetate, and ethyl cyanacetate and ethyl
monochloracetate prepared as described, were hydrolyzed at
25°, 35°, and 50°C. by making decinormal solutions of the
esters in decinormal hydrochloric acid in 250°" and 500° flasks
fitted with ground glass stoppers and keeping the flasks well
submerged in a thermostat during the course of the reactions.
The reaction velocity was determined by titrating at intervals
25°" of the reaction mixture, diluted with 100™* of cold water,
with decinormal barium hydroxide, using phenolphthalein as
an indicator. For the purpose of comparing the velocity con-
stants the three esters were hydrolyzed under the same condi-
tions of temperature and concentration of catalyzing acid. The
velocity constants recorded in Table I were calculated as for
monomolecular reactions from the titration formula,

K =" fog(T,-T.,)-1og(T.-T.)]

since cyanacetic and monochloracetice acids are relatively very
weak acids in comparison to hydrochloric acid, used as a cata-
lyzing acid, although they are many times stronger than acetic
acid. The results of the hydrolysis experiments are given in
detail in Table I and in summary form in Table III. It will
be observed that the velocity constants for ethyl cyanacetate
are very much lower than for ethyl acetate and also consider-
ably lower than for ethyl monochloracetate, in fact, lower than
would be anticipated from the dissociation constants of the
three acids, acetic 0°0018, monochloracetic 0°155 and eyan-
acetic 0°370. This is the result which may be expected if the
molecules of ethyl cyanacetate exist, at least in part, in poly-
merized form in dilute acid solution.

Hydrolysis in Water Solution.—Decinormal solutions of
ethyl acetate, ethyl monochloracetate and ethyl cyanacetate in
water alone were hydrolyzed at 35° and 50°C. and 25™* por-
tions of the reaction mixture were titrated at intervals in the man-
ner previously described. In this case the hydrolytic action of
water is accelerated only by the acids liberated from the respec-
tive esters, a simple instance of autocatalysis. The results were
calculated in per cent of ester hydrolyzed at given intervals
and are recorded in detail in Table II and in summary form
in Table III. It would be expected that the ester which
liberates the most strongly dissociated acid would hydrolyze |

* This Journal, xxvi, 253.

W. A. Drushel—Hydrolysis of Esters in Fatty Acids. 29

most rapidly. Table II shows that both ethyl cyanacetate and
ethyl monochloracetate are hydrolyzed much more rapidly
than ethyl acetate, and that ethyl monochloracetate is hydro-
lyzed more rapidly than ethyl cyanacetate although cyanacetie
acid is a stronger acid than monochloracetic acid. This again
is the result which may be expected if the ethyl cyanacetate
molecules exist partly in polymeric form in aqueous solution.
Suspecting the rapid increase in acidity of the ethyl mono-
chloracetate solution to be partly due to a decomposition of
the ester molecule with the liberation of hydrochloric acid, a
portion of the reaction mixture was occasionally titrated with
decinormal silver nitrate. No measurable decomposition in

TABLE I,
Ethyl cyanacetate in N/10 HCl.
A. At 25° C.
Ethyl acetate Kthyl chloracetate Ethyl cyanacetate
I II
Tim ani. 1021 Tin min, + 108 K Panemin, 102K fin min. = 10°-K
0 0 0 0
180 ~=64°6 75 46:0 120 10°35 180 10°4
300 69°3 1120 46°] 1480 10°4 420) 10°9
390 69°] 2700 A5°7 2990 10°4 1280 LOet
1260 66°4 4000 46°3 4290 10°6 2730 10°2
1780 67°3 4510 45°] 5675 10°1 4390 9°9
2745 68°5 5770 45°8 7120 9:9 6010 9°8
3195 68°6 == ees —
—- 45'8 10°3 10°2
Otel:
B. At 35° C.
0 0 0
61 159°2 129 92°7 900 22°4
IAD 158°9 240 92°4 1105 22°3
240 158°8 360 92°4 1300 24°0)
420 159°6 480 92°4 1440 23:2
540 159°3 1650 88°5 2430 23°3
715 159°8 == 2670 23°2
=== 217) 3780 23°0
159°3 ——
23°1
C. At 50° C.
0 0 0
5 491°7 20 318°9 20 75°0
20 496°4 50 321°9 50 78:0
390 4986 110 314°9 110 774
50 38 501°5 180 320°3 180 tile
80 8 500°0 240 321°5 1140 76°6
ETO, 2497-2 300 329°6 2970 76°8
180 493°2 —-—- —
SS 321°2 76°8

496°9

30 W. A. Drushel—Hydrolysis of Esters in Fatty Acids.

this direction was observed even at 50°C. The hydrolysis
reactions apparently proceeded smoothly according to the fol-
lowing equations :
Cl-CH,-COOC,H, + HOHZCIl-CH,-COOH + C,H.OH, and
CN-CH -COOUC,H, + HOHZCN-CH_-COOH + CHI@EE

TABLE II.

Ethyl cyanacetate in water alone.

A. At 35° C.
Ethyl acetate Ethyl chloracetate Ethyl cyanacetate
Tinhr. @hydrol. Tinhr. 4 hydrol. Tin hr. —@-hydtok
) 6) 6)
50°5 0 50°5 6°6 30 2°5
1S 0°3 111°5 15°3 50°5 4-4
163°5 0°5 163°5 24°5 149 13°3
281 1°4 281 41°3 isco 15°8
385 2°2 385 52°9 201 22°3
476 owl 476 59°2 240 2'0°3
573 3°9 DTS 63°7 294 - O09
313) 38°1
B: At 50-6:
0) 0 0
24 0:2 2 4°2 2 Dial
53 0:4 : 24 9°9 24 3°4
76 0°5 53 35°4 933) 8°8
96 0°7 76 aloha 76 22°4
120 0°9 96 70:2 96 30°3
145 ie 120 80°6 120 38°8
145 87°9 145 48°7
TABLE III.
Summary.
Hydrolysis in N/10 HCl
Ethyl Ethyl
Kthyl acetate chloracetate cyanacetate
oa 10° K 10° K 10° K
PAL O22 C: Oiieal, 45°8 10°25
At 35°C; 159 3 Oey Zearal
At -bO° CC: 496°9 321°2 76°9
Hydrolysis in water alone
at ak 4g
inhr. @hydrol. inhr. ¢hydrol. inhr. ¢% hydrol.
At 35> C. 3347 1°8 oon Aes 337 38°1
At 50° C. 145 le? 145 87°9 145 48°7

Hydrolysis in Alkaline Solution.—Decinormal solutions of
ethyl cyanacetate in decinormal and fifth normal solutions of
barium hydroxide were placed in a thermostat at 25° and 35°C.
The decomposition of the ester apparently took place in two

W.A. Drushel—Hydrolysis of Esters in Fatty Acids. 31

stages. The first reaction proceeded too rapidly to make accu-
rate velocity measurements, having reached an equilibrium in
from five to ten minutes with a loss in the alkalinity of the
solution nearly equivalent to the concentration of ester used.
No apparent formation of ammonia occurred in this first reac-
tion and it no doubt resulted only in the liberation of alcohol
and the formation of basic or neutral barium cyanacetate accord-
ing to the equations:
CN-CH,-COOC,H, + Ba(OH),——>
~ CN-CH,—COO-Ba-OH + C,H—OH, or

2CN-CH,-COOC,H, + Ba(OH),—~>
(CN-CH,-COO-),Ba+ 2C,H,-OH

Several hours after the alkalinity of the reaction mixture
had reached an equilibrium the presence of ammonia became
apparent and clusters of needle-shaped crystals began to
deposit on the walls of the flasks containing the reaction mix-
tures. This reaction continued for several days at 35°C. and
for more than two weeks at 25°C. with an increase in the
amount of crystalline product and ammonia without any
increase in the alkalinity of the reaction mixture. This reac-
tion evidently consists of the hydrolysis of the cyanogen group
with the formation of free ammonia and barium malonate
according to the following equation:

CN-CH,-COO-Ba-OH + HOH—>Ba(COO),CH,+NH,. ~

The crystalline salt formed in this reaction on analysis
proved to be barium malonate.
~ Summary.—When ethyl cyanacetate is hydrolyzed in deci-
normal aqueous hydrochloric acid the rate of hydrolysis is
much lower than that of ethyl monochloracetate under the
same conditions, the effect of the replacement of hydrogen by
cyanogen in the acetyl group being a much greater depression
of the velocity of hydrolysis than would be expected from the
strength of the cyanetic acid generated in the reaction. In.
water alone the hydrolysis of ethyl cyanacetate also proceeds
more slowly than the hydrolysis of ethyl monochloracetate —
although cyanacetate acid is more strongly dissociated than |
monochloracetic acid. This marked retardation in the hydrol-
ysis reaction in the presence of the cyanogen group may be
due to an effect analogous to what in the esterification reaction
is called steric hindrance, or the possibility of the existence of
polymerized molecules of cyanacetic ester in aqueous solution
may be suggested as an explanation of the retarded action.

In alkaline solution the hydrolysis of ethyl cyanacetate pro-
ceeds in two stages. The first is a very rapid decomposition
of the ester into alcohol and the alkali cyanacetate, and the
second is the hydrolysis of the alkali cyanacetate to the alkali
malonate and ammonia.

32 OC. LR. Keyes—Less Mantle and Kansan Drift-Sheet.

Art. 1V.—felations of Missouri River Less Mantle and
Kansan Drift-Sheet ; by CHARLES R. Keyes.

For the enormous deposits of loess which border the Missouri
River a glacial origin has never proved a very satisfactory
explanation. Their genetic relations have long continued to
be one of the most puzzling geologic problems of the region.
Regarding thein as wind-formed accumulations has only par-
tially removed the difficulties presented. There have ee
remained many seeming incongruities.

So long and so closely have the southern limits of the drift-
sheet, a remarkable belt of Bluff deposits, or loess, and the
course of the Missouri River been associated with one another
that something of a genetic relationship between them has
been often inferred. The older glacial boundaries practically
follow the course of the river from its headwaters to its mouth.
_ In southeast South Dakota a younger drift-sheet also touches
the great stream.

Noteworthy among the peculiarities of the loess of the region
are: (1) Its great thickness and conspicuous capping of the
bluffs on both sides of the river, a circumstance which early
gave it the name of “ Bluff Deposit > * ; (2) its effectual man-
tling of the Kansan drift-sheet + ; (3) its position in many locali-
ties both above and below the ‘drift + ; (4) its greater thick-
ness and higher elevation on the east bluff of the river than on
the west side, as first suggested by me in Missouri, and after-
wards determined by Bain in Iowa; (5) its extension far for-
ward from the drift-border§; (6) its expansion indefinitely
backward over the Kansan drift- sheet | ; (7) its notable non-
restriction to the immediate vicinity of the drift-border, but, as
recently shown, its extension for great distances westward from
the river ; (8) ‘its deposition on the surface of the country inde-
pendent of hypsometric conditions** ; (9) the multiple terranal
character which it displays in many placestt+; (10) its develop-
ment beneath the Kansan drift-sheet.¢{

Sinee presenting §§ reasons, a decade and a half ago, arguing
for an eolian origia of the Missouri River leess, the conclusions

* Swallow : Geol. Surv. Missouri, 1st and 2d Ann. Repts., p. 69, 1855.

+ Todd: Missouri Geol. Surv., vol. x, p. 129, 1896.

t Call and McGee: This Journal (3), vol. xxiv, p. 202, 1882; also, Todd
and Bain: Proc. Iowa Acad. Sci., vol. ii, p. 20, 895.

§ Todd : Missouri Geol. Surv., vol, x, p. 132, 1896.

| Bain : Iowa Geol. Surv., vol, 1X5: ‘1, 1890.

*| Bull. Geol. Soc. America, vol. xxii, 1911.

** Calvin : Iowa Geol. Surv., vol. xi, p. 444, 1901.

tt Wilcox: Iowa Geol. Surv., vol. xiii, p. 716, 1904.

tt Udden : Iowa Geol. Surv., vol. xi, p. 249, 1901.
§§ Keyes: This Journai (4), vol. vi, p. 299, 1898.

C. R. Keyes—Less Mantle and Kansan Drift-Sheet. 33

then arrived at have been without reserve accepted by Lever-
en Bain,t Shimek,¢ Calvin,§ Udden,| and others who have
worked in the region. When I first set forth this evidence I
was inclined to derive all of the lcess-materials directly from
the extensive mud-flats and sand-bars which line the great
stream. ‘These sources no doubt are more than ample to sup-
.ply the necessary matter for the loess deposits as they appear
to-day ; yet it now seems probable, in the light of wider investi-
gations, that a greater part of the silty materials comes from
more distant localities. Although, at the present moment,
quantitative determinations are not available, the volume of
wind-borne dusts derived from the dry, upland plains to the
west and settling upon and beyond the Missouri River belt
must be very great. The latest considerations on this point
suggest that not only the contiguous country and the semi-
arid belt but the desert regions of southwestern United States
are large contributors to the loess of the Mississippi Valley.

- Notwithstanding the fact that it had been long known that
the Missouri River loess extended forward from the limits »
of the drift, there has been little attempt to ascertain the prob-
able distances. In all physical respects, except perhaps color,
the loess is indistinguishable from the so-called “ Plains marls,”
which so deeply mantle the surface of Kansas and Nebraska ;
and it cannot be told from the adobe soils of the arid regions
that are unquestionably accumulations of wind-blown dusts.
The recognition of the identity of the three deposits not only
eveatly simplifies the consideration of their origin, but it indi-
cates clearly the complete independence of formation of the
loess and the drift. The similarity in physical characters is
more than co-incidental ; and once the comparison is made of
the three soils in the field there remains no hesitancy 1 in pro-
nouncing them identical in origin.

What is really presented by the drift and loess sections at
the Missouri River is a marked overlap of eolian dusts coming
from the southwest and of glacial deposits derived from the
northeast. In spite of the fact that the eolic formations attain
vast development in the region under consideration, their true
relations and character are greatly obscured by the vigorous
action of the rains, this belt being within the influence of inoist
climate ; they are confused by the presence of extensive glacial
formations : they are easily misinterpreted because the typical
deposits have never been traced forward from the glacial
boundary ; and they are not generally critically examined by

* Zeitschrift f. Gletscherkunde, iv, p. 299, 1910.

+ Iowa Geol. Surv., vol. ix, p. 91, 1899.

} Proc. lowa Acad. Sci., vol, xiv, p. 247, 1907.
3 Iowa Geol. Surv., vol. xi, p. 442, 1901.

| Ibid., vol. xi, p. 248, 1901.

Am. Jour. Sci.—FourtH SERIES, VoL. XXXIII, No. 193.—January, 1912.
3 :

34. OC. R. Keyes—Less Manile and Kansan Drift-Sheet.

reason of the fact that continental terranes of eolic origin have
been little understood. That the real nature of the deposits in
question was not inductively established long ago is due largely
to the circumstance that they were invariably approached from
the side of moist-climate conditions instead of from the side of
aridity.

HIGoae

It is quite probable, therefore, that towards the Missouri
River the Plains deposits represent (1) a Tertiary leess-section
of indeterminable thickness, (2) an extensive Pre-Kansan lcess
which also once covered the country east of the river, but of
which few traces now remain on account of its profound dis-
turbance by the advance of the ice-sheet, (3) a lcess-sheet
equivalent to the Kansan drift that is doubtless everywhere
near the glacial border quite thin, (4) an extensive Post-Kansan
loess, which is well developed west of the river covering the
surface of the entire region, passing eastward over the Kansan
drift-sheet, interlocks with the other drift-sheets in central and
eastern lowa, and continues at the present time to form as
rapidly as loess has ever formed in the past. The several rela-
tionships are graphically represented in the accompanying dia-

gram (fig. 1).

Des Moines, Iowa.

WZ. Schaller-— Crystallized Turquoise from Virginia. 35

Arr. V.—Crystallized Turquoise from Virginia; by
Warpemar T. ScHALLER.

Introduction.

A sAmpieE of a bright blue mineral, from near Lynch Sta-
tion, Campbell County, Virginia, was brought to the Geolog-
ical Survey for identification by Mr. J. H. Watkins. As a
few preliminary tests failed to identify the mineral with any
known species, a complete study of it was undertaken. The
results obtained show that the supposed new mineral is identi-
eal with turquoise. The chief interest, however, lies in the
fact that this turquoise is well crystallized and it was possible
to measure several of the minute crystals and determine thereby
the crystallography of the mineral. I am deeply indebted to
Mr. Watkins for his kindness in furnishing the material (now
deposited in the United States National Museum) and in allow-
ing this description to be published.

The matrix of the specimen consists of irregular fragments
of glassy quartz of various sizes, cemented together by thin
layers of turquoise crystals. On one side of the specimen the
turquoise forms a drusy, botryoidal layer, cavernous in texture
and including many small irregular fragments of the glassy
quartz. The turquoise, with its many included quartz frag-
ments, polishes well and makes a very handsome ornamental
stone. ;

The spheres, bristling with minute crystals, which form
the botryoidal surface, average about two or three millimeters
in diameter. The individual crystals rarely are as much as a
third of a millimeter long, being usually smaller and much
thinner.

General description of mineral.

The turquoise is bright blue in color and vitreous in luster.
Cleavage is present, possibly in two directions. The mineral
is brittle and has a hardness of about 5, though the minute
size and brittleness of the crystals make it difficult to deter-
mine the hardness closely. The density of the sample ana-
lyzed, determined with a pycnometer, is 2°816, which, when
corrected for the 12°57 per cent insoluble material (mostly
quartz) present (see analysis beyond), gives for the pure tur-
quoise the value 2°84. |

Examined under the microscope, the crystals are clear and
transparent and the material is very pure. Pleochroism is dis-
tinct, from colorless to pale bluish. Extinction is inclined on
all sections and, as verified by the measurements, the crystals

386 W. 7. Schaller—Crystallized Turquoise from Virginia.

are triclinic. None of the sections showed a good interference
fizure, though such as were seen indicated biaxiality. One
cleavage plate, possibly parallel to J/(1 10), showed extinction
of 12° against the vertical direction and 12° against the other
edge (110 ~. 011%). A different cleavage section, of a rhombic
shape, showed extinction values of 5° and 34° respectively, but
the orientation of this piece could not be determined. The
double refraction of the mineral is high, about 0:04. The
refractive indices are about 1°61 for a and 1°65 for y. Lacroix*
gives the value 1°63 for the mean index.

Crystallography.

The crystals are very minute and so closely grown together
that it was almost impossible to obtain any suitable for measure-
ment. One complete crystal was found that gave fairly good
reflections and the measurements were verified by those
obtained on a second, less perfect, crystal. A third incom-
plete one also yielded a few measurements. The size of the
first two crystals measured is as follows:

2 hierar (¢ axis)
32™™ wide (6 axis)

“325 hie h (¢ axis)

Cryst. No, Ho a wae. bt

Cryst. INOV2 = Vane: -40™" wide (6 axis)
“12™™ thick (@+axis)>

The crystals are triclinic and in angles very near to those of
chaleosiderite. In fact, the angular values of turquoise and
chalcosiderite are so close that the erystallographical elements
of chalcosiderite have been adopted for those of turquoise, as
the crystals of the latter mineral are but poorly adapted for
accurate measurements. Were it not for the knowledge of the
crystallography of chalcosiderite Gsomorphous with turquoise,
see beyond under chemical composition) which we possess,
it is doubtful if the orientation of the turquoise crystals could
have been interpreted.

The values for turquoise are then:

@:0:¢=0°7910: 1+ 06051; a= 92°58), B= 93° 300 > == eee
Forms: 6 {010}, a {100}, m {110}, M7 {110}, & {011}.

The comparison of the measured angles with the calculated
onest are shown below.
* Lacroix, A., Mineralogie de la France, vol. iv, p. 529, 1910.

+ These calculated values are, with one exception, taken from the values
calculated for chalcosiderite by Maskelyne, Journ, Chem. Soc., vol. xxviii,

p. 586, 1875

W. 7. Schaller — Crystallized Turquoise from Virginia. 87

Comparison of measured and calculated angles, turquoise.

Measured
Angle Cryst. No.1 Cryst. No.2 Cryst.No.3 Calculated
(3 5S SST as Gn SES 9 SS Se
110 A 100 Be MO Ve a. ase 44° 50’
100 A 110 31 14 3128 Sh, 25. 31 10
110 A 110 104 14 ps pan ae 104 03 104 00
110 A 010* 37 28 SOOT ee bias 40 54
Olin iO a 107 42 ODE EE Dn) Ves a os 105 36
OURO OWN rs ae. DOBRO OMY Wy aero 95 45
Rb Oates oe UO TOO Wie reese 109 36
OR rHOMOR hen so. 1 2G eee sree coke ETO £9
* The faces of {010} gave very poor reflections.
Fie. 1.
3 m a
MM
M
a)
a mm

Fic. 1. Turquoise crystal.
b {010}, a {100}, m {110}, M {110}, & {011}.
The forms a {100} and JZ {110} are large and striated ver-
tically, a generally more striated than JZ. The prism m {110}

is narrow and striated parallel to the edge (110) : (011).
Between m and & {011} lies an undetermined small face very

38 W. TZ. Schaller—Crystallized Turquoise from Virginia.

mueh striated.’. The clinopinacoid 6 (010{ is very small and
uneven and gives a very poor reflection. The dome & {011} is
the only terminal face definitely determined and is strongly
striated on crystal-No. 1, while perfectly smooth and yielding
an excellent reflection on crystal No. 2. It may be that the
face of & on crystal No. 2 is acleavage face, as an easy cleavage
parallel to this dome was noted by Maskelyne on Geer

The habit of the crystals is shown in figure 1.

The pointed appearance of the minute crystals is due ms the
sharpness of the corners where the intersections of & {011} with
the faces of the prism zone yield acute points.

Chemical Composition.

Abundant material was on hand for the analysis, which was
made on carefully selected pieces free from all impurities
except for the quartz. It was found that the mineral is insol-
uble in boilmg hydrochloric acid, but after gentle ignition
(when it has turned brown) it is readily soluble in acids. The
mineral does not lose any water below 200° and retains its
blue color at this temperature. Between 200° and 650° all
the water is given off* and the mineral becomes greenish in
color. On higher heating the greenish color changes to a
brown. The mineral is infusible before the blowpipe but
becomes brown.

The average analysis is shown in the table below in the first
column, while in the second column is given the same analysis
with the insoluble matter (quartz) deducted. The ratios
derived herefrom are also given.

Analysis and ratios of turquoise.

Same with
insol. matter Ratios
Analysis deducted = ———-*+-——--— 5

Oks Ss eee 29°84 34°13 “940 2°07 on 2
ATO: Ge eee Slo 36°50 °357 : te
He Oe ee es 18 21 001 2 ae
CuO Reese TESm 9-00 “113 “Oy stt ait

9

i @) & eee 17°59 20°12 ats 9°64 %

99°96 99°96

The formula derived from the ratios of the analysis is as

follows:
Cu0.3Al,0,.2P,0,.9H,0.

* Nearly all of the water is expelled below 400°.

W. 7. Schaller—Crystallized Turquoise from Virginia. 39.

Following Penfield’s* suggestion as to. the relation of the
hydroxy! groups, this formula can be interpreted as:
CuOH.6[ Al(OH),].H,.(PO,),.

I believe that. this formula expresses the definite composition
of turquoise, and a comparison with other analyses shows that
this formula is doubtless the correct one.

Among the best analyses of turquoise is the one by Pen-
field+ on material from Lincoln County, Nevada. This tur-
quoise. was “ of exceptionally fine quality. . ... very fine-
grained, of a beautiful robin’s-egg blue color, and broke with a
smooth fracture. . . . When examined under the micro-
scope, the turquoise seemed to be perfectly uniform, showing
no evidence of being madeup of two substances . . . it
acted somewhat on polarized light.” Density given as 2°791.

In the following table are given the analysis of the turquoise
_ from Virginia, Penfield’s analysis of turquoise from Lincoln
Co., Nevada, and in the third column the composition calcu-
lated for the formula proposed :

Analyses of turquoise.
Calculated for

Virginia Nevada Cu0O.3A1,03.2P205.9H,0

ORS Cire oaths 34°18 34°12
124i O ees eae a ln es 36°50 35°03 36°84
CRO) ee re et 7B 1°44 et ay
CuO wis oie es 9°00 8°57 9°57
PE OR cere VON 20°12 19°38 19°47
JBanS/o] PRS Cate Sea hai amis 0°93 ee

99°96 99°53 100°00

The agreement of the three analyses is very close, so that the
formula OuO.3A1,0,.2P,0,.9H,O expresses definitely the com-
position of this mineral.

Of the other analyses in which the purity of material is not
SO definitely known as in the two analyses just cited, there are
quoted only those given by Penfield.

The high alumina may be partly accounted for by the
admixture of a little aluminous rock. By considering some of
the iron present as ferrous oxide, FeO, isomorphously replacing
the CuO, the analyses agree very well with the values ealcu-
lated for the composition.

The idea of Penfield’s that the composition of the mineral —
should be expressed as [Al(OH),,Fe(OH),,CuOH,H],PO, can
be more definitely fixed now, as the analysis of crystals of tur-
_* Penfield, S. L., On the Chemical Composition of Turquoise. This

Journal ; vol. Da P. 046, 1900.
+ Loe. cit. t Loc. cit.

40 W. T. Schaller—Crystallized Turquoise from Virginia.

Analyses of turquoise.

Persia. Russia. California. New Mexico. Clarke

Caleulated Church Nicolajew Moore —————--+-————-_,
sco 6 KOR 34°12 32°86 34°42 33°21 31°96 32°86 28.63
Al,O, . 36°84 40°19 [35°79] 35°98 39°53 36°88 37.88
Fe,O. - eS 2A5* 3°52 Pe i asia 2°40 4°07

2
CuQ_. 9-57 527 27°67 780 630 7°51 6°56
H,O.. 19°47 19°34 1860 19°98 19°80 19°60 18-49
Ser HL O-36¢ .--. .--- 1288 “54l) 4-207

—_— = oe

100°00 100°47 100-00 99°96 98°87 99°79 99°83
Dope s 2°75 2°S9 2°86 2°80

- *Given as FeO. The figures would be in better agreement with values
ealculated from formula if the iron were considered in the ferrous condition.

+ MnO. t Includes some Fe.QOs.
§ Insoluble, 1°15; CaO, 0°18. || Insoluble, 0°16 ; CaO, 0°38.
“| Insoluble.

quoise shows that the Al(OH),,OuOH, and H are present in
fixed amounts, namely in the ratioof 6: 1:5. Pentield’s own
analysis agrees very closely with these figures.*

The crystallographical measurements have shown the appar-
ent isomorphism of turquoise and chaleosiderite. The formula
given for chalcosiderite is CuO.3Fe,O,.2P,0,.8H,O,which differs
in form from that proposed for turquoise by one molecule less of
water. From Maskelyne’st description of the material used for
the analysis of chalcosiderite it seems probable that the sample
was contaminated by a little andrewsite, limenite and dufrenite.
These all contain less watert than chalcosiderite, so that the
value obtained is probably a little low and the true amount of
water for pure chalcosiderite is higher than that given. The
correct formula for chalcosiderite is then more probably to be
written with 9H,O instead of 8H,O. The isomorphous char-
acter of this mineral with turquoise is then clearly brought
out.

Turquoise, Cu0.3Al,0,.2P,0,.9H,O. triclinic.
Chalcosiderite, CuO.3Fe,O,.2P,0,.9H,O. triclinic.

Summary.

In closing, the three main points developed in this paper
may be briefly restated :

(1). Turquoise is triclinic with the crystal form as determined.

(2). Turquoise has the definite composition CuQ.3Al1,0,.2P,0..
9H,0.
(8). Turquoise and chalcosiderite are isomorphous.

* Penfield deduced the ratios 7 : 1 : 6 from his analysis, but 6 : 1 : 5 is still
closer.

+ Maskelyne, N. S., On Andrewsite and Chalkosiderite. Journ. Chem.
Soc., vol. xxviii, p. 586, 1875.

t Andrewsite has 8°8 percent, limonite 14°5 percent, and dufrenite 10°5
per cent water, while chalcosiderite has 15°00 per cent.

F.. H. Lahee—Crescentic Fractures of Glacial Origin. 41

Arr. VI.—Crescentic Fractures of Glacial Origin ; by ¥. H.
LAHEE.

Tue terms, ‘crescentic fracture,’ ‘crescentic crack,’ and
‘erescentic cross-fracture, have been used in the geological
literature* to denote certain short, curved cracks which have
been observed, usually in sets, on the glaciated surfaces of
hard, brittle, homogeneous rocks. Since these fractures bear
a constant and definite relation to the direction of ice motion,
as indicated by the striae, their origin has been reasonably
attributed to glacial action. |

During the past summer the writer discovered such an excel-
lent example of these fractures on a ledge brought to his notice
by Mr. R. W. Sayles, that he considered it worth while to
make a detailed study of them and prepare the results for pub-
lication.

The ledge above referred to is one of a group of roches
moutonnées of quartzite, situated on the unwooded eastern end
of Northey Hill in Lisbon, N. H. According to Hitchcock,t
this rock is a member of the ‘Coés group’ which was listed by
him as later than the ‘Cambrian clay slate’ and earlier than
the ‘Helderberg quartzites, slates, and limestones.’{ In his
more recent paper,§ this quartzite is represented on the map
(plate 43) by a heavy black line in the area of staurolite schist
south of Streeter Pond.

Lithologically, this quartzite varies from a rock which is
friable, distinctly bedded,| and more or less argillaceous, to
one that is very hard, massive, and nearly pure. Microscopic
sections of the latter phase display a compact mass of angular
grains, closely cemented together, with no signs of their orig-
inal outlines. The compactness of the rock is demonstrated in
the section by the sharpness of outline of the glaciated surface
which cuts straight across the grains without peripheral crush-
ing (fig. 1, a-6). The texture of this quartzite is medium.

Most of the outcrops, especially on the backbone and north-
ern slope of the hill, are of the hard variety. They are of
typical roche moutonnée form, with the gentle stoss side on
the north. The. surface on which the crescentic cracks are
best developed, measuring roughly 600 square feet in area, is
' * See the following: Winchell, N. H., Geol. and Nat. His. Surv. of Minn.,
6th Ann. Rept., pp. 106, 107, 1877; Andrews, Kd., this Journal (8), xxvi,
1888, pp: 101, 102, 1883 ; Chamberlin, hee OA Use G. S., 3d Ann. Rept.,
1883, pp. 363, 364, 1883 : ‘and, Gilbert, & K., Bull. Geol. Soc. Am., xvii, pp.
308, 304, 1906.

+ Hitchcock, C. H., Geol. of N. H., vol. ii, pp. 275, 317, 318, 1877.

t Ibid., p. 278.

& Hitchcock, C. H., Bull. Geol. Soc. Am., xv, p. 470, 1904.

al Stratification : N. 55°-65°R., 60°-80°N.

42 EF. H. Lahee—Crescentie Fractures of Glacial Origin.

itself a nearly flat stoss slope which has an inclination of about
10° northeastward (in a direction, N.65°E.). Upon all these
glaciated surfaces there is a high polish, and numerous, nearly
parallel, fine striae trend N.7°-10°E. It is a conspicuous fact
that the fractures occur on the northern sides of the roches

Bie...

Fic. 1. Section through quartzite showing glaciated surface (a-b), direc-
tion of ice movement (arrow), and seven crescentic fractures, passing into
the rock from a-b.

moutonnées, and, further, that they are particularly well devel-
oped near the crest of the hill.

The crescentic fractures themselves are grouped in sets, or
series, in which the separate members succeed one another at
short intervals* in the direction of ice motion, that is, parallel
to the striae. Each fracture is concave forward.t Its trac-
ing on the surface of the rock is an hyperbolic-curvet of which
the transverse axis is also the axis of the series to which that
crack belongs (and therefore the general direction of ice
motion). The asymptotes of the curve usually form an angle of
about 90°. In any given set all the cracks are not of equal
length; there are many short ones for each long one. Hence
they are most numerous near the common axis (fig. 2).

The position of the axis is not infrequently marked by a
stria, or even bv a shallow groove which may be as much as
half an inch wide; but such evidences of actual abrasion are
not always present. )

At the surface of the outcrop, and near the axis, the fracture
is distinct and clean-cut and it passes directly through those
grains of the rock that may happen to be in its course (fig. 1);

* In one case 60 to the linear inch, parallel to the striae, were counted.

+ We use forward meaning with the ice motion. Andrews, Chamberlin,
and Gilbert, noted that crescentic cracks are concave forward and suggested
this as a criterion for determining glacier motion. They also observed that,
in this respect, these cracks resemble chatter-marks.

In the present locality the shape of the roches moutonnées, the ‘ drag-lines’
on the lee sides of hard rock obstructions, and other features, are sufficient
evidence for inferring that the ice advance was from north to south, and that
the late Pleistocene local glaciers, which Hitchcock (Geol. of N. H., Ill, pp.
233-238) describes as flowing north and west from the White Mountains,
either did not traverse Northey Hill, or, if so, were no more effective in caus-
ing striation and the usual accompanying phenomena here than they were in
the region over which he shows they flowed (Bethlehem, etc.).

¢ And therefore not truly crescentic. We use the term crescentie, how-
ever, following the rule of precedence,

F. H. Lahee—Crescentic Fractures of Glacial Origin. 43

but when traced outward, away from the axis, or downward,
into the rock (as seen in microscopic slides), it often wanders
between the grains and may jump small intervals and become
echelon in habit, as in the case of echelon jointing. Within
the rock the fracture surface dips toward the axis, or forward,

Fig. 2.

Fic. 2. Plan of a series of crescentic fractures. X-Y is the direction in
which the ice advanced. a-b is referred to as the ‘length’ of the longer
cracks.

at an angle varying from 60° to 80° (fig. 1). As for their size,
individual cracks range up to seven inches in length (a-40, fig. 2),
although commonly this dimension is between 1/4” and 2”;
and their depth is rarely over 1/4”.

These crescentic fractures, then, are of glacial origin. Gil-
bert has suggested that they may be due to frictional resistance
between the ice and the bed-rock, locally increased by the
presence of sand-pockets in the ice-base.* In view of this
interpretation it is interesting to observe that the long north-
ern slope of Northey Hill rests upon mica and _ staurolite
schists which are very friable and easily pulverized. We are
inclined, however, to attribute the cause to more concentrated
action than could result from fine, disintegrated materials,
even though they were irregularly scattered. Thus, as evi-
dence for the operation of a pointed or edged tool are (1) the
increase in the number of fissures toward the axes of the sets ;
(2) the dying out of these fractures, not only downward, but
also laterally, away from the axes; (38) the frequent association,
in a particular manner, of striae and grooves with many of the
sets ; and (4) the fact that the curves are hyperbolic. Accord-
ing to this view, the tool, in each case, may have been one of
the rock fragments with which the ice must have been loaded.

It is worthy of remark that actual contact of this tool with
the bed-rock does not seem to have been necessary for the pro- .

* Op. cit., p. 304,

44. F. H. Lahee—Crescentic Fractures of Glacial Origin.

duction of the fractures, sce many sets are not accompanied
by striae or grooves. The scratch associated with a group of
fractures denotes merely a greater intensity of the force which
first occasioned these fractures; or, in other words, a set of
fractures, in itself, is evidence of a less intense force than the
set accompanied by a groove.

The distribution of this force within the bed-rock seems to

have been tensional. ‘If the friction on some spot is greater.

than on the surrounding area, the rock just beneath that spot
is moved forward in relation to the surrounding rock through
a minute but finite space. This relative movement involves
compression about the downstream side of the affected rock
and tension about its upstream side...... rupture occur-
ring when the tensile stress exceeds the strength of the rock,”*
and this degree of tensile stress appears to have been arrived
at rhythmically, as in the case of chatter-marks, since the cres-
centic fractures are rather evenly spaced along the axis of any
given series. Thus the crescentic fracture resembles the
chatter-mark not only in form and orientation, but also in
the method of operation of the forces involved.
_ In addition to the conditions already mentioned, another is
indicated by the position of the fractures, especially (and
almost entirely) upon gently northward-sloping ledges on the
north side of the hill near its crest. This is where the gray-
ity component of reszstance offered by the hill to the onward
motion of the ice would be practically nil and would be pass-
ing into a gravity component of assistance to such motion.
To the north of this place the ice was shoved up; to the south
of it, the ice was pushed down. Topographic form seems to
have controlled, to some extent, the production of the frac-
tures.t

Summarizing, we infer that the conditions important in the
formation of crescentic cracks are: (1) a hard, brittle bed-rock ;
(2) a relatively heavy body of ice moving over this rock; (3)
the presence in the ice-base of abundant rock fragments either
in contact, or nearly in contact, with the bed-rock ; (4) the
origin of local tensile stresses within this bed-rock, near its sur-
face, by virtue of frictional resistance between it and the frag-
ments; (5) a gentle slope of the overridden surface toward the
direction from which the ice is coming; and (6) the position
of this surface near the crest of a hill, “that i is, between slopes
opposed to, and dipping with, the ice motion, and conse-
quently where there should be in process material changes in
the relations of the interacting forces.

Harvard University, Cambridge, Mass., Oct. 24, 1911.

* Gilbert, G. K., op. cit., p. 304.‘

+ The writer finds no mention, in the literature, of the exact relation
between the topography and other occurrences of the crescentic fractures.
The conclusion just presented is drawn from the Northey Hill locaiity only.

{

Mixter—Heat of Formation of Titanium Dioxide. 45

Arr. VII.—The Heat of Formation of Titanium Dioxide ;
oy W. G, Mixrer.

[Contributions from the Sheffield Chemical Laboratory of Yale University. ]

In 1909 the writer determined the heat of formation of tita-
nium dioxide by the sodium-peroxide method. The value
found at that time was 215,600°.* In an article+ which
appeared shortly after the wr iter’ s, Weiss and Kaiser gave the
results obtained by them by burning titanium in oxygen. The
average of their experiments is 97,7 ‘79° for the heat of forma-
tion of titanium dioxide. It will be seen that the value found
by them is less than 50 per cent of the value found in this
laboratory. This great difference led the writer to attempt the
burning of titanium in oxygen.

A preliminary test showed that a platinum tray or cup would
not answer tor holding the metal in the bomb since the heat of
the combustion melts platinnm. Furthermore it seemed best to
have the particles of titanium separated as much as possible to
insure complete oxidation. With this object in view the fol-
lowing method was used. A weighed amount of cotton wool
was placed in the hemispherical bottom of a sterling silver
bomb having a capacity of 100°, and titanium in grains or
powder was scattered over the cotton. The ignition was by
' means of a cotton thread suspended from a small wire connect-
ing the electrodes in the bomb. The cotton wool burned
instantly and scattered and ignited the metal. After the com-
bustion the titanium oxide was found mostly in one globule
sticking to the bottom of the bomb. It was white on the out-
side but dark colored and crystalline on the fractured surface.
In all cases the large globule was hollow, an indication of slight
dissociation of the oxide with sudden fall of gas pressure owing
to cooling. The titanium used in experiments 1 to 5 was from
the same pulverized metal used in the work two years ago. It
was ground again in an agate mortar and separated by sifting
into two lots, one of grains a millimeter and less in diameter
and one of powder. The former was used in the first three
and the latter in the fourth and fifth experiments. It was
shown in the previous paper that the metal was quite pure.
The low calorimetric results obtained with the powdered sample
raised the question of its purity and therefore it was analyzed.
By the pyrosulphate method 0-4765 gram of the powder gave
97-2, and by solution in hydrochloric acid and precipitation
with ammonia 0:2025 gram gave 96-4 ‘per cent of titanium.

* This Journal, xxxii, 393 ; abstract in Zentralblatt, ii, 180, 1909.
+ Zeitschr. anorg. Chem., Ixv, 397.

46 Mixter— Heat of Formation of Titanium Dioxide.

The average is 96°8. Presumably the powder had oxidized.
For the sixth and seventh experiments another lump of titanium
from the same lot as first used was broken up and only the
coarser portion used. It dissolved too slowly in hydrochloric
acid, hence a pyrosulphate fusion was made. The result with
0°3109 gram was 100°1 per cent of titanium.

In the first five experiments all of the oxide taken from the
bomb was washed to remove a slight amount of silver nitrate
present. Then it was dried, weighed, dissolved in molten potas-
sium pyrosulphate and from the fusion TiO, was obtained in
the usual way. The weight of the TiO, obtained less that of
the oxide taken was the amount of oxygen required to com-
pletely oxidize the oxide. In the sixth and seventh experi-
ments a better method was used, namely: a weighed amount
of finely powdered oxide from the bomb was heated until it
ceased to gain in weight, the color changing from brown to
nearly white.

To find the thermal effect of 32 grams of oxygen combining
with titanium in the same ratio asin a combustion in the bomb,
let

m, = mass of titanium placed in the bomb.
m, = mass of the portion used of the titanium oxides
taken from the bomb.
m, = mass of oxygen added to m, to convert all of it into
Os
« = mass of titanium in M.,,.
y = total mass of oxygen combined in the bomb.
beg ae
=e ——
: Perea
mM,
LL ee =n,

Let A equal observed heat minus the heat due to cotton, then
ii re: :
; 32 is the heat effect of 32 grams of oxygen combining with

titanium under the conditions of the calorimetric experiment.
In caleulating the heat effect of 32 grams of oxygen in experl-
ments 4 and 5, m, is multiplied by 0°968 since the powdered
metal used was found to contain 96°8 per cent of titanium.

The table contains the experimental data and the results
derived.

The heat effects of 48°1.grams of titanium combining with
oxygen in the same ratios as in the bomb are, owing to incom-
plete oxidation, too low for the reaction Ti+O, = TiO,. They
prove, however, conclusively that the heat of combustion of

47

of Titanium Diowide.

con O

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48 Mixter—Heat of Formation of Titanium Diowide.

titanium is over 200,000°. The mean of all of the results for
the heat effect of 32 grams of oxygen combining with titanium
is 218,500°. Excluding those of experiments 4 and 5 with the
finely powdered metal, the composition of which is not aceu-
rately known, the mean is 218,000°. The last two results are
to be regarded as the best, as larger quantities of metal were
used and the method employed for finding the amount of oxy-
gen required to complete the oxidation was more accurate than
the one used in the other determinations. The last two results
give for Ti+0O, = TiO, (crystalline)+218,400% This is 1-1
per cent higher than found two years ago by the sodium-
peroxide method,* which was 215,600°, for “the heat of forma-
tion of amor phous titanium dioxide.

Note on the Spontaneous Oxidation of Titanium in the Air.

The powdered titanium mentioned on page 45 contained not
over 97 per cent of metal. Another sample prepared from a
lump of pure titanium was ground in an agate mortar from time
totime. Then 2°028 grams were left for four months in a small
loosely stoppered vial. At the end of this period the weight
was found to be unchanged. Analyses were made as follows:
One portion, 0°3067 gram, was dissolved in a beaker in hydro-
chloric acid and a few drops of nitric acid were added and the
solution was evaporated to dryness. Then the residue was dis-
solved in hydrochloric acid. The solution was complete.
Finally the titanic acid was precipitated by ammonia, washed,
ignited, and weighed with the usual precautions. Another
portion, 0°3119 gram, was dissolved in a platinum dish in hot
concentrated sulphuric acid, to which a few drops of nitric
acid were added. The solution was complete. The analysis
was carried out as just described. The two results were
respectively 96°6 and 97:1 per cent of titanium.

The 8 per cent of oxygen found by difference corresponds
to 7:5 per cent of dioxide or 12 per cent of monoxide of: :
titanium in the powders analyzed. As only clean fragments
of pure metal were pulverized, the conclusion is that titanium
oxidizes superficially in the air. Since the metal does not
gain weight, in time the oxide forms a protective coating. The
only statement that I have found in the literature bearing on
the question is one in Abegg, III, ii, p. 407, that Schneider
found that titanium heated for 15 hours at 100°-120° gained
in weight 0:06 per cent.

* Loc. cit.

NV. L. Bowen—The Composition of Nephelite. 49

Arr. VIII.— The Composition of Nephelite ; by N. L. Bowen.

THE composition of natural nephelite is a much discussed
question. The earliest formula, expressing the composition as
that of a simple orthosilicate (Na,K)AISiO,, is now generally
recognized as incorrect since analyses always show somewhat
higher silica than this formula requires. The formula (Nak),
AJI,Si,O,,, which is now commonly given in text-books of min-
eralogy, obviously attempts to account for this excess silica.
Several analyses of excellent material have, however, been
advanced by different investigators as evidence of the incor-
rectness of this formula. These analyses demonstrate that no

definite formula can be assigned to nephelite since the excess

of silica is variable in amount.

Moreover, the preparation of ‘artificial soda-nephelite’,
NaAISiO,, by Doelter and others, showing crystallographic
and optical properties essentially those of natural. nephelite,
demonstrated long since that this compound is the ‘essential
constituent’ of natural nephelite.

The writer recently prepared this artificial soda-nephelite
and determined its properties. The marked degree of corre-
spondence with the natural mineral is set forth in the follow-
ing table: |

Opt.
Cryst’n char. @ € G habit
NaAlsiO, (artif.) hex. -. 1°537 1°533 2°619 prismand base
Nephelite (nat.) hex. -. 1°541 1°537 2°55-2°65 prism and base

commonest

Several different investigators recognized this essential rela-
tion and sought to explain the composition of nephelite by
imagining it to bea ‘mixture’ of NaAISiO, with a potash
molecule, either K AlSi,O,, or K,A1,8i,O,,, or K,A1,8i,0.,,.

Each of these potash compounds has a silica ratio higher
than that in an orthosilicate, and its presence in variable
amount was intended to explain the excess of silica and its
variable nature.

The preparation of soda nephelite by the writer, just men-
tioned, was accomplished by fusing together Na,CO,,A1,O, and
SiO, in the proper proportions. It was, however, found that a
‘pure’ product was obtained only with some difficulty on
account of the partial volatilization of soda at high tempera-
tures. When the ‘impure’ mixture first obtained was crys-
tallized at a low temperature the microscope revealed nephelite

Am. Jour. Scol.—FourtTH SERIES, VoL. XXXIII, No. 198.—January, 1912,
4 :

50 NV. L. Bowen—The Composition of Nephelite.

and corundum (Al,O,). But the loss of soda gave not only
excess alumina. but also excess silica, which, however, did not
appear in any form, and therefore must have been held in
solid solution in the nephelite. By mere chance, then, the
explanation of the excess silica content of nephelite was hit
upon. It is held in solid solution and is therefore variable,
but no potash content is necessary. |

This fact suggests that in natural nephelites potash and
excess silica may be quite independent of each other. An
examination of analyses proves that it is indeed so. This
examination is readily accomplished with the aid of the follow-
ing diagram, where composition is plotted on triangular coordi-
nates with SiO,,K,O.A],O, and Na,O,A1I,O, as apices. Only the
significant segment of the plot is shown. CaO has been
deducted from the analyses together with sufficient Al,O, and
SiO, to form CaA1,Si,O,.

Each small numbered circle represents the composition of a
nephelite. There is no apparent arrangement to the points.
Obviously nephelites cannot be considered as a ‘mixture’ of
soda nephelite with any potash compound, for all the points
would then lie on the straight line joining these two composi-
tions. Potash and silica vary quite independently.

An experimental study of the composition of nephelite was
begun by the writer by making up mixtures in which there
was excess silica (deliberate) but no excess alumina. The com-
position Na,O,AJ,O,,2.28i0, (A of diagram) was crystallized.
below 1200°, the temperature being kept low to prevent the
formation of the high temperature form of nephelite (carne-
gieite). The product was a completely crystalline perfectly
homogeneous mass with properties essentially those of the
orthosilicate (Na,O,A1,O,,28i0,). The excess silica had simply
disappeared in solid solution, as had been accidentally found
before.

Mixtures with still greater excess of silica were experimented
with in the attempt to find the limit of solubility and the
excess phase after solubility was exceeded, but the increasing
viscosity, and the necessity of crystallizing at a low tempera-
ture, prevented the formation of a determinable crystalline
product. We have apparently a scanty amount of experi-
mental results on which to base any conclusion, and yet when
used in conjunction with facts known to be true of rocks, cer-
tain conclusions may be drawn.

It is more than probable that, had the attempts above men-
tioned been attended with success, albite (Na,O.A1,O,.681i0,)
would have been found as the excess phase. By analogy, then,
with an ordinary aqueous solution of salt we would speak of
our solution as one of albite in nephelite. The excess phase

N. L. Bowen—The Composition of Nephelite. 51

Fie. 1.
357% Na,OA!,O,
69% SiO,
0Secda-nephelite
‘
25
75
oN, Al, Si, O,,
/ 2.0

20

5 Leucite
os
25
KAI, Si,0.,
® Kaliophi hte
65% SiO,

35% K,OAI,O,

1. Hintze, analysis 23.

2. Foote and Bradley, this Journal, xxxi, 25, 1911.

3, 7, 8 and 9. Morozewicz, Bull. Acad. Sci., Cracovie, 958, 1907.

6. Adams and Barlow, Mem. No. 6, Geol. Surv. Can., p. 236.
10. Hintze, analysis 34.

certainly would not have been silica, for the evidence from
nature is that silica and nephelite do not occur together.
The only other possibility is a compound of the type Na,O
Al,0,2+78i0,, of which the most likely is albite, again from
evidence in nature.

52 N. L. Bowen—The Composition of Nephelite.

Foote and Bradley,* in a recent paper, express the opinion
that the excess silica of natural nephelites must be regarded as
present in solid solution. Their conclusion has the great
advantage of being stated in modern phraseology, but there
appears to be nothing in this view which is essentially differ-
ent from and, therefore, refutes the older view of the pres-
ence in variable amount of some compound of higher silica
content.

Foote and Bradley do, however, point out certain facts
which suggest to the reader that the compound determining
the excess silica is the soda compound albite and not a potash
compound as the older views have insisted upon. One of
these facts is that the nephelites are ‘saturated’ with silica
when found in contact with the polysilicate albite, but Foote
and Bradley themselves apparently consider that contact with
sanidine should bring about a like result.

Still more recently Schaller,+ seizing the truth in Foote and
Bradley’s discussion, has made the explicit statement that
nephelites may be considered as composed of the three mole-
cnles NaAISi0,, KAISiO, and NaA1$Si,O,. The random posi-
tion of the points on the diagram shows that the expression in
terms of three components is a step in the right direction.
Moreover the conclusion agrees with that indicated by experi-
mental results.

Schaller supports his conclusion by testing it against actual
analyses and finds a satisfactory concordance. But it should
be pointed out that this test alone is not decisive. Had
Schaller tried KAISi,O,, or KAISi,.0,, or Na, ALSi,0,,, or
NaAlISi,O, instead of NaAISi,O,, he would have found equally
good concordance. This fact becomes obvious by reference to
the diagram, since all the points representing compositions of
nephelite fall within the triangles having for their common
apices soda-nephelite and kaliophilite, and for the third apex
the compounds mentioned respectively.

It so happens that all natural nephelites on whose analyses
we may rely are doubtful to this extent, and at first sight it
would appear that there is no reason for choosing any one as a
third component rather than any other. The synthetic nephe-
lite (A), however, leaves us to choose only between Na, Al,Si,O,,,
NaAISi,O, and NaAISi,O,, of which the most likely is, as we
have seen, albite. It is probable that there are natural nephe-
lites whose composition would lie above the soda-nephelite,
orthoclase line and for which albite would again be the only
choice.

* This Journal, xxxi, 25,1911. +Jour. Wash. Acad. Science, Sept. 19, 1911.

¢ Nephelite from Denise, Haute Loire, France (anal. 7, Dana’s System),
has a composition which would place it barely above the orthoclase, soda-

nephelite line. The low summation in this analysis makes it probable,
however, that no great significance can be attached to this fact.

WN. L. Bowen—The Composition of Nephelite. 53

For a great many nephelites, then, mere expression of com-
position in terms of three components may be accomplished in a
number of different ways, but for a systematic method which
we may hope to apply to all possible nephelites we must use
the three molecules NaA]SiO,, KAISiO,, and NaAISi,O,, that
Schaller has suggested. The artificial nephelite A enables one
to come to this decision.

The ability to come to this definite decision also makes it
possible to predict when nephelite may be expected to be
‘saturated’ with silica. The presence* of orthoclase in a
rock may be considered as having a ‘silicifying’ effect on
nephelite, but this effect would be limited, for the resultant
composition could never pass above the orthoclase-soda-nephe-
lite line. The artificial nephelite A shows that the composi-
tion may lie above that line. It is, therefore, only in the
presence of albite itself that nephelites may be expected to be
‘saturated’ with silica.

It would appear that the presence of jadeite should bring
about a like result, but this possibility may be disregarded in
nature. The presence of the jadeite molecule in dilute solu-
tion in a hornblende or pyroxene would not have a comparable
effect.

Indeed this remark applies equally well to albite itself. If
the albite molecule were present as oligoclase or andesine it
would, theoretically, not have an equal ‘silicifying’ effect on
nephelite, for a nephelite saturated with albite would be in
equilibrium only with a plagioclase saturated with albite and
the only plagioclase saturated with albite is albite itself. On
the other hand, a nephelite found associated with anorthoclase
saturated with albite should itself be saturated with albite.
The conditions necessary for the saturation of nephelite with
albite are so unlikely to occur that it may be safely said that
natural nephelites are probably never saturated.

Summary.

1. A diagram is given which shows that the composition
of nephelites cannot be explained by assuming mutual solid
solution of any two components. It is necessary to imagine
solid solution among three components.

2. Mere expression of the composition of nephelites in
terms of three components may be accomplished in a number
of different ways.

3. From the results of synthetic work it becomes possible
to decide upon one of these methods as the only one applica-

* By ‘‘ presence” it is necessary to understand intimate association during
the process of crystallization, not mere proximity.

54 AL fas Srom Montana.

ble to all possible nephelites. The decision falls upon the
three components NaAlSiO,, KAISiO,, and NaAISsi,O,, sug-
gested by Schaller.

4. Conclusions are drawn as to when nephelite may be
expected to be saturated with silica.

Mineralogical Laboratory,
Massachusetts Institute of Technology, Boston.

Art. 1X.— Baddeleyite from Montana ; by Austin F. Rogers.

On some corundum specimens from Montana, obtained from
Ward’s Natural Science Establishment, the writer noticed a
black submetallic mineral. The nature of the mineral was
not evident at sight, but it was soon identified by physical and
chemical tests as baddeleyite or native zirconia, ZrO,,.

Baddeleyite is a very rare mineral, first described from the
gem-bearing gravels of Ceylon by Fletcher.* It had also been
found in decomposed jacupirangite (magnetite-pyroxenite) at
Jacupiranga, Sao Paulo, Brazil, and was called brazilite by
Hussak,+ who latert withdrew his name in favor of baddeley-
ite. Hussak§ has also described baddeleyite from Ano,
Sweden, where it occurs in magnetite-olivine segregations in
nephelite-syenite.

The specimens obtained of Ward’s were from Montana, but
the exact locality was not stated. Similar specimens contain-
ing baddeleyite purchased from Mr. R. M. Wilke of Palo Alto,
California, are from the property of the Bozeman Corundum
Company, which according to Pratt|| is fourteen miles south-
west of Bozeman, Montana.

Occurrence.—The baddeleyite is an accessory constituent of
a gneissoid corundum-syenite containing microcline-microper-
thite, biotite, and corundum, with subordinate amounts of mus-
covite, sillimanite, and zircon. It occurs in minute crystals
and rounded blebs with a maximum size of about 3™™. The
baddeleyite is found in both the feldspar and the corundum,
but is especially abundant on the surface of the corundum, and
often adheres to the feldspar when the corundum erystals are
broken out of the matrix.

* Mineralogical Magazine, vol. x, p. 148, 1893.
+ Neues Jahrb. Min., 1892, vol. ii, p. 141.
¢ Min. Petr. Mitth., vol. xiv, p. 395, 1895.

& Neues Jahrb. Min., 1898, vol, li, p. 228.
| Bull. 269, U.S. G. ‘9. ae Cs 133, 1906.

A. F. Royers—Baddeleyite from Montana. 55

Crystal Form.—The baddeleyite crystals are square-pris-
matic or tabular-prismatic 1 in habit with only one well-defined
zone with the forms {100}, {110:, and {010%. Eight crystals
were measured on the reflection goniometer with indifferent
results, the angle for (100 : 110) varying from about 44° to 46°.
Finally, one crystal was found which gave the following meas-
urements :

Average Cale.

er tt (44 oy 44° O5f 44> BG! 44° 94") 44° 90’
ft) O10") 45°31", 45° 35'.45° 38" «45° 35" «45° 40!
100 : 010 89° 57’, 90° 0',90° 0’ 89° 59’ 90° 0’

The calculated angles established by Blake and Smith* are
given in the last column.

For the angle (100: 110) Fletcher gives 44° 0’ and Hussak,
44°174’. The terminal faces are obscure and rounded, but on
one crystal faces of the form {111} were identified by the fol-
lowing measurements, (010: 111) = = 63° 15’ (average of 62° 30’
and 64° 0’), the calculated value according to Blake and Smith
being 64° 18’.

Physical Tests—The cleavage seems to be in four direc-
tions, parallel to {100, 6110}, and $010:. The hardness is
about 64, for it scratches glass faintly and in turn is scratched
by quartz. The luster is submetallic or metallic adamantine.
The color is black, but in fragments it is translucent brownish
red. The donble refraction is strong, and the index of refrac-
tion is greater than that of methylene iodide. Some fragments
show several sets of twinning lamelle crossing each other. In
thin-sections the baddeleyite appears as elongate crystals with
almost parallel extinction and slight pleochroism, the greatest
absorption being parallel to the length of the crystal.

Pyrognostic “Tests—The mineral is practically infusible
when heated before the blowpipe, but examination with a
high-power microscope shows a slight sprouting on the edges.
In the oxygen-gas blowpipet it is fairly easily fusible to a
black globule. ‘In the closed tube it is unaltered. When
heated in the platinum forceps it glows with a brilliant light,
which recalls the fact that zirconia is the principal constituent
of the filament of the Nernst lamp.

Chemical Tests.—In fine powder the baddeleyite is insoluble
in a sodium metaphosphate bead but is soluble in a borax bead
giving a faint iron test. It is insoluble in aqua regia but is
decomposed by strong sulphuric acid. .The hydrochloric acid
solution of the soda fusion turns turmeric paper orange, and
since no green flame was obtained with boracic acid flux this

* Mineralogical Magazine, vol. xiv, p. 378, 1907.
+ See Luquer, Sch. Mines Quart., vol. xxix, p. 179, 1908.

56 A. I. Rogers—Baddeleyite from Montana.

test is proof that zirconium is present. The acid solution of
the soda fusion with ammonium hydroxide gave a white floc- °
culent precipitate which is insoluble in KOH, but soluble in
oxalic acid. The sulphuric acid solution with ammonium
hydroxide gave a precipitate which glows when heated in
platinum forceps before the blowpipe.

Baddeleyite as a Rock-formmg Mineral.—Baddeleyite is
one of the rare accessory minerals of igneous rocks. Asar as
known, it is confined to rocks low in silica, the jacupirangite of
Brazil having only 38 per cent SiO,, and the present corundum-
syenite about 44 per cent. The deficiency in silica is proba-
bly the reason baddeleyite forms rather than zircon.

Identity with Baddeleyite—F rom the presence of zirconium
and the crystal habit one might call the mineral zircon, badde-
leyite, or one of the zirconium-pyroxenes, lavenite, wohlerite,
or hiortdahlite. It is distinguished from zircon by luster, hard-
ness, and cleavage; from altered zircon by the absence of water,
and from the three zirconium pyroxenes mentioned by the
solubility and fusibility. The angles in the prism zone
[100 :110: 010] agree better with the baddeleyite angles than
with the angles of the other minerals. The sum total of the
characters undoubtedly identifies the mineral as baddeleyite.

Stanford University, California, September, 1911.

Chemistry and Physics. 57

SCTENDIEPIC INTELLIGENCE.

Il. CHEmistRY AND Puysics.

1. Uranium Hexafluoride.—Since no hexavalent halogen com-
pound of uranium has been previously prepared, the preparation
of the fluoride UF, by Rurr and HEInzELMANN is of considerable
interest. It appears that a supposed previous preparation of this
compound by Ditte was not founded on fact. Three methods
were worked out for the preparation of the compound: 1. The
action of fluorine upon uranium pentachloride ; 2. The action of
anhydrous hydrofluoric acid upon uranium pentachloride ; 3. ‘The
action of fluorine upon metallic uranium or uranium carbide.
According to the first two methods the product consisted of a
mixture of two fluorides, according to the equations

9UC1,+5F, = UF,+UF,+5Cl, and
2UCl,+5H,F, = UF,+ UF,+10HCl.

The higher fluoride, being very volatile, is easily separated from
the other one, but when prepared according to the second method
it was separated only with considerable difficulty from the excess
of anhydrous hydrofluoric acid. The action of pure fluorine
upon metallic uranium gave, as Moissan had shown, a product
consisting chiefly of the tetrafluoride, but it was found that when
a little chlorine was mixed with the fluorine, complete conversion
intu hexafluoride took place. The chlorine appears to act as a
catalytic agent in this case.

Uranium hexafluoride is a very volatile, pale yellowish, crystal-
line solid which boils at 55° C. at atmospheric pressure. Its
melting-point, 69°5° C., lies above its boiling-point, so that a pres-
sure of about two atmospheres is required to melt it. The sub-
stance is extremely reactive ; it is very sensitive toward moisture;
it reacts with hydrogen even when cold ; the chief product of its
reduction appears to be uranium tetrafluoride. Its reaction with
sulphur is particularly interesting, as it seems to give a new gase-
ous fluoride of sulphur.—Zeztschr. anorgan. Chem., \xxii, 63.

H. L. W.

2. The Atomic Weight of LHatra-terrestrial Iron.—Since, as
far as is known, atomic weight determinations have always in the
past been carried out with material of terrestrial origin, it seemed
worth while to Baxrrr and THorvarpson to make such a deter-
mination on an element of meteoric origin. Iron was selected as
the subject of investigation, and for the purpose a piece of a 63 lb.
meteoric iron found in 1903 near Cumpas, Mexico, was used.
After an elaborate series of purification operations, ferrous bro-
mide was prepared and analyzed according to a method that had
been previously employed by the authors in connection with ter-
restrial iron. The results indicated no appreciable difference

58 Scientific Intelligence.

between the atomic weights of the two kinds of iron, for the
average of eight determinations on the meteoric material was
55°832, while the outcome of the results of the other work was
55°838.—Jour. Amer. Chem. Soc., xxxiil, No. 3. H. L. W.

3. The Compounds of Ammonia and Water.—The question of
the existence of the compound NH,OH in solutions of NH, in
water has attracted much attention in the past, but while the
theory of the existence of the hydroxide has been a plausible one,
it has been opposed by several investigators. Smits and Postma
have now shown from freezing-point determinations of mixtures
of NH,and H,O that the compounds NH,.H,O and 2NH.,.H,O,
corresponding to NH,OH and (NH.,),O, certainly exist, and that
these are the only compounds formed. They melt at about
—77° C. and —78° C. respectively, or a little below the melting
point of pure NH., while there are eutectics between the two
compounds and between each of them and a constituent. The
existence of these compounds, although it gives no proof of their
chemical constitution, undoubtedly strengthens the hydroxyl and
oxide theory, for it shows that NH, can be regarded as combin-
ing with water in the same way that an alkali metal does, for
example, to produce KOH and K,O. It may be added that
Ruppert has obtained the same results by freezing-point deter-
minations as those that have been mentioned, but published them
somewhat later.—Zeitschr. anorgan. Chem.,\xxi, 250. H. L. W.

4. The Quantitative Determination of Fluorine as Calcium
Fluoride.—The usual method for carrying out this determina-
tion, following Berzelius, is to precipitate the calcium fluoride
together with calcium carbonate, and, after filtering and igniting
the mixture, to dissolve out the calcium carbonate with dilute
acetic acid and finally collect and weigh the fluoride. Srarck
and THoriIn have made a modification of this method, which con-
sists In precipitating calcium fluoride in the presence of an exactly
known amount of an oxalate in a solution containing about two
cubic centimeters of free acetic acid. The amount of oxalate
should be about the same as that of the fluoride. The precipita-
tion is made in the hot solution by the addition of calcium chlo-
ride solution. The mixture, which filters as well as calcium
oxalate alone, is collected on asbestos, dried at 210°C., and
weighed. By deducting the known amount of calcium oxalate,
the weight of fluoride is found. From the results obtained by
the authors it appears that the method gives very satisfactory
results, and it is evidently a great improvement upon the old
method.—Zeitschr. analyt. Chem., li, 14. H. L. W.

5. The Volumetric Determination of Antimony in Alloys.—
Dr. G. S. Jamrizson of the Sheffield Laboratory has applied
Andrews’ iodate titration to this determination. The alloy, such
as hard lead or solder, is dissolved in concentrated sulphuric acid
by heating to boiling, the residue is treated with a mixture of
equal volumes of strong hydrochloric acid and water, the lead
sulphate is filtered off and washed with hydrochloric of the same

Chemistry and Physics. 59

strength, and the filtrate is titrated directly in a bottle in the
presence of a little chloroform with potassium iodate solution
until the color of iodine, which is produced in the chloroform, at
last disappears. The reaction in the presence of the strong
hydrochloric acid proceeds according to the equation

2SbCl, +K10, +6HCl = 28bCl, + KC1+1Cl +3H,0.

Since tin, copper, and iron do not interfere with the method, it
is convenient in many cases, and it appears to give very accurate
results.—Jour. Indust. and Eng. Chem., ii, No. 4. H. L. W.

6. The Radio-activity of the Dirkheim Mineral Waters.—
Since it had been found by Ebler in an examination of the “ Max-
quelle ” water of Diirkheim that a certain amount of radio-activ-
ity appeared to follow the alkali-metals, and since on this account
it was suspected that a sixth alkali metal with radio-active prop-
erties might exist in this water, EBLER and FELLNER, in connec-
tion with an elaborate investigation of the radio-activity of these
waters and their products, have made a further study of the
question of the presence of a new alkali metal. The result, how-
ever, 1s disappointing from a chemical point of view, for they
found that potassium salts prepared from the water of this spring
showed no more radio-activity than ordinary potassium salts.—
Leitschr. anorg. Chem., \xxii, 233. He LA We |

7. Bulletin of the Bureau of Standards.—The third number
of volume VII, recently issued, opens with a paper by L. W.
AUSTIN, giving in detail the results of Some quantitative experi-
ments in long-distance radiotelegraphy. 'These tests were carried
on two years since under the auspices of the Navy Department
‘between two cruisers and the wireless station at Brant Rock.
Measurements were made up to a distance of one thousand miles,
their chief object being the determination vf the law governing
variations of strength of signal with the distance. The results
arrived at, briefly stated, are as follows :

““(a) Over salt water the electrical waves decrease in intensity
in proportion to the distance as found by Duddell and Taylor. In
addition they are subject to an absorption which varies with the
wave length and which may be expressed mathematically by the

terme “°. The complete expression for the received current
is then
K
ie ee ad,
fucka tl

This is true in general for day transmission, ‘The absorption at
night is entirely irregular, varying from zero to the day value,
but is onan average much less during the winter than in summer.
Variations also appear to occur during the daytime, but these are
probably in general small.

“(6) The received antenna currents between two stations with
salt water between are proportional to the product of the heights
of the sending and receiving antennas and inversely proportional

60 Scientific Intelligence.

to the wave length, provided the antenna resistances remain con-
stant. These experiments were carried on with flat-top antenna
heights of from 30 to 80 feet and wave lengths from approxi-
mately 1500 to 4000 meters.

“(c) Taking account of the influence of antenna height and
wave length, the above equation may be extended and a general
day transmission formula written as follows :

co 7 0:0015d -
S L. le pin V7
Ad

Ip = 4°25

where the currents are given in amperes and all lengths in kilo-
meters. This formula has been tested for sending currents from
7 to 30 amperes, antenna heights 37 to 130 feet, wave lengths
from 300 to 3750 meters, and distances up to 1000 nautical miles.

“In regard to the value of the day absorption it is only possi-
ble to say that the above expression is satisfied within the limits
of error of the observations. It is quite possible that when
observations are made at distances of 2000 to 3000 miles, the
value of.the absorption coefficient will have to be corrected by
10 or even 20 per cent, as this amount of error could exist with-
out discovery at the distances covered in these experiments. It
is also possible that the square-root law relating the absorption
with the wave length is only an approximation.”

The other papers in the same number include one by C. E.
Waters on the behavior of high-boiling mineral oils on heating in
the air; another by J. R. Cain on determination of vanadium in
vanadium and chrome-vanadium steels; by E. Buckingham and
J. H. Dellinger on the constant C, of Planck’s equation for the
intensity of radiation ; by T. T. Fitch and C. J. Huber on Amert-
can voltmeters and ammeters; by P. G. Agnew on the current
transformer ; and by H. S. Carhart on thermodynamics of con-
centration cells.

CircuLaRr No. 24 (pp. 41) gives a summary of the published
work of the Bureau of Standards, which is remarkable in extent,
considering the short time since the Bureau was established.
Seven volumes of the Bulletin have appeared, the first in 1904-5 ;
in all 174 papers are enumerated, some of these now in press ;
these are here classified and their contents briefly indicated. <A
series of thirty-one circulars of the Bureau is also enumerated ;
these give the regulations under which the tests and comparisons
of the Bureau are made, with a general statement as to its work.

8. Annual Tables of Constants and Numerical Data, Chemi-
cal, Physical and Technological.—The first volume of the Annual
Tables of Constants and Numerical Data, Chemical, Physical
and ‘Technological, compiled and published by an international
commission, appointed by the 7th International Congress of
Applied Chemistry (see Science, August 4, 1911, p. 158), is now
open to subscription. Subscription blanks, the terms of sub-
scription and descriptive leaflets may be obtained from any one

Chenustry and Physics. 61

of the three American Commissioners: Dr. G. N. Lewis, the
Massachusetts Institute of Technology, Boston, Mass. ; Professor
G. F. Hull, Dartmouth College, Hanover, N. H., and Professor
J. Stieglitz, the University of Chicago, Chicago, Il]. After Jan.
15th, 1912 the price of the volume is likely to be increased.

9. The Sun; by Cuartes G. ABpBot. Pp. xv, 448; 26 plates,
72 figures. New York, 1911 (D. Appleton & Company).—A nota-
ble work which every student of physics and of astronomy will
find of absorbing interest. It is the first considerable book bear-
ing its title since that of Professor C. A. Young, so usefully and
widely known, published just thirty years earlier ; and it is pleas-
ing to find that its frontispiece, like that of its predecessor, is a
reproduction of 8. P. Langley’s famous drawing of a typical sun-
spot, unfortunately somewhat marred, however, by a partial fill-
ing of the nucleus of the spot. This is to be regretted because too
many contemporary readers will get an inadequate impression of
the merit of the wonderful original drawing.

It is impossible in a brief review to do more than indicate in
the most cursory manner some of the important advances in astro-
physics which are here admirably set forth. The first five chap-
ters cover much the same ground as Young’s treatise, with
amplified and modernized discussion of methods for determining
the radiation of the sun, together with excellent reproductions of
some of the most significant spectroheliograms from the Mt.
Wilson observatory. Of the remaining five chapters, the seventh,
—The sun as the earth’s source of heat—and the tenth—The sun
among the stars—perhaps contain the greater number of modern
additions to knowledge which would interest a philosophical
reader ; but the chapter giving a succinct history of the efforts of
inventors to utilize solar energy is interesting and valuable. The
excellence of the reproductions of recent photographs of nebulz
should not pass unnoted. en Sar.

lo: “Fhystcal Optics ; by Ropnrr W. Woop. Pp. xvi, 705 ; 2
plates, 399 figures. New York, 1911 (The Macmillan Company).—
This is a second and enlarged edition of the work reviewed at
length in this Journal (see vol. xxii, p. 193, 1906). The additions
in this volume are material both in quantity and in importance ;
of these the last chapter, on the principle of relativity, may be
especially named on account of its interest. C. 8. H.

11. Ldumination, its Distribution and Measurement; by
ALEXANDER PeLHam TROTTER. Pp. xvii, 2923; 209 figures. Lon-
don, 1911 (Macmillan & Co.)—The frontispiece is a reproduc-
tion of a portrait by Perroneau of Pierre Bouguer, “the father of
photometry,” to the memory of whom this volume is dedicated.
This book is an expansion of a paper which, on May 10, 1892,
was read before the Institution of Civil Engineers and which was
first published in volume ex of the Proceedings of the Institution.
The paper was subsequently rewritten and it then appeared in
The Iluminating Engineer.

The subject matter is divided into three parts. The first deals
with the primary and derived units of light, with the theory of

62 Scientific Intelligence.

the distribution of illumination, and. with the application of that
theory to the spacing and height of lamps. The second part
describes instruments and methods employed for measuring light
and illumination. The last part gives a few practical examples
of the measurement of ijlumination. The book is intended for
‘practical engineers’, so that graphical methods are employed
throughout, to the exclusion of equations and formule. “The
calculated curves and diagrams have been drawn on a large scale
and most of them are accurate within the thickness of the line.”
The appendix comprises five tables of numbers, useful in photo-
metric calculations, and also an explanation of the ‘‘Refraction
Goniometer.” Then follows a fairly complete bibliography of
the subject of illumination. On the whole, the book is of a very
elementary character. Hue
12. Kometen und Elektronen ; von Aucusto Rieu. Deutsch
von Max Iklé. Pp. 64. Leipzig, 1911 (Akademische Verlags-
gesellschaft M. B. H.).—This is an excellent popular exposition
of the modern theory which attributes the phenomena of comets’
tails to the action of radiation pressure upon the electrons and
ions of which the tail is supposed to be constituted. An interest-
ing feature of the pamphlet is the collection, in the last chapter,
of the results of observations on the earth’s atmosphere during
the passage of the earth through the tail of Halley’s comet.
Though the effects were much less marked than had been expected,
and are perhaps in many cases doubtful, yet there are a number
of observations recorded which are suggestive and interesting.
H. A. B.

Il. Gzrotogy AND MINERALOGY.

1. Publications of the Geological Survey of the United States ;
GEORGE Oris Smitu, Director.—Recent publications of the U.S.
Geological Survey are noted in the following list (continued from
vol. xxxil, pp. 320, 321):

Monocraru.—The Geology of the Lake Superior Region ; by
CHARLES R. Van Hise and CHarues K. Leiru. Pp. 641; 49
plates, 76 figures.

PROFESSIONAL Paper No. 73.—The Tertiary Gravels of the
Sierra Nevada of California; by WatpEmMar LinpGREN. Pp.
226 ; 28 plates, 16 figures.

Minerat ReEsources.—Advance chapters in the production
in 1910 of Platinum and allied metals, of Petroleum, of Magne-
site, of the Stone Industry, ete.

BuLuetins.—No. 466. Retracement of the Boundary Line
between Idaho and Washington from the junction of Snake and
Clearwater Rivers northward to the International Boundary. R.
B. Marsuatt, Chief Geographer. Pp. 39; 7 plates, 1 figure.

No. 467. Geology and Mineral Resources of parts of the
Alaska Peninsula; by Wattace W. Arwoop. Pp. 137; 14
plates, 18 figures.

Geology and Mineralogy. 3 — 68

No. 474. Coals of the State of Washington ; by E. Ecetz-
sToN SmitH. Pp. 206; 8 plates.

No. 478. Geology and Ore Deposits near Lake City, Colorado ;
by Joun D. Irvine and Howranp Bancrorr. Pp. 128; 8
plates, 33 figures.

No. 483. Economic Geology of Richmond, Virginia, and
Vicinity ; by N. H. Darron. Pp. 48 ; 10 plates, 1 figure.

No. 484. The Granites of Connecticut ; by T. Netson Date
and Hrerpert EK. Grecory. Prepared in codperation with the
Geological and Natural History Survey of Connecticut. Pp. 137;
7 plates, 12 figures.

Nos. 486, 487, 488, 489. Results of Spirit Leveling; R. B.
MarsHa.1, Chief Geographer. No. 486. In Colorado, 1896-1910.
Pp. 107, 1 plate. No. 487. In Idaho, 1896-1909. Pp. 46,1
plate. No. 488. In Nevada, 1897-1909. Pp. 28,1 plate. No.
489. In Utah, 1897-1910. Pp. 38, 1 plate.

No. 490. Mineralogical Notes. Series I; by Watpemar T.
SCHALLER. Pp. 109 ; 14 figures.

No. 491. The Data of Geochemistry. Second Edition; by
Frank W. CrarKeE. Pp. 782.

No. 495. Bibliography of North American Geology for 1910,
with subject index ; by Joun M. Nicxizs. Pp. 179.

Water Supply Paprers—No. 239. The quality of the Sur-
face Waters of Illinois; by W. D. Cotiins. Pp. 94 ; 3 plates.

Nos. 261, 269, 271, 272, 288. Surface Water Supply of the United
States, 1909. Prepared under the direction of M. O. Lrieuron.
No. 261, Part Il. North Atlantic Coast; by H. K. Barrows, C.
C. Covert, R. H. Botster. Pp. 309; 5 plates, 1 figure. No.
269. Part IX, Colorado River Basin; by W. B. FrEEmMan
and R. H. Boustrer. Pp. 247; 9 plates, 1 figure. No. 271.
Part XI, California ; by W. B. Crapr and F. F. Hensuaw. Pp.
256; 6 plates, 1 figure. No. 272. Part XII, North Pacific
Coast ; by J. C. Stevens, EH. C. LaRue and F. F. Hensuaw.
Pp. 5213; 8 plates. No. 288. Part VIII, Western Gulf of
Mexico; by W. B. Freeman and J. G. Marusers. Pp. 149;
3 plates, 1 figure.

No. 278. Water Resources of Antelope Valley, California ; by
Harry R. Jounson. Pp. 92; 7 plates, 11 figures.

2. U. 8. Bureau of Mines, Josepa A. Hoimes, Director.—
The work of the Bureau of Mines, established in 1910, has been
carried actively forward. The Bulletins recently issued include
the following:

No. 7. Essential Factors in the Formation of Producer Gas ;
by J. K. Crement, L. H. Apams, and C. N. Haskins. Pp. 58;
16 figures.

No. 8. The Flow of Heat through Furnace Walls ; by W. T.
Ray and Henry Kreisincer. Pp. 32, 19 figures.

No. 12. Apparatus and Methods for the Sampling and Analy-
sis of Furnace Gases ; by J. C. W. Frazer and EK. J. Horrman.
Pp. 122; 6 figures.

64 Seventijic Intelligence.

No. 13. Résumé of Producer-Gas Investigations. Oct. 1, 1904—
June 30, 1910; by R. H. Fernatp and C. D. Smiru. Pp. 393 ;
12 plates, 250 figtires.

No.14. Briquetting Tests of Lignite at Pittsburg, Pa., 1908-9,
with a chapter on Sulphite-Pitch Binder; by Cuarces L. Wricar.
Pp. 64; 11 plates, 4 figures.

No. 15. Physical and Chemical Properties of the Petroleums
of the San Joaquin valley, Cal.; by I. C. Atnpw and W. A.
Jacoss. With a chapter on Analyses of Natural Gas of Southern
California; by G. A. BURRELL.

Several Technical Papers have also been issued, and further the
following Miners’ Circulars: No. 3 on Coal-dust Explosives ; by
G. 8. Ric—; No. 4, on Use and Care of Mine-rescue breathing
Apparatus ; by James W. Paut.

No. 5. Electrical Accidents in Mines; their our and
Treatment ; by H. BH) Crank. ©1911. >

3. Geological Survey of New Jersey. Henry B. Keane
State Geologist. Jron Mines and Mining in New Jersey; by
Witiiam 8. Baytey. Vol. VIL of the Final Report Series of
the State Geologist. Pp. xv, 512 ; 13 plates, 31 figures, 2 pocket
maps. Trenton, N. J., 1910.—A large amount of data relating
to the iron ores of New Jersey, distributed through some forty
volumes of the Annual Reports, have been brought together in
the present volume, which is thus a thorough presentation of all
that is important in regard to the iron-mining industry of the
state. Although the work is essentially a compilation, the thor- °
oughness with which the facts have been assembled will be |
appreciated from the statement that every mine hole has been
revisited and every mine dump carefully examined. As is well
known, the iron ores of New Jersey are chiefly magnetite, which
occurs in the pre-Cambrian rocks of the state. The larger part
of the volume is devoted, consequently, to the general statement
of the occurrences and origin of the magnetite, followed by
detailed facts in regard to individual mines. An account is also
given of the bog ores and of limonite, which in former years
were extensively mined, although of relatively small importance
at the present time. The occurrences of hematite are limited in
number and have never been extensively mined.

4. Geological Survey of Alabama; KucEenr ALLEN SMITH,
State Geologist.—The following Bulletins have recently appeared:

No. 10. Reconnoissance Report on the Fayette Gas Field,
Alabama; by M. J. Munn. Pp. 66; 2 plates, 2 maps. Pre-
pared in cooperation with the U. 8S. Geological Survey.

No. 11. Roads and Road Materials of Alabama; by WiLLi1am
F. Provutry. Pp. 148; 20 plates, 2 figures.

5. The Data of Geochemistry, Second Edition; by FRanK
WIGGLESWORTH CLARKE. Pp. 782 (U.S. Geol. Surv., Bull. 491).
—The first edition of this invaluable work was published in 1908
and noticed in this Journal at that time (see vol. xxv, p. 458).
In its revised and enlarged form it now appears with sixty-six addi-

Geology and’ Mineralogy. 65

tional pages. The labor of the author in thus bringing the vol-
ume up to date will be appreciated by a large number of workers
in science.

6. American Permian Vertebrates ; by Samunn W. Wixt1Is-
Ton. Pp. 145; 39 plates and many text illustrations. University
of Chicago Press, 1911.—In this book Professor Williston brings
together ‘‘a series of monographic studies, together with briefer
notes and descriptions, of new or little-known amphibians and
reptiles from the Permian deposits of Texas and New Mexico.”
He does not think it worth while as yet to “enter extensively
into many suggested morphological and taxonomical discussions.”
We need “ more facts, many more facts, and I have little faith in
any system of classification based upon our present knowledge of
these older land vertebrates.” However, certain morphological
problems are set forth and what the author regards as “ the legiti-
mate conclusions regarding the immediate relationships of the
forms under discussion” are given.

The two wonderful graveyards of Permian vertebrates dis-
covered by Professor Williston in Texas are described under the
captions Cacops Bone-Bed and Craddock Bone-Bed, while some-
thing is also added of the Permian locality of New Mexico.

Many of the animals described in this volume are based on

omplete or nearly complete skeletons, and herein lies the greatest
value of the book. ‘Then, too, all of the illustrations were made
by the author. The orders Temnospondyli, Cotylosauria and
Theromorpha are defined, along with eight of their families and
seventeen species. : C. 8.

7, Analyses of Stone Meteorites; by O. C. Farrineton.
Field Museum of Natural History. Publication 151. Geol.
Series, vol. iii, No. 9, pp. 195-226.—The author a few years
since published a compilation of the analyses of iron meteorites,
and he has now accomplished a similar work for stone meteorites.
Some one hundred and twenty-five analyses are included, and to
them the principles of the Quantitative Classification for terres-
trial rocks, with some necessary modifications, have been care-
fully applied. It is interesting to quote here the general average
arrived at for the composition of stone meteorites, which agrees
pretty closely with that earlier obtained by Merrill.

AVERAGE COMPOSITION OF STONE METEORITES.

PaO) Aiea, Bye nia WSLS at ele Sige ieee tai BONE 39°12
PUNO) 255 Ge20Gs sells Sosceseetl co: 2°62
Jel, (aR RS et edie 0s See meade eden ea °38
AO) amin OW nn eek Se ee Nae ee Se he le AD
UES eA ace aig ah ne dee a 16°13
Si SOL) Maes SLES aC ate. Sn te ee Ra te deg 18
DNHIUG VE OES te il oe Rear ae eee ae a 21
MeO eles. ceie ss beecnrese cess ll. 22°49
RO AO)E bryan apneic Lege oe Mein Ce ke ES 2°31

Am. Jour. Sci.—Fourtu Series, Vou. XXXIII, No. 198.—Janvary, 1912.
5

66 Scientific Intelligence.

Nase er ee a Sh he ie Re 81
REO eh dee i 2 De eee 20
PIO ee ee ss eee eee 20
He forte ber ae NV 11°46
NGS teh ih id fo eee 1715
Cor So Be Noe eS Soe ea eee 05
a ts I a ee ee 1°98
IP hh be hE Ah) Yea 04
P.Oe. ete ee 03
Owe sit tah FOS ee Bie ee eeeeae 06
Ni! Mn, Cu, Sn 2 22.5221 ee 02
WiO) ys. So 02
SnQ eo 2c ee er 02

99°82

The following table also gives the average composition of iron
meteorites compiled from 318 analyses. Further, the proportion

AVERAGE COMPOSITION OF IRON METEORITES.
Bewecec kee ose oS a ee ee es

Nile os Soe es Se A ee eee 8°52
CO ese ed 2 eed ee “59
ge S peel Baten) = (ay Ae ae a
a Py REN cy eee Seer 04
CO? iri Se Lae pete sy ee "08
Ou den2 22S Sees Ce ee 02
Or one Se ee ee Ol

100°23

of elements present in meteorites of both classes has been com-
puted as given below, following out the suggestion of the author
that this may very probably correspond with the proportions of
the elements in the earth as a whole.

PROPORTION OF ELEMENTS IN THE HARTH AS A WHOLE
AS DEDUCED FROM METEORITES.

fron 22 oo fo eee ee 72°06
Oxyoen . 22... 3. 2 ee eee 10°10
Nickel 2... 22 2 oe eee 6°50
Silicon 205380. 2 oe ee "scan Ne et Daa as 5:20
Magnesium... 2.22 eee 3°80
Sulphur 222-23... oe 49
Oaleiums...<. 22, a ee 46
Cobalt. = 22. ee 44
Aluminium «..2° 25 39
podium 2.22. 2.5. Soe ee a 4
Phosphorus .. 2. ou 2. -S2ees ee eee 14
Chromium 2.2... =. 6) eee eee ‘09
Potassium °..-. 23: 3. See eee 04
Carbon ... ss. eee ee 04
Manecanese f° 152 2 ee eee 03
Other elements 4202) 2 eee 05

Geology and Mineralogy. 67

He closes with the following paragraph :

The large proportion of iron in the constitution of the earth
indicated by meteorites is in accord with the earth’s density,
rigidity, and magnetic proportions. Assuming the density of .
the rocks of the earth’s crust to be 2°8, which may be too high,
and combining with it metal of the density of 7°8, which is an
average of the density of iron meteorites, it will be found that
77°58 per cent of metal will be required to obtain a density of
5°57, that of the earth as a whole. This is very nearly that of
the sum of the metals in the above result after eliminating the
proportions present as oxides. Such a proportion of iron would
seem to be in accord, as has been stated, with the earth’s
rigidity and magnetic properties.

8. The Mineralogy of Pennsylvania. Part Two. Chemical
Analyses ; Joun Everman. Pp. 25. Easton, Pa., 1911.—The
first part of these contributions was issued more than twenty
years ago, and was noticed in the Journal at that time (see vol.
XXXVil, 501, 1889). ‘The present part contains chemical analyses
of many species, and also records of new localities. Unfortu-
nately the results of a large number of analyses made were
destroyed by fire sometime since, but those here given are numer-
ous and will be of value to mineralogists.

9. Praktikum der experimentellen Mineralogie ; von Dr.
Ernst SoMMERFELDT. Pp. xi, 192, 61 text figures,1 plate. Ber-
lin, 1911 (Gebriider Borntraeger).—This is a convenient little
book for the student who must instruct himself in practical min-
eralogy. It takes up briefly the successive parts of the subject,
and on the chemical side is much fuller than the elementary
textbooks usually are ; there is, for example, a chapter giving the
fundamental principles underlying the phenomena of fusion and
crystallization of substances under different conditions.

10. Uraninite from German Hast Africa.—The uraninite
locality in the mica quarries of the Uruguru Mts., German East
Africa, has recently afforded, as announced by R. Brauns, a large
cubic crystal weighing 154 grams and measuring 3°5 x 2°5 X 2 cen-
timeters. The specific gravity found was 7:7; that of the pure
nucleus being 8°84 and of the crust 4°82. The locality was first
described by W. Marckwald in 1906.— Centralblatt Min., 1906,
ps 701; 1911, -p: 689.

11. Production of Platinum in 1910.—The increased demand
for platinum in recent years, chiefly caused by its use in jewelry,
and the resulting rise in price reaching $45 per ounce in Septem-
ber, 1911, gives especial interest to the advanced chapter by W.
Lindgren on its production in 1910 from Mineral Resources of the
United States. Unfortunately the increased demand has thus far
brought no considerable increase in quantity. In this country
crude platinum is obtained in small quantities from the placer
mines of California and Oregon. The amount for 1910 was 337
and 53 ounces respectively. The production of crude platinum
in troy ounces for the world at large for 1909 and 1910 is given
in the following table.

68 Scientific Intelligence.

1909 1910
BSBA ee Co et oe ae ae * 264,000, * 275,000
Womwd ar ooo os Soe tt ee beet ee eee * 30 * 30
New South Wales 2.10.4 7200 ee ee eee bees 440) 332
Maite te teh) Pe 2s eee a ee ae ee * 6,000 10,000
United. States, domestic crude <u: . 22. 354- {232 See 672 390
United States, from foreign and domestic matte and

HuihOn 2. a hes oe te ne ee +600; +1,000

Borneo and Sumatra i205 5o6 2 a eee * 500 * 200

272,242) 286,952
= * Estimated. + Refined.

12. Les-Syenites Nepheliniques de l Archipel de Los et leur
Mineraux ; par A. Lacrorx. Nouv. Arch. d. Mus. (5), ii, 1-132,
pl. i-x. 1911.—It is indeed remarkable what a variety of types
of rocks, mineralogical and structural, are afforded by the highly
alkalic magmas. This observation is, in fact, almost trite, since
nearly every few months there occurs some new example of it.
The variety of minerals which may be present seems almost end-
less, and new ones constantly present themselves. These features
are strikingly illustrated in Lacroix’s last work on rocks of
this family. The Los Islands are a group of three small islands
close to the shore of French Guinea on the west coast of Africa.
The existence of nephelite rocks in them was first made known in
1887 by Giirich, and Lacroix himself has published at several
times preliminary notes on material brought from them. The
present work is based on rather full collections made by several
persons, and the information obtained permits the publication of
a preliminary geologic sketch-map.

In addition to types of nephelite-syenites with egirite and with
alkalic amphibole the usual members of this clan are well repre-
sented ; pulaskite, aplites with nephelite, syenites with lovenite,
with hiortdahlite, with hauyn and with sodalite, tinguaites, and
micro-monzonites, micro-essexites, micro-theralites, micro-shon-
kinites, camptonites and monchiquites are among the varieties
present. Of especial interest is an occurrence of lujavrite in the
midst of an area of pegmatite and of tawite (rock composed
essentially of sodalite) recalling those of Greenland and Kola. A
special type of lamprophyre, consisting of phenocrysts of andesine-
labradorite, augite, apatite and titanomagnetite in a groundmass
of andesine laths, biotite, titanite, and a little barkevikite and
augite, which is neither a camptonite nor a kersantite, is called
(not very happily to English ears) topsadlite, from the name of
the cape upon which the dike occurs. The chemical composition
of this is as follows:

Si0., Al.Os, FesOs, FeO, MgO, CaO, Na.O, K20, H20, P20s, TiO,

48°88 20°56 3°34 5°29 3:09 8:34 4°75 2°56 0°32 0°73 1:°69=—99-55
In the quantitative classification this is andose.

Geology and Mineralogy. 69

An interesting new mineral is sodium fluoride, which is called
villiaumite (after Villiaume, the collector of the material), which
occurs as one of the accessory constituents of the nephelite-syenite
in several places in the form of violet or carmine-red grains. It
is thought to be tetragonal ; cleavages good 001 and 100; double
refraction almost wanting, but is negative ; index 1°328, less than
that of water and smallest of known minerals ; hardness 2-2°5 ;
specific gravity 2°8. It has in thick sections pleochroism in the
red variety. Is soluble in water.

The name of Josite is given to a mineral whose properties are
much like those of cancrinite, from which it differs, however, in
several particulars, notably in lesser birefringence (:001-‘012).
Material could not be obtained for chemical investigation.

In addition to those mentioned, other interesting rare minerals
found in these rocks are astrophyllite, rinkite, wohlerite, eudialyte,
catapleiite and pyrochlore.

Lacroix contrasts these rocks with those which constitute the
adjoining coast, and which he describes as hypersthene granites
{charnockite) and norite of the Ivory Coast, and gabbros and
peridotites (wehrlite and dunite) of French Guinea. He finds
that the analyses of the wehrlite and dunite prove them to fall in
unnamed sections of the Quantitative Classification and he pro-
poses for the former the designation kakoulimose (V, 1 (4), 1 (1),
2) and for the latter guinéose (V, 1 (5), 1 (1), 2).

The memoir contains a considerable number of analyses and is
an important addition to our knowledge of the alkalic rocks.
The fine plates show many interesting petrographic details. As
no associated rocks, or strata, are known, the occurrences add
nothing at present to our knowledge of the origin of such rocks,
or to their geological age. D Weeks

13. Potash in the United States.—The efforts being made to
find a supply of potash in this country are detailed in an advance
chapter by Hoyt 8. Garr from the Contributions to Economic
Geology. The work of Gilbert and Russell showed reasonable
ground for the theory that concentrated beds of workable and
commercially valuable salines may exist in the strata underlying
the Great Basin deserts. Accordingly work at Fallon, in northern
Nevada, was begun on October 6; on December 1 the well was
360 feet deep, and it is expected that drilling will be continued
until a depth of at least 1,000 feet is reached. ‘The author adds
that “There is a good possibility that deposits of the Stassfurt
type exist in the United States. Probably the only feasible
method of exploring for such deposits is by drilling. The work
at Fallon is now fairly started but is no more than a beginning on
the project as a whole. It is well that the work should proceed
cautiously at the start, as little is to be gained by hasty or ill-
considered expenditure. Hxperience gained in the preliminary
tests now under way should help to make each succeeding test
more effectual. It is to be hoped that the project already under-
taken will be carried to a satisfactory conclusion, and if this is to

70 Scientific Intelligence.

be accomplished the work will have to be continued beyond the
limits of the present appropriation. .. . The German discovery
was made only after five years’ work in a single shaft, and it
would be hardly reasonable to expect immediate results in this
country.”

III. Muiscettanrous Screntiric INTELLIGENCE.

1. Heredity in Relation to Evolution and Animal Breeding ;
by Wiuiiam E. Castie. Pp. xii, 184, with many illustrations
and diagrams. New York, 1911. (D. Appleton and Company.)
—Ata time like the present, when new discoveries in genetics
are being made with such bewildering rapidity that it is almost
impossible for the layman to realize the significance of the vast
amount of accumulated data, it is important that a popular sum-
mary should be made occasionally, showing exactly what the
actual advance in the science has been. No one in this country
is better fitted by his experience in experimental breeding to
discuss this matter than the author of this attractive little book,
and he has succeeded admirably, with the aid of well-chosen
illustrations and diagrams, in his attempt to present in a manner
intelligible to the general reader the essential principles involved
in the hereditary processes, and their significance in the breeding
and improvement of races of plants and animals. The work is
naturally based upon the applications of Mendel’s law of heredity
to the inheritance and evolution of characters, including the
effects of inbreeding and the inheritance of sex. WwW. RB. C.

2. Animal Intelligence: Experimental Studies ; by Epwarp
L. Tuornpike. Pp. viii, 297. New York, 1911 (The Macmil-
lan Company).—The Publication of Thorndike’s studies on the
Associative Processes in Animals (in the Phychological Review,
1898) may be said to have inaugurated in this country the study
of animal intelligence and behavior by exact experimental meth-
ods. This paper was followed by others on the Instinctive
Reactions of Young Chicks, the Phychology of Fishes, and the
Mental Life of the Monkeys. These studies have been reprinted
in this book, and to them have been added essays on the Laws
and Hypotheses of Behavior and the Evolution of the Human
Intellect. Not only will the collection of these papers and their
publication in accessible form be appreciated by all students of
animal behavior, but the articles are in themselves well adapted
to form the chapters of a book of general interest. Ww. R. C.

3. The Parasitic Amebe of Man; by Cuaruzs F. Crate.
Published with the authority of the’ Surgeon General of the
United States Army. Pp. x, 253; 30 figures. Philadelphia,
1911 (J. B. Lippincott Company). “For a number of years it
has been generally known that some of the more serious human

Miscellaneous Intelligence. (a

diseases, such as certain forms of dysentery, are due to the presence
of parasitic amcebee. This book describes in detail all the kinds
of amcebe found in the human body and discusses the life cycle
and reactions of each species, with emphasis on its distribution
in the body and its relation, if any, to disease. W.3s.) Cs

4. The Inland Lakes of’ Wisconsin: The Dissolved Gases
of the Water and their Biological Significance ; by Epwarp A.
Biree and Cuancry Jupay. Bull. xxii, pp. xx, 259. Wisconsin
Geological and Natural History Survey, 1911.—This book dis-
cusses the distribution of gases in the water of certain lakes, with
the variation at different depths and over a considerable period of
time, and the correlation between the presence of the various gases
and the abundance of organisms. Waid. ©.

5. A Laboratory Guide in Bacteriology ;. by Pau G.
HeInEMAN. 2d ed. Pp. 193. Chicago (The University of
‘Chicago Press).—The book is well suited for an elementary
guide in general bacteriological technic. Its scope is indicated
by the following divisions ; ‘bacteriological technic, general bac-
teriology, impor ‘tant pathogenic bacteria, the bacteriological exam-
ination of water and sewage, of milk and of soil, and yeasts,
moulds, ete. Dee Rs

6. Annual Report of the Board of Regents of the Siith-

sonian Institution, showing the Operations, Hxependitures and
- Condition of the Institution for the Year ending June 30, 1910,
Pp. vii, 688, with numerous illustrations. Washington, 1911.—
The annual volume of the Smithsonian Institution opens with the
report of the Secretary, which was noticed in this Journal at the
time of its advance publication (see vol. xxxi, p. 155). The gen-
eral Appendix which follows (pp. 111-688), in accordance with
the plan followed since 1889, contains a selection of papers cover-
ing a wide range of topics, but all of interest to the general pub-
lic both in matter and in method of presentation. One of these
is a republished paper by Octave Chanute giving a fully illus-
trated account of recent progress in aviation. There are also
papers on the atmosphere of the sun by H. Deslandres; on the
future habitability of the earth by T. C. Chamberlin ; on methods
of testing explosives by C. E. Munroe. In continuation of a
series of earlier papers, F. H. Newell discusses the progress made
in the reclamation of arid lands in the western part of the United
States ; other papers of more or less distinctly original character
are by C. M. Clark on the development of electric power from the
Mississippi River ; on a review of current research in isostasy by
Bailey Willis, and on forest preservation by Henry 8. Graves.

7. Twenty-seventh Annual Report of the Bureau of American
Ethnology to the Secretary of the Smithsonian Institution, 1905—
1906. Pp. 672; 132 figures, one map. Washington, 1911.—This
volume contains the administrative report of the Chief of the
Bureau, W. H. Houimezs (pp. 1-14) and accompanying this (pp.
17-672) an exhaustive monograph on the Omaha tribe of the
Sioux nation. This has been prepared by Miss Atice C.

72 Scientifie Intelligence.

FLetcHer, who, for many years, has been carrying on these
studies under relations which allowed of intimate knowledge of
the Indians and their life. As joint author, a member of the
tribe, Francis La Flesche, has been associated. The ceremonies
and customs of the tribe are given with much fulness, and thus
we gain a representation of the people as they existed during the
earlier part of the last century. The value of the work is much
increased from the fact that it 1s based upon the original material
gathered directly from the natives themselves.

The Bureau has also published the following Bulletins :

No. 44. Indian Languages of Mexico and Central America ;
by Crrus Tuomas assisted by Jonn R. Swanton. Pp. vii, 108,
with Linguistic map of Mexico and Central America.

No. 51. Antiquities of the Mesa Verde National Park: Cliff
Palace ; by Jesse W. Fewxes. Pp. 82; 35 plates, 4 figures.

8. Appleton’s Scientific Primers. Edited by J. Rrynoips
GREEN.—This series of science primers includes the following :
Chemistry by W. A. Titpen ; Biology by R. J. Harvey Gigson;
Botany by J. Reynotps Green; Geology by J. W. Grucory.
These little volumes have been prepared for a reader having no
previous knowledge of the various subjects, and although very
brief and elementary in character, the effort has been to present
the subjects from the modern standpoint. It is suggested that
the Chemistry Primer should be taken up first, to be followed by
that on Biology, and then the more special subjects of Botany
and Geology.

&

OBITUARY.

Sir JosepH Datton Hooker, the eminent English botanist,
died on December 11 in the ninety-fifth year of his age. Born
in.-1817, he accompanied, when only twenty-one, the expedition
of Sir James Ross to the Antarctic as assistant-surgeon on board
the Erebus. In 1847 he traveled extensively in the Himalayas
investigating the flora of the region, and later he made other —
botanical expeditions to the Hast. In 1855 he was made assistant.
director of the Kew Gardens and ten years later he became
Director, succeeding in that position his father, Sir William
Hooker. His contributions to botany, in the development of
the Kew Gardens as well as in the results of his original dis-
coveries and investigations, have given him a rare position in
English science.

Professor GEorGE Davison, for thirty years head of the United
State Coast and Geodetic Survey of the Pacific coast and Pro-
fessor emeritus in the University. of California, died early in
December at the age of eighty-six -years..

Dr. Witi1am SUTHERLAND, well known through his work in
molecular physics, died at Melbourne on October 4 at the age of
fifty-two years. :

Professor GiorGio SpEzia, the Italian geologist, died at Turin
on November 10. :

New Circulars.

84: Eighth Mineral List: A descriptive list of new arrivals,
| rare and showy minerals.

85: Minerals for Sale by Weight: Price list of minerals for
blowpipe and laboratory work.

86: Minerals and Rocks for Working Collections: List of
common minerals and rocks for study specimens; prices

from 1% cents up.

Catalogue 26: Biological Supplies: New illustrated price list
of material for dissection; study and display specimens;
special dissections; models, etc. Szxth edition.

Any or all of the above lists will be sent free on request. We are
constantly acquiring new material and publishing new lists. It pays to
be on our mailing list.

Ward’s Natural Science Establishment

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A Supply-House for Scientific Material.

Founded 1862. Incorporated 1890.
DEPARTMENTS:

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Mineralogy, including also Rocks, Meteorites, etc.
Palaeontology. : Archaeology and Ethnology.
Invertebrates, including Biology, Conchology, ete.
Zoology, including Osteology and Taxidermy.

Human Anatomy, including Craniology, Odontology, ete.
Models, Plaster Casts and Wall-Charts in all departments.

Circulars in any department free on request; address

Wards ‘Natural Science Establishment,
76-104 College Ave., Rochester, New York, U.S. A.

2

CONTENTS.

Arr. I. —Physiography of Newfoundland ; by W. H. Twas
HOPEL . 2 2o2 Sos he Se oe See ee
IL—Hydrocarbon Found in the Diamond and Carbonad
District of Bahia, Brazil ; by J. C. Branner._-. ._-_-

IIJ.—Hydrolysis of Esters 3 Substituted gee Acids ; b
opr wegeee Big Spier cane ya So, ee en ee ie

LMR foo US eee ee a en
VI.—Crescentic Fractures of Glacial Origin ; by F. =
LAHEL ee ee ee
VII.—Heat of Formation of Titanium Dioxide ; by WwW. G.
WHXTER, Oo oe Fe ee

VIII.—Composition of Nephelite ; by N. L. BowEn__..--
IX.—Baddeleyite from Montana ; by A. F. Rogers ...-- 4

SOIENTIFIC INTELLIGENCE.

Chemistry and Physics—Uranium Hexafiuoride, Rurr and HeEINzELu: er
Atomic Weight of Extra-terrestrial Iron, BAXTER and THORVALDSON, 57.—
Compounds “of Ammonia and Water, Smits and Posrma : Quantita :
Determination of Fluorine as Calcium Fluoride, Starck and THOR
Volumetric Determination of Antimony in Alloys, G. S. Jamixzson, 5
Radio-activity of the Dtirkheim Mineral Waters, EBLeR and FELLN
Bulletin of the Bureau of Standards, 59.—Annual Tables of Constants :
Numerical Data, Chemical, Physical and Technological, 60.—The Su
C. G. ABBOT: Physical Optics, R. W. Woop: Illumination, its Distri
tion and Measurement, A. P. TRoTTER, 61.—Kometen und Micka
A. Ricut, 62.

Geology and Mineralogy—Publications of the Geological Survey of
United States, 62.—U. 8S. Bureau of Mines, 63— Geological Survey of Ne ou
Jersey : Geological Survey of Alabama: Data of Geochemistry, F. W.
CLARKE, 64. — American Permian Vertebrates, S. W. Winston :, Anal
of Stone Meteorites, O. C. FARRINGTON, 60. —Mineralogy of Pennsyly
Praktikum der experimentellen Mineralogie, E. SomMERFELDT : Urani
from German East Africa: Production of Platinum in 1910, 67.—Les ©
Syenites Nepheliniques de l’Archipel de Los et leur Mineraux, A. LAcrol ae
68.—Potash in the United States, H. S. Gaur, 69.

Miscellaneous Scientific Intelligence— Heredity in Relation to Evolution
Animal Breeding, W. E. Castte: Animal Intelligence, Experimen
Studies#E, L. THornpIKE: Parasitic Amcebe of Man, C. F, Craia, 70.-
Inland Lakes of Wisconsin: A Laboratory Guide in Bacteriology, PB
HeInEMAN: Annual Report of the Board of Regents of the Smithson
institution : Twenty-seventh Annual Report of ‘the Bureau of Ameri E
Ethnology: Appleton’s Scientific Primers, 71.

Obituary—JOSEPH DALTON HOOKER: GEORGE Davison: WILLIAM SUTH
LAND : GIORGIO SPEZIA. E :

ibra ny, [aoe of eee. ae pee

di
Ye > 58 i

XXXII, FEBRUARY, 1912.

Established by BENJAMIN SILLIMAN in 1818, _ |

THE

‘ a MERIT O A N |
JOURNAL OF SCIENCE.

Epiror: EDWARD S. DANA.

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‘Prorrssors GEORGE L. GOODALE, JOHN TROWBRIDGE,
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. LOUIS V. PIRSSON, HERBERT E. GREGORY
AND HORACE S. UHLER, or New Haven,

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NEW YEAR ANNOUNCEMENT.

I beg to advise my numerous patrons that the past half year
has been an exceptional one for Mineralogists, considering the
number of shipments which I have received from home and
abroad. My stock now consists of some of the choicest speci-
mens of foreign and domestic minerals, a list of which would
more than fill this page several times. J am always in a posi-
tion to supply or procure nearly anything my customers
desire, as my stock consists of the best quality specimens, both
crystallized and massive, polished and ornamental minerals, cut
and rough gems, also a number of Antique Cameos, Carvings,

Mosaics, ete.
In addition to the above I carry a full line of synthetic gems.

Are you acquainted with my plan of sending shipments on
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mf F . .
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THE

AMERICAN JOURNAL OF SCIENCE

[FOURTH SERIES. |]

oe

Art. X.—A Study of Some American Fossil Cycads.— Part
VI.* On the Smaller Flower-Buds of Cycadeordea ; by
G. R. WiELAND.

[Preliminary Notes published by permission of the oe Institution
of Washington. |

iy continuing the studies of silicified cycads begun in 1898
one of the most pleasing results obtained has been the discovery
that some of the large and fine trunks at first thought to bear
rather young fructifications are full grown plants, their flower-
buds being in reality of quite mature pygmic type.

Of these trunks, which evidently fall into several distinct
specific series, the one to which most study has been devoted
is No. 3 of the Yale collections. Originally referred by num-
ber only together with various other Yale cycads and one U.S.
National Museum specimen to Cycadeoidea dacotensis,+ this
handsome columnar trunk or possibly branch is, as it now
proves, in nowise to be confused with younger examples of
that species. Instead it clearly agrees specifically with those
notably beautiful branched trunks figured under the name
Cycadeoidea Marshiana on Plate VI, figures 7 and 9, and on
Plates “UL, WOOL aingl IOs snouts al of my American Fossil
Cycads (Structure).

Conversely, the superb branching trunk figured by Wardt
and signalized as “the type” of Cycadeoidea Marshiana has
not been found to present any real differences from Cycadeoidea

* Parts I-III of these studies of American fossil cycads appeared serially
in this Journal for March—-May, 1899, Part IV in June, 1901, and Part V in
August, 1911: See also December, !904—The Proembryo of the Bennettitez,
February, 1908—Historic Fossil Cycads, and December, 1911—On the
Williamsonian Tribe.

+ Ward, Lester F., Cretaceous formations of the Black Hills. Washington,

1899
ft Loe. cit., Plates CI-CIII.

Am. Jour. Sc1.—Fourta Series, Vou. XX XIII, No. 194.—Frsrvuary, 1912,
6

74 G. R. Wieland—American Fossil Cycads.

dacotensis Macbride. In fact several cylindrical cores drilled
from this latter trunk contain bispor angiate strobili well enough
conserved to make it certain that they have the same structure
as those cut from such typical specimens of Cycadeordea daco-
tensis as Yale trunk No. 214, illustrated at length in my
American Fossil Cyeads (Str uctur e), Plates XXX V-—XLII,
and especially the handsome State University of Lowa flower-
bud shown in the colored frontispiece and on Plate XXXIV.

While likewise, bearing in mind that the present rectifica-
tion is only one of convenience, this same fate of relegation to
Cycadeoidea dacotensis appar ently awaits the fine National
Musen m trunk nominated as “the type and only perfect speci-
men” of Cycadeoidea Minnekahtensis ; for it too is a form
with medium to large-sized fructifications, and of the two
accompanying fragmentary paratypes the fine armor slab num-
bered 24 in the Yale collections and also figured in the original
description® has been studied at length and found to bea @.
dacotensis. Nor can we reconcile either C. colossalis or Wellsii,
the only other species of antecedent description, with the lesser
flowered forms to which we wish to turn our attention.

It thus follows from the material now before us and the
trunks secondarily referred to by Ward in his original descrip-
tions, as well as from the chronologic order of type discussion,
that while ( lycadeordea Marshiana is an unassailably well-
founded species, its actual characters are very different from
those for several years thought to mark it. Instead of being
near to and diflicultly disting uishable from C. dacotensis with
large flowers of eighteen to twenty microsporophylls, C.
Marshiana proves to be a small-flowered type with only
eleven or twelve microsporophylls of distinctly reduced form.
In fact these flowers are, as described below, the smallest of any
in the silicitied series so far found complete. That several of
the trunks of mueb smaller growth with far smaller fronds, like
C. rhombica and the evidently branched C. nana, bore even
smaller flowers, is known from various small fruits and ovulate
cones, but not so far from complete flowers.

These latter, however, appear to be distinct, in consequence
of which C. Marshiana is now based on (1) the trunks men-
tioned above as figured under that name in my American Fos-
sil Cyeads, (2) those illustrated here, (8) certain other Yale
specimens enumerated by Ward,t and (4) the magnificent
quaaruply-branched specimen several years since transterred
from the Yale collections to those of the Paris Museum.
While a further specimen requiring examination in this cen-
nection is the U.S. National oe trunk No. 2 figured by
Ward as the type of C. Colez (loc. cit., Pl. CX).

* Loc. cit.> Pi liaxexayaniite
+ Loe. cit. and in this Journal, Noy. 1900.

Further Notes on Floral Structures. 5

Nor does it, adding yet another word, seem even remotely
probable that any of the earlier named Maryland or European
Cycads agree with or could ever be found to preocecupy C.
Marshiana ; for the Maryland forms appear to be, in agree-
ment with all European forms, distinctly columnar, while
Cycadeoidea marylandica (Font.) Capellini et Solms is most
like Cycadeoidea etrusca Capellini et Solms, the flowers of
which have been briefly restudied by the writer thanks to the
interest of Oapellini.*

It thus transpires that so far as more definitely known the
larger branching specimens from Minnekahta are mainly
included in the huge, large-flowered Cycadeoidea dacotensis,
which probably includes C. colossalis, C. minnekahtensis and
several other species, with C. swperba as a closely related type.
The medium-sized specimens, bearing in mind that it is the
adult fruit-bearing plant that is spoken of, mostly belong to
Cycadeoidea Marshiana ; and following this well represented
type comes, amongst smaller forms of branching trunks, the
interesting C. nana, further to be mentioned below. But a
closer scanning of these various forms need not now be
attempted, the only object of the preceding paragraphs having
been to fairly explain what the true specific names of the
flowers and parent trunks here considered really is.

Though before turning to the description of the flowers of
Cycadeoidea Marshiana, which is thus the main object of this
study, it may, however, conduce to clearness both now and
hereafter to observe that the changes in specific. assignments
which must inevitably follow the closer study of the silicified
cycads can scarcely be regarded as taking away from the net
value of Professor Ward’s earlier determinations and descrip-
tions based on macroscopic characters alone. In 1899 the
writer published his opinion that it was fortunate for scientific
uniformity that Professor Ward had studied the entire Ameri-
can series then known; and this,view still seems just. True
enough, when the trunks of the greater Yale collections assem-
bled by 1902 came to be searched rigorously for the purpos®
of matching isolated parts of trunks, the catalogue list savas
reduced by about forty numbers, it being found that i some
instances parts of one and the same trunk had reached the |
Museum in different collections, sometimes received several
years apart. And it also became evident that the great branch-
ing trunks of the Minnekahta series as thus frequently disso-
ciated in the course of collecting had in considerable part
simply defied accurate assignment on the basis of outer
characters.

But, on the other hand, all subsequent study has indicated
the substantial accuracy of the entire specific alignment first

* See Historic Fossil Cycads, this Journal, Feb. 1908.

76 G. R. Wieland—American Fossil Cycads.

proposed for the unbranched series of trunks from Black
Hawk including: Cycadeoidea Jenneyana, ingens, aspera, for-
mosa, Stilwelli, excelsa, and rhombica ; so that in the end
the somewhat arbitrary use of macroscopic characters has
proven an indispensable convenience. For not only is there
rather more connectedness in the determination of the Ameri-
can series of species than in the nearly equal number of Euro-
pean forms, but these latter are on last analysis quite as
distinctly based on macroscopic diagnoses and even more des-
tined to revision.
* * * + x“ aS ae

The Cycadeoidea Marshiana trunk No. 3 of the Yale col-
lection, as at once appears in figure 1, bears many partly eroded
bract groups irregularly scattered all over the lateral armor
surface, plainly indicating the position of the deeply imbedded
fructifications. And as already noted, attention was first
directed to these rather inconspicuous flowers while searching
for younger fruits of C. dacotensis, it being at the time over-
looked that such even when very young develop a huge pedun-
cular axis as in the examples shown in Plate XX XIX, fig. 1,
and on Plate XLI of the American Fossil Cyecads. <A partly
unexpected result was therefore obtained when the cutting of
sections from core No. II of theseries here illustrated revealed
the presence of the quite full-sized, though apparently not
fully matured complete flower of figures 2and 3. But unluck-
ily the first section, a longitudinal one, did not chance to tra-
verse the floral axis; and it was not until several additional
sections were cut that the peripheral synangia were finally
observed and the position of the small flowers, no larger than a
five centimeter length of a medium-sized lead pencil, accu-
rately located in the core.

It was in consequence much hoped that in the course of the
further study of trunk No. 3, a second bud might be found
with a non-dehiscent disk in good conservation permitting
more perfect sectioning ; for the correct technique of course
requires two initial sections for the exact location of the first
or any other longitudinal section. And the study was carried
on until three additional cores were drilled out, these including
the very large one illustrated in figures 5 and 6, and alone con-
taining four separate strobili. But none of the new cores’
yielded an additional disk, although no less than nine more
axes were found present, making a total of ten fruits studied
in the four cores removed from trunk 3. Only in a single
instance was even a trace of a disk found persistent; in section
722, cut from the fourth and last core, one sees a considerable
mass of broken down disk tissue just above the cone as indi-
cated at S, figure 4. Evidently the disks at times slowly shriv-

Trier Notes on Floral Structures. TE

elled up in their much enclosed position instead of being early
disengaged after pollinial growth. In the eight other axes
growth had continued well beyond the disk dehiscing stage
so evident in figure 2 6; though the basal collar is always dis-

Pied:

Fie. 1. Cycadeoidea Marshiana. x 1/4.

From Minnekahta, South Dakota; Yale Collection No. 3.—View showing
drill holes, and a small cavity at B due to breaking away or non-conserva-
tion of a small branch.

The larger drill hole yielded the core from which was cut the sections of
figures 5 and 6, and the smaller beneath the cavity B the bisporangiate
strobilus of figures 2,3, and 3 A. The arrows, some fourteen in number,
locate various additional bract-enclosed axes, and many others are present.
It appears that most if not all of these fruits belong to a single fertile period,
the fruits being in some preémbryonal stage.

78 G. RB. Wieland—American Fossil Cycads.

tinct, it being held certain that these flowers uniformly bore
disks—were truly bi- or “ amphisporangiate.” In the sections
cut from the largest cone, figure 5, the testal walls are clearly
outlined by zonal conservation and one may plainly see the
more or less collapsed nucellar sacks in the seed interiors.
Notwithstanding this well advanced ovulate growth of the
great majority of the axes of trunk 3, it still seems probable
that amongst the numerous remaining bract groups, various of

ro)
which are indicated by the arrows of figure 1, a few may still

Fic. 2A.

T. 3.11.5 728, x3

L. S. 713+ 7i4

Fie. 2. Cycadeoidea Marshiana. [A x 2°5. B x 1°5.]

A. Longitudinal section through ovulate cone, fruit No. 3 of Yale trunk
No. 3. As the section finally passes out a little to one side of the strobilar
axis the terminal brush does not appear. At S remnant of disk collar.
Compare with figure 7.

B. Longitudinal section of bisporangiate strobilus of Yale trunk No. 3,
composed from two nearly tandem sections, Nos. 715 and 714. The disk has
either wilted loose prematurely or is on the point of dehiscence, having left
at S precisely the sane remnant of the campanular insertion as at Sin A.

The microsporophyll rachides with short pinnules appear in solid black,
but the decurved rachidal tips do not traverse the central axis, the section
being slightly tangential, as may-be exactly noted in figure 34 of the trans-
verse section 761. Compare by number or letter the complementary trans-
verse sections as illustrated in figure 3.

enclose complete flowers. But in view of the results recited
further search was abandoned and the parts of core No. II

Pager Notes on Floral Structures. va!)

were cemented together again in their natural place for the
completion of the oriented sections showing the structure of

the entire flower bud, as now to be described.

Fie. 3.

— Sy
Gas MY N SS! BARS SSS S SS
Lo ~ N= — PN SSaTrsy
— ~ SS BSS >
NS ~ Te S> Te

BYP IZ YNN SSS =) Anny ¢
E \ SS = Z ZI. SQV SS

yy

yy
Ged

Z
a
=

A
¢

S
if

Y
1
Hh
ly
MY
iy
Ge
™
—

4
LY,

G:

ve
DE pis
ye

Ws.

y

y

a
SS
SX
Led
.

Ze
eS
im
)
a=,
<———-

ES
re
= Zs

—-=

yi

WS \ WY
WG Ce \ Wt
LW \ ‘ ih

) Wyn N TN \ KK Qn mh if Da
) ) Fe SAN QRS A
NN YI. NY RASS {
HANG eae A Sas
} IW ‘

\

)

y /
hy ) Mi J
Seth AGAIN)
NY

>a S DZ a}

=

Of 1.3.8. 728-1C

Fie. 8. Oycadeoidea Marshiana.

The series of transverse sections cut from the bisporangiate flower bud
No. 2 of Yale trunk No. 3. The exact level of each is indicated by letter
(B, C, a, 6, ec), and by section number in the longitudinal view, figure 2 B.

Observe that the upper figures are more enlarged than the lower ones. At
f are the fronds, and 0b’ shows the line where the bract ramentum rests in
that of a leaf base.—UI and ll’ mark the trial saw cuts spoken of in the text.

Note that the lower section ¢ (S. 717) traverses the level of disk dehiscence,
while in the two succeeding sections 6 and a the disk collar is continuous.
Between these two sections b and a the ovulate axis finally terminates, and
between a and C (No. 728) disk division into the fronds f, f occurs.—Con-
tinue to figure3 A. For exact size compare with figure 2. B.—Cf. continua-

tion fig. 3A.

80 G. R. Wieland—American Fossil Cycads.

THE Flower or Cycadeoidea Marshiana.

I. Yale trunk No. 3.—Figures 2, 3, ete.

The orientation of the series of sections of the sole complete
flower obtained from trunk 8 will at once be apparent on
inspection of the figures. And it will doubtless be granted
that the lesser difficulty of limitation to this single example is
more than compensated for by the resultant fixing of the period
of disk dehiscence at a given immature stage of ovulate growth,
even more accurately than in Cycadeoidea dacotensis. More-
over the series taken as a whole is nearly enough ideal to dis-
play the floral features with precision; while the traversal of
transverse sections 717, 726 and 725 by trial saw-cuts and the
necessity of using approximately tandem sections for the longi-
tudinal view figure 26 has in nowise taken away from Mr.
Barkentin’s figures. These have all that excellence lent alone
by the study of serial sections by both author and artist with
free use of photographs and joint verification of every detail.

High oA

C3ULA)S 761
Fie. 3A. Cycadeoidea Marshiana. Section 761, Yale trunk No. 3. x 10.

Supplementary figure in continuation of transverse series shown in figure
5d. The section traverses the microsporophylls at a point just beneath the
down-curving of the rachidal apices, the grouping of which plainly appears
at the center of the figure.

In this camera lucida drawing by the writer the ornate sculpturing of the
sporophylls, and especially the grouping and attachment of the synangia
plainly appear.

The longitudinal section 714, figure 2B, stands at right angles to the base
line of the present section, and cross reference to the several figures shows
the location of all the sections.

The silicification of the armor of trunk No. 3 does not
extend to the clear indication of the finer tissues of the
enclosed flowers, although all larger tissue zones and features
are clearly stained and outlined. So that in the bisporangiate
bud one clearly sees the main anatomical details, the peduncle
with its wood zones, the course at least of the bundles given
off, the bracts enveloped deeply in hairy ramentum, the out-
lines of the disk and component fronds with the position of
the disk and rachidal bundles (figure 3A, section 761), the pin-

Further Notes on Floral Structures. 81

nules and attached synangia with quite well-marked traces of
wall structure, and finally the central ovulate cone with its
large pithy axis bearing the young zone of seed stems and
interseminal scales. And we can also see traces of the sporan
gia, either a young condition being indicated, or pollen shed-

Fie. 4.

ob

\\
i We { y
sa) Wig

WZ

SS =
Cr

CSAS
~N RG
BN li
\\ \

A
YZ

SSS Se

|

=f

=——
—————————————

Fie. 4. Cycadeoidea Marshiana.

Longitudinal and serial transverse sections through core in which are
embedded two adjacent ovulate cones. x38/2nearly. The secant lines in
sections 723-725 indicate the position of the longitudinal section 722. In
the latter the position of the foregoing transverse sections is indicated. At
§ in 722 there is a mass of tissue left by the breaking down of a disk.

82 G. R. Wieland—American Fossil Cycads.

7
IOS
A SSS

SSS

Fic. 5. Cycadeoidea Marshiana.

Two transverse sections in series with those of the succeeding figure 6.
All five were cut from the core 7 centimeters in diameter drilled from the
larger drill hole noted in figure 1.

The lower section is drawn from a polished surface. It traverses four
peduncles, and is slightly oblique to their axes the upper of which is cut
from 12 to 18™™ more proximally than the lower. Continue to figure 6.

Further Notes on Floral Structures. 83

\
SV) JSS
YSN

if lf KG

SSS eS
[I SSQTHA
Y) Ve
> >
SS

4) \ =>
nn =<
pee
poe

Y

LB

YZ
NS ZH
DIEZANN

Teo ieee
Fie. 6. Oycadeoidea Marshiana.

Three sections in series with those of figure 5. The upper transverse sec-
tion No. 756 passes at a distance of 8 to 12™™ above S. 757, figure 5; and
the two lower longitudinal sections 726 and 7 lie between S. 757 and S. 756
at exactly right angles to each other as marked. Hach of these sections
traverses the basal part of an ovulate strobilus in which the young seeds
are fairly distinct, and may even approach full size ; though fertilization is
not thought to have occurred.—S. No. 706 and the preceding SS. of fig. 5
are shown x 7/8, and SS. 726, 7 are x 2 nearly.

84 G. R. Wieland—American Fossil Cycads.

ding and sporangial collapse having occurred. The seeds show
but little structure, being distinctly younger than those of fig-
ure 6, already mentioned as showing testal zones and distinet
nucellar sacks.

Cell walls are however generally obscure: one cannot make
out the bract structure; and similarly the disk and rachidegs,
though very clearly outlined, appear only as an indistinctly
granular groundmass traversed by lighter colored traces of the
bundles, fortunately continuous enough to show the pattern
of the bundle system. But even so the assemblage of fairly
well-conserved features taken together with the entire outline
of all organs affords a clear view of the form and general
structure of the flower.

On noting that seven rachides are to be seen in sections 726
and 728, and then comparing the series of decurved apices in
section 761, figure 3a, it becomes evident that the disk divides
into twelve small microsporophylls as in the young and quite
small flower of Cycadella wyomingensis (American Fossil
Cycads, figure 93 [) and the very large flowered C. engens of
the columnar series, instead of dividing imto seventeen or
eighteen large staminate fronds as in C. ducotensis and various
of the Wellzamsonia staminate disks or flowers. The point at
which the campanula splits into the separate fronds is accu-
rately located between sections 715 and 728, figure 3, at a
hight of about a centimeter above the apex of the ovulate cone,
which is not a precisely fixable point because ending as a long
thin brush of sterile organs at last almost hair-like.

The length of the microsporophylls can only be estimated
within fairly close limits because of the destruction of the
mid-region of the bud summit by erosion; but estimating this
loss at about one centimeter and adding for the decurved tips
1:5 centimeters, the full length of the microsporophylls appears
to have been about 5:5 centimeters. Whence after allowing
for the diameter*of the ovulate cone, the flower as imagined
in an arbitrarily expanded form would have a diameter of ten
or twelve centimeters.

The rachis and pinnules, as one readily sees in the longitu-
dinal section fig. 26 and the transverse section fig. 3A, are
much moulded and furrowed by appression faces or even crin-
kled, but withal in a manner producing ornate patterns where
these organs are cut to advantage in regular-series. The pin-
nules are broad of base and must tend to confluence with each
other. They are a centimeter long in the mid-rachidal region
and diminish much in length towards both base and apex of
the frond; so that each frond if laid out flat would have a
more or less elongate-elliptical acuminately tipped, pinnately
parted to pinnately divided form.

Further Notes on Floral Structures. 85

The synangia are well enough advanced in growth to outline
themselves distinctly, being in reality better conserved than
one might expect from the condition of some of the other tis-
sues. But the individual sporangia cannot be clearly made
out, and no distinct pollen appears. Inasmuch, therefore, as
the synangia have only from half to two-thirds.the size seen in
C. dacotensis buds, in which the size agrees with that of Marat-
tiaceous synangial types, either a somewhat young stage of
growth is indicated, or as is more likely, an incompletely devel-
oped stage due to some failure in floral growth such as would
readily have been produced by events leading up to fossil-
ization.

WiC 4.
A. B

LZ
ZA
SS

LEFF x25,

T3.8. 756.

:

4.
Fic. 7. Oycadeoidea Marshiana. Yale trunk No. 38.

S. 756. Ramentum in transverse section,—study suggested for use in
determining species. The area shown includes the line f f separating the
larger leaf-base ramenta from the small bract ramenta. In both cases the
hairs are characteristically one cell thick, except that occasionally the leaf-
base ramental scales are thicker. [Compare with Bennettites Gibsonianus. |

8.780. Transverse section through core containing two ovulate cones
which have shed their staminate disks. The section traverses the outer
armor, and cuts through the ovulate cone of the upper axis, but passes above
that of the lower. At 1 is the saw cut for the longitudinal section 728 shown
in figure 2. A, q.v. Natural size.

On the other hand, the possibility that the synangia lke the
flowers were of small size, and the pollen all shed, should not
be lost sight of ; and as bearing on this point the supplement-
ary section No. 717 was cut in order to better bring out the fact
that the disk bears the same appearance of wilting and dehis-
cing just above the insertion as in C. dacotensis buds, where an
approach to floral maturity 1s seemingly indicated.

But in neither case is it necessary to assume that the stam-
inate frond was normally of much larger size than here seen ;
while the ovulate zone is already notably older than in the
C. dacotensis buds, it even being possible that the mature stro-
bilus of trunk 38 did not reach a markedly greater size than in

86 G. R. Wieland—American Fossil Cycads.

the largest of the ten axes so far studied. (Cf. fig. 6.)\—A fairly
well grown or mature C. dacotensis cone is shown in my Amer-
ican Fossil Cycads, p. 67, under the name C. Marshiana, and
on the opposite page 66, under the latter name, a form that
belongs to some third species not yet satisfactorily determined.
Cone species and the later growth of cones is, however, a long
and difficult subject which cannot be taken up in connection
with discussion of the partly uncertain growth stage of the
flower before us.

II. Flower-Buds of Yale Specimen No. 164.—Figures 8, 9.

This superb silicitied cyead was made the subject of special
description with reference to branching in my American Fossil

Fic. 8.

Fic. 8. Cycadeoidea Marshiana. Yale trunk No. 129.

Exceptionally handsome trunk with fruits small and young, but of the
same type as those of figure 9. Minnekahta, South Dakota.

Cycads (structure), pages 41-43, and illustrated in relief on
Plates VII and VIII. Here too, small fruits were supposed
to be young until several thin sections showed the presence of
mature flowers adjudged to be of the same species as those of
trunk No. 3, although sections of the ovulate cones yet require
to be cut,—this task not being relatively urgent since no change
of name is involved in the specific reference of this cycad here
and earlier made. —

Further Notes on Floral Structures. 87

The first section cut is that of fig. 9A, showing distinct
agreement of the staminate disk with the corresponding trans-
verse section from the flower of trunk 3 seen in figure 3, section
728, and in figure 3 6. And the meaning of the section was
further confirmed by a rigid search all over the surface of the
trunk, taken point by point, resulting in the detection of a
single additional example, clear of outline but previously over-
looked. This flower has not been cut from the trunk, where
it appears just as shown in figure 9 B. The synangia are
apparently larger than in trunk 3, which is realiy yet another
reason for supposing the flower of that trunk to be not quite
fully grown. But caution in judging without thin sections is
required, here or in the case of any flower or strobilus,—more

| Migeeg)y
A B

Fie. 9. Cycadeoidea Marshiana,

Two bisporangiate flower buds from trunk 164 of the Yale Collection. (For
figures of this trunk see American Fossil Cyeads, Plate VIII et seq.)

(A) Transverse thin section through the summit of a flower with nine
microsporophylls. The section passes at some distance above the ovulate
cone, and no decurved tips of microsporophylls appear at the center. En-
larged about twice.

(B) Drawing of a portion of the surface of branch (C, Plate VIII, Amer.
Fos. Cycads) showing partly eroded flower bud. The mass of synangia and
pittings corresponding to the rachides of eleven microsporophylls plainly
appear. Shown in natural size.

especially where but a few axes are studied. The number of
disk divisions is clearly eleven ; so that while the study of this
form still rests mainly on macroscopic features, there is little
doubt as to its identity.

_ Probable Habitus of Cycadeoidea nana of Ward.
Figure 10.
The subject of small cyead flowers and the branching habit
is further illustrated by the quintuply-branched trunk of fig.

10, consisting in a central stem, two large basal and two lesser
lateral branches. This exceedingly interesting specimen was

88 G. f. Wieland—American Fossil Cycads.

collected by the writer himself while engaged in private explo-
ration carried on in the Black Hills region throughout the
summer of 1902. It was found after some days of patient
search at the well known Minnekahta locality, supposedly ex-
hausted by previous collecting. The specimen has an added
interest and importance as one of the few trunks found in place.
It lay on its side imbedded in a characteristic stratum of stra-
ticulate clayey sandstone, and only a few square inches of the
upper face of the main stem could be seen.

Had this handsome and finely conserved specimen been
eroded ont like most American and the Italian Cycadeoideas,
the basal branches, which were already fractured across their

Fie. 10.

Fic. 10. Cycadeoidea nana. x 1/6.

The main central stem gives rise to the two low-set branches I and IIT,
and the smaller lateral branches III and IV. That numbered IV is the
smallest and fails of the good preservation seen in the others. —Near the
Roman numeral IV is located the ovulate fruit mentioned in the text.—
[Minnekahta, 8. D., Author’s Collection. |

junction with the main stem, would have become separated,
and probably could never have been brought into their natural
position. It is thus by good fortune that the trunk adds
precious testimony to our knowledge of the branching types.
Moreover, had one of the basal branches been found sepa-
rated it would in all likelihood have been referred to the species
C. nana,* hitherto with some reservation regarded as an un-

* See Ward, loc. cit., pls. elvi, elvii.

Further Notes on Floral Structures. 89

branched cycad. To this species therefore the trunk should be
provisionally assioned. Although a rather young form, several
fruits are present, and an ovulate strobilus one centimeter in
diameter and about two in length has, m strong contrast to the
C. Marshiana strobili figured above, the same flatly convex
type of parenchymatous “cushion as C. Wielandi. Wheuce it
follows that C. dacotensis with the allied C. superba, C. Marsh-
zana, and C. nana, include a clear succession of forms passing
from. the largest of compactly branched cyecads to lesser and
finally small-sized and small-flowered, more freely branched
trunks.

The floral indices of this series are therefore distinct ;
C. dacotensis having a larger disk of seventeen or more fronds
and C. Marshiana a much smaller flower with eleven or twelve
fronds, while in C. nana the disk is unknown but the ovulate
cone varies from that of both the foregoing species in its con-
vex instead of elongate parenchymatous cushion. And as will
be illustrated in subsequent studies already fairly complete,
this same transition from the elongate primitive type of stro-
bilar axis to a convex or nearly flat parenchymatous cushion is
as strikingly illustrated by the strictly columnar species of the
Black Hawk lecalities. There too, an elongate axis is present
in the fruits of the great C. engens and the tall C. Jenneyana,
while the fine columnar trunk C. excelsa bears the largest cones
with the shortened or reduced axis or cushion uve yet seen.

% % * x % s

A few of the suggestions arising from the present study of
small cyead flowers in connection with the trunks that bear them
may well be given a tentative record here.

Much stress has been laid in my American Fossil Cycads on
the process of branch formation with increased flower output,
in view of which Cycadeoidea Marshiana and C. nana have
much interest asnow shown to typify the extreme of branch devel-
opment and floral reduction in the Cycadeordew. But it is not
necessary to assume this family to be a direct derivative of
simple stemmed types; its immediate ancestry may have had
freely branched forms with much slenderer stems. Even with-
out considering Cordaites it is obvious that free branching of
gymnosperms and reduction of floral organs are very ancient.

it is then among the Williamsonian tribe that the search for
types of branch development and floral reduction must be con-
tinued. Nor can the role of the threefold process of branching,
sporophyll reduction, and acquisition of the angiospermous
emplacement in older eycadophytans have been a meaningless
one. This course of change must have been in evidence by
Permian time, while Wielandiella with wholly reduced sta-

Am. Jour. Sci.—FourtH SERIES, VoL. XX XIII, No. 194.—Frxsrvuary, 1912.
7

90

G. R. Wieland—American Fossil Cycads.

mens shows it to have been far advanced in the Trias. It
indeed suggests an evolutionary process that may well have
been the most significant of all that went on amongst the plants

of the early Mesozoic forests.

Even in the Cy a side line reduction of flowers from

Fic. 11. Cycadeoidea turrita.

eee

Mature seed containing em-
bryo cut in nearly the true
median plane showing the mi-
cropylar tube of three layers,
a heavy inner palisaded, a thin
middle, and a lighter outer pal-
isaded layer,—the tube interior
being filled with a soft tissue.
Two of the five to six wings of
the ‘‘ blow off” appear. These
are the smallest mature seeds
of Cycadeoidea so far known.

was obvious.

primitive crowns had proceeded
well beyond the mere limits of
floral size in the Angiosperms,
and the conviction grows that
such changes were the identical
ones responsible for the advent
of these now dominant plants.
Twelve years ago this seemed
the first probability. To-day it
is a theory undergoing demon-
stration, whether we regard the
Angiosperms as monophyletic or,
as seems vastly more reasonable
in the light of the once dominant
eycadophytan plexus, polyphyletie.
Cosmopolitan and plastic races,
already ancient of lineage, are
better conceived of as moving
forward: en masse with little loss
in diversity of features.
Regarding the general outlines
of such an evolutionary course,
fair inferences were possible with
Cycadeoidea alone well known.
That this type had an ancestry in
which spiral insertion of leafy fer-
tile organs on a main axis was as
distinct as in the female Cycas
And that these
organs were of strictly Cycadalean
nature appeared likewise evident
before the restoration of Wed-
trichia, equally balanced in its
characters between Cycadaceans
and Cycadeoideans, or perchance
even representing one of those
long occulted Medullosans. But
with thisform before us we know,
in fine, that the more or less dis-
tinctly monaxial insertion of fer-
tile organs was long retained, that

the whorl of stamens with disk growth early appeared, and
that concomitant floral reduction ue branch formation were

at least in part late.

Further Notes on Floral Structures. ae

Weltrichia, as an early member of the Williamsonian tribe,
of which the habitus is now so fortunately known, Cycadeotdea,
and Wielandiella thus stand in reciprocal relationship. The
first is simple, primitive, cycadean, but fairly started on the
course of change leading towards angiospermous floral types.
The second has by reason of silicification added most to our
knowledge, but its xerophytic, stereotyped features have long
obscured our conception of how truly generalized the eycado-
phytans really are in stem leaf and fruit. While the third with
its slender freely dichotomized branches and laminar leaves, in
reality but little removed from any pinnately net-veined type,
has all but completed the process of microsporophyll reduction.

More or less in contrast to this staminate reduction, the com-
plexly organized Cycadophytan seeds are uniformly ancient of
type. In their coats are best seen Cycadofilicalean or Pterido-
spermous features that add not a little in gaining ideas of race
relationship ; although at the same time both style and stig-
matic surface begin to appear as structures of secondary origin
and function. It is in the seeds that but recently the distinct
resemblances to Gnetum have been noted that may go to indi-
cate this as some long persistent non-plastic form that origi-
nated when the great races preceding the Angiosperms began
to convert Paleozoic structures to Mesozoic needs.

And similarly the hiatus between flower and inflorescence,
once held all but impassable, may be but slight if Zwmbou
proves to be another such a laterally related but even older and
more stereotyped line; it being quite conceivable that con-
tinued reduction of lateral branches bearing, like those of
Cycadeoidea, flowers derived from strobilar crowns, could
finally give rise to Tumboan and other types of inflorescence.

92 Smith—The Occurrence of Coral Reefs

Art. XI.— The -Occurrence of Coral Reefs in the Triassic

of North America ;* by James Perrin Smiru.

THE occurrence, in the strata of past ages, of reef-building
corals of modern groups gives us our best record of climatic
conditions in those times. The modern reef-builders are now
confined to the tropics, and it is only reasonable to assume that
they have always been confined to regions where the waters
had a tropical temperature.

No corals of any sort are known as yet in the Lower Triassic,
anywhere in the world, although the Hexacoralla must have
lived somewhere during that time, since they are known before
and after it. In the Middle Triassic of the Alpine province
reet-building corals occur, but are not abundant enough to
form reefs. They are not yet described from any other region.
Towards the end of the Upper Triassic reef-building corals
became abundant in the Alps, where they have long been
known, and where they formed genuine reefs that had an
important influence on the topography. There they extend up
to latitude 45° N., showing that in this epoch the Alpine
province enjoyed a warm climate. The chief coral zone of
the Alpine province occurs in the Noric epoch of the Upper
Triassic, not far above the rich ammonite limestone of the
Karnice epoch. The occurrence of this same coral fauna, in the
same stratigraphic position, in localities far removed from the
Mediterranean Region would be ample proof that the favor-
able conditions were widely distributed over the earth in this
epoch. This would also tend to show the probability of the
amelioration of the general temperature, at least over the
northern hemisphere, during this epoch.

Reef-building corals have been found in the Himalayas in
India in the Noric beds, but are not yet described; their evi-
dence as to physical conditions is just as positive, even though
we do not yet know by what names they should be called.

In his studies of Triassic stratigraphy in northern California
the writer was long ago impressed by the fact that the lime-
stone there resembles coral rock, and fragments were found
that suggested remains of corals. Several years ago this was
confirmed by the discovery of abundant corals in many places
on the limestone ridge between Squaw Creek and Pitt River,
and on Cow Creek south of Pitt River. The general section
of the Triassic of Shasta County is given below, to show the
position of the coral zone.

In the section given above, the thickness of the beds is only
approximate, varying from the maximum near the junction of
* Published with permission of the Director of the U. S. Geological Survey.

in the Triassic of North America. 93
Triassic Section of Shasta County, California.
Thickness
48
©’s| Black slates, with Pseudomonotis subcireularis. ? 800 ft.
(Ooh
2 Spiriferina beds, hard siliceous limestone, full of
5 brachiopods.
4 PAR MERAGG IE TE Sr 100 ft.
Coral zone, with numerous reefs, of Astreidz, .
e Tsastrea, Stephanocenia, Astrocenia, Tham-
q nastrea, and Thecosmilia.
Bo | S ceri Sa
2 4 3 Juvavites beds, hard limestone, with abundant
s 5 Ss ammonites, Juvavites, Gonionotites, Disco- | 50 ¢4
a mo lees phyllites, Tropites Telleri, T. laestrigonus, :
D Shue ete .
® hd =) .
a 3 |ge
P 2 N 2| Trachyceras beds, shaly limestone, with Trop-
i Atlee: Ss ites subbullatus, T. torquillus, T. Diller, 50 ft
a S Discotropites sandlingensis, Paratropites, r
4 B Trachyceras Lecontei, T. shastense, ete.
Halobia superba shales, calcareous shales, full of 100 ft
Halobia superba, and a few crushed Trachyceras. F
Halobia rugosa slates, black argillites, with Halo- | , 150 ft
bia rugosa, and crushed Trachyceras. 3 Z
Unconformity ?
© | :
= BS +2 8 Black siliceous shales, altered tuffs, and igneous
SO 8 / 9's aS rocks, with Ceratites conf. humboldtensis, |? 1900 ft.
=a a 2) Ptychites, ete.
Unconformity
Rn Sa | Ae .
5 Nosoni tzffs and shaly limestones, with Fusulina
i 2 elongata, etc.
fora
ol, (S|
pS McCloud limestone, with Fusulina robusta, F.
& cylindrica, ete.
1

Squaw Creek and Pitt River, to less than half so much on the
North Fork, 15 miles to the north, where the limestone

almost disappears entirely.

The Tropites subbullatus beds are divided into two zones, each
about fifty feet thick. In the lower are numerous Tvopites
subbullatus, T. torquillus, T. Dilleri, T. Morloti, T. fuso-
bullatus, Discotropites sandlingensis, Trachyceras Leconte?,
T. shastense, Arcestes pacificus, Clionites, Halobia superba,
and many undescribed species of Zropites, Trachyceras, ete.

In the higher division, the /uwvavites or Atractites beds are

94 Smith—The Occurrence of Coral Reefs

many, Jwvavites subinterruptus, J. subintermittens, J. Ldgar,
Tropites laestrigonus, T. Telleri, Homerites semiglobosus,
Discotropites Theron, D. Laurae, Pinacoceras rex, Marga-
rites senilis, Gonionotites, Metasibirites, Choristoceras, and
many other species, new and old, Tropites of the group of 7.
Telleri, Discotropites, of the group of 7. Laurae, Atractites
and Dictyoconites.

A tew feet above the highest /wvavites beds lies the coral
zone with reefs made up chiefiy of Astraeidae, [sastraea pro-
Sunda, Phyllocoenra cf. decussata, Monthivaulica ct. Mojsvari,
Thecosmilia ct. fenestrata, Stephanocoenia cf. juvavica,
Thamnastraea cf. rectilamellosa Spongiomorpha cf. ramosa,
ete.

This coral zone was found from near Pitt River, east of
DeLamar, northward to the North Fork, always in the same
horizon, between the Z7opztes limestones and the Pseudo-
monotis shales.

A few miles south of Pitt River, near the junction of Cedar
Creek with Little Cow Creek, the Hosselkas limestone out-
crops again, and the coral zone is here well developed. The
thickness is not so great as north of Pitt River, being reduced
to not much more than one hundred feet, the Zropites beds
having almost disappeared. Here the writer found in the
coral zone banks or reefs of Zhecosmilia ct. fenestrata, [sas-
traea profunda Reuss, Stephanocoenia ct. guvavica, Latumean-
dra cf. eucystes, and Thamnastraea cf. rectilamellosa.

At this locality, as on Squaw Creek, the coral zone lies well
up in the Hosselkus limestone, and below the Pseudomonotis
shales.

In the Blue Mountains of northeastern Oregon, m Baker
County, at Martin’s bridge, near the junction of Paddy Creek
with Eagle River, the writer discovered in 1908 a small coral
reef in the Upper Triassic limestones, of which a section is
given below. j

It will be noted that this section is entirely different, in the
lithologic sequence, from that of Shasta County, California.
Nothing lower than the Halobia shales was found, and the
writer could not determine just what part corresponded to the
Hosselkus limestone, since the Zvopites beds were not exposed,
if they are present in that region. Nor could the Pseudo-
monotis shales be found above the coral zone, probably being
represented by the barren limestone. The lower shales, with
Halobia ct. superba, were also found at the junction of the
two forks of Eagle ‘River, at Anthony’s hydraulic mine, but
there the limestones that should contain the coral reef are
crystalline, and the fossils destroyed. Massive limestone is
abundant on the North Fork of Eagle River, but they are
everywhere changed to marble.

in the Triassic of North America. 95

Section on Eagle River, Baker County, Oregon,
Thickness

Massive limestone without visible fossils. 60 ft.

Dark brown argillaceous shales, with Halobia cf. austriaca, |1Qq f
and other species of Halobia, and Daonella ? ;

5 Thin bedded limestone, with banks of corals, Thecosmilia

a norica Frech, Spongiomorpha cf. acyclica Frech, Mont- AQ ft

= livaultia norica Frech, Heterastridium conglobatum :

a Reuss.

(cd)

=

= Barren shales. 500 ft.
Massive limestone without fossils. 100 ft.

Caleareous shales, with Halobia cf. superba, H. cf. salina- | 30 ft.
rum, H. cf. austriaca, Dittmarites sp. ? etc. visible

Some years ago Mr. H. W. Turner discovered some corals
in limestone in Dunlop Canyon, Pilot Mountain, near Mina,
Esmeralda County, Nevada. These were sent to the writer,
who pronounced them Jurassic, as reported by J. E. Spurr*
upon this identification. A recent examination of these corals
has shown them to be more probably of Upper Triassic age,
which is in perfect accord with the stratigraphy. The species
determined are: Montlivaultia cf. marmorea, Astrocoenia cf.
Waltheri, and Pentacrinus sp. indet. The two species of
coral are well known forms in the Noric beds of the Alps, and
Astrocoenia Waltheri occurs also in the Norie coral zone of
Shasta County, California. The Lower and Middle Jurassic
of the Great Basin area are not known in the coral-reef facies
anywhere.

A few years ago Dr. G. C. Martin, of the U. 8. Geological
Survey, discovered in the region of Cook’s Inlet, Alaska, some
coral-bearing limestones. Among the specimens sent by Dr.
Martin from this locality the writer has determined : J/sastraeca
ef. profunda, Thecosmilia cf. fenestrata, Phyllocoenia et.
decussata, P. ct. incrassata, Astrocoenia ef. Waltheri, Mont-
livaultia cf. Mojsvari, and Spongiomorpha sp. indet.

This coral fauna is undoubtedly the same as that in the
lower Noric zone of Shasta County, California, and has several
species in common with that fauna.

This discovery of reef-building corals in Alaska extends
their range northward from 45° in the Alps, and in the Blue
Mountains of Oregon, to 60° N. Lat. The coral zone in Cali-
fornia, Oregon, Nevada, and Alaska belongs to the same hori-

* Bull. 208, U. S. Geol. Survey, p. 102, 1908.

96 Smith—The Occurrence of Coral feef's, ete.

zon, and contains the fauna of the classic Zlambach beds of
the Fischerwiese in the Tyrolian Alps, that is of the Noric
horizon of the Upper Triassic.

The group of Astraeidae is abundant in all these localities,
except in the Blue Mountains, and since they are still impor-
tant reef-builders, and now confined to the hottest parts of the
tropics, where the temperature does not fall below 74° F., it is
reasonable to suppose that in Triassic time they lived under
approximately the same conditions. This makes it probable,
if not certain, that the sea had a tropical temperature up to
60° N. Lat., at least in the Pacific Ocean.

Speculations as to ancient temperatures of the sea are inter-
esting, but of much more importance to geologists is the fact
that this Noric coral fauna gives us a new and distinct bench-
mark, which in its marked characters and wide distribution
equals that of the zone of Zropites subbullatus, and enables
the positive correlation of strata that heretofore have been a
puzzle to stratigraphers.

Stanford University, California.

Dale—Ordovician Outlier at Hyde Manor in Sudbury. 97

Arr. XII.— The Ordovician Outlier at Hyde Manor in
Sudbury, Vermont; by T. Netson Datz.*

In a paper on the geology of the north end of the Taconic
Ranget the writer called attention to the generally divergent
strikes of the Lower Cambrian and Ordovician in the town of
Sudbury, Vt., as a key to the perplexing geology of the western
side of the Taconic Range. These were regarded as pointing
to a crustal movement at the close of Lower Cambrian time
which raised the Cambrian beds, west of the later formed axis
of the range, above water, and to their submergence in Ordo-
vician time, which was followed, at the close of Ordovician
time, by another movement which refolded the Cambrian beds
with the Ordovician, in places producing a folded overlap pos-
sibly accompanied by minor faulting. One of the pieces of
evidence offered was a small outlier of Ordovician limestone
in what was then the golf course of Hyde Manor, about 14
miles SSE. of Sudbury village and 54 miles about WSW. of
Brandon, in Rutland County, Vt.

Dr. Rudolph Ruedemann, ‘Assistant Paleontologist of New
York State, in a recent paper§$ reproduced a part of the
writer’s plate from this Journal and referred to the outlier in
these words:

“Tt is there quite probable that the whole folded plate of
Cambric rocks has been pushed along a slightly inclined fault
plane from the east over the Lower Siluric rocks, and that the
outlier of Stockbridge limestone does not rest in a small syn-
cline of the Cambric, as it would seem, but protrudes from
below the Cambrie or is a “ Fenster,’ as the European geolo-
gists term it (an outlier of younger rock protruding through
older rock in consequence of extensive overthrust and partial
weathering away of the overthrusted mass).”’

In July and August, 1910, the writer spent a few days at
- Hyde Manor in order to determine the real relations of the
outher and with the aid of two men and dynamite four exca-
vations were made. The distances between outcrops and
excavations were measured with a steel tape. Thin sections
of the schist underlying the outlier on the north side and
overlying it on the east were examined microscopically to fix
the directions of bedding and cleavage. In May, 1911, the

* Published by permission of the Director of the U. S. Geol. Survey.

+ This Journal, Ser. 4, vol. xvii, pp. 185-190, pl. xi, 1904.

t Ibid., p. 187, footnote, also p. 189, middle, pl. xi, black dot on section.

§ Rudolph Ruedemann: Types of inliers observed in New York, N. Y.

State Museum Bull. No. 133, 5th Rept. of the Director, 1908, Albany, 1909,
pp. 190, 191, fig. 33.

98 Dale—Ordovician Outlier at Hyde Manor in Sudbury.

Rie ae

‘

THE ORDOVICIAN OUTLIER AT HYDE MANOR ,SUDBURY, VERMONT.

ence . Skea ee % i e eS we
——— . o s = . s . 2 >
>: +. SI FE between.~\-. 7:

uy

“D+ dimest. & schist seat Ge

f Grpovician’ 7 Foe ORDOV
:. AE MESTONEC 60k ia See
ReneS Soh aS CG ee SCHIST

>. CRINOIDS = .+"

4 © 7?
oy Sema

eG, | CUECT ODS
' Shoe as

510 20 30 40 50 Feet
SESS eet

BED STRIKE XDIP

lacaal CLEAVAGE: =

= BED HORIZONTAL
e ROCK EXPOSURE

MW CORE DRILL HOLE

ORDOV. LIMEST. OUTLIER . ESE.
INTERFOLDED WITHE SCHIST '

True North

SCHIST
ORDOV. LI MEST. €
( probably) uti —

locality was again visited and in company with Messrs. Arthur
Keith, E. O. Ulrich, and C. W. Hayes of the U. 8. Geol. Sur-
vey. More dynamiting was done at one old point and two

Dale— Ordovician Outlier at Hyde Manor in Sudbury. 99

new ones. The Ordovician age of the outlier was definitely
established by the admission by Mr. Ulrich of the finding of a
Streptelasma and crinoids in it on a previous visit. Finally
through the kindness of the late Mr. Fletcher Proctor, Presi-
dent of the Vermont Marble Co., the writer was also enabled
to have some core-drilling done, which was accomplished in
December 1911.

The results of all the excavations and of the core-drilling,
and the structure at the important outcrops, are shown on the

Hie. 2.

EXCAV. I EXCAV. 2 EXCAV.6

C
SCHIST

F

NORTH ELM CAV. . CORE DRILL

IQ Inches |
SECT.INPLANE DIPPING 45 W.

"FENSTER THEORY INTERFOLDED OUTLIER

THRUST PLANE — —.~. ee
ae a —— } | f

A eo op LLL

T.N.DALE

W.

map (fig. 1) and also in the diagrams of fig. 2. The details are

given in the following paragraphs.

Excavation 1 (fig. 2, A).—A trench was first dug from a large
outcrop of Cambrian schist east of the northeast corner of the
outlier, and a continuous exposure of the schist obtained to its

eastern edge on the north. Then blasting was resorted to. The

schist was found to overlie the limestone and to dip 35° E. The
limestone surface dips about the same, but at one point 45° E.
Further blasting to a depth of 5 ft. below rock surface reached a
small cave with water which stopped operations. The foliation
of the limestone here dips about 35° E. ‘

100 Dale—Ordovician Outlier at Hyde Manor in Sudbury.

Excavation 2 (fig. 2, B).—At the northern edge and near its
western side schist and limestone were found in contact along a
steep E.—W. line, but at a depth of 5 ft. the schist was found to
underlie the limestone. Both rocks have a cleavage foliation
dipping 55° roughly E. But that of the schist dips SE. while its
bedding dips 75° NW. and the lower contact surface of the lime-
stone about 8° EK. That this probably corresponds to bedding is
shown at a point east of one of the elms, where a small plicated
bed of dolomite in the limestone is about horizontal and its plica-
tions strike N. 15° W., which is one of the strikes typical of the
Ordovician in Sudbury. Near the elm this horizontal bedding
crosses a low easterly dipping cleavage, but on the east side of
the outlier the small dolomite beds dip east, about with the
cleavage.

Excavation 8.—Here a trench was dug 3 ft. deep through soil
to the schist and this was exposed by blasting to a depth of 14
inches. The schist foliation dips 40° eastward. |

Excavation 6 (fig. 2, C)—A trench was dug from the Cam-
brian schist north or northeast of the northeast corner of outlier,
and the contact of schist and limestone was exposed by blasting.
Both rocks were found to be interfolded in a direction at right
to the strike but their relations deeper down were not determined.

Outcrops near elms (fig. 2, D).—These elms are on the west
side of the outlier. One is growing on it, and schist crops out
in contact with limestone and has a foliation dipping east under
it. South of the other elm the two rocks are within a few inches
of each other.

Excavations 4 and 56 (fig. 2, E).—Here a little trenching
exposed a surface of schist 10 ft. long doubled on itself and
embracing on the south a limestone fold, 5 ft. thick at its widest
part. Two openings were made: one on the line of section
showed the limestone dipping about 45° E. between two schist
masses to a depth of at least 5 ft. The other exposed the apex
of the fold with an axial plane dipping 45° E. The bed surface
of the apex (not its solution surface) lies in a vertical E.-—W.
plane and the schist surrounds the apex. The strike is N.20E.

Limestone ledge west of outlier.—This contains crinoids and,
has a marked foliation dipping eastward and entered on map as
cleavage. The course of bedding is not clear.

Core-drill hole (fig. 2, F).—In May, 1911, one or two charges
of dynamite were put in at the point indicated on the map by a
star which is about 10 ft. NE. of the northern elm. The lime-
stone became exposed to a depth of 2 ft. 1im. At this depth
Mr. Charles E. Connell, Supt. Brandon Marble Co., on Dee. 1,
1911, had a core drill put in, using crushed steel for an abrasive.
After penetrating 5 inches of limestone the drill crossed 9 ft. of
soft rock, which it ground up mostly into sand. This effervesces
strongly with dilute HCl and under the microscope shows parti-
cles of calcite, quartz and schist. The magnet extracts consider-
able fine steel due to the abrasive. On Dec. 2 the drill struck

Dale—Ordovician Outlier at Hyde Manor in Sudbury. 101

solid schist and went a foot into it. At the end of another foot
the core barrel became clogged and was left in the hole with its
core. As the limestone of the outlier contains some dark sericitic
streaks, the calcitic, quartzose sand with schist particles, brought
up by the drill, is evidently finely ground weathered limestone.
The cores obtained consist of 4:4 inches of limestone, and 4:5
inches of schist in 9 pieces. ‘The pieces of schist all have a
marked easterly dipping cleavage and one piece, an inch thick,
has a quartz lamina crossing the cleavage. The diameter of this
core along the cleavage is 23 by 24 in.* 3

Conclusions.—The isolated mass of Ordovican limestone on
the old golf course of Hyde Manor in Sudbury, Vt., is sur-
rounded and underlain by schists of Lower Cambrian age upon
which it rests unconformably and with which it is nterfolded in
synclinal attitude, and with which it is also interfolded on a part
of its northern side in a direction at right angles to the strike,
as shown in the section of fig. | and diagrams A—F and H
of fig. 2. This interfolding of the two formations reappears
40 ft. northwest of the outlier, where a small limestone fold
with an axial plane dipping 45° E. has a pitch lying in an
E.-W. vertical plane.

In view of the evidence, the application of the ‘“ Fenster ”’
theory of Alpine geologists to the relations in Sudbury as
shown in diagram G of fig. 2 is quite untenable. Valuable as
is the use of the imagination in geological investigations, geo-
logical science is still best advanced by careful observation and
induction. In this instance the induction has been verified by
physical demonstration through core-drilling.

The main mass of Ordovician limestone west of the outlier
is probably continuous with that interfolded with the Cam-
brian schists at excavations 4 and 5, and was, of course, once
continuous with the outlier or the beds adjacent to it. A little
north of the latitude of the outlier a well marked anticline
appears in the Ordovician limestone and the alternation of
tongues (synclines) of Hudson schist and of Ordovician limestone
shown on the map of the original article on this localityt
ealls for such an anticline at that point, but the outlier is so
near a Hudson schist tongue on the southwest that the anti-
cline can hardly be developed there nor is evidence of its pres-
ence obtainable.

The general importance of the outlier is that it is as yet the
only point iu Western Vermont and Eastern New York where
the Ordovician can be seen unconformably on the Lower

* As questions may arise as to this drilling the names of the workmen are
given : Geo. McBride of Brandon and Dennis Sullivan of Sudbury. Mr. OC. E.
Connell of Brandon was also present when the solid slate was struck at depth

of 11 ft. 6 in. from surface.
+ This Journal, vol. xvii, pl. xi, 1904.

102 Dale— Ordovician Outlier at Hyde Manor in Sudbury.

Cambrian, the refolding of these formations at the close of
Ordovician time having in other places obscured any original
divergence in their strike. As on the eastern side of the Cam-
brian belt, 2 miles nearly ENE. of the outlier, Cambrian and
Ordovician are also in marked unconformity, a westward thrust
of the Cambrian on the west side is not consistent with an
eastward thrust of it on the east side, which the proposed
“Fenster” theory would involve. Minor faulting may well
have occurred on both sides in the refolding of two unconform-
able formations, but it was a secondary element. The prime
factors in the relations of the two formations are: a crustal
movement at the close of Lower Cambrian; emergence and
erosion of the Cambrian beds, followed by their submerg-
ence and the transgression of the Ordovician, and finally
another crustal movement, but at a slightly different angle
from the earlier one, which refolded both formations.

The little outlier is a structural specimen, still an setw and
small indeed, but preserving the record of one transgression,
two crustal movements, and two periods of erosion which
affected several hundred square miles of the Taconic region.

Pittsfield, -Mass.,
Dec. 16, 1911.

ws Es. Wells—Color-Effect of Isomorphous Miature. 1038

Art. XIII.—On a Color- Effect of Lsomorphous Mixture ; by
Horace L. WE Ls. .

Ir appears to be a general rule that crystals composed of iso-
morphous substances, in case either or each of these is colored,
assume a color intermediate. between the colors of the com-
ponents, and so faras the writer is aware, no unexpected
colors have been observed in such mixtures. For instance, it
was found in this laboratory several years ago* that the yellow
salt Cs,PbCl], and the deep blue salt Cs,SbCl, gave green mix-
tures, as would be expected.

I have recently observed a curious color-effect when the
Cs,PbCl,,t which was mentioned above, crystallizes with
Cs,TeCl,.t Both of these salts form bright yellow crys-
talline precipitates. The lead compound has the color of sul-
phur, while the tellurium compound has a slightly brighter
tint, but their colors are so nearly alike that they can hardly be
distinguished without direct comparison. Both of the salts
crystallize in isometric octahedra, like K,PtCl, and many other
compounds of the same type.

These two yellow salts of lead and tellurium are sparingly
soluble in hydrochloric acid, and, therefore, are easily prepared.
When the conditions are such that both are deposited at the
same time from a solution, the product always has a bright
orange-red color, which is the peculiarity of the isomorphous
mixture.

This bright red mixture was first observed in connection
with the fractional crystallization of about 600 g. of the salt
Cs,TeCl,. The object of this operation was to find if in this
way any separation of tellurium into different elements could
be effected, and it is sufficient to say that the results of a very
extensive fractionation were entirely negative in regard to any
such separation.

The salt used for this systematic crystallization was prepared
from crude tellurium, as it was considered best to purify care-
fully the tellurium of the end-products, rather than the whole
of it. When the fractionation had been carried on to a con-
siderable extent, it was observed that the products at the solu-
ble end showed a bright red color, and since this substance was
not recognized as any known cesium double chloride, it
attracted attention as a possible indication of the presence of
the much-sought impurity in tellurium. However, a qualita-

* Wells and Metzger, Amer. Chem. Jour., xxvi, 268, 1901.

+ H. L. Wells, this Journal (3), xlvi, 180, 1898.
{ H. L. Wheeler, ibid., xlv, 267, 1898.

104. H. L. Wells—Color-Lifect of Isomorphous Mixture.

tive examination of the red product showed nothing unusual
in it except the presence of much lead. Then it was found
that it could be readily prepared by dissolving cesium, lead
and tellurium salts in hot agua regia and cooling or evaporat-
ing to crystallization. It should be explained that the pres-
ence of the lead tetrachloride compound in the mother-liquor
from the fractional crystallization was due to the presence in
the hydrochloric acid solution of a considerable amount of
nitric acid which had been used in dissolving the crude tellu-
rium. The lead was an impurity in the latter.

The separate salts Cs,PbCl, and Cs,TeCl, were prepared
repeatedly from agua regza solution, but they gave invariably
pure yellow products. Under precisely tbe same conditions
when both tellurium and lead were present the products were
always red, and there was no very marked variation in this
red color when the proportions of lead and tellurium were
changed considerably. The red products formed octahedral
erystals like the yellow salts, and they were of similar size.

It was suspected that the red substance might be a triple
salt of cesium, tellurium and lead, but analyses of several
crops showed that there was no constant relation between the
lead and tellurium, and that recrystallization from agua regia
changed the composition of a product very much by increas-
ing the proportion of the lead compound. Therefore it must
be coneluded that the products were isomorphous mixtures.

The following analyses were made of separate crops of the
red mixture, where V was obtained by a single recrystalliza-
tion of LV:

IT III IV Vv

I
CsrebGl wi say 412 553 477 570 88-4
‘65 6) oe eae 57-6... | 44-8: 9 51-3 485) ee

It is to be noticed that when the two yellow salts in separate,
very small crystals are mixed, either dry or under hydrochloric
acid, there is no development of any red color, so that it
appears that light in passing from one kind of erystal to the
other kind gives no unusual effect. Hence it is evident that
the effect under consideration is due to the crystallization of the
two things together.

Sheffield Laboratory, New Haven, Conn.,
December, 1911.

Rogers—Lorandite from the Rambler Mine, Wyoming. 105

Art. XIV.—Lorandite from the Rambler Mine, Wyoming ;
by Austin F. Roars. 7

I am indebted to Mr. Berger, of Placerville, California, for
an interesting specimen from the Rambler mine, near Encamp-
ment, in southern Wyoming. This specimen consists of dark
fine-grained massive pyrite, upon which are implanted barite
crystals and well-formed crystals of orpiment. With the orpi-
ment and barite are associated several orange-red realgar crys-
tals and a single deep red crystal of what proved to be
lorandite or thallium metasulfarsenite, TlAsS,. This is the

100 cleavage

Ss
=

second known occurrence of lorandite, the. original locality
being Allchar in Macedonia.*

The crystal mentioned is an imperfect one, of about 4™
size, bounded by the faces of a rhombic prism with interfacial
angles of about 90° (ealc., 93°) and by three cleavages in one
zone, which is at right angles to the prism zone. Using
Goldschmidt’s orientation,t the prism faces constitute the
{110? form and the three cleavages are parallel to {100},
{O01}, and {101:. The accompanying figure (plan and side
elevation) gives an idea of the crystal. All the faces but
{110} are cleavages. The following angles measured on the
reflection goniometer prove that the crystal is lorandite. The
first mentioned angle was measured on a detached fragment,

Measured Calculated
HOW (ela yes OON(ely.) ==>. 24.1. 52°49" 52°27"
COn (ely )eeLO(Ely.) 2250 2-.. Oa 51°49’

while the other angle was measured by mounting the matrix
specimen on the goniometer, as it was feared that the crystal
would go to pieces if detached from its matrix. The cleavage
parallel to {100} is very perfect, that parallel to {001} good,
and that parallel to {101} fair. The luster is adamantine on

* Krenner, abstract in Zeitschr. Kryst. Min., vol. xxvii, p. 98, 1897.
+ Zeitschr. Kryst. Min., vol. xxx, pp. 272-294, 1899.

Am. Jour. Sci.—FourtTH SERIES, VoL. XX XIII, No. 194.—FEesruary, 1912.
8

106 Logers—Lorandite from the Rambler Mine, Wyoming.

the cleavage faces, but the prism faces {110} are dull. Even
if bright they could not be measured on account of the close
proximity of the matrix.

Fragments are prismatic, non-pleochroic, and have parallel
extinction. Lorandite is monoclinic, but the cleavages are in
the zone of the ortho-axis and so have parallel extinction.

On charcoal lorandite fuses easily to a black globule, color-
ing the flame bright green. It gives a green flame when fused
on platinum wire and alloys with the platinum. In the closed
tube it fuses to black globules, giving a black and red subli-
mate and also minute colorless adamantine crystals of As,O,,.

The lorandite is soluble in nitric acid, turning yellow. With
chloroplatinic acid the solution gives a light yellow precipitate
(T],PtCl,). After evaporating off the nitric acid, potassium
iodide gives a yellow precipitate (TII). The nitric acid solu-
tion with hydrochloric acid gives a white precipitate (TICl).

With the spectroscope this white precipitate of thallium
chloride gave a single bright line in the green. With a pure
thallium salt the green line appeared at exactly the same
position.

Although the blowpipe and chemical tests were made with
a very limited amount of material consisting of minute
detached fragments, the identity of the mineral with lorandite
is well established. The spectroscope proves it to bea thallium
mineral and the goniometrical measurements prove it to have
the crystal form of lorandite. The blowpipe and chemical
tests are confirmatory.

Stanford University, California,
Oct. 1911.

CO. Barus—LRate of Decay of Nucler. 107

Art. XV.—The Rate of Decay of Different Sizes of Nuclei,
Determined by Arid of the Coronas of Cloudy Condensa-
tion ;* by C. Barus.

A SERIES of experiments into which I entered at some length
and which, though from the nature of the experiment they
cannot lay claim to a high order of precision, nevertheless lead
to very definite results, are contained in the following table,
which is an example of many similar results. These nuclei
were produced by X-rays (of moderate intensity) in an alumi-
num-covered fog chamber, with short exposures to the radia-
tion. The data show that no persistent nuclei of the usual
large type appreciably occur, since these, if present, require
almost no supersaturation of moist air, for condensation.
Moreover, the vapor nuclei of dust-free wet air are not caught
in my fog chamber, im the presence of ions, or else their num-
ber is specially determined and small in comparison with the
nuclei here obtained by the X-rays. This premised, the table
gives the relative drop of pressure 6p/p from p, the lapse of

_ TasuE.—Decay of different sizes of nuclei (radius r), the number n present

being determined by the coronas of cloudy condensation. dn/dt = — bn’.
t
op/p Lapse, sec. wx Os? bx 10 pr ht
26 0 73°8 43 "66
se 30 °9 ae mss
=a 15 1°3 te Sk
28 0 484° 2 61
ae 30 15°7 ai ses
°30 15 32°8 3 54
es 60 6°4 a a
33 15 36°8 “4 48
ae 60 29°7 Be or
=. 30 29° Bee ae
120 PANES) =
240 6°2 a
IDE fay, 44 =
15 55° rh
30 113°5 Be
60 86°7 ae
120 55°0 Be
240 38°8 oe
41). £, air 31°3 ae

“= * Abridged from the Report to the Carnegie Institution of Washington,
LD ENOE

108 C. Barus—Rate of Decay of Nuclei.

time, ¢, between the instant the X-radiation is cut off and the
instant of the ‘exhaustion made to catch the remaining ions,
together with the number of nuclei, n, per cu. em. caught, as
estimated from the apertures of the corresponding coronas.
The column 7 is an estimate of the size of nuclei, obtained
trom the drop of pressure 6p, and 0 is the rate of decay. In
the table, the nucleation discovered in dust-free wet air at any
drop of pressure 6p/p, in the absence of X-radiation is always
relatively small, even at the highest exhaustions made. Never-
theless, the persistence of these nuclei, surviving as much as
even ten minutes after exposure, is remarkably large, as if all
nuclei (vapor nuclei and ions) were eventually caught together.
The results, in fact, often point to an almost indetinite persist-
ence. On the other hand, at the lower exhaustion, the number
of nuclei soon vanishes. The rates of decay are determined by
the usual equation

1
A = bat or dn/dt = — bn’

Briefly, therefore, at a sufficiently high drop in pressure,
5p/p = °35, the nuclei produced in the presence of ions in dust-
free moist air by the (moderate) X-rays, decay at phenomenally
small rates, or are almost indefinitely persistent, whereas larger
nuclei decay faster in proportion to their size.

Similar facts were brought out by all the other tests with
coronas. As 6p/p decreases, or 7 the radius of the nucleus
increases, 6 increases at a rapidly accelerated rate, from very
small values 6 =10~’ to enormous values. The small coefh-
cient 6 is less than 1/10 the normal value obtained for ions
with the electrometer (of the order of 107°), while the large
values are nearly fifty times the normal value.

The interpretation of these results is made difficult by the
variability of the X-ray bulb. It is safe to assert, however,
that the large ions or nuclei produced by the X-rays in dust-
free wet air vanish with relatively enormous rapidity, whereas
the very small nuclei are almost indefinitely persistent, and
that there is a definite relation between the rate of decay and
the size of nucleus. If, therefore, we regard these nuclei as
water droplets of different sizes, evaporation is rapid until a
limiting diameter depending on the intensity of radiation is.
reached, after which evaporation nearly ceases. It is also
probable, that the limiting diameter increases with the intens-
ity of radiation, so that with strong X-rays almost no super-
saturation is required. If, therefore, the X-rays produce any
chemical body which may go into solution, as has been sup-
posed, the greater or less abundance of this body, supplied by
greater or less intensity of X-radiation, would account for
larger or smaller persistent nuclei.

C. Barus—Displacement Interferometer. 109

Art. XVI.—A Displacement Interferometer Adapted for
High Temperature Measurement, Adiabatic Transforma-
tions of a Gas, etc. ;* by C. Barus.

1. Elliptic Interferences.—Interferometry by displacement
has an advantage inasmuch as the observer never loses the
ellipses, even when the displacement is sudden. Their center
may always be brought back again to a given spectrum line, by
the micrometer. Moreover, since

N,=epneoos k — — a =ecos h (u+2B/cos’ &)
where JV, is the reduced micrometer reading, ¢ the thickness,
p the index of refraction of the glass plate of the grating, for
the wave length A, # the angle of refraction, and where
w= A+B/n’, the sensitiveness, may be regulated by decreas-
ing the thickness of the grating, e, by aid of a compensator of
thickness e’, for the virtual thickness is now e—e’. Hence,
since for radial motion the sensitiveness per fringe across any
given Fraunhofer line is

dN / dn = 2/2

this may be combined with the shift of ellipses controlled by
V,, in any ratio. The limit of this procedure is conditioned
by the size of the ellipses or the available. size of the field of
the telescope, since when e—e’ approaches zero the ellipses
become enormous.

Furthermore it has been shownt that the quantity du/dr
occurring in the value of VV, may be computed preliminarily
from observations of AV, = V,—WZ,’, between definite Fraun- |
hofer lines, particularly when the angles of incidence JZ, and
of refraction , are small. In sucha case the constant 8eB = B
mearly, where (/ = 0)

Ap= B(1/N—1/A%g), AN. = B(1/d*—1 /d*2).

Finally if AY is the motion of the micrometer to bring the

center of ellipses back to a given line
AN = (u—1) é’

where ¢’ is the thickness of the compensator. If é’ is large, one
may expect to distinguish between the indices of refraction of
a birefringent crystal, when the source of light is polarized.
Again when the arms or the interfering beams of light are
long, the refraction of a gas and its relation to temperature and
pressure are determinable.

* Abridged from the Report to the Carnegie Institution of Washington.

Reprinted by permission.
Le esncete Publications, No. 149, 1911, chap. v, § 44.

110 C. Barus— Displacement Interferometer.

In view of these advantages among others, I have con-
structed a definite form of apparatus for displacement inter-
ferometry, specially adapted for general observations, such for
instance as I have in view with fog particles. The apparatus
is to be light, portable, rigid, with relatively long distance
between the opaque orthogonal mirrors JZ and JV, and the
oblique mirror or grating, as well as height of mirrors above
the arms, and with an easy adjustment for different angles of
incidence J, large and small. In the following apparatus, figs.
1, 2, and 3, the distance between the center and either remote
mirror is about 35°. It may easily be enlarged many times.
The angles of incidence 7 = 15°, 45°, and 75°, are available at
once for the given braces, though of course other angles may
be used.

The long arms and feet of the apparatus, which in general
form is naturally much like a spectrometer, are made of 1/4
inch gas pipe, and the braces are heavy strips of tin plate, bent
so as to be U-shaped in cross section, much like umbrella
steel, with the ends bolted down. In the drawing (of which
fig. 1 isthe plan and fig. 2 the elevation) the axles are cylindric
or slightly conical. In my own apparatus sufficient rotation,
180°, of the parts was secured by ordinary well-cut gas pipe
screws. The long arms of gas pipe a, ¢, d, e are not only con-
venient for the attachment of objects to be examined, by ordi-
nary clamps, but they admit of a circulation of cold water, so
that their lengths remain invariable whatever be the tempera-
ture of the environment of air.

The tripod, figs. 1 and 2, carries a standard @ of 3/8 inch
gas pipe, which is secured snugly by the cross-coupling /.
From this the horizontal rigid arms, @ and ¢, lead respectively
to the collimator A and to the slide micrometer C and they are
screwed into / parallel to the plane of fig. 1. The arm e
which carries the telescope # must be revolvable around Q,
a wide axle PP’ and braces 6” diverging as they approach @Y
sufficing for the purpose. The telescope is used for reading
only, and need not be clamped. It must, however, be quite
firm so as not to shake the instrument.

The standard @ is prolonged above the cross-coupling /¢ as
shown at 7 and the graduated plate at A (for measuring the
angle of incidence /) rotates around @ prolonged. The plate
may be clamped by the set screw 7’. Radially to 4, the lat-
eral arm d@ is bolted below the plate at 7. JD carries the
opaque mirror J/, which thus rotates around QY with A.

The adjustment chosen is such that the parts J/, VV, G (the
grating), the telescope #' and the collimator A may be dis-
placed upward several inches, in the clear. It is thus possible,
for instance, to place the fog chamber between JG or VG.

C. Barus—Displacement Interferometer. 111

The inside of 7 or Q prolonged is ground and receives the
hollow eylindrical plug 7 of the table Z and this may be
clamped by the set screws 4’.

Upon J stands the grating G secured by the screw g to the
ring-shaped support HZ, which reposes in an annular gutter in J
on three leveling screws. Moreover a spiral spring (not shown)

Figs. 1, 2, 3.

in the inside of the hollow conical tube 2, pulls down the ring
H firmly upon J, so that nothing is liable to fall on transporta-
tion. The ruled surface of the grating G@ is toward the light
or collimator A and in the axis of rotation. The adjustment
need not be very accurate. The rulings are parallel to the
slit.

Certain details of the parts of the apparatus may now be
pointed out. The collimator A may be raised or lowered on
its vertical stem or clamped in any position by aid of the wing
nut, a’, ona longitudinally split tube. It may also be slightly

112 C. Barus—Displacement Interferometer.

inclined to the horizontal, either by the hinge indicated in the
figure, or by the special device shown in fig. 8, where the tele-
scope or collimator reposes on Y’s made of strips of elastic
brass aa. These are so adjusted that the end of Z'at a’ is
naturally higher than at a. The ring 6 and the thumb screw ¢
then lowers this end against the upward pressure of all the
springs. Reading telescopes so mounted are firm and the
device is very convenient if a slight inclination is to be
imparted. They are removed by loosening c, and slipping Z’
out of the ring, 0.

The tube @ ends on the left in the cross-coupling, which
also admits the adjustable standard @” and affords an attach-
ment for the braces 66 (U-shaped in section), the other ends
of which are bolted down to the nearer feet of the tripod.
Thus A is held sufficiently rigid by the braced system aa” bb.
An inch or a 3/4 inch objective and a 6 inch focus is sufficient
and by reason of its lightness perhaps preferable to a larger
and heavier tube. Theslit may usually be opened about 1/2™™.

In a similar way steadiness, elevation and inclination of the
telescope / is secured, the tube ¢ and e” (adjustable foot) and
the braces 6” terminating in the cross-coupling e’ as has been
suggested. An inch objective and a 6 inch focus is adequate.
Cross hairs are convenient but not necessary, as the spectrum
lines are available when sunlight is used. If the are light is
used, strong sodium lines are usually in the field with the
spectrum.

The opaque mirror JZ is controlled by three leveling screws
(horizontal and vertical axes) and a suitable spring in the cap-
sule D. It is adjusted vertically like the telescope and kept
firm by the tubes d and d” (adjustable foot) and braces 0’ b’, all
parts meeting at the cross-coupling d’. The braces 6’ 6’ are of
equal length. Hence they may be bolted down to two of the
feet of the tripod in succession, while the tube d together
with the plate A take the three positions at 30°, 90°, and 150°
to the rod a. The grating G does not turn with A but must
be specially adjusted to corresponding angles of 15°, 45°, and
75°, as easily determined by the reflected rays.

Finally the slide micrometer is sustained by the tubes ¢ and
ce” (adjustable foot) and the braces 06, all parts meeting in the
cross-coupling ¢’. The latter carries the table L, to which the
slide micrometer C, with its drum at 7) is bolted down. WV is
the opaque mirror adjusted by three leveling screws and a
spring (horizontal and vertical axes) within the capsule 6. The
slide should have from 1 inch to 2 inches of clear play and _ its
displacements should be determinable to about 00005™. The
opaque mirrors JZ and WV may both be silvered on the back
and thus last indefinitely.

C. Barus—Displacement Interferometer. 113

Since the telescope / rotates both around its own axis e” and
around the standard Q, elaborate centering of the grating G
is not usually necessary. ‘The latter is mounted between strips
of cardboard or wood and secured by the screw g, the brass
clutches being about twice as far apart as the thickness of the
erating. In other words, the grating may be slightly moved in
a direction normal to itself.

To adjust the parts, sunlight (preferably) or are light is
passed into the widened slit of the collimator, in a dark room,
so that the spots falling on the mirrors J/ ar NV (the erating
being suitably turned) and on the objective of the telescope #
are seen and the different reflected images brought nearly into
coincidence. A further adjustment is then made through the

telescope /, two of the usual four images of the slit (now nar-
rowed) being ¢ placed in coincidence horizontally and vertically
by manipulating the leveling screws on B. Specks of dust, or
nicks in the slit, greatly facilitate this adjustment. The tele-
scope is then turned to the diffraction spectrum, preferably of
the first order, and the drum actuated till the interferences
appear. Naturally the distances GV and Gud are to be
approximately equal to begin with. The solitary ellipses are
best for general purposes and they usually correspond to unde-
viated yellowish and bluish single slit images. The multiple
slit image is to be avoided. If the rings are not quite centered
in the spectrum, they may be made so by cautiously adjusting
the screws at 6, which tip the mirror about a herizontal axis.
The telescope may be moved with its foot sliding on a plane.
The three possible positions of the mirror JV (positive uncom-
pensated, self-compensated, negatively uncompensated) are
about 1°" apart on the micrometer, for a plate of glass -68™
thick. When the are lamp is used, the accentuated sodium
lines in the spectrum may be used in place of the white unde-
viated images of the slit, both for adjustment of the two
spectra for coincidence and as a fiducial mark, in place of the
cross hairs in the telescope. For a small angle of incidence the
sodium lines of higher orders of spectra are also liable to be
available.

To measure the angle of incidence /, the table / is turned
in its socket, until the reflected image of the slit coincides with
the slit itself. A hole is cut in the top or side of the collima-
tor tube near the slit (not shown), for this purpose. ‘There-
upon the table / is turned back again until the images coincide
in the telescope. The angle read off on the graduated plate A
is /, the reflected ray travelling over 2/. The table J is pro-
vided with an index and vernier (also omitted in the diagram).

The apparatus described being made virtually of hollow
parts is light enough to be carried about with convenience.

114 C. Barus—Displacement Interferometer.

In the case of the figure where the angle of incidence J is
small, the distance from IZ to V isabout 70™. It may easily
be increased to several times this, by inserting longer gas pipes at
e¢ and d with appropriate braces. The fringes are very stable
even when the instrument stands on a table fastened to a wall
bracket. They naturally quiver when the observer is manipu-
lating the micrometer screw, but they return at once to quies-
cence when the hands are removed. To obviate quivering, i.e.
to follow the motion of individual rings, the usual tangent
screw method may be employed.

2. Other Interferences.—The same apparatus may be adapted
for observing the linear diffraction-reflection interferences
described by Mr. M. Barus and myself.* The equations here
available are

dé =2A/2cos7z; de’ =2A/2cosd; Se” = rA/2 (cos O—Cos #)

where de, d¢’ and de” are the respective increments of the air
spaces between the face (rulings) of the grating and the par-
allel opaque mirror in front of it, per fringe passing the cross
hairs of the telescope, or a given spectrum line, > the wave
length of light and ¢ and @ the angles of incidence and dif-
fraction in air. For the measurement of de, A, 2, @ should be
known or determinable.

For these observations let the micrometer C be removed
from its plate Z and now bolted down on the graduated plate
K (figs. 1, 2), the table Z and appurtenances being discarded.
This must be so done that the face of the opaque mirror VV
now mounted on the rigid part of the micrometer and the rul-
ings of the grating (remounted on the slide of the micrometer)
are in the axis of rotation, with the lines of the grating parallel
to it and the slit. Hence the mirror must be adjustable by
aid of a capsule with set screws (horizontal and vertical axes of
rotation) and springs. The grating has its independent mount-
ing with three similar set screws and springs. Usually WV will
be attached to some apparatus whose linear excursions are to
be found, and for this purpose of attachment the cross-coup-
ling # in fig. 1 is abundantly supplied with screw sockets
(front and rear, not shown), so that such parts may be here
secured. A counterpoise, for instance, may be added in the
rear.

To prepare for observation, the plate A and the telescope #
are turned until a suitable angle of incidence 7 and of diffrac-
tion @ are obtained. The fringes are seen when grating and
mirror are sufficiently near together (the distance apart may be
as much as 1™), on condition that the direct images of the slit

* The grating interferometer. Science, xxxi, 394, 1910; Phil. Mag. (6),
xx, p. 45, 1910; Carnegie Publications, No. 149, chap. 2, 1911.

C. Barus—IMsplacement Interferometer. 115

from the front face of mirror and the rear face of grating are
in coincidence horizontally and vertically. 2’ may be revolved
for this preliminary adjustment. To find the angle of inci-
dence, the graduated plate A& is turned from the given position
of coincidence until the image of the slit falls upon the slit
itself at the end of the collimator A, as explained above. If
the fringes are not sharp, they may be made so by further
adjusting the set screws of J or the grating, by trial. This
usually succeeds easily, remembering that the fringes move
about a horizontal axis normal to the mirror when the mirror
moves about a horizontal axis parallel to its face. For other
details the earlier paper should be consulted.

15. Other Measurements: High Temperature, Adiabatic
Transformations, etc.—The displacement interferometer con-
structed with its arms made of gas pipe is adapted for high
temperature investigation, if a current of cold water, at con-
stant temperature, be passed through the arms in question;
they will then be kept at invariable length, however much the
atmosphere about them may change in temperature. Further-
more, since the distance between the central grating and the
opaque mirror may easily be increased to a meter or more,
tubes of considerable length may be inserted in the interfering
beams of light. The displacement interferometer should be
used with the angle of incidence nearly zero, in which case
this angle vanishes from the micrometer reading and the
observing telescope lies in a particularly convenient position
side by side with the opaque mirror on the micrometer. This
is thus immediately at hand.

It seemed to me, therefore, that a particularly interesting
subject for investigation would be the relation of temperature
and pressure of the index of refraction wu of air. According
to Lorentz* the ~«—1 for air follows the equation

p= C(p—1)8
(p pressure, C constant, 6 absolute temperature), coinciding in
form to the intrinsic equation of a gas since the temperature
coefficient of w—1 for air is very nearly equal to its coefficient
of expansion. Mascart finds this not quite true. Pressures
are to be corrected by (1+ 8p) where 8 is equal to -000,007,2
relative to em. of mereury and the temperature coefticient is
a =°00382. At all events, the temperature coefficient a is so
large that a method of high temperature measurement is not
out of the question on the one hand, while on the other the
variation of a throughout long ranges of temperature is itself
of considerable interest. I have, therefore, made a few tenta-
tive measurements at low temperatures to test the apparatus

* See the admirable summary in Landolt and Boernstein’s Tables.

116 C. Barus— Displacement Interferometer.

and have found it trustworthy throughout. In the following
table the apparatus is adjusted with an angle of incidence of
I =15°. The index of refraction is determined from the dis-
placement of ellipses when the air contained in a longitudinal
sealed tube in one of the component beams of light which
interfere is alternately filled with air at pressure p and
exhausted, at a given temperature 7 This tube was 23°8™
long and of brass, surrounded with a close fitting tubular tem-
perature bath. |

TaBLE I.—Index of Refraction of Air from shift A N of ellipses. e=23°8™.
Angle of incidence [=15°.

Barometer Vacuum Shift Shift AN U t

em. cm. (scale pts.) cm.

76°95 5 13°27 00663 1:000279 30°?
19°

76:98 4 13°48 00674 ~—- 1:000283 23°
Wyle

Tegel “4 14°54 00727 1:000306 9°
21°

77°15 4 13°55 00677 1:000284 91°
Ae

The first two columns of the table show the barometric height
and degree of exhaustion (residual pressure) ; the third the
micrometer displacement of the opaque mirror which brings
the centers of ellipses back to their original position with
reference to a given spectrum line. This reading is taken on
the drum on the micrometer, the scale parts being -0005°™.
When electric arc light is used, the accentuated sodium line is
always in presence in the spectrum and makes an excellent
fiducial line for the centers of the ellipses. A single exhaus-
tion is sutticient for two readings, as the displacement occurs
on exhaustion (from red to green, for instance) and is measured
by the turn of the micrometer to bring the ellipses back; while
on readmitting air the displacement is in the opposed direction
and is again measured by restoring the center of ellipses to the
position of the sodium line. If this displacement of the opaque
mirror on the micrometer is A V cm. the index required is

eS AEG

if eis the length of the tube. AV must be given in cm. as
shown in the fourth column of the table and from this the p of
the fifth is found at the temperature ¢ in the last column.
They refer to the wave length of the D line, as this was taken
as the fiducial mark. The absolute values of w are good but
here of relatively little interest, as no attempt. was made to
standardize the screw, etc. of the measuring apparatus, and the

C. Barus—Displacement Interferometer. a

water circulation had not been installed. The temperature
coefficient may be found without this. If, therefore, »—1
is expressed in terms of ¢ the result is a = -0036, or of the
order expected.

From this datum the working conditions of the apparatus
may be specified. For a tube 23-8 long the micrometer
displacement per degree C. is ‘051 scale parts or -0005™ each ;
i. e., the micrometer displacement is about *000,025™ per
degree C’., or about 10-*™ per degree C. per cm. of length of
tube. Thus a minimum of about 2° C. is directly appreciable
in the given case, or for a tube about half a meter long a mini-
mum of 1° @. should be appreciable at all temperatures. This
moreover would correspond to the evanescence of two rings in
succession, whereas in the above apparatus a little less than one
ring vanishes per degree C., at all temperatures. The displace-
ment of ellipses for an atmosphere of pressure is roughly from
the D, nearly to the # line.

In this method the arms need not be of invariable length
except during the short period of exhaustion, as the data are
obtained by differences.

To turn to the second method for obtaining the same result:
the displacement of ellipses is accompanied by the radial
motion of rings to and from the center and the number vanish-
ing may be connted. If 2 is the mean wave length between
the initial and fina] position of the rings and v is the number
of rings vanishing, then the equivalent micrometer displace-
ment would be

AN=nd/2

so that the micrometer reading A WV need not be taken. Hence
p—1+nnr/2¢

To make use of the method, a fine screw stopcock is to be
inserted through which dry air may be admitted, at any rate,
into the exhausted tube. In this way the motion of the rings
toward the center may be controlled, perfectly, and their evan-
escence specified. The experiment is very interesting. Clearly
the arms must be kept at invariable length while the rings are
being counted, i. e., until they cease to move, when the pres-
sure is against normal. The following fioure contains an
example of many results of this kind. Here the abscissas
denote the number of rings which have vanished and the
ordinates the corresponding pressure, the latter increasing from
afew mm. to an atmosphere. The line of observations hap-
pens to be nearly continuous. An interruption of the count is,
however, of no serious consequence, as the slope of the line is
alone in question when the initial pressure and final pressure

118 C. Barus—LMsplacement Interferometer.

are known. It is surprising .to note how closely these observa-
tions lie on a straight line. They do so quite within the errors
of observation.

The slope of the line is

70°0 —2°8
210
i. e., °32™ of mercury at 0° C., per ring vanishing; or, a little
over 3 rings (8°125) per cm. of mercury. The mean wave
length in question (between the D and F line) is about
> = 55°38 x 107°. Hence, as the effective barometer was
76°95" — 50 = 76°45" and the tube length 23°8™.

a ple ee Xe lone
ih a 39 23°8

= 1320

= 1°0002806

The datum obtained from the displacement of ellipses at
thesame temperature (unfortunately not taken) was 1:000279.

C. Barus—Displacement Interferometer. 119

Inasmuch as the water circulation was omitted during the ring
measurements and the exact value of X was not specially found,
the agreement is as close as may be expected.

The two data selected from many similar results show how
easily both methods may be used for mutual corroboration.
Clearly the ring method, since it involves the evanescence of
236 rings, is more sensitive, but also less expeditious. It is not,
however, necessary to observe all the rings; the disappearance
of a reasonable number, say 25 or 50, establishes the rate of
evanescence per cm. of mercury, or more conveniently the
number of cm. of mercury per vanishing ring. If this is
determined at the beginning and end of exhaustion the mean
result is adequate.

If the air tube of the apparatus is so modified that the air
may be heated electrically the ring method should be equally
available for temperature measurements. The results could be
compared with a thermo-couple having its fine junction inserted
in the tube and read simultaneously.

Asa method of pressure measurement, since fora tube 23°8™
long, 3°12 rings vanish per cm. of mercury, 1. e., about -1313
rings per cm. of tube length per cm. of mercury pressure, the
method is not very sensitive unless a long tube be used. A tube
1 meter long would, for instance, give 13 rings per cm. of mer-
cury, admitting of the measurement of pressure to °08°™ per
ring. One might estimate to -5°, while a more highly refract-
ing gas would secure greater precision.

The method of pressure measurement has the rare advan-
tage, however, of being absolutely instantaneous, as reproducing
immediately the state of the gas. It is therefore remarkably well
adapted for the study of adiabatic phenomena. Many equa-
tions relatively to such transformation of gases are thus open
to investigation. Since (w—1) =A W/e = nd/2e and p =
C'(u—1) 6, |

4 = CAN /e= Crn/2,
the variations of p/é are directly given by the number, n, of
rings vanishing. But the relation of p and 6 is also given
either by the intrinsic equation of the gas or by its adiabatic
equation, according to the transformation which has been

imposed on the gas, so that p and 6 are each determinable.

Brown University, Providence, R. I.

120 Kindle— Unconformity at the Base of the

Art. XVII.—TZhe Unconformity at the Base of the Chatta-
nooga Shale in Kentucky ;* by Epwarp M. Kinp ie.

Introduction.—It is proposed to describe in this paper the
physical evidences of the unconformity which exists at the base
of the Chattanooga shale in Kentucky. This unconformity
occurs in a region of horizontal or but slightly inclined rocks,
- so that there is no discordance of the strata involved to render
it conspicuous or easily detected. For this reason, perhaps,
physical evidence of it appears to have been generally over-
looked by the authors of State and Federal reports on the
geology of the region. Professor Foerste and others, however,
in various papers on the geology of Kentucky, have evidently
inferred an unconformity at the base of the shale on the evi-
dence of missing faunas at its base.

A photograph and description of the contact of the Chatta-.
nooga shale and Devonian limestone in middle Tennéssee has
been published by Professor Schuchertt to illustrate the com-
plete absence of evidence of unconformity between the two
formations, aside from the age of their faunas, and our depend-
ence upon the discordance in the superposed faunas for our
knowledge of the hiatus between them.

In eastern Tennessee an unconformity at the base of the
Chattanooga has been reported in several of the folios.

The writer § has previously called attention to the evidence
of an erosion interval at the base of the shale at one or two
points on the western side of the Cincinnati geanticline. But
the widely distributed evidence of land conditions and a con-
siderable amount of subaerial erosion immediately preceding
the deposition of the Chattanooga shale interval, if recognized in
Kentucky by any geologist, has thus far remained unrecorded.
- The photographs which accompany this paper (figs. 2 and
3) make it sufficiently clear that physical evidence of the most
unequivocal kind is available to supplement the evidence of
unconformity furnished by the faunas. Such evidence in con-
nection with faunal breaks substitutes a known for an unknown
factor in problems where a hiatus is involved. If this factor
of the geologic equation is left for deductive resolution from
the faunal factors alone, it may turn out very differently in the

* Published with the permission of the Director of the U. S. Geological
Bese te of North America, Bull. Geol. Soc. America, vol. xx,
p. 441, pl. 47, 1910.

t Knoxville, Loudon, Maynardsville, Morristown, and Columbia Folios,
U.S. Geol. Survey.

§ Williams, H. S., and Kindle, E. M., Contributions to Devonian Paleon-
tology, 1903, Bull. U. S. Geol. Survey, No. 244, pp. 20-21, 1905.

Chattanooga Shale in Kentucky. 121

hands of different men. Through the deductive method based
on the faunas alone one geologist may find in the total absence
of a fauna or faunas evidence of land conditions during the
interval represented by the missing fauna; another with dif-
ferent predilections may interpret this absence, if no evidence
of subaerial erosion has been adduced, to marine scour or tem-
porary suspension of sedimentation without land conditions.

Geologists agree that unconformities mark important datum
planes in stratigraphic geology. Hence the evidence for them
is of sufficient importance to warrant full and complete presen-
tation from both the biological and physical points of view.

In this particular case the faunal evidence affords sufficient
proof of unconformity independent of physical evidence, but
in various other cases unconformities have been introduced by
geologists where theoretic considerations regarding supposed
diastrophic movements appeared to require their presence. An
example of this kind of unconformity is one recently placed
within the New Albany shale* of Indiana (Chattanooga) with-
out a vestige of direct evidence in support of it. The history
of such an unconformity as this hypothetical one within the
New Albany is likely to be similar to that of the unconformity
which was drawn at the top of the Chattanooga in central Ten-
nessee some years ago by Hayes and Ulrich.t In a recent
paper by the last named author} this unconformity is aban-
doned without any explanation of the nature of the defects in
the original evidence. It appears to have migrated to the top
of the next formation above the Chattanooga, designated by
Ulrich the Ridgetop. Whatever the ultimate verdict regard-
ing the unconformity at the top of the Chattanooga shale may
be, the following discussion will show that the unconformity at
the base of this formation does not belong to the evanescent
class of unconformities.

Distribution of the Chattanooga Shale.—The Chattanooga
shale, briefly characterized, is a formation composed chiefly of
black fissile carbonaceous shale ranging from about 240 feet in
the northern part of the state to 25 feet in the southern part.
The areal distribution of the Chattanooga shale as an outerop-
ping formation in Kentucky is confined to two geographically
separable areas. By far the larger and more important of these
is the narrow semicircular band which borders the dome of
Ordovician and Silurian rocks in Northern Kentucky on the
east, south, and west. From Vanceburg on the east to Louis-
ville on the west the Chattanooga shale extends around the

* Ulrich, E. O., Revision of the Paleozoic System, Bull. Geol. Soc. Amer-
ica, vol. xxii, p]. 28, 191}.

+ Folio U. S. Geol. Survey, No. 95, 1903.
¢{ Bull. Geol. Soc. America, vol. xxii, pl. 29, 1911.

Am. Jour. ScI.—FourtH SErigs, Vout. XX XIII, No. 194.—Frprvuary, 1912.
9

122 Kindle— Uneonformity at the Base of the

dome of older rocks in a broadly crescent-shaped belt having a
zigzag line of outcrop more than 250 miles in length. Sepa-
rated from this area by a narrow belt of Carboniferous rocks
is the valley of the Cumberland River in southern Kentucky.
The black shale extends up this valley from Tennessee about
50 miles. It is probable that this formation extends without
interruption across the entire state beneath the younger rocks
outside the above described areas in which strata older than
the Chattanooga shale are the surface rocks. _

Description of unconformity.—A large number of outcrops
showing the contact of the Chattanooga shale and older rocks,
which are widely distributed along the lines of exposure of the
shale as outlined above, have been studied by the writer. In
nearly every district visited physical evidences of an erosion
interval have been observed. These evidences may be referred
to three classes, namely: (1) irregular of mammillary surface
of the subjacent limestone, (2) beds of residuary clay beneath
the shale, and (8) deeply excavated trenches and shale-filled
cavities of solution in the underlying limestone. The first and
second named phenomena have a wide distribution, but the
third, as might be expected, is found rather rarely. In local-
ties where the limestone base of the black shale has been
recently denuded of the shale, one very frequently finds the
surface of the limestone hollowed and pitted in the peculiar,
irregular, and often angular manner similar to that which may
be seen at nearly any limestone quarry where the rock has been
stripped of its residuary clay. A good example of this hum-
mocky surface on the Devonian limestone where the shale has
been recently removed occurs sontheast of Crab Orchard, Ken-
tucky, 13 miles on the Gum Sulphur road. Near the school-
house at this locality the highly uneven hummocky surtace of
the limestone can be traced directly under a 10-inch bed of
reddish brown clay which separates the black shale from the
weather-worn limestone below. Here one sees in the vertical
cross-section of the limestone beneath the shale the angular
ridges, truncated cones, and mammillary protuberances covered
with a clay which differs from the usual residuary limestone
clay only in being of a duller color. The correspondence in
appearance between the surface of this irregularly worn lime-
stone and that usually seen in limestones recently denuded of
their clay covering is complete and unmistakable. Numerous
examples of subaerial erosion of this kind have been observed
around the fringe of Chattanooga shale which circles the older
rocks south of the Ohio. On the west side of the Cincinnati
geanticline, south of the Ohio river 15 miles, evidences of the
pre-Chattanooga erosion interval are apparent near Brooks
station. In the bed of Brooks Run, between the railroad and

Chattanooga Shale in Kentucky. | 123

the wagon road, the lowest strata of the black shale lie in shal-
low, irregularly eroded pockets in the limestone. In some of
these a thin layer of reddish clay was observed between the
limestone and the undisturbed black shale.

In the southwestern part of the black shale area of outcrop
near Rileys station in Marion county, unconformity at the base
of the shale is well exposed in a small ravine a few hundred
yards northwest of the railroad station. Here the hollows in
the limestone under the black shale are deeply filled with dull
red residuary clay, while but a thin band of the clay covers the
intervening elevated ridges in the limestone. The upper sur-
face of the latter is extremely uneven and seldom conforms
with the approximately parallel bedding planes in the lime-
stone. The unconformity as it is seen here is illustrated by

[==]
TS ES a] Ee ee ee Re ee eT a a Raeay SITE
7

Fic. 1. Section at Rileys, Kentucky, showing irregular surface of Devo- =
nian limestone and residuary clay beneath the Chattanooga shale. A Devo-
nian limestone, B residuary clay, C Chattanooga shale.

fig. 1. The maximum thickness of the residuary clay which
has been observed at the base of the black shale occurs in Mad-
ison County, southwest of Berea, near the head of the west
fork of Rocky Branch. The clay has a thickness in places of
3 feet or more at this locality. It is a brown clay containing
numerous fragments of the chert which characterizes the under-
lying Devonian limestone on Rocky Branch. The clay lies at
this locality in deeply excavated troughs and pot-like depres-
sions in the limestone. The upper part of this clay shows indi-
cations of having been reworked. One or more thin papery
bands of shale show a superposed bed of clay.

The place usually occupied by the residuary clay which has
been described is sometimes filled on the eastern side of the
Cincinnati geanticline by a limonite ore. The iron ore has
been found in the form of small lenticular and widely sepa-
rated masses over a line of outcrop nearly 150 miles in length,
extending through Boyle, Lincoln, Montgomery, and Casey
counties as far north as Peebles, Ohio. This ore was exten-
sively worked at one time near Preston, Ky., where the bed
Is said to have had a thickness of from 7 to 15 feet.

a

124 Kindle— Unconformity at the Base of the

The most striking examples of pre-Chattanooga erosion in
the Devonian ‘limestone which have been observed occur
at Irvine, Ky. A considerable exposure along the railway
west of town shows the contact of the Chattanooga shale
and the Devonian limestone to be, as it often is, a horizontal
line with no intervening residuary clay and no departure
from exact parallelism of the adjacent formations. Foerste*
has published photographs illustrating this type of the contact
elsewhere in Kentucky. Near town, however, this apparent

Fie. 2.

Fic. 2. Chattanooga shale and Devonian limestone unconformity at
Irvine, Kentucky. The Chattanooga shale is marked A, and the Devonian
limestone B.

conformity of the two formations terminates abruptly, ond we
find the black shale resting for several yards on a highly irreg-
ular surface of the Devonian limestone, and on one side of the
section abutting against a vertical wall of limestone about 8 feet

in height. The general relations of the two formations at this
oint are shown in the photograph fig. 2, The beds marked

2 are a nearly pure limestone of Onondaga age. Those marked
A Rare the basal beds of the Chattanooga shale, which at this
horizon includes some dark magnesian and silicious beds inter-
bedded with black shale. In the illustration the hammer
rests upon the side of the limestone ledge and the hand of
the man upon the shale. The details of this vertical contact

* Kentucky Geol. Surv. Bull. No. 7, figs. 8, 9, 1996.

Chattanooga Shale in Kentucky. 125

are shown more clearly in fig. 3, in which the hammer
rests with one end against the shale and the other against the
limestone. ~ Fig. 3 also shows more clearly than fig. 2 the walls
of a small water-worn cavity in the lower half of the ledge

Higa io:

»

Fic. 3. Close view of a portion of the black shale and limestone contact
line shown in fig. 2. A solution cavity in the limestone filled with black shale
is seen under the hat. The shale is marked A, and the limestone B.

which extends nearly, if not quite, to the bottom of the lime-
stone. This cavity, filled with a deposit of the black shale, is

126 LKaindle— Uneonformity at the Base of the

seen in the photograph just above the bag. The hat rests upon
the upper part:of the filling of the Chattanooga shale. Since
the Devonian limestone in the vicinity of Irvine seldom ex-
ceeds 10 feet in. thickness, it is evident from the photographs
that it was locally almost, if not entirely, cut through by sub-
aerial erosion previous to Chattanooga sedimentation. Another
exposure of the contact of the two formations which occurs in
the small ravine between the town and the station at Irvine
shows a still more advanced stage of denudation of the lime-
stone than that illustrated in the photographs. Here the Devo-
nian limestone has been reduced to large disassociated bowlders.
These have been enveloped by the Chattanooga shale, which
lies upon and around them and rests directly on the subjacent
Silurian shale between the bowlders.

The significance of the remarkable and apparently haphazard
variations in the thickness of the Devonian limestone in east
central Kentucky to which Foerste* has called attention,
becomes evident in the light of the preceding examples of sub-
aerial erosion of this formation subsequent to Chattanooga
shale deposition. ‘These variations in thickness range from a
few inches to 47 feet according to Foerste. The following
striking cases are quoted from Professor Foerste’s report : +

“ Another thick section of Devonian limestone occurs three
miles southwest of Cartersville, where the road to Crab Orchard
crosses the headwaters of Harmon creek. Here the Devonian
limestone is seventeen feet thick. Half way between this locality
and Crab Orchard the thickness of the Devonian limestone is only
six feet, so that the Devonian limestone appears to become thin-
ner from both areas toward this middle region. . . . Directly
north of Berea the thickness of the Devonian section is thirteen
and a half feet. - Four miles north of Berea it is reduced to three
inches. Evidences of thinning are seen also in going from Berea
northeast, toward Bobtown. In the vicinity of Bobtown, and
from this region forat least three miles toward the east and north-
east, the thickness of the Devonian limestone is reduced to about
one foot or less, except at the Mat Moody Store, a mile and a
quarter toward the southeast of Bobtown. Here the thickness
of the Devonian limestone is at least four feet four inches, again
suggesting an irregular thinning of the Devonian limestone toward
the north.”

It would seem to be a reasonable inference that the subaerial
erosion which rendered the Devonian limestone cavernous and
in places reduced it to a bed of bowlders as at Irvine, may, where
the pre-Chattanooga relief was greater, or the drainage more

* The Silurian, Devonian, and Irvine formations of Hast-Central Kentucky,

Kentucky Geol. Survey, Bull. No. 7, p. 89-92, 1906.
+ Idem., p. 90.

Chattanooga Shale in Kentucky. 127

deeply incised, have removed it altogether. The very irregular
and patchy distribution of the Devonian limestone which obtains
in southern Kentucky and adjacent parts of Tennessee, taken
in connection with the evidences of its partial erosion in central
and northern Kentucky, strongly suggests that this formation
has been completely removed over a considerable area near the
Kentucky-Tennessee line and over smaller areas in central
Kentucky. In the latter area the Devonian limestone is gen-
erally present where the Chattanooga shale is found, but over
certain areas, as the regions between Bardstown and New
Haven, between Raywick and Loretta, and south of Stanford,
it is entirely absent. Farther south it is not the absence but
the presence of the Devonian limestone which is exceptional,
Southwest of the southern limit of the Devonian limestone in
Kentucky, as indicated on Foerste’s+ map, a detached area of
this formation occurs on the Rolling Fork River. The writer
has found another on the Green River near Edith P.O. A
third occurs south of the Tennessee line on the Harpeth River.
In the light of the evidence which has been presented of the
extensive denudation of the Devonian limestone at Irvine, it
appears nearly certain that these outlying patches of limestone
are remnants of a once continuous sheet of Devonian limestone.
Its relatively greater degree of denudation is doubtless the
result of the greater elevation of the axis of the Cincinnati
geanticline in southern Kentucky and northern Tennessee.
Time interval represented.—Any conclusion concerning the
time interval represented by the unconformity which has been
described must rest upon the determination of the age of the
formations involved. The complexity of this question is
apparent when we consider that the unconformity involves at
its base at least six distinct formationsin Kentucky ranging in
age from Ordovician to Middle Devonian. ‘This, of course,
raises the question whether in one part of the area land con-
ditions began as early as Ordovician and in another part as late
as post-Hamilton time, or whether differential erosion is respon-
sible for the difference in age. The evidence already given of
the nearly complete denudation of the Devonian limestone by
subaerial erosion at one locality seems to strongly support the
probability that the absence of the later formations in part of
the Kentucky area is due to denudation rather than to land
conditions having persisted in certain areas froin Ordovician
to the beginning of Chattanooga sedimentation. Obviously the
question of transgression or overlap comes into the problem,
But we have to discover whether the transgression proceeded
rapidly and at approximately the same rate from all sides, or

* Silurian and Devonian limestones of Tennessee and Kentucky, Bull.
Geol. Soc. America, vol. xii, fig. 8, 1901.

128 Kindle— Unconformity at the Base of the

whether it proceeded very slowly and chiefly in the direction of
the oldest rocks-exposed at the base of the unconformity. The
latter view seems to have been maintained by some geologists
as a corollary of the dogma of very slight erosion of Silurian and
Devonian lands. The photographs and other evidence here
presented indicate the necessity of very materially modifying
this assumption. It is of course possible to have had a south-
erly transgression of the black shale across Kentucky at the
close of such a cycle of erosion as has been indicated in this
paper, but proof of this must rest on evidence of distinctly dif-
ferent age values of the basal faunas of the black shale at
the north and at the south. It is desirable here to ascertain
just what evidence there is, if any, for such differences in the
age of the shale. Prof. Edward Orton, Jr.,* appears to have
been one of the first to claim that the black shale in Kentucky
represented only the “ Upper or Cleveland Division” of the
Ohio shale. His statement is as follows: “The shale that
covers the Lower Silurian limestone in central Kentucky is the
Upper or Cleveland Division.” This opinion concerning the age
of the Chattanooga shale is comparable to some which have
followed it in the poverty of evidence on which it rests and
the positive phrasing which might mislead one unfamiliar with
the subject to suppose that it represents an established fact.
No complete or entirely adequate discussion of the time
interva! represented by the unconformity at the base of the
Chattanooga shale can be given until the fauna and strati-
graphy of this formation have been described in detail.
Although generally considered to be nearly barren of organic
remains, the writer has found the carbonaceous beds of the
Chattanooga shale to carry a conodont fauna which is quite
as abundant in the lower or Huron shale of Ohio and Kentucky
as it is in the upper or Cleveland shale. These minute but
beautifully preserved fossils may be obtained at any locality
and at any horizon in the black shales from Lake Erie to
Alabama. These fossils have long been known in Ohio in the
upper beds of the Ohio shale, but with the exception of a very
few species have remained undetermined and undescribed.
When they have been described and the species which are con-
fined to the upper and lower horizons of the shale distinguished,
they will prove an invaluable aid in correlating the different
parts of the Ohio shale in Ohio with their equivalents in the
Chattanooga shale in Kentucky and farther south. Until this
has been done, however, any attempt to make use of these
fossils in correlating subdivisions of the Ohio and Chattanooga
shale must be considered premature and futile. Hence, in the
present discussion of the age of the interval represented by the

* Geol. Survey of Ohio, vol. vii, p. 23, 1893.

Chattanooga Shale in Kentucky. 129

unconformity at the base of the Chattanooga shale, the previ-
ously adduced evidence of the age of the shale will be consid-
ered chiefly.

Devonian fossils have been found by various geologists
in the lower part of the Chattanooga shale in Kentucky
and in its equivalent, the new Albany shale, in Indiana.
For a summary of the literature relating to the Devonian
age of the. Ohio shale which has appeared previous to
1898, the reader is referred to Dr. George H. Girty’s*
important contribution to the age of the Chattanooga shale
in eastern Kentucky. Somewhat later the writer; published
a short list of Devonian fossils obtained from the Chattanooga
shale on the western side of the Cincinnati geanticline. The
whole of the Chattanooga shale was generally considered to be
of Genesee age until Prof. H. S. Williamst{ reported that Car-
boniferous fossils appeared in the topmost beds of the formation
at Irvine. The excellent stratigraphic work done by Foerste
and Morse§ in northern Kentucky has shown that these Car-
boniferous fossils at Irvine occur in beds which are the south-
ern extensions of the Berea, Bedford, and Sunbury formations
of southern Ohio. They have shown that about 4 feet of the
uppermost beds previously included in the 150 feet of the
Ohio or Chattanooga shale in east central Kentucky are the
stratigraphic equivalents of beds which in northern Ohio imme-
diately follow the Ohio shale and have a total thickness of about
150 feet. The thinning of these beds in crossing southern
Ohio and northern Kentucky, though very marked, harmonizes
fully with the attenuation which the Ohio shale suffers in being
reduced from a thickness of more than 2400 feet east of Cleve-
land to less than 150 feet at Irvine, Kentucky.

On the basis of diastrophism Grabau, | Schuchert,4/ and
Ulrich** have referred the Chattanooga shale in Tennessee to
the Mississippian. These authors, though differing widely as to
the direction of movement of the transgression, agree In assum-
ing that it culminated in the deposition of the Chattanooga
shale in Mississippian time. Concerning this correlation and
the method by which it was derived, it is perhaps sufficient
to quote Professor Schuchert’s remarks on the diastrophic
method. He states:

* Description of a Devonian fauna found in the Devonian black shale of
eastern Kentucky, this Journal, vol. vi, p. 385, 1898.

+ Bull. U. S. Geol. Survey, No, 244, D. 20, 1905.

{ This Journal, vol. iii, p. 398, 1897,

§ Jour. of Geology, vol. xvii, pp. 164-167, 1909.

| Types of Sedimentary Overlap, Bull. Geol. Soc. America, vol. xvii, pp.
599-701, 1906.

pe eee of North America, Bull. Geol. Soc. America, vol. xx,

** Revision of the Paleozoic Systems, Bull. Geol. Soe. America, vol. xxii,
No. 3, p. 807, pl. 29, 1911.

130 Kindle— Unconformity at the Base of the

“In fact, the principle of diastrophism can rarely be used before
taking the fossil. evidence into account, for it is the latter that
fixes and determines physical events. Diastrophism, however, is
of much value in paleontography, but it must follow, not precede,
the evidence furnished by the fossils.”

None of these authors has given us any faunal evidence for
transferring the Chattanooga shale to the Carboniferous from
the Devonian, where it had been generally placed and to which
it had previously been referred by one of them,* and separated
from the Carboniferous by an unconformity.t Probably all
of the paleontologie evidence which the advocates of the
Carboniferous age of the Chattanooga shale might claim to
support their view has been presented by Dr. R. S. Bassler.
Although his paper does not eschew diastrophism, it proceeds
mainly on the paleontologie basis and consequently invites
our careful consideration and critical examination. The con-
tentions which Bassler makes in his paper are reducible to
three distinct theses, which may be stated thus: (1) The Chat-
tanooga shale of central Tennessee is a distinct formation
from the Chattanooga shale of the U. 8. Geological Survey
folios of eastern Tennessee. (2) The Chattanooga shale should
be correlated with the Cleveland shale of Ohio. (8) The
Cleveland shale of Ohio is of Waverlyan age.§ Inasmuch as
Dr. Bassler admits the Devonian age of the east Tennessee
black shale, it is evident that the first proposition is of pri-
mary importance to his argument. It is stated by Bassler
as follows: “ East and northeast of this Chattanooga band
of outerop a similar black shale, but of undoubted Devonian
age, has been mapped as the Chattanooga shale.” In support
of the distinctness of the eastern and central Tennessee Chatta-
nooga shale I find in Dr. Bassler’s paper no evidence adduced
beyond the reference of the central Tennessee Chattanooga to
the Carboniferous. This reference rests primarily on evidence
submitted by Newberry nearly forty years ago, the validity
of which I am compelled to deny for reasons to be shown
presently. During the past summer the writer has discovered
in the most easterly outcrops of the Chattanooga shale in

* Ulrich, E. O., Prof. Paper, U. S. Geol. Survey, No. 36, p. 25, and Folio
U.S. G. 8. No. 95. :

+ Hayes, C. W., and Ulrich, E. O., Folio U.S. Geol. Survey, No. 95, 1903.

¢ The Waverlyan Period of Tennessee, Proc. U. S. Nat. Museum. vol. xli,
pp. 209-224, 1911. :

§ Note.—In another paper|| the whole of the Ohio shale in Ohio has been
referred to the Mississippian by Dr. Bassler. This reference, however, was
evidently an oversight as regards the lower division of the Ohio shale, since
no evidence has ever been offered by Bassler or any one else tending to prove
that the lower portion of the Ohio shale is of later age than Devonian. So
we may confine our discussion of the proposed revision to the evidence rela- .
ting to the position of the Cleveland and Chattanooga shales.

| This Journal, vol. xxxi, p. 20, 1911.
{| Idem, p. 215.

Chattanooga Shale in Kentucky. 131

Tennessee the same conodont fauna which characterizes this
formation at Chattanooga, the type locality. In view of this
discovery of the same fauna on both sides of the barrier, which
some geologists have assumed to separate the black shale of
eastern and middle Tennessee, the claim of the distinctness
of the shale in the two areas appears to be no longer tenable
Since the Devonian age of the east Tennessee black shale has
already been conceded, the finding of a conodont fauna which
shows the essential faunal unity of the shale in both areas car-
ries with it the evidence of the Devonian age of both.

With the second proposition the writer does not take issue
except to state that it is probable that the Chattanooga shale
in Tennessee will be shown to be the equivalent, not only of
the Cleveland shale, but of much of the remainder of the Ohio
shale as well.

With the third proposition I am compelled to disagree. Dr.
Bassler does not claim to present any new evidence for refer-
ring the Cleveland shale to the Carboniferous but briefly
restates* the evidence which led Newberry to refer these beds
to the Waverly in 1874. It seems probable that Bassler was
not aware of the excellent reasons which have led the authors
of the official reports of the Ohio Survey since Professor New-
berry’s time to discard the evidence brought forward by
Newberry and place the Cleveland shaie in the Devonian. In
the space here available it is only possible to refer briefly to
the stratigraphic mistakes made by Newberry which must
throw grave doubt upon any evidence which he presented for
the Carboniferous age of the Cleveland shale. Prof. Prossert
has fully discussed some of these in his paper on the Sunbury
shale, to which the reader is referred. It is necessary for the
reader to recall in this connection’ that in northern Ohio the
Cleveland shale, which is the highest member of the Ohio shale,
is separated from a Carboniferous black shale above it, called
the Sunbury, and from a Devonian black shale below, called
the Huron, by drab shale and sandstone formations of variable
thicknesses. It was easy in the early reconnoissance work
of the Ohio Survey to confuse these three black shales. We
have Newberry’s own statement that he did confuse the Cleve-
Jand and Huron shales in northern Ohio. Concerning this
he wrote: “ This dip misled us and the thinning of the Erie
shale, bringing the Cleveland down near to the Huron, caused
these two to be confounded.”’t It appears that this confusion
of the upper and lower shales was not detected by Newberry
until 1886, or twelve years after he announced the discovery

* Proc. U. 8. Nat. Museum, vol. xli, p. 218, 1911.

+ The Sunbury Shale of Ohio, Jour. of Geology, vol. x, pp. 262-312, 1902.
¢ Mon. U. S. Geol. Survey, xvi, p. 127, 1889.

132 Kindle— Onconformity at the Base of the

of the Waverly fauna at the base of the Cleveland shale which
Bassler cites as evidence of the Carboniferous age of the
Cleveland.

No one who has made a detailed study of the relations of
the Carboniferous Sunbury to the two lower black shales from
the northern to the southern boundary of Ohio, can doubt that
the shale which Newberry called Cleveland in the 1874
Report* is the Sunbury shale. It was in this volume that
Newberry published the list of Waverly fossils, including
Syringothyris typa, which he reported to have been found
below the Cleveland shale. It appears that the authenticity
of this find was called in question during Professor Newberry’s
lifetime, and in a later discussiont of the matter he states that
these fossils were collected by an assistant who was not able to
relocate the horizon when requested to do so. The writer and
Mr. P. V. Roundy searched very carefully the section from
which this fauna was reported to have been obtained, but
found immediately below the Cleveland shale a Chemung
fauna without any trace of Waverly species. Many other
geologists have studied the northern Ohio sections since Wavy-
erly fossils were reported by Newberry from below the Cleve-
land shale, but not one, so far as the writer is aware, claims to
have found Waverly fossils at this horizon.{ In view of these
facts I think we may safely conclude that the collector of this
fauna incorrectly identified the formation from which his
Waverly fossils came.

If, for the reasons already stated, we dismiss from considera
tion the Syringothyris fauna as evidence in this case, we find
that we must depend almost wholly for evidence of its age
upon the affinities of the rich fish and conodont faunas which
characterize the Cleveland shale. When Professor Newberry
found himself unable to substantiate his previously published
statement of the occurrence of a Waverly fauna at the base of
the Cleveland shale, he continued to maintain the Carbonifer-
ous age of the formation chiefly on the evidence of the occur-
rence in it of three genera of Carboniferous fishes, namely,
Hoplonchus, Orodus, and Polyrhizodus.§ Concerning this
evidence it is well to recall that most of the fossil fishes
described by Newberry were obtained for him by collectors
on whom he depended for the correct designation of their
geologic horizon. Since Professor Newberry had himself con-
fused the Sunbury and Cleveland shales, the opportunities

* Geol. Survey of Ohio, vol. ii, Pt. 1, p. 95.

+ Mon. U. S. Geoi. Survey, xvi, p. 127, 1889.

t{ Note: It may be observed here that the Waverly fauna recently reported
in Kentucky by Foerste (Ohio Naturalist, vol. ix, No. 7, pp. 515-528, 1 pl.,
1909), was found below the Kentucky representative of the Sunbury shale.

$The Paleozoic Fishes of North America, Mon, U. S. Geol. Survey, xvi,
p. 128, 1889.

Chattanooga Shale in Kentucky. 133

which existed for the collectors to confuse them are too evi-
dent to require discussion. If these genera occur in the Cleve-
land shale at Bedford, as Professor Newberry believed, recent
workers in this field should have found at least one or two of
them. We have, however, the testimony* of two paleoichthyol-
ogists, Dr. L. Hussakof and Prof. KE. B. Branson, who have
been persistent collectors in the Cleveland shale of northern
Ohio, that they have never found any of these genera in it.
Professor Bransont writes as follows:

“‘T have never collected any specimens of the genera mentioned
in your letter, from the Cleveland shale, nor have I ever seen
Carboniferous fish remains of any kind in the shales. ... . We
had quite a large collection of Cleveland shale material in Oberlin
College Museum, but all of it indicated the Devonian age of the
formation.”

Dr. Hussakof indicates his experience in the following
words :

“In regard to your query about Hoplonchus, Orodus and
Polyrhizodus—\ have never found any of them in the Cleveland
shale.” {

In view of this kind of testimony from paleontologists thor-
oughly familiar with the fish fauna of the Cleveland shale,
both through extended collecting and study of all the important
collections made by others, we seem forced to conclude that
the Carboniferous fishes which Newberry records from the
Cleveland shale came probably from the Sunbury instead of
the Cleveland.

When Newberry’s monograph on the Paleozoic ‘fishes of
North America was published he was not aware that any of the
twenty-eight fossil fishes which had been described from the
Cleveland shale occurred in the Huron shale of northern Ohio,
for he states§ that “none of the fossil fishes described from
northern Ohio should be credited to the Huron.” Progress
has been made since this was written in our knowledge of the
range of the Cleveland shale fishes. It has been comparatively
small, however, because the group of collectors who have made
the Cleveland shale famous for its fossil fishes, all lived on or
near outcrops of this formation and gave comparatively little
attention to the more remote area in northern Ohio in which
the Huron shale reaches the surface. Branson| has, however,
shown that at least one of the Cleveland shale fishes, Dinzch-
thys intermedius, oceurs in the Huron shale in its typical area
near Huron, Ohio. It may be pointed out, too, that one at

* Letters to the writer.
+ Letter to the writer, Nov. 23, 1911.
+ Letter to the writer, Nov. 11, 1911.

8 Mon. U.S. Geol. Survey, xvi p. 127, 1889.
| Science, n. s., vol. xxviii, p. 94, 1908.

134 Kindle— Uneonformity at the Base of the

least of the fishes credited to the Huron shale by Newberry |
and unknown in the Cleveland, came, not from the Huron,
but from the Olentangy shale at the base of the Huron. This
conclusion is evident from the remarks concerning Callogna-
thus reqularis on page 60 of Newberry’s monograph* although
it is referred under the description of the species to the Huron
shale. With increasing knowledge of the fish fauna of the
Huron we may confidently expect the discovery of a consider-
able number of species common to both the Huron and the
Cleveland shales. The general resemblance of the conodont
faunas of the two formations seems fully to justify this pre-
sumption. The writer’s collection from the Huron shale will,
when studied, it is believed, add other species of fishes to those
which are known to be common to the Huron and Cleveland
shales.

Professor Newberry, in his latest reference to the conodonts
of the Cleveland shale, dismissed the evidence which these fos-
sils might have yielded him with the statement that “the mil-
lions of conodonts in it have no geological significance.”+ This
view is evidently not shared by Dr. Bassler, who has based his
correlation of the Chattanooga shale of Tennessee and the
Cleveland shale of Ohio entirely on the similarity of the
conodont faunas in the two. Nor is it shared by the writer,
although, as previously stated, detailed discussion of the evi-
dence which this group will afford must wait the description
of the conodont faunas recently discovered by the writer in
the Huron shale in northern Ohio. A preliminary examina-
tion of the conodont fauna of the Huron shale shows that it is
very similar to that of the Cleveland shale. The most impor-
tant facts now available, as bearing directly on the question of
the age of the Cleveland shale, relate to the known range
outside of Ohio of the species which have been recognized in
it. Only three of the Cleveland shale species of conodonts
have thus far been recorded from other formations. These
are Prionides angulatus Hinde, Prionides erraticus Hinde,
and Polignathus dubius Hinde. These species are recorded
only from Hamilton and Genesee horizons{ elsewhere, so that

* Mon. U.S. Geol. Survey, No. 16, 1889.

+ Mon. U.S. Geol. Survey, xvi, page 128, 1889.

+t Hinde, George H., On Conodonts from the Chazy and Cincinnati Group
of the Cambro-Silurian, and from the Hamilton and Genesee-shale Divisions
of the Devonian, in Canada and the United States. Quart. Jour. Geol. Soc.,
London, vol. xxxv, pp. 351-368, 1879.

Clarke, J. M., Annelid Teeth from the lower portion of the Hamilton
Group and from the Naples Shales of Ontario Co.,N. Y. N.Y. State Geol.,
Sixth Ann. Rep. for 1886, pp. 30-33, pl. Al.

Grabau, A. W., The Paleontology of Highteen Mile Creek and the Lake

Shore Sections of Erie County, New York. Bull. Buffalo Soc. Nat. Sci.,
vol. vi, pp. 150-158, figs. 833A-331, 34-46, 1899.

Chattanooga Shale in Kentucky. 135

the conodonts, so far as their evidence is recorded, indicate a
Devonian age for the Cleveland shale.

Résumé of conclusions concerning age of unconformity.—
Briefly summarizing the discussion of the question of the age
of the Cleveland shale, we may say that (1) the evidence of
the Waverly fauna originally brought forward by Newberry
and restated by Bassler should be eliminated from considera-
tion, because neither Newberry nor any of his successors have
been able to substantiate it by finding a similar fauna at the
base of the Cleveland. (2) Later workers have failed to find
any of the Carboniferous fishes claimed by Newberry to occur
in it. (8) Some of the large fossil fishes which characterize
the Cleveland are represented by identical species in rocks of
demonstrated Devonian age. (4) The Cleveland shale cono-
donts, so far as their range has been recorded, are known
elsewhere only from Devonian rocks.

If there is extant no valid evidence of the Carboniferous age
of the Cleveland shale, as the preceding review of it appears
to indicate, the correlation of the Chattanooga shale, either in
part or an toto with the Cleveland, affords strong evidence OIE,
instead of against, its Devonian age as has been assumed by
Dr. Bassler. This evidence in the north is fully corrobo-
rated in the south by the discovery of a conodont fauna in a
black shale of admitted Devonian age in east Tennessee which
is identical with that in the Chattanooga shale. Thus we see
that correlation of the Cleveland shale with its equivalent or
partial equivalent, both in northern Ohio and eastern Tennes-
see, indicates its Devonian age.

With respect to the unconformity at the base of the Chatta-
nooga shale, the important and obvious fact which appears
from this discussion of the age of the Chattanooga is, that it
does not transgress Devonian time. The field work of the
writer has furnished convincing evidence, both stratigraphic
and faunal, that the Chattanooga shale in Kentucky represents
the Huron as well as the higher beds of the Ohio shale. Detailed
presentation of the faunal and stratigraphic evidence of the
continuity of the Huron shale across Kentucky must, however,
await the appearance of the writer’s report on the fauna and
stratigraphy of the Chattanooga shale. Only the evidence
of one of the fossil fishes will be introduced here. Dr. L.
Hussakof writes* concerning one of the fossil fishes obtained
from this horizon by the writer and Mr. P. A. Bungart on
Copperas Creek, east of Indian Fields, Clarke Co., Kentucky,
as follows:

“The specimen from Copperas Creek is without any question
Dinichthys herzeri Newberry, the species supposed to be indica-

* A letter to the writer, Nov. 28, 1911.

136 Kindle—Chattanooga Shale in Kentucky.

tive of the Huron shale. Your specimen shows even the series
of denticles alomg the front face of the ‘ premaxillary’ just as in
the type specimen.”

The fauna which most geologists have held to indicate a
Genesee age for the Chattanooga in Kentucky the writer has
found on all sides of the Cincinnati arch in Kentucky, but
confined to the lower beds of the formation. There appear to
be no good grounds for questioning this assignment of the
basal beds of the Chattanooga to Genesee time. The land
conditions represented by the unconformity could not then
have continued later than the Genesee. Their initiation could
not have been earlier than late Hamilton. Limestone of this
age underlies the shale near Louisville. Hamilton fossils
have been found in the Harpeth River valley a short distance
south of the Kentucky-Tennessee boundary. When the Devo-
nian limestone has been carefully studied in the intermediate
territory in Kentucky, Hamilton fossils will doubtless be
found in various localities where the rocks of this age have
partially escaped erosion. It would appear, therefore, that
the unconformity involved a time representing either early
Genesee or late Hamilton time, or both.

The evidence available with regard to the age of the black
shale sediments in eastern Tennessee and southwest V1 irginia,
indicate land conditions that were contemporaneous with .
those which have been described in Kentucky. The uncon-
formity at the base of the Chattanooga shale in eastern
Tennessee* indicates that a land area existed in that region
previous to Chattanooga sedimentation which was doubtless
continuous with land conditions in southwest Virginia and
central Tennessee and Kentucky, but which may have begun
at an earlier period than in Kentucky. The unconformity in
eastern Tennessee and southwestern Virginia is followed by
shales with a fauna similar to that which we find above it
in the Chattanooga in Kentucky. We must conclude, there-
fore, that while pre-Chattanooga land conditions may have
begun considerably earlier, they did not last appreciably longer
in eastern Tennessee and southwest Virginia than in Kentucky.

* Keith, Arthur, Knoxville, Loudon, Maynardsville, and Morristown
Folios, U. 8S. Geol. Survey.

-

Washington—Suggestion for Mineral Nomenclature. 137

Arr. XVIII.—A Suggestion for Mineral Nomenclature ; by
Henry 8. WAsHINGTON.

Introduction.—That the science of mineralogy may be
regarded as a branch of descriptive chemistry (but one which
deals only with substances occurring in nature) is recognized
in the prevalent mineral classifications, where the chemical
composition is the primary and most important factor. The
character of the negative (acidic) ion controls for the for-
mation of the largest classes, and subclasses may be based on
the character of the positive (basic) ion, in some cases preceded
by separation into anhydrous and hydrated compounds. In all
these subclasses minerals which belong to the same acidic type
are placed together. The ultimate smallest groups, which
bring together minerals regarded as most closely related, are
based on 1 similarity i in crystal form, dependent on isomor phous
replacement, either entire or partial, and either in the negative
or the positive portion of the molecule; while again dissimi-
larity in crystal form due to polymorphism of substances with
the same empirical chemical composition, serves to distinguish
between groups chemically alike.

The crystal form, therefore, is a necessary diagnostic, as
important for the formulation of our idea of any mineral as
its chemical composition. As Miers* expresses it, for the defini-
tion of minerals “we are forced to employ at least two proper-
ties, namely the chemical composition and the crystalline
form: these two, when completely known, are necessary and
sufficient for the definition and determination of any mineral.”
The less important characters, such as color, structure, habit,

_ state of aggregation, and minor details of chemical composition,

are (or should be) used only to distinguish very subordinate
(varietal) divisions, and, as Miers justly says, far too much
importance has been oenerally assigned to them in naming
minerals. Many cases will also occur to every mineralogist
of minerals which stand alone and can only be referred to
indefinite positions in the classes, dependent on the general
character of the negative ion; that is, they show no intimate
relations with other minerals through both ‘their chemical and
crystallographic characters and constitute the sole represen-
tatives of potential groups, which thus correspond to the mono-
typic genera of botany and zoology.

In this necessary utilization of both chemical composition
and crystallographic characters, the definition and classification
of minerals differ from, and may justly be considered as in

*H. A. Miers, Mineralogy, London, 1902, p. 2

Am. Jour. Sci.—FourtTH SERIES, VoL. XX XIII, No. 194.—Frsruary, 1912.
10

1388 Washington—Suggestion for Mineral Nomenclature.

advance of, the classification and definitions of descriptive
chemistry, which only take cognizance of the ultimate chemi-
cal composition of the substance as revealed by analysis, and
its molecular structure as shown by its reactions, replacements,
molecular weight, ete. To the chemist, CaCO, is only calcium
carbonate, whether its erystal form is tr igonal or orthorhombie,
with correlated differences in specitic gravity, optic characters,
ete. To the mineralogist these two forms are different min-
erals, though the chemical composition is expressed by the
same empirical formula.

This recognition of polymorphous or physically isomeric
forms of the same empirical molecule as different substances
and the converse relationship between substances of closely
similar crystal form and of the same chemical type, though dif-
fering in composition through isomorphous replacement, is
but a logical following out of the teachings of physical chem-
istry. It is an extension of the definition of “substance” to
include, in addition to the chemical composition, the relations ©
of the physical and chemical characters of matter to the con-
ditions of equilibrium which control crystallization. That the
recognition of the essential difference between substances (in
this sense) with the same ultimate chemical composition is
valid and necessary, is shown by consideration of such cases as
diamond and graphite (C), pyrite and marcasite (FeS,), or cal-
cite and aragonite (CaCO,). In these the differences in the
physical characters, and to no less an extent in many of the
chemical characters, as resistance to reagents, of the members
of each pair are so great that they must be regarded as dis-
tinct substances. This would be true even from the purely |
chemical point of view, since the physical differences, espe-
ically those like specific gravity and specific heat, indicate
differences in the molecular weight and very probably in
molecular structure.

It may be noted here that among minerals there are i
ascertained cases of chemical isomerism, in which the distinct
physical and chemical characters, due to profound and _persist-
ent differences in the molecular structure, persist after the sub-
stance has been changed into an amorphous state, as by fusion
or solution, and then recrystallized.* Numerous illustrations
of this are furnished by organic chemistry, the most classical
being that of urea and ammonium isocyanate. Among
minerals it is difficult to prove the existence of such cases,
though they unquestionably occur, and Grotht regards pyrite
and marcasite, and cyanite, sillimanite and andalusite, respec-

* Groth, Introduction to Chemical Crystallography, New York, 1906, p. 3.

Groth, Chemische Krystallographie, Leipzig, Pt. I, 1906, p. 155, and
ry, grapnhie, pzig, , » P :
Pt. II, 1908, p. 258.

P

Washington—Suggestion for Mineral Nomenclature. 139

tively, as cases in point. Whether there is any essential dif-
ference between physical and chemical isomerism may perhaps
be doubted, but further discussion of this topic is uncalled for
here.

In spite of this advanced state of the classification of min-
eralogy, the nomenclature is in much the same condition as in
the time of Pliny, when minerals were named after their qual-
ities, localities, or uses, with the systematic termination -ctes
or -2tis (modern -2¢e), the only innovations being the intro-
duction of names after persons and certain other arbitrary ter-
minations. Despite attempts to introduce binomial names,
analogous to those of botany and zoology, or those based on
chemical characters, systematic mineralogy has adhered closely

to the nomenclature of the first century A. D.*

Asaconsequence, mineral nomenclature, like that of the older
rock classifications, is unable to express the facts of classification.
Roots derived from names of places or persons can convey in
themselves absolutely no idea of the mineralogical characters,
and even those derived from chemical or physical characters
are applicable to many different minerals. Thus cuprite
applies equally well to CuO as Cu,O, and octahedrite would be
an appropriate name for magnetite, franklinite, or fluorite.
All such name roots are purely arbitrary in their mnemonic
connotations, but at the same time, by long association, a laige
proportion of mineral name roots convey very definite ideas of
the mineral and chemical characters.

_ Again, with the uniform and monotonous general use of a
single termination (-ite), and the arbitrary and unsystematic
employment of others, the characters and relations of minerals,
and even of mineral groups, are concealed. No distinction is
evident from the name between a rare or uncharacteristic vari-
etal form of a certain mineral (as hiddenite or sagenite), and
a large mineral group which may include many distinct min-
erals (as zeolite or chlorite). In the case of a few of the com-
monest and largest groups of related minerals we have names,
fortunately distinctive because of their terminations, which

-may be applied to the group as a whole, as spinel, feldspar,

garnet, pyroxene, amphibole, mica; and the general usefulness
and common application of these is sufficient evidence of the
value of such group names. In other cases the difficulty of
expressing relationships is got round and the need supplied by
the word “group” after the name of a typical representative:
as the pyrite, calcite, aragonite, olivine, and apatite groups.
In all these group names the underlying idea which connects
the members is adherence to a certain type of chemical formula,
with isomorphous replacement, and, of equal importance, close

* Cf. Dana, System Mineralogy, 1892, p. xl.

140 Washington—Suggestion for Mineral Nomenclature.

similarity in the crystal form as shown by the system, axial

relations, and often cleavage. As regards the crystal system,
in the largest groups this similarity need not amount to iden-
tity, as in the feldspars, pyroxenes and amphiboles, but in gen-
eral the idea of a mineral group implies identity of crystal
system modified only in its details by the slight morphotropic
changes consequent on isomorphous replacement.

It will thus be seen that a mineral nomenclature should be
able to express in the name a fairly definite idea of the chemi-
cal composition and type of compound, as well as the crystal
system, and at the same time indicate the relations to other
minerals, and especially the membership of a mineral in its
particular “group.” It is the object of this paper to lay stress
on the importance of the recognition in mineralogical classifi-
cation of this idea of mineral groups, distinguished by close
similarity in chemical composition and erystal form, and made
up of distinct mineral members, and to suggest a nomenclature
which will express these relations, based on the general prinei-
ples of chemical nomenclature, but providing also for the
recognition of the crystal form as an element of the classifica-
tion.

The System of Nomenclature.—As compared with the ecar-
bon compounds, minerals, and especially the silicates, present
very great difficulties in the study of their molecular constitu-
tion. This is because of their high fusing points, non-volatility,
insolubility, general chemical stability at ordinary or even very
high temperatures (so that replacements of portions of the
molecule are difficult), and impossibility of determination of the
molecular weight, assuming that the term “ molecular weight”
is applicable to a solid body. Although we now realize the
importance of this branch of mineralogy, and are beginning to
recognize, especially among the silicates, the complex chemical
constitution of many minerals and the existence of certain
radicals or atomic groups analogous to those of organic chem-
istry, yet we are generally forced to be content with the expres-
sion of the chemical composition by simple empirical formulas.
The constitutional and graphic formulas of but very few min-
erals can be given with any degree of confidence, and in the
vast majority of cases we are absolutely in the dark.

Mineralogy is essentially in the condition of organic chemis-
try of the early days, when the composition of alcohol could only
be expressed émpirically as C,H,O, that of lactic acid as C,H,O,,
and that of urea as CH,ON,; - wher eas at present we can “confi-
dently express them by the constitutional for mulas, (O,H,)
(OH), (CH,) (CHOH) (COOH), and (CO) (NH,),, systemati-
cally known as ethyl alcohol, o-hydroxypropionic acid, and
carbonyl amide, the last differing in constitutional formula
from the isomeric ammonium isocyanate, (CON) (NH,).

Veashingiow.~ Suggestion Jor Mineral Nomenclature. 141

Indeed, the theory of mineral constitution at present is in
many ways analogous to the “theory of types” in organic
chemistry, formulated by Gerhardt about 1850,as is seen in
the general reference of the silicate minerals to simple silicic
acids, H,SiO,, H.,SiO,, H,Si,0,, ete. Kekulé’s “ theory of linked
atoms” has now superseded this in organic chemistry, * and
the applicability of this to mineral chemistry has only recently
begun to be realized.

The study of the molecular constitution of minerals and
attempts at the establishment of constitutional formulas have
been undertaken by T'schermak, Groth, Clarke, and many others,
either throngh direct experiment or study of alteration pro-
ducts, but so far with doubtful success in most cases, and it
will probably be many years before mineralogy attains to the
knowledge requisite for formulas like those of modern organic
chemistry.

In three important papers Penfieldt established the complex
character of the acidic portion of the tourmalines and amphi-
boles, and showed the effect of the mass action of the complex
acid in controlling crystallization, allowing replacement of the
hydrogen atoms of the hypothetical acid by very different ele-
ments or radicals, and with different valences, but without
change in crystal form. He also speaks of these acids as tour-
maline acid and amphibole acid, with the implication that an
essential character of their salts is adherence to the particular
erystal form of tourmaline and amphibole respectively.

More recently the problem of the constitution of some sili-
cates has been studied by Tschermak, Baschieri and others.t
These investigators have identified certain silicic acids, which
they call after the mineral names, among them being: anorthi-
tic acid (H,Si0,) albitic acid (H,Si,O,), leucitic acid (H,Si,O,),
heulanditie acid (H,,Si,O,,), granatic acid (H,8i,O, and dato-
litic acid (H,Si,O,). Their method, it may be remarked, does
not apparently permit of discrimination between a purely sili-
cic or an alumo- or boro-silicic acid, and none of these workers
suggests, like Pentield, that the acid or the acid name implies
the crystal form of its salts.

It is suggested here that this concept of Penfield of silicate
minerals as salts of mineral acids, in many cases of much
greater complexity than is implied by the empirical formula,
with the implication of the adherence of the salts to a charac-

*Cf. C. Schorlemmer, Rise and Development of Organic Chemistry, Lon-
don, 1894, pp. 39, 69, and 155.

+ This Journal, vii, p. 97, 1899: x, p. 19, 1900; xxiii, p. 28, 1907.

+t Tschermak, Sb. Ak. Wiss. Wien, exii (1), p. 300, 1905, exiv (1), p. 455,
i909, exy (1), p. 217, 1906.) HE. Baschieri, Proc. verb. Soc. Tose. , Xvi, p. 34,

1907: Atti Soc. Tose. Mem., xxiv, p. 133, 1908. Himmelbauer, Sb. Ak.
Wiss. Wien, cxv(1), p. 1184, 1906.

142 Washington—Suggestion for Mineral Nomenclature.

teristic crystal form, be extended to minerals in general and
made the basis of a mineral nomenclature. From this point of
view silicate minerals would not be considered simply as salts of
orthosilicic acid (H,Si0,), metasilicic acid (H,Si0,), disilicic acid
(H,Si,O,), and so forth; as substitution derivatives of normal
aluminum silicates according to Clarke, (which correspond to
the old theory of types); or of multiples of silica according to
Goldschmidt: but each group would be considered as salts of a
particular silico- or alumino-silico- acid characterized by the parti-
cular crystal form and symmetry of its salts, and capable of
ismorphous replacement either of its basic hydrogens or in the
acidic portion.

This concept may be most appropriately applied to mineral
groups, distifguished as at present by identity of chemical
type and close similarity in crystal form, but it may be equally
_ well applied to monotypic “groups”, represented, so far as now
known, by only one mineral and which exhibit no evident
near relationships, either chemical or crystallographic, as is the
case with beryl and calamine. It is also clear that it would
be applicable to minerals of simple as well as highly complex
constitution. A further poimt, and one of great importance,
is that a system of nomenclature based on this concept would
be applicable whether the structural or constitutional formula,
or even the exact chemical composition, of the mineral acid
were known or not, as the salts of a given mineral acid (in this
sense) would be identifiable and their relationship established
by their conforming to a certain empirical chemical formula
and crystal form. Thus the various pyroxenes and amphiboles
are members of two different, but well-characterized, and uni-
versally recognized “natural” groups, though we are as yet
almost wholly ignorant of their molecular constitution, know-
ing only that they may be referred, but do not necessarily be-
long, to the metasilicates, but are undoubtedly much more com-
plex than is indicated by the empirical formulas. We cannot
even determine which group is the more complex.

Such a nomenclature would be rational and would be analo-
gous to that of morganic chemistry, of which mineralogy may
be considered to be a branch, except that the crystallographic
character is implied in the name and is an integral part of the
definition. It might even be suggested that such a nomencla-
ture as is here suggested is also applicable to artificial salts, and
would be found especially useful with such highly complex
compounds as the silicotungstates, phosphomolybdates, cobalt-
ammine compounds, the various groups of which might be
named after chemists who have been especially identified with
their study.

While in advance of the present inadequate nomenclature,

Washington—Suggestion for Mineral Nomenclature. 148

in that not only chemical and crystallographic characters but min-
eral relationships would be indicated, the suggested nomen-
clature would not, nor is it intended to, replace this for general
use. The two would exist simultaneously, though used
for different purposes, as the new nomenclature would lend
itself readily to, and would probably aid in, the study and
investigation of the molecular constitution of minerals and in
other ways. In ordinary parlance and for usual purposes min-
erals, especially the common ones, would go by their present
names, while when greater precision and exactitude were needed,
especially in theoretical discussion, the suggested nomenclature
could be used. Similarly, in inorganic and especially in organic
chemistry, the common names are ordinarily used instead of
the longer and more complex scientific names, which are. sys-
tematic and indicate the chemical constitution. 3

For the purposes of such a nomenclature the large store of
present mineral names may be drawn on for the necessary roots,
since these roots would have in most cases sufficient mnemonic
connotations to give directly an idea of the general chemical
and crystal characters. Well-known or fairly well-known roots
are sufficiently numerous to cover nearly the whole field of
mineralogy. Though new minerals are being discovered with
some frequency, representatives of entirely new mineral groups
are comparatively rare, as many of the new minerals are refer-
able to groups already known, and with increasingly exact
knowledge of chemical composition and molecular structure,
many minerals of hitherto unknown or uncertain affinities are
being correlated with other groups, as the sodalites and the
garnets.

It is suggested that the names of minerals (excepting for the
present the elements and hydrocarbons) be formed similarly to
those of oxides and salts in morganic chemistry, as ferric oxide,
sodium chloride, potassium sulphate, but with the crystal char-
acter implied in the name. Such mineral names will be bino-
mial in general, composed of one term denoting the basic
(positive) portion of the molecule and another denoting the
acidic (negative) portion. As the acidic portion is of major
importance in classification it will be considered first.

The name of the mineral acid, or the acidic portion of its
salts, will imply not only general chemical composition and
type, but the crystal symmetry and general crystallographic
relations of its salts, subject to the morphotropic changes due
to isomorphous replacement.

The acid (negative) radical of a mineral group will be denoted
by a root derived from the present name of atypical and appro-
priate member, preferably that best known or first named.
To this root, in general shorn of its present termination (except

144. Washington—Suggestion for Mineral Nomenclature.

for euphony or to avoid confusion with ordinary chemical
salts), will be affixed the termination used in inorganic chem-
istry for the type of compound represented. For the mineral
acid itself this termination would then be -zc, for a binary com-
pound (oxide, sulphide, ete.) it will be -zde, for the sulpho-acid
and analogous salts,*. and for the oxy-acid salts, it will be -ate.
As noted above, it will not be necessary to know the constitu-
tional formula of the acid or mineral group to name it, as it
may be defined by its empirical formula and crystal form.

The water of crystallization of hydrated mineral salts may
in general be considered for the purposes of nomenclature as
part of the negative portion of the molecule, since not only do
nearly all hydrates differ crystallographically from the anhy-
drous salts, but the crystal form varies with the number of mole-
cules of water present when several hydrates exist.

Such simple designations, implying always the crystal system
characteristic of the salts of the mineral acid, will suffice for
the negative (acidic) portion of isomorphous mineral groups in
which the acid radical is identical in all (the base alone varying
through isomorphous replacement), or for monotypic mineral
groups. Thus, the members of the calcite, aragonite, and
olivine groups are respectively salts of calcitic, aragonic, and
olivinice acids, or calcitates, aragonates, and olivinates; while
eyanite and calamine are the only known disthenate and ecala-
mate respectively.

When, however, in a group the chief element in the acidic
portion is replaceable isomorphously, by different elements, as
with the pyrite and apatite groups or, as in the pyroxenes and
feldspars, there are marked differences in the crystal symmetry,
the acidic portion remaining chemically the same, it becomes
necessary to indicate these differences in the nomenclature.
This may best be done in two ways, according to which of the
cases 1s involved.

In the case of isomorphous replacement in the acidic portion
the different compositions may be expressed by the use of
appropriate prefixes to the acidic term used without a hyphen.
Thus all members of the pyritohedrally isometric pyrite
group would be pyrides, but pyrite and hauerite would be
sulpyrides, and smaltite and chloanthite arsenpyrides. Among
the silicates the presence of unusual or non-typical elements
partially replacing silica may be expressed by similar syllables
pretixed to the acidic name with a hyphen. Thus rosen-
buschite and lavenite would be zirco-diopsidates. In some eases,
when the isomorphous replacement in the acidic portion is
complex, it may be advisable to use very much shortened syl-

* The regular termination -ite would be inadvisable for these, as liable to
confusion with present names.

Washington—Suggestion for Mineral Nomenclature. 145

labic forms for the various elements, as will be explained when
the naming of the base is considered.

In the case of the more complex mineral acids, especially
among the silicates, as the alumo-silicates or boro-silicates, in
which only the subsidiary acidic element is’ isomorphously
replaceable, the replacement will be indicated by the use of
appropriate chemical syllables prefixed to the acidic term, used
with a hyphen. Thus, if the garnets are regarded as salts
of complex alumo-. ete.- acids, they would be called alumi-
garnetates, ferri-garnetates, and chromi- garnetates, and simi-
larly members of the datolite group would be bori-datolates,
alumi-datolates or yttri-datolates, represented by datolite, euclase,
and gadolinite. This will serve to distinguish such complex salts
from those of mineral acids in which one characteristic element
exists and is wholly replaced, as in the apatite group, which
would be called phosphapatates, arsenapatates, and vanada-
patates.

When the differences are those of crystal symmetry, as in
the pyroxene and feldspar groups, the general group names
will be formed as above by a root derived from the present
group name or best representative, followed by the termi
nations -oze for the acid, -ode for binary compounds, and -ote
for sulpho-and oxy-salts. The various subgroups, distinguished
by differmg but related crystal systems, will be designated by
the use of the appropriate roots and regular terminations as
described above. Thus all the members of the pyroxene group
would be salts of pyroxenoic acid or pyroxenotes, while the
orthorhombic members would be hypersthenates, the mono-
clinie diopsidates, and the triclinic rhodonates.

The rare cases among minerals of homologous series, corre-
sponding to the paraffins and olefines of organic chemistry, in
which each member differs from the preceding by a constant
increase of a certain atomic group, must also be considered.
These are best represented by the humite group, better called
“series.” The members of such a series may be designated as
to the acidic portion by the use of the prefixes wn2-, b2-, ter-,
etc., to indicate the number of the varying radical, as will be
shown later.

The base or bases present will be indicated by the use of the
name or names of the positive element or elements, either as
such or expressed by appropriate syllables when more than one
base is present. It may be suggested that the relative impor-
tance of the several isomorphous bases present be indicated by
a definite order in the syllables and that the most important
be placed last, the preceding ones being in the nature of mod-
ifiers. This can also be emphasized by using the full name
for the most important base, and a contracted adjectival form,

146 Washington—Sugqgestion for Mineral Nomenclature.

ending in @ or 0, for the others. When two bases are of equal
importance, present in about equal molecular amounts, the
combined full names may be used, though this last might better
be reserved for definite double salts, as dolomite. Illustrating
the above idea, forsterite would be called magnesium olivinate,
most chrysolite ferro-magnesium olivinate, hyalosiderite might
be magnesi-ferrous olivinate, and fayalite ferrous olivinate.

In many minerals, however, several bases are present and in
these cases, and even when there are only two, the designation
of the base may become long and cumbrous. It may therefore be
desirable to have all the bases represented by syllables as com-
pact and condensed as possible, so long as this can be done with-
out sacrificing clearness. Jor this purpose it is suggested that
the first syllable of the element name may be used, joined
together without linking vowels or hyphens, the order being
significant of the relative importance, asabove. Thus enstatite
would be magnesium hypersthenate, bronzite fermag hypersthe-
nate, and a highly ferrous hypersthene magfer hypersthenate.

Witn the increasing recognition of the presence of radicals
in minerals it becomes necessary, as a matter of convenience, to
designate these by short terms, and here we may well follow
the lead of organic chemistry, where we find such indispen-
sable radical names as ethyl, butyl, phenyl, acetyl, derived from
their most prominent compounds. Similarly we might desig-
nate the mineral radical, Al(F,OH), essential in topaz, as topyl;
Mg(Fj{OH), present in the chondrodrite series, as chondry] ;
and (BOH), which Penfield has shown to be present in tourma-
lines, as tourmyl. Such radical names would take the place of
element names when present as bases.

The objection will, of course, be raised against the use of
such syllables that they are barbarous, uncouth, and cacopho-
nous. In reply to this it may be said that, while they will
undoubtedly appear so at first, usage will gradually render
them easy, natural, and less awkward. As a case in point
may be cited the terminology of organic chemistry, where we
find such words as carboxyl, aldoxim, azoxybenzol, glyoxal,
phthalisoimide, and a host of others. The same objections
could have been, and probably were, raised against these,
but to express the lengthy and complicated names of organic
compounds the chemist has found such syllables absolutely nec-
essarv. They are readily understandable and give an imme-
diate insight into the composition of the substance, have
wholly lost their original ‘“‘ barbarousness,” and new ones are
freely coined when needed.

Acid and basic salts present some difficulties, as it is not
always possible as yet to determine the function of hydrogen
or hydroxyl in minerals. When definitely known to be basic

Washington—Suggestion for Mineral Nomenclature. 147

or acid salts they may be so designated, but in general they
may be designated by special acidic names for the group, since
the acidity or basicity almost always determines a crystal form
different from that of the normal salt.

Names formed as suggested above have certain analogies
with some of the present mineral names, in which isomorphous
replacement is indicated by the use of chemical modifiers, as
soda-microline, manganopectolite, cuprodescloizite, natrojaro-
site, plumbo-jarosite and soda-mica. Even in these we can see
the lack of system in present nomenclature, since these names
belong to two distinct categories. In the one the modifier
expresses only partial replacement of the characteristic element
of the type mineral by an isomorphous one, as in the first three
examples, which are presumably cases of solid solution and
should be regarded as varieties of the type, or as intermediate
between two extremes. In the last three cases there is entore
replacement by the element denoted in the name, and such
minerals are definite compounds and must be regarded as dis-
tinct species. For this reason natrojarosite and plumbojarosite
are better entitled to recognition as distinct minerals than are
soda-microcline (anorthoclase) or manganopectolite, and should
have special names not formed on this plan, while paragonite has
properly replaced the earlier soda-mica, which last should be
used for a mica in which the potassium is only partially replaced
by sodium.

The names of the suggested nomenclature are properly appli-
cable only to minerals of the second kind just mentioned, that
is to definite compounds, since it is essentially an inorganic
chemical nomenclature, in which mixed erystals should be
named by calling them mixtures of their components. In
mineralogy the case is somewhat different, it is true, as such
mixed crystals are often important and fairly well-defined min-
eral species, and names for them are necessary. Some latitude
and discretionary power niust, therefore, be allowed, and while
all rather indefinite mixed crystals need not receive specific
recognition or names, there will be many cases, especially
when the mixture is of mineralogical importance, fairly con-
stant in composition, or with some approximation to simple
stoichiometric ratios, when names as above should be bestowed.
To meet the common case of the indefinite or variable isomor-
phous replacement, it may be suggested that the syllable -ec be
added to the compounded elemental syllables used for the base.
Thus the various hypersthenes and bronzites would be called
collectively fermagic hypersthenates, and the lime-soda feld-
spars would be calsodic albates.

Llliustrations of the System.—It is impracticable to give
here a complete illustration of the application of the system to

148 Washington—Suggestion for Mineral Nomenclature.

all known minerals, so that only a few selected cases are given
which will illustrate the points brought out above. It is pur-
posed to publish elsewhere a fairly complete list, already
prepared, which will serve as a basis for the suggested nomen-
clature.

SPHALERITE GROUP.

Sphalerides, R"(S,Se,Te), isometric, tetrahedral.

Sphalerite, ZnS Zine sulsphaleride
Metacinnabarite, HgS Mercury sulsphaleride
Alabandite, MnsS Manganese sulsphaleride
Tiemannite, HgSe Mercury selsphaleride
Onofrite Hg(S,Se) Mercury selsulsphaleride
Coloradoite, HgTe Mercury telsphaleride

Pyrite GRovp.

Pyrides, R(S,As,Sb),, isometric, pyritohedral.

Pyrite, FeS, Tron sulpyride
Hauerite, Mn§S, Manganese sulpyride
Laurite, RuS, ’ Ruthenium sulpyride
Smaltite, CoAs, Cobalt arsenpyride
Chloanthite, NiAs, Nickel arsenpyride
Sperrylite, PtAs, Platinum arsenpyride
Cobaltite, Co(S, As), Cobalt sularsenpyride
Gersdorftite, Ni(S, As), Nickel sularsenpyride

MARCASITE GROUP.

Marcasides, R(S,As),, orthorhombic.

Marcasite, FeS, Iron sulmarcaside
Léllingite, FeAs, Iron arsenmarcaside
Safflorite, CaAs, Cobalt arsenmarcaside
Rammelsbergite, NiAs, Nickel arsenmarcaside

HEMATITE GROUP.
Hematides, R,O,, trigonal.

Corundum, Al,O, Aluminum hematide
Hematite, Fe,O, Tron hematide
Ilmenite, (Fe,T1),0, Titanferri hematide

Geikielite, (Mg,Ti),O, Titanmagnesi hematide
Pyrophanite, (Mn,T1),O, Titanmangani hematide

If the members of this group are considered to be aluminates,
ferrates, etc., the appropriate names would be : Aluminum alhem-
atate, iron ferhematate, iron titanhematate, magnesium titan-
hematate, and manganese titanhematate.

Washington—Suggestion for Mineral Nomenclature.

CALCITE GROUP.

Calcitates, R",CO,, trigonal.

Calcite, CaCO,

Magnesite, MgCO,
Dolomite, CaMg(CQ,),
Ankerite, (Mg,Fe)Ca(CO,),
Siderite, FeCO,
Rhodochrosite, MnCO,

Calcium calcitate
Magnesium calcitate
Magnesicalcium calcitate
Fermag-calcium calcitate
Ferrous calcitate
Manganese calcitate

FELDSPAR GROUP.*

Feldspathotes, S

R’AISi,0,
| R’A1,Si,0,

ADULAR SUBGROUP.

Adularates, monoclinic.

Orthoclase, K A1Si,O,
Barbierite, NaAlSi, O.
Celsian, BaAl, Si, O.

Potassium adularate
Sodium adularate
Barium adularate

ALBITE SUBGROUP.

Albates, R'AlSsi,O,,

Microcline, K.A1Si,O,
Albite, NaAlsi EO
Anorthoclase, (K, 'Na) AISi, O,

triclinic

Potassium albate
Sodium albate ,
Potassisodium albate

ANORTHITE SUBGROUP.

Anorthates, R"Al,Si,O,,

Anorthite, CaA1,Si,O,
Carnegieite, Na, A1,S8i,O,

triclinic.

Calcium anorthate
Sodium anorthate

Mixed Salts.

Oligoclase, Ab, An,
Andesine, Ab, An,
Labradorite, Ab, An,

Caldisod anorth-albate
Sodeal alb-anorthate
Soddical alb-anorthate

PYROXENE GROUP.

ao1,O

o monoclinic-triclinic.

149

Pyroxenotes, , orthorhombic, monoclinic, triclinie.

R’R’” SiO,

*The constitution and relations of the feldspars, lenads and zeolites will
form the subject of a subsequent paper.

150 Washington—Suggestion for Mineral Nomenclature.

HyYPERSTHENE SUBGROUP.

Hypersthenates, orthorhombic.

Enstatite, Mg,Si,0, Magnesium hypersthenate
Bronzite, (Fe,Mg),Si,O, Ferromagnesium hypersthenate
Hypersthene, (Mg,Fe),Si,0, Magnesiferrous hypersthenate

DiopsipE SUBGROUP.
Diopsidates, monoclinic.

Diopside, CaMgS8i,O, Calcimagnesium diopsidate
Hedenbergite, Cak’eSi,O, Calciferrous diopsidate
Wollastonite, Ca,Si,O, Calcium diopsidate
mCaMegsi,O Py p> 2
Augite, | n(Mg, Fe) (Al,Fe),SiO, Alfercalmag diopsidate
Acmite, NaFeSi,0, Ferrisodium diopsidate
Jadeite, NaAIS8i,O, Alumisodium diopsidate
Spodumene, LiAISi,0, Alumilithium diopsidate
Pectolite, HNaCa,Si,O, Acid sodicalcium diopsidate

RHODONITE SUBGROUP.

Rhodonates, triclinic.

Rhodonite, Mn,8i,0, Manganese rhodonate
Babingtonite, ne Si oar: Ferricalcium rhodonate

OLIVINE GROUP.

Olivinates, R",Si,O,, orthorhombic.

2 4)

Forsterite, Mg.Si,O, Magnesium olivinate
Monticellite, CaMgsi,O, Calcimagnesium olivinate
Chrysolite, (Fe,Mg),Si,O, - Ferromagnesium olivinate ~
Fayalite, Fe,Si,O, Ferrous olivinate
Tephroite, Mn,8i,O, Manganous olivinate
Glaucochroite, CaMn8i,O, Calcimanganous olivinate

CHONDRODITE SERIES.

Chondrodates, R",,_,(R"(F,OH)),(SiO,),, orthorhombic
Prolectite, Me(Mg(F,OH)),(Si0,)
Magnesium uni-chondrodate
Chondrodite, Mg,(Mg(F,OH)),(Si0,),
Magnesium bi-chondrodate

i

Humite, Me. {Me(F,OH)), (Si0,),
Magnesium ter-chondrodate
Leucopheenicite, Mn,(MnOH),(Si0,),

Manganese ter-chondrodate
Clinohumite, Mg.(Mg(F,OH)),(S810,),

Magnesium quadri-chondrodate

Washington—Suggestion for Mineral Nomenclature. 151

DAaTOLITE GROUP.
Datolates, R",R'Si,O,,, monoclinic.

10?

Datolite, H,Ca,B,8i,0,, Acid calcium bori-datolate
Euclase, H,G1,A1,8i,O,, Acid glucinum alumi-datolate
Gadolinite, FeG],Y,Si,O,, Ferro glucinum yttri-datolate
Homilite, FeCa,B,Si,0O,, Ferro calcium bori-datolate

SPINEL GROUP.

Spinelates, R"R'’,O., isometric.

Spinel, MgAl,O, Magnesium alumispinelate
Hercynite, FeAl,O, Ferrous alumispinelate
Gahnite, Zr Al,O, Zine alumispinelate
Magnetite, FeFe,O, Ferrous ferrispinelate
Chromite, FeCr,O, Ferrous chromispinelate

APATITE GROUP.
Apatates, R" (F, Cl) ((P, As, V)O,),, hexagonal.

Apatite, Ca,(F,Cl)(PO,), — Calcium phosphapatate
Pyromorphite, Pb,Cl(PO,), Lead phosphapatate
Mimetite, Pb,Cl(AsQ,), : Lead arsenapatate
Svabite, Ca,F(As9O,), Calcium arsenapatate
Vanadinite, Pb,Cl(VO,), Lead vanadapatate

Locust, N. J., November, 1911.

152 Zodd—Optical Resolution of the Saturnian Ring.

Art. XIX.—Optical Fesolution of the Saturnian Ring ;
| by Davip Topp.

OBSERVATIONAL research upon the ring of Saturn may be
embraced in ten stages :

(1) Galileo (1564-1642) represented the Saturnian system
triform. “Uliemum (altissemum) planetam tergeminum
observavi,’ he announced and he drew the ring as two separate,
we and lesser spherical bodies on either side of the planetary

all. |

(2) Scheiner (1575-1650) connected these two bodies with
the planet, making it appear like a head with large ears, or a
ae plaque with ansae (handles) as they were called, and
still are.

(5) Rieciol (1598-1671) and Hevelius (1611-1687), with
larger and better telescopes, came very near the real ring form
and all but guessed the true shape of the puzzling anomaly.

(4) Huygens (1629-95) was the first who divined the ring as
such, and he gave a full and accurate description of it as fol-
lows: “Anulo cingitur tenuc plano nusquam cohaerente ad
eclipticam inclinato.”’ His characterization of the ring first
explained all the appearances that had battled his predecessors :
how the ring might disappear and reappear, and in about 30°
years could pass through a complete cycle of phases, from abso-
lute invisibility to the amplest widening. |

(5) Cassini (1625-1712), with a better telescope, showed that
the ring had symmetric dark markings on it which divided it
into two parts though unequal in breadth, the inner one the
brighter and broader.

(6) Encke (1791-1865) discovered a similar division of the
outer ring into two parts, though he found it impossible to trace
the dark dividing line all the way round. In facet, it is often
invisible at the present day.

(7) Bond (1789-1859) and Dawes (1799-1868) discovered a
broad, dusky ring inside the inner Huygenian ring, and
seemingly joined to its inner edge. |

(8) Barnard (1857—_), by observing with the Lick telescope
the transit of Japetus through the shadow of ball and rings,
found the satellite readily visible in passing the crape ring,
fainter by the bright ring, while it disappeared completely in
the shadow of the ball. |

(9) Keeler (1857-1900) photographed the spectrum of the
ring, and measured the displacement in spectral lines of the
inner and outer edge of the bright ring. This displacement
he found exactly what it should be if the ring were not solid,
but made up of clouds of particles revolving round Saturn,
as shoals of satellites in full accord with the Keplerian har-
monic law. The ring might still, however, be gaseous.

It only remained to visualize the separate particles of which
the ring is composed. There are many telescopes powerful
enough to make this observation possible ; and the highly unfa-

Todd— Optical Resolution of the Saturnian Ring. 158

vorable conditions of our lower atmosphere are alone respon-
sible for failure hitherto to resolve the ring into its component
satellites.

The writer has for many years observed Saturn at every
favorable opportunity, and with the highest magnifying pow-
ers that the conditions of atmosphere would admit. In 1905,
when the 18-inch Olark glass was first mounted at Amherst,
the rmg was toc much foreshortened and the inner regions of
the ansae too restricted in area. In 1907 when the glass was
taken to Chile for photographing Mars, the ring was passing
its period of edgewise visibility: the desert seeing, however,
was most of the time superb, and resolution of the ring would
have been relatively easy, from our station at Alianza in the
foothills of the Andes, had the presentation of the ring been
favorable.

Since remounting the telescope at Amherst, every opportu-
nity of exceptional definition has been embraced. Further-
more, the objective has been fitted with an exterior iris
diaphragm, conveniently operated from the eye-end; and the
absolute necessity of such an appliance in all telescopic work
requiring fine definition has been proved beyond adoubt. The
pupil of the eye automatically opens and closes, in adaptation
to the strength of illumination of the object toward which it is
turned ; and the addition of a great objective to the optical
system requires further adaptation of the amount of light it
gathers to that particular magnifying power which the special
condition of the always turbulent air will allow.

The weather conditions of the peculiar autumn of 1911 gave
many opportunities when resolution of the Saturnian ring near its
extremities was suspected ; but not until the perfectly quiescent
nights of October 28 and 29 was there a near approach to that
serenity and entire atmospheric calm which I had before
experienced but twice: on the summit of Fuji-san in 1887, and
in the desert of Tarapaca in northern Chile twenty years later.
The power on this occasion was pushed nearer to the limit than
I had ever found it possible to do before at Amherst. The
sky, too, was absolutely clear of haze, so that a power of 950
gave only very slightly scattered illumination in the field. In
moments of best definition a power of 1400 was found to per-
form satisfactorily with an aperture of 16 inches.

Near the extremities of the inner bright ring there was a:
lenticular shading, as drawn by Proctor (1837-88), and less
pronouncedly by Barnard; and it was in this especial region that,
in moments of the best vision, a certain sparkling flocculence
was more or less steadily glimpsed ; scintillant much as fine
snowflakes sun-illumined at the close of a storm. There was
no longer in the writer’s mind any doubt that the separate
component satellites of the ring had been seen, at least in that

Am. Jour. Sct.—FourtH Series, VoL. X XXIII, No. 194.—Fresruary, 1912.
ily

154 ZLodd—Optical Resolution of the Saturnian Ring.

part of the inner Huygenian ring which is adjacent to the
extremities of sits major axis. The degree of amplification
seemed too great for resolution of the dusky ring; in fact,
with the highest powers it was very difficult to discern this
ring at all. The accompanying sketch of the critical region of
the planet is a crude attempt to show approximately the area
of the resolution in the following ansa, though it was by no
means so regular either in character or outline as the engraver
has represented it. It should be viewed not less than eight
feet from the eye.

Through November, December, and early January every
favorable opportunity of observing Saturn was embraced, but

at no time did the seeing approach. the excellence of late Octo-

Following Ansa of Saturn, Oct. 28, 29, 1911.

ber. Usual winter conditions having evidently set in for a
permanency, no further opportunity for verification of the res-
olution appeared likely to offer during the current presentation.
A Latin dispatch was therefore fr amed, with the assistance of
my colleague, Dr. Houghton, and for warded to Sir David Guill,
as follows: Saturni anulorum clarorum extertorumgue axium
matorum prope extrema, me adiuvantibus validissimis tele-
scopiis, quandam flocculentiam scintillantem observavi, quam
oculorum dissipationem anult esse interpretatus sum.

By a like fatality that rendered Schiaparelli’s canali into
canals, oculorum dissipatio became, not optical resolution, its
true English equivalent, but dzsstpatcon,—a simple translitera-
tion which implied a breaking up or dissolution of the ring:
an idea wholly foreign to the writer, who is no friend o catas-
trophic theories of the Saturnian ring.

Amherst College Observatory, January 16, 1912.

OU

Chemistry and Physics. ig

SOEEN PEE TC INEHUULEGEN CE.

J. CHrmistRyY AND Puysics.

1. Canadium, an Alleged New Element of the Platinum
Group.—The announcement is made by A. G. FRENCH, a metal-
lurgist of the Nelson district in British Columbia, that he has
discovered a new noble metal and has named it canadium in honor
of the Dominion. It was found in the dike rocks in the Nelson
district, occurring associated with platinum metals in quantities
from a few pennyweights to three ounces per ton. It occurs pure
in semi-crystalline grains, and in short rods about half a milli-
meter in length and one-tenth of a millimeter in thickness. It
has been found also in the form of scales in platinum-bearing
ores. These particles, which have a bluish-white color, contain
the metal alloyed with a volatile substance which may be osmium,
as it is dispelled by the blowpipe, leaving a brilliant bead of “ cana-
dium.” The new metal is not platinum, ruthenium, palladium,
nor osmium, as it is much softer than these and is more fusible,
being quite readily melted by the blowpipe. It is not oxidized
by long heating in the oxidizing blowpipe flame. It is soluble in
nitric and hydrochloric acids, and in mixtures of the two acids with-
out residue, and the solution in nitric acid gives no precipitate
with sodium chloride solution. Therefore it is not silver, a fact
which is also indicated by the circumstance that the metal is not
blackened by alkaline sulphides. The metal is not colored by
tincture of iodine, and the nitrate solution gives no precipitate
with potassium iodide. These tests show that it is not palladium.
Its melting-point is somewhat lower than that of gold or silver,
and very much lower than that of palladium. It is electro-neg-
ative to silver. When it is alloyed with gold and silver in “ part-
ing” proportions, dilute nitric acid dissolves the silver first and
then the new element, leaving gold and the usual brown form,
but if the action is stopped when the silver is all dissolved, and
the dark residue is then dried and pressed with a knife-blade, the
color is a most beautiful and brilliant white. The new metal
may then be dissolved by further treatment with nitric acid, pre-
cipitated by zinc, and cupelled with lead to a white bead which
is not colored by alkaline sulphides.

If the description given is accurate, a new metal would seem
to be indicated, and a more thorough chemical examination on a
larger scale, which is intended to be made soon, will be awaited
with much interest.— Chem. News, civ, 283. H. L. W.

2. The Alleged Complexity of Tellurium.—The anomalous posi-
tion of the atomic weight of tellurium in the Periodic System has
led to many-attempts in recent years to separate it into elements
of higher and lower atomic weights, and many such efforts have
led to negative results. However, some recent work has indi-
cated that the fractional decomposition of tellurium tetrachloride

156 Scientific Intelligence.

by means of hot water gave a product which showed a lower atomic
weight for tellurium than the one usually accepted. In fact an
atomic weight as low as 124°32 was obtained by Flint from such
fractionated material in one case, in place of the usual atomic
weight, 127°5. Since Baker and Bennett had previously failed
to find any change in tellurium by this same method, as well as
by six other methods, Harcourt and BaKeEr have repeated the
work. Starting with some very pure telluric acid, they made four
fractional precipitations in series from solutions of the tetrachlo-
ride by pouring them into boiling water. The tellurium of the
final product was carefully purified and its atomic weight was
determined by converting it into the tetrabromide. Five results
gave the numbers 127°55, 127°55, 127°53, 127°53, and 127°53, while
determinations on material similarly purified, but without the
attempted fractionation, gave a mean result of 127°53. Since the
results showed no evidence of the slightest change by means of
the fractional precipitation, the operation was not carried further.
The authors believe that the low results previously mentioned
were due to contamination of the dioxide with trioxide, which
was shown to give a precipitate with an orange color. It is evi-
dent, at all events, that no fractionation of tellurium into dif-
ferent elements has as yet been effected.— Chem. News, civ, 260.
H bes We

3. A New Quantitative Separation of Iron from Manganese.—
J. A. SancHEz has found that when pyridine is added to a neu-
tral or slightly acid solution of ferric and manganous salts, all the
iron 1s precipitated as hydroxide, while the manganese remains in
solution. It is stated that in this way it is possible to separate
0:0005 g. of manganese from 1g. of iron. Neutralization of nearly
all the free acid by caustic soda or potash, adding pyridine, boil-
ing for 10 minutes, and washing the precipitate first with hot
water saturated with pyridine, then with hot water alone, are
recommended. No test analyses are given, nor is any statement
made in regard to the behavior of nickel and cobalt in the sepa-
ration, but it is stated that zinc goes partly into the precipitate
and partly into solution.— Bulletin, ix, 880. H. L,. WW:

4, Famous Chemists ; by E. Roperts. 12mo, pp. 247. Lon-
don and New York, 1911 (The Macmillan Company).—The object
of this little book is to give an account of the chief work of the
most famous chemists, and to indicate briefly the part played by each
in the development of the science. The subjects treated are Stahl,
Boyle, Black, Cavendish, Priestly, Scheele, Lavoisier, Berthollet,
Dalton, Davy, Gay-Lussac, Berzelius, Faraday, Dumas, W ohler,
Liebig, Graham, Bunsen, Hofmann, Pasteur, Williamson, Frank-
land, Kekulé, Mendeleeff, Perkin, and Victor Meyer. The
essays include the important biographical facts as well as the
principal achievements of these heroes of chemistry. The arti-
cles are clear, concise, and well written, and the book will
be very useful to those who wish to obtain an outline of the
development of modern chemistry. H, i. We

Chemistry and Physics. 157

5. Quantitative Chemical Analysis ; by CiroweEs and Co.Le-
MAN. 8yvo, pp. 565. Philadelphia, 1911 (P. Blakiston’s Son & Co.).
This text-book is so well known and widely used, both in Great
Britain, the place of its origin, and in the United States, that the
appearance of the present ninth edition requires no comment
except the statement that the text of the much improved eighth
edition, which appeared two years ago, has been carefully revised
with the result that some additions and improvements have been
made, and errors have been corrected. HisoLs. We

6. Photometric Paddle- Wheels. — James R. Mitnez_ has
recently described a new form of rotating photometric sector
similar to a paddle-wheel in appearance, and consisting, in one
form, of two flat, triangular vanes fixed to the shaft of a motor
by which they are rotated. The amount of light interrupted
depends on the azimuth of the base, which angular measurement
can be made with a high degree of accuracy. The author gives
a mathematical discussion of this new type of apparatus, in which
are deduced formule for the intensities of the light transmitted
under different conditions, and for the greatest width of the
beam of light that can be employed ; and a graphical tabulation
of the values of these formul in different cases is provided.
The mounting and details of an actual instrument are also
described, together with an additional mechanism for the pur-
pose of automatically recording the photometric measurements
obtained.—Proc. Roy. Soc. Edinburgh, vol. xxxi, pp. 655-683.

7. A Text-Book of Physics; by Lovis BrvirR SPINNEY.
Pp. xi, 605. New York, 1911 (The Macmillan Co.).—This vol-
ume is designed primarily for use as a text in courses offered to
engineering and technical students. Hence, special emphasis is
laid on the practical aspects of the subject. Illustrations of phys-
ical laws are drawn as far as possible from familiar phenomena,
and physical principles are exemplified by numerous important
applications. Particular emphasis is placed upon the subject of
Mechanics. Also, it is expected that the book will be used as a
basis for class-room work and that it will be supplemented by a
course of experimentally illustrated lectures and suitable labora-
tory exercises. The text is up to date and includes, of course,
a discussion of ionization and radio-activity. A knowledge of
plane trigonometry and elementary chemistry is assumed. The
figures are large, well-drawn and interesting, and Gothic type
is used for emphasis. 325 problems for solution are distributed
throughout the volume.

As regards minor details the book possesses both satisfactory
and unsatisfactory characteristics. For instance, on page 26 an
acceleration is given as “2 miles per hour per minute,” which is
very helpful to students who find difficulty in grasping the full
meaning of 2 miles per sec. per sec. On the other hand, the term
moment of inertia is introduced symbolically on page 39, but its
physical significance is first brought out on page 81. =-H. SS. U.

158 Scientific Intelligence.

8. Tables of Physical and Chemical Constants and some
Mathematical Functions ; by G. W. C. Kaye and T. H. Lasy.
Pp. vi, 153. London, 1911 (Longmans, Green, & Co.).
need of a comparatively small volume of up-to-date tables of
physical and chemical constants has been felt for some time, not
only by the authors but also by the writer of this notice. Hence
it seems fair to assume that this volume will appeal strongly to
others who are engaged either in giving instruction to laboratory
classes or in original investigations.

The material has been wisely selected and the manner of pre-
sentation is excellent. Thus, in addition to the data incorporated
in the older reference books of this type, fifteen pages are devoted
to ionization and radio-activity. Also a table of e-* is appended.
The utility of the volume is enhanced by the insertion, in the
case of many of the sections, of a brief résumé containing refer-
ences to such books and original papers as may be profitably
consulted. The authors say in their preface: ‘Every effort has
been made to keep the material up to date; ..... ae

All numbers, units, etc., deserving special emphasis are printed
in bold-faced type and an index to the pages is given. The book
is bound in a flexible cover, so that it will lie open flat or lend
itself to any other convenient position of holding.

In conclusion, the present writer desires to state explicitly that
the book appeals very strongly to him and he hopes that many
other instructors and investigators will not only give the tables
practical trial, but will also take advantage of the prefatory
invitation of the authors, namely, “..... we shall be very glad
to receive suggestions and to be informed of any mistakes which,
despite every care, have eluded us.” If this is done, a very
valuable set of convenient and reliable tables may be produced
in the course of a few years. H. 8. U.

9. Llektrochemische Umformer [Galvanische Elemente] ;
von Jouannes Zacuarias. Pp. xii, 262; 122 figures. Vienna and
Leipzig, 1911 (A. Hartleben). —The author considers the custo-
mary classification of cells, as primary and secondary elements, to
be unsatisfactory and illogical, and hence he bases all of his
discussions on the use, performance and manner of working or
discharging cells. Consequently the title, ‘“ Electrochemical
Transformers,” has been selected ‘‘to comprise all devices which
serve to transform chemical energy into electrical work by the
wet process.”

Special attention is given to hecienics for furnishing strong
currents and to the so-called “earth cells.” Also, a special section
is devoted to a detailed account of pocket lamps. Accumulators
or secondary batteries are not given prominence. Numerous
tables and curves are distributed throughout the text to illustrate
the behavior of different types of cells under almost every con-
ceivable condition of activity.

The author maintains a practical point of view, so that the
book should appeal primarily to those who desire to select a bat-
tery which is most suitable for fulfilling specified working condi-
tions. H. Sou

Geology and Natural History. 159

10. Die Neue Welt der Plissigen Kristalle ; by O. Leumann,
8vo, pp. 388. Leipzig, 1911 (Akademische Verlagsgesellschaft).
—To anyone acquainted only with ordinary crystals, the idea
of a liquid crystal—a substance which, if deformed, will flow back
into crystalline shape—is hard to grasp. Professor Lehman is
the discoverer of this class of substances and has done more work
in the field than has any other investigator, so he speaks with
authority.

Rather curiously, liquid crystals are hardly mentioned in the
first hundred and fifty pages of the book. Instead various other
subjects are considered which are often only remotely connected
with liquid crystals but which have been investigated by the
author at one time or another. [or instance, there is an account
of the author’s discovery of the transition temperature and a
description of his crystallization miscroscope. The description of
liquid crystals, their preparation and properties, occupies about
a hundred pages and appears to be very well presented. There
are chapters following which it is difficult to account for in a
book of this character—chapters, for instance, on the growth of
living things, latent life and soul (latentes Leben und Seele),
atom souls (Atomseelen), and muscle power (Muskelkraft).

Taken as a whole, the book is an account of the author’s scien-
tific work rather than an account of liquid crystals. The part
devoted to the latter appears to be very good. ‘The rest may be
excellent, but it is on subjects having little to do with the title
page. H. W. F.

Il. Grotogy ano Naturat History.

1. Thirty-second Annual Report of the United States Geo-
logical Survey. GrorGE Otis Smiru, Director. Pp. 143;
2 maps. Washington, 1911.—-The operations of the Survey
for the year 1910-11 continue the gratifying record made in
previous years. When the value and amount of work is com-
pared with the aggregate cost ($1,477,440) it seems evident
that no governmental bureau is yielding greater returns in pro-
portion to the amount expended. It is satisfactory to note that
the Survey is becoming each year more generally useful to the
various departments involved with governmental administration.
More than any other bureau it stands as a scientific adviser to the
government in all matters relating to the development of natural
resources. In the development of plans for wiser distribution
and control of public lands, water supply, irrigation, coal, oil, and
ore deposits, it is essential that some bureau possessing high skill
and freedom from political control should be given charge; and it
speaks well for the reputation of the Survey that this particular
bureau should be relied upon to furnish accurate and unbiased
information as the basis for legislative enactments. Because of
the changes in the Department of the Interior which have placed

160 Scientific Intelligence.

the administration of public lands on a more scientific basis, the
work of the Land Classification Board has become an important
feature of the Survey’s activity, and under the direction of W. C.
Mendenhall, the present chairman, is increasing 1n amount and in
accuracy. Fortunately the past work of the Survey has been
done in such a manner that extensive records and studies cover-
ing along term of years are available. Without these data public
land legislation would be necessarily unsatisfactory.

The general value of the Survey to the country is indicated by
the growing demand for its publications. During the year under
consideration the number of reports and maps issued reached
the enormous total of 1,208,797 (488,930 books, 34,117 folios,
684,129 maps). Of this amount half a million maps were sold,
an increase of 15 per cent over the previous years. The demand
in some instances is so great that second editions were required of
five Bulletins, twelve Water-Supply Papers, and of the Mineral
Resources of the United States.

An examination of the outline map showing the area covered
by topographic surveys indicates substantial progress during the
year. The maps of six states have been completed ; 50 per cent |
of nine other states has been covered ; and only five states show
less than 10 per cent of their area repr esented by maps.

The organization of the Bureau of Mines, relieving the Survey
of a portion of its economic work, which was only remotely
related to it, seems on the whole to have been a satisfactory
arrangement ; it allows for the enlargement of its work along
scientific lines as well as of basal studies in conservation.

It is an interesting indication of the growth of interest in scien-
tific studies and the appreciation of expert scientific knowledge as
a basis of legislation that various new bureaus have from time to
time been created from sections in the Survey, without decreas-
ing the staff or scope of the work of the parent organization.

H. E. G.

2. The Granites of Connecticut ; by T. Netson Date and
H. E. Greeory. Bull. 484, U. 8. Geol. Survey, pp. 137, pl. vi.
Washington, 1911.—This is a continuation of the very useful
reports on the granite industry in the eastern states published in
recent years by the Survey. The subject is treated both from
the scientific and economic standpoint, but in such a manner as
to make the more purely scientific parts quite intelligible to the
general reader.

In part one, which is devoted to the scientific portion of the
work, Professor Gregory first treats in a broad, concise way of
the salient features of the geology of the state with especial ref-
erence to the origin, nature, and classification of the rocks, the
distribution of the bodies of granite being shown on a colored
geologic map on the scale of 1-500,000. Professor Dale follows
with a discussion of various features of the granites, such as their
structure, rock variations, weathering and discoloration. The
treatment of rift and grain and of sheeting is interesting, though

Geology and Natural History. 161

no new views are advanced, but the author suggests that the
dome structure may, perhaps, be due to anticlinal arches in the
strata that originally overlaid the granites.

The second part of the work, by Dale, is devoted to a descrip-
tion of the various quarries in the state and to their products.
In many instances their location is shown by small maps and the
geologic features are described in detail with the aid of diagrams.
In nearly all cases the result of a study of the rocks in thin
section are briefly given, and where available, chemical analyses
are added.

While the main value of the work is on the economic side
and it should prove itself technically useful to those engaged in
the industry, there is nevertheless much of interest and impor-
tance to the geologist and petrographer that is not merely local,
but general, in its application. | Hi. YAGe

3. The Mount McKinley Region, Alaska; by AtFrep H.
Brooks. With Descriptions of the Igneous Rocks and of the
Bonnifield and Kantishna Districts ; by L. M. Prinpie. Prof.
Paper 70, U. 8. Geol. Surv., 4°, pp. 234, pls. 18, 3 maps. Washing-
ton, 1911.—In his preface Mr. Brooks, who has long been known
for his explorations and pioneer geologic work in Alaska, states
that the object of the volume is to give to geologists an epitome
of its stratigraphy, structure, and geologic history, and to furnish
the prospector with a concise summary of present knowledge of
its mineral wealth. Available information regarding the climate,
vegetation, agricultural land, wild animals, and means of commu-
nication is added for the benefit of intending hunters and settlers.
It would be impossible in a brief notice to give any adequate
account of the large amount of information which this volume
contains in succinct form. It represents a compendium of the
labors in the field of a number of workers, chief of whom has
been the senior author. The results of the reconnaissances here
given will be of great value in the future when more detailed
work is undertaken. Eee Vie:

4. Bulletin of the Seismological Society of America.—The
Fourth number of volume I, recently issued, contains among
other articles, one on the California earthquake of July 1, 1911,
by E. C. Tempxieton. The shock, although not to be compared
with that of 1906, was the most severe that has been felt since
then, and was felt over an area whose maximum dimension was
about four hundred miles, extending from Sacramento to Los
Angeles. It was most severe in the region of San Francisco Bay.
The shock came without preliminary tremor, and consisted of
“two rather distinct periods of vibration, of which the first, with
a duration of between five and eight seconds, was the more intense.
After a lull of about five seconds came the second period of vibra-
tion, with a duration of about five seconds. The shock was
accompanied by a dull, rambling sound, described as similar to
the roar of a distant railway train, the sound preceding the shock
by two or three seconds.” . . . ‘The maximum intensity occurred

162 Scientijic Intelligence.

in the vicinity of Coyote, a small town built on the alluvial floor
of Santa Clara Valley, twelve miles southeast of San Jose. The
intensity throughout the hills between Coyote and Mt. Hamilton,
while apparently not as great as it was near Coyote itself, was the
greatest reached at any place where the immediately underlying
formation does not consist of unconsolidated, filled-in material.
The time of the shock at Lick Observatory on Mt. Hamilton is
the earliest reliable time reported. Coupled with the fact that
the earthquake materially increased the flow of several streams
near Mt. Hamilton, these facts seem to indicate that the epicenter
was in the region between Coyote and Mt. Hamilton. ‘he move-
ment probably occurred at a considerable depth, with the dis-
placement entirely taken up by the overlying material, leaving no
trace or rift on the surface.”

Some post-Glacial faults near Banning, Ontario, are described
by A. C. Lawson. They occur in a region of marked stability,
and are found to exist on the glaciated surface of Archean rocks.
The chief facts stated in regard to them are as follows: “The
glacial strive are constant in direction over this surface, and their
course is N.20° E. This glaciated surface is dislocated by a
series of reverse or overthrust faults. The fault-plane in most of
these is coincident with the cleavage of the slates, and since this
dips to the north the result is a series of southerly facing and
overhanging scarps, inclined to the horizon at 65°. ‘The edge or
crest of the up-thrust block is thus rather acute, being about 25°,
and this acute edge is usually perfectly sharp and unworn except
for artificial breaks. The reéntrant angle at the base of the
scarp, where it meets the horizontal surface of the next lower
block to the south, is equally sharp. In no ease could any fault
breccia or gouge be detected even on a microscopic scale ; nor
was any well-defined slickensiding observable, although in some
cases the surface of the scarp appeared to be smoother than the
ordinary cleavage face and even to have a faint polish.

“In every case observed the movement on the faults appeared
to be in the direction of the dip, or to have no horizontal compo-
nent except that normal to the strike. This could be determined
by observing the displacement of particular strize or grooves.
On the up-thrust block the striz, which make an angle of 61°
with the strike of the faults, extend out to the very brink of the
scarp, and on the adjacent block to the south the striz pass in
under the overhanging scarp and abut against its base. These
fault scarps are small but numerous. The highest one measured
3% inches vertically, and the others range down to one-eighth of
an inch in height. In a distance of 66 feet across the strike
twenty-four scarps were counted, and as the faulted surface
passed beneath the drift on both sides of this, there is every
reason to suppose that there are many more than could be ob-
served.”

Similar faults have been described by other authors, but it
seems doubtful whether they are to be referred properly to oro-

Geology and Natural History. 163

genic force. The author states that : “The stresses which gave
rise to those faults may possibly be very superficial and in no way
connected with those deeper seated forces which deform the
earth’s crust in a large way. It is at least noteworthy that we
have in these cases to deal with a peculiar type of faulting which
is almost wholly confined, so far as our knowledge goes, to slatey
and shaley rocks. ‘The close spacing of the faults, the distri-
bution of the movement, the small amount of overthrust in each
particular fault, and their confinement to soft, relatively plastic
rocks, suggest that they are perhaps due to stresses connected
with a volume change near the surface of the rocks concerned.”

5. Atlas Photographique des Formes du Relief Terrestre ; par
J. Brunues, E. Cuaix, Emm. p—E Martonne. Geneva (Kditeurs,
Fred. Boissonnas et Cie.).—In this Journal for April, 1911, the
plan adopted by the Geographical Congress at Geneva for the
publication of an Atlas of terrestrial relief-forms was explained in
detail. This plan originated in 1907, when M. E. Chaix proposed
the publication of an “Atlas de l’ Erosion,” in which M. J. Brunhes
later agreed to codperate. In 1908 the ninth International Con-
gress of Geography took the matter up and the scheme which
has now taken shape was developed. The specimen number,
which has recently been distributed, is gratifying as showing
the admirable way in which the promises of the prospectus have
been fulfilled. Eight plates are here given, each with the text
required to explain the views. One of these is of the Grand
Combin, showing the forms produced by mechanical disintegra-
tion and by glacial influences ; another of the Ravin de Théus
illustrates the elementary forms of erosion by streams of water ;
another of James Peak, Colorado, exhibits the subdued forms of
a high mountain modified by glacial action ; still another gives
two striking views of desert dunes at Taghit in southern Algeria.
All the plates are reproduced from excellent photographs with
striking fidelity. A special sheet gives in detail the classification
of the forms to be illustrated in the complete work ; there are
nine general types, and each of these is more or less minutely
subdivided. The value of the work as a whole to geographers,
geologists, and the intelligent public at large can hardly be over-
estimated, and it is not to be doubted that the 300 subscribers
will be soon obtained who are needed to make the publication
possible at a moderate price. Circulars and other information
may be obtained from the executive committee : Prof. J. Brunhes,
Fribourg, Switzerland ; Prof. E. Chaix, 23 Ave. du Mail, Geneva,
and Prof. EK. de Martonne, 248 Bd. Raspail, Paris.

6.. New Zealand Botanical Notes, by B. C. Aston. These
include: (1) Botanical Notes made on a Journey across the
Tararuas, Trans. N. Z. Inst., Vol. XLII, 25 pages, 1 map, 7 plates,
1909. (2) List of Phanerogamic Plants indigenous in the Welling-
ton Province. Ibid, Vol. XLIII, pp. 22, sketch map, 1910.
(3) Some effects of Imported Animals on the Indigenous Vege-
tation. Read before Wellington Philosophical Society, May 10th,

164 Scientific Intelligence.

1911.—These render available existing data and add materially to
our knowledge ‘of the interesting flora of the South Temperate
Zone. The collections made inthe Tararua Mountains are from
a district not previously visited by a naturalist, and furnish new
data regarding distribution and ecological relations. The illus-
trations are unusually good and pertinent. H. E. G.

7. Fungous Diseases of Plants, with chapters on Physiol-
ogy, Culture Methods and Technique ; by Bensamin M. Dueear.
Pp. xii + 508, with 240 text-figures. New York and Boston,
1911 (Ginn & Company).—The majority of American works on
parasitic fungi have dealt primarily or exclusively with the fungi
themselves, rather than with their host plants. Professor Dug-
gar’s book, which forms a volume of the Country Life Education
Series, is a notable exception to this rule and lays special emphasis
on the host plants, describing clearly the changes which they
nndergo through the presence of the parasites and calling atten-
tion to methods by which further infection can be prevented or
controlled, After a series of chapters devoted to culture methods
and technique, the diseases are taken up in representative types
arranged according to the systematic position of the parasites, the
Myxomycetes and Bacteria being considered first and then the
Phycomycetes, Ascomycetes and Basidiomycetes. In most cases
the parasites selected for description are those which attack culti-
vated plants or plants which are otherwise of economic interest.
The illustrations, many of which are reproduced from photo-
graphs, form an excellent feature of the book. A. W. E.

8. Practical Botany; by JoserpH Y. Breraen and Oris W.
CALDWELL. Pp. vil + 545 with 388 text-figures. New York and
Boston, 1911 (Ginn & Company).—Professor Bergen’s element-
ary text-books of botany have long been recognized by teachers
as valuable and practicable adjuncts to their work. The present
volume, which maintains the usual high standard, is written in
response to the demand for text-books which shall emphasize the
connection between science and daily life. It gives the essential
facts regarding the structure and functions of plants, but also
shows how they play a part in agriculture, in the spread of disease,
and in yielding products of economic significance. Chapters on
ecology and on the geographical distribution of plants are like-
wise included. ‘The illustrations are largely new and are remark-
ably clear and satisfactory. A.W. E.

9. A Practical Course in Botany, with especial reference to
its bearings on Agriculture, Economics, and Sanitation; by E.
F. AnpRews. Pp.ix + 374, with 15 plates and 511 text-figures.
New York, Cincinnati, and Chicago, 1911 (American Book
Company).—The present text-book is written particularly for
schools which are not provided with a full laboratory outfit.
Microscopic structure, therefore, receives but a limited amount
of attention, and most of the work suggested can be carried on
by the direct examination of material in the class room or in the
field. With the exception of the concluding chapter, which gives

Miscellaneous Intelligence. 165

a brief description of cryptogams, the book is almost entirely
devoted to flowering plants, and the subjects treated are taken
up in the following order: the seed, germination and growth, the
root, the stem, buds and branches, the leaf, the flower, fruits, the
response of the plant to its surroundings. Practical questions
are interspersed throughout, and considerable attention is given to
topics of economic importance. ‘The illustrations are profuse and
well selected. A. W. E.

III. Misce,ruansovus Screntiric INTELLIGENCE.

1. Report of the Secretary of the Smithsonian Institution for
the Year ending June 30, 1911. Pp. 91. Washington, 1911.—
The Smithsonian Institution is so remarkably efficient, not only
in its general activity, but also in the variety of spheres in which
it works, that the annual report of the Secretary, Dr. Cuar.zs D.
W atcort, always contains much that is of general interest. One
point to be noted is that a sum of $40,000 has been bequeathed
to the Institution by George W. Poore, of Lowell, Massachusetts,
who died in December, 1910. The income is to be added to the
principal until a total of $250,000 has been reached, when the
income of the fund so established is to be used for the purposes
for which the Institution was created. This clearly indicates an
appreciation on the part of the public of the work which the
Smithsonian is doing, and gives reason to hope for further
bequests in the future. A trust fund, yielding an income of
$12,000, was earlier established by Mrs. E. H. Harriman, to be
devoted particularly to the study of. American mammals and
other animals. Of the special explorations and researches is to
be mentioned, first, the remarkable work of the Secretary, at the
trilobite locality on the slope of Mt. Stephen, near the Canadian
Pacific Railroad. The exhaustive biological survey of the
Panama Canal zone is now established on a solid basis, through
the contribution of funds from outside. The Rainey expedition
in Africa, the bird studies in the Aleutian Islands in the Behring
Sea, and the anthropological researches of Dr. Hrdlitka in Peru,
are other lines along which the work of the Institution has been
extended.

As regards publications, some 200,000 copies of various issues
have been distributed through the past year, while the Depart-
ment of International Exchanges has handled some 229,000 pack-
ages, weighing 561,000 pounds. The structural work on the new
National Museum was completed on June 20, 1911, just six years
after the excavations for the foundations were commenced. The
collections have been largely removed to the new building and
reinstalled, while 200,000 specimens of animals and plants have
been added.

The work of the Astrophysical Observatory, under Mr. C. G.
AxBBoT, is detailed in Appendix V, from which the following

166 Scientific Intelligence.

summary is quoted: “‘ The year has been distinguished by a suc-
cessful expedition to Mount Whitney. The results obtained
there confirm the view that determinations of the intensity of the
solar radiation outside the earth’s atmosphere by the spectrobolo-
metric method of high and low sun observation are not dependent
on the observer’s altitude above sea level, provided the conditions
are otherwise good. The Mount Whitney expedition furnished
opportunities also for measurements of the brightness of the sky
by day and by night, the influence of water vapor on the snn’s
spectrum, and the distribution of the sun’s energy spectrum out-
side the atmosphere. Solar-constant observations and closely
related researches were continued daily at Mount Wilson until
November, 1910, and were taken up again in June, 1911.

Further research tends to confirm the conclusion that the sun’s
output of radiation varies from day to day in a manner irregular
in period and quantity, but roughly running its courses within
periods of 5 to 10 days in time and 3 to 10 per cent in amplitude.
Assurance seems now complete that this result will be tested in
the next fiscal year by long-continued daily observations made
simultaneously at two widely separated stations.

Many copies of the silver disk secondary pyrheliometer have
been standardized and sent out to observers in this and foreign
countries to promote exactly comparable observations of the sun’s
radiation.

Measurements of the transparency, for long-wave radiation, of
columns of air containing known quantities of water vapor have
been continued, and promise highly interesting results.”

The following has recently been issued: Classified List of
Smithsonian Publications available for distribution, January, 1912.
Jey aly 20

2. Report of the Librarian of Congress and Report of the
Superintendent of the Library Building and Grounds for the
fiscal year ending June 30, 1911. Pp. 244; 5 plates. Washing-
ton, 1911.—The Report of the Librarian of Congress, Mr. HERBERT
Putnam, shows that the expenditures for the past year amounted
to $655,000. The appropriations for the coming year are about
$50,000 less, chiefly because a smaller amount is needed for the
new book-stacks. The gain m number of books is nearly 100,000,
making the total about 1,900,000; there have been also some
60,000 accessions in the way of maps, music, and prints. It is
interesting to note two bequests from abroad, one in 1910 from
the late Henry Harrisse, the historian of the period of the Colum-
bian discovery. ‘This includes a full set of his own writings,
annotated, with books, maps, and manuscripts on related topics.
The other bequest of May, 1911, was from the late Dr. A. B.
Meyer, of Dresden, of the letters of Professor F. Blumentritt,
concerning certain matters in the Philippines. The articles
themselves have not thus far been received. A list is also given
of a series of gifts which, although not remarkable as concerning
collections of books, show that the Library is becoming rich

Miscellaneous Intelligence. 167

through what it receives from donors as well as by what it
acquires by purchase and, directly and indirectly, from the
Government.

3. Das Schicksal der Planeten ; by SvANTE ARRHENIUS. Pp.
55. Leipzig, 1911 (Akad. Verlagsges. M. B. H.). — Professor
Arrhenius is well known as a writer on cosmogonic subjects and
one welcomes this little tract containing a brief exposition of his
conclusions concerning the present and future conditions of the
inner planets. In reaching his results the author does not confine
himself to any one department of physical science : the estab-
lished facts of astronomy, geology, chemistry, physics, and biol-
ogy are all brought into service. More particularly, stress is laid
on the application of the physiography of the arid parts of the
earth’s surface in order to explain present conditions on Mars and
the Moon.

The appearance of a popular account of more extensive re-
searches elsewhere calls for a criticism of the manner rather than
of the matter. Jn setting forth his views, Professor Arrhenius
writes clearly and easily, avoiding involved sentences and quali-
fying clauses. For this the reader is grateful. It has, however,
perhaps caused the author to fall into a too dogmatic statement
of his conélusions. The subject is not one on which any large
body of scientific men are agreed, and the uninitiated, for whom
the publication is apparently intended, may accept as the final
results of science what should properly be considered the views
of one of its exponents. Ernest W. Brown.

4. The Capture Theory of Cosmical Hvolution; by T. J. J.
SEE, F.R.S. 4to, pp. vil, 735. Lynn, Mass., 1910 (Thomas P.
Nichols & Son Co.).—This is the second volume of the author’s
“ Researches on the Evolution of the Stellar System.” It is
elegantly printed and the plates, nearly 100 in number, mostly
reproductions of astronomical photographs, are most admirable.

The term ‘‘ Capture Theory,” first used to designate the method
of formation of the Jovian family of comets, is taken by Dr.
See as the name for his system of cosmogony. The “capture,”
however, is made possible on a grand scale only by the agency of
a resisting medium of cosmic dust which can be supplied where
necessary from the vapors of a central body through light pres-
sure. ‘The author pronounces his theory to be incompatible with
the Nebular Hypothesis of LaPlace, and constantly refers to the
latter as disproved.

It is true that the Nebular Hypothesis has been found insuffi-
cient to explain the process of evolution indicated by the struc-
ture of many of the nebule, and notably the great class of spiral
nebule, and that tidal evolution as developed by Darwin adds a
new chapter to it; but astronomers will hardly agree to relegate
it to the category of “creeds outworn ” until Dr. See’s arguments
have been subjected to a rigorous criticism. They will rather
still lean to the opinion expressed by Simon Newcomb at the close
of his brilliant: career that he yet retained “a little incredulity as

168 Scientific Intelligence.

to our power, in the present state of science, to reach even a high
degree of probability in cosmogony.”

The following extract from the publishers’ notice of this work
is mostly erroneous and quite misleading :

‘‘Since the accompanying standard circular was prepared, in the summer
of 1910, Professor See’s celebrated discoveries in Cosmogony have been
confirmed by many eminent astronomers; so that the Capture Theory has
triumphed all along the line. Foremost among these verifications must be
ranked Professor E. W. Brown’s confirmation of the Capture of Satellites,
announced to the American Association for the Advancement of Science
at the Minneapolis meeting, December, 1910 (Science, Jan. 20, 1911, p. 93),
and more elaborately treated in the Monthly Notices of the Royal Astro-
nomical Society for March, 1911, p. 453. In this paper Professor Brown
shows, by an extension of the methods adopted by Professor See, that the
asteroids are transferred from beyond Jupiter’s orbit to the zone within, and
that some of them may become satellites in the process of transition. The
captured satellites may move either direct or retrograde, as first announced
by Professor See in May, 1909.” W. B.

5. Lhe Teaching of Geometry ; by Davin EvcEener Smiru,
Teachers College, Columbia University. 12mo, pp. v, 339.
Boston and New York, 1911 (Ginn & Co.).—This is a clear dis-
cussion of the merits of Geometry, of the means for making the
subject more attractive and of its relation to the other sciences.
The rise of Geometry is outlined, and the evolution of the method
of teaching it, and the development of its definitions and assump-
tions. The mathematical curriculum has been subject of late
to such severe attacks by exponents of loose theories of education
that the support afforded by such a broad view of the subject is
welcome. W. B.

6. The Hindu-Arabic Numerals ; by D. E. Smita and L. C.
KARPINSKY. 12mo, pp. 160, Boston and New York, 1911 (Ginn
& Co.).—A very complete and scholarly treatise on the origin
and introduction into Europe of the modern number system.
Copious notes and references put the reader in touch with all the
important literature of a subject which has an even stronger
interest as bearing on the history of civilization than on its
mathematical side.

Few stop to think how much of modern progress depends on
these labor-saving symbols, and fewer still realize that their
general acceptance in the transactions of commerce dates back
only four centuries, and that a system of place values strug-
gled for a thousand years to supplant the crude notation of the
Romans. Specially interesting in this volume 1s the chapter on
the symbol zero, the invention of which came long after that of
the others, which without it were of comparatively little ‘use.
The author aptly points out how the production of this crux ot
the system was beyond the power of any race but the Hindus,—
though to them in complete harmony with the philosophy whose
highest good is the Nirvana. Ww. B.

OBITUARY.

Major CtarencE E. Durron, the eminent geologist, died on
January 4 in the seventy-first year of his age. A notice is
deferred to a later number.

New Circulars.

84: Eighth Mineral List: A descriptive list of new arrivals,
rare and showy minerals.

85: Minerals for Sale by Weight: Price list of minerals for
blowpipe and laboratory work.

86: Minerals and Rocks for Working Collections: List of
common minerals and rocks for study specimens; prices
from 1% cents up.

Catalogue 26: Biological Supplies: New illustrated price list
of material for disséction; study and display specimens;
special disseetions; models, etc. Szxth edition.

Any or atl of the above lists will be sent free on request. We are
constantly acquiring new material and publishing new lists. It pays to
be on our mailing list.

Ward’s Natural Science Establishment
76-104 Cotiecr AVE., Rocuester, N. Y.

Warns Naturat Science EstaBlisHMENT

A Supply-House for Scientific Material.

Founded 1862. Incorporated 1890.

DEPARTMENTS:
Geology, including Phenomenal and Physiographic.

Mineralogy, including also Rocks, Meteorites, etc.
Palaeontology. Archaeology and EKthnology.
Invertebrates, including Biology, Conchology, ete.
Zoology, including Osteology and Taxidermy.

Human Anatomy, including Craniology, Odontology, ete.
Models, Plaster Cast and Wall-Charts in all departments.

+

Circulars in any department free on request; address

Wards Natural Science Establishment,
76-104 College Ave., Rochester, New York, U.S. A.

<
sa
Nig

CONTE KN T'S.

Arr. X.—Study of Some American Fossil Cycads —Part —
VI. On the Smaller Flower-Buds of Cycadeoidea ; by

G. R. WiELAND |

XI.—Occurrence of Coral* Reefs in the Triassic of North —
America ; by J. P. Smita

XII.—Ordovician Outlier at Hyde Manor in Sudbury, Ver-
mont ; by T. N. Date

XIII. —Color- Kifect of Isomorphous Mixture; by H. L.

XIJV.—Lorandite trom the Rambler Mine, Wyoming ;
A. F. RoGERs

XV.—Rate of Decay of Different Sizes of Nutter Deter-
mined by Aid of the Coronas of Cloudy Condensation ;
by C. Barus

XV1I.—Displacement Interferometer Adapted for High Tem-
perature. Measurement, Adiabatic Transformations of a
Gas, etc. ; by C. Barus

XVII.—Unconformity at the Base of the Chattanooga Shale

in Kentucky; by E. M. Kinpie

XVIil.—Sueggestion for Mineral Nomenclature; by H. 8.
W ASHINGTON .

—-—- |= e-|\ ge ee er ee te ee eK Ke Bw ew KM ee eC eee er eK ewe er Ke ere A

XIX.—Optical Resolution of the Saturnian Ring ; by D.

SCIENTIFIC INTELLIGENCE.

Chemistry and Pkysics—Canadium, an Alleged New E}ement of the Platinum
Group, A. G. Frencu: Alleged Complexity of Tellurium, Harcourt and
BAKER, 100.—New Quantitative Separation of Iron from Manganese, J. A.
SANCHEZ: Famous Chemists, E. Rogerrs, 156.—Quantitative Chemical
Analysis, CLowEs and CoL=Man: Photometric Paddle-Wheels, J. R.
Minne: Text-Book of Physics, L. B. Spinney, 157.—Tables of Physical
and Chemical Constants and some Mathematical Functions, G. W. C.
Kayes and 1. H. Lasy: Electrochemische Umformer, J. ZACHARIAS, 108.
—Neue Welt der Fltissigen Kristalle, O. LEnmMaAnn, 159.

Geology and Natural History—Thirty-second Annual Report of the United
States Geological Survey, G. O. SmirH, 159.—Granites of Connecticut, T.
N. Dae and H. E. Greeory, 160.—The Mount McKinley Region, Alaska:
Bulletin of the Seismological Society of America, 161.—Atlas Photo-
graphique des Formes du Relief Terrestre, J. BRUNHES, K. CHarx, HE. DE
Martonne: New Zealand Botanical Notes, B. C. Aston, 168. —Fungous
Diseases of Plants, B. M. DueGar: Practical Botany, J. 'Y. BercEn and
O. W. CALDWELL: A Practical Course in Botany, E. F, ANDREWws, 164.

Miscellaneous Scientific Intelligence—Report of the Secretary of the Smith-
sonian Institation, 165.—Report of the Librarian of Congress and Report
of the Superintendent of the Library Building, 166.—Das Schicksal der
Planeten, 5. ARRHENIUS: The Capture Theory of Cosmical Evolution, T.
J. J. See, 167.—The Teaching of Geometry, D. E. Smira: The Hindu-
Arabic Nunes D. KE. SmirH and L. C. Karpinsxy, 168.

Obituary—C. E. Dutton.

i
————_

Library, Bureau of Ethnology. AOA,

S VOL. XXXIll. MARCH, 1912.

Ey

an a

Established by BENJAMIN SILLIMAN in 1818. |

THE

AMERICAN

| JOURNAL OF SCIENCE.

ASSOCIATE EDITORS

Prorsssors GEORGE L. GOODALE, JOHN TROWBRIDGE,
W. G. FARLOW anp WM. M. DAVIS, or CampBrince,

PROFESSORS ADDISON EK. VERRILL, HORACE L. WELIS,
- LOUIS V. PIRSSON, HERBERT E. GREGORY
and HORACE 8S. UHLER, or New Haven,

Proressor HENRY S. WILLIAMS, or ItHaca,
Proressor JOSEPH S. AMES, or Battimore,
Me. J. S. DILLER, or Wasuineton.

FOURTH SERIES
VOL. XXXIII—[W HOLE NUMBER, CLXXXIII.]
No. 195—MARCH, 1912.

NEW HAVEN, CONNECTICUT
1912.

THE TUTTLE, MOREHOUSE & TAYLOR CO., PRINTERS, 123 TEMPLE STREET.

| Published monthly, Six dollars per year, in advance. $6.40 to countries in the

| Postal Union ; $6.25 to Canada. Remittances should be made either by money orders,
Tegistered letters, or bank checks (preferably on New York banks).

- ae a

NEW ARRIVALS.

The following is a brief list of the most important specimens recently
received :

Native antimony, massive and polished sections, White River, Cal.

Awaruite, metallic pebbles, Smith River, Cal.

Obsidian, black, brown and red, Smith River, Cal.

Hanksite, loose crystals, San Bernardino, Cal.

Andalusite, var. Chiastolite, polished matrix specimens with beautiful
markings, also polished loose xls., Fresno Co., Cal.

Californite, Fresno Co., Cal.

Chalcedony and Opal, San Benito, Cal.

Stibiotantalite, Mesa Grande, Cal.

Calaverite, Cripple Creek, Colo.

Pink quartz xls., near Aibuquerque, N. M.

Nytramblygonite, Cafion City, Colo.

White Labradorite, also cut cabachon and brilliant, southern Oregon.

Opalized Wood with sparkling veins of gem opal, Northern Humboldt,
Nevada.

Waringtonite, new occurrence, formerly found in Cornwall, Eng.; also in
combination with aurichalcite, Smithsonite, azurite and brochantite, Dry
Cafion, Tooela Co., Utah.

Brochantite, Azurite, Smithsonite, Aurichalcite, Malachite, Dry Cafion,
Utah.

lodyrite, Nevada.

Zincite and Pyrochroite, remarkable specimen, Franklin Furnace, Nive

Gageite with Zincite-leucophoenicite, Frankiin Furnace, New Jersey.

Lapis Lazuli, polished slabs, Baikal, Siberia.

Malachite, polished specimens, Ural Mts.

Emeralds, fine specimens in matrix, Ural Mts.

Alexandrite, Golden Beryl, Aquamarines, Ouvardvite, Perovskite, Pyro-

morphite, Ural Mts.
Dioptase, Khirgese Steppes, Siberia.
Semsyite, xlzd., Felsobanya.
Hessite, Botes, Hungary.
Stephanite and Pyrargyrite, Hungary.
Blue Chalcedony, xlzd., Hungary.
Stibnite specimens and with barite, Hungary.
Herrengrundite, Herrengrund, Hungary.
Cinnabar, very choice, with dolomite and white quartz, China.
Cinnabar, Spain and California.
Stibnite and Bismuth, Japan.
Kroéknkite, large specimens, Chili.
Proustite, Chili and Bohemia.
Octahedrite, Rathite, Cyanite, Anatase, Switzerland.
Argyrodite, Saxony.
Liroconite and Tennantite, Cornwall, Eng.
Millerite, Westphalia.
Embolite and Stolzite, New South Wales.
Opal bird bones and opal shells, N. S. W.
Cerussite, New South Wales.
Phenacite, gem xls., Brazil.
Tourmalines, Brazil; Mesa Grande, Cal.; Elba; Madagascar ; Maine.
Synthetic gems; rubies; blue, white, yellow and pink sapphires, all sizes.
Further information and prices furnished on request.

~

ASH. PE Te rea.
81—83 Fulton Street, New York City.

THE

AMERICAN JOURNAL OF SCIENCE

[FOURTH SERIES.|]

Art. XX.—The Mineral Sulphides of Iron, by E. T. Atuen,
J. L. Crensoaw, and Joun Jounston; with Orystallo-
graphic Study, by Esper 8. Larsen.

INTRODUCTION.

Application of Chemistry to the problems of ore depo-
sition.—The problems of ore deposition have claimed the
attention of geologists for a long time, both for economic
and for scientific reasons. The difficult questions as to the
origin of ores and the conditions of their genesis have been
zealously studied, and with notable success; yet despite the
great advances which have been made, no one will question
that the scarcity of chemical data has been a serious drawback
in the development of the subject. A laboratory investigation
of some phases of it involves, indeed, difficulties which are still
to be surmounted, but the problems ‘of the temperature ranges
within which the minerals have erystallized, the composition
of the solutions from which they have come, and the agencies
which have precipitated them are in general not only within
the bounds of chemical possibility but within the limits of
present day methods.

Lhe sulphides of cron.—The sulphide ores from a chemical
view-point are of very great interest, and geologically, they are
of high importance. The sulphides of iron, in particular, fre-
quently carry paying quantities of gold and nickel, and when
themselves barren, are so frequently associated with other
valuable ores as to hold a place of unusual significance in a
general consideration of the subject of ore deposition. The
chemical knowledge of these substances is still very meager.
Syntheses of pyrite and pyrrhotite were made long ago by

Am. Jour. ScI.—FourtH SERIES, Vout. XX XIII, No. 195.—Marcu, 1912.

12

170 Allen, Crenshaw, Johnston, and Larsen—

Wohler, Rammelsberg and others, but for the most part by
methods which throw little ight on their formation in nature.*

Method of study.—In the investigation of this subject the
synthetic method has been largely followed, while the most
significant properties, reactions and relations of the substances
have been studied. Some of the material will be chiefly of
chemical interest, but the effort has been made to give special
attention to the chemical geology involved and to this end the
authors have consulted frequently with several eminent geolo-
gists who are specialists in this field. The experience and
suggestions of these scientists have been of great value and will
be duly acknowledged in the proper place. No optical studies
‘were of course possible on opaque minerals, but erystallo-
graphic measurements were made and such microscopic studies
as the character of the material admitted of.

I. The disulphides (£eS,) Pyrite and Marcasite.

Two disulphides of iron are known—pyyrite, hard, lustrous,
brassy-yellow, of sp. gr. 5027+ at 25°, and crystallizing in
the regular system; and mareasite, yellowish grey in color,
a little softer than pyrite, of sp. gr. 4°887+ at 25° and erystal-
lizing in the orthorhombic system. Both minerals are almost
insoluble in hot hydrochloric and dilute sulphuric acids, and
both are decomposed by nitric acid. Both are slowly oxidized
by free oxygen, the products being, according to conditions,
sulphur dioxide and ferrous sulphate, or sulphuric acid and
ferrous or ferric sulphate,—sometimes, in fact, sulphuric
acid and ferric hydroxide. The conditions have not been
investigated completely, though certain definite statements
can be made at the present time. In a closed vessel containing
ir, l.e., with an excess of sulphide, the products are sulphur
dioxide and ferrous sulphate. When the minerals are heated
to 100° in air or ground dry in a mortar, these are the jirst
products at least. The-sulphur dioxide changes pretty readily,
of course, to sulphuric acid. When kept in contact with
air and moisture at 75° most of the iron takes the form of
ferric hydroxide. Many oxidizing agents, important among
which, from a geological standpoint, are ferric sulphate and
copper sulphate solutions, change pyrite and marcasite into
ferrous sulphate, sulphur and sulphuric acid. Im nitrie acid
of 1:4 sp. gr., powdered pyrite dissolves completely, while
marecasite separates sulphur.{ Both minerals are so nearly

* An exception should be made of the excellent work of Senarmont, Ann.
Ch. Phys., xxxii, 129, 1851.

+ These specific gravities were determined on very pure natural minerals,

the analyses of which are given on p. 177.
+ Brush and Penfield’s Determinative Mineralogy, 15th ed., p. 252.

Mineral Sulphides of Iron. 171

insoluble in water that some statements* regarding their solu-
bility, found in the literature, could only have been made on
the basis of experiments in which atmospheric oxygen wa
not excluded. In all these instances the two minerals pahave
much alike, though marcasite is always more soluble in any
medium and is more readily changed by oxidizing agents.

Formation of wron disulphide in nature.— Geologists appear
pretty well agreed that pyrite sometimes crystallizes direct from
rock magmas. Pyrite, however, in the great majority of cases,
and mareasite in all cases, crystallize from water solutions,
though the nature of the process is purely a matter of conjec-
ture. Here a general line of division should be made between
the products of hot and the products of cold solutions. The
pyrite of deep veins, metamorphic contacts and hot springs, as
well as magmas, has ‘been formed by hot solutions, and such solu-
tions never contain strong mineral acids, but are generally if
not always alkaline. The pyrite and marcasite of surface veins,
on the other hand, are formed from cold solutions which often
contain considerable sulphuric acid. We shall find cogent
reasons for the conclusion that the chemistry of these two proc-
esses is similar, but first let us consider the formation of iron
disulphide from surface solutions. Here the geologic hypothe-
sis is that both minerals have been formed by the “reduction ”
of ferrous sulphate through the agency of organic matter, and
indeed, the frequent occurrence of pyrite in coal and its occa
sional formation on wood gives plausibility to this view. It is
plain that the soluble sulphate of iron could not be changed by
simple reduction to the disulphide, though one might imagine
such a reaction as the following equation imperfectly repre-
sents :

TC (vegetable matter) +4FeSO,= 2FeCO,+2FeS,+5CO,,.
Some experiments have been tried in this laboratory in the
hope of “reducing” ferrous sulphate with organic matter, but
the results have not been promising. The action of starch and
glucose on aqueous solutions at 300° was either slight or nil.
On the other hand, the possibilities of hydrogen sulphide are
suggestive. Pyrite and marcasite are very often found with
simpler sulphides,—those of lead and zinc for example, which
may be easily formed by the action of hydrogen sulphide; and
furthermore, hydrogen sulphide is a substance widely distrib-
uted in nature. Without denying that carbonaceous substances
may in some instances be directly active in the formation of
pyrite and marcasite, we will proceed to show that both min-
erals may be formed through the agency of hydrogen sulphide,
and under conditions which doubtless prevail commonly in
nature.

* See Doelter, Tschermak’s Min. Petr. Mitt., N. F. xi, 322, 1890; Neues
Jabrb., ii, 273, 1894.

172

Allen, Crenshaw, Johnston, and Larsen—

Synthesis of iron disulphide.—Apparatus.—All the experi-
ments on the synthesis of pyrite and marcasite were done in

Fic.1. Bomb used
in heating sealed

tubes.

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sealed tubes, enclosed in steel bombs and
heated in resistance furnaces. Several kinds
of glass were tried for the tubes, all of which
were naturally more or less attacked. The
Jena combustion glass and so-called “ durax”
glass were the only kinds which were found
to stand satisfactorily the action of water
solutions at the higher temperatures (up to
350°), and even these are pretty rapidly
attacked by alkaline solutions. To prevent
bursting, the glass tubes were enclosed in
heavy steel bombs (see fig. 1), about 80 in
length by 25™™ inside and 43™™ outside diam-
eter, having thus a thickness of nearly a
centimeter. These bombs were closed at
one end by an iron plug, P, which was
welded in. The other end was threaded
on the outside and closed with a cap. To
insure a tight joint, three concentric grooves
about 1°" deep were cut on the open end of
the bomb. On this was laid a copper dise,
Ff, 3™™ thick, on which was placed a steel dise,
D,1™ thick. The cap was then screwed down
by means of a long steel lever. The steel
disc was used to prevent the shearing of the
copper disc in screwing down the cap. The
joint was Inbricated with oil and graph-
ite. The glass tubes were put into the
bombs and water was added before closing
the latter, so that the pressure on the inside
of the glass tubes would be compensated.
These bombs will hold satisfactorily up to
temperatures of 400°.

Furnaces.—The furnaces in which the
bombs were heated were electric resistance
furnaces, the coils of which were of nickel
wire 0°8™" in diameter, wound on a sheet-
iron tube 5™ in diameter, which was first
wrapped with asbestos paper. The tube and
coil were surrounded by another sheet-iron

cylinder 15°" in diameter. The space between the two was filled

with light magnesium oxide.

Caps, also of sheet-iron, fitted

tightly over both ends of the outside tube, leaving at the upper
end (the furnaces were set in an inclined position) a space about

Mineral Sulphides of Iron. 173

6°" long for the head of the bomb. A hole about 6™ in diam-
eter through the lower cap admitted the thermo-element. The
variation in temperature along the outer wall of the bomb, from
a point about 5°" from the lower end to another 20™ farther
up, was only about 5°, which is within the error of the direct-
reading oalvanometer used. This instrument was calibrated
within that degree of accuracy, but as none of the tempera-
tures involved had reference to any critical point, it was not
considered worth while to measure more accurately.
The action of hydrogen sulphide on ferric salis.—The first
-action of hydrogen sulphide on ferric salts is, of course, the
immediate reduction of the latter and the simultaneous precip-
itation of sulphur: Fe,(SO,), + H,S = 2FeSO, + H,SO, +S.
No further action has hitherto been noticed, but in a closed
vessel where the hydrogen sulphide is prevented from oxida-
tion or escape, a second reaction proceeds, viz: FeSO,+S+
H,S = FeS,+ H,SO,, At room temperatures, the velocity
of this change is very slow, but at 200° it is relatively rapid.
The following data prove beyond question the nature of this
latter reaction :

3g. FeSO,.7H,O with 0°17 g. H,SO,, 0°75 g. sulphur and
100° water saturated at 0° with H,S, were sealed up in a glass
tube and heated about 2 days at 200°. The product was
purified by washing first with water, then digesting with
ammonium sulphide to remove excess of sulphur, washing again
with water, boiling out with 20 per cent hydrochloric acid,
and finally washing in an atmosphere of carbon dioxide and
drying in vacuo.

Analysis: Product taken, 0:°5044 9. Fe,O, found, 0°3346 g.
Found Cal. for FeS.
1S xe OS 46°44% 46°56%

Another product was formed by heating at 100° for six days
the following system: 5 g. FeSO,.7H,0, 0-5 ano. Ohman ESO),
and 100° water saturated at 0° with H AS The product was
purified in a way similar to the above.

Analysis: Product taken, 0°5003 g. BaSO, found, 1:9598 g.

< 0°5006 g. Fe AOR [0°83 295 g.
Found Cal. for FeS,
[Ra COURS Sree ae ae 46°06% 46°56%
ie ane) Gi Daas aes 53°81 53°44
99°87 100°00

Both these products were similar to natural marcasite in color
and luster. Their crystaliime nature was very obvious to the
unaided eye, though the crystals were small.

174 Allen, Crenshaw, Johnston, and Larsen—

Methods of distinguishing pyrite from marcasite.—To
distinguish between the disulphides pyrite and marcasite, two
methods were employed.

1. Crystals were prepared large enough for goniometric meas-
urement. When hydrogen sulphide and sulphur act directly
on a solution of ferrous sulphate, the crystals are in general

HG. 2:

Fic. 2. Apparatus
for the slow forma-
tion of crystals of iron
disulphide.

minute. They increase in size with rise in
temperature and several other conditions.
One of the most important of these is slow
formation. This can be brought about by
a simple device (fig. 2). Into a glass tube
of about 18™™ inside diameter and 65™ in
length, is poured through a funnel about
7-10 g. of sodium thiosulphate (Na,S,O,.
5H,O) dissolved in 80° water. The fer-
ric salt is contained in another smaller
tube which slips into the larger. The
small tube has a diameter of 15™™" out-
side and a length of 45°". It is supported
above the thiosulphate solution by a piece
of glass tnbing a little longer than the depth
of the liquid. When the outer tube is
sealed, the whole is heated in a bomb as
usual. Ata temperature of 200°, hydrogen
sulphide is slowly generated from the thio-
sulphate solution, according to the follow-
ing equation: Na,S,O, + H,O = Na,SO, +
H,S. By the action of the gas on the ferric
salt solution, crystals of measurable size
have been repeatedly formed. This scheme,
however, could not be satisfactorily used in
studying the influence of various conditions
on the crystal form. Obviously, not all the
crystals of any product could be measured,
and it was, of course, a thankless if not
impossible task to identify all of them micro-
scopically. Therefore, a quantitative esti-
mation of the two minerals in mixtures
could not be made. Besides, the method of
syuthesis is very slow.

2. Stokes’s oxidation method. Some years
ago, a chemical method for distinguishing
between pyrite and marcasite was worked
out by H. N. Stokes.* Since free use of
this method has been made, it will be nec-
essary to explain it in some detail. It

*H. N. Stokes, Bull. U. S. Geol. Survey, 186.

Mineral Sulphides of Iron. 175

depends on the difference in behavior between the two min-
erals toward a solution of ferric sulphate. In both cases the
sulphide which is used in excess reduces the ferric salt com-
pletely to ferrous sulphate, while the mineral itself is oxidized
to ferrous sulphate, sulphuric acid and free sulphur. It is in
the relative quantities of the products that the difference
between pyrite and marcasite shows itself. The reaction may
be represented in two stages as follows:

1. FeS,+Fe,(SO,), = 3FeSO, +28
2. 28+6Fe,(SO,), +8H,O = 12FeSO, +8 H,80,

In that portion of the sulphide which takes part in the reaction,
the percentage of the sulphur which is oxidized to sulphuric
acid depends on conditions, but, ceteris paribus, the quantity
is much greater for pyrite than for marcasite. In order to
distinguish between the two it is therefore necessary to deter-
mine what percentage of the sulphur is oxidized to sulphuric
acid. Stokes found it most advantageous to use a standard
solution (ferric ammonium alum) containing 1 g. of iron and
4-0 g.* free sulphuric acid per liter, and to operate at the boil-
ing temperature. Under these conditions, he found that 60
per cent of the sulphur in pyrite was oxidized, and only 18 per
cent of the sulphur in marcasite. Instead of determining
directly the quantity of free sulphur or sulphuric acid formed
in the reaction, Stokes measured the increase in the concentra-
tion of ferrous iron in solution. By stochiometrical caleula-
tion, for the details of which the original paper must be con-
8°336
ean
percentage of sulphur in the reacting sulphide which is oxidized
to sulphuric acid, 6 the ferrous iron, ¢ the total iron in the
solution at the end of the operation, and a the total iron in the
original solution. There is one point on which Stokes does
not express a perfectly clear view, viz: whether the solution
at the end of the oxidation should contain any ferric iron or
not. Asa matter of fact, the reaction, when successful, pro-
ceeds to completion, so that all the iron at the end of the
operation is ferrous; 6 and ¢ are consequently identical, and
8°33b

— 25.
b—a
Stokes determined the ferrous iron by direct titration with
permanganate. Afterwards he reduced the solution and titra-
ted again so as to determine the ¢o¢a/ iron, ferrous and ferric.
This reduction and subsequent titration are evidently super-
fluous. The process has been improved in several other

sulted, he derived the formula, p = 95, where p is the

the formula may therefore be simplified to p=

*This is our interpretation of Stokes’s statement: ‘‘16°™? of 25 per cent
sulphuric acid.”

176 Allen, Crenshaw, Johnston, and Larsen—

details also. The sulphide has to be very ‘carefully purified.
Obviously, any other product which could reduce the solution,
or anything like ferrous sulphate or ferric hydroxide which
could in any way increase the concentration of the ferrous iron,
would interfere with correct conclusions. In the main, Stokes’
procedure has been followed, though a new apparatus: for

HIG. 5.

Fic. 3. Apparatus for washing substances out of contact with air.

washing substances out of contact with the air has been
devised and used. This apparatus, which is shown in the
adjoining figure (fig. 3), has proved of very general utility and
convenience. A consists of two parts, the lower of brass, the
upper of glass cemented into a brass ring. /' is a ground
joint between this ring and another similar ring soldered to

Mineral Sulphides of Lron. 177

the lower half of the apparatus. In use, this joint is greased
with vaseline and the rings are held in place by two spring
clamps which are not shown in the figure. The two vessels
D and F are used to contain, respectively, hydrochloric acid
and boiled water cooled in carbon dioxide, with which two
liquids the ground sulphide in & is successively washed. The
pressure of the carbon dioxide which enters the apparatus at
HT is sufficient to drive either liquid over into 6 when the
proper stop-cocks are opened. G opens into a filter flask
filled nearly full of water, connected with the water pump.
Suction is carefully regulated by a pinch-cock. The appara-
tus is successively evacuated by the pump and filled with car-
bon dioxide before using. In drying the material m the
vacuum desiccator, instead of using the water pump as Stokes
did, we have evacuated by an oil or mercury pump to a frac-
tion of a millimeter. At the end of a half hour the sulphide
is not dry but it does not contain enough water to affect the
result essentially. In the determination of the ferrous iron,
we have employed a weight burette instead of a volume
burette. ,

Results with natural pyrite and marcasite——The minerals
employed were pyrite from Elba* and marecasite from Joplin,
Mo. They were purified with great care and then analyzed.t
The only impurities found were small quantities of silica and
a minute trace of copper in the marcasite.

Marcasite Pyrite ° Cal. for FeS.
Fe 46°53 46°49 46°56
S 53°30 53°49 53°44
SiO, 20 04
100°08 100°02 100°00

The oxidation coefficients obtained by us were 56 for pyrite
and 14 for marcasite, while Stokes found 60 and 18 respect-
ively. The differences have not been entirely accounted for,
though we have taken somewhat greater precautions in our
work. However, and this is the point to be emphasized, the
results of each are probably consistent among themselves.

Determination of the relative quantities of pyrite and
marcasite in miatures.—By grinding together the two min-
erals in different proportions and then determining the oxida-
tion number for the mixture, Stokes constructed a curve repre-

*In some of the later experiments, a pyrite from Leadville, Col., con-
taining 0°1 per cent copper, was used.

+ For the method of analysis, see Allen and Johnston, Zs. anorg. Chem.,
ies, 102,191:

178 Allen, Crenshaw, Johnston, and Larsen—

senting the oxidation coefficients for all possible mixtures.
His curve had the form of a eutectic curve with the lowest
point at ten per cent, pyrite having an oxidation coetticient of
about 15. Fig. 4 shows the curve which we obtained for mix-
tures of pyrite and marcasite. Careful experiment failed to
reveal any mixture which gave a lower oxidation coefficient
than pure marcasite. The difficulty of determining accurately
the composition of an unknown mixture, by a measurement of

Hae. 4:

Oxidation coefficient.
oo Hq (>) | [or}
S = S S

~
So

po
fo)

0 10 20 30 40 50 60 70 80 90 100

Marcasite. Pyrite,

Fie. 4. Curve showing the oxidation coefficients for mixtures of pyrite
and marcasite.

the oxidation coefficient, is obvious from the form of the curve ;
indeed, differences of two to three per cent (of the weight of
the mixture) were usually found in duplicate determinations.
Yet, though we cannot confirm the statement of Stokes regard-
ing ‘the accuracy of the method, we have found it of great
value in studying synthetic products of iron disulphide, the
mineral composition of which must otherwise have remained
unknown, and have been thus enabled to work out the essen-
tial conditions which govern the formation of pyrite or marca-

Mineral Sulphides of Iron. 179

site. Of course, the method only applies where the substance
contains no other reducing agent than pyrite and marcasite.
If, therefore, we had present another crystal form of FeS,, the
results would be unreliable. Although both pyrite and mar-
casite have been repeatedly detected by the microscope in the
synthetic products, no evidence of another form has come to
light. It is possible that in some instances (which will be
pointed out in the proper place) amorphous FeS, may
have been present. In most cases, however, the crystalline
structure was so apparent even to the unaided eye that the
presence of any amorphous material was quite unlikely, and
this conclusion was only confirmed by the microscopic study.

Marcasite.— Marcasite is the principal product when hydro-
gen sulphide acts directly on ferric sulphate at 200°.

Exp. 15g. NH,Fe(SO,),.12H,0 in 100° water saturated
at room temperature with hydrogen sulphide, was sealed up and
heated in a bomb for several days at 200°. To insure a suffi-
cient quantity of the product for experiment, three tubes were
thus heated under the same conditions. The product was
removed, ground fine, purified, and the oxidation number
determined. It was found to be 23°6, corresponding to about
43 per cent pyrite.

Influence of free acid on the proportion of marcasite.—The
equation H,S + Fe,(SO,), = S-+ 2FeSO, + H,SO, shows that
sulphuric acid is a product of the reaction in which the marca-
site forms, and its concentration evidently increases as the
reaction proceeds. It was, therefore, a plausible hypothesis
that the concentration of acid influences the crystal form ; it
seemed possible that the pyrite might have formed in the
earlier stages of the process, when the acid was weaker. If
this view were correct, a greater initial concentration of acid
should result in more mareasite. The hypothesis is proved
correct as shown by the results collated in the adjoining table.

TABLE I,
The effect of free H.SO, on the formation of marcasite at 200°.

Taken Found
Water saturated Oxidation} Per cent
NH,Fe(SO,)2.12 H.O with H.S Free H.SO,* number pyrite
5 g. HOO) 0°50 g. 23°6 43°
og. LOOT 0°57 g. 18°9 25°
Do 2. LOO: Oni 8) os 17°0 10°0
og. LOO * Metis: (2 16°5 7°5

* This includes the acid formed in reduction of the ferric iron by hydro-

gen sulphide.

180 Allen, Crenshaw, Johnston, and Larsen—

ANG aj opel PA

Effect of temperature on the formation of marcasite.

Taken Found
FeSO,. Water satu- ey

Tem- 7,0 Sulphur | Free H.S0,| rated with | Oxidation |Percent
perature HS at 0° number | pyrite

300° Dd g. 0d g. One LOOr: 29°0 57°5

300° og. 0'5 g. O17 &. LOOrs 28°4 56°5

200° Os 0°5 g. 0-17 g. 1GO. 20°7 32°0

100° 5 g. 0d g. 0°17 g. LOOK. 16° 6°0

100° Dg. 0:5 1a: Orliire. 1OO;¢" Livi 10°0

Table II shows the influence of temperature on the reaction.
Here ferrous sulphate and sulphur, the products of the action
of hydrogen sulphide on ferric sulphate, were taken. The
quantities of acid used, by inadvertence, were considerably less
than intended, but the evidence shows the influence of tempera-
ture very plainly. The higher the temperature the greater is the
quantity of pyrite formed. A word is here needed on the
question of the formation temperature. The furnace was first
heated to the required temperature, then the cold bomb con-
taining the tube was introduced. Obviously, the reaction could
not take place entirely at one temperature. At the lower tem-
peratures, however, the reaction is very slow, so that the time
required for the bomb to reach the temperature of the furnace
is not important. When the bombs were heated to 300°, many
hours were required to reach the maximum temperature. It
would not be worth while, after having shown that the two
variables, temperature and acid concentration, both influence
the product of this reaction, to study the problem in great
detail, but it is interesting to note that the reaction will proceed
at ordinary temperatures, and also that pure marcasite may be
obtained by a proper combination of the two variables. Thus
at 100° the precipitate formed from a solution containing
1°18 per cent of free sulphuric acid gives the oxidation coefi-
cient 14°5 and is therefore pure mareasite. From 2 liters of a
solution which contained 3 per cent of hydrous ferrous sulphate
and 0°15 per cent of free sulphuric acid, 1 gr. of precipitate was
obtained at room temperature in about three weeks. Unfortu-
ately, there was an accident in the determination of the oxida-
tion coefficient of this product, but we can state that it contained
less than 10 per cent of pyrite. For every temperature there
appears to be a quantity of acid which inhibits the reaction:

Mineral Sulphides of Lron. 181

FeSO,+H,S+S = Fe8S,+H,SO,. The quantity is smaller the
lower the temperature. It appears to bear no relation to the
solubility of the sulphide, for at room temperature this quantity
is only a small fraction of 1 percent. At 200° it lies between
3°5 per cent and 5 per cent; at least this is true for periods of
a few weeks.

Crystals of marcasite. of marcasite
were obtained by the slow action of hydrogen sulphide on fer-
ric sulphate or chloride at several temperatures up to 300°
(see p. 174). The general problem of making measurable erys-
tals is one of the most troublesome in synthetic mineralogy.
As yet we have no light on the means of controlling the
number of nuclei which form in the process of crystallization.
In general, the more soluble minerals are obtained in larger
crystals. Likewise, larger crystals are obtained from a medium
in which they are more soluble. In preparing well-formed
mareasite crystals, some unaccountable failures were met with,
though generally the products obtained by the method previ-
ously described contained a number of ‘crystals which were
measurable. The marcasite crystals were like the natural
mineral in color and luster and the axial ratio deduced from
the angular measurements was @:6:¢c = 0°7646:1:1°2176 as
compared with 0°7580 : 1: 1:2122 for natural marcasite (Gold-
schmidt). The striations which marked the crystals agreed
with orthorhombic and not with regular symmetry (see Ul,
Crystallographic Study).

Formation of pyrite.*—While the product of the action of
sulphur and hydrogen sulphide on ferrous salts is largely mar-
casite, the percentage increasing with the quantity of free acid
present, pyrite is the principal product where the solution
remains neutral or but shghtly acid.

Action of hydrogen sulphide on ferric hydroxide.—F reshly
precipitated ferric hydroxide is instantly blackened by hydrogen
sulphide. The product is a mixture of ferrous sulphide and
sulphur, as shown by the following. Freshly precipitated fer-
ric hydroxide was washed free of soluble salts, suspended in
water and treated for some time with hydrogen sulphide. A
portion of the black amorphous precipitate dissolved in cold
dilute acid with evolution of hydrogen sulphide, leaving a
residue of amorphous sulphur. Another portion was first
digested with ammonium sulphide solution. After filtering

*For former syntheses of pyrite, see Wohler (Ann., xvii, 260, 1836).
W obler heated an intimate mixture of Fe.0;,S, and NH.Cl till the NH.Cl
was sublimed. He obtained some small brass yellow tertrahedra and octa-
hedra. Senarmont (loc. cit.) obtained FeS. by heating ferrous salt solutions
with alkaline polysulphides. Geitner (Ann. 129, 350, 1864) heated metallic

iron with a solution of sulphur dioxide to about 200°. His product may
have been marcasite. See also Doelter (Zs. Kryst., xi, 30, 1886).

182 Allen, Crenshaw, Johnston, and Larsen—

and washing out the excess of reagent, the black residue dis-
solved without leaving any sulphur behind. The product
therefore must have contained free sulphur and could not have
been ferric sulphide, Fe,S,, though the latter, according to
Gedel,* decomposes with dilute acid, giving the same products
as the above mixture. A product made by the action of
hydrogen sulphide on ferric hydroxide was washed into a glass
tube with about 100° water, saturated with hydrogen sulphide
at room temperature, sealed and heated at 140° for seven days.
The solution when cooled and opened still smelled strongly of
hydrogen sulphide. The product had become quite dense and
had a yellowish grey color. It was boiled in hydrochlorie acid
for some time to dissolve any unchanged ferric hydroxide, or
ferrous sulphide, and further purified as usual. The oxidation
number was 49, corresponding to 87 percent of pyrite. The
work was repeated with ferric hydroxidet+ which had been
dried at 100° to make it easier to handle: It proved, however,
much less susceptible to hydrogen sulphide. It had to be heated
repeatedly at 140° with saturated hydrogen sulphide water
before the color of the oxide of iron had disappeared entirely.
After purification, the product gave the oxidation number 50°4,
corresponding to 90 per cent pyrite.

Action of sulphur on pyrrhotite wm the presence of a sol-
vent.—The formation of pyrite, just described, is evidently a
result of the direct union of sulphur and ferrous sulphide, the
first product of the reaction. The hydrogen sulphide water
probably acts as a weak solvent. Similarly, the marcasite may
be regarded as a product of the addition of sulphur to ferrous
sulphide, which forms gradually from solution. The formation
of pyrite by the action of sulphur on crystalline pyrrhotite,
the relation of which to ferrous sulphide will be shown farther
on, proves conclusively that, at a given temperature, it is not
the exact nature of the solid phase which reacts with the sul-
phur, but the composition of the solution in which it forms,
that determines whether the product shall be pyrite or marca-
site. 2°2g. pyrrhotite prepared in the laboratory, and 0°8 g.
of sulphur were put into a glass tube, to which was added a
solution of 0:1 g. of sodium bicarbonate in 100° water. Before
sealing the tube, the solution was partially saturated with hydro-
gen sulphide. In composition this solution was similar to that.
of a warm “sulphur” spring, and it served as a solvent for the
sulphur, which was gradually absorbed by the pyrrhotite. The
tube and its contents were heated for two months at 70°.
The product at the end of that time still contained sulphur and
undecomposed pyrrhotite. To remove the latter it was boiled

* Jour. fiir Gasbel., xlviii., pp. 400 and 428, 1905.
+ According to Gedel (loc. cit.), Fe203;.H2O is thus obtained.

Mineral Sulphides of Iron. 183

for a long time with 20 per cent hydrochloric acid. The res-
idue was dense and brassy-yellow. It was finely ground, puri-
fied as usual, and tested by Stokes’s method. It gave an oxi-
dation number of 55-1, which corresponds to pure pyrite within
the limits of error of the method. To make sure that no mis-
take had been made in this test, some pure natural pyrite was
compared the next day with the same ferric sulphate solution.
100° of the sulphate solution, after it had been reduced with
the synthetic pyrite, required 42°51 g. of permanganate solution.
100° which had been reduced by natural pyrite took 42°56 g.
of the permanganate.

The action of sulphur on pyrrhotite was tried again at 300°,
where the reaction was of course much more rapid than at 70°.

Into the tube were put 5 g. powdered pyrrhotite, 1°75 2. sul-
phur, 0°2 g. NaHCO,, and 100° water partially saturated with
HS. The tube was heated four days at 300°. The oxidation
number of the purified product was 52:0, corresponding to
about 95 per cent pyrite. It is possible that these products
contained a very little undecomposed pyrrhotite or perhaps
amorphous FeS,, both of which would have undoubtedly had
a similar effect as marcasite in lowering the oxidation number.

TABLE III.

The oxidation numbers of FeS. formed from alkali polysulphide solution.

FeSO,. Temper- |Oxidation| Py-
Time | Water | 7H.O NaS. Sulphur ature number | rite
ae plain : A z
3 days | 100 eee ee 0rd S300 54 | 97%
a plain ee 0
5 days | 100 1s Sta opener L2H) 25200 405 | 71%
lain
yce Pp . . ie)
7 days | 106 a Sasi) Ake 75 g. 100 26 ad

The action of alkali polysulphides on ferrous salts.—
eehacmony in 1851 showed by analysis that the product ue
the action of alkali polysulphides on ferrous salts at 180°
FeS,. The question of the crystal form was not riveebigatall
The black amorphous precipitatet which is obtained at room
temperature by the above reaction appears to be a mixture of
sulphur and ferrous sulphide, at least it decomposes with dilute
acids, giving a residue of amorphous sulphur, while hydrogen
sulphide escapes. On heating, disulphide of iron gradually

* Loe. cit.
+ Gedel (loc. cit.) claims that this precipitate is Fe.Ss.

184 Allen, Crenshaw, Johnston, and Larsen—

forms, though some of the black precipitate is still unchanged
after it has been heated several days at 100° with excess of the
polysulphide. The oxidation coefficients of several such prod-
ucts formed at different temperatures, and carefully purified as
usual, are given in Table III. Evidently they are not pure
pyrite, a result somewhat surprising in view of the previous
work; for if we obtain marcasite from the more acid solutions,
marcasite with pyrite from those which contain less acid, and
pure pyrite from practically neutral solutions, we should natu-
rally expect pure pyrite from alkaline solutions. Further inves-
tigation has led us to believe that the products of the alkaline
solutions do not contain marcasite, but are mixed with amor-
phous disulphide. Stokes explained, very plausibly, that the
reason why marcasite gave more free sulphur than pyrite when
it reacted with ferric sulphate was because it was more soluble ;
a fortiori, amorphous disulphide would give, under similar
conditions, still more free sulphur because it is the most solu-
ble of the three. The evidence for the existence of amorphous
disulphide in the products of alkaline solutions is as follows:
While the products of acid solutions which contain the most
mareasite are the best crystallized, those from alkaline solu-
tions which, judging by their oxidation coefficients, contain
the most, are almost black, dull and lusterless at the lower
temperatures. The quantity of pyrite is increased by raising
the temperature or prolonging the time of reaction,—both con-
ditions which are favorable to the crystallization of an amorph-
ous substance. Moreover, marcasite is not changed by heating
in alkali polysulphide solutions, as we found by heating some
of the natural mineral in powdered form for several days at
300° with polysulphide of sodium. The oxidation coefficient
remained 14:5. The influence of temperature on the formation
of pyrite from ferrous salts and alkali polysulphides is shown
in Table If1. ‘The Anas of time is proved by the two fol-
lowing experiments: 3g. FeSO,.7H,0O, 2°5 g. Na,S, and 0°75 g.
sulphur, and 100° water, were heated 2 tae at 100°. The pro-
duct contained about 75 per cent pyrite.* similar system —
heated for 7 days.at the same temperature gave a product contain-
ing about 95 per cent pyrite. The results are calculated on the
supposition that they contain marcasite; if they contain amor-
phous disulphide instead, the true percentage of pyrite should
of course be higher, since a given quantity of amorphous disul-
phide would be equivalent to a greater quantity of the less sol-
uble mareasite, but the order of the results would of course
remain thesame. The products obtained at 300° were yellower,
* There is an apparent discrepancy between this last result and the one

quoted in Table III under the caption ‘‘ 100°.” In the latter case the excess
of polysulphide was much smaller.

Mineral Sulphides of Iron. 185

denser, and in direct sunlight showed a decided metallic luster,
while their oxidation coefficients approach those of pure pyrite.
It may therefore be safely stated that the product of the union
of ferrous sulphide and sulphur from an alkali polysulphide
solution is at first amorphous disulphide of iron which gradu-
ally crystallizes to pyrite.*

The formation of wron disulphide by the action of sodium
thiosulphate on ferrous salts—In the endeavor to explain the
formation of pyrite and marcasite in nature, the following
hypothesis presented itself. Iron disulphide of either form
may oxidize under surface conditions to ferrous thiosulphate
by direct addition of oxygen ; this is transported by circulating
waters to some point where it is reduced again to its former
condition. Ina partial study of the oxidation of marcasite,
no trace of thiosulphate was discovered. At the same time
the effort to obtain the disulphide of iron by reduction of
the thiosulphate was successful. When water solutions of
ferrous sulphate and sodium thiosulphate are heated in sealed
tubes, even to temperatures under 100°, the iron disulphide is
precipitated with sulphur. By quantitative experiments which
follow, the reaction is proved to be:

4Na,S,0, + FeSO, = FeS, +38 + 4Na,SO,.

ie eke yous HesO) (1,0, 18-o. Na.S.0,.5H,0, and 25°
water were heated in a sealed tube for 9 days at 90°. All buta
trace of the iron was precipitated. The precipitate of FeS,+S
was washed in air-free water and driedin vacuo. The sulphur
was extracted by carbon disulphide and the residue of FeS, was
weighed.
Cal. from the

Found above equation
FeS,+5 3°82 3°85
FeS, ailcy 2°16

Exp. 2. 2g. FeSO,.7H,O, 18 g. Na,S,O,.5H,O and 35° water
were sealed in CO, and heated for one day at about 150°. The
precipitate was filtered and washed with air-free water. The
solntion was boiled in, a current of carbon dioxide to remove a
trace of hydrogen sulphide, and an aliquot part was titrated
with standard iodine solution.

No.i. 1/5 of the solution required 16°135 e. iodine solution.
Cal. for th» whole, 80°675 g. iodine solution.

No. 2. 2/5 of the solution required 32°332 g. iodine solution.

* In a recent paper (Zs. angewandte Chem., xxiv, 97, 1911), ‘‘ Die Bildung
von HKisen Bisulphide in Lésungen und die Enstehungen der nattirlichen Pyrit-

lagern,” W. Feld states that whenever sulphur and ferrous sulphide are boiled
in neutral or weakly acid solutions, pyrite forms.

Am. Jour. Sct.—Fourts Series, Vou. XX XIII, No. 195.—Marcg, 1912.
18

186 Allen, Crenshaw, Johnston, and Larsen—

Cal. for the whole, 80°830 g. iodine solution. The iodine solu-
tion contained “005445 g. iodine per g.

80°675 and 80°830 g. iodine solution are respectively equiva-
lent to 0°858 and 0°860 g. Na,8,O,.511,0. Therefore 7-142 ge.
and 7140 g. Na,$,O,.5H,O were consumed in the reaction.
The equation demands 7-137 g. for 5g. FeSO,.7H,0.

Found Cal.
FeS,+5 1547 1°556
Fes, 0°872 0°863

Sodium thiosulphate when heated with water in sealed tubes
forms hydrogen sulphide and sodium sulphate. Na,S,O,+H,O=
H,S+Na,SO,. The reaction at 200° is quite incomplete,
though no thiosulphate was obtained when a solution of sodium
sulphate saturated with hydrogen sulphide was heated under
the same conditions. When 1g. Na,S,O,.5H,O and 20° water
were heated 4 days at 200°, the thiosulphate undecomposed, as
determined by standard iodine solution, was 0°753 g. 0°247 @
decomposed is equivalent to 0°141 ¢. Na,SO,. The solution
after titrating with iodine was precipitated with barium
chloride. BaSO, found 0°223 ¢. equivalent to 0°1386Na,SO,,.

At first it was thought that the reaction between ferrous sul-
phate and sodium thiosulphate was to be explained as follows:
(1) Na,S,O,+H,0 = Na,SO,+H.S, (2) FeSO,+4H,8 = FeS,+
388+4H,O. Later it was found that from ferrous chloride the
same mixture of sulphur and FeS, was precipitated. Of
course, the reaction represented by equation (2) could not go
on with ferrous chloride. Therefore, the following is probably
the true explanation of the reaction.

(1.) FeSO,+Na,8,0, = Na,SO,+ FeS,0,
(2.) Fes, O, +3Na,8,0, = FeS, +38+43Na, SO,

Form of Fes, obtained by heating ferrous salts with sodium
thiosulphate.—N either marcasite nor pyrite is obtained pure in |
this reaction. ‘The product shows in crusts the color of pyrite,
but it is poorly erystallized and may contain amorphous disul-
phide. A product prepared at 90°, tested by Stokes’ method,
behaved like a mixture of 70 per cent pyrite and 30 per cent
marcasite. Another product formed at 800°* tested in the
same way acted like a mixture of 72 per cent pyrite and 28
per cent mareasite. Though this reaction—the reduction of
ferrous thiosulphate by sodium thiosulphate—doubtless has no
significance as applied to geology, it is probable that the fer-
rous thiosulphate might be reduced by other reagents, and it is
possible that ferrous thiosulphate may be formed in nature
under some conditions, but of this we have no evidence.

* This was the maximum temperature. The reaction may have been com-
plete before this temperature was reached.

Mineral Sulphides of Iron. 187

The transformation of marcasite into pyrite.—More than
fifty years ago, Wohler* tried the experiment of heating both
minerals for four hours at the temperature of boiling sulphur
(about 445°) without observing any change in either of them.
Our own results indicate that marcasite undoubtedly changes
here, but very slowly. When marecasite was heated at 610° in
hydrogen sulphide gas for 3 hours, it lost about 2°5 per cent
sulphur and became strongly magnetic, owing, of course, to the
formation of some pyrrhotite. A finely ground sample, after
being thoroughly boiled out with hydrochloric acid, appeared
decidedly yellower and less lustrous than marcasite.t+

The comparison is best made by placing the sample to be
tested alongside of a fragment of marcasite which has had all
tarnish removed by recent boiling in hydrochloric acid (Stokes).
A finely ground and purified sample of the heated marcasite
gave the oxidation number 56 instead of 14 as previously. At
525°, a sample of marcasite heated 4$ hours in hydrogen
sulphide gave the oxidation number 55:8. Under similar
conditions at 450°, a sample of marcasite heated 4 hours gave
the oxidation number 15-7, which corresponds to 5°5 per cent
of pyrite. The sample was returned to the furnace and heated
again 5 hours. This time the top layer in the crucible gave,
after purification, the oxidation number 27, corresponding to
58 per cent pyrite, while a deeper layer in the same crucible
gave 31, which indicates about 61 per cent of pyrite. At 450°,
therefore, dry heating in H,S changes marcasite to pyrite
rather slowly—50 per cent—60 per cent in 9 hours. Heated
to 410° for 4 hours, the oxidation number was 13:5, showing
that no measurable change had occurred.

J. Konigsberger and O. Reichenheimt found a marked
decrease in the electrical resistance of marcasite in the neigh-.
borhood of 520°. They noted that the sulphide then possessed
a specific resistance of the same order as pyrite, and rightly in-
terpreted their results to mean that marcasite had changed into
pyrite and the change is irreversible. It is difficult to see in
their results, however, any support of their statement that the
change appears to begin between 250° and 300°, while our
results contradict it.

An effort was made to effect the transformation at a lower
temperature in the wet way. At 350° marcasite heated in a
sealed tube with a small amount of dilute sulphuric acid partly
changed to ferrous sulphate and sulphur dioxide, but the solid

* Ann. Chem. Pharm., 90, 256, 1854.

+ Pyrite is naturally a more lustrous mineral than marcasite. The duller
color of heated marcasite is to be ascribed to the very large number of

minute crystals in the product, and the lack of continuous surfaces.
¢{ Neues Jahrb., ii, 36, 1906.

188 Allen, Crenshaw, Johnston, and Larsen—

portion gave no sign of change, and at 300° a powdered sample
which was repeatedly heated for several days’ time with
sodium sulphide and polysulphide solutions was equally
unaffected. |

Density.—The density of the marcasite heated to 610° rose
from 4887 to 4911. The density of pure pyrite is 5-°02+
The change in color, and, more convincingly, the oxidation
number, show that the substance is pure pyrite after heating,
yet its density is too low. The explanation is probably to be
sought in the porosity of the product.

Influence of pressure on the change marcasite> pyrite.—Dr.
A. Ludwig, at our request, kindly undertook some experiments
on the influence of pressure in transforming marcasite to
pyrite. A few grams of marcasite were compressed for five
hours at a pressure of about 10,000 atmospheres. At the end
of the period, the oxidation by Stokes’ method showed no
change in the substance. Later Johnston and Adams devised
an apparatus in which the marcasite could be heated by a
resistance coil while subjected to hydrostatic pressure of about
2000 atmospheres in petroleum oil. A number of experiments
were tried between 300° and 400°, but Stokes’ reaction showed
no pyrite formation. The oxidation method was perhaps not
quite so certain here on account of the fact that the oil was
partially decomposed at the higher temperatures and the
product may have contained some reducing matter which could
not be removed by petroleum “ether.” A mixture of pyrite
and marcasite containing any such reducing impurity, as we
have seen (p. 184), would give too low an oxidation number.
Thus it might happen that a little pyrite could be overlooked.
These experiments are of considerable interest because there
are very few data on the effect of pressure in irreversible
changes.* We do not know whether a difference in density in
the right direction would favor the change or not, since
Le Chatelier’s law applies only to reversible changes. If the
speed of the change is influenced by pressure quite apart from
the volume relation, it may perhaps be retarded rather than
accelerated. Until apparatus is developed which will give
higher temperatures and at the same time high pressures, this
problem must wait. At present the assumption,t which has
been made in geology, that pressure favors all changes which
are accompanied by reduction in volume, irrespective of their
reversibility, is unwarranted.

Monotropic relation of marcasite to pyrite.—A crucible con-
taining 50 g. pyrite was rapidly heated (20° per minute) in H,S

* Van’t Hoff, Vorlesungen, 2nd. Hd., Braunschweig, 1901, vol. I, p. 236.

+ See Van Hise, A Treatise on Metamorphism, Monograph No. 47, U.S.
Geol. Survey, 1904, pp. 215, 368.

Mineral Sulphides of Iron. 189

over a range from 400° to 600°. The curve was perfectly
smooth. When a similar charge of marcasite was heated in
the same way, an acceleration of the temperature was plainly
seen on the curve between 500° and 600°. (See fig. 5.) The

Temperature.

TES Ot

USDaRoa Ease
Sea
hou |

SLL
een re AA eae
Pee ea oe
Aree ee oe ee
Bia PEAY OW ey te

Creel ca
AVA
EE

SStkhes haa nae
PSA

LRP VA
cogs ia | ld 2 7 i a
AAA
oo Se een See
ae ee er ee
4 Ea a a
ae |. ist A Ae nihasy

1 5 eA SS tL dG

A

pee BESET
ah
ae

aan ay ss ea pe ae
ea
SCO: dea oe ee

Time.

Fic. 5. Thermal curves showing evolution of heat when marcasite is
changed into pyrite. (Curves 3, 4 and 5.) Curves 1 and 2 are thermal
curves of pyrite.

190 Allen, Crenshaw, Johnston, and Larsen—

experiment was repeated several times with similar results.
Under these conditions, there is a plain evolution of heat
accompanying the change of marcasité into pyrite. This
shows, of course, that marcasite possesses the more energy* of
the two andisa monotropic form. This condition of instability
isin accord with the more rapid oxidation of mareasite in
nature, and in it is probably to be found the reason for the dif-
ference in behavior between marcasite and pyrite toward other
oxidizing agents. Monotropic forms often crystallize from
some particular solvent or within a limited temperature range.

The formation of marcasite from acid solutions is in accord:

with this, though as yet we do not understand the reason for
it. A rise in temperature doubtless increases the velocity of
the change marcasite > pyrite. At low temperatures this
becomes infinitesimal or zero; above 450° it becomes measur-
able. This irreversible relation has a bearing on the question
of paramorphs of iron disulphide, for it is impossible to see
how pyrite could change to marcasite without first passing into
- solution, while the opposite change is experimentally estab-
lished. Paramorphs of pyrite after marcasite are certainly
possible, but paramorphs of marcasite after pyrite are evidently
impossible.

The agency of organic matter in the formation of natural
pyrite and marcasite.—The fact that pyrite is sometimes found
in nature replacing wood has been alluded to. Liversidget gives
an example of recent pyrite which is found on twigs in a hot
spring at Tampo, N. Z. The sulphides of southwestern Mis-
souri, including pyrite and mareasite, are frequently associated
with asphaltic matter, and in Oklahoma this is sometimes so
great in quantity as to interfere with the concentration of the
ores. (Lindgren.) It is pretty generally believed by geolog-
ists that the organic matter of certain shales acted as a precip-
itant of the pyrite they contain. Such a shale underlies the
sulphide deposits of Wisconsin. We learn from Mr. W. H.
Emmons of the U. 8. Geological Survey that this shale con-
tains a small quantity of hydrogen sulphide, which naturally
may have been the precipitating agent. Coals, also, in which
pyrite is commonly found, are frequently permeated with
hydrogen sulphide.

The role of micro-organisms in the formation of iron di-
sulphide.—The question naturally arises whether there is any
connection between organic matter and the formation of

* Cavazzi (Rend. Accad., Bologna, N.S., ii, 205, 1898) states that the
heats of combustion of pyrite and marcasite are identical (1550 cal. ). This is
certainly incorrect.

+ J. Royal Soc. N. S. Wales, xi, 262, 1877.

7)

Mineral Sulphides of Iron. 191

hydrogen sulphide. In the putrefaction of organic matter
hydrogen sulphide is one of the products, and Gautier* has
surmised that the pyrite which sometimes forms the substance
of fossil bones and shells is precipitated by hydrogen sulphide
which is given off slowly by the organic matter during its de-
composition. The formation of pyrite in this case would dif-
fer from that described in the previous pages only in the source
of the hydrogen sulphide, which is here a product of micro-
organisms.

There is another way in which micro-organisms produce
hydrogen sulphide, and that is by the reduction of sulphates.
According to Beyerinck,+ a considerable number of bacteria,
alow, flagellata and infusoria show this kind of aetivity.
Spirillum desulfuricans is one of the most important. As these
organisms are active only in neutral or alkaline solutions, fer-
rous sulphide is precipitated whenever ferrous salts as well as
sulphates are present. The black mud of many swamps, pools,
and even seas (e.g., the Black Sea), as well as sea coasts,t
which are intermittently overflowed, contains ferrous sulphide.
Mr. C. A. Davis of the U. 8. Bureau of Mines, who has had
large experience on this subject, informs us that he has always
found hydrogen suiphide in peat-bogs into which tide-water
finds its way. Apparently, the formation of pyrite or mar-
casite through the agency of micro-organisms has not been
observed, but only an influx of. air with excess of hydrogen
sulphide would be needed to change the ferrous sulphide into
disulphide. ‘That micro-organisms are directly responsible for
any great quantity of the pyrite or marcasite of nature seems
unlikely because in the first place they are probably not active
far from the surface of the ground. They have been dis-
covered at depths of only four or five meters.§ A fraction of
a per cent of free acid usually inhibits the growth of these
organisms; therefore they could not live in the solutions from
which marcasite appears to have formed. Pyrite and marca-
site are not infrequently associated with minerals like chalco-
pyrite, which proves the presence of copper in the original
solutions, and copper is exceedingly poisonous to practically
all micro-organisms. It is possible, however, that the reduc-
tion of sulphates like gypsum and sodium sulphate by micro-
organisms may be an important source of hydrogen sulphide
in nature.

Distinct conditions leading to pyrite or marcasite in nature.
—The geological relations of marcasite indicate that it is a

*C.R., cxvi, 1494, 1892.

+ Centr. Bakter. u. Parasitenkunde, i, pp. 1, 49, 104, 1895.

{H2S was found in sea-water by B. Leroy, Ann. Ch. Ph. , lviii, 382, 1846.
S$ Hygiene des Bodens, Josef von Fodor, Jena, vol. i, Pt. “i. p. op 18938.

192 Allen, Crenshaw, Johnston, and Larsen—

product of surface conditions. The oxidation of either pyrite
or marcasite gives first a mixture of sulphuric acid and ferrous
sulphate which by further oxidation easily gives ferric sul-
phate. The action of hydrogen sulphide and atmospheric
oxygen simultaneously on the acid ferrous solution would
lead to the same goal. We have found how hydrogen sulphide
acting on acid solutions, especially in the cold, gives rise to
mareasite. We have also found that above 450° mareasite
could not form, thus further confirming geological deductions.

Pyrite, being a stable form, probably crystallizes under a
considerably wider range of conditions than marcasite. The
evidence of synthetic study is that the formation of pyrite
is favored by high temperature and by solutions which con-
tain little or no free acid. In accord with these, we have the
following geological deductions. First, pyrite is a product of
hot springs. In the springs of Carlsbad, which have a tem-
perature of about 55° C., recent pyrite is observed.* The
waters contain sulphates and a trace of hydrogen sulphide,
and are slightly alkaline. The lagoons of Tuscany are deposit-
ing pyrite from their hot waters. Bunsen{ found that the
hot vapors of the fumaroles of Iceland were gradually chang-
ing the ferrous silicate of the basalts into pyrite.

More important geologically is the fact that the product of
deep veins by ascending waters is always pyrite, never marca-
site. Such waters are naturally hot, and commonly if not
always alkaline.{ We can now see that a separation of pyrite
from a magma is entirely possible, while the temperature of
any magma would doubtless be incompatible with the existence
of mareasite.

The occurrence of pyrite and marcasite together.—Hintze§
mentions thirty-one instances where pyrite and marcasite are
found intergrown or precipitated one upon the other. Stokes|
also tested a number of specimens which proved to be mix-
tures of pyrite and marcasite, some of them intergrown in con-
centric layers. In other places, e.g., in Joplin, Missouri, the
two minerals have been observed by us in the same hand spe-
cimen.4] According to F. L. Ransome,** the two minerals
occur together, though perhaps not intergrown, in Goldfield,
Nevada. These facts show very strikingly not only the small
influence of nuclei mn directing the form of the disulphide

* Daubrée, Géologie expérimentale, Paris, 1879, p. 93.

+ Pogg. Ann., Ixxxili, 259, 1851.

{A hot acid solution in contact with carbonate or most silicate rocks
would first be neutralized and then become alkaline.

ieee der Mineralogie, vol. i, pp. 724-778, 820-882.

oc. Cit, j
ee W.S. T. Smith and Siebenthal, U. S. G. S. Folio 148.

-** Private communication. Specimens were also submitted by Mr.
Ransome.

Mineral Sulphides of Lron. 193

which separates from solution, but also that comparatively
slight differences in conditions may give rise to one or the
other. Further, that the two minerals may have formed
at the same time in some instances. The synthetic experi-
ments which have been described proved that the minerals
very commonly formed together,* as polymorphic forms which
are monotropic are apt to do. Cold solutions which were sufhi-
ciently acid gave mareasite ; warm or hot solutions, either neu-
tral or alkaline, gave pyrite, and intermediate conditions gave
mixtures.

IT, Pyrrhotite.

Composition.—Special interest attaches to the composition
of pyrrhotite, which, despite much discussion, is still an unset-
tled question. The various formulae,t Fe,S,, Fe,,S,,, Fe,S, +,
and FeS which have been assigned to it by various authors
rest on widely varying analytical data. The analytical
methods have no doubt been at fault, but the more important
question concerns the physical homogeneity of the substance.
This has been unusually troublesome. Pyrrhotite almost
always occurs in the massive condition, a circumstance which
naturally arouses suspicions of its purity, while its opacity
makes it impossible to put the question to an optical test.

Many years ago Lindstrémt subjected all the known analyses
of this mineral to a careful critique. Those which for any
reason, such as defective analytical methods or impure mate-
rial, appeared unconvincing were rejected.§ In the remainder,
the ratio] of iron to sulphur was calculated and found to vary
from 1:1°06 up to 1:1°19. Some years later Habermehl4 inves-
tigated the same question. He crushed pyrrhotite to a fine
powder, covered it with water, and endeavored, by means of a
strong horseshoe magnet, to separate it into fractions varying
in magnetic intensity. Such fractions as he obtained in this
way showed no systematic difference in composition. Haber-
mehl used in his experiments the pyrrhotite from Bodenmais.

A very satisfactory general discussion of the question of
admixtures in pyrrhotite is also given in Habermehl’s paper.
He decided that pyrrhotite could not contain free sulphur
because carbon disulphide removes none from it, neither could

*Tt may be, however, that pyrite was formed first and was succeeded by
marcasite as the acidity of the solution increased.

| Sidot judged from experimental work with Fe;0, and H.S that pyrrho-
tite should have the formula Fe;S,, C. R. lxvi, 1257, 1868.

_ $ Ofv. Ak. Stockh., xxxii, No. 2, 25, 1875.
§ 18 analyses out of 43 were thus rejected.
|| In the calculation of the ratios Lindstrém took, in place of the small

percentage of nickel found in many of these analyses, the equivalent of iron.
“| Ber. Oberhess. Ges. fiir Natur- und Heilkunde, xviii, 83, Giessen, 1879.

194 Allen, Crenshaw, Johnston, and Larsen—

it contain any disulphide of iron because this is insoluble in
hydrochloric acid, while only sulphur remains after pyrrhotite
has been boiled with this reagent. Judging from the proper-
ties ascribed to Fe,S,, he concluded that this also could not be
present. Habermehl was thus forced to conclude, like Lind-
strom, though on the basis of further evidence, that pyrrhotite
was variable in composition, and it may here be said that no
evidence of later date has ever disproved this conclusion. At
that time a homogeneous solid of variable composition was an
anomaly. ‘To-day such substances are quite generally recog-
nized under the category of solid solutions.

fypothesis of solid solution.—We proposed to test the
hypothesis of solid solution by preparing a series of synthetic
pyrrhotites and measuring some property of them. Pyrrhotite
was prepared by Berzelius, Rammelsberg and others, generally
by heating pyrite. One can also begin with mareasite, which,
as we have seen, is first changed to pyrite between 450° and
600°, or with sulphur and iron. We have tried all three
methods, though most of the work has been done with pyrite
from Elba. This very pure mineral, an analysis of which was
given on p. 177, Part I, was kept in a vacuum desiccator,
from which portions were taken from time to time as required.

Apparatus.—The apparatus used in the synthesis of pyrrho-
tite appears in fig. 6. The crucible, C, containing the pyrite
is of unglazed porcelain, 48" high x37™™ outside diameter at
the top and 22™™ at the bottom. It has a doubly perforated
graphite cover, 4, through the central orifice of which passed
the glazed Marquardt jacket, A, which shields the thermo-
element. Through the second orifice passes a similar tube, B,
open at the lower end, which is traversed by a current of
hydrogen sulphide.*

The crucible is inclosed in a large porcelain tube, D, 40 —45™™
inside and 50™” outside diameter, and 50° in length. In some
of the experiments the crucible was supported in the hot zone
by a strong graphite rod, G, which was fastened to the cover,
F, and clamped outside the large tube, D, while the cover itself
was fastened to the crucible by three small pegs. By means of
this device, the crucible could be quickly lowered at any time
to the bottom of D and thus rapidly cooled. In other experi-
ments, a much shorter porcelain tube was substituted for D,
in which instances the crucible was supported by a fire-clay
pedestal which rested on the bottom of the tube. The upper

* Since the ferrous sulphide from which hydrogen sulphide is generated,

contains free iron, the gas was passed through boiling sulphur to remove
hydrogen, before reaching the furnace.

Mineral Sulphides of Iron. 195

Fic. 6.

LS
SSN
= SS

(7S “are 5 ne
fhe, \ee iM, VF
Akon E |PS fz
We if Vig “G7
Wiis 4a ye,
CHUN iy
ay, = ¢ Wy)

WS
SS

S

aS
Xx
VN

RS

SV““
BEX
SON

WS
SS

Was <<
WSs

SSIS
WANN

ORS
ARN

Fia. 6. Apparatus for the preparation of pyrrhotite.

end of the tube in all cases is closed by the graphite cover, //,
through which pass A and &. The crucible and its contents
are heated by a platinum-resistance furnace, /, as shown in
the figure.

196 Allen, Crenshaw, Johnston, and Larsen—

Synthesis— When heated in hydrogen sulphide, pyrite de-
composes gradually into sulphur and pyrrhotite. The decom-
position may be first detected at about 575° (see p. 205). At
about 665° it proceeds rapidly ; still, even after some hours at
750°, the dissociation is never quite complete, and when the
pyrite used is rather coarse (sized between screens of 8-40
meshes per cm.), several per cent of it persist in the product.
The latter is therefore melted and cooled, and the resulting
material, which is now free from pyrite,* serves as a starting
point in the preparation of pure pyrrhotite.

When this is reheated it loses or gains sulphur according to
conditions. A series of products was made by heating the sul-
phide in hydrogen sulphide for some hours at different meas-
ured temper atur es, and then cooling it in nitrogen.t To
facilitate the formation of homogeneous products the sulphide
was carefully sized between screens of 16 and 40 meshes per
em. ‘These products were all similar in appearance to natural
pyrrhotite. They were all dense, opaque, metallic, more
brownish than pyrite, and only very slightly tarnished. Some
tests were made to prove that the quantity of oxide on the
surface was negligible.

Weighed samples were heated in dry hydrogen to a red heat
and the water formed was absorbed by passing through a
calcium chloride tube. The surface of the grains became
bright in a few minutes. The tube was cooled in hydrogen,
which was then displaced from the apparatus by dry air. The
water thus collected corresponded to less than 0-1 per cent of
oxygen in two different tests. Furthermore it will be noted
later that the preparations which were cooled in nitrogen were
comparable in density with those which were prepared in
another way and were not tarnished in the slightest degree
(see p. 199).

Composition of synthetic pyrrhotite—The sulphur was
determined in each of the synthetic pyrrhotites by a methodt
worked out in this laboratory, which was proved accurate
within at least 0°2 per cent of the sulphur present.

Treitschke and Tammann§ state that the fused sulphide of

* Except for a slight superficial layer which decomposes in the next
a The nitrogen was prepared by Knorre’s method (Die Chem. Ind., xxv.,
531, 550, 1902 ; Chem. Centralb., i, 125, 1903), i. e., by dropping a saturated
solution of sodium nitrite from a dropping funnel into a solution of ammo-
nium sulphate and potassium chromate. The gas was passed through dilute
sulphuric acid to remove ammonia, and then successively through long col-
umns of chromic acid to remove oxides of nitrogen ; sulphuric acid to remove
moisture, and finally over-heated copper to remove oxygen, or any traces of
oxide of nitrogen which may have escaped.

t+ Allen and Johnston, Jour. Ind. & Eng. Chem., ii, 196, 1910; Zs.

anorg. Chem., lxix, 102, 1911.
§ Z. anorg. Chem., xlix, 320, 1906.

Mineral Sulphides of Lron. 197

iron corrodes and dissolves porcelain, but it should be noted
that they made their fusions in carbon-resistance furnaces
without further protection from the air.

Our unglazed crucibles appeared quite unattacked in an
atmosphere of hydrogen sulphide. Analyses revealed the
presence of about 0°25 per cent of silica in our preparations,
though we believe that most of this was derived from minute
fragments of the crucible, which are difficult to exclude entirely
when the cake of sulphide ; is broken out of the crucible. Thus
No. 7 gave 0°33 per cent, No. 10, 0°26 per cent, and No. 3
gave 0°22 per cent and 0-24 per cent of silica in duplicate deter-
minations. This of course includes the silica in the original
pyrite, which, however, was negligible, —-04 per cent.

felation of the specific volume to the composition.—The
specific gravity* of each preparation was determined and from

TaBLE IV.t+

Composition, density and specific volumes of pyrrhotites.

Total Cal. eel ‘al. dens. :

Sulphur Cal. Fes ae as ap a5" : ates gp Y.

1 aG (2 99°59 | 4°769 4°755 0°2103
2 36°86 99°37 °63 4°768 4°755 0°2108
3 30°71 98°04 1°96 4°691 4°677 0°2138
4 38°45 96°89 oul 4°657 4°643 0°2154
5 38°54 96°73 ao 4°646 4°632 0°2159
6 38°64 96°57 3°43 4°648 4°634 0°2158
7 38°84 96°26 Sa 4°633 4°619 0°2165
8 39°09 95°86 4°14 4°602 4°589 0°2179
9 39°49 95°23 4°77 4°598 4°585 0°2181
10 40°30 93°96 6°04 4°533 4°520 0°2212

+ Conditions of formation.

1. From pyrite, melted in H.S, kept a little above m. p. for 1h. in nitro-
gen and then cooled in nitrogen.

2. From sulphur and iron, otherwise like 1.

3. From pyrite, heated to equilibrium in H.S at 1800°, then quickly
cooled.

4, From pyrite, heated in H.S to 900°, then cooled in nitrogen.
. From pyrite, melted in H.S and cooled rather slowly in same.
. From marcasite, melted in H.S and cooled rather slowly in the same.
. From pyrite, heated to 800° 6 h. in H.S, then cooled in nitrogen.
From pyrite, heated to 700° 24h. in H.S, then cooled in nitrogen.
From pyrite, heated to 600° 3h. in H.S, ‘then cooled in nitrogen.

10. From pyrite, heated to 600° 15h. in Hy S, then quickly cooled in the
same.

* Day and Allen, Publication No, 31, p. 55, Carnegie Institution of Wash-
ington.

SO FS Ot

Specific volume.

198 Allen, Crenshaw, Johnston, and Larsen—

this the density (at 4°) and the specific volume was calculated.
Table IV contains these data. Column 1 contains the total
percentage of sulphur, Columns 2 and 3 the quantities a
FeS and S calculated on the hypothesis that pyrrhotite is

solid solution of sulphur in ferrous sulphide. In fig. 7 are
plotted as abscissas the quantities of dissolved sulphur (Column

Inne. 7

we

leis) 2 \ adie ae Se

0°2200

0°2178

HePASe
eRe Meme ae,

0°2150

EEE Ee
PST ae a i a
Pe ee
BV @hatieateaetee
ee

1 2 3 +L 4) 6
Percentage of dissolved sulphur.

0°2125

0-2100

Fig. 7%. The variation of specific volume with the dissolved sulphur in
pyrrhotite.

8, Table IV), and as ordinates the specific volumes (Column 6,
Table IV). It will be noticed that the scale of the plot is very
large and the locus of the points is not only a continuous curve
as the theory of solid solutions demands, but it is also a straight

Mineral Sulphides of Iron. 199

line within the limits of the errors.* If we compare this line
with the dotted line joining the specific volumes of sulphur
and ferrous sulphide, we see that a considerable contraction has
taken place in the process of solution.+

Lgquilibrium between solid pyrrhotite and the partial
pressure of sulphur in hydrogen sulphide.—The composition
of a variable phase of two components, iron and sulphur, as
pyrrhotite is shown to be, would of course be fixed when both
temperature and pressure are fixed. By heating in hydrogen
sulphide the pressure is fixed, though not independently of the
temperature. To obtain equilibrium, the products were heated
for about three hours, at the measured temperature, and then
by the device shown in fig. 6, the crucible and its contents were
quickly lowered to the bottom of the enclosing tube. The
process of heating and quick cooling in hydrogen sulphide was
repeated until the density of the product was constant. The
densities of the products thus successively prepared usually
agreed exactly in the third decimal place. The rate at which
the sulphur is absorbed by pyrrhotite in the cooling is too slow
to affect these results except possibly in the determinations
made at the highest temperatures (1100°-1300°), where a small
quantity of sulphur may perhaps be taken up. As this point
is important, some data on the rate at which the cooling
proceeded are here given.

lima temperatures 22-3. 5.52 1300" § 1100° 800° 600°

Temperature after 1 min._-.-_-_- Boe CO RE es itraee
« Once eM A580 ASO LM. FL
‘< “¢ 8 ie tigen. We ee i ly AO Ona ee ae
13 rT: 34 Sa ea lb a Nie AO ae nas
73 C5 is Cathe oa Boh? 4: iit Sate 805°
és SOREN Sia Ale willy rik 365° ee ep ea es ae
&< CGRP WG ah MCC aie eel es 6S, Se a

In Table V are collected the quantities of sulphur dissolved
in pyrrhotite at different temperatures in hydrogen sulphide
gas. The sulphur in Nos. 1 and 6 was determined by analysis ;
in the rest it was calculated from the specific gravity. The
results in ‘Table VI, showing the dependence of composition
on temperature when the products are cooled in nitrogen, are
given by way of control. In fig. 8, the curve in space shows
how the composition of pyrrhotite varies with both tempera-

* Three of the points are beyond the errors of the determination of
sulphur, and specific gravity, but if we allow a small error in homogeneity
in the process of preparation, probably occasioned by the splinters of por-
celain, the statement holds for these points also.

+ The density of rhombic sulphur is very nearly 2°075, and its specific
volume is therefore 0°4819. The specific volume of the ferrous sulphide is
estimated by extrapolation to be 0°2093.

200 Allen, Crenshaw, Johnston, and Larsen—

ture and pressure. The discontinuity in the curve between
1165° and 1200° which is conditioned by the change of state
will be discussed later (p. 207).
Maximum percentage of sulphur in pyrrhotite.—The most
concentrated solution of sulphur in ferrous sulphide obtained

Ps)
Q

re) °
oo

aya

SEREEEno
PLCC saan ana
SERRE
SACP a
[CES
CD oe eee
Po
LM
PO oe
eT ey a
Pe) aaa
We | ake ole Leelee ka
SV /L LL LL Le fe
BLIP LL SLD IE
LLAN PIL dA
LILAL TIS LITA
LILLIA SI J ae
YT ITI ot
VOU LIL
y VI NG EE
VELL ELLA LL ELE
Vp Lila Leela
Jihad PLD L LE
WLLL DEI
SEELEY
ETA SLIME.
WAV de AWIDAVMIAIA I ANT

We AN NNN SS

y

REE
Beers

NSS
SOUS

SSS

\ SGI

alae aa aati
i Sea

SAUER NESSES

‘

RSS SSAA ANN

\

RS SERS SSNS

DSS SAIN NGS
NONNGRAUN

NAN NESS
SN

NR

pee

Fig. 8. Curve in space showing the dependence of the composition of

pyrrhotite on temperature and pressure.

C (composition) = percentage of dissolved sulphur.

P = pressure in millimeters of mercury.

T = temperature. ;
synthetically contains 6 per cent of sulphur and 94 per cent of
FeS. This solution was obtained at 600°, where the absorption
of sulphur from hydrogen sulphide is slow. At 575° the
reaction was so slow that the attempt to get a saturated product
was discontinued. At 550°,as we will show farther on,
pyrite is formed. The curve in fig. 9 shows an extrapola-

Mineral Sulphides of Iron. 201

TABLE V.

Sulphur dissolved by FeS in an atmosphere of H.S
at measured temperatures.

Time of heating Percentage of

Temperature Time in which dissolved
equilibrium Total sulphur
was reached

| .
] 600° ene ay he 6°04
2 800° oat? (a 4°41
3 1000° Dy ss Ap 3°6
4 1100° Pd i der 6 3°3
9) 1165° Dh se Dei 3°2
6 11200~ 20 min. 14“ 2°5
7 1300° BOW os TS 1°96
TABLE VI.

Sulphur in pyrrhotite cooled in nitrogen from
various temperatures.

Time of heatin Percent
Lolipeneiiue in H.S ‘ dissolved pater
1 eno Few minutes “41
2 About 1200° 14 h. °63
3 1000° 6 h. 2°70*
4 900° 6 h. 3‘1l
5 800° 6 h. 3°74
6 700° 2th. 4°14
a 600° oni, 4°77

* The sulphur in No. 3 was calculated from the density.

tion from which we judge the maximum quantity of sulphur
in pyrrhotite obtained by heating in hydrogen sulphide must be
about 6°5 per cent. If we compute the analyses of natural
pyrrhotite in terms of FeS and S, we find that the limit of solu-
bility agrees well with this. The highest value calculated from
Lindstrom’st figures is 6:08 per cent. From Rose’st analyses
we derive the value of 6°76 per cent. The maximum percentage
of sulphur in the pyrrhotite analyses quoted by Danas is 40°46
per cent. This particular occurrence, however, contained about
0°5 per cent of copper and cannot, therefore, be satisfactorily
t Loe. cit.

¢ Gmelin Kraut Handbuch der Ch., 6th Ed., Vol. III, pt. 1, 382.
§ System of Mineralogy, 6th Ed., p. 74.

Am. Jour. Sct.—FourtTH SERIES, VOL. Pedal No. 195.—Marcgu, 1912.
14

Percentage of dissolved sulphur.

202 Allen, Crenshaw, Johnston, and Larsen—

used for a calculation of this sort. Dana gives also an analysis
of pyrrhotite by Funaro, which contained 40°27 per cent total
sulphur, equivalent to 6 per cent of dissolved sulphur. This
pyrrhotite contained also 3°16 per cent of nickel, which, accord-
ing to Penfield, is mechanically intermixed with pyrrhotite in
the form of pentlandite. If this be true, the ratio of sulphur to

Fie. 9.

Senme. Saas
EEEEEE AEE
Be ee Sse a

Be ofc e a

ic Sees SS a ea a

Bera Saree 0.

Ee Sr Re Pes
ee a
cae ,

aa eee eee eee
SS ane

500° 600° 700° 800° 900° 1000° 1100° 1200° 1300°

Temperature.

Fic. 9. Curve showing the percentage of sulphur dissolved by ferrous
sulphide in hydrogen sulphide gas as the temperature varies.

iron in the pyrrhotite would be raised a little, since pentlandite
belongs to the type of sulphides MS, and the equivalent
quantities of iron and nickel are almost the same.

Some allowance for errors in the analyses of the natural
mineral should be made; still, the agreement between the
maximum quantities of sulphur in the natural and synthetic
pyrrhotite is striking.

Relation between pyrrhotite and pyrite.—The diagram in
fig. 10 shows the relation between pyrrhotite and pyrite. The
curve 1, 1 shows the partial pressures of sulphur vapor in one
atmosphere of hydrogen sulphide, as they vary with tempera-
ture. These results are taken from Preunner and Schupp,* and

* Zs. phys. Chem., Ixviii, 161, 1909.

Mineral HTS of Iron. 203

are extrapolated above 1130° and below 750°. Curve 2, 2,
represents so far as may be with partial data the dissociation
pressures of pyrite at various temperatures. Here it is assumed
that the vapor pressure at 665° is one atmosphere (see p. 205).
At 550° pyrrhotite was found to pass over into pyrite when

Fie. 10.

, 1

100
90
80
70
60
a)
40
30
20
10

el
Pee
=o SECs eae
LE eee
Se Oe ee, ae ee
ie a ee
ar ames oa
Je a ee ee
PA AMA Lbs el
ool A ee

500 600 700 800 900 1000 1100 1200

Temperature.

Pressure in millimeters of mercury.

Fie. 10. Curve 1,1, shows the partial pressures of sulphur in hydrogen
sulphide at various temperatures (Preunner and Schupp). Curve 2, 2, shows
approximately the dissociation pressure of pyrite.

heated in hydrogen sulphide. This was proved by the fact
that the color changed to the yellower color of pyrite and the
density increased, whereas pyrrhotite decreases in density with
increase of sulphur. At 575° pyrrhotite showed no change in

204

Allen, Crenshaw, Johnston, and Larsen—

ite a Pl

iil FB = th a
WGA Poe a I ose

REVERE as eee
ee eee
BRESIR eee ee eee
a en ae
ee eae.
a Se ne le
a vs refs lB aiken ed

SRR SHAME RE SR Shae)

PMR EREMRGE See:
poe ee MOTE
pela Pe

De Fae PLE
PERERA CHIE AE
CR Ee eS ee aS
Sieh aie Ge wie a
sl aie al Ei

[i
PE) UN eee ea
ie a ee Eee
Fie is Fe oc i AP oe Fs
pelted val Eh Ee el
ll call alata Blea al I a
Pe eh) aad Gea
eee ea ia hs
HERE EAA EE

Ht A A

Wl I an al I CO
TTT a7 a lk
CEA Eee
PCH

© i
v

pik si:

Time in hours.
ge in specific gravity with time on heating pyrrhotite in hydrogen sulphide.

Curves showing the chan
refer to the temperatures 500°, 550°, 575° and 600°.

The curves

irc del.

Mineral Sulphides of Iron. 205

color but continued to decrease in weight the longer it was
heated. These facts are graphically shown in fig. 11. Pyrite
under the same conditions gave inside of a few hours a per-
ceptible quantity of pyrrhotite, which was proved by testing
with warm hydrochloric acid. At 565° the pyrite formed in
several hours only a doubtful trace of pyrrhotite, if any.
Between 550° and 575°, therefore, the two curves 1, 1 and
2, 2 cross, and, at that point, about 565°, at a pressure of
about 5™" of sulphur, pyrite should be in equilibrium with a
pyrrhotite containing about 6°5 per cent of dissolved sul-
phur. How this quantity would vary with conditions we
do not yet know, though, as we have just seen, the solu-
tion of sulphur in ferrous sulphide of maximum concen-
tration found in nature, formed presumably from water solu-
tions, does not vary much from it.

The change from pyrite to pyrrhotite is, then, a reversible
reaction, FeS,2 = FeS(S),+(1—2)S. Simce the system
contains a gaseous phase, the temperature at which the change
occurs is manifestly dependent on pressure.

Dissociation point.—lt has been previously stated that
pyrite undergoes dissociation into pyrrhotite and sulphur and
that this dissociation is detectable at 575° after the lapse of
several hours, when the heating is done in hydrogen sulphide.
If the heating is continued at a moderate rate (2° per min.)
a strong absorption of heat manifests itself at about 665°.
Here, under these conditions of heating, the dissociation there-
fore becomes suddenly accelerated, and it is probable that the
pressure of the escaping sulphur reaches one atmosphere.
The solid phases pyrite and pyrrhotite, 1. e., the saturated solu-
tion of sulphur in ferrous sulphide, should at-a fixed tempera-
ture maintain a fixed pressure. As a matter of fact, the point
is not sharp; the temperature gradually rises through an inter-
val of about 20°. This is probably due to the formation of a
coating of pyrrhotite on the pyrite grains, which retards the
dissociation, so that the system requires a gradually rising tem-
perature to maintain the pressure. The fact that undecom-
posed pyrite persists so tenaciously in the product seems to
support this view. <A typical thermal curve for pyrite in this
region is shown in fig. 12. It is seen to have the same general
form as a melting point curve and the end of the heat absorp-
tion is more sharply marked than the beginning, though for
the reasons stated the latter has the greater significance. The
following data show that the absorption ends pretty uniformly
at about 685°:

El. V 6050 mv. = 686°
gs 60387 mv. = 684°
El. S 6083 mv. = 686°
ae 6060 mv. = 684°

206 Allen, Crenshaw, Johnston, and Larsen—

Inversion in ferrous sulphide.—Le Chatelier and Ziegler *
discovered a transformation in commercial ferrous sulphide at
about 130°. This has been confirmed by Treitschke and
Tammannt and by Rinne and Boeke.t The last named

Fie: 12.

MP8 ie eama rs Oe a, Fe
bo both A "Tal le PS ell a
Bt a FT PRS
BREE AEAS SEERA
Pate aE ae et a
feo lL RRR Rl
BRR GSR MMS Winks bl

Le a id eS
Rea ee ee eas eer
ee
TEP RRP RARER S is =
CoS Pe Gs GE A Po

a EE ee
[a TES SISA eS A a a
Hel il a Me ek a cl Sa
Oa le
ee DE TE
BRAM sui
ae Ge a ee
if hui Ee eel valdel op [CALE kN
os cod od s| teal fll eb ah
polileali (cal ool i bie a eal aa eee aaa
Last TB \ ci Sai ea eh Sh eS
i ee ed SO
BH sy

s

ka
e
al
[4
ee
Ea
EI
LI
i
(al
St
Son
ES
44 ees Bee
aa i
Ea
ey
es
MI
Fic, 12. Curve showing the dissociation of aA into pyrrhotite and sulphur

O
iT)
To}

6500
600.

2 !

authors were unable to find any heat absorption in approxi-

mately pure ferrous sulphide, though the addition of iron (or

carbon), which they believe goes into solid solution, makes the

heat change manifest. The dissolved iron is supposed by
* Bull. Soc. d’Encouragement de l’Industrie, Sept. 1902, 368.

t Loe. cit.
¢ Zs. anorg. Chem., liii, 338, 1907.

Mineral Sulphides of Iron. 207

Rinne and Boeke to facilitate the transformation, first by
raising the temperature at which it takes place, and second by
loosening the crystal structure. The transformation point in
the presence of 7 per cent dissolved iron is found to be 138°,
and further addition of iron does not change it. At lower
temperatures a temperature interval is found, and the inver-
sion is lowered, but the temperature cannot be followed in
mixtures containing less than 5 per cent dissolved iron. Our
results confirm the above in so far as the experiments were
earried. The change could not be detected in pyrrhotite or
pure troilite. It is a natural inference that the change does
take place in these also, but that presumably the heat absorp-
tion in them is very gradual and is therefore overlooked.
Melting temperature of pyrrhotite.—Pyrrhotite melts in
hydrogen sulphide at 1183°. (Table VII.) Of course, a solid
solution melts through an interval and not at a point, but we
have as yet no quantitative methods which enable us to deter-
mine the length of such an interval at high temperatures. The
maximum of the heat absorption falls at the above point. The
melts seem to be quite thin,* and there is usually little or no
undercooling, if the temperature is not too rapidly lowered.

TABLE VII.
Melting temperatures | Freezing temperatures
Prepara- Thermoele-
tion ment
mv. degrees mv. degrees
1 VIE f 11589 1181 11590 1181
2 = 11585 1181
3 ss ' 11585 1181
4 A 11683 11838
5) ve 11687 11838
6 $s 11675 1182
6 es 11700 1184
7 iN 11705 1184
8 11690 1183

—

Examples of freezing and cooling curves of pyrrhotite in
hydrogen sulphide are plotted in fig. 18. By reference to fig.
9 we notice that the liquid pyrrhotite contains still a consid-
erable excess of sulphur above the ferrous sulphide ratio, and
that the quantity is less than it is in the solid. From Beck-
mann’s formulat for the change of melting temperature with

* See Friedrich, Metallurgie, vii, 257, 1910.
+ Ostwald’s Lehrbuch der Chemie, vol. ii, pt. 3, p. 38.

Temperature,

208 Allen, Crenshaw, Johnston, and Larsen—

e (OC, —C,), where A

is the change in the melting point, T is the melting point
(absolute) of the solvent, 2 is the heat of fusion of the same, and
C, and O, the concentr ations of the solute in the liquid and solid
respectively, we find that the melting temperature is raised if

wae . 4 : a
composition in a solid solution A =.

Hie. 13.

1220°

ceeeseeeeeetnennne
1210°
i) ial Ul ool lc

1200°

1190°

1180° Laan a a imitans =

1170°
1160°

1150°

7 nal a
Tiassa

11380°

Time in Minutes.
Fic. 18. Melting and freezing curves of pyrrhotite in hydrogen sulphide.

the liquid which first forms contains less of the solute than the
original solution. We do not, to be sure, know the composi-
tion of the first liquid which forms, but as the sina liquid prod-
uct contains less sulphur than the original solid, it 1s 1mpossi-
ble to believe that this is not the case with the first liquid also.

Melting temperature of pyrrhotite in sulphur vapor. —If
this conclusion is correct, it follows that by raising the pressure

Mineral Sulphides of Lron. 209

of the sulphur vapor in which the pyrrhotite is melted, the
quantity of sulphur in the product should also be raised, and
the melting point with it. In accord with expectation, the
maximum heat absorption in melting was raised about 5° when
the change of state took place in an atmosphere of sulphur
vapor. Theapparatus used was the same as that shown in fig. 6,
except that a second furnace below the one shown in the figure
was used for boiling the sulphur. At the bottom of the tube
were placed 100 grams of sulphur, and the temperature of the
lower furnace (measured outside the tube) was raised gradually
to a little above the boiling point of the sulphur, and only
after the sulphur burned freely at the top of the tube was the
temperature of the crucible raised through the melting inter-
val. The experimental data follow :

JBN ego \ eee ogni 11740 m. vy. 1188°
Ae OG Ws ISS) ee
20 ae 1186°

The maximum heat absorption is only about 5° higher than
it is when the pyrrhotite melts in hydrogen sulphide. <A care-
ful comparison with the latter on a succeeding day in the same
apparatus left no doubt as to the reality of rise in the temper-
ature and as to its order of magnitude.

Melting temp. of pyrrhotite in H,S on the
succeeding day, with the same element
and otherwise same conditions .__.-_-- LiGSs sme hss.

11686 m. Vv. NE

Melting point of ferrous sulphide, HeS.—Since the melt-
ing temperature of pyrrhotite is raised by increasing the pres-
sure of sulphur vapor above it, pure ferrous sulphide must melt
at a temperature lower than any of the sulphur solutions. In
the effort to obtain this point the crucible containing the pyr-
rhotite was heated in a vacuum furnace. The dissolved sulphur
volatilized in vacuo, as expected, but there was a further loss,
though a slow one, which was found to be due to a dissoci-
ation of the ferrous sulphide into the elements, a circumstance
which naturally prevented the exact location of the melting

oint.
The apparatus employed is shown in fig. 14. A is a glazed
porcelain tube, closed at one end, 50 in length. The open
end is closed by the perforated brass plug DY, through which
passes the porcelain tube 6 which protects the thermoelement
ff from the action of the fused sulphide. This plug has a side
tube also of brass which connects with the pump. An air-
tight joint between the tube and plug is made with Kotinski
cement, (CC. It was found necessary also to close the tube B by

210 Allen, Crenshaw, Johnston, and Larsen—

eS
D Nis
Ni
NIB E
1?
B
|
E

Q

l OF —
ULLZL2 E7777 7770) x

U2ZZ277 72777222 Lf

Fie. 14. Vacuum
furnace.

ISS.
Nak TTT IPI IIIT

seccccrcsacececececccemras > 10 PUMP closed end. A small

cementing in a small
glass plug, because
the former invariably
leaked through the

hole is drilled through

this tube at O, so that

all the air in the appa-
ratus may be removed by the pump. The
crucible of unglazed porcelain has a capacity
of 15 g. of pyrrhotite. It rests on a ring of
refractory clay, and is heated as usual by a
resistance furnace after the apparatus has
been exhausted by the oil pump.

Repeated determinations of the melting
temperature of ferrous sulphide under these
conditions, showed in general that each suc-
cessive determination was a few degrees
lower than the one which preceded it, and
analyses of the products as well as determi-
nations of their density showed that they
contained less sulphur than ferrous sulphide.
The following data make it evident that
ferrous sulphide slowly dissociates into
sulphur and iron, in the vicinity of its melt-
ing point, and that the successively lower
melting temperatures obtained are caused ~
by the gradual accumulation of free iron in
the melt. About 15 g. of a sulphide previ-
ously melted in the vacuum furnace, and
shown to contain less sulphur than ferrous
sulphide, was introduced again into the vac-
uum apparatus, which was then completely
exhausted by the pump. The pump was
then stopped and the heating was begun.
At about the melting temperature the pres-
sure had increased to 9°5™™. The product
was now melted and frozen several times,
and then the apparatus was cooled to room
temperature. Next morning the manometer
read 8™™, showing that the pressure was not
due to a leakage but doubtless to the evolu-
tion of gases occluded by the crucible and
by the glaze of the porcelain.* When the
crucible was removed from the vacuum tube

* For data on this point, see Holborn and Day, On
the Gas Thermometer at High Temperatures, this
Journal (4), viii, 178, 185, 1899 ; Guichard, The Gases

Disengaged from the Walls of Tubes of Glass, Porce-
lain, and Silica,C. R., clii, 876, 1911.

Mineral Sulphides of Iron. 211

the contents were found to possess a bright metallic luster, while
about 10™ above the cover of the resistance furnace a ring of
sulphur was condensed on the inside of the tube. This exper-
iment was repeated with similar results. A sulphide contain-
ing 36°02 per cent of sulphur (FeS contains 36°45 per cent)
was heated as before. This time the manometer read 5:5™™
at the melting temperature. When the apparatus was cold the
reading was 5-0". This product was also perfectly bright and
a ring of sulphur was again visible* on the cool part of the
tube. The product was analyzed again and found to have
lost still more sulphur. The following table (Table VIII)
shows that the percentage of sulphur, the specific gravity, and
the last melting point of three different products prepared in
vacuo are in accord, i. e., the density increases with the per-
centage of free iron and the melting “point” falls. The melt-
ing temperature of No. 3 should of course be lower than No.
2, but these temperatures are not easy to locate exactly ; a part
of the difficulty is perhaps due to the fact that we are dealing
with a mixture, in which the heat absorption is not sharp.

TaBLE VIII.

Properties of pyrrhotite after melting in vacuo.

Melting Melting
temperature|tem perature Free iron

in in Sp. gr. | Density Percent} calcu-
No. | microvolts| degrees at 25° (4°) |Sp. vol.jsulphur) lated

1 11508 1165 4°816 | 4°802 | °-2082) 36°02) 1:23%
2 11346 1156 4-861 | 4°847 | °2063 | 35°71] 2°08
3 11416 ITA Fi 4°883 | 4°869 | -2054| 35°41) 2°91

It is quite evident from the above data that the true melting
point of ferrous sulphide can only be determined by heating
in sulphur vapor, the pressure of which is equal to the disso-
ciation pressure of the sulphide. We may safely say that this
point will be found to lie between 1183°, the melting temper-
ature of a product formed in hydrogen sulphide of one atmos-
phere pressure, and 1165°, and that the point is within 5° of
1170°. Treitschke and Tammann,+t working with impure mate-
rial, by extrapolation estimated the melting point of ferrous
sulphide at 13800°. Biltz,t heating precipitated sulphide of

* The sulphur was identified by solution and crystallization from carbon
bisulphide. About 100™% was thus recovered.

+ Zs. anorg. Chem., xlix, 328, 1906.
¢ Zs. anorg. Chem., lix, 273, 1908.

212 Allen, Crenshaw, Johnston, and Larsen—

iron in an atmosphere of nitrogen, obtained 1197°+2°. Fried-
rich, who took considerable pains with the composition of his
material, preparing it by the fusion of synthetic pyrrhotite
with the calculated quantity of iron, found an average of 1171°.*

Crystals of pyrrhotite——Measurable crystals of pyrrhotite
were readily formed by the action of hydrogen sulphide on
solutions of ferrous salts in glass tubes which contained some
air. The yield was small and it cannot be stated, in the absence
of optical tests, that the different crystals were identical in
composition; in fact, Mr. Larsen finds crystallographic evi-
dence that there were differences of composition. The manifest
impossibility of finding the composition of individual crystals
and of proving that the crystals of any one preparation were
identical, made it useless to attack the imteresting question,
how the angles in crystals of the pyrrhotite series vary with
composition. Crystals were prepared at 80°, at 225°, and at
some other temperatures, therefore presumably above and
below the inversion temperatures, but in the absence of direct
evidence on either pure ferrous sulphide, or pyrrhotite of any
composition (see p. 206) this can not be stated with certainty.
Mr. Larsen believes there is good crystallographic evidence for
two crystal forms, the upper form orthorhombic, the lower
hexagonal.

Troilite and its relation to pyrrhotite.—The knowledge of
troilite is defective on account of the scarcity and poor develop-
ment of material, but the analyses on record, and its behavior
towards acids, prove that it is essentially ferrous sulphide, con-
taminated generally with the sulphides of cobalt and nickel.
The mineral is found only in meteorites embedded in a matrix
of metallic iron, and it is evidently the contact with free iron
and not the peculiar conditions of meteorite formation which
accounts for the lack of dissolved sulphur in troilite. It is
probable that the stony portions of meteorites contain ordinary
pyrrhotite.

Lorenzt has described a method for the preparation of
ferrous sulphide (artificial troilite) which depends on the same
principle, i. e., formation in the presence of excess of iron.
Metallic iron is simply heated to redness in hydrogen sulphide.
Crystalline crusts of silvery luster which are easily detached
from the unchanged metal, are produced inthis way. Analyses
of these crusts by Lorenz approached ferrous sulphide, but not
closely. The only determination of sulphur gave 87 per cent,
which corresponds to 0°85 per cent of dissolved sulphur. Two
products were made by us in this way. They agreed with Lor-

* Loe. cit.

+ Dana, A System of Min., 6th Ed., p. 78.
+ Ber., xxiv, 1501, 1891.

Mineral Sulphides of Lron. 213

enz’s description completely, but they were not ferrous sulphide.
The first, formed at 850° from soft iron wire, had a specific
gravity at 25° of 4°739, corresponding to a specific volume (4°)
of 0°2116. The second, formed at 950°, had a sp. gr. of 4°748,
corresponding to a specific volume of 0°2112. Making no
allowance for the impurities in the iron, we calculate from
these numbers (see p. 198) 1:1 per cent and 0-9 per cent of dis-
solved sulphur respectively. The diffusion of sulphur into the
iron is evidently too slow here to give a homogeneous product.
An examination of these crystals under the microscope,
for which the authors are indebted to Dr. F. E. Wright,
showed that they were either hexagonal:or pseudohexagonal,
but they were not adapted to measurement on the goniometer.

Efforts to prepare ferrous sulphide in the wet way were no
more successful. Weinschenk* claims to have formed it by
the action of hydrogen sulphide on a solution of ferrous
chloride in sealed tubes. The product consisted of microscopic
hexagonal plates, which Weinschenk states did not lose sulphur
when heated to redness in hydrogen and therefore were fer-
rous sulphide. His experimental work is doubtless in error,
for Habermehl,t+ many years earlier, had shown that pyrrhotite
under these conditions loses sulphur continuously and gradually
approaches pure iron.

Weinschenk’s work was repeated by us. Pure ferrous
chloride was prepared repeatedly with much care, dissolved in
an aqueous solution of carbon dioxide and subjected to the action
of hydrogen sulphide, made in several ways (by the action of
the water on sodium thiosulphate; and by the action of dilute
sulphuric acid on ammonium thiocyanate). In no case was pure
ferrous sulphide obtained. Free sulphur, either from secondary
reactions or perhaps from the dissociation of hydrogen sulphide,
even at 200°, always appeared to give pyrrhotite. After our
further experience in heating pyrrhotite in vacuo, we state with
confidence that pure ferrous sulphide has doubtless never been
made.

Mineralogically, troilite has no claim to a separate mineral
species any more than have pyrrhotites of different composi-
tion; it is simply the end member of the series of solid solu-
tions. This is abundantly attested by the synthetic evidence
submitted in the foregoing pages. Jt may also be noted by
way of further evidence that the specific gravity of natural
troilite or rather the specific volume calculated from it, agrees
tolerably well with the extrapolated value in fig. 7, and the best
erystallographict work on troilite, imperfect though the
material was, indicates that it is hexagonal, as it should be.

* Zs. Kryst., xvii, 499, 1890. + Loc. cit.
¢ Linck, Ber., xxxii, 895, 1899.

214 Allen, Crenshaw, Johnston, and Larsen—

Application of data on pyrrhotite to geology.—-Very little
of the chemistry of pyrrhotite worked out in these pages will
probably find application in geology. However, the following
points have a practical bearing.

1. The readiness with which pyrrhotite changes to pyrite,
and the reverse, has been specially noted. The transformation
of pyrrhotite into pyrite through the agency of vein-forming
solutions which probably contained polysulphides, is an
observed fact in geology; but the dissociation of pyrite has
apparently not been noted, although certain phenomena in the
vicinity of contacts would suggest this. The most distinet
phenomenon which points to such a reaction is the almost con-
stant presence of pyrrhotite in contact metamorphic shales.
In-such shales pyrite develops normally at some distance from
the contact, while close to it, pyrrhotite is universally present
and there is little, if any, pyrite. (Lindgren.) The occurrence
of pyrrhotite which could be proved to have formed in this
way would point to a temperature above 500°,— much
higher if the dissociation occurred under considerable pressure.
Pseudomorphs of pyrite after pyrrhotite do not seem to have
been observed, but they would probably be readily formed by
the action of polysulphides on pyrrhotite crystals. Pseudo-
morphs of marcasite after pyrrhotite have been described by
Schéudox and Schroeder* and by Pogue.t The synthetic
experiments (see p. 179) suggest that these were formed by
the addition of sulphur from slightly acid solutions containing
hydrogen sulphide and free sulphur in suspension.

2. The possibility of the formation of pyrrhotite from
slightly acid solutions at temperatures as low as 80° has been
made clear in the foregoing pages. The crystals made in this
way were generally associated with crystals of pyrite and per-
haps mareasite, a fact which shows how readily the former unite
with sulphur. This is probably the reason why the pyrrhotite
of nature never seems to form under the above conditions, for
such could only occur in surface solutions where there is more
or less access of air. This, with hydrogen sulphide, would
give free sulphur.

3. Pyrrhotite is regarded in certain instances as a primary
constituent of eruptives. Its intimate intergrowth in such
cases with silicates such as augite and olivine strongly suggests
the conclusion that both have separated from a common magma.
Now it is well known that molten sulphides of this sort are all
but immiscible with molten silicates ;in other words, a system
like this would separate into two layers. It would bea matter
of great interest to determine whether the addition of water,
aqueous sodium sulphide or even of a more complex solution

* Jahrest. Niedersachsischen geol. Vereins Hannover, p. 132, 1909.
+ Proc. U. S. Nat. Mus) xxxix"o7G, 1Oide

Mineral Sulphides of Lron. 215

would bring a two-layered system of this character to homo-
geneity, but at present the problem is experimentally beyond
our means.

Summary.
[Including the results of Part III, as follows. |

1. The formation of iron disulphide was accomplished (1) by
the action of hydrogen sulphide on ferric salts, or the action
of sulphur and hydrogen sulphide on ferrous salts; (2) by the
addition of sulphur from solution to amorphous ferrous sul-
phide or pyrrhotite; (3) by the action of soluble polysulphides
on ferrous salts; (4) by the action of soluble thiosulphates
on ferrous salts according to the equation 4M,8,0,+FeX,=
38M,SO,+FeS,+2MX+38. The first three methods may be
generalized as the action of sulphur on ferrous sulphide: (a)
in acid solutions; (6) in nearly neutral solutions, and (c) in
alkaline solutions, since in (1) we may assume that ferrous sul-
phide first forms by the action of hydrogen sulphide on the
ferrous salt, and in (8) we know that polysulphides first pre-
cipitate a mixture of ferrous sulphide and sulphur. Marcasite
was obtained with certainty only by method (1); low tempera-
tures and free acid favor its formation. A solution containing
about 1 per cent of free sulphuric acid at 100° gives pure mar-
easite. Less acid solutions at higher temperatures give mix-
tures of marcasite and pyrite. The other methods give pyrite
which, under certain conditions, may be mixed with amorphous
disulphide. It is possible that some marcasite may be formed
by method (4).

2. Marcasite and pyrite were identified in the above products :
(1) By microscopic examination and crystallographic measure-
ment. The pyrite crystals showed only the cube and the octa-
hedron. Marcasite crystals were formed for the first time.
They were commonly twinned after (110), and their habits are
shown in figures 15 and 16, Pt. III. The axial ratios of the syn-
thetic mineral are @:b:¢ = 0°7646:1: 1:2176 and agree remark-
ably well with those of the natural mineral. (2) By Stokes’s
oxidation method, which serves also for the analysis of mix-
tures of the two minerals.

3. Marcasite changes to pyrite with evolution of heat. The
change proceeds very slowly at 450° and is not accelerated by
pressures even of 10,000 atmospheres. Marcasite is mono-
tropic toward pyrite. This is in accord with the greater incli-
nation of marcasite to oxidize, its assumed greater solubility,
and the fact that its formation is conditioned by the composi-
tion of the solution from which it crystallizes.

4, The fact that marcasite never occurs as a primary con-
stituent of magmas, while pyrite sometimes does, is explained

216 Allen, Crenshaw, Johnston, and Larsen—

by the fact that marcasite cannot exist above 450°. The forma-
tion of pyrite in deep veins and hot springs is explained by the
fact that the waters from which it came were alkaline. The
marecasite of surface veins was probably formed from cold
acid solutions, while mixtures of marcasite with pyrite were
probably conditioned by higher temperature (up to 300°),
or the presence of less acid, or both. Micro-organisms may
have been active in the formation of pyrite and marcasite by
giving rise to hydrogen sulphide.

5. Pyrrhotite was formed by the decomposition of pyrite or
heated marcasite, or by heating iron with excess of sulphur.
The dissociation of pyrite into pyrrhotite and sulphur is readily
reversible. At 565° (about) pyrite and pyrrhotite are in equi-
librium with the partial pressure of sulphur in H,S, which here
amounts to about 5™™ (data of Preunner and Schupp); at 550°
in hydrogen sulphide, the pyrrhotite passes into pyrite, and at
575° the reverse action proceeds. At about 665° the evolu-
tion of sulphur from pyrite becomes rapid and a marked
absorption of heat results. The pressure of the sulphur vapor
here probably reaches one atmosphere. |

6. Pyrrhotite is of variable composition. Its composition at
any temperature depends on the pressure of sulphur vapor in
which it is heated. Though it has not been found feasible to
vary the temperature and pressure independently, a series of
products were prepared by first decomposing pyrite and then
reheating the resulting material to various measured tempera-
tures in hydrogen sulphide and finally chilling in the same or
cooling in nitrogen. The products lowest in sulphur were
obtained in the latter way. These products all resemble natu-
ral pyrrhotite in physical and chemical properties. Their
specific volumes vary continuously with composition and
pyrrhotite is therefore to be regarded as a solid solution of
sulphur in ferrous sulphide. The maximum percentage of
dissolved sulphur in synthetic pyrrhotite was 6-04 per cent at
600°. By extrapolation the saturated solution at 565°, below
which point pyrite forms, was estimated to be 6°5 per cent.
This corresponds closely to the maximum percentage of sul-
phur reported in natural pyrrhotite.

7. Equilibria between pyrrhotite and the partial pressure of
sulphur in dissociated hydrogen sulphide were determined at
different temperatures, by sufficiently long heating and then
rapid cooling. The dissolved sulphur varied under these con-
ditions from 6:0 per cent at 600° to 2:0 per cent at 1300°. The
curve shows a discontinuity at the melting temperature, at the
beginning of which there is a sudden decrease in the percent-
age of sulphur.

Mineral Sulphides of Iron. 217

8. The melting poimt of pure ferrous sulphide could not be
exactly determined because the compound dissociates at high
temperatures into its elements. by heating it in a vacuum
this dissociation was placed beyond doubt, though the dissoeia-
tion was so slow that the melting point could be located
approximately. It may safely be put at 1170°-45°. In hydro-
gen sulphide, the melting temperature is raised, because the
solid solution thus formed contains more sulphur than the first
portion of liquid to which it melts. The limits of the melting
interval cannot be determined as yet, but the maximum heat
absorption falls at 1183°. In one atmosphere of sulphur vapor
this temperature rises to 1187°.

9. Crystals of pyrrhotite, the measurements of which are
recorded under the Crystallographic Study, were repeatediy
formed at various temperatures between 80° and 225° by the
action of hydrogen sulphide on slightly acid solutions of ferrous
salt containing some ferric salt. The product usually con-
tained some crystals of disulphide.

10. The crystallographic study confirms the work of Rinne
and Boeke and others, that there are two crystal forms of
pyrrhotite. The high temperature form, a-pyrrhotite, appears
to be orthorhombic and the axial ratios vary from a:b:¢=
0°5793 :1:0°9267 to 0°5793:1:0°9927, depending on the amount
of the dissolved sulphur present (?). The habits of the crys-
tals are shown in figs. 17, 18 and 20, Pt. Ill. @-pyrrhotite is
hexagonal, and ¢ varies from 0°8632 to 0°8742. The crystal
habit is shown in figs. 22 and 23, Pt. ILI.

The crystal constants .of natural pyrrhotite can not be
assumed to be invariable, since the composition of the mineral
is not constant, and the crystal angles of the synthetic mineral
are variable. ‘The lack of agreement among mineralogists
regarding the crystal system to which pyrrhotite belongs can
be explained on the theory that there are two forms of pyrrho-
tite.

11. Troilite is only the end member of the pyrrhotite series
and not a distinct mineral species. Thus far, it has not been
prepared free from metallic iron. |

In conclusion, the authors wish to express their hearty
thanks to Dr. Carl Alsberg and Dr. Oswald Schreiner for
important references, and to Dr. F. L. Ransome, Dr. W. H.
Emmons and Mr. C. A. Davis for valuable geological informa-
tion, and especially to Mr. W. Lindgren, not only for placing
at our disposal the generalized results of his extensive experi-
ence, but for reading this paper and making a number of
important suggestions.

Geophysical Laboratory,

Carnegie Institution of Washington,
Washington, D. C., Dec. 1, 1911.

Am. Jour. Sct.—FourtTH SrErRies, VoL. XX XIIT, No. 195.—Marcg, 1912.
15

218 Allen, Crenshaw, Johnston, and Larsen—

ITIL. Crystallographic Study.

As the sulphides of iron are all opaque, the ordinary optical
tests are not available and the mineralogic study is confined
to the determination of the color, luster, cleavage, magnetic
properties, crystal form, chemical properties, ete. Color and
magnetism are important diagnostic properties of the sulphides
of iron, while the crystal form and the chemical properties
give positive evidence of the identity of the artificial prepara-
tions with the natural minerals. In general the synthetic iron
sulphides prepared in the dry way or by the inversion of one
form into another in the solid state are massive and without
crystal form, and only the color, magnetic and chemical prop-
erties can be determined. The iron sulphides precipitated
from solutions usually consist of a network of crystals, or of
drusy crusts. Some preparations have crystals which are large
enough for measurement on the Goldschmidt goniometer ;
most of the crystals measured are from 0-2 to 0°-4™™ in length,
though one erystal of §-pyrrhotite is about a millimeter in
length, and one crystal of marcasite is even a little larger. In
many of the preparations the crystals are all very minute—
less than a tenth of a millimeter in length and often much
less—and the crystallographic study was confined to an exam-
ination of the material under the microscope. The crystal
habit, however, of each of the four minerals is characteristic,
and even the minute crystals can usually be determined.

Pyrite.

In some preparations the larger crystals of pyrite are half a
millimeter across and can be easily recognized with a pocket
lens by their color and crystal form. Much smaller crystals
can be determined by the use of the microscope. The crystals
usually show both the cube and the octahedral faces, but both
forms also occur alone; pyritohedrons were not observed; the
faces are always much warped and very imperfect. For the
several crystals measured on the goniometer, the angles were
seldom over half a degree from the theoretical value, and a
closer agreement cannot be expected.

Marcasite.

The color of the synthetic marcasite is identical with that of
the natural mineral, but the color test is not altogether satisfac-
tory on minute erystals, even when brightened by heating in
acid. The erystal habit, however, is characteristic, and the
goniometric measurements of some of the jiarger crystals show
a very close agreement with those of the natural mineral.

Mineral Sulphides of Lron. 219

The common habit of the synthetic marcasite is shown in
elinographic projection in fig. 15. The crystals are twinned
with the face m (110)* as twinning plane, they are tabular par-
allel to the twinning: plane and elongated along the vertical
axis. The prisms m }110}, especially the large faces parallel
to the twinning plane, are deeply striated parallel to the base.
The domes e $101} and / {011} are also prominent. Crystals of
a second habit, which are common in some preparations, are
more symmetrical in their development and less often twinned ;
in them the domes, ¢ {101} and Z}011}, are characteristic forms

Fig. 15. Fic. 16.

TL

[]

| AN

SU

HU

38

TM A ae |

WHT

Fie. 15, Artificial marcasite showing the forms m {110}, e {101}, and
1{011\. Twinned after (110).

Fic. 16. Artificial marcasite showing the forms m {110}, e {101}, 7 {011},
and s {111}.

and the striated prisms, m {110}, are usually prominent. The
erystal represented in fig. 16 is of this habit, but the prisms
and pyramids s {111} are more prominent than usual. Several
erystals were seen under the microscope which resemble the
fiveling pictured by Dana.t A preparation formed as usual,
but at room temperature, consists of strings of minute crystals’
which have a rhombic outline under the microscope, and some-
times the obtuse angle of the rhombs is truncated by a face
_ which is probably the prism, m (110).

*Throughout this paper parentheses are used to indicate crystal faces ;

brackets, to indicate the entire crystal form.
+ System of Mineralogy, 6th edition, p. 95.

220 Allen, Crenshaw, Johnston, and-Larsen—

Crystals of marcasite large enough for measurement on the
goniometer were found in several preparations ; most of them
are only a few tenths of a millimeter in length, but a few are
about a millimeter long. Seven fairly satisfactory crystals
from two different preparations were measured. Only one of
these is not twinned. The signals were seldom sharp, blurred
signals, striated zones, and vicinal faces being the rule. The
faces of {111} usually gave fairly sharp reflections, but between
(111) and (111) there was a more or less complete band of sig-
nals, and that for the face (110) seldom stood out sharply from
the others. In some of the tabular twinned crystals the faces
of §110{ which are parallel to the twinning plane yielded bright
sionals, or else there were several bright signals near these faces.
The reflections from the faces of {011; were usually bright, but
vicinal development often made their exact position uncertain.
Between (011) and (011) there was usually a dim series of sig-
nals, but the reflection signals of the faces of (O11; did not
stand out from the others. The faces of {101} gave fairly
sharp signals. In one crystal the reflections of the faces of
‘772: took the place of those from §111{ at the ends of the
series of signals of this zone. Most ee the twinned, tabular
crystals gave a dim but nearly continuous line of sionals from
the large faces (110) through the face (011) and the corre-
sponding face (011) to (110). The faces 101? of both individ-

uals lie on this zone, whose symbol is ee k. It is poorly
developed on the untwinned crystal.

Crystal angles of synthetic marcasite.—Of the seven crys-
tals to be described, the first five were from a preparation of
October 16, 1908, and were formed by the action of H,S on an
acid solution of FeSO, for four days at a maximum tempera-
ture of 300°. The crystals of this preparation are all of the
habit shown in fig. 15. Crystals 6 and 7 were from a prepara-
tion of October 28, 1908, and were formed at a maximum tem-
perature of 220°. The common habit of the erystals of this
preparation is shown in fig. 16, but the pyramids and prisms
are often less prominent; there are some twinned crystals
similar to those shown in fig. 15

Table [X lists the weighted average of the angles measured
for each crystal, the crystal constants of synthetic marecasite,
and the corresponding constants of the natural mineral as
given by Gemacher and Goldschmidt.

The agreement shown by Table I between the angles and
axial ratios of natural marcasite and those of the synthetic
mineral is very good. Both commonly show twinning with
(110) as twinning plane, and both have the two unit domes and
the pyramids as common faces. The base, however, which is

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Mineral Sulphides of Iron.

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222 Allen, Crenshaw, Johnston, and Larsen—

usually prominent in the natural mineral, was not observed on
the synthetic crystals, while the prism zone is often more
prominent on the artificial crystals. The natural mineral is
described as having the brachydomes and pinacoids deeply
striated parallel to the edge (010) (001); the synthetic mineral
is similarly striated, the pyramid and prism zones are even
more prominently striated parallel to the base, and the zone
h+t=k on some of the crystals is a more or less continuous
series of faces due to striations.

Pyrrhotite.

The experiments of Rinne and Beeke* show an inversion in
FeS with 7 per cent, the maximum amount, of dissolved iron
at 138°. On decreasing the amount of dissolved iron to 5 per
cent the absorption of heat takes place between 90° and 98°.
Although they were not able to observe a heat absorption in
FeS with less than 5 per cent of dissolved iron or in natural
pyrrhotite, they state that the inversion takes place but is
too sluggish to be observed. Ferrous sulphide with a little
carbon showed the inversion at 134°5°, while meteoric troilite
with a little carbon inverted at about 148°.

The present crystallographic study tends strongly to confirm
the work of Rinne and Beeke. The low temperature form or
£-pyrrhotite appears to be hexagonal, while the high temper-
ature form or a-pyrrhotite appears to be orthorhombic. The
measured interfacial angles for the two forms are near together
and the fact that these angles vary with the amount of sulphur
in excess of that required for FeS, together with the impos-
sibility of determining the chemical composition of the meas-
ured crystals, makes a comparison of the crystal constants of
the two forms impossible. However, the crystal habit, the
twinning, and the development of the faces on’ the two forms
afford good evidence for the view that they belong to different
crystal systems.

The color of the synthetic. pyrrhotite is similar to that of the
natural mineral. That prepared by melting iron and sulphur
together is a little darker and has more of a grayish cast than
the natural mineral. The crystals from some preparations of
a-pyrrhotite are only slightly magnetic while those from others
are strongly so. The crystals always show polarity with the
poles along the a-axis. The poles for 6-pyrrhotite are along
the c-axis in the one crystal observed.

a- Pyrrhotite.

Twenty-two fairly satisfactory crystals of a-pyrrhotite, repre-
senting four different preparations, were measured on the

* Zs, anorg. Chemie, liii, 338-348, 1907.

Mineral Sulphides of Iron. 223

goniometer. The crystals are almost certainly orthorhombic
in symmetry, although the angles in the prism zone are very
nearly 60°. In the following discussion, the crystals are
treated as orthorhombic. The crystals are usually twinned

Fie. 17.

Fic. 17, Artificial a-pyrrhotite showing the forms m {110}, 6 {010}, and
ec {001}. Twinned after (023).

Eie. 18.

aa

Fie. 18. Artificial e-pyrrhotite showing the forms 6 {010}, ¢ {001}, and
p {111}.

with the twinning plane (023); one crystal is twinned only
after (021), and two crystals are twinned after both laws.
The twinned crystals are tabular parallel to the base and elon-

224 Allen, Crenshaw, Johnston, and Larsen—

gated in the direction of the a-axis. The untwinned crystals
are also nearly always much elongated along the a-axis, and
have as their principal forms {001}, {010}, {111$. Tabular
crystals of hexagonal shape are rare.

Crystals A to H are from two different preparations
formed by the action of H,S on an acid solution of FeSO,
at a maximum temperature of 225° C. They are about
0°3 X 0°15 x 0:05" in dimensions. Most of the crystals are
tabular parallel to the base and elongated along the @ axis;
they are twinned after (023); {001!, {010}, and {110} are

Fic. 19.

Fic. 19. Stereographic projection of a simple erystal of a-pyrrhotite
showing the development of the striation and vicinal faces.

the dominant forms. Fig. 17 shows one of these crystals.
Crystal H simulates a tabular hexagonal crystal; it is not
twinned and is bounded by the forms {001{, {010}, $110,
SO1L}, {112%, {0213, and {111}. Crystals of this type are
uncommon.

A third preparation was formed at about 200° C. The
inside tube contained 3 g@. FeCl,, 1°° 20 per cent HCl, and 25°
boiled H,O. After heating at about 200° ©. for several days,
the sealed tube was allowed to stand at room temperature from
June 16, 1909 to March 23, 1910. There was a considerable

Mineral Sulphides of Iron. 225

yield of pyrrhotite crystals. They are strongly magnetic and
show polarity with the poles along the @ axis. Many of them
are about 0°3"™ in length and about a fifth as thick and broad.
Twinning is rare and the base resembles a hexagon much elon-
gated along one diameter and delicately striated parallel to the
six sides. There area very few hexagonal tablets and twinned
crystals similar to those of preparations 1 and 2. The six
measured crystals, I to N, are all similar in habit to the crystal

Fig. 20.

Fie, 20. Artificial a-pyrrhotite showing the forms c {001}, b {010), » {111},
h {021}, and g {011}. Twinned after (021).

shown in fig. 18, and the dominant forms are {001}, {010}, and
{111!. One crystal showed also the form }021} poorly devel-
oped, and another crystal showed {091;. Fig. 19 is the stereo-
graphic projection of crystal I. The crystals were mounted
along the @ axis. They did not, in general, give sharp signals
and measured angles Hope (001) and (010) were in some
cases out as much as 2°; while the measurements for the faces
4111; were only a little better.

A fourth preparation was formed by the action of H,S on a
solution of acid FeCl at a maximum temperature of 210°.
Nearly all of the crystals are tabular parallel to the base and

226 Allen, Crenshaw, Johnston, and Larsen—

elongated along the @ axis. Several of them are 0°5™ in
length. Out of seven crystals measured, one is twinned after
the law: twinning plane (021); three are twinned after the
law: twinning plane (023); two after both laws, and one
erystal is an untwinned hexagonal tablet. The crystals resem-
ble the untwinned crystals of lot 3 in that the dominant forms
are {O01}, }010%, and {111}, but {021}, {O11%, {0.1.20}, {110},
and }112; were also recognized. Fig. 20 represents one of these
crystals twinned after (121). Fig. 21 is the stereographic
projection of crystal U, which is twinned after both (028) and
(021). One of the individuals of the twin after (023) is poorly
developed on the part of the crystal shown.

HiG.weile

O21

a

ie “aa at

Fie. 21. Stereographic projection of a crystal of a-pyrrhotite twinned
after both (021) and (023). The half of the crystal represented on the pro-
jection shows few of the faces of one of the individuals after (023). The
faces of the crystal twin after (021) are underscored once, those of the twin
after (023) twice.

Table X gives a summary of all the crystals of a-pyrrhotite
which were measured. The designation of the crystal is given
in column one and the number of the preparation from which
it came in column two. Column three lists the faces recog-
nized on the crystal, and column four gives the average of the
angle between the faces (110) and (010). The eight sueceed-
ing columns give the weighted averages of the measured inter-
facial angles each followed by the value of py, computed from
that angle. Next to the last column lists the weighted aver-
Ages of the constant p., which is equal to the vertical axis, c.
The final column gives all measured angles not listed in any ‘of
the previous columns.

Mineral Sulphides of Iron. 227

A comparison of the different values of p, with the average
value, c, for any crystal shows that the difference is greater
than 2 per cent only for erystal A, and in this case the angle
from which py, was computed was so unreliable that it was not
considered in computing the average. In all cases where the
angle from which any p, was computed seemed to be reliable
the difference between p, and ¢ is less than 1 per cent of ce.
Au error as large as 1 per cent in ¢ may, therefore, be regarded
as exceptional. One possible exception is crystal I, as the
measurements on it were unsatisfactory and it has, therefore,
been discarded in the discussion to follow. If, however, we
compare the value of ¢ for the different crystals we find a maxi-
mum difference of 0:0660 between crystals M and T or a dif-
ference of nearly 7 per cent of their mean value. Moreover,
the two extremes are neither exceptionally high nor excep-
tionally low but the other crystals are pretty evenly distributed
between them. It seems certain, therefore, that the crystal
constants of a-pyrrhotite vary considerably in accord with the
variable composition of the mineral.

A further study of Table II shows that while the crystals of
a given preparation show a considerable difference in the con-
stant, ec, yet those-of preparation 3 are uniformly high, those
of preparation 4 generally low, and those of preparation 1 and
2 intermediate. Unfortunately it was not found possible to
determine the relation between the value of ¢ and the chemi-
cal composition, as, even were any of the crystals large enough
for an analysis, it is probable that they are built up of succes-
sive shells of different composition.

No consistent variation in the angle (100) (110) was recog-
nized but it probably varies with c. The measurements were
usually not good but the average value of 59° 55’ is probably
within 15’ of the true value. Computing the axial ratios of
a-pyrrhotite for the limiting values given by crystals M and T
we! have:.@:6:¢0°5793:170°9267 to 0°5793 : 170-9927... It
is probable that the limits are considerably greater than this.
Table XI lists the observed faces and the interfacial angles as
computed from the above values of the axial ratios.

The symmetry and crystal constants of a-pyrrhotite.—
The evidence that a-pyrrhotite is orthorhombic in symmetry
is good, although it may not be conclusive. The angles in the
prism zone were not proven to differ from sixty degrees, but
the habit of the crystals consistently indicates orthorhombic
rather than hexagonal symmetry. A very few crystals
resembled hexagonal tablets. Nearly all of the crystals of the
first two preparations were developed much like the crystal
shown in fig. 17, although small domes and pyramids were
found on many of the measured erystals. The habit and

Crystal

|

Radia Cap

No. of Pre-

paration

228 Allen, Crenshaw, Johnston, and Larsen—
TABLE X.—SUMMARY OF CRYSTAL
3.4 3.2
ees gee 2S =
Faces represented = Sas S22 S
= das PD, 4s Do S
(001) (010) (110) (112)|60°=- ~ “\66" 30" 0:9834|____ = 2a eee eee
(001) (010) (110) 59°32), Ge. so 2 UD800l) - ae “oe
(001) (010) (119) 59°50 M6be a Ob Tee ee ge ee
(001) (010) (110) (100)/60° 10’ |65° 27’ 09639] ._---- a
(011) (023)
(001) (010) (110) 59° 57 |63° 159" OOS 7allyae es Nee
(001) (010) (111) (221)|/60°+ ~ 164° 5° 0-9388|_ 22 22) =e
(001) (020) (110) (992)159° 57’ 165° 57%. 0-9732|_.__2 eee
(001) (01 0):(110),(021)|60° 4: 9.4] Jana.) Ieee ee 62° 444
(111) (011) (112)
(001) (010) (111) 60° 507 2k 1 5 alti Sele _.-3¢
(001), (010) (111), (091)|59° 56" |....--2) Lose
(V01) (010) (111) GOR ob) ive 2 ne eas _ See
(001) (010) (111) DO SD Gas eich ey ee a3
(001) (010) (111) GO tee ier a see ee a ee os baae
(001), (O10) (O21) (D597 95970 Nees. ess eee 63° 15)
(001) (010) (021) (111)|59°.53" [65° 30° “0°9646)_ 2-2 22 eae 62° 31m
(011) (112)
WOOL) (OFC) (O24) (TIAGO Se I a ea eee ~ 2. 162° Tae
(OO) (O10) (0259) 2G 1) GO sak nee ee ee eee 55°18’ 0°9545/62° 19’
(O71
old. announcer BIR: BGs WY. a Lee 1.2 62° 26'
(111) (0°1:20)
(001) (010) (110) (021)|59° 44' 66° 10? 30°07 12) (232) aa 62° Ie
(111) (011)
(001) (010) (021) (111)/60°+ |62° 50’ 0°9160/52° 25’+ _____- 61° 38)
(O11
ReMV eat Tn esURCAT NTN aE ee 40' 0:9495/55° 30’ 0°9503/62° 8’

(011) (1.1.34)

the development of different faces in the zone (047) from
those in the zone (AA7) strongly indicate orthorhombic sym-

metry.

exceptions, developed as is the crystal shown in fig. 18.

The erystals of the third preparation were, with few
The

development of the zonal and vicinal faces is shown in fig. 19,
which is a stereographic projection of crystal I. The other
crystals of this lot are much like this, although the striations

of the zone (0 £2) are not usually so prominent.

The erystals

a |

Mineral Sulphides of Iron.

MEASUREMENTS OF a@—PYRRHOTITE

229

|

ais aon &

= S 3 Average Other measured

a ea ne Go=e angles

Ss S S
Po = Po Ss De S Pp.
a. ee eee 4850) O96 TOU 9834 OE aie Ep ee Recke
__ | re LY 8) LOS he Oecd | ee POCORN oe hets ses ae Lae ee
re ee eh OOM eo ae OR GIS e | oe tn eel
ww) AAS OY 0-9713 Bo ee eee (0639 (OO Fh (O2I == 32202
Mee Be ye eh iy Bu ME fe ck sat) I Wh ATK (YLO Ne aa bt ge a ee ere
a ete Oahu ke eevee Po) vee O-O380 (O01) (221 )s274° 59’
PINS tere re) A 0°9732 (001) (992)=83° 41’
0°9701162° 44’ 0: 9750/43° 59’ 0-9646 ASO OGG O od toor ee sete ee
a Gee Ae OOS me hee ete ee EQ O SSE Tes .
ee. GomeebeO IS (Ole oe eee es) eh 09878 (001) (091)=83° 17”,
ee (Ome mOS Meee, Soe hee edt Oh (OP98O7 ree Lk St RN Stel
ee: fe 3209667)... 2. Me ales Sees et wo ale ears 5 OL OGG No Say reaeaee Cte a ee A
es... CeO OS OD aiaes ea Ol ets | 1 109997 RENEE ENIGEETS 3 ety ie
MAING M4 O OSOn| le eee Bete Le, OPOSO UAE Ea ee
0°9614/62° 34’ 0°9681|48° 51’ 0°9607|44° 12’ 0-97479 0:9669 LADS st OT Oh eae
ee 7 GO TA OrO5 4S). Yo eee so eee cee 22 Hef SHNOCO SANS ROT She i se Lee
BESO] cc TES ere eee) ap cence eee eee $122 3/0°9530 1 \\(0O1) (O7T)=281% 407
ee AS ee eh a ak 2 (095718. (O00) (0, 20) o> toy
9594162 ° 40% 0°9772148° 50’ O'9601)_. -._- _L ee AOR SGG OR PE ONE Me oe te
092621612 58’ 0°9437/48° 10’ 0°9380|_____. ...-- OSE TA Ie BAe
9456/62° 10’ 0°9517|._..... 2..- A\adgk wel) Revey 0°9485 |(001) (1.1.34)=8° 10’

of the fourth preparation are usually twinned, and the common
habit of these crystals is shown in fig. 20.
twinned after (021) and the crystals which are twinned after
(023) are similar, except for the twinning law. ‘These crystals
are also elongated along the a axis and show a very different
development in the zone (0 #7) from that in the zone (A //).
Fig. 21, which is a stereographic projection of crystal U, shows
the development of the zonal and vicinal faces.

This crystal is

Several other

230 Allen, Crenshaw, Johnston, and Larsen—

TABLE XI.—Computed interfacial angles of a-pyrrhotite for different
values of the axial ratios.

Gr )0:9267 | c= 09924
(001) (O11) | 42° 49’ 44° 47!
(112) a2 427 44° 40’
(021) | 61° 39’ 63° 16’
(111) Ble, ieee. 13)
010) | 90° o' 90° 0!
HG} |. 90> 0% 90° 0’
(100) 90° 0’ 90° 0!
(023) 31° 49! 33° 30’
(221) (A 52) 75° 50!
(010) (110) BO) 55) Do). 5)
(100) (100) 90° 0! 90-0"
Angle between
twins after (023) 63° 24! 67° 0
Angle between
twins after (021) 56° 42! 53° 28’

preparations were made up largely of crystals of high-temper-
ature pyrrhotite, and, although no measurable crystals were
found, the microscopic study showed that they were very simi- ©
lar in habit to the measured crystals. On the other hand, the
crystals from the three preparations which were formed at
100° C. and below, invariably had a very different habit (p. 231).

B-Pyrrhotite.

Three crystals of pyrrhotite formed below the inversion
temperature were measured. ‘They were each from a different
preparation and should give a fair idea of the crystal habit and
crystal constants of 6-pyrrhotite. Their habit and the measured
angles afford good reasons for supposing that @-pyrrhotite is
hexagonal. The most prominent faces recognized were those
of m , §1010? and z {2021', but those of ¢ {0001} were rather
prominent on one crystal, and the vicinal form 2a {16.0.16.7}
on two crystals; the faces of the form « {5051} were subordi-
nate on one crystal. All three of the crystals were twinned
with (1011) as the twinning plane, giving cruciform twins with
an angle of approximately 90° between the two individuals.
Figures 22 and 23 are clinographic projections of the two habits
of the crystals.

The best crystal came from a preparation which was formed
by heating for 8 days at a maximum temperature of 80° C. a

Mineral Sulphides of fron. 231

sealed glass tube which contained a dilute solution of FeSO,
saturated with H,S at 0° C. The yield of 6-pyrrhotite was
small and consisted of the measured crystal which was about
1™™ in length, a crystal about half as large and a few crystals
less than 0-2" in length. All were twinned and otherwise

Fic. 22. Artificial G-pyrrhotite showing the forms m {1010} and z {2021}.
Twinned after (1011). M is

Fie. 23. Artificial 6-pyrrhotite showing the forms m {1010}, z {2021}, and
ce {0001}. Twinned after (1011).

similar to the measured crystal. This crystal, which was
mounted on the goniometer along the ¢-axis of one of the
individuals, gave blurred and multiple signals, but it was not
striated, and most of the faces could. be located to within about
ten minutes. The only forms developed were the prisms
{1010} and the steep pyramids {2021%. Figure 22 is the cli-
-nographic projection of the crystal. Six fairly good measure-
ments of the angle (2021) ~ (2021) gave values of 53° 29’, 53° 30’,
58° 31’, 58° 6’, 58° 15’, 58° 41’, averaging 53° 22’; hence the
polar angle of (2021) is 63° 19’. Two good measurements of
the angle between (1010) and (1010) were 89° 41’ and 89° 49’,

averaging 89° 45’. The twinning plane is therefore 1011.
The angles measured between the prisms were never over 30’
from 60°.

The conditions of formation of the second crystal were simi-
lar to those of the first but the maximum temperature was
about 100°* and the tube was allowed to stand at room tem-

* We do not know the inversion temperature of FeS with an excess of
sulphur and can not, therefore, be certain that this and the following ecrys-

tals were formed below that temperature. Their habit, however, is evidence
that they belong to the low temperature form.

232 Allen, Crenshaw, Johnston, and Larsen—

perature for about three months before opening. A consider-
able number of small, twinned crystals similar to the measured
crystal and in no case over 0°15"™ in length were formed.
The measured crystal was similar in its development to erys-
tal 1, except that the pyramids were somewhat striated paral-
lel to the base and {16.0.16.7; was the dominant pyramid.
The reflections were not quite so good as those of the first
crystal. Six measurements of the polar angle of (16.0. 16.7)
varied from 66° 0’ to 66° 31’, averaging 66° 18’. The signals
for the face (2021) did not stand out sharply from the other
sionals of its zone, but three measurements of the angle
between the points where the strings of signals for the pyra-
mid zones of the two individuals intersected gave 52° 47’,

53° 32’, and 52° 34’, averaging 52° 58’. The polar angle of
(2021) is, therefore, 63° 31. One good measurement of the
angle between the prism faces of the two individuals was
90° 14’.. The angles in the prism zone may differ as much as
30’ from 60°.

The third preparation was formed as was the second but the
crystals differed in that the base was rather prominent and the
form {5051} was present. The habit of these crystals is
shown in fig. 23. The measured crystal which was less than
0-2"" in length gave rather poor signals, and many of the
faces were very poor or missing. There was a continuous
line of signals from the prisms to the pyramids (2021) and the
angle between the intersections of these zones belonging to
the two individuals measured 52° 34’ and 52° 0’, averaging
52° 20’. Therefore the polar angle of (2021) is 68° 50’. The
angle between the bases of the two individuals measured
90° 7’. Three measurements of the polar angle of (16. 0.16.7)
La 66° 25’ with a maximum deviation of 19’. Five
measurements of the polar angle of (5051) averaged 78° 55’
with a maximum deviation of 26’. The angles between ae
prisms could not be measured accurately but they differed
from 60° by less than 20’.

The data for the three measured crystals of 8-pyrrhotite are
assembled in Table XII. The table shows the principal inter-
facial angles as measured on each erystal and as computed
from the average value of the constant p,, the faces observed .
on each crystal and the value of the vertical axis c. There is
a close agreement between the measured and the computed
angles and it seems certain that the difference in the value of
p,. for the different crystals represents an actual difference in
the crystal constants. Their difference is easily accounted for,
as the amount of sulphur in pyrrhotite varies considerably.

A comparison of the two Forms of pyrrhotite.—The follow-
ing criteria for distinguishing between the two forms of

Mineral Sulphides of Lron.

233

pyrrhotite applied to all of the artificial crystals which were
examined and should serve as more or less reliable means of
distinguishing between the two forms in both natural and syn-

thetic erystals :

1. The habit of @-pyrrhotite is hexagonal and the dominant
forms are the prism, and a steep pyramid, and sometimes also

the base (figs. 22 and 28).

a-pyrrhotite, on the other hand, is

always tabular parallel to the base; a few of the crystals
appear to be hexagonal, but most of them are much elongated
in the direction of the a axis and the orthorhombic symmetry
is further shown by the common association of the forms {001},
{100}, and $111} (figs. 17, 18 and 20).

2. The low temperature form (8) is almost invariably devel-
oped as cruciform twins with an angle of about 90° between
the two individuals (twinning plane 1011), while the high tem-
perature form (a) is usually twinned after (023) with the two
individuals at about 65° to each other, and sometimes also
after (021) with the two individuals at about 55° to each other.

3. The constant p, for the measured crystals of §-pyrrho-
tite varied from 0°9967 to 1:0100, while for a-pyrrhotite it
varied from 0:9267 to 0°9927. While crystals for which the
value of p, was approximately 1:0000 were found in both

TABLE XII.
Crystal data of 6-Pyrrhotite.

Crystal 1 Crystal 2
Computed Compnted
Observed |p)— 0°9967| Observed | po=1'004
Polar angle |
(2021) 0 Ga WOM PGs 19" 68° ai PGs 3
Angle between
UNL eh ar ea 89° 45’ | 89° 42’ | 90° 14’ | 90° 14’
Polar angle
ma (5051) 022. Tr 158 Lam th
Polar angle
ir 8620.16.77) 5.2. Be Ss pat ive 66° 18’ | 66° 27’
2 (Horo). (2021), | \ClOLO) ia. (202 1)
(16.0.16.7)
Cee or 0°8632 0°8695

Crystal 3
Computed
Observed | p )>=1°01
63.50" "Ga 40!
907 B90" 34!
Terao ie 48)
660251 (66° 35°
(1010) (2021)
(16.0.16.7) (0001)
(5051)
0°8742

Am. Jour. Sci.—Fourts Series, Vout. XX XIII, No. 195.—Marcg, 1912.
16

234 Allen, Crenshaw, Johnston, and Larsen—

forms and the unknown limiting values would introduce a
greater ambiguity, yet crystals for which p, is considerably
less than 1:0000 are likely to be a-pyrrhotite while those for
which p, is considerably greater than 1:000 are probably -
pyrrhotite.

Natural Pyrrhotite.

Pyrrhotite has generally been considered hexagonal, but as
early as 1878 Streng* suggested that it was orthorhombic and
isomorphous with sternbergite. However, in 1882 het con-
cluded that the mineral was hexagonal from a study of the erystal
form, etch figures, heating curve, and magnetic properties.
Vrba,t Frenzel,§ and Dom Pedro von Sachsen- -Coburg|
measured crystals whose angles indicated orthorhombic sym-
metry. Crystals associated with limestone containing garnets
are described by Roth*] as elongated along a horizontal axis
and hence orthorhombic in habit. Nicol™ described crystals
with a “decided orthorhombic appearance.” Recently Weisstt
studied the magnetic properties of pyrrhotite and concluded
that it was probably monoclinic but that it could not have a
higher symmetry than orthorhombic. Kaisert{{ concluded,
from a study of magnetic and other properties, that the mineral
occurred in twinned orthorhombic crystals.

There has also been a lack of agreement in the measured
angles and length of the vertical axis. Table XIII gives the
important crystal data for the eleven measured crystals
of natural pyrrhotite which seemed to be most reliable.
The first column contains the name of the author ; the second,
the observed faces in the order of their prominence on the
crystal giving the hexagonal symbol assigned by Dana;
the third column gives the habit of the crystal; the
fourth column, the most probable value of p,. The occurrence .
and associated minerals are listed in the fifth column. The
values for the constant p, are reliable only for the crystals of
Busz, Nicol, Seligmann, Kenngott, Rose, and perhaps Shep-
hard. The crystal of D’ Achiardi gave values of p, ranging from
0°9658 to 1:0240 depending on which pyramid was used in the
calculation. That of Dom Pedro gave no good measurements.
The two erystals of Streng and the one of Dana afforded
measurements on only one pyramid and the value of p, de-
pends upon the symbol assigned to it.

* Jahrb. Min’, p. 797, 1878. + Jahrb. Min., i, p. 183, 1882.

t Zs. Kryst. Min., iii, p. 190, 1879. § Min. Petr. Mitt., iii, 297, 1881.

|| Min. Petr. Mitt., x, 451, 1888. 4] Z. Kryst. Min., ix, 309, 1884.

*%* 7s. Kryst. Min. | Xxxi, 58, 1899.

t+ Jour. de Phys., ‘pp. 469 and 829, 1905; Centralbl. Min., p. 338, 1906.
tt Centralbl. Min., p. 261, 1906.

235

Mineral Sulphides of Iron.

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‘ALILOHUYAG IVUALVN dO SIVISAUD GHUASVA ‘PITX WIAV,

236 Allen, etc.—Mineral Sulphides of lron.

The results of the different investigations are brought into
agreement by the recognition of the two forms of pyrrhotite
and also of the change in p, with a change in the composition
of the mineral. The early view of Streng* that pyrrhotite is
orthorhombic and belongs to the chalcocite group holds true
for a-pyrrhotite, while §-pyrrhotite is hexagonal. Further
investigation may show that other members of these groups are
dimorphic.

A further study of Table XIIT shows that most of the eleven
crystals were probably formed as a-pyrrhotite. Crystals 1 to
3 have low values for p,, tabular habits, and crystal 3, at least,
has an association which would indicate the high temperature
form. Orystal 2, in particular, is described as having a “decided
orthorhombic appearance’ and the orthorhombic axis is shown
by the elongation along it and the development of the form
{921} but not {041}, and of {011} but not §{112%. Crystals 4
and 5 from Kongsberg might belong to either form, but their
tabular habit suggests a-pyrrhotite. Crystal 6 has the tabular
habit of a-pyrrhotite. Crystal 10 has a tabular habit and is,
in addition, associated with minerals which indicate the high
temperature form. The occurrence of crystals 7 and 8 in
meteorites places them as a-pyrrhotite. The hexagonal
development and the twinning of crystal 9 indicate 6-pyrrho-
tite, but the association with feldspar, etc., and the position of
the magnetic poles are not consistent with this view.

Any list of the faces which have been found on a-pyrrhotite
will be somewhat uncertain since some of the measured crystals
might belong to either form, and, besides, the variable charac-
ter of p, makes it impossible to assign a symbol to some of the
measured pyramids. The following list omits doubtful faces
and marks with a star those found only on synthetic erystals.

e (001) F (012) j (061) r (221)
b (010) e (023)* n (201) s (331)
a (100) g (011) g (114) u (623)
m (110) h (021) » (112)
Z (310) i (041) p (111)

* Loc. cit.

Bowie— Gravity Anomalies and Geologic Formations. 237

Art. XXI.—Some Relations between Gravity Anomalies
and the Geologic Formation in the United States ; by
Witit1am Bowte.*

In the report of an investigation of the effect of topography
and isostatic compensation on the intensity of gravity, which will
soon appear as a Coast and Geodetic Survey publication, there
are shown certain relations between the signs of the gravity
anomalies and the geologic formations on which are located the
89 gravity stations considered. There are now available 35
additional stations, making 124 in all, and it is proposed in this
paper to give the results of an additional study of the relations
between the anomalies and the surface geologic formations,
which confirm the earlier unpublished conclusions.

The anomaly of gravity, which is used in this paper, is the
difference between the observed gravity and the theoretical
gravity for the latitude of the station, corrected for elevation,
and for the effect of the topography and its isostatic compen-
sation. ‘The isostatic compensation is assumed to be complete
under every separate portion of the earth’s surface. If the
surface density at the station is 2°67, which was that used in
the computations, and the densities of the successive layers in
the earth’s crust are normal (except as they may be affected by
the compensation), and if the isostatic compensation of the
topography is complete and uniformly distributed from the
surface to a depth of 114 kilometers, then the anomaly will be
zero. It is assumed that every part of the surface at a depth
of 114 kilometers below sea level has equal pressure at all
points and, consequently, is in a state of hydrostatic equili-
brium. An anomaly at a station, different from zero, shows a
departure from normal conditions. If the anomaly is positive,
the observed is greater than the theoretical gravity ; and the
reverse is the case for negative anomalies.

The computations are based upon the theory of complete
compensation of the separate topographic features ; the com-
pensation being uniformly distributed to a depth of 114 kilo-
meters. It is reasonably certain that each topographic feature
is not completely compensated locally, and that the compen-
sation is not distributed uniformly to a depth of 114 kilometers.
But the gravity operations prove that the average condition
over areas of large extent approximate very closely that of
complete local isostatic compensation, uniformly distributed to
a depth of 114 kilometers. They show that the United States

* Read before the Geological Society of America, at Washington, D. C.,

December 30, 1911, by William Bowie, Inspector of Geodetic Work, U. S.
Coast and Geodetic Survey.

238 Bowie—Gravity Anomalies and Geologic Formations.

is not held up by the rigidity of the earth’s crust, and that no
area within the United States, as large as the State of Ohio,
for instance (41,000 square miles), is so supported.

On the whole, the gravity anomalies in the United States are
very small, and there is, apparently, no connection between the
size and sign of the anomaly and the character of the topog-
raphy. On the other hand, there is, apparently, a relation be-
tween the surface geologic formation and the anomalies.

Of the 124 stations in the United States, 10 are in areas
of Precambrian formation, 31 are in Paleozoic, 20 are in
Mesozoic, 30 are in Cenozoic, 11 are in Effusive or Intrusive,
and 22 are unclassified. The geological map of North Amer-
ica, by Gannett and Willis, of 1906, was used in making
decisions as to the geologic formation at the stations.

Those stations were left unclassified which plotted on the
map near the dividing line between two formations, or when
in such areas as at Ely and Winnemucca, Nevada, where
there are rocks of several geologic ages within a few miles of
the station.

The table shown below gives the means of the anomalies in
dynes (or centimeters) with and without regard to sign, for the
several groups of gravity stations. The average gravity in the
United States is about 980 dynes or centimeters.

Geologic Number of Mean with re- Mean without

Formation Stations gard to sign regard to sign
Precambrian, = 22 2208 10 +°016 026
PaleozoiGs, aa Le Si — ‘008 019
Mesoz0IG, 22355" sage 20 +002 7015
Cenozoic j.2 Sate ee 29 —°008 021
Intrusive and Effusive 11 —'007 015
Wnelasstiedissen eee 22 SEOs "020
All gravionsee se eee 1123 0 7019

The mean with regard to sign for all anomalies is zero, and
without regard to sign it is (019 dyne. The anomalies in the
oldest formation have a comparatively large plus mean with
the sign considered. Eight of the ten Precambrian stations
have plus anomalies. The average size of the anomalies in the
oldest formation is much larger than the mean of all. The
most recent formation shows a decided minus anomaly with
regard to sign. The formations of the intermediate ages have
anomalies which are practically normal. The intrusive and
effusive anomalies have a mean of —:007 with regard to sign,
but the average size is much smaller than the mean of all.
The mean of the intrusive anomalies is —-003 and of the effu-
sive is —‘011. The number of anomalies in each of these

Bowie— Gravity Anomalies and Geologic Formations. 239 —

two formations is so small that no definite conclusions can be
safely drawn from them. It is not necessary to consider the
unclassified anomalies.

It may appear obvious that this relation between the oldest
and newest formations and the anomalies is what should have
been expected inasmuch as the densities of the oldest rocks
are, on the average, greater and those of the recent rocks
lesser than the average surface density, 2°67, used in the com-
putations. But it will appear, on reflection, that after all these
cannot be mere surface phenomena.

Let it be assumed that the pressure at the depth of 114 kilo-
meters under a Precambrian station is normal; that is, the crust
is in a state of perfect isostasy, and that the average anomaly
with regard to sign of +°016 is caused by an excess in density of
the geologic formation just under the station. Thenif the for-
mation considered extends 1,300 meters out from the station and
1,000 feet below it, this material would have an increase in den-
sity of 1:47. With the same radius but with a depth of 5,000
feet, the material would have an increase in density of 0°48.
With 10,000 feet, there would be an increase of -40.

If it is assumed that the formation considered extends 19
kilometers around the station and 1,000 feet down, then an
increase in density of 1:37 would be necessary to cause an
anomaly of +:016. Witha depth of 10,000 feet, the increase
would be :13.

The maximum anomaly in the Precambrian formation is
+°054 dyne, therefore the increases in density above the normal
would be three and one-half times those previously stated. If
this formation is assumed to extend 19 kilometers from the
station and to a depth of 10,000 feet, the increase in density
would have to be ‘45 greater than the normal.

The mean with regard to sign of the anomalies in the Ceno-
zoic formation is —°008, and the changes in density necessary
to cause this anomaly are one-half the size and of the opposite
sign of the changes necessary to cause the mean Precambrian
anomaly with regard to sign of +'016. The maximum anom-
aly in the Cenozoic is —°091, and to cause this a decrease in
density of -80 is necessary in the material extending 19 kilo-
meters from the station and to a depth of 10,000 feet.

Now let it be assumed that there is normal pressure under
a station at the depth of 114 kilometers, and the density of the
surface geology is also normal, and that an anomaly is caused
by an excess of density in a stratum of material 5,000 feet in
thickness, 10,000 feet below the station, which extends horizon-
tally 19 kilometers from the station. Under these conditions
an increase of °32 in the normal density would be necessary to
cause an anomaly of +°016.

240 Bowie—Gravity Anomalies and Geologic Formations.

It is seen that, under the assumptions stated, large changes
in the normal densities are necessary, even in thick strata, to
account for anomalies of average size. On the other hand,
only small changes in density are necessary if 1t is assumed that
the anomalies are caused by a departure from the state of per-
fect isostasy in the earth’s crust. An anomaly of +:016 would
be caused by a change of -02 from normal density in the
material of a column 19 kilometers in radius and 120 kilo-
meters in depth. The largest anomaly, :091, would be caused
by a change in density of only °12. |

If a column with a radius of 167 kilometers and depth of
114 kilometers be considered, then an increase in density of
only :005 is necessary to produce an anomaly of +°016 and a
decrease of only ‘03 in normal density is necessary to cause the
Seattle anomaly of —:091.

In the same sized column the average Cenozoic anomaly
with regard to sign, +°008, would be caused by a decrease in
density of only -002.

It appears to be improbable that the average sized anomalies
found in certain geologic formations are the result of greater
or smaller densities of the surface materials than that used in
the reductions, nor is it likely that the cause is an abnormal
density in a stratum of moderate thickness in the upper portion
of the crust. Such changes in density no doubt have some
effect in causing the anomalies, but it appears to be probable
that the principal cause of all except the smaller anomalies is an
actual departure from the condition of perfect isostasy in the
crust of the earth in the vicinity of the station.

It is extremely interesting that the gravity anomalies, though
very small, show a relation to the geologic formation at the
earth’s surface.

Coast and Geodetic Survey,
Washington, D. C.

Watson— Association of Natiwe Gold with Sillumanite. 241

Art. XXII.—An Association of Natwe Gold with Silli-

manite ; by THomas Lronarp Watson.

Axovut a year ago Doctor Craig R. Arnold of Dahlonega,
Georgia, kindly sent me a very interesting specimen of pegma-
tite partly incased in mica schist, which contained in places
abundant large and small flakes of elementary gold readily
visible to the unaided eye. A thin section was cut from the
most favorable free gold-bearing portion of the rock for micro-
scopic study of the relations of the gold to the silicate minerals.
In view of the numerous published statements in recent years
on the occurrence of primary gold in igneous and metamorphic
rocks,* I consider the Georgia occurrence, regardless of min-
eral associations, to be of some interest as illustrating, micro-
scopically, the subsequent formation of the gold in the rock,
which from its observed relations by the naked eye might
readily be inferred to have formed contemporaneously with the

- rock minerals.+

A personal communication from Doctor Arnold informs me
that the locality from which the specimen came is on Coosa
Creek, some four or five miles south of Blairsville, Union
County, Georgia. Although located in the Coosa Creek gold
belt, where gold mining has been engaged in from time to time
for many years, the several State Survey reports on gold contain
no geologic information on the area beyond the mere state-
ment that the rocks are schists or gneisses. There has been
some development work in the nature of inclines relative to
water level at the locality from which the specimen was taken,
but, so far as | am aware, practically nothing is known of the
field relations.

The specimen is fresh and apparently represents mostly
vein matter, partly wrapped in a thin veneer of mica schist.
Quartz greatly predominates, but some feldspar is observed,

and this portion of the specimen has the appearance of a peg-

matite of irregular but moderately coarse crystallization of the
two minerals with some mica. The schist portion of the speci-

_men is a mixture of large shreds and scales of biotite and mus-

covite through which are distributed somewhat numerous
rose-colored crystals of garnet. That portion of the specimen
showing much visible elementary gold from which the thin
section was cut, corresponds more nearly to the schist although

*See Lincoln, F. C., Certain Natural Associations of Gold, Econ. Geol-
ogy, vol. vi, pp. 247-802, 1911. Lincoln cites references to the literature.

+ This statement refers to the enclosing rock and not to the pegmatite, for
it is believed the gold was probably introduced with the pegmatite and

therefore contemporaneous in crystallization with its chief minerals, quartz
and feldspar.

242 Watson—Association of Native Gold with Sillimanite.

the appearance is that of gradation from pegmatite into schist,
while in other portions the two rock phases are rather sharply
differentiated from each other.

In the hand specimen abundant large and small flecks of
native gold are noted in intimate association with biotite, the
light-colored minerals, and garnet, suggesting in the latter
mineral partial rimming and filling of minute fractures or rifts.

Under the microscope the thin section shows intergrowths
of biotite and muscovite, quartz, sillimanite, orthoclase and
plagioclase feldspar, garnet, occasional pyrite, and several
unimportant microscopic accessory minerals. Biotite is partly
altered to chlorite, is dark brown in color, has strong absorp-
tion, and contains numerous inclusions of zircon surrounded
by characteristic dark borders. Muscovite, in large and small
shreds possessing good cleavage and partly intergrown with
biotite, is plentiful. Orthoclase is probably in slight EXCESS
over plagioclase and both feldspars show intergrowths with
quartz in micrographic structure. A considerable portion of
the thin section is occupied by an aggregate of sillimanite
fibers having partial radiating arrangement, intergrown with
biotite, and “closely associated with muscovite, the longer axis
of the sillimanite fibers crossing at all angles the cleavage
direction of muscovite. Much of the sillimanite is colored
brown and is pleochroic from fine scales of biotite lying
between the sillimanite fibers. ‘The relations of the two min-
erals suggest possible derivation of sillimanite, in part at least,
from biotite, a change which according to Van Hise* may take
place under conditions of elevated temperature and pressure.
Quartz shows optical disturbance and contains liquid and solid
inclusions. Garnet is without crystal boundaries and exhibits
rifts or minute fractures. Pyrite is only sparingly present but
appears entirely fresh.

That portion of the specimen from which the thin section
was cut shows unusual richness in native gold, the particles of
which range from tiny granules up to irregular grains 2™™ or
more in diameter. The gold occurs associated with all the
principal minerals including sillimanite and garnet, and is in
juxtaposition with several grains of pyrite, partly enclosed by
biotite; but in each case the boundaries between the two min-
erals are sharply defined and the pyrite shows no indication of
alteration. It occurs as interstitial grains between the quartz
and feldspar and the other minerals, and in some cases is
embedded in the substance of the quartz and feldspar, and to a

*Van Hise, C. R., A Treatise on Metamorphism, Mon. No. XLVII, U.S.
Geol. Survey, pp. 342-343, 1904. Dr. Van Hise states that biotite rarely
alters into hypersthene and sillimanite, and the formation of these from

biotite “usually oceurs in connection with contact reactions of igneous
rocks ;

Watson—Association of Native Gold with Sillimanite. 248

limited extent with their micrographic intergrowths. It is
interleaved along cleavage directions with both biotite and
muscovite, occasionally extending across the cleavage in frac-
tures and sometimes formed along the mineral boundaries,
being especially noticeable as partial rims to biotite; between
the acicular crystals of sillimanite, sometimes as large and

rea:

Fic. 1. Photomicrograph showing relation of native gold (in black) to
quartz and feldspar (white areas), garnet (light-colored mineral of high
relief near center of figure), and biotite the intermediate dark mineral, a
large shred of which occupies the lower part of the figure. Gold partially
rims and fills fractures in the garnet, and lies along the cleavage positions
in the biotite. Magnified 60 diameters.

small irregular areas and sometimes filling distinct fractures in
the mineral; and partially rimming and filling microscopic
rifts in the carnet.

These diverse relations of the gold to the rock minerals are
shown in figures 1 and 2, which are microphotographs of dif-
ferent parts of the thin section. An interesting feature of the
rock is the presence of abundant sillimanite and native gold in
intimate association, as indicated in fig. 2. Microscopic study
discloses the relations of the two minerals to each other to be
such as to indicate that the sillimanite formed in advance of
the gold. Rifts or microscopic fractures are shown in the
sillimanite, garnet, and micas, and the quartz exhibits strain
phenomena. Muscovite is not infrequently bent and sheared
and sometimes broken across. ‘These structures have devel-
oped since the formation of the rock, and since the gold fre-

244 Watson—Association of Native Gold with Sillimanite.

quently fills them, it is clear that it has been introduced
subsequent to the formation of both the original and meta-
morphic minerals, such as garnet and sillimanite. Some pyrite
is present in the rock, and while the gold is closely associated
with it in some instances there is no evidence suggesting the
derivation of the gold from pyrite by alteration. In the

iG:

Fic. 2. Photomicograph showing relation of native gold (in black) to
sillimanite, the fine fibrous mineral which occupies most of the field. Gold
is shown as irregular black areas in the sillimanite partly lying between
fibers and partly filling fractures.‘ White mineral occupying marginal posi-
tions is muscovite showing some thin foils of gold (black) interleaved along
cleavage directions. Intermediate dark mineral is biotite with partial rims
of free gold (black), Magnified 60 diameters.

absence of accurate knowledge of the field relations, conelu-
sions based wholly on the single hand specimen and thin sec-
tion are of doubtful value; but so far as these can be relied on
the evidence suggests that the gold was probably introduced
into the wall rock with the pegmatite-making solutions and
formed in the relations to the rock minerals as described above
and as indicated in the two figures photographed from the thin
section.
Brooks Museum, University of Virginia.

L. A. Bauer— Ocean Gravity Observations. 245

Art. XXIIIl.—Hecker’s Remarks on Ocean Gravity Obser-
vations ; by L. A. Bauvsr.

Ir is frequently suggested by persons, presumably familiar
with previous work, that it would be desirable to include gravity
observations on the Carnegie. We are told that ocean gravity
work, of requisite accuracy, is one of the few remaining heroic
problems. Before deciding on any additional work a careful
survey is made of existing knowledge and of the actual require-
ments for obtaining trustworthy data. I was thus led into an
examination of past ocean gravity work, viz., that by Dr.
Hecker on three cruises between 1901-09, under the auspices
of the International Geodetic Association and published in
three monographs aggregating 500 quarto pages. Examina-
tion was made at first only in general; however, I soon became
engaged in an exhaustive examination of the entire problem,
not only going this time more deeply into Hecker’s methods of
observation and of computation, but also consulting experts in
thermometry and barometry of the U. 8. Bureau of Standards
and of the U.S. Weather Bureau, besides well-known geod-

esists and physicists. The final result of this preparatory study
was the paper “ On Gravity Determinations at Sea” published
in this Journal, January, 1911. This paper received the en-
dorsement of several well-known investigators to whom the
manuscript was submitted before publication. Its special aim
was to arouse general interest in this difficult subject and to
assist in making clear the direction in which further advance
was necessary. Returning December 24 from a cruise of the
Carnegie, I found that Dr. Hecker had made reply to some points
in my paper. His remarks were originally published in the
journal of which he is chief editor (Gerland’s Beitrige zur
Geophysik, Bd. xi, Heft 1, June, 1911, p. 200); in Novem-
ber a modified translation "appeared in this Journal. Refer-
ences throughout this article will be to this translation.

I must begin by correcting some of Hecker’s statements.
He infers that we have introduced for gravity work on the
Carnegie an inferior method of reading the boiling-point ther-
mometer, viz., with a hand lens instead of a telescope, as he had
done. I had stated explicitly (/. ¢., p. 4) that the boiling-point
observations on the Carnegie were not made for the purpose of
gravity determinations; ‘‘the prime purpose being to obtain
data for controlling the corrections of our aneroids, the instru-
mental equipment was in accordance with this aim.”’ This was
on our first cruise; on the present cruise we have replaced the
hand lens by a telescope, but we are not yet willing to regard
our individual results as gravity determinations.

246 L. A. Bauer—Ocean Gravity Observations.

The experts consulted agreed that it would not be safe to
rely exclusively upon barometers, as did Hecker, damped to
sucha degree that, as he confesses, observations made with them
at sea, under supposedly ideal conditions, were not of the
desired accuracy. Thus he says (/.¢., p. 890), “this, of course,
cannot be otherwise, for, as is well known, highly damped
barometers, when perfectly at rest, do not have very accurate
readings.” As the final outcome of all conferences and expe-
riences, the conclusion has been reached that it will not be
worth while to take up gravity work seriously on the Carnegie
unless substantial improvements can be made upon the boiling-
point—barometer method; we are continuing, however, with
our present equipment, the necessary observations for the con-
trol of our aneroids. I shall have to postpone for some future
occasion the report upon this feature of our work.*

In spite of all care bestowed, the possibilities of appreciable
errors are sO numerous as to raise the question whether gray-
ity data obtained by Hecker’s method would yield individual
results of requisite accuracy. These errors in themselves
appear trivial until converted into gravitational quantities.
Thus, for example, an error in the boiling-point temperature
of but 0°-001 C. corresponds to about 0:035™ or 1/28000 part
of g, the order of accuracy required, 1 am informed, to meet
modern requirements. It may be that Hecker considers that
he has reached this accuracy. As the result of my exami-
nation I was led to the conelusion (/.c., p. 161) that “it will
not be surprising if it be found that many of the most recently
published results are in error by an amount approximating to
0-1°", or about 1/10000 part of g.”

Hecker questions my statement regarding his thermometer
corrections. The facts as derived from his three publications
are as follows (pp. 6-7, 1903; pp. 81-83, 1906, and pp. 39-40,
1910). The ¢otal corrections of thermometers employed in the
Atlantic cruise of 1901, the Indian and Pacific Ocean cruise of
1904-05, and in the Black Sea work of 1909, were determined
but once, viz., before starting out in 1901. If I understand
him rightly, only the corrections dependent upon inequal-
ities of bore of tube (the calibration corrections) were deter-
mined a second time, namely, at the end of the work in 1904-5.
All other corrections, however, ¢. g., those dependent upon the
zero, the fundamental interval, reduction to standard scale, ete ,

* Hecker is correct with regard to the impossibility of reading successive
high and low phases of the barometers used on the Carnegie ; 1 had misin-
terpreted the observer’s notes. However, since then we have made some
preliminary experiments in which successive high and low readings were
obtained by using a hand magnifier and estimating the readings, as closely
as possible, with the eye and attempting to secure the requisite accuracy by

multiplying the observations under varied conditions on the principle suc-
cessfully used in our magnetic work. —

"*

L. A. Baver—Ocean Gravity Observations. 247

were ascertained only once. Thus the comparison of Hecker’s
thermometers with the standard of the Physikalische Reichs-
anstalt, or with any other standard, were never again repeated
as far as known. Hecker does not give the actual observed
corrections, but, instead, a table computed therefrom, which,
except for very slight corrections due to the second determi-
nation of the calibration corrections, is used for the three
eruises. Hecker assumed that the variations in the mentioned
corrections, with age and use of thermometers, would either be
negligible or “give only a constant difference,” and hence
enter into the ‘miscellaneous constant term of his observation
equation. How justifiable these assumptions are I leave others
to judge. Due to the severe conditions imposed by his stren-
uous program, Hecker had serious trouble at times with his
thermometers—sufiicient, indeed, to require rejection of some
series. The caliber corrections, Lam informed by thermometry
experts, are the ones least liable to appreciable changes, and
from their re-determination no certain conclusions can be ©
drawn as to the behavior of the other and more important
corrections.

Since Hecker criticises our proposal as to the necessity of
frequent controls of the zero point, it will be of interest to
quote from such an eminent authority on precise thermometry
as Professor Callendar: ‘“ The effect [of zero changes] cannot
be calculated or predicted in any series of observations because
it depends in so complicated a manner on the past history and
on the time. It is a most serious difficulty in accurate mercu-
rial thermometry, especially at high temperatures. The most
satisfactory method of correction appears to be to observe the
zero immediately after each reading and to reckon the temper-
ature from the variable zero thus observed.” The various
experts consulted in this country are in entire accord with Pro-
fessor Callendar. Now this is what Hecker says (/. ¢., p. 392) :
“The reason why I made no freezing-point observations is that
they would have introduced new errors into the observations ;
for freezing-point observations are also subject to errors.’
Experienced physicists would say that the neglect of the zero
control introduced greater uncertainty than that of a zero
determination. Hecker depended too much upon the possibil-
ity of eliminating all outstanding evils by general least square
adjustments ; this same remark applies to other matters referred
to in his comments, ¢. g., barometer corrections.

A word with regard to Hecker’s least square treatment of his
observational quantities. While I have pointed out wherein
his observational work was in some respects not wholly satis-
factory, I am inclined to think that the error due to reduction
will be found to be greater than the purely observational one.

248 L. A. Bauer—Ocean Gravity Observations.

I have shown (/.¢., p. 10) that his unknown quantities “are
not strictly instrumental or ship constants, but depend upon
the area (extent and geographic position) from which they are
derived.” Hecker does not appreciate that they can hence
only be used within the area embraced by the stations entering
into his adjustments and not outside, for extrapolation pur-
poses. For example, in his 1910 revision Hecker assumes that
the unknowns derived from selected stations between the
Tongas and San Francisco likewise hold for the disturbed
region, Sydney to the Tongas. The 1910 computation increases
the gravity anomalies between Sydney and Tonga at times by
0-1" and more over those of 1908; the largest gravity anomaly
of all his cruises, +0°393™, is now placed in this region, viz.,
off the north extremity of New Zealand. The 1908 compu-
tation, on the other hand, gave as the largest anomaly, +0°319™,
off Honolulu. The Sydney-Tonga region is that for which
Hecker appeals to Kohlschitter’s paper in confirmation of his
work. Kohlschiitter’s own observations were not made on the
ocean but on land, in German East Africa. His general con-
clusion would doubtless hold as well for Hecker’s 1908 results
as for those of 1910.

Omitting the rejected port observations, it is found for the
Atlantic work that 44 out of 47 available results were utilized,
whereas for the Indian and Pacific Ocean cruise, out of 136
collected results 65 enter into the least square adjustments for
the derivation of the required unknowns. Those who must
utilize Hecker’s anomalies should bear in mind the extent to
which they are already subject to the law of accidental distri-
bution assumed in the adjustments. It may also be of interest
to record here, that for 85 per cent of the total work the appli-
cation of correction due to course and speed of vessel and the
rejection of the port results has increased the sums of the
gravity anomalies squared, the increase being most pronounced
where extrapolated coefficients have been used. | ,

Hecker has overlooked the salient feature of our proposed
plan, viz., the prime importance of so arranging observational
work as to admit of but one logical method of reduction, and
the necessity of restricting the unknowns to a few physically
determinable ones. I hope that I shall not be regarded as un-
appreciative of his labors. In fact, only one who is himself
engaged in ocean observational work can adequately realize
the countless difficulties which had to be overcome. My chief
aim has been to assist in setting before those who use his
results their precise limitations. |

Washington, D. C., January 22, 1912.

F. H. Lahee—Metamorphism and Geological Structure, 249

Arr. XXIV.— Relations of the Degree of Metamorphism to
Geological Structure and to Acid Igneous Intrusion in the
Narragansett Basin, Rhode Island ;* by F. H. Lanes.

Part I.

CONTENTS.
Acknowledgments.
Introduction.
Structural Geology.
Theoretical considerations.

‘hes The borders of the Basin.

. The Basin strata.
Major folding
Strikes.
Dips.
Pitch.
Axial planes.
Continuity of the major folds.
Relative number of folds across the Basin.
Minor folding.
Areal distribution of variations in the major and minor
folding.
Conclusions.

ACKNOWLEDGMENTS.

For the use of laboratory equipment and for valuable advice
in the preparation of the original thesis, the writer wishes to
express his gratitude to Professor J. KE. Wolff and Professor
J. B. Woodworth, under whose direction the work was carried
on; and for numerous suggestions and favors, to Professors
W. M. Davis, A. Sauveur, and C. Palache; to Dr. Ernest
Howe; and to Messrs. R. W. Sayles, J. A. S. Monks, Wm.
Burns, and W. P. Haynes.

INTRODUCTION.

The Narragansett Basin is a body of Carboniferous strata,
fifty miles long, from fourteen to twenty-five miles wide, and.
with a total stratigraphic thickness of somewhat more than two
miles.t From the southern coast of eastern Rhode Island it
trends northward as far asa line between Fall River and Provi-
dence, including the major part of Narragansett Bay within its
boundaries, and thence, bending more to the east, extends in a
northeasterly direction to near Hanover, Massachusetts.

Topographically the Basin is represented by a shallow
depression with an uneven surface, between bordering

* The present paper is an abstract of a thesis accepted for the degree of
Doctor of Philosophy in Geology, at Harvard University, in June, 1911.

+Shaler, N. S., Foerste, A. F., and Woodworth, J. B., Geology of the

Narragansett Basin. U.S. G.S., Monog. XXXIII. 1899. See pp. 208-210,
336, 338, 345, 358, and 373, and Plate xxx.

Am. Jour. Sci.—FourtH Series, Vout. XX XIII, No. 195.—Manrcg, 1912.
aly

250 +. H. Lahee—Metamorphism and Geological Structure.
tie. 4.
SS Post- Carboniferous.

ES Carboniferous.
SSSSs Pre- Carboniferous.

t) ‘ 2 3

Scale in miles

Fic. 1. Outline map of the southern half of the Narragansett Basin.
Many of the dips and strikes are somewhat generalized. References to
numbered localities will be found in the text.

Ff. H. Lahee—Metamorphism and Geological Structure. 251

ridges of harder rocks. A few inliers of the harder rocks
occur surrounded by the Carboniferous (see fig. 1). On all
sides, except in the broken southern rim, the same statements
hold true, namely, that the predominating border rocks are
granites or granite gneisses and that these granites are intrusive
into sedimentary formations, now much metamorphosed. The
granites (Sterling granite series) in South Kingstown are prob-
ably post-Carboniferous and the schists enclosed in them,
Carboniferous ;* but.elsewhere the plutonics are pre-Carbon-
iferous, as is proved by the presence of their disintegrated
débris in the Carboniferous.

The strata of the Basin are shales, sandstones, arkoses, and
conglomerates, which have been folded, metamorphosed, and
injected by an acid series of dikes and veins, offshoots from the
post-Carboniferous granites of Kingstown. The anticlines are
relatively long and narrow, after the Aypalachian pattern, and
crumpling of minor dimensions often occurs superposed upon
the major folds. Although there are innumerable exceptions,
the metamorphism, regarded from a broad standpoint, is dis-
tinctly greater in the southern part of the field than in the
northern. The acid intrusives range in composition from highly
feldspathic pegmatites to veins of pure massive quartz. More-
over, they are much larger, and there are many more of them,
in South Kingstown than farther northward and eastward.

Throughout the Basin, then, the texture and composition of
the sedimentary rocks, the complexity of the folding, the
degree of metamorphism, and the composition and abundance
of the acid dikes, are variable factors. It has been our aim to
investigate the kinds and degrees of metamorphism and to
correlate them with the other variable factors just mentioned,
with stratigraphic depth, and with geographic position in the
Basin. The greater portion of the work has been carried on
in the southern half of the field, where the exposurés are more
satisfactory.

The first part of this paper will treat of the Structural Geol-
ogy of the Carboniferous rocks; the second, of the Petrology
and Metamorphism of the Carboniferous rocks; and the third,
of the post-Carboniferous intrusives. There is no need of
describing the pre-Carboniferous rocks in detail. Their impor-
tance for us rests (1) upon their having constituted the floor ~
upon which the Basin sediments were laid down, and (2) upon
their relations to the forces which deformed these sediments ;
and these matters will be taken up under the other heads.

The remark is perhaps unnecessary that no attempt could be
made to obtain exact quantitative results, because the relations

*Loughlin, G. F., Intrusive Granites and Associated Metamorphic Sedi-
ments in Southwestern Rhode Island, this Journal, xxix, p. 447, 1910.

Py ee coche 2 Lahee—Metamorphism and Geological Structure.

between such factors as mineral composition and intensity of
deformation, or degree of deformation and stratigraphic depth,
and the like, obviously cannot be measured with precision.
‘Yet a broad, general quantitative dependence can be deter-
mined.

STRUCTURAL GEOLOGY OF THE CARBONIFEROUS FORMATION.

THEORETICAL ConstDERATIONS.— Before describing the struc-
tural geology of the basin, let us see what variations in inten-
sity of folding may be expected, on theoretical grounds, in a
region of deformed strata.

A fold, in the geological sense, is the expression of a

ay

HiGs 2.

Fie. 2. Diagram of an elliptical quaquaversai anticline. a-e-b-f, axial
plane.

a-b, direction of operation of minimum component of force.
c-d, direction of operation of maximum component of force.

compressural forces which have operated upon variable resist-
ances. In most cases the pressure has been applied along
approximately horizontal lines. However numerous the forces
may have been, they may be regarded as having been equiva-
lent to two components, —one of maximum value, which acted
parallel to the greatest compression, and one ‘of minimum
value, which acted parallel to the least compression, at right
angles to the first.

The simplest illustration is the quaquaversal anticline (see
fig. 2). Here a—6 is the direction of the minimum component,
and c-d is that of the maximum component. Pitch, measured
along the slopes ea and ed, is really dip in the axial plane,
a-e-b—-f. Whenever there is a pitch—and it may be stated asa

F. H. Lahee—Metamorphism and Geological Structure. 258

rule that pitch is practically universal in regions of folding*—
the deforming forces were variable in direction and they
may be considered as resolvable into two components as above
explained. The ratio between these components will then be
indicated by the ratio between the degrees of compression
perpendicular to, and parallel to, the axis of the given fold.
According to Van Hise,t folding may be parallel or simz-
lar. In parallel folding the contacts between adjacent beds

Fic. 3. Fie. 4.

Fie. 3. Parallel folding. A-B, fundamental curve.
Fie. 4. Similar folding.

are parallel to one another and the thickness of any bed is
essentially uniform throughout (see fig. 3). On the other
hand, in similar folding the contacts between adjacent beds are
identical in size and shape and the thickness of every stratum
is considerably greater in the axial regions than on the limbs ¢
(see fig. 4). Again, in parallel folding that curve in which
all anticlines and synclines are of equal size and shape may be
termed fundamental to the structure (A-B, fig. 3). Above
the fundamental curve synclines narrow and become ‘pinched’
or ‘carinate’, and below it anticlines undergo the same altera-
tion in form. Obviously no such discrimination is possible in
similar folding. It may be shown that, while deformation is
in process, differential movement (shearing) near the funda-
mental curve is at a maximum in the limbs and at a minimum
in the crests and troughs; but that, away from this curve,
both upward and downward, the locus of maximum differen-
tial movement migrates from the limbs to the axial regions,

*See, for example, the following: Reade, T. M., The Origin of Mountain
Ranges, xxx, p.178. London, 1886. Reade, T. M., The Evolution of Earth
Structure with a Theory of Geomorphic Changes, p. 195. London, 19038.
Shaler, N. S., etc., op. cit., p. 382. Wan Hise, C. R., Deformation of Rocks,
, Jour. Geol., iv, pp. 312, 344, 348-349. 1896.

+ Van Hise, C. R., Principles of North American pre-Cambrian Geology.
U.S. G.§., Ann. Rept. XVI, Pt. I, 1894-1895, pp. 598, 599. Also, by the
same author, Deformation of Rocks, Jour. Geol., iv, pp. 210, 211, 1896.

¢{ Van Hise, C. R., Principles of North American pre-Cambrian Geology,

pp. 598-601. Also, Heim, A., Untersuchungen tiber den Mechanismus der
Gebirgsbildung, Basel, 1878, p. 48.

254 F. H. Lahee—Metamorphism and Geological Structure.

reaching these where the folds are most acutely pinched. In
similar folding maximum shearing is always in the limbs.*

If strata, deformed after the parallel pattern, have a pitch,
carinate anticlines become flat and flat synclines become eari-
nate, when traced in the direction of pitch; but in similar
folding, since dips are always steeper on the limbs than on the
axes, no amount of pitch can alter these relations. Parallel
folding, representing less readjustment of beds than similar
folding, is more common and is generally on a larger scale
than the latter. It must be remembered that these state-
ments apply to mathematical ideals only, and that, under nat-
ural conditions, there is considerable variation. The two
types are not always sharply distinguished; yet there is suffi-
cient approximation to the ideal to make the classification
valuable.

Given a force in operation, a more rigid body will oppose
deformation by this force more successfully than a less rigid
body. If adjacent rocks of different degrees of rigidity are
under lateral compression, whether the forces be regarded as
acting parallel or perpendicular to the contact surfaces
between the rock masses, there is a tendency for transmission
of these forces by the stronger body.t| The first condition—
of force parallel to contact, i.e., about parallel to the beds—is
that for the development of competent structure ;t the second
condition—of force about perpendicular to contact—is illus-
trated by the relations between hard crystalline border-rocks
and less resistant basin sediments, after deformation of the
original land surface has progressed far enough. In nature
the differences of rigidity are practically never so great that
one rock merely transmits the force while the other accom-
plishes all the accommodation. Both usually suffer, but one
less than the other.

The more rigid a rock mass under compressive strain, the
farther from the point of application of the force will the
effects of that force appear. For this reason, unless a stratum
has competency sufficient to enable it to span the breadth of
the deformed belt, the folds are apt to be closer and more
numerous near the point of application and to die: out away
from it;§ and the less the rigidity of such a stratum, the
more rapidly will the folds subside.

* Van Hise, C. R., ‘‘Principles’”, etc., p. 598.

+ Harker, A., On Slaty Cleavage... , Rept. Brit. Assoc. Adv. Sci.,
1885, p. 848. Heim, A.: Op. cit., p. 40.
aes Hise, C. R., Deformation of Rocks, Jour. Geol., iv, pp. 204, 472,

t Willis, B., The Mechanics of Appalachian Structure, U. 8. G.S., Ann.

Rept. XIII, Pt. II, 1891-1892, p. 247.
S Shaler, N. S., -etc., op. cit., p. 16.

F.. H, Lahee—Metamorphism and Geological Structure. 255

According to the foregoing review of theoretical facts,
variations in the intensity of deformation may be due (1) to
the type of folding; (2) to the position of the outcrop in the
fold; (8) to the degree of rigidity of the rock: and, (4) to the
distance of the outcrop from the point of application of the
force. Provided the proper conditions prevail, then, we
should expect to find such variations in the structure of the
Narragansett Basin.

In the deseription which is to follow, we shall be able
neither to mention strikes and dips of individual outcrops *
nor to debate the pros and cons of questionable intepretations
of the folding.t The method of procedure will be indicated
and then the facts will be presented in summary form.

Tue Borprers oF THE Basin.—As may be seen on the map,
the borders of the Basin have many irregularities of trend.
Oauses for these changes in direction may be: (1) a pre-Carbon-
iferous hill-and-valley topography, forming the floor of the
Basin; (2) the deformation of a more level pre-Carboniterous
land surface ; or, (8) a system of post-Carboniferous faults. If
the first supposition were true, the Carboniferous sediments
should often abut against the pre-Carboniferous, and there
should be little dependency between strikes of the strata and
strikes of the surface of unconformity separating the Carbon-
iferous and the pre-Carboniferous. But such is not the case.
There is a remarkably close parallelism between the attitude of
this surface of unconformity and the attitudes of the adjacent
Basin sediments. Indeed, it is just what would be expected it
the Bason floor had been originally comparatively flat and had
later shared in the diastrophism of the overlying strata. Fur-
ther evidence for deformation of the basement, according to
Shaler, is to be seen in a certain amount of schistose structure
in the eastern and western border-rocks, which decreases in
intensity away from the Basin.t

The Basin floor has been deformed not only by bending, but
also by faulting. This is indicated locally by exceptional
straightness of the rim, by apparent displacement of beds or of
groups of beds, and by zones of fault brecciation. Whether all
of this fracturing is of the normal, or tension, type, or whether
some of it is of the reversed, or compression, type, could not be
determined. Certainly many of the faults are normal.

Summarizing, we infer (1) that the original floor of the
Basin, which comes to the present topographic level in or near
_ *The strikes and dips have been more or less generalized for different
localities and have been plotted on the map (fig. 1).

+ For these see Shaler, N. S., ete., op. cit., and Lahee, F. H., A study of
Metamorphism in the Carboniferous Formation of the Narragansett Basin ;

thesis deposited in Gore Hall, Harvard University, in 1911.
¢ Shaler, N. S., op. cit., pp. 19-20.

256 FF. H. Lahee—Metamorphism and Geological Structure.

the pre-Carboniferous borders, had a relatively flat, or at most
a gently undulating, surface; and (2) that this surface under-
went deformation, both by folding and by faulting, in com-
pany with the superjacent strata.

Tue Basin Srrata.—In drawing conclusions with respect
to the structural relations of the Carboniferous strata, consid-
erable latitude of interpretation is inevitable. Among.other
reasons this is partly because plant remains, although common,
have not yet been proved to be of value in this region as indices
of stratigraphic horizon, and furthermore, because the entire
series of shales, sandstones, and conglomerates, of the Basin,
while characterized by numerous textural variations, is so sim-
ilar throughout that mineral composition and lithologie strue-
ture are almost worthless for correlation. In general, however,
a broad sequence has been made out, passing upward from
basal conglomerates and arkoses (Pondville arkose, Natick con-
glomerate, etc.), through a great thickness of conglomerates,
sandstones, and shales with some coal seams (Kingstown and
Aquidneck series), to an overlying coarse conglomerate (Digh-
ton and Purgatory conglomerates).

The deformation of these sediments has produced folds of
various sizes and shapes. We shall make a distinction between
major folds, which are sufficiently large and important to be
represented in an ordinary generalized vertical section, and
minor folds, which would usually be omitted from such a
section. By contortion we mean complex minor deformation
in which the strata are bent into closed or overturned folds, or -
are otherwise severely compressed. Upon this arbitrary classi-
fication we shall base the succeeding description.

Major folding.— Evidences for variations in the major folds
may be observed in such factors as the direction of strike, the
degree of dip, the direction and amount of dip of axial planes,
and the direction and amount of pitch, if there is a pitch.

Strikes—The greatest regularity of strikes (between 5° and
20° E. of N.) occurs in the Kingstown formation, (1) in the
western coast belt—between the western border and the west-
ern coast of Narragansett Bay—on Boston Neck (B:15)* and
northward to Barber’s Height (B:12), and (2) in northern
Conanicut Island (D:10-13). That is to say, great uniformity
is found only in the southwestern portion of the Basin where
dips, as a rule, are rather’steep. Such parallelism signifies that
the maximum component of force was here practically supreme.

Somewhat less uniformity of direction is shown between
Hamilton (Loc. 8, B:11) and East Greenwich in the western
coast belt, and also on Prudence Island.

* The map (fig. 1) is codrdinated by letters and figures along the margins.

Some localities are numbered. These will be indicated as follows in the
text: Loc. 10, C:138, i. e., Locality 10 in.codrdinate square, C: 13.

F. H. Lahee—Metamorphism and Geological Structure. 257

Districts in which the strikes are conspicuously variable are
as follows: Northwest of Watchemoket Cove (D:1), Ponham
Rock-Riverside area (D and E: 2), southeastern Cranston (A :4),
Warwick Neck, Bristol Neck, Hope Island, Potter’s Cove on
Conanicut Island @loenia: E: 13), eastern ‘coast of Mackerel
Cove (Loe. 21, D:14), Beaver Tail Peninsula (Loe. 28, D: 14), |
Coaster’s Harbor Island (lee 20 sts) asiiees Point. district
(Loe. 42, F:15), area north and northeast of Warren Neck
(H_ and 1:3 and 4), Brayton Point (Loc. 49, J :5), and the east-
ern coast belt.

Strikes of the western coast belt, then, are fairly regular,
although with some rather abrupt changes in direction. On
the contrary, strikes of the eastern border region are very irreg-
ular and, except along the coast north of Stone Bridge (Loc. 47,
I:8), have no particular relation to the eastern edge of the
Basin. The lack of system here is probably due in part to
faulting.

Dips.—Without entering into detail, we may say that steep
dips predominate in the southern portion of the area, and low
dips in the northern. Many of the actual readings are recorded
on the map.

Pitch.—A. definite northward pitch is indicated in the fol-
lowing places: Warwick Neck, Rumstick Neck, Hope Island,
southeast coast of Prudence Island, Gould Island, southern
Swansea, and High Hill Point (Loc. 45, [: 11-12). Southward
pitch was recorded near Silver Spring (Loe. 3, D-E: 2), half a
mile northeast of Riverside (E: 2), northeastern coast of Pru-
dence Island, north side of Butt’s Hill (near Loc. 35, H: 9), one
mile west of Portsmouth Village Cd :9), Coddington Cove (Loe.
31, F: 12-138), Beacon Hill (Loc. 32, F: 13), probably north of
the Paradise tract (11:14), and at Easton’s Point.

Pitch is more commonly low than high. In general, it is
high where adjacent strikes and dips are variable (Swansea,
Coddington Cove, Warwick Neck), or where adjacent dips are
steep (Gould Island); and it is low in the broad folds (Pru-
dence Island, Easton’s Point); but there are exceptions.

Axial planes.*—Axial planes are vertical or dip either east-
ward or westward without regard to whether the fold is nearer
the eastern or western border of the Basin. That is to say,
with reference to these border regions as comparatively rigid
beams through which the forces were applied against the sedi-
ments, both overthrusting and underthrusting were produced.

Continuity of the major folds.—Because of these variations
in strike, dip, pitch, and symmetry, and especially because of
the wide water intervals between the land areas, the identity
of separate folds can rarely be discerned across many miles.

* See generalized sections, figs. 5 to 7.

258 LF. H. Lahee—Metamorphism and Geological Structure.

Almost without exception, however, the axes of the major folds
trend a little east of north, thus proving that the maximum
deforming forces acted along approximately east-west lines.
ftelative number of folds across the Basin.—FKast-west sec-
tions across the Basin show a varying number of folds in differ-
ent latitudes. To illustrate this fact, sections along lines A-A,
B-B, and C-C (fig. 1) have been drawn, as nearly as possible
perpendicular to the strike (see figs. 5 to 7). By dividing the
number of major folds (both anticlines and synclines) inter-

Ries. 9,96, 7;

ide

a

x
ey
oN Sp) eS ~ ‘
Ss
NX
‘N

== ~

=
=
&
=<
S$
S

Scale in miles.

Fie. 5. Generalized vertical section along the line A-A in fig. 1.
Fic. 6. Generalized vertical section along the line B-B in fig. 1.
Fic. 7 Generalized vertical section along the line C-C in fig. 1.

sected by any line by the length of this line, we may estimate
the number of folds per unit of length of the given line, that
is, per unit of width of the Basin where the line is situated.
In each case land and water areas are traversed. Since the
determination of the folding is founded upon data obtained on
land, we have calculated the results not only upon the total
lengths of the lines, but also upon the sums of their land
portions. An important source of error lies in the method of
interpreting the geological structure, and the opportunity for
mistake is greater in the north than in the south. To offset
such error we have chosen, in each case, that interpretation
which assumes the greatest reasonable number of folds. For
example, in the Cranston area, where the structure has been
explained by some as monoclinal and by others as consisting of

ae

‘fall River

F.. H. Lahee—Metamorphism and Geological Structure. 259

two synclines and an anticline, we have adopted the latter
hypothesis. Following are the results:

Line. Fold Length Numberof Sumofland Number of folds per

tra- of line folds per portions in ten miles of

versed. inmiles. ten miles. miles. land breadth.
A. 9 19 4°73 16 5°62
134 138 16 8°12 8°75 14°85
C. 16 13°5 11°85 9 Nireay ts:

This table indicates that the number of principal folds per
unit of Basin width, and, therefore, the degree of compression,
regularly increases southward.

Minor folding.—Contortion of the strata was recorded at
the localities listed below:

Number of Location on

locality* map Type of rock
1 Dey Shale, sandstone, little conglomeratet
4, D-E : 2-3 Chiefly sandstone and shale
5. D:6 Shale
6. De 7 Shale and sandstone
7 Cheer. Shale and fine sandstone
Rao: C : 13-14 Shale and sandstone
ie C: 1a Shale and sandstone
iD. B: 16 Shale and sandstone (inclusions)
13. E16 Shale and sandstone (inclusions)
14. C-D : 138 Chiefly shale and sandstone
15. D : 10-11 Chiefly shale
16. | Dae a Chiefly shale
18. Hee iS Shale
19. De ts Shale
20. C-D : 14 Shale and sandstone
Dal DP rt Shale
22. Dis b4 Shale
25 DLS Shale
26. De b5 Shale
2. Bes 12 Chiefly shale
28. EK-F : 13 Shale and arkose
29. Re 3.3 Shale, sandstone, and conglomerate
30. F : 12-18 Shale and sandstone
33. Teg Chiefly shale
36. |e Mesa Bh Chiefly shale
37. be 2 Chiefly shale
38. H:14 Shale and arkose
40. G:14 Shale, sandstone, and conglomerate
Al. F-G: 15 Shale
44, ie ke Chiefly finer rocks
46. dis £0 Chiefly sandstone and conglomerate
48. ba28 Shale, sandstone, and conglomerate
49 o.3 Shale and fine sandstone
50. GanG Shale and sandstone

* These numbers are plotted on the map.
+ For convenience the rocks are here spoken of as shales, sandstones, or
conglomerates, whether or not they have been metamorphosed.

260 FF. H. Lahee—Metamorphism and Geological Structure.

Localities 4, 16, 27, and 33 are near the axial regions of
major folds (all pinched anticlines) ; 10, 14, 15, 20, and 48 are
on the limbs of major folds ; and the others cannot be surely
placed in this respect. Evidently, then, there is no hard and
fast rule for the location of contortion in the larger folds.

If the map be divided into four equal rectangles (by lines in
F and in 8 of the codrdinate squares, fig. 1), three of the locali-
ties of contortion will be included in the northeastern area ;
five in the northwestern; eleven in the southeastern ; and fif-
teen in the southwestern. That is, more contortion is found
southward and westward in the Basin.*

In five of the localities the contortion affects shale, sandstone,
and conglomerate, or sandstone and conglomerate ; in twenty-
nine it affects shale and sandstone—usually fine—or shale alone.
According to this, contortion is limited chiefly to the clastics of
finer texture (see p. 254).

Areal distribution of variations in the major and minor
folding.—Taking into consideration both dip and strike of
major and minor folding, we could show that, if we should
pass across certain regions in the Basin, the complexity of the
deformation would increase. Thus, there is evidence for an
increase in the complexity of folding,

(1) westward, in East Providence (D-E: 1-2);

(2) eastward ‘and westward from the middle of the western
coast belt, north of East Greenwich ;

(3) southward, in Warwick Neck

(4) westward, in the western coast belt, between East Green-
wich and Wickford ;

(5) southward, in the western coast belt, south of East
Greenwich ;

(6) eastward, in Prudence Island ;

(7) westward, from Prudence Island to Hope Island ;

(8) eastward, in northern Conanicut Island;

(9) westward, from southern Conanicut Island to the western
coast belt ;

(10) southward, on Aquidneck Island ;

(11) eastward, in northern Aquidneck ‘Island ;

(12) eastward, from Aquidneck Island to the eastern coast
belt;

(13) westward, from middle Aquidneck Island to eastern
Prudence Island, Coddington Point, and Coaster’s Harbor
Island; and |

(14) southward, in Swansea.

Obviously there is not uniform increase in complexity from

* This relation is not due essentially to a greater number of outcrops in
the southern district.

F.. H. Lahee—Metamorphism and Geological Structure. 261

the middle of the Basin to the walls. Such an increase does
occur, however, within three or four miles of the borders,
a phenomenon which might be explained by the greater
proximity of these rocks to the pre-Carboniferous mass which
transmitted, probably in part, the deforming thrust.

Apparently there are alternating, nearly north-south belts of
greater or less intensity, belts which cannot usually be traced
continuously. These belts are as follows: (1) along the west-
ern border; (2) Warwick Neck, northern Narragansett Bay,
and Providence River in the latitude of East Providence,
and the city of Providence; (3) eastern part of northern
Conanicut Island; (4) Gould Island, Coaster’s Harbor Island,
Coddington Point, and eastern Prudence Island; and, (5)
Sakonnet River, and eastern coast belt.

These facts refer to variations along east-west lines. As for
north-south directions, only southward intensification of the
deformation was noted, and this was in Swansea and, in gen-
eral, from the latitude of Prudence Island.

Conclusions.— From the preceding statements certain infer-
ences may be drawn.

(1.) The high dips of Carboniferous strata resting wneon-
formably upon the pre-Carboniferous border rocks, the frequent
parallelism of strikes of the Carboniferous sediments with the
trend of the border, and the diversity of overturn and under-
turn relations at the borders, as exhibited by the axial planes,
indicate that the forces which operated through the pre-Car-
boniferous, whatever their original character, must have been
multiple in value and in direction at nearly all places where
they encountered the Carboniferous.

(2.) Within the Basin strata these forces acted in all direc-
tions, but with much greater intensity along east-west lines
than along north-south lines.

(3.) In different parts of the Basin the deformation effected
by these forces varies in complexity according (q@) to variations
in the direction and potency of the forces themselves ; (0) to the
texture (and therefore rigidity) of the rock affected ; and (c)
to vertical position in a given fold.

(4.) Variations in the deformation, due to variations in the
forces, are so distributed that (a) there is a marked increase in
the complexity of folding and in the amount of compression
from north to south; (6) there are approximately north-south
alternating belts of more or less intense deformation ; and (ce)
within a few miles of the border there is sometimes observable
an increase in intensity.

(5.) Variations in the deformation (only minor folding), due
to differences of texture, are important, but local. Finer rocks
are more highly contorted than coarser ones.

262 FE. H. Lahee—Metamorphism and Geological Structure.

(6.) Variations in the deformation, due to vertical position in
the folds, are of little importance and are commonly local.
The folding appears to be of the parallel type except in rare
instances of very minute crumpling.

(7.) The factors upon which variations in the folding are ©
dependent, mentioned in order of lessening importanee, are:

(a) relative position of outcrop along north-south lines ;

(6) rock texture ;

(c) distance of outcrop from walls of Basin ;

(d@) relative vertical position of outcrop in fold.
Cambridge, Mass., Jan. 6, 1912.

(To be continued.)

Warren—Ilmenite Rocks near St. Urbain, Quebec. 268

Art. XXV.—The Llmenite Rocks near St. Urbain, Quebec ;
A New Occurrence of Rutile and Sapphirine ; by CHARLES
H. Warren.

Introductory.—-One of the notable occurrences of ilmenite,
mentioned in treatises on mineralogy, is that near Bay St.
Paul, a town located on the north shore of the St. Lawrence
River, about sixty miles east of Quebec. This occurrence is
more accurately located as being just west of the little village
of St. Urbain in the parish of that name, which is located about
ten miles north of Bay St. Paul on the River Gouffre. In the
Geology of Canada, 1863, Dr. T. 8. Hunt gives a brief descrip-
tion of this occurrence. He states that the ilmenite bodies are
“intercalated in the stratification’ of the anorthosite rock in
which they occur. One bed, 90 feet thick, was traced for a
distance of 300 feet, and was reported continuous for over a
mile. Writing further, he states, ‘it contains in many parts
orange-red transparent grains of pure titanic acid.” The
density is given as from 4°56 to 4°66. A chemical analysis
gave: TiO, 48°60; Fe,O,, 10°42 ; FeO, 37:06; MgO, 3-6. Total,
99°68. Just what type of ore this analysis represents is not
stated, but assuming it to be a fairly correct analysis, the molec-
ular ratio derived from it indicates that it was made on rutile-
free material. The presence of the rutile appears to have
been practically forgotten, at least no other mention of it
occurs in the literature so far as the writer is aware. Its pres-
ence in the ilmenite was again noted in the summer of 1909
by Dr. W. R. Whitney of Schenectady, N. Y., while on a visit
to the locality, and it was through the latter’s interest in the
deposit that the writer had an opportunity of visiting the
locality in the spring of 1910. A representative collection of
material was made at that time with the expectation of later
using it for a thorough study of this unusual rock. A more
careful examination of the material in the laboratory showed
it to be more unusual in character than was at first supposed,
but, unfortunately, it was also found that the material had
suffered so much from alteration that it has been thought best
to deter any exhaustive chemical study in the hope that fresher
material may eventually be obtained, when it is also hoped
that further details regarding the extent of the rutile-bearing
portions may be also available.

The Kncelosing Anorthosite.—Like so many other occur-
rences of ilmenite the containing rock of the St. Urbain deposits
is an anorthosite. The extent of the anorthosite area in the
present instance is not known, but it appears to be a large one,
and may be, as was believed by Hunt, continuous with the

264 Warren—Llmenite Rocks near St. Urbain, Quebec ;

anorthosite located near Quebec, just north of the Chateau
Richér, and known by that name. It is probably distinct from
the great mass of anorthosite lying to the north and northeast
about the upper waters of the Saguenay.

The anorthosite calls for no special description. It may be
noted, however, that it is rather poor in femic constituents,
and that such as occur are largely or wholly altered to chloritie
or serpentinous products. The disseminated grains of ilmenite
are always highly xenomorphic. Locally the rock shows some
crushing, and throughout, the feldspars, which are chiefly ande-
sine, show some evidence of strains.

The Ilmenite Masses in General.—The contacts with the
ilmenite bodies are, as a rule, quite sharp, although there is in
places some gr adation. Along the contacts there is commonly
a narrow band of a dark brown mica developed. Small spheri-
cal or irregular masses of ilmenite occur at many places in the
vicinity of St. Urbain, also narrow dike-like streaks. The
larger bodies appear in general to have the form of elongated
masses, sometimes dike-like in their general outlines. The
elongation follows an indistinct gneissoid structure in the
anorthosite, which here has an east-westerly direction. The
dip is usually highly inclined, although some of the ore bodies
bend over and lie almost horizontally, conforming, doubtless,
to local flextures in the enclosing rock.

Large Deposit of Rutile-free Ilmenite.—One of the two
most important exposures of the ilmenite rock is found about
one-half way up the hillside, which rises rather steeply directly
west of the village of St. Urbain and forms the western rim of
the broad valley of the River Gouffre. The ilmenite has been
partially uncovered, and probably a few thousand tons were
mined many years ago for iron. In fact, the ruins of an old
smelter may still be seen just below the deposit. The total
exposure at the old workings is perhaps 100 feet wide by 200
feet long (east and west.) Good outcrops occur at intervals
for some distance to the west along the bed of a small stream
which runs down the hillside at this point. On the south side
of workings a dike-like body of very massive ilmenite is
exposed and may be followed up the hill for some 200 feet.
This has an average width of about 10 feet and near its upper
end bifureates, one branch bending off to the northwest. A few
feet north of this, another dike, possibly ramifying below with
the first, bends off to the north with a flattening dip until it
becomes almost horizontal. Just north of this again comes
another mass, which has been uncovered over an area measur-
ing some 70 feet on a side, with a depth, as exposed, of some
20 feet. This is cut near its northernmost exposure by a nar-
row streak of anorthosite rock with a nearly vertical dip and
an east-west trend.

New Occurrence of Rutile and Sapphirine. 265

Megascopieally, the ilmenite rock from this occurrence con-
sists essentially of a dense black, medium to rather coarsely
granular ilmenite, through which are scattered small grains of
feldspar, or its decomposition products, occasional grains of a
dark green spinel, and plates of dark brown mica. Long

exposure to surface weathering develops a brown limonite coat,
but, as a whole, the ilmenite tock is v ery resistant to weather-
ing processes. ‘The ore, studied in thin sections and on pol-
ished surfaces, shows that the ilmenite, as well as the other
constituents, lack altogether any crystallographic outlines.
The ilmenite grains range in size from individuals 3-4"™™ in
eross section to ones 10-19™, the average being perhaps 6—7"™.
The feldspar is the same variety as that in the anorthosite se
forms rounded grains. It is often largely replaced by second-
ary products. Lying along the border of many of the feldspar
grains, next to the ilmenite, biotite is developed. This may
lie parallel to the margin or may project out into the feldspar,
sometimes replacing a good portion of it. Its occurrence is
such as to suggest that it may be of later origin than the feld-
spar, developed, perhaps, during the late magmatic period, or
during a subsequent period of metamorphism. It possesses a
very marked pleochroism and absorption: light brown or almost
colorless to deep reddish brown. The axial angle as measured
with the microscope was found to be 10 degrees. It resembles
closely mica, often observed in a somewhat similar connection
elsewhere, and is doubtless an iron rich variety. Alteration
changes it toa chlorite. The spinel is of a dull green color,
feebly translucent, isotropic, and is to be referred to the vari-
ety pleonast. Its grains are entirely without crystalline out-
lines, and it occurs both with the ilmenite and abont the’ feld-
spar grains. Quantitative estimates show that considerable
portions of the ore will not contain over 2 to 2°5 per cent cf
accessories, but the general run will carry from 5 to 6 per cent.

Structure and Composition of the Limenite Grains.—Exam-
ined with a strong direct illumination, polished surfaces of the
ilmenite show that individual grains are not of homogeneous
composition, although all are identical in character. They are
made up of a very fine lamellar intergrowth of two kinds of
material. One kind, comprising what is roughly estimated as
one-fifth to one-quarter of the whole, is of a bright steel-gray
color and follows, as a rule, a nearly straight course across the
grains. Many of them pinch out within the grain and in some
the strips have the form of very flat, lensiform bodies; again
they are slightly curved in outline. In width they vary from
0:003 to 0:02"™. The second series are uniformly broader
than the first and run from 0:036™™ to 0:09"™ in width. These
are of a dull black color. The whole intergrowth suggests in

Am. Jour. Sci.—FourtH SrErigs, Vou. XX XIII, No. 195.—Marcna, 1912.
18

266 Warren—Llmenite Rocks near St. Urbain, Quebec ;

appearance a fine microperthite structure. If a polished sur-
face be immersed in cold dilute hydrochloric acid, the latter
very soon shows the characteristic color of ferric chloride,
becoming in the course of two or three hours quite strongly
colored. The solution gives reactions for ferric iron only.
Pure magnetite, similarly treated, dissolves somewhat more
readily, but the solution’ reacts strongly for both ferric and
ferrous iron. The steel-gray lamelle are deepened by the
action of the acid forming tiny grooves, indicating that it is
this part of the intergrowth that is dissolved. As will be seen
from the chemical analysis of the ore given later, the percent-
age of ferric oxide present is in general agreement with the
percentage of the steel-gray lamelle. These facts point
strongly to the conclusion that the latter are hematite in inti-
mate crystallographic intergrowth with ilmenite. It may also
be noted that the ilmenite grains are not affected by an ordi-
nary magnet, and indeed require a strong field on an electro-
magnet in order to be attracted to the point of picking up.
Their weak magnetic properties indicate quite clearly that
there is no magnetite present. The very fine powder rubbed
on smooth white paper gives a dull brownish black streak
(with perhaps a slight reddish tint) edentecal in ape a
with the streak similarly obtained from a mixture of # pure
magnetite (black streak) and + hematite (dark red str eal).

To the writer this intergrowth appears to have some interest
in connection with the composition of “ titanic-irons” gener-
ally, and the disputed question of the isomorphism of hematite
and ilmenite. While it is impossible to make an exact estimate
of the amount of ferric oxide present as such in the inter-
growth, the approximate estimate given above agrees approx-
imately with the per cent of ferric oxide found by analysis.
From this it appears that the amount of Fe,O, mixed isomorph-
ously with the ilmenite must be small. The excess of Fe,O, so
commonly reported in ilmenite analyses has generally been
accepted to mean that the ilmenite and hematite molecules are
isomorphous. If the ilmenite grains in the present instance
possess the structure originally assumed by them on crystal-
lization from the magmatic condition, the idea at once presents
itself that the Fe,O, present in ilmenite may be always in large
part, at least, present in the form of a fine intergrowth, and
the desirability of examining carefully prepared polished and
etched specimens of ilmenite whose chemical composition is
accurately known is at once apparent. It is of course by no
means certain that the intergrowth is an original structure.
The two molecules may have erystallized originally as an iso-
morphous mixture and subsequently, under changed conditions
of temperature, ete., being no longer stable in the isomorphous

New Occurrence of Rutile and Sapphirine. 267

state, separated, forming the intergrowth described. Such a
change may have been considerably facilitated by the meta-
morphism to which this rock has to some degree been sub-
jected. It is to be noted that, although the two minerals
have very nearly the same crystallographic constants, they
differ somewhat in symmetry, and the accepted formule: for
the two are not strictly analogous, ilmenite being RTiO, and
hematite Fe,O,. It may, therefore, be questioned whether the
crystallographic and chemical analogies of the two are sufi-
ciently close to permit of isomorphous mixture to more than a
very limited degree, but close enough to condition an intimate.
and definite crystallographic intergrowth. It is hoped that a
further study of the relations existing between ilmenite and
hematite and also magnetite when these molecules occur
together may soon be carried out.

Deposit with Rutile-Sapphirine-Bearing Llmenite.—The
second, and in the present instance, the most interesting
deposit, is located near the top of the same ridge as the pre-
vious one, about one-half a mile to the southwest. It has been
pretty well exposed for a length of about 300 feet and for 50
teet in width. At one point the ilmenite rock has been opened
up to a depth of about 15 feet and to a less depth in several
others. Its contacts with the anorthosite, where exposed, have
a roughly east and west trend and are nearly vertical. In the
ore are several streaks of anorthosite which have also a nearly
vertical extension and a more or less marked schistosity follow-
ing much the same direction. There is also in the ore in
places a feebly marked banding with the same trend. Further
west and southwest of this deposit several small dike-like
masses of ilmenite are exposed with the same orientation, but
these carry no rutile, ete.

The mineralogical character of the greater part of the ilmen-
ite rock in this mass is essentially the same as that previously
deseribed. The grain, however, appears on the average to be
a little finer. A portion of the deposit differs from the rest
and from other known bodies of ilmenite associated with anor-
thosite rocks, in containing a notable percentage of rutile and a
smaller amount of the rare mineral sapphirine.

The rutile-bearing portion was first observed as a streak two
feet wide, with a nearly vertical dip and an indistinctly marked
banding parallel to the walls which ran east and west. The
passage of this streak into the rutile-free ilmenite on both sides
was very sudden. ‘Toward the west the rutile-bearing portion
widened, and was somewhat less sharply defined, and there is
evidence which points to the occurrence of rutile-bearing bands
and patches. It appears, however, to always change quite
sharply into the rutile-free rock. It was traced for several hun-
dred feet.

268 Warren—ILlmenite Rocks near St. Urbain, Quebec ;

Cutting the ore-body in the rutile-bearing portion is a streak
of anorthosite rock which itself carries more or less rutile.
The rutile makes up from two to three per cent of this rock as
nearly, as it was possible to estimate it. It is associated with
ilmenite and a considerable amount of biotite. These minerals
are arranged along distinct lines of schistosity. No sapphirine
has been noted in this rock.

The rutedle-bearing rock is of a brownish black color and con-
sists of a rather finely granular ilmenite thickly sprinkled with
grains of an orange-red rutile, a smaller amount of feldspar,
biotite, sapphirine, or their decomposition products, and spinel.
The sapphirine cannot be distinguished without the aid of a
good lens, and then only upon very close inspection, about
the feldspar and ilmenite grains in the form of very dark,
greenish black grains. The less altered ore is firm, but
weathered portions are somewhat friable. All of the material
collected shows more or less limonite along cracks and joints.
In a limited portion of the rutile-bearing rock fairly numerous
plagioclase grains or groups of grains, often larger than the
average in size, are present. These feldspars sometimes reach
a length of two or three centimeters and one centimeter in
width, and are characteristically associated with a strong devel-
opment of biotite plates.

Microscopic thin-sections of the rutile-bearing rock disclose
a highly xenomorphic texture for all of the constituent
minerals with the one exception of the spinel inclusions in
some of the feldspar grains. The ilmenite forms an almost
continuous background in which the other minerals lie. Its
grains, although irregular in outline, are roughly equidimen-
sional and are fairly uniform in size, their average cross-section
being about 8™". They consist of the same lamellar inter-
growths as previously described, but the two sets of lamellee are
narrower than in the former case, conforming to the smaller
average size of the grains. The rutile is in the form of simple
crystal grains or clusters of such, and is of a beautiful orange or
golden brown color with a barely perceptible pleochroism. The
cleavages are prominently developed. Twinning is rare. In-
dividual grains attain a diameter of 3°5™™. From this size they
run down to mere specks, the average being in the neighbor-
hood of 0°6™". It is distributed quite uniformly through the
ilmenite and occurs also with the other minerals, being some-
times enclosed in their grains. The spinel is rather sparingly
present and forms grains comparable in size to those of the
rutile. In the feldspar-rich portions of the rutile-bearing rock,
it also occurs included in the feldspars in the form of exceed-
ingly minute crystals. These inclusions deserve a brief
description. Many of the feldspars are crowded with them.

New Occurrence of Rutile and Sapphirine. 269

They are of a pale, dull green color and as a rule are
definitely orientated with reference to the enclosing crystal.
Just what the orientation is has not been made out. Many
of the spinels have a highly perfect octahedral habit, the
whole erystal coming into view with slight changes of
focus. Other erystals show the characteristic cross-sections
of distorted octahedrons, or form flat, triangular plates. These
attain a diameter of 015", though usually smaller. Again
the spinels have the habit of relatively greatly elongated rods,
or somewhat flattened blades arranged in lines across the feld-
spars. The inclusions are isotropic, although being wholly
enclosed in the feldspar, which often exhibits a slight disturb-
ance in its optical properties about the inclusions, they often
seem to be slightly doubly-refracting themselves. Minute
inclusions of sapphirine have also been noted occasionally
associated with the spinels, but these have a different color and
are irregular in outline.

The feldspars are an andesine like that of the anorthosite.
They are as a rale quite evenly distributed and of fairly uniform
size comparable with the ilmenite, but occasionally, as noted,
they become more numerous and of larger size, and form groups
of grains. Many of them show evidences of strains and slight
bending. In even the fresher material collected the feldspar
is usually partly replaced by secondary products, particularly
where biotite and sapphirine were present with it, and in more
highly altered specimens it is entirely gone.

The biotite is sometimes quite abundant and .has the same
characteristics as previously described. It is most intimately
associated with the plagioclase, and where sapphirine is present
it appears to have developed later than this mineral. Its
position about the margins of the feldspar, or replacing part of
it is here, as elsewhere, strongly suggestive of a later second-
ary origin. Its alteration is to chloritic products.

An oceasional grain of apatite has been noted, but it is
hardly present as more than a trace.

The sapphirine, which is of especial interest here, it being
not only a new occurrence of this rare mineral, but also in a
new association, seems to be confined to portions of the
ilmenite rock which carry rutile. Even when alteration has
destroyed both plagioclase and sapphirine, the characteristic
alteration products enable it to be seen that the sapphirine has
been a quite constant associate of the feldspar in the rutile-
bearing portion. That there is some intimate relation be-
tween the feldspar and the sapphirine is shown by the fact that
the latter generally lies between the feldspar and the ilmenite.
It is often seen as a narrow band extending around the feld-
spar. (See fig. 1.) The band may widen out into a larger

270 Warren—Llmenite Rocks near St. Urbain, Quebec ;

mass. Again, the feldspar may be surrounded by sapphirine
of nearly or quite equal area. About a single feldspar grain
the sapphirine usually has, throughout the greater portion of
its extent, a uniform orientation. The mineral also includes
ilmenite and rutile grains, and in one instance, at least, has
been noted in contact with spmel. Where the feldspar is more
abundant the sapphirine is also more strongly developed and
its grains have in some instances fairly continuous distribution

Hires:

Fic. 1. Microphotograph of thin-section, showing plagioclase (white) al-
most entirely surrounded by sapphirine (gray) either as a narrow band or as
larger grains between it and the ilmenite (black) or rutile (dark, mottled).
The plagioclase shows many minute microlites of spinel. Magnif. about
90 ; ordinary light.

through the section, and often lie, with and without included
ilmenite and rutile, between the feldspar crystals, or even
included in them. In such sections as much as 20 per cent
has been observed with about an equal amount of feldspar and
rutile, a little spinel, and the remainder ilmenite. Here, the
larger grains frequently attain a diameter of 3-0™", the aver-

New Occurrence of Rutile and Sapphirine. 271

age being somewhat smaller (0-4 or 0-7"). Quantitative
estimates of the amount present indicate something like 3-5
per cent for the general run of the rutile-bearing rock.

No trace of crystallographic outline has been noted on the
sapphirine and there is only a faint suggestion of two inter-
secting cleavages. The fracture is marked, being developed
in the form of prominent irregular cracks and is “highly con-
choidal. The pleochroism is strong, a, pale, smoky brown to
almost colorless, b=c, deep sapphire-blue, sometimes with a
shade of green. The single refraction is strong, a, having been
determined by the immersion method as approximately 1°729
for sodium light. The double-refraction is very low, not ex-
ceeding 0°005. The interference tints in many sections show
deep berlin blues. The optical character is clearly negative,
the axial angle rather large, and the dispersion is marked 7 <v.
It is to be noted that the index of refraction is higher than
that of the sapphire from the original locality in Greenland
in specimens studied by the writer.

The sapphirine from India* corresponds to that of the
present locality very closely in color, and the index for a has
been determined by the writer as about 1°726.

The sapphirine from St. Urbain shows nearly always a more

‘or less extensive.alteration not observed in the ease of the

Indian and Greenland varieties. This begins as a finely
fibrous or foliated development along the curved fracture lines
and margins. Further alteration develops a fine aggregate
of more distinctly foliated material which suggests tale in
appearance. These products become mingled with chlorite,
biotite and ferruginous material, resulting from the alteration
of the associated minerals, which renders it difficult to deter-
mine the exact character of the alteration. N evertheless, the
appearance of the alteration is quite characteristic and as noted
above, permit it to be easily seen that the sapphirine was
originally more abundant than at present.

The alteration of the sapphirine, as well as its intimate asso-
ciation with the other minerals, made it difficult to obtain
suitable material for a chemical analysis. By means of an
electro-magnet and heavy solutions, some 3 grms. sapphirine
contaminated with the other minerals and alteration products
were separated from a sample of rutile concentrates, generously
placed at the writer’s disposal by Mr. E. R. Berry of the
General Electric Company of Lynn. In barium-mercuric iodide
solution, grains of seemingly pure sapphirine sank just after

* Petrological Study of Some Rocks from the Hill Tracts, Vizagapatam
District, Madras Presidency. Walker and Connor, Records Geological Sur-
vey of India, vol. xxxvi, Part 1, 1907. The writer is indebted to Professors

Walker of Toronto and Palache of Cambridge, Mass., for specimens of the
Indian and Greenland minerals which were studied in this connection.

272 Warren—Llmenite Rocks near St. Urbain, Quebec ;

epidote, specific gravity 3°54. Less pure grains continued to sink
down to a specific gravity of 3-48. The true specific gravity
probably lies somewhat above 3°5.

he material was further purified by fusing its fine powder .
with sodium carbonate, which has only a slight action on the
sapphirine but decomposes the other minerals, including the
rutile and the alteration products of the sapphirine. Some-
thing over a gram of material was obtained in this manner,
which, examined under the microscope, was found to be
entirely free from impurities, and upon this a chemical anal-
ysis yielded the results given below in column 1. In the other
columns are given other analyses of sapphirine.

1 Il Til IV V ve Vil

SiO, eas Be 18°44 14°56 14°51 14°86 * 14°76) aig Os alec
Al,O, By oe 62°98 60°49 63°1l 63°25 63°23 G4:44 765-59
FeO am 22) Mn 0753 27 rr
cs ce GaO 938). 22

KReO ae) 9508 7°65 3°92 1°99 1°65 1°66 "65
MgO BAS bee sme LS28 tales 16°85 19°28 19°75. T9:83eer9-7s
Done eos 56 “A ON Aes Sends 34 |
Total 222 1002785100239 99°79 99°38 99°39 99:22 99°79
So ors. 9) Sn parole ice) B43 2. egos

I—Mineral from St. Urbain, Quebec : Warren.
II— §« “India: Walker and Collins, Records, Geol.
Surv. of India, vol. xxxvi, Part I, 1907.

IiI—_ _* “ Fiskernas, Greenland : Stromeyer, Unters.,
Misch. Mineralk., 1871, 391.

Iv— <* ‘© Fiskernas, Greenland: Damour, Bull. Soc.
Geol., vi, 315, 1849.

V— <* “ Fiskernis, Greenland : Schluttig, Inaug. Diss.,

Leipzig, xxii, 1884, and Zs. Kr., xiii, 74.
AVG (aie os “ Fiskernas, Greenland: Lorenzen, Medd.
Gronl., vil, 184.
Vil 7 “© Fiskernas, Greenland: Ussing, Zs. Kr., 15,
[Oe O00.
Below are given the molecular ratios derived from the above

analyses: FeO has been combined with MgO and listed as RO,
Fe,O, and Mn,O, as R,O,,.

I II Til IV V View vem
rel KG cate Sats 2a 0'224 0°942 0°242 0°247 0246 0216 0-214=
RO en ae 617 "5938 621 12620 620 - 631) tae
HORSE ‘508 ("5384 "475 08" "5169" 5 UR aa
SiO 2:00 | 2°00" 2:00: (2:00), 2°00 FON07 ean

Oe See hes 5°51 4°90 5°18 5°02 5°08 5°84 6°05
5 meena: 4°53 4°4] 3°92 4°11 4°19 4°79 4°69

New Occurrence of Rutile and Sapphirine. 2783

The ratios derived from the analyses of Lorenzen and Ussing
(VI and VII) lead to the formula given by them, Mg, A],,Si, 0),
although it is to be noted that there is a considerable deficiency
in the RO fivure in both cases, and in VI of R,O,. The ratios
derived from the analyses of. Stromeyer (III), Damour (IV),
and Schluttig (V) agree rather more closely with the formula
Mg,Al,,S8i,O,,. The ratios of the St. Urbain sapphirine lie about
half way between these two formulee, while those of the Indian
mineral depart rather widely from both, although they perhaps
favor the second type. Ussing, in discussing the composition
of the mineral, attributed the relatively higher silica values of
the older analyses of Stromeyer, Damour, and Sehluttig to the
presence of mica or other impurities. This criticism cannot

apply in the case of the St. Urbain mineral, nor apparently in
that of the Indian mineral; and as the analysis of the mineral
presents no difficulties, it does not seem as if the differences
ean be attributed to analytical errors. The composition is
that of a very basic silicate, and does not appear to conform to
any simple formula. It seems probable that there may be some
solid solution relation existing between the molecules which
make up the mineral; at least this is the only apparent expla-
nation of the variations in composition which it shows.

_ It may be noted that there are two types of the mineral from
Greenland (see Ussing), one of a light blue color, the other
having a deeper blue color and occurring in a more ferrugi-
nous association. Ussing suggests that the deeper blue color
may be due to the presence of more iron in this type, an idea
in keeping with the higher iron content of the St. Urbain and
Indian minerals.

Origin of the Sapphirine.—In the case of the sapphirine
from Fiskernas in Greenland, the mineral appears to be of met-
amorphie origin, occurring, according to Steenstrup,* in small
ellipsoidal or irregular masses in mica-schist or gneiss, high

im MgO and AJI,O, but low in silica. Walker, in the paper

alluded to, pr esents strong evidence to the effect that the Indian
sapphirine is also of metamorphic (contact) origin, having been
formed by the action of ultra-basic, spinel-bearmg rocks of the
charnockite series, on a sillimanite schist. Its occurrence as a
metamorphic mineral in these two instances suggests strongly
that it may be also of metamorphic origin at St. Urbain, an
hypothesis which is perhaps also suppor ted by the peculiar and
intimate association of the mineral with the feldspar. If so, it
must represent a reaction product between the feldspar and the

spinel, although in the absence of any lime-bearing silicate of

a secondary nature, such as epidote or hornblende, it is diffi-
* Medd. om Gronl., Kopenhagen, 1884, vii, 15.

274 Warren—Llmenite Rocks near St. Urbain, Quebec ;

cult to picture the exact character of the reaction which pro-
duced it. It is perhaps possible that it was formed by a
reaction between the alumina and silica of the plagioclase and
the spinel, some sodium and silica being eliminated and the
remaining feldspar crystallizing as a somewhat more basic
lime-soda feldspar. The optical properties of the feldspar asso-
ciated with the sapphirine do not indicate, however, that it
is more basic than that elsewhere in the ilmenite nor in the
enclosing anorthosite. Nor is it at all clear why the sapphirine
should not have formed in those portions of the ilmenite rock,
also containing the same plagioclase but free from rutile, these
having certainly undergone substantially the same metamor-
phism as the rutile-bearing portions. Taking everything into
consideration, the writer believes that the sapphirine in this
instance is a magmatic mineral.

Quantitative Study of the Rutile-bearing Rocks.—Two
quantitative estimates (Rosival) of the mineral composition of
the rutile-bearing rock have been made on large, thin sections,
one cut from a sample which appeared richer than the average
in rutile, and the other from a rutile-poor sample. The results
were as follows:

Futile te ite eyes ae oecs mek meracs DOr hes
Timeniteshemagice sie ee 739 84°5
Sapphinine «Lae ves Ween 3°2 0-7
Rest (oO Beene eee naar ome oe

100-0 100°0

It is certain, as noted, that the sapphirine as judged by its
characteristic alteration products was originally more abund-
ant than at present, so that a part of the material listed as
“rest” represents sapphirine once present. The average of
the percentages for rutile is 15°8 per cent, which is probably
not far from the true average rutile content of the rutile-bear-
ing portion.

As stated, it has not been deemed worth while to make at
present an exhaustive chemical analysis of the rock on account
of its considerable degree of alteration. A fairly complete
analysis* has, however, been made on a sample of the rutile-
rich type similar to that on which the Rosival estimate, given
in column I, above, was made. The results are as follows:

* This analysis was made by Mr. R. S. Anderson in connection with a
thesis presented as one of the requirements for graduation in the course in
Mining Engineering at the Massachusetts Institute of Technology. The work
was done under the supervision of Professor William Hall of the Depart-

ment of Chemistry, and the writer. Each result is the average of at least
two, and in the case of FeO and TiOzg, of three determinations.

New Occurrence of Rutile and Sapphirine. 275

Per cent Molec. ratio Ilmenite Rutile Hematite Rest
si0, Bb eaye 2°94 0°037 eng 3% Oey. mes gt a thea
i©, Say POOROO 667 0°382 0'285 apbeas) ph hs
Al,O, eee 1°65 "016 ee ag (oe Bed oh, poveeine
Fe,O, Ones ail Booed OM "085 tela iy ut hy 0°085 bch
MeO. 2. 24°49 BNO) | °344 E )aone es shh Mos
nih 6 a °30 ca et A eae See Eun EAN
MgO Bora 4°04 ‘101 "038 ais eats Bete.
CaO... 30 "007 eae Ses yn yes

99°98 Bates 58% 22°8% 13°6% 56%

It is of course impossible, on account of the uncertainty as
to the exact amounts of the accessory constituents present and
of their composition, also as to the exact composition of the
ilmenite molecule, to calculate the true mineral composition of
the rock. An approximation may, however, be made by assum-
ing that about one-tenth of the RO in the ilmenite is MgO,
calculating the excess of TiO, as rutile and of Fe,O, as hema-
tite and neglecting the SiO,, ete. Such a calculation gives the
approximate results shown after the analysisin the table. The
percentages summarized are: I]menite-hematite, 71°6 per cent ;
rutile, 22°6 per cent: rest, 5°6 per cent. These results are in
fair agreement with the results of the Rosival estimate given
in column I above. The hematite amounts to about one-fifth
of the ilmenite-hematite mixture, which is a figure somewhat
lower than that obtained by a very crude estimate made with
the microscope on an etched specimen. The results are, as a
whole, mutually confirmatory to a quite satisfactory degree.

While no attempt will be made at this time to classify the
rock in the “ Quantitative System,” it is easily seen that it falls
in a new position in the perfemane class, perhaps in close
company with the interesting ilmenite-rutile-apatite rocks
recently described* from Virginia by Dr. Watson. In view
of the occurrence of so much free titanic oxide as primary
rutile, it appears to the writer that it will be necessary to give
TiO, a special significance in classifying this and analogous
rocks in the “‘ Quantitative System.”

Origin, Crystallization, Name.—That the ilmenite masses
in general so commonly associated with anorthosite or gabbroid
rocks are the result of magmatic differentiation seems to be
generally accepted. In the case of the rutile-sapphirine-
bearing portion there appears to be no good reason to doubt
that it represents a portion of one of these differentiated
masses in which there was a notable excess of titanic oxide
and a somewhat smaller excess of magnesia and alumina.

*U. 8S. G. S., Bull. 430, p. 206, et seq.

276 Warren—Llmenite Rocks near St. Urbain, Quebec ;

The texture of the rocks are thought to represent substantially
that which developed upon crystallization from a magmatic con-
dition. Like so many anorthosites the present one has un-
doubtedly been subjected to more or less dynamic action, but
it does not seem to have been particularly severe about and in
the ilmenite rocks. The rutile grains show no sign of strains
nor crushing. Granting for the ilmenite-hematite intergrowth
a secondary origin, which is open to question, its development
could not have much, if at all, moditied the original texture
of the rock. The feldspar also shows but little evidence of
severe strains or crushing. Furthermore, if we assume that
both the sapphirine and the biotite are due to secondary reac-
tions, during or subsequent to the actual crystallization of the
magma, the changes involved are clearly incompetent to account
for the formation of the rutile as a secondary mineral; nor is
there any other evidence of mineralization or chemical changes
adequate to produce it. It is, furthermore, most unlikely that
if the rutile is of secondary origin its occurrence would be
confined to portions of the mass, the remainder of which has
been most surely subjected to the same dynamic and metamor-
phic action. |

It is believed that the rutile-sapphirine-bearing rock repre-
sents a magmatic crystallization, and as such it is a new and
extreme ultra-basic type, which is deserving of a distinct name.
Accordingly the name Urbainzte is proposed for it, with the
expectation that the same stem will be used with an appropri-
ate termination for its designation in the “ Quantitative Sys-
tem ” so soon as fresh material can be secured for a satisfactory
chemical analysis.

Without going into a discussion of the question here, the
writer ventures to express the opinion, founded in part on the
textural and mineralogical evidence above presented, that these
masses of ilmenite rock, if they are, as now believed, products
of magmatic differentiation, have crystallized as units from
partial magmas of like composition to the resulting rocks sub-
sequent to their differentiation from the parent anorthosite
magma, and that they have not been formed by the gradual
accumulation of separate grains through a process of fractional
crystallization.

Summary.

I.—Large masses of rock consisting largely of titanic-iron
ore occur in anorthosite in the Parish of St. Urbain, Province
of Quebec, Canada. These masses have in general an elongate
form, sometimes dike-like, conforming to the structure of the
enclosing rock.

II.—In the main they consist of ilmenite, hematite, with
accessory andesine, green spinel and biotite. Throughout a con-

New Occurrence of Rutile and Sapphirine. 207

siderable portion of one of these masses, rutile is an essential
and abundant constituent (ca. 15 per cent). In such there is
also present a smaller (3-5 per cent) amount of the rare mineral
- sapphirine. The latter may be very abundant in certain limited
portions of the rutile-bearing rock where plagioclase is also
more abundant. It is intimately associated with the feldspar,
commonly lying about its grains, often as a narrow band, and
separating it from the ilmenite. Rutile is also present with
ilmenite and biotite in a stringer of anorthosite closely associ-
ated with the rutile-bearing ilmenite rock.

I11.—The rutile-sapphirine-bearing rock forms quite sharply
defined portions of the ilmenite rock and appears to be of mag-
matic origin, representing a part of the segregation exception-
ally rich in titanic oxide, to a less extent In magnesia and
alumina, and deficient in silica.

ITV.—A new occurrence of sapphire is recorded and in a
new association. Although possibly of metamorphic origin,
like the sapphirine in the two occurrences previously known,
it is thought in the present instance to be of magmatic origin.
A. chemical analysis made on material of exceptional purity
shows that it resembles closely the sapphirine from the Hill
Tracts, Vizagapatam District, India. It is pointed out that the
molecular ratios derived from the analysis and from that of the
Indian mineral show a considerable departure from the one
usually accepted for the mineral, and do not correspond to any
simple formula, and the existence of solid solution relations
between the molecules making up the mineral are suggested.

V.—Microscopic and chemical evidence is presented to show
that the titanic-iron of these rocks consists of an intimate, very
fine, lamellar crystallographic intergrowth of ilmenite and
hematite, in which the hematite makes up something like one-
fifth of the mixture. It is pointed out that this relationship
suggests that the Fe,O, in so many ilmenites may be in large
part, at least, present as hematite crystallographically inter-
grown and not as an isomorphous mixture.

VI.—A chemical analysis of the rutile-bearing rock, also
quantitative estimates of the mineral composition as determined
with the microscope, are given. These are in fair agreement,
and show that the rock is unique in composition, and repre-
sents an extreme and new ultra-basic type of igneous rock.
The name U/rbainite is proposed to designate rocks of this type.

Mineralogical, Petrographical Laboratory,

Massachusetts Institute of Technology,
Boston, Mass.

278 ~ Scientifie Intelligence.

SCIEN TIFICUNTELLIGE NC

I. CyHemistry AND Puysics.

1. The Quantitative Determination of Manganese in the Form
of Various Oxides.—Raixow and Tiscukow have found that the
higher oxides of manganese are reduced to MnO by ignition in a
stream of hydrogen in a Rose crucible. The reduction is has-
tened to a certain extent by increase in temperature, but it depends
chiefly upon the speed of the stream of hydrogen, so that with a
rapid stream of hydrogen the reduction is complete in a few min-
utes, even with the moderate heat of a Teclu burner, and the MnO
is entirely homogeneous and of a pale green color. This novel
form for weighing manganese is recommended by the authors as
one of the most accurate.

The conversion of manganese oxides into Mn,O, has also been
studied. It was found that MnO is converted quantitatively into
the protosesquioxide by ignition in the air over the blast-lamp,
but that, if the temperature is not high enough, oxidation to Mn,O,
gradually takes place. However, by igniting a higher oxide in a
stream of dry carbon dioxide in a Rose crucible with a Teclu
burner, pure Mn,O, is obtained, and this method of weighing
manganese is also recommended as accurate.

The authors have found that the oxides of manganese, when
heated in the air for a long time by means of a Bunsen burner,
are quantitatively converted into Mn,O,, and that this conversion
takes place more rapidly in a stream of oxygen. ‘The conversion
of manganese carbonate into Mn,O, can be accomplished by heat-
ing in an oxygen atmosphere, at first strongly with a Bunsen
burner, and then at a red heat. The Mn,O, is deep black and
entirely homogeneous. The conversion of manganese sulphate
into Mn,O, is not so simple. It must be ignited alternately for
about 5 to 10 minutes in hydrogen and then in the air, and when
no more SO, is given off by ignition in the air it can be brought
into the form of Mn,O, by ignition at a red heat in oxygen.—
Leitschr. analyt. Chem., li, 135. H. L. We

2. A Pernitride of Carbon.—G. Darzens has announced the
preparation of cyanogen trinitride, CN,, which according to the
present views has the structural formula

N
pS bs
| N—C=N
N—
The compound was easily prepared by the reaction of sodium
trinitride with cyanogen bromide in aqueous solution.

NaN, +BrCN=N,CN + NaBr.

Chemistry and Physies. 279

The reaction is accompanied with the disengagement of consider-
able heat, and when it is complete the solution is extracted with
ether, and after the ether has been dried with anhydrous sodium
sulphate, it is distilled off under diminished pressure, leaving the
carbon tetranitride in the form of a white crystalline body. It
melts at 35°50° C., commences to decompose at 90° C., and deto-
nates violently at 150° C. The danger of explosion is such that
only small quantities, two or three tenths of a gram, should be
prepared in a single operation.— Bulletin, xi, 4. He de We

3. Portland Cement.—E. JANEcKE has made an extensive study
of cement clinker and has reached the conclusion that a compound
8CaO0.2S8i0,. Al,O,, melting at 1382° C., is the important constit-
uent of this material. This is believed to be an actual compound
rather than an eutectic mixture, because it melts at a higher tem-
perature than the mixtures that approach it in composition. The
compound has been previously noticed by Tornebohm as a con-
stituent of cement and called by him “‘alite.” The author says
there is no great difficulty in making a constitutional formula for
the compound, and advances a provisional one containing four
rings, two of which are like the following one :

O2Ca On a:
Cin eG et =

In the opinion of the reviewer it would be preferable, since the
structure is entirely unknown, to give the simplest formula con-
sistent with valency, for example the following :

~~ O-—Ca— O-— AlL=O
Op Ca

Si< 6 Cea
be Oy Ca,

WL Oe Ora
O — Ca

“~O — Ca— O —- AlL=O

Furthermore, the formula just given has a theoretical advantage
in allowing for a simple combination with water in the setting of
the cement, while in the complicated ring formula such a combi-
nation with water would appear to be much less simple.—Zeztschr.
anorgan. Chem., 1xxili, 200. H. L. W.

4, Annual Report of the International Committee on Atomic
Weights for 1912.-The committee, CLarkKE, OstwaLp, THORPE,
and UrBaIN, give a summary of the work on atomic weights that
has been published during the past year. It deals with 18 ele-
ments, and is of considerable importance. It isinteresting to notice
that their International Table for 1912 contains 82 elements. The
single one added to last year’s table is Niton, the radium emana-
tion, to which the weight 222°4is given. The changes made since
last year are: calcium 40°07, erbium 167°7, iron 55°84, mercury
200°6, tantalum 181°5, and vanadium 51:0. HH, Ly W.

280 . Scventifie Intelligence.

=

5. The Hydrates of Sodium Carbonate.-W EGSCHEIDER has
recently discussed the compounds of sodium carbonate with water
of crystallization, and has reached the conclusion that besides the
stable salts Na, CO, .H,O (thermonatrite) and Na,CO,.10H,O,
only one unstable hydrate, Na,CO,.7H,O has been cer tainly
established. A considerable number of other hydrates have been
described, all of which appear to have been mixtures of two
hydrates or of a hydrate with mother-liquor.—Zeitschr. anorgan.
Chem., \xxiil, 256. H. L. W.

6. Canadium.—In connection with the announcement men-
tioned in this department last month, of the discovery of “ cana-
dium,” a supposed new element of the platinum group, attention |
has been called to “ amarillium,” an alleged new element discoy-
ered by Courtis in a copper carbonate ore from the Frazer Claims,
Similakameen, British Columbia, in 1903.* This was described as
having properties somewhat similar to those of ‘ canadium,” and
it was believed to form a link between the platinum-palladium
and the iron-nickel groups of metals. Nothing further has been
heard of “amarillium,” so that it may be presumed that it did
not prove to be a new element.— Chem. News, ev, 36. H L. W.

7. The Intrinsic Brightness of the Starlit Sky.—Important
researches have been made in recent years on the number and
distribution in the sky of stars of different magnitudes. The sta-
tistical data which serve as a basis for the calculations are so
difficult to obtain that it is a matter of importance to find a direct
verification of them. Such a verification may be sought by meas-
urement of the mean intrinsic brightness of the sky in different
regions of the celestial sphere. In 1903 Townley applied photo-
graphic processes to the solution of this problem, but, since his
exposures required one hour, the method recently devised and
tested by C. Fasry seems preferable and very promising.

The apparatus used is extremely simple, and it may be briefly
described as follows: A lens or telescope objective of focal
length 48°", and aperture 5°, is mounted at one end of a tube
which projects at its other end into a suitable box. ‘This box is
closed on the inside by a transverse diaphragm, which is pierced
by a circular aperture whose diameter can be varied at will and
whose center coincides with the principal focus of the telescope
objective. On the side of the diaphragm more remote from this
lens an optical system of short focus and large aperture is affixed.
Because of the réle which this system plays, Fabry calls it the
“microscope objective” and says: “It is not necessary that this
objective should have good optical qualities ; it consists, in my
apparatus, of two simple lenses, each of 20 dioptrics, forming
a system of focal distance f=3'15™, and of 3:5 usable diam-
eter.” This lens system projects on a photographic plate an
image of the telescope objective. The image is uniformly illumi-
nated and of 3™™ diameter, irrespective of the diameter of the

* Trans. Amer. Inst. Min. Engrs., xxxiii, 347.

Chemistry and Physics. 281

aperture in the diaphragm and of the distribution of stars in the
region observed. The whole apparatus forms a sort of photo-
graphic telescope, mounted on a simple, jointed support which is
furnished with levelling screws. A coudé finder, attached to the
apparatus, makes it possible to point towards any desired region
of the sky and, in particular, to center the image of a selected star
exactly on the opening of the diaphragm.

Two successive exposures are required to determine the intrin-
sic brightness of the sky. One exposure is taken when the image,
formed by the telescope objective, of a comparison star is focused
exactly on the center of the aperture in the diaphragm, the latter
being cut down to the same diameter as the image. The image
on the photographic plate is then produced solely by the light of
the star. The other exposure is made with a large aperture when
the telescope is pointed towards the region of the sky to be inves- .
tigated. In this case, the image on the plate is due to the light of
all that portion of the celestial sphere which is projected through
the aperture. By varying the radius of the aperture it is possible,
after a few trials, to obtain the same density of negative for a
certain projected area of the sky as for the comparison star, the
time of exposure being exactly the same in both cases. It is then
a very simple matter to calculate the luminous intensity of one
square degree relative to the standard star. Fabry used Polaris
for reference and found that, for the non-galactic sky, an aperture
of diameter 3°" gave satisfactory results with 10 minute expo-
sures on “Sigma” Lumiére plates. There are other ways of experi-
menting with this apparatus which depend upon the photographic
law of reciprocity; but it seems superfluous to describe them in
detail because of their obvious nature.

Fabry has tested his apparatus on two regions of the sky, one
near the star e Ursae Minoris in galactic latitude 30°, and the
other between 8 and A Cygni in the Milky Way. After compar-
ing his results with those obtained visually by Newcomb and by
Burns, he concludes that the agreement is as good as could be
expected under the circumstances. It may be remarked, however,
that there is an unexplained lack of accord between the results of
statistical investigations and of direct determinations of the in-
trinsic brightness of the sky.— Astrophys. Jour., vol. xxxi, p. 394. ©

H. 8. U.

8. Magnetische Spektren der B-Strahlen des Radiums.—It has
been shown by von Banyer, Meirner, and Haun that the “mag-
netic spectra” of the B-rays emitted by the members of the tho-
rium series are, in almost all cases, discontinuous. For B-rays
having speeds equal to, or less than, about 70 per cent of the
velocity of light the spectral bands are very well defined, but for
the very rapidly moving #-rays the images are comparatively
indefinite and “washed out.” The above named investigators
have since turned their attention to the @-rays projected on the
occasion of the disintegration of certain members of the radium
series and have obtained the interesting results summarized below.

Am. Jour. Sct.—FourtH Smries, VoL. XXXIII, No. 195.—Marcg, 1912.
19

282 . Scientific Intelligence.

As a consequence of previous work, by various experimenters,
on the absorption of £-rays coming from the radium family, it
was expected that three groups of bands, pertaining respectively
to Ra, Rab, and RaC, would be found in the magnetic spectrum.
A photographic negative obtained with the active deposit of
radium, when a field of about 107°5 gauss was used, showed 9
bands for the B-rays in addition to the single stripe which was
produced by the practically undeviated a-rays. On another nega-
tive, corresponding to a field of 215 gauss, it was possible to
measure the magnetic linear dispersion of 7 B-ray stripes or bands.
The greatest deviation was, in this case, about 5™™. The nega-
tive is reproduced in the paper and most of the bands show quite
distinctly. By appropriate, and rather obvious methods, the
authors identified the rays which pertain to radium B and C
respectively (both of these ‘‘ elements” being present in the active
deposit). For radium C there were four discrete pencils of B-rays
having speeds of 98, 94, 86, and 80 per cent of the velocity of
light. Radium B was associated with the following speeds :
74, 69, 63, 41, and 36 per cent of 3X10" cm/sec, Lastly, the
magnetic spectrum of radium itself was investigated. The repro-
duction of the negative shows two well-separated stripes corre-
sponding approximately to speeds of 65 and 52 per cent of the
velocity of light. In conclusion it may be remarked that additional
interest attaches to this series of experiments because in the earlier
investigations of Kaufmann, Bucherer, and others the discontinuity
of the magnetic spectrum had not been detected.— Physikal.
ZLischr., Dec. 1, 1911. H. S. U.

9. The Production of Characteristic Réntgen Radiations.—In
an earlier paper R. WuippineTon gave a detailed account of his
investigation of the production and properties of soft Réntgen
radiation (Proc. Roy. Soc., vol. 1xxxv, pp. 99-118). He has since
extended his research on X-rays to the chief properties of charac-
teristic radiations. These properties may be stated as follows :
(a) It is only when the primary rays contain a constituent more
penetrating than the characteristic to be excited that the stimu-
lation can be effected. (b) The penetrating power of a charac-
teristic radiation increases with the atomic weight of the emitting
element. (The adjectives “ homogeneous” and “ fluorescent” are
often used, in this connection, in place of “ characteristic.”) The
experiments described define the quality of the softest primary
radiation which can stimulate a characteristic, in terms of the
speed of the cathode rays within the exciting X-ray tube.

Certain parts of the apparatus used merit a brief description.
The cathode rays were produced in a discharge tube which was
fitted with aspecial hardening device (loc. cit.). By this means the
speed of the cathode rays could be instantly changed to almost
any desired value without altering the gas pressure. 'The cathode
rays were admitted through a horizontal, radial tube into a brass
cylinder whose axis of revolution was horizontal. The outside of
this cylinder was wound with a solenoid so that a uniform mag-

Chemistry and Physies. 283

netic field would be established at right angles to the incoming
cathode rays when a steady current flowed through the solenoid.
These rays were spread out into a ‘magnetic spectrum” since
they possessed different speeds ; each speed corresponding to a
circular trajectory lying in a vertical plane and having its center
in a vertical line tangent to the cylinder near the mouth of the
inlet tube. The cylinder was provided with a vertical, radial out-
let tube which opened into the cylinder at its lowest element of
surface and in the plane of the magnetic fan or spectrum. Oon-
sequently only such rays as were deviated through about one
right angle could escape from the cylinder. By varying the cur-
rent in the solenoid and by altering the hardness of the discharge
tube it was possible to send through the outlet tube a pencil of
cathode rays containing approximately one speed, this speed
being of practically any desired value. The emergent pencil
entered a Faraday cylinder, impinged upon an inclined, silver
anticathode and excited the primary X-rays. A.beam of these
Rontgen rays was allowed to pass through a thin aluminium
window and to fall upon a plate of the secondary radiator under
investigation. The actual measurements were not novel and
therefore further experimental details would be superfluous.

The elements employed as secondary radiators were aluminium,
chromium, iron, nickel, copper, zinc, and selenium. For each
secondary radiator a curve was plotted with abscisse proportional
to the fourth power of the speed of the cathode rays which gave
rise to the primary X-rays. The ordinates were proportional to
the energy of the secondary Réntgen rays. In general, the por-
tions of the graphs nearest to the axis of abscissas are decidedly
curved, being concave towards the axis of energy. As soon as
the energy attains a certain value, depending upon the material
of the secondary radiator, the graphs change into straight lines
and continue to be straight for all higher values of the speeds of
the cathode rays. The curved portions of the graphs are ascribed
to scattered Réntgen radiation whose absorption coefficient dimin-
ishes as the speed of the cathode rays increases. Special care
was taken to determine from the graphs the critical values of
the speeds, that is, to determine the points at which the graphs
change from curves into straight lines.

The results of this series of experiments may be summarized as
follows: (a) ‘‘ The energy emitted in the form of Réntgen radi-
ation by a cathode particle when suddenly stopped is proportional
to the fourth power of its velocity.” (b) ‘The primary rays from
a Rontgen ray tube can only excite the radiation characteristic
of a radiator of atomic weight w when the velocity of the parent
cathode rays exceeds wX10°cm/sec.” ‘This law holds fairly
closely for the radiators Al, Cr, Fe, Ni, Cu, Zn, and Se.”

Result (a) was deduced theoretically by Sir J. J. Thomson
_ and published in the Philosophical Magazine for August, 1907.—
Proc. Loy. Soc., vol. Ixxxv, p. 328, 1911. HL, Si Ue

10. Weitere Messungen tiber Wellenlangennormaleim Hisenspek-
trum.—It was resolved in 1907, at the Meudon meeting of the

284 ' Scientific Intelligence.

International Union for Solar Research, to take as secondary stand-
ards of wave-length the means of the data obtained by interfer-
ometer methods at three independent laboratories, The radiations
were to be obtained from the iron are under specified condi-
tions, and the primary standards were to be the three cadmium
lines sine had been measured with an extremely high degree of
accuracy, first by Michelson and later by Benoit, Fabry, and
Perot. Fabry and Buisson, at Meudon, determined the’ wave-
lengths of 115 lines (chiefly due to iron), from 2 2373°737 to
A 6494994. Eversheim at Bonn and Pfund at Johns Hopkins
took up independently the same problem. The final means of the
three sets of determinations were tabulated in the Astrophysical
Journal for October, 1910, These means comprised 49 lines from
XN 4282°408 to d 6494993 inclusive. At this time the wave-lengths
of the ultra-violet lines as determined by Fabry and Buisson had
not been verified by Eversheim and Pfund.

Very recently Eversurem has published the wave-lengths of
26 iron lines from » 3370°787 to A 4282°408. In order to work in
the ultra-violet the glass portions of the apparatus were replaced
by quartz. The interferometer plates were obtained by subject-
ing the quartz to a special process of fusion and pressing. A
noteworthy improvement in the interferometer proper consisted
in making the emergence “plate” in the form of a plano-convex
lens, which was half-silvered on the plane surface, of course.
This device did away with one lens and minimized several pos-
sible sources of error. Another improvement was made in the
silvering process. Eversheim says that the receipt was sent to
him in a private communication from Pfund. The details are
given in the paper under consideration. The cadmium and iron
radiations were photographed simultaneously. Finally, the cor-
rections for the variations with wave-length of the change of
phase on reflection were very carefully determined by studying
the interference curves of equal thickness, so-called.

The extremes of the probable errors of the newly measured
lines are given as 0:0002A and 0:0010A. The greatest arithmet-
ical difference between the wave-lengths of the same lines as
determined by Fabry and Buisson and by Eversheim amounts to
0-003A, while the simple average of the numerical differences only
equals 000144. Five wave- lengths have identically the same
values. The interferometer method seems, therefore, to be about
as reliable in the ultra-violet as in the visible spectrum. Evers-
heim expresses the hope of extending his table up to A 2300 as
soon as possible.—Ann. d. Phys., No. 15, 1911. HOS: Ut

ll. The Sun’s Energy-Spectrum and Temperature.—The distri-
bution of energy in the solar spectrum outside of the earth’s
atmosphere has been deduced by C. G. Assor from the spectro-
bolometric observations made at Washington, Mount Wilson, and
Mount Whitney during the interval 1903 to 1910. The corre-
sponding means obtained at each of these three stations agree
with one another as well as do the constituent data used to calcu-

Chemistry and Physics. 285

late the means for any one observatory. ‘The mean intensities of
radiation have been investigated for 18 wave-lengths comprised
between, and inclusive of, the limits 0°30 » and 2°50 yp. The solar
energy-spectrum is plotted together with the theoretical curves
for a black body at temperatures of 6200° and 7000° absolute
Centigrade. For the adopted mean spectrum-energy-curve the
maximum of energy falls at 0°470 wu.

Using the Wien displacement formula, d,,T=2930 (A,,=0°470,),
the effective solar temperature is found to be 6230° absolute Cen-
tigrade. If, on the other hand, the Stefan formula for total radi-
ation, E=76'8x10—" I, be employed, the aforesaid temperature
comes out 5830° absolute. (In making this calculation Abbot

uses the following numbers: solar radius = 696 x 10° km, mean
radius of earth’s orbit =14,956 ¥ 10° km, and the solar constant =
1922 calories per cm* per min.) In his summary Abbot says :
“The conclusion is drawn from the observations cited that the
sun’s emission approximates roughly to that of a “black-body” at
6000° absolute Centigrade, but that on account of influences prob-
ably active, we ought to assign a solar radiating temperature of
the order of 7000° absclute Centigrade.” The discussion by
Abbot of these probable sources of error is too long to be repro-
duced here; suffice it to say that, in general, these influences
would lead us to too low a value for the mean solar temperature.
— Astrophys. Jour., vol. xxxiv, Oct. 1911, p. 197. H: 8.0.
_ 12. College Physics ; by Joun OrEN RexEp and Kart Eucen
GutHE. Pp. xxviii, 622. New York, 1911 (The Macmillan Co.).
—Since the authors have deemed it wise to present the chief divi-
sions of the subject in a rather unusual sequence, it seems fair
and pertinent to make the following quotation from their preface.
“Owing to the more obvious relations existing between them, the
subject of heat is made to follow immediately after the distinctly
material phenomena of mechanics and sound ; electricity precedes
light, and the subject of radiation, usually found under the differ-
ent chapters of heat, electricity and light, is treated separately
after these subjects have been presented.” “It has also been
thought best, even at the sacrifice of historical consistency, to
begin the subject of electricity with current electricity, in order
to secure the advantage of the greater familiarity of the student
with the phenomena of applied electricity.”

Certain other salient features of the book merit enumeration.
References are frequently made, by means of unobtrusive foot-
notes, to the laboratory experiments described in Reed and
Guthe’s “Manual of Physical Measurements,” (3d edition, George
Wahr, Ann Arbor.) Numerous references to original papers
are also made in the foot-notes, to the end that the student may
acquire interest both in the historical and critical aspects of
scientific investigation. Several of these references presuppose a
reading knowledge of scientific German. ‘The text assumes an
acquaintance, on the part of the student, with a few formule
of plane trigonometry and with the calculus notation of deriva-

286 ; Scientific Intelligence.

tives. The table of contents is followed by a convenient list of
the 20 tables of physical constants which are distributed through-
out the volume. 294 problems, with the numerical answers given,
are placed immediately after the explanations of the principles
which they involve.

Attention should be called to the fact that in certain minor
details the authors diverge from custom, just as the above quota-
tion shows that they have done in the arrangement of the general
subject-matter. For example, speed and velocity are differen-

tiated respectively by the symbols v and v. Formule for
uniformly accelerated motion are written with double signs, as
“s=v,ttat*/2”, thus giving to “a” an arithmetical rather
than an algebraic significance. Thesame preference for arithmetic
over algebra is emphasized by the authors’ italics in the follow-
ing sentence of page 417: “The potential, due to all the charges,
is simply the arithmetical sum of the potentials due to the in-
dividual charges.” ae = Gest Oi

II. Grotogy AND MINERALOGY.

1. Zhe Geology of the Lake Superior Region ; by CHARLES
Ricuarp Van Hise and Cuartes KenneEtTH Leiry. Monograph
LII, United States Geological Survey. Pp. 641, pls. xlix, figs. 76.
Washington, 1911.—This work brings into one volume the results
of the studies which have been carried forward since the organi-
zation of the national survey. The great economic value of the
region, its structural complexity, and the absence of fossils have
resulted in concentrating upon it probably a greater amount of
study than upon any other area of similar size in the world.
There is displayed, furthermore, an unusually complete succession
of pre-Cambrian rock systems reaching back to the Archean,
making the region one of high general and theoretic as well as
economic interest. The authors, who more than any other men
have advanced the knowledge of Lake Superior geology, have
completed an admirable piece of work in this volume. In it is
not only collected a résumé of the descriptive geology of the vari-
ous districts, but there is given also a discussion of the genesis of
the iron, copper, and silver ores and the conditions of sedimen-
tation which prevailed through the successive periods.

The region which is discussed embraces about 181,000 square
miles and is accompanied by a general geological map on a scale
of 1 to 1,000,000. In an enumeration of certain features of the
volume, attention should be called to Chapter IV, Physical Geog-
raphy of the Lake Superior Region, by Lawrence Martin, which
deals with the several baselevels of erosion, the resulting relief,
and the origin of the present Lake Superior Basin. Chapters V
to XIV inclusive give the geology of the several iron districts.
Chapter XV contains sixty-one pages on the Keweenawan series.

Geology and Mineralogy. 287

Chapters XVII, XVIII, XIX discuss the iron, copper, and silver
ores, W. J. Mead codperating in the chapter on iron ores ; and
chapter XX gives a résumé of the general geology.

From the mass of valuable material contained within this mon-
ograph may be singled out for special mention a few points of
novel interest. As a result of studies of a theoretic nature and
laboratory experiments in addition to field observations, it is be-
lieved that the iron ores were mostly deposited as marine forma-
tions and the iron salts rapidly extracted from lavas while they
were still hot, partly from juvenile emanations. Ordinary surface
weathering seems to have played but a small part in the initial
concentration. In regard to the formation of greenalite the chem-
ical studies are especially instructive, as it was found possible to
produce artificial greenalite. The reaction of salt water upon hot
basalts or porphyries results in sodium silicate. This reacts
directly with soluble ferrous salts, for instance FeSO,, and pro-
duces a mixture of ferrous silicate aud free silica. If a soluble
magnesium salt is also present it is added to the precipitate,
explaining the presence of magnesia in greenalite. This was the
dominant original mineral and is still abundant, but secondary
concentrations have resulted from oxidizing and hydrating of the
iron minerals in place, leaching the silica, and convergence of
iron carried temporarily in solution. The hematite and magne-
tite ores are the end results.

Under the chapter on general geology may be noted the dis-
cussion as to the dominantly igneous character of the Archean.
It was followed by a period of uplift and profound erosion which
planed across the older structure. Upon this was laid down the
Lower Huronian, regarded by the authors as a terrestrial deposit
north of Lake Superior, as a series of marine formations on the
south. Following this period and separated from it and from
each other by great unconformities came the Middle and Upper
Huronian considered as dominantly marine, and the Keweenawan,
looked upon as dominantly terrestrial. The characters of many
formations change in passing from south to north, and the authors
regard this as of probable significance in the great development
of the iron ores in this region rather than over the great Cana-
dian shield. ‘The Lake Superior region, then, may be regarded
broadly as a part of a great metallographic province containing
a variety of ores associated with volcanism, which may be associ-
ated with folding along an old shore zone.” Sy Bs

2. The Hlastic-Redound Theory of Earthquakes ; by Harry
Fietpine Rep. University of California Publications, Bulletin
of the Department of Geology, vol. vi, No. 19, pp. 413-444, 1911.
—In this text, elaborated from a lecture given at the University
of California, Professor Reid presents in briefer form that theory
of the movement causing the California earthquake which he has
published in the report by the Carnegie Institution. He here
gives it a greater degree of generality and shows how certain
other earthquakes conform to the theory of a slow progressive

288 ~ Seventifie Intelligence.

movement between crust blocks with accumulating strain, the
earthquake being the result of a breaking accompanying relief of
strain and involving in the sudden movement only a limited zone
of strain between two crust blocks. J. B.

3. La Sismologie moderne (Les tremblements de Terre) ; par -
le Comte de Montessus de Ballore, Director of the seismologic
Bureau of the Republic of Chil. Pp. 284, pls. and figs. 64.
Paris, 1911 (Librairie Armand Colin).—The author of this
work is well known as a student of earthquakes, and the purpose
which he has had in writing this very readable book is indicated
in the preface. Such great catastrophes as that of Messina have
awakened a wide interest in earthquakes, but in France no popu-
lar work of an authoritative nature has previously met this
demand. as:

4. Periodic Variations of Glaciers.—The condition of gla-
clers with reference to stages of advance and retreat has been
recorded by the International Commission on Glaciers for the
year 1910 (Zeitschrift fiir Gletscherkunde, vi, pp. 81-103, Dec.
1911. In the Swiss Alps, of 54 glaciers observed, 16 show actual
or probable increase as compared with an average of 10°3 per
cent for the years between 1897 and 1909, while only 36 show
actual or doubtful decrease, as compared with 55, the average
for the 13 years previous. In the eastern Alps a single glacier on
the Wildspitze, reported as advancing in 1909, has been joined by
two others; 9 are stationary as compared with two in 1909, while
22 out of 34 under observation are known to be retreating. The
glaciers about Mt. Blane considered as a whole show a decrease.
The five glaciers observed in Sweden have advanced and the
measurement of the Norwegian glaciers gives the following
results: Jotunheim, 4 advancing, 23 retreating; Folgefond, 2
advancing; Jostedalbrae, S advancing, 6 decreasing; Okstind
Mountains, 4 increasing, 2 decreasing.

In North America the few glaciers reported from the Rockies
and the Cascades, also a number north of Juneau and near the
headwaters of Copper River, are retreating, while in the Fair-
weather range in the Yakutat Bay region and on Copper River
the glaciers exhibit an advance. ‘The advance of 9 glaciers in the
Yakutat Bay region is believed to be due to accessions from
avalanches resulting from the earthquakes of September 1899.
The glaciers about Prince William Sound give some indication of.
a general but not very large advance.

This record of glaciers for 1910 needs to be supplemented by
reports from other parts of the world, but the data at hand indi-
cates that while there is no general advance yet the decrease in
length and mass of existing glaciers which has been continuous
for the past two or three decades is not being maintained.

H. E. G.

5. Interpretation of Peneplains.—The studies of Mr. E. C.
ANDREWS in the analysis of corrasion and the interpretation of
topographic forms carved by water and by ice are important con-

Geology and Mineralogy. 289

tributions to the science of physiography. In a recently pub-
lished paper, Erosion and its Significance (Jour. and Proc. Royal
Soc. N. 8. Wales, xlv, pp. 116-136, 1911) the factors involved
in the interpretation and correlation of peneplains are discussed.
The conclusion reached is expressed as follows : ‘‘ Whenever two
peneplain or [old age] surfaces are found associated in resistant
rock structures, such as granites, crystalline schists, and dense
quartzites or sandstones, and the two such surfaces are situated
one above the other and the two are separated by a youthful or
mature topography, it may be considered that they were formerly
continuous, but are now discontinuous, owing to earth processes
other than those due to erosive activities. Such earth -processes
may be either warping or faulting. This is absolutely irrespec-
tive of any irregularity of plan possessed by the youthful topog-.
raphy separating the two peneplains.” (p. 131).

Mr. Andrews announces that a paper on the physiographic
criteria of faulting is in preparation. H. E. G.

6. Australia in tts Physiographic and Economic Aspects ; by
GRIFFITH Taylor. Pp. 256; 60 figures. Oxford, 1911 (Claren-
don Press).—The continent of Australia receives scant treatment
in standard atlases and reference books. Much of the published
‘geology and geography consists of detailed studies of discon-
nected areas and the economic studies are in large part statisticat.
The book by Mr. Taylor will therefore find a place among geog-
raphers and other students interested in the relation of man and
his activities to the topography, climate and products of the
region in which he dwells.

Chapters I-XI treat of Physiographic Aspects, including cli-
mate, vegetation, and regional treatment of physiographic prov-
inces. Economic Aspects are discussed in Chapters XIUI-X XIV,
under the headings : stock raising, agriculture, mining, transport,
and minor industries.

As regards possibilities for settlement, the combined Australian

provinces are divided as follows: Arid, 44 per cent—244 per
cent useless, 193 per cent useless in bad seasons; 17 per cent
suited for tropical agriculture ; 39 per cent suited for profitable
white settlements, i. e. 28 per cent good pastoral land, 11 per
cent good farming land. When the geographic conditions are
viewed as a whole, it is considered possible that the present popu-
lation of 5,000,000 may reach 19,000,000 before the close of the
century. H. E. G.
_ 7. Canada, Department of Mines ; Wiitiam TEMPLEMAN,
Minister of Mines.—The list given below includes the publications
of the Canadian Department of Mines received since the last
enumeration (vol. xxxi, p. 574). (1) In the GroLocicaL SuRVEY
Branou, R. W. Brock, Director :

Summary Report of the Geological Survey Branch of the
Department of Mines for the calendar year 1910. Pp. 314; 8
figures and 1 map.

Report on a part of the North West Territories drained by the
Winisk and Attawapiskat Rivers; by Writtiam McInnzs. Pp.
58; 5 plates, 1 map.

290 ~ Serentifie Intelligence.

Report on a Traverse through the southern part of the North
West Territories from Lac Seul to Cat Lake in 1902 ; by Airrep
W.G. Witson. Pp. 25.

Memoir No. 4. Geological Reconnaissance along the Line of
the National Transcontinental Railway in Western Quebec ; by
W.J. Witson. Pp. 56; 5 plates, 1 map.

No. 9-E. Bighorn Coal Basin, Alberta; by G. S. Mattocu.
Pp. 66 5; with one map.

No. 10. An Instrumental Survey of the Shorelines of the
Extinct Lakes Algonquin and Nipissing in Southwestern Ontario;
by J. W. Gotpruwair. Pp. 57; 4 plates, 4 maps.

No. 11—T. Triangulation and Spirit Leveling of Vancouver
Island, B. C., 1909 ; : by R. H. Coapman. Pp. 31, with one map.

No. 15—P. On a Trenton Echinoderm Fauna at Kirkfield,
Ontario ; by FRANK SPRINGER. Pp. 68; 5 plates, 3 figures,

No. 16—E. The Clay and Shale Deposits of Nova Scotia and
Portions of New Brunswick ; by Hxrnricu Riss, assisted by .
JosEPH KEELE. Pp. 155 ; 32 plates, 16 figures.

Also several geological maps of Lake Timiskaming, ete.

(2) In the Mines Brancu, A. P. Low, Deputy Minister,
EuGENE HaAanet, Director, the following :

Summary Report of the Mines Branch for the calendar year
ending December 31, 1910. Pp. ix, 243; 16 plates, 1 figure,
1 map.

Special Reports on the following: Gypsum Deposits of the
Maritime Provinces ; by Witi1am FE’. JENNIson. Pp. 171, with
36 plates, 19 figures, and 3 maps.

On the Molybdenum Ores of Canada; by T. L. WaLker. Pp.
64, with 14 plates and 10 figures.

Western Portion of Torbrook Iron Ore Deposits, Nova Scotia;
by Howextts Fecurerrr. Pp. 13; 4 plates, 1 map.

Also Reports for 1910, by Joun McLetsu, Chief of the Division
of Mineral Resources and Statistics. The Production of Cement,
Lime, Clay Products, Stone, and other Structural Materials. Pp.
60. The Production of Iron and Steel. Pp. 38. The Production
of Coal and Coke. Pp. 31. A General Summary of the Mineral
Production of Canada during the calendar year 1910. Pp. 37.
The total value of all products for 1910 is given as nearly 107
million dollars, having increased from 64 millions in 1900, 17 mil-
lions in 1890, and 10 millions in 1886.

8. On the present distribution and origin of the calcareous
concretions in coal seams, known as “coal balls” ; by M. C.
Srores and D. M. 8. Watson. Phil. Trans. Royal Soc. London,
Ser. B, vol. cc, pp. 167-218, pls. 17-19, 1907.—This very inter-
esting paper shows conclusively that the coal balls found in thin
coal beds of the “Lower Coal Measures” in Lancashire, York-
shire and Cheshire, England, were formed in situ. The general
conclusions of the authors are as follows :

‘“‘Groves of large trees with smaller herbs and ferns finding
place between and around their stems grew in the flat swampy

Geology and Mineralogy. 291.

levels between the higher ground and the sea. The water round
their roots was brackish or salt, as is the water of the mangrove
swamps to-day, and into its quiet pools and shallows twigs and
branches, stems, leaves, and fruits fell or were blown. ‘These
fragments sank into the mass of débris already saturated and
were there shut out from the atmosphere and preserved by the salt
water in which they lay immersed. Parts of the plants decayed
and thus liberated the organic carbon, which began its slow task
of reducing the sulphates and depositing them as insoluble car-
bonates. This process continued long without the entry of
impurities or the deposition of anything but plant remains, and
the rootlets of the living plants wandered among the dead ones,
finding their way even through the heart of their stems or seeds.

“‘ All the time the land was slowly sinking, and when several
feet of débris had accumulated the level sank more abruptly till
the plants were well submerged and the place where the forest
trees had lived was covered by the waters of an arm of the sea.
Over them was deposited fine mud, with the shells of Goniatites
and Aviculopecten, which lived and died in the waters. The
plant masses below were continually withdrawing the sulphates
of lime and magnesium from the sea water and depositing them
as carbonates round-the many centres started among the frag-
ments of plants. The supply of salts was inexhaustible, for new
water mingled continually with the old and brought fresh
sources of mineral to petrify the plants. Thus in the heart of the
masses of coal were formed large and small concretions of
carbonate, some regular as balls and very large, others minute
and uniting together to form wisps or sheets of stone lying in
the coal.

SE Ee

“In the sea above, the currents carried fragments of plants
from the neighbouring land, brought by the streams from the
higher ground. These sank in the muddy floor and were grad-
ually crushed by the silt collecting above them, till they were
flattened as impressions in the beds which afterwards formed
shalesh *.*

“These drifted plants, whether their fate was to be enclosed in
the preserving nodules or to be crushed into the shales, had prin-
cipally come from regions different from those which had pro-
duced the half-formed coal now lying immediately below them.

‘“‘ Slowly they too were covered by the fine deposits which col-
lected gently over them, until the sea bottom rose again to form
anew land. All this time the plants were preserved in the coal
balls without disturbance or hurt, and although the coal-forming
débris had been pressed down into coal which was now but a foot
in thickness, they remained uncrusbed in their original form.

se ta as | heh 2

“Thus, the ‘coal balls’ in the coal are the relics of a forest
which grew quietly in the swamp in the place where they are now
found, while the plants in the shales and in the roof nodules

292 ~ Serentific Intelligence.

above had drifted out to sea from other districts and bear in the
character of their structures the impress of the different type of
land on which they lived ” (pp. 210, 212). C..8.

9. The early Paleozoic Bryozoa of the Baltic Provinces ; by
Ray 8. Basster. U.S. Nat. Mus., Bull. 77, 1911, pp. 382, pls.
13 and 226 text illustrations.—This important work on the Ordo-
vician Bryozoa of Esthonia and Sweden describes in detail 161
forms, and of these 69 are either new species or new varieties.
All of these fossils are also carefuily located in the geologic hori-
zons, and as SO many species are common to Europe and North
America, this evidence furnishes the author with excellent faunal
criteria for exact intercontinental stratigraphic correlation. On
an average about 35 per cent (or a total of 65 out of 161) of the
species are common to the Baltic area and America. On the basis
of this evidence the author has the decided advantage of all pre-
vious stratigraphers and he makes out a good case, proving his
detailed correlations, and also that the Ordovician sequence of
EKsthonia when compared with that of the interior of America is
very incomplete. His main conclusion is “that the greater part of
the Russian Ordovician section may be directly correlated with
the Black River group of America, while the Upper Lyckholm
and Borkholm limestones are the equivalents of the Richmond
group” (2).

The author then takes up a short study of the Arctic American
Ordovician faunas and finds “that the geologic section at Baffin
Land consists of Black River strata resting upon the old erystal-
line rocks, followed by an early Trenton formation equal to the
Stewartville and Prosser limestones of Minnesota, and this in turn
succeeded [apparently] unconformably by the widespread coral
zone of the Richmond group” (36). He has plotted on a paleo-
geographic map (43) all the known Arctic occurrences of Black
River and early Trenton deposits, and brings out very clearly the
striking new knowledge that the faunas entombed in these rocks
are from the Arctic ocean and that its waters and life have spread
at times during the Ordovician southward into northern Kurope
and into America as far as Tennessee. This distribution is now
established and is further borne out by the similar spread of the
Silurian faunas which Weller published many years ago showing
that they too are also largely of Arctic and North European
origin. Cpa:

10. A description of the fossil fish remains of the Cretaceous,
Eocene, and Miocene formations of New Jersey ; by Henry W.
Fow.er. Geol. Surv. N. J., Bulletin 4, 1911, pp. 192, with 108
text figures.—This work isa descriptive and fully illustrated sum-
mary of the fish remains, essentially sharks and chimeras, found
in the late Mesozoic and Tertiary deposits of New Jersey. Of
species there are over 90 (sharks 43, chimeras 21, true fishes 24,
uncertain 3), and of these but 4 are new forms. CG.) Saige

11. Types of Ore Deposits ; edited by H. Fosrzr Bain. Pp.
378, with 345 figures. San Francisco, 1911 (Mining and Scientific

Geology and Mineralogy. 293

Press).—This book is designed to present an accurate account of
the present state of opinion regarding the genesis of ores. ‘The
different chapters have been written by men each of whom is an
authority concerning the type of deposit that he describes. Many
of the papers have appeared previously in various magazines, ete.
The following list of chapter subjects with their authors is suffi-
cient proof of the character and value of the volume: Introduc-
tion by H. Foster Bain ; The Clinton Type of Iron Ore Deposits
by C. H. Smyth, Jr.; The Lake Superior Type of Iron Ore
Deposits by C. K. Leith ; Flats and Pitches of the Wiscon-
sin Lead and Zine District by H. Foster Bain ; Lead and Zine
Deposits of the Ozark Region by E. R. Buckley ; Native Copper
Deposits by Alfred C. Lane ; Cobalt District, Ontario, by 8. F.
Emmons ; Geology at Treadwell Mines by Oscar F. Hershey ;
The Saddle Reef by T. A. Rickard ; Contact Deposits by James
F. Kemp ; The Conglomerates of the Witwatersrand by F. H.
Hatch ; Replacement Orebodies and the Criteria by Means of
which they may be Recognized by J. D. Irving; Outcrop of Ore-
bodies by William H. Emmons; Some Causes of Ore-Shoots by
R. A. F. Penrose, Jr. Wan He Et

12. Brief Notices of. some Recently Described Minerals.—
MuTuMannirs is a telluride of gold and silver from Nagyag in
Transylvania. The mineral has been earlier called miillerine, gelb-
erz and weistellur and by Schrauf was referred to krennerite
(see Dana, Syst. Min., p. 104). ZGambonini, however, makes it
distinct with the formula (Ag, Au) Te; this is based upon the
following analysis by C. Gastaldi: Te 46°44 Au 22:90 Ag 26:36
Pb 2°58 = 98:28. The name is given in honor of W. Muthmann
of Munich.—Zettschr. Aryst., xxix, 246, 1911.

YTTROFLUORITE is a fluoride of caleium and the yttrium earths
described by Th. Vogt from a pegmatite in northern Norway.
It resembles fluorite in form but shows only imperfect octahedral
cleavage. The luster is vitreous ; the color yellow to brown or
green ; hardness = 4°5 ; specific gravity 3°56. An analysis gave:

F CaO Y-earths Ce-earths alk. ign.
45°54 54°89 17°35 1°68 0°15 0°67 H.O under 100°
0-22 = 120°50, or deducting O 19°17 = 101°38.
Yttrofluorite is near yttrocerite but differs in its larger percent-
age of the yttrium-earths and practical absence of water.— Cen-
tralbl. Min., 1911, 373.

EICHBERGITE is a Sulphide of copper, iron, antimony and bis-
muth from the magnesite deposits of Kichberg in the Semmering,
Austria ; it is described by O. Grosspietsch. It occurs in massive
form with indistinct crystalline structure. The color is iron-gray;
luster metallic ; hardness over 6 ; specific gravity 5°36. An analy-
sis gave :

Ss Bi Sb Cu Fe
12°74 51°53 30°00 3°62 1°45 = 99°34

The calculated formula is (Cu,Fe),8.3(Bi,Sb),S,.— Centralbl.

Min., X, 1911, 434.

294 - Serentifie Intelligence.

FERMORITE is a new arsenate and phosphate of calcium and
strontium described by G. F. Herbert Smith and G. T. Prior
from the manganese-ore deposits of India. The mineral is appar-
ently hexagonal in crystallization but occurs chiefly massive ; it
is pale pinkish white to white in color and translucent with a
greasy luster. The hardness is 5, and the specific gravity 3°518.
An analysis (Prior) gave :

As20O;5 lea Os CaO SrO F H,O insol.
25°23 20°11 44°34 9°93 0°83 cr 0°08 = 100°52

The formula deduced is analogous to that of apatite; written in
the old form it is : 3[(Ca,Sr),(P,As),O,].Ca(OH,F),. The locality
is at Sitapar in the Chhindwara district, Central Provinces, India.
It is named after Dr. L. Leigh Fermor of the Geological Survey
of India. The manganese deposits of Kajlidongri in the Jhabna
State have also afforded crystallized specimens of the rare min-
eral TELASITE.—Min. Mag., xvi, 84, 86, 1911.

THORVEITITE is a Silicate of certain rare elements (scandium 44
p. ¢, also yttrium, didymium, erbium, e¢ al.) from the Iveland
parish in the Satersdal, Southern Norway ; it is described by J.
Schetelig and named after the discoverer, O. Thorveit. It occurs
in orthorhombic crystals of simple habit, but uniformly twins.
The prismatic cleavage (73° 25’) is distinct ; the hardness is 6-7 ;
the specific gravity 3°571; color grayish green with a luster
inclining to adamantine. The mean of two analyses gave:

SiO. 42°86, R.O, 57°67, ign. 0-44 = 100-97

The prominent rare elements present are named above ; their
molecular weight is 157°1.

CHROMITITE is a supposed new chromium mineral to which
the formula Fe,O,.Cr,O, is assigned. It is described by M. Z.
Zovitschitsch as derived from sands washed down from Mt.
Zeljin in Servia. It occurs in brilliant octahedral crystals which
are feebly magnetic and have a specific gravity of 3:1; they are
insoluble in mineral acids.—Sitzungsber. Akad. Wien, cxvii (IIb),
p. 813, an Zs Koyst., 1, 83.

Ill. MisceLLAnrovus Screntiric INTELLIGENCE.

1. Fourth Report of the Wellcome Tropical Research Labora-
tories, at the Gordon Memorial College, Khartoum; Vol. A.
Medical, ANDREW Batrour, Director. Pp. 404, with numerous
illustrations, including 14 colored plates. Department of Educa-
tion, Sudan Government, Khartoum, 1911.— The Wellcome
Research Laboratories at Khartoum were founded in 1903 for
the investigation of problems connected with the development of
the Sudan. Of primary importance is the study of the conditions
of hygiene and sanitation, and the nature of the diseases affecting
the people and animals, especially the communicable diseases. A

Miscellaneous Intelligence. 295

secondary object is the study of the fungi and insects injurious to
the crops and animals, the analysis of foods, water, minerals,
ores and fuels, and all such other matters as pertain to the eco-
nomic development of the natural resources of the country.

The first of these aspects—the medical—is treated in the beau-
tifully illustrated quarto volume in hand, while the second aspect
—General Science—will be represented by a similar volume
shortly to be published.

The present book consists of some forty separate, but related,
papers dealing with the general matters of tropical hygiene and
blood examination, with special reports on the recent discoveries
relating to the diagnosis and treatment of particular diseases.
Especial attention has been given to the means of identification
and the study of the life cycles of the parasites involved, and
many new and important facts have been discovered. The
volume also includes special reports by the Sleeping Sickness and
Kala-azar Commissions.

The results of the work of the laboratories up to the year 1908
have been published in four quarto volumes, and the fact that the
important researches described in the present report have
been accomplished during the past three years emphasizes
the remarkable industry of a corps of workers under climatic and
other conditions that would seem far from ideal for the most con-
centrated effort. W. R. C.

2. Hinfihrung in die Mykologie der Nahrungsmittelgewerbe ;
von Dr. ALEXANDER Kossowicz. Pp. viii, 138; 5 plates, 21
text figures. Berlin, 1911 (Gebriider Borntraeger).

Hinfiihrung in die Mykologie der Genussmittel und in die
Gdrungsphysiologie ; von Dr. A. Kossowicz. Pp. viii, 211;
2 plates, 50 text figures. Berlin, 1911 (Gebriider Borntraeger).
The present “pure food movement” and the increased interest
in the problems of the preparation and preservation of foods
have encouraged the publication of books bearing on these topics,
in a form which shall not be too technical for others than the
extreme specialist. One of the Kossowicz monographs reviews
the nature of the microflora of various familiar products—milk
and its derivatives, meat, eggs, and fruits—together with sugges-
tions respecting the preservation of them. The second deals
with the microbiology of the fermentation industries, the manu-
facture of vinegar and mustard, tobacco fermentation, and the
biological factors involved in the preparation of coffee, tea, cocoa
and vanilla for the market. Though unembarrassed by extreme
details, the subject matter is obviously intended for individuals
possessed of some scientifle and technical training rather than for
the layman. An extensive bibliography is included in each
volume. i Ba Me

3. Principles of Human Nutrition. A Study in Practical
Dietetics ; by Wurman H. Jorpayn, Director of the New York
Agricultural Experiment Station. Pp. xxi, 450. New York,
1912 (The Macmillan Company).—The book is intended to

296. . . Seientifie Intelligence.

supply a rational basis for practical dietetics. With this end in:
view the entire field of the nutritive phenomena—digestion,
absorption, metabolism—is reviewed in relation to the anatomical
parts of the body and physiological processes involved. The
chemical nature of the foodstuffs and the transformation which
they experience prior to their utilization by the organization are
discussed. From the popular standpoint—and to this the volume
is especially intended to contribute—the applications of the scien-:
tific facts to correct dietary habits are presented in a form
acceptable to those with limited scientific training. There are
many elements of novelty, various unique view-points, and evi-
dences of the up-to-date character of the compilation everywhere.
The addendum of analyses of American food materials gives an
added practical value to the volume. L. B. M.

4. Ostwald’s EKlassiker der exacten Wissenschaften. Leipzig,
1911 (Wilhelm Engelmann).—The following are recent additions
to this valuable series of scientific classics :

No. 181. Méchain und Delambre: Grundlagen des dezimalen
metrischen Systems oder Messung des Meridianbogens zwischen
Breiten von Diinkirchen und Barcelona.

Borda und Cassini: Versuche tiber die Lange des Sekunden-
pendels in Paris. In Auswahl tibersetzt und herausgegeben ; von
Dr. WaAtTER Brock. Pp. 200.

No. 182. Vollstindigere Theorie der Maschinen, die durch
Reaktion des Wassers in Bewegung versetzt werden; von
L. Eurer. Herausgegeben von Ernest A. Braver und M.
WINKELMANN. Pp. 94.

aguee Fas SEE = Z|
OBITUARY.

Professor GEORGE JARVIS BrusH, an assistant editor of this
Journal from 1863 to 1879, died at his home in New Haven on
February 6 in his eighty-first year. He was appointed Professor
of Mineralogy in the Sheffield Scientific School of Yale University
in 1864, and became Director of the School in 1872. In 1898 he
retired from active service but remained President of the Sheffield
Trustees until his death. A notice of Professor Brush is deferred
until a later number.

Sir Joseru Lisrer, famous for his discovery of the antiseptic
treatment in surgery, died in London on February 11 at the age of
eighty-five years. He served as Professor of Surgery in Glasgow
and Edinburgh Universities, and in King’s College, London.

CHARLES GILBERT WHEELER, the chemist and mining geolo-
gist, died on January 30 at the age of seventy-five years.

Mr. J. B. Epovarp Bornet, the eminent French phycologist,
died at Paris on December 18, at the age of eighty-three years.

oe /
age
Ete

New Circulars.

84: Eighth Mineral List: A descriptive list of new arrivals,
rare and showy minerals.

85: Minerals for Sale by Weight: Price list of minerals for
blowpipe and laboratory work.

86: Minerals and Rocks for Working Collections: List of
common minerals and rocks for study specimens; prices
from 1% cents up.

Catalogue 26: Biological Supplies: New illustrated price list
of material for dissection; study and display specimens;
special dissections; models, etc. Szxth edition.

Any or all of the above lists will be sent free on request. We are
constantly acquiring new material and publishing new lists. It pays to
be on our mailing list. .

Ward’s Natural Science Establishment.
76-104 Cotnuck AvE., Rocurstrer, N. Y.

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A Supply-House for Scientific Material.

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DEPARTMENTS:

Geology, including Phenomenal and Physiographic.
Mineralogy, including also Rocks, Meteorites, ete.
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Zoology, including Osteology and Taxidermy.

Human Anatomy, including Craniology, Odontology, ete.
Models, Plaster Casts and Wall-Charts in all departments.

Circulars in any department free on request; address

: Wards Natural Science Establishment,
; 76-104 College Ave., Rochester, New York, U.S. A.

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Page
Art. XX.—Mineral Sulphides of Iron; by E. T. Aten,
J. L. Crensuaw, and J. Jonnston; with Crystallo-
graphic Study, by HOS. baRsen 220/22 = eee 169 ©

Geologic Formations in the United States ; by W. Bowre 237 -

X XIT.—Association of Native Gold with Sillimanite ; by T.
LL. WATSON * 322 eS es ee ee 241

X XITI.—Hecker’s Remarks on Ocean Ce Observations ;
by L. AU Baunr 5: 246 2s ee 945

XXIV.—Relations of the Degree of Metamorphism to Geo-
logical Structure and to Acid Igneous Intrusion in the
Narragansett Basin, Rhode Island; by F. H. Lannr___ 249

XXV.—Ilmenite Rocks near St. Urbain, Quebec; A New
Occurrence of Rutile and Sapphirine ; by C. H. Warren 263

SCIENTIFIC INTELLIGENCE.

|

XXI.—Some Relations between Gravity Anomalies and the

Chemistry and Physics—Quantitative Determination of Manganese, Rarkow
and TiscHkow: A Pernitride of Carbon, G. Darzrens, 278.—Portland
Cement, EK. JANeEcKE: Annual Report of the International Committee on
Atomic Weights for 1912.—Hydrates of Sodium Carbonate, WEGSCHEIDER :
Canadium : Intrinsic Brightness of the Starlit Sky, C. Faspry, 280.—Mag-
netische Spektren der 6-Strahlen des Radiums, 281.—Production of Char-
acteristic Réntgen Radiations,. R. WHIDDINGTON, 282.—Weitere Messungen
tiber Wellenlangennormale im Hisenspektrum, EVERSHEIM, 283.—The Sun’s
Energy-Spectrum and Temperature, C. G. ABBoT, 284.—College Physics,
J. O. Reep and K. E. Gurus, 289.

Geology and Mineralogy—Geology of the Lake Superior Region, C. R. Van
Hise and C. K. Leitu, 286.—Elastic-Rebound Theory of Earthquakes, H.
F. Rein, 287.—La Sismologie moderne, Comte de MONTESSUS DE BALLORE :
Periodic Variations of Glaciers: Interpretation of Peneplains, E. C.
ANDREWS, 288.— Australia in its Physiographic and Heonomic Aspects, G.
TayLoR: Canada, Department of Mines, 289.—The present distribution
and origin of ‘‘ Coal Balls,” M. C. Stopes and D. M. S. Watson, 290.—
Early Paleozoic Bryozoa of the Baltic Provinces, R. S. Basster: Fossil
Fish remains of the Cretaceous of New Jersey, H. W. Fowuer: Types of
Ore Deposits, H. F. Bain, 292.—Brief Notices of some Recently Described
Minerals, 293.

Miscellaneous Scientific Intelligence—Fourth Report of tho Wellcome Tropi-
cal Research Laboratories, A. BaLrour, 294.—Einfihrung in die Mykol-
ogie, A. Kossowicz: Principles of Human Nutrition, W. H. Jorpan, 295.
Ostwald’s Klassiker der exacten Wissenschaften, 296.

Obituary—G. J. Brusu: J. Lister: C.G. WHEELER: J. B. E. Borner, 296,

ay . ° ° ase es ; A
~ Smithsonian Institution. A-pd

Syl. XXXII. | APRIL, 1912.

. Established by BENJAMIN SILLIMAN in 1818. .

THE

AMERICAN
JOURNAL OF SCIENCE.

Epiror: EDWARD S. DANA.

pe \

ASSOCIATE EDITORS

Prorressors GEORGE L. GOODALE, JOHN TROWBRIDGE,
W. G. FARLOW anp WM. M. DAVIS, or Cameprince,

Prorressors ADDISON FE. VERRILL, HORACE TI, WELLS, |
LOUIS V. PIRSSON, HERBERT Ff. GREGORY
AnD HORACE S. UHLER, or New HAVEN,

Prorzssor HENRY S. WILLIAMS, or Inuaca,
Proressorn JOSEPH S. AMES, or Battimore,
Mr. J. S. DILLER, or Wasuineron.

| FOURTH SERIES
VOL. XXXIII-[WHOLE NUMBER, CLXXXIIL]
No. 196—APRIL, 1912. 2

WITH PLATES J \ND II, °

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egistered letters, or bank checks (preferably on New York banks).

NEW ARRIVALS.

The following is a brief list of the most important specimens recently
received :

Native antimony, massive and polished sections, White River, Cal.

Awaruite, metallic pebbles, Smith River, Cal.

Obsidian, black, brown and red, Smith River, Cal.

- Hanksite, loose crystals, San Bernardino, Cal.

Andalusite, var. Chiastolite, polished matrix specimens with beautiful
markings, also polished loose xls., Fresno Co., Cal.

Californite, Fresno Co., Cal.

Chalcedony and Opal, San Benito, Cal.

Stibiotantalite, Mesa Grande, Cal.

Calaverite; Cripple Creek, Colo.

Pink quartz xls., near Aibuquerque, N. M.

Nytramblygonite, Cafion City, Colo.

White Labradorite. also cut cabachon and brilliant, southern Oregon.

Opalized Wood with sparkling veins of gem opal, Northern Humboldt,
Nevada. .

Waringtonite, new occurrence, formerly found in Cornwall, Eng.;.also in
combination with aurichalcite, Smithsonite, azurite and brochantite, Dry
Cafion, Tooela Co., Utah.

Brochantite, Azurite, Smithsonite, Aurichalcite, Malachite, Dry Cafion,
Utah.

lodyrite, Nevada.

Zincite and Pyrochroite, eae eale specimen, Franklin Furnace, N. J.

Gageite with Zincite-leucophoenicite, Frankiin Furnace, New J ersey.

Lapis Lazuli, polished slabs, Baikal, Siberia.

Malachite, polished specimens, Ural Mts.

Emeralds, fine specimens in matrix, Ural Mts.

Alexandrite, Golden Beryl, Aquamarines, Ouvarovite, Perovskite, Pyro-
morphite, Ural Mts.

Dioptase, Khirgese Steppes, Siberia.

Semsyite, xlzd., Felsobanya.

Hessite, Botes, "Hungary.

Stephanite and Pyrargyrite, Hungary.

Blue Chalcedony, xlzd., Hungary.

Stibnite specimens and with barite, Hungary.

Herrengrundite, Herrengrund, Hun gary.

Cinnabar, very choice, with dolomite and white quartz, China.

Cinnabar, Spain and California. -

Stibnite and Bismuth, Japan. :

Kroknkite, large specimens, Chili.

Proustite, Chili and Bohemia.

Octahedrite, Rathite, Cyanite, Anatase, Switzerland.

Argyrodite, Saxony.

Liroconite and Tennantite, Cornwall, Eng.

Millerite, Westphalia.

Embolite and Stolzite, New South Wales. :

Opal bird bones and opal shells, N. S. W.

Cerussite, New South Wales.

Phenacite, gem xls., Brazil.

Tourmalines, Brazil; Mesa Grande, Cal.; Elba; Madagascar ; Maine.

Synthetic gems; rubies; blue, white, yellow and pink sapphires, all sizes.

Further information and prices furnished on request.

> et
=

A. H. PETEREIT,
-81—83 Fulton Street, New York City.

Am. Jour. Sci., Vol. XXXII], 1912.

Plate I,

SACSAHUAMAN |
SS | genie

YALE PERUVIAN EXPEDITION

CUZCO
AND
ENVIRONS
SURVRYRD AND DRAWN

hy
KAT HENDRIKSEN
RR Statton |) +

4
moor: W

PE

AMERICAN JOURNAL OF SCIENCE

“(FOUREM SERIES. |

soe

Art. XXVI.—The Discovery of Pre-lMstoric Human
Remains near Cuzco, Peru; by. Hiram Bineuam, Director
of the Yale Peruvian Expedition. (With Plates I and II.)

Tur Yale Peruvian Expedition was organized to do archzeo-
logical, geographical, geological, and topographical reconnais-
sance. We spent the first part of July, 1911, in and about
Cuzco. On the morning of July 6, while walking up a gulch
called Ayahuaycco quebrada west of Cuzco (fig. 1), in company
with Professor Harry W. Foote, the collector- naturalist of the
Expedition, and Dr. William G. ‘Er ving, our surgeon, I noticed —
a few bones and several pieces of pottery interstratified with
the gravel bank of the gulch and apparently exposed by recent
erosion. This led me to examine both sides of the gulch very
carefully. A hundred yards above the point where the first
bones were noticed we found that erosion had cut through an
ancient ash-heap containing a large number of fragments of
bones and pottery. Still farther up the gulch and on the side
toward Cuzco I discovered a section of stone wall built of
roughly finished stones more or less carefully fitted together
(fig. 2). At first sight this wall appeared to have been built to
prevent further washing away of that side of the gulch. Then
I noticed that above the wall and flush with its surface the bank
appeared to consist of stratified material, indicating that per-
haps the wall antedated the gravel deposits.

Fifty feet up the quebrada another portion of wall appeared.
Between this and the section first seen the gravel bank some-
what protruded. On top of the bank was a cultivated field.
_ In order to see whether the wall extended behind this gravel
bank, under the field, and whether the two portions were con-
tinuous, I excavated and found, after half an hour’s work on
the compact gravel, that there was more wall behind the

Am. Jour. Sc1.—FourtH SEeRies, Vout. XX XIII, No. 196.—Aprit, 1912.
20

298 . Bingham—Discovery of Pre-Historic

Mie. 4

co

Fic.1. The Cuzco Valley. The upper photograph shows the Sacsahuaman
fortress and is panoramic with the left border of the lower photograph, which
shows the Ayahuaycco quebrada.

Human Remains near Cuzco, Peru. 299

stratified sides of the gulch (fig. 3). The Prefect of Cuzco later
helped me to secure fe services of six Indians, with whose aid
we cut through the wall and found it was shear three feet

Hines

Fic. 2. Stratified gravel overlying a buried wall in Ayahuaycco
quebrada.

thick and nine feet in height, carefully faced on both sides and
filled in with rubble. As this type of stonework is not uncom-
mon in the foundations of some of the older buildings in the
western part of the city of Cuzco, and as it is usually called by

“

300 H. Bingham—IMscovery of Pre-Historic |

the inhabitants Incaic, I was at once struck by the idea that
this kind of wall must be very much older than we should be
led to suppose by our present ideas of Inca civilization. Such
a thesis would be necessary to account for a wall completely
covered over to a depth of six or eight feet by a compact
gravel bank, a bank later eroded to a depth of ten feet. Fur-

Ric. 3

Fic. 8. Portion of buried wall after partial excavation.

ther investigation in this part of the gulch revealed numbers
of potsherds and bones.

A few days later I followed the Ayahuayceo quebrada up

to its head, using a road on its east side. In various places I
was struck by evidences of ancient civilization. Ash-heaps,
recent and ancient, a stone-paved area which may have been a
threshing floor or market place, and numbers of bones and

+

Humun Remains near Cuzco, Peru. 301

Fie. 4.

Fie. 4, Ayahuayeco quebrada. Profile view of bluff in which vertebrate
remains were found. Cuzco in the middle distance. The man in the fore-
ground is standing in front of the excavation.

potsherds offered a most interesting field for speculation and
study. Ayahuayeco means “ the cadaver quebrada ” or “ dead
man’s gulch,’ or “the valley of dead bodies.” There is a

‘

302 HI. Bingham—Discovery of Pre-Historic

tradition that this valley was once used as a burial place for
plague victims in Cuzco, possibly not more than three genera-

? 4 i 2
r : ie x
: ‘ 234 SRST? *
+ oF. ae Yer AS Pe
Pag Vee 4 Pag
F »
\ F 23
Pe ( “ ; a
,

Fic. 5. The bone locality before excavation. The projecting femur first
discovered lies directly beneath the hammer. Note the stratification from
a point about one foot above the bone down to the base of the bluff.

tions ago. Such a story appears to be well borne out by the
great number of human bones that occur in thetalus slopes. I
was most anxious to see whether anything could be found defi-
nitely 2 sztw, where the stratification had not been disturbed.

Human Remains near Cuzco, Peru. 303

After proceeding up the valley for more than half a mile it
narrowed and the east side, along which I was walking, became
very precipitous (fig. 4). The road had apparently recently
been widened and this made the bank at this place practically
perpendicular. About five feet above the road I saw what at
first looked like one of the small rocks which are freely inter-
spersed throughout the compact gravel of this region. Some-

Fig. 6.

Fic. 6. The vertebrate remains after partial excavation. The photograph
shows the long narrow lense of vertebrate material and the jumbled state of
the bones. The fallen end of the femur, in the lower left-hand corner, was
originally in the stratum which the other bones occupied.

thing about it led me to examine it more closely, and I then
recognized that it was apparently the end of a human bone,
probably a femur (fig. 5).

I was at once so impressed by the possibilities, in case it
should turn out to be true that this was a human bone and had
been buried centuries ago under seventy-five or a hundred
feet of gravel, that I refrained from disturbing the bone until
I could get the geologist and the naturalist of the Expedition
to witness its excavation. Professor Isaiah Bowman, who had
already made studies in the Central Andes, and was the geolo-
gist-geographer of the Expedition, was at this time only a few
days away making a preliminary study of the Anta basin. On
his return to Cuzco Professor Bowman was requested to make
a physiographic study of the gulch in which the human remains
had been found. The results of his study are presented in a

304 LH. Bingham—Discovery of Pre-Historic 3

iG.

Fic. 7. Looking squarely at the face of the bluff. The bones were col-
lected from the excavation between the men at the foot of the hill.

separate article following this. Our topographer, Mr. Kai
Hendriksen, made a detailed map of the gulch and a rough

Am. Jour. Sci., Vol. XXXIII, 1912. Plate II.

YALE ee EXPEDITION )
Ayahuayeco Quebrada Yi

CUZCO, PERU

Surveyed and Drawn

BY
KAL HENDRIKSEN

Altitudes based on Railroad Survey

Human Remains near Cuzco, Peru. 305

sketch map of the vicinity of Cuzco, showing the relation of the
gulch to the well-known ruins in the neighborhood. These
maps are also included in the present number (Plates I and II).

On the afternoon of July 11 Professor Bowman and I exca-
vated the femur and found behind it fragments of a number
of other bones. These we took out as carefully as possible.
They were excessively fragile. The femur was unable to sup-
port four inches of its own weight, and after that much had been
excavated the exposed end fell off (ig. 6). The gravel was some-
what damp but could hardly be called moist. The bones were
dry and powdery. It is difficult to describe their color. Perhaps
“ashy grey” is as near as anything. The end of the femur,
first seen, was so like the pebbles as to be distinguished from
them only with the greatest difficulty.

Professor Foote was asked to photograph the wall, portions
of the gulch, and the location of the bones, before, during and
after the process of excavation. The accompanying illustra-
tions were nearly all taken by him (fig. 7).

The bones were carried to our hotel, where they were again
photographed, soaked in melted vaseline and then packed in
cotton batting. On my return to the States in December, the
bones were submitted to Dr. George F. Eaton, curator of
osteology in the Peabody Museum, for examination. His
report is also presented herewith (p. 325).

It was a keen disappointment that we were not able to
spend more time in Cuzco. Notwithstanding my great inter-
est in these prehistoric human remains, I felt that 1t was wiser
to carry out the plans originally adopted for the Expedition,
although that meant a hurried departure from Cuzco without
doing more than is shown by the results presented herewith.
It seems to me extremely desirable to continue the work of
exploration and excavation in and about Cuzco, for it is highly
probable that important data bearing on Inca and pre-Inca
civilization may be obtained here.

EXPLANATION OF PLATES.

PLATE Ll. Cuzco and Environs.

a: The Cathedral. 6: La Compania. c: La Merced. d: San Fran-
cisco. e: SantaClara. f: Hospital. g: Santa Ana. h: Santo Domingo.

Intersection of arrows in upper left hand corner indicates location of bone
deposit in Ayahuayeco Quebrada. Altitudes based on railroad survey.
Contour interval 20 ft. Shaded area: present limits of the city of Cuzco.

PLATE II. Ayahuaycco Quebrada.

’ BM 1: Bench mark about 100 ft. west of excavation where human and
other bones were found on roadside at base of high bluff. BM 5: Bench
mark near talus slopes, containing many bones and potsherds. BM6: Paved
area. BM ‘7: Recent ash heaps. BM 8-9-10: Location of buried wall.
WT: Watertank. g: Santa Ana church.

4

306 Bowman—Geologic Relations of the Cuzco Remains.

Art. XX VII.—(Part Il) Zhe Geologic Relations of the Cuzco

Remains ;* by Isatan Bowman.

Historic Cuzco lies at the head of one of the most beautiful
intermontane valley-basins in the Central Andes. The broad
flat basin floor is deeply cloaked with land waste which also
extends well up the bordering slopes and the tributary valleys.
High mountains rim about the basin like a gigantic wall and
their slopes m a few places lead up to summits snow-covered
during the southern winter. The upper grass-covered slopes
are the home of mountain shepherds who find in the other-
wise unoccupied lands of their bleak territory ample room
for their flocks and herds. Upon the lower slopes of the
mountains the agricultural Indian breaks a tough sod here and
there and plants his chief vegetable, the potato. Farther
down, on the fringe of alluvium, are grain fields, potato
patches, and bright green alfalfa meadows—almost all irrigated
land, intensively cultivated, and supporting a dense popula-
tion. Mae

The Cuzco basin (fig. 1) is about fifteen miles long. Its
width varies from a few hundred yards at the narrow lower
outlet of the basin to several miles a little below Cuzco. The
floor of the basin is from 11,000 to 11,500 feet above sea level.
Dozens of small streams rising in the surrounding highlands
follow steep irregular courses and furnish water to the irriga-
tion ditches. Among these the Huatanay and the Tulumaynu are
the most important. All of these streams bear down quantities
of land waste (now much less than formerly) and all have dis-
sected the marginal belt of alluvium and even the alluvial floor
of the basin, which they formerly built up. Therefore at some
time in the recent geologic past the streams of the basin have
changed from aggrading to degrading agents.

It is in one of the ravines cut into the bordering alluvium that

the gravel deposits are exposed in which the Cuzco man was
fonnd.t The present city extends up to the mouth of the
ravine as shown in fig. 4. The lower ravine appears to have
been occupied by man for a long time. Several feet from the
surface and interstratitied with the surface material are artificial
beds of wood ashes alternating with thin yellowish-brown lay-
ers of sand and gravel. It appears that when the present
slopes were being fashioned, and before erosion had gashed the
alluvium, man inhabited the region and that he has witnessed

* Tam indebted to Professors Schuchert, Gregory, Barrell, Lull, and
MacCurdy, for criticisms.

+ For an account of the discovery by Professor Bingham see the preceding
paper.

oe.

Bowman— Geologic Relations of the Cuzco Remains. 307

the change from an aggrading to a degrading surface. A
buried wall, the subject of another paper,* points in the same
direction. Far up the slopes of uninhabited though still eul-
tivated spurs one may find these ash beds, and mingled with
them are bones of many kinds, shells, charred corn and quifa,
and bits of broken pottery. Though the relations of this sort
of material to the surface in every place indicate that man has
long been an inhabitant of the region, no antiquity can be
claimed for any of that examined during the work of the
present expedition, for it all lies buried in but five or six feet
of material. It is, however, equally well stratified and shows
that the earliest ash and charcoal material was accumulated
while alluviation was still going on. This should not, however,
be confused with the strong alluviation of the elacial period.
The ash material is interstratified with lower, younger, and
thinner alluvium whose lowermost layers may be not more
than a few thousand years old.

Evidences of man’s existence in the Central Andes in late
glacial or early post-glacial time were reported by the writer
several years ago.t From the position of certain abandoned
trails and ruined corrals in the Huasco basin and from the
nature of associated strand lines and terraces, it is certain that
man lived in the region in early times and that he was contem-
poraneous with a large lake where there are at present only a
few scattered ponds and marshes. We have now from the
Cuzco basin the actual remains of man found embedded in
gravels of still earler date. The following paragraphs deal
with the geologic and geographic character of the gravel beds
in point. “Te their age can be fixed we shall also be able to tell
the age of the remains interstratified with them.

Summary of Results.

A brief summary of the chief features of the case will serve
to guide the reader in his interpretation of the details of the
problem.

The bones found near Cuzco were contemporaneous with the
compact gravels in which they were embedded. They were
disposed in the form of a lense about 10 feet long and 6 inches
thick. From (1) their disposition with respect to each other,
(2) their relations with the bedding planes, and (3) their worn
condition, it 1s concluded that they were interstratified with the
gravel beds. The age of the beds thus becomes the critical
factor in the interpretation. From a detailed study of the

‘* A buried wall at Cuzco: Its climatic significance and its relations to
the question of a Pre-Inca Race.

+ Isaiah Bowman, Man and Climatic Change in South America, Geog.
Journ. (London), March, 1909, pp. 268-278.

308 Bowman—Geologic Relations of the Cuzco Remains.

geology of the upper Cuzco basin with special reference to
glacial forms, it is concluded (1) that the beds belong toa
elacial series, (2) that the bones were deposited during a period
of pronounced alluviation, and (8) that since the deposition of
the bones from 75 to 150 feet of gravel were deposited over
them and later partly eroded. The age of the vertebrate
remains may be provisionally estimated at 20,000 to 40,000
years.

The weaknesses of the case lie in the following facts: (1)
Certain vertebrate remains* found associated with the human
bones may be referred to bison, but they are not sharply dif-
ferentiated from the bones of modern cattle. Bison remains
have not been found either in other places in the Central
Andes or elsewhere in South America. The distinctions
between these fragmentary bones and those of modern eattle
are not sufficiently well-marked to enable one to say absolutely
that they could not be bones of domesticated eattle. Further-
more, certain canine bones gathered in connection with the
human remains cannot be said to be unlike those of the
modern domesticated dog. While both these pieces of evidence
are negative in character and do not actually disprove the case,
they raise wholesome doubts that can not be dispelled save by
further field work, especially excavation. (2) In the second
place, there is one untested possibility and until that test is
applied the case cannot be said to be proved absolutely. It is
within the limits of possibility, although it still seems very
unlikely, that the bluff in which the bones were found may be
faced by younger gravel and that the bones were found in a
gravel veneer deposited during later periods of partial valley
filling. Until excavation is carried on, the interpretation must
rest, not upon all the facts, as X, but upon X-1 facts. Indeed
excavation may show that ‘the facts in hand are really xX or
X-3 in number.

Criteria.

In determining the age of buried human remains account
must be taken of two guiding principles :

(1) The remains and the beds in which they are found must
be proved to be contemporaneous.

(2) The age of the beds must be determined by independent
means.

The possibility of landslips, of recent changes im the beha-
vior of streams, and of burial by human hands or by ani-
mals, must be considered in minutest detail. This is forced

* For both the nature of the vertebrate material and the characteristics

of the individual bones see the report by Dr. George F. Eaton in this number
of the Journal (p. 329).

Bowman—CGeologic Relations of the Cuzco Remains. 309

upon one not only by the rigid demands of scientific method
but also because failure to collect and interpret all data bearing
on the problem may lead to unsatisfactory conclusions and has
in fact cast doubt on the authenticity of one after another of
the reported discoveries of human remains. It is, therefore,
essential that the structure and composition of the deposits,
the conditions of burial, and the physiographic history of the
region be discussed in detail.

If human remains were common in hard rock of Tertiary or
Cretaceous age the case would be quite different. The in-
durated rock would show such clear signs of disturbance in
case of burial as to leave no one in doubt; the lapse of time
after deposition would be so great that a certain degree of
fossilization would have resulted; morphological. differences
between the buried bones and the bones of existing forms
would be distinguishable ; associated fossils world supply col-
lateral evidence as to age. Butin America the conditions are
far from this ideal. Human remains are always reported from
loose surface material ; if the material is gravel the question of
stratification arises; even if the remains are interstratified they
. show no prominent variations from existing types; and in
almost all cases no other fossils accompany the remains to
throw hght upon their geologic relations.

INTERSTRATIFICATION OF BONES AND GRAVEL.

The coarse gravels in which the Cuzco man was found are
rudely stratified in places; in other places they are very
markedly stratified. The stratification at the precise locality
where the bones lay was coarse though the pebbles range in
size from a pea to a walnut and are mixed with ordinary yellow
quartz sand. The bones themselves formed part of a stratum
of shghtly finer material, and occurred in the form of a layer
about ten feet long and six inches thick (fig. 6). Stratification
within the limits of the six-inch layer was observed. It shows
clearly in the photograph, fig. 5.

Not only were the gravels about and within the six-inch
layer disposed in a stratified manner but the bones themselves
were in positions signifying natural deposition by water rather
than artificial deposition through human burial. With refer-
ence to a vertical plane they lay in a jumbled state; all were
essentially flat with reference to a horizontal plane. One rib
lay at the extreme right end of the ten-foot limit, another at
the extreme left. Mixed with the human remains were bones
of a bison, a wolf, anda l!ama. There can be no question of
the plain facts in the case as regards interstratification.

310 Bowman—Geologic Relations of the Cuzco Remains.

We must now consider the possibility of landslip. A block
of gravel may slide by slow degrees from the top of a bluff
and come to rest at the foot with stratification intact and with
a dip in conformity with that of the beds in the undisturbed
parent mass. In such a ease it is evident that (1) between the
disturbed and the undisturbed masses a break will occur and
(2) both the material and the thickness and alternation of the
beds will show marked contrasts on the two sides of the break.
Now the bluff in which the Cuzco man was found is to some
extent ravined and broken by landslips. East of the locality a
series of small slips extend down valley for several hundred feet
with characteristics quite unlike the undisturbed condition of
the lense containing the bones. The line of separation between
them and the parent mass is everywhere ragged with both
horizontal and vertical variations. Material has been dragged
down from an upper surface and is exposed to view near the
bottom of the ravine. Such material exhibits recent unfos-
silized shells, even human bones and pieces of broken pottery,
carbonized wood and corn, and the ashes of old and long-aban-
doned hearths or camp fires.

No one who sees these clear evidences of the displacement
of material by landslips can fail to see the necessity for giving
the mass containing the human remains the most rigid exami-
nation. At first sight the immediate surroundings indeed sug-
gest a jandslip. Immediately above the stratum containing
the bones was a break in the face of the bluff about four feet
long (fig. 5). It rose in a curved line about two feet above the
layer in which the bones were disposed and suggested the
upper part of a grave, especially as the break exhibited a mould
of organic material. After the excavation work was done, as
much care was exercised in the examination of this break as in
the gathering of the bones. Upon excavation of the gravel
alone the line of the break and forward from it two facts were
discovered : (1) the break extended downward but a few inches
and merged into hard undisturbed material in which the bed-
ding planes ran apparently without interruption from within
the main gravel mass to the outer edge of the bluff; (2) the
mould consisted principally of a fungous growth mixed with
a few species ot lichens.

At tirst the mould-covered material seemed quite out of
harmony with the undisturbed structure of the gravel beneath
it, but when a larger area of bluff face had been examined a
clear explanation was afforded quite apart from the idea of a
grave. Anywhere along the faces of these gravel blufis one
may find the same material disposed in the same way. The
break afforded an opportunity for the display of the mould but
was in no way related to it. Upon the outermost surface of

Bowman— Geologic Relations of the Cuzco Remains. 311

the bluff was an earthy coating deposited from the clouds of
dust raised by the feet of passing flocks and caravans. ‘The
same gray-yellow appearance is exhibited upon all surfaces not
recently eroded. Upon removing the thin surtace of such a
bluff one comes upon what might be called an under surface
somewhat like the under layer of skin on the human body and
upon or in this are countless hosts of fungi. Their branching
filaments or hyphae ramify through every pore; by scraping
away the surface carefully one may exhibit a oreat area of
fungous- -covered gravel. Beyond the outer film of material

Fic. 8.

Flat-topped spur

Vertebrate eek

Fig. 8.* Topographic profile of ravine in which the vertebrate remains
were found, Compare with figs. 1, 4, 7, and 9. Scale: 1 inch = 200 feet,
vertical and horizontal. Shaded area represents bed rock exposed in tribu-
tary ravine. Degrees indicate declivity of ravine slopes at different eleva-
tions.

one comes in turn upon the yellow unmodified gravel free
from dust and fungi. The linear distance from the face of
the bluff to the undisturbed material is never more than two
or three inches and generally but a half inch to an inch.

The structure of the main mass of material in which the
bones were deposited may be observed in a ravine but fifty
feet west of the bone locality. The unbroken character of the
mass, its stratified condition, the fact that it les as it was
deposited with moderate inclination of the material down-
valley, its smooth upper surface (fig. 1), its compact condition,
the entire absence of recent material within the body of the
gravel,—all these are features easy of observation and about
which it would seem there could néver be any question either
as regards the facts or their interpretation.

Across the ravine from the bone locality a tributary gully
extends far into the undisturbed gravels (fig. 9); the coarse-
ness of the material, its degree of stratification, and its angle

* Wor figures 1-7 inclusive see preceding article.

‘

312 Bowman—Geologic Relations of the Cuzco Remains.

of inclination agree almost exactly with the characteristics of
the mass in which the bones were discovered. That a land-
slip of even large size should take place in such a manner as
to lead to equality of related features on opposite sides of a
ravine lies almost beyond the realm of possibilities. It is of
course possible that a break may exist of which there is no
surface indication, a break to be discovered only by extensive
excavation. Even in that event the explanation requires no

Fie. 9.

Fic.9. South side of ravine of fig. 8. Complementary to fig. 4. The
channel on the left is common to both photographs.

important modification. That the bones should be covered
with 75 to 150 feet of gravel in any position is the fact of out-
standing importance.

The progressive deflection of the stream to the north as
shown in figs. 4 and 8 has given the bluff a very steep
descent. Only a rather newly-made bluff in a dry climate
would be expected to retain for any length of time such a
sharp profile. The lower ten-foot section is almost vertical
(88°), a condition due to artificial steepening in constructing

Bowman— Geologic [relations of the Cuzco Remains. 3138

the road seen in fig. 4. From the nature of the road-bed and
the bluff it is inferred that the bluff originally had a profile rep-
resented by the broken line of fig. 8 (left, bottom). The con-
struction of the road, therefore, further steepened a naturally
steep bluff and carried the face of it back far enough to expose
one end of a buried bone. It is possible that in building the
road other associated bones were excavated and lost ; also that
much more material of a similar nature might still ‘be found.
Further excavation was impossible, however, because of other
problems and because of the desire to leave the bluff (at least
for the present) relatively undisturbed, so that interested stu-
dents might see it almost in its original condition.

PHYSIOGRAPHIC DETERMINATIONS.

When the geologic history of comparatively fresh deposits
is desired, the application of physiographic principles is indis-
pensable. Fossils may be wholly absent, or if present may be
so closely related to the existing fauna and flora as to be of
little value. In the present case we have to determine, first, a
problem in structural geology—whether or not the bones
occurred interstratified in deposits m place; and, second, and
more important, the age of the deposits as determined (1) by
the topographic forms developed on them and (2) by their geo-
graphic relations. The facts of structure are in this case rel-
atively simple. The physiographic facts and relations are
much more complex, though it is believed that they are no less
substantial and convincing.

That the reader may have a proper guide in the examination
of the evidence, I shall at once present the conclusions that the
facts in the succeeding paragraphs seem to establish :

1. The deposits in which the vertebrate remains were found
have the same age as deposits of similar composition and
topographic relations all about the borders of the Cuzco basin.

2. The deposits belong to the glacial series; and to the
latter of two main groups.

3. They were formed in a time of glaciation on the sur-
rounding highlands and of alluviation in the valleys.

4. Since the burial of the Cuzco man thick bodies of gravel
were deposited, and later eroded.

5. Since the deep erosion of the gravels there have been
two minor periods of alluviation.

6. The gravels of glacial derivation rest upon (a) deformed
_and eroded sedimentary rocks of Tertiary and Paleozoic age
and (b) igneous rock of pre-Tertiary age.

The principal geologic and physiographic relations are shown
in fio, 10. “The higher summits and intermediate slopes are

Am. Jour. Scr. —Fourti SERIES, Vou. XXXII, No. 196.—Aprit, 1912.

2

x

314 Bowman—Geologic Relations of the Cuzco Remains.

developed upon pre-Tertiary rock. Tertiary strata underlie
the benchland of the middle distance and appear as alternating
light and dark bands in fig. 18. Upon the Tertiary shales,
clays, and sandstones are the glacial gravels and sands. They
consist of a finer, older series, overlaid by a coarser, younger
series ; and both are now in process of dissection. ‘Not only

Races 0!

Fie. 10. Distant snow-capped mountains, part of Cuzco Valley in middle
distance, and two series of glacial deposits, with unconformable relations, in
the foreground.

the differences of composition, but also the line of separation
between the two series of gravels may be clearly seen in fig. 10.

The glacial gravels of the Cuzco basin occur on all of the
lower and most of the higher valley slopes and floors. They
lie upon older eroded rock and are themselves being eroded at
a rapid rate to-day no matter what their position. It follows
that they represent a period in which erosion was halted upon

all those slopes and on the floors of all those valleys on which

fi

Bowman— Geologic Relations of the Cuzco Remains. 315

they lie. They could not have been formed under present
conditions, for they are being eroded by the existing streams.
They were formed during a time when waste was being shed
from all of the higher valley heads and mountain slopes and
collected principally on the lower slopes. Wherever the
gravel deposits are traced into the higher valleys they may be
seen to interlock or interfinger with glacial deposits—actual
moraines or irregular masses of unstratified material. The
interlocking relation is observable at a number of points in the
Cuzco basin and is, besides, one of the most common relations
throughout the Central Andes. I have studied similar cases
all the way from southern Bolivia to central Pern. Further-
more, the condition is widely encountered im other continents :
it has been noted in both North America and Europe under
such a variety of topographic relations that its meaning is one
of the clearest in physiographic geology. It would require no
further emphasis were it not for the great importance attach-
ing to it in the present instance.

It is characteristic of glacial gravels and sands that they
occur in many valleys whose heads were not occupied by the
ice. Among this class are the deposits in the ravine in which
the human remains were found. It is inferred, however, that
they have the same age as those which exhibit an interlocking
relation in adjacent valleys. This appears at first sight to
border so closely on mere analogy, that particular attention
should be directed to the following argument for their age.

Starting at the glaciated head of any of the higher vaileys
of the Cuzco basin, one passes down over the morainic deposits
to the more regularly distributed and stratified alluvium of the
middle and lower sections of the valley. At the valley mouths
one looks out upon a great belt of alluvium fringing the lower
slopes and appearing to extend tongue-like up all the tributary
valleys. The plane of the surface on which one stands is coin-
cident with that of the surface of the adjacent deposits. There
is lack of continuity only where some more massive or some
longer spur extends far out into the basin, though such breaks
are rare. One can find no marked differences between the
deposits of the unglaciated and the glaciated valleys. In all
cases the material is coarse, in all cases it leads to upper rocky
slopes stripped bare of waste: the upper surfaces of the deposits
of both the glaciated and the unglaciated valleys fall into a
common plane: both have the same geographic position: along
their common border, the deposits interlock in as clear a
manner as do the glacial and alluvial material at the glaciated
valley heads: both classes are benched, showing that there has
been at least one important halt in the cutting down of the
deposits since their formation. These are not accidental con-

316 Bowman—Geologic Relations of the Cuzco Remains.

cordanees ; for they would imply a repetition of accidents of
both time and place. There are, to be sure, certain differences
between the deposits, but they are differences of detail. The
deposits at the mouths of the larger valleys are thicker ; while
both classes are coarse, those from the glaciated valley heads
are coarser; though both classes are eroded and are being
eroded, the thicker deposits are eroded to a greater depth,
though as a rule at a higher absolute elevation. The principal
characteristics of the belt of alluvium are brought out in figs.
1 and 10.

That the deposits of these two classes are contemporaneous
points conclusively to some climatic condition which affected
both alike, whether or not that condition led, as in some eases,
to glaciation. It is inferred from the former extension of gla-
cial systems that the climate of the Pleistocene was colder: it
nas not always been necessary from the conditions of a given
place also to postulate greater precipitation, though such a
postulate is imperative in many cases, including the one under
consideration. The basis for the inference is relatively simple.
Before the Pleistocene, waste supply and waste removal main-
tained a certain balance whereby large quantities of waste
clung to the upper slopes, while another part of the waste
was transported down valley without important aggradation.
With the advent of the Pleistocene, waste was shed more
rapidly from the upper slopes than it could be removed from
the lower slopes and a fringe of alluvium was formed. That
this should result in valleys whose heads were unglaciated
means that a greater amount of water and snow (water by later
periodic melting) fell on these valleys, and if on these valleys
on all vallevs tributary to the basin.

The conditions governing the actual formation of glaciers
on the mountains about Cuzco are relatively few in number.
Glaciers formed (1) in those valleys that reached above 12,500
feet, (2) in valleys with headwater tributaries able to supply
important masses of snow or ice. Fig. 11 represents a glaci-
ated valley at 13,000 feet. It has an extensive system of
tributary slopes and minor valleys extending up to summits
above 14,000 feet, where snow now collects in important
amounts during the southern winter. Neighboring unglaci-
ated valleys have few contributing slopes and a lower summit
altitude.

The topographic characters of the glaciated portions of the
valleys about Cuzco are strongly marked. Glacial striz occur,
though these are relatively few in number since the rock in so
many instances is soft and upon exposure to weathering the
strie are soon destroyed. The lowest marks of glaciation are
at 12,250 feet (aneroid), in the valley of the Chacimayu south-

Bowman— Geologic Relations of the Cuzco Remains. 317

west of Cuzco.* In many valleys glacial features are devel-
oped at a much higher level. In other valleys outside the
Cuzco basin the limits of glaciation are much lower. For
example, between Ollantaytambo and Torontoy, well-developed
terminal moraines at least 400 feet high stand but 8,500 feet
(aneroid) above sea level.

Besides strize the glaciated valleys exhibit slopes of character-

Mies

Fig. 11. Glaciated head of the Chacimayu valley. Note the smooth floor
and steep sides. Looking up-valley from station in which fig. 12 was taken.

istic pattern. Fig. 11 represents the glaciated head of the
Chacimayn; fig. 12 represents the unglaciated lower and

* Near the fortress of Sacsahuaman, north of Cuzco, is a famous grooved
and striated knob of rock. The remarkable nature of the grooves has often
been described though never properly interpreted. Proof that the surface
was slickensided and not glaciated will be presented in a later paper on the
geology and geography of the Cuzco basin.

318 Bowman— Geologic Relations of the Cuzco Remains.

middle portions of the same valley. The two photographs
were taken from the same point, so that the foreground
of the one may be identified in the other. The glaciated
portion of the valley is marked by a smooth and locally flat
floor, steep marginal walls (in places precipitous), a ground
moraine, and a flatter gradient than the unglaciated valley

Fie. 12.

Fie. 12. Middle section of the Chacimayu valley showing alluvium on
valley floor and sides and the absence of glacial features. Looking down-
valley from station in which fig. 11 was taken.

exhibits. Like the alluvium in the lower valleys, certain
features are here in process of destruction, and could not
have been made under existing conditions. The steep mar-
ginal walls are in ‘process of dissection, and the resulting waste
is spread over the margins of the valley floor. The lower end of
the glaciated portion of the valley is being invaded by ravines

Bowman— Geologic Relations of the Cuzco Remains. 319

tributary to the unglaciated part of the valley. In time the
entire flat-floored portion will be dissected to the point where
no flat floor remains; the steep marginal walls will ultimately
be reduced in gradient, and the strize obliterated. The form of
the upper valley will then harmonize with the form of the
unglaciated portion of the valley farther down. If the gravels
had been deposited in post-glacial time, glacial forms in the
valley heads would be destroyed by that great headwater ero-
sion which the valley alluvium demands.

The bluff in whose face the Cuzco man and associated ver-
tebrate remains were found leads up by steep slopes to a broad,
smooth, and almost flat-topped gravel spur, one of a group of
spurs whose upper surfaces fall into a common plane as in fig.
1. In all cases the borders of the spurs are marked by bluffs
of steep descent, indeed in many cases they are unscalable
and the infrequent paths run by selected routes. The highest
bluffs rise several hundred feet above the valley floors. Their
height and steepness are clearly dependent on the climate,
which is semi-arid and marked by light, infrequent rains.
Seepage lines are rare and occur only at low levels. So coarse
and steep are the bluffs, so well drained, and so scantily
watered that many of them exhibit not the slightest sign of
seepage though all bear on their surfaces and margins signs of
_water action. Later alluvium derived from older rock waste is
in evidence everywhere either as a fringe about the bases of
the bluffs or as long trailing masses of gravel along the dry
channels of the tributary streams.

The relation of the bones to the surface of the bluff leads
to some important considerations. The finding of material on
the immediate face of the bluff does not merely by virtue of
that position indicate with certainty natural burial during the
upbuilding of the formation and reéxposi:re as a result of
present erosion. Though the bluff is very steep, a number of
plant forms cling to it. These catch particles of falling or
sliding material and even pieces of pottery. In a number of
cases it was noted that the vegetation responsible for such
obstruction in time dies and may be entirely or almost entirely
removed. Surficial objects are then left attached to the
face of the bluff, from which they may be easily removed.
The steeper the bluff the more difficult the retention on a
sloping surface becomes. The patchy mantle of foreign mate-
rial is always loose, unstratified, fine-textured, and in strong
contrast to the undisturbed material directly beneath it. As
contrasted to such surface drift, it is noteworthy that the verte-
brate remains were not on the face of the bluff but eight
inches back from the face measuring to the median line of
the deposits: also that they were stratified with the gravels,

320 Bowman—Geologic Relation of the Cuzco Remains.

mixed with material of about the same texture and compo-
sition, and that they lay in a nearly horizontal plane.

The form of the bluff at the locality in point may be appre-
ciated by the photograph, fig. 4, and by the profile, fig. 10,
based on measurements. The topographic relations and the

Haeeds:

Fic. 18. Mountains on the border of the Cuzco basin. The white strata
of the terrace at the foot of the mountain are of Tertiaryage. The alluvium
covered floor of the basin shows in the foreground.

eeographic position may be understood from the maps (Plates
I and II), which exhibit so many details that further description
is hardly required.

AGE OF DEPOSITS.

In order that the antiquity of these remains may be con-
sidered in a concrete way, we shall now examine the deposits
with a view to determining their age. It may be clearly seen
from fig. 10 that the coarse gravels of the region are the upper-

Ty eT

Bowman— Geologic Relations of the Cuzco Remains. 321

most of two glacial series. The coarse deposits and not the
lower fine deposits have intimate relations with glacial material
in the higher valleys. Therefore the coarse deposits were
formed at the time of the last glaciation. Although two
periods of glaciation may be identified throughout the Central
Andes, I have nowhere been able to find any evidence of great
differences of age. The lower, finer, eroded deposits appear
to be in as fresh a condition as the overlying coarse material
both at the contact and below it. This suggests that the
deposits may correspond to those of the earlier and later Wis-
consin glacial stages, the last in a series of six glacial epochs
of which evidence is found in central North America.

The topographic and drainage relations that in the United
States have made it possible to estimate the age of the deposits
of the last glacial invasions, and indeed of some of the earlier
ones, are not duplicated in the Central Andes; nor have I
been able to find other relations that will serve the same pur-
pose. Estimates of the age of glacial deposits in South America
rest upon comparison with elacial deposits in the northern
hemisphere and the conclusion that glaciation was contempo-
raneous in the two hemispheres; in other words, that the cli- |
matic conditions which produce glaciation are of cosmic origin.
Although I have studied the glacial deposits of the Central
Andes in a great variety of climates and have examined glacial
deposits in six of our northern states and in Canada, I can see
no essential difference in the degree of weathering. The
striking feature in all cases is the freshness of the material and
the comparatively youthful, in many cases merely incipient,
erosion of glacial forms. Direct evidence of contemporaneity
has been presented by Steinmann.* In a later paper the
writer will present a new line of evidence in support of the
same conclusion.

If we take contemporaneous glaciation in the northern and
southern hemispheres as the basis for further consideration, we
shall have as the age of the older deposit of the first epoch
40,000 to 150,000 years and the age of the later coarse deposits
in which the Cuzco man was found as 20,000 to 60,000 years.
The layers in which the bones were found do not lie higher
than midway in the coarser series ; I should be inclined, were
it not for the remains in them, to place them in the lower half
of the coarser series, which would give them 40,000 to 60,000
years.t A conservative statement then is that the bones
appear to be from 20,000 to 40,000 years old, or that they have

*Uber Diluvium in Siid-Amerika, von G. Steinmann, Sonder-Abdruck
aus den Monatsberichte der deutschen-geologischen Gesellschaft, Jahrg.

1906, Nr. 8/10.
+See Chamberlin and Salisbury, Geology, vol. iii, 1906, p. 420.

322 Bowman— Geologic Lelations of the Cuzco Remains.

been buried from three to six times longer than the historic
period.

The Scandinavian geologists argue for a much shorter post-
glacial period than American geologists have heretofore con-
ceded.* Their time estimates, calculated on the basis of the
thickness, rate of formation and character of clay and bog
deposits, give the post-glacial period a length of 15,000 to
20,000 years or less. We have to note of course that their
results, based on facts gathered much nearer the center of an
old ice field, are not strictly comparable with results from
Niagara and the Finger Lakes district, near the edge of the
glaciated country. All of these figures should be regarded as
rough estimates which express an opinion, or as a calculation
with a wide margin of error.

CONDITIONS OF BURIAL.

One asks at once how the bones could be preserved for so
long a period. We are all familiar with the decayed condition
of bones buried for even a short period of 20, 50, or 100 years.
The bones of the Cuzco man are distinctly weathered but they
do not fall apart. They are so fragile that we broke some of
them in excavation though we used great care; yet they are
sufficiently firm, or at least some of them are, to display a
clean mark when scratched with the knife. On the whole
their comparative freshness is striking in view of a probable
age of 20,000 to 40,000 years. On the other hand, it must be
remembered that human bones equally well preserved have
been recovered from the shell heaps and kitchen-middens of
Europe; that human bones no more decayed than these have
been found in far older glacial deposits in France, Switzerland,
and England; and that more important than the question of
state of decay is the question of conditions of burial. The
position of the bones within the zone of weathering, the char-
acter of the material, the climatic conditions, and the state of
the bones at the time of burial are all-important considerations
which are discussed in the following paragraphs.

The bones of the Cuzco man, as well as the related verte-
brate remains, all show a certain degree of erosion as if they
had been for a short time in the grip of a stream. The finer
details are wanting and projecting points are moderately worn.
The facts that only the projecting points are rounded and the
finer detail lost on the more exposed portions and that the
amount of erosion is small argues distinctly in favor of the fresh-
ness of the material at the tume of burial. It the bones had

*See especially the collection of papers published by the International

Geological Congress, Stockholm, 1910, under the title: ‘‘ Die Veranderungen
des Klimas seit dem Maximum der letzten Eiszeit.”

Bowman—Geologic Relations of the Cuzco Remains. 323

been decayed before being caught by the aggrading stream,
their more fragile portions would be worn, though not without
respect to exposure of more projecting parts. The projecting
points are not necessarily the parts to decay more readily. It
may be safely argued from these two conditions also that the
bones were decidedly fresh at the time of burial, a condition
favoring long preservation.

The bones lay in the zone of weathering, that is to say in
the zone between the surface and the ground water. At the
time the deposits were forming over them they undoubtedly
lay for a part of the time in the ground water and not in the
zone of weathering. When the deposits were later eroded and
the present ravines formed, the level of the ground-water zone
was lowered to the point where the bones once more lay in the
zone of weathering. The rate of weathering is, however, not
uniform in this zone ; it is accelerated by strong temperature
changes, by pronounced rise and fall of the ground water with
the wet and the dry seasons, and by a greater amount of capil-
lary water surrounding the soil grains. It is also hastened by
soil acids which in turn depend upon conditions of drainage
and of vegetable growth, being most abundant where the veg-
etation is abundant and the drainage poor.

Organic material buried in the gravel deposits of the Cuzco
region at some depth in general would be well-preserved
because of (1) the thorough drainage, (2) the absence of impor-
tant amounts of vegetable acids in the soils owing to the rapid
drainage and the scanty vegetation, (3) the absence of strong
changes in temperature during the greater part of the period
of burial, and (4) occurrence during the later stages of erosion
on the face of a bluff where, though air could penetrate, the
bones were surrounded by material almost air-dry.

Tur NATURE OF THE EVIDENCE.

Very few of the published arguments for the antiquity of
human remains rest, as in the present instance, upon physio-
_ graphic facts. It is, therefore, necessary to indicate the nature
of the physiographic evidence herein presented, its strong and
its weak points, and particularly, the necessity forits use. The
gravels have no fossils that in themselves throw lght upon
the age of the beds; the long erosion interval between the
inclined and dissected Tertiary strata and the glacial gravels
overlying them still further reduces the value of purely strati-
graphic evidence; and the gravels are in process of vigorous
dissection to-day, hence they were formed at some past time.
We have, then, to deal with a phase of recent geologic history,
without being able to rely upon any facts of structure or

324 Bowman—Geologic Relations of the Cuzco Remains.

stratigraphy. It follows, that without a recognition of the
physiographic evidence, no determinations of the geologic age
of the deposits could be made. Indeed, archeeology in general
deals so constantly with surface deposits, their thickness, rate
of formation, geologic relations and probable age, that archeeo-
logic collections can not be properly made if related physio-
graphic facts are ignored.

The original plan of the Expedition did not include execava-
tion or detailed archeeologic work, nor was any effort made to
do highly detailed geologic work. It was essentially an explo-
ratory expedition. Furthermore, I came to the study of the
bones, and the gravels in which they were embedded, with
grave doubts as to the value of the find. A rather extended
reading of anthropologie literature bearing on the antiquity of
man convinced me, some years ago, that almost all of our
reported cases of buried human remains in North America are
not authentic, or the arguments are not sound. I expected to
find some doubtful evidence that would entirely destroy any
supposed value the Cuzco material might have. Upon exami-
nation the geologic evidence appeared very convincing and
the proof clear. At the least a detailed study of the physio-
graphic geology of the head of the Cuzco basin was demanded.
When this study had been completed, I again returned to the
bone locality, in a skeptical frame of mind, prepared to find
some fact that would destroy my former arguments.

There is not the slightest thread on which I am able to hang
any positive doubt, save the arch of material over the bones.
It was at first thought to be either the natural arch of the top
of a grave or a dividing plane between an earlier and a later
deposit, and that the bones lay in the outer, later deposit, made
long after the glacial period. The former hypothesis proved
to be untenable, because the gravel became firm before the
bones were reached, while excavating downward from the
crack. In testing the latter hypothesis, a similar difficulty
arose. No break could be found between the stratified gravel
of fig. 5 and the stratified gravel in the steepest part of the
bluff. Although a search was made for signs of a break, show-
ing that erosion was followed by alluviation, and for facts
showing that the fill material contained the bones, nothing con-
clusive or even suggestive could be found.

If, upon excavation, material should be found which clearly
indicates the burial of remains belonging to species introduced
by the Spaniards, it will have to be concluded that a break
exists between the gravels on the face of the bluff and the
gravels in the main mass of the spur. It will then be neces-
sary, even if not before, to excavate until the position and
character of the break are definitely determined. Should such

G. F. Eaton— Remains of Man and Lower Animals. 325

evidence be found (and only excavation appears to be capable -
_ of finding it), we shall have to conclude that the lowest terrace
was still aggrading at the time of the Spanish Conquest and
that after the aggradation cycle had been completed, degrada-
tion followed, the valley being worn down to a depth of about
thirty feet. )

The bovine cannon bone and rib of the Cuzco collection
resemble bison more than they do modern domesticated cattle.
-But apart from the present find there is no evidence that the
bison existed in South America, and while it is possible that its
remains may yet be found, it is very suggestive that none have
been reported until now. It is, of course, necessary always to
find the first occurrence. Nevertheless, there is a basis for
doubt in the fact that the species has escaped discovery until
now. Further excavation is needed, for the same body of
gravels may yield material that will put the conclusions upon
a more solid foundation. If later studies should yield evi-
dence in favor of the conclusion that the material belongs
to the Spanish period, we shall have still the fact of inter-
stratification as a starting point, and the conclusions based upon
that fact will have almost equal interest with the conclusions
here stated, as to the glacial age of the material. Changes of
such magnitude indicate a swing of the climatic pendulum
but little short of remarkable.

Art. XX VIII—feport on the Remains of Man and of
Lower Animals from the Vicinity of Cuzco, Peru; by
GrorGE F. Harton.

THE vertebrate remains described in this report were dis-
covered in the vicinity of Ouzco, Peru, by Professor Hiram
Bingham, Director of the Yale Peruvian Expedition of 1911.
To him I am indebted for the privilege of studying this inter-
esting and valuable collection.

Under the List of Genera and Species are enumerated the
specimens that are sufficiently characteristic for identification.
Each bone is numbered in this List, so that by turning to the
corresponding numbers in the following Description ot Mate-
rial, further information regarding the more important speci-
mens may be found.

326 G. F. Haton—LRemains of Man and Lower Animals.

List oF GENERA AND SPECIES.

Homo sapiens.
(Representing at least three individuals.)

. A fragment of the cranium.

An imperfect 5th thoracic rib.

An imperfect 9th thoracic rib.

Fragments of a right os innominatum.

A nearly complete right femur.

An imperfect left femur.

A fragment of a right femur.

Several fragments of the shaft of a left femur.

WaT OP WON

Canis sp.

9. The shaft of a left tibia.

Bos sp.

10. A left metatarsus.
11. A fragment of a right radius.
12, A fragment of a Ist right thoracic rib.

Lama guanacus.

13. A nearly complete left tibia.
14. The ends of a left tibia.

15. A fragment of a left humerus.
16. A left caleaneum.

DESCRIPTION OF MATERIAL.

Homo sapiens.

The human remains comprise the following specimens:

1. An irregular fragment of a right parietal bone, measuring
about 75° along the sagittal suture and 2:°0™ along the coronal
suture. Posteriorly the fragment is about 6°0™ wide. The
sutures are moderately tortuous, and the bone, which is of fair
but not remarkable thickness, is presumably from an adult
skull. The outer and inner tables are firm and well preserved,
the latter showing the Pacchionian depressions and the charac-
teristic grooves made by the branches of the middle meningeal
artery. It is, of course, useless to attempt to describe the
particular type of cranium represented by such a small frag-
ment further than to state that the sagittal and transverse
curvatures are moderate rather than extreme, and present no

G. F. Laton—Lemains of Man and Lower Animals. 327

Bie ch,

Fie. 14.* General view of the principal human bones.

indications whatever of pathological or artificial deformation.
The fragment is too short to show the presence or absence of
an interparietal bone, the so-called os Ince.

2. An incomplete right 5th thoracic rib.

* For figures 1-13 inclusive see the two preceding articles.

°

328 G. F. Katon—Remains of Man and Lower Animals.

MiGs as:

ABV bi Mina ea

Fic. 15. General view of the bone fragments and of some of the human
bones of fig. 14.

3. The greater part of a right 9th thoracic rib of fairly
robust character, though not of especially large size.

4. An incomplete right os innominatum in four fragments.
Practically all that is “preserved is the ilium, the pubis being

G. F. Haton—Remains of Man and Lower Animals. 329

- Jost, as well as nearly the whole of the ischium, with the excep-
tion of a little of the ischiatic portion of the acetabulum. The
imperfect condition of this bone and the absence of the sacrum
render it impossible to measure all the pelvic diameters and to
calculate the conventional pelvic indices; but an approximate
idea of the size of the pelvis may be obtained from the follow-
ing linear measurements :

From the posterior superior spine to the anterior superior
spine, 16°0%,

From the summit of the iliac crest to the nearest point on
the acetabular rim, 12-0.

This bone is of massive form throughout, with well-devel-
oped rugosities.. That it is from a male skeleton is further
shown by the absence of a prae-auricular sulcus. Possibly this
pelvis belonged to the same individual as the bone next
described.

5. A nearly complete right femur. The contours of the
ends of this bone are massive in proportion to its length, and
the shaft also is well developed, though not especially large.
It is necessary to record here only a few of the measurements
that have been taken of this femur, in order to indicate its
essential form. :

Measurements of Femur, Bone 4.

(1) Physiological length, or length in oblique position 42°4°™
(2); Mroeitamtenicy lencthey. (hoy ae 41°]
* (8) Transverse diameter at a point 3°™ distal to the most

prominent part of the lesser trochanter -_--_--- 3°6
(4) Antero-posterior diameter at same point .--.-_.--.- 2°6
(5) Index of superior platymeria = ie Wn eee 72-2
(This is a ratio, not a metric length.)
(6) Transverse diameter at middle of shaft... .._-_-- a Bae
(7) Antero-posterior diameter at middle of shaft. -_--. -- 2°9
(8) Proximal breadth, taken from the free surface of —
the head across the great trochanter __--..---- 9°6
(OQ); Vexntical diameter of head. = "2 5 pet. 4°8
(10) Transverse diameter of head ..-. .--..--.-.-.---- 4°7
(11) Collo-diaphysial angle, paresis eres 6 LP 9°
(12) Maximum transverse diameter of distal epiphysis..- 88°"

The distal end of the femur is also characterized by a wide
inter-condylar notch. No comparison can be made of the antero-
posterior lengths of the condyles, as the median condyle is
imperfect. The curvature of ‘the shaft is slight. The linea
aspera is prominent, as indicated by the pilastric index. of
~ Am. Jour, Sct.—FourtH’ SERIES, VoL. XX XIII, No. 196.—Aprin, 1912: !

22

330 G. F. Eaton—Remains of Man and Lower Animais.

107:7, obtained from the diameters at the middle of the shaft.
The gluteal line is well developed, but there is no actual third
trochanter. The anterior inter-trochanteric line is indistinetly
marked, and the anterior surface of the shaft immediately
below this line is slightly concave, while the external surface
of the upper part of the shaft is bowed a little outward. The
resulting platymeria, or femoral flattening, does not, on the
whole, afford any satisfactory racial indications. Manouvrier
attributes platymeria to excessive use of certain muscles of the
leg in climbing steep slopes—a theory that is not ill-suited
to the present case, the topography and geology of the region
where the bone was found also favoring the supposition that
we have to do with a hili-man or mountaineer.

The form and size of this femur, as recorded in the fore-
going measurements and description, fall within the range of
femoral variation in normal adult male Peruvians of the later
Inca period. I have already stated that this femur may possibly
have belonged to the same individual as the pelvic fragments,
bone 4. The two bones are of compatible size and form, and
would represent a thickset and muscular man about 5 feet and
4 inches (1°625”) in height (fig. 14).

It is clear that no proof of great antiquity can be drawn
from the characters of the human skeletal parts submitted to
me, agreeing, as they do, in all essential respects with the bones
of a recent people. Until additional skeletal material is
obtained, showing characters more primitive than those already
noted, the burden of proof of great antiquity must rest on
geological and paleontological evidence.

6. An imperfect left femur of considerably smaller size than
that designated as number 5. While of the same general
type as the larger bone, it is a little less robust in its propor-
tions. The proximal end is poorly preserved and the distal
end is missing. A very crude calculation gives a physio-
logical length of 38-0°" (15 inches).

7. The proximal portion of a right femur of nearly the same
size and form as number 6.

8. Several fragments from the shaft of a left femur of about
the same size as number 6.

Canis sp.

9. The shaft of a left tibia. Although this bone is much
battered, and both ends have been broken off, it is clearly from
the skeleton of a wolf or wolf-like dog. It closely resembles
the tibia of a small Gray Wolf, Canis occidentalis.

In this connection it is interesting to note that three distinct
varieties or breeds of domestic dogs are known to have existed
in Peru during the later Inca period. Dr. Nehring has described

G. F. Katon—Remains of Man and Lower Animals. 331

these as follows: (1) A small-sized breed of the bulldog or
pugdog type, characterized by a short snout, with undershot
jaw; (2) a small house-dog like a Dachshund, with slender
snout; and (3) a larger slender-limbed dog, with wolf-like
skull, originally described by Tschudi under the name Canis
inge pecuarvus. According to Dr. Nehring, the two smaller
breeds were derived from the larger wolf-like variety, which,
he states, was itself derived from the American wolf. The
presence of a tibia of a large wolf-like dog among the bones
collected at Cuzco, while it offers no proof. of oreat antiquity,
certainly does not in any way render such a view untenable.

Bos sp.

10. The metatarsus, or “cannon bone,” of the left hind leg.
The length of the bone without the distal epiphysis, which was
not preserved, is 19:0°", or 74 inches. Subsequent to the loss
of the epiphysis, and prior to deposition in the locality where
found, the bone has been eroded to such an extent that the
sharp edges of its modelling are destroyed.

11. A small fragment of a right radius.

Oy A fragment. lOiuea Uist right thoracie rib.

Realizing the importance of determining whether these
bovine remains belong to a feral or to a domestic race, I have
endeavored to obtain all possible evidence on this difficult
question. As these fragmentary bones (10, 11, and 12) are
among the least characteristic parts of the skeleton, their exact
specific identification is beset with almost insuperable dithicul-
ties. While it is a simple matter to distinguish the hind
cannon bone of a slender-limbed dairy cow from that of an
adult Bison, a careful study of a large series of specimens
shows that metatarsi of an intermediate type exist, which
bafile specific identification unless accompanied by other more
characteristic skeletal parts. This is true of the cannon bone
designated as bone 10. The fact that the epiphysis is missing
warrants the supposition that the bone is from a young animal,
and accordingly had not attained its full growth. The frag-
ment of a radius (bone 11) is too meager to be of any assistance
in the present search for specific characters. The bovine
specimen that is of greatest interest is the fragment of a 1st
rib, designated as bone 12. I have examined the Ist ribs of |
the following Bison, Bos americanus: An adult male and an
adult female in the Yale University Museum; an adult male
and a young female in the U.S. National Museum; and an
adult male and a young female in the Museum of the Brooklyn
Institute of Arts and Sciences. In all these, the origin of the
external intercostal muscle is marked anteriorly by a well-

3382 G. LF. Katon—Remains of Man and Lower Animals.

defined ridge on the lower third of the bone, near its posterior
border, and the external surface of the rib anterior to this
ridge is somewhat flat and approximately parallel to the plane
of the internal surface. As might be expected, the 1st ribs of
the females and of the younger animals of both sexes have
the ridge less strongly marked than is the case with the older
males. The Ist rib of the extinct Bison, Bos occidentalis, has
essentially the same typical form. I have also examined the
ist ribs of a number of domestic cattle, the Bos taurus of
zoologists, including two dairy cows , three well-grown beef ~
animals of uncertain breed, and two “fully adult Long- horned
Texas Steers. In all these ‘examples of Bos tawrus, the ridge
that bounds the origin of the external intercostal muscle ante-
riorly is placed much further forward on the lower end of
the bone, and no such extensive flattened surface appears in
front of this ridge as was noted in the examples of Bos
AMETICANUS.

In respect to these apparently differential characters, the
fragmentary bovine rib from Cuzco, designated as bone 12, is
of the form that appears to be characteristic of the Bisons, and
differs from the form seen in all the domestic cattle that 1 have
examined. However, it resembles the rib of a female Bison
or of an immature male, rather than the rugose rib of a mature
male.

Since a fair statement includes a reference to all possible
adverse evidence, it is well to note here that the 1st ribs of the
Zebus, or Brahmin cattle, Los indicus, are variable in form,
and intermediate between the Bisontic and Taurine types.
But the possibility of Zebu ancestry affecting the form of. the
Ist ribs of any South American cattle would seem extremely
remote, because, as Professor Lydekker states in his work Oxen,
Sheep and Goats of All Lands, Living and Extinct: “There
being no other primitive wild ox [other than Bos taurus
primigenius, the Aurochs|] in Europe, and an Eastern deriva-
tion in the highest degree improbable, it is evident that all the
domesticated breeds of European cattle must trace their ances-
try to the aurochs. It may indeed be admitted that some of
the breeds—especially those of Eastern Europe—may have
crossed with African or Indian cattle, but this does not affect
the general proposition.”

It cannot be denied that the material examined suggests the
possibility that some species of Bison is here represented, yet
it would hardly be in accordance with conservative methods to
differentiate Bison from domestic cattle solely by characters
obtained from a study of the Ist ribs of a small heel OT of
individuals,

G. F. Haton— Remains of Man and Lower Animals. 3338

If the material collected at Cuzco dates from a time preced-
ing the Spanish Conquest, it would of course appear that the
bovine bones included in the collection pertain to some species
of Bison, for no other feral group of the Bovide need be con-
sidered. Such a conclusion, while by no means untenable
on general grounds, might not be readily accepted by zoologists
familiar with the principles concerned in the distribution of
animals; for, although it is recorded that the Spaniards found
captive Bison at Montezuma’s capital, the American Bison in
the free state is not known to have ranged further south than
the northeastern provinces of Mexico.

13, 14, 15, and 16. These more or less fragmentary bones
are confidently referred to Lama guanacus, the Guanaco, the
feral species from which the domestic breeds of Llama and
Alpaca are supposed to be derived.

No attempt has been made in this report to render any
account of the chemical composition of the material described,
as the conditions governing the destruction of osseous tissue,
its mineral replacement, etc., are so varied and uncertain that
chemical changes in the broader sense are no longer regarded
by the highest authorities as reliable criteria of age.

Yale University Museum, March 15, 1912.

334 HH. L. Ward—EKstimation of Lead, Nickel, and Zine.

Arr. XXIX.—The Estimation of Lead, Nickel, and Zine
by Precipitation as Oxalates and Titration with Potassium
Permanganate ; by H. L. Warp.

[Contributions from the Kent Chemical Laboratory of Yale Univ.—cexxix.]}

Determination of Lead.

Rets in some investigations on the use of oxalates in analysis
precipitated lead as the oxalate* by adding ammonium oxalate
to a neutral solution of a lead salt and breaking up the result-
ing soluble double oxalate with a large excess of acetic acid.
The insoluble lead oxalate was filtered off and ignited, and the
lead was weighed as the oxide. It was thought that lead oxa-
late precipitated under these conditions might be of such
composition that titration with permanganate would give a
true estimate of the amount of lead present.

In the experiments of Table I the oxalate was precipitated
by the addition of sohd ammonium oxalate to the boiling solu-
tion of lead nitrate, containing the amount of acetic acid spec-
ified. The precipitate was collected on asbestos in a perforated
erucible, and washed with small amounts of water. The oxalic
acid was then set free by treatment with warm dilute sulphuric
acid and titrated with potassium permanganate. ‘

TABLE I,

The Determination of Lead by Precipitation with Ammonium Oxalate
in the Presence of Strong Acetic Acid.

Lead present Volume Acetic Ammo-
as the at precipi- acid nium Lead
nitrate tation present oxalate found Error
erm. em? em? grm. grm. erm.
0°0050 100 25 3 0°0016 —0°0036
0°0250 100 20 5) 0°0246 — 0'0004
0°0500 100 5) 3 0'0454 —0°0046
0°0500 100 10 3 0°0480 —0°0020
0°0500 100 25 5 0°0496 —0°0004
0°0500 200 50 7 0°0477 — 0°0023
0:0050 100 50 + 0°0048 | —0°0002
0°0050 100 50 + 0°0045 —0°0005
0°0250 100 50 4 0°0256 + 0°0006
0°0250 100 50 + 0°0250 +0°0000
0°0500 100 50 4 0°0505 +0:'0005
0°1000 200 100 8 - 0°1002 + 0:0002

It will be noticed in the first part of the table, where the
amount of acetic acid does not exceed one-fourth of the solu-

* Ber. Dtsch. Chem. Ges., xiii, 502.

H. L. Ward—Estimation of Lead, Nickel, and Zine. 335

tion, that precipitation is incomplete. If, however, glacial
acetic acid makes up one-half the volume of the solution the
results are accurate.

Oxalic acid has been used as a precipitant for lead by a number
of investigators.* The determinations of Table Il were made
by adding crystallized oxalic acid to a boiling solution of lead
nitrate, filtering, washing, and titrating the oxalate with per-
manganate as before. When no acetic acid is present, precip-
itation is not quite complete, but the errors are much less than
when ammonium oxalate is used as a precipitant, as may be
seen from a comparison with Table I. Acetic acid added in
equal volume to the solution secures complete precipitation
even in the presence of considerable amounts of ammonium or
potassium salts, provided the amount of lead salt present is not
too small.

TAB TEL,

The Determination of Lead as Oxalate by Precipitation with Oxalic Acid
in the Presence of strong Acetic Acid.

Lead Volume
present at

as precipi- Acetic Oxalic Salts Lead
nitrate tation acid acid present found Error
erm. Crier treme orm erm. erm. erm.
0°0500 50 afd 2 La 0°0491 —0'0009
0°0500 100 he - a 0°0488 —0°0012
0°1000 50 Ee 2 sae 0°0994 —0°0006
0°1000 100 Lhe - we 0°0990 —0°0010.
0°0050 50 25 af an 0°0050 + 0°0000
0°0250 50 25 1 by 0°0256 + 0°0006
0°1000 100 50 2 3 0°1002 +0:0002

Potassium Acetate present
0°1000 50 ot 2 2 0°0962 —0°0038
0°1000 100 ah ~ oh 0:0988 —0°0012
0°1000 100 50 2 2 0°0997 —0°0003
0°1000 100 50 2 “2 0°1000 + 0°0000
Ammonium Acetate present

0°0050 50 25 1 Ef 2c 0°0040 — 0°0010
0°0250 100 50 2 5° 0°0227 — 0°0023
0°1000 100 50 2 2° 0°1000 +0:°0000

+ Béttiger & Pollatz, Chemical Abstracts, ii; 645 : Mohr-Classen, Lehr-
buch der Chemische Analytische Titermethode, 228; Low, Jour. Amer,
Chem. Soc., xxx, 587.

3386 H. L. Ward—Estimation of Lead, Nickel, and Zine.

Determination of Nickel.

Classen has shown* that nickel may be completely precipi-
tated by treating the soluble nickel potassium oxalate with a
large amount of acetic acid. The oxalate formed under these
circumstances may be ignited to the oxide and weighed as such.
It seemed desirable to determine whether this oxalate is of such
composition as to allow the estimation of nickel by titrating
the oxalate radical with potassium permanganate. The pro-
cedure first tried was that recommended by Classen. To a
solution of a known amount of nickel sulphate was added a con-
siderable excess of potassium oxalate and the liquid heated to
boiling, when the oxalate first formed went into solution as
nickel potassium oxalate. Two volumes of acetic acid were
then added to precipitate the nickel oxalate. It was found
necessary, in order to secure a product which could be filtered,
to heat the acetic acid and to run slowly, with constant stir-
ring, into the boiling solution of the double salt. Upon this
treatment a flocky precipitate formed, which on standing
for some time at 60°-70° went over to a fine powder. By
filtration and titration with permanganate it was discovered -
that the oxalate obtained under these conditions had a tendency
to include some of the precipitant, causing high results on
titration. On ignition also large positive errors were obtained,
but if the oxide was washed to remove the potassium carbonate
formed, a very good estimation of the amount of nickel present
was secured.

It seemed possible that the use of oxalic acid as a precipitant
might eliminate the errors due to inclusion, but it was found.
that if oxalic acid was added to the boiling solution of a nickel
salt containing an equal volume of acetic acid, the oxalate
formed came down quickly and in an extremely finely divided
condition. The first experiment of Table II] was made in this
manner, but in the majority of instances filtration proved to be
impossible. If, however, precipitation was made in water soln-
tion and acetic acid added later to throw out the last traces of
nickel, the oxalate came out more slowly and in a form suitable
for filtration.

The nickel sulphate taken for analysis was dissolved in water
and the solution standardized both by precipitation as nickelic
hydroxide and ignition to the oxide and by throwing out as
metallic nickel on the rotating cathode. To a definite amount
of this solution, diluted to the required voluine and heated to
boiling, was added an excess of crystallized oxalic acid. Upon
cooling, acetic acid was run in and the precipitate allowed to
settle over night. The smaller amounts of nickel did not come
out from the water solution, and even after adding acetic acid

* Classen, Zeitschr. anal. Chem., xvi, 470.

H. L. Ward—Estimation of Lead, Nickel, and Linc. 3837

it was necessary to heat it to start precipitation. The nickel
oxalate was filtered off on asbestos in a perforated crucible
and washed with small amounts of water. The crucible was
placed in a beaker containing about 25° of dilute (1:4) sul-
phuric'acid and heat applied to effect the solution of the oxa-
late. The volume of the solution was then made up to about
200°" and cobalt sulphate added until a slight pinkish tinge
appeared. This procedure, recommended by Gibbs, was neces-
sary to secure a definite end-point, as the green color of the
nickel masked the complementary pink of the permanganate.
The contents of the beaker were then heated to boiling and
titration made in the usual manner. The results appear in

TABLE III.

The Determination of Nickel by Precipitation with Oxalic Acid
and Treatment with Acetic Acid.

Volume
Nickel of water Acetic
as solution at Oxalic acid Nickel

sulphate precipitation acid added found Error

erm. em? erm. em? erm. erm,
0°05038 100 2 50 0°0502 —0°0001
0°0050 100 2 100 0°0054 + 0°0004
0°0251 100 2 100 0°0258 +0:0007 .
0°0503 0) 2 100 0°0514 +0°0011
0°0503 100 2 100 0:0502 —0°0001
O1257 - 100 2 100 O12 71 + 0°0014

Table III. The positive errors may be assigned to two causes,
inclusion of the precipitant and uncertainty of end-point when
titrating in colored solutions.

Determination of Zine as the Oxalate.

It was found to be possible to estimate zine volumetrically as
the oxalate by the process already outlined for nickel. In this
case, no colored salts being present in the solution on nitration,
a more definite end point was secured and the results obtained
are much more accurate, as appears in Table IV.

TABLE IV.

The Determination of Zinc by Precipitation with Oxalic Acid
and Treatment with Acetic Acid.

Zine Volume
as at Oxalic Acetic Zine

acetate precipitation acid acid found Error

erm. em? germ. em? erm. grm.
0°0055 100 2 100 0°0056 + 0°0001
0°0274 100 2 100 0°0276 + 0°0002
0°0548 50 2 50 0°0553 +0:°0005
0°0548 100 2 100 0°0550 + 0°0002
0°1370 100 2 100 Olan +0°0002

3388 H. L. Ward—Kstimation of Lead, Nickel, and Zine.

The oxalate of zine obtained by the method of Classen* was
contaminated with potassium oxalate and therefore could not
be used to determine the amount of zinc present. On ignition
and washing of the oxide obtained, it was shown that all the
zine was recovered.

Summary.

Experiments have been given to show that lead may be
determined by precipitation, either with ammonium oxalate or
oxalic acid, in the presence of large volumes of acetic acid and
titration of the oxalate formed with permanganate.

Nickel has been estimated by precipitation by oxalic acid in
water solution, the addition of acetic acid to separate the metal
remaining in solution, and titration with permanganate.
Errors may occur in this method from inclusion of the pre-
cipitant or indefiniteness of the end point. |

Zine may be estimated very accurately by the method used
for nickel.

* Classen, Zeitschr. anal. Chem., xvi, 470.

Case and Williston—Description of Reptilian Skulls. 339

Arr. XXX.—A Description of the Skulls of Diadectes lentus
and Animasaurus carinatus ; by E. C. Case and 8. W.
_ WILLIstTon.

Tue two skulls here described have recently come to light.
The first was collected by Case in the Baldwin Bone Bed on
Poleo Creek in Rio Arriba County, New Mexico, and the
second was collected by Baldwin near Animas, Colorado
nearly thirty years ago, but has lain undescribed among the
abundant material of Yale University. The matrix of the
second skull, an indurated blue clay, is different from any
occurring in the New Mexican localities, but the similarity of
the skull to that of Diadectes and the geographical proximity
indicate that it is a member of the same fauna.

DiapEctrres LeNtus Marsh. (Figs. 1 and 2.)

Nothodon tentus Marsh, this Journal, vol. xv, p. 410, 1878.

Nothodon lentus Case, Publication 145, Carnegie Institution, p. 30, 1911.

Nothodon lentus Williston, American Permian Vertebrates, Chicago, p. 16,
tf.

The only portions of the skull of this animal known pre-
viously were the few teeth described by Marsh and the imper-
feet top of a skull described by Williston in the paper cited
above. The history of the discovery and description of the
original specimen has been given by Williston in the paper
cited above (pages 7 and 8) and need not be repeated. The
uncertainty as to the generic identity of Wothodon and Dia-
dectes has been removed by the discovery of this specimen
associated with typical diadectid vertebree with hyposphene
and hypantrum in the original Baldwin bone bed.

The skull was found in a matrix of soft, blackish, friable
clay on the banks of Poleo Creek about a mile above its junc-
tion with the Puerco river in Rio Arriba County, New Mex-
ico. Closely associated with the skull were found the two
jaws described in this paper and they would have been
regarded as belonging to the same specimen if several other
jaws of the same size had not been found with them.

The anterior portion of the skull, as far back as the post-
orbital region, was taken out in plaster and the relation of the
parts can not be questioned. The posterior portion was
broken in the ground and recovered as fragments. As
restored, the skull resembles very closely that of Diadectes in
form and proportions.

Lhe top of the skull is very rugose in the occipital and fron-
tal regions, but on the sides of the temporal and facial regions
the bones are marked by a sculpture of fine pits. “The

340 Case and Williston—Description of Reptilian Skulls.

sutures can not be made out nor can any grooves such as fig-
ured by Williston (Am. Permian Verts., fig. 1 and pl. xxxviil)
be seen. In the specimen figured by Williston the bones
were separated and the sutures thus determined resemble very
closely those shown in the single specimen of Diadectes from
Texas, in which the sutures can be made out. Cope mentions
the occurrence of grooves on the skull of Chilonyax, consider-
ing them to be the marks of attachment of corneous plates,
but these could not be seen by Case. Seeley mentioned the
occurrence of mucous grooves on the skull of Pareiasaurus,
but this has been questioned. So far as we are aware, these
are the only mentioned cases of anything resembling the
grooves described by Williston. The only notable differences
from the skull of Diadectes phaseolinus, the best known, are:

1. There are no pits on the surface of the supraoccipital bone.

2. The pits on the surface of the temporal region are very
obseure and cannot be certainly distinguished from the deep
interspaces of the rugosities. :

3. There are small pits on the surface of the prosquamosal
bones just anterior to the upper anterior border of the quad-
rate. :

4, The jugal descends to the lower edge of the quadrate.

These differences are certainly not of generic value.

The nares are far anterior and in the crushed condition of
the specimen appear to look upward; this is, however, an exag-
geration of the natural condition, in which the nares were
inclined somewhat inward and forward and looked almost
directly outward. The nasal canal is inclined inward and down-
ward and opens on the sides of the palatines and prevomers
(vomers) at the posterior edge of the premaxiliaries, a little
posterior to the anterior opening.

The orbits are elongate oval in outline and inclined slightly
inward at the upper edge.

The parietal foramen is, as in all the Dzadectidae, ‘enor-
mous’. These are the only openings in the skull except the
otic.

The premawillaries are short and very heavy. Each one
carries four strong incisor teeth (not two as described by Marsh)
very prominent and protuberant; this is most evident in the
median ones; the inclination becomes less in the outer teeth.
The inner surface of the crown is beveled by a flat surface
forming a strong chisel-like cutting edge. The surface of the
crown is smooth but the roots are marked by deep striations.
An isolated incisor tooth from another specimen has an imper-
fect root 22™™ long with the crown 17:5™ long. There can
remain no question of the true thecodonty of the teeth.

The mawillaries have the alveolar portion greatly swollen

Case and Williston—Description of Reptilian Skulls. 341

to accommodate the wide sockets for the teeth. The outer por-
tion, forming the sides of the facial region, is thin and marked
with a sculpture of fine pits. The swollen portion departs
abruptly from the inner side, forming a gently swelling promi-
nence; from a point near the middle of the inner side of this
swollen portion rises the palatine process of the maxillary
which projects from the bone at a fairly steep angle and leaves
a deep groove between it and the bone proper. The process
is thin and the lower edge is slightly rugose. It extends in a
gentle curve, following the outline of the inner edge of the
maxillary, from the third or fourth tooth to beyond the last
tooth. The character of this process has been in doubt, Cope
and Oase believing that it might possibly be the palatine bone,
but the condition of this specimen leaves no doubt of its true
nature. There are 11 maxillary teeth; the first has the form
of the incisors except that the face is not so broad and chisel-
like. It is smaller than the incisors and there is no approach
to a canine character. The second is smaller than the first
and more conical in form. Both of these are nearly vertical.
The succeeding teeth, except the last, have the characteristic
transverse widening; the first of these, the third of the series,
has a sharp median cusp and the inner and outer edges are
rounded ; the rest, except the eleventh, have a median cusp and
lateral cusps on the inner and outer edges, identical with the
teeth of Diadectes phaseolinus Cope. The teeth increase in
width to the sixth or seventh and then decrease to the poste-
rior end. The eleventh is not preserved, but the outline of the
base shows it to have been small and conical. When first
erupted the enamel of the teeth was marked by rugose lines
which radiate from the central cusp, but these are soon removed
by wear, and in old individuals the surface is nearly flat.
There is a deep pit on the inner side of the base of each of the
teeth, marking the position of successional teeth.

The prevomers (vomers) are paired aud articulate strongly
with the premaxillaries in front, the pterygoids behind, and
the palatines laterally. They are of considerable vertical
extent and closely applied to each other in the median line.
Case (Publication 145, Carnegie Institution, p. 71) has described
the posterior ends of the prevomers as spreading apart above
at the posterior end and receiving the lower edge of the eth-
noid. It is now apparent that this open portion is the anterior
end of the pterygoids or the posterior of the palatines. The
lower surface of the prevomers is flat and there is a series of
small, sharp, conical teeth about a millimeter in length. The
posterior limit can not be determined as the suture between
the prevomer and the pterygoid is not distinguishable.

The. palatenes are gently convex upward; the outer edge is

842 Case and Williston—Description of Reptilian Skulls.

attached to the maxillaries throughout their length; there is
no palatine vacuity. The position of the palatine-pterygoid
suture can not be made out. The anterior portion of the
inner edge of the palatine is applied to the outer surface of
the prevomers, the attachment being by overlap. There are
no teeth on the palatine.

Fig. 1. Palate of Diadectes lentus Marsh. x 4. Mus. University of
Chicago.

The pterygoids are slightly convex upwards in the anterior
portion ; the inner edges of the two bones meet, if at all, at
the anterior ends, leaving an elongate vacuity which widens
posteriorly. It is uncertain whether the anterior ends of the
pterygoids meet or whether the vacuity is closed by the union
of the prevomers (vomers). The edges of the pterygoids form-
ing the sides of the median vacuity are lined with small teeth ~
and the flat surface of the bone adjacent to the posterior part
of the vacuity is covered with small shagreen-like teeth. ‘The

Case and Williston—Description of Reptilian Skulls. 348

middle portion of the pterygoid widens and is slightly concave
on the lower face; this portion is marked by a low line con-
vex anteriorly. On the outer side of the middle of the bone
is the low ectopterygoid process: its outer edge and a portion
of the upper surface is shghtly rugose, but there is no approach
to the prominence which the same process gains in Labido-
saurus and Captorhinus and there are no teeth on the process.
Near the median vacuity there is slightly prominence on the
inner edge of the bone which curves inward and backward
over the vacuity. The articulation with the basisphenoid is
by. strong flat faces. The pterygoids are separate from the
basisphenoids in the specimen, but were found articulated in
position so that the nature of the free articulation is beyond
doubt. Posteriorly the pterygoids send the usual vertical
plates back to join the quadrate.

There is no evidence of an ectopterygoid. This bone has
been in question, but it seems to us there can no longer be
doubt of its absence.

The basesphenotd is represented by the anterior end, only.
There is a sinall but well developed foramen in the middle
line. The parasphenoid rostrum is strong; the lower edge is
thick and flat but the upper edge is thin and the whole bone
becomes thin anteriorly; it terminates freely a little beyond
the point where the median vacuity is closed by the approxi-
mation of the pterygoids or prevomers. It is apparently this
bone which was figured by Case as the ethmoid in Diadectes
phaseolinus. It is worthy of note that this bone, so strong in
this specimen, is wanting in many of the described skulls of
Diadectes, perhaps by accident, and it was originally reported
that it was absent.

Above the parasphenoid process there are the shattered
remains of very thin plates of bone which can not be restored.
It is apparent that they were paired and that they reached up
to the lower surface of the parietal or frontal bones. They
are probably the anterior ends of the sphenoid plates described
by Case.

The guadrate resembles the same bone in the specimen of
Diadectes described by Case from Texas (No. 4839 Am. Mus.
Nat. Hist.), but the shaft is a little longer and there is a promi-
nent tuberosity on the posterior surface just above the articular
surface. It is probable that there was such a tuberosity on
the Texas specimen but that it was destroyed by the accidents
of fossilization.

It is necessary here to correct certain errors in the restora-
tion of the skull of Dzadectes published by Broom (Bull. Am.
Mus. Nat. Hist., vol. xxviii, Art. XX, pp. 216-217, figs. 11
and 12). In figure ithe side view, Broom shows an ‘enlarged
anterior maxillary tooth resembling a canine, a diastema,

344 Case and Williston—Description of Reptilian Skulls.

and a decrease in the size of the incisors from within outward.
The character of the incisors is evidently hypothetical as they
are shaded, but the arrangement is wrong as can, be made
out from this specimen and from several others in the Ameri-
can Museum. There is no diastema and in no specimen of
Diadectes is there any indication of an enlarged maxillary. It
was upon such an error that Cope founded the genus Empedzas.

In figure 12, the palate, the arrangement of the bones is
wrong. The premaxillaries are never so wide, antero-poste-
riorly, as figured ; the prevomers extend much farther forward
than figured ; the palatine process of the maxillary is figured
as a palatine; the pterygoids are figured as short bones with

Fic. 2. Lower jaw of Diadectes lentus Marsh. x1. Mus. University
of Chicago.

the prevomers extending back as far as the posterior end of
the maxillaries; an ectopterygoid is figured,—as already stated
we find no evidence of such a bone in the Diadectide. We
have studied the known skulls of )zadectes carefully for several
years and have found no evidence to warrant drawing the
sutures of the temporal region so definitely as Broom has done,
though they may be corr ect.

The lower jaw.—The resemblance to the lower jaw of the
specimens of Diadectes from Texas is very close, but the jaws
from New Mexico show the sutures and permit. the outline of
the individual bones to be determined. On the inner side the
suture between the splenial and dentary is distinct in front
but is not traceable behind : its probable continuation is indi-
cated by the dots in the figure. Below the anterior Meckelian
opening the suture between the splenial and the surangular 1s
very distinct. The splenial takes the usual large part in the
symphysis. The suture between the angular and the bone
above it in the posterior portion of the jaw is distinct, but it is
somewhat uncertain what this bone is. The articular is not
marked off by distinct sutures, but on the surface of the bridge
between the anterior and posterior openings of the lower

Case and Williston—Description of Reptilian Skulls. 345

jaw there is a low, slightly rugose ridge which appears to mark
the portion of a suture which has closed. If this is true, the
portion of the bridge behind the rugose line may be the ante-
rior portion of the articular, and the anterior portion of the
bridge may represent the prearticular ; the ridge may, however,
be only a surface for the attachment of muscles. The coronoid
is a very small bone visible on the inner side of the jaw. The
surangular behind and the dentary in front send processes up-
ward which aid in the formation of the coronoid process. The
sutures on the outer side of the jaw can not be made out except
where a break in one of the Jaws shows that the suture between
the dentary and the surangular runs downward a little anterior
to the coronoid process. The articular face of the articular
has two deep parallel grooves which limited the motion of the
jaw to the vertical plane. There are fifteen teeth in the jaw.
The posterior one is small and conical; the next eight have the
expanded form characteristic of the genus. The first four have
the chisel-like form of true incisors, the fifth is nearly conical,
the sixth has the crown shghtly expanded and carries a single
median tubercle. The other have wide crowns with three
tubercles. The wear was on the outer side of the teeth in the
lower jaw and the inner side in the upper.

Animasaurus carinatus, gen. et sp. nov. (Fig. 2.)

The specimen consists of a fairly perfect skull (No. 1107
Mus. Yale Univ.). It is slightly injured in the anterior part so
that the premaxillaries, the anterior ends of the maxillaries and
_ the nares are lost. The anterior portion of the facial region is

crushed down upon the palate. The teeth are all destroyed,
but the outlines of the roots show them to have been trans-
versely expanded as in Diadectes. The condition of the speci-
men is such that the sutures can not be made out and the hard
matrix can not be entirely removed from the palate, but enough
has been taken away, aided by a fortunate break, to make the
structure evident.

The superior surface of the skull_—Due to the position of
the quadrate, the posterior portion of the skull is proportion-
ately much broader than in Diadectes though the occipital por-
tion is narrower. The surface is roughened by sculpture and the
development of tubercular prominences which recall those of
the genus Chilonyx. ‘This appearance is heightened by the
position of the quadrate, which slants inwards instead of lying
nearly parallel to the lateral surface, narrowing the occipital
region. The parietal foramen is very large, approximately
20°" broad by 25™™ long. This opening is farther forward
than in Diadectes, a line drawn through the posterior edges of
the orbits cutting through it at near the center; in Diadectes

Am. JOUR. Sci.—FourtH SERIES, VoL. XX XIII, No. 196.—Aprin, 1912.

20

346 Case and Williston—Description of Reptilian Skulls.

such a line passes anterior to the opening. The outlines of the
various bones can not be made out but it is evident that the
trontal was very short and took no part in the superior border
of the orbit.

The lateral aspect of the skull.—Allowing for the crushed
condition of the anterior end, the lateral profile resembles that
of Diadectes. The orbits appear to be narrowed vertically, but
this is evidently due to crushing. On the right side there is

IZ

I

|

M}

1 \ NY aa
a) Af, y > \WNiihn uy {fA
Ue i mmm \\ \ (

Fie. 3. Palate of Animasaurus carinatus Case and Williston. x 4. No.
817, Mus. Yale University.

a large opening in the temporal region but this is of accidental
origin instead of a true temporal foramen, as is evidenced by the
sharp break of the edges and the lack of a corresponding open-
ing on the opposite side.

The palatal aspect of the skull.—This shows the great differ-
ence between this genus and Diadectes. The alveolar edges of
the maxillaries are broadened as in Yadectes for the accom-
modation of the widened teeth, but the palatine process of the
maxillary is perhaps different: it appears to rise from the inner
edge of the alveolar surface instead of from the middle of the
inner side of the swollen portion of the bone and there is no deep
groove between it and the maxillary proper. The pterygoids
and prevomers are united in the median line throughout their

Case and Williston— Description of Reptilian Skulls. 347

length, forming a deep median keel; there is no median vacuity
between the pterygoids but posterior to them there is a deep
vacuity, the circular opening of which looks backwards and
downwards at an angle of nearly 45° to the horizontal axis of
the skull.

Lhe posterior aspect of the skull.—The occipital portion is
narrower than Diadectes owing to the position of the quadrates
and the paroccipitals and exoccipitals are shorter. The artic-
ular face of the quadrate is much narrower than in Diadectes
and the whole bone occupies a very different position with rela-
tion to the basicranium. In Diadectes lentus the quadrate lies
much farther forward, the articular surface being opposite the
posterior end of the basisphenoid ; in /)iadectes phaseolinus
the articular face of the quadrate lies opposite the middle of
the same bone, while in Animasaurus carinatus it les pos-
terior to the posterior end of the bone. This accounts largely
for the wider appearance of the posterior end of the skull in
the latter.

The individual bones can not all be made out, but such as
can are described below.

The maxillaries are similar to those of Diadectes except as
noted in the description of the palatine process. The posterior
end of the bone is continuous with and on the same level as
the jugal; in Yzadectesit stands out as prominent point. There
are nine bases of teeth and alveoli in the portion of the bone
preserved. The posterior one was small and conical, as indi-
cated by the base. The others are gradually enlarged until
the 6 or 7 from the posterior end is reached, then they begin
to diminish in size. There should be two more teeth in the
maxillary if the number was the same as in Dzadectes.

The pterygoids have the general form of those in Dzadectes,;
the posterior vertical plate, reaching to the quadrate, is iden-
tical in form; the ectopterygoid process is similar but is more
prominent. Laterally the pterygoid joins the maxillary with
no indication of an ectopterygoid bone, but the sutures can
not be made out. Anterior to the ectopterygoid process the
bone widens and dips beneath the matrix, but it is apparent
from a break on the left side that it joins the palatine and
maxillary as in Diadectes. Just anterior to the ectopterygoid
process there is a large shallow pit on the flat surface of the bone
but there is no perforation. In fact there is not, in any Ameri-
can Permian reptile known to us, any indication of a lateral
palatal opening or of a separate ectopterygoid. On the inner
side of the bone the posterior portion rises abruptly to form
the side of the circular vacuity anterior to the basisphenoid.
Immediately in front of this opening the keel formed by the
conjoined edges of the pterygoids of the two sides is very high.

348 Case and Williston—Description of Reptilian Skults.

The edges of the two bones forming the keel were lined with
small conical teeth, now indicated by the bases. At the pos-
terior end there are four such teeth in 15™”; similar teeth ean
be detected throughout the length of the keel. No small teeth
can be detected on the sides of the pterygoids adjoining the
keel, but this may be due to the condition of the bone or the
accidents of preparation; the surface of the bone is partly
destroyed.

The prevomers are hidden by the matrix except the lower
edge; it seems probable, however, from the appearance of the
upper surface of the palate, revealed by the crushing of the
facial region, that the palatines had the same relation to the
prevomers as in Diadectes.

The basisphenoid is similar to that of Diadectes but is very
much longer and there is no foramen in the median line. In
the deep pit anterior to the basisphenoid can be seen the pos-
terior end of a strong parasphenoid rostrum. The posterior end
of the basisphenoid is not entirely cleared but it is quite similar
in general form to that of Diadectes.

The guadrate is inclined inward so that its outer surface looks
rather backward than outward. There is no indication of the
pit opposite the anterior edge of the quadrate. The inner edge
describes the same sharp curve as in Diadectes and there is
the same deep notch at the upper end of the otic opening.
The articular face is very much narrower than in Diadectes,
the anterior p, sterior diameter being only 9°5™™ and the trans.
verse at least 24™™- “+ Duadectes lentus the same diameters
are 17™™ and 24™". imoreover the outer half of the articular
surface is nearly the same width as the inner; in Dadectes
the outer is much wider than the inner.

The genus evidently belongs in the family Dzadectide, but
may be distinguished by the following characters :

1. The union of the pterygoids in the midline to form,
with the prevomers, a prominent keel.

2. The absence of any interpterygoid space. :

3. The elongation of the basisphenoid and the absence of
a foramen in the median line.

4. The inward inclination of the quadrates narrowing the
occipital region.

The animal must have been similar in form and habits to
Diadectes. It has been customary to regard the members of
this family «s herbivorous, but the strong, chisel-like incisor
teeth, the absence of any power of trituration in the unworn
maxillary teeth and the possibility of the use of the palatine
processes of the maxillaries as accessory agents of mastication
lead to the caspicion that the animals were not exclusively if
at all herbi. \cous, and that they may have ine’uded the less
well-protected invertebrates in their diet.

G. S. Jamieson—Determination of Mercury. 349

Arr. XX XI.—A New Volumetric Method for the Determina-
tion of Mercury ; by GrorcEe 8. JAMIESON.

Amone the methods that have been proposed for the volu-
metric determination of mercury, the titration in nitric acid
solution by means of ammonium thiocyanate,* according to
Volhard’s method for silver, while it appears to be very accu-
rate, is not generally applicable because it cannot be used in
the presence of chlorides. The method of Ruppt consists in
adding potassium iodide and an excess of sodium hydroxide to
any mercuric solution, then precipitating the finely divided
metal by means of for maldehyde, and, after acidifying with
acetic acid, dissolving the metal with standard iodine solution
and titrating back with sodium thiosulphate. This method is
simple and rapid, and while it seems to be a good one for
small quantities of mercury, my experience with it is that it
gives seriously low results with amounts of mercuric chloride as
large as 0-1 to 0-2 grams. Tempel’s method,{ which consists
in titrating mercurous chloride (or iodide) with iodine and thio-
sulphate, is undoubtedly very accurate, if it is used with
proper precautions to completely dissolve ‘the mercurous chlor-
ide in the iodine solution.§

The method to be described is based upon the titration of
mercurous chloride with potassium iodate in the presence of
15 to 20 per cent of actual hydrochlori acid and*a small volume
of an immiscible solvent, such as chsjroform. This general
method of titration is the well known one of L. W. Andrews, |
but as far as is known it has not been applied previously to the
titration of mercurous chloride. It has the advantage over
Hempel’s method in requiring ouly a single, very stable volu-
metric solution, instead of two solutions which cannot be pre-
served for a long time unchanged, while the method of titra-
tion appears to be no less exact. It is to be observed that the
1odate titration cannot be applied to mercurous iodide without
the employment of an entirely different factor, since the iodine
would affect the results.

It has been found that mercurous chloride reacts with potas-
slum iodate according to the theoretical requirements of the
equation

4HeCl+ KIO, +6HCl = 4HeCl, + KC1+I1C1+3H,O

* Cohn, Berichte, xxxiv, 3502: Rupp, ibid., xxxv, 2015.
1 Lie, soexx, 3702.

+ Sutton, 10th edition, p. 263.

S Smith, Chem. News, ev, 14. her aaed

|| Jour, Amer. Chem. Soc., xxv, 756, 1903. | aa

350 G. S. Jamieson—Determination of Mercury.

In order to test the method, a solution of potassium iodate
was standardized with pure sublimed iodine, using Andrews’
titration under the same conditions as are described beyond
for the mercurous chloride titration.

Iodine taken KIO; used Wt. of I for 1¢¢
AN <3: eee "10038 See “008488
Bee °1998 2326 00846
Average a eare ae! 00847

Since the reaction in the case of iodine is represented by the
equation

41+KIO,+6HCl = KCl1+51C1+3H,0

the strength of the potassium iodate solution was 1°=-015728
of HgCl.

For the following titrations a sample of pure mercurous
chloride which had been dried at 130°-135° C. for several
hours and well pulverized was used. The titrations were car-
ried out in a glass stoppered bottle of 250°° capacity in the
presence of 20° of water, 30° of concentrated hydrochloric
acid, and 6° of chloroform, with thorough shaking of the
closed bottle between the additions of the potassium iodate
solution. As is usual in such titrations, the chloroform globule
at first increases in iodine color and then this color is gradually
removed. The end-point is the disappearance of this violet
color. It was observed that dried mercurous chloride reacts
more slowly in this operation than the precipitated substance
which was titrated without drying in some of the experiments
to be described beyond, so that in this case very thorough
shaking and occasional crushing of the lumps with a glass rod
were required. The following table gives the results of the
titrations :

HgCl taken KIOs ce. HeCl found Error

lf “49995 31°80 "49995 "00008
EE “5000 31°80 “4999 ‘0001
Iil 5005 31°80 “4999 —°0006
IV “6001 38°15 "5997 — 0004
V “4999 31°80 “4999 "0000

The results show a very satisfactory agreement among them-
selves and with theory.

Since most kinds of organic matter do not interfere with
this method of titration, it is applicable to various mixtures
containing calomel. It was tried with calomel tablets contain-
ing milk sugar, after pulverizing several tablets to obtain a
uniform pte. Quantitative determinations of the calomel
were also made by treating portions of the substance with
water slightly acidified with hydrochloric acid and weighing

G. S. Jamteson— Determination of Mercury. 351

the washed and dried residue. The following results were
obtained :

Substance taken KIO; used HgCl found
"48115 LORS OS 53°91%
6783 23°25 53°89
"1976 gravimetric 53°94
"5694 7. 54°00

The method was applied also to the determination of mer-
cury in a mercuric compound by converting the latter into
mereurous chloride and then titrating. For this purpose
weighed portions of mercuric chloride were dissolved in warm
water with the addition of a few drops of hydrochloric acid ;
an excess of phosphorous acid solution was then added, and
after thorough stirring the precipitate in each case was allowed
to settle for about twelve hours. It was then collected on a
filter paper and well washed with cold water. The precipitate
with the paper was put into the titration bottle, and any pre-
cipitate adhering to the beaker and stirring rod was collected
by wiping with a piece of filter paper and also put into the
bottle. The titrations were carried out as previously described
with the following results: (1° KIO, = :013354*H@)

HegCl, KIO; sol.

No. taken used Hg found He cale. Error
Ji "39545 ml EE "28985 "29048 — -0006&
KI 3107 72, "2997 "2294 +:0003
Iil °49038 CL a | ‘3619 *3619 "0000
IV 3315 18°83 "2444 "2447 — 0003
V *3407 18°8 "2511 *2515 —°0004

The results show that the method is an accurate one.

Sheffield Scientific School,
New Haven, Gonn., February, 1912.

352 G. S. Jamieson— Determination of Hydrazine.

Arr. XXXII.—A Volumetric Method for the Determination
| of Lydrazine ; Dy Grorce 8. JAMIESON.

A metHop for the determination of hydrazine has been
described by Rimini* and recently tested further by Hale and
Redfield.| This is based upon the oxidation of the hydrazine
compound in aqueous solution by the addition of an excess of
standard potassium iodate solution, according to the following
equation :

5(N,H,.H,SO,) +4K10, = 5N,4+12H,O+21,+2K,S0,+3H,S0,

The liquid is then boiled until the iodine is expelled and the
excess of potassium iodate is found after cooling by adding
potassium iodide, acidifying with sulphuric acid, and titrating
with sodium thiosulphate solution. The chief objection to this
method, according to Hale and Redfield, is the length of time
requir ed for the analysis.

The method to be described here is based upon the titration
of hydrazine by potassium iodate in a strong hydrochloric acid
solution, according to the general method of L. W. Andrews.?
It has the advantages of being rapid, and requiring the use of
only a single, very stable volumetric solution. Besides, as will
be seen from the results that follow, it is very accurate.

In order to test the method, a solution containing 3-567 g. of
KIO, in 1000° was prepared. According to the equation of
the expected reaction

N,H,.H,SO,+ KIO,+2HCl = N,+1Cl1+3H,0 +KC1+H,S0,

the equivalent of this solution is 1° = :002169 ¢. N,H,.H,SO,
and 1°° = -:000534 ¢. N,H,. Weighed portions of pure hydra-
zine sulphate were placed in a 250° glass stoppered bottle
together with 20° of water, 30° of hydrochloric acid and 6%
of chloroform. Then the potassium iodate solution was run
in gradually, with shaking between the additions, until the
chloroform, after increasing and then diminishing in color, was
just decolorized. The following results were obtained :

N.H,.H2SO, N.H,.H2SO,
taken KIO; used found Sirona
I "04878 Dora "04888 +0001
1g "0434 S29 "0432 —°0002
III "0589 273 "0592 +:0003
ITV "0472 21°9 "0475 +0008
iV. "0986 45°65 70990 + 0004
VI °1060 49°00 "10638 +:0003

* Gazz. chim. ital., xxix, I, 265, 1899.
+ Journ. Amer, Chem. Soc., xxxiii, 1862, 1911.
t Journ. Amer. Chem. Soc., xxv, 756, 1903.

G. S. Jamieson—Determination of Hydrazine. 358

Determinations of hydrazine in the sparingly soluble double
sulphates of zine, cobalt, nickel, and cadmium were made in
order to test the method further. The double salts were pre-
pared by mixing hot solutions of the component sulphates in
the presence of a little sulphuric acid, and after digesting for
some time on the steam-bath, the crystalline products were
filtered off by suction, washed with cold water and dried at
100° C. The titrations were carried out in the same way as
described above in the case of the simple sulphate. It was
observed that the nickel salt reacted very slowly, apparently
on account of difficult solubility, while the other compounds
were titrated about as readily as hydrazine sulphate alone.

The following results were obtained:

Substance KIO; used N.H, found Calculated
ZnSO,(N,H,),-H,SO, °11632 4.3°9°° 19'83% 19°81%
6¢ (19

‘0880 32°6 1907
P@dsO (NEL) ESO, 1591 51°25 Deo ivie 29
Cs 1396 45°10 17°25 ef
INISO, ONE) SO, »-0692 26°30 20°29 20°23
ty 0890 33°80 20°28 ce
CoSO,(N,H,),.H,SO, :1308 49°20 20-09 20°20
re "1059 39°70 20°02 ub

Sheffield Scientific School,
New Haven, Conn., February, 1912.

354 FF. H. Lahee—Metamorphism and Geological Structure.

Arr. XX XIII.— Relations of the Degree a Metamorphism
to Geological Structure and to Acid Igneous Intrusion in
the Narragansett Basin, Pehode Island; by F. H. Lanzr.

(Continued from p. 262.)

Part II.

ContTENTS.

Petrology of the Carboniferous sediments.
Introductory remarks.
Study of the specimens.
Coals.
Pelites.
Psammites.
Psephites.
Summary.
Relations of the degree of metamorphism to rock-texture.
Geographical distribution of the degrees of metamorphism.
Relations between the degree of metamorphism and stratigraphic depth.
Relations between the degree of metamorphism and the intensity of
the folding. 2
Strikes. :
Dips.
Pitch.
Axial planes.
Relative number of folds across the Basin.
Minor folding.
Relations of the schistosity to the bedding.
Conclusions,

PETROLOGY OF THE CARBONIFEROUS SEDIMENTS.

Inrropuctory Rrmarxs.—Aside from the effects of meta-
morphism, the Carboniferous formation of the Narragansett
Basin consists of a series of shaly, sandy, and conglomeratic
rocks, which are notable (1) for their rapid textural variations,
both parallel and perpendicular to the bedding; (2) for the
abundant presence in them of such lithologic structures as local
unconformity and cross-bedding; (3) for the considerable
proportion of soluble clastic minerals in them; and, (4) for
their content of fossil land organisms and coaly ‘layers, with a
total absence of anything marine. Although these features
may be said to characterize the formation as a whole, they do
not all belong to all horizons. The evidences point (1) to a
prolific source of materials; (2) to the incompleteness of
chemical weathering here in Carboniferous times; and, (3) to
rapid deposition by stream action, partly on land and partly in
standing bodies of fresh water.

After the Carboniferous strata were laid down, they were
folded and metamorphosed, the original minerals being recrys-
tallized in some cases or breaking up and recombining to form

‘ ; \ !
Xe Fr
4 ™
ae
a

F.. H. Lahee—Metamorphism and Geological Structure. 355

new and entirely different minerals in other cases. Every
stage in the process, almost from the beginnings of the change
to the highest metamorphism, is exhibited by these sediments
in different parts of the Basin.

Srupy oF THE SpEctmENS.—In our treatment of the petrol-
ogy, we shall consider the metamorphism as having four
degrees, called Stages A to D. The metamorphism is incip-
ient in Stage A; distinct, but rather low, in Stage B; consid-
erable to high in Stage C; and at a maximum in Stage D.
We shall describe in order the coals, the pelites (shales, slates,
and mud schists), the psammiites (sandstones, grits, arkoses, and
their metamorphosed derivatives), and the psephites (conglom-
erates and conglomerate gneisses).

Coals.— W hile the coals form a very insignificant proportion
of the whole stratigraphic series, they are important in that
they illustrate certain principles which apply, though less
clearly, to the other sediments. The least altered specimens
(Stage A) are soft and friable and crumble into small regular
polyhedra. There is a direction of easy splitting parallel to
the bedding (primary cleavage). Soslight has been the deforma-
tion that most delicately ribbed impressions of Cordaites have
been hardly distorted.

With an increase in the metamorphism (Stages B and C),
the rock becomes less brittle, less friable, and somewhat harder
and denser. A secondary cleavage is developed, with flat or
undulating surfaces, and these surfaces are often slickensided
or have a bright gloss which is due to internal rock movement
under pressure.

The extreme stage of metamorphism (Stage D) is found near
large, massive quartz veins which, as will be explained subse-
quently, are abundant in certain localities. Here the secondary
cleavage is extremely thin and contorted and there is a great
deal of slickensiding and glazing. Chemical analyses show
that, with this increase in metamorphism, the ratio of fixed
carbon to volatile constituents becomes greater. The coals
pass from anthracite to graphite or ‘plumbago’. None of the
phases are marked by the occurrence of minerals typically of
metamorphic origin.

In their present condition the coal seams are far from being
uniform in thickness, for the compression to which they were
subjected during the folding had the effect of thinning where
the strain was at a maximum and of thickening where it was
at a minimum, so that they are now ribbed or ‘rolled.’ This
distortion involved shearing and brecciation. Shearing and its
consequent high degrees of metamorphism are characteristic of
the thinner portions; and brecciation is more common in the
thickened portions in which lower stages of metamorphism
prevail. |

356 FF. H. Lahee—Metamorphism and Geological Structure.

The different phases may all occur in one locality, or even in
one seam, especially in regions of varying intensity of folding
1G: , Aquidneck Island) (see fig. 21,-p. 365) ; but where the de-
for sed is extreme (western coast belt), only the higher stages
are found. The degree of metamorphism, then, is dependent,
at least in part, npon the amount and kind of deformation.

Pelites.—According to their content of carbonaceous matter,
the pelites, representing original muds and clays, range in
color from black to light gray or greenish. They occur chiefly
in the Kingstown and “Aquidneck formations. With the
darker phases coal seams are often associated.

In their least metamorphosed condition (Stage A) these
rocks (shales) are dull and they break with rough, irregular
surfaces—usually more easily parallel to the bedding. The
finer the texture and the more abundant the plant remains, the
more perfect is this primary cleavage. The principal minerals,
as observed with the microscope, are carbonaceous powder ;
quartz, in minute, angular fragments, sometimes with undulose
extinction; and a very little feldspar, sericite, and ilmenite.
All but the sericite are clastic in origin. There is no distinct
parallelism in the arrangement of the constituents, unless
it is in a streaking of the carbonaceous matter parallel to the
bedding.

Low “metamorphism (Stage B) is indicated meg gascopically by
a fair secondary cleavage, by a gloss on the cleavage surfaces,
due to a parallel arrangement of sericite laths, and by distor-
tion of fossils if these are present. Microscopie examination
shows the rock to have a composition similar to that of speci-
mens in Stage A; but here the ilmenite is metamorphic in
origin, as seen by its relations to the other constituents (see
fig. 1), the sericite is more abundant, and a little chlorite
occurs. The quartz grains have suffered more granulation and
slicing, particularly in the coarser rocks, and have sometimes
been ‘squeezed out into lenticular aggregates (see figs. 4 to 10).
The parallel arrangement of these elongate quartz grains and
aggregates and of a large proportion of the sericite laths is the
cause of the secondary cleavage. The ilmenite has no definite
orientation.

In the pelites of Stage C the sericitic gloss, just described,
has been enhanced in brilliancy by the richer development of
this mica; the secondary cleavage is usually more perfect ; and
in most cases there has been anamorphic chemical rearrange-
ment with the consequent growth of ‘knots’ or metacrystals.*

* A name used by Lane in reference to phenocrysts in metamorphic rocks,
the metacrysts being of later origin than the groundmass. See Lane, A. C.,
Studies of the Grain of Igneous Intrusives, Bull. Geol. Soc Am., xiv, 369,
1905.

F. H. Lahee—Metamorphism and Geological Structure. 357

Under the microscope the finer portions of the rock (ground-
mass when metacrysts occur) display certain features different
from those seen in Stage B. For instance, in addition to the
straining, crushing, and slicing of the quartz, some grains are
partly or wholly recrystallized (see fig. 11); that is, some of
the quartz is metamorphic. Furthermore, occasionally a little
secondary aibite or oligoclase may be discovered ; and the
ilmenite individuals have grown so large and conspicuous as
to be classed with the metacrysts.

Hines RiGe 2. Fre. 3.

SS

Fics. 1-3. Progressive elongation of crystals of ilmenite accompanying
increase of metamorphism. All are of secondary origin. The outlines in
fig. 1 and fig. 2 and the white areas included in fig. 2 are due to quartz. The
arrows indicate the direction of the schistosity.

The ‘ knots,’ or ‘ knoten,’ are oval granular aggregates (see
figs. 13 and 14), measuring one millimeter or less in length
and lying with their long axes parallel to the cleavage. They
consist of quartz, chlorite, muscovite, and calcite, with a little
ilmenite, rutile, and hmonite. While generally lacking signs
of distortion, in zones of maximum shearing their constituents
have assumed positions of alignment parallel to the adjacent
geroundmass minerals. The cleavage of the rock curves round
them. Laterally they are confined by strings of sericite; at
their ends the sericite of the body of the rock gradually gives
place to chlorite and muscovite, micas which are especially
characteristic of these knots.

Although any of the minerals just cited may be found in
any portion of a knot, there is ordinarily an obscure concentrie
arrangement, particularly in the least sheared forms (fig. 14).
The principal constituent, quartz, predominates in the central
part of the knot, and is there coarser than nearer the periphery.
Just outside of the quartz core, which may also contain some
calcite, rutile, ete., is an annular belt of unevenly distributed
patches of calcite which encloses streaks and bunches of pow-
dery limonite. In one instance the shape of the belt was
rudely hexagonal. In another the limonite occurred in two
sets of parallel streaks which crossed the core. Such features
suggest pseudomorphism.

The outer peripheral portion of the knot is composed of
finely granular quartz with chlorite and muscovite laths and

358 LF H. Lahee—Metamorphism and Geoiogical Structure.

small ilmenite crystals. After treating a crushed knot with
dilute hydrochloric acid, the residue was found to contain
minute, nicely shaped crystals and reticulated aggregates of
_ rutile about ilmenite plates.

On the whole the facts indicate that these knots represent
the positions of once existing crystals of some mineral which
decomposed into a pseudomorphic form and was then modified
by addition of material, by reerystallization, and by mechani-
eal rearrangement.

The metacrysts, in pelites of Stage C, named in the order of
decreasing frequency, are, ilmenite, biotite, garnet, and ottre-
lite. They are not all found in all specimens. Generally one
or two are conspicuous and the others are scarce or absent.
These four minerals were formed contemporaneous with, or
later than, the schistosity. Only one among them, the ilmen-
tie acquires parallel orientation of its crystals in Stage C (see

g. 2). Sometimes biotite has a linear parallelism such that
ne length of its plates are parallel, but the widths lie in all
positions perpendicular to this common direction. Although
isometric and therefore equidimensional, garnet is distinctly a
mineral which develops under dynamic and not under static
conditions. Ottrelite, which is very rare, is wholly unrelated
in size, shape, and orientation, to the schistosity, and is conse-
quently of late anamorphic derivation under static stress.
The infrequent lack of dimensional parallelism in the ilmenite
and the more common absence of the same in the biotite are
due to the fact that these minerals, too, under such cireum-
stances, originated under static pressure.

The most highly metamorphosed pelites (Stage D) are char-
acterized by as large a percentage of white mica (muscovite or
sericite) as the composition of the rock will permit; by a very
high sheen on the fracture surfaces ; and by an excellent cleay-
age. Asseen in thin sections, the quar tz grains are commonly
elongate (fig. 12) and may be grouped in ribbon-like aggre-
gates. Their shape, their clearness, their freedom from strain-
shadows, and their relations to the adjacent minerals, point to
the conclusion that they are secondary or recrystallized quartz.
Both as single grains and as aggregates, they are oriented with
their longest dimensions parallel. Together with the similarly
disposed mica, they are the chief cause for the very good
cleavage.

Among the metacrysts, ilmenite occurs in small plates par-
allel to the schistosity (fig. 3); biotite here acquires elongate
habit in single plates and as aggregates, which le with their
lengths parallel to the cleavage (fig. 17); and garnet and ottre-
lite possess the same characters which they had in Stage C (figs.
18 and 20).

F. H. Lahee—Metamorphism and Geological Structure. 359

HnGe4s Hig. do,

Hie. 8.

Fies. 4-12. Changes in quartz, which accompany increasing meta-
morphism. In fig. 4 the grains are still uncrushed and unstrained, and dis-
play their clastic outlines. Figs. 5 and 6 show mottled extinction passing
into granulation. In fig. 7 conspicuous granulation is terminal and small
muscovite laths have grown a little way into the ends of the quartz grain.
Fig. 8 represents zonal granulation, due to shearing. Fig. 9 shows both
terminal and zonal granulation and undulose extinction. The curving lines
indicate the direction of schistosity. With complete granulation, flattening,
and some recrystallization, the original grains become flattened aggregates,
as drawn in cross-section in fig. 10. Figs. 11 and 12 are of grains of quartz .
which owe their elongate shape entirely to recrystallization.

Fic. 14.

Wie. 13. ‘Knot’ showing elongation parallel to schistosity and distribu-
tion of sericite, thickly plastered against the sides of the ‘ knot,’ but less
abundant at its ends.

Fie. 14. ‘Knot’ (partly drawn), showing coarser center and ring-like
arrangement of calcite patches containing limonite (black patches).

360 EF. H. Lahee—Metamorphism and Geological Structure.

Psammites.—The psammites are the commonest rocks in
the Basin formation. They occur at all horizons. As con-
trasted with the pelites, they are coarser, contain less carbon-
aceous matter, and number feldspar and muscovite among their

Ries 16. Nigel

Fies. 15-17. Changes in biotite, which accompany increasing metamorph-
ism. Fig. 10: low metamorphism; the mica bears no relation to schis-
tosity, which is indicated in the dimensional parallelism of included quartz
grains. Fig. 16: shreds along the edges of the mica bend into parallelism
with the schistosity. Fig. 17: aggregates are elongate parallel to the schis-
tosity (arrow); the metamorphism is high.

Hig ws. - Fie. 19. Fic. 20;

Z ae
2.98 O05 0

5s!
BS o10gS)

Ai aSh

S
2°
e
By

00 2° 0.2005

°
Sf a8 102-50
fotles

AZ

“oO

0 0.
< “ei
2)

?

Fie. 18. Garnet metacryst. The schistosity curves round it. Secondary
chlorite is developed at the poles of compression (right and left). The black
patch is ilmenite.

Fic. 19. Hornblende metacryst, including quartz grains and an ilmenite
crystal.

Fie. 20. Ottrelite metacryst, showing hour-glass structure (due to peculiar
distribution of included quartz and carbonaceous matter of the groundmass).
The black crystals are ilmenite.

original constituents. Those specimens which are least meta-
morphosed (Stage A) already exhibit alteration of orthoclase
to sericite, but this mica has no definite alignment. Both quartz
and feldspar grains still possess their clastic forms (fig. 4).
Flattening of fossil casts and bending of the primary musco-
vite flakes are the only signs of distortion, and these are caused
by superincumbent weight and not by shearing.

F. H. Lahee—Metamorphism and Geological Structure. 361

In many respects the succeeding stages of metamorphism in
the psammites are like those in the pelites. Thus, the tokens
of advancing metamorphism, as observed in Stages B to D, are
(1) an increase in the quantity of sericite (here formed largely
from clastic feldspar grains) ; (2) the acquisition of dimensional
parallelism by this sericite; (8) the consequent origin of a
secondary rock cleavage; (4) the transformation of fragmental
quartz grains, by a process of granulation (see figs. 6 to 9) suc-
ceeding a state of mottled extinction (fig. 5), into lenticular
ageregates (fig. 10) of small, somewhat elongate, parallel gran-
ules, and (5) the resulting improvement of the rock cleavage ;
(6) the further lengthening of the quartz grains by recrystalli-
zation (figs. 11 and 12); (7) the growth of such new minerals
as ilmenite, biotite, garnet, hornblende (fig. 19), and zoisite ;
and (8) the acquisition of dimensional parallelism by ilmenite
and later by biotite, first as aggregates (fig. 17) and then as
individual plates.

These changes take place in the same order and under the
-same circumstances as those which were described for the
pelites. Yet, on the whole, any given degree of perfection of
the secondary cleavage is attained somewhat earlier in the
_pelites than in the psammites. There is no necessity for
explaining the characters of the several stages in detail.

Psephites.—Although stratigraphically the conglomerates
and their derivatives have as wide a range as the psammites,
their total thickness is less. Their largest expression is in the
Dighton or Purgatory conglomerate, the uppermost member of
the Carboniferous formation in this region.

Consisting of both matrix and pebbles, the psephites may be
studied from two standpoints; but since the matrix, in ail
stages of metamorphism, resembles the psammites in the same
stages, we may confine ourselves chiefly to describing the
nature of the pebbles. A considerable majority of these are
of quartzite. Granite and vein quartz are also not uncommon,
and locally, at certain horizons, there are abundant, rather
angular fragments of carbonaceous shale, probably intraforma-
tional. The last are relatively soft, and therefore, as might
be expected, they are somewhat compressed even in the least
crushed specimens (Stage A). As usual, this early phase of
metamorphism is marked by scarcity of sericite and by absence
of a secondary rock cleavage. :

Pebbles of Stage B differ from those of Stage A in being
thinly coated with sericite, which gives a silky luster to their
surfaces. At the same time there is more sericite in the
matrix.

A. further increase in the development of this mica is exhib-

| Am. Jour. Scr.—FourtH SrrRigs, Vou. XX XITI, No. 196.—Aprin, 1912.
24

362 F. H. Lahee—Metamorphism and Geological Structure.

ited by specimens of Stage C. Here the sericite occurs, not
only in the matrix and plastered outside the pebbles, but also,
toa certain extent, within them. Metacrysts of ilmenite,
biotite, and garnet are sometimes present in the matrix. Many
of the pebbles—even the more resistant ones—particularly
when examined with the microscope, show signs of distortion
in their own oval shape and also in the elongate form of their
individual grains. If two pebbles are in contact, one often
indents the other. The lengths of the pebbles and of their
constituents are roughly parallel to a secondary cleavage
(schistosity) which has been produced in the matrix at this stage.

In Stage D the hardest pebbles may be sheared, flattened or
elongated, bent, warped, and fluted. The less resistant ones
have been squeezed into mere sheets and are cleaved parallel to
their flatness. Recrystallization in pebbles and matrix is at a
maximum. In both parts of the rock sericite is plentiful, and
the metacrysts themselves may be nearly as abundant in the
pebbles as in the matrix.

The study of these phases in the psephites brought out the
fact that spindle-shaped pebbles (linear schistosity) are charac-
teristic of lower metaphorism than are flattened, sheet-like
pebbles (plane schistosity). Moreover, when the matrix, as a
whole, is more resistant to deformation than the separate peb-
bles, the pebbles first reveal evidences of incipient metamorph-
ism, and, at any given stage in the history of the rock, they
are at a stage of metamorphism somewhat higher than that
of the surrounding matrix; and when the matrix is less resist-
ant than the pebbles, the reverse of this statement is true.
That is to say, deformation first affects the weaker portions of
the rock.

Summary.*—The Carboniferous sediments, originally nor-
mal fresh-water clastics, which represented the products of
immature weathering, have been altered by dynamic and static
metamorphism. During the process certain new minerals
developed. In different specimens these minerals vary in
species, in quantity, in orientation, and in size of the individual
particles, and it is found that the variations are consistent with,
and may therefore be used to some extent as indices of, the
degree of metamorphism to which the rock has been subjected.
Other factors, such as perfection of cleavage, deformation of
pebbles, etc., serve in the same capacity. According to these
indices the specimens have been classified in groups, each of
which is characterized by a particular stage of metamorphism.

* In the foregoing outline the major portion of the petrographic investiga-
tion, with all its details of megascopic and microscopic description, has
been omitted. We have endeavored to present a fair, though concise, idea

of the kind and amount of metamorphism, and of the method adopted in the
work.

F.. H. Lahee—Metamorphism and Geological Structure. 363

The degrees of metamorphism may now be studied with
reference (1) to rock texture; (2) to geographical distribution ;
(8) to stratigraphic depth ; and, (4) to deformation. Follow-
ing this, the relations of the schistosity to the bedding, a
subject closely allied to (4), just mentioned, will receive con-
sideration.

RELATIONS OF THE DEGREE OF METAMORPHISM TO Rock
TEXTURE.

A comparison of the degrees of metamorphism in rocks of
coarse and fine grain from different parts of the Basin would
be unprofitable, for many other factors might enter to disguise
the true relations. Such a comparison must obviously be one
of purely local significance.

Theoretically, shales, being finer than sandstones, should
yield to folding first; and, since folding implies more or less
rearrangement of the rock particles (deformation by flowage
or by minute fracture), metamorphism should also commence
first in the shales. This statement would seem to indicate
that, in a series of strata which differ from one another in
texture, the finer beds would be more intensely crumpled,*
and hence more highly metamorphosed, than the coarser beds,
after a given period of time, metamorphism being in process
all the while.

What are the conditions in the Narragansett Basin? From
each of twenty-two localities visited in the field work, two or
more specimens of different texture were obtained. Follow-
ing is a list of these specimens :

Conglomerates. Sandstones. Shales.
General Stage of Stage of Stage of
locality metamorphism metamorphism metamorphism
Just north
OfC%s I B B C
Est A A —
H:4 —_ A A
Grid B B —
Cant _ D C
B:9 C CO C
9 — D C
Be oapeags | — C C
Orel? — C D
1B ea) ae D D
Dis D C
Rie t — C and D C
Ets 1B) _ B

*See remarks on competent structure and reference thereto in Part I of
this paper. This Journal, last number, p. 254,

364 LF. H. Lahee—Metamorphism and Geological Structure.

Conglomerates. Sandstones. Shales.
General Stage of Stage of Stage of
locality metamorphism metamorphism metamorphism
H:43 C and B B —
Bo — C C
| ei 8, D — C
J eye a A C
yes — B A
H:9 C C —
B:14 — D C
D:14 D = C
G:14 C — B

According to this table, (1) there are thirteen cases of like
metamorphism in specimens of different texture; (2) there is
one case of conglomerate having higher metamorphism than
sandstone; (8) there are four cases of conglomerate having
higher metamorphism than shale; (4) there are seven cases of
sandstone having higher metamorphism than shale; and (5)
there are two cases of shale having higher metamorphism than
sandstone. Thus, out of twenty-seven comparisons, there are
only two instances of the finer rock having the greater meta-
morphism. The same lack of concordance between fact and
theory was also frequently observed in the field.

As for the explanation of this condition, while we realize
that the definition of degree of metamorphism, as used in this
paper, is wholly arbitrary and that the opportunity for error
in assigning such degrees is therefore considerable, we believe
that the general conclusion which may be drawn will still
remain unmodified. Since the Purgatory conglomerate, the
uppermost member of the Carboniferous formation in this
region, shows evidence of intense metamorphism in the zone of
flow, it is clear that all these rocks must have been under a very
thick cover at the time of their deformation. Probably
adjacent beds, measuring but a few feet in thickness, are not
affected with very marked differentiation according to texture,
under the great pressures existing at such depths. Shearing
is as apt to occur in a sandstone as in a shale. Moreover, as
has been stated by Daubrée* and by Harker,+ more heat is
developed by friction in the interstitial movements of coarse
rocks than in those of fine-grained rocks, and such heat no
doubt assists in the metamorphic processes.

We infer, then, that, in single outcrops, differences of texture
have little or no direct influence upon the distribution of the
degrees of metamorphism in those outcrops.

* Daubrée, A., Synthetical Studies and Experiments on Metamorphism.
Translation by T. Egleston. Smith. Inst., An. Rept., pp. 463-465, 1861.

+ Harker, A., On Slaty Cleavage .... Brit. Assoc. Adv. Sci., Rept.,
p. 848, 1885.

FH. Lahee—Metamorphism and Geological Structure. 365

aS Post- Carboniferous.
a | Carboniferous.
RA Pre- Carboniferous.

r) ‘ 2 3
Scale in miles

-

=e

i KINGST

Fic. 21. Outline map of the southern half of the Narragansett Basin.
Many of the dips and strikes are somewhat generalized. References to

numbered localities will be found in the text.

366 LF. H. Lahee—Metamorphism and Geological Structure.

GEOGRAPHICAL DISTRIBUTION OF THE DEGREES OF MRETas-
MORPHISM.

Some investigators in this region have noticed differences in
the intensity of metamorphism in passing across belts two or
three miles in breadth. Dale observed that the Carboniferous
strata have been more metamorphosed on Conanicut and Dutch
islands than in southern Aquidneck Island.* Foerste showed
that the rocks of Prudence Island are less altered than those
of Hope Island.+ And both Foerstet and Collie§ remarked
upon the increase in metamorphism westward across northern
Conanicut Island. In our field studies we have found a
like advance in metamorphism eastward and westward from
the middle north-south strip of the western coast belt
north of East Greenwich; southward, in the western coast
belt, south of Wickford; and eastward, from Aquidneck
Island to the eastern coast belt. These variations are not uni-
form and, in some cases, are not very conspicuous.

Of more importance is a study of the distribution of the
degrees of metamorphism in the Basin as a whole. This we
have done graphically as follows: The position of the eight
hundred or nine hundred specimens examined was plotted on
the map. For each of these, the kind of rock (coal, shale,
sandstone, or conglomerate) was indicated by a symbol, and
the stages of metamorphism (A, B, C, and D) were shown by
four different colors. The map was then divided into four
equal rectangles, as in fig. 21, and the allotment of the speci-
mens determined. The results are tabulated below.

Conglomerate Sandstone Shale Coal Totals

NE. rectangle :

Stage A: 0 0 3 0 3
Stage B: 2 8 4 0 14
Stage C: 0 2 2 0 4
Stage D: 0 0 0 0 0

Totals : 2 10 9 0 21

NW. rectangle :

Stage A: 2 5 1 1 9
Stage B: 1 2 1 0 4
Stage C: 4 6 2 1 13
Stage D: 0 1 1 0 2

Totals : 7 14 5 2 28

*Dale, T. N., The Geology of the Mouth of Narragansett Bay. Proc.
Newport Nat. His. Soc., Doc. 3, 1884, p. 6.

+ Shaler, N. S., Woodworth, J. B., and Foerste, A. F.: Geology of the
Narragansett Basin. U.S. G. S., Monog, xxxiii, 1899, p, 241.

tIbid., p. 230.

S$ Collie, G. L., Geology of Conanicut Island, R.I. Trans. Wise. Acad., x,
1894-1895, pp. 201, 217.

F.. H. Lahee—Metamorphism and Geological Structure. 367

Conglomerate Sandstone Shale Coal Totals
SE. Rectangle :

Stage A: 0 2 5 0 7
Stage B: 2 9 6 1 18
Stage C : 10 5 10 1 26
Stage D: 2 0 1 0 3

Totals: 14 16 22 2 54

SW. Rectangle :

Stage A: 1 1 1 ) 3
Stage B: 0) 0 2 0 2
Stage C: 5 7 14 1 27
Stage D: 3 14 13 0 30

Totals : 9 22 30 1 62

The relative number of examples of each stage for each
rectangle may be calculated on a percentage basis :

Rectangle Stage A Stage B Stage C Stage D Total
NE. 14°286% 66°667% 19°:047% 0% 100°00%
NW. 382°148 14°286 46°428 7°148% 100:00
SE. 12°963 33°333 48°148 5°555 100°00
SW. 4°918 3°279 42°623 49°180 100°00

Grouping Stages A and B (rather low metamorphism)
together, and Stages C and D (rather high metamorphism)
together :

Rectangle Stages A and B Stages C and D
NE. 80°953% 19°047%
NW. 46°429 53°571
SE. 46°296 53°704
SW. 8°197 91°803

These figures demonstrate plainly that the degree of meta-
morphism in the southern half of the Basin increases west-
ward and southward.*

RELATIONS BETWEEN THE DEGREE OF METAMORPHISM AND
STRATIGRAPHIC DEPTH.

This subject may be approached in two ways: we may study
specimens brought up from known depths in borings or in
mines, or we may examine surface outcrops of which the strati-
graphic position is at least fairly certain.

(1) In regard to the first suggestion, Professor Woodwortht
cited the statement of Professor Coliier Cobb, that “the

* We have already suggested that the western coals are most highly meta-

morphosed. See p. 356.
{ Shaler, N. S., Woodworth, J. B., and Foerste, A. F.: op. cit., p. 191.

368 F. H. Lahee—Metamorphism and Geological Structure.

amount of metamorphism varies with the depth, being greater
at the bottom (of bore-holes) than near the surface.” Cobb
drew this conclusion from his study, in 1887, of a set of cores
obtained from two bore-holes in Portsmouth, R. I. (near Loe.
34, H: 9, fig. 21). We have made a thorough re-examination
of the same cores with the following results :

Hote 1 Hoek 2

Actual Stage of Actual Stage of
depth Rock metam. depth Rock metam.
13’ 1” Coarse sandstone A
36’ 7" Medium “ C
99' Q! 14 6< A
OOK 3 yikes = oe A
114’ 2” Coarse “ A
129’ 3” Fine, dark shale A
149’ 3” Medium sandstone B
286'11” Fine, dark shale C 194’ 7” Banded shale A
109! 10” (1 (T (74 A.
233' 2” Medium sandstone A
944! <4 (a4 66 B
pay, Eley a -: ce B
325’ 11” Coarse shale A
334’ 4” Medium sandstone A
336’ 10” Fine sandstone B
. 380' 3” Coarse sandstone <A
484’ 4” Coarse shale CO
Hou. 04! Ee 3 C

In Hole 1, if it were not for the first mentioned shale, the
metamorphism would show a regular increase downward ; but
this specimen proves that high metamorphism is not necessarily
limited to great depth in the Basin.

In Hole 2 there is practically no alteration from top to bot-
tom. An exception occurs at 36’ 7”, where the highest meta-
morphism in the boring is recorded.

Although the data furnished by these specimens are scanty,
nevertheless the facts which they set forth are not to be dis-
regarded. They indicate (1) that, at least as low as 400 feet,
depth has no obvious effect. upon the intensity of the meta-
morphism, and (2) that a high degree of alteration may occur
near the surface and at considerable depths alike.

(2) According to the interpretation of the structural geology,
strata in the Wickford district are at about the same horizon
as those of the Bonnet ; yet the metamorphism is more intense
in the latter region. The rocks of Dutch Island (Loe. 14,
C-D: 13, fig. 21), Beaver Head (Loc. 20, C-D: 14), and west-

Fs H. Lahee—Metamorphism and Geological Structure. 369

ern northern Conanicut, are stratigraphically lower, and are
more metamorphosed, than those of northeastern Conanicut.
In northern Aquidneck Island, the rocks of the eastern and
western coasts are below those of the central portion of the
island; but the eastern outcrops display more alteration than
do the middle and western outcrops. The conglomerate of
High Hill Point (Loe. 45, 1: 11-12), correlated with the Pur-
gatory conglomerate of southeastern Aquidneck, is more highly
sheared than the latter. Finally, the arkose and associated
rocks, which are presumably low in the series, are scarcely
metamorphosed on the eastern coast of Mackerel Cove (Loc.
22, D:14), and are not severely crushed on Sachuest Neck
(H_: 14).

These and other comparisons which might be made, compel
us to believe that the degree of metamorphism is not inti-
mately dependent upon stratigraphic depth. As in the case of
texture, this may be on account of the great thickness of the
overlying cover during the process of metamorphism, by virtue
of which differential values were reduced.

e

RELATIONS BETWEEN THE DEGREE OF METAMORPHISM AND THE
INTENSITY OF THE FOLDING.

In describing the structural geology, we discussed strikes,
dips, pitch, axial planes, relative number of folds across the
Basin, and minor folding.* The degree of metamorphism
may now be studied with reference to each of these topics.

Strikes. —The most regular strikes were said to occur in the
western coast belt on Boston Neck and northward to Barber’s
Height (Loc. 9, B—C: 12) and in northern Conanicut Island ;
and the fact was explained by the inference that the action of
the maximum component of the forces of deformation was
here predominant. These are also districts of almost uni-
formly high metamorphism.

In the western coast belt between Hamilton (Loc. 8, B: 11)
and East Greenwich, and on Prudence Island, strikes are
somewhat variable. The degree of metamorphism is constant
and is high in these areas.

Elsewhere strikes are less regular and, coincidently, varia-
tions in the metamorphism within short distances are greater.

Thus, there seems to be a correspondence between the
degree of regularity in the strikes of the major folding, on the
one hand, and the intensity of the metamorphism, on the
other hand.

Dires.—The degree of metamorphism is more often high
than low where dips are steep; but locally it may be high in
outcrops with a gentle dip.

* This Journal, last number, pp. 256-259.

3870 FF. H. Lahee—Metamorphism and Geological Structure.

Pircu.—The stage of metamorphism has no bearing upon
the direction of pitch. It is usually high in regions where the
pitch is steep, and may be high where pitch is low.

AxIAL PLANES.—The intensity of metamorphism is unre-
lated to the direction of dip of the axial planes.

RELATIVE NUMBER OF FOLDS ACROSS THE Basin.—In treating
this subject, we concluded “ that the number of principal folds
per unit of Basin width, and therefore the degree of compres-
sion, regularly increases southward.”* As regards the geo-
graphic distribution of the degrees of metamorphism, we stated
“that the degree of metamorphism in the southern half of the
Basin increases westward and southward” (see p. 15). Clearly,
here is concordance of phenomena.

Minor Frotpine.—Below are listed the localities of contor-
tiont in an order such as to emphasize their positions in the
major folds and to bring out the relations between the degrees
of metamorphism and the amount of contortion:

Stages of metamor-

Position in Locality Metamorphism phism in hand- Degree of
fold number in general specimens contortion
Cg. Ss. Sh.

In axial 4 Moderate -2 xe) ye ei) Miedema
regions of 16 High > D CC _ Considerable
anticlines 27 5 Dicey Cor shies

33. Considerable Clipe. aC +

Situated on 10 High .. D .. ., Considergiie
limbs of 14 « SiaPaneles Deel fic =
folds is a peed Un iD, “

20 é D cis D 6c
48 ce a ah is ce

Position in 1. Mich a]{"to tee
folds 5 Slight oo foo oe Slee
uncertain 6 Low -. B <A _ Considerable

7 High Site E sa “
14. ce D D Heap “ce
12 ¢ Pee! D “s 6“
13 6 5 D on 6c
1 8 ce id St: ce
ili 9 ¢ oa = “i ee
Dil ce Ag. x" Gee (<4
22 6c bag, BY. D 74
25 “e Ned i yn ce
26 6c = hie D “<¢
29 Considerable cebu pie ee

* See this Journal, last number, p. 259. + Ibid., p. 259.

{ Wherever there is no record in this column, the data were obtained in
the field only.

F. H. Lahee—Metamorphism and Geological Structure. 371

30 Moderate ‘eS =) Bae Moderate

36 Considerable ia bis ee Considerable
37. Low <2 eta! Ae | utoderate

38 Moderate oe Considerable
40 ce C... UB eis =

A] = aks beh We a ko derate

44 Considerable CE, Wietergis ©. ieee

49 Variable sz> © A. Wanable

50 Moderate at Be eee Moderate

This table indicates a close dependence of the intensity of
metamorphism upon the degree of contortion. Whether the
outcrops are situated on the limbs or in the axial regions of
major folds appears to make no difference.

RELATIONS OF THE SCHISTOSITY TO THE BEDDING.

In a majority of the outcrops examined the schistosity was
nearly, if not quite, parallel to the stratification.* However,
while this is true of the coarser rocks, it does not so often hold
for the pelites. Very notable exceptions are frequent in the
greenish schists of southern Conanicut Island.

Linear schistosity, when well developed, may trend parallel
to the strike of the beds, or parallel to their dip, or in some
other direction. Most often, perhaps, it coincides with the
strike. This relation is not commonly evident in the psammitic
and pelitic rocks on account of their fine texture; but in the
conglomerates it is easily discerned in the attitude of the
elongated pebbies.t The data obtained in the field work
prove that parallelism with dip or strike is generally in regions
where the strikes are uniform (western coast belt, southern
Aquidneck Island), and that departures from this relation are

* Collie (op. cit., p. 213) described this for Conanicut Island, and inferred
that the ‘‘ schistosity was developed pari passu with the tilting of the rocks,
and that both processes were due to dynamic pressure.”

+ The lengths of distorted pebbles in metamorphosed conglomerates have
been recorded as parallel to the strike of the beds, by H. H. Reusch (Die
Fossilien Fuhrenden Krystallinischen Schiefer von Bergen in Norwegen.
German translation by R. Baldauf. Leipzig, 1883. Pp. 52-53); Ed. Hitch-
cock (Final Report on the Geology of Mass. Amherst and Northampton,
1841. P. 535; and also, On the Conversion of certain Conglomerates, etc.,
this Journal (2), xxxi, 372. 1861. P. 384); and W. O. Crosby (Contribu-
tions to the Geology of Eastern Mass., Bos. Soc. Nat. His., Occas. Papers,
1880. Pp. 148-149). On the other hand, the case in which the pebbles lie
lengthwise parallel to the dip has been described by Ed. Hitchcock (On the
Conversion of certain Conglomerates, etc. Loc. cit., p. 380); C. H. Hitchcock
(General Report upon the Geology of Maine; in the Sixth Ann. Rept. of the
Secretary of the Maine Board of Agriculture, 1861. P. 182); and W. P.
Blake (The Plasticity of Pebbles and Rocks: Proc. Am. Assoc. Adv. Sci.,
xviii, p. 199. 1869. P. 201). These differences are caused, no doubt, by
the diversity of orientation of the maximum, intermediate, and minimum
values of complex forces during deformation.

372 F. H. Lauhee—Metamorphism and Geological Structure.

especially characteristic of districts in which the dips and the
strikes are variable. As illustrating the latter case may be
mentioned the area north and northeast of Warren Neck, 1. e.,
the southern nose of the great Swansea syncline.

On the whole, the attitude of the schistosity in different
portions of the Basin is closely related to the attitude of the
stratification.

CONCLUSIONS.

Following are the conclusions arrived at from the study of
the Carboniferous rocks of the Basin :

1. During the period of their deformation, the Carbon-
iferous sediments were deeply buried.

2. On account of the thick cover, or for other reasons,
variations in the degree of metamorphism have been directly
determined neither by alternating differences of texture nor
by relative stratigraphic depth.

3. The degree of metamorphism is closely related to the
kind and intensity of the folding, for (@) metamorphism and
compression increase in severity in a southward direction; (6)
the greatest metamorphism occurs in the region where there
is greatest regularity of strikes; (¢) contortion of the beds is
accompanied by a high degree of metamorphism ; and, (d@) the
attitude of the schistosity generally bears a close relation to
the attitude of the bedding.

Cambridge, Mass., Feb. 1, 1912.
(To be concluded.)

~

ee)
“I
oo

Chemistry and Physics.
SCIENTIFIC INTELLIGENCE.

Il. CHEmIsTRY AND Puysics.

1. Separation of Titanium from Niobium, Tantalum, Tho-
rium, and Zirconium.—lIt has been found by J. H. Mutier that
salicylic acid shows a different behavior with titanium hydroxide
than with the other “ metallic acids.” An excess of salicylic acid
added to alkaline niobate or tantalate solutions completely pre-
cipitates the acids, but the presence of an alkaline fluoride pre-
vents this precipitation. Orthotitanic acid dissolves in salicylic
acid, giving, in the absence of fluorides, an intensely yellow solu-
tion. Zirconium and thorium hydroxides dissolve with difficulty
in salicylic acid, but after ignition the resulting oxides are prac-
tically insoluble in it.

Known amounts of the oxides of niobium, tantalum, zirconium

and thorium were each mixed with known weights of titanic
oxide, and the mixtures were then fused with 5 grams of potas-
sium carbonate, the fusions were taken up in 350-400° of water
at 60° and treated with 14-15 g. of salicylic acid, and heated for
8 or 4 hours at the boiling temperature. Then the precipitates
were allowed to settle, filtered rapidly, and washed with boiling
water. The concentrated filtrates were treated with ammonium
hydroxide, when titanium was precipitated, washed and ignited
to oxide. The precipitates were invariably contaminated with
alkali salicylates which could not be removed by washing. The
ignited oxides were, therefore, fused with potassium bisulphate and
weighed in the usual manner.

The results given from test-analyses show remarkably good
results in the separation of elements which has heretofore been
exceedingly difficult or even impossible in some of the cases.
From the tabular statement of the results it appears that three
or four fusions are necessary with any but very small amounts of
titanic acid, although nothing is said about this point in the
description of the method.

The exceedingly strong color of the salicylic acid solution of
titanic acid was used satisfactorily in determining the titanium in
several mixtures, but the author considers this calorimetric
method as of little practical value, owing to the interference of
the common contaminants of titanic oxide.—Jour. Amer. Chem.
Soc., XXxill, 1506. H. L. W.

2. Cementite—This important constituent of steels, Fe,C,
which may be called also tri-ferro-carbide, has recently been care-
fully studied by Rurr and GerstTEN with interesting results.
The substance was prepared according to well known principles
by suddenly cooling molten iron saturated with carbon and treat-
ing the pulverized product at first for a long time with dilute
acetic acid, then pulverizing the residue and treating it further

374 ~ Setentifie Inteiligence.

with 1/5 normal hydrochloric acid, and finally after removing
material of low specific gravity by stirring and decantation, wash-
ing with alcohol and ether and drying ina vacuum. The mate-
rial thus prepared appears to have been unusually pure, as it was
crystalline in character, gave analytical results very close to
those required by theory, and contained no graphite. The product
was dark gray with a tint of bronze in some cases, and very
brittle. Some of the larger fragments were used for hardness
determinations with the surprising result that this was found to
be only just above 3, according to the mineralogical scale. The
conclusion is reached, therefore, that it is not the hardness of the
carbide itself which causes the hardness of suddenly cooled steel,
but that of its solid solution in y-iron.

The authors have determined the heat of combustion of their
product and have found 375:1 cal. per molecule of Fe,C, when
burnt to Fe,O, and CO,. By comparing this result with their
own determinations of the heat of combustion of pure iron and
the known value for graphitic carbon, they have calculated the
heat of formation as follows:

3Fe+C = Fe,C—15:1 cal.

The compound is consequently shown to be endothermic, whereas
previous indirect calculations had indicated an exorthermic com-
bination of +8940 cal.— Berichte, xlv, 63. H. L. W.

3. The Use of Sulphur Monochloride for Decomposing Cer-
tain Minerals.—The process of decomposing various minerals by
means of sulphur monochloride was described by Edgar F. Smith
in 1898. Since that time the method has been applied by various
other chemists. W. B. Hicks, of the University of Pennsyl-
vania, has recently applied this method to the decomposition of
fergusonite, zschynite and samarskite, which are rare-earth min-
erals containing columbium and tantalum. The process consists
in heating the finely pulverized mineral in a boat in a combustion-
tube in contact with the vapor of sulphur monochloride, with the
result that columbium, tantalum, titanium and tungsten are
volatilized as chlorides and may be collected in nitric acid, while
the rare earths, together with silica, are left behind in the boat.
The method appears to possess advantages over the usual methods
of decomposition by means of fusion with acid potassium sulphate
or the acid fluoride.—Jonr. Amer. Chem. Soc., xxxiil, 1492.

H. L. W.

4. Determination of Water.—ZEREWITINOFF has devised a
rapid and accurate method for the determination of water in
various substances, which is interesting on account of being
based on a new principle. He treats the substance, for example
coal or starch, in a special form of apparatus with perfectly dry
pyridine. This liquid is very hygroscopic and, therefore, takes
up the water from the substance. A proper amount of methyl
magnesium iodide in amyl ether solution is then added whereby
methane is liberated, and the volume of this gas is at once meas-

Chemistry and Physics. 375

ured in the special apparatus, and from this gas volume the
weight of water present is calculated. The reaction taking
place is as follows :

2CH,MgI+H,O = 2CH,+MgI,+Mg0O.

For the preparation of the reagents, which requires special pre-
cautions, as well as for the description of the apparatus, the
“measuring part of which is based upon Lunge’s nitrometer, refer-
ence must be made to the original article.—Zeitschr. analyt.
Chem., li, 680. H. L. W.

5. Reduction of Vanadic Acid in Concentrated Sulphuric Acid
Solution.—Cain and Hostetter have found that vanadium pen-
toxide in concentrated sulphuric acid solution is reduced imme-
diately and quantitatively to the quadrivalent condition by
hydrogen peroxide. All that is necessary is to evaporate the
solution until fumes are given off freely, cool, add a slight excess
of 3 per cent hydrogen peroxide, cover the flask and fume strongly
for a few minutes to destroy the excess of hydrogen peroxide,
after which the solution may be titrated with permanganate. It
was found that molybdenum, titanium and iron are not similarly
reduced, and that persulphates and also Caro’s acid have the
same effect as hydrogen peroxide upon the vanadium pentoxide.—
Jour. Amer. Chem. Soc., Xxxiv, 274. H. L. W.

6. Die Zersetzung von Stickstoffdioxyd im elektrischen Glimm-
strom.—An easily reproducible, beautiful and instructive demon-
stration experiment was performed by J. ZENNECK before the
Physical Section of the 83d Convention of German Scientists at
Karlsruhe, on September 26, 1911. The apparatus was con-
structed of glass, and it may be described as follows.

A cylindrical bulb with its long axis vertical was partly filled
with pure nitrogen tetroxide, N,O,, which was maintained in its
more complex molecular condition and liquid state by surround-
ing the bulb with a freezing mixture of ice and common salt. A
horizontal glass tube of convenient diameter connected the top of
the bulb with a discharge tube, to be described later on. The
horizontal tube was drawn down to capillary dimensions not far
from its union with the bulb. Beyond the capillary section this
tube was provided with a glass stopcock. The discharge tube
was shaped like a vertical U, with relatively long “legs” or par-
allel branches which were comparatively close together. Near
the upper end of each leg a short, horizontal section of glass
tubing was sealed in place. These inlet and outlet tubes were at
the same level and both were situated in the plane of the U-tube.
The object of these tubes was to enable the experimenter to con-
nect the discharge tube with the above-mentioned horizontal
tube leading from the bulb, and with the rest of the train of
apparatus, by means of short pieces of rubber “ connecting tub-
ing.” Above the common level of the horizontal tubes each leg
of the U-tube was sealed to a vertical, cylindrical bulb. Each
bulb contained an electrode whose wire was sealed into the top of

376 . Seientific Intelligence.

the bulb and then continued to one terminal of the secondary of
a spark coil. The primary coil was fed with an alternating
current. Thus the discharge tube was simply a long vacuum
tube bent through 180° at the middle of its length. The outlet
tube was joined to a second discharge tube which was spherical
in form and which was provided with two lateral tubes each con-
taining one electrode. These side tubes were in the same vertical
line and hence at right angles to the several sections of connect-'
ing tubing. The inlet and outlet tubes of the spherical discharge
bulb lay along a horizontal diameter, and each was furnished with
a glass stop-cock. The last outlet tube led to a Gaede mercury
pump. Usually the pump was regulated so as to maintain a
pressure of about 1™™ of mercury in the region of the inlet of
the U-tube, and this corresponded to a rate of flow of the gas of
about 8 meters per sec., at the same place.

When all three cocks were open and the U-tube alone was suit-
ably excited, the following striking phenomena could be observed.
Just below the inlet tube the discharge was yellow with a tinge
of orange, and this was succeeded by a bluish violet region lower
down in the limb. Still further down in this branch and through-
out the entire curved portion of the U a greenish yellow light
was emitted. In the second leg, and immediately below the out-
let tube, the gas radiated bright red. If the electric current was
decreased, while the flow of gas was maintained constant, the
regions of different hues grew appreciably longer. Increasing
the current shortened the colored segments. On the other hand,
when the electrical conditions were kept invariable, the aforesaid
regions increased or decreased in length according as the rate of
flow of gas was made larger or smaller.

That these phenomena are due to successive stages in the dis-
sociation of nitrogen dioxide may be shown by the aid of the
spherical discharge tube. Without exciting either tube, the gas
is drawn slowly through the entire system for some time, and
then the cocks on both sides of the spherical bulb are closed. On
sending the electric current through this bulb the discharge first
assumes a reddish yellow color, which gradually passes over into
bluish violet. Suddenly the color changes to greenish yellow and
this, in turn, slowly gives place to bright red. Thus the various
stages of dissociation which are seen simultaneously, but spread
out linearly, in the U-tube are presented in succession, but in the
same general region, in the closed vacuum bulb.

The question of the physical significance of the various color
changes has been investigated spectroscopically by J. Zenneck
and B. Strasser.* The first spectrum, of orange yellow color,
belongs either to the tetroxide or the dioxide of nitrogen, since
both of these vapors seem to give practically the same radiation.
The second spectrum is due to some “labile” oxide intermediate
between the dioxide and nitric oxide, perhaps nitrogen trioxide.
Nitric oxide gives rise to the third spectrum, while the fourth is

* Phys. Ztschr., No. 26, p. 1201, Dec., 1911.

Chemistry and Physics. 3877

chiefly due to nitrogen and oxygen gases separately.— Verh. d.
deutsch. phys. Gesellsch., No. 21, p. 953, 1911. H. S. U.

7. The Mechanism of the Semi-permeable Membrane, and a
New Method of Determining Osmotic Pressure.—Heretotore, the
semi-permeable membranes used in measuring osmotic pressures
had to fulfil the condition of rigidity, either directly or by being
deposited in a rigid support. A very ingenious scheme for abol-
ishing this difficult requirement has been devised and tested by
F. T. Trouton. Although the principles involved are of a gen-
eral nature, it will be conducive to clearness to restrict the follow-
ing explanation to a typical case.

Suppose the problem is to find the value of the osmotic pressure
of an aqueous solution of pure sugar of a given concentration.
For theoretical purposes, we may imagine a rectangular glass
vessel, of the type often used in stationary storage cells, separated
into two compartments by a vertical, transverse, impervious
diaphragm, ¢. g., a sheet of glass. This diaphragm must not
extend to the level of the top of the vessel. One compartment is
nearly filled with water, and the other with sugar solution.
These liquids are then placed in hydrostatic communication by
having superposed upon their upper surfaces a layer of liquid
ether of sufficient depth to completely submerge the upper edge
of the partition. Since sugar is insoluble in ether, while ether
dissolves a small percentage of water, it follows that the layer of
ether will take the role of the usual effectively rigid, semi-per-
meable membrane. In fact, this is the key-note of Trouton’s
innovation, namely, to substitute a liquid semipermeable partition
for a rigid one. To be sure, both water and sugar solution take
up some ether, but this complication is not serious since it can be
relegated to the sphere of determinate corrections. Ether dis-
solves about 1:05 per cent of water when placed in contact with
the same, but ether absorbs less than this from a sugar solution,
the amount depending upon the concentration of the solution.
For equilibrium at the water-ether surface the ether must, there-
fore, contain 1°05 per cent of water, while at the solution-ether
interface a smaller quantity is necessary to establish equilibrium.
Diffusion through the ether prevents this equilibrium from being
established, consequently, water will pass across from the water
side to the solution side of the partition. If the ether could rig-
idly maintain its position so as to prevent any increase in the
volume of the sugar solution, the hydrostatic pressure of this
solution would increase, due to the accession of water. Under
these ideal circumstances the process would come to an end when,
owing to the increase of pressure, the percentage of water
absorbed by the ether from the sugar solution attained the same
value as the fraction of pure water taken up by the ether at
atmospheric pressure. The pressure competent to effect this
state of equilibrium in the ether wonld be the equivalent of the
osmotic pressure of the sugar solution.

Am. Jour. Sci.—FourtH Srrises, VoL. XX XIII, No. 196.—Aprit, 1912.
25

378 . Seientific Intelligence.

Effective rigidity can be imparted to the ether by the apparatus
designed by Trouton and used by Burgess. It consisted of a
vertical, copper U-tube strong enough to withstand an internal
pressure of more than 100 atmospheres in excess over the outside
atmospheric pressure. One of the parallel branches of the tube
was permanently connected with a pressure gauge, and the upper
ends of both branches were provided with stopcocks and inlet
tubes. In charging the apparatus the first step was to introduce
enough sugar solution to half-fill the tube. Then ether was
sucked into the branch which was not directly associated with
the gauge, and the cock closed. Next, air was pumped into the
other branch of the U-tube until the gauge registered the desired
pressure, after which the second cock was closed. After sufficient
time had elapsed for the ether to take up its full complement of
water from the solution, the cock of the branch containing the
ether was opened, thus allowing the compressed air in the other
branch to force the ether out into the auxiliary testing tubes.
The water content of the ether was determined by passing the
moist ether, as vapor, through calcium chloride drying tubes
which were maintained at 40°C. ‘This was sufficiently warm
to prevent ether condensing in the tubes, and yet was found not
to be too high for substantially absorbing all the water.” This
entire process was repeated at different pressures, so that all the
necessary data were obtained for plotting a curve having for the
abscissas of 1ts points, pressures in atmospheres, and for the ordi-
nates, percentages of water absorbed by the ether. For a con-
centration of 600 grams of sugar per liter of solution the aforesaid
percentages increased from 0°939 to 1143 as the pressure changed
from 1 atmosphere to 110°5 atmospheres. The curve is somewhat
convex towards the pressure axis. At about 79 atmospheres the
per cent of water taken from the sugar solution by the ether was
read off from the curve as 1°055, which is numerically the same
as for the absorption of water by ether at a pressure of one
atmosphere. Consequently, the osmotic pressure equals 79 atmos-
pheres. Interpolating for the given concentration from the
curves of Lord Berkeley and Mr. Hartley, the osmotic pressure
as determined by the ferrocyanide of copper method was found
by Trouton to be 81 atmospheres. The agreement is quite satis-
factory in view of the fact that Trouton has not yet attempted to
perfect his method, and to take into account all necessary correc-
tions for variations in temperature, in concentration, ete.—Pro-
ceedings Roy. Soc., \xxxvi, p. 149, Jan., 1912. H. S. U.

8. Note on the Monatomicity of Neon, Krypton and Xenon.—
Having at his disposal relatively large quantities of pure neon,
krypton and xenon, and being of the opinion that the monato-
micity of these gases had been taken for granted on somewhat
insufficient evidence, Str Wirtttam Ramsay has quite recently
determined y, the ratio of the specific heat at constant pressure
to that at constant volume, for each of these gases. The appa-
ratus used was of the same type as the one described in the mono-

Chenustry and Physics. 379

graph on argon,* the experimental process consisting essentially
in comparing the wave-length of sound in each rare gas with the
wave-length in air for the same frequency, by Kundt’s method.
The mean values of the wave-lengths for air, neon, krypton and
xenon at 19° C. were found to be 5°584™, 7:220°™, 3:°626™ and
2°364™ respectively. Taking the densities of these gases, in the
order named, as 14°479, 10°10, 41°46 and 65°11, and assuming y
equal to 1:408 for air, it follows that the ratio of the specific
heats of neon, krypton and xenon equals respectively 1°642, 1°689
and 1°666. Ramsay concludes :—‘‘'These numbers approximate
within the limits of experimental error to the theoretical ratio
1667, and it therefore follows that neon, krypton, and xenon,
like helium and argon, must be regarded as monatomic.” “ Their
molecular and their atomic weights are identical.”— Proceedings
voy. Soc.) Ixxxvi, p. 100, Jan., 1912. H. S. U.
9. Modern Microscopy ; by M. I. Cross and Martin J. Core.
Fourth edition, revised and enlarged. Pp. xvii, 325, with 113
figures and 6 plates. Chicago, 1912 (Chicago Medical Book Co.).
—‘“ Jn the preparation of this new edition, the original intention
that it should be for beginners and students has been steadily
kept in view.” ‘The volume is divided into three parts, of which
the first deals with microscopes and auxiliary apparatus such as
ray-filters, artificial sources of light, text-books, etc. Care is
taken to define and explain the significance of many optical
terms, for example, aplanatism, chromatic over-correction, spheri-
cal aberration, etc. In short, this Part, which comprises 136
_ pages, will enable an intelligent beginner to purchase wisely and
to subsequently use and care for his apparatus to best advantage.
Part II, of 82 pages, is devoted to staining, section cutting
and, in a word, to the general preparation of microscopic objects.
Part III, covering 100 pages, is entirely new, and it is divided
into seven chapters, each of which was written by a specialist.
It gives information on many subjects in which amateur micro-
scopists in particular are interested, such as: interference figures
of arragonite, larvae of hydrachnid parasites, bacillus anthracis,
etc. The six plates belong to this Part and they are clear, beau-
tiful reproductions of the original negatives. In conclusion, the
subject is presented in such an attractive and elegant manner
that the book deserves to win many converts to the branch of
science with which it deals. He Seu
10. Laboratory Problems in Physics ; by Franxuin T. Jones
and, Ropert R. Tatnatyn. Pp. ix, 81. New York, 1912 (The
Macmillan Co.).—This book is in part a liberal revision of Crew
and 'Tatnall’s ‘“‘ Laboratory Manual of Physics” and, with regard
to its contents, the authors say: ‘‘ While these exercises may be
used in connection with any text-book, the order adopted is that
of Crew and Jones’s ‘ Elements of Physics.’” The 72 experi-
ments suggested are intentionally of an elementary nature, they

* Phil. Trans., A, 1895, Vol. 186, Part I, p. 228.

380 ~ Screntifie Intelligence.

cover all of the usual subdivisions of physics, and they seem to
be well arranged and wisely selected. The description of each
exercise is presented under the subtitles : ‘“ Problem, Apparatus,
Experiment, and Application.” In most cases, the paragraphs
under “‘ Experiment ” include a well-drawn diagram of the appa-
ratus and a blank tabular form to indicate a systematic plan for
recording the numerical data. The “ Application” is a note-
worthy feature of the volume and, in each case, it comprises
several pertinent questions to be answered by the ‘student. For
example, in the case of the pendulum, one question is this:—“ A
block of stone, just swung clear of the ground by a derrick at
the top of a high building, is observed to make one complete
swing in 15 se¢. » & How high is the building?” The last four
pages of the book are devoted to the metric system and toa table
of 16 “ Useful Numbers,” such as :—“10 The specific heat of ice
is about 0°505.” The typographical errors are few and unim-
portant. On the whole, the book seems admirably adapted to
subserve the purposes of the authors. H. 8. U.
11. Storage Batteries ; by Harry W. Morse. Pp. 266, with
106 text-figures. New York, 1912 (The Macmillan Co.).—This
book does not contain a preface, but the author’s aim and object
may be inferred from the last paragraph of the introductory
chapter, which reads:—‘‘ The following chapters are based on
lectures which have been given for the last few years at Harvard
University.” ‘‘In the course the work on storage cells is pre-
ceded by study of the general theory of.galvanic cells, and the
simplest of this theory has been included in this book.” “ No
attempt has been made to give any of the detail of storage bat-
tery engineering, but only to introduce the reader to the peculi-
arities of the cell itself.”
The author possesses the happy faculty of presenting his sub-
ject in an easy and entertaining style without sacrificing logical
sequence and scientific accuracy and thoroughness in the least.
Thus, it is rather attractive to read of “the heyday of galvanic
cells” and of “‘a unique battery which harks back to the earliest
form.” 'The curves and diagrams are well-drawn and to the
point, and the text abounds in solutions of typical numerical
examples. Finally, the treatment is well-balanced, since neither
the physical nor the chemical aspect of the subject is given undue
prominence. H. S.e
12. A Laboratory Manual of Physics and Applied EHlectric-
ity; arranged and edited by Epwarp L. Nicuors. Vol. I.
Junior Course in General Physics; revised and rewritten by
Ernest Buaker. Pp. xiii, 417; with 135 figures. New York,
1912 (The Macmillan Co.). ’—The excellence of the first edition
of this book has already been pointed out in this Journal, (see
vol. xlvili, 346, 1894). The revised edition of this manual difters
very appreciably in several respects from the earlier publication.
As indicated above, it has been almost entirely rewritten.
Changes have been made in the treatment of many of the experi-

Geology. 381

ments retained, a few have been omitted, and about forty new
experiments have been incorporated. In addition to the tables
of natural functions, which are common to both editions, 18
tables of physical and mathematical constants have been placed
near the end of the new volume. Asa consequence of all these
mutations the manual has expanded from 294 to 417 pages. If
possible, the quality of the book has kept pace with its increase
i scope. H. Si: Ui.
13. Die Bearbeitung des Glases auf dem Blasetische; by D.
Dsaxonow and W. Lrermantorr. 2d edition. Pp. xv, 196,
with 34 text-figures. Berlin, 1911 (R. Friedlander & Sohn).—
The real author of this manual is Lermantoff, since he had as a
nucleus for the first edition, which appeared in 1895, only a few
fragmentary notes left by Djakonow, who died in 1888. Ler-
mantoff has taken great pains to supplement his own knowledge
of the art by consulting with three of the best professional glass-
blowers of St. Petersburg. Consequently the book is character-
ized by giving the most minute details as to how to proceed in
any given case. Undoubtedly it is very reliable and up to date.
On the other hand, the volume is not well-balanced because pages
128 to 155 are devoted to the making of mercury-in-glass ther-
mometers, while pages 155 to 195 deal with the calibration of
such thermometers, a theme which pertains to laboratory manuals
but not to a practical guide to glass-blowing. He) SeUy

Il. Gronoey.

1. West Virginia Geological Survey: Wirt, Roane, and
Calhoun Counties; by Ray V. HENNEN, Assistant Geologist.
1911. 573 pp., 3 maps, 15 plates, 6 figures.—In common with
the previously issued West Virginia Reports, the description of
Calhoun, Roane and Wirt counties is prepared in such a manner
as to be directly useful to those interested in petroleum, gas and
coal, and agriculture. The value of soil is particularly empha-
sized by the State Geologist and attention is called to the damage
resulting from deforestation. A chapter on the Historical and
Industrial Development of the area, and a meagre discussion of
the Physivgraphy is followed by a detailed study of the Geology,
including chapters on General Geology, the Dunkard Series, the
Monongahela Series, the Conemaugh Series. An unusually large
list of carefully measured sections is given. An examination of
the geologic structure shows the area to be located on the eastern
flank of the Great Appalachian geosyncline, which in this area is
modified by minor folds, embracing six anticlines and five syn-
clines. The care with which structure contours have been worked
out and recorded on the map is justified by the fact that structure
is the primary control in the distribution of oil and gas,——the
chief mineral wealth of this group of counties. The results of

382. Scientific Intelligence.

strictly economic studies are recorded under the headings
Petroleum and Natural Gas (pp. 276-467); Coal Resources (pp.
468-497); Clays, Road Materials and Stone (pp. 498-506). The
chapter on Agriculture and Soils is the work of W. H. Latimer ~
and F. N. Meeker of the Bureau of Soils. H. E. G.

2. Geological Survey of New Jersey; Henry B. Kéuet,
State Geologist. Bulletins 1-5, including Annual Report for
1910. 1911.--Beginning with the present report, the publications
of the New Jersey Survey will be listed as Bulletins and issued in
two forms,—separately and bound into an annual volume. The
change will be welcomed by those who have occasion to use
these valuable reports. Under the new arrangement the follow-
ing bulletins have appeared :

Bulletin 1, Annual Administrative Report of the State Geolo-
gist for 1910. 48 pp.

Bulletin 2, Report on the Approximate Cost of a Canal between
Bay Head and the Shrewsbury River, by H. B. Kiimmel. 20 pp.,
map and profiles.

Bulletin 3, Flora of the Raritan Formation, by Edward W.
Berry. 231 pp., 29 plates, 3 figures. 7

Bulletin 4, Description of the Fossil Fish Remains of the Cre-
taceous, Eocene and Miocene Formations of New Jersey, by Henry
W. Fowler. 192 pp., 108 figures.

Bulletin 5, Mineral Industry of New Jersey for 1910, by Henry
B. Kiimmel and 8. Percy Jones. 24 pp. |

Announcement is made that an entirely new geologic map of
the state is In preparation to replace the map of 1890, which is
not only out of date, but has been out of print for many years.

H. E. G.

3. The State of the Ice in the Arctic Seas (Isforholdene i de
arktiske Have). 1911, pp. xxill, 5 maps.—At the request of the
Seventh International Geographical Congress, the Danish Meteor-
ological Institute issues an annual bulletin on Arctic ice printed
in Dutch and in English based on data from all available sources.
The present report, prepared by Commander C. I. Hansen, records
by months the condition of the ice at various localities and a
summary for each region. Separate maps for April, May, June,
July and August are included. H. E.G.

4, Wisconsin Geological und Natural History Survey; E. A.
Brrer, Director; W. O. Horcuktss, State Geologist. Bulletin
No. X XIII, Economic Series No. 14, 1911. Reconnoissance Soil
Survey of Part of Northwestern Wisconsin, by SAamuEL WeErD-
MAN, assisted by E. B. Hatt and F. 8S. Mussackx. Pp. 102, map
in pocket, 15 plates, 16 text figures —The region covered by the
Survey has an area of 6,705 square miles and includes the counties
of Eau Claire, Chippewa, Rusk, Barren, Dunn, Pepin, Pierce,
St. Croix, and Polk. In addition to a study of soils and of
agricultural conditions, this report discusses the geology, geog-
raphy, water supplies, climate, etc., and presents results in a
manner very acceptable to those who wish a general knowledge

Geology. 383

of the physical geography of this portion of the Prairie Plains
Province.

5. Annual Progress Report of the Geological Survey of West
Australia for the year 1910. Pp. 31; 2 maps, 2 figures. Perth,
1911.—The active staff of the Western Australia Survey includes
the following officers in addition to A. Gibb Maitland, the Govern-
ment Geologist : H. P. Woodward, Charles G. Gibson, H. W. B.
Talbot, L. Glauert, and E. 8. Simpson, the latter in charge of the
Survey Laboratory. Four Bulletins were issued during the year,
viz., Bulletin 36, Paleontological Contributions to the Geology
of Western Australia, III (this Journal, xxxi, p. 239, 1911) ;
Bulletin 38, The Irwin River Coalfield and the adjacent Districts
from Arrino to Northampton (this Journal, xxxi, p. 239, 1911);
Bulletin 39, Geological Observations in the Country between
Wiluna, Hall’s Creek and Tanami (this Journal, xxxi, 574);
Bulletin 41, Geology and Ore Deposits of the West Pilbara
Goldfield (in press). .

The annual report for 1910 contains an interesting history of
the Survey from its informal organization in 1847. Since 1887
the work has been carried on continually by a small but active
group of geologists. The nature of the work undertaken may be
judged from the list of publications which comprises 58 reports
on gold deposits, 10 on copper and lead, 7 on tin, 3 on iron ores,
10 on coal and oil, 3 on phosphates, 12 on miscellaneous mineral
deposits, 10 on general geologic subjects, 1 on petrography, 1
on paleontology, 23 on ground water. Besides preliminary reports
on various phases of geologic work (chiefly economic) the Annual
Progress Report for 1910 includes a discussion by Mr. Gibson of
the “‘ Principal Geological Features of the Kalgoorlie Goldfield,”
together with a geological map of this region, which has con-
tributed more than half of the total production of gold in the
state. H. E. G.

6. The Uses of Peat.—Bulletin 16 of the Bureau of Mines
(pp. 214) contains an account by Cuartes A. Davis of the uses
of peat for fuel and other purposes. The subject is one of
importance, for thus far this country has made little progress in
this direction, as compared with what has been done abroad. As
fuel it has its highest value and is most efficient as a source of
producer gas; but it is useful also, in place of wood, in brick
manufacture, ceramic firing, and lime burning. This whole sub-
ject is discussed in much detail and many important facts brought
out. Peat is also available in a variety of manufacturing pur-
poses, as those calling for a fibrous vegetable product; the
comparative abundance of wood has, however, prevented the
development of this in the United States, as compared with
Europe, where wood is much more scarce. Agriculturally peat
lands may be cultivated with profit, if the right crops are chosen,
and sufficient care is used to put the lands in the best condition
by draining, decomposing, and fertilizing the peat.

384 . Seventific Intelligence.

III. Muscetnanrous Screntiric INTELLIGENCE.

1. Carnegie Institution of Washington. Year Book. No, 10,
1911, RosertS. Woopwarp, President. Pp. xvi, 296; 9 plates.
Washington, January, 1912.—The publication of the tenth annual
report of the Carnegie Institution is an event of uch importance,
and gains a special interest from the fact that during the past
year an addition of $10,000,000 to the fund of the foundation has
been made by Mr. Carnegie; the total endowment now reaches
the princely figure of $22,000,000, yielding an annual income of
$1,100,000. The past year has also been marked by the comple-
tion of the meridian astronomical work at the temporary observa-
tory at San Luis, Argentina. The observations, carefully planned
in advance by Professor Boss, were begun in April, 1909, and
so expeditiously carried out that about a year since the observers
returned to Dudley Observatory at Albany. Professor R. H.
Tucker was the astronomer in charge of the work. It 1s also to
be noted that the past year has seen the completion and equip-
ment, at a cost of $25,000, of the 70-foot motor boat called the
“Anton Dohrn” ; it will be used for the department of Marine
Biology, which has its center at Tortugas, Florida.

The sum allotted for the ten departments, to which the funds
of the Institution are particularly devoted, amounted to very
nearly $500,000, while about $100,000 more were appropriated
for the minor grants, although not all expended. The total
expenditures of the Institution since its beginning amount to
about $5,500,000, of which $4,000,000 have been applied directly
to research, more than $300,000 to publications, and $400,000 to
administration. The Institution now owns two astronomical
observatories, five laboratories and a non-magnetic ship, besides
numerous buildings and pieces of real estate. Some 201 separate
volumes have been published and a total of 90,730 volumes dis-
tributed.

The report of the President, from which these facts are taken,
also gives a brief summary of the results accomplished by the
several organized departments of research, ten in number, as well
as of the investigations of the research associates. ‘These sub-
jects are further discussed in detail by the gentlemen in charge,
who give a most interesting account of the work that has been
prosecuted in their respective lines. It is only by a careful read-
ing of these individual reports, which make up the bulk of the
present volume, that an adequate idea can be obtained of the
manifold results that are being accomplished by the Carnegie
Institution. A special descriptive pamphlet of 34 pages with
numerous illustrations has been issued commemorative of this
tenth anniversary.

2. Publications of the Carnegie Institution.—Recent publi-
cations of the Carnegie Institution are noted in the following
list (continued from vol. xxxii, p. 327):

Miscellaneous Intellagence. 385

No. 27. Bacteria in relation to Plant Diseases; by Erwin F.
Smith. Volume II. History, general Considerations, Vascu-
lar Diseases. Pp. vili, 368; 20 plates, 148 figures.

No. 88, Part Il. Dynamic Meteorology and Hydrography ; by
V. Bserxnes and different collaborators. Part [[--Kinematies.
Pp. vii, 175, 4to. 113 figures and 60 folio plates in separate cover.

No. 140. The Eusporangiate. The Comparative Morphology
of the Ophioglossacez and Marattiacee ; by Douariass H. Camp-
BELLE.) Pp, vi, 229 ; 13 plates, 192 figures.

No. 145. <A Revision of the Cotylosauria of North America ;
by E. C. Case. Pp. iii, 122; 14 plates, 52 figures.

No. 146. Revision of the Amphibia and Pisces of the Permian
of North America; by E. C. Case, with a description of Permian
Insects by E. H. SeLiarps, and a discussion of the Fossil Fishes
by Lovis Hussaxor. Pp. vu, 179, 4to ; 32 plates. |

No. 147. Determinations of Stellar Parallax ; by Henry N.
Russett, based upon Photographs taken at the Cambridge
Observatory by ArTtHuR R. Hinks and the writer, with Magni-
tudes and Spectra determined at the Harvard College Observa-
tory under direction of Epwarp C. PickErinG. Pp. iv, 142.

No. 155. A Comparative Study of Temperature Fluctuations
in different Parts of the Human Body; by Francis G. BENE-
pict and Enaar P. Stack. Pp. v, 73; 38 figures.

No. 156, Part II. Feeding Experiments with Isolated Food-
Substances ; by THomas B. OsBoRNE and WAFAYETTE B. MENDEL,
with the codperation of Epona LL. Ferry. Pp. 1, 55138 ; 2
plates, Tables XX XI-XX XVI, Charts X XTI-CX XIX.

No. 157. High Temperature Gas Thermometry by Arruur
L. Day and Rosertr B. Sosman, with An Investigation of the
Metals by E. T. Aten. Pp. vi, 129; 18 figures.

No. 158. The Methods of Petrographic-Microscopic Research:
Their Relative Accuracy and Range of Application; by FRep.
Eucrnre Wricur. Pp. 204; 11 plates, 118 figures.

No. 160. The Absorption Spectra of Solutions of comparatively
Rare Salts, including those of Gadolinium, Dysprosium, and Sama-
rium, etc.; by Harry C. Jones and W. W.Srrone. Pp. vii,
112, with 67 plates.

No. 162. Ctenophores of the Atlantic Coast of North America;
by AtFrREeD G. Mayer. Pp. 58; 17 plates, 76 figures.

The Classics of International Law ; edited by James Brown
Scorr. luris et Iudicii Fecialis, sive, Iuris inter Gentes, et
Quaestionum de eodem Explicatio; by Ricuarp ZoucuE, edited
by T. E. Hotuanp.

Vol. I A Reproduction of the First Hdition (1650), with
Introduction, List of Errata and Table of Authors. Pp. xvi, 204.

Vok Il) A Translation: of the Text; by J. L. Brizgry. Pp.
xvi, 186.

A pamphlet (pp. 90) under date of February 6, 1912 is devoted
to a Price List, Classified descriptive Lists and Index of Authors.

386 . Scientific Intelligence.

3. Hlements of the Differential and Integral Calculus
(Revised Edition); by W. A. GranviLLE. 8vo, pp. xv, 463
(Ginn & Co.).—Professor Granville’s removal from the sphere of
teaching to a college presidency will, it is to be feared, terminate
his activity in the production of text-books in Mathematics. His
Calculus is unequaled by any we know in the number and excel-
lence of its working problems, on which in this subject preémi-
nently the student’s effective knowledge of the science must
depend. The revised edition is enriched by considerable additions
to the problems and by a portrait of Leibnitz. The changes in
the text are unimportant. W. B.

4. The Theory and Practice of Technical Writing; by SamuE.
C. Harte. Pp. vil, 301, with numerous figures. New York,
1911 (The Macmillan Company).—This work is of somewhat
novel character, since it is planned to guide the engineer in his
task of presenting his reports in a manner that shall be at once
clear and effective. It has been assumed too much, hitherto, that
technical writing would take care of itself, and hardly required
the same care as discussions more general and literary in their
character. ‘The author discusses with much clearness the various
principles of logical structure, and then the practical application
of these to the cases in hand, which may be treated in different
form, according to the audience for which they are prepared.
The Appendix gives a series of useful illustrative examples.

5. Publications of the Harvard College Observatory ; Kpwarp
C. PickERING, Director.—Recent publications are noted in the
following list (continued from vol. xxxil, p. 327):

Annats.—Vol. LXII, Part II. Ledger of Zone Observations
made with the 8-inch Meridian Circle during the years 1888-1898;
by ARTHUR SEARLE. Pp. 149-253.

Vol. UX XI, No. 2. Spectra and Photographic Magnitudes
of Stars in Standard Regions; by Wuitiramina P. FLEMING.
Pp. 27-45. ;

Circutars.—No. 167. Stars Having Peculiar Spectra. 31 New
Variable Stars. Epwarp C. Pickrrine. Pp. 3; 2 tables.

No. 169. Photometric Observations of Asteriods. Pp. 4;
1 figure.

6.. Publications of the Allegheny Observatory of the Univer-
sity of Pittsburgh.—The following have recently been issued ;
Vol. I, No. 14. The Spectrum and Orbit of 8 Scorpii, by Zac-
cHEUS DanieL and FRANK SCHLESINGER. Pp. 127-1387.

A simple method for adjusting the Polar Axis of an Equato-
rial Telescope ; by FRANK ScHLESINGER (Popular Astronomy,
1911).

Obituary. 387 —

MAJOR C. E. DUTTON.

CLARENCE Epwarp DutTron was born on May 15, 1841, in
Wallingford, Connecticut, and died on January 4, 1912, at Engle-
wood, New Jersey. He was graduated at Yale College in 1860
at the early age of 19 and entered the army in September, 1862
as Ist leutenant and adjutant of the 21st Connecticut regiment.
Six months later he was promoted captain. In 1864 he was
transferred to the Ordnance Corps, reached the rank of Major
May 1, 1890, and was retired at his own request with the same
rank, Feb. 7, 1901.

Although he was in the military service from his majority to
his death, the best years of his life were spent in geological work
and it is for this that he will be remembered. As he informed
Mr. J. 8. Diller,* his interest was first attracted to paleontology,
which he studied under the guidance of Hall and Whitfield,
while he was stationed at the Watervliet arsenal. Later when at
Washington he became acquainted with Henry, Baird and Powell
and by the first was induced to consent to a detail for duty with
the U. 8. Geographical and Geological Survey of the Rocky
Mountain Region, beginning May 15,1875. In this position he
devoted himself to the study of the Plateau regions of the far
West and especially of the physical problems there presented.
His results are recorded in three monographs of which the second
forms Monograph II of the present U. 8. Geological Survey and
contains Mr. W. H. Holmes’s marvellous illustrations of the
Grand Cafion. The material for this volume and for his
Geology of the High Plateaus of Utah had been gathered under
the Powell Survey and thus belong to a period when “ explora-
tion” or “reconnaissance” represented more accurately than
‘“‘survey ” the standard aimed at. This was in the circumstances
inevitable. At the close of the war of secession almost nothing
was known of the geology of the far West and it was impossible
even to plan a thorough survey until the general nature of the
country had been ascertained. In addition to his own work he
contributed lithological discussions to Mr. Gilbert’s famous
memoir on the Henry Mountains.

These early works of Dutton as well as his later publications
are marked by clearness and simplicity of presentation. Very
few American men of science have possessed to so marked a
degree that sympathy with the reader which is the secret of
arranging ideas in the order in which they will be most easily
grasped, and that lucidity of statement unattainable without a
copious vocabulary. Ease of expression, however, may be a
dangerous gift and Dutton did not always reason soundly.

A writer thus gifted is not merely widely read and quoted but
is given merit to which he makes no claim. Dutton frankly
acknowledged the fact that Babbage and John Herschel before
1840 were independently led to the theory of isostasy. Dutton

* See Mr. Diller’s excellent paper on Dutton, Bull. Seism. Soc. Amer., vol. i,
No. 4, Dee. 1911.

388 © Serentific Intelligence. ‘

of course only invented the name, but he is widely credited with

being the first to announce the principle.

After the organization of the present Survey, Dutton was
detailed to serve with it and, in a position nominally new, he
continued to act with the associates of earlier years. In 1884
he examined Mount Taylor and the Zufii Plateau, his memoir
appearing the next year. This gave him an opportunity to
modify, in the light of recent discoveries, some of his earlier
views of the region.

After the completion of his Plateau studies Dutton’s most
important contribution to geology was his study of the Charles-
ton Earthquake of 1886. In one respect he then had a unique
opportunity. Clock time was standardized in the United States
in 1883 and the Charleston earthquake was the first of conse-
quence to occur in a region where clocks kept the same time or
comparable time. Thus the observations of shock on that occa-
sion could be coordinated as in no previous case and of this
Dutton made full use. His method of ascertaining the depth of
the hypocentrum is a somewhat rough one, but there is no reason
to doubt that it gives the order of magnitude of the quantity
sought in cases in which the shock may be regarded as emanating
from a restricted space or area.

Dutton returned to military duty in September, 1890, but did
not abandon his interest in geology. He took the occasion of
furloughs to visit Mexican volcanoes as in earlier times he had
visited Hawaii and thus collected much of the material for his
last important work, ‘‘ Karthquakes in the light of the new Seis-
mology,” 1904. This book shows Dutton at his best. It is
excellent reading and contains much information, but it is far
from being exhaustive and cannot be regarded as an adequate
presentment of the subject at the time of its publication.

GEORGE F. BECKER.

Proressor THomas Harrison Montcomery, Jr., of the Zodlog-

ical department of the University of Pennsylvania, died on March »

19 at the age of thirty-five years. Although a youug man he had
already published a large number of papers on biological subjects
and was the author of a work entitled “Analysis of racial descent
in Animals.”

ProFeEssor JOHN BERNHARDT Situ, of Rutgers College, and
since 1894 State Entomologist of New Jersey, died on March 12
in the fifty-fourth year of hisage. He was the originator of many
of the modern methods of fighting the mosquito pest by drain-
age of swamps in which the insects breed.

Proressor Rarpu 8. Tarr, of the department of Physical
Geography at Cornell University, died suddenly at his home in
Ithaca on March 21; he was forty-eight years old. A notice is
deferred.

New Circulars.

84: Eighth Mineral List: A descriptive list of new arrivals,
rare and showy minerals.

85: Minerals for Sale by Weight: Price list of minerals for
blowpipe and laboratory work.

86: Minerals and Rocks for Working Collections: List of
common minerals and rocks for study specimens; prices

from 1% cents up.

Catalogue 26: Biological Supplies: New illustrated price list
of material for dissection; study and display specimens;
‘special dissections; models, etc. Szxth edition.

Any or all of the above lists will be sent free on request. We are
constantly acquiring new material and publishing new lists. It pays to
be on our mailing list.

Ward’s Natural Science Establishment
76-104 Cotrnecr AVE., Rocuxster, N. Y.

Warn’s Natura Science EstasiisoMENt

A Supply-House for Scientific Material.

Founded 1862. Incorporated 1890.
DEPARTMENTS:

Geology, including Phenomenal and Physiographic.
Mineralogy, including also Rocks, Meteorites, etc.
Palaeontology. Archaeology and Ethnology.
Invertebrates, including Biology, Conchology, ete.
Zoology, including Osteology and Taxidermy.

Human Anatomy, including Craniology, Odontology, ete.
Models, Plaster Casts and Wall-Charts in all departments.

Circulars in any department free on request; address

Ward's Natural Science Establishment,
76-104 College Ave., Rochester, New York, U.S. A.

C.O NEE NUTS:

| | ee ee
Art. XXVI.—Discovery of Pre-Historic Human Remains

near Cuzco, Peru; by H. Brneuam, Director of the Yale

Peruvian Expedition. (With Plates I and II) -__....- 297
“XXVIL—Geologic Relations of the Cuzco Remains; by
I. BowMAN 2. 23 92352 2a. ae ee 306

~XXVIIL —Report on the Remains of Man and of Lower

Animals from the Vicinity of Cuzco, Peru; by G. F.
WATON 203 52a See ee 325

| XXIX.—KEstimation of Lead, Nickel, and Zinc by Precipita-

tion as Oxalates and Titration with Potassium Perman-
ganate; by H. L. WARD 22.2225. 5.2 2642

XX X.—Description of the Skulls of Diadectes lentus and

Animasaurus carinatus ; by E. C. Casz and 8. W. Wiz-

LISTON 2 2 58 ee ee

XX XI.—New Volumetric Method fon the Determination of
Mercury ; by G'S. JamMipson .-.2--2 2! 2-3

XXXII.— Volumetric Method for the Determination of
Hydrazine; by G..S. JAMIESON ...-.-- 34... 233 eee

XX XIII.—Relations of the Degree of Metamorphism to Geo-
logical Structure and to Acid Igneous Intrusion in the
Narragansett Basin, Rhode Island ; by F. H. Lanner... 354

SCIENTIFIC INTELLIGENCE.

Chemistry and Physics—Separation of Titanium from Niobium, Tantalum,
Thorium, and Zirconium, J. H. MuLLER: Cementite, Rurr and GERSTEN,
373.—Use of Sulphur Monochloride for Decomposing Certain Minerals,
W. 8B. Hicks: Determination of Water, ZEREWITINOFF, 374.—Reduction
of Vanadic Acid in Concentrated Sulphuric Acid Solution, Carin and
Hostetter : Die Zersetzung von Stickstoffdioxyd im elektrischen Glimm-
strom, J. ZENNECK, 375.— Mechanism of the Semi-permeable Membrane,
and a New Method of Determining Osmotic Pressure, F. T. Trouton,
377.—Note on the Monatomicity of Neon, Krypton and Xenon, Sir W.
Ramsay, 378.—Modern Microscopy, M. I. Cross and M. J. Cote: Labo-
ratory Problems in Physics, F. T. Jones and R. R. Tatnauy, 379.—
Storage Batteries, H. W. Morse: A Laboratory Manual of Physics and
Applied Electricity, 380.—Die Bearbeitung des Glases auf dem Blase-
tische, D. Drakonow and W. LrermanrTorr, 381.

Geology—West Virginia Geological Survey: Wirt, Roane, and Calhoun
Counties, R. V. Henney, 381.—Geological Survey of New Jersey: State
of the Ice in the Arctic Seas : Wisconsin Geological and Natural His-
tory Survey, 882.—Annual Progress Report of the Geological Survey of
West Australia for the year 1910: Uses of Peat, C. A. Davis, 383.

Miscellaneous Scientific Intelligence—Carnegie Institution of Washington
Year Book No. 10, 1911: Publications of the Carnegie Institution, 384.—
Elements of the Differential and Integral Calculus, W. A. GRANVILLE:
Theory and Practice of Technical Writing, S. C. Harte: Publications
of the Harvard College Observatory: Publications of the Allegheny
Observatory of the University of Pittsburgh, 386.

. Obituary —C. E. Dutton, 387: T. H. Montgomery, Jr.: J. B. Smita: R. S.
TARR, 388,

nr Ol i comma = DL heipw™®

RT Maa INI nS

THE

mweMHRLCAN

Epiror: EDWARD S. DANA.

ASSOCIATE EDITORS

LOUIS WV PIRSSON, HERBERT ite GREGORY
_ AND HORACE S. UHLER, or New Haven,

Proresson HENRY S. WILLIAMS, or Iruaca,
_ Proressor JOSEPH S. AMES, or Batriors,
Mr. J. S. DILLER, or WaAsurncton.

FOURTH SERIES
“XXXIU—[WHOLE NUMBER, ChAT u

ee main

No. 197—MAY, 1912. <casonian Insp

/ figs
WITH ONE PLATE, ce 2 aay oY 19 | .
- ation a! RA x At % |
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£OT2°.

Six dollars per year, in advance. $6.40 to countries in the
nada. Remittances should be made either by money orders,

pee cs (preferably on New York banks). ms

PAM

SPRING ANNOUNCEMENT.

As I am just sending to the printer an elaborate
Catalogue describing a Large Collection which will
be ready for distribution by the first of May, I
would kindly request all readers of the American
Journal of Science who request a copy of the above,
to send me their names, which | will gladly send
free of charge. It contains valuable information for
Museum or individual collectors in Mineralogy.

Kindly mention the Journal when sending request.

A. H. PETEREIT,
81-83 Fulton Street, New York City.

Phone, Beekman 1856.

THE

AMERICAN JOURNAL OF SCIENCE

[FOURTH SERIES.]

of

GEORGE JARVIS BRUSH.

Prorressor Brusx, whose long life of active service for
science and Yale University closed on February 6th, will
always be remembered as a pioneer in the building up of. scien-
tific education in this country. His energy, his indomitable
will, his courage in contending with obstacles, and his rare
administrative ability were devoted, for nearly forty years,
with intense singleheartedness to the School of science from
which he obtained his degree in 1852. As the reward of his
devotion and that of his colleagues, he had the satisfaction of
seeing the School expand steadily from the smallest of begin-
nings until it was established as a vigorous and growing
department of Yale University. He began his work when
the value of science, and that of the scientific methods of the
laboratory, were but meagerly appreciated in the country:
when he resigned from active service in 1898, science had won
a large place in every institution and schools of science were
to be found at many centers of learning.

Professor Brush was also an able and trained worker in a
special field of science, contributing largely to mineralogy
through his own original work and acting as an inspiration to
his students who carried on the research in his favorite subject
when his energies were diverted into administrative lines.

GrorGE JARvis Brusu was born on December 15th, 1831.
He was the seventh in line of descent from Thomas Brush
who settled in Southold, Long Island, in 1653 and who is’
believed to have been the first of the name in America. The
father of Mr. Brush was Jarvis Brush, and his mother, Sarah
Keeler; the family home was in Brooklyn, N. Y., where the
father was in active and successful business as a commission
and importing merchant. In 1835, when still a young man, he
retired from business, satisfied with the competency he had
gained, and moved with his family to Danbury, Connecticut,
where he resided for some six years. until 1841, when he

Am, Jour. Sc1.—Fourts Series, Vou. XX XIII, No. 197.—May, 1912.
. 26

390 George Jarvis, Brush.

returned to Brooklyn. The early education of George was
received in private schools in these two places. When fifteen
years old he was sent to a school at West Cornwall, Connecticut,
kept by Mr. Theodore 8S. Gold, and it was here that his interest
in science was first aroused. Mr. Gold was an admirable
teacher for such a student, for he was enthusiastically devoted
to mineralogy and other branches of natural history, and had a
rare power in arousing the interest of his pupils in these sub-
jects. Although young Brush was with Mr. Gold only six
months, the effect upon his subsequent career was profound.
The evidence of this was not shown, however, at once, for the
traditions of the family led him to look forward to a business
lite. After leaving the West Cornwall school he took a posi-
tion with a mercantile house in Maiden Lane, New York City,
and remained there about two years ; occasional mineral excur-
sions were his only indulgence in science. But fate had a wider
career in store for him. In consequence of a serions illness in
1848 he was compelled to give up the confining life of business,
and it was decided that he should devote himself to farming.
This decision led him to come to New Haven in October, 1848,
to attend the lectures of Professors John P. Norton and Ben-
jamin Silliman, Jr., in agricultural and practical chemistry,
recently established in connection with Yale College. The
College catalogue for 1848 includes his name as a member of
the second class in the “ School of Applied Chemistry.” His
work in New Haven was, however, interrupted when in Octo-
ber, 1850, he went to Louisville, Kentucky, as assistant to
Professor Benjamin Silliman, Jr., instructor of chemistry and
toxicology in the medical department of Louisville University,
a position which he retained till the spring of 1852. During
this period, in the spring and summer of 1851, he travelled
extensively in Europe as one of the party of the elder Pro-
fessor Benjamin Silliman. At the Yale commencement of
1852, after a special examination made necessary by the absence
alluded to, he received the new degree of Ph. B. just estab-
lished. It is most inter esting that the man who was destined
to build up this department of the institution into the str ong
and flourishing Sheffield Scientific School should have been a
member of the first class to receive a degree. In this class of
1852, which began with fourteen members, seven were gradu-
ated, ‘four of whom later became pr ominent in science, and one
of these, Professor Wiliam H. Brewer, worked shoulder to
shoulder with Brush in the work for the School for many
ears.
: The college year of 1852-53 was spent as assistant in chem-
istry at the Univer sity of Virginia, and it was here that, associ-
ated with Professor J. Lawrence Smith, a series of studies were
prosecuted on the “re-examination of American minerals”; three

George Jarvis Brush. 391

papers with this title were published in volumes xv and xvi of
this Journal. This work in mineral chemistry served to show
both his ability in research, his grasp of scientific methods, and
his interest in the subject. It also made him feel the necessity
of further scientific study and training ; and, after spending the
summer of 1853 as assistant in charge of the department of
mineralogy in the Crystal Palace at the International Exposition
in New York, he sailed in the following November to Ger-
many. The years 1853 to 1855 were spent in Germany, at
first at Munich with Liebig, von Kobell, and Pettenkofer, and
later at the mining school at Freiberg, Saxony. These years
were rich in results, not only in the scientitic training they
gave, but also in the opportunities for close association with
his professors and fellow students.

In 1855 Mr. Brush was elected professor of metallurgy at
New Haven, in the Yale Scientific School that had been slowly
developing ever since its beginning in 1846. To train himself
for his future work he spent another year abroad, studying at
the Royal School of Mines in London and also visiting the
chief mines and smelting works of Great Britain and the con-
tinent. In January, 1857, he entered upon the duties of his
professorship of metallurgy: later, in 1864, his chair was
broadened so as to include mineralogy, and in 1871 it was
finally limited to the latter subject, the one in which he was
particularly interested. Of his work after the time when he
became professor in the Scientific School, one who was later
his colleague for many years wrote of him in 1881 : *

“From this time on the history of Professor Brush has been
the history of the special scientific department of Yale College,
which, in 1860, owing to the liberal benefactions of Mr. Joseph E.
Sheffield, received the name of the Sheffield Scientific School.
He came to it while it was not only without reputation, but with-
out appreciation or expectation. He came to it while it was poor
beyond even that decent poverty which apparently belongs, in the
nature of things, to institutions of learning—while it was in a state
of mind so unorganized that as a whole it could hardly be said to
have a being at all. It exhibited, indeed, a good deal of life in
the College catalogue, but beyond that its vitality did not extend.
There was vigor enough in certain of its departments, especially
in that of civil engineering, under the charge of Professor William
A. Norton ; but in such cases it was a vigor due to the energy of
the individual instructor, and therefore almost certain to disap-
pear whenever he disappeared. To bring these scattered units
into an organic whole, to build up a complete and consistent
scheme of scientific education, which should have both definite
and lofty aims, which should train men thoroughly in scientific
methods, and which should continue to exist by its own inherent
vitality after the men who established it should have passed

* Popular Science Monthly, vol. xx, pp. 119, 120, Nov. 1881.

392 George Jarvis Brush.

away—all this became by degrees a main work of Professor Brush’s
life. His energy, his judgment, his executive capacity, and his
devotion soon gave him the leading direction in the affairs of the
institution. He was fora long period its secretary ; he has always
been its treasurer ; and when, in 1872, a more formal organization
of its faculty was felt to be desirable, he was elected as its presid-
ing officer, a position which he still retains. Others have done
their part toward developing various departments of the School,
but its growth, as a whole, the position which it has acquired
among scientific institutions, whatever that position may be, has
been due to him very much more than to any other one man con-
nected “with it... .”

In 1872, as above stated, Professor Brush was made director
of the Sheffield Scientific School, to which he had already
devoted fifteen years of his life. This position he held until
1898, when he resigned his active duties, both professorial and
administrative. His time and energies of necessity were, from
1872 on, more and more absorbed by the labor of planning for
the School as a whole and caring for its many interests. In
1873, Dr. George W. Hawes was appointed assistant in miner-
alogy, and much of the active work of teaching devolved upon
him; thus in the later seventies, Professor Brush had practi-
cally resigned his laboratory mstruction and finally, in 1884, he
was compelled to give up his lectures also. Dr. Hawes
remained in charge of the department until 1879, during which
time the classes in laboratory work were transferred to the Pea-
body Museum after its completion in 1876. In 1879, Dr. Hawes
was called to Washington and Dr. 8. L. Penfield took his
place as instructor in mineralogy; later the latter was made
assistant professor (1888), and finally professor of mineralogy
(1893); in his able hands Professor Brush felt that his favorite
subject was fully cared for, as was well proved by the work
that was published from the Sheffield laboratory of mineralogy.
It may well be imagined with what deep sorrow the elder Pro-
fessor saw each of his assistants and helpers cut down in their
prime, Hawes in 1882 and Penfield in 1906.

In 1898, as has been stated, Brush resigned his active
responsibilities as professor and director. The remaining years
of his life were for the most part spent in New Haven in close
touch with the same interests to which he had devoted his life.
He continued as secretary and treasurer of the Sheffield
Trustees until 1900, when he retired as secretary and was
elected President of the Board. He gave up the treasurership
in 1904, but retained the presidency until the end, presiding
at the annual meeting in November, 1911.

During the period that has been alluded to, Brush took the
liveliest interest in all that pertained to mineralogy, the instruc-
tion, the active research, and the increase of his private collec-

George Jarvis Brush. 393

tion, althongh he himself, as he sometimes a little pathetically
expressed it, was “ doomed to turn the crank of the machine.”
The various duties of the director of the rapidly growing
School, financial and administrative, were, however, fully to
his taste, and it can hardly be regretted that his time and
strength were given so fully to them. His health, on the
whole, was not seriously impaired as years increased, until the
spring of 1911, when a trouble with the heart developed which
from that time increasingly limited his physical activity. The
decline was slow and for the most part, until near the end,
without suffering, and on February 6th he passed gently away.
The great kindliness of his strong nature was never shown
more clearly than in the closing months of his life. In 1864
he was married to Harriet Silliman Trumbull, who died in
1910; three daughters survive him.

The interest taken in minerals by Mr. Brush when a boy of
fifteen, was rapidly developed during his student years under
the stimulating influences at Munich and Freiberg. This
interest continued unchanged through his life, though, as has
been stated, the pressure of administrative work finally robbed
him of the opportunity for active study. He developed early
a remarkably keen eye for recognizing mineral species, even
those which were a puzzle to an ordinary mineralogist. When
a schoolboy with Mr. Gold he began to collect minerals, and
as years went on and his ability to obtain specimens by pur-
chase or exchange increased, he accumulated a large and very
valuable collection. This collection was especially notable for
its completeness for the purposes of scientific study and the
type specimens which it contained ; the history of each speci-
men was also recorded with the utmost care. His active work
as a collector, aided by that of his associates, continued till
1904, when he formally presented his collection, then number-
ing about 15,000 specimens, to the Sheffield Scientific School,
adding to this gift a fund of $10,000 for its maintenance and
increase. This collection was housed in the old building of the
Sheffield School until its removal to his room in the Peabody
Museum in 1876. Here it remained until 1904, when it was
placed in a room specially prepared for it in Kirtland Hall.
He took the greatest satisfaction in having it cared for,
arranged, and catalogued ; and one of the keenest pleasures of
his later years consisted in going over the collection and aiding
in the final work upon it.

A mineralogist with so keen an eye and interest in his sub-
ject must of necessity have been both a teacher and investiga-
tor. In the former direction the influence of Professor Brush
was widely felt, particularly during the decade beginning with
1864. Many students were inspired by his enthusiasm and
earried the knowledge and skill acquired from him to other

394 George Jarvis Brush.

centers of learning. The work of Professor Brush in the
original study of minerals began in 1849, when he was only
eighteen years old. From then for twenty-five years he was
active, and a series of about thirty papers gives a record of the
results attained. In 1878 and later, he took time from his
absorbing administrative labors, and, in conjunction with a
younger colleague, published a series of papers on the newly
discovered locality at Branchville, Connecticut. |

In 1874 his “ Manual of Determinative Mineralogy” was
brought out; this contained a clear summary of blowpipe
methods and principles, and also a series of determinative
tables adapted from the German tables of von Kobell. In the
preparation of this work, especially the latter part, Dr. Hawes
took a prominent part. <A revised edition was issued in 1878,
and later the work was entirely rewritten on an expanded scale
by Professor Penfield. The most important editions of the
book as thus revised were those of 1896 and 1898. Professor
Brush also made important contributions to the System of
Mineralogy of Professor James D. Dana. Of the ten supple-
ments to the fourth edition of 1854, he prepared the eighth,
ninth and tenth. In the preparation of the fifth edition of
1868, he took an important part: the statements of the blow-
pipe characters of the different species were written by him,
and in most cases the facts given were based upon his own
independent experiments. His close knowledge of mineralogy
also enabled him to aid the author at many points in the
prosecution of his task. The first appendix to the fifth edi-
tion, issued in 1872, was prepared by Professor Brush.
Another contribution to the science to which he was devoted
was the presidential address before the American Association
for the Advancement of Science at Montreal in 1882; this was
a thorough and valuable summary of the early history of
American Mineralogy. Professor Brush became an associate
editor of this Journal in 18638 and retained that position until
1879. The pages of the Journal contain about all of his
papers on mineralogical subjects.

It has been shown that the influence of his early life tended
to turn Mr. Brush into an active business career. Fortunately
for the world this was not to be his life’s work, but to one
familiar with him and what he accomplished, the influence of
this early training is clearly shown. He was distinctly a man
of affairs, of quick, sure judgment, firmness of resolution, and
great energy. The successive steps by which the Sheffield
Scientific School grew under his guidance from 1857 on show
at every stage his ability and his strong hand. This is not the
place to go into this subject in detail, but the success of this,
the most important work of his life, can hardly be overesti-

George Jurvis Brush. 395

mated. The School at the beginning had almost no funds, but
it early attracted the interest of Mr. Joseph E. Sheffield and
this interest was wisely and tactfully guided and stimulated by
Mr. Brush. As the result of this, the School received from
Mr. Sheffield a considerable endowment and in 1861 was
formally called the Sheffield Scientific School. The endow-
meut was still further increased later, especially by the pro-
visions of the will of Mr. Sheffield, who died in 1882. It
would be difficult, without detailed historical discussion, to give
any adequate idea of the complexity and difficulty of the prob-
lems of the growing School and of the skill and wisdom with
which they were met and solved by Mr. Brush. One particu-
lar matter may be mentioned here. The School, in 1863, became
the land grant College of Connecticut under the land grant, act
of the Federal Government. ‘The sale of the land yielded an
income which was most important to the School at a critical
time in its growth. Later, in 1892, this fund was transferred
by the State to the Storrs Agricultural College, but in the con-
test over the subject the interests of the School were so ably
handled by Mr. Brush that in the settlement it received out-
right a sum of $150,000, thus putting it in a better position
than that which it had before occupied.

The financial skill shown in the management of the interests
of the School was also used for the benefit of the funds of the
Peabody Museum, of which Mr. Brush was one of the original
trustees appointed in the deed of gift of Mr. George Peabody
in 1866. It was largely through his able management that the
original $150,000 grew so steadily and surely that the
$100,000 set apart at the beginning amounted to the $176,000
needed to pay for the building completed ten years later.
Mr. Brush sometimes alluded with satisfaction to the fact that
he had the foresight to exchange the five per cent Massachu-
setts State bonds of the original Peabody gift for the seven-
thirties of the civil war loan, thus producing a rapid increase
in the available funds. It is also interesting to note that for
many years he was a director in the Jackson Iron Company of
the Lake Superior district. He was, further, a director in the
New York, New Haven, and Hartford Railroad from 1893
until his death, attending all the meetings with great regularity.

Professor Brush was elected a member ot the National
Academy of Sciences in 1868 and received the degree of
Doctor of Laws from Harvard University in 1886. He pre-
sided as president of the American Association for the
Advancement of Science at Cincinnati in 1881, and delivered
the presidential address at Montreal the following year. He
was an honorary member of the Mineralogical Society of Eng-
land, a foreign member of the Geological Society of London,

396

George Jarvis Brush.

of the Geological Society of Edinburgh, of the Royal Bavarian
Academy of Sciences of Munich, and various other learned
societies, both at hor c and abroad.

The portrait accompanying this sketch has been reproduced

from a photograph taken about 1897. BSED,
Bibliography.

1849. Analysis of Albite, this Journal, vol. viii (2d series), p.390. Analyses
of Indianite, ibid., vol. viii, p. 391.

1850. Determination of Water in the anhydrous Prehnite of Whitney, ibid.,
vol. x, p. 121. Analyses of American Spodumene, ibid., vol. x,

. 870.

1852. Fluor of Illinois, ibid., vol. xiv, p. 112.

1853. Reéxamination of American Minerals (with J. Lavivenes Smith), three
papers, ibid., vol. xv, p. 207, vol. xvi, p. 41 and p. 365.

1854. Chemical Composition of Clintonite, ibid., vol. xviii, p. 407. Test
for Zirconia, tbid., vol. xvili, p. 419.

1855. On Prosopite, ibid., vol. xx, p. 273.

1857. On Dechenite, ibid., vol. xxiv, p.116. On Parathorite, ibid., vol. xxiv,
p. 124. On Antigorite, ibid., vol. xxiv, p. 128.

1858. On Chaleodite, ibid., vol. xxv, D. 198. Mineralogical Notices, ibid.,
vol. xxvi, p. 64.

1859. On Boltonite, ibid., vol. xxvii, p. 395.

1860. Eighth supplement to Dana’s Mineralogy, ibid., vol. xxix, p. 363.
1861. Ninth sepplement to Dana’s Mineralogy, ibid., vol. xxxi, p. 304. On
Crystalline Hydrate of Magnesia, ibid., vol. XXXil, p. $4.

1862. Tenth supplement to Dana’s Mineralogy, ibid., vol. Xxxiv, p. 202. On
Amblygonite from Maine, ¢bid., vol. XXxiv, p. 243. On Triphyl-
ine at Norwich, Mass., ibid., vol. xxxiv, p. 402. .

18638. On Childrenite, ibid., vol. xxxvi, pp. 122, 257. Tucson Meteoric
Iron, ibid., vol. xxxvi, p. 152.

1864. On Tephroite, ibid., vol. xxxvii, p. 66.

1865. On Artificial Diopside. ibid., vol. XKKIX. p, loc.

1866. On Ccokeite and Jefferisite, ibid., vol. 5 [Ts 0) 246. New Mineral
Localities. ibid., vol. xlii, p. 268.

1867. Native Hydrates of Iron, ibid., vol, xliv, p. 219.

1868. On Sussexite, ibid., vol. xlvi, pp. 140, 240.

1869. On Hortonolite, ibid., vol. xlvili, p. 17. On Durangite, vol. xlviii,
p. 179. A Meteoric Stone from Alabama, ibid., vol. xlviii, p. 240,
The Magnetite in the Pennsbury Mica, ibid., vol. xlviii, p. 360.

1871. On Gahnite of New Jersey, ibid., vol. i (38d series), p. 28. On Ral-
stonite, ibid., vol. ii, p. 80.

1872. Appendix to the fifth edition of Dana’s Mineralogy, New York,

1878. On Anglesite from Arizona, this Journal, vol. v, p. 421.

1874. Manual of Determinative Mineralogy, New York.

1876. On Durangite, this Journal, vol. xi, p. 464.

1878-90. On the Mineral Locality at Branchville, Connecticut with Edward

1880.

1881.
1882.

1883.

S. Dana), five papers, ibid., vol. xv, pp. 398, 481 ; vol. xvi, pp.
a3, 114; vol; xvii, p.73a0% ’ vol. xviii, 5 OF 45: vol. XK pile 857,
301; vol. xxxix, p. 201.

On the Relation of Childrenite and Eosphorite (with Edward 8S. Dana),
ibid., vol. xix, p. 816. On Crystallized Danburite from Russell,
N. Y. (with Edward S. Dana), ibid., vol. xx, p. 111.

On American Sulpho-selenides of Mercury, ibid., vol. xxi, p. 312.

A Sketch of the Progress of American Mineralogy. Proc. Amer.
Assoc, Adv. Sci., xxxi, 1, 1882.

On Scovillite (with S. L. Penfield), this Journai, vol. xxv, p. 409. .

LR. S. Lull—Life of the Connecticut Trias. 397

Arr. XXXIV.—The Life of the Connecticut Trias ; by

Ricwarp Swann Liur*

{Contribution from the Paleontological Laboratory, Peabody Museum, Yale
University, New Haven, Conn., U.S. A.]

Introduction.
The Connecticut Valley.
Extent.
Age and geological history.
Theories of deposition of sediments.
Physical environment.
Vegetal environment.
The Fauna.
Invertebrates.
Vertebrates.
Résumé.

One of the most interesting chapters in the earth’s past his-
tory is that of the time when there were laid down the Triassic
strata of the famed Connecticut valley, interesting in the pro-
fusion of its indicated life, and fascinating in the bafiling
obscurity which shrouds most of its former denizens, the only
records of whose existence are “ footprints on the sands of
time.”

It is not surprising, therefore, that geologists should have
turned to the collecting and deciphering of such records with
zeal; nor is it to be marveled at that, after the exhaustive
researches of the late President Hitchcock, workers should
have turned to more productive fields, leaving the footprints
aside as relics of little moment compared with the wonderful
discoveries of the great unknown West. _.

Except for small summary papers by Professor Charles H.
Hitchcock containing descriptions of some new species, and
occasional papers by other authors, nothing was done from the
time of the publication of Edward Hitchcock’s notable “ Ich-
nology of New England” in 1858, and the Supplement to it
in 1865, until 1904, when a new study of the tracks in the light
of recent paleontology was published by the present author.

Skeletal remains which were brought to light from time to
time were described mainly by Professor Marsh in this Journal,
and by E. Hitchcock, Jr. (1865) and by Cope (1869) ; and later
summarized by Marsh in his “ Dinosaurs of North America”
(1896).

A final, more exhaustive study of the skeletal remains was
made by Professor Friedrich von Huene in his “ Dinosaurier

* Extracted from a monograph on ‘‘ Triassic Life of the Connecticut
Valley,” to be published as a Bulletin of the Connecticut Geological and

Natural History Survey. By permission of the Director, Professor William
North Rice.

398 Le. S. Lull—Life of the Connecticut Trias.

der Aussereuropeischen Trias.” No serious attempt, how-
ever, has been made to reconstruct the physical conditions of
the Trias and to repeople the Connecticut lands of that time
with their living, breathing, strenuous inhabitants. The pur-
pose of this essay, therefore, 1s to reconstruct the environment,
both physiographic and climatic, to clothe it with its proper
vegetative life, and to discuss as fully as may be the animate
nature of that distant day.

One of the most remarkable features of the fossil remains of
the Connecticut valley is the dearth of actual bones and the
marvellous abundance of footprints—conditions exactly the
reverse of those found in other fossil fields, for, outside the
Triassic of New England and New Jersey, footprints are rarely
met with, whereas the bones in some localities are nearly as nu-
merous as in the Valley of Dry Bones, the vision of which was
vouchsafed to Ezekiel. Somewhat similar conditions to those
in the Connecticut valley seem to prevail in the Southwest and
elsewhere, but in no other known locality is the profusion of
footprints so great. In spite of this the discovery of bones
preceded a scientific appreciation of the tracks by nearly a
score of years, though doubtless the latter were often seen by
observers like Pliny Moody in 1802, who failed to realize their
great significance. The reference of one to the footprint of
‘““Noah’s raven” is probably only one of the many similar inter-
pretations in the folk-lore of the Connecticut valley.

The profusion of species of animals represented by the tracks,
which of course included the creatures the skeletons of which
are known, is, so far as my present knowledge goes, as great if
not greater than that of any other known vertebrate fauna of
prehistoric times, and emphasizes once more the usual incom-
pleteness of our geologic record and the countless multitudes
of creatures which peopled our globe in the more remote ages.

The Connecticut Valley.

The tracks of the Newark system, which include the fossils
under consideration, occupy a number of areas along the eastern
coast of North America, of which the best known are that of
the far-famed Connecticut valley, and the adjacent one stretch-
ing from New York through New Jersey, Pennsylvania, and
Maryland into Virginia.

The Connecticut valley area, extending as it does across the
states of Massachusetts and Connecticut, follows in general the
depression now occupied by the Connecticut river, except in
its lower course where the river forsakes the ancient valley at
Middletown and cuts its way through the Eastern Highlands,
reaching the Sound far to the eastward. The length of the

LR. S. Lull—Life of the Connecticut Trias. 399

Triassic trough is about 110 miles, from the village of Northfield,
Massachusetts, on the north, to New Haven bay on the south.
Its width varies, but averages some 18 miles, the total area
being not far from 2000 square miles. »

This Triassic depression is bounded on either side by eleva-
tions of the more ancient crystalline rock, none younger than
the Paleozoic, the weathering of which constituted the source
of the Triassic sediments. The age of the latter, which has
been referred to the Newark system, is usually correlated with
the Rheetic of the Old World, though Eastman in his recent
paper on the ‘Triassic fishes of Connecticut (Bulletin 18,
Conn. Geol. & Nat. Hist. Survey, p. 32), in speaking of the
fish fauna, says: “The Triassic fish fauna of eastern North
America is of a more or less manifold nature, and corresponds
in a general way to the interval between the uppermost Mu-
schelkalk and the basal division of the Keuper in the Mediter-
ranean region.” The English footprints found in the Lower
Keuper Storeton quarry near Liverpool, however, do not
resemble those of the Connecticut valley in a single instance,
though a three-toed dinosaurian track described by Sollas as
Brontozoum thompsoni which was found at Newton Nottage,
Glamorganshire, and referred to the Lower Keuper (Magnesian
Conglomerate), shows affinities with those in the Connecticut
fauna.

According to the usage of the United States Geological
Survey, the non-committal name of Jura-Trias has often been
applied to the strata in North America, and as I shall show,
the very distinctive dinosaurian fossils are confined to the
upper portion of the Newark system both in the Connecticut
valley and in New Jersey, while in the lower beds creatures of
very different rank predominated.

In a region of the classic interest which envelops the Con-
necticut valley, embracing as it does some of our most vener-
able seats of learning, and cradling some of America’s greatest
geologists, it is not surprising that the discussion as to the
origin of the Newark rocks should have been animated. The
theories of the method of deposition vary all the way, from
submarine, through estuarine to continental, and involve a
considerable range of climatic conditions as well.

Emerson, in the Holyoke Folio (1898), p. 8, discussed the
origin of the Newark deposits in the Connecticut valley as
follows :

“The events of the Paleozoic age, constituting a prolonged
history of geographic changes, had come to a close, and a land
not greatly unlike the present in general configuration had
been established, when a new sedimentary record was begun in
a bay occupying the position of the Connecticut Valley in

400 RR. S. Lull—Life of the Connecticut Trias.

Connecticut and Massachusetts. The shores of the bay were
the west scarp of the Worcester County plateau on the east and
the east scarp of the Green Mountain plateau on the west, and
extending from near Brattleboro, Vermont, to New Haven,
Connecticut. The sea waters rose to a considerable height
above the present level of the bordering plateaus and spread
sediments brought in from these elevated regions on either
side of the bay. The shoreward sediments on the east are
represented by the Mount Toby conglomerates, and the Sugar-
loaf arkose is the synchronous deposit formed along the
western shore. The Longmeadow sandstone was deposited in
the shallower and quieter off-shore area, and in the central zone
of the latter area, where the basin was widest, the still finer
Chicopee shale was laid down. All these deposits are partly
contemporaneous sediments, differing as the strength of the
current and the character of the shore rocks affected them.
Strong tides, like those of the Bay of Fundy, seem to have swept
up the west side of the bay, carrying the material of the gran-
itic shore rocks far north, to rest against a shore made of dark
schists, and the return currents ran along the east shore, carry-
ing the eastern shorewash south, while quieter waters and shift-
ing currents spread the sediments in the central area.

“The accumulation of sediments was interrupted by an
eruption of lava through a fissure in the earth’s crust, which
opened along the bottom of the basin. The lava flowed east
and west along the bay, as tar oozes and spreads from a erack,
and solidified in a sheet which may have been 2 or 3 miles wide
and about 400 feet thick in its central part. This is the main
sheet or Holyoke diabase. This sheet was soon covered with
sand layers, but its thickness was such that it shallowed the
waters to near tide level, and thus occasioned extensive mud flats.
This was an area suitable for the formation and preservation
of unique records of the life of the time. The curiously shaped
and often huge reptiles of that age wandered over the mud
exposed at low tide, and their footprints, being covered by the
deposit of the next flood tide, constitute the so-called ‘ bird
tracks’ which have been found in such great numbers and
perfection.

“The sands had reached a considerable thickness over the
first trap bed when a second outflow of the trap followed, rep- |
resented by the posterior bed or Hampden diabase. Immedi-
ately after the outflow of this sheet an explosive eruption took
place, and blocks of diabase and pulverized lava were spread by
the waters over a broad area, forming the Granby tuff bed. A
third period of voleanic activity followed, during which a line
of small voleanoes broke out along the old fissure beneath the
bay. The area was next the scene of dislocations or faults, by

R. 8. Lull—Life of the Connecticut Trias. 401

which the mass of sediment and volcanic rocks was divided into
great blocks, often extending north and south. The blocks
slipped one past another alone nearly vertical planes. In these
dislocations the strata were generally tilted eastward.
In these movements, associated perhaps with general uplift of
the area, the bay became land and the rocks were exposed to
erosion.”

A view of the deposition of the Newark rocks more in keep-
ing with the organic phenomena is that set forth by Davis in
1898 (pp. 32, 33) as follows:

7 lhe) pre- Triassic peneplain might have been warped so as
to alter the action of the quiescent old rivers that had before
flowed across it, yet not to drown or to pond them. Such a
change would set the streams to eroding in their steepened
courses, and to depositing where their load increased above
their ability of transportation. As with marine or lacustrine
deposits, the thickness of the strata thus produced would
depend on the duration of the opportunity for their deposition.
A progressive warping, always raising the eroded districts and
depressing the area of deposition, would in any of these cases
afford the condition for accumulating strata of great total
thickness. The heavy accumulations of river-borne waste on
the broad plains of California, of the Po, or of the Indo-Gan-
getic depression, all agree in testifying that rivers may form
extensive stratified deposits, and that the deposits may be fine
as well as coarse. They are characteristically cross bedded
and variable, and they may frequently contain rain-pitted or
sun-cracked lavers. . ..

“In contrast to marine deposits, Penck has suggested the
name ‘continental’ for deposits formed on land areas, whether
in lakes, by rivers, by winds, under the creeping action of
waste slopes, or under all these conditions combined. ‘This
term seems more applicable than any other to the Triassic
deposits of Connecticut. It withdraws them from. necessary
association with a marine origin, for which there is no sufii-
cient evidence, and at the same time it avoids what is to-day an
impossible task—that of assigning a particular origin to one or
another member of the formation. A continental origin of
the formation would accord with Dana’s conclusion that the
Triassic beds ‘are either fresh-water or brackish-water deposits.’
There may possibly be included an occasional marine deposit
along the axis of the depressed trough, for at one time or
another a faster movement of depression than usual may have
outstripped deposition and thus caused submergence ; but, in
the absence of marine fossils, the burden of proof must lie on
those who directly maintain the occurrence of marine de-
posits.”

402 R.S. Lull—Life of the Connecticut Trias.

In general geologists now regard the theory of the conti-
nental deposition of the Connecticut valley sediments as definitely
proven.

The Physical Environment.

The weight of evidence seems to show that the physical en-
vironment within which the animals of the Triassic lived con-
sisted of several broad depressions along what is now the north-
ern Atlantic coast. It is, nevertheless, inconceivable that
creatures of such ample locomotive powers as the majority of
the Connecticut valley remains would imply were limited to
the actual troughs, but they must have roamed far and wide
across the uplands as well, though naturally their records of
wanderings would only be made where sedimentation was in
progress.

The climatic conditions of Triassic times may be judged by
three criteria: the character of the sediment itself. the physical
phenomena impressed upon the strata, and the evidence of the
organic life.

Barrell (1908, p. 183), who has made extensive studies. upon
the relations between climate and sedimentation, comes to the
conclusion that the “dominant red color of the whole of the Tri-
assic formation, considered in connection with its feldspathic
sandstones, indicative of the kind of erosion, mud-cracked shales,
disseminated gypsum, and calcite, indicative of conditions of
sedimentation, point ... to a subarid climate,’ and further-
more that “the Triassic conglomerates ... are associated with
many features of climatic significance . . . which independently
indicate a semiarid climate with hot summers and possibly cold
winters ” (p. 259).

Fenner (1908, p. 305), in describing the shales of the New
Jersey Newark areas, summarized the physical phenomena
thus :

“They are finely comminuted siliceous material, strongly im-
pregnated with oxide of iron. Their laminations may be
paper-like in thinness, but are generally coarser. On exposure
to the weather they break up into a multitude of crumbly
fragments. Mica scales are very plentiful. The surfaces of
the laminz frequently show a multitude of irregular markings
—grooves, pits, curved lines, lumps, smooth patches of
irregular shape, ete., not all of which can be deciphered with
any certainty. Many, however, can be identified. Mud-
cracks, rain-pits, and worm-grooves are frequent. ill-marks
are sometimes found. At times films of impalpable sediment
are found in the depressions in the lumpy surfaces of certain
sandstone layers, which, in their delicate markings, suggest
irresistibly the frothy scum left in hollows after a rain.’

Lt. S. Lull—Life of the Connecticut Trias. 403

One very characteristic physical phenomenon impressed
upon the sandstones and shales of the Connecticut valley is
that of mud-cracking as the fresh deposits dried under the
ardent heat of the Triassic sun. These cracks are often found
associated with the fossil] footprints, and in many instances,
notably from the Portland, Connecticut, sandstone quarries,
they lie in the axes of the digital impressions, often radiating
from the tips of the toes, thus showing conclusively that the
drying was subsequent to the passage of the animal, the cracks
following the already weakened lines of least resistance.

Yet another very characteristic Connecticut valley phenom-
enon is that to which the elder Hitchcock gave the poetic
name of “Nature’s Hieroglyphics.” As he says, the most
remarkable locality is at the Portland quarries, ““where some-
times the surface looks like mosaic, or rather like a pavement
of polygonal masses, with mortar between the pieces.” Bar-
rell describes this as “mud-cracks filled with seolian sands.”
He says (pp. 279-80) :—

“Silt and sand will be blown over and fill up the cracks
developed by the drying of argillaceous water-laid deposits.
Consequently, the sand is filled in under the raised rims of the
polygonal discs and becomes continuous with the mantle of
sand above. In this way the concavity upward of the indi-
vidual plates is preserved and the mud-cracks are not
obliterated, even in a silty clay which would crack and
crumble immediately upon being rewet by the advancing
waters of the following inundation. Experiments by the
writer [Barrell] go to show that the upturned edges of the
clay plates would not usually hold their form while the broad
sweep of sand-laden waters. should deposit clean sand both
under the edges and over the plates. The concavity of the
plates thus testifies to eolian burial and such may be distin-
guished from mud-cracked flats buried by fluvial action.”

Other phenomena indicative of climatic conditions are the
impressions of frequent hard showers, such as are often
observed in semi-arid regions, and pieces of recent sun-cracked
mud deeply pitted with rain impressions secured by Professor
Marsh on the Laramie plains in 1868 might well be of Triassic
origin.

Still other phenomena, namely the impressions found in
Portland and attributed to a fucoid to which was given the
name of Dendrophycus triassicus by Newberry (1888, ps2),
have been seen in actual formation upon the clay banks of
streams, and are nothing less than the wonderfully wrought-
out series of branching rill marks made by tiny streams of
trickling water.

The animals of the Connecticut Trias, in so far as_ they

404 R.S. Lull—Life of the Connecticut Trias.

throw light upon past climatic conditions, include the remains
of at least two species of shells, both belonging to the fresh-
water Unionidee, which pr eclude the possibility of saline tidal
waters, at least in the neighborhood of Wilbraham, Massa-
chusetts, a locality which, unfortunately for the estuari ine theory
of origin, is far to the south of places where the sediment
would seem to demand the strongest tides. On the other
hand, the presence of shells implies more or less permanent
waters, either in slow moving or impounded condition. The
one insect reported from the valley is found in great abund-
ance at Turners Falls, Massachusetts, and has been described
as the aquatic larva of a neuropterous insect, hence again
implying the presence of waters of some duration. If the
period of larval life was equivalent to that of the ephemerids
of to-day, the water must have continued not one season but
three; this may, however, have been an annual insect the
larval life of which would require but a transitory stream.
The invertebrate trails show no characters which would debar
them from such a climatic environment as Barrell has assumed
for the Connecticut Triassic.

Fishes are, with the exception of one crossopterygian, all
ganoids. And, while confined stratigraphically to two or three
black shale bands, their geographical range is from Turners
Falls to New Haven. They are, however, all of fresh-water
affinities, and may well represent the recurrence of climatic
cycles of greater than average humidity and consequent expan-
sion of the aquatic habitat, or a disturbance of the drainage,
due to volcanic damming or deformation, the climatic condi-
tions remaining constant.

Over the terrestrial vertebrates, aside from a few of the
forms unquestionably dinosaurian, so deep a shadow of obseur-
ity rests that safe conclusions may hardly be drawn. There is
no reason to suppose that allare reptilian; and, if the Amphibia
of that day were of similar constitution to the present-day
descendants, to whoma one per cent solution of salt is fatal, the
proof of their presence would preclude the possibility of.
marine waters, and add their evidence in favor of continental
deposition to that of the lower forms. There are, however,
stegocephahans known from brackish water deposits.

On the Laramie plains in 1899, when conditions were dry
even. for a semi-arid climate, I found in the dust of the ground
within the tent a large and lively salamander of brilliant color-
ing whose advent and departure were alike mysterious. Van
Dyke i in his description of the desert remarks that all desert
trails run in straight lines, showing the animal to be not prowl-
ing but intent in getting across to the mountain. The same is
true of the fossil trails of the Connecticut valley ; and from the

R. S. Lull—Life of the Connecticut Trias. 405

compact type of foot, long stride, sometimes suddenly lengthen-
ing marvellously, and the narrow trackway of many species, it
can easily be seen that the character imposed by the desert of
speed and great travelling powers was here at a high premium.
As I have shown elsewhere (1910, p. 37), a climate of semi-
aridity, compelling cursorial adaptation as a means of getting
food but more especially water, may well have been an impel-
ling cause in dinosaurian evolution. Bipedality among lizards
of to-day is, so far as I am aware, confined to denizens of semi-
desert environment, certain instances being the large frilled
lizard, Chlamydosaurus (Sayville Kent), “ot Australia, and
several lacertilian species of our own Southwest.

That water was rare and at a premium when the rains. did
come is evidenced by the frequency of the association of rain-
prints with dinosaurian tracks and the above-mentioned mud-
eracks which followed the passage of the animal. Again, the
depth of the impression of the tracks of two species of animals
upon the same strata is sometimes entirely out of proportion to
the apparent difference in the makers’ size, for the presump-
tion is that then as now the supporting area of an animal’s
feet must have borne a certain ratio to the weight in accord-
ance with the type of environment to which the creature was
adapted. The inference is, therefore, that the passage of the
two animals was on their way to or from a water hole during a
period of desiccation, and that the deeper impression was made
some time before the shallower one and nearer the time of the
preceding rains.

The Vegetal Ee onan et

Chamberlin and Salisbury (Vol. ii, pp. 38-40) speak thus
of the plant life of the Triassic:

“The record of the vegetation is very imperfect. The
vegetation was probably scanty in reality, for ... arid
tracts imply conditions inhospitable to plant life. An environ-
ment that could give rise so generally to coarse red sandstones
and conglomerates—even limestone conglomerates—could not
well be congenial to luxuriant vegetation.

“The Triassic was distinctly an age of gymnosperms the
world over; the supremacy of the pteridophytes had ceased,
though ferns, true to their persistent nature, still held an
important place, and the equisetales were a more vital factor
than now. ... conifers of the types that had come in dur-
ing the Permian, and kindred new ones, were prominent,
while the cycadean group was still in a stage of deployment
and occupied the central place of interest. . . . The Triassic
conifers bore the scrawny aspect of the walchias and voltzias
of the Permian. ... It does not appear from the record that

Am. Jour. Sci1.—FourtsH Series, Vou. XX XIII, No. 197.—May, 1912,

9
a

406 RL. §. Lull-—Life of the Connecticut Trias.

any of these gymnosperms were especially large, but on the
contrary rather dwarfish, the conifers bearing the aspects now
found on sandy barrens and arid tracts. The calamites had
given place to true equiseta, which were represented by forms
that were gigantic in comparison with modern types. .. .

‘““In the closing stages of the period, the Rheetic epoch and
its equivalents, there seems to have been much amelioration of
the previous hostile conditions and a much ampler develop-
ment of the flora. The larger part of the known American
fossils belong to this stage. In favored portions of the Newark
series from Connecticut to North Carolina, plant remains
occur, and in the coal-beds of the latter state and of Virginia,
the flora is more amply represented.”

The Fauna.

In both vertebrate and invertebrate relics the proportion of
known fossils to footprints 1s much the same, the former being
of such extreme rarity as to warrant special mention of practi-
eally every find.

Invertebrates.

Of the actual fossils the species represented are but four,—
two known species of molluscs, a small phyllopod crustacean,
Estheria sp., and a single insect species of which fortunately
there are numerous examples, all, however, from three or four
localities in the neighborhood of Turners Falls, Mass., and
near Middletown, Conn., though whether the latter locality
yields the same form as that at Turners Falls is unknown.

A brief summary of the invertebrate species follows :

Of the phylum Arthropoda the Class Hexapoda is repre-
sented by the one known species Mormolucoides articulatus
Hitchcock. This creature was first described by Hitchcock in
1858 as a crustacean and its true relationships were discovered
by J. D. Dana, to whom Hitchcock sent specimens for examin-
ation. Dana, in a postscript to his letter reporting on the
insect, says: ‘ The larve was probably the larve of a neuropter-
ous insect, which often has false legs along the abdomen ; but,
if so, it is surprising that there are no legs to the corselet,
neuropterous larves having three pairs.” This insect was
afterwards studied by Scudder, who published an elaborate
monograph amplifying the previous descriptions. It remained,
however, for the present writer to have the good fortune to
find upon a single individual among many impressed upon the
shale, well-preserved remains of the antenne and limbs which
served still further to verify the taxonomic conclusions of
Dana. These are described in detail in the memoir from
which this extract is made. The further placing of this insect

RR. S. Lull—Life of the Connecticut Trias. 407

in the classificatory scheme brings it into the order Neu-
roptera, family Sialide.

A second arthropod has just been announced (Jan. 1912) by
Miss Mignon Talbot, professor of geology in Mount Holyoke
College, and represents in all probability a new species of the
phyllopod genus Hstherza, heretofore reported from the New
Jersey—Pennsylvania area but not from the Connecticut valley.
The locality is West Holyoke, Massachusetts, which would
place it geologically in the ‘“‘ Lower Series of granitic, coarse
sandstones,” exactly what one would be led to expect from the
distribution of the genus in the New Jersey—Pennsylvania area.

Mollusca have been reported several times from the Con-
necticut valley, but the only authentic find seems to be that
recorded by Emerson (1900, p. 58). This slab, which has
been sent to me for study, is from near Wilbraham, Massa-
chusetts, and contains at least 14 imperfect impressions repre-
senting at least 2 species of undoubted Unio, the type of
Emerson’s species being similar to U. alatus. It should here-
after be known as Unio wilbrahamensis. The second species
is quite distinct from the first but is too imperfect to character-
ize. It is also unquestionably Unzo, and may hereafter be
known as U. emersoni in honor of Professor Emerson. Ano-
plophora, the genus to which Emerson referred the first species,
Schuchert says is probably always marine, and the shells in
question are doubtless in fresh-water deposits. The slab, which
is a portion of an ice-transported bowlder, the parent ledge of
which is probably unknown and therefore not necessarily as
far south in the valley as Wilbraham, gives evidence of having
been deposited in permanent waters, a habitat in keeping with
that of present-day Unios. Wilbraham being toward the east-
ern side of the valley, is, therefore, near the summit of the
Newark series stratigraphically.

Invertebrate Trails.

A summary of the invertebrate trails given by Professor C.
H. Hitcheock in 1889 is as follows:

Hexapod Arthropoda, 8 genera and 24 species.

Inferior Arthropoda, including larval forms and worins, 10
genera, 16 species.

Mollusea, 4 genera and 6 species.

Incerte sedis, 5 genera, 6 species.

This places the total number of invertebrate and questionable
trails at 52. In view of the number of undoubted vertebrate
species known from the Newark system and the teeming num-
ber of living invertebrates, especially arthropods, compared
with vertebrates, even under adverse climatic conditions, this

408 R.S. Lull—Life of the Connecticut Trias.

number does not seem excessive. In fact, I imagine it may
fall far short of the number of continental invertebrates of
Newark time. My own grouping modified from that of
Hitcheock (1889) is as follows:

Phylum Arthropoda
Class Insecta

Genera Acanthichnus with 9 species; Bifurculupes with
5 species; Lithographus with 3 species; Copeza with one
species; Hexapodichnus with 2 species; Conopsoides with 2
species; Harpepus with one species; Sagzttarius with one
species. |

Class Incertz sedis

Genera Lunula, one species; Pterichnus, 2 species; Ham-
ipes, one species; Sphwrapus, 2 species; Grammepus, 2
species; Stratipes, one species ; Saltator, 2 species.

Phylum Vermes

The old term Vermes is used as being more non-committal
than Annelida, as one cannot be sure that in every case the
following track-makers were oligochete annelids, though doubt-
less some were.

Genera Herpystezoum with 4 species; Halysichnus, 2
species; Cunicularius, one species; Cochlea, one species;
Cochlichnus, one species.

Phylum Mollusea ?

Under this head are placed some peculiar multiple trails, the
duplication of which seems to debar them from the worms.
Genera Bisulcus, one species; Zrisulcus, one species.

Genera of doubtful origin and character.

Genera arpagopus, one species; Grammichnus, one
species ; Climacodichnus, one species; ’/nzgmichnus, one
species. 7 | |

The Aquatic Vertebrates.

Among the vertebrate fossils found in the Newark rocks of
the Connecticut valley, two classes, fishes and reptiles, are rep-
resented by actual osseous remains; the latter surely, and prob-
ably the Amphibia, are recorded by their footprints. Whether
or not the two higher classes, the birds and mamunals, are rep-
resented is not yet proven, though mammalian remains are
known from the Newark system in North Carolina and the

R. S. Lull—Life of the Connecticut Trias. 409

first authentic avian relics, those of Archwopteryx, already a
long way along the road to avian perfection, coming as it does
from the Middle Jurassic, would surely imply birds in some
stage of their evolution during Newark time.

Professor OC. R. Eastman, in a characteristically excellent
paper (1911, p. 28), gives the following summary :

“List of Fossil Fishes occurring in the ‘ Newark’ or Upper
Triassic Rocks of Eastern North America. [In this list the
names of those species occurring in the Connecticut valley are
denoted by an asterisk. |

Crossopterygil
Family Ceelacanthidee
1. *Diplurus longicaudatus Newberry
Actinopterygil
Family Catopteridee

. *Catopterus gracilis J. H. Redfield
. * Catopterus redfieldi Egerton
Dictyopyge macrura (W. C. Redfield)

wm CO bo

Family Semionotide

5. *Acentrophorus chicopensis Newberry
6. *Semionotus agassizi (W. C. Redfield)
7. Semionotus brauni (Newberry)
8. Semionotus elegans (Newberry)
9. *Semionotus fultus (Agassiz)
10. Semionotus gigas (Newberry)
11. Semionotus lineatus (Newberry)
12. *Semionotus micropterus (Newberry)
13. *Semionotus ovatus (W. C. Redfield)
14. Semitonotus robustus (Newberry)
15. *Semionotus tenuiceps (Agassiz)

Family Eugnathidee
16. *Ptycholepis marshi Newberry.”

This fauna, except for one crossopterygian, is made up exclu-
sively of ganoids and, judging by comparisons made with fish
faunas of the Old World, is considered to be “of more or less
manifold nature, and corresponds in a general way to the inter-
val between the ‘uppermost Muschelkalk and the basal division
of the Keuper in the Mediterranean region.”

The fish remains are nearly all from the two general levels
of black bituminous shale, which also contain the plant relics,
in varying profusion. Rarely are footprints found in juxta-
position to the fishes and never, so far as I am aware, upon the

,

410 LR. S. Lull—Life of the Connecticut Trias.

fish-bearing shales themselves. Geologically, the shale bands
are associated with the trap outflows, an anterior bed following
immediately upon the anterior trap sheet to a thickness of from
50 to 100 feet and a posterior zone of about 100 feet imme-
diately preceding the posterior trap, the relationship of the
shale and trap being in one case the reverse of the other.
Greographically, the fish localities are distributed from Turners
Falls, Massachusetts, to Lake Saltonstall, New Haven, Con-
necticut.

The Terrestrial Vertebrates.

Reference has already been made to the great disparity in
numbers of actual bone remains as compared with the foot-
prints, and while the number of the latter contained in our
museums is so great as to be unrecorded, and many more have
been destroyed, the skeletal remains are by no means as rare as
is generally supposed, for as a matter of fact no fewer than
three genera and five species of dinosaurs, one of a belodon,
and two species of aétosaurs have been described from the
Connecticut valley area alone, while the actual number of
specimens naturally exceeds this record of forms. Geograph-
ically, osseous remains are reported from Greenfield, Belcher-
town, South Hadley, and Springfield, Massachusetts ; and from
East Windsor, Ellington, Manchester, New Haven and Sims-
bury in Connecticut. The footprints occur scatteringly the
entire length of the valley from above Turners Falls to New
Haven, but the greatest abundance both of separate localities
and profusion of species and specimens is in the more northern
portion of the area, specifically around Turners Falls and near
South Hadley, Massachusetts. Hitchcock, in the “Ichnology
of Massachusetts,” enumerates no fewer than 38 quarries for
fossil footprints, and a very few localities have been discovered
since that time. The geological sequence of the various fossil
and footprint localities is shown in the appended table.

The creatures known from the bones are as follows :—

Class Reptilia

Order Parasuchia Huxley

Suborder Aétosauria Nicholson and Lydekker (= Pseudosuchia
Zittel)

Family Aétosauridz
Stegomus arcuatus Marsh

From the lower series of granitic, coarse sandstones (Fair
Haven arkose), New Haven, Conn.

RL. S. Lull—Life of the Connecticut Trias. 411

Stegomus longipes Emerson and Loomis

From the upper series of sandstones (Longmeadow sand-
stone), Longmeadow, Mass.

Suborder Phytosauria Baur
Family Phytosauride McGregor
; Rhytidodon ( Belodon) validus Marsh

From the lower series of granitic, coarse sandstones, of
Simsbury, Conn.

Order Dinosauria Owen
Suborder Theropoda Marsh (Carnivorous Dinosaurs)
Superfamily Megalosauria Baur

Family Anchisauridz Marsh
Anchisaurus (Megadactylus) polyzelus (Kk. Hitchcock, Jr.)

From the upper series of sandstones and shales (Longmeadow
sandstone), Springfield, Mass.

Anchisaurus colurus Marsh
From the upper series, Manchester and East Windsor, Conn.

Anchisaurus solus Marsh

From the upper series of Manchester.

Ammosaurus major Marsh
From the upper series of Manchester.

Superfamily Compsognatha Huxley
Podokesaurus holyokensis Talbot

From the upper series (Longmeadow sandstone), South
Hadley, Mass.

These forms may be briefly described as follows :—

The Parasuchia were reptiles, more or less lizard-like in
form with an outer armor consisting of bony plates which are
in part segmentally arranged. They were distinguished from
the later crocodiles mainly by the position of the internal nares
(nostrils), which were normal and not shifted to the rear by
the growth of a secondary bony palate. In the modern
crocodiles this is a device to prevent strangling while devour-
Ing prey under water by bringing the nasal chamber in direct
communication with the glottis. The Parasuchia were both
aquatic, fish-eating forms and, in the aétosaurs, truly terrestrial
reptiles though still doubtless of carnivorous habits.

x

412 Le. S. Lull—Life of the Connecticut Trias.

Stegomus arcuatus Marsh is represented by the imp. ssion
of the dorsal armor only, showing it to have consisted of nar-
row transverse plates extending from the mid-line well across

ices 1

Fie. 1. Restoration of Stegomus longipes Emerson and Loomis. About
two-sevenths natural size. Modeled by R. 8. Lull.

the back, flanked by smaller plates along the sides, each series
overlapping its successor behind. ‘The animal was estimated

Ini 2s

Fic. 2. Anchisaurus colurus Marsh. Right side of the statuette showing
the flesh. One-twenty-first natural size. Modeled by R. 8. Lull.

_by Professor Marsh to have been of “ moderate size, prob-
ably eight or ten feet long.” It is preserved in the Yale
University Museum.

RL. S. Lull—Life of the Connecticut Trias. 413

Steyamus longipes Emerson and Loomis is much more com-
pletely known, as nearly the’entire armor from neck to rump
is preserved as well as the skull, sacrum, and remains of the
limb-bones. The latter give indication of long slender legs,
the whole organism indicating an animal of small size with
limbs of such character as to indicate most strongly a correla-
tion with certain abundant footprints of the genus Batrachopus
in which the long step and narrow trackway indicate a mam-
mal-like gait though the feet themselves were still typically
reptilian. A restoration of Stegomus longipes is here shown

Hig. 3.

Fic. 8. Anchisaurus colurus Marsh. Left side of the statuette showing
the skeleton. One-twenty-first natural size. Modeled by R.S. Lull,

(fig. 1), the original specimen being preserved in the museum
of Amherst College.

The specimen of /?hytidodon validus described by Marsh as
Belodon is much more meagre, consisting as it does of a single
incomplete scapula. It pertains, however, to a very well-
known genus, abundant remains of which have been found
elsewhere than within the valley limitations, so that the entire
character of the animal is approximately known. This creature
was of decidedly more crocodile-like aspect, being comparable
to the modern gavials which inhabit the large rivers of India,
with their long attenuated snout and slender conical teeth.
Rhytidodon also doubtless resembled the gavial in its fish-eat-
ing habits, and the finding of such remains at Simsbury, _

414 R. S. Lull—Life of the Connecticut Trias.

Connecticut, implies the presence during early Newark time of
a large river or fresh-water lake containing sufficient fish for the
maintenance of animals which may have attained the length of
a dozen feet. The original specimen of /?hytidodon validus
is preserved in the Yale Museum.

The Connecticut valley dinosaurs, known from their osseous
remains, are all carnivores, but within that group, the Thero-
poda, two sorts are represented, the heavier, more powerfully
aggressive anchisaurs and theslender, swift-running podokesaur, “
representing the two main phyla of the suborder. The
anchisaurs, represented by two genera and four species, were .
animals of fairly robust proportions, especially Ammosaurus
major, bipedal though with fore-limbs proportionately larger
than in the carnivores of later geologic time, and still well fit-
ted for grasping their prey. There is no evidence, however—
and their footprints are known by the hundreds—that they ever
placed the hands upon the ground even while resting. The
teeth in the skull of Anchisaurus colurus are not of the piere-
ing and cutting type seen in the larger, more aggressive car-
nivores known elsewhere, but are somewhat spatulate, amply
sufficient, however, for the feebler reptilian and amphibian
creatures which doubtless formed their prey. The light, hol-
low bones, together with complete bipedalism, imply swift
movement over a wide range of territory.

Of the known anchisaurs Anchisaurus solus is the smallest
with an estimated length of about 34 feet. A. colurus reached
7 feet, and A. polyzelus was of nearly equivalent size, the
former being slightly the larger, while Ammosaurus major
was an animal of perhaps 82 feet in length. A restoration of
Anchisaurus colurus, both skeleton and flesh, is here shown
(figs. 2, 3). :

With the exception of the type of Anchisaurus polyzelus,
which is preserved at Amherst College, the Yale Museum con-
tains all the known material pertaining to this group.

Podokesaurus holyokensis represents the latest discovery of
dinosaurian remains in the Connecticut valley region. It was
found by Miss Mignon Talbot during 1910. This animal,
known from the entire skeleton of the trunk and much
of the tail and limbs but unfortunately lacking the head and
anterior portion of the neck, has been restored by the writer
(fig. 4) as a long-limbed type with an excessively long and slender
tail. The head is‘restored from that of Compsognathus of the
middle Jurassic of Bavaria, but the rest is based almost with-
out exception upon the skeleton. The estimated length of
Podokesaurus is 3% feet.

Podokesaurus was essentially a slender, cnrsorial animal,
carnivorous in habits, but from the very slenderness which

R. S. Lull—Life of the Connecticut Trias. 415

gave it such celerity of movement necessarily confined to
feeble prey of which the various footprints manifest so great
an abundance. That it was related to the group represented

Fie. 4.

Fie, 4. Podokesaurus holyokensis Talbot. Restoration about one-tenth
natural size. Modeled by R. S. Lull.

later by Ornitholestes from the Morrison and Ornithomimus
from the close of the Cretaceous seems certain ; in fact, I see

Fie. 5.

Fic. 0. Anomepus scambus Hitchcock. Restoration of a plant-feeding
dinosaur, based uppn footprints and the skeleton of Hypsilophodon fowii
from the British Wealden. About one-fourteenth natural size. Modeled by
R. 8. Lull.

416 RL. S. Lull—Life of the Connecticut Trias.

no feature to debar it from a more or less direct ancestry to
its American successors in time.

The Vertebrate Footprints.

The vertebrate tracks are so numerous and so varied withal
that the reader is referred to another extract of the Connecti-
cut valley memoir, to appear shortly, for the list with a brief
diagnosis of each of the several genera.

They represent cursorial quadrupedal forms similar to Ste-
gomus, and dinosaurs both carnivorous and herbivorous as
well. Of the former some are very large, indicating animals
of at least 27 feet provided the proportions were those of AJdlo-
saurus, for instance, of the Morrison, while on the other hand
there are tracks of such extreme delicacy among the bipedal
group that the application of the term dinosaur or “ terrible
lizard” to such as made them seems absurd. There are also
the trails of occasionally erect forms and of true quadrupeds,
some doubtless of lizard- or salamander-like shape, but all of
these are of small size as compared with the dinosaurian foot-
prints.

Geologically the first known footprints are reported from
the anterior shales and are all apparently referable to carnivor-
ous dinosaurs. The posterior shales are of interest in that here
are found the first plant-feeding dinosaur tracks in the Newark
rocks. Itis not until the upper series of sandstones and shales
is reached that the great profusion of tracks is manifest, not
that the animals were necessarily any more numerous, but that
the acme in the perfection of track preservation for which this
region is so noted was reached.

In all the total number of footprint genera is 43 while the
species exceed this, there being no fewer than 98 all told.

Résumé.

The story of the Connecticut valley, as the evidence at hand
now reveals it, may be summarized as follows:

Far back in the remote Triassic period, when the Aer of
Reptiles was yet young, there were laid down in a oradually
deepening trough in the older rocks the great accumulations
of gravels, sands, and clays, interbedded with vast lava sheets,
which constitute the sediments of the Newark system. The
older notions of the submarine or estuarine origin of these
rocks have been abandoned on the ground of their containing no
relics whatever of marine or even brackish water origin, and
of the difficulty of accounting for the deposition of the sedi-
ments except by tidal currents of far greater transporting
power and governed by laws of movement at variance with

R.S. Lull—Life of the Connecticut Trias. 417

any on earth to-day. On the other hand, evidence seems to
point to continental deposits, the result of the ordinary sub-
aérial agencies of winds and rains and rivers, such as require
no ingenious straining of nature’s laws to account for the
accumulation of vast deposits in the course of time. The
origin of the sediments was the wasting of the older rocks
which formed the limiting highlands on either side of the depres-
sion: and the organic remains, all of fresh-water or terrestrial
origin, testify to the presence, from time to time at least, of
standing bodies of water of considerable extent ; of seasonally,
if not continually, flowing rivers; and of extensive land areas
with slowly drying pools left after the infrequent, but tor-
rential showers characteristic of arid to semi-arid regions of the
present day. That there were climatic cycles, such as Hunt-
ington (1907, 1911) has observed in the Near East, I have no
doubt, and I have reason to believe from the evidence of the
fossil vertebrates that the climate during the earlier part of
the Newark period may have been less arid than toward its
close.

The vegetation bore the mark of antiquity in its monoto-
nous sombre greens, for brilliantly colored flowering plants had
not yet appeared, and apparently there was that sparseness and
lack of profusion, except locally, which characterizes our great
Southwest. The plants were of three main sorts: ferns,
cyeads, and conifers, looked upon by existing animate life as
undesirable food, but which for utter want of a better must
have tempted some of the denizens of Triassic time, for we
have evidence of mild-mannered herbivores among the rapa-
cious devourers of flesh.

Of the organic remains, those of vegetable origin consist of
the impressions and casts of the trunks of trees, some of the
latter found at Portland being of such size as to mdicate a
stream of no mean transporting power; and of the impressions
of leaves, twigs, and fruits, occasionally containing a delicate
film of carbon which preserves the most intricate detail with
wonderful fidelity. Here and there the vegetable remains
were of sufficient abundance to influence the production of
black bituminous shale bands of 60 to 100 feet in thickness,
formed during periods of the accumulation of waters which
supported a teeming population of fishes; but never within
this area were conditions ripe for the formation of beds of coal
such as are found in the Newark strata from Virginia south-
ward. \ |
Animate life left its record rarely in the form of shells or
bones, but in marvellous abundance in trails and footprints,
some of such clarity of meaning that he who runs may read,
others of more difficult and questionable interpretation, yet
others exasperating in their baffling obscurity.

418 LR. S. Lull—Life of the Connecticut Trias.

Both vertebrates and invertebrates are thus represented.
Of the latter the actual fossils are impressions of at least two
species of shells, allied to the modern fresh-water Unios, a small
crustacean, and a single aquatic insect species, the last occur-
ring in profusion of numbers, and bearing the unique distinc-
tion of being the oldest true insect Jarva known. Some of the
trails are worm-like as though made by annelids, others show
serially repeated footmarks in pairs of fours or sixes or more,
indicating the presence of other arthropods than Mormolu-
coides, many of which were doubtless insects, others myria-
pods, perhaps spiders and scorpions, and fresh-water crusta-
ceans as well. Some of these are smal]l and of wondrous
delicacy, others larger than the trails of any insects of fresh-
water crustaceans known, which must represent giants among
their race.

The fishes, all of the old-fashioned armored sort, have been
alluded to as occurring in abundance from time to time in the
black shale bands, representing lake deposits with a luxuriant
growth of plants.

The terrestrial vertebrate skeletons are all reptilian remains ;
three those of phytosaurs, remotely related to living crocodiles,
and, in one instance at least, economically equivalent to the
fish-eating gavials of the Far East. The others are all dino-
saurs of average size and representative kinds, neither the
largest nor the most specialized which lived during the time of
which we speak being known to us. Unfortunately, too, the
dinosaurian skeletons were those of contemporaries and, there-
fore, in themselves throw no direct light upon evolutionary
history. Of the five species four are so nearly related as to
be of one family and three of one genus, while the other rep-
resents a different race, which in its ultimate -culmination was
far apart from the group for which the others stand, though
all were sanguinary devourers of flesh.

The footprints represent two, possibly three, great classes of
terrestrial beings. Amphibia of salamandrine form were per-
haps present, and doubtless representatives of the more archaic
armored stegocephalians as well, though one cannot indicate
the track of either with assurance. Of the reptiles, the possi-
bilities of time and place would indicate lizards, turtles, and
dinosaurs among the more familiar forms, and these unques-
tionably were represented in the fauna, and among those less
known the Rhynchocephalia, phytosaurs, aétosaurs, and thero-
morphs are within the possibilities. -

Whether or not birds were present is still a mooted question.
The elder Hitchcock considered all of the bird-like tracks
unquestionably to have been of avian origin, but the discovery
of dinosaurian remains soon swung popular, if not scientific,

R.S. Lull—Life of the Connecticut Trias. 419

opinion to the opposite extreme, and all the tracks were
believed to have been made by dinosaurs. I believe, in most
instances, this group of footprints is demonstrably dinosaurian.
There are some, however, of which I am not so sure; but the
only final proof of the existence of Triassic birds will be the
actual discovery of their remains, for the earliest yet known,
Archeopteryx, of the uppermost middle Jurassic, lived thou-
sands of years subsequent to the close of Newark time. If Pro-
fessor Osborn is right In supposing the pro-avian to have been
arboreal, I should not look for its trail over the sands of the
Connecticut valley, and I seriously question whether at so
remote a time degenerate terrestrial birds had been evolved.
On the other hand, the cursorial origin of birds is conceivable,
and if true would be possible within the environment we are
discussing.

Of the mammals, though known apparently in Dromothe-
rium and Microconodon from contemporaneous rocks of not
very remote geographical locality, we have no record. Their
known habitat in the Triassic had a very different climatic
and vegetal environment from that of the Connecticut valley ;
and this, as in the case of birds, would seem to debar them
from the limits of this area.

Geologically, the history of Newark times was a tremendous
drama of which the prologue speaks of the degradation of the
ancient hills and the setting of the stage in the form of an
extensive though relatively slight depression, with the estab-
lishment of the sediment-bearing drainage from the environing
upland. Four great acts, of which the first and last were much
the longest, succeed each other in time, separated by interacts
of appalling grandeur, when vast sheets of molten rock welled
from the depths and spread far and wide, blotting out the old
and preparing the stage for newer and different players. Of
the sequence of the scenes within the acts, the order is not so
surely recorded, since they differed in their position in the
valley, in the nature of the sediment in which their record is
written and in the forms that peopled the stage. The whole
drama is incredibly long as we measure time, for each succeed-
ing day with its dawning, morning hours, high noon, declining
sun, and long night added but the smallest increment to the
gradually accumulating sediments, though, as has been said,
“Neither time nor space flow evenly,” and there were tempes-
tuous days whose contribution to the mass made up for the
calm passage of those to follow, yet when one thinks of the
two and one-half miles of accumulations which these days rep-
resent, he can feebly grasp at a realization of the extent of
Newark time.

During the long first act, in the course of which were laid

420 LR. S. Lulli—Life of the Connecticut Trias.

down the six or seven thousand feet of the lower series of
granitic, coarse sandstones, we have but little record of the
action; but two entrances are recorded, one of which is at
New Haven when the heavily armored Stegomus arcuatus
appears, whose habits we can scarcely conjecture, as the burial
of its body in river sediment means little. The second scene
at Simsbury is more intelligible because, while part of a
shoulder blade only is preserved, it is from the representative
of a genus fzhytidodon which is almost completely known,
hence we are justified in applying the old Cuvierian principle
and reconstructing, not only a long-snouted, fish-eating animal
from a single bone, but its fish-supporting, aquatic environ-
ment as a stage setting as well.

This act closed with the first lava outpouring, the so-called
anterior trap, which was followed immediately by the second
act, that of the anterior shales, interesting in being ushered in
by the first fish- and plant-bearing black shaie deposit, followed
in the region round about Mount Holyoke and Mount Tom by
the first recorded appearance of dinosaurs in the Connecticut
valley. Of these Lubrontes giganteus, one of the very largest,
was among the first, possibly representing a form like the
larger genera well known from their bones in the Old World.
Others were the larger species of Anchisauripus, indicating
the presence of Ammosaurus-like dinosaurs as well. This
second act, with but a thousand or more feet to its credit, was
the briefest of all, and the interact following, as befits the
middle of the drama, was the most stupendous with the accu-
mulation of the 500 feet of lava which constitutes the main
trap sheet.

Act III, during which the posterior shales were laid down,
is still more prolific of animate records, for the known foot-
prints not only increase in number, but here for the first time
we find those of Anomepus giving the earliest reasonably sure
record of the advent of plant-feeding dinosaurs, while that of
Grallator cursorius shows that accompanying their larger,
fiercer brethren were the lighter, more agile dinosaurs of comp-
sognathoid type. This act closed with another scene, during
which the plant- and fish-bearing black shales could be aceu-
mulated. The relative duration of these posterior shales was
somewhat greater than that of the anterior deposition, but was
followed by the smallest of all the lava outpourings, that of
the posterior trap.

It is only in the final act that the profusion of the cast be-
comes evident, for at various levels within the 3,500 feet
of its accumulations, but notably toward its close, at Port-
land, around South Hadley, and within and about Turners
Falls, are recorded by far the great majority of the known

RL. S. Lull—Life of the Connecticut Trias. 421.

genera and species of the footprints of the Trias ; while
equivalent beds, mainly from South Hadley southward to
Manchester, Connecticut, have yielded all of the osseous dino-
saurian remains. One is “impressed with the profusion of trails
which imply swift motion, as though conditions were hard and
life the antithesis of one of languorous ease, the principal fea-
ture which gives rise 2 to the belief of locally increasing aridity
of climate.

Here more than in any other act of paleontological history
one is conscious of an obscnring drop scene in the middle dis-
tance, behind which may be seen with tantalizing clarity the
passing and repassing feet of a great host of players: some
rapidly, as though impelled by urgent impulse ; others slow-
moving, ponderous, the like of which the paleontologist has
never seen. Occasionally one passes before the curtain and
there, while fully exposed to our scientific vision, a tragedy
is enacted, for bones are ever symbolical of death ; but the foot-
prints are those of creatures in the full tide of life.

Bibliography.

Barrell, J. 1908. Studies for students: Relations between climate and ter-
restrial deposits ; Jour. Geol., XVI, 159-190, 255-295, 363-384.

Chamberlin, T. C., and Salisbury, R. D. 1906. Geology, Vol. III, Earth
History, Mesozoic, Cenozoic, I-XI, 1-624, figs. 270, New York.

Davis, W. M. 1898. The Triassic formation of Connecticut ; U.S. Geol.
Surv., 18th Ann. Rept., Pt. IT, 9-192, pls. I-XX, figs. 1-52.

Eastman, C.R. 1911. Triassic fishes of Connecticut ; Bull. 18, Conn. Geol.
and Nat. Hist. Surv., 7-75, pls. I-XI, figs. 1-8.

Emerson, B. K. 1898. Holyoke folio, Massachusetts—-Connecticut : U8.
Geol. Surv., Geol. Atlas of UL. S., folio No. 50.
1900. A new bivalve from the Connecticut river Trias ; Amer.
Jour. Sci. (4), X, 58, 1 fig.

Fenner, C.N. 1908. Features indicative of physiographic conditions pre-
vailing at the time of the trap extrusions in New Jersey ; Jour.
Geol., XVI, 299-327, 16 figs.

Hitchcock, C. H. 1889. Recent progress in ichnology ; Proc. Boston Soc.
Nat. Hist., XXIV, 117-127.

Hitcheock, E. 1858. Ichnology of New England, 1-220, pls. 60. Boston.
1865. ee to the ichnology of New England, I-X,
1-96, pls. I-XX, Boston.

Huntington, E. 1907. The ‘pulse of Asia, Boston.
1911. Palestine and its transformation, Boston.

Lull, R.S. 1904. Fossil footprints of the Jura-Trias of North America ;
Mem. Boston Soc. Nat. Hist., V, 461-557, 1 pl., 34 figs.
1910. Dinosaurian distribution ; Amer. Jour. Sci. (4), X XIX,
1-39, 10 figs.

Newberry, J. S. 1888. Fossil fishes and fossil plants of the Triassic rocks
of New Jersey and the Connecticut valley; U.S. Geol. Surv.,
Mono. XIV, I-XIV, 1-152, pls. -X XVI.

Am. Jour. Sct.—Fourt SERIES, VoL. X XXIII, No. 197.—May, 1912.

‘

422 Lt. S. Lull—Life of the Connecticut Trias.

Geologic Section of the Newark System of Connecticut

(modified from Schuchert).

Character of
sediments

Thickness Characteristic fossils

Upper series of sand-
stones and shales
with local conglom-
erates

The great majority of known footprints

| of all varieties, vertebrate and inver-

tebrate; also Mormolucoides articu-
latus.

8,500 ft. + Anchisaurus spp., Ammosaurus and
Podokesaurus, among dinosaurian
skeletons.

Stegomus longipes, skeleton.

Posterior trap sheet

150 ft.

Black bituminous zone

100 ft. Plants and fishes

Posterior shales

Dinosaur tracks. First plant-feeding
1,200 ft. | dinosaur footprints known. Mt. Tom
East, Middlefield, etc.

Main trap sheet

Anterior shales

Black shales

Anterior trap sheet

Lower series
granitic,
coarse*sandstone
(With intrusive trap
sheet, 500-600 feet
thick)

Sandstone

Gneisses, schists, and
granites
‘Pre-Mesozoic

500 ft.

First known dinosaurian footprints.
1,000 ft. — Qarnivores. Mt. Tom West and Mt.
Holyoke ; Higby, Conn.

50 te 100 ft. Plants and fishes

200 ft.

5,000 to (Rhytidodon validus, Simsbury, Conn.
6.500 ft Stegomus arcuatus, New Haven, Conn.
ys "* | Estheria sp. West Holyoke, Mass.

200 to 300 ft. |

HI. L. Ward—Oxalate-Permanganate Process. 423

Art. XXXV.—The Oxalate-Permanganate Process for the
Determination ef Copper Associated with Cadmium,
Arsenic, Iron, or Lead; by H. L. Warp.

[Contributions from the Kent Chemical Laboratory of Yale Univ.—ccxxx. ]

-Ir has been shown by Peters* in a paper from this labora-
tory that copper oxalate may be precipitated by oxalic acid
with practical completeness from solutions of a copper salt,
provided the volume of the liquid is not too great and that
the amount of copper present exceeds a minimum value, some-
what dependent on conditions. Still more recently, it has been
shownt that the condition of supersaturation, which is respon-
sible for failure in the precipitation of minimum amounts of
copper oxalate, may be easily overcome by freezing the solu-
tion, by addition of alcohol to the amount of 50 per cent of the
solution, and, in a higher degree, by evaporation to dryness or
by the addition of large amounts of acetic acid. The best and
most convenient procedure for the precipitation of large as
well as small amounts of copper oxalate ideal in composition, con-
sists in adding 2 grms. of oxalic acid to 50% or 4 grms. to 100°"
of the 50 per cent acetic acid solution of the copper salt con-
taining 5 to 10 per cent of nitric acid. The permanganate
titration of the washed oxalate, in the presence of sulphuric
acid, gives a very accurate determination of the copper.

The present paper is an account of attempts to apply the
latter two processes in separations of copper from cadmium,
arsenic, and iron, ard in the determination of copper after sep-
arating the lead as sulphate.

In the experiments of the first part of Table I a standard
solution of copper sulphate was treated with one gram of oxalic
acid, added in the solid form to the boiling solution of about
50°™* volume, and the liquid was then evaporated on the steam
bath. Extraction was made with the amounts of nitric acid
indicated and water to make up a volume of 50™*. The liquid
was then boiled for 10 minutes in contact with the precipi-
tate and allowed to cool. The oxalate was collected upon
asbestos in a perforated crucible and washed carefully with
small amounts of water. The crucible with its contents was
placed in a beaker and covered with about 200% of hot water,
containing 25°™* of dilute sulphuric acid (1:4), and approxi-
mately N/10 potassium permanganate of known standard
added to coloration.

* This Journal [4], x,
+ Gooch and Ward, ibid. 4, xxvii, 448.

494 H. L. Ward—Oxalate-Permanganate Process.

The experiments of the second part of the table were per-
formed similarly, except that the active mass of the oxalic acid
was increased by the addition of more of the crystals before
extraction. It will be noticed that when the concentration of
the oxalic acid is slight, even the smaller amounts of nitric acid
cause considerable errors and that these errors increase with the
percentage of nitric acid present. When, however, oxalic acid
is added nearly to the saturation point of the liquid, the losses
are not large and do not increase materially even when very
large quantities of nitric acid are used in the extraction. It is
evident, also, that about one milligram of copper goes into
solution and the process is only accurate up to this amount.

TABLE I,
The Effect of Desiccation and Extraction with Nitric Acid.

Volume of
Volume liquid
Copper at precip- usedin Nitric Oxalic Copper

taken itation extraction acid acid found Error
grm. em? em? cm? erm. grm. grm.
vA.
Small Amounts of Oxalic Acid
0°0504 50 50 1 1 0°0497 —0:0007
0°0504 50 50 2 1 0°0492 —0°0012
0°0504 50 50 3 1 0°0487 —0°0017
0°0504 50 50 4 i 0°0479 —0°0025
0°0504 50 50 9) 1 0°0469 —0°0035
B.

Large Amounts of Oxalic Acid.

0°0504 50 50 3 6 0°0495 —0-0009
0°0504 50 50 4 6 0°0495 —0:0009
0°0504 50 50 5 6 0°0491 —0°0013
0°0504 50 50 ) 6 0°0495 —0:0009
0°0504 50 50 10 6 0°0486 —0°'0018
0°0504 50 50 15 6 0°0486 —O0:0018
0°0504 50 50 20 6 0°0487 —0°0017
0°0504 50 50 25 5 0°0491 —0°0013
0°0504 50 50 25 5 0°0491 —0°0013
0°0504 50 50 40 5 0°0494 —0-°0010

The Separation of Copper from Cadmium as Oxalate.

It was found that the procedure outlined above does not
secure a complete separation of copper from cadmium, as some
of the latter element is included with the copper and cannot
be dissolved even on treatment with concentrated solutions of hot
nitric acid. If, however, nitric acid is added before precipita-
tion, the oxalate of cadmium separates out only on evaporation,
when it readily dissolves on treatment with more acid.

HA. L. Ward—Oxalate-Permanganate Process. 425

The first process used for the separation of copper and cad-
mium is as follows: To the boiling concentrated solution of
the nitrates or sulphates of copper and cadmium, containing
5° of strong nitric acid, is added 4 grms. of crystallized oxalic
acid. The solution is evaporated to dryness on the steam bath
and the residue is taken up with cold water containing nitric
acid, it being unnecessary to heat the acid to bring about the
solution of the cadmium. The precipitate is transferred to
the perforated crucible by means of the filtrate and washing
is done with small amounts of water. The crucible is then
placed in a beaker containing about 25°" of dilute (1:4) sulphu-
ric acid and 200°" of water heated to boiling, and the dissolved
oxalate is titrated with permanganate. It is necessary to use
a large excess of oxalic acid in the precipitation, for some of
it is destroyed by the nitric acid on evaporation to dryness.
It will be seen from Table II that when 10 per cent nitric acid
is used in extraction, the errors, while all negative, are within
permissible limits. On using 20 per cent acid, however, a
considerably greater amount of oxalate goes into solution.
This process, at best, is not extremely accurate.

TABLE II.

Separation of Copper from Cadmium by Desiccation and Extraction.

Nitric Volume Liquid Nitric acid
Cad- acid on at usedin used in

Copper. mium precipi- precipi- Oxalic extrac- extrac- Copper
present present tation tation acid tion tion found Error

erm. grm. em? cm? germ. cem* em? erm. erm.
00514 0-01 5 50 yee 50 5 0°0507 —0-:0007
0°0514 0°06 5 50 + 50 5 0°0506 —0-°0008
w-0051. - 0°10 3) 50 + 50 5 0°0048 —0°0003
0°0504 0°10 3) 50 4 50 5 0°0502 —0:0002
0°0514 0°10 5 50 a 50 5 0°0508 —0-°0006
0°0514 0°20 5) 50 + 50 5 0°0508 —0°0006
0°1542 0°20 5) 50 50 5 071587 —0-0005
0°0516 0°30 5 50 - 50 5 0°0507 —0:°0009
0'0504 0°10 D 50 2 50 10 0°0488 —0:°0016
0°0504 0°10 5 50 4 50 10 0°0494 —0°0010
0°0514 0:20 5 50 + 50 10 0°0500 —0:'0014

It has been shown in the previous paper* that copper may
be precipitated very completely from solutions of its salts by
oxahe acid, provided one-half the volume of the solution con-
sists of glacial acetic acid, and that considerable amounts of
nitric acid may be present without causing appreciable error.
In separating copper from cadmium by this second process, pre-
cipitation is brought about by oxalic acid in a solution one-half

* This Journal [4], xxvii, 448, 1909.

49296 H. L. Ward—Ocalate-Permanganate Process.

of whose volume is glacial acetic acid containing free nitric
acid. The oxalic acid is added in the solid form to the boiling
solution and the resulting oxalate allowed to stand over night.
Filtration, washing and titration are made in the same manner
as in the former method.

It will be noticed that in the first part of Table III, where
small amounts of oxalic acid have been used in the precip-
itation, the results have a tendency to come low, especially
when the larger amounts of nitric acid are present. At least
3°5 orm. to 4 grm. of oxalic acid should be used for every
100° of solution, but more causes trouble by crystallizing out.
It is then necessary to dissolve the crystals in water, which
may cause a slight error due to solubility, or to use the mixture
of ‘equal parts water, acetic acid and alcohol recommended by
Classen.* When very little copper is present not more than
5° of nitric acid should be added before precipitation. With
amounts exceeding 50 mg. 10°™* should be used to 100%™* of
liquid. A separation may be thus secured from 0:20 grm. of
cadmium. With 0°3 grm. of cadmium and 50 mg. of copper
it is possible to obtain satisfactory results when the volume on
precipitation is increased to 200° If 0-15 grm. of copper is
present, even under these conditions, some of the cadmium
comes down with the copper. Increasing the volume of nitric

TABLE III.

Separation of Copper from Cadmium by Precipitation from a Solution Con-
taining a Large Amount of Acetic Acid.

Cad- Volume .

Copper minum at pre- Oxalic Acetic Nitric Copper

present present cipitation acid acid acid found Error
germ. grm. em? erm. em? em? germ. grm.
0°0051 0°10 50 1 25 9) 0°0052 +0:0001
0°0051 0°10 100 2 50 9) 0°0045 —0°0006
0°0051 0°10 100 2 50 5 0°0043 —0:0008
0°0253 0°20. 100 2 50 10 0°0251 —0°0002
0°0511 0°20 100 2 50 9) 0°0512 +0°0001
0°1538 0°20 100 2 50 9) 0°1545 +0°0012
0°1533 0°20 100 2 50 10 0°1525 —0°0008
0°0051 0°20 100 4 50 5 0°:0049 —0°0002
0°0255 0°20 100 + 50 10 0°0257 +0:°0002
0°0510 0°20 100 + 50 10 0°0512 +0°0002
0°1530 0°20 120 3°5 50 10 0°1533 +0°'0008
0°0051 0°30 100 + 50 9) 0°0053 +0°0002
0°0511 0°30 100 + 50 10 0°0520 +0°0009
0°0511 0°30 200 8 100 10 0°0510 —0°0001
0°1533 0°30 100 + 50 10 0°1556 +0°0023
0'1538 0°30 100 + 50 20 0°1556 +0°0023
0°1629 0°30 200 8 100 10 0°1643 +0°0014
0°1629 0°30 100 + 50 10 0°1686 +0:0007

* Zeitschr. anal. Chem., xviii, 179.

HT. L. Ward—Oxalate-Permanganate Process. 427

acid present to 20°™* does not entirely eliminate the error when
the volume is kept at 100°. Another method, used in the
last experiment of the table, is to precipitate in water solution
and add the acetic acid afterward to throw out the last traces
of copper. This secures a somewhat sharper separation in the
case of the larger amounts of the metals.

The Separation of Copper from Arsenic as Oxalate.

In the first attempt to separate copper from arsenic the evap-
oration process used for cadmium was tried. No nitric acid
was added on precipitation, as the arsenic comes down only on
evaporation and may be dissolved again. Less nitric acid was
also used in.the extraction. In the experiments of Table IV
the arsenic was present in the form of potassium arsenate, as
it was found much easier to make a sharp separation when the
arsenic was in the higher condition of oxidation. Even then
it was difficult with the larger amounts to bring the arsenic
entirely into solution.

TABLE IV.
Separation of Copper from Arsenic by Desiccation and Extraction.
Volume Solution Nitric
Arsenic at pre- used in acid used

Copper presentas cipita- Oxalic extrac- inex- Copper
present arsenate tion acid tion traction found Error

grm. grm. em? grm. em? em? grm. germ.
0°0051 0°10 50 i 50 2 0:0047 —0-°0004
0°0504 0°05 50 1 50 2 0°0499 —0:0005
0°0504 0°05 50 1 50 2 0°0501 —0°00038
0°0504 0°10 50 1 50 2 0°0503 —0°'0001
0°0504 0°10 50 1 50 2 0°0497 —0°0007
0°0504 OrZ00= 50 1 50 2 6°0498 —0°0006
0°1533 0°20 50 fh 50 2 0°1528 —0:0005

On precipitation from a solution containing a large amount
of acetic acid according to the procedure before described for
cadmium, a very sharp and satisfactory separation was secured.
The results of some experiments appear in Table V. In the
case of the larger amounts of copper it was found necessary to
add nitric acid before precipitation to render the precipitate
erystalline and suitable for filtration.

TABLE V.

Separation of Copper from Arsenic by Precipitation in a Solution Containing
a Large Amount of Acetic Acid.

Arsenic Volume

present at pre- Acetic
Copper as arsen- cipita- Oxalic acid Nitric Copper
present ate tion acid present acid found Error
erm. erm. cm? germ, em? em? germ, erm.
0'0051 0°20 ~ 100 2 50 0°2 0°0052 +0°'9001
0°0051 0°30 100 4 50 O°4 0°0054 +0°0003
0°0511 0°30 100 + 50 0°4 0°0505 —0°0006
0°1530 =0°20 100 + 50 10:0 0°1530 +0°0000
0°1533 0°30 100 5 50 10°0 0°1530 —0°0003

428 H. L. Ward—Oxalate-Permanganate Process.

The Separation of Copper from Iron as the Oxalate.

To secure the complete precipitation of copper in the pres-
ence of iron the first method tried was evaporation to dryness,
carried out exactly as in the case of arsenic. No nitric acid
was used on precipitation and the residue was extracted with
very dilute acid, after the addition in most cases of crystallized
oxalic acid other than that nsed in the precipitation. The
results of experiments appear in Table VI. It is plain that
when only a moderate amount of iron is present the copper
may be estimated with a fair degree of accuracy, but when the
iron much exceeds 0°16 grm., the figures show, not an increase
due to the inclusion of the oxalate of iron, as would be ex-
pected, but a loss in copper due to incomplete precipitation.
The filtrate also gives a test for copper. The method, there-
fore only gives satisfactory results when not more than 0:1
germ. of iron is present. |
TaB_e VI.

Separation of Copper from Iron by Desiccation and Extraction.
Oxalic Dilu- Nitric Oxalic

Volume acid tion acid acid

at on on On 9.5.02

Copper Iron preci-. preci- ex- X=... s@k-

pre- pre- __— pita- pita- trac- trac- trac- Copper
sent sent tion tion tion tion tion found Error
erm. orm) )em" erm. em? =. .cm? )ierm! --oeme grm.

0°0504 0°0593 50 i 50 2 2 0°0500 —0:0004
0°0504 0°0393 50 1 50 2 2 0°0501 —0:0003
0°0504 0°0393 50 1 50 2 2 0°0499 —0°0005
0:0504 0°0786 50 1 50 2 2 0°0499 —0°'0005
0°0511 0°1000 50 ih 50 5) 5) 0°0506 —0:0005
071533 0°1000 50 1 50 5 3 0°1527 —0-°0006
0°0051 O0°1572 50 2 50 5) 2 0°0036 —0°0015
0°0504 0°1572 50 1 50 2 2 0°0497 —0-0007
0°0504 0°1572 50 if 50 2 2 0-0597 —0:0007
0°1542 0°1572 50 + 50 3) + 0°1524 —0°0018
0°0511 0°2000 50 1 50 5 3 0°0475 —0:0036
0°0511 0°2000 50 | 50 5) 3 0°0475 —0°'0036
0°0511 0°2000 50 5) 50 5 3 0°0491 —0°0020
0°0511 0°3404 50 4 50 3) + 0°0482 —0°0029

The effect of precipitation in a solution containing one-half
its volume of glacial acetic acid is shown in Table VIL.

It appears that when no nitric acid is present, the errors
are positive, indicating that some of the iron comes down
with the copper. When, however, the solution contains much
free nitric acid, losses appear and these losses increase with
the amount of nitric acid present. It is evident, therefore,
that the solution should not be strongly acid with both these
acids at precipitation.

H. L. Ward—Oxalate-Permanganate Process. 429

TABLE VII.

The Separation of Copper and Iron by Precipitation in a Solution Contain-
ing Large Amounts of Acetic Acid.

Volume
at

Copper Iron precipi- Oxalic Nitric Acetic Copper

present present tation acid acid acid found Error
erm. erm. em? erm. em? em? erm. germ.
0°0511 0°100 50 2 LA 25 0°0524 +0°0013
80-0511 0°100 100 2 ae 50 0°0524 +0°0013
0°0510 0°188 100 Les 50 0°0514 +0°0004
0°0510 0°188 100 + 2 50 0°0511 +0°0001
0°0510 0°188 100 = 5 50 0°0499 —0:0011
6:0511... 0°100 100 2 10 50 0:0475 —0°'0036
00511 0°100 100 + 10 50 0°0489 —0'0022
070510 0°188 100 + 10 50 070487 —0°0023
0°0510 0°188 110 + 10 50 0°0468 —0:'0042

It appears, however, that when the precipitation is made in
a solution just acid with acetic acid and a lar ge excess of this
acid is added after cooling to throw out the last traces of
copper, the oxalate contains very little iron. The most success-
ful procedure is to treat the solution with potassium hydroxide
to faint alkalinity, then to make it just acid with acetic
acid to precipitate at the boiling temperature with a large
excess of oxalic acid. After cooling, about two volumes of
acetic acid are added and the oxalate allowed to settle over
night. Filtration and titration are made in the usual manner.
Results of this procedure are given in Table VIII.

TABLE VIII.

hehe of Copper from Iron by Precipitation in Nearly Neutral Water
Solution with Subseauent Addition of Acetic Acid.

Volume Acetic

Copper Tron at pre- Oxalic acid Copper
present present cipitation acid - added found >.) Hirror,

erm. erm. em? grm,. . em? erm. erm.
0°0051 0°31 50 6 100 0°0049 —0'0002
0°0051 0°45 50 6 100 0°0046 —0'0005
0°0543 0°15 50 6 100 0°0544 +0°0001
0°05438 0°21 50 6 100 0°0542 —0O:'0001
0°05438 0°31 50 6 100 0°0546 +0°0008
0°0543 0°45 100 12 200 0°0538 —0°0005
0°1629 0°45 50 6 100 0:1649 +0°0020
0°1629 0°45 100 12 200 0°1629 +0°0000

Shonld much free acid be present originally it should be
removed by evaporation before neutralizing the remainder with
the potassium hydroxide ; and if potassium oxalate crystallizes
out, as may happen if much potassium salt is present with the
large amount of oxalic acid, it is best dissolved in a mixture of

430 HH. L. Ward—Ovxalate-Permanganate Process.

alcohol, water, and acetic acid in equal parts. When very large
amounts of iron are present it is more satisfactory to increase
the dilution on precipitation to 100°. It is necessary in all
cases to have present a very large excess of oxalic acid to secure
the complete insolubility of the copper.

Peters found that when potassium nitrate was present in the
water solution of a copper salt, all the copper was not thrown
down by oxalic acid. It becomes desirable, therefore, to ascer-
tain whether copper oxalate is completely insoluble in the
presence of commonly occurring salts, when one-half the solu-
tion consists of acetic acid. The results of experiments shown
in Table LX show clearly that the separation of the oxalate
is complete even when very small amounts of oxalic acid are
used. The potassium salts were chosen in preference to the
sodium salts because potassium oxalate is much more soluble
in water and is therefore less likely to crystallize out in the
course of an analysis. Ammonium salts may not be present,
as a soluble double oxalate is formed, which is stable in the
presence of a’large amount of free acetic acid.

In the experiments detailed in the last division of the table
concentrated hydrochloric acid was neutralized with potassium
hydroxide and acetic acid added before precipitation.

TABLE IX.

Effect of Salts on the Precipitation of Copper Oxalate in the Presence of
Acetic Acid. :

Volume
Copper Salt at pre- Oxalic Acetic - Copper
present present cipitation acid acid found Error
grm. grm. em? erm. em? grm. grm.
KNO; present.
0°0501 10 100 1 50 0°0504 +4-0°0003
0°0501 3°0 100 i 50 0°0504 +0°0003
K.SO,4 present
0°0501 120 100 it 30 0°0500 —0-'0001
KCl present
0°0050 2°0 100 1 50 0°0045 —0'0005
0°0250 2°0 100 1 50 0'0246 —0°0004
0°0501 1°0 100 1 50 0°0501 +0°0000
0°0501 3°0 100 1 50 0°0501 +0°0000
HCl
em? HCl neutralized with KOH

0°0511 i 100 if 50 0°0513 +0°0002
0°0511 2 100 1 50 0°0510 —0°0001
00511 3 100 1 50 070511 +0°0000
0'0511 5 100 1 50 0:0501 —0°0010
0°0511 3 100 1 50 070511 +0°0000
0°1002 5 150 1 100 01001 —0-'0001

H. L. Ward—Oxalate-Permanganate Process. 481

The Determination of Copper Associated with Lead.—
The oxalate of lead, though fairly soluble in nitric acid, shows
a tendency to be included in the precipitation of an oxalate
which is insoluble in that acid. For this reason it was found
impossible to separate copper from lead as oxalate, even in a
solution very strongly acid with nitric acid. It has been shown
in a previous paper* that copper oxalate is insoluble in a 10
per cent solution of sulphuric acid containing one-half its vol-
ume of acetic acid and a large excess of oxalie acid. The
method proposed, therefore, is to add to a solution of lead and
copper as nitrates an equal volume of acetic acid and then from
3 to 5™* of sulphuric acid. Under these conditions the lead is
completely precipitated as the sulphate and may be filtered off
and weighed as such. The filtrate is then evaporated somewhat,
a little more acetic acid added and the copper estimated as
the oxalate in the usual manner. The results are shown in

Table X.

TABLE X.

The Separation of Copper and Lead. Both determined.

Volume
Sul- at pre-
Copper Lead phuric Acetic cipita- Oxalic Copper Error Lead Error
present present acid acid _ tion acid found copper found lead
grm. grm. emis ems. ‘em. germ. grm. grm. grm. grm.

0°0511 0°0500 3 50 110 2 0°0513 +0°0002 0°0499 —0°0001
0°0511 0°1000 oe 50 100 2 0°0508 —0°00038 0°0996 —0:0004
0°0511 0°1000 3) 50 100 2 9°0508 —0°0003 0:0997 —0-:0003

Since the lead sulphate does not interfere with the perman-
ganate titration, it is possible, as shown in Table XJ, to estimate

TaBLE XI.
Determination of Copper in Presence of Lead. Lead not determined.
Sul-

Copper Lead phuric Acetic Dilu- Oxalic Copper
present present acid acid tion acid found Error

grm, grm. em’, em, em’, grm. erm. erm.
0°0511 0°10 5 50 100 2 0°0508 —0°0003
0°1533 0°20 5) 50 100 2 0°1527 —0°0006
0°1533 0°20 5 50 100 2 0°1530 —0°'0003
0°0511 0°25 5 50 100 Z 070511 +0°0000
0°1086 0°25 5 50 100 4 0°1081 —0°0005
0°0051 0°30 5 50 160 4 0°0052 +0°0001
0°0511 0°30 5 50 100 + 0°0508 —0°0003
0°0543 0°30 10 50 100 + 0°0537 —0°0006
0°1022 0°30 10 50 100 2 0°1018 —0°0004
0°0511 0°40 3 50 100 2 0°0509 —0°0002

* This Journal [4], xxvii, 448, 1909.

432 HH. L. Ward—Oxalate-Permanganate Process.

the copper as oxalate by precipitation and titration without
first filtering off the sulphate of lead. In this case the sulphate
is precipitated as before, the solution heated to boiling and
oxalic acid added. The sulphate and oxalate are then filtered
off together, heated to boiling with dilute sulphuric acid and
the oxalate titrated with permanganate. 7

Summary.

It has been shown in this paper that copper may be
estimated in the presence of cadmium by precipitation as
oxalate, in the presence of nitric acid and subsequent evapo-
ration to dryness, the residue then being extracted with nitric
acid, and the oxalate filtered off and titrated with potassium
permanganate. A still more accurate determination is obtained
by precipitation of the oxalate in the presence of a large
amount of free acetic acid and small amounts of free nitric
acid.

Copper may be separated from arsenic in the higher condi-
tion by the same methods as are applicable in the presence
of cadmium.

Copper may be separated from small amounts of iron by
desiccation of the oxalate in the presence of nitric acid and
extraction with dilute nitric acid. A better method and one
more universally applicable is to precipitate the copper by
adding oxalic acid to the water solution of the salts of
iron and copper and adding two volumes of acetic acid to
separate the small amount of copper remaining in solution.

Copper associated with lead may be estimated by first pre-
cipitating the latter metal with sulphuric acid in a solution
containing a large amount of free acetic acid and then throwing
out the copper by oxalic acid (either before or after filtration),
and determining the copper by titration in the usual manner.

Foote and Bradley— Chemical Composition of Analeite. 438

Arr. XXX VI—On Solid Solution in Minerals. I1.—The
Chemical Composition of Anatlcite; by H. W. Footr and
W. M. Bravery. :

THE mineral analcite is the most important normal meta-
silicate among the zeolites and occurring, as it does, in excel-
lent crystals, its chemical composition has been the subject of
repeated investigations. The formula which has been derived
from the analyses, and which is commonly accepted, is Na,A],
(SiO,),.2H,O. A consideration of the ratios derived from
many analyses will show, however, that this formula is not in
good agreement with the facts. This is well illustrated in
Table I, in which the ratios of all the analcite analyses given
in Dana’s Mineralogy have been calculated.

TABLE I,
Ratios obtained from Analyses of Analcite given in Dana’s Mineralogy.
SiO, Al.Os3, ete. Na.O, etc. H.O

INGOs i aioe i Bas Seg 1°16 1°00 2°37
Pee? pea 4°30 O07 7 2°15
SEL, e100 1°23 ‘e 1°62
AN ae a8 4°39 Itt f 2°22
5 iat Bie oy eRe! EES, L041 a 2°30
OVE weer 4°17 1:06 % VED
CE a 4°25 94 % 2°08
oe aa 4°26 1:14 2°20
eG ae A 3°89 99 oe 1°96

AChE ae teat Sort one of 2°14
Ui paar Tea 3°67 oT # Toa
J Zp plal cy 3°57 93 1°81
aco ten ek 3°74 LO, ee 1°94
Pao ce 4°05 1:07 af 2°10
Moy ase 4°49 1°09 ef 2°49
HOle 2 oa 78 4°00 1:00 = 2°04
Me Gen ee Ls 4°15 "98 - a 2°14
Suiass 4°27 Om e 2°15
IES Yet Aisceey 2 3°76 “97 2°00
BO Vo athe 4°48 1°14 e 2°36
alls Bee ae 4°02 101 i 2°03
ipl a oe 4°03 1°00 “t 2°00
Wat ate ee Act | 1:07 a 2°14

It is impossible to judge of the value of many of the analyses
whose ratios have just been given, for in the original descrip-
tions there is usually either no statement made regarding the
quality of the material analyzed or the analysis was primarily
undertaken to show that analcite was a constituent of certain

434 Foote and Bradley—Chemical Composition of Analette.

rocks. An analysis by Hillebrand,* No. 18 in the table, and
another by Clarke & Steiger,t+ not quoted by Dana, appear to
be among the best that have been made. Their results, and
the ratios derived from them, are given below:

Analysis by Hillebrand.

Per cent Ratio
BIOs LE 258 Sea Oeil: 4:27
ALO Aa fae ache 22°43 TOU
NaOree Seee 13°47 1°00
HOP Se tee 2-15

Analysis by Clarke and Steiger.

SIOM Se Aso G06 4°82
AlOee ae 21:48 ) :
Be.O; 225 eeee 18 Vos
CaQ ch as et kG ES
NajOe eee 12°20 re
Te SG eve ete ee hoa 8°96 2°53

A glance at all the ratios given above will show that the
ratio between soda and alumina is nearly 1:1, but that silica
and water vary largely from the ratios 4 and 2 demanded by
the formula. In Table I the ratio for silica is greater than 4°2
in ten cases, it is less than 3°9 in six cases, and it is between
4 and 4:2 in only seven cases. Similar irregularities are true
as regards the ratio for water. Clarke and Steiger,{ in com-
menting on their analysis given above, state: “It is at once
evident... 2 1G. at that our sample of the mineral varies nota-
bly in composition from the requirements of theory. The
silica is 25 per cent too high while alumina and soda are cor-
respondingly low. No probable impurity and no presumable
errors of manipulation can account for so great a divergence.
The variations are large enough, common enough and regular
enough to command attention.” These investigators have sug-
gested that the mineral is an isomorphous mixture of ortho-
and trisilicate, the formula of which can be reduced to the
simple expression NaAlX.H,O in which X_ represents -
nSiO, -+ mSi,O,. This modification, however, does not take
account of the water, which appears to be as variable as silica.

The evidence to be gathered from the data which have been
given points on the whole to a case of variable composition,
such as was previously found in the case of nephelite$ and
which can be explained by assuming solid solution. Consider-

* Bull. U. S. Geol. Surv., xx, 27, 1885.
+ This Journal [4], viii, 251, 1899.

t Loc. cit.
-§ This Journal [4], xxxi, 20, 1911.

Foote and Bradley—Chemical Composition of Anateite. 435

ing the uncertain quality of many of the analyses, however,
we have undertaken a new series.

The material used in the analyses, which will be given below,
fulfilled two conditions: it was of ideal quality and it came
from widely different localities. All the specimens were well-
erystallized and all were colorless or translucent, with one ex-
ception, that from the Kerguelen Islands, which was milk-white.
The attempt was made to obtain samples from localities which
had furnished material for the analyses giving ratios less than
4 for silica, as quoted in Table I, but we were not successful.
In some cases, the crystals required no special treatment in
order to prepare a sample suitable for analysis. In others,
where small glassy crystals had been removed from the rock, a
thin layer of foreign matter would usually adhere. ‘To entirely
free the crystals from this substance, it was found necessary to
erush them and after sifting the fragments to a uniform size,
to treat them with heavy solution.

Microscopic examination of all the samples prepared for
analysis proved them to be free from inclusions and to have a
perfectly homogeneous glassy structure. In several cases, the
specific gravity of the mineral was obtained from that of the
heavy solution, while in others the ordinary method with a
balance was used. The results obtained were as follows:

TaBLE II.—Specific Gravity of Analcite.

No. Locality Specific gravity
ee wor Islands. N.S... 6282 feet. 2°254

Ze Ov clopeam ene <2 ui ee dee Se 2°260

Oey eRCeroimeletpylisnm seis at My 9°257

au Nictoria, Austratia .c2 2.24 sel. 2°219

pave Witchiean, SU Se se. OS. 6 2: 2°9293

Gr. Momtreal, Can isies 20.22). : 2°93)1

It seems desirable to give at least a brief outline of the
methods of analysis, although the mineral is a simple one from
an analytical standpoint. At the very outset it may be stated
that great care was exercised in regard to the purity of the
reagents, and platinum vessels were used wherever possible.
The mineral being readily decomposed by hydrochloric acid
made it possible to omit the ordinary fusion with sodium car-
bonate and thus obviate the use of a solid reagent at this point.
Two evaporations were made to render silica insoluble, which
was treated in the ordinary manner. It may be stated that the
specimen from the Kerguelen Islands, which was milk-white in
color, decomposed with separation of silica and also with the
formation of gelatinous silica when treated with hydrochloric
acid. In all other cases the mineral decomposed only with
separation of silica. Alumina was precipitated by ammonia,

436 Foote and Bradley—Chemical Composition of Analcite.

and after igniting and weighing was fused with potassium
bisulphate in order to make a volumetric determination of iron
possible. Calcium was absent in all cases, and not more than
the merest trace of magnesium was found. Alkalies were
determined by a Smith fusion, and water by ignition. The
analyses and the ratios calculated from them are given below

(Table III).

TaBLeE III.—New Analyses of Analcite.
1. Two Islands, N.S.

I dG Average Ratio
roi 0 ee weap ge F 2 59°90 55°90 50°90 4°46
€ He ‘ 3° pe
EA OR a ee 2 bs 2 ees ae 1:06
He Oly wees Ll 12 11
BS J 2 Sete ‘06 Heras "08
NasOuy fae. 12°85 12°96 12-91 ee
LO wee oes 8°38 8°33 8°35 2°24
99°68 99°72 99°70
2. Cyclopean Islands.
di if Average Ratio
SLOWS cae t_ Bb 54°39 54°42 54°41 4°16
AND AD) Fee ak ee ho 23°52 23°62 ee
HELO, ot: 12 13 12 ee
el] ¢ e = . 2,
K,0 cee eel 1 z a
aO Ue eee 13°30 13°42 13°36
BLO. ge Arye 8°24 8°25 8°24 2
99°90 99°85 99°87
3. Kerguelen Islands.
iE Te Average Ratio
DIO. Neen toe 54°49 54°86 54°68 4°18
AAO) Cee 23°23 23°43 23°33 1:05
Bie ©) ee eee “15 "14 14
K Oye ake ee ne Ue 1:00
Na Oe 13°37 13°57 13°47
ELM = 2 eee 846 8°47 8°46 age Be
99°70 100°50 100°10
4. Victoria, Australia.

I II Average Ratio
BIOs 22 oe ee wa oEOe 55°02 55°06 4°29
Bed tiie Aan ee a 22°84 22°87 22°85 eS
Besa) a ath 15 15 15 nee

DD e .
ee Ag ioe to a 1:00
Na Oras 13°20 13°16 13°18 |
MO 2te ee 8°32 8°44 8°38 2°19

0 —————

99°85 99°74 o3779

Foote and Bradley—Chemical Composition of Analcite. 437

_ 8. Michigan, U.S. A.

1B Average Ratio

DIO) so a eats 56°43 56°48 4°45

TAOS. ahi 21°85 22°42 22°13 1:02
Me@ ieee °26 ZG 21

K,O Pe "09 "13 ‘ll 1:00
INaEOie Shiota ee 12°92 13°16 13°04

15 OS eee 8°37 8°41 8°39 pad
100°02 SP MLGO al 100°36

6. Montreal, Canada.

I II Average Ratio

Sk eae pears 56°96 56°72 56°84 4°61

IO) hehe 2S 22°88 22°81 1:09
Ret Or iss on” °25 Ly) 22

1: OG See pee 16 ‘21 "19 1:00
Na Ove onto 12°67 27 2 12°69

1 CC aia aaa 8°23 8°31 8°27 2°25
101°02 101°038 eS LOI02

The summary of the ratios obtained in these six new analy-
ses is given below. There are included also the ratios from the
analyses by Hillebrand (No. 7) and by Clarke and Steiger
(No. 8), which appear to be as good as any that have been made.

TABLE 1V,—Summary of Ratios,

No. SiO, Al,Os, ete. Na,0O, etc. H.0.
l. 4°46 1°06 1:00 2°24
2. 4°16 AO eg ne PN
3. 4°18 1°05 oe 2517
4, 4°29 1°05 oe 2°18)
5. 4°45 1°02 os 2°21
6. 4°61 1°09 Se 2°25
is 4°27 1°01 & 2°15
8. 4°82 LO7 sy 2°53

The ratios in Table IV confirm the general statement which
was made from a consideration of old analyses, that the
accepted formula is not in good agreement with the facts of
analysis. Silica and water both show ratios which are always
higher than the formula requires, and in most cases are very
much higher. The ratio Na,O:AJ),O, is nearly 1:1. The
average of all results 1:1°05. The ratio H,O:Si0, is very
close indeed to1:2. Considering the low molecular weight of
water, this ratio is as close as could be expected. The average
is 1:1°97. To sum up the matter, soda and alumina on the

Am. Jour. Sci1.—FourtH SERIES, VOL. XXXIII, No. 197.—May, 1912.

438 Foote and Bradley— Chemical Composition of Analcite.

one hand, and silica and water on the other, show simple con-
stant ratios, but there is no ratio either simple or constant
between alumina (or soda) and silica (or water). The case
appears to be very similar indeed to that of nephelite,* in
which the ratio of soda to alumina was simple while their ratio
to silica varied largely. The results can be accounted for very
simply by assuming in analeite that the excess of water and
silica over the amount corresponding to the simple ratios is
due to solid solution. The formula of analeite can then be
written Na, Al(SiO,),.2H,0.72H,81,0,. The point must be
emphasized that this does not mean that the compound H,Si,O,
as such is necessarily present in solid solution. The real com-
ponents, for instance, may be Na,A1,(SiO,),.2H,O and Na,Al,
S1,0,,.83H,0. Other possible components may also be chosen.
There is no possible way, at the present time, of deciding defi-
nitely in regard to the actual components, and furthermore,
this seems unnecessary. The facts all point to a case of solid
solution of the unusual type found in nephelite where there
appear to be isomorphous relations existing between chemical
compounds of very different type, and these facts are suffici-
ently well expressed in the formula as it has been written
above. i

In deriving the formula, we have used only the eight ratios
given in Table IV, six of which are calculated fron: our own
analyses. As shown in Table I, a number of analyses have
been made in which the silica ratio is considerably below the
ratio number 4, and these cannot be represented by the formula
given above. We were unable to obtain any specimens of
analcite giving these low ratios and it is impossible to judge of
the accuracy of the analyses and the quality of the material
used in cases where these low ratios have been found. Until
it can be demonstrated that such cases actually occur In pure
analcites, we prefer to leave the formula as given. If the
occurrence of the low ratios is proved, a slight change in the
components chosen will take account of it.

It is interesting to note that the water in analciteft as well as
most of the other zeolitest does not behave like ordinary water
of crystallization. The vapor pressure at a given temperature
does not remain constant as the substance is dehydrated as, for
instance, tle vapor of Glauber’s salt does, but it continually
diminishes, behaving in this respect like the vapor pressure of
an amorphous hydroxide such as silicic acid. or this reason,
zeolites do not lose a definite number of molecules of water by
heating at a certain temperature or through a certain range of

* Loe. cit.
+ Friedel, Bull. Soc. Min., xix, 363, 1896 ; xxii, 5, 1899.
+Tammann, Zeitschr. phys. Chem., xxvii, 323, 1898.

Foote and Bradley— Chemical Composition of Nephelite. 489

temperature, just the reverse of the common behavior of
hydrated salts. The explanation has been that water exists in
zeolites in a condition of solid solution. Our data, obtained
entirely from analyses, supports this view but indicates also
that part of the silica is in a similar condition. It would be
possible theoretically, however, for the water to behave as
ordinary water of crystallization and still have the isomorphous
relations derived above.

It is hoped that the deductions advanced in this article may
find similar application to other zeolites.

In closing the authors desire to express their thanks to
Professor L. V. Pirsson for many valued suggestions. All the
material for this investigation was very generously furnished
by Professor W. E. Ford from the Brush collection, to whom
our thanks are also due.

Chemical and Mineralogical Laboratories of the

Sheffield Scientific School of Yale University,
New Haven, Conn., Feb. 1912.

Art. XX XViI—TZhe Chemical Composition of Nephelite ;
by H. W. Foorr and W. M. Braptey.

In a previous article,* we have shown from a series of
analyses that the composition of the mineral nephelite does not
correspond to the simple formula NaAISiO, but that there is a
variable excess of silica beyond the amount required by the
formula. Since the material was entirely homogeneous, we
showed that the results could be accounted for very simply by
assuming that the excess of silica was present in some form in
solid solution. We did not attempt to determine the molec-
ular condition of the dissolved silica—whether it was present
as albite, for instance, or in any other form (p. 31). Recently,
two articles have appeared on the composition of nephelite,
one by Schallert+ the other by Bowen.{ Schaller prefers to
account for the excess of silica by assuming an isomorphous
mixture of nephelite with an hexagonal albite, while Bowen
assumes that albite itself accounts for the excess. The pres-
ence of kaliophilite with nephelite as an isomorphous mixture
of the ordinary type is of course to be assumed but has nothing
to do with the excess of silica in the ratios. The difference in
our views, then, amounts to this, that we assume silica is pres-

* This Journal, xxxi, 25, 1911. + Wash. Acad. Sci., i, 109, 1911.
{ This Journal, xxxiii, 49, 1912.

440 Foote and Bradley—Chemical Composition of Nephelite.

ent in solid solution, leaving the question entirely open as to
what form the excess takes. It might, for instance, be present
as hexagonal albite as Schaller suggests, just as it might be
present in some other form. Schaller, on the other hand,
suggests that the particular form which the excess of silica
takes is that of an hexagonal albite and Bowen suggests albite
and leaves the system of crystallization undecided.

Considering the fact that the greatest uncertainty still pre-
vails in regard to the actual molecular condition of dissolved
substances in other types of solution which have been much
more investigated, it seems impossible to decide definitely in
regard to what molecular aggregates are actually present in
nephelite. It appeared to us, when writing the first article
(p. 31), as it does now, that it is better to avoid any definite
assumption which cannot be proved, regarding the molecular
condition of the dissolved silica. Our main point was to show
there was an unusual case of solid solution and that it was
unnecessary to assume any definite molecular condition for the
excess of silica. While it may later be shown that albite
actually exists in solid solution, this at present must be regarded
as pure conjecture. The albite molecule, if present, would
have very peculiar properties, entirely unlike albite as it exists
either in pure condition or isomorphous with other feldspars,
since nephelite with its excess of silica is completely soluble
in N/4 hydrochloric acid. This evidence, however, we recog-
nize fully is not proof that the albite molecule is absent. It
cannot be proved either way at present. Hence our point,
that it is better to leave the question as to the molecular con-
dition of excess of silica entirely open.

There is one point regarding the amount of silica which
nephelite can take up, which needs mention. Bowen states
(p. 58): “It is therefore only in the presence of albite itself
that nephelites may be expected to be saturated with silica.”
This is a conelusion which we also drew in our article, but later
Bowen states: ‘‘ The conditions necessary for the saturation of
nephelite with albite are so unlikely to occur that it may
be safely said that natural nephelites are probably never
saturated.” It was shown in our former article that three
nephelites, which were associated with albite, and one asso-
ciated with microcline-microperthite, exhibited a constant .
maximum ratio for silica, and we suggested that this repre-
sented the saturation value. The objection could, perhaps, be
raised that the nephelite and albite were not formed simulta-
neously, so that the former was not necessarily saturated.
Probably no one will doubt the assertion that if a magma_ |
deposits both nephelite and albite together, the former must
be saturated with silica at the temperature of solidification.
There is plenty of evidence that this process has taken place. :

.

Foote and Bradley— Chemical Composition of Nephelite. 441

It has been shown by Bayley* and by Morozewiez+ that rocks
occur where both nephelite and very pure albite must have been
formed simultaneously. Morozewiez in particular has shown
that in the rock investigated by him, albite crystallized
throughout the entire time when nephelite was forming. The
nephelite in both rocks was analyzed. It is probable that the
material was not as carefully purified as in the cases considered
in our former article, since the object was to show that neph-
elite was present and not to derive its formula. Still, the
results should show approximately the limiting ratio for silica,
when nephelite is saturated. The ratios calculated from their
analyses are as follows:

Bayley Morozewicz
(anal. by Clarke)
Si0, SATS oa ag pO 2°15 2°15
Al,O, ACE es Dn ce aa 1:00 1°00
CN Ie OU O es ce "94 "95

The ratios between alumina and alkalies is not as sharp as it
should be, perhaps. If, instead of calling alumina 1, the error
is allowed to rest equally on alumina and alkalies, whichzseems
fair, the ratios become :

Bayley Morozewicz
(anal. by Clarke)
DIO see ees ees FSS: 2°21 2°21
Jil sO nie Sie ee 1°03 1°08
GNAIOVOL Soha 97 98

Whichever way.the ratios are calculated, the value for silica
comes very close to 2°2, which represents the limiting ratio.
The value which we obtained before was 2°21. Since the two
values are practically identical, there seems to be no reason
whatever for modifying our original statement regarding this
ratio. Judging purely by the evidence available, we cannot
agree with Bowen ‘that natural nephelites are probably never
saturated.’

It is to be hoped that the problem may be attacked from
the synthetic standpoint in an adequate way. By this
means, it will perhaps be shown whether the saturation limit
changes appreciably with the temperature of formation, and
also whether the potassium content affects this limit to any
great extent.

Chemical and Mineralogical Laboratories of the
Sheffield Scientific School of Yale University,
. New Haven, Conn., February, 1912.

* Bull. Geol. Soc. Amer,, iii, 231, 1892. +Min. Petr. Mitt., xxi, 238, 1902.

442 A. Olsson—New Genus of Paleechinoidea.

Art. XXX VIIl— Description of a new Genus and Species of

Paleechinoidea ;* by Axe Oxsson.

Lepidechinoides gen. nov.

SHAPE subspheroidal with five ambulacrals and five inter-
ambulacral fields. Ambulacrum consisting of two columns of
alternately arranged plates imbricating aborally. Each of the
ambulacral plates pierced in the middle by a pair of pores set
close together. In addition each ambulacral plate is pierced
on the extreme ventral surface by a single pore situated on the
adjacent ends of the plates. Interambulacrum composed of six _
columns of adorally imbricating plates. Adambulacral plates

—

=,
ek

an
nh
i

fl

Lepidechinoides ithacensis Olsson.

Fic. 1. Side view of specimen enlarged three diameters.
Nos. 1, 2, 3, 4, 5, 6, indicate number of column. 1’, 2’, 3’, 4’, initial
plates.

shghtly smaller than the second column of plates and perforated
near ambulacral edge. The interior plates of the interambu-
lacral series more or less hexagenal in shape, except those on
the extreme ventral surface, which are small and scale-like.
Spines small and striated, dilated at the base. |

* The writer is indebted to Prof. H. S. Williams for the many kind sug-
gestions in the preparation of this paper.

4

A. Olsson—New Genus of Paleechinoidea. = 448

Lepidechinoides ithacensis sp. nov.

Ambulacral plates about three to each of the adambulacral
plates bordering them. Each plate perforated m the middle
by a pair of pores set close together. Arrangement of plates
alternate and imbricated aborally. Interambulacrum consist-
ing of six columns of rather large plates imbricated adorally.
Second column of plates larger than the adambulacral plates.
Adambulacral plates rhombic or pentagonal in shape and per-
forated near the ambulacral edge. The inner series of inter-
ambulacral plates more or less hexagonal in shape, except
those on the extreme ventral surface, which are small and
scale-like. These plates pierced in the center except those on
the ventral surface. On the oral surface a few of the ambu-
lacral plates are pierced by a pore each on their adjacent ends,
but they are confined to this region. Secondary spines small
and striated and dilated at the base for attachment. |

Length 275°

Width 4°

Width of ambulacral area 4™™

Width of interambulacral area at middle 17™"

After a careful study of the specimen and of the descrip-
tions and figures of the other three genera in the family,
viz.—Lepidocentrus Miller, Perischodomus McCoy, and
Lepidechinus Hall, the following points of resemblance and
differences were made out. In
the imbrication of both areas it
approaches Lepidechinus and
Perischodomus and differs from
Lepidocentrus, in which the am-
bulacral plates are inflexible.
As in Lepidechinus, the initial
plate 1’ is retained. It is small
and irregularly foursided, its
ventral apex is sharp and does
not appear to have suffered from
resorption. This specimen in its
possession of only six columns Fies. 2, 3. Secondary spines
of interambulacral plates is not enlarged ten diameters.
so highly accelerated in its de-
velopment as the genus Lepide-
chanus and the species Lepido-
centrus mullert Schultze. In Lepidechinus rarispinus Hall
the introduction of new plates is so rapid that each initial
plate touches the next. In Lepidechinoides the plates 2, 3, 4
and 5 follow each other rapidly, as shown in figure, but between
plates 5 and 6 there are three intervening plates. The exact

S44 A. Olsson—New Genus of Paleechinordea.

size and shape of the adambulacrals cannot be ascertained -
because of the overlapping of the second column of plates;
they appear, however, to be rhombic or pentagonal in shape
and slightly smaller than the second column of plates, which
are undoubtedly the largest of the mterambulacrals in this
species. The remainder of the interambulacral plates are
mainly hexagonal in shape, quite perfectly so near the dorsal
surface, but on passing ventrally their edges become rounded.
On the extreme oral surface the adambulacral plates are small
and seale-like, closely resembling those of Lepzdechinus.
Along a line through the initial plate 4’, the diameters through
these plates are as follows: 2°75™™, 4™™, 3™™, 38™™, 3°75™™, and
2°75™". The number of columns of interambulacrals is vari-
able even in the same genus and may, therefore, only be con-
sidered of specific value. The list below gives the range of
the number of columns of interambulacrals in the various
species in the genera of the family Lepidocentride.

(Eu) Lepidocentrus rhenanus Schultze 5 I

(Eu) © mullert Beyr 11 I
(Ku) e eifilianus Miller unknown
(Ku) Perischodomus biserialis McCoy 5 I

Z illinoisensis W orthern & Miller

5 or more I
Lepidechinus rarispinus Hall 11 I
ts imbricatus Hall 8 I
Lepidechinoides tthacensis 6 I

In the number of ambulacral plates to each of the adambu-
lacrals there is some variation. As could be expected both in
Lepidocentrus and Perischodomus, in which the adambu-
lacrals are large—being the largest of the interambulacrals—
there are many ambulacrals to each of the adambulacrals,
while in Lepidechinus and in Lepidechinoides, in which the
adaimbulacrals are relatively small, the opposite is the case, as
shown below.

Lepidocentrus rhenanus Schultze 7-8 A

es mullert Beyr 7-8 A

4g eifilianus Miller unknown
Perischodomus biserialis McCoy 5-8 or more A

a illinoisensis Worthen & Miller
Lepidechinus rarispinus Hall 3-4 A

ne imbricatus Hall

Lepidechinoides ithacensis 3-4 A

In the above brief summation of a few of the generic char-
acters, it is evident that it is fairly close to Lepidechinus Hall.
It has for one of its most important differences the perforation
of the ambulacral plates in the center and not on the distal

A. Olsson—New Genus of Palwechinoidea. 445

end. Any variation in the ambulacral plates is of great
importance and must be considered of at least generic value.
Lepidechinoides differs also from Lepidechinus in its posses-
sion of fewer columns of interambulacrals and, more impor-
tantly, in having these plates more or less hexagonal in shape
and not scale-like as in the latter genus. In this latter char-
acter Lepidechinoides appears to represent a more primitive
form. Jackson in his Studies of Paleeechinoidea* shows in
reference to Lepidechinus rarispinus Hall, that the rhombic
and hexagonal shape of the dorsal, or newly added interambu-
lacral plates, have phylogenetic significance, having characters
seen normally in less specialized genera and indicating deriva-
tion from forms which did not have imbricating plates.
Moreover those forms with scale-like imbricating plates are
specialized and not primitive types.

From the Devonian of America there are at present three
genera and four species of Paleeechinodea, representing two
families Lepzdovidaride Bather (Archwocidaride McCoy)
and Lepidocentride Lovén. WVanuxem in his Report of the
~ 8d Geological District, p. 184, mentions some doubtful remains
of echinoids from Dryden which he called Achinus drydenen-
sis. These specimens were later examined by Hall,+ who
referred them to the genus Hocidaris Desor. They are
described as being from the shaly sandstones of the Chemung
group, 1,000 feet above the Tully limestone, representing
therefor the Enfield shales of the Portage formation. The
genus Kocidaris belongs in the family Lepidocidaride and with
Aenocidaris clavigera Schultze of Europe are the only mem-
bers of the family found below the Sub-Carboniferous. The
family Lepidocentride Loven is now represented in America
by the two genera Lepidechinus and Lepidechinoides herein
described. Of the genus Lepidechinus two species are known,
viz., L. rarispinus Hall from the Chemung of Pennsylvania,
and the Waverly group of Ohio and ZL. zmbricatus Hall from
the Burlington limestone of Lowa. Lepidechinordes ithacensis
therefore represents the earliest known echinoid from America
although in Europe the genus Bothriocidaris Kichwald, of
which two species are known, is from the Ordovician. The
geological position of all the species in the family Lepidocen-
tridee is shown below:

Lepidocentrus rhenanus Schultze

Gs mullert Beyr, middle Devonian of Muhlen- ~
berg—near Geroldstein Eifel

fi eifilianus Miller, Devonian of Nohn Eifel

* Bull. Geol. Soc. of Am., vol. vii, p. 228, 1896.
+ 20th Annual Report of State Cab. Nat. Hist. of N. Y., 1868, p. 343.

446 A. Olsson—New Genus of Palwechinoidea.

Perischodomus biserialis McCoy
Ve illinoisensis Worthen & Muller Chester lime-
stone—Pope Co. Ill.
Lepidechinus rarispinus Hall, Chemung Penn. and Wav-
erly
= imbricatus Hall, Burlington limestone— Bur-
lington Ohio
Lepidechinoides tthacensis Ithaca beds Portage formation
NONE

The type specimen herein described was found at the Uni-
versity quarry, sometimes called the McCormick quarry, near
the lower border of the Cornell campus. This quarry is situ-
ated in the zone* characterized by the presence of Spurifer
mesastrialis and Cryptonella eudora, which in the Ithaca
region are rar ely found above or below these beds. This zone
is contined to about twenty-five feet in the center of the Ithaca
shale member and of which fifteen feet are exposed in this
quarry. It is made up of hard sandstone layers with few shale
beds. Fossiliferous layers sometimes occur so thickly filled
with fossils as to produce an impure siliceous limestone. On
passing eastward this zone is believed to thicken and to be
represented in the Chenango valley by the Oneonta sandstone,
which there overlies the Ithaca. Besides Spirifer mesa-
strialis and Cryptonella eudora, the following fossils are
quite characteristic of this zone: Actinopteria boydi ; Cama-
rotechia eximia; Leiorhynchus mesacostale; Orthoceras
bebryxz ; Gomphoceras tumidum and Stictapora meeki asso-
ciated with numerous crinoid stems.

Those who desire a more detailed comparison of the genus
herein described with the other genera in the family will —
the works listed below to be of service:

Hall. Desc. New Spec. Crin., 1861, p. 18.

Hall. 20th Rep. N. Y. State Cab. Nat. Hist., 1868, p. 340,
pl. 9, fig. 10.

Keeping, W. Notes on the Paleozoic Echini, Quart. Jour.
Geol. Soc., London, vol. xxxii, p. 35, 1876.

Worthen & Miller, Geol. Surv. “aL, vol. vil, 1883, p. 333,
pl. ol, fiers:

Jackson, R. T. Bull. Geol. Soc. Am., vol. vii, 1896, p. 222-242.

Klem, M. J. A Revision of the Paleozoic Palzechinoidea
with complete bibliography. St. Louis Acad. Science
Trans., vol. xiv, 1904, pp. 1-98, 6 pl.

Ithaca, N. Y.
Jan. 4, 1912.

* Bull. U. S. G. S., No. 8, p.17. Watkins Glen-Catatonk folio, U.S.G.5.,
No. 169, field edition, pp. 64, 65, 92, library edition, pp. 6, 8, 12

F, H. Lahee—Metamorphism and Geological Structure. 447

Art. XXIV.— Relations of the Degree of Metamorphism to
Geological Structure and to Acid Igneous Intrusion in the
Narragansett Basin, Rhode Island; by .Freprrick H.
LAHEE.

(Concluded from p, 372.)
mohieal JU0G

CONTENTS.

Petrology of the post-Carboniferous rocks.
Basic intrusives.

Description.

Relations of the minette to the Carboniferous sediments.

Summary.

Acid intrusives.

Introductory remarks.

General and theoretical considerations.

The granite phase.

Description.

Relations to the Carboniferous sediments.

The pegmatite phase.

Description.

Relations between the pegmatite phase and the granite
phase.

Relations of the pegmatite phase to the Carboniferous
sediments.

The quartz vein phase.

Description.

Relations between the guartz vein phase and the pegma-
tite phase.

Relations of the quartz vein phase to the Carboniferous
sediments.

Summary.

Relations of the intrusion of the acid intrusives to the folding,
metamorphism, and schistosity of the Carboniferous
sediments.

Conclusions to the study of the acid intrusives.

Relations between the minette dikes and the acid intr usives.
Summary and conclusions.

PETROLOGY OF THE Post-CARBONIFEROUS Rocks.

Post-CARBONIFEROUS rocks, intrusive into the sediments of
the Narragansett Basin, may be classified from a relative stand-
point as basic or acid. To the former category belong a few
minette dikes; and to the latter, an extensive series of acid
intrusives ranging from granites, through pegmatites, to quartz
veins.* These we shall consider in the order named.

* Occasional aplite stringers, belonging to this series, cut the granites, and
one or two have been seen to intersect the pegmatite.

448 LF. H. Lahee—Metamorphism and Geological Structure.

-

Basic INTRUSIVES.

Description.—Dikes of minette have been found in southern
Conanicut Island, and of these there are seven instances.* Six
cut the fine greenish schists of the Beaver Tail Peninsula
(fig. 1, Loc. 28,14:D) and one cuts the pre-Carboniferous
Conanicut granite.

These dikes consist of biotite and orthoclase, together with
some microcline, plagioclase, apatite, zircon, titanite, and the
secondary minerals, chlorite, calcite, epidote, limonite, and leu-
coxene.t The biotite, as noted by Collie and Pirsson, reveals
evidence of two generations. The older is represented by
large idiomorphic plates which are clouded—darkly near the
peripheries, but shading off inward—and which contain very
fine rutile needles and leucoxene powder. The rutile needles
are especially abundant near the edges of the plates. They
are arranged in three directions, each at 60° to the others, in
planes parallel to the basal pinacoid of the mica. The leu-
coxene, while sparsely distributed, is more plentiful near the
borders of the mica flakes.

Of the younger generation numerous smaller plates are seen
and also zones which encircle the earlier phenocrysts. This
later form, whether as separate crystals or as border zones, is
clear, greenish, and pleochroic, and contains no rutile nor leu-
coxene. When it occurs surrounding individuals of the first
generation, it is in optical orientation with them. Both types
have partly or wholly altered to chlorite.

In the section investigated by the writer, there was no par-
allel orientation of the constituents, and evidences of crushing
were slight. In other specimens there is a distinct schistosity.
Pirssont attributed the rutile inclusions in the biotite pheno-
erysts to the influence of the forces which produced this
schistosity ; but since the biotite crystals are surrounded by
zones of unrestrained mica and since the orthoclase grains may
abut against or enclose such coated phenocrysts with their
rutile needles, we conclude that the anomalous features
described for the biotite of the first generation were of mag-
matic origin. |

—-Lelations of the minette tothe Carboniferous sediments.—
In some places the minette seems to have been intruded into

* Certain ones of these dikes were described by the following writers in the
works cited: Foerste, A. F., in Geology of the Narragansett Basin, by
Shaler, N. S., Foerste, A. F., and Woodworth, J. B., U. S. G.S., Monog.
XXxili, 1899, p. 252. Pirsson, L. V., in his Geology and Petrography of
Conanicut Island, this Journal (8), xlvi, p. 868, 1898. Collie, G. L., in his
Geology of Conanicut Island, Trans. Wisc. Acad., x, p. 199, 1894-1895.
Crosby, W. O., in his Contribution to the Geology of Newport Neck and
Conanicut Island, this Journal, iv, 230, 1897.

+ Pirsson gives a chemical analysis: op. cit., p. 375.
t Op. cit., pp. 375-376.

LF. H. Lahee—Metamorphism and Geological Structure. 449

joint planes or along the cleavage of the southern Conanicut
Carboniferous schists. Or, again, the dikes may cut indis-
criminately across such structures. In most cases their thick-
ness is rather variable. Short apophyses may pass from them
into the country rock, and small inclusions of the latter may be
seen. Exomorphieally the schists have been somewhat baked
and bleached. The most obvious endomorphic features are
the decrease in size of grain toward the contact and the par-
allelism of the biotite flakes with the walls (flow structure), as
noted by Collie* and Pirsson.+ Locally these dikes show some
folding and schistosity. Veins of massive, milky quartz, some-
times of considerable size, intersect them with sharp contacts.

From these petrographic and. structural relations, it would
seem that the minette dikes were injected into the Carbonifer-
ous sediments before the period of deformation came to an end,
yet after schistosity and jointing had been developed in the
country rock.

—Summary.—Dikes of minette (a) have been found ina few
places in the southern part of Conanicut Island ; (0) are clearly
intrusive into, and are, therefore, later than, the Carboniferous
sediments and the pre- “Carboniferous Conanicut granite ; (¢)
were injected during the general period of deformation of the
Carboniferous series; (@) are themselves cut by numerous
veins of massive, milky quartz.

Acip INTRUSIVES.

Introductory remarks.—We have already mentioned the
fact that the granitic rocks in South Kingstown are probably
intrusive into the Carboniferous sediments, and that they are
not pre-Carboniferous as had formerly been supposed. Since
these granites—part of the Sterling series—are especially
prominent on Boston Neck (B: 14 and 15, fig. 1), they may be
referred to as the ‘ Boston Neck granite.’ They appear to be
closely related in origin to the great group of pegmatites and
quartz veins which likewise cut the Carboniferous rocks.
Herein we shall denote the Boston Neck granite, the pegma-
tites, and the associated quartz veins by the general term,
‘ Acid Intrusive Series.’§

* Op, cit., p, 228. + Ojos eit.

{Pirsson (op. cit., pp. 871-372) said that the schistosity, folding, and
faulting in the dikes were caused by dynamic forces acting along north-south
lines after intrusion. Collie (op. cit., pp. 228-230) stated that the nearly
north-south dikes are schistose because they lie nearly at right angles to the
direction of the forces; the east-west ones are foided and faulted.

§ Dr. Loughlin, in his ‘Intrusive Granites and Associated Metamorphic
Sediments in Southwestern R. I.’ (this Journal. xxix, 447, 1910), presents
evidences for the genetic relationship of the granites of southwestern Rhode
Island, the pegmatites, and the quartz veins. From investigations carried
on in the extreme eastern portion of Dr. Loughlin’s area and eastward, pre-
vious to the publication of the paper just cited, the writer had arrived at
similar conclusions, and, certainly in that region where the fields of work
overlap, he is in agreement with Dr. Loughlin.

450 FH. Lahee—Metamorphism and Geological Structure.

General and theoretical considerations.—As in the discus-
sion of the structural geology of the Basin (Part I of this
paper), here also we shall put theory before fact. Accepting
the doctrine commonly held to-day, eee that most peg-
matites are of magmatic derivation,* we shall review below
certain facts which may assist in the determination of the
relations between the Acid Intrusive Series and the Basin
sediments.

The importance of the role played by catalyzers, or mineral-
izers, in the crystallization of magmas, and especially of acid
magmas, is widely recognized. These mineralizers “have been
detined as volatile substances which, without entering into the
final composition of minerals, render possible or facilitate their
formation and erystallization.”+ This they do by reducing the
viscosity of the magma and by lowering the freezing-points
of its constituents.t Harker continues, “There is..... no
reason for excluding the case in which the mineralizer, or part
of it, enters into the mineral as finally constituted.”’s ” Among
the chief catalytic agents may be cited fluorine, chlorine, boric
acid, carbon dioxide, hydrogen, and water gas.

* For summaries of theories for the origin of pegmatite, see the following :

Brégger, W. C., Die Mineralien der Syenitpegmatitgange der stdnor-
wegischen Augit und Nephelinsyenite. Zeitschr. fiir Kryst., xvi, I Theil,
pp. 215-225, 1890. Trans. by N. N. Evans, Can. Record of Sci., vi, pp. 33-
46 and 61-71.

Williams, G. H., General Relations of the Granite Rocks in the Middle
Atlantic Piedmont Plateau, U.S. G. S., Ann. Rept., xv, p. 657, 1894.

Van Hise, C. R., A Treatise on Metamorphism, U.S. G. S., Monog. xlvii,
1904. Pp. 721-724.

For recent statements on the subject, see:

Harker, A., Natural History of Igneous Rocks, N. Y., 1909.

Iddings, J. P., Igneous Rocks, N. Y., 1909.

Bastin, E. $., Geology of the Pegmatites and Associated Rocks of Maine.
WS. G48... ball, 4405 a9ilds

+ Harker, A., op. cit., p. 286.

¢{ Daubrée early demonstrated the function of water in’ promoting the.
crystallization of anhydrous minerals far below their fusion points.
Ooat). A., Etiides synthetiques de Géologie Expérimentale, Paris, 1879,

234.)

rig Harker, A., op. cit., p. 287. Thus, muscovite, containing OH, may be
regarded by the aid of mineralizers. Nernst, however, defines the process of
catalysis as ‘‘an increase in velocity of reaction caused by the presence of
substances which do not take part in it, although the reaction is capable of
taking place without their presence.” (Nernst, W., Theoretical Chemistry.
London, 1904, p. 566.) See also Doelter, C., Physikalisch-Chemische
Mineralogie, Leipzig, 1905, pp. 110 et seq.

Writing on this subject, Bastin suggested the application of Raoult’s law
to rock magmas ‘‘to the extent that magmatic constituents of low molecular
weight may exert greater influence in lowering the freezing point, decreas-
ing the viscosity, and affecting textures, than do constituents of high mole-
cular weight” (Bastin, E. S., op. cit., p. 31).

|| See Harker, A., op. cit., p. 295. Among the catalyzers, especial
importance is attributed, by Bastin (on. cit., pp. 30-31), to the influence of
water gas and of hy drogen in helping the crystallization of pegmatite.
These substances largely escape as the magma cools.

F.. H. Lahee—Metamorphism and Geological Structiire. 451

Let us consider, by way of illustration, an ideally regular
mass of granitic magma which has been injected into a relatively
cool rock formation. We may take it for granted that such
an intrusion cannot lose heat uniformly thr oughout its volume.
The marginal regions must cool more rapidly “than the interior.
Hence, ceteris paribus, the processes of cooling and of con-
solidation must progress inward from the contact with the
country rock. In other words, these processes must be cen-
tripetal.* }

Until the magma has quite hardened as a granite, there must
be a constantly diminishing residuum which, as appears from
the study of many examples, is known to have a tendency to
increase in acidity. Since the mineralizers do not, except to a
slight degree, enter into the reactions which they assist, their
relative quantity in the diminishing remainder of the freezing
magma must necessarily grow. Thus we havea liquid residuum
in which the proportion of acid constituents and of catalyzers
is steadily increasing.f

Without the cataly tic agents such minerals as albite, ortho-
clase, and quartz would be so viscous that they could not erys-
tallize. With these agents present, however, the molecular
mobility of the remaining acid minerals is so augmented that
erystallization is not only possible, but is even assisted to such
a degree that the resulting crystals may be much larger than
the average grain of the main body of the rock. In this way
pegmatite may originate as a late product in the consolidation
of the magma.}

In the ideal case, then, according to this explanation, we
might expect to find a mass of pegmatite in the heart of the
intrusive body. If the tension due to cooling had developed
joints, dikes of pegmatite might extend out as apophyses from
the inner pegmatite segregation into the normal granite. The
first type would have blended contacts; theoretically, the
second type might possess sharp contacts where the granite had
already hardened, at some distance from the central segrega-
tion. “When derived in this way, pegmatites may be called
residual.

Here it is necessary to observe that an intrusive body of
ideal regularity of shape, such as we have been considering, is
not natural. The great granite masses, being usually of the
batholithie variety, are highly irregular. Moreover, they are

* Compare Crosby, W. O., and Fuller, M. L., The Origin of Pegmatites,
Tech. Quart., ix, p. 825, 1896, p. 301.

+ See, for example, Van Hise, C. R., op. cit., p. 728

{ The pegmatite mass found in the Quincy quarry, Mass.. and recently
described by Warren and Palache, is probably of thistype. (Warren, C.H.,

and Palache, C., The Pegmatites of the Riebeckite—Aigirite Granite of
Quincy, Mass., U. S. A., Proc. Am. Acad., xlvii, 125, 1911, p. 146.)

452 Ff. H. Lahee—Metamorphism and Geological Structure.

peculiar to the deeper parts of mountain ranges,* and, such
being the case, often cut a country rock which has been ren-
dered schistose by dynamic action consequent upon folding.
On this account, actual field data show, not the hypothetical
pegmatite core with its apophyses, but, instead, scattered here
and there in the granite, numerous, relatively small, shapeless
or elongate segregations having blended contacts. Dikes with
sharply defined edges are less common. The small segrega-
tions of pegmatite, representing separate loci of the final
operation of the concentrated mineralizers, indicate that, within
layers parallel to the general external surface of the mass, con-
solidation is far from uniform. No doubt this is due in part
to the unevenness of the contact.

Very often a marginal pegmatite zone may be observed
between the main granite (or other plutonic) body and the
country rock. From such a marginal zone dikes of pegmatite
radiate outward. If the country rock is bedded or schistose,
they follow its structural planes. Contacts of this marginal
phase, both with the granite and with the country rock, are
often blended, but they become more distinct away from the
granite. Similar zones surround xenoliths.

The marginal pegmatite with its offshoots into the country
rock is obviously a contact effect and cannot be a late phase in
the centripetal consolidation of the granite body. Crosby,
recognizing this discrimination, attributed it to the capacity of
the magma, at high temperature, to absorb water from the
country rock, this water later functioning as the main catalytic
agent in the ultimate crystallization of the marginal peg-
matite.t

According to this theory, a wedge of magma, in its forward
advance into the country rock, would imbibe more and more
water, and would have its fluidity augmented. Consequently,
its penetrative efficiency and its tendency to freeze with peg-
matite texture would increase. Loss of heat or lack of supply
would bring the process to an end. Crystallization, if com-
mencing after the cessation of injection, would proceed from
the walls inward, and the first formed minerals would be more
basic than the last. Thus the dike would acquire an acid

* Daly speaks of granites as being primarily mountain rocks (Daly, R. A.,
Abyssal Igneous Injection. .... This Journal (4), xxii, p. 196, 1906,
p. 214-215. See also Geikie, A., Text-book of Geology, 4th ed., Lon-
don, 1903, p. 724.

+ Crosby, W. O., and Fuller, M. L., loc. cit., pp. 348-352. Van Hise
writes: ... ‘‘In many and perhaps most cases the water in the outlying
pegmatite dikes and veins..... has been largely derived from the sur-
rounding rocks.” (Van Hise, C. R., A Treatise on Metamorphism, U. S.
G.S., Monog. xlvii, 1904, p. 728.) On the other hand, Geikie (op. cit.,

p. 768) and Harker (op. cit., p. 303), referring to the investigations of others,
state that hot intrusions expel volatile substances from the country rock.

F. H. Lahee—Metamorphism and Geological Structure. 453

central region.* If, on the other hand, crystallization were
initiated before the cessation of injection, the advancing
magma might grow more acid by selective formation of the
more basic constituents along the walls. In this manner, a
dike, composed of quartz, feldspar, etc., might consist of quartz
only at its outer end.

We may add further that in pegmatites or quartz veins of
which the crystallization has been thus controlled by extrane-
ous water, the relative amount of such minerals as topaz, tour-
maline, and fluorite, should be small.

‘As for the metamorphic effects ascribed to pegmatites, the
investigations of many geologists have demonstrated that
granite intrusions have often, although not always, produced
considerable exomorphic alteration.t The changes are due
partly to heat and partly to the action of escaping volatile con-

stituents.t The effects include induration, recrystallization,
lit-par-lit “injection, and metasomatism. Ata distance, recrys-
tallization in impure clastics may be evidenced by the presence
of rutile needles; nearer the intrusive, by the occurrence of
‘knots’ and the micas; and still nearer, by such minerals as
feldspar, andalusite, garnet, and amphibole, and by the aggrega-
tion of siliceous matter into large irregular quartz grains.

Concerning the relative importance of heat and volatile con-
stituents in producing contact metamorphism, Geikie writes,
“It would appear that mere dry heat produces only a small
amount of chemical alteration.” Also,..... “the presence of
pneumatolytic agents....has been largely influential, com-
bined, doubtless, with great pressure, high temperature, and a
continuance of these conditions for vast periods of time.’’§
The French school lays much stress upon the importance of
metasomatic processes due to the action of gases. Harker

* This type of distribution of the constituents, according to which the
more basic minerals are marginal and the more acid ones are central, has
been described by Smith and Calkins (Smith, G. O., and Calkins, F. C., A
Geological Reconnaissance across the Cascade Range near the 40th Parallel.
U.S. G.S., Bull. 235, 1904, p. 76), H. H. Reusch (Die Fossilien Fuhrenden
Krystallinischen Schiefer von Bergen in Norwegen. German trans. by R.
Baldauf, Leipzig, 1883), and many others. But Watson notes dikes in which
quartz and feldspar are marginal, and mica, tourmaline, and garnet are con-
centrated in the middle zone (Watson, T. iB: On the Occurrence of Aplite.
Pegmatite, and Tourmaline Bunches in the Stone Mountain Granite of
Georgia, Jour. Geol., x, p. 186, 1902).

+ Geikie, A., op; cit., pp. 726,.778 et seq.

¢{G. W. Hawes notes the addition of boric acid (this Journal, xxi, p. 21,
1881). Certain volatile components, such as water gas and carbon dioxide,
may be driven out of minerals in the country rock by the heat and may then
play an active part in the iu PoE (Van Hise, C. R., op. cit., p. 713).

§ Geikie, A., op. cit., p. 767.

|| See Harker, A. Gp fete: p. 305), for a summary ‘of the French views,
and for several references. Michel: “Lévy and Lacroix are noted.

Am, Jour. Sct1.—FourtTsH SERIES, VoL. XX XIII, No. 197.—May, 1912.
30

454 F. H. Lahee—Metamorphism and Geological Structure.

contrasts the more intense thermal effects occasioned by basic
intrusives, which contain few or no mineralizers, with the less
intense effects of granites and other acid rocks.* He regards
pneumatolytic metamorphism, however, as limited to a rather
narrow zone next the contact.t

It is probable that the temperature of the magma at the
time of its injection is not excessively high. This is indicated
in the country rock by the absence of proof of true fusion
along the contacts and by the abundance of minerals which
developed during the metamorphism and which can erystal-
lize only at relatively low temperatures—considerably below
their freezing-points. Such are the micas, the amphiboles, the
alkali-feldspars, quartz, tourmaline, and many others.{ Since
these minerals are also among the more important constituents
of the granite itself, they prove a comparatively low tempera-
ture of consolidation for the magma.§

The ragged edges of inclusions (xenoliths), and, adjacent to
the country rock, the coarseness of texture of the intrusions,
do not of necessity prove a very high temperature for the
latter. Magmatic solution (not fusion) may account for this
feature in the inclusions, and moderate warmth will explain
the coarse texture.

The granite phase: Description—Coming now to the
description of the Acid Intrusive Series, we find that the
Boston Neck granite occurs at various places along the western
coast of Narragansett Bay from Watson’s Pier (between locs.
11 and 12, C:15, fig. 1) southward, and inland on Little Neck
(B:16, fig. 1), Boston Neck, and Tower Hill(A and B: 14 and
15

This rock is typically of medium grain ; is white, pinkish, or
cream-colored; and consists predominantly of microcline, with
quartz, micropegmatite, microperthite, a coarsely twinned
plagioclase, and orthoclase. A little biotite or muscovite may
be present, and apatite, zircon, magnetite, rutile, and garnet,
are among the less common constituents. Megascopically, a
varying degree of schistosity is seen. Under the microscope,
the quartz appears somewhat strained, the feldspar grains may
be cracked or faulted, and the micas are more or less bent.

* Harker, A... op. cit., p..189;

+ Ibid., p. 304.

+ Ibid., pp. 187, 284.

§ Harker (op. cit., p. 186) quotes Lehmann’s estimate of 500° as ‘‘probably
by no means too low.” Referring to Sorby’s investigations on the vacuoles
of crystals, he shows that the results obtained by Sorby lead to the same
conclusion (pp. 187-189). See also Geikie, A., op. cit., pp. 412-4138. E. S.
Bastin (op. cit., pp. 38-39), applying the data of Wright and Larsen, arrives
at the conclusion that pegmatites crystallize not far below, nor far above,
575°C. (See Wright, E. F., and Larsen, E. S., Quartz as a Geologic Ther-
mometer, this Journal, iv, 28. 1909.)

|| Geikie, A., op. cit., pp. 767, 776.

F. H. Lahee—Metamorphism and Geological Structure. 455

= Post-Carbon iferous.
(Garr) Carboniferous.
Rsv Pre-Carboniferous.

C) t 2 3
Scale in miles

i KINGST

Fig. 1. Outline map of the southern half of the Narragansett Basin,

456 FF. Hf. Lahee—Metamorphism and Geological Structure.

—Lelations of the granite phase to the Carboniferous sedi-
ments._—Within the Boston Neck granite are many elongate,
highly metamorphosed inclusions of schist, which, as inferred
from their structural and petrologic relations, are undoubtedly
parts of the Carboniferous formation of the Basin.* The
dimensions of these xenoliths vary from an inch to several
scores of feet. In general, their lengths trend nearly north-
south, i. e., about parallel to the strikes of the bedding of the
adjacent Carboniferous strata, and their schistosity runs in the
same direction. Their extremities are often ragged, and some-
times strips may be observed to have been torn away and
removed a short distance before having been frozen in. Apo-
physes project into them from the granite.

At the contact there is more or less blending, due either to
solution or to interpenetration by the magma at the time of
injection. Near the more basic xenoliths the granite may dis-
play an increase in its content of biotite and garnet. Micro-
scopic sections show that grains of the feldspars which are char-
acteristic of the intrusive may occur in the inclusion, abundant
near the contact, but decreasing in amount away from it.
While the granite never becomes aphanitic adjacent to the
country rock, it may grow sensibly finer. Apparently the
schists were comparatively warm when intrusion took place.

There can be no doubt, therefore, that the Boston Neck
granite is irruptive into, and consequently later than, the
Carboniferous strata.

The pegmatite phase: Description.—Pegmatite is found,
not only at various localities in the granite area, but also nearly
as far northward as Hamilton (Loe. 8, B-C:11, fig. 1), and
eastward, in the form of small dikelets, on Dutch Island
(Loe. 14, C-D: 18).

These pegmatites are composed chiefly of microcline, micro-
perthite, graphic granite, and quartz, a little orthoclase, acid
plagioclase, and muscovite. Biotite may be present instead of,
or accompanying, the muscovite. Garnet may be plentiful.
‘Pneumatolytic minerals,’ such as beryl, tourmaline, topaz, and
fluorite, are very rare. Tourmaline alone has been found in
one instance by the writer. Kemp stated that, westward,
tourmaline, monazite, and molybdenite have been observed.+
Of the principal constituents, the feldspars occurs in crystals,
often excellently shaped, up to thirty inches in length. Quartz
grains, too, may measure as much as two or three feet across.
Muscovite occurs either as thick plates, sometimes two inches
, * Shaler, N.S., Foerste, A. F.. and Woodworth, J. B., Geology of the
Narragansett Basin, U. 8. G.S., Monog. xxxiii, 1899, pp. 249, 377.

+Kemp, J. F., Granites of Southern Rhode Island and Connecticut. Bull.
Geol. Soc. Am., x, p. 361, 1899.

F.. H. Lahee—Metamorphism and Geological Structure. 457

wide, or in the form of radiating aggregates known as ‘ plumose
mica.’ The garnets seldom attain dimensions greater than 4
inch. j .

—felations between the pegmatite phase and the granite
phase.—From the foregoing remarks it is evident that the
composition of the pegmatite closely resembles that of the
Boston Neck granite—so closely, indeed, that if for no other
reason, we should be inclined to regard both as genetically akin.
There are other grounds, however, for thisassumption. In the
first place, pegmatite may traverse the granite in the form of
dikes or as regular patches and streaks. Especially in the latter
case, the two rocks grade into one another so insensibly that
no boundary can be set between them. These pegmatite bodies
would seem to be of the residual type, as described above. In
the second place, the granite sometimes becomes pegmatitic
toward the Carboniferous schists, so that its contact zones,
instead of being finer in texture, may be coarser than its normal
phase, and its apophyses into the schists may be, and in fact
generally are, pegmatitic. This is marginal pegmatite. Along
the coast south of Watson’s Pier, granite and pegmatite may
be seen thus intimately associated with blended contacts, the
effect often being that of schlieren on a large scale. South-
ward, the pegmatite phase becomes less important; northward,
the granite phase becomes less important. The last evidences
of the granite are seen in narrow streaks in a large pegmatite
dike on the Bonnet (small projection of western coast in
C:14, fig. 1).

—felations of the pegmatite phase to the Carboniferous
sedimenis.—Those pegmatite dikes which cut the Carboniferous
formation may be many feet or less than an inch in thickness.
On Boston Neck they are very numerous and very large, and
the schists occupy relatively little space. Exposures on the
Bonnet, for instanee, are chiefly of the schists which, however,
are intersected by five or six large dikes and many little ones.
Still farther north, on Barber’s Height (Loc. 9, B: 12), pegma-
tite is rarely encountered.

Great thickness does not necessarily imply great length ;
for intrusives twenty or thirty feet across may thin out and
come to an end (at the topographic level) within a space of
twenty-live feet. On the other hand, apophyses from the
larger dikes may run with nearly a uniform width of only five
or six inches for distances of several scores of feet; but they
commonly end by tapering to a point within a few yards of
their parent body. Sometimes the thickness may alternately
increase and decrease, even to such a degree that an intrusion
appears in cross-section as a succession of short, discontinuous,

458 F. H. Lahee—Metamorphism and Geological Structure.

lens-shaped masses.* (See fig. 2.) Some of the dikes are
straight; others have elbow-bends; and still others appear to
be highly contorted (see figs. 2-12).

As regards contact phenomena, the margins of these dikes,
although ordinarily pretty sharply defined, may display bend-
ing in a narrow zone. The edges are often jagged or otherwise
irregular, in a way to suggest that the schists were torn, and
not ‘broken, at the time of irruption. Elongate, bent, shredded
inclusions, as frequent here as in the granite, generally trend
parallel to the walls. Within the smaller dikes, not more than
a few inches in thickness, the central zone may consist of
nearly pure quartz, or of quartz and muscovite, and the feld-
spars with a little quartz and muscovite are then limited to the
marginal portions. Biotite and garnet were also observed to
occur more particularly near the contact.

Pig. 2
SSS
ie, 25

———
ee

Fic. 2. Lenses of pegmatite in schist. (Seen on the Bonnet.)

Fie. 38. Dikes of coarse granite cutting schist. (Tower Hill.)

Fie. 4. Dike, largely of quartz with a little feldspar, cutting across
schistosity. (The Bonnet.)

Many of these apophyses show a progressive Increase in
acidity away from their point of origin, and this modification
may go so far that they are composed of quartz only near their
tapering extremities. In other words, the pegmatite dikes
may grade into quartz veins.

The country rock may exhibit evidences of exomorphic —
alteration in the recrystallization of its constituents, in the
formation of knot-like bunches of quartz up to one- half an inch
across, or in the introduction of such minerals as feldspar and
especially muscovite and sericite.t It may possess a charac-
teristic greasy lustre consequent upon such changes.

* Similar successions of lenticular masses are described by E. S. Bastin.
(Quartz and Feldspar Deposits of Maine, U. 8. G. S., Bull. 315, p. 383;
1906, p. 384.)

+ Sericite is no doubt the result of dynamic metamorphism, an effect of the
intrusion of the pegmatites.

F.. H. Lahee—Metamorphism and Geological Structure. 459

As we have explained in Part I, the strikes of the beds
in the southwestern portion of the Basin are nearly north-south
and the. dips are commonly steep eastward (fig. 1). The
attitude of the schistosity is usually similar. These structures
(either or both) had a general directional influence upon the
intrnsives, and this influence was more efficient southward.
Thus, in the Watson’s Pier district, the dikes, which are pre-
vailingly of large size, usually trend along north-south lines.
On the other hand, in the Bonnet exposures,* large dikes are

Hie. 5. Fie. 6.

Ne)
i=)

a

Fic. 0. Pegmatite dikes in schist. Note the distortion of the schistosity
against the dikes. (Southern end of Boston Neck.)

Fic. 6. Pegmatite dike cutting Carboniferous sehist and having inclu-
sions of the same. (Figs. 6 to 12 are of features seen on the Bonnet.)

few and, when present, may cut the strata obliquely or may
bend sharply from a nearly north-south course and, crossing
the beds nearly perpendicular to the strikes, disappear under
the waters of the Bay or landward beneath the soil.

Small dikes and apophyses are more numerous on the Bon-
net than on Boston Neck. In the former place many of them
show absolutely no dependence upon structures in the country
rock. A few have been seen to extend into joints of an east-
west set. When they are approximately or quite parallel to the
cleavage, they may be relatively long and narrow and of pretty
uniform thickness (fig. 4); where they cross the cleavage, they
are shorter, thicker, bunchy or highly irregular in shape, or
are convoluted (see figs. 5-11). Yet that this is not always
true is proved by the straightness of such stringers as the
middle third of the small apophysis on the left in fig. 11.
Sometimes pinching seems to have brought about a separation
of the dike (fig. 10). In this case, however, it should be noted
that the two ends do not lie in the same cleavage plane. In spite

* The strata of the Bonnet have a well developed cleavage which strikes a

little east of north and has an average dip of 60° E. Differences of texture,
where visible in these rocks, prove that the bedding has a like attitude.

460 F. H. Lahee—Metamorphism and Geological Structure.

of these suggestions of folding and squeezing, the lithological
structure and the texture of the pegmatite display little, if any,
evidence of crushing.

iivivel ¢. Fic. 8.

SS

Fie. 7. Tortuous dike of pegmatite cutting the schistosity, yet with a
tendency to trend parallel to this structure.

Fie. 8. Thick pegmatite dike, which, although irregular, shows a ten-
dency to trend parallel to the schistosity of the country rock.

Hig, 9; Fie, 10.
pe ee SS _
ey oo,

eS

Fic. 9. Pegmatite dike with a loop-like lateral extension which encloses
a large xenolith of the country rock.

Fic. 10. Pegmatite dike, showing relations between the schistosity and
the edges of the dike.

Fie. 11. Fie. 12.
= = age
=
eee
g =e
Cohan cE

Fic. 11. Crumpling of schistosity against dike of pegmatite.
Fic. 12. Irregular dike of pegmatite, bedding (parallel to the upper lines
in the diagram), and cleavage (parallel to the lower lines in the diagran.).

Absolute parallelism of the intrusive and the foliation of the
country rock are very rare. When the cleavage is intersected
at an acute angle, it may be nearly coincident with the sinuosi-
ties of the contact (fig. 10). When it distinctly abuts against
the dike, it may be minutely crumped or may fan out (figs. 10
and 11).

F.. H. Lahee—Metamorphism and Geological Structure. 461

Immediately above the dikes depicted in figs. 10 and 12, the
stratification, which was perfectly clear in the junction of a
fine dark schist and a coarse light schist, had its dip and strike
about parallel to the average attitude of the schistosity. Care-
ful search was made for bedding where crumpling might
occur, but with little success. In only one instance there
were very obscure traces of close folding. Yet the very fact
that the cleavage is contorted proves that the pre-existing
stratification must also have suffered deformation of like
nature.

The quartz vein phase: Description.—Large and small
veins of quartz are found throughout the southern half of the
Narragansett Basin. They are more abundant southward and
westward. ,

The quartz of these veins is milky or creamy in color.
Feldspar has been found in small quantity, generally near the
margins of the veins, as far north as the Devil’s-Foot Ledge
(an B:9, where vertical dip is shown, fig. 1), near East Green-
wich, and, eastward, on Dutch and Conanicut islands. Locally,
a little chlorite, muscovite, sericite, pyrite, etc., have been dis-
covered.

Miarolitie cavities are occasionally seen (Kast Providence
area and Sachuest Neck), and, in these, crystal terminations
may be well developed; but, as a rule, the quartz is maésive.
Comb-siructure was not recorded.

—TLvelations between the quartz vein phase and the pegmatite
phase.—We have explained above that pegmatite apophyses
may become wholly quartzose at their extremities. We now
see that the quartz veins may contain some feldspar. Every
gradation between typical pegmatite dikes and pure quartz
veins may be observed in this region. On the Bonnet, where
all the varieties are best illustrated, quartz veins sometimes cut
the pegmatite. Hence we infer that the quartz veins are
genetically allied to the pegmatites and represent the extreme
acid phase of the Acid Intrusive Series.*

—Lvelations of the quartz vein phase to the Carboniferous
sediments.—Those veins which cut the Carboniferous sedi-
ments are of every variety of shape and size. Usually they are

* The same relation between quartz veins and pegmatite dikes has been
recorded in other regions by I. H. Ogilvie (Geology of the Paradox Lake
Quadrangle, N. Y., N. Y. State Mus. Bull. 96, 1905), xx ; Van Hise (op.
cit., p. 724); T. T. Read (Nodular-Bearing Schists near Pearl, Col., Jour.
Geol., xi, p. 498, 1903) ; J. F. Kemp (The Role of the Igneous Rocks in the
Formation of Veins, Am. Inst. Min. Eng., Trans. xxxi, p. 169, 1902);
Crosby and Fuller (op. cit., pp. 829, 884); G. H. Williams (General Rela-
tions of the Granitic Rocks in the Middle Atlantic Piedmont Plateau, U.S.
G.S., Ann. Rept. xv, p. 657, 1894); C. R. Van Hise (Principles of North

American Pre-Cambrian Geology, U.S. G. S., Ann. Rept. xvi, Pt. I, p. 581,
1895, p. 688) ; and many others.

462 F. A. Lahee—M etamorphism and Geological Structure.

not sheet-like, but tend rather to occur as large, irregular
masses or banches, from which short and long stringers run
out in all directions. The shapeless type is particularly char-
acteristic of those veins which are in the pelitic and graphitic
rocks, while the sheet forms are found chiefly in the psamiites
and psephites, where they occupy joint-fissures. It is im-
portant to note not only that a great majority of these veins
are in rocks of fine texture, but also that they are especially
abundant where the country rock is much contorted. Loeal-
ities where quartz veins are numerous and where contortion in
the schists is at a maximum are as follows: southern end of
Warwick Neck (D:7); part of the coast of Bristol Neck,
northwest of Bristol (G : 5-6); Brayton Point (Loc. 49, J :5);
several places along the eastern coast of Aquidneck Island ;
along the eastern shore of the Sakonnet River, north of Brown
Point (Loe. 44, [: 12); Sachuest Neck; Gould Island (KE: 12);
numerous points on the eastern coast of northern Conanicut
Island ; on Freebody’s Hill (between Locs. 17 and 19, D: 13)
and on the Beaver Tail Peninsula (Loc. 28, D: 14 and 15),
Conanicut Island; Dutch Island (Loc. 14, C-D:13); and at
points along the western coast of the Bay. Whether introduc-
tion of the veins was consequent upon the intense folding, or
vice versa, is a question to be discussed later.

As with the pegmatite apophyses on the Bonnet, the state-
ment holds here also that veins which cross the schistosity are
generally thicker and more contorted than those which run
nearly parallel to it. Except in this way, the veins exhibit
very little dependence upon directional structures of the coun-
try rock.

The edges of the veins, always sharply outlined, are ordin-
arily uneven or jagged. Horses of the country rock are not
infrequent. Exomorphic change is seen in an excess of
sericite, oriented parallel to the contact as if caused by pressure
concentrated near the vein.

The presence of feldspar along the margins, as already
described for certain cases, might be attributed to the action of
the injected material upon a country rock containing the
elements of this feldspar; but the fact that the relative propor-
tion of this mineral (1) does not vary sympathetically with dif-
ferences in the composition of the surrounding rock, and (2),
when studied at different localities and compared, reveals a
general and uniform increase in a southwesterly direction,
toward the pegmatites and the granite, discountenances such
an assumption.

Summary.—We may now summarize the points brought
out in describing the Acid Intrusive Series, at the same time
applying the facts noted under the theoretical considerations.

FE. H. Lahee—Metamorphism and Geological Structure. 468

(1). The Boston Neck granite is genetically related to the
pegmatites, for (a) both contain essentially the same minerals ;
(b) both phases may alternate, schlieren-like, in the same dike ;
and (c) the granite may be seen to grade into the pegmatite.

(2). The pegmatites and the quartz veins are genetically
related, for the pegmatites, by constant increase in their rela-
tive content of quartz and decrease in their relative content of
feldspar and other minerals, grade into true quartz veins.

(3). The Acid Intrusive Series (Boston Neck granite, peg-
matites, and quartz veins) is intrusive into the Carboniferous
sediments of the Basin, for (a) it cuts the sediments in dike
form ; (b) it contains inclusions of the sediments; (c) it shows
endomorphic effects in contact with the sediments; and (d)
the sediments display exomorphic alteration near the intrusive
rocks.

(4). Of the several members of the Acid Intrusive Series,
(a) the residual pegmatite represents a somewhat later stage of
erystallization than the main body of the granite; (b) the mar-
ginal pegmatite probably crystallized about the same time as
the contact portions of the granite body; (c) the offshoots from
_ the marginal pegmatite zone, and the quartz veins, represent a
later stage of crystallization than do the marginal pegmatites
proper.

Hence, the younger members of the series are more acid
than the older members.

(5). The Acid Intrusive Series is distributed as follows:
(a) the granite occurs only southwest and west of the south-
western part of the Narragansett Basin, as a border rock ; here,
too, are the residual pegmatites; (b) the marginal pegmatite
and its offshoots occur chiefly in the southwestern portion of
the Basin, and have somewhat greater extent than the granite,
northward, northeastward, and eastward ; (c) the quartz veins
occur locally in all parts of the southern half of the Basin, but
more abundantly southwestward toward the pegmatites.*

Hence, the series exhibits higher acidity and evidence of
more intense operation of mineralizers, with increasing distance
from the granite.

(6). The most important catalytic agent active in the crys-
tallization of these intrusive rocks appears to have been water
gas, for there are found very few of the rarer ‘ pneumatolytic
minerals,’ the occurrence of which would be a token of the
presence of other volatile constituents.

(7). Evidences for solution and chemical alteration as contact
phenomena—slight in any caset—are most pronounced near

* Such distribution may not be due to horizontal distance from a vertical,
or nearly vertical, contact, for the upper surface of the granite may slope
northward and eastward.

+ It is therefore questionable whether solution has contributed much toward

opening the spaces for these bodies, as was suggested by Crosby and Fuller
for similar dikes and veins (op. cit., p. 388).

464 FE. 1. Lahee—Metumorphism and Geological Structure.

the granite, less so near the pegmatites, and least near the
uartz veins.

(8). While the quartz veins are not dynamically metamor-
phosed, and the pegmatites have suffered at most only slight
crushing, the granite, which represents the oldest phase of the
series, locally has prominent gneissic structure.

—Lelations of the intrusion of the acid intrusives to the
folding, metamorphism, and schistosity of the Carboniferous
sediments.— We have said (p. 456) that, while the granite may
grow finer adjacent to the country rock, it never becomes aph-
anitic. Indeed, in some places it shows no diminution of
texture. There is no marked sign of chilling. Instead, the
phenomena indicate that the country rock was relatively warm
at the time of intrusion.

The marginal zones of the pegmatite dikes are frequently of
finer grain than the central regions. This might be explained
partly or largely by the influence of the inwardly assembling
mineralizers, and, to a less degree, by that of surrounding tem-
perature conditions. Nevertheless, here again, nothing sug-
gests a cool country rock.

Because of the massive nature of the quartz veins, it is
impossible to ascertain their relations to the sediments in this
particular.

We conclude that the temperature of the country rock, at
the time of intrusion, was high.

Exomorphic alteration, due to injection of the Acid Intru-
sive Series, includes solution, introduction of minerals peculiar
to the intrusive, and recrystallization of original constituents
of the country rock. These changes are such as to imply the
codperation of considerable heat and pressure, of solvent
power, of the action of mineralizing agents, and of long time.
They are characteristic and are distinct from the results of
dynamic metamorphism, as described in Part II for the entire
area investigated, in spite of the fact that this metamorphism
is more severe westward and southward. The zone of contact
metamorphism is limited to but a few feet in breadth. We
must infer that the Acid Intrusive Series, although responsible
for some contact metamorphism, did not cause the widespread
metamorphism of the basin.

We noticed that the Acid Intrusive Series exhibits a depend-
ence upon certain directional structures (stratification and
schistosity) in the country rock, and that this dependence
increases southward. It follows from the distribution of the
series that the degree of dependence of the different members
varies inversely as their degree of acidity. And it follows,
further, that this degree of dependence is less in the younger
intrusives: for the more acid members, representing an
advanced stage of differentiation, are somewhat later in origin.

F.. H. Lahee—Metamorphism and Geological Structure. 465

Again, we have shown that, in the Bonnet-Boston Neck
region, stratification appears to coincide with the planes of
schistosity. The Carboniferous rocks of this district are of
comparatively uniform texture. Conglomerate schists are fine-
grained and are rare, and very fine pelitic schists are not com-
mon. The bulk of the sediments are sandstone schists which
range from coarse to fine. We might conclude, then, that the
stratification, per se, would not have afforded easy access to an
intrusion —certainly by no means as easy as if the sedimentary
series consisted of rapidly alternating textures.

On the other hand, since schistosity 1s well developed, it
would seem to have offered relatively little resistance to the
injection of magma along its planes.

These facts being admitted, we may assume provisionally
that those dikes which trend parallel to the schistosity and
bedding were guided more efficiently by the schistosity than
by the bedding.

Northward and eastward the quartz veins are best developed
in pelitic and coaly rocks, that is, in rocks of fine grain. Ina
large sense, then, these veins may be said to be related to the
stratification ; but they occur in huge masses which cut promis-
cuously across the finer lamine of bedding and cleavage
alike, and are, therefore, not immediately dependent upon
either structure.

The intimate relations between the pegmatite dikes and the
schistosity of the Carboniferous sediments were described
above (p. 457 et seq.). Among the features there mentioned,
the conspicuous lack of dependence of the intrusions upon the
direction of the schistosity, their occurrence sometimes in
series of lenticular bunches or in irregular masses, which seem
to have been squeezed apart, and their frequently tortuous
shape, are strongly suggestive of their having been injected
before the period of deformation and metamorphism, and of
their having been subsequently folded together with the sedi-
ments. but against this supposition, the following objections
may be raised: (1) The internal structure of the dikes reveals
little or no crushing. (2) Inclusions have schistosity which is
practically identical with that of the country rock in respect to
degree, nature, and direction. (8) Loops of pegmatite, which
surround such inclusions, prove that all curves of these dikes
could not have been parallel to the bedding. (4) In many
cases the loops are of a type difficult to explain if injection
preceded folding. (4) In the midst of an area containing
numerous, often highly tortuous dikes, perfectly or nearly
straight apophyses sometimes extend for considerable distances.
(6) The method in which the cleavage abuts against the dikes,
either by fanning out (fig. 12) or with minute local crumpling

466 FF. #1. Thee aie phism and Geological Structure.

(fig. 11), is snggestive, not of interference by the dikes, as if
already present, but of pressure exerted against the cleavage
by the force of the incoming intrusive.* (7) Except in one
doubtful instance, the stratification, wherever discernible, is

regular and not contorted. We admit, however, that, where
the cleavage is crumpled, the bedding laminge also must have

suffered some minor deformation; but there are faint indica-
tions that both cleavage and stratification, when folded as well
as when relatively plane, are approximately coincident.

From these statements we infer that the intrusion of the
dikes—at least of those on the Bonnet—was chiefly subsequent
to the deformation of the enclosing Carboniferous sediments.

Conclusions to the study of the acid inirusives.—In regard
to the Acid Intrusive Series, we conclude: (1) that, since
endomorphie and exomorphic metamorphism are slight, the
intrusion was weak ; (2) that, since the granite sometimes has a
conspicuous oneissic structure, it was injected while the forces
that caused the folding of the country rock were still active;
(3) that, since the pegmatite shows at most only shght crush-
ing, its dikes entered in general toward the close of the period
of deformation; (4) that, since the quartz veins are not
dynamically metamor phosed, they were injected after deforma-
tion was at an end; (5) that, since injection of the Acid In-
trusive Series , initiated during the process of folding, was not
completed until after the close of this process, and, since the
quartz veins are a differentiation product of the pegmatites,
while the pegmatites, in their turn, are a differentiation
product of the granite, therefore, the period of intrusion must
have been of long duration sf (6) that, since the processes of

* Compare Bastin, speaking of the Maine pegmatites: ‘‘The bending of
the schist folia in the manner shown indicates also that the pegmatite when
intruded behaved to a certain extent like a solid body capable of exerting
differential thrust on the inclosing walls of schist.”” (Bastin, E. S., Geology
of the Pegmatites and Associated Rocks of Maine, U. S.G.S., Bull. 445, 1911,
p. 34.)

+ Accurate statements of the relative ages of folding, intrusion of acid
rocks, and production of metamorphism in regions where these phenomena
occur, are rare in the geological literature. The following may be men-
tioned: G. O. Smith and F. C. Calkins described schists cut by granodiorite
and by pegmatites which were somewhat gneissic. (A Geological Reconnais-
sance across the Cascade Range near the 40th Parallel, U.S. G.S., Bull.
235, 1904.) E. S. Bastin held that the schist of Boothbay Harbor, Maine,
has been intruded by granite and related pegmatite later than deformation
and metamorphism. (Quartz and Feldspar Deposits of Maine, U. 8. G.S.,
Bull. 315, 1906, p. 384.) From studies in various localities, W. O. Crosby
wrote, ‘‘In every instance the pegmatite is clearly younger than the foliation
of the enclosing rocks.” (Crosby and Fuller, op. cit., p. 339.) R. A. Daly
mentioned phyllites cut by quartz veins which seemed to have shared in the
crushing, but most of which were later. (The Geology of Ascutney Moun-
tain, Vt., U.S. G.S., Bull. 209, 1903, p. 15.) In his ‘Granites of Maine
(U. S. G. S., Bull. 313, 1907), T. N. Dale said of the Waldoboro quarry,
‘‘The granite sends small apophyses into the schist and also contains inclu-

F. H. Lahee—Metamorphism and Geological Structure. 467

intrusion and of deformation were in part contemporaneous,
the forces active in the folding may have assisted in determin-
ing the shapes and directions of the dikes ;* and, (7) that, not
being the cause of the regional metamorphism of the Basin,t
and, moreover, having its inception during deformation, the
process of intrusion may have been a consequence of the action
of the deforming forces.

RELATIONS BETWEEN THE MINETTE DIKES AND THE ACID IN-
TRUSIVES.—Because the minette dikes and the Boston Neck
granite entered the Carboniferous strata during the period of
deformation, there is strong reason to suppose that they may
be related to one another. Someone has suggested that the
pegmatites and quartz veins, on the one hand, and _ the
minettes, on the other hand, represent complementary poles
of differentiation. Advocates of this view would have to
explain (1) why the minettes are so often intersected by quartz
veins which are almost certainly of the Acid Intrusive Series ;
(2) why there are so few minette dikes as compared with the
vast number of pegmatite dikes and quartz veins; and (8) why

sions of it. The granite was erupted (sic) after or during the folding of the
schist, otherwise it would have become a gneiss” (p. 51). We find in
Geikie’s ‘Text-Book’ that the granites of southeastern Ireland were injected
into Lower Silurian rocks after the latter were folded (p. 726). Finally,
we may quote from T. A. Jagger and E. Howe (The Laccoliths of the Black
Hills, U.S. G.S., Ann. Rept. 21, Pt. III, 1901): ‘‘Throughout the Rocky
Mountains igneous phenomena have accompanied colossal movements of
uplift, folding, and faulting” (p. 187). ‘‘The history of intrusion in the
Black Hills is believed to be intimately associated with the history of the
larger deformation. Intrusion is not conceived to have been in any sense a
cause of the greater uplift, but an effect” (p. 282). ‘‘Cross recognized in
the Mosquito Range and Tenmile district the influence of orographic move-
ments concomitant with intrusion” (p. 286). ‘‘In many places (in the
Rocky Mountains) intrusions accompanied or followed the greater move-
ments...” (p. 287).

* Compare A. Harker: ....‘‘When very large bodies of magma are
intruded under a considerable cover, their form and disposition may be
determined mainly by the distribution of stress which thus finds relief, with
very little regard to the structure of the encasing rocks” (Natural History
of Igneous Rocks, N. Y., 1909, p. 83).

+ G. F. Loughlin wrote: ‘‘The details of metamorphism in the Kingstown
area have not been exhaustively studied, but itis very evident, from the
field work done, that vertical dips and the most complete recrystallization of
the sediments are found where granitic intrusions are most abundant.
There seems, then, no reason for doubting that in the Kingstown area....
the granite intrusion accompanied metamorphism and folding. As the
Kingstown sediments have been determined to be of Carboniferous age, the
time of granite intrusion and folding may be correlated with the Appala-
chian Revolution.” (Intrusive Granites and Associated Metamorphic Sedi-
ments in Southwestern R.I., this Journal, xxix, 447, 1910, p. 445.) The
first statement seems to lead one to infer that the metamorphism of the
sediments was largely due to intrusion ; but, as we have attempted to ex-
plain, we regard the amount of metamorphism primarily caused by the
intrusion to be slight in comparison with that due to folding and concomitant
shearing, together with the static after-effects.

468 FH. Lahee—Metamorphism and Geological Structure.

the minettes display evidences of much more shearing than is
seen in the pegmatites and quartz veins. The number of the
minette dikes is so small, and their importance in the present
discussion is so slight, that they will not be considered further
here.

SUMMARY AND CONCLUSIONS.

(1). The Narragansett Basin is a body of Carboniferous
strata which (a) have been deformed according to the Appa-
lachian type of folding; (0) have been regionally metamor-

phosed ; and (¢) have been intruded by igneous rocks.

_ (2). The Basin is surrounded on nearly all sides by a nearly
continuous border of pre-Carboniferous rocks from which the
Carboniferous sediments were derived. The border is inter-
rupted by the post-Carboniferous intrusives, in South Kings-
town, and by arms of the sea, between Narragansett Pier and
Sakonnet Point.

(3). The Carboniferous strata represent sediments which
(a) were heterogeneous in composition, containing varying
amounts of feldspar, ilmenite, magnetite, carbonaceous matter,
etc.; (>) were deposited by fresh water; and (c) were brought
together and laid down by currents which had rather rapid
variations in direction, rate, and carrying power.

(4). The folding of the strata in the southern half of the
Basin was caused by forces which acted radially, but with
much greater intensity along approximately east-west lines than
along north-south lines.

(5). In different parts of the southern half of the Basin, the
deformation effected by these forces shows variations in inten-
sity——variations which owe their origin (@) to variations in the
forces; (6) to vertical position in a given fold ; or (¢) to rock
texture.

(6). The intensity of the deformation, that is, the degree of
compression, as seen in the principal folds and in the minor
folding and contortion, increased southward.

(7). The regional metamorphism is both dynamic and static.

(8). The effects of the dynamic regional metamorphism (@)
are seen in all parts of the southern half of the Basin; (0) are
not directly related to textural differences and to stratigraphic
depth ; (¢) increase in intensity southward and westward.

(9). The schistosity of the Carboniferous sediments is often
related, in respect to attitude, to the bedding.

(10). The effects of the static regional metamorphism are
superposed upon the effects of the dynamic metamorphism and
are a consequence of the continuation of anamorphic chemical
changes after mechanical movement had ceased.

FH. Lahee—Metamorphism and Geological Structure. 469

(11). The post-Carboniferous intrusives include a few
minette dikes, on the one‘hand, and an extensive, perhaps
related, series of granites, pegmatites, and quartz veins (Acid
Intrusive Series), on the other hand.

(12). Of the Acid Intrusive Series, the granite (Boston Neck
granite) is oldest, the pegmatites are younger, and the quartz
veins represent the latest differentiation phase.

(13). The Boston Neck granite is limited to Boston and
Little Necks, the Tower Hill ridge, and westward (Sterling
granite); the pegmatites have a wider distribution (within the
Basin), north to Barber’s Height and east to Dutch Island;
and the quartz veins, although most abundant in the south-
western portion of the Basin, occur throughout the area
investigated.

(14). These igneous rocks (Acid Intrusive Series and prob-
ably minettes) were injected during, and immediately sub-
sequent to, the folding of the Carboniferous sediments.

(15). More or less static and dynamic metamorphism attended
the intrusion of these igneous rocks, but this metamorphism is
local and is of a distinctly different character from the regional
metamorphism due to the folding.

We conclude, then, that the Carboniferous strata of the
Narragansett Basin, after deep burial, were folded by forces
that acted with greater intensity in the south; that, contem-
poraneous with, and consequent upon, this deformation, these
sediments were regionally metamorphosed ; that this deforma-
tion and this metamorphism were accompanied, in their later
stages, by the intrusion of certain igneous rocks—a_ process
which continued, with magmatic differentiation, for some time
after folding ceased; and that, these facts being accepted, the
regional metamorphism, and the injection of the post-Carbon-
iferous igneous rocks, may be regarded as nearly parallel effects
of the mountain-building forces.

Cambridge, Mass.,
February 5, 1912.

- Am. Jour. Sor.—Fourra Srrtss, Vou: XXXIII, No. 197,—May, 1912,

470 J. E. Burbank—One Phase of Microseismic Motion.

Art. XXXIX.—One Phase of Microseismic Motion ; by
J. E. Burpank.

SEIsMoLogists generally include in the term microseismic
motion all pulsations and movements of the earth’s crust which
are not attributable to earthquakes or to motion of a more or
less violent and abrupt nature.

Microseisms may be due to local causes, as industrial opera-
tions and ordinary traffic, storms and waves on adjacent shores,
frost action, and possibly by wind, tide, and waves on distant
shores. The kind and number of microseisms recorded at any
place will naturally be limited by the adjustment and damping
of the pendulum and the nature of the record, as a photo-
graphic registering seismograph with high magnification will
record microseisms when a mechanically registering seismo-
graph would give only a smooth straight line. Moreover, with
-mechanical registration the recording surface may not always
be uniformly coated with lampblack and hence will offer vary-
ing resistance to the lateral movement of the writing stylus.
The mechanical registration with low magnification offers a
distinct advantage in studying certain microseisms, since it
does not give such a large mass of detail, in which it is often
difficult to identify a particular type of motion.

At the Cheltenham Magnetic Observatory we have been
studying the relation between microseismic motion and the
variations in atmospheric pressure since 1906. Our seismo-
graph is a two-component, 10 kilogram, horizontal pendulum,
of the Omori type, with mechanical registration and magnifi-
cation of ten times. The periods of the pendulums have been
kept between 24 and 29 seconds. With the seismograph oper-
ating under these conditions, only the more pronounced micro-
seisms are recorded, yet it is an interesting fact that during
nearly five years record there have been not more than 25 eases
of moderate barometric changes in connection with which mi-
croseisms might have been expected and were not found on
the seismograph traces.

The microseisms accompanying atmospheric pressure vari- .
ations have aremarkably regular wave-like motion which almost
always shows a rhythmical increase and decrease of amplitude
indicating interference. The waves occur in groups of from
6 to 12, and vary in amplitude with the intensity of the baro-
metric variation. The most pronounced cases indicate a move-
ment of the earth particles at this place amounting to about
0-05 millimeters on each side of their mean position.

The results of our observations from September 1, 1906, to

J. EF. Burbank—One Phase of Microseismic Motion. 471

January 31, 1908, were published* in tabular form, with full
notes on the atmospheric pressure conditions. These results
showed that the most pronounced microseisms were almost
invariably connected with the passage of deep lows across the
coast line from land to sea, or vice versa. It was also pointed
out that the water area under the pressure disturbance would
be in hydrostatic equilibrium, while the land area would be
subject to astress which would be greatest at the shore line,
hence we should expect the greatest microseismic motion when
the center of a low area moves rapidly over the coast line.

This reasoning has been confirmed by approximately 100
well-defined cases during the past 5 years. In fact, during the

eriod under investigation there has not been a single case of a
well-defined low area which has crossed the coast line between
Maine and Florida which has not been accompanied by well-
defined microseisms. It was also noted in the above paper
that a rapid rising or falling pressure over the coast was
accompanied by microseisms.

This type of microseisms has been studied by Dr. Otto
Klotz of Ottawa, Canada, who finds that the most marked
cases at Ottawa are connected with the passage of low areas
down the St. Lawrence and into the Gulf. He considers the
microseisms due to difference in pressure, which is in agree-
ment with our conclusions.

The movement of a low area down the St. Lawrence and
into the Gulf should be regarded as a passage across the coast
line, although Dr. Klotz makes the statement} that such pas-
sage is not marked by microseisms. This statement is not in
agreement with our results at Cheltenham, which is peculiarly
well located geographically for the study of such phenomena.
Of 300 microseisms recorded here between September 1, 1906,
and June 30, 1911, all but 32, about 10 per cent, have been
definitely connected with some change of pressure occurring
over the coast line between Labrador and Texas.

That a change of pressure over land areas alone, although of
considerable intensity, does not produce appreciable tremors is
borne out by the following observations ; in many cases intense
depressions have developed over the Mississippi valley and
over the Lakes and have moved northward and eastward en-
tirely unaccompanied by microseisms until they had approached
sufficiently near the ocean to cause a steep pressure gradient
over the coast. Another small group in which a low develops
over the Gulf or the lower Mississippi valley and moves rapidiy
northeastward, passing out to sea over the middle Atlantic

* Journal Terrestrial Magnetism, vol. xiii, pp. 1-20, March, 1908.

+ Department of the Interior, Canada, Report of Chief Astronomer, 1908,
pp. 24-40.

472, J. EF. Burbank—One Phase of Microseismic Motion.

states,—in such cases no appreciable microseisms occur until it
approaches the coast, when they begin and reach their greatest
intensity while the center is passing out to sea. Another very
rare condition is when a low develops over the Gulf states and
moves northeastward. along the Allegheny mountains, passing
into Canada without producing any great pressure changes
along the coast line; in such cases no microseisms are recogni-
zable. Still another very rare case is when a low develops
over the ocean east of Florida and recurves northwestward,
passing inland over the South Atlantic coast. The micro-
seisms rapidly decrease after the center passes inland, although
it may still be of considerable intensity.

Of the 268 microseisms recorded here during the last 5 years
and which appear connected with atmospheric variations,
approximately two-thirds occur in the period October to April,
when pressure changes are more frequent and abrupt; they
occur very rarely during June, July, and August, when pres-
, sure gradients are very small. During these winter months
these microscisms often continue for several days, diminishing
and increasing in intensity as a succession of abrupt pressure
changes from low to high sweep over the coast into the Atlan-
tic Ocean.

A detailed study of all these cases confirms the general con-
clusions already set forth in connection with my earlier paper;
hence the tabulation and detailed notes are omitted from this
paper, and only conclusions stated.

Of the 268 microseisms above mentioned, 74 were connected
with lows moving over the Gulf of St. Lawrence; 20 of these
were of sufficient amplitude to determine the period, which
varied from 2°8 to 3-5 seconds, with 4 cases of 3°6, 4°6, 5:0,
and 6:0 seconds respectively—68 lows moved wholly or in part
over the coast of New England; of these 21 showed periods
ranging from 3:0 to 3°5 seconds, with one 3°8, one 4:0, and two
, 5:0 seconds, the remainder being too ill-defined to allow deter-
mination of period—73 microseisms were connected with pres-
sure changes occurring over the Middle Atlantic coast between
New York City and Cape Hatteras; nearly all of these were
lows and show periods ranging from 3°0 to 3°5 seconds, with 5
cases ranging from 3°8 to 5:0 seconds. There were 20 cases
connected with the South Atlantic coast, nearly all being due
to lows passing northeastward into the ocean and often moving
northward parallel to the coast with decreasing intensity; most
of these gave intense microseisms with the usual period, one
case having a period of 5:0 seconds; in addition to these
were 13 cases of lows forming in the Gulf, or the ocean east
of Florida, also including hurricanes which approach the Flor-
ida peninsula or the Gulf coast; these show the usual periods

J. E. Burbank—One Phase of Microseismic Motion. 473

with one marked exception: on October 16-17 a hurricane,
with pressure about 29°05 inches, was in the Gulf southwest
of Florida and the microseisms had a period from 5-0 to 5:8
seconds; on the 18th, when the center had approached the
Florida coast and was passing inland, the period had decreased
to 3°5 seconds and the amplitude gr eatly i increased.

In general the period of the microseisms is from 3:0 to 3°5
seconds regardless of the part of the coast under strain. Peri-
ods greater than 3°6 seconds apparently occur only when the
low is of great extent and the center almost wholly over the
ocean. It would appear from this that the period of the micro-
seisms varies with the extent of the disturbed water area.

In general, pressure changes due to high areas are too grad-
ual and widespread to produce microseisms of appreciable
intensity, although about 40 cases have been noted, nearly all
being cases in which a depression was closely followed by a high
area of marked intensity.

In my earlier paper it was suggested that the microseisms
might be connected with the movements of large masses of
water set in motion by the wind accompanying the pressure
changes. This assumption is not borne out by a comparison
of the winds, normal to the coast line, and the microseisms
occurring during the period January 1 to June 30, 1910.
During this period there were strong microseisms on days when
there was little or no wind along the coast, and also days when
there were high winds without any well- marked microseisms.
In general, high areas are accompanied by winds when they
approach the coast, although they are rarely accompanied by
microseisms.

Another point of interest is that the period of the micro-
seisms does not appear to be conditioned by the geological nature
of the part of the coast line over which the low is passing, as
all parts of the coast give essentially the same periods. It
seems probable that this period is a characteristic of the local-
ity in which the seismograph is mounted, although the change
of period during different microseisms is ditiicult to explain on
that basis. Klotz at Ottawa observed periods of 5 to 6 seconds
with occasional changes to 3 seconds.

The above conclusions by no means preclude the probability
of microseisms being produced by the movement of lows and
highs wholly over the land area; in fact it is extremely prob-
able that they do occur, and could be readily recorded by a
sufficiently sensitive seismograph, but it is evident that, at least
for the eastern part of the United States, the most “marked
microseisms are those related to the variations of pressure
along the coast line.

474 J. EF. Burbank—Microseisms Caused by Frost Action.

Art. XL.— Microseisms Caused by Frost Action; by J. E.

BuRBANK.

In a paper on “Some Apparent Variations of the Vertical
etc.”* the writer called attention to a class of minute earth
movements or microseisms of very small amplitude and irreg-
ular period varying from 8 seconds to 2 minutes. At that
time only a few cases had been identified.

Recently an abstract of a paper by B. Gutenbergt has come

to my attention. In this abstract it is stated that the distri-

bution of frost in southwestern Europe up to about 60° N.
Lat. and 30° E. Long. can be determined from the records of
the 100 kilogram pendulum of the Geophysical Institute at
Gottingen. The movement showed a well-defined daily period,
max. about 6 a. m. and min. about 3 p. m. and an amplitude
which on one occasion showed an earth movement in the
north-south direction as great as $ millimeter on each side of
the position of rest. One would infer that these microseisms
sometimes occur when the ground at some distance is freezing
and thawing, while at Gottingen it was not frozen. It is diff-
cult to understand how the expansion and contraction of the
surface layers in freezing and thawing can produce vibrations
or variations of level of sufficient magnitude to be recorded
more than a few kilometers beyond the frost zone.

Cheltenham is so located that the approach of cold waves
and freezing of the ground can be studied several days before
they reach us, and often the zone of frost is only a short
distance, 100 to 200 kilometers, to the north of the station,
while the ground at Cheltenhain is not frozen. Our pendulumst
are not as sensitive as those used by Gutenberg, and a move-
ment of the earth particles of less than -02 millimeter would
not be recognized.

An examination of our seismograms for a period of several
years past shows that whenever actual freezing or thawing of
the ground is taking place at Cheltenham these microseisms
are recorded as irregular tilts or movements of the pendulum
back and forth in a somewhat jerky and irregular manner.
The most common period is between 8 and 14 seconds, but
they frequently have a period as great as two minutes. The
amplitude increases with the intensity of the freezing or thaw-
ing, the usual range of motion of the earth particles being
between ‘02 and ‘10 millimeters. These microseisms are con-

* This Journal, vol. xxx, Nov. 1910, p. 382.

+ Physikalische Zeitschrift, 1910, pp. 1184-5.
tSee preceding paper.

J. H. Burbank—Microseisms Caused by Frost Action. 45

tinuous as long as the ground is frozen and continue without
appreciable diminution when the frozen ground is covered
with a blanket of snow. When the ground is covered with
snow the microseisms are due to the thawing out of the lower
layers of frozen ground in contact with the warmer layers
below.

Attention was especially directed to those cases of cold
Waves with freezing temperatures approaching Cheltenham
and in no case could any microseisms be detected until the
ground at Cheltenham had begun to freeze.

The above evidence does not disprove a relation between
microseisms and frost action at a distance, but it places a limit
on the magnitude of such action.

Cheltenham, Md., August, 1911.

Art. XLI.—Dahllite (Podolite) from Tonopah, Nevada ;
Velckerite, a New Basic Calewum Phosphate; Remarks
on the Chemical Composition of Apatite and Phosphate
fiock; by Austin F. Rogers; with Analyses by G. E.
Postma.

My attention was directed to a chemical study of apatite
and related minerals by the recognition of a calcium carbono-
phosphate on a mineral specimen from Tonopah, Nevada,
kindly sent to me by Mr. S. C. Herold, a mining engineer.
This specimen, which is from the Mizpah mine of the Tonopah
Mining Company, consists of iodyrite, hyalite, quartz, man-
ganese dioxide, and a white drusy coating of minute hexagonal
erystals. As these hexagonal crystals seemed to effervesce in
acid, they were provisionally referred to calcite. Optical tests
failed to confirm this determination, for the fragments had
weak, instead of strong, double refraction. The weak double
refraction suggested apatite. As a good phosphate test was
obtained, the mineral naturally was called apatite and the effer-
vescence was attributed to an error in observation.

On reading a paper* on the probable identity of dahllite with
podolite, it occurred to me that the Tonopah mineral might
belong to one of these carbono-phosphates, so the solubility
test was tried again very carefully. There was distinct effer-
vescence with warm nitric acid. Observed under the micro-
scope, the bubbles come from the hexagonal crystals and from

* Schaller, this Journal, vol. xxx, 309, 1910.

476 Rogers—Dahllite ( Podolite) from Tonopah, Nevada.

irregular fragments with weak double refraction, so the effer-
vescence is not due to admixed calcite. Moreover, there is
practically no effervescence until the acid is heated. Good
tests for calcium and the phosphate radical and a slight test
for chlorine were obtained. A faint test for fluorine was
obtained by heating the powdered mineral with silica and con-
centrated sulphuric acid, and condensing the fumes on moist-
ened black paper.*

To further prove the identity of the mineral, chemical

analyses were made by Mr. G. E. Postma, chemistry student at
Stanford University. Unfortunately, a very limited amount
of material was available. The carbonate and phosphate
radicals were determined in a large, very impure sample with
these results} (average of two):

In a much purer sample consisting of only 74 mg., calcium,
fluorine, and the phosphate radical together with insoluble
matter (principally quartz) were determined with the following
results : |

One BS Sie on See ge 32°56
PO Meo oe ee 47-03
IA ek te eas tee 0°29
Insolkis Se eee 1D

The amount of carbonate radical in the sample can be eal-

culated from the preceding analysis. The excess of oxygen
can be obtained by subtracting the amounts of the constituents
in the form given above from the amounts in the ordinary form
of oxides. This oxygen excess amounts to 1:07 per cent. We
then have the following figures:

‘ Molecular ratios
Gla gat hah Brae 32°56 0°814 10°00
PO, CE ere vel, ae ee 47°03 0°495 6:08
ly ee ee ee ee 0°29 0°007
(CO, ppl Sis ps Re ioe 2°48) 0°041 ‘onus 1°40
(O EP eR Te ie 1:07) 0:066

The fluorine percentage is probably low, as it usually is.
The ratio of Ca, PO,, (CO,, F,, O) is very closely 10: 6: 1, slight
errors probably giving high oxygen. The Tonopah mineral
can be interpreted as an isomorphous mixture of 3Ca,(PO,)..

CaCO,, 3Ca,(PO,),.CaO, and 3Ca,(PO,),.CaF,. It is necessary

* Browning, this Journal, vol. xxxii, 249, 1911.
+ In accordance with the modern views of chemistry, analyses are recorded
in the form of metals and acid radicals.

” ee ee eee eS ee ee ee ~_s

Rogers—Dahllite ( Podolite) from Tonopah, Nevada, 477

to assume that oxygen replaces fluorine and the carbonate
radical on account of the small amounts of these constituents.
As the carbonate-phosphate molecule is present to the extent
of at least half, the mineral should be called dahllite (or
podolite).

The optical properties. of the mineral are also interesting.
The erystals are hexagonal tabular in habit as represented in
ficure 1. The interior of the crystals is almost opaque white,
while the exterior is subtransparent. The central portion of

1s ae Die Ae

Dahllite (Podolite) from Tonopah, Nevada.

the crystals, including a narrow zone of the subtransparent
part (black area of fig. 2), is dark between crossed nicols, while
the remainder of the subtransparent exterior is double refract-
ing and divided into six sectors. These sectors extinguish in
opposite pairs at an angle of 7° or 8° with the edge as
indicated in fig. 2 and give negative biaxial interference figures
in convergent light. ki 4

The hexagonal prism is either {6170} (or {1670$) with axial
plane parallel to {1010} or_it is {1010} with axial plane
parallel to {617 0} (or {1670:), for the theoretical angle
(1010 A 6170) is 7° 85’. If the prism is 6170}, as seems prob-
able, the crystals have the symmetry of the hexagonal
‘pyramidal or apatite class.

In the podolite described by Tschirwinsky* the biaxial sec-
tors extend to the center of the crystal. The question arises
as to whether all the Tonopah mineral, or only the exterior, is
dahllite (podolite). This can not be definitely settled as the
mineral contains some fluorine and also an excess of oxygen,
but probably the exterior of the crystals more nearly approaches
dahllite (podolite) than the interior.

The formula for podolite established by Tschirwinskyt is
3Ca,(PO,),.CaCO,. Schaller{t gives good arguments for con-
sidering podolite and dahllite as identical. The name dabllite
given by Brégger and Backstrom§ has priority.

* Centralblat. Mineral., etc., 1907, pp. 279-283. + Loe. cit.

t Loe. cit.
§ Ofv. Akad. Stockh., xlv, 498, 1888 ; Dana System, 6th ed., p. 866.

478 Rogers—Dahllite (Podolite) from Tonopah, Nevada.

The isomorphism, or at least the replacement of fluorine by
the carbonate radical, is proved by several analyses* of apatite
taken from the literature.

Ca PO, F COs Cl
Portland, Canada ----- 38°62 54°03 3°38 LLU yes
Londongrove, Penn._.. 38°53 55°40 1°95 1°93 0°94
Templeton, Canada__-.- 37°77 55°52 Lsk7 3°14 0°42

The second analysis, made by Carnot,t corresponds almost
exactly to the formula 3Ca,(PO,),.Ca(F,,Cl,,CO,).

I have examined apatite from fourteen different localities
and have found that, with one possible exception, they give
effervescence in hot nitric acid. These include apatites from
Canada, Arkansas, Norway, among them both fluor-apatites
and chlor-apatites. It may seem strange that fluorine and the
carbonate radical should replace each other and that the com-
pounds 3Ca,(PO,),.CaF, and 3Ca,(PO,),.CaCO, should be
isomorphous. The isomorphism of these compounds can be
explained by the mass-effect of 3Ca,(PO,),.Ca (formula weight
==971) in these compounds ; the fluorine and carbonate radical
have relatively little influence. This explanation of isomor-
phism we owe to Penfield, who explained the chemical com-
position of tourmaline by the mass-effect of Al,(B.OH),Si,O,,
in the molecule H,A1,(B.OH),Si,O,,, it making little difference
whether the hydrogen is replaced by alumininm, magnesium,
iron, or the alkalies. The isomorphism of PbFe,OH),,(SO,),
(plumbojarosite) with K,Fe(OH),.(SO,), (jarosite) Penfield
explained in the same way. A similar explanation will doubt-
less hold for other mineral groups.

A critical study of apatite analyses will convince one of the
existence of a basic calcium phosphate, for many of the
analyses show a deficiency of both fluorine and chlorine and
also of the carbonate radical. In tabular form I have collected
here several apatite analyses showing this deficiency. The
oxygen is obtained by subtracting the sum of the constituents
in the present form from their sum as oxides. The almost
perfect summations prove that this is justified. It was thought
that perhaps the carbonate radical had been overlooked in
these apatites. Accordingly Mr. Postma analyzed a specimen
of Zillerthal apatite, obtained from Dr. Krantz of Bonn, Ger-
many. ‘This apatite occurs in large white tabular crystals.
Mr. Postma’s analysis, which is the last one in the preceding
list, shows only a slight amount of the carbonate radical.

* These and other analyses have been recalculated in the form of metals

and acid radicals. —
+ Bull. Fr. Soc. Min., xix, 135, 1896.

Rogers—Dahllite (Podolite) from Tonopah, Nevada. 479

Oxygen
Defici-
Ca PO, F CI.” H.O. ” Mise. ency Total

Mt. Greiner et Gol-

ere ae ees 38°06 57°31 0°23 0°12 0°35 3°18 0-72 99:97
Krageroe, Norwayt- 38°96 55°24 —- 0°81 0°44 3°96 1°48 100°89
Krageroe, Norwayt. 38°73 55°53 —- 1:52 0°22 3:10 1°30 99-90
(GE ic a 38°27 53°12 1:03 1°82 0°46 3°80 139" 99789
Aillerthals.<..-.--~ 40°44 57:50 0°62 —- 0°15 1°37 100:08
Zillerthal||-....___- 39°83 57:07 1:20 —- 0°30 CO,=0 23 0°92 99°55

The existence of the compound 3Ca,(PO,),.CaO is proved by
the analyses of Vcelcker, Hoskyns-Abrahall, Carnot, and
Postma. Fora mineral with this composition or one in which
this molecule predominates I propose the name velckerite, as
Veelcker was the first investigator to show that apatite was
sometimes deficient in fluorine and chlorine. Hoskyns-Abra-
hall wrote the formula for apatite thus: Ca,,(PO,),(O,F,,Cl.,).
Groth** substitutes hydroxyl for oxygen, principally for a
priory reasons. In the above analyses the water percentage
is too low to make up the deficiency as hydroxyl, the average
being 0°32 as against 1:19 for oxygen. The isomorphism of
veeleckerite with fluor-apatite and chlor-apatite may also be
explained by mass-effect isomorphism, one atom of oxygen
replacing two atoms of fluorine.

Thus we have four isomorphous compounds :

Fluor-apatite ..------ 3Ca,(PO,),.CaF,
Chlor-apatite ..------ 3Ca,(PO,),.CaCl,
Wahtiitern. = jbo 8Ca,(PO,),.CaCO,
V etckertte: - 22-2 _-- + .3c0a( FO) Cae

The names fluor-apatite and chlor-apatite are well established
in the literature. The name carb-apatite++ was proposed for
the carbono-phosphate but was withdrawn in favor of podolite.
Dahllite, however, has priority over both carb-apatite and
podolite. Veelekerite is a better name than the name Oxy-
apatite suggested by analogy and gives recognition to Vcelcker
for his work on the chemical composition of apatite. On
account of the difficulty of recognizing these minerals without
chemical analysis, apatite may be used as a group name, the
general formula being 3Ca,(PO,),.Ca(F,,Cl,,CO,,O).

Besides 3Ca,(PO,),,;CaCO,, a number of other calcium
carbono-phosphates have been described. They are as follows:

* Carnot, Bull. Fr. Soc. Min., xix, 135.

+ Velcker, Ber. Ch. Ges., xvi, 2460, 1883.

{ Jannasch, Zs. anorg. Chem., vii, 154, 1894.

§ Hoskyns-Abrahall, Zs. Kryst., xxi, 389. || Postma. mn a

“| In the case of the Norwegian apatites, which contain chlorine but no
fluorine, there is no doubt of this, for the chlorine determination is a very
accurate one.

** Tab. Uebersicht der Mineralien, 4th ed., p. 87.
++ Tschirwinsky, loc. cit.

480 Logers—Dahllite (Podolite) from Tonopah, Nevada.

Dabilite 223 eee 2Ca,(PO,),.CaCO,.4H,O
Nrancolitey 252 a= Ca,(CaF),(PO,),.CaCO,.H,O
Stattelite ss 22s. se a fibrous variety of francolite
Collophanite _- ---- £3Ca,(PO,),.yCa. CO, 2110

Dahllite, as shown by Schaller, is probably identical with
podolite. The formula assigned to francolite seems anomalous, —
as it does fit into the series given above. There are but two
analyses of francolite on record and they do not agree. One
has 9°04 per ceut Cal’,, 2°84 per cent CaCO,, and no water,
while the other has 7°68 per cent CaF,, 5:10 per cent CaCO,
and 1°59 per cent water. Francolite is pseudohexgonal like
dahllite (podolite). The axial plane is parallel to the hexagonal
outline, but this is probably not an essential difference. Lacroix
regards staffelite as a fibrous variety of francolite. Additional
analyses are necessary before francolite (or staffelite) can be
assigned definite rank as a mineral species.

Collophanite was described by Sandberger,* who gave the
formula Ca,(PO,),.H,O after deducting 3°96 per cent CaCoO,,
which he considered to be an impurity. The analysis of
Kéottnitz gives 3Ca,(PO,),.CaCO,.3H,O, but Lacroixt gives
#Ca,(PO,),.yCaCO,.zH,O. Besides the “original collophanite
there is only one other analysis, that of Shepard,t which after
deducting 4°64 per cent gypsum gives 3Ca,(PO,),.H,O. So the
composition of collophanite is not settled. There is a possi-
bility that collophanite is an amorphous mineral with the for-
mula 3Ca,(PO,),.CaCO,.zH,O, thus bearing the same relation
to dahllite (podolite) that “opal (SiO,.cH,O) does to quartz
(Si0,).

Of the various carbono-phosphates only one, viz. dahllite
(podolite) with the formula 3Ca,(PO,),.CaCQ,, is, in my opinion,
entitled to recognition as a mineral species.

Several suggestions as to the chemical composition of phos-
phate rock, phosphate nodules, and similar materials have
recently been made. Stutzer§ regards phosphate rock as made
up principally of amorphous calcium phosphate. Lacroix|
believes them to be mixtures of collophanite with smaller amounts
of francolite and dahllite (2Ca,(PO,),.CaCO,4H,O). According
to Cameron and Bell these materials are solid solutions of
CaO and P,O,.

On account of the inaccuracy of the fluorine determination
and on account of the water, iron, aluminium, and calcium
carbonate present, analyses of phosphate rocks are difficult

* Jb. Min., p. 308, 1870.
+ Mineralogie de la France, vol. iv, 56, 1911.
¢ This Journal, xxxiii, 402, 1882.

S Die Lagerstitten der Nicht- Erze, Band I, P. aoe 1911.
| Loe. cit.

Rogers—Dahllite ( Podolite) from Tonopah, Nevada. 481

to interpret. It is usually impossible to decide whether the
substances mentioned are essential constituents or impurities.
A satisfactory explanation must account for the almost inva-
riable presence of the carbonate radical, the usual presence of
fluorine and a fairly constant ratio of 10Ca to 6PO, as well
as for variations in the amounts of the constituents.

An analysis by Mr. Postma of a dark brown egg-shaped
nodule with radiated structure collected by Mr. R. M. Wilke
in Volhynia, Russia, gave the following results:

OF ies aaa 38°81 Wei. @' 222 fa ees 1°93
[Ehsaan 46°82 OGM Borate 3°93
CONE 2s. 2 6:46 nisalise tase 3°22
een see OME Organic matter 1°87
Gi sees Sa tr.

This is a typical analysis, but it contains an excess of CaCO,
over that required for 3Ca,(PO,),,CaCO,,.
The following are analyses of the purer phosphate rocks, ete.:

Ca POZ? "CO; iH HO) Mise. 10 Total

emer ee re eee 37°72 53:04 2:00 — 3:02 2°89 1°32 99-99
[SST Sr eS ee oooh AGL 246 92°28 9215 1-20). 4 99°51
Malden Island —._-_.--- o4-Go0 49:43) 9a°238 === 5-48 ) 716 £07) 10000
- Crawford Mts., Utah.. 36°41 48°59 2°34 0°40 1:05 $°55 1°55 98°89
ousillae 2052-40. -2.- epi 00-04..0° Lo O-86 ) 7:05, “0:80 —— 99-49
Mountlagse 228k. 37°02 50°27 5°45 1:50 4°30 -— 0°08 99°12
Ambermos 2.5. 5252- Shoo omarion e900 ==) 3°61-< =F .100-00
TEN Tero ne anos ico ico 2:46. 3o:0a.-5°0L,) —— 100;30

——+-—_—~
Ibeaumiles en oS 36°98 51°82 2°26 3:40 4°%5 ee O90

A few contain an excess of CaCO, over that required for the
dahllite (podolite) molecule. The excess oxygen given in the
next to the last column is necessary to give good summations.
As phosphate rocks and nodules are not of definite chemical
composition, they perhaps do not deserve recognition as min-
erals, but as far as can be ascertained they seem to be mixtures
of fluor-apatite, voelckerite, and dahllite (podolite) as repre-
sented by the formula 3Ca,(PO,),.Ca(F,,0,CO,). Chlorine is
practically absent from these substances. The water is proba-
bly not essential, but there is a possibility of the substance
3Ca,(PO,),. CaCO, .vH,O or 8Ca,(PO,), . Ca(F,,0,CO,).#H,O,
which will account for varying amounts of water.

For convenience of the reader I have given the theoretical
percentages of the minerals discussed in the form of metals
and acid radicals.

482 Logers—Dahllite (Podolite) from Tonopah, Nevada.

Ca, PO, F Cl CO; : O H.O

Fluor-apatite -...-.---- 39°62. 56°00 3°83) == == > ===
Chior-apatite2es-7e 4 38°39 54°81 —— 680 .-—. ==) 22
Dahllite (podolite)__.__. 38°86 = 55°35 — aoe BD) ee bea
Voeltkeritte 22 22225222 40°70 ONT © A a) Se
Original dahllite -____-_- oo a4 } (0218 © ==) ==5 88 Bee Ps Ko
Prancolites4. eee aans 39°07 50°62 3°40 ee ge to) aie

I tested the solubility of some specimens of pyromorphite
and found that several gave a distinct effervescence in hot nitric
acid. Pyromorphite from the Buffalo claim on Lower Sugar
Loaf creek in Marion County, Arkansas collected by Drasiise:
Branner was analyzed* by Mr. Postma with the following

results :
Molecular ratios

-———* mae
Ue Mere es 66°73 0°322 nen
ayn sat ae 4°02 07100 §
16) A ae 23°82 0-250 6°0
CO ine Lie 1:93 0-032 ae
Clits Wi a 2°55 0-035 |
insoles ee 0°42 .

This pyromorphite, which is the polyspherite variety, occurs
as a gray or greenish-gray crust on galena and is clearly an
alteration product of the galena. It effervesces slightly in cold
nitric acid. With the exception of a slight excess of the
carbonate radical the analysis is very closely 10(Pb,Ca) : 6PO,:
1(Cl,,CO,). This analysis is considered proof that the carbonate
radical may replace chlorine in pyromorphite, as there is not
enough chlorine to form the pyromorphite molecule. On
account of the accuracy of the chlorine determination there
seems to be no doubt of this explanation. Several analyses of
pyromorphite cited in Dana’s System of Mineralogy show a
deficiency in chlorine which may be explained by the presence
of either the carbonate radical or oxygen.

In conclusion I may say that this paper makes no pretense
to a final solution of the difficult problem of the chemical
composition of apatite, phosphate rock, etc. Many accurate
analyses will be necessary for that task.

Stanford University, California,
February, 1912.

* A closely agreeing analysis is given in Vol. V (p. 87) of Arkansas Geo-
logical Survey Reports,

Wellisch and Bronson—Actwe Deposit of Radium. 483

Arr. XLII—TZhe Distribution of the Active Deposit of
Radium m an LHlectric Field; by E. M. Wetutscu and
H. L. Bronson.

1. Introductory.

THE present paper contains the results of a series of experi-
ments which were carried out at the Sloane Physical Labor-
atory of Yale College, and which were undertaken with a view
of throwing light on the mechanism involved in the transmis-
sion of the active deposit of radium to the electrodes in an
electric field or to the exposed solid surfaces in the absence of
such field. In order to account for this transport of activity
one of us* had already suggested a theory in which the view
was taken that the transmission was effected as a result of the
interaction between the active deposit particles (or restatoms)
and the ions formed in the gas by the radiation accompanying
the radio-active disintegration ; in particular, an attempt was
made to explain on this theory the experimental result
obtained by Rutherfordt and Franck{ that the restatoms
moved through the gas with the same velocity as the positive
ions.

The original object proposed in the present experiment was
to ascertain whether the distribution of activity on the elec-
trodes could be affected in any way by the application of an
extraneous source of ionization such, for instance, as that pro-
duced by causing intense Rontgen rays to pass through the

as.

: We might be permitted to anticipate here the results of the
present experimental investigation and to state that, although
the application of such extraneous source of ionization has so
far been found to produce little or no effect on the distribution
of activity, nevertheless a decided interaction has been found
to take place between the restatoms and the ions produced by
the radiations which accompany the formation of these
particles.

The results of previous experimenters with regard to the
distribution of the active deposit under various conditions have
shown a lack of agreement which in our present experiments
has been traced to the fact that the potentials employed were
often far from sufficient to saturate even approximately the
radio-active ions.

* Wellisch, Verh. Deutsch. Phys. Ges., xiii, p. 159, 1911.

+ Rutherford, Phil. Mag. (6), v, p. 95, 1908.
¢ Franck, Verh. Deutsch. Phys. Ges., xi, p. 897, 1909.

484 Wellisch and Bronson—Distribution of the Active

2. Experimental Procedure.

The radium emanation used in our experiments was obtained
from two sources, for the use of both of which we are indebted
to the kindness of Prof. Boltwood. One source consisted
of a solution of radium salt contained in a glass vessel so con-
structed as to permit vigorous bubbling when a current of gas
was passed through it; the other source was a quantity of
carnotite contained in a glass jar, which was adjusted to per-
mit of rapid connexion to the testing vessel.

The emanation was in most cases passed through glass-wool
and phosphorus pentoxide before entering the test vessel; no
effect on the distribution was observed, however, by omitting
these precautions.

Different forms of test vessels were employed; the vessel
which was used practically throughout and to which all our
experiments apply, unless mention is made to the contrary,
consisted of a brass cylinder with an aluminium bottom and a
brass central electrode sprung into a stout brass holder so as to
permit of rapid detachment. The vessel was provided with a
guard tube which was connected to earth; this guard tube was
slightly tapered so as to make a good fit with the ebonite plug
which supported the central electrode. Stop-cock grease was
employed to ensure complete tightness. |

The dimensions of this vessel were as follows :

Height of containing portion..--_-.---- 140 mm
Inneridiameter >. 222 seus eee ee 5Se Mates
Exposed length of central electrode..--. 101 “
Diameter of central electrode__...._.-_- Mess

The measurements of the activity of the central electrode were
made in a vessel identical to the above except that, as men-
tioned below, no ebonite and in consequence no guard tube
was employed.

The diagram of connexions and the disposition of apparatus
are given in fig.1. The test-vessel A was supported by brass
clips mounted on ebonite; these clips were connected to the
battery through carbon resistances R, R’, the changes of poten-
tial being effected by means of the adjustable contacts s, s’,
and the key L. JB represents a parallel plate vessel which was
employed in order to communicate definite induced charges to
the electrometer system whenever occasion arose. C is a
capacity consisting of two thin sheets of tinfoil separated by a
thin sheet of mica; this capacity, together with that of B,
could be added to the system by means of the key K, and the
total capacity of the system was then increased 214 times.
The electrometer was of the Dolezalek pattern with a platinum

Deposit of Radium in an Electric Field. ' 485

suspension. The needle was charged to a potential of 120
volts, and with this potential the sensitiveness was 180™™ per
volt on a scale about 1 meter distant.

The Roéntgen-ray bulb, which was enclosed in a lead-covered
box and which was employed whenever it was desired to
increase the ionization current in the test-vessel, is not shown

Hie. ol.
E

DX eee

D
= &

U

S)

Nh---== [-----IIh

E

in the diagram; the rays were admitted through an aperture
in the lead directly beneath the aluminium bottom of the
vessel. |

For potentials up to 1200 volts a battery of small accumula-
tors was employed. For the larger potentials a Wimshurst
machine was used which was driven by an electric motor ; it
was found that the voltage obtained by this means was surpris-
ingly steady, although the slight variations were sufficient to
prevent any accurate measurements of the ionization current
through the gas. The voltage was regulated by means of an

Am. Jour. Sct.—FourtH SERIES, Vou. XXXIITI, No. 197.—May, 1912.
32

‘

486 Wellisch and Bronson—Lstribution of the Active

adjustable spark-gap, and was measured with a Braun electro-
meter.

The method of procedure was in general as follows: after
the introduction of the emanation the vessel was allowed to
remain in position under the desired conditions of potential,
pressure, etc., for a period sufficiently long to enable the
emanation and the resulting activity to get into equilibrium.
This period was usually about three hours, and was never less
than 14 hours; readings of the ionization current were taken
at intervals so as to note the growth of activity and the estab-
lishment of equilibrium. The emanation was blown out by
means of a strong current of air from a force-pump ; the ebon-
ite plug containing the central electrode was removed, care
being taken that this electrode did not touch the ease.

The activity on the case was measured by observing the
ionization current to which it gave rise; for this purpose a
fresh electrode was suspended in the vessel by means of the
brass holder shown in the diagram; by thus avoiding the use
of ebonite the activity could be measured with great precision.
This procedure was rendered necessary because, as is subse-
quently shown, an accurate determination of the activity on
the case was the most unportant factor in the experiments.
Tt was found that handling ebonite insulation, even with great
precaution, resulted in the production of disturbing electrical
effects which were sufficient to render uncertain the subsequent
measurements. The activity at any time after the removal of
the emanation was then measured by observing the electro-
meter rate.

In order to determine the activ ity on the central electrode
this electrode was removed from its holder by means of a pin,
which passed through a small hole, and was then suspended
in the second vessel in the same manner as described above ;
the electrometer rate could then be taken at any definite time
dating from the removal of the emanation.

In practice it was found convenient to measure the case
activity at 10, 15, and 20 minutes, and the central electrode
activity at 25, °30, and 35 minutes after the emanation had been
removed ; the maximum activity, 7. ¢. the activity when in
equilibrium with the emanation, was then calculated by means
of the figures given by one of us* for the rate of decay of the
activity resulting from a long exposure. The consistency of
this caleulated maximum determined the number of readings
necessary for the measurement of the activity, but usually those
just mentioned amply sufficed.

* Bronson, Phil. Mag. (6), xii, p.73, 1906. In order to calculate the max-
imum activity from the rates determined at the times given above, the

observed rates have to be multiplied by the factors 2-02, 2:25, 2°41, 2°58,
2°75, and 2°96 respectively.

Deposit of Radium in an Electric Freld. 487

In practically all our experiments the activities were meas-
ured by observing the ionization currents to which they gave
rise in air under the ordinary conditions when a_ potential
of +160 volts was applied to the vessel employed. Although
this potential was not sufficient to saturate the currents, sub-
sequent experiments showed that the ratio of the two activities
as thus measured was not altered by using a larger voltage.

A. typical set of readings is given later. 3

3. Haperiments with Small Applied Potentials.

It is well known that for moderately high potentials the
activity is concentrated to a very large extent on the negative
electrode in an electric field ; Schmidt* has shown that when
small potentials are employed the cathode activity decreases
in a manner analogous to the diminution in electric current
which follows as a result of recombination of ions; in fact, he
came to the conclusion that the active deposit particles behave
in a manner similar to the positive ions. ‘The first set of
experiments tried in the present series had as object to find
whether the amount of activity that was deposited on the
cathode when a small positive potential was applied to the
ease could be altered when the ionization in the gas was so
increased by means of Rontgen rays that the electric current
through the gas was at least as great as if a large potential had
been applied without any extraneous source of ionization.

In this set of experiments the rods were exposed as
cathodes to the process of activation for a period of 10 min-
utes, both with and without the application of Rontgen rays,
the testing vessel containing air at 1 atmosphere; the activ-
ities were measured at various intervals atter removal, and
were then directly compared. Preliminary trials which were
made showed that in the process of removing one rod and sub-
stituting another less than 2 per cent of the emanation escaped.

A result of one set of measurements is given below: |

With +4 volts on case and 10 minutes exposure, activity of
cathode 10 minutes after removal is represented by an electro-
meter rate of 1:1™™ per sec.

With same applied potential and strong Réntgen rays pass-
ing through the vessel during the whole time of exposure, the
corresponding rate was ‘88.

As arough idea of the relative currents involved the follow-
ing figures are given; in these instances the rates were deter-
mined with the extra capacity added to the system.

Ionization current immediately after introduction of ema-
nation and with +160 volts on case: 33™™ per see. :

with 4 volts rate was 1:05;
with 4 volts and Rontgen rays rate was 5:21.

* Schmidt, Phys. Zeitschr., ix, p. 184, 1908.

‘

488 Wellisch and Bronson—Distribution of the Active

In the last two instances there was, of course, a deposit
of activity on the walls of the vessel.

Other experiments were made with the same object, in some
instances large amounts of activity being previously concen-
trated on the walls of the vessel so as to increase still further
the ionization. The results were of the same nature, viz., to
show a small decrease in the amount of activity deposited on
the cathode when additional ionization was produced; the
decrease could be accounted for if we adopt the view that the
restatoms behave as positive ions, and are subject to increased
recombination with the negative ions produced by the appli-
cation of the extraneous radiation.

4, Experiments with Larger Potentials. Air at 1 atmosphere.

Experiments were next made to ascertain the percentage of
the total activity that was deposited on the cathode when larger
positive potentials were applied to the case. The result of this
set of measurements is given below (Table I), and is exhibited
as a curve in fig. 2, which refers to air at 1 atmosphere; the

? po ee prMosPHERE poe | |

0 750 1500 2250 3000 3750 4500
Potential in volts

po
>
c=)

2)
So

“|

Percentage cathode activity

method of procedure for determining the points has already
been given in section 2.

It will be seen from an inspection of this curve that the per-
centage cathode activity always increased with the applied
potential, a result which indicates that there are practically no
negative carriers of activity ; all the so-called anode activity to
which reference is made by many investigators is due to the
diffusion to the walls of the vessel of uncharged restatoms. A
slight correction has on this account to be made for the amount of
unchar ged activity that diffuses to the cathode during the expo-
sure ; this correction was made by estimating the relative areas
of the exposed surfaces of cathode and case, which were found to

ee

Deposit of Radium in an Electric Field. 489

‘PABER).L:

Kmanation in Air at 1 Atmosphere.

Potential in Percentage cathode

volts activity
18 42°7
160 fou
900 85°9
975 : 86°6
2250 86°9
2800 88°5
3250 89°0
4000 91°3

be in the ratio 1:50, and assuming that the uncharged restatoms
were distributed in this proportion. The true percentage
cathode activity, that is, the number of positive carriers
expressed as a percentage of the total number of carriers, is
obtained from the percentage cathode activity (p), as deter-

amet

mined experimentally, by evaluating the expression

All values given in this paper for the percentage cathode activ-
ity denote the true percentage obtained by correcting in this
manner.

A typical set of measurements is given below:

Emanation passed through P,O, and glass-wool into
vessel containing air at 1 atmosphere. +975 volts
on case. Exposure about 2 hours.

Equilibrium rate with added capacity: 6°17.

Activity on case, measured at 10 and 15 minutes after
removal of emanation ; rates with added capacity : -19
and ‘17 respectively.

Activity on cathode measured at 20 and 25 minutes
after removal of emanation ; rates with added capac-
ity : 1:05 and ‘98 respectively.

Calculated maximum activity on case: °38.

Ditto cathode: 2°53.

Ratio of max. cathode to max. case activity: 6°66: 1.

Percentage cathode activity: 86-9.

True percentage cathode activity as corrected for dif-
fusion of uncharged carriers to cathode: 86°6.

It is difficult to estimate with precision the experimental
error in the determination of the percentage cathode activity.
A slight error probably arises from the fact that the cathode

‘

490 Wellisch and Bronson—Distribution of the Active

and case activities are determined by means of ionization
which is differently distributed. This has been shown experi-
mentally to have a negligible effect on the relative values of
the percentage cathode activities for different potentials, the
determination of which was really the object of the experi-
ment. As mentioned above, it was important to make an accu-
rate determination of the maximum activity on the case. An
error in the determination of this activity leads to approxi-
mately the same percentage error in the determination of the
percentage cathode activity; this error in all our experiments
is probably less than 2 per cent.

The plotting of a curve such as that of fig. 2 is obviously
only possible if the percentage cathode activity is independent
of the amount of emanation used in the experiment. This fact
was demonstrated repeatedly during the course of our inves-
tigations ; ; as an instance of the wide range over which this
holds it may be mentioned that the percentage cathode activity
was the same with 900 volts on the case when the amounts of
emanation in the vessel were such as to afford equilibrium rates
of 5°32 without any added capacity and 16:1 with the added
capacity, 7. e. rates which are roughly in the ratio 1:65. When
we are working in the earlier part of the curve, 7. e. with
relatively small potentials, this Independence no longer holds
good; but for the higher potentials the effect of the amount
of emanation within a lar ve range becomes negligible.

The curve bears a striking resemblance to the curves which
have been experimentally determined for ionization by a-par-
ticles. Many observers have drawn attention to the “lack of
saturation” which is a marked feature of such curves; in par-
ticular, this phenomenon has been the subject of special i inves-
tivation by Bragg,* Kleeman,t Moulin,t and Wheelock.§
Reference is made to this point later (section 7). The similar-
ity was so striking as to suggest a more detailed study of the
ionization curves for emanation in equilibrium and with differ-
ent applied potentials.

It was found that within the limits of error the ratio of the
two ionization currents obtained for two potentials not too
low] was, like the percentage cathode activity, independent of
the amount of emanation in the vessel; and, moreover, that

* Bragg, Phil. Mag. (6), xi, p. 466, 1906.

+ Kleeman, Phil. Mag. (6), xii, p. 278, 1906.

t+ Moulin, Compt. Rend., exlviii, p. 1757, 1909; Le Radium, vii, p. 350,
Bate this Journal, xxx, p. 238, 1910.

| The potentials should be sufficiently large to prevent volume recom-
bination, as distinguished from columnar recombination, 7%. e. should be
sufficient to saturate a uniform distribution of Réntgen-ray ions equal in
number to those produced by the a-radiation.

Deposit of Radium in an Electric Field. 491

this ratio was identical with the ratio of the percentage cathode
activities corresponding to these two potentials.

As an example of the results obtained in this connection it
will suffice to compare the ratio 1:09 of the percentage cathode
activities obtained with potentials 975 and 160 volts respec-
tively with the corresponding ionization currents. From our
values for the ionization currents in air at 1 atmosphere
pressure obtained in three experiments when widely different
quantities of emanation were employed, we deduce the follow-
ing figures :

Ratio of current with V volts to that with 160 volts :
=—E NO wien!) Vi ==8)7 5
=1°10 when V=980,
=1:07 when V=900.

It would serve no useful purpose to reproduce in full any of
the ionization curves because, in the, first instance, the early
slope of the curve depends markedly on the amount of emana-
tion employed, and, secondly, because the comparison could
only be made over the limited range from about 100 to 1000
volts, as the ionization current could not be accurately
measured when the larger potentials were employed.

That the equality of the ionization and activity ratios still
holds approximately at low voltages when a constant amount
of emanation was employed was verified by measuring the per-
centage cathode activity with 18 volts applied, and the ioniza-
tion currents for 18 volts and higher potentials, it being known
that the percentage cathode activity at the higher potentials
was independent of the amount of emanation in the vessel.
The following results were obtained :

Percentage cathode activity with 18 volts: 42°7

Ditto 160 volts: 79°1

Ratio : °54
Tonization current with._..___-_- LS: volts.) 6:6
Ditto 160 volts: 11-4

Ratio; 58

The agreement is only rough, and further experiments will
be necessary at these small potentials.

The percentage cathode activity increases so slowly with the
higher potentials applied that it appeared as if some definite
fraction of the activity was always bound to be deposited on
the case. Subsequent experiments made with large potentials
obtained by using the Wimshurst machine showed, however,
that the percentage cathode activity continually increased with
the potential. It isnot out of place to mention briefly here
two sets of experiments which were conducted prior to the ase
of the Wimshurst machine.

\

492 Wellisch and Bronson—Distribution of the Active

It was suggested that, if a large uniform electric field were
applied, possibly the number of uncharged carriers might
become insignificant. For this purpose the emanation was
introduced into a vessel consisting of*two parallel electrodes of
aluminium (each 58™™ in diameter) insulated by an ebonite
ring 20" thick; the vessel contained air at a pressure of 1
atmosphere. Experiments made with applied potentials of
160 and 1000 volts gave values of 75 and 82°6 respectively for
the percentage of positively charged carriers.

The second set of experiments had as object to determine
whether RaA was deposited on the case. To test this point
the cylindrical vessels were employed as usual and large
potentials applied, but exposures of only 1 minute duration
were made. It was found that the resulting curve of decay of
the case activity had the characteristic properties of the curves
of decay for the activity uae to a short exposure to the radium
emanation.

Mention might also Be briefly made here of some experi-

ments which were performed to ascertain whether there was

any alteration in value of the percentage cathode activity
resulting from a long exposure with large positive potentials
applied to the case when thr oughout the exposure the ioniza-
tion current was greatly iner eased by the passage of Rontgen
rays through the vessel. The alteration, if any, was very
small, and for the present, at any rate, we must assume that
the action of the Roéntgen rays is without effect on the dis-
tribution of the activity.

5. Heperiments with Air.at Reduced Pressure.

The experimental results described in the preceding section
strongly suggest that over a wide range of potentials the per-
centage of the total activity which is deposited on the case
represents the percentage lack of saturation of the positive
ionization current. These experiments related to the activity
distribution in air at a pressure of 1 atmosphere. Now
Moulin and Wheelock have shown (doc. czt.) that the ioniza-
tion produced by a-particles is more readily saturated when
the pressure of the gas is reduced; it was, therefore, of interest
to determine whether the percentage cathode activity would
follow the positive ionization current when the gas pressure
was reduced. For this purpose the emanation was introduced
into the testing vessel, which contained air at a pressure of
260™™, and the percentage cathode activity was determined for
various applied positive potentials. The results are given
below (Table IT), and are exhibited as a curve in fig. 2.

Deposit of Radium in an Hlectric Field. 493

TABLE II.
Emanation in air at pressure of 260™™.

Potential in | Percentage cathode

volts. activity
80 82°5
150 82°5
Cas) 81°8
790 82°2
1130 81°8
2250 83°8
2250 84°2

It is noticeable that although the percentage cathode activity
for 150 volts is greater than the corresponding value for a
pressure of 1 atmosphere, nevertheless when the higher
potentials are reached the values are smaller at the lower
pressure.

When the ionization due to the emanation in equilibrium
with its activity and in air at a pressure of 260" was measured
for various applied positive potentials, it was observed that
the alteration of ionization with potential was so extremely
slow as to suggest saturation. Over the range for which the
ionization could be measured this alteration was too small to
justify comparison with the figures given for the percentage
cathode activity; the striking feature is that both curves
approach more nearly to the horizontal than the corr esponding
curves for a pressure of 1 atmosphere. The figures for the
lower pressure show that for large potentials the activity is
farther from saturation than at 1 atmosphere; it is therefore
only reasonable to conclude that in the case of ionization the
percentage lack of saturation is greater at the lower than at
the higher pressure.

The figures given in Table II, although sufficiently con-
sistent to justify the conclusion just given, nevertheless exhibit
slight irregularities which are being made the subject of
further investigation. In the first instance the values for the
percentage cathode activity for potentials in the neighborhood
of 1000 volts show a slight falling off as compared with those
corresponding to the smaller potentials. The explanation of
this effect appears to le in a distortion of the field in the
neighborhood of the ebonite piug, arising from some action of
the a-radiation on the ebonite; this distortion would result in
some of the cathode activity being deposited on the plug
instead of on the central electrode. Corresponding difficulties
arose for the ionization measurements at the reduced pressures.

494. Wellisch and Bronson—Distribution of the Active

The increase of the percentage cathode activity in the neigh-
borhood of 2000 volts is probably real, although the number
of experiments in this connection is not yet sufficient to justify
any definite statement. It is, however, of interest to record
that throughout the exposure with these high potentials a
large current due to ionization by collision was passing through
the gas.

EF Falls it might here be mentioned that a complete set of
observations for the distribution of the activity with various
applied potentials, both for air at 1 atmosphere and for air at
a pressure of 250"™, had previously been made, using the same
test-vessel, but with the guard-tube projecting a short distance
into the volume of the gas. By reason of this some of the
activity which belonged properly to the cathode was measured
as “case activity,” so that the resulting values for the percent-
age cathode activity were too small. The curves obtained both
for activity and ionization exhibited the same general features
as those previously described. Some of the results obtained
are given below; these figures are not comparable with those
given above, which were all obtained after the guard-tube had
been cut down.

Emanation in Air at 1 atmosphere.

Potential in Percentage cathode
volts activity
160 76°2
880 84°1
2750 86°2

Emanation in Air at 250™™ pressure.

Potential in Percentage cathode
volts activity
160 81°2
920 81°9
2500 82°1

6. Experiments with Air at Pressures greater than
1 atmosphere.

Several experiments were performed to ascertain the distri-

bution of activity when the air in the testing vessel was at a
vif rt ry °

pressure greater than 1 atmosphere. The results are given in

Deposit of Radium in an Llectrie Field. 495

Table III: they were obtained in the early stages of the
research when little information was at hand concerning the
distribution of the activity for various potentials. For this -
reason the experiments appear very unsystematic; however,
the results will serve to convey a good idea of the difficulty of
obtaining approximate saturation of the activity, even with
large applied potentials.

TABLE IIT.
Pressure, Potential in Percentage cathode
atm. volts activity
1°6 +700 68°8
2°0 650 64:1
2°5 160 55°2
2°5 150 60°1
3°13 880 575
3°33 3750 80°6
3°O3 750 53°8

The difficulty of saturating the ionization current through
the gas likewise made itself manifest at these pressures; as an
example it may be mentioned that with an applied potential
of 1100 volts the ionization current due to a constant source
of radiation increased as the pressure was increased from 1 to
24 atmospheres, and then continually decreased with any
further increase in the pressure.

These considerations afford an explanation for the maximum
of cathode activity which has been found by several experi-
menters to set in at certain pressures when a constant potential
is employed.

No indication of any decided effect upon the distribution of
the activity was obtained by subjecting the gas throughout the
exposure to the influence of a strong source of Rontgen rays.
In this experiment the vessel contained emanation in air at a
pressure of 3% atmospheres; the applied positive potential was
1100 volts; the equilibrium rate with added capacity was 5™™
per sec., and with the Rontgen rays acting was 25™™ per sec.
The percentage cathode activity was 56:2, which is of the order
that might have been expected from the previous results.

7. Discussion of Hxperimental Results.

In the interpretation of the experimental results which have
been obtained in connection with the distribution of activity
the question arises immediately: what is the reason for the

496 Wellisch and Bronson—Distribution of the Active

difficulty in saturating the cathode activity? Even under the
most favorable conditions which have been employed in our
work there is still about 10 per cent of the activity deposited
on the walls of the testing vessel. In an attempt to answer
this question we are at once led to the ccrresponding problem
in connection with the ionization current which passes through
the gas during the activation of the electrodes. Mention has
already been made of the researches of Bragg, Kleeman, Mon-
lin, and Wheelock in connection with this aspect of the prob-
lem. Bragg explained the difficulty of saturating the loniza-
tion due to a-particles by introducing the conception of initial
recombination; viz., that the electron which is expelled in the
process of ionization returns in a number of cases to its parent
atom, and exceptionally strong electric fields are needed to
exercise any appreciable preventive effect upon this tendency
to recombine. Kleeman extended the experimental work,
using Brage’s theory as a basis. Moulin ascribed the difficulty
of obtaining saturation to the fact that the a-particles ionized
in columns, so that the density of ionization is not uniform
throughout the gas when sufficiently small volumes of gas are
considered. This localization of the ions would naturally
result in a recombination more intense than that which would
correspond to a uniform distribution in the usual acceptation
of the term. Moulin showed that saturation appeared to be
most difficult when the columns were parallel to the lines of
foree of the electric field; when, however, the a-particles
moved across the lines the ionization tended more readily to
saturation. Wheelock continued the work, adopting the idea
of columnar ionization; in particular, he showed that when
the pressure was reduced to about one-third of an atmosphere
saturation set in fairly readily. There can be little doubt as
to the reality of this columnar effect and the intense recom-
bination resulting from the local distribution of the ions ; this
is clearly brought out by the slowness with which the ioniza-
tion current increases with the potential in the early stage of
any curve for a-particle ionization. The experimental results
obtained in the present research appear to lead to a radically
different explanation of the shape of the ionization curves at
the higher potentials. It has been shown that for potentials
which are not too low the ratio of the percentage cathode
activities for two different potentials is equal to the ratio of the
corresponding ionization currents due to the a-particles, and
over a wide range is independent of the amount of emanation
employed, that is, of the intensity of the intrinsic ionization.
This experimental result has already led to the suggestion that
the fraction of the total activity which is deposited on the walls
of the testing vessel is a measure of the lack of saturation of

Deposit of Radium in an Electric Field. 497

the ionization current, so that in general the percentage case
activity is equal to the percentage lack of saturation of the
current. The values given in section 5 for the percentage
cathode activities at a pressure of 260™" are smaller for the
higher potentials than the corresponding values for atmospheric
pressure; we are consequently constramed to regard the per-
centage lack of saturation as being greater for the ionization
currents at the lower pressure than at the higher pressure.
The horizontality of the curves would thus appear to furnish
no evidence as to the degree of saturation. The curves both
for activity and ionization current do not appear to have hori-
zontal asymptotes such as belong to the ordinary saturation
curves for Réntgen-ray ionization. We must rather look upon
the curves as having a continued upward slope, even when we
are considering the ionization curves corresponding to low
pressures. This upward slope suggests that extra ionization
is produced by the electric field after the a-particle has ceased
to ionize.

On this view there must be present in the gas certain mole-
cules, or neutrons, which are in a condition allowing of rela-
tively easy ionization. It is highly probable that the molecules
have already been put in this unstable condition by the action
of the a-particle; we may look upon this condition as the result
of ineffectual attempts by the a-particle at ionization, possibly
as the result of actual ionization immediately succeeded by
initial recombination. However, these molecules are left by
the a-particle in an electrically neutral although unstable con-
dition, and a certain number of them are afterwards resolved
into ions, probably as a result of collision with the ions already
established in the columns.

These neutrons are in all probability formed most numer-
ously during the early part of the range of the a-particle, when
it is moving with its largest velocity. The approximately hori-
zontal parts of the ionization curves such as are obtained at
low pressures, or when the a-particle moves perpendicularly to
the lines of electric force, would therefore only represent satu-
ration in the sense that all the free ions have been brought over
to the electrodes because in these cases it is unlikely that an
appreciable number of neutrons would be resolved into ions.

As far as the active deposit particles are concerned we may
regard them as neutral restatoms which have been exposed to
the action of the a-particle at the moment of disintegration of
the emanation atom ; we would thus expect them to be for the
most part radio-active neutrons which have in general to be sub-
jected to further influence before acquiring a positive charge.

Experiments which are now in progress suggest also that the
shape of the Bragg-Kleeman ionization curve can be accounted

498 Wellisch and Bronson—Active Deposit of Radium.

for by the formation of neutrons and ions in different propor-
tions along the entire range of the a-particle.

8. Summary.

(1) The distribution in an electric field of the activity result-
ing from a long exposure to the emanation of radium has been
determined for various conditions of pressure, potential, ete.

(2) There appear to be no negatively charged carriers,
all the so-called anode activity being due to the diffusion of
uncharged carriers.

(3) The effect on the distribution spunea by causing Ront-
gen rays to pass through the gas during the exposure has been
investigated ; this effect was appreciable only when the activity
and ionization were far from saturation.

(4) The difficulty of obtaining saturation both for the cath-
ode activity and for the a-ray ionization currents has been
explained as being due to the formation by the a-particle of
neutrons, some of which are subsequently resolved into ions,
probably by collision with ions already established in the
columns.

Chemistry and Physics. 499

SCIENTIFIC INTELLIGENCE.

I. CHEMISTRY AND PHYSICS.

1. The Melting-point of Spodumene.-—EnvELL and Riexe have
made some new observations upon this subject and have drawn
interesting geological conclusions from their results. They used
spodumene from Branchville, which appears to be much purer
than the material from Stirling which has been used by Doelter
for melting-point determinations. The authors find that the min-
eral, when heated for an hour or more to about 950° C., changes
its specific gravity from 3°147 to about 2°37, a gain in volume of
24 per cent. At the same time, between 920° and 980° C., the
monoclinic substance loses its double refraction and acquires a
lower average index of refraction ; and the heating-curve shows
a change at nearly the same temperature. It was found that the
material must be finely powdered to show these changes accu-
rately. The authors consider 950° C. as the true “ melting-point ”
of spodumene, although it is perfectly hard and solid at this tem-
perature and it does not actually fuse until a temperature of about
1380° C. is reached. ‘They do not admit the existence of a solid,
isotropic modification of the mineral, because there is no differ-
ence between the specific: gravity and index of refraction of the
unfused solid and the glass.

Since spodumene occurs at Branchville, Conn., in a pegmatite
vein, the authors suggest that it may serve as a measure of geo-
logical temperature, as they believe that it could not be formed
above about 950° C. ‘They consider the effect of pressure as prac-
tically of little importance, since from Clapeyron’s formula they
calculate the effect as only 7° C. per kilometer in depth.—Zeitschr.
anorgan. Chem., xxiv, 33. H, L. W.

2. The Detection of Nitric Acid in the Presence of Nitrous
Acid.— SEN and Dry have found that hydrazine reacts with
nitrous acid according to the following equations :

N.H, + 2HNO,= N, + N,O + 3H,O
N,H, + HNO, = NH, + N,O + H,O

They have, therefore, used hydrazine sulphate for the purpose of
removing nitrites, in order that nitrates, upon which the reagent
has no action, may be detected. The method appears to be much
more accurate than that of Piccini, which depends upon the remo-
val of nitrous acid by means of urea in the presence of dilute sul-
phuric acid, because this reaction is not rapid enough to prevent
the formation of traces of nitric acid from the spontaneous decom-
position of the free nitrous acid. The hydrazine method has the
advantage that the nitrous acid does not need to be set free by
another acid, since the sulphuric acid combined with the hydra-
sine furnishes sufficient acid for the decomposition of the nitrite,
and moreover the reaction goes so rapidly that no nitric acid can

500 Scientific Intelligence.

be formed. Experiments with pure sodium nitrite showed that
there was no odor of nitrous gases in the nitrogen escaping from
the reaction with hydrazine sulphate, and that the solution after
the reaction was complete gave no test for nitric acid with diphe-
nylamine in concentrated sulphuric acid. — Zeitschr. unorgan.
Chem., |xxiv, 52. H, de, We

3. The Chemical Constitution of Ilmenite. — W. Mancuor has
made analyses of a massive titanic iton ore from Ekersund in
Norway and a crystal of ilmenite from the Urals. The results in
the two analyses are very dissimilar, and the ilmenite analysis is
incomplete, but the latter is of some interest because the ferric
oxide was determined by dissolving the substance, out of contact
with air, in hydrochloric acid and using iodimetry. ‘This deter-
mination indicates that the ratio of TiO, to FeO approaches 1: 1.
This is used as an argument in favor of the ilmenite formula
Ti0O,. FeO, and in opposition to the view that it is a mixture of
Ti,0, and Fe,O,. It appears that the same formula was indi-
cated much more satisfactorily by the work of Penfield and Foote
(this Journal, iv, 108, 1897). ‘The author has attempted to show
by direct experiment that Ti1,O, is not contained in the mineral
by demonstrating that the powdered samples when boiled either
with alkalies or acids evolve no hydrogen gas. Although the
author considers these experiments to be conclusive, it does not
appear that this is the case, for if a titanous salt and a ferric salt
were formed at the same time it is perfectly well known that, at
least in acid solution, the ferric salt would be reduced, and if the
ferric salt were in excess no hydrogen could possibly be given off.
In the case of alkalies, if any reaction at all occurred, it might
happen that nascent hydrogen would reduce ferric oxide instead
of forming a gas.—Zeitschr. anorgan. Chem., |xxiv, 79.

H. L.- W.

4. Determination of Alkalies in Silicates.—For this determi-
nation E. MAx1nen has used fusion with about 10 parts of cal-
cium chloride in the place of J. Lawrence Smith’s method. The
platinum crucible in which the fusion is made is placed in a hole
in a piece of asbestos board in such a way that only the lower half
of the crucible comes in contact with the flame. This part of the
crucible is gradually brought to a full red heat by means of a
Teclu burner, and so maintained for 25 or 30 minutes. The
treatment is then similar to that usually employed in Smith’s
method. Specially prepared calcium chloride was required, as
the commercial product was found to contain alkalies. The
results with several feldspars and rocks were good, but it appears
to the reviewer that, on account of the very large amount of cal-
cium chloride going into solution, which necessitates a double
precipitation of calcium carbonate, the process will not replace
the usual one.—Zeitschr. anorgan. Chem., \xxiv, 74. H. L. W.

5. A Dictionary of Applied Chemistry ; by Str EKpwarp
Tuorpk, C.B., LL.D., F.R.S., assisted by Eminent Contributors.
Revised and Enlarged Edition in Five Volumes. Volume I (A-

Chemistry and Physics. 501

CHE). 8vo, pp. 758 ; London, 1912 (Longmans, Green and Co.).
—Twenty-two years have elapsed since the first edition of this
well-known book of reference made its appearance as a companion
to Watts’ Dictionary. During this period chemistry has advanced
to such an extent in its applications to the arts and manufactures
that a complete revision and a great enlargement of scope in
the present edition have been necessary. It will consist of five
volumes in the place of the original three volumes.

An inspection of the new volume shows evidence of thorough
work on the part of the contributors, who have been selected not
only from the United Kingdom but also from America, Germany,
Switzerland, etc. The work appears to have been thoroughly
revised and modernized, particularly as far as the topics in which
great advances have been made in the last two decades are con-
cerned. No detailed review of a book of such magnitude and
complexity can be attempted here, but a few of the prominent and
interesting articles in the present volume may be mentioned, such
as ‘“‘ Acetylene as an Illuminant,” ‘ Analysis,” “ Aluminium,”
“ Brewing,” ‘ Carbohydrates,” and ‘ Cellulose.” H. L. W.

6. On the Properties of the Rays Producing Aurora Borealis.
—It has been generally assumed that aurore are caused by elec-
tromagnetic disturbances in the earth’s atmosphere due to radia-
tions from the sun, but the precise nature of these radiations has
not been established heretofore. An appreciable advance towards
the solution of the problem has been made by L. VEGarp, who
starts with the hypothesis that the incident radiations are small
. electrified particles or rays. ‘The straight-lined streamers of the
aurore would require a radiation which is but little scattered and
this condition is fulfilled by a-rays and not by B-rays. The
abruptness with which the luminosity stops at the lower edges of
the streamers corresponds to the well-defined range of a-particles
ina gas. The ionization, due to a homogeneous pencil of a-rays,
is known to increase as the speed decreases, attaining a maximum
value near the point where the rays are stopped. This fact has
its counterpart in the increase in luminosity observed near the
lowest parts of auroral bands and streamers. By comparing the
altitudes at which the a-rays from various radio-active substances
would be stopped by the earth’s atmosphere with the observed
heights of aurore, Vegard shows that the agreement is as good
as can be expected from the data at hand. The parallel, drapery
bands can be accounted for by the assumption of groups of homo-
geneous rays from the same source. A mathematical investiga-
tion of the paths which would be followed by charged particles
entering the earth’s atmosphere from the sun, leads to the conclu-
sion that a positive charge is most consistent with the observed
positions of aurore. ‘Thus it is seen, that the majority of auroral
forms may be explained on the assumption that they are due to
a-rays emitted by radio-active substances of the sun.— Phil. Magq.,
XXlil, p. 211, February, 1912. H.ASa Ue

7. The Pressure of a Blow.—In a discourse delivered at the
Royal Institution on January 26, Prof. Bertram Hopxinson

Am. Jour. Sci1.—FourtH Smries, Vou. XX XIII, No. 197.—May, 1912.
30

502 Scientific Intelligence.

gave some very striking figures and described some highly inter-
esting phenomena associated with blows produced in various
ways. An account of only a few typical cases may be here pre-
sented.

Suppose that each of two equal billiard balls has a speed of
eight feet per second and that they are moving towards each
other along their line of centers. At the very instant of touch-
ing there is, of course, no pressure between the balls, but as the
centers continue to approach, each sphere becomes flattened at
the region of contact. This region is circular and it rapidly
increases in area until the balls as wholes are brought to rest, that
is, until the work done against the elastic forces of restitution is
equal to the original kinetic energy of the system. For the case
in question the distance of approach is 14/1000 of an inch and
the force equals 1,300 lbs. The circle of contact has a diameter
of one-sixth of an inch, so that the average pressure amounts to
27 tons per square inch. The distribution of pressure, however,
is not uniform, the pressure at the center of the areas of contact
being 11/2 times as great as the average pressure. The subse-
quent behavior of the spheres is of no interest in this connec-
tion. If very hard, hollow steel balls, having the same mass as
the ivory spheres, are caused to collide with a relative speed of
16 feet per second, the distance of approach will be less, the area
of contact smaller, and the maximum pressure much greater than
for the billiard balls. This pressure when averaged over the
circle of contact attains a value of 280 tons per square inch.
These results of theoretical computation for steel balls have been
verified by comparing the calculated time of contact with the
interval obtained experimentally by the aid of appropriate elec-
trical apparatus» ‘The time of contact for the ivory spheres, men-
tioned above, was 1/4000 of a second.

A case involving an inelastic substance is afforded by the
impact of an elongated lead rifle bullet against a hard steel plate.
Under the enormous pressures developed lead flows very freely,
so that, in the absence of any lateral support, each cross-sectional
disc of the bullet maintains its speed practically unchanged until
it comes in direct contact with the steel. The pressure exerted
by the bullet is, probably, sensibly constant, since it depends
upon the square of the speed, but not upon the length or diam-
eter of the projectile. Increase in diameter only alters the area
over which the force is applied, and increase in length the time
during which it acts. As a practical example, consider a Lee-
Metford bullet moving with the normal speed of 1,800 feet per
second. This projectile is 1 1/4 inches in length, it has a mass
of about 0°03 lb., and it would be stopped in 1 /18000 of a second.
The force required to destroy the 1-7 lb.-second units of momentum
would be 15 tons. Since the area of cross-section of the bullet
is 1/14 of a square inch, the mean pressure would amount to 210
tons per square inch.

Passing over several interesting cases involving the propaga-

Chemistry and Physics. 503

tion of longitudinal waves along steel rods, we shall now consider

-very briefly some entirely new investigations made by Hopkinson

on the effects produced by detonating small cylinders of gun-
cotton in contact with steel plates. The gun-cotton is converted
into gas at small volume, high temperature, and enormous pres-
sure, in roughly three or four millionths of a second. The only
thing which restrains the expansion of the gas is the inertia of
the surrounding air, and the pressure accordingly drops with very
great rapidity. It is estimated that the pressure falls from 120
tons per square inch to atmospheric value in about 1 / 25000 of a
second. ‘Ihe same pressure is, of course, exerted by the gas upon
any rigid surface with which the gun-cotton is in contact, and the
force so produced has the characteristics of a blow, namely, great
intensity and short duration. If a cylinder of gun-cotton weigh-
ing one or two ounces is placed in contact with a plate of mild
steel one half an inch thick, or less, and if the explosive is then
detonated, the effect will be to punch a clean hole through the
plate, of approximately the same diameter as that of the cylinder
of gun-cotton, just as if a projectile had passed through the plate.
On the other hand, if the steel plate had a thickness of three-
quarters of an inch, a very curious result would be obtained. A
depression would be formed on the side of the plate next to the
explosive, while a disc of steel of corresponding diameter would
be torn off from the opposite face of the plate and projected with
very high speed. ‘The speed, in fact, corresponds to a large frac-
tion of the whole momentum of the blow. By detonating a two-
ounce cylinder of gun-cotton in contact with a still thicker plate
of steel, a depression and a complementary bulge were produced
on the respective faces of the plate. When the plate was sawed
in two in a plane containing the centers of the dent and of the
lump, the presence of an internal crack was brought to light,
thus showing the beginning of that separation which was com-
plete in the case of the plate three-quarters of aninch thick. All
of these phenomena can be accounted for by simple mechanical
principles involving the reflection of longitudinal or sound waves
in the metal.

In conclusion, a few words with regard to the behavior of large
projectiles and armor-plate may not be without interest. Modern
shells are made of a special steel of great strength and consider-
able ductility, the region of the point only being subsequently
hardened by thermal treatment. When a shell of this construc-
tion strikes normally against a plate of wrought iron, or even
mild steel, it ploughs straight through the plate, pushes a plug of
metal before it, and emerges unscathed. <A rim or lip is formed
on the incidence face of the plate, which is analogous to the rim
arising when a hole is blown in a lead plate by means of a gun-
cotton primer. ‘To bring a 14-inch shell, having a speed of 2,000
feet per second, to rest would require at least 2°5 feet of wrought
iron. Modern armor plate is made as hard as possible on the
outside surface, the back being left tough and ductile. When a

504 Scientific [ntelligence.

shell with a hard point is incident normally on such armor, both
the projectile and the plate are seriously damaged, but the former
does not penetrate the latter. Hven when a thinner plate is
pierced by the shell the projectile is usually smashed to pieces in
the act. To overcome this lack of penetrating power it has
become the custom, in recent years, to provide the point of the
shell with a cap of soft steel. In this event, the projectile
punches a clean hole both in its cap and through the armor plate.
In some instances the shell is so nearly intact as to admit of its
being used over again. The cap seems to form a ring around the
nose of the shell at just the right instant, preventing any lateral
deformation or flow of the tip, thus concentrating the blow over
a small area and enabling the projectile to pierce the armor.—
Nature, February 15, 1912, p. 5381. HH. Segue

8. A Photographic Study of Vortex Rings in Liquids.—
For purposes of demonstration, vortex rings are usually made
in air by sending puffs of smoke through a circular opening in the
front of a suitable box. It has been shown quite recently, how-
ever, by Epwin F. Norrurvp that more beautiful and instructive
results can be obtained by using liquids of small viscosity instead
of air. The essential parts of the apparatus used and a few of
the phenomena produced may be briefly described as follows:

The rectangular experimental tank was chiefly made of plate
glass and its length, depth, and width were respectively 151™,
59°5°", and 12°". The vortex rings were projected by means of
a cylindrical can or “gun” 7-7 in diameter and 6°6°" axial
length. One end of this can consisted of a flexible diaphragm
of phosphor bronze which could be given an impulse by the
plunger of an electromagnet. The muzzle end of the gun was
partly closed by any one of a set of metal discs which contained
one or more holes of various shapes and dimensions. A circular
hole 1™ in diameter and at the center of the disc was usually
employed to produce single vortex rings. To produce double
rings two holes each of 0°85°™ diameter were provided with their
centers at a distance of 1°275°" from the axis of the cylinder. The
tank was generally filled with slightly acidulated water whereas
the can contained strongly alkaline water which was deeply
colored with phenol phthalein. By this scheme the necessity of
refilling the tank after one or two “shots” was avoided because
the deep red vortex rings disappeared completely as soon as they
lost their form and became dispersed.

Before investigating photographically the behavior of the rings,
Northrup observed the following noteworthy properties of the
vortices. The speed of the rings was initially about two meters
per second and, when free to do so, they moved in straight lines
with their planes perpendicular to the direction of propagation.
They did not appropriate suspended particles of slightly greater
density than the medium in which they moved. When a tightly-
stretched sheet of chiffon cloth was interposed in the path of the
vortex, the ring would pass through the net without being

Chemistry and Physics. 505

destroyed or greatly retarded. In fact, a ring would break
through a sheet of tissue paper, but it would be scattered by the
impact. Also, a light watch-chain would be bent into a decided
curve by a square blow of a ring, hence the kinetic energy of the
rings was quite appreciable. When two rings were sent simul-
taneously from opposite ends of the tank they would be destroyed
if their lines of propagation coincided exactly, but they would
separate and avoid one another if they were so aimed as to bring
their edges into contact if the rectilinear motion persisted. Inter-
nal reflection at the free surface of the acidulated water took place
in a beautiful manner when the angle of incidence exceeded about
68°. As the surface of the water was approached the upper edge of
the rmg would gain in speed as compared with the lower edge
and the plane of the vortex would tilt in such a manner as to
maintain itself always normal to the direction of propagation.
For smaller angles of incidence than the critical angle the ring
would burst through the surface with a spurt of water. Refrac-
tion was also shown by filling the lower half of the tank with a
concentrated salt solution, and the upper half with pure water.
Vortex rings issuing from a truly circular hole do not vibrate,
but rings projected from an elliptical opening exhibit a vibratory
motion in their own plane. These vibrations are very rapid and
consist in changing from ellipses with vertical major axes to
ellipses with the longer axis horizontal.

Most interesting results were obtained with two circular holes
inthe muzzle disc of the gun. “The tworings, which issue simul-
taneously from the two holes, begin to attract each other the
moment they leave the gun, and at a distance from the gun of
about 6 to 8™ they come together with great suddenness, uniting
to form a single ring of approximately twice the circumference
of one of them.” The rings thus formed proceed with the same
speed as a single ring, but the vibratory motions are rather com-
plicated. The component vibrations can only be fully appreciated
by reference to the reproductions of the stereoscopic photographs
in which the original paper abounds.

Experiments were performed which showed that, in the case
of two non-miscible liquids of different densities, it is possible to
project a vortex of the less dense liquid through the medium of
greater density, but it is not possible to reverse the process. For
example, a ring of kerosene oil can be projected through water,
but a vortex of carbon tetrachloride cannot. By projecting rings
of liquid paraftin through hot water and thence into a substratum
of cold water, very pretty solid rings of paraffin were obtained
and preserved.

The difficulties attendant upon photographing the vibrating
rings were comparatively great and the requisite assemblage of
apparatus was too complicated to admit of description in this
place. Suffice it to say that full details of the experimental pro-
cesses together with a relatively large number of photographic
reproductions are given in the September and October numbers
(1911) of the Journal of the Franklin Institute—Muture, Feb-
ruary 1, 1912, p. 463. Ss Wie

506 Scientific Intelligence.

9. Note on Nevil Maskelyne’s Article, “ On the Trisection of
an Angle”; by H. 8. Us LER (communicated).—In the Philo-
sophical Magazine for April, 1912, a geometrical construction is
given by Maskelyne, on page 647, which he states will trisect any
angle. This claim is surprising because the construction is not
qualified as an approximation and also because no proof is sug-
gested in the article. It is the purpose of the writer to show that
the aforesaid construction is not valid. ‘To accomplish this, it is
sufficient to prove that a right angle will not be trisected in the
manner indicated by Maskelyne.

In the accompanying figure the letters have the same signifi-
cance as in the original article.

Let = af [0 =sdb = dg =e ecg alk

From the right triangle caf, ¢f = +/10.

Since ah bisects Z cab, ch = 3¢f = 24/10.

ah? = ac? + ch? — 2a0. ch. cos (Lacf) = 3 = ak’.

Considering ae and ab as axes of w and y respectively, it

follows that the equation of the line ef is « + 2y —2 = 0,
and of the circle JK, 87+ 8y?’— 9 = 0. Consequently the
1/26 +4 eae):

Laat 20

coordinates of & are (

Geology. 507

16 —4/26

Hence, tan (Zcak) = =
24/26 +8

= 4/26 — 455 = 0°599019

and Zcak = 30° 55' 21".

Therefore, in this special case, the error amounts to nearly one
degree. It may be remarked, in conclusion, that we have worked
out an analytical expression, for the general case, connecting
Zcak with Zcab and found that this function is not satisfied by
putting Zcab = 3(Zcak).

Il. Grotoey.

1, Publications of the United States Geological Survey ;
GrorGE Otis Smitu, Director.—Recent publications of the U. 8.
Geological Survey are noted in the following list (continued from
p. 62, Jan., 1912) :

Torpocrapuic ATLAS.—Sixty-five sheets.

Foxrios.—No. 178. Foxburg—Clarion Folio, Pennsylvania ; by
K. W. Suaw and J. M. Munn. Pp. 17; columnar section, 4
topographic and geologic maps.

No. 179. Pawpaw-—Hancock Folio. Maryland—West Virginia—
Pennsylvania ; by GrorRGE W.SrosE and Cuarues K. Swarrz.
Pp. 24; 3 topographic and geologic maps ; 20 half tone views.

No. 180. Claysville Folio, Pennsylvania; by M. J. Munn.
Pp. 14; sections, 4 topographic and geologic maps. 10 figures.

No. 181. Bismarck Folio, North Dakota; by A. G. Lronarp.
Pp. 8; 1 topographic, 1 geologic map.

Minerat Resources of the United States. Calendar year
1910. Part I.—Metals. Pp. 796; 1 plate, 9 figures. Part I1.—
Nonmetals. Pp. 1005; 17 plates, 10 figures. ‘lhe individual
chapters of this invaluable compilation have already been issued
in advance.

Buiuetins.—No. 470. Contributions to Economic Geology
(Short Papers and Preliminary Reports), 1910. Part I.—Metals
and Nonmetals except Fuels. C. W. Hayrs and WaLpEmMaAr
LinpGREN, Geologists in Charge. Pp. 558; 17 plates, 64 figures.

No. 485. A Geologic Reconnaissance of the [iamna Region,
Alaska; by G. C. Martin and F. J. Karz. Pp. 138; 9 plates,
20 figures.

No. 493. Results of Spirit Leveling in Illinois, 1999, 1910 ; R.
B. Marsuaattz, Chief Geographer. Pp. 115; 1 plate.

No. 494. The New Madrid Earthquake; by Myron L.
Fourier. Pp. 119; 10 plates, 18 figures.

No 496. Results of Triangulation and Primary Traverse for
the Years 1909 and 1910. R. B. Marsnwatu. Chief Geographer.
Pp. 3925; 2 plates.

No. 497. A Reconnaissance of the Jarbridge, Contact, and
Elk Mountain Mining Districts, Elko County, Nevada; by F. C.
SCHRADER. Pp. 162; 26 plates, 3 figures.

508 Scientific Intelligence.

No. 499. Coal Near the Black Hills, Wyoming—South
Dakota; by R. W. Stone. Pp. 66; 7 plates, 8 figures.

No. 500. Geology and Coal Fields of the Lower Matanuska
Valley, Alaska; by G. C. Martin and F. J. Katz. Pp. 98; 19
plates, 12 figures.

No. 504. The Sitka Mining District, -Alaska; by ApoLpnH
Knorr. Pp. 32; 1 plate, 4 figures.

No. 505. Mining Laws of Australia and New Zealand; by
ARTHUR C. VeEatcuH with a preface by WaLTER L. FisnEr. Pp.
180.

No. 511. Alunite: a newly discovered deposit near Marysvale,
Utah ; by B. 8. Butter and H. 8. GaLz. Pp. 64; 3 plates.
This new locality for alunite gives promise of affording a consid-
erable amount of the potash so much needed in this country.

W aTER-SUPPLY Paprers.—No. 280. Gaging Stations maintained
by the U. 8. Geological Survey, 1888-1910, and Survey Publica-
tions relating to Water Resources; compiled by B. D. Woop.
Pp. 102.

Nos. 282, 286, 287. Surface Water Supply of the United -
States, 1910; prepared under the direction of M. O. Lrteuron.
No. 282. Part II. South Atlantic Coast and Eastern Gulf of
Mexico; by M. R. Hatt and J.G. MatuErs. Pp. 109; 3 plates.
No. 286. Part VI. Missouri River Basin; by W. A. Lams, W.
B. Freeman, Raymonp Ricuarps, and R. C. Rice. Pp. vii, 308;
4 plates, 1 figure. No. 287. Part VII. Lower Mississippi Basin;
by W. B. FRrEman and J. G. Maruers. Pp. 91; 2 plates.

2. Cambro- Ordovician Boundary in British Columbia with
description of fossils ; by CHartes D. Watcotr. Smithsonian
Mise. Col., 57, No. 7, pp. 229-237, pl. 35, 1912.—Until now the
boundary between the Cambrian and Ordovician of America has
not been clearly established on paleontologic evidence. Due to
the discovery of fossils by J. A. Allan of the Geological Survey
of Canada, and later by L. D. Burling, Walcott is now able to
indicate this division with certainty for the Rocky Mountain
region. Some time ago he placed the line at the top of the Sher-
brooke formation which has in its upper beds Lingulella isse and
a Ptychoparia, fossils indicating the Upper Cambrian. This
formation is now known to be tollowed by the Chancellor, about
2500 feet thick, then the Ottertail blue limestone with a thickness
of 1550+ feet. The latter yields Lingulella cf. isse, Agnostus,
and Ptychoparia, fossils indicating Cambrian time.

Above the Ottertail formation appear interbedded cherts, cherty
limestones, dolomitic limestones and siliceous and caleareous
slates and shales over 6000 feet in thickness, referred to the
Goodsir formation. In the lower part Allan found the new
species here described by Walcott as Obolus mollisonensis, Lin-
guiella? allani, L. moosensis and Ceratopyge canadensis.

“The discovery of fairly well characterized specimens of the
trilobitic genus Ceratopyge associated with brachiopods of the
same general type as those found in the Ceratopyge shale of

Geology. 509

Sweden is most important, as it gives the first definite suggestion
of a base for the Ordovician in the section along the Canadian
Pacific Railway west of the Continental Divide. In Sweden the
Ceratopyge shale and limestone are now by general assent placed
at the base of the Ordovician, and with our knowledge of the
stratigraphy of the upper portion of this section as determined by
Mr. Allan I am inclined to agree with him in placing, at least
tentatively, the boundary between the Cambrian and Ordovician
at the summit of the Ottertail limestone and the base of the
Goodsir formation” (2380). CUR:

3. The Sardinian Cambrian Genus Olenopsis in America ;
by Cuartes D. Watcorr. Smithsonian Misc. Col., 57, No. 8,
pp. 239-249, pl. 36, 1912.—The author here describes three
species of Olenopsis derived from the upper part of the Lower
Cambrian of Pennsylvania and from the passage beds at the base
of the Middle Cambrian in Montana, Alberta, and British
Columbia. The genus was originally discovered in Sardinia,
where its exact stratigraphic position remained undetermined.
Walcott shows in this paper that the Sardinian species probably
is of the time of the strata “beneath the Middle Cambrian
Paradoxides beds, either in passage beds from the Lower to the
Middle Cambrian, or in the upper beds of the Lower Cambrian”

239). c. S.

ee Cambrian Branchiopoda, Malacostraca, Trilobita,
and Merostomata; by Cuartes D. Watcorr. Smithsonian
Mise. Col., 57, pp. 148-228, pls. 24-34, 1912.—In this preliminary
paper of extraordinary interest are described 1 new order, 5 new
families, 5 old and 19 new genera (of Branchiopoda, Opabinia,
Leanchoilia, Yohoia, Bidentia, Naraoia, Burgessia, and Wap-
tia ; of Malacostraca, Hurdia, Tuzoia, Odaraia, Fieldia, and
Carnarvonia,; of trilobites, Marrella, Nathorstia, Mollisonia,
and Zontoia ; of Merostomata, Molaria, Habelia, and Emerald-
ella), and 31 newspecies. Nearly all are derived from the Burgess
shale off Middle Cambrian age near Field, British Columbia.
This shale has furnished the author with no less than 56 genera
derived from a block of shale not over 6 by 40 feet in area and
7 feet in thickness. No other locality has given us such an
astonishing insight not only into the life of the] Middle Cambrian
but as well into what must have been the stage and diversity of
invertebrate life in pre-Cambrian time. Nevertheless the Burgess
shale record is said to be imperfect for “We have only a portion
of a crustacean fauna that was already developed early in
Cambrian time” (153).

Students of trilobites will be much interested to know that
these animals (certainly at least Neolenus) had a pair of long
joited caudal rami that are not unlike those in Apus. On the
other hand Marrella is a trilobite suggesting Apus in its long and
tapering abdomen.

Walcott states that these Middle Cambrian Branchiopoda and
Malacostraca have normally 6 pairs of cephalic appendages, if the

510 Scientific Intelligence.

stalked eyes are regarded as representing the first pair. These
“are not very unlike those of recent crustaceans of the same
orders,” while the thuracic appendages appear to be based on the
typical crustacean biramose limb.

‘The author thinks it probable that the Branchiopoda, Mala-
costraca, Ostracoda, Trilobita, and Merostomata had their origin
previous to the Cambrian. In regard to Bernard’s interesting
theory that Apus was developed out of a “browsing carnivorous
annelid with its first 5 segments (head) bent so that its mouth
faced ventrally and posteriorly,” Walcott “examined the Bur-
gess shale annelidan and crustacean fauna to ascertain if there
was an annelid that could be considered as representing his hypo-
thetical crustacean annelid, and nearer to it in structure than
Apus. I found specimens of Canadia spinosa Walcott laterally
flattened in the shale with the head bent down, so that the mouth
faces posteriorly (Smiths. Misc. Col., 57, No. 5, 1911, pl. 23, fig.
4), also that 14 out of 24 specimens have the head bent under
and out of sight beneath the flattened body. Possibly these
annelids and the crustaceans were derived from the same general
type of animal” (162).

‘““As to the relations of the Branchiopoda, Leptostraca (repre-
senting the Malacostraca), Trilobita, and Merostomata the inter-
relationship of the four so-called subclasses is found to be very
intimate. In Opabinia and Leanchoilia the typical branchiopod
is clearly present. In Waptia the Leptostraca is very near at
hand as developed in Hymenocaris.

“In Marrella the trilobite is foreshadowed, and Nathorstia is a
generalized trilobite as the trilobite appears to be a specialized
branchiopod, adapted largely for creeping on the bottom. The
trilobite gives some conception of a possible form between the
Branchiopoda and the Aglaspidz of the Merostomata” (163).

From the Apodide “it is assumed that the Branchiopoda came,
and from the Branchiopoda stock three distinct branches were
developed prior to or during Cambrian time.” In one line of
descent “it is assumed that the Trilobita are directly descendent
from the Branchiopoda and forms grouped under the order
Aglaspina derived from the Trilobita. ‘The order Limulava is
considered as being intermediate between Aglaspina and the
Eurypterida, and that the two orders Limulava and Aglaspina
serve to connect the Trilobita and the Eurypterida.

“Krom the Eurypterida we pass to the Xiphosura. It is
thought that the Phyllocarida, as represented by the group of
forms included under the Hymenocarina, came from the Branchio-
poda, but on a different line of descent from the Trilobita and
the orders grouped under the Merostomata.

“The ostracods are assumed to have been derived from the
Branchiopoda, but on a different line of descent from the Trilo-
bita and Phyllocarida” (163-4). C.'S.

5. Strophomena and other fossils from Cincinnatian and
Mohawkian horizons, chiefly in Ohio, Indiana, and Kentucky ;

Geology. Bll

by Ave. F. Forrsts. Bull. Sci. Lab., Denison Univ., xvii, pp.
17-174, pls. i-xvill, 1912.—The greater part of this work is
devoted to detailed descriptions of 41 species (9 new).of brachio-
pods and 2 other new fossil forms. Throughout. the descriptions
and on the introductory pages is presented an immense amount of
stratigraphic detail along with the geographic distribution of the
Species discussed. On page 23 is a revised table of the Cincin-
natian and Mohawkian formations embracing no fewer than 50
stratigraphic subdivisions. In the last paragraph (page 139) the
author makes three generic changes affecting brachiopod genera
proposed by him in 1909, but the reasons for the substitutions are
not stated. These are Schizoramma for Schizonema, Pionodema
for Bathycelia, and Hneuclodema for Cyclocelia. C. S.

6. The Arnheim formation within the areas traversed by the
Cincinnati geanticline ; by Auc. F. Forrstre. Ohio Naturalist,
xil, No. 3, pp. 429-453, pls. xx—xx1i,1912.—The Arnheim formation
is in the upper part of the Ordovician and at the base of the Rich-
mond series. Its distribution in Kentucky, Indiana, and Ohio is
here described. It is in this formation that the Richmond faunas
make their appearance, but the source whence this migration
came the author does not state, though he seems to favor an
entrance from the southwest toward the northeast. ‘The Arnheim
is also a time of crustal warping and the breaking down of some
unknown barrier, permitting the introduction of the Richmond
fauna. Cc. S.

7. Paleontologia Universalis, ser. 8, fasc. 3, July, 1911.—This
recently published fasciculus of reproductions and emendations
of poorly understood invertebrate species (1821-1850) treats of
25 forms recorded on 56 sheets. C. S.

8. Petrographic Methods. 'Translated from the German of
HK. WEINSCHENK by R. W. CrarxK. 8°, pp. 396, figs. 371. New
York, 1912 (McGraw-Hill Co.).—No more convincing evidence
of the fact that petrology has become a definite science, which
occupies a field of its own, can be found than in the appearance of
volumes devoted to a description and discussion of its technical
methods, such as the one before us, and that noticed in the follow-
ing review. This work of Professor Weinschenk has now been
used for several years in the original, and has met in German-
speaking countries with very favorable consideration in the field
for which it was designed. It does not aim at the comprehen-
sive and mathematical treatment of subjects which characterizes
the great work of Rosenbusch and Wiilfing, but seeks in simpler
form, and mostly without mathematical discussion, to convey to
the student the essential principles which underlie the optical
study, investigation, and determination of crystalline substances.
This is accomplished by careful and extended explanations and
description of apparatus and of the proper methods of its use.
The form of presentation of the matter is, therefore, not merely
synoptic of a larger work, as is too often the case in manuals
which are designedly somewhat elementary in character, but
rather full, so far as the field is covered.

512 Scientific Intelligence.

The second part of the work is devoted to a description of the
rock-making minerals. In this the matter is considerably con-
densed to bring it within the limits of the work. The essential
material only is given and the subject matter of the less common,
or less important species, is more condensed by use of smaller

type. A set of tables, such as are found in most of the well-.

known texts, concludes the work.

The translator has done his part of the work carefully and well.
The book is well printed and attractively bound, and is illustrated
by numerous diagrams, cuts, and half tones, which add greatly
to the understanding of the text. While the work will not
replace the more comprehensive manuals, which are necessary to
the advanced students and teachers of petrography, it will, with-
out doubt, find a very useful field of its own with beginners and
with those who desire a simpler method of treatment of the sub-
ject matter. Le Veees

9. The Methods of Petrographic-Microscopic Research ; by
FrepD. EucENE Wriaut. 8°, pp. 204, 11 plates, 118 figures, 1912.
Carnegie Institution, Washington.—This work is almost the
antithesis of the one noticed above. Its intent is seen in the sub-
title, which reads “ Their relative accuracy and range of applica-
tion.” It is probably the most serious, scholarly and generally
comprehensive investigation of the optical methods employed in
petrographic research, to the extent indicated in the sub-title,
which has yet appeared, and it cannot fail to have a great
influence in promoting more careful and thorough work along
these lines. It is in no sense a text-book, and is no work for
beginners, but it is one which should be in the hands of every
teacher and advanced worker in petrography. It begins with an
investigation of the microscope, which is thoroughly discussed as
an instrument of precision in optical research. After this various
subjects, such as color, pleochroism, optical characters of bire-
fracting substances, refractive indices, birefringence and its meas-
urement, extinction angles, optic axial angles, etc., are treated in
successive chapters. ‘The various methods and apparatus invented
in recent years, largely by the author, in the Geophysical Labor-
atory of the Carnegie Institution, are for the most part usefully
included. A series of carefully constructed plates, using various
modes of projection, furnish, by graphic methods, quick and easy
solutions of problems of determination, as, for instance, to reduce
the optic angle observed in air to be the true angle in the sub-
stance, when the index of refraction is known.

It is work of this character, the result of careful, accurate,
intelligent and highly trained effort directed to a particular field
of science, that makes the productions of the institution which
produces them of such a high degree of merit. Tiny Nis es

10. The Soil Solution: The nutrient medium for plant growth;
by Frank K. Cameron. Pp. iv, 125, with Index and 3 ills.
Easton, Pa., 1911 (The Chemical Publishing Co.).--For some
years the Soil Survey at Washington has been engaged, among

Miscellaneous Intelligence. 513

other things, in a careful study of the chemistry of soils. The
result has been a large number of valuable quantitative determina-
tions that have cleared up many points concerning soil fertility,
and have indicated the lines which many of the later investigations
should follow. The main results of these Government studies
have been organized in an attractive manner and presented by .
the chemist in charge in the form of a book as above. A few
chapters, such as ‘‘’The Mineral Constituents of the Soil Solution,”
and “The Organic Constituents of the Soil Solution,” are here
presented practically as they appeared in Government Bulletins,
except that a large number of relatively unimportant citations
have been omitted. The organization of these and other chap-
ters with reference to each other has been carefully done, so that
the work is a unit. In addition, a preliminary chapter on The
Soil, others on Soil Management, Soil Water, Fertilizers and
Alkah, make the book a well-rounded treatise on soils from the
chemical standpoint. it, 1B,

2
Til. MiscELLANEOUS SCIENTIFIC INTELLIGENCE.

National Academy of Sciences.—The annual spring meeting
of ke National Academy of Sciences was held in Washington on
April 16-18 ; some forty-five members were present.

dive following gentlemen were elected to membership in the
Academy: John Jacob Abel, Johns Hopkins University; Charles
Benedict Davenport, Station for Experimental Evolution, Cold
Spring Harbor, N. Y. ; Samuel James Meltzer, Rockefeller Insti-
tute for Medical Research, New York; Harry Fielding Reid,
Johns Hopkins University ; Roland Thaxter, Harvard Univer-
sity ; William Morton Wheeler, Harvard University ; David
White, U. 8. Geological Survey, Washington, D. C., and Robert
Williams Wood, Johns Hopkins University.

Sir John Murr ay was elected a foreign associate of the
Academy.

The following is a list of the papers presented at the meeting :

GEORGE EK. Have: The new tower telescope of the Mount Wilson Solar
Observatory.

W. W. CAMPBELL: Radial velocities of 213 brighter Class A stars. Radial
velocities of 190 brighter Class F stars. Some characteristics of stellar
motions.

W.4J. HumpuHreys: Holes in the air.

R. A. Harper: The organization of the cell colony in Pediastrum.

D. H. CAMPBELL: On the morphology and systematic position of Calycu-
laria radiculosa (Sande Lac) Stephens.

WLLIAM TRELEASE: A revision of Phoradendron.

H. F. Ossorn: Biological Foundation of Bergson’s ‘‘ Creative Evolution.”

Harvey CusHinG: Some observations on the functions of the pituitary
body.

Jacques LorB: The activation of the animal egg from the physico-chemical
standpoint.

J. A. Hotmes: The national phases of the mining industry.

C. G. Appor: The solar radiation.

K. S. Morse: Biographical memoir of C. O. Whitman.

G. L. GoopALE: Biographical memoir of Alexander Agassiz.

514 — Seventifie Intelligence.

2. The Carnegie Foundation for the Advancement of Teach-
ing. Sixth Annual Report of the President, Henry S. Prircu-
Err, and of the Treasurer, Ropurt A. Franks. Pp. vi, 154.
New York City, October, 1911.—The total fund now in the hands
of the Trustees of the Carnegie Foundation amounts to something
more than $12,000,000, giving an income for the past year of
$590,500. Of this latter sum, all but about $10,000 was expended,
most of it for retiring allowances and pensions to teachers and
their widows ; less than $54,000 was needed for administrative
expenses. The fact that income and expenditure are now so
closely balanced gives emphasis to the discussion by the President
in this report as to the general subject of college pensions. In
his judgment they should carry with them, as is true of many
sunilar funds, a contributory feature. He urges, also, that inas-
much as the Foundation can in the future care for only a small
fraction of the college teachers in America, it is the duty of each
college to mature plans for assuming its own obligations in this
direction. It is to be noted that of the additional gift of $5,000,-
000 promised by Mr. Carnegie in March, 1908, the first mstallment
Of $1,000,000 was paid in March a year ago. ‘The total number
of institutions now on the accepted list is seventy-two, the Uni-
versity of Virginia having been added during the current year.

The present volume contains, in its second part (pp. 45-123), a
considerable number of chapters by the President, dealing with
the vital general problems in which the universities and the pro-
fessional schools of the country are concerned. He notes a remark-
able development in the educational movement in the United States
as shown in the increase of students, the adjustment of the college
to the four-year high school, and the increase of the number of
secondary schools of the four-year type. He sees also a gratifying
progress in the various lines of professional work and in the move-
ment of State institutions towards educational and political free-
dom.

3. Report of Superintendent of the Coast and Geodetic Sur-
vey, O..H. TrrtMann, showing the Progress of the Work from
Suly 1, 1910, to June 30, 1911. Pp. 584; 9 pocket maps. Wash-
ington, 1912. -—The annual volume from the Coast and Geodetic
Survey gives the usual interesting summary, by the superinten-
dent, of the work done in the country and the outlying terri-
tories. To be noticed is a reconnaissance for primary triangula-
tion to extend from the 39th parallel triangulation near Colorado
Springs to the Canadian boundary. This was begun in May and,
at the end of the year, four hundred miles of progress had been
made. It is also stated that the Texas—California are of primary
triangulation from Texas to the Pacific coast, connecting the 98th
meridian triangulation with that in the vicinity of San Diego,
was completed during the year. Progress has also been made in
the surveying and marking of the boundary lines between the
United States and Canada. Of the six Appendixes accompanying
the volume are to be mentioned : one on the magnetic observa-
tions of the Survey, by R. L. Faris; on triangulation along the

Obituary. 515

98th meridian, Nebraska to Canada and Duluth, by William
Bowie, and on the same meridian, Seguin to Point Isabel, Texas,
by A. L. Baldwin; on triangulation along the east coast of
Florida’and the Keys, by H. C. Mitchell.

4. Bulletin of the Bureau of Standards ; 8. W. STRATTON,
Director.—The first number of volume VIII, Jan. 1912, is de-
voted to a paper of 237 pages, by Epwarp B. Rosa and F. W.
GROVER, containing formulas and tables for the calculation of
mutual and self-inductance (revised).

The following important technologic papers have also been
issued by the Bureau of Standards :

No. 2. The Strength of reinforced Concrete Beams; Results
of Tests of 333 Beams (first series) ; by R. L. Humpurey and
Louis H. Lossr. Pp. 200; 45 figures.

No. 3. Tests of the absorptive and permeable Properties of
Portland Cement Mortars and Concretes, together with Tests of
damp-proofing and water-proofing Compounds and Materials; by
Rupoies J. Wic and P. H. Bares. Pp. 127 ; 53 figures.

No. 5. The Effect of high pressure Steam on the crushing
Strength of Portland Cement, Mortar, and Concrete ; by RuDOLPH
dma WiG. 2p. 25.) 1%

OBITUARY.

Ratpn StockMAan Tarr, Professor of Physical Geography in
Cornell University, died suddenly, after a brief illness, on March
21st at the age of forty-eight.

He was born at Gloucester, Mass., Jan. 15th, 1864, and early
showed a bent for natural history studies. After a brief period
of study in the Summer School of Zoology at Salem, Mass., in
the fall of 1881 he entered the zoological laboratory of Alpheus
Hyatt, acting as his assistant for two years. He took part in the
deep-sea explorations of the “Fish Hawk” and “ Albatross” sent
out by the U.S. Fish Commission in 1883 ; assisted Professor
Shaler in the field work on the Geology of Cape Ann ; and in the
year 1889 was assistant on the Texas Geological Survey. While
engaged in these various modes of practical scientific work in
science he was registered as a student at Harvard, graduating
from the Lawrence Scientific School with the degree of B.S. in
1891. In 1892 he was appointed Assistant Professor of Dynamic
Geology and Physical Geography in Cornell University and
Professor of Physical Geography in 1906, the position he held at
the time of his death.

In addition to excursions and explorations in and about Ithaca,
New York state, carried on both for training of his classes in
physiography and as research, he made more extended researches
in Alaska and Greenland, chiefly studying glaciers, and spent the
years 1901—2 and 1909-10 in Europe studying similar problems.

Professor Tarr wrote several text-books on Physical Geography,
the latest. of which, “ A Laboratory Manual of Physical Geog-
raphy” by R. 8. Tarr and O. D. VanEngeln, was published in

516 Scientific Intelligence.

1910. He also prepared a beautifully illustrated “ Monograph on
the Yakutat Bay Region, Alaska, Physiography and Glacial
Geology ” which was published in 1909 as Professional Paper
No. 64 of the U. 8. Geological Survey. He assisted in the prepa-
ration of the ‘‘ Watkins Glen—Catatonk Folio” (published the
same year by the Survey) comprising the area of two 15-minute
quadrangles immediately surrounding Ithaca and Cornell Uni-
versity. Among his published papers are also numerous contri-
butions to scientific and educational journals.

He was vigorously at work up to a few days of his death.
The correcting of proof-sheets of a Professional Paper for the
U. 8. Geological Survey on “ Alaskan earthquakes” and the
writing of a text-book on ‘ Advanced Physiography” were
brought to a close by his death. During the past winter he had
been actively engaged experimenting upon glacier and pond-ice,
seeking evidence of the determining causes and conditions of the
motion of glaciers. Dr. O. D. VanEngeln was assisting him in
these experiments and will continue them and prepare the record
of the experiments for publication. A scientific account of his
four expeditions to Alaska to study its glaciers had but recently
been finished. Professor Lawrence Martin was associated with
him in its preparation and will complete it for publication. He
was also looking eagerly forward to making further explorations in
Newfoundland during the coming summer when his life was sud-
denly terminated. Professor Tarr was one of the first American
teachers to give university rank to the physical geography of the
high school curriculum. His training under Davis at Harvard
specially fitted him for the task and at Cornell he found the
opportunity to build up a well-equipped physiographic laboratory
for the scientific teaching and investigation of the problems of
physiography. He was a vigorous explorer, a keen observer, a
ready speaker, an interesting and inspiring teacher and will be
greatly missed not only by his many pupils but by physiographers
at home and abroad, among whom he had already attained high
rank. He was President of the Association of American Geog-
raphers, foreign correspondent of the Geological Society of
London, fellow of the Geological Society of America and member
of other scientific and educational societies ; and associate editor
of the Journal of Geography and of the “ Bulletin” of the Ameri-
can Geographical Society and corresponding member of La Com-
mission Internationale des Glaciers. H. S. W.

Proressor A. Lawrence Rorcn, the meteorologist, died on
April 7 at the age of fifty-one years. In 1885 he established and
subsequently maintained the Blue Hill Meteorological Observa-
tory. He was the first to use kites in the recording of the mete-
orological data of the upper atmosphere, and through this work,
his investigation of clouds and in other similar lines, his contri-
butions to science were numerous and important.

PROFESSOR OsBORNE REYNOLDS, distinguished for his impor-
tant contributions to engineering and theoretical physics, died on
February 21 at the age of seventy years.

New Circulars.

84: Eighth Mineral List: A descriptive list of new arrivals,
rare and showy minerals.

85: Minerals for Sale by Weight: Price list of minerals for
blowpipe and laboratory work.

86: Minerals and Rocks for Working Collections: List of
common minerals and rocks for study specimens; prices
from 1% cents up.

Catalogue 26: Biological Supplies: New illustrated price list
of material for dissection; study and display specimens;
special dissections; models, etc. Svxth edition.

Any or all of the above lists will be sent free on request. We are
constantly acquiring new material and publishing new lists. It pays to
be on our mailing list.

Ward’s Natural Science Establishment
76-104 Cotruce AvE., ce Rocnester, N. Y.

Warps Naturat Science EstaBlisHMENT

A Supply-House for Scientific Material.

Founded 1862. Incorporated 1890.
DEPARTMENTS:

Geology, including Phenomenal and Physiographic.
Mineralogy, including also Rocks, Meteorites, etc.
Palaeontology. Archaeology and Ethnology.
Invertebrates, including Biology, .Conchology, ete.
Zoology, including Osteology and Taxidermy.

Human Anatomy, including Craniology, Odontology, ete.
Models, Plaster Casts and Wall-Charts in all departments.

Circulars in any department free on request; address

Wards Natural Science Establishment,
76-104 College Ave., Rochester, New York, U.S, A.

CON PEN ASS:

Page
Grorce Jarvis Brose. With a Portrait _____...._._.._ 889
Arr. XXXIV.—Life of the Connecticut Trias; by R. 8._
LULL wees Le oS eee Ge Se ee
XXX V.—Oxalate-Permanganate Process for the Determina-
tion of Copper Associated with Cadmium, Arsenic, Iron,
or Lead ; by ELL WARD 223 eee er ee 493
XXXVL-—Solid Solution in Minerals. I1.—The Chemical
Composition of Analcite; by H. W. Foorr and W. M.
Brann. se a “eee ee eat 433
XXX VII.—Chemical Composition of Nephelite ; by H. W.
Foors and W.-M. Brxpiny oe ee 439
XXX VIII.— Description of a new Genus and Saale: of
Paleechinoidea ; by Axet OLssON-°__.- 5.27

X XIV.—Relations of the Degree of Metamorphism to Geo-

logical Structure and to Acid Tgneous Intrusion in the Nar-
ragansett Basin, Rhode Island ; by F. H. Lanes. Pt. IIL 447
XXXTX. —One Picea of Michoseiamic Motion; by J. E.
BURBANK 6230. ean Seva ee So Se ee
XL.—Microseisms Caused by Frost Action; by J. icra
BANKS ioysscee st port Cee me ee aaron .-.. 474
XLI.—Dahllite (Podolite) from Tonopah, “Nevada; Veele-
kerite, a New Basic Calcium Phosphate ; Remarks on
the Chemical Composition of Apatite and Phosphate
Rock ;--by A. at Rogers ; with Analyses by G. E.
Postma o(.2 0 os Seg ee ee 475
XLII.—Distribution of the Active Deposit of Radium in an
Electric Field; by E. M. Wetuiscu and H. L. Bronson 483

SCIENTIFIC INTELLIGENCE.

Chemistry and Physics—Melting-point of Spodumene, ENDELL and EIBKE:
Detection of Nitric Acid in the Presence of Nitrous Acid, Sen and Dery,
499.—Chemical Constitution of Ilmenite, W. Mancuor: Determination of
Alkalies in Silicates, E. MAKtnEN : Dictionary of Applied Chemistry, 500.
— Properties of the Rays Producing Aurora Borealis, L. VEGARD : Pressure
of a Blow, B. Hopxinson, 501.—Photographic Study of Vortex Rings in
Liquids, E. F. Norterup, 504.—Note on Nevil Maskelyne’s Article, ‘‘ On
the Trisection of an Angle,” H. S. UHLER, 506.
Geology—Publications of the United States Geological Survey, 507. -Cambro-
Ordovician Boundary in British Columbia with description of fossils,
C. D. Watcortt, 508.—Sardinian Cambrian Genus Olenopsis in America,
C. D. Waucotr: Middle Cambrian Branchiopoda, Malaccos*raca, Trilobita,
and Merostomata, C. D. WaucotTt, 509.—Strophomena and other fossils
from Cincinnatian and Mohawkian horizons, A. F. Forrste: Arnheim
formation within the areas traversed by the Cincinnati geanticline, A. F.
ForrstE : Paleontologia Universalis: Petrographie Methods, 511.— Methods
of Petrograpbic-Microscopic Research, F. E. Wricut: The Soil Solution ;
the nutrient medium for plant growth, F. K. Cameron, 512.

Miscellaneous Scientific Intelligence—Naticnal Academy of Sciences, 513.—

Sixth Annual Report Carnegie Foundation for the Advancement of Teach-
ing: Report of Superintendent of the Coast and Geodetic Survey, O. H.
TitTMANN, 514.--Bulletin of the Bureau of Standards, 515.

Obituary—R. S. Tarr, 515: A. L. Rotcw: O. Reynoxps, 516.

:
F.
4

Library, Bureau of Ethnology.

e- VOL. XXXII. JUNE, 1912)
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JOURNAL OF SCIENCE,

Epiror: EDWARD S. DANA.

ASSOCIATE EDITORS

ee eT |
% AMERICAN
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Proressors GEORGE L. GOODALE, J OHN TROWBRIDGE,
W. G. FARLOW ann WM. M. DAVIS, or Camprince,

PROFESSORS ADDISON E. VERRILL, HORACE L. WELLS,
LOUIS V. PIRSSON, HERBERT E. GREGORY
AND HORACE S. UHLER, or New Haven,

Proresson HENRY S. WILLIAMS, or Iruaca,
Proressor JOSEPH S. AMES, or Battiore,
Mr. J. S. DILLER, or Wasuinerton.

FOURTH SERIES
VOL. XXXITI-[WHOLE NUMBER, CLX XXIII}.

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SPRING ANNOUNCEMENT.

As I am just sending to the printer an elaborate
Catalogue describing a Large Collection which will
be ready for distribution by the first of May, |
would kindly request all readers of the American
Journal of Science who request a copy of the above,
to send me thew names, which I will gladly send
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AMERICAN JOURNAL OF SCIENCE

PeOwh rH SERIES. ]

gp

Art. XLITI.—Zhe Nitrogen Thermometer Scale from 300°
to 630°, with a Direct Determination of the Boiling Point
of Sulphur ; by Artuur L. Day and Rozerr B. Sosmayn.

1. Purpose and Plan of the Investigation.

In our recent investigation of the fundamental high tempera-
ture scale with the gas thermometer,* attention was chiefly
directed to the temperature region above 1000°. The lower
temperatures had been determined with considerable accuracy
in an investigation undertaken in the Reichsanstalt+ some
years earlier (1900) and there was no reason to suspect. any
uncertainty in it of greater magnitude than the errors of
observation determined at that time (2° to 3°). This does not
mean that it was considered unnecessary to reduce the mag-
nitude of the errors, which were known or suspected to exist
in the Reichsanstalt instrument,—quite the contrary. All our
efforts throughout an investigation which has now continued
since 1904 have been put forth in the direction of reducing
these errors to a minimum, but this was done more especially
because of their much oreater influence upon temperature
determinations above 1000° than because of any specific
demand which then existed for a new or better temperature
scale in the region below that temperature.
The situation from our viewpoint at the time of publication
* Preliminary Publications :
Day and Clement, Phys. Rev., xxiv, 531, 1907 (Abstract).
Day and Clement, this Journal (4), xxvi, 405-4638, 1908.
Day and Sosman, ie (4), xxix, 98-161, 1910.
R. B. Sosman, me (4), xxx, 1-10, 1910.
Final Publication :
Day and Sosman, Carnegie Institution Pub. No. 157, 1911.
+ Holborn and Day, Ann. Physik (4), ii, 505-545, 1900; this Journal (4),
x, 171-206, 1900.

Am. Jour. ScI.—FourtTH Series, Vout. XX XIII, No. 198.—June, 1912.
34

518 Day and Sosman—WNitrogen Thermometer Scale

of our final results (1911) was accurately summed up in one of
our closing paragraphs as follows:

“The chief source of present uncertainty [in high-tempera-
ture gas-thermometer measurements] is the temperature dis-
tribution over the surface of the bulb in an air bath. It would
be possible to eliminate this error in the lower portion of the
scale by substituting a liquid bath which could be stirred.
In fact, this was done for temperatures below 500° in the
earlier work of Holborn and Day, but has not, so far, been
tried in the present investigation because of the relatively
secondary importance of the lower temperatures to the ultimate
purpose of the investigation (the study of silicates). For the
higher temperatures, no satigfactory liquid bath has been
found.”* (Publication of the’ Carnegie Institution No. 157,
p..125, 19415) i

The lower temperatures upon this scale, determined in an .

air bath, come out about 1° lower than the corresponding
temperatures of the Reichsanstalt scale (determined in a liquid
bath). These temperatures are compared below:

Holborn and Day Day and Sosman
1900 1911

Cadmium (melting point) .-.. 321°7° 320307
Zinc as ie feoaerster 2 ORG 418°2
AMtIMO NY 949 oemee ier ae PO Oab 629°2

This circumstance was the more conspicuous, and perhaps
the more open to suspicion, because a discrepancy of precisely
the same order of magnitude (1°) had appeared between air-
bath and liquid-bath determinations in the neighborhood of
400° in the work of Holborn and Day in 1900, which even-
tually led them to reject the measurements made at that
temperature in the air bath. It is, therefore, not surprising
that the reappearance of this discrepancy should attract con-
siderable attention even though this difference of 1° is within
the stated and admitted limits of accuracy of the Reichsanstalt
scale (2° to 3°). It is also serving a useful purpose in directing
attention to an uncertainty which had remained undisturbed
for so long that it probably had been forgotten, for there is
abundant reason to believe that to-day, with a modern gas
thermometer, adjusted to give appropriate sensitiveness, these
temperatures can be determined with much greater accuracy
than 1°. :

That the Reichsanstalt is also of this opinion is shown by the
recent publication of a new series of measurementst of these

* Prof. Holborn has directed attention to the same limitations in our
results at these temperatures, in a recent paper, to which further reference

will be made presently.
+ Holborn and Henning, Ann. Physik (4), xxxv, 761-774, 1911.

with Boiling Point of Sulphur. 519

temperatures. The gas thermometer measurements were made
in a liquid bath, using a sensitive resistance thermometer to
transfer the temperature from the bath containing the gas
thermometer bulb to the (independent) sulphur boiling point
apparatus. The lower temperatures were then interpolated by
means of the platinum resistance thermometer. The new
determinations were published so recently that there has been
no opportunity for confirmation by other experimenters, but
they appear to be free from any error greater than one or two
tenths of a degree, and therefore indicate a very considerable
increase in the accuracy of the results when compared with the
earlier (1900) scale which is now in general use. Holborn
and Henning’s new results, on the thermodynamic scale, are in
part as follows :

Benzophenone (boiling point)----- 30589 °
Cadmium (melting point) .--.---- 320-92
Zine "a pe eae Mapas tlie 419-40
Sulpunte (boiling point) 2-220 _- 444°51

In certain studies* now under way in this laboratory on the
effect of pressure upon equilibria greater accuracy is now
required in the measurement of these particular temperatures
than had previously been necessary. We therefore determined
to repeat these measurements, with more elaborate precautions
to secure a uniform temperature about the bulb, this being, as
stated above, the one factor in our measurements about which
some uncertainty remained. At any rate it was important to
establish the identity and the magnitude of the error in the
earlier measurements which may have been due to this cause.

2. Apparatus.

No attempt will be made to describe in detail the gas
thermometer and accessories used in this investigation. A full
description of the apparatus, with illustrations, will be found
in the publications to which reference has been made. No
change whatever was made in the gas thermometer system for
these measurements, except for the substitution, about the
bulb, of a liquid bath, made up from potassium and sodium
nitrates in eutectic proportions (55 per cent KNO,, 45 per cent
NaNO,). This bath was introduced into the furnace bomb
described in connection with the earlier apparatus in place of
the platinum wire furnace previously used. The insulating
material was dried magnesia powder, as heretofore, and the
bomb was water-jacketed throughout to protect the manometer.
The general appearance of the furnace is shown by the accom-
panying diagram (fig. 1).

* Johnston and Adams, this Journal, xxxi, 501-517, 1911.

520. Day and Sosman—Nitrogen Thermometer Scale

The vessel which contained the nitrates consisted of a eylin-
drical wrought iron tank.152™™" in inside diameter and of 7™™
wall thickness, into which the bottom plate was welded with an
oxy-acetylene Hame. This detail is perhaps worth some em-
phasis, because it was the only tank of three which were made
up with various joints in the bottom which proved able to hold
the nitrates up to a temperature of 630° without leaking.

Bre a: Fic. 2.

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Fic. 1. Nitrogen-thermometer bulb in double nitrate bath. (The two
thermoelements on the outside of the bulb are not shown.)

Fie. 2. Apparatus for the determination of the melting point of zine in
the nitrogen thermometer nitrate bath.

Seale: 1 to 6°.

As at first used this tank was merely a covered vessel with-
out partitions into which a turbine stirrer, operated by an elec-
tric motor, was inserted. The comparatively loose lower bearing
of the turbine was lubricated by the liquid itself, the upper one
was water-cooled. Alongside of this stirrer, and 30™™ distant
from it in the bath, was the bulb of the gas thermometer.
Although the stirring in the tank was vigorous, temperature
differences amounting to 0°4° appeared between the top and the
bottom of the bulb at 400°. The current in the liquid was up-

with Boiling Point of Sulphur. 521

ward in the turbine tube and downward past the bulb. With
this arrangement the top of the bulb was cooler.

In an air bath it had not proved possible to reduce the vari-
ation of temperature over the surface of the bulb below 1°, so
that the liquid bath, even in this form, was an improvement over
the air bath. But still greater uniformity was desired. After
some experimenting, which need not be described here, the
arrangement shown in the diagram (fig. 1) was adopted. It
amounted, briefly, to one bath within another; that is, the tube
containing the stirrer was continued across the bottom of the
tank and upward about the bulb, which it fitted with but little
clearance (10"™) in order to insure the very rapid circulation
of a thin layer of liquid past the bulb, while the remainder of
the bath remained at an approximately uniform temperature
without. With this arrangement no systematic temperature
differences greater than the errors of observatioh of the ther-
moelements (0°1°) were observed.

3. Method of Procedure.

In this apparatus temperatures were read simultaneously (1)
upon the gas thermometer, (2) upon three thermoelements dis-
tributed at different points in the bath,—one in a re-entrant tube
extending to the center of the bulb, and one each at the top
and bottom of the outside wall.

For the measurements at the benzophenone boiling-point
thermoelements of copper-constantan and of platinum-platin-
rhodium (Heraeus) were used, for the higher temperatures
platinum-platinrhodium only. After a trial of the copper-
constantan elements at the next higher temperature (zine), evi-
dence of permanent changes in their readings was obtained
which was more than sufficient to offset their increased sensi-
tiveness. They were accordingly abandoned in work at the
higher temperatures.

A thermoelement suggested by Geibel,* of gold against an
alloy of 60 gold, 40 palladium, was also tried. This gives an
electromotive force about equal to that of copper-constantan
and over six times that of the platinum-platinrhodium element.
But the alloy wire proved so inhomogeneous that the accuracy
of the element was much less than that of the platinrhodium,
and it was accordingly rejected.

Through the courteous codperation of the Bureau of Stand-
ards, a sensitive resistance thermometer in charge of Drs.
Dickinson and Mueller of the Bureau was placed alongside the
bulb during a part of the measurements, and later a similar
instrument ingeniously constructed for the purpose by Dr.

* Zs. anorg. Chem., lxix, 38-46, 1910.

522 Day and Sosman—Nitrogen Thermometer Scale

Dickinson was introduced into the re-entrant tube of the gas
thermometer bulb itself. The resistance thermometer, which
was easily sensitive to a few thousandths of a degree, revealed
small temperature fluctuations (0°05°) in the rapidly circulating
liquid outside the bulb but no systematic temperature differ-
ences. Within the re-entrant tube the fluctuations were no
longer felt. :

With these precautions to guard against temperature differ-
ences about the bulb, temperatures were measured (1) at the
boiling-point of benzophenone, (2) at the melting-point of zine,
(3) at the melting-point of antimony.* The three thermo-
elements, after removal from the nitrate bath, were placed in
one or the other of the following: in a vapor bath of boiling
benzophenone, in an apparatus for determining the zinc melt-
ing-point, or in a similar apparatus containing antimony ; after
which they were returned to the gas thermometer furnace for
the verification of their readings. This series of operations
constituted aset of observations as carried out in the tables which
follow. Inasmuch as the gas thermometer was brought as close
as practicable to the temperature of the points (benzophenone,
zine, etc.) selected as standards, the intermediary role of the
thermoelements was merely that of a transfer agent, in which
role the individual properties of the thermoelements do not
appear at all provided the wires were originally homogeneous.
The danger of contamination of the elements and consequent
inhomogeneity is negligible at these temperatures. Even if
such contamination had crept in, it would have discovered itself
in differences between the readings of the elements with each
change in the gradient, of which differences no trace was
found.

By way of providing a strictly rigorous test of the accuracy
of the transfer of temperature from gas thermometer bulb to
the reference standards and its independence of the intermedi-
ary thermoelement, a special arrangement was devised in the
case of zine as follows: A steel bulb was made up with approx-
imately the dimensions of the gas thermometer bulb and sus-
pended in the same position in the nitrate bath. Enclosed in
this bulb was the charge of zinc in its graphite crucible (fig. 2).
In this crucible the thermoelement occupied the same position
which it occupied in reference to the gas thermometer bulb,
and all other conditions were, of course, identical. The zine
melting-points were determined in this way, i. e., in a nitrate
bath in which there were no measurable temperature differ-
ences in the region about the melting zine and with the tem-

* The zine and antimony were the same charges which were used in the

previous investigation. The analyses may be found in Pub. 157, pp. 87 and
88 ; this Journal, xxix, p. 159.

with Boiling Point of Sulphur. 523

perature gradient along the thermoelements identical with that
surrounding the gas thermometer bulb itself.

4, Boiling Point of Sulphur.

Finally an attempt was made to establish one temperature in
this region from which the intermediary thermoelement should
be completely eliminated. The gas thermometer bulb itself
was immersed in the vapor of boiling sulphur. For this deter-
mination the nitrate bath was replaced by an appropriate sul-
phur boiling-point apparatus, all other conditions remaining
the same. In building this apparatus, which is shown in fig. 3,
the experience of the Bureau of Standards was utilized for the
most part. To this design certain modifications suggested by
the unpublished work of Prof. G. A. Hulett of Princeton were
added by way of rendering the determination, as far as prac-
ticable, independent of particular exper imental conditions
employed.

Heat was supplied electrically from a coil of high resistance
wire about the sulphur tube, the coil ending about 2° below the
level of the surface of the liquid sulphur (Bureau of Standards
usage). An independent coil surrounded the vapor region, sep-
arated from it by an annular air space of about 1™ i (Hulett).
The bulb was surrounded first by a shield of sheet aluminium
(Bureau of Standards) with holes near the top and bottom to
permit the free circulation of the sulphur vapor and a hole in
the center of the bottom diaphram to permit the escape of liquid
sulphur which chanced to condense on the shield. The shield
afforded protection against any direct interchange of radiation
with the furnace or with the boiling liquid and its steep con-
ical roof diverted the condensing liquid sulphur away from the
bulb. Subsequently with the purpose of varying these condi-
tions the aluminium shield was replaced by another of similar
form but of glass (Hulett) and of somewhat smaller diameter.
This was suspended from the conicai aluminium roof of the
first shield, which now overhung the side walls by several mil-
limeters, with the effect that liquid sulphur condensing upon
the cone could drip from the overhang instead of running
down-the side wall past the bulb. The radiation conditions
were also radically altered by this substitution of glass for
aluminium both around the bulb and below it.

Further variation was provided by changing the current in
the two heating coils. Variations of some 35 per cent in the
main coil about the boiling liquid were tried and the upper coil
was varied from zero (Bureau of Standards usage) to over 40
per cent of the current in the main coil. Or, in other terms,
the 1°" air jacket about the vapor was varied in temperature

524. Day and Sosman—Nitrogen Thermometer Scale

from the normal gradient (without heat in the upper coil) to a
temperature equal to that of the sulphur vapor itself.

None of these changes produced any measurable change in
the temperature of the sulphur vapor as recorded by the gas
thermometer provided enough heat was supplied to fill the
tube with vapor. During some of the measurements the vapor
escaped freely between the glass tube and aluminium cover and
burned there.

The remaining details and relative dimensions of the sulphur

HIG. 3.

Fic. 3. Apparatus for direct determination of the boiling point of sulphur
with the nitrogen thermometer. Scale: 1 to 6:0.

vapor bath will be clear from the diagram (fig. 3), which is
drawn to scale. The arrangement shown in the figure is the
one with the aluminium shield.

The sulphur used was distilled to free it from a black residue
which was found in both of two different preparations of C.P.
sulphur. This residue, which is partly if not wholly ferrous
sulphide, would probably have had no appreciable effect on the
boiling point. After the close of these experiments the
sulphur boiling apparatus was sent to the Bureau of Standards,
where a number of- measurements were made of the tempera-

with Boiling Point of Sulphur. 525

ture of the vapor within the aluminium shield compared with
the corresponding temperature in one of the sulphur baths
which Waidner and Burgess* have standardized and described
in connection with their measurements with the platinum
resistance thermometer. This comparison has been described
by Messrs. Dickinson and Mueller.t The differences amounted
in maximum to 0:04°, which may afford some measure of the
certainty with which the temperature of the sulphur vapor is
reproduced in an apparatus differing considerably from the
conventional form and dimensions.

At the close of the measurements the gas thermometer bulb
and manometer were disconnected. In order to make certain
that our calculation of the volume of the unheated space con-
tained no unknown constant error, that portion of this space
lying outside the furnace was deter mined directly, as follows:
the mereury was brought up to the fixed point with the capil-
lary open to the air. The connection between the two arms
of the manometer was then closed, and a known volume of air
(about 0-1°°) was drawn in through the capillary by drawing
off a weighed amount of mercury from the short arm. The
open end of the capillary was then sealed, the manometer con-
nection reopened, and the mercury again brought up to the
fixed point. The pressure necessary to effect this is a measure
of the volume of the space in the capillary and connections.
The results were:

Direct determinations ._.. ..-- 0:159°¢

0°164°°
SN LPS a Dads Se AR GE A Stig RECTAN ye ek ck O- 162°
Caleulateds ins, £909... 235 0-168

The difference is negligible.

Finally, the location on the brass scale of the gas thermo-
meter of the “fixed point” which is situated in the top of the
short arm of the instrument and which defines its “constant
volume,” was redetermined and found to have become dis-
placed by 0°18™™ since the initial determination in 1909. An
appropriate correction was accordingly made to this constant
in computing the results.

These various checks and verifications complete the observa-
tions. The more important constants of the instrument and
the formula used in the calculations are reproduced below from
the previous paper.

* Bull. Bur. Stds., vi, 150-230, 1909.

+ J. Washington Acad., ii, 176-180, 1912.
meu. No. 107, pe oe.

526 Day and Sosman—Nitrogen Thermometer Scale

Material of the bulb: pure platinum 80 per cent
pure rhodium 20 per cent

Volume of bulb: V,=205-82°

Volume of unheated space: v,=0°309°°

oO.
=0'00150
lz

0

Expansion coefficient of bulb material: 10° B=8'79 + 0:00161 ¢

Gas: pure nitrogen.

Initial pressure of gas (see Table I): ,=about 500™™.

Pressure coefficient of gas (see Table II): a = 0:0036679 to
0°0036681.

Formula used in the computations:

Doo Meets
V.

0

in which p, and p are the corrected pressures at 0° and ¢ respec-
tively.

5. Experimental Results with Nitrate Bath.

Table I contains the measurements of the zero-point of the
instrument before and after each heating and serves to show
that its variations are wholly within the accidental errors of
reading of barometer and manometer. In the third column
p’, is the measured initial pressure of the gas in millimeters
of mereury at zero degrees. The application of the correction
for the “unheated space” gives the pressures (p,) of column 4.

The measurements included in Table If are introduced
merely as a rough check on the pressure coefiicient (a) of the
gas. A much more accurate determination has been made of
this constant for nitrogen by Chappuis* and his value of it
(0:0036681, corresponding to a pressure of 502™™") was used in
the calculations which follow. These measurements merely
afford a rough confirmation of this value within the somewhat
larger limits of error of our instrument. Columns 3 and 4
contain the pressures at the boiling point of water corrected as
in Table I.

In Table II], columns 3 and 4 contain the pressure measure-
ments near the three fixed temperatures of reference, reduced
as before; ¢ (column 5) is the gas thermometer temperature in
the nitrate bath and e (column 6) the corresponding electromo-
tive force of the thermoelement in microvolts ; ¢ (column 7) is
the electromotive force of the same elements in benzophenone,
zine and antimony respectively and the final column contains
the corresponding gas thermometer temperatures.

* Trav. Mem. Bur. Int., vol. xiii, 1907.

with Bowing Point of Sulphur.

527

TABLE I, Measurements of po.
Date Serial No. Po Po
1911 First Gas Filling.
17 Oct i 486°03 485°98
Oe as 4 486°05 486°00
a a 7 486°06 486°01
Ags Bs 8 486°05 486°00
Second Gas Filling. |
D6. °° 9 501°91 501°86
Dy, sos SE 10 501°91 901°86
Silk act 12 501°87. 501°82
Sy 6 13 501°88 901°83
2 Nov 15 501°94* 501:89*
Genre 17 501°89_ 501°84
Oveeees 18 901°91 901°86
Te Tey 4 e* 22 501°84 501°79
1 USSR eta 24 901°81 501°76
eye < 26 501°87 501°82
Qo 31° 29 001°81 501°76
6 Dec 30 501°79 501°74
Shae 8 35 901°84 S01:79
Abe SaaS 38 901°82 | HOUT
Didin 56 43 901°83 501°78
Diewes 48 501°77 SON y 2
aOR?
2 Feb. 54 501°86 901°81
Beano” 61 901°88 901°83
TABLE IIT. Measurements of pj 00.
Serial
Date No. 10h p Barom. t a
1912
15 Feb. 58 683°51 | 683°69 | 754°3 | 99°790 | 0:00386684
oe 09 683°49 | 683°67 | 753°7 | 99°768 | 0°0036685
hs 60 683°46 | 683°64 | 753°4 | 99°757 | 0:0036686
Mean| 0°0036685

* High wind, both mercury columns varying.

528 Day and Sosman—Nitrogen Thermometer Scale

TABLE III. Gas Thermometer Measurements in Nitrate Bath.

Serial | | eat |Temp. of
Date No. p | p | t e | fixed fixed
| | point point

Benzophenone, boiling point.

(outs | | |
18 “Oet.| 32 4 1023-736 | 1024°47 | 306°97 | 2379.8 | 2369°2 | 305°82
vO i oe 6 1020°60 1021°69 | 305°37 | 2364°7 | 23869°2 | 305°86
gO as 11 1 4 053°07 | 1054°18 | 304°91 14944*| 14996 | 305°82
1. Nov.| 14 | 1054°84 | 1055°97 | 805°91 | 15002*| 15005 | 305-96
| | | Mean | 305-87
Zinc, melting point.
18 Oct.| 38 | 1216°27 | 1218°05 | 418°78 | 3429°4 ) 3433-7 | 419-94
2D a6. SE 5 | 1215°85 | 1217°61 | 418°53 | 3427°1 | 3433°7 | 419-24
4 Nov.| 16 | 1256°96 | 1258°76 | 419°32 | 3432°2 | 3433°7 419°48t
17 “© | 25 | 1256°54 | 1258°35 | 419°18 | 3432°9 | 3433°7 | 419-27
18 “| 27 | 1255-85 | 1257°69 | 418°80 | 3429°0 | 3433°7 | 419°31
18 “| 28 | 1254°96 | 1256°80 | 418°29 | 3423°8 | 3433°7 | 419-36
| Mean | 419-28

Antimony, melting point.

10 Nov.) 19 | 1627°10 | 1630°58 | 629°66 | 5525°8 | 5527-7 | 629°84
10 “ | 20 | 1627:09 | 1630°57 | 629°66 5525°2 5527-7 | 629-90
10 “ | 21 | 1626-96 | 1630-44 | 629°58 | 5524-2 | 5527-7 | 629-92
14. “ 93 | 1625-08 | 1628°59 | 628°54 | 5515°5 | 5527°7 | 629°78

| : | | Mean | 629°85

* Copper-constantan thermoelement. :
+ Wide temperature variation on manometer. This value is omitted
from the mean.

6. Interpolation Formula.

For convenient interpolation with thermoelements in this
temperature region, the following equation is accurate within
0°3° as far as the melting point of copper, but may not be used
beyond that temperature or below the boiling point of ben-
zophenone :

é = —308+4+8:2294¢+°001649 ¢

In terms of the standard element used in our recent publica-
tion upon this subject,* this equation gives the following
electromotive forces : .

* Publication No. 157, Carnegie Institution of Washington, pp. 109 ef seq.
For the measurement and interpolation of temperatures above 1082°6°, the

reader is referred to the same pages; for temperatures below 305°9° to page
536, following (Adams and Johnston).

with Boiling Point of Sulphur.

Fixed point

Benzophenone

(boiling point)
Cadmium

(melting point)
Zinc

(melting point)
Antimony

(melting point)
Silver

(melting point)

0

(melting point)
Copper

(melting point)

ifs Experimental Results on Sulphur.

Standard

Temperature | thermo-
(Nitrogen element

Thermometer) (in
microvolts)

305°9> 2365
320°8 2502
419°3 3429
629°8 5530
960°0 91138
1062°4 10295
1082°6 10534

529

Difference

een Obs. — Cal.

(in

microvolts)| yyy. Dede:
2364 | +1 | +0.1
2502 0 0:0
3432 tnt OF LE ee
5529 + +01
9112 Bey ey)
10296 2s Shee OS
10534 0 0-0

Table IV contains the measurements made in the sulphur
vapor bath. p’ and p represent the gas thermometer pressures
corrected as before, ¢ the resulting “temperature, followed by
, and the

the barometer reading reduced to sea level at lat. 45°

boiling temperature reduced to 760™™ pressure.

TABLE IV. Direct Measurement of Boiling Point of Sulphur.

Serial
Date No.
1912
31 Jan 49
(75 50
(‘a4 51
1 Feb. 52
(T4 53
3 Feb. Die)
(43 56
ce 57

p

1298°77
1298°83
1298°84
1299°14
1299°14
1299-70
1299°50
1299°55

1301°07
1301°16
1301°17
1801°44
1301°44
1302°00
1301°81
1301°87

t at

t Barom. | 760™™
443°21 746°3 | 444°45
443°26 TALO | 444-43
443°27 ye a (a ie. © BP.
443°42 T48°4 | 444°47
443°42 748°2 | 444°48
443°73 752 Or | 44445
443°62 (olete ) 4474 0
443°66 (DEO P4424 7
Mean | 444:45

Thermometer Scale

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with Boiling Point of Sulphur. 5381

In Table V are brought together all the gas thermometer
determinations of the boiling point of sulphur since 1890 with
the necessary information for an intelligent comparison of the
determinations. Column 5 contains the initial pressure of the
gas used, and column 6 the original value published by the
author with a reference to the place of publication. Two
of these determinations were subsequently corrected by the
authors themselves. These corrections (with the reference)
are given in column 7.

Inasmuch as these various determinations were made under

somewhat different gas conditions, the results are not directly
comparable without reduction to some common unit. The
four columns which follow contain such reductions for pur-
poses of convenient comparison. Our own observations are
directly comparable with the numbers contained in the column
“Const. vol. nitrogen scale, p, = 500.” The fairest compar-
ison is afforded by reduction to the thermodynamic scale, in
view of the fact that the different gases used by the various
observers depart in varying degree from the behavior of a per-
fect gas expanding at constant volume from the same initial
pressure. Itshould be noted that the small differences between
the four columns.are really arithmetical and not experimental,
since none of the original determinations can claim an accuracy
closer than 0°05°.

The Callendar and Griffiths determination above, which is
often quoted as direct, is in reality indirect. In his first inves-
tigation (Phil. Trans. 1887) Callendar showed that his parabolic
formula represented within 1° the variation of the resistance of.
platinum with the temperature as determined by the constant
pressure air thermometer as far as 600°. In this later work
(Phil. Trans. 1891) he showed by a comparison of two resist-
ance thermometers with the air thermometer, using sulphur
merely as a constant temperature bath, that his original value

of 6 = 1°57 would still represent the results for these ther-

mometers within the limits of error. This value of 6 was then
used to calculate the sulphur boiling point determined with
several platinum thermometers in the usual (Meyer) form of
sulphur boiling tube.*

* The air thermometer observations of Callendar and Griffiths in sulphur
vapor comprise fourteen readings, made between 4:52 and 5:30 p. m. on

Friday, September 12, 1890, and between 8:25 and 9:07 the following morn-
ing, as follows (Phil. Trans., 182 A, 1891, p. 189):

Friday, Sept. 12, 1890. Saturday, Sept. 13, 1890.
Time Temperature Time Temperature
4:52 444 °52° 8:25 444°51°
5:02 444-90 8:28 444-51
5:06 444°68 8:88 444-52
9:18 444°77 — . 8:42 444°58

* 8:21 444°79 8:48 444°54
5:26 444-94 8:50 444°52

5:30 444-98 9:07 444:61

582 Day and Sosman—WNitrogen Thermometer Scale

8. Summary.

The new gas thermometer temperatures which this investi-
gation has given us are brought together in Table VI, ex-
pressed (column 2) in terms of nitrogen expanding at con-

Concerning the sulphur used with the air thermometer, the following
information is offered (p. 140) :

‘‘The sulphur used on the Friday was poured out of the apparatus before
it soiidified. It was found to be much discoloured, owing to the presence of
various impurities due to residues of oil, red lead, etc., used in fitting the
iron tubes together. Fresh sulphur was used on the Saturday, and this, on
examination, appeared to have suffered hardly any change.”

Notwithstanding the fact that the conditions surrounding the observations
of Saturday appear the more favorable, these are EOC, with this state-
ment (p. 140): :

‘The mean values of ¢ deduced from the observations with the platinum
thermometers M, and M2, by assuming the value 6=1°'570 in formula (d), are:
On Friday, t= 444°78°C.

On Saturday, t = 444°84°C.

‘“The mean values of ¢ deduced from the simultaneous observations with
the ai thermometer are:

On Friday, ¢t = 444:°80°C.
On Saturday, t = 444°52° C.

‘The value found on Friday is seen to agree perfectly with that de-
duced from the observations with the platinum thermometers. The value
of ¢t deduced from Saturday’s observations is 0°32° too low; but it is prob-
able that the value of mk, used in reducing the observations taken on that
day, is a little too great.”’

We may, therefore, conclude that these experiments, SO
far as . they g go, are a complete verification of the value of é found in 1887,
and show that the platinum wire has not altered appreciably in the
interval.”

»

Of the apparatus used, the following details are taken from another part
of the paper (p. 120) :

‘““Two new thermometers, M, and Mz, were therefore constructed out of
the remainder of the old spiral [1887], and were very carefully compared
with the air thermometer at a temperature very near the boiling-point of
sulphur. . . . The result agrees perfectly with that found in 1887, and
shows that the value of the d-coefficient has not altered appreciably in the
interval.

‘‘ The apparatus used for this comparison [the sulphur bath used with the
air thermometer], although useful as a constant high-temperature bath, was
not very well suited for determining the actual temperature of the sulphur
vapour. Another series of experiments was therefore undertaken in a Meyer
tube, which proved to be more convenient for the purpose.”

On page 145 occurs the following statement of the final result (obtained in
the Meyer tube with resistance thermometers only) :

‘‘ Assuming 0d = 1'd70 for thermometers L, M, and Me, we find for the
corresponding air-temperature the value
t = 444°53° C.
We believe this to be within 0°1° of the true temperature of the vapour of
sulphur boiling freely under a pressure of 760™™.”

The value assumed for 0 is entirely dependent upon the temperature
determined with the air thermometer, and can uot be more accurate than
this determination. From the air thermometer measurements above quoted,
05° would appear to be a fairer measure of the uncertainty of the final sul-
phur point.

with Boiling Point of Suiphur.

5398

stant volume from an initial pressure of 760™" and (column 3)

in terms of the thermodynamie scale.

These values replace

the corresponding temperatures published in our papers to

which reference has been made.

TABLE VI.—SUMMARIZED TABLE.

Point

Benzophenone (Kahlbaum)
boiling pt. at 760™™

Cadmium, melting pt.

Zinc, melting pt.

Sulphur, boiling pt. at
760™™

Antimony (Kahlbaum),
melting pt.

Aluminum, melting point

Temperature
Notes
Const. vol.| Thermo-
p,—1 at. | dynamic
305°85 305'9 |Transferred by platin-
rhodium and copper-con-
stantan thermoelements.
o20°8 320°9 Interpolated.
419°3 419°4 Transferred by thermo-
elements.
444-40 444-55 | Direct.
629°8 6380°0 Transferred by thermo-
elements.
698°5 698°7 ‘| Interpolated.

Finally a comparative table is added showing in terms of the
same (thermodynamic) scale a comparison of our results with
those obtained by Holborn and Henning in the latest work
published from the Reichsanstalt.

TABLE VII.—CoOMPARATIVE TABLE.

Thermodynamic Scale.

Pout Holborn and Hen- | Day and Sosman

ning 1911 1912

Benzophenpne 305°9 305°9

Cadmium 320°9 320°9

Zine 419°4 419°5

Sulphur 444°51 444-55

Holborn and Day
Antimony 630°6 630°0

Geophysical Laboratory,

Carnegie Institution of Washington,

March, 1912.

Am. Jour. Sct.—FourtH Srries, Vou. XX XIII, No. 198.—Junz, 1912.
3 |

5384 Adams and Johnston—Standard Scale of Temperatures.

Art. XLIV.—A Wote on the Standard Scale of Tempera-
tures between 200° and 1100°; by L. H. Apams and J.
J OHNSTON.

A YEAR ago, at the time when the original measurements
recorded in this note were completed, there was an outstand-
ing uncertainty of about 1° in the temperature scale around
400°; at the present time, by reason of the concordant results
obtained in the best series of gas thermometer determinations
within this region—those recently published by Holborn and
Henning* and Day and Sosmant—this uncertainty is not more
than 0°1°, and is probably less than this, at temperatures up to
500°. The definite establishment of the temperature scale ren-
ders the conclusions presented in this note to some extent
supererogatory ; nevertheless, it has been thought worth while
to present them, as, at the least, they serve to confirm those
expressed in the pr eceding paper.

In what follows, we present independent thermoelectric
measurements at the boiling points of naphthalene and benzo-
phenone and of the freezing points of four metals—tin, bis-
muth, cadminm and lead ; the agreement of these results with
the best resistance thermometer measurements of the same
fixed points shows that the thermocouple is not inferior to the
resistance thermometer as an accurate temperature-measuring
device within the temperature range in question. Moreover,
we propose to show that the most thorough and most extensive
series of resistance thermometer measurements—those of
Waidner and Burgess, made at the Bureau of Standards—are
also in remarkable agreement over the whole range of
temperature (up to 1100°) with the gas thermometer measure-
ments of Day and Sosman, when they are expressed in the
same scale. At the same time this comparison shows that, if
we consider all of the points,t excepting sulphur, to be fixed
by the gas thermometer work, and on this basis set up an
interpolation formula and galeulate therefrom the boiling
point of sulphur, the resistance thermometer measurements
lead to a value (444°55°) identical with the gas thermometer
determinations.

Calibration of the Thermoelements.

In connection with another investigation$ it became neces-
sary to calibrate carefully some copper-constantan thermo-

* Ann. Physik, xxxv, 361-74, 1911. t+ Preceding paper.

t Namely, the boiling points of naphthalene and benzophenone, and the
freezing points of tin, cadmium, zinc, antimony, silver and copper.

§ This Journal (4), xxxi, 501- 17, 1911.

Adams and Johnston—Standard Scale of Temperatures. 535

couples, which were then employed in determining the freez-
ing points of the metals tin, bismuth, cadmium and lead.*
This calibration has been described in the paper just referred
to; but the account there given must be amplified by the fol-
lowing additions and corrections, which are rendered necessary
by the slight changes in the temperature scale resulting from
the new and more accurate gas thermometer determinations at
temperatures up to 500°.

It has been found+ that too much reliance can not be placed
on the readings of copper-constantan thermoelements at the
zine point (419°4°), for some diminution of electromotive force
sets in, not serious, but sufficient to preclude the most accurate
measurement. For this reason we have ceased to make use of
the zine point as a calibration temperature; for the same
reason, we give the calibration curve only up to about 360°.

The calibration temperatures, expressed in the corrected
seale, together with the corresponding values of the electro-
motive force of the standard element, are given in Table I.

TaBLE I.—Calibration Temperatures.

e in microvolts Difference
t
Observed Calculated? In microvolts | In degrees
0 0 0 0°0 0°0
25°00 979 980°0 =F) —°025
50°00 2012 2012°7 +0°7 +°016
75°00 3096 3095°8 +0°2 | +°005
100°00 4997 4226°1 +0°9 +°019
217°95 10119 LOT19"S —0°3 —°005
306°1° 15007 15007°0 0°0 0:0

1 The benzophenone used was from Merck, which melts (at 46°9°) 0°3°
lower, and boils 0°2° higher, than that obtained from Kahlbaum (Waidner
and Burgess, Bull. Bur. Standards, vii, 6). The f. p. of our Merck benzo-
phenone was also 46°9° ; consequently we have added 0°2° to the accepted
b. p. (805°9°) of Kahlbaum benzophenone.

* From the equation e=38'100¢ +0°04442 ? —0-00002856 t?, obtained by
the method of least squares,e as measured at the zinc point (419°4°) was
21755 microvolts; the equation gives 21688, which does not differ by more
than what one might expect in view of the extrapolation through more than
110".

To reproduce the above data, a quadratic equation is insuf-
ficient, except over a very short range, and so is the cubic

Sikae-/eit., p. 008.
+ Cf. Day and Sosman, preceding paper, p. 521.

0 arn

5364 Adams and Johnston—Standard Scale of Temperatures.

TABLE II.—Standard Calibration Curve for copper-constantan
difference for every 100 microvolts.
Kahlbaum), 14996.

Fixed points: 0°, 0; 100°,

e | 0 1000 2000 3000 4000

0 0: 25°50 49-70 72°83 95:08
2°62 4 2:36 2:26 2-18

100 2-62 27°97 52-06 75°09 97-26
2-60 246 2-35 2:25 O17

200 5:22 30°43 54-41 Teak 99°43
2°59 2:45 2-33 2-25 27)

300 7°81 32°88 56°74 79°59 101:60
2°57 24h 2°83 2:24 2-16

400| 10°38 35°32 59-07 81°83 103°76
2°55 243 2°32 2 Oo is 2:15

500/| 12-93 37°75 61°39 84:06 105:91
2-54 2-41 2°31 2:22 aU

600| 15:47 © 40°16 63-70 86:28 10805
2°58 2:40 2:30 2-21 21h

700; 18:00 42°56 66°00 88.49 110°19
2°51 2°39 2:28 2:20 2:13

800} 20°51 44:95 68°28 90°69 112-32
2-50 2°38 2:28 2:20 2°12

900 23-01 ATES 70°56 92°89 © 114-44
29 2°37 2°87 2:19 2:12

1000 25:50 49-70 72°88 95:08 116°56

e 10000 11000 12000. 13000 14000

Q| 215-72 234-32 252-61 270°63 288°41
L877) Loy 1-8 179 Ie.

100 | 217°59 236°16 25442 272 A2 290°18
IG 1-84 TESTI 179 176

200 | 219:46 238-00 256°23 DA 21 291-94
1-87, PRY TSE 78: 1:76

300 | 221°33 239-84 25804 275°99 293°70
87, 183 PBA 73 1:76
400 | 223-20 241°67 259°85 DRT 295°46 .
1°86 183 1°80 TES £76

500! 225-06 243-50 261°65 279°55 297-22
1°86 T8e 180 C78 1G

600 | 226-92 24533 263°45 281°33 298-97
185 182 180 key, 175

700} 228-77 24715 265°25. 283-10 300°72
1°85 182 1°80 LUG 75

800 | 230-62 248-97 267°05 28487 302°47
V85 1°82 179 197 75

900 | 232-47 250°79 268-84 28664 30422
1:85 182 179 Pay L7G

234:32 252°61 270°63 288°41 305:97

Adams and Johnston—Standard Scale of Temperatures. 537

thermo-elements, giving the temperature and the temperature

4226 ; 217:95° (naphthalene), 10119;

305°9° (benzophenone,

7000

8000

5000 6000 9000 e
116°56 137°40 157°66 177°43 19677. * 0
211 2°05 2-00 1:95 1:91
118°67 139°45 159-66 179°38 198°68 100
2:10 2-04 2:00 1:95 gt
120°77 141-49 161°66 181°33 200-59 200
2:10 2-04 1:99 194 1:90
17 143-53 163°65 132% 202-49 300
2-09 2°03 1:98 194 | 1:90
124:96 145-56 165°63 185°21 204-39 400
2:09 2:08 1:98 94 1:90
12705 147°59 167°61 187°15 206°29 - 500
2:08 2:02 oF, 1:93 AS
129'13 149-61 169°58 189-08 208°18 600
2-08 2:02 eo 1:93 1:89
131-21 151°63 171°55 191:01 210°07 700
2-07 2-01 1:96 1:92 189
133°28 153864 173°51 192:98 211-96 800
2:06 2-01 1:96 1:92 U'88
135°34 155°65 175247 194°85 213°84 900
2:06 2-01 1:96 1:92 TEE:
137:40 157-66 177°48 196°77 ee 72 1000
15000 16000 17000 18000 nia Aldey. Se e
305:97 323°35 340°58 SOCOOke ka ily Seepules 0
eG FB a
307:72 325-08 BAOED OAD ital RNR Rarer 3d |. ge a sy 100
Lith BIS FPO
309-46 32681 SAAS OOD siege MEGA Sy wolelisd ee 1 (ane eae 200
174 173 EO
311°20 328-54 Brose y let MER AAGO ETS sold ie es Ut aed DE 300
Ly, 1:72 IL
8312-94 330-26 BA EIESALD SiS Nae. Gal See Dae tOe ape ae tee ae 400
Ly 172 G75
314°68 331°98 Be wles ious he mig emer tna IE ig SAS CME 500
316°42 sud 333°70 rat 35084 ae
33: CPSC NE BAL NSU REIT A STACY ASDA Oe!
: L774 172 aL may
18°16 385°42 BO DOR ete hme etn NRE HAS Ying,
e778 1:72 OM oO
319-89 387°14 Sof its PO ah Getta) Seay) had
7G 1°72 70 ot
321-62 338°86 SIO OO are es een enNC ek aCe ninety
| Fie, 172 170 poo
823°35 340°58 |. OM MOOM MEE ual Gta Wah a uit aes) eas ati 1000

538 Adams and Johnston—Standard Scale of Temperatures.

equation of the form ‘=Ae+ Be’+ Ce’ ;* but they can, as we
found, be fitted very closely by the inverse form of function,
6— Att Be 4 Or. Accordingly, on this basis a least square
solution for all the points in Table I was made; this resulted
in the equation
€ =38'105 ¢+0°04442 ¢’—0:00002856 ¢°,

from which the figures in the third column of Table I have
been computed. The agreement is excellent; it cannot, how-
ever, be used as a valid argument in favor of the accuracy of
either the temperature scale or of the measurements, as any-
one can readily convince himself by working with a number of
similar cubies. Incidentally, it may be noted that in making
such a least square solution, it is inadmissible to hghten the
work by dividing through by ¢, which would necessitate only
the least square solution of a quadratic; for the solution
obtained by proceeding in this way, although apparently a
cubic equation, is that appropriate to the condition that the
deviation of the curve from the values of e/¢ (instead of e)
shall be a minimum.

By means of this equation, values of e and of de/dé for each
10° up to 360° were computed; the slight irregularities being
evened out by adjustment of the successive differences. By
interpolation from these results, and adjustment of the suc-
cessive differences again, a table was constructed giving ¢ for
each 100 microvolts; this is presented in Table II,+ to which
are also appended the E. M. F.’s corresponding to the fixed
reference points.

This table may be used for any copper- -constantan element
with the aid of its deviation curve, which is obtained by
plotting at severalt known temperatures the differences
between the readings of the element in question and the stand-
ard curve.§ Its use thus saves much recalculation of thermo-
element curves. The absolute uncertainty of temperatures
deduced from the above table should, we believe, not now
exceed 0°1°; temperature differences over a small range are
probably accurate at least to 0°02°. For this reason the values
of temperatures and differences in Table II are given to
hundredths of degrees.

The Identity of the Readings of Thermoelement and Resistance
Thermometer at Boiling Points and Melting Points.

The initial series of measurements gave differences between
the freezing point of tin and the naphthalene point on the one

* This was tried because its use would have saved so much trouble in cal-
culating the most convenient form of table—that giving ¢ for round values
of e.

+ This table replaces Table I of the previous publication (loc. cit., p. 510).

{ For accurate work, comparison at anumber of temperatures is advisable,
since the slope of the deviation curve is likely to change sign once or oftener.

§ This matter is more fully treated by Sosman, this Journal, xxx, 7, 1910.

Adams and Johnston—Standard Scale of Temperatures. 539

hand and between the freezing point of cadmium and the
benzophenone point on the other,—using our own apparatus and
materials—which were 0°2° higher than the corresponding dit-
ferences obtained by Waidner and Burgess at the Bureau of
Standards. This lack of agreement disappeared* when we
determined all the points on the identical samples of material
used by Waidner and Burgess. This we were enabled to do
through the kindness of Dr. G. K. Burgess in lending us his
boiling point apparatus and his pots of tin, cadmium and lead,
and we desire here to acknowledge our indebtedness to him.

TABLE ITT.
Boiling Point of Naphthalene and Benzophenone.

From Thermoelectric|from Resistance Ther-
measurements mometer measurements
(Adams & Johnston)| (Waidner & Burgess)
Sub- Source eye tm TEL a1 era) ee eM we TS MA oe
stance paratus | couple! AA iGanree
aed As given
Microvolts | Degrees »|dueed to our
iby them ceed
Naph-|Merck A K 1585-7‘)
thalene|/Kahlbaum| 5b E 1585°3 |
Kahlbaum| B © Pe HOMO (24-95), 28-0 217°97
Merck A CHOU:
5 a CP HOLS"5 |
Ss zu CF 10120;
2 J
Benzo-|Merck (b)| A EK 2366°2 |
phe- eooes(alinae 2 ty 2366°3 |
none |
By ia hati C F008 S271 i
a coy A C. 15007" | (30671) | 306°2 306°11
feet |) S- (Cp abso LO, 4
BO ws niet C, |15004: |
(oe es Cr 15005°5* |

' Couple E is of Pt—PtRh; Ci, Ce, Cs, are of copper-constantan.

? Bull. Bur. Standards, vii, 4, 5 (reprint No. 148).

3 The values given in the last column have been reduced from those in the
column to the left by means of the differences between the scales as deter-
mined in a way to be described later (p. 543); i. e., these values are on the
basis that the b. p. of sulphur is 444 55°.

* Mean of two or more determinations often separated by a monthor so in
me The maximum deviation from the mean in any of these cases was

*The divergence was due to slight impurities in our tin and to the fact
that the benzophenone used was from Merck (cf. footnote to Table I).

540 Adams and Johnston—Standard Scale of Temperatures.

Freezing Points of Metals.

From Thermoelectric From Resistance Ther-
measurements mometer measurements
Quantity (Adams & Johnston) (Waidner & Burgess)
Metal Source | of | Thermo- i
| metal couple’ 4 When re-
| orms. | | Microvolts Degrees re seg duced 2 our
seale
|
Sn |Kahlbaum| i500 | C, | 10861: | 231-75)
ASRS eae? 10859 | 231°71
Jest ik, CS 10863: | 231°79|
200 C, 10856: 231°67 |
1) 231°92 231°88
200 | E 1706° | 231-9 |
dt ideas" 17067741 231-0.
1500 | « 1706: | 231°9 |
Shimik as LOG | 23169 |
Bi J.T. Baker OS NS020" 24) 270099)
Ce 13015- | 270-905
Cd |Kahlbaum C, | 15860- | 320°921|
1 . 20°92 || |
| of PPB es | 320 82) | 301-014 ne
E 2502°5 | 320°9 |
Pb |Kahlbaum E 2560°5 | 327°2
| | | |
| BO Pew ea 27°19
| | Go | 16227- |igoy-28)) 327
| |} C6226: v41'327-303
| | |

‘Couple E is of Pt—PtRh; C., Ceo, Cs, are of copper-constantan.

? Bull. Bur. Standards, vi, 173 (reprint No. 124).

>The values given in the last column have been reduced from those in the
column to the left by means of the differences between the scales as deter-
mined in a way to be described later (p. 543); i. e., these values are on the
basis that the b. p. of sulphur is 444°55°.

4 Melting point.

In Table III we present our results. In the boiling point
experiments, three forms of apparatus were used; one (B in
the table) of glass,* with an aluminium shield for the thermo-
couple; the second (A) of brass, with an inner tube of thin
copper to prevent radiation; and the third (S) similar to the
second, but of slightly different dimensions. Four different
elements were used; one (E) of platinum-platin-rhodium, the
other three (C,, C,, C,) of copper-constantan (No. 30 wire=
0°25™™ diam.).

* Lent to us by Dr. Burgess.

Adams and Johnston—Standard Scale of Temperatures. 541

The electromotive forces at the freezing points were reduced
to degrees with the aid of Table Il; the boiling points were
reduced to normal pressure by means of this table and the
formule: for naphthalene, ¢,,, = ¢—0°058 (py—760); for
benzophenone, ¢,,. = ¢—0°063 (p—760). The freezing points
have been given to hundredths of a degree, as relative values
for purposes of comparison only; their absolute accuracy is of
the order of 0-1°.

This table shows that the boiling points are independent of
the apparatus and sample of material employed, and that the
freezing points can be reproduced satisfactorily on different
days and with varying set-up; e. g., the results are independent
of the size and kind of tube—glass or porecelain—used to
protect the thermocouple from the metal, and of the size of
the charge.

In order to make the data of Waidner and Burgess more
truly comparable with our own, we have reduced them to the
scale of temperature on which our own values are based
(cf. postea, Table V), and present these reduced values in the
last column of Table III. The differences between the values
for the adjacent freezing and boiling points are compared in
Table IV with the analogous differences derived from our
thermoelectric measurements.

TaBLE I[V.—Comparison of Temperature Intervals as measured by Thermo-
elements and by the Resistance Thermometer.

Temperature difference as derived from
measurements with

Interval Thermoelements |Resistance Thermometer
Waidner Holborn
Us Cs le Burgess | & Henning
Sn-naphthalene (138°9.13°78)13°78| 13°91 laced
Cd-benzophenone, Merck 14°8/14°82,14°82) 14°81 {Matte
Cd-benzophenone, Kahlbaum 15°0)15°02,15°02| 15°01 15°03

Pb—Ca 6:3) 6:36 oe 6-43

The differences, therefore, as determined by us with platin-
rhodium and copper-constantan thermoelements in various
forms of apparatus on the one hand, and with resistance ther-
mometers at the Bureau of Standards or at the Reichsanstalt
on the other, agree very satisfactorily. This proves conclu-

* When reading only to one microvolt, as we were, it is illusory to give the

readings of the platin-rhodinm element closer than the nearest tenth of a
degree.

542 Adams and Johnston—Standard Scale of Tenyperatures.

sively, that there is no systematic deviation whatever, within
the range of these measurements, between the readings of
these two kinds of thermometers—either at boiling points or
at melting or freezing points—when both are calibrated with
reference to the same temperature scale.

This position is confirmed by a direct comparison of the
series of measurements by Waidner and Burgess of the resist-
ances of platinum thermometers with the recent gas thermome-
ter measurements of Day and Sosman,* transferred by means
of thermoelements to the same fixed points. So far we have
dealt with temperatures less than about 330°; but the compari-
son just referred to enables us to extend the same conclusion
to the copper point (1083°), beyond which the readings of the
resistance thermometer are no longer trustworthy.

Comparison of the Series of Resistance Thermometer Measure-
ments (Waidner and Burgess) with Gas Thermometer Deter-
minations (Day and Sosman) at the same Fixed Points.

For a fair comparison it is essential that the results be
expressed in the same scale of temperatures; for this we have
adopted the thermodynamic scale. We have accordingly
applied the appropriate corrections, taking a mean of the cor-
rection numbers collated by Buckingham, to the results of Day
and Sosman, which were determined on the constant volume
scale. The uncertainty of the gas thermometer determinations
is indeed comparable with the magnitude of these corrections ;
nevertheless, we have, for the sake of definiteness, considered
it advisable to apply them.

The results as given by Waidner and Burgesst were derived
by means of the Callendar formula,§ the third calibration tem-
perature being the sulphur boiling point taken as 444°70°. In
order to refer these values to the comparison scale, it seemed
simplest to substitute in the Callendar equation the simulta-

* This Journal, xxix, 93-161, 1910; Carnegie Institution of Washington,
Publication No. 157, 1911. Cf. also preceding paper.

t Bull. Bur. Standards, iii, 288-9, 1907 ; (reprint No. 57).

t Ibid., vi, 150-228, 1910, (reprint No. 124); vii, 1-11, 1910, (reprint No.
143).

t

§ The Callendar formula is t—pt = 6 Ga, _
temperature, and pt (the so-called platinum temperature) is defined by the
relation

t :
1) where ¢ is the true

ret 100 (R, — Ro)

e a Pio0 na Ro
(R is the resistance att). 0 is a deviation constant derived by means of the
formula from the third calibration temperature (usually the sulphur boiling
point); for pure platinum 6, as thus obtained, is close to1°50. The formula

is essentially a simple quadratic relation of the form
159, Say af at + bt?

Adams and Johnston—Standard Scale of Temperatures. 543

neous values of the thermodynamic temperature (¢) and the
platinum temperatures of a single resistance thermometer™ as
measured by Waidner and Burgess, and to compute in this
way the corresponding values of 6’. These values vary irreg-
ularly at the lower temperatures, as might be expected, since
the influence of variation of 6 is small when ¢ is small; but at
the higher temperatures they show a distinct upward trend, and
can be represented very fairly by the relation 6’ = 1:489+
6:000015¢. These values of 6’ were combined with the respec-
tive platinum temperatures to give new values of the temper-
ature, which were then subtracted from the temperatures as
given by Waidner and Burgess;{ thus giving the differences
between the two scales at these points. These differences
were applied to the average values given by Waidner and
Burgess, giving the “corrected” average temperatures pre-
sented in Table V, column [I. Alongside of this we have
tabulated (column 1) the temperatures on the thermodynamic
scale as derived from the work of Day and Sosman, and (in
column III) the differences between these two sets of measure-
nents.

The differences at the tin and zine points are no doubt due
to the fact that in these two cases the determinations were
made on different samples of metal; with these two slight
exceptions the agreement is all that could be desired. This
concordance shows further that if we derive an interpolation
formula for the resistance thermometer based on all of the
points excepting sulphur, and calenlate by means of this formula
the boiling temperature of sulphur, we obtain a result identical
with the direct gas thermometer determination of this fixed
point.

If we recalculate the above temperatures, using a fixed value
of 6 based on the newer determinations of the sulphur point, we
obtain results which are practically identical with those of
column II (Table V) except at the silver and copper points,
which would on this ‘basis be lower by 0°6° and 0-9° respec-
tively. This silver point would still be within the limits of
accuracy of the gas thermometer measurements at that point,
but the divergence at the copper point (1°3°) is somewhat
greater than the probable error.

This raises the question of the range through which the
simple, and very convenient, Callendar formula is applicable
in accurate work. It does not hold for impure platinum or
for palladium ;t nor does it hold for pure platinum at all tem-

*No. 1787C ; this instrument was used over the widest range and appears
to ke the most satisfactory of those used at the Bureau of Standards.

+ That is, the temperatures as derived from a fixed 0, obtained by calibra-
tion at 0°, 100°, and the S b.p. taken as 444°70°.

{ Waidner and Burgess, Bull. Bureau Standards, vi, 176, 183.

544 Adams and Johnston—Standard Scale of Temperatures.

TaBLE V.—Comparison of the ‘‘ Corrected’? Temperatures (measured by the
Resistance Thermometer) with Determinations by the Gas Thermometer
and with Thermoelements. Thermodynamic Scale.

‘* Corrected”
Temp. based on |. temps. from re-
gas fee ISIE ther- Dittorsn ces
measurements mometer meas-
(D. & S.) urements
(W. & B.)
te | II Ii—I
Nph. b.p. 217°95" | 217-97 +002
Sn f.p. ew | 231°88 1S
Bnz._ b.p. 305°90* | 305°91 Ol
Cd so 320°92° 320°92 ‘00
Pb sie 327°39° 327°35 — ‘04
Zn f.p. 419°4* 419°24 — ‘16
Ss b.p. 444°55° | 444°55 "00
Sb 1G op 630°0°* | 630°36 + 736
Ag tp: 960°4° | 960°7 ara:
Cu Tp: VOSs-2- | 1082°8 — 4

1 The temperatures are given to hundredths for purposes of comparison.

? Holborn and Henning, Ann. Physik, xxxv, 761-74, 1911.

7From the thermoelectric measurements of Table IV above.

4Temperatures transferred from gas thermometer measurement to fixed
point by thermocouples.

° Direct gas thermometer determination.

peratures below 0°C. Indeed Travers and Gwyer say: “A
standard scale of temperature, based on Callendar’s three fixed
points, using standard wire, and taking 1°5 for the value of 6,
would obviously lead to absurd results at low temperatures ; and
the converse may be said of our own observations,’’* and con-
clude that the Callendar formula cannot be made use of except
for interpolation. There is thus ground for believing that the
accuracy ot the results calculated from the change of resistance
of pure platinum by means of the simple Callendar formula
is, to some extent, fortuitous. The small variation of 6 intro-
duces uncertainties which would appear to be too great for the
most accurate work, except over the temperature range included
between the fixed calibration points 0° —444°55°), and a short

region beyond (perhaps to 750°).+ On the other hand, it must
be. admitted, that the cubic term (which expresses the varia-
tion of 6 with the temperature) is very small—so small that its
effect is searcely greater than the uncertainty in the gas ther-
mometer determinations at higher temperatures.

* Proc. Roy. Soc. London, Ixxiv, 1904-5.

+ The effect of slight changes of 6 on the calculated temperatures may be
gauged from the following : that a change of 0°2° in the boiling point of sul-
phur changes db by 1 per cent (and proportionally for other small changes) ;
this in turn affects temperatures of 300°, or lower, by 01° or less, but affects
the antimony point by 0'5°, and the copper point by 1°6°.

Adams and Johnston—Standard Scale of Temperatures. 545

In this connection one point remains to be noted, namely, the
accuracy of the Reichsanstalt scale in the region 1000-1100°.
Holborn and Valentiner state in one place* that the uncertainty
at 1000° amounts to 2—3°; in another place,t in discussing the
reliability of their newer measurements at high temperatures,
they state that there is a difference amounting to 5° between
the older (1900) and the newer (1906) Reichsanstalt determ1-
nations at 1100°, and continue: ‘‘ The deviation from the mean
would still fall within the limits of error of the earlier deter-
minations. We consider it better, however, to attach greater
weight to the former measurements, because the temperature
eradient in the gas thermometer bulb was much smaller in the
earlier measurements.” This may well be, for they give figurest
which show that in the 1906 determinations at 1124° there
were differences of temperature from one point of the bulb to
another of as much as 346 microvolts, or about 29°.

Summary.

In this note a new calibration curve for copper-constantan
thermoelements, extending from 0° up to 360°, is given, together
with a series of independent measurements of the temperature
differences between the boiling-points of naphthalene (217-95°)
and benzophenone (305:9°), on the one hand, and the freezing
points of tin, bismuth, cadmium, and lead on the other. These
measurements lead to the following values of the freezing
PolMicsnom Zola 8 bia" Od. 320-9" 3 Pb, 3273") lhe
concordance of these values with those obtained by other meas-
urements show that the thermoelement is not inferior to the
resistance thermometer within this range of temperature
(0—860°). Moreover, a comparison of the gas-thermometer
determinations with the results obtained by means of those
interpolation instruments (thermoelement, resistance ther-
mometer, etc.), which measure not temperature independently
but a well-defined physical property which changes con-
tinuously with the temperature, affords an excellent oppor-
tunity, through this continuity, for the discovery of inconsis-
tencies in the gas thermometer measurements. The remarkable
concordance of the present series of thermoelectric measure-
ments and of the most extensive recent series of resistance ther-
mometer measurements (Bureau of Standards), with the recent
gas thermometer determinations made in this laboratory, serves,
therefore, as an eflicient and independent check upon the trust-
_worthiness of the present gas thermometer scale between 0°
and) 11007:

Geophysical Laboratory, Carnegie Institution of Washington,

Washington, D. C., March 20, 1912.

* Sitzungsber. Akad. Wiss. Berlin, xliv, 414, 1906.
+ Ann. Physik, xxii, 19, 1907. { Loe. cit., p. 8.

546 WW. Rk. Barss—Measurements of Radio-activity.

Art. XLV.—Wote on Measurements of Ladio-activity by
means of Alpha Rays; by W. R. Barss.

Ir is a well known fact that in a gas ionized by a-particles
a saturation current is obtained only when a much larger poten-
tial gradient is applied between the plates of the ionization
chamber than is necessary when #- or X-rays are the ionizing
agents. Bragg and Kleeman* showed that a current through a
gas, ionized by a-particies, was still unsaturated when calculation
showed that the number of ions lost by general recombination
was small. The effect was ascribed to “Initial Recombina-
tion’; i.e., to some of the ions being but partially separated
from their parent molecules by the action of the a-particles.
In the absence of an external electric field these ions fall back
on their parent molecules and are thus neutralized. An intense
electric field is snpposed to complete the separation of the ions
and to produce saturation. On this hypothesis, lack of satura-
tion would not depend on the size or shape of the ionization
vessel and saturation would be more easily obtained under
diminished pressure. |

Kleemant has shown that lack of saturation with weak ioni-
zation by a-particles is not due to diffusion of the ions, nor
does it depend on the recombination coefficient. He has
shown that ‘Initial Recombination ” is very small in gases
ionized by #-, y- and X-rays; in other words, these ionizing
agents effect a more complete separation of negative ions from
their parent molecules.

Moulint has proposed an explanation of the mechanism of
ionization by a-particles as follows. The ions formed by the
a-particles are not distributed uniformly throughout the gas,
but each a-particle has, associated with it, a column of ions, the
axis of the column being along the path of the particle. Lack
of saturation is explained by recombination of ions of opposite
sign within each column. This recombination between ions of
the same column ought to exceed that which would be obtained
for the same number of ions distributed throughout the volume
of the gas. The amount of the recombination between ions of
the same column should be much greater when the field is
applied in a direction parallel to the direction of the column,
than when it is applied in a direction perpendicular to it; for
the parallel field would leave the.columns intact, while the
perpendicular field would break each column into two parts by

* Phil. Mag., xi, p. 466, 1906.

+ Phil. Mag., xii, p. 278, 1906.
+ Le Radium, May, 1908, p. 186.

W. &. Barss—Measurements of Radio-activity. 547

separating the positive and negative ions. Hence the lack of
saturation should be more apparent in the former case than in
the latter. These facts were experimentally determined by
Moulin. He obtained saturation for the parallel field at 1200
to 1500 volts per centimeter while for the perpendicular field
only about 200 volts per centimeter were necessary.

Moulin coneludes that general recombination within the
columns (proportional to the square of the density of loniza-
tion within the columns) is so much greater than “Initial Re-
combination” that the latter is negligible in comparison.

Ionization by a-particles was further investigated by Whee-
lock ;* among other results, he obtained the following. When
an electric field is applied parallel to the path of the a-parti-
cle and therefore parallel to the axis of the column of ions, the
eolumn would not be broken up and the recombination occur-
ring would be between ions belonging to the same column.
Since each particle makes the same number of ions along its
path, the density of ionization would be the same in any one
column and therefore it would be expected that the ratio of
currents obtained with sources of different intensities would be
constant for different potential gradients applied. When the
field is applied perpendicular to the column and when the
source of lonization is small, very few columns would exist in
the ionization vessel during the time required for the ions to
be carried over to their respective electrodes. Hence there
would be little chance for recombination between the columns,
so that it would be expected that the ratio of currents obtained
with sources of different intensities would be constant as in the
ease of the parallel field. When the field is perpendicular
and the source of ionization is stronger, enough columns might
exist between the electrodes at one time to make recombina-
tion possible, not only between ions of the same column but
between those of different columns. In this case the ratio of
currents obtained with different source intensities might not
be constant because of the added recombination of ions of dif-
ferent columns.

Wheelock found that the ratio of the current produced by a
more intense source of rays to that produced by a weaker
source is constant for the parallel field; that it is approxi-
mately so for the perpendicular field when the sources are
both weak, and that it increases slightly with the potential
gradient applied when the sources are stronger. This is as
would be expected if the ions formed by a-particles are arranged
in columns.

When the gas is ionized by §- or X-rays it would not be
expected that the ratio of currents obtained for different source

*This Journal, xxx, 233, 1910.

548 OW. Re. Barss— Measurements of Radio-activity.

intensities would be constant. Here the ions are distributed
throughout the volume of the gas, and general recombination,
which depends upon the ionization density, i.e., upon the
number of ions per cubic centimeter in the gas, would increase
as the ionization itself is mereased, unless a saturating field is
applied.

In a great number of important investigations in the subject
of radio-activity, it has been assumed that the quantity of
radio-active material present was proportional to the ionization
currents produced by the a-rays. In these experiments, elec-
trical fields have been applied which would have been ampie
to cause saturation if the ionization had been produced by
8- or X-rays, but which are now known to be quite inadequate
to produce saturation when a-rays are employed. Results
which have been obtained in this way are of fundamental
importance in the theory of radio-active transformation. They
include the determination of relative quantities of radio-active
substances by the “ Kmanation Method” and the method of
thin films, as well as nearly all the measurements of rates of
decay of such substances. It is safe to say that in no case in
which such measurements have been made with an electroscope,
in air at atmospheric pressure, has a saturating potential been
applied, or even very closely approached. The fact that a
fairly consistent body of measurements and constants has been
built up by many investigators, notwithstanding this apparent
flaw in their experimental arrangements, shows that the con-
siderations advanced above must have a considerable degree of
validity. The object of the present experiments is to test this
point specifically in the important case when the a-rays are
produced by an emanation mixed with the ionized gas. In
this case the sources of the rays are scattered through the gas
and on the walls of the vessel, and the paths of the a-particles
and their attending columns of ions extend in all directions ;
so that the geometrical complication is as great as it can
well be.

We might reasonably expect the ratio of currents to be con-
stant in this case, at least for small source intensities. If the
number of a-particles is small, there will be only a few columns
of ions existing together during the time required for the ions
to be carried to their respective electrodes. It is true that a
portion of the a-particles will cross each other and that the
separated columns of ions will also sometimes cross each other,
thus producing some recombination between ions of different
columns. But even when this happens, the crossing will usu-
ally be at an angle, and the length of each column is so great
compared with the diameter of its cross section that even if
they do intersect, the amount of this recombination will be neg-

W. R. Barss— Measurements of Lradio-activity. 549

ligible compared to the recombination between ions of the
same column. |

As the intensity of the source is increased, the number of col-
umns of ions existing together is also increased. The proba-
bility that different columns will cross each other is greater and
therefore the amount of recombination between ions of dif-
ferent columns will be greater. So that, as in the case of the
perpendicular field, the ratio of the larger current to the smaller
will probably increase as the potential gradient is increased.

In the present experiments, a cylindrical tin chamber was
used 13:5% high and 10-5 in diameter. A central brass

HiG.. L:

cE Ur eta ts eee Be eR

Ionization current

8 16 40 80 200
Field in volts

electrode, provided with an earthed guard ring, was connected
to a tilted electroscope of the Wilson type, the leaf of which
was observed by means of a microscope having a graduated
scale in the eyepiece. This central electrode and the leaf of
the electroscope were grounded through a potentiometer by
means of which each deflection due to the ionization current
was calibrated in terms of potential. The capacity of the sys-
tem was kept constant, so that these calibrated readings varied
directly as the actual ionization currents. Different potentials
were applied to the case of the chamber. Radium emanation
was used as an ionizing agent; it has a half value period of
about four days, so that it provided a suitable source of varying
intensity.

One series of observed data is given in the following table
V is the potential in volts applied to the case. CO, represents
the corresponding ionization current for a given intensity ; O,
the ionization current for a weaker intensity, ete.

Am. Jour. Sci.—FourtH Series, Vou. XX XIII, No. 198.—June,’ 1912.
3

550 W. Lt. Barss—Measurements of Radio-activity.

V C, C, Cs Cs C;

2 “72 ware) “40 peor "16

= 1°60 1°15 °85 "50 38

8 2°50 1:90 1°40 *80 tars)

16 2°90 2°20 1°50 "96 65

40 3°35 2°40 1°75 1°05 “75

80 3°O3 2°58 1°86 1°10 ‘78

200 3°65 2°80 1°95 1°16 *80

400 3°80 Zo 2°05 °83
600 3°90 3°00 2°08

A series of curves plotted from these data is given in fig. 1:
abscissee represent the potential V applied to the case. Ourve
1 has for its ordinates the values given in OC, above, curve 2 the
values in C,, ete.

Ratios of ionization currents are given in the following table:

Vv C,/C. C:/Cs C,/O. C,/Cs

2 1°31 1:80 3°13 4°50

4 1°39 1°88 3°20 4:2]

8 1°31 1°80 3°12 4:54

16 1°32 1°93 3°02 4°45

40 1-30 p Se 21-04 3°19 4:46

80 1°36 1°89 3°21 4:59

200 1°30 1°87 3°14 4:56

ADO wed eh SBM 1°85 4°57
600 1°30 1°87

It is evident that the current ratios are constant within the
limits of experimental error.

In the above data the potential applied to the case was nega-
tive. A series of readings was made with the potential posi-
tive giving similar results.

The radium emanation used was drawn from carnotite,
the amount of emanation being equivalent to the amount in
equilibrium with about 10-* gm. of radium. It remains to
be tried to what degree the intensity may be increased before
there is a change in the current ratios.

Summary.

When the a-particles are moving in all directions with
respect to the electric field, and when the source of ionization
is not too intense, the ratio of the currents obtained from two
sources of different intensities is constant for different poten-
tials applied to the ionization chamber.

No great errors are involved even when currents are used
less than one-fifth of the saturation value.

In conclusion, I want to thank Professor Bumstead for his
many suggestions throughout the experiment.

Sloane Physical Laboratory, Yale University, New Haven, Conn.

LN. L. Bowen—The Binary System. 551

Art. XLVI.—The Binary System: Na,Al,Si,O, (Nephelite,
Carnegieite )— Ca Al,Si,0, (Anorthite) ; by N. L. Bowrn.*

CONTENTS :

Introduction.
Preparation of Materials.
Preliminary Study.
Heating Curves.

Method.

Results—Table I.
Quenchings.

Method.

Results—Table IT.
Equilibrium Diagram.
Discussion of Equilibrium Diagram.
Optical Study.

Properties of Anorthite.
Carnegieite.
Nephelite.

Solid Solutions.
Work of Earlier Investigators.

Carnegieite.

Nephelite.

Anorthite.

Application to Natural Minerals.

Anorthite.

Nephelite

Nephelite Mix-Crystals.

Other Solid Solutions.

Carnegieite.
Thermometry.

General.

INTRODUCTION.

The study of the system WNa,A1,Si,0,—Ca Al,Si,0, was
undertaken because of the very considerable importance of
these compounds as rock-forming constituents.

The compound CaA],8i,O, occurs in nature as the mineral
anorthite. The preparation of anorthite in the laboratory has
been accomplished by a number of workers.

The compound Na, A],Si,0, (NaAISi0,) approximates in com-
position the natural mineral nephelite and has been prepared in
a form resembling that of nephelite. It is mentioned in text-
books of mineralogy as artificial soda-nephelite and is given a
place in order to bring out the chemical relationship within the
hexagonal group of which nephelite is the best known member.

Preparation of Materials.

In the preparation of mixtures for exact thermal work, it is
important that only the purest material should be used. The
calcium carbonate was of tested purity, the alumina was freed

* Presented in partial fulfillment of the requirements for the degree of

Doctor of Philosophy in the Department of Geology at the Massachusetts
Institute of Technology ; May, 1912.

Or

52 N. L. Bowen—The Binary System.

from all but the last trace of alkalis by boiling with a solution
of ammonium chloride and igniting. A very pure silica was
obtained by grinding selected quartz and treating with hydro-
ehloric acid. Anhydrous sodium carbonate was made from
the hydrated compound by heating for eight hours at 300°C.
It was proved that the material so obtained corresponded with
the formula Na,CO, by converting to chloride and weighing.

To make anorthite CaCO,, Al,O,, and SiO, were mixed in
the proper proportions and fused in a Fletcher gas furnace at
about 1600°. Three fusions, the product being “finely ground
before each, gave a glass which er ystallized to a perfectly
homogeneous mass of anorthite.

In the preparation of the soda compound Na,CO,, A1l,O,, and
SiO, were mixed and the same procedure followed, but not
with equal success. When the resultant glass was crystallized,
instead of the homogeneous product to be expected, the micro-
scope showed, scattered throughout, plates and needles of Al,O,
(corundum) uncombined. Repeated fusion did not remedy
the difficulty. Finally, it was determined by analysis of the
glass that some Na,O ‘had been volatilized at the high tempera-
ture of the gas furnace. The materials had been mixed in the
proportion to give :—

Na2,O Al.Os Si02 Sum
lea a | 30°89 42°34 = 100-00
Analysis showed 20°50 36°62 42°85 == 99:97

By heating the intimately mixed oxides at a low temperature
(about 800°C) in an electric furnace, grinding and reheating
four times, it was found possible to cause the oxides to com-
bine without loss of soda. The whole could then be melted to
a glass which gave on slow cooling a perfectly homogeneous
crystalline mass with no excess of alumina.*

Even after combination some alumina develops in the per-
fectly homogeneous mass if held near its melting point for
several days, from which it appears that some soda may still be
lost after long heating. No very definite statements can be
made concerning this phenomenon inasmuch as every effort
was concentrated on its avoidance.

Preliminary Study.

A stock of the pure end members being ready, intermediate
mixtures corresponding to each 10 per cent interval were
made up.

* The loss of soda gave, of course, an excess in both silica and alumina.
The silica undoubtedly went to form a small quantity of a more highly sili-

cated compound, probably albite, which, however, did not appear as such
and, therefore, must have disappeared in solid solution. Apparently no

compound in which the ratio, = 20s is greater than unity could form under

a0’
the existing conditions and the a alanis was left free.

NV. L. Bowen—The Binary System. 553

A preliminary study was carried out by putting some of each
mixture in a separate platinum crystallizing dish and holding
all at an approximately constant temperature in an electric fur-
nace for a couple of days. The products were then examined
under the microscope. This procedure was repeated at mod-
erate temperature intervals over some range. The detail of
this work need not be given here because it is not in itself of
great importance, but is a very useful preliminary to the more
precise determinations. It was noted that all compositions
erystallize readily; that, in the mixtures, no reactions pro-
ducing new components took place, leaving the system truly of
two components. The existence of a eutectic point in the
neighborhood of 1300° C. was indicated. Two ditferent forms
of the soda compound were observed, the one appearing at low
and the other at higher temperatures. The low temperature
form is analogous to nephelite and will henceforth, for con-
venience, be referred to simply as nephelite. The high tem-
perature form had formerly been prepared at this laboratory,
and given the name carnegieite. At low temperatures mixtures
containing up to 30 per cent anorthite are perfectly homoge-
neous, showing the ability of the low temperature form to hold
over 30 per cent of the anorthite molecule in solid solution.
The lime compound was observed in only one form, anorthite.

Heating Curves.

With this preliminary information it was possible to proceed
with the exact determination more expeditiously.

Small quantities of each mixture were crystallized at about
1200° C. (below the eutectic point indicated above), and heating
curves run on each. The method employed was that found at
the Geophysical laboratory to be the best in mineral work.’ *
The charge is of about 2gms.; the bare thermocouple of plati-
num-platinum-rhodium dips into the charge and is connected
with a potentiometer system which measures the E.M.F. set
up at the thermocouple contact. A curve has been prepared
giving the E.M.F. corresponding to temperatures between 0°
and 1550° C. for standard elements calibrated against the gas
thermometer. Such standard elements are used to calibrate
the elements employed in the course of the work.

The furnace in which the charge is heated is an electrical
resistance furnace in which a coil of platinum wire is the con-
ducting material.

In running a heating curve the temperature of the furnace
is caused to rise gradually and regularly. The temperature of
the thermocouple in the charge is read at regular time inter-

* Wor references see list at end of article.

554 NV. L. Bowen—The Binary System.

vals, and temperature is plotted against time. If there is no
energy change within the charge, its temperature also rises reg-
ularly, but at the appearance of a new phase the rate of heating
of the charge (the gradient of the heating curve) experiences a
change depending upon the energy involved in the change of
hase.

se During the change of phase, on account of heat absorption,
the temperature of the charge either remains constant or rises
more slowly than the temperature of the furnace, but upon
completion of the change of phase the temperature rises rap-
idly to that of the furnace. It is this.sudden increase in the
rate of heating of the charge which is commonly termed a
‘break’ on the heating curve. The temperature at which a
break occurs is, then, the temperature at which the disappear-
ance of a phase of the system is completed. In Table [ the
temperatures at which breaks were obtained on heating curves
are given opposite the corresponding composition.

TABLE I.
Wit %, Upper point Kutectic Inversion Knickpunkt
CaAl 2 Si 2 O 8 .

One a eee 1527 ee 1504 2 ae
ORs Sear e ares 1525 meee 1305 LA
HQ ic oe ie ne 1473 sks 1335 1352
PEt pouees sige eM lo a a <A EM ke 1354
7d | PSM SR Ape Ty Sede Bf aaee 25 Were 1360
20 Peat ates. eee ry ote ef oe 1352
SOp2 ese > og Ma eee 25S aoe SNe 1349
AOS sce ee oe Eyer 1310° ee ee
DO Sat ee Se crs 1305 ae eet
OS ibs cere arenas Baie 1304 ipig Ahe ee
5) VA aes Oe Sle RAL ane 1302 2 EE ee
7 OA EMS OLL 1437 1307 mA oe uns
BOs Sra eee ee 1484 1306 Ee aes
B04 ve BU Bepery 1522 Seacre of p42 ier
LOO Ses ge: 1550 Eyed ey ttes Jee
1OON S38 2 Seen 1549 SiSe a woes

These results are plotted on the temperature-composition
diagram (Diagram I).

In the diagram each circle shows a temperature at which a
break occurred on the heating curve for the corresponding
composition. The general form of the equilibrium diagram is
suggested. There is a eutectic point at about 1302°. Another
triple point, possibly a ‘ knickpunkt,’ occurs at about 1352°.
The general form of the liquidus curves is indicated. Small
heat effects obtained in the pure sodium compound and in the

N. L. Bowen—The Binary System. 555

DIAGRAM I.

{0 20 30 40 SO COO .7 GO SO {00
Na, Al, 51, O,, ‘% CaAl, Si, Op Wet.

mixture with 10 per cent CaAl,$i,O, are shown by small
circles and are undoubtedly due to inversion.

VQuenchings.

In Table I there are many blanks. Doubtless, some ofthese
could have been filled in by especially careful work with heat-
ing curves, but a different method was adopted for obtaining
the same informatiou.

The use of the quenching furnace* combined with the micro-
scopic examination of the charges offers a trustworthy method

556 NV. L. Bowen—The Binary System.

of obtaining information as to temperatures at which phases
appear and disappear, and at the same time a knowledge of the
nature of the phases themselves.

A small charge of any mixture, wrapped in platinum foil, is
held at a definite temperature for a period of time which 1s
deemed sufficient to insure equilibrium for that temperature
and composition, and is then quenched by allowing it to fall
into a dish of mercury at room temperature.

The chilling is so abrupt that any phase present at the fur-
nace temperature is ‘fixed’ and ready to be studied under the
microscope. by running a series of quenchings progress is
made towards a knowledge of the phases present at equilibrium
for each composition, at all. temperatures—in short, towards
the data necessary for an equilibrium diagram.

By the quenching method many changes of phase may be
detected and studied which either take place too slowly or
involve too little energy change to give an appreciable break
on a heating curve. With many transformations, moreover,
especially in the more viscous substances, superheating is likely
to oceur when the heating is rapid, as in running a heating
curve, so that the actual break observed may come at a temper-
ature higher than that at which the transformation concerned
would take place if equilibrium prevailed. In quenching work
it is the endeavor to make the time sufficiently long that all
transformations which can take place at the temperature of the
furnace may be complete.

In this work the thermoelement junction in the quenching
furnace was distant from the charge 1/2 em. or more. The
small temperature difference between the charge and the fur-
nace element was determined at frequent intervals over the
temperature range desired by hanging a standard element in
the position of the charge and reading both. The differences
found were applied as corrections to the readings of the fur-
nace element in the course of the work.

The furnace temperature was kept constant by noting it fre-
quently and making the necessary changes in the resistance of
the circuit. For the more careful work the current from a
storage battery was used.

Several scores of quenchings were made. Of these, only the
more significant will be tabulated (Table II), more especially
those which determine the limit of stability for the various
phases.

No

15
16
eG
18
19
20
21
22

25

NV. L. Bowen—The Binary System.

TABLE II.

(a) Inversion,

Temp. Time
L245 = 6 hrs.
L252 1 hr.
1245 lela
1252 6 hrs.
1260 elo
1252 iL lowe,
1245 i Vawes
1235 Teh
1260 4 hrs.
1275 olave:
WS 17) 7 hrs.
1282 4 hrs.
1294 Lng
1296 Pilar:

Phases found
after quenching

Ne only
Ne & Cg
Ne & Cg
Cg only
Ce only
Cg only
Ne & Cg
Ne & Cg
Ne only
Ne & Cg
Co & Ne
Ne only

Ne & Cg (trace)

Ne & Cg

* Ne = Nephelite, Cg = Carnegieite.

(b) Nephelite solidus.

See also (solid solution An in Ne).

Tere 6 hrs.
MEST 2 hrs.
1340 lave:
1343 1 hr.
1328 lon?
Loe 2 ities
1310 2) | OMESS
oaleg Daves

(c) Ne liquidus.

Ne only
Ne only
Ne only
Ne & glass
Ne & glass
Ne only
Ne only
Ne & glass

See also eutectic composition.

Compo- Form
sition at start
Wt. %
; CaAl.SicOs
0 Ne*
0 Ne
0 Cg*
0 Cg
0 glass
0 glass
0 glass
0 glass
5 Ne
5 Ne
10 glass
10 Ne
10 Ne
10 Ne
20 glass
20 Ne
20 Ne
20 Ne
25 glass
25 glass
30 glass
30 glass
40 An & Ne
20 glass
20 glass
25 glass
50 An & Ne
60 An & Ne
30 An & Ne

1320° i Joye

(d) Cg liquidus

Lag? Th tae:
el ay ie hie
1374 Telere

(e) An liquidus.

1330° 1 hr.
1380 1 hr.
1392 1 hr,

glass only
glass only
glass only

DOT

glass & Ne (bare trace)

glass & Cg (bare trace)
glass only
glass & Cg (rare)

558 NV. L. Bowen—The Binary System.

(f) Change of phase at ‘ Knickpunkt.’

33 3 Ne 1357° 6 hrs. Cg only

34 5 Ne 1357 6 hrs. Cg & glass trace.

35 10 Ne 1357 6 hrs. Cg & glass

36 20 Ne 1357 6 hrs. Cg & glass

37 30 Ne 1357 7 hrs. glass only

38 3 Ne 1346 6 hrs. Cg only

39 5 Ne 1346 6 hrs. Cg & Ne

40 10 Ne 1346 6 hrs. Cg & Ne

41 20 Ne 1346 6 hrs. Ne & glass “ \)

40 ay Ne 1346 Ghrs. glass&Ne - Y

(g) Eutectic composition.

43 50 glass 1304° 2hrs. An & glass

14 40 glass 1304 2hrs. Ne & glass

45 47°5 glass 1304 2hrs. An & glass

46 46 glass 1304 lhr. <An& glass

47 45 glass 1304 lhr. Ne& glass
(h) Solid solution An in Ne.

48 30 glass 1295°ca 2days Ne only

49 32 glass 1295°ca 2days Ne only

50 35 glass 1295°ca 2days Ne & An (mere trace)
(k) Solid solution Ne in An.

51 98°5 glass 1250° 2 days An only

52 98 glass 1250 2days An & Ne (trace)

53 £7 glass 1290 2hrs. An& Ne

(1) Solid solution An in Cg.

(See also change of phase at ‘ Knickpunkt.’)
54 3 glass 1350° 6 hrs. Cg only
55 5 glass 1350 6 hrs. Cg & Ne (trace)

Many of these quenching results are worthy of special dis-
cussion, but this may be undertaken more profitably after they
have been combined with the heating curve results and plotted
on a temperature-composition diagram (Diagram II: Equili-
brium ‘Diagram). .

Explanations of Signs and Terms.

In Diagram II the circles indicate heating curve breaks ; the
numbered crosses indicate temperatures and compositions at
which quenchings were made, the numbers corresponding with
those in Table II where the phases present are given. The
data make possible the drawing in of the curves separating the
fields of stability of the various phases. On each field the
phases present at equilibrium are marked. Nephelite is used

N. L. Bowen—The Binary Pee 559

to indicate the hexagonal form of Na, Al 91,0, and also the
isomorphous hexagonal mix-crystals with 0—35 per cent CaAl,
Si,O,. Carnegieite is used to indicate the triclinic form of
Na, Al,Si,O, and also the isomorphous triclinic mix - crystals
with 0—5 per cent Ca,Al,Si,0O,. Anorthite indicates triclinic

DiaGRam II,

1460

A Ni e lila, ITE
CAR a air FI
Im ae
1! eee
2
| pn ree 4

Oe »,, ; yo CaAl, Si, O, fee
EQUILIBRIUM DIAGRAM,

1420

1360"

CARNE

1840°

1800"

aS

CaA1,8i,O, and also the isomorphous triclinic mix-crystals with -
O—2 per cent Na,AI,Si,O,.

Throughout the text abbreviations are used: Ne to indi-
cate nephelite (NaAISiO, hex.); Cg to indicate carnegieite
NaAISiO, triclinic); An to indicate anorthite (CaA1,8i,O, tri-
clinic). Nephelite mix-crystals are indicated, Ne,,An,, or Ne,,-
An,,, the subscript numbers indicating the weight percentage
of NaAISiO, and of CaA1,Si,O, present in the mix-crystal. In
like manner, carnegieite mix-crystals are referred to, —Cg,,An,
and anorthite mix-crystal —An,,Ne,. NaAISiO, and Na,Al,
Si,0, are used interchangeably. The purpose in using the

560 NV. L. Bowen—The Binary System.

latter form is that of bringing out clearly the analogy between
the two components. No knowledge of the molecular weight
is implied. Diagram II is the only diagram here contained on
which certain points are lettered, and when these points are
referred to by letter in the text, it has not always been con-
sidered necessary to specify Diagram II.

Discussion of Table II and Equilibrium Diagram.

Inversion Phenomena (Table LI (a)).—In the heating curve
work a break was obtained with nephelite (Ne) at 1305°.
The heat effect was small and undoubtedly due to inversion.
In the quenchings it was, however, found that nephelite will
go over to carnegieite at a temperature considerably below
1305°. Held at 1245° for 6 hours there was no formation of
carnegieite, but at 1252° for only one hour the charge was
largely converted to carnegieite. These results indicate an
inversion temperature between 1245° and 1252°. By starting
with carnegieite (Cg) confirmatory results were obtained.
Crystallized at a high temperature and then held at successively
lower and lower temperatures, it was found that at 1252° no
change took place in 6 hours, but that at 1245° partial con-
version to nephelite was observed within one hour. From
these results the inversion temperature is shown to he between
1245° and 1252° or at 1248° (approx.). Close to the transition
temperature the inversion is only partial in either direction,
after several hours. At a temperature (about 1500°) more
removed from the transition point nephelite is converted
entirely to carnegieite within an hour. The reverse change
does not proceed to completion so readily, but was effected by
heating carnegieite over a Bunsen burner for 60 honrs.

Glass of composition NaAISiO, crystallizes as carnegieite
at any temperature above 1248°. At temperatures only a
few degrees below 1248° where nephelite is the stable
phase glass crystallizes as both nephelite and carnegieite,
whereas nephelite itself shows no tendency to change to
carnegieite at these temperatures. It seems possible that the
unstable glass in assuming the stable form nephelite passes
through the “less unstable’ form carnegieite which may
persist for a considerable time and is therefore found in the
quenched products. Glass held at temperatures considerably
below 1248° erystallizes only as nephelite. If the ‘“‘less
unstable” form, carnegieite, is formed at these temperatures it
inverts quickly to nephelite.

With the nephelite mix-crystal (Ne,,An,,) a small heat effect
suggestive of inversion was obtained at 1335°, somewhat higher
than that in Ne. The results of quenchings indicate again

N. L. Bowen—The Binary System. 561

that this temperature is considerably higher than that at which
inversion will take place if the time is sufficiently long.
Ne,,An,, may be held at 1282° (84° above the inversion point
of Ne) for four hours without change. Held at 1294° for one
hour a trace of the carnegieite form and at 1296° for one hour
considerable carnegieite separates.

These results indicate that carnegieite first separates from
Ne,,An,, between 1282-1294° or at about 1290°. This rapid
rise in the temperatures of inversion of nephelite as CaA!,Si,O,
is taken into solid solution was confirmed in Ne,,An, (1265°)
and in Ne,,An,, which shows only the nephelite form at 1340°.

It is not possible to confirm these inversion temperatures by
starting with the carnegieite form and studying the reverse
change as was done with Ne and Cg because the behavior of
these solid solutions is much less simple than that of the pure
compound.

Jt is well known that according to theory a solid solution
should, in general, melt, not at adefinite temperature to form a
liquid of its own composition, but that melting should be dis-
tributed over a temperature interval, the liquid first formed
differmg in composition (concentration) from the solid.
Similarly the inversion of a solid solution takes place over an
interval, the concentration in the first small quantity of the
new crystal form being either greater or less than that in the
old. It is mainly in these characteristics that a solid solution
differs from a definite compound.

Both melting interval and inversion interval are exhibited
by the nephelite solid solutions. Any point on the curve EK C
represents the temperature of the lower limit of the inversion
interval for the corresponding composition and was located, as
has been described by holding nephelite of that composition at
higher and higher temperatures until evidence of inversion to
carnegieite was obtained. Any point on the curve E D rep-
resents the temperature of the upper limit of the inversion in-
terval for the corresponding composition. Only the end points
E and D are accurately located and the middle portion qualita-
tively indicated (Table II (f) and (J)).

The concentration of CaA1,Si,O, m the carnegieite solid
solution (E D) is much less than that in the nephelite solid solu-
tion (EC) in equilibrium with it at any temperature. Beckman’
has developed an equation for the amount of change in the in-
version (or melting) point of a substance by the solution in it

of = (C,—C,) where AT=
change in inversion temperature, T= absolute temperature of
the version point in the pure substance, /=its heat of trans-
formation, C,= concentration of the solution above the inver-

of anothersubstanee. Itreads A T=

562 NV. L. Bowen—The Binary System.

sion point and C,—concentration of the solution below. In
the present case, as has been stated, the concentration below
the inversion point (nephelite) is much greater than that above
(carnegieite), therefore C,—C, is posztive and relatively large
and so also AT’. This corresponds well with the sharp 72se in
the inversion temperature of nephelite occasioned by the solid
solution of CaA1,8i,O,. Qualitatively, the facts fill the require-
ments of thermo-dynamic theory.

The Nephelite Solidus and Liquidus (Table 11 (b) and
(c) ).—The melting-interval of the nephelite solid solutions has
already been mentioned. The solidus C F and the liquidus
B G have the same significance in this connection as have KC
and E D with respect to the inversion interval.

In mineral work it is not possible to locate solidus and
liquidus by the method of separating solid and lhquid phases
from an equilibrium mixture at various temperatures and
determining the composition of each phase. The solidus was
located by finding the temperature at which nephelite mix-
crystals of different compositions first showed signs of melting
and the liquidus by finding the temperature at which melting
was barely completed. After location of the curves in this
manner the composition of liquid and solid in equilibrium with
each other at various temperatures can be predicted with the
degree of accuracy attained in the location.

The “Knickpunkt” (Table IT (f)).—Breaks were obtained
on some of the heating curves at 1352° (approx.). Quench-
ings show that this is the temperature at which the two
solid phases, carnegieite and nephelite, are in equilibrium
with liquid. The carnegieite has the composition Cg,,
AnD), nephelite Ne,,An,(C) and the liquid has 28°5 per
cent CaAl,Si,O,(B), the compositions being known from the
positions of these points determined by quenchings and not
from analysis (Table II (a), (b), (ce) and (1).

The Eutectic (Table LI (g)).—Breaks were obtained on
many of the heating curves at 1302° (approx.). Quenchings
proved that at this temperature nephelite (Ne,,An,,) and
anorthite (An,,Ne,) are in equilibrium with a liquid with 45°5
per cent CaA],Si,O, (eutectic). The exact composition of the
eutectic mixture was obtained by holding the furnace slightly
above the eutectic point and hanging in it four or five charges
of the same mixture, one above another, on a platinum wire.
The charge at one end of the wire is in the hottest part of the
furnace a few degrees above the eutectic temperature and for
compositions close to the eutectic is completely molten. The
one at the other end is in a cooler part of the furnace a few
degrees below the eutectic and completely crystalline. One or
more of the intermediate charges is at a temperature only very

N. L. Bowen—The Binary System. 563

slightly above the eutectic point and will show on quenching
the excess phase. By examining all, the excess phase for the
composition used will be determined, and by repeating with
other mixtures the eutectic may be placed within narrow
limits. In this manner it was shown that in the mixture with
45 per cent CaA1,Si,O, nephelite was the excess phase, and with
46 per cent, anorthite. The eutectic composition is, therefore,
between the two, approximately at 45 per cent Oa Al, siOF

The Limits of Solid Solution (Table LT (h) (k) & (2). a
solution may be defined simply as a homogeneous mixture, and
with this in mind it is readily seen that the limit of solid solu-
tion might be determined by finding the first composition
(concentration) which shows any trace of inhomogeneity. This
method is, as a rule, the best in mineral work. The most
important solid solutions encountered in this system are the
nephelite mix-crystals. At a temperature slightly below the
eutectic point the first mixture which showed anorthite in
excess was that with 35 per cent CaAI,Si,0O,; in this the
anorthite was a mere trace. The extreme solid solution is,
therefore, approximately Ne,,An,,.

The maximum concentration of CaA],Si,O, in carnegieite is
obtained at the temperature of the ‘knickpunkt’ 1352°, where
the composition of the carnegieite mix-trystals is Ce,,An,
(approx.).

The Liquidus of Anorthite (Lable LI (e) ).—The upper por-
tion of the anorthite liquidus was established by heating-curve
breaks. With lesser concentration of anorthite the magnitude
of the eutectic break obscured the upper point, and in these
mixtures the liquidus was located by quenching from various
temperatures and finding that temperature at which the last
trace of anorthite melted.

In a similar manner part of the carnegieite liquidus was

located (Table II (d)).
— Optical Study.

In the microscopic examination of the product of each
experiment the method employed for identifying constituents
was that of determining refractive indices in the crushed
grains by immersion in liquids of known refractive index.
This method is especially useful for detecting small quantities
of any component. If the preparation be placed in a liquid
which matches the mean index of the excess constituent, even
very minute quantities of another constituent show up mar kedly,
except in the rare case of different substances with nearly
identical refractive indices. Moreover, it is possible to deter-
mine in the crushed grains most of the properties by which
minerals are identified in thin section, such as order of bire-
fringence, optical character, ete.

564 NV. L. Bowen—The Binary System.

Anorthite.

The optical properties of anorthite (An) had previously
been determined in detail at the Geophysical laboratory by H.
E. Merwin, and the figures given are the results of his work.

a = 1:576, y = 17589, y—a= 013. 2V—80°+3°
B= 1583, G = 2°765.

Carnegieite.

Carnegieite (Cg) always shows polysynthetic twinning simi-
lar to that in albite, with high extinction, up to 36°, against
the twinning lines. Other less persistent twinning lamelle
appear crossing these at various angles, often giving a micro-
cline-like structure. On account of the universal intricate
twinning, many of the optical properties are difficult of deter-
mination. The indices, obtained by matching with a liquid in
sodium light and determining the index of the liquid on the
Abbe refractometer, gave

y — ole oe 1900) a ae 00D

The mean index is therefore low, comparable with that of leu-
cite. The birefringence, measured with the compensating
quartz wedge,* gave -0052 and ‘0048 in different plates. Opti-
cal character negative, 2 V small estimated at 12°-15°, proba-
bly triclinic.

All efforts to obtain euhedral crystals failed. In all charges
showing carnegieite and glass (area A D B, Diagram I1) the
carnegieite is always in rounded erystalline globules. An
attempt to grow crystals in a flux gave nothing but similar
globules.

The density of crystallme carnegieite (Cg) is 2°518 at 21°,
determined in Thoulet’s solution on carefully selected material,
free from air bubbles.

Nephelite.

In all charges consisting of nephelite and glass (area C BG
F, Diagram II), the nephelite appears under the microscope in
perfect hexagonal basal sections, dark with crossed nicols, or
rectangular prismatic sections with parallel extinction, indicat-
ing the hexagonal nature of these mix-crystals.

Of the pure sodium compound, nephelite, euhedral crystals
were prepared in sodium tungstate over a Bunsen burner.
These were in all cases bounded by the prism and terminated
only by the base. One of these was measured on the two-
circle reflecting goniometer and the hexagonal nature con-
firmed. The maximum deviation from 60° of the measured
prism angle was 16’, and the average deviation 8’, with fair to

N. L. Bowen—The Binary System. 565

good signals. The indices, determined by the immersion
method in sodium light, gave » = 1°537,¢=1°533. Bire-
fringence 004, slightly, but noticeably less than that in
carnegieite.

‘About half a gram of these crystals was tested for tungstic
acid by boiling with hydrochloric acid. Only pure white
silica was left with no yellow tinge. The amount of tungstic
acid could not have been more than a trace.

The density of these crystals is 2°619 at 21°. The degree of
correspondence of the artificial compound with the natural
mineral is shown in the following table:

Opt.
Cryst’n. Char. @ € G habit
NaAlIsi0, (artif.) hex neg 1537 1°533 2°619 prism and
base
Nephelite (nat.) hex neg 1°541 1°537 255-265 prism and
base
(predominant)

It may be fortuitous that there is close correspondence with
Gladstone’s law in the relation between the mean indices and
densities of the two forms of the soda compound, but the fact
is, perhaps, worthy of note. Gladstone’s law states that the

m—1.,
is constant, whatever the state of

specific refractive energy

d
molecular aggregation.
We have then
oe oi

HOTMCanMeOtelt eu yee - —— A034

: 2°513

: 1°535 —
for, nephelite {522.2 Pet ete "2042

2°619

Nephelite Mix- Crystals.

It was found possible to determine definitely the variation,
with composition, of the optical properties of the hexagonal
mix-erystals or solid solutions from Ne to Ne,,An,,. With
increasing proportion of the lime molecule, the birefringence
of -004 (negative) grows less, passes through zero and finally
becomes -002 (positive).

The indices were determined in sodium light at room tem-
perature by the immersion method. The results are shown in
Table III and in the plot Diagram III, in which the size of
the circles is a rough measure of the accuracy of the determi-
nations.

Am. Jour. Scir.—FourtH Series, Vout. XX XIII, No. 198.—Junz, 1912.

566 NV. L. Bowen—The Binary System.

Tasie III.
Indices of Refraction of Nephelite Mix-crystals.
%
CaAl.Si.Os 2) é Birefringence Optical character

0 1°537 1°533 "004 —
10 1°537 1°535 ‘002 _—
20 1537 1537— very weak —
23 1°537 1°537 none isotropic
25 1°537 1537+ very weak --
35 1°537 1:539 "002 +

It will be noted that the refractive index of the ordinary ray
remains sensibly constant, while that of the extraordinary ray
mounts from 1°53838 to 1539. At the composition Ne,,An,,

Diacram III.

|. 59 :
LOST Ww
L555

LOSS

10 39

2o
% CaAlsSi203 :

(approx.) we have the uniaue case of hexagonal crystals iso-
tropic with respect to sodium light.

Two different kinds of material were available for these
determinations: homogeneous crystalline aggregates prepared
by crystallizing the various compositions at about 1200° (area
E C F H, Diagram IJ) and euhedral crystals Ne,,An,,—Ne,,
An,, embedded in glass obtained from quenchings within the
area BG F, Diagram Il. With the former material the
optical character of nephelite (Ne) was determined as negative
and that of nephelite (Ne,,An,,) as positive by the ordinary
interference figure method. With the latter material the
optical character could be determined where the birefringence
was extremely small because the relation of indices to erystal-
lographie directions was known. Important aid was thus given

NV. L. Bowen-—The Binary System. 567

in determining the refractive indices; for example, both
indices of crystals varying in composition from Ne,,An,, to
Ne,,An,, appear to match the 1:537 liquid, but Ne,,An,, is
weakly birefracting and determinable in the prismatic section
of a crystal as definitely negative and therefore w>e. Ina
similar manner it was shown that Ne,,An,, is positive and
therefore «>. The positive character of crystals Ne,,An,,
indicated by the interference figure was confirmed in these
erystals of known orientation.

A curious fact which gave rise to some difficulty in some of
the quenchings may be noted here. The nephelite mix-erystals
with 23 per cent CaA],Si,O, (approx.) are in equilibrium at
1335° with a melt containing 36 per cent CaA1,Si,O, (approx).
(Area C BF G, Diagram II.) When quenched the er ystals are
sensibly isotropic and have an index 1:537 and the glass, it so
happens, has the same index.* Neither by a difference of
index nor by the presence of birefringence do the crystals
become distinguishable from the glass. Thus, in several
charges quenched from 1335° the presence of nephelite in the
glass could not be detected, although the necessity of its pres-
ence could be proven from charges quenched at a slightly
higher or lower temperature, in which charges the extreme
similarity of nephelite with the glass was approached, but not
quite attamed. Jor this reason the attempt to accurately
locate the intersection of the liquidus B G on the ordinate of
35 per cent CaA1,8i,O, failed. The curve may, however, be
regarded as sufficiently established by the other known points.

The Work of Earlier Investigators.

Several different workers have succeeded in preparing the
nephelite form of NaAISi0O,, but the carnegieite form has
seldom been encountered. This is rather a curious fact, for
carnegieite crystallizes readily from the pure melt, whereas
nephelite is obtained only with very slow cooling} or with the
aid of fluxes. Carnegieite was first prepared by Thugutt’ by
fusing an artificial ‘nepheline hydrate.’ He obtained a mineral
with polysynthetic twinning and high extinction angles, prob-
ably triclinic. Following the suggestion of Lemberg, this
mineral was called soda-anorthite.

In 1905, carnegieite was prepared at the Geophysical labor-
atory and the new name proposed. (Published 1910.)* But

* The index of this glass corresponds approximately with that calculated
for it from the indices of anorthite glass and carnegieite glass in the propor-
tion 36: 64.

+ With slow cooling, the temperature of the preparation is for a long

period in the region slightly below the inversion point, permitting the for-
mation of the low temperature form, nephelite.

568 NV. L. Bowen—The Binary System.

few thermal determinations were made, so that its melting
point and its relation to nephelite were not ascertained. It
was not known at that time that some soda might be volatilized
during the preparation of the compound, but a reéxamination
of some of the samples then made gives evidence that there is
a slight shortage in soda demonstrated by a slight excess of
alumina. The optical properties of this material vary slightly
from those of the purer niaterial, since prepared, the figures
for which are given here. For the same reason the density
2°513 found here is probably more accurate than that formerly
found (2°571).

Gerh. Stein,’ by crystallizing “ soda-nepheline” directly from
the melt, obtained a granular, strongly double-refracting mass.
It is possible that Stein obtained carnegieite, of which the
double refraction, though hardly strong, as ordinarily under-
stood, is higher than that of nephelite.

Nephelite.—The formation of soda-nephelite was first accom-
plished by Fouqué and Lévy in 1878 by simple fusion of its
constituents. With the addition of a flux (sodium vanadate)
Hautefeuille (1880) succeeded in making measureable hexago-
nal erystals.”

In 1884 Doelter” prepared not only the simple orthosilicate,
NaAISiO, but mixtures with excess silica and the potash and
lime content of natural nephelite.

Many others have succeeded in making nephelite as one
constituent of a complex mixture, or by the action of aqueous
carbonate solutions on various compounds. This work has no
special interest from the point of view of this paper, and will
merely be referred to here.

Doelter found that Na,AI,Si,0, (NaAISiO,) and CaA1],Si,O,
were capable of forming mix-crystals, as did the present writer.
It appears that Doelter found a somewhat greater range of
miscibility.

Wallace,” by the slow cooling of a melt of composition NaAl
SiO,, obtained a completely crystalline mass with low retrac-
tive index and low birefringence which he refers to as soda-
nephelite. At the same time it should be noted that Wallace
observed in thin section a microline-like structure and since
this is a structure charcteristic of carnegieite there can be no
doubt that some carnegieite was present.

On account of the long time necessary to obtain complete
inversion in the direction carnegieite-nephelite, it may be stated
as more than probable that much of the material prepared by
direct fusion and described as soda-nephelite in the literature
has contained some carnegieite. A rough similarity in optical
properties is the reason for the failure to differentiate the two.
The method of identification by immersion in refractive liquids
eliminates this possibility.

NV. L. Bowen—The Binary System. 569

Wallace found that a mixture of composition NaAIlSiO, was
completely molten at 13850°. The writer finds that NaAISi0O,
does not melt till a temperature of 1526° is attained, the actual
fizures obtained in two determinations being 1527° and 1525°,
of which the figure given is the mean (Table I). Possibly
Wallace approached the unstable equilibrium nephelite-melt
on cooling.

An indistinct heat effect was obtained by Wallace on the
cooling curve at 1260°. The writer found a small heat effect,
due to inversion, on the heating curve at 1805°. Allen found
a point at 1289°.* The diversity of results is due to the
indefinite nature of heating-curve breaks representing a slug-
gish transformation involving no great heat effect. The
determination by the method of quenching gave 1248°
(approx.) for the inversion point (Table IJ).

Anorthite—Anorthite, like nephelite, was first prepared in
1878 by Fouqué and Lévy” by simple fusion of its oxides.
No special interest attaches to the numerous other preparations
of this mineral. !

The melting point of artificial anorthite is sufficiently sharp
to be used by Day and Sosman™ as a reference point. (1550°)
on the temperature scale. Brun’ obtained by his very different
method (calorimetric) 1544°-1562°.

Mixtures.—Schleimer™ has made determinations of the melt-
ing ‘points’ of mixtures of anorthite and nephelite using natural
minerals. His mixtures are of very different composition from
those used in this investigation and the temperatures found
need have no relation to those found here.

Application to Natural Minerals.

Anorthite.—Several natural anorthites approximate closely
to the theoretical composition. The melting points of some
of these have been determined. Brun,’ working with Seger
cones, and Douglas,” the latest worker with the meldometer,
have obtained figures that differ comparatively little from the
figure given by Day and Sosman for pure anorthite.

Anorthite from Idsu, Japan, 1490-1520°— Brun.
Anorthite “ Mte. Somma, 1505°— Douglas.

Nephelite.—\|n a recent paper” the writer has shown that
experimental results are in accord with Schaller’s statement
that natural nephelites may be regarded as solid solutions of
the three molecules NaAlSiO,, KAISiO, and NaAJIS&i,O,.

Natural nephelites, then, differ considerably in composition
from the compound NaAISiO, used in this work and the

* Geophysical Laboratory, unpublished notes.

570 NV. L. Bowen—The Binary System.

difference in thermal properties is correspondingly great. Thus
it was found by the writer that nephelite from Magnet Cove
quenched from 1870° gave only a clear glass and therefore
melts at some temperature below 1370°. Moreover, Wright®
has found that molten ‘ nephelite’ (Magnet Cove) erystallizes
directly as nephelite without first showing the carnegieite
form. In this respect nephelite from Magnet Cove behaves
like the artificial nephelites with 28-5—35 per cent CaA1,Si,O,
in solid solution.

Nephelite Mia-Crystals.— The extreme nephelite mix-
crystals with 35 per cent CaA1,Si,O, contain approximately 7
per cent CaO. The lime content of natural nephelites never
approaches such an amount. In nature, however, nephelite
never occurs in intimate association with pure anorthite,
although very often it does occur with a plagioclase. <A plag-
ioclase is a solution of anorthite in albite just as the mix-
crystals above referred to consist of a solution of anorthite in
nephelite. When all three substances are present there is,
theoretically, a definite distribution ratio of anorthite between
albite and nephelite, this ratio being equal to the ratio of
solubilities. Albite dissolves anorthite to an unlimited extent.
Nephelite dissolves 35 per cent. We have

C 1
c= = = 35/100 3 (approx.)

2

where C,= concentration of anorthite in the plagioclase.
C,= concentration of anorthite in the nephelite.

Obviously only when C,=—1 G. e. pure anorthite) will
C,=35/100. For every other plagioclase there corresponds a
definite composition of nephelite in equilibrium with it and
the concentration of anorthite in plagioclase is three times that
in the nephelite. The natural minerals always contain import-
ant quantities of other molecules which introduce variations,
and viscosity may be such as to inhibit equilibrium, but the
distribution should probably be of the order indicated. The
analysis of a nephelite from Vesuvius shows the highest lime
percentage (2°20 per cent) (11 per cent CaAl,Si,0,) of all
analyses of that mineral that have been made with sufiicient
care to warrant their consideration.” This nephelite should
be in equilibrium with a plagioclase of approximate composi-
tion Ab,An.,.

Other Solid Solutions.—The zeolite, thomsonite, consists of
CaAI,8i,0, with Na,AI,Si,O, up to 50 per cent, and corre-
sponds in composition with some of the writer’s mixtures with
the addition of water. If, as Zambonini” concludes from the
result of experiments, thomsonite is not a definite hydrate, the

NV. L. Bowen—The Binary System. 571

existence of anhydrous orthorhomie crystals of like composition
is to be expected. The orthorhombic mineral barsowite may
represent one of these anhydrous thomsonites. The best
analyses of that mineral give it a composition close to that of
anorthite, with some soda and small quantities of other oxides.

No orthorhombic mix-crystals were encountered in the
present work, but it is quite possible that such a series may
be capable of existence at low temperatures where changes are
so slow as to be obtainable only with the efficient fluxes of
nature.

That nephelite will hold 35 per cent anorthite in solid solu-
tion, whereas carnegieite, which, like anorthite, is triclinic, will
hold at most 5 per cent, comes rather as a surprise. That
miscibility m the solid state does not always follow from
crystallographic similarity is, however, well exemplified in a
number of cases.

The very limited solubility of Na,A1,Si,O, in anorthite has
some importance in the light of the Linosa feldspar of abnor-
mal composition recently described by Washington and
Wright." These writers came to the decision that the com-
position of the feldspar might be written Ab,An,,Cg,. The
writer has found that solid solution of Ne in pes extends
only up to 2 per cent, while, if the explanation of the Linosa
feldspar offered by Washington and Wright is correct, solid
solution of Ne in the plagioclase Ab,An,, extends to 5°5 per
cent.

Carnegiette.—The mineral carnegieite has -never been
definitely identified in nature. Most natural nephelites prob-
ably erystallized as such, for, if formed by inversion from e¢ar-
negieite, the crystals would be unlikely to show continuous
orientation.

In order that carnegieite might occur in a rock it is necessary
that its crystallization should have taken place at a temperature
above that at which the crystal form would change to that of
nephelite, otherwise nephelite would occur. The inversion
temperature 1248° applies only to the pure compound
NaAISiO,. The presence of other substances affects this in-
version point only when those substances can be taken into
solid solution by the nephelite or carnegieite. In this work
the effect of anorthite has been determined, and is such that
crystallization would have to occur at a temperature still
higher than 1248° in order that carnegieite might form, the
maximum raising being about 100°.

The effect of the other substances which nephelite is capable
of holding in solid solution is, however, still unknown, but the
evidence is that the averegate effect is not sufficient to carry
the inversion point below the temperature at which the ecrystal-

572 NV. L. Bowen—The Binary System.

‘

lization of nephelite from most rock magmas would begin,
otherwise carnegieite would be common.

From certain magmas very rich in ‘nephelite,’ the erystal-
lization of carnegieite might be expected, but even this state-
ment needs qualification, for, as we have seen, some nephelite,
viz. that from Magnet Cove, may crystallize from its own melt
directly as nephelite.

E. Esch” describes an abnormal nephelite from the nephe-
linite of Etinde voleano in German Kamerun. This mineral
shows inclined extinction and a complicated twinning and is
biaxial. In these properties it agrees better with carnegieite
than with nephelite. On the other hand, the crystal outline is
like that of nephelite and the determined mean ‘index, 1:5376,
very close to that of nephelite, but such an index is not im-
possible in carnegieite with certain compounds in solid solu-
tion. The mineral may possibly be carnegieite, but no definite
decision can be arrived at until the possibilities of solid solution
in carnegieite have been further investigated. This single in-
stance appears to be the only one in which a mineral whose
properties suggest carnegieite has been described.

Thermometry.

In the fact of its non-appearance in nature, carnegieite is like
a great many other allotropic forms of minerals that have been
made in the laboratory. These modifications are, in nearly all
eases, the high temperature forms and their absence constitutes
one of the proofs of the prevailingly low temperatures of
natural magmas during crystallization.

It is evident from the discussion in the preceding paragraph
that care must be exercised in putting to use the inversion
of nephelite on the geologic thermometer scale.”

Minerals of simple, definite composition, Si0,, CaSiO,, and
others have definite inversion points and the limits of stability
of each form give definite points on the scale. On the other
hand, a mineral of variable composition has a temperature of
inversion which varies conjointly. With known composition,
however, it will be possible, when sufficient experimental data
has accumulated, to set equally definite limits to its stability as
is exemplified in the present case of nephelite with variable
content of lime.

There is reason to believe, as has been pointed ont, that
natural nephelites first crystallized as such.

In the event of the discovery of carnegieite in a rock its
crystallization above 1200°* could probably be asserted with
but little fear of error.

*It is necessary to leave some margin for a possible lowering due to solid
solution.

NV. L. Bowen—The Binary System. 573

General.

It is encouraging to note the occurrence within the mineral
kingdom of one of Roozeboom’s theoretically possible types
involving both solid solution and enantrotropism. Some little
hope of the eventual discovery of genera! laws, applicable even
to the complex mixtures known as magmas, is aroused. The
accumulation of precise quantitative data is the means to this
end.

In conclusion the writer desires to thank E.S. Shepherd and
FP. E. Wright of the Geophysical Laboratory for. much help
and advice throughout the course of the experimental work.

Geophysical Laboratory, Washington, D. C.
Massachusetts Institute of Technology,
Boston, Mass.

REFERENCES.

W. P. White, this Journal, xxvili, 453, 1909.
Shepherd & Rankin, ibid., xxviii, 293, 1909.
Ostwald’s Lehrbuch der Chemie, vol. 2, pt. 2, 38-68.
Die Silikatschmelzlésungen, ii, p. 128.

Harker, Science Progress, No. 6. Oct., 1907.
Wright, F. E., this Journal, xxvi, 349, 1908.

Neues Jahrb. B. B., ix, 561, 1894.

This Journal, xxix, 52.

Zs. anorgan. Chemie, lv, 160, 1907.

10. Ibid., lxiii, 1-48, 1909.

11. Synthése des minéraux et des roches, p. 156.

12. Zs. Kryst., ix, 321, 1884.

18. Arch. sci. phys. et nat. (4), xiii, 352, 1902.

14. This Journal, xxxi, 341.

15. Arch. sci. phys. et nat. (4), xviii, 5387, 1904.

NGOs di Gre Ons, 1907. pr 145:

17. Neues Jahrb., i, 20, p. 158, 1884.

18. Neues Jahrb., ii, p. 1, 1908.

19. Sitz. d. k. Akad. Wien, exvii, 581, 1908.

20. Morozewicz, Bull. Acad. Sci. Cracovie, p. 958, 1907.
21. Mem. Roy. Acead. Lincei, xiv, 140, 1905.

22. Sitzb. Berl. Akad., xviii. 400, 1901.

23. See Wright and Larsen, this Journal, xxvii, 421, 1909.
24. Bowen, N. L., ibid., xxxiii, 49, 1912.

SSO SOE SIO

574. EE. T. Wherry—New Occurrence of Carnotite.

Art. XLVII—A WMNew Occurrence of Carnotite ;* by
| Epear T. WHerry.

Introduction.

THE more or less definite bright yellow uranium-vanadium
mineral known as carnotite has been heretofore observed at a
number of points in western Colorado and eastern Utah,f and
as an alteration product of “ davidite,” a rare-earth-bearing
rutile, at “ Radium Hill,’ South Australia.t The purpose of
the present paper is to call attention to its occurrence near
Mauch Chunk, Carbon County, Pennsylvania.

In Genth’s Mineralogy of Pennsylvania§ autunite was

stated to “have lately been found in a conglomerate from:

the neighborhood of Mauch Chunk,” the exact locality being,
however, unknown. Specimens labeled similarly are included
in several of the old collections of Pennsylvania minerals, but
a study of these and of a considerable quantity of material col-
lected at what is probably the original locality, the eastern
end of Mt. Pisgah, immediately north of the town of Mauch
Chunk, has shown that the mineral in question is really to
be classed as carnotite.

Although the locality was re-discovered, by accident, by
the writer in 1908, and the nature of the mineral proved by
qualitative tests, detailed study was deferred in the hope of
obtaining more satisfactory material when opportunity should
present itself for thorough examination of the deposit. As this
hope has not been realized, in spite of exhaustive search, it
was decided to proceed with analysis of the specimens on hand,
and to publish an account of the occurrence.

General Description.

The mineral presents the form of an amorphous to minutely
crystalline bright yellow coating or impregnation in a conglom-
erate, often penetrating cracks in the quartz pebbles. Micro-
scopic examination shows it to be quite impure, containing
much limonite and clayey matter, and even the most crystalline-
looking specimens show only an occasional translucent rectan-
cular flake, with straight extinction, suggesting the tetragonal
or orthorhombic system.

* Presented at the Baltimore meeting of the A. A. A. S., 1908; abstract
in Science, vol. xxix, p. 751, 1909.

+ Hillebrand and Ransome, Bull. U. S. Geol. Survey, No. 262, pp. 9-31,
1905; Fleck and Haldane, Rept. State Bur. Mines, Colorado, 1905-06, pp.
47-115, 1907; Gale, Bull. U. S. Geol. Survey, No. 315, pp. 110-117, 1907 ;
Bull. No. 340, pp. 256-262, 1908.

¢{ Crook and Blake, Mineralogical Magazine, vol. xv, pp. 271-284, 1910.

$ Report B, 2nd Penna. Geol. Survey, p. 144, 1874.

E. T. Wherry—New Occurrence of Carnotite. 575

Chemical Composition.

Material for analysis was obtained by scraping off the
coating from a specimen of rather friable conglomerate, and
contained accordingly considerable amounts of quartz, as well
as some limonite and kaolin. As the yellow substance proved
to be entirely soluble in dilute nitric acid, while the greater
part of these impurities are insoluble, this seemed adequate for
the purpose in hand. Uranium and vanadium were determined
by the method of Campbell and Griffin,* which was first tested
on knowh solutions of the metals and found to give very
accurate results. Iron and calcium were obtained in the usual
ways, water by loss on ignition, and potassium, by difference.
Barium, lead, and phosphoric acid could not be detected with
certainty ; the strong radio-activity of the mineral indicates
the presence of radium, although its amount is of course too
small to be estimated, while lack of material also prevented
establishment of the presence of helium.

The analytical results are given in the first column of the
accompanying table, and the figur es obtained by deducting the
insoluble matter, iron oxide and water, and recalculating the
remainder to 100 per cent, in the second. The iron is cer tainly
present as limonite, and while a part of the water may belong
to the carnotite, the amount in this form is indeterminate, so
it is best disregarded i in calculating the formula. The results
are given in the first decimal place only because of the unsatis-
factory character of the sample. Most of this work was carried
out, under the direction of the writer, by Mr. J. 8. Long of
Lehigh University, to whom much credit is due for skilful
handling of the problems presented.

Analysis and Ratios.

it 2 Ratios

ot Nw
EG eee tee 21°1 116 1-00
OU) ee 93°8 69°8 243 2°09
11 ( 0) Co eae al i
(CS ie SS a 165 4-4 79
me@a(dil 2. [1-6] 4-7 0 # rae pate

SS 10°5

Insoluble 0a 49:3 eye

100°0 100°0

Without attempting to place undue confidence in these
results, it cannot be denied that they show a tendency to
approach a definite ratio, (Ca, K,)O.2U0,.V,O,, or (Ca, K,)

* Jour. Ind. Eng. Chem., vol. i, pp. 661-665, 1909.

576 Ek. T. Wherry—New Occurrence of Carnotite.

(UO,),(VO,),, which is identical with that indicated by the
previous work on carnotite.* Hillebrandt+ has shown, to be
sure, that different samples of the mineral from Colorado vary
rather widely in composition, yet throughout his and the other
published analyses the ratio 1:2:1 for the three oxides is
continually indicated. This is shown by the following table,
in which the analyses have been recalculated to 100 per cent
after deducting, as probably foreign to the mineral, the iron
and phosphoric acid and also the water, whose amount is so
variable that its role is uncertain.

Analyses of Carnotite (Recalculated).

1 ) 3 4 5 6
VES Gaus oath: 21°16 - 21-28 «88708. ~=99-79. °ot-5 Ome
TOs heehee a2: 67°41 66°85 65°44. 64:79 -64°70 Seeses
BOs eee pee age Gt tgs 4°59 4:19 4°73 5°86
TAO acs sacs 11°43) 11°87 7°94 8:44 9°07 6:75
100:00 100°:00 100°00 100:00 100:00 100-00
7 8 9 10 Caleulated 1:2:1
V0 2 ees 4a FOURS 2 an0S" ee H9B8<Os OT 29°44 OIRaH
AIO Ge iri ceet nls 65°27 - 65568 41662). 698 "0°65 67°64
Oe ae wee 6°48 6°40 352 A-4 6°91 i
FY NS RS Sees 6°40 4°87 74 A:T ee 11°02

100°00: .1T00°00" “10020 1:00:06 100°00 190°00

1, 2, Colorado: Friedel and Cumenge, Bull. Soc. Franc. Min., vol. xxii,
p. 26, 1899 and elsewhere ; considerable R’O probably present but overlooked
and weighed with the R’.0 (Hillebrand).

3-8, Colorado: Hillebrand, Bull. U. S. Geol. Survey, No. 262, p. 25, 1905.

9, South Australia : Crook and Blake, Min. Mag., vol. xv, p. 271, 1910.

10, Pennsylvania. The results of the present study.

Calculated, a, for R" = Ca; b;for KR’ = K.

The cause of the variations in these analyses is not altogether
clear; but, after all, they are perhaps no greater than is to be
expected in view of the non-homogenous character of the sam-
ples examined, and the difficulties of the analytical procedure.
In any case the evident similarity of the material from the
three widely separated localities justifies no other conclusion
than that we are dealing with a definite mineral species, of the
formula (Ca,K,) (UO,),(V O,)..

This formula at once suggests relationship with the uranite
or autunite group, the members of which contain, however,
from 8 to 10 molecules of water of crystallization. The
amount of water found in the various samples of carnotite

* Cf. Crook and Blake, loc. cit. + Loe. cit.

E. T. Wherry—New Occurrence of Carnotite. 577

varies from none in the Australian to perhaps 6 molecules
in the Pennsylvania mineral, but then it must be remembered
that most of this material is amorphous, leaving the question
open as to its possible water content when well crystallized.
The mineral may therefore be provisionally admitted to that
group, which, named according to Washington’s suggestion*
(with one modification, the retaining of -ite as a termination,
which, in the writer’s opinion, may be desirable, to avoid con-
fusion with chemical terms), becomes :

Uranite Group.
R”(UO,),(R’O,),.8H,O ; chiefly orthorhombie.

Autunite-..-- Ca (UO,),(PO,),.8H,O. Calcium phosphuranite
Uranospinite. Ca (UO,),(AsO,),.8H,O. a arsenuranite
Torbernite ... Cu (UO,),(PO,),.8H,O. Copper phosphuranite
Zeunerite ._--- Cu, (UO,),(AsO,),.8H,O. ss arsenuranite
Uranocircite.. Ba (UO,),(PO,),.8H,O. Barium phosphuranite
Carnotite (Ca,K,) (UO,),(VO,),.XH,O. Calcium-potassium
vanaduranite

Geological Relations.

Mt. Pisgah, the ridge extending westward from the Lehigh
River just north of the town of Mauch Chunk, represents a
synclinal mass of the Pottsville formation, the great series of
interbedded sandstones and conglomerates regarded as the
lowest member of the Pennsylvanian, overlying the Mauch
Chunk red shale, the top of the Mississipian.t The contact
between these formations, as exposed in the cuts of the high-
way and electric railroad across the eastern end of the ridge, is
not a sharp one, but shows interbedding of the two types of
sediment through a thickness of at least 100 feet. In addition
to the red shale, there are also small lenses of black shale in
the midst of the conglomerates.

The carnotite occurs in scattered streaks and patches through-
out the lower portion of the conglomerate, not extending far
above the last red shale layer, although ledges of conglomerate
continue to be exposed 600 feet farther to the summit of the
ridge. As the road turns westward, gradually rising across
the beds, the layer containing it can be followed to a distance
of 2000 feet, but then disappears beneath the roadway, and no
trace of the mineral could be found at the corresponding hori-
zon where again exposed near Tamaqua, 10 miles further west.
Although its distribution is quite irregular, it is certainly most

* This Journal, vol. xxxiii, pp. 187-151, 1912.

+ For a full description of these formations see Stevenson, Bull. Geol. Soe.
Amer., vol. xiv, pp. 15-96, 1903 ; vol. xv, pp. 37-210, 1904.

578 = x. T. Wherry— New Occurrence of Carnotite.

frequently met with in the vicinity of the masses of black
shale, and in fact small nodules of it are occasionally found in
the shale itself.

That it has been deposited in its present form by circulating
surface waters is clear. It is often locally concentrated along
the more porous beds, and streaks may be observed beneath
cracks in the rock from which water trickles out during wet
weather. But its source is apparently to be sought in these
lenses of black shale.

These dark shales do not owe their color to carbon, as might
be supposed at first sight, but, as shown by microscopic exam-
ination, chiefly to the presence of hornblende, biotite, and other
silicates in a fine state of subdivision, yet, in part, in fairly
fresh condition. They can best be accounted for as a result of
the peculiar climatic conditions which, as pointed out by
Barrell,* prevailed here during late Mississippian times.

Under ordinary conditions of weathering silicates are decom-
posed, and only silica, kaolin, and ferric oxide remain to enter
into the formation of sedimentary deposits. But in arid cli-
mates disintegration in general exceeds decomposition, so that
heaps of greatly broken up, but comparatively unaltered, min-
erals will accumulate, and, when a more or Jess sudden change
to conditions of heavier rainfall sets in, considerable quantities
of these undecomposed minerals may be carried down into
places of accumulation of sediments. ‘These dark shales are
believed, then, to represent “ black sand” streaks, which, by
reason of their distinctive specific gravity, have accumulated at
points where the flow of the streams was favorable.

The materials of this portion of the Pottsville conglomerate
were evidently derived from the crystalline Highlands of
Pennsylvania, New Jersey, and New York; for while white
quartz makes up the majority of the pebbles, occasional pieces
of banded gneiss, crystalline limestone, and serpentine, of types
familiar in that region can be seen in the carnotite-bearing
beds. It has been found by Hillebrand ¢ that vanadium is an
almost universal constituent of igneous rocks, including the
metamorphies of this Highland region, and is largely contained
in their dark silicates. Under ordinary conditions of weath-
ering much of this vanadium is carried away in solution, so
that the average sediments contain only one-fifth to one-tenth
as much as the rocks from which they were derived. In the
present instance, however, it would seem reasonable to expect
the concentration of practically all of the vanadium in the
black shales as a purely mechanical process. Analysis of sev-
eral samples of these rocks showed amounts varying from 0-08

* Bull. Geol. Soc. Amer., vol. xviii, pp. 449-476, 1907.
+ Bull. U. S. Geol. Survey No. 167, pp. 49-55, 1900.

E. T. Wherry—New Occurrence of Carnotite. 579

to 0°21 per cent V,O,. These specimens were free from any
visible admixture of carnotite, and that no microscopie inclu-
sions of such a mineral were present was proved by the insolu-
bility of the vanadium in nitric acid, as well as the absence of
proportionate amounts of uranium, noted in the succeeding
paragraph. This vanadium probably replaces other sesquiox-
ides in the silicates;* and as the fine state of division of the
latter renders them easily attacked by surface waters, oxidation
of the vanadous compound and development of some second-
ary vanadate is the natural thing to expect.

‘Uranium is also present in the metamorphic rocks of the
New York—Pennsylvania Highlands, as shown by the radio-
activity} of several widespread minerals, such as allanite and
zircon, as well as the occasional appearance of columbite,
uraninite, etc. Because of analytical difficulties no attempts
have been made to determine its proportion in these rocks as a
whole, but it may perhaps mount into the hundredths per cent.
On the disintegration of the rocks, as described above, the
uranium-bearing minerals would, of course, be expected to
accumulate in the black sand lenses, along with those carrying
the vanadium. Chemical examination showed, however, only
about 0:002 per cent of UO, to be present, an amount whose
concentration by circulating waters seems rather unlikely. It
is not impossible that some of the pebbles of the conglomerate
may contain uranium minerals, but no definite evidence of
this has been, or, in the nature of the case, is likely to be,
obtained, so that the immediate source of the uranium enter-
ing into the carnotite remains obscure, although in the total
absence of deep-seated vein phenomena there can be little
question as to its ultimate derivation in some manner from the
sediments.

The conclusion to be drawn from these studies is, then, that
the development of the carnotite at this locality has been made
possible by mechanical concentration of uranium and vanadium
minerals originally distributed through large bodies of erys-
talline rocks, brought about by a sudden change from a dry to
a moist climate. ‘To claim an identical origin “for the deposits
in Colorado and Utah would be hazardous, yet the published
descriptions show that they also occur in arenaceous forma-
tions overlying ‘“* Red Beds,” and if similar climatic changes
were responsible for the change i in character of the sedimenta-
tion there, it is quite possible that the concentration of the
constituents of the mineral has been brought about in the same
manner.

Indeed, it may be permissible to suggest that the frequent

* Cf. Hillebrand, loc. cit.
+ Wherry, Jour. Frank. Inst. , vol. clxv, pp. 59-78, 1908.

580 Ff. T. Wherry—New Occurrence of Carnotite.

association of these elements uranium and vanadium with coal,
pointed out more particularly by Clarke,* has a similar signifi-
cance. The upper portion of the Pottsville formation in the
Mauch Chunk region contains interbedded coal seams, the
development of which was certainly connected with the favor-
able stimulus to plant growth resulting from the same change
of climate which made possible the formation of the carnotite.

In general, even though the association is not a genetic one, it
seems reasonable to expect that, whenever the period preced-
ing that of coal formation has been so dry that dark silicates
have been broken up and transported to the points where the
coal flora is to develop without extensive decomposition, the
elements uranium and vanadium may be looked for as con-
stituents of the ash. Or, in other words, in their presence or
absence, we may have a new method of throwing hight on cer-
tain details of the climatic conditions of past geologic times.

Summary.

1. Carnotite has been discovered in a new locality, Mauch
Chunk, Carbon County, Pennsylvania.

2. As it agrees in composition with material from Colorado
and South Australia, and these agree among themselves better
than has usually been supposed, carnotite is entitled to be
classed as a distinct mineral species, with the formula (Ca,K,)
(UO,), (VO,),, belonging to the uranite group.

3. The vanadium and probably the uranium also have been
extracted by circulating surface waters from black shales,
which have been formed in the midst of conglomerates by
mechanical concentration of dark minerals from the crystalline
rocks to the south and east, following the change from arid to
moist climatic conditions at the beginning of Pennsylvanian
time.

4, Asthe Colorado deposits occur in a similar position, their
origin may have been the same, and it is suggested that the
frequent association of these elements with coal may also be
connected with such a climatic change.

Lehigh University, South Bethlehem, Pa.,
February 26, 1912.

* Bull. U. S. Geol. Survey No. 491, pp. 672-678, 1911.

H. P. Cushing—Age of the Cleveland Shale of Ohio. 581

Art. XLVIII.—TZhe Age of the Cleveland Shale of Ohio ;
by H. P. Cusuina.

Lntroduction.—In the February number of this Journal
appeared an article entitled “ Unconformity at the Base of the
Chattanooga Shale in Kentucky.” In addition to describing
the unconformity, the author endeavors to fix its date and
its duration, and this endeavor leads to a discussion of the age
of certain rocks in Ohio with which I have some familiarity.
The author also expresses his personal opinion of the correct- |
ness of the work of certain geologists, in part no longer living,
and since I think that in one notable instance his judoment i 18
at fault, I wish also to say a word concerning it.

That the Newberr y Survey erred in correlating the Cleveland
shale of northern Ohio with the Sunbury (Waverly black shale)
of southern Ohio was but natural, and was later freely acknowl-
edged by Dr. Newberry himself ; the error of correlating the
black shale along the lake shore west of Cleveland with the
Huron shale he himself corrected later, as Mr. Kindle points
out. But it seems to me that neither of these has the remotest
connection with the argument given in the following quotation:

“When Prof. Newberry found himself unable to substan-
tiate his previously published statement of the occurrence of a
Waverly fauna at the base of the Cleveland shale, he continued
to maintain the Carboniferous age of the formation chiefly on
the evidence of the occurrence in it of three genera of Carbon-
iferous fishes, namely, Hoplonchus, Orodus, and Polyrhizodus.*

Concerning this evidence it is well to recall that most of the
fossil fishes described by Newberry were obtained for him by
collectors on whom he depended for the correct designation of
their. geologic horizon. Since Prof. Newberry had himself con-
fused the Sunbury and Cleveland shales, the opportunities
‘which existed for the collectors to confuse them are too evident
to require discussion.” tT

Now, leaving wholly aside the question as to the accuracy of
the work of the group of excellent geologists who constituted
the corps of the Second Geological Survey, what I wish to
point out is that there was practically no opportunity for con-
fusion of these two formations, in so far as tnese three genera
of fishes were concerned. All three are described from the
Cleveland shale at Bedford.t Because the Cleveland and
Sunbury were confused in a long-range correlation the full
width of the State, is far from making it “too evident to
require discussion” that the two were confused at a single

elon. xvi, UL os Gerona pe lice.

+ This Journal. Feb. 1912, p. 182.
{ Geol. Surv. Ohio, Pal., vol. ii, pp. 90, 51, 55.

Am. Jour. Sci1.—FourRtTH SERIES, Vor. XXXIII, No, 198.—Junz, 1912.
38

~

582 H. P. Cushing—Age of the Cleveland Shale of Ohio.

locality. There is no real Sunbury in the section at Bedford,
the horizon being occupied by a few feet of light-colored shale.
Above this there is a blackish shale, the Orangeville, but the
merest tyro in geology conld not confuse this with the Cleve-
land when one considers the prominence of the Berea grit in —
that uninterrupted section. But the matter is finally settled
for us by Newberry’s definite pronouncement that he collected
these fossils himself; he says: “ At Bedford I obtained from
this stratum quite a number of fish-teeth consisting of species
of Polyrhizodus, Cladodus, and Orodus ; all Carboniferous
sharks.” *

Aside from the frequent tiny scales of Paleoniscus (?) remains
of fishes are rare fossils in the Cleveland shale. The local
collector, he who diligently scans his ledges day after day
throughout the year, can make collections at some localities.
But the geologist, spending a day or two at a locality and then
moving on, is exceedingly fortunate if he finds in that time
any fish remains whatever worth taking along. Under these
circumstances the fact that subsequent collectors have failed to
report these forms from the Cleveland shale is not so surpris-
ing as it might seem. Some years ago, however, I collected
from the Cleveland shale at Bedford a fragment of a spine,
which tends to substantiate Newberry’s assertion.

Age of the Cleveland Shale.—I have had in manuscript for
some time a report on the geology of three quadrangles in the
Cleveland vicinity, the result of recent field work. LEarlier
work had given me a familiarity with the formations concerned
all across northern Ohio. In two respects this work has a
bearing on the problem discussed by Mr. Kindle, and these I
wish br iefly to set forth.

Shales west of Cleveland—At Cleveland the Cleveland hale
is a band of black, slaty shale, 20 to 50 feet thick, which is
most sharply delimited from the underlying Chagrin shale and
the overlying Bedford shale. The same conditions persist east ~
of the city. But in West Cleveland the true Cleveland shale is
underlaid by from 15 to 20 feet of blackish soft shale, with thin
bands of blue shale, which separates it from the Chagrin below.
This is well exposed along Big Creek. A few miles farther
west, along Rocky river, this ‘blackish shale has increased to
60 feet in thickness, and ‘the steady increase in thickness seems
to continue to the west edge of the Berea quadrangle, beyond
which our detailed work has not gone. ‘This increasing thick-
ness, coupled with a westerly dip, puts the Chagrin ‘summit
below the lake tevel at Avon Point.

Now this blackish shale must be one of three things: it may
represent a lateral change in character of the Chagrin shale ;
it may represent a downward thickening of the Cleveland shale,

* Geol. Surv. Ohio, vol. i, p. 189.

H. P. Cushing—Age of the Cleveland Shale of Ohio. 588

as Newberry finally regarded it ; or it may represent a differ-
ent formation from either. The Chagrin overlapped on the
region from the east; the Cleveland came in from the south
and pinches out to the east ; and it seems as though this black-
ish shale did hkewise; it increases in thickness westward so
far as we have carried it, and it wedges out at Cleveland. Its
rate of overlap is much more rapid than that of the Cleveland,
which is the chief reason for my present disposition to regard
it as a separate formation, separated from the Cleveland by a
small break, rather than as a lower, overlapping portion of the
Cleveland. That it is a separate formation from, and has
nothing to do with, the Chagrin I feel reasonably sure. But
Iam far from claiming that the matter is settled one way or
the other. Though much like the Cleveland lithologically, it
can be distinguished from it; and since it is wholly absent
from the type sections of the ‘Cleveland shale, I am calling it
the Olmsted shale, from the excellent exposures of it along
Rocky river.

Unless I greatly.mistake, the large collections of fishes which
have been made in Lorain county have come from this Olmsted
shale, not from the true Cleveland. Certainly this is true of
the collections from the lake shore. And in any ease this is the
shale which Newberry called Huron in the Ohio reports, and
re-identified as Cleveland in Monograph xvi.

Now the point of all this is, does this blackish Olmsted shale
keep on increasing in thickness westward, and what thickness
does it finally attain? And what 2s its thickness along the
Huron river? This is the type locality of the Huron shale.
At Cleveland the drill shows a thickness of 1200 feet of shale,
Chagrin and so-called Huron, between the Cleveland shale
and the Devonian limestones. At Lorain, 25 miles west of
Cleveland, there remains less than 700 feet (probably not over
600) of this thickness between the Olmsted shale and the
limestone. If the same rate of disappearance by overlap con-
tinues, there will not be much of this shale series left by the time
the Huron river is reached. How much, then, of the so-called
Huron shale in Lake county is real Huron, and how much is
Olmsted? The former is older than the Chagrin shale, which
is exposed at Cleveland, the latter probably younger and cer-
tainly not older. I cannot answer this question as yet. I
merely know enough to suggest caution in regard to drawing
any conclusions from the supposed age of the Huron shale at
the type locality. I surmise that much of it is Olmsted : just
as I surmise that much of the Ohio shale at Columbus is
Olmsted. If so, many of the supposed Huron fishes may not
be Huron fishes at all.

Shales east of Cleveband.—Passing east from Cleveland, the
Cleveland shale runs for some 50 miles to the eastward and
then seems to pinch out. It occurs on the west side of the

584 H. P. Cushing—Age of the Cleveland Shale of Ohio.

Grand river valley in Ashtabula county, but has not been found
on the east side. The country there is, however, poorly
adapted to furnish exposures of the proper horizon.

At the same time the Chagrin formation underneath increases
in thickness eastward with great rapidity, and in its eastern
extension fossils are much more abundant and range through a
greater vertical thickness of the formation than is the case about
Cleveland. In its upper portion also faunas seem to come in
which are no longer typical Chemung faunas, but higher ones.
I have, for example, collected abundant Syringothyris near J ef-
ferson, at least 100 feet below the summit of the beds which were
formerly referred to the “ Erie” (now Chagrin) shale by New-
berry. These upper faunas have not been diligently collected
and studied, except perhaps very recently by Prosser. My im-
pression is that there comes over into the eastern townships of
Ohio a thinned and thinning edge of the formations which, in
western New York and Pennsylvania, have been called the
Oswayo and Knapp, or the Conewango and Knapp formations,
and which are regarded as younger than the Chemung. So
far as I know, these beds have not as yet been noted on the
west side of Grand river, while the Cleveland shale has not
been found on the east side. The Cleveland pinches out going
east, the others toward the west. Until the district has been
thoroughly covered in the effort to find the two in the same
section, so that their relative ages may be determined beyond
question, some doubt must attach to it. It seems to me
to be most probable that the Cleveland overrides the other,
and is the younger, in which case it can hardly be classed as
Devonian in age. My reason for the belief is that, up to the
point of its disappearance, the Cleveland sticks tightly to the
base of the Bedford ; and the Bedford overrides these other
formations on the east side of the Grand river valley. But I
most frankly admit that this is nothing but a surmise. I sim-
ply want to point it out as a possibility, and to urge it as the
most promising method of settling what the age of the Cleve-
land shale really is. But until it is shown that the Cleveland
does not override these formations, the conditions seem to me
to strongly suggest caution in asserting the Devonian age of
the Cleveland shale. Just as the conditions to the west of
Cleveland seem to me to suggest caution in asserting that the
whole, or even the greater part, of the Huron shale is older
than the Chagrin.

In closing I wish to make one more suggestion, namely, that
if the Conodont faunas of the.Huron and Cleveland shales are |
to receive detailed study, it would add much to the importance
and completeness of the results if the similar faunas of the
Sunbury were included. I think no one questions the Waver-
lyan age of the Sunbury.

Western Reserve University, Cleveland, Ohio.

Chemistry and Physics. 585

SCIENTIFIC INTELLIGENCE;
I. CwHemistry AND Puysics.

1. Ultra-filiration in Chemical Analysis.—ZstgMonpDy, WILKE-
DorFurt and Gatrecki have devised a method of analytical fil-
tration which permits the collection of the most finely divided
precipitates, and even of many colloidal substances where the
particles are invisible, such as those of certain gold and ferric
oxide “solutions.” The method appears to be suitable also for
removing turbidity in cases where ordinary filtration with paper
is unavailing. To prepare these filters a film of collodion is first
prepared by diluting 200° of 6 per cent collodion with 200° of
ether and 500° of absolute alcohol, carefully pouring and spread-
ing a film of this liquid upon plate-glass, waiting until most of
the ether has evaporated and the collodion is no longer sticky,
then plunging the whole into water. After 10 or 15 minutes the
film may be separated from the glass and it may then be pre-
served under water for a long time. The sieve-like bottom of a
porcelain filtering funnel is now provided with a piece of mois-
tened ordinary ashless filter paper, then a piece of the collodion
film is laid upon the paper in the funnel, suction is applied with a
water-jet pump, and the filter is pressed a little against the sides
of the funnel, so that the collodion filtering surface may be-con-
tinuous and practically air-tight. Filtrations can now be made
in the usual way with this filter, but the process is considerably
slower than with paper alone. The authors have tested the
method by collecting colloidal gold and ferric oxide and weighing
the substances after ignition, both on the analytical balance and
with Nernst’s micro-balance. They have compared the weight
of silver chloride filtered in this way, and with ordinary paper,
with closely agreeing results. By collecting barium sulphates
immediately after precipitation they have re-discovered the long-
known fact that this substance forms supersaturated solutions
and is not at once completely precipitated— Berichte, xlv, 579.

H. L. W.

2. Magnesia Rods as a Substitute for Platinum Wire. —
KH. W ADEKIND recommends the use of small magnesia rods, about
1™™ in diameter, for use in various blow-pipe tests. The best
material for the rods is not pure magnesia, but the same mix-
ture that is used for the supports of incandescent gas mantles.
The rods serve well for producing flame colorations, as the mass
itself after short ignition in the Bunsen flame gives no coloration,
With the salts of the alkali-earth metals the flame-color is not
as persistent with the rods as with platinum wire, but it is quite
sufficient for ordinary qualitative tests. It is possible with the
magnesia rods to produce much larger borax and salt of phospho-
rus beads than with platinum wire, a circumstance which is advan-
tageous particularly in the test for silica. The colors of the

586 Serentific Intelligence.

beads are especially striking on account of the white background
furnished by the rod. Fusions for the manganese and chromium
tests can be made very satisfactorily upon these rods. The rods
serve well also in the place of asbestos fibers, for producing sub-
limates from the flame upon porcelain. The rods are stuck
into a cork for use, and after using the end is broken off, so that
beads and fusions may be preserved for reference. The cost of
the rods, about 1™™ thick and 15° long, is 1 to14 pfennig in
Germany, so that there is considerable economy in their use as
compared with platinum wire.— Berichte, xlv, 382. H. Tk We
3. The Combustion of Carbon Monoxide.—The combustion of
carbon monoxide has been usually regarded as taking place
according to the equation 2CO+0, = 2CO,. This equation does
indeed express the final result, but itis known that the reaction
is not a direct one, for Dixon has shown that traces of moisture
are indispensable for the reaction even at high temperatures, and
Remsen has found even at 300° ozone is incapable of oxidizing
the gas. However, moist palladium-black, even at ordinary tem-
perature, causes carbon monoxide and oxygen to combine.
Traube has attempted to explain these facts by assuming an
intermediate formation of hydrogen peroxide as follows

CO+H,0+0, = CO,+H,0,
CO+H,0, = CO,+H,O

WIELAND now presents a new view of the matter. He has found
that moist palladium-black, in absence of oxygen, causes the oxi-
dation of carbon monoxide, apparently according to the equation
CO+H,0 = CO,+H,, and he has shown that a first product of
the reaction is formic acid : CO+H,O = HCOOH. Then, since
palladium-black rapidly decomposes formic acid, as 1s well known,
the final result is:

HCOOH = CO, +H, (combined with Pa).

Wieland has been able to show further, that formic acid is pro-
duced also in the combustion of carbon monoxide at a high tem-
perature, by directing the flame against ice and examining the
resulting water. Therefore, it appears that the mechanism of
the carbon monoxide combustion under all conditions consists in
its combination with water and the splitting off of hydrogen
from the resulting formic acid. In the presence of oxygen this
hydrogen oxidizes at once to produce water for further reaction,
and it is in this combination of hydrogen with oxygen that the
traces of hydrogen peroxide observed by Traube are produced.—
Lerichte, x\v, 679. HS is ye

4. The Purity of Commercial Metals.—F. Myuivus has made
analyses of a number of very pure metals obtained from Kahl-
baum, Determinations were made of the metallic impurities by
the use of samples of 100 grams or more. In most cases the
analysis was facilitated by the fractional er ystallization of a large
part of the metal in the form of a pure salt which left the impuri-
ties in the mother-liquor. The zinc, cadmium, tin and lead each

Chemistry and Physics. 587

contained less than 0:01 per cent of impurities, which is a very
satisfactory result. The zinc and cadmium had been purified by
distillation, the tin by electrolysis, and the lead by the reduction
of a pure salt. The author classifies commercially pure metals
into grades of purity, a maximum of 10 per cent impurity repre-
senting the first grade, while maxima of 1 per cent, 0°1 per cent,
and 0:01 per cent represent the second, third and fourth grades,
respectively. He remarks that technical products of the fourth
grade, that is with less than 0-V1 per cent of impurities, may be
obtained at present in the cases of gold, silver, platinum, mer-
cury, copper, tin, lead, cadmium and zinc. This does not take
into account the possible presence of small amounts of oxygen in
the more oxidizable metals. —Zeitschr. analyt. Chem., |xxiv, 407.
Ee ls We

5. The Effect of Temperature upon Radio-active Disintegra-
tion.—That high temperature has no detectable influence on the
intensity and nature of y-rays from various radio-active sub-
stances has been conclusively demonstrated by the investigations
of Bronson, Engler, Schmidt and others. Perhaps the severest
test was that applied by Rutherford and Petavel, who showed
that the y-radiation from radium emanation exposed momentarily
to a pressure of about 1200 atmospheres and a temperature at
least as high as 2500° C., produced by an explosion of cordite,
was not altered at the instant of explosion. A temporary reduc-
tion of 9 per cent in the activity, observed after the explosion,
was due to a charge of distribution of radium C within the bomb,
caused by its volatilization and subsequent condensation, and was
in complete agreement with the decrease calculated theoretically.
On the other hand, the results obtained with B-rays have been
very discordant, save in one respect, namely, that high tempera-
ture seems to have some effect on the emission of rays of this
kind. Since the question is of great theoretical importance, it is
worthy of note that the matter has been finally settled by the
systematic investigation of ALEXANDER 8S. RussEeLu, who under-
took the work at the request of Professor Rutherford.

The furnace used consisted of a silica tube 12°5™ long, 2°2°™
internal diameter, open at both ends, and wound with a helix of
platinum wire. ‘The whole was jacketed with “ Kieseleuhr ” for
thermal insulation. The temperatures were measured with a
platinum rhodium thermo-couple. A value of 1150° C. was easily
attained but usually not exceeded. ‘The radio-active materials
studied were sealed in quartz tubes which were suspended cen-
trally in the furnace by means of thin nickel wire. When thus
mounted there was a clear path between every point of the tube
and the lead electroscope, the distance being from 40 to 60™.

In the case of pure radium C, deposited on nickel by von
Lerch’s method, the decay of the radiations during three hours
was measured, the containing quartz tube being maintained at
1150° C. for the first 90 minutes, and at room temperature for the
rest of the time. The @-rays were studied over the entire inter-

588 Scientific Intelligence.

val and the y-rays only at the high temperature. This experi-
ment agreed with subsequent tests in showing that neither the
Q- nor the y-rays of radium C are affected by high temperatures.
Under all conditions both radiations decayed exponentially, fall-
ing to half value in about 19°4 minutes.

Experiments with the active deposit gave the following results.
The B-ray activity decayed at the theoretical rate both at 1150° C,
and at 200° C., and the amount of activity was unaltered by the
temperature changes. Of the 35 points determined, 2 were
within 3 per cent, 2 within 2 per cent, and 31 were within 1
per cent of the theoretical values. Im lke manner, the y-ray
points fellon a smooth curve without abnormalities at the high
temperatures ; 29 points agreed within 1 per cent with the theo-
retical values, and the remaining 4 points within 2°5 per cent.

The rest of the investigation deals with the volatilization of
radium C inside quartz tubes, with experiments on the radium
emanation, and with the partition of homogeneously distributed
activity. The conclusions drawn by Russell from the entire
research may now be quoted.

“(a) The effect of temperature upon the rate of decay, and
the amount of B- and y-ray activity, of radium emanation, active
deposit, and radium C have been investigated.” ‘The results
are entirely negative.”

“(b) Radium B and radium ©, and very probably radium A,
may be completely volatilised inside sealed quartz tubes at a tem-
perature of 650°.” ‘ Radium B commences to volatilise at room
temperatures.”

“‘(c¢) All abnormalities of activity of @-rays obtained by pre-
vious authors, and by the author of this paper, can be completely
explained on two simple grounds, a change of distribution and a
change of partition, of radium C inside quartz tubes, produced by
changes of temperature.”— Proc. Roy. Soc., 1xxxvi, p. 240, Feb.
1912. H. SS] 0p

6. Das magnetische Spektrum der B-Strahlen des Thoriums.—
The investigation of the B-rays from mesothorium 2 and its disinte-
gration products has been successfully continued by von BAEYER,
Haun and Meirner. The advance is due primarily to an im-
proved process of electrolytic deposition, devised by Meitner,
which makes it possible to obtain very fine wires of higher activ-
ity and consequently to take much sharper photographs of the
magnetic spectra than formerly.

A strong preparation of mesothorium, which had been freed
from radio-thorium about a day earlier, was used in the electro-
lytic process. Only mesothorium 2 and a trace of the newly-
formed radio-thorium were deposited on the silver cathode. The
negatives were taken in the same manner as for the B-rays of
radium (see this Journal, vol. xxxiil, page 281). In general, the
deviating field amounted to 138 gauss. The time of exposure
was one-half hour in the case of a wire which was 0°1™™ in diam-
eter and which was covered with mesothorium 2 having an activ-

Chemistry and Physies. 589

ity corresponding, by the y-ray method, to 6 mg. of radium
bromide. The negative shows six strong spectral lines, one
(undeviated) for the a-ray pencil and five for the B-ray pencils.
The line for the slowest B-rays is resolved into two distinct com-
ponents, a fact which the earlier work did not bring out. A
photograph taken with a stronger magnetic field show ed two addi-
tional but weak lines, and this leads. the authors to remark: “It
is probable that, with stronger preparations and greater resolving
power, the existence of still other weak B-rays could be demon-
strated.” On the other hand, the improved experimental con-
ditions did not essentially change the continuity of the broad,
diffuse band produced by the swifter B-rays.

Since, as is. well known, mesothorium 2 has a_ half-value
period of 6:2 hours, the authors thought that it ought to be
possible to show photographically the growth of thorium X,
thorium emanation, and the resulting active deposit. In order to
test this point, a second exposure was made, 24 hours later, to
the same active wire mentioned above. A new line, ascribed to
thorium X, shows very distinctly on this negative, whereas the
spectrum of mesothorium 2 is appreciably fainter. A third expo-
sure of twelve hours duration was made eight days after the first.
It contains no lines of mesothorium 2, it verifies the second neg-
ative, and it shows a second, less-deviated, fainter line of thorium
X. Also, a still less deviated line of thorium A may be seen in
the reproduction. The photographs of this set are scientifically
beautiful and very instructive.

The second division of the paper deals with the 6-rays from
the active deposit of thorium. The details of this section will be
passed over in order to quote the third division, in which are
collected the latest results of this work. Mesothorium 2 gives rise
to swift B-rays, exceeding 0°7 of the speed of light. Im addition
there are two weak lines corresponding to speeds of 0°66 and 0°60,
and five strong B-ray pencils of speeds 0°57, 0°50, 0°43, 0°39, and
0°37. Thorium X gives 0°51 “weak” and 0°47 “strong.” Tho-
rium A gives 0°72 weak and 0°63 very strong. Th (B+C+D)
has fast B-rays ower 0-7-2; OF BoChOn tf together with 0°36 weak
and 0°29 strong.— Physikal. Ztschr., April 1, 1912. Hie Su Ui.

7. Applied Physics for Secondary Schools ; V. D. Hawxrns.
Pp. ix, 199. New York, 1912 (Longmans, Green & Co.).—The
author is of the opinion that modern text-books on elementary
physics are too mathematical and far too difficult to be mastered
in one year by the average high school pupil. Therefore he has
written a very elementary book which is based on the belief that
the best methods of teaching the subject are as follows: “1. By
a brief text for all of which the pupil will be held responsible,
and, 2. By the addition of many interesting local applications to
be supplied by both teachers and pupils.” The diagrams are well
drawn and the topics selected are very interesting. H.S.-Us

8. Die Messung vertikaler Luftstrémungen ; ‘by Patt LupeE-
wie. Pp. 30, with 23 text-figures and 4 charts. Leipzig, 1911

590 Scientific Intelligence.

(S. Hirzel).—The author describes in detail a self-recording
anemometer which he designed especially for the study of verti-
cal currents of air. This instrument, in conjunction with a
Bestelmeyer variometer, was used throughout three free-balloon
trips and the assemblage of apparatus gave very satisfactory
results. HB siave!
9. The Teaching of Physics for Purposes of General Edu-
cation ; by C. Risore Mann. Pp. xxv, 304. New York, 1912
(The Macmillan Co.).—One of the liveliest themes of present
educational discussion is that of the distinction between voca-
tional and cultural work. This volume is the expression of an
effort to show how, in the case of physics, the two points of view
may be amalgamated into one. The subject-matter is divided
into three parts. In the first part the development of the present
situation is traced. The second deals with the origin of physics,
and the attempt is made to establish the leading characteristics
of this branch of science and to define its possibilities as a means
of general education. In the third part the purpose of physics
teaching is stated, and suggestions are made as to how this
object may be attained. ‘The index is immediately preceded by
an alphabetical bibliography of the more important and easily
accessible journal articles which have appeared during the last six
or seven years and which are not mentioned in the main body of
the book. The volume is of such pedagogical importance that it
should, at least, be consulted by every conscientious teacher of
the subject. E Ss
10. Uber Zerfallprozesse in der Natur ; by C. EnciER. Pp. 33.
Leipzig, 1911 (S. Hirzel).—This pamphlet is a revised account of
an address made by the author on September 25, 1911 before the
83d convention of German scientists and physicians held in
Karlsruhe. The conclusion finally reached is that, in all proba-
bility, the persistence of solar radiation, and therefore the exist-
ence and maintenance of all terrestrial life, is made possible by
the disintegration of an ‘‘endothermic substance” in the sun and
not to exothermic processes of combination, as was formerly
supposed. H. 8. U.

ti -GRrOLOGY:

1. The Hvolution of the Vertebrates and their Kin; by
WitiiamM Patten. Pp. xxi, 1-486, with 309 illustrations. Phil-
adelphia, 1912 (P. Blakiston’s Son & Co.).—In this work Pro-
fessor Patten sets forth most exhaustively his theory that the
vertebrates arose from arachnid-like arthropods, basing his evi-
dence upon comparative physiology, anatomy, embryology and
paleontology. The essential features of the better known anne-
lid theory are included in the arachnid theory, because both
arachnids and annelids agree in the fundamental nature of their
metameric structure, but, as Patten says, ‘when standing alone,
the annelid theory ceases to be of value as a working hypothe-

Geology. 591

sis * * * because we find no traces in the annelids of those illumi-
nating modifications of metamerism so characteristic of the arach-
nids, and that afford us the required data for filling in, and
explaining, the enormous gap between the unspecialized meta-
meres of an annelid and the groups of highly specialized meta-
meres in the head of a vertebrate.”

“The tunicate, echinoderm, balanoglossus, amphioxus, etc.,
theories have similar inherent weaknesses, indicating that they
must be subordinated to some larger view.” ‘These groups are
therefore considered but degenerate offshoots of a common
arthropod-vertebrate stock. One naturally looks on the arthro-
pods as the probable ancestors of the vertebrates, because they
are the most highly organized of .segmented invertebrates and
because the histological structure of their muscles, nerves, sense
organs, cartilages, etc., closely resembles that of the vertebrates.

The problem Patten considers a perfectly simple one in princi-
ple although involving an enormous amount of detail in its appli-
cation. ‘“‘ We have merely to strip off the superficial disguise of
our hypothetical arachnid ancestors,” he says, “and see whether
either their underlying structure, their mode of growth, the
general direction and historic sequence of their evolution, does or
does not harmonize with the assumption that they are the ances-
tors of the vertebrates. We venture to state at the outset, that
in our judgment they do harmonize with this assumption, and so
fully and in such detail as to leave no other conclusion open than
that the vertebrates arose from arachnid-like arthropods.”

The nature of the evidence presented includes : A, cephalogene-
sis in arthropods; Bb, embryology ; C, arachnid cephalogenesis
prophetic of the vertebrate head ; D, paleontology ; and the
range in its complexity can readily be understood by the follow-
ing chapter headings : Outline of the arachnid theory ; Evolution
of the nervous system in segmented animals ; Subdivisions of the
brain; Minute structure of brain and cord of arachnids ; Periphe-
ral nerves and ganglia;. General and special cutaneous sense
organs ; Larval ocelli and the parietal eye: The compound eyes
of arthropods and the lateral eyes of vertebrates ; The olfactory
organs of arthropods and vertebrates; The functions of the
brain; The heart; Early stages of arthropod and vertebrate
embryos; The old mouth and the new, locomotor and respira-
tory appendages ; Variation and monstrosities; The dermal skele-
ton ; Endocranium, branchial and neural cartilages ; The middle
cord, the lemmatochord and the notochord ; Ostracoderms and
the marine arachnids ; The ostracoderms ; The vertebrates.

Part II discusses the zoological position of the Acraniata,
including a contrast of craniates and acraniates ; the Cirripedes,
tunicates and echinoderms ; the Enteropneusta, Pterobranchia,
Polyzoa, Brachiopoda, Phoronida and Chetognatha ; summary
and conclusion. :

The illustrations are beautifully done, being based upon mar-
vellously detailed preparations as well as upon numerous models
representing transitional stages and upon various specimens and

592 Scientific Intelligence.

restorations of the extinct ostracoderms, which the author consid-
ers aS representing an annectant but “entirely distinct class
lying between the arthropods and vertebrates, and having
some of the characteristics of each, but not truly belonging to
either. ‘Their supreme interest lies in the force they give to the
suggestion that the vertebrates sprang from the arthropods.”

Professor Patten has done a brilliant, painstaking piece of
work, which will prove of great value as a contribution to the
morphology and embryology of arachnids, ostracoderms, and ver-
tebrates, whether his main thesis receives general acceptance or
not. x Rey Seppe

2. Die Wirbeltiere ; eine Ubersicht tiber die fossilen und leben-
den Formen ; von Dr. Otro JABKEL. Pp. vill, 252; 280 text
figures. Berlin, 1911 (Gebriider Borntraeger).—Perhaps the most
remarkable feature of this book is, the taxonomic scheme which
the author presents, in parts the most radical departure from the
generally accepted classifications which we have seen. Briefly,
Jaekel divides the Vertebrata into three “ Unterstimme,” Prote-
trapoda, Eotetrapoda, and Tetrapoda: the first including the
tunicates, the second the fishes, and the third the higher forms.

The third Unterstamm, Tetrapoda, includes no fewer than
seven classes with some curious transpositions of groups, such,
for instance, as the inclusion in the class Paratheria of such
orders as the Therapsidi, Testudinati, Anomodontia, Therio-
dontia, and monotremes !

This classification, extreme as it is, will find few supporters, as
it implies phylogenies much at variance with the best opinion.
Many of the illustrations, which are from various sources, are
excellent, though very few were specially prepared for the book
under review. Some of the author’s original restorations, most
of which have appeared elsewhere, are grotesque to say the least.

, R. 0S,) ae

3. American Permian Vertebrates ; by SamuEL W. WILLIs-
TON. Pp. 145, with frontispiece, pls. i-xxxvill, and 32 text figures,
University of Chicago Press, Chicago, Iil., 1911.—This book, as
the author says, ‘comprises a series of monographic studies,
together with briefer notes and descriptions, of new or little-known
amphibians and reptiles from the Permian deposits of Texas and
New Mexico.” The collections upon which the studies are based
are mainly three: that of the University of Chicago made in
recent years by field parties under the charge of Mr. Paul Miller
or the author, earlier collections of the University of Texas made
by Professor E. C. Case, and the great Marsh collection in the
Peabody Museum at Yale, which proves an increasingly fruitful
field for research as its varied treasures are brought to light,
Professor Williston’s work is offered more as a contribution to
our knowledge of ancient reptiles and amphibians, with such sum-
maries and definitions, based chiefly upon American forms, as our
present knowledge permits, than as a final classification of these
ancient forms. The illustrations of the work throughout were
made by the author. R. 8. L.

Geology. 593

4, Maryland Geological Survey (Lower Cretaceous); Balti-
more, 1911. 8vo, pp. 622 and 117 plates.—The fine series of
reports on the Geology and Paleontology of Maryland, of which
the volumes on the Eocene, the Miocene, and the Plio-Pleistocene
have hitherto appeared, is here continued in a handsome fourth
volume on the Lower Cretaceous, or Potomac Group, of the
Maryland-Virginia area. The work forms one of the primary
units in the elaboration of the continental geology, dealing fully
and thoroughly as it does with the type sections for the Lower
Cretaceous of the Atlantic border at their maximum of lithologic
and paleontologic differentiation.

The Potomac Group is described physiographically by Messrs.
Ciark, Bipsins and Berry as a series of some 600 to 700 feet
of estuarine fluviatile deposits resting on the old crystalline floor
or ““Weverton peneplain” on which important present-day drain-
age lines were already established. In general harmony with the
continental border warp of the floor, the Potomac surface has a
lessening slope to the southeastward. ‘Three subdivisions each
clearly separated by nonconformity are finally established, the
Patuxent, the Arundel and the Patapsco ; Patuxent-Arundel time
being equivalent to the Neocomian and Barremian, and Patapsco
time to the Albian following an Aptian hiatus.

The Arundel reptilia, mainly including the series of dinosaurians
collected by Hatcher and studied by Marsh, are revised and re-
illustrated by Professor R. 8. Luiz, of Yale University, who
finds a distinct correlation with the Morrison of the West.

The limited invertebrate fauna of the Arundel and Patapsco is
described by Professor Ciark ; while the main body of the
volume is occupied by Dr. E. W. Berry in a restudy and illustra-
tion of the Potomac flora.

Following a survey of the Lower Cretaceous flor of the world
the Potomac plants are given a far more usable treatment than
has hitherto been available to paleobotanists. For the Cyca-
deoidea types of the Patuxent (?) the diagnoses of Ward are con-
veniently retained. But it is held that the view of Wieland and
others that such plants are very near the angiosperm (Ranales,
etc.) line of descent ‘overlooks the wide difference in structure
throughout the vegetative body, where the characters are much
more conservative, and furnish a much safer clue to filiation than
do the reproductive parts, especially when of the indicated plas-
ticity of those of the Cycadophytes.” The text is throughout
illustrated by clear figures, and the excellent heliotypes of the
early dicotyls of the Patapsco, the oldest of the continent, must
hold high interest for botanists. G. R. W.

5. A Method of Removing Tests from Fossils; by S. S.
BucKMAN (communicated).—A note under this title appeared in this
Journal, August, 1911 (vol. xxxil, p. 163). By some accident, in
the second line of the second paragraph the epithet “close-grained”
was printed “coarse-grained.” ‘The present note is designed to
eall attention to this small error. A coarse-grained core is not at all

594 Scientific Intelligence.

desirable for the process of removing tests by heat ; in fact, a
hard internal core which gives the best results has a grain of fine
and close texture. A grain that is coarse is found in the cores of
fossils from some of the Lower Odlites, when the rocks are truly
odlitic ; and such cores do not yield good muscle impressions, the
core being only too apt to crumble away with the test. <A coarse-
grained core is found in fossils from some of the siliceous sands,
like the Greensand ; it may be coarse-grained and incoherent, so
that when the test is removed the whole core crumbles and
nothing remains. On the other hand, calcareous sands, and also
clays, often yield specimens (Brachiopods) with good cores of
close texture; it does not follow that, because the external
matrix is soft and easily removable, the core will not be hard.
Such matters are only to be learned by experiment. Some speci-
mens explode when heated ; this bas happened with some phos-
phatized fossils, and with Rhynchonelle from the white tufa of
Wiirttemberg. The loss among the latter from this cause was very
considerable ; but when the operation was successful the results
were very interesting ; the deep muscle-scars showing on the
cores as raised lumps near the umbo are striking features.

Experience seems to show that in all cases the application of
heat should be steady and gentle. If too fierce a flame be used,
the tests do not seem to separate so readily from the core.
Perhaps this is due to some sort of fusion taking place.

Thame, Oxon, England.

6. Virginia Geological Survey; Tuomas L. Watson,
Director. Bulletin No. 1V, The Physiography and Geology of
the Coastal Plain Province of Virginia; by W. B. Cuarxk and
B. LERoy MItxer ; with chapters on the Lower Cretaceous by
Epw. W. Berry and the Economic Geology by T. L. Watson.
Pp. 274; plates I-XIX. Charlottesville, 1912.—Nearly twenty
years’ study of the Virginia Coastal Plain by Professor Clark,
supplemented by detailed field work carried on in recent years by ~
Professor Miller and by investigations of Dr. Twitchell, Mr.
Berry, Mr. Vaughn, and others, has resulted in a very satisfactory
interpretation of the physiography and geology of this province.
Bulletin IV is, therefore, likely to become a standard reference
text for the study of surface features, structure and stratigraphy
of the entire Coastal Plains province from New York to Florida.
The present report contains a descriptive bibliography of papers
published between 1783 and 1911, a chapter on physiography
(pp. 13-59), chapters on geology, including numerous sections,
fossil lists, correlation and geological history of Cretaceous, Ter-
tiary and Quaternary (pp. 59-222), and a chapter on Economic
products (pp. 223-262). BH. BE: G:

7. West Virginia Geological Survey ; by I. C. Wuire, State
Geologist. Report on Jackson, Mason and Putnam Counties ;
by Cuartes E. Kregs. 1911. Pp. xiv, 387 ; 3 maps, 31 plates,
5 sketches. Wheeling, 1911.—Consistent with the plan adopted
by the West Virginia Survey, particular attention has been given

Geology. 595

in the Jackson—Mason—Putnam county reports to features of eco-
nomic interest. The chapter on soils (pp. 297-354) is sufficiently
detailed to be of direct use to agriculturists ; numerous oil and
gas well records are given (pp. 200-246) and coal resources are
studied in detail both as regards geological occurrence and the
present state of the industry. In this connection the contour
map of the surface of the Pittsburg Coal is of special interest.
The geological map exhibits in a striking way the abandoned
Teays valley and its relations to the Kanawha and Ohio valleys.
HH. E.G.

8. Wisconsin Geological and Natural History Survey ; E.
A. Birest, Director. Bulletin No. XXIV, Soil Series No. 1.
1911. Reconnoissance Soil Survey of Marinette County, by
SamuEL WeErpMan and PEercy O. Woop. Pp. 44; 1 map, 4
plates, 1 figure-—In common with Bulletin XX XIII (this Jour-
nal, xxxili, 382), the Soil Survey of Marinette county contains
interesting geographic material, as well as data and recommenda-
tions of special interest to agricuiturists. H. E. G.

9. Building Stones and Clays: their Origin, Characters and
Examination ; by Epwin C. Ecker. Pp. 264; 37 figures. New
York, 1912 (John Wiley & Sons).—Most texts on economic
geology include, with the strictly economic discussions, consider-
able matter better presented in standard texts covering a wider ~
range of topics. ‘The present book retains this characteristic of
its class, and although designed to be of direct use to stone- and
clay-working interests, yet several chapters in it might well form

art of a general text-book for classes in elementary geology.
Mr. Eckel has, however, succeeded better than most writers in
Separating “practical” discussions from matters of scientific
interest, even calling attention to the uselessness of chemical
analyses as tests for certain structural materials. The most dis-
tinctive features of the book,—the parts which amply justify its
existence—are chapters on Field Examination and Valuation of
_ Stone Properties, the Laboratory Testing of Stone, and Field
Examination of Clay Properties. Rather full lists of references
are given,—lists which would be of more use if classified accord-
ing to quality or method of treatment. The object of including
many pages of statistics of production for 1909 is not apparent.
H. E. G.

10. Mineralogy ; by ¥. H. Hatcu. Fourth Edition. Pp. 253;
124 illustrations. London and New York (Whittaker & Co.,
1912).—In this fourth edition the author has rewritten and en-
larged the volume first issued in 1892. The subject is briefly but
clearly presented, the species described being, first, those impor-
tant in rock formation; second, the ores of the prominent metals;
third, the salts and useful minerals other than ores; fourth, gems,
The introductory chapters discuss the general morphological,
physical, and chemical properties of minerals.

596 Scientific Intelligence.

III. MuisceLtuanrovus ScrentiIFic INTSLLIGENCE.

1. Annals of the Association of American Geographers ;
edited by R. E. Doper. Vol. I, 1911, pp. 1-164, with figures and
plates.—The Association of American Gecgraphers, organized in
1904, has now inaugurated a publication policy one of whose re-
sults is the above volume. It is proposed to publish from time to
time certain of the most important papers presented at the annual
meetings, and since the society is the only geographical organi-
zation which makes achievement in research a condition of
membership, the Annals of the Association shouJd be of unusual
interest and value. The present volume is of special importance
to librarians and geographers, for it contains titles and abstracts
of all papers presented to the society (1904-1910 inclusive) and
heretofore not published or published in variable form in different
journals.

Under the circumstances, certain features of the make-up _
deserve attention. We note with satisfaction the quarto size of
the volume which permits the presentation of large-scale maps,
sketches, and photographs and a dignified text-page. Everyone
agrees that octavo size is perhaps a little more convenient, a fact
that has begotten a school of extremists who will not have quartos
under any circumstances. Foot-note references are another praise-
worthy feature. ‘he inconvenience of reference from page to
notes at the end of a volume and back again 1s so great that there
seems to be no compensating advantage in their separation. The
time has passed when this can be called a difference of opinion ;
it is the difference between good and bad judgment.

The papers in Volume I are well chosen and represent some-
thing of the range of modern geography: “The Causes of
Vegetational Cycles” (Cowles) ; ‘The Colorado or Front Range :
A Study in Physiographic Presentation” (Davis) ; ‘‘ Geography
in the Development of the Alaska Coal Deposits” (Brooks) ;
‘““A Geographic Study of Mesa Verde” (Atwood). Cowles’ paper
is not only a model in clear scientific writing but also a revelation
to many of the value of geography in ecological research. As
indicated by the sub-title, the second paper is concerned prima-
rily with form in physiographic writing and embodies in final
form the ideas presented in Professor Davis’ recent papers on
this subiect together with certain new features as to method. It
is an extraordinarily useful and brilliant essay that, we venture
to say, will be as eagerly read a hundred years hence as now.
Brooks’ paper is a closely organized study in the economic geog-
raphy of the Alaskan coal fields. Atwood discusses the origin of
Mesa Verde and the relation of its physiographic character to the
homes and activities of the Cliff Dwellers. Lie

2. Annual Report of the Director of the Field Museum of
Natural History, Freprerick J. V. SxKirr, for the year 1911.
Report series, vol. [V, No. 2; pp. 101-182, plates XVII—X XIX.
Chicago, January, 1912.—The Annual Report by Dr. Skiff states
that the past year has been an important one for the Field

Miscellaneous Intelligence. 597

Museum of Natural History in Chicago, since the site for a new
building in Jackson Park has been accepted by the trustees.
Further, the plans for the new building in all their details have
been completed and approved, and the articles of specification for
the contracts also drawn up. ‘This represents the results of six
years’ work, and when the transfer is accomplished, the collec-
tions will have a permanent and safe home. The Museum has
been active, not only in extending its collections and developing its
exhibits,as detailed and illustrated in this Report, but also in various
expeditions to distant points. There are here included the Meek
expedition to Panama and the Osgood expedition to Venezuela.
Further, Dr. B. Laufer, after an absence of three years in the far
Kast, has returned bringing upwards of 10,000 ethnological speci-
mens from Tibet and China ; this collection is now being installed,
and a Museum publication on jade, by Dr. Laufer, is promised.
A botanical expedition has also been under way, since last
August, in the northern tropics and the far Kast.

It is also announced that a contribution of $250,000 has been
made by Mr. Norman W. Harris for the extension of the work of
the Museum into the public schools of Chicago. The total sum
expended in the year for the maintenance of the Museum amounted
to $150,000, to which must be added about $50,000 more for
cases, expeditions and collections.

3. The Science Reports of the Tohoku Imperial University,
Sendai, Japan. Vol.I, No. 1; pp. 1-66 with 8 plates—The Uni-
versity at Sendai, Japan, has recently established a series of
Science Reports, of which No. 1 is now at hand. Professor
Hayashi, the librarian of the University, is head of the publica-
tion committee and communications in regard to the publications
should be sent to him. To the present number he contributes
two mathematical articles, and in addition there is a paper
(pp. 1-42), by Professor K. Honda on the thermo-magnetic
properties of the elements. This investigation has been extended
to 43 of the 81 elements, and the results are given in full, with
the aid of six-plates. The oxidation of aniline IIT is discussed by
R. Majima, and a brief paper on the secondary undulations of
the Canadian tides, by K. Honda and W. Bell Dawson, closes
the number.

4. Fourth Report of the Wellcome Tropical Research Labora-
tories at the Gordon Memorial College, Khartoum; ANDREW
Batrour, Director. Vol. B, General Science. Pp. 334, with
numerous maps, illustrations, and colored plates. Department
of Education, Sudan Government, Khartoum, 1911.—The March
issue of this Journal (p. 294) contained a notice of the medical
volume of this report. The companion volume on general sci-
ence contains some sixteen fully illustrated articles on a variety
of topics, written by members of the staff and other specialists.
The principal papers discuss the chemical analyses of soils and
products ; gum production ; insects injurious to man, animals, and
crops; birds; scorpions; snakes; protozoa; gold mining; tribal
customs ; and municipal engineering. W. BG:

Am. JouR. a Seriges, VoL. XXXIITI, No. 198.—Junz, 1912.

598 Scientific Intelligence.

5. The Life and Love of the Insect; by J. Henri Fasres
translated by ALEXANDER TrrxErRA de Martros. Pp.' x, 262,
with 12 plates. London, 1911 (Adam and Charles Black).—
English readers who are unfamiliar with the French language
and who have a taste for natural history stories will appreciate
the translation of this volume of essays selected from the volu-
minous writings of this ‘ Insect’s Homer,” as the author has been
called. In the keenness of the observations described and the
vividness of the language used the ten or more volumes of Sou-
venirs Lntomologiques are unequaled by any scientific production
of recent years. The stories of the life and love of the insect are
made. to possess an interest to the sympathetic reader fully equal
to that of an imaginative novel, and yet each statement rests
upon the actual observation of the writer.

This little volume consists of eighteen essays, of which ten
describe the natural history of various species of elsewhere
prosaic dung-beetles, the remaining chapters dealing with wasps,
bees, weevils, and scorpions. The translation has been well
done. W. RB. ©.

6. The Evolution of Animal Intelligence ; by 8. J. Hotmes.
Pp. v, 296, with 18 figures, New York, 1911 (Henry Holt &
Company).—The subject of animal behavior and intelligence has
been one of the latest of the biological studies to receive sufficient
attention to be classed asa science. The writer of the present
book has done good service in presenting the subject in the stage
of development which the study has now reached. One quickly
notes the experimental attitude of the observer free from preju-
dice in place of the older anthropomorphic explanation of an
animal’s behavior. :

In his treatment ot the subject the writer first discusses
simple reflexes and tropisms and the behavior of the protozoa.
Then follow chapters on instincts and modifications of behavior,
pleasure, pain, and the beginning of intelligence, leading finally
to the mental life of monkeys. It may be of interest to note that
the author assumes that the step from simple instincts to the
formation of associations by experience, that is, intelligence, has
been taken many times in the course of evolution. He considers
the crustacea and mollusks as the lowest phyla of animals in
which intelligence can be satisfactorily demonstrated. Ww. R. ¢.

OBITUARY.

Professor P. N. LepeprEw, the Russian physicist, died in March
last.

Professor Auguste Téprer of Dresden, the inventor of the
Topler mercury pump, died in March at the age of seventy-six
rears.

: Professor Epwarp Divers, from 1873 to 1899 Professor of
Chemistry in the Imperial University, Japan, died on March 8 in
his seventy-fifth year.

Mr. Georce Borup, a member of the Peary North Pole Expe-
dition and himself planning, with Donald B. MacMillan, an
expedition to Crocker Land the coming summer, lost his life by
drowning on April 28.

INDEX TO VOLUME XXXIII.*

A

Abbot, C. G., The Sun, 61.

Academy, National, meeting at Wash-
ington, 513.

Adams, L. H., standard scale of
temperatures, 034.

Alabama geol. survey, 64.

Alaska, Mt. McKinley region, Brooks
and Prindle, 161.

Allegheny Observatory, 386.

Allen, E. T., mineral sulphides of
iron, 169.

American Geographers, Annals, 596.

Animal Intelligence, Holmes, 598;
Thorndike, 70.

Appleton’s Scientific Primers, Green,
72.

Arctic seas, state of ice in, 382.

Atlas, des Formes du Relief terres-
tre, 168.

Atomic weights, International Com-
mittee on, 279.

Aurora Borealis, rays producing,
Vegard, 501.

Australia, Physiographic
Taylor, 289.

Aspects,

B

Bacteriology, Heineman, 71.

Bain, H. Foster, Ore Deposits, 292.

Barss, W. R., measurements of
radio-activity, 546.

' Barus, C., rate of decay of nuclei,
107; displacement interferometer,
109.

Batteries, Storage, Morse, 380.

Bauer, L. A., Hecker on ocean grav-
ity observations, 245.

Bergen, J. Y., Botany, 164.

Bingham, H., pre-historic human
remains at Cuzco, Peru, 297.

Blaker, E., Physics, 380.

Blow, pressure of, Hopkinson, 9501.

Botanical notes, New Zealand, As-
ton, 163.

Botany, Practical, Bergen and Cald-
well, 164; Andrews, 164.

Bowen, N. L., composition of nephe-
lite, 49; the nephelite-anorthite
system, 551.

Bowie, W., gravity anomalies and
geologic formation in the United
States, 237,

Bowman, I., geologic relations of the
Cuzco remains, 306.

Bradley, W. M., composition of
analcite, 483 ; of nephelite, 439.

Branner, J. C., hydrocarbon from
Brazil, 20.

Brazil, hydrocarbon from Bahia,
Branner, 205.

Bronson, H. L., deposit of radium in
electric field, 483.

Brush, George J., obituary notice,
296, 389.

Building Stones and Clays, Eckel.595.

Burbank, J. E., microseismic motion,
470; microseisms caused by frost
action, 474.

C

Calculus, Granville, 386.

Caldwell, O. W., Botany, 164.

Cameron, F. K., Soil Solution, 512.

estore Geol. Survey publications,
289.

Carnegie Foundation, 6th annual
report, 514,

— Institution of Washington, Year
peor No. 10, 384; publications,
a4.

Case, E. C., reptilian skulls, 339.

Castle, W. E., Heredity in relation
to Evolution, 70.

Chemical Analysis, Quantitative,
Clowes.and Coleman, 1957.

— — ultra-filtration in, 589.

Chemistry, Applied, Dictionary of,
Thorpe, 500. -

CHEMISTRY.

Alkalies, determination, Makinen,
500.

Amarillium, 280.

Ammonia and water, compounds,
Smits and Postma, 58.

* This Index contains the general heads, CHEMISTRY (incl. chem. physics) ,GEOLOGY,
MINERALS, OBITUARY, ROCKS, and under each the titles of Articles referring thereto

are mentioned.

600

Antimony in alloys, determination,
Jamieson, 58.

Canadium, supposed new element,
French, 155, 280.
Carbon monoxide,

Wieland, 586.
— pernitride, Darzens, 278.
Cementite, Ruff and Gerstein, 373.
Color effect and isomorphous mix-
ture, Wells, 103.
Esters, hydrolysis in fatty acids,
Drushel, 27.

Fluorine, determination, Starck and
Thorin, 58. }
Hydrazine, determination, Jamie-

son, 302.
Tron, atomic weight of meteoric,
Baxter and Thorvaldson, 57.

— separation from manganese, San-
chez, 156.
Lead, nickel,
Ward, 384.
Magnesia rods as a substitute for
platinum wire, Wadekind, 585.
Manganese, determination, Raikow

and Tischkow, 278 ; 106.
Mercury determination, Jamieson,

349.

combustion,

etc.,

Neon, krypton and xenon, monato-

micity, Ramsay, 378.

Nitric acid, detection, Sen and
Dey, 499.

Oxalate permanganate
Ward, 428.

Portland cement, Janecke, 279.

Radium, deposit in electric field,
Wellisch and Bronson, 483.

Sodium carbonate, hydrates, Weg-
scheider, 280.

Sulphur monochloride for decom-
posing certain minerals, Hicks,
o74.

Tellurium, alleged complexity, Har-
court and Baker, 155.

Titanium,
bium, ete., Muller, 373.

— dioxide, heat of formation, Mix-
ter, 45.

Uranium hexafluoride,
Heinzelmann, 957.

Ruff and

Vanadic acid, reduction, Cain and |

Hostetter, 375.

Water, determination, Zerewitinoff,
Be
2) (x.

Chemists, Famous, Roberts, 156.

Clark, R. W., Petrographic methods, |

511.
Clarke, F. W., Data of Geochem-
istry, 64.
Coast Survey, report, 514.
Cole, M. J., Microscopy, 379.
Comets and Electrons, Righi, 62.

estimation,

process, |

separation from nio-|
|

INDEX.

Connecticut, Granites of, Dale and
Gregory, 160.

— Trias, Life of, Lull, 397.

Constants, chemical and physical,

Tables, 60, 158.

Coral reefs in the Triassic of No.
America, Smith, 92.

Craig, C. F., Parasitic Amcebe of
Man, 70.

Crenshaw, J. L., mineral sulphides
of iron, 169.

Cross, M. I., Microscopy, 379.

Cushing, H. P., age of Cleveland
shale of Ohio, 581.

D

Dale, T. N., Ordovician outlier, Sud-
bury, Vermont, 97; granites of
Connecticut, 160.

Dana, E. S., obituary notice of
George J. Brush, 389.

Day, A. L., nitrogen thermometer
scale, with boiling point of sul-
phur, 517.

Drushel, W. A., hydrolysis of esters
in fatty acids, 27.

Duggar, B. M., Fungous Diseases of
Plants, 164.

E

Earthquakes, elastic-rebound theory,
Reid, 287.

Eaton, G. F., remains of man at
Cuzco, Peru, 820.

Eckel, E. C., Building Stones and
Clays, 5995.

_Elektrochemische Umformer, Zach-

arias, 108.

Ethnology, Bureau of American,
annual report, 71.

Evolution, Capture Theory of Cos-
mical, See, 167.

Eyerman, J., Mineralogy of Pennsyl-
vania, 67.

F

Fabre, J.H., Life of the Insect, 598.
| Farrington, O. C., analysis of stone

meteorites, 69.
Field Museum of Natural History,
annual report, 596.

| Filtration in analysis, 585.
| Foote, H. W., composition of anal-

cite, 453; of nephelite, 439.
Fungous Diseases of Plants, Duggar,
164.

G
Geochemistry, Data, Clarke, 64.

Geographers, American, annals, 596.

INDEX.

GEOLOGICAL REPORTS.

Alabama, 64.

Canada, 289.

Maryland, 593.

New Jersey, 64, 382.

United States, 32d annual report,
159; publications, 62, 507.

Virginia, 594.

West Australia, 383.

West Virginia, 381, 594.

Wisconsin, 882, 595.

GEOLOGY.

Arnheim, formation, Foerste, 511.

Branchiopoda, etc., Middle Cam-
brian, Walcott, 509.

Bryozoa, Paleozoic, of Baltic Prov-
inces, Bassler, 292.

Cambro-Ordovician in British Co-
lumbia, Walcott, 508.

Carboniferous of Narragansett Ba-
sin, Lahee, 249, 354, 447.

Chattanooga shale in Kentucky,
unconformity at base, Kindle,
120.

Cleveland shale of Ohio, age, Cush-
ing. 581.

‘“Coal balls,” Stopes and Watson,
290.

Cycads, American fossil, Wieland,
Part vis 13:

Fish, fossil, Cretaceous of New
Jersey, Fowler, 292.

Glacial fractures, crescentic origin
of, Lahee, 41.

Glaciers, periodic variations, 288.

Gravity anomalies and _ geologic
formations, Bowie, 237.

Human remains, pre-historic, from
Cuzco, Peru, Bingham, 297;
Eaton, 325; Bowman, 306.

Lake Superior region, geology, Van
Hise and Leith, 286.

Loess, Missouri river, Keyes, 82.

Metamcrphism and geological struc-
ture in the Narragansett Basin,
Lahee, 249, 354, 447.

Missouri river loess, Keyes, 32.

Olenopsis in America, Walcott, 509.

Ordovician outlier, Sudbury, Ver-
mont, Dale, 97.

Paleechinoidea, new genus, Ols-

son, 442.

Peneplains, interpretations, An-
drews, 288.

Permian Vertebrates, American,

Williston, 65, 592.
Skulls, descriptions of reptilian,
Case and Williston, 339.

601

Strophomena and other
Foerste, 510.
Trias, Connecticut, life of, Lull,
397.
Triassic of No. America, coral reefs
in, Smith, 92.
Geometry, Smith, 168.
Geophysical Laboratory,
from, 169, 517, 534, 551.
Glass-blowing, 380.
Granville, W. A., Calculus, 386.
Gravity, ocean, observations, Hecker
on, Bauer, 245.
Gregory, H. E., Granites of Con-
necticut, 160.
Guthe, K. E., College Physics, 285.

fossils,

papers

H

Harvard College Observatory, 386.

Hatch, F. H., Mineralogy, 5995.

Heineman, P. G., Bacteriology, 71.

Heredity in relation to Evolution,
Castle, 70.

Hindu-Arabic Minerals, Smith and
Karpinsky, 168.

Human remains, pre-historic,
Cuzco, Peru, 297, 306, 820.

at

I

Ice in the Arctic seas, 582.

Illumination, Trotter, 61. ~

Insect, Life of, Fabre, 598.

Interferometer, displacement,
Barus, 109.

Iron, mineral sulphides of, Allen,
Crenshaw and Johnston, 169; crys-
tallographic study, Larsen, 169.

— spectrum, wave-lengths of, Ever-
sheim, 283.

J

Jaekel, O., Die Wirbeltiere, 592.

Jamieson, G. S., determination of
mercury, 349 ; of hydrazine, 392.

Johnston, J., mineral sulphides of
iron, 169; standard scale of tem-
peratures, 534.

Jones, F. T., Physics Problems, 379.

Jordan, W. H., Human Nutrition,
295.

K

Kentucky, Chattanooga shale, un-
conformity, Kindle, 120.

Keyes, C. R., Missouri river loess
and Kansan drift-sheet, 32.

602

Kindle, E. M., unconformity of
Chattanooga shale in Kentucky,
120.

Kristalle, fliissigen, Lehmann, 199.

=

Lacroix, A., nephelite syenites of |

Los, 68.

Lahee, F. H., crescentic fractures of
glacial origin, 41; metamorphism
and geological structure in the
Narragansett Basin, 249, 304, 447.

Lake Superior region, geology, Van
Hise and Leith, 286.

Larsen, E. S., crystallographic study
of mineral sulphides of iron, 169.

Lehmann, Fliissige Kristalle, 159.

Library of Congress, annual report,
166.

Lull, R. S., life of the Connecticut
Trias, 397.

M

Man, Parasitic Amcebe, Craig, 70.

— prehistoric. remains near Cuzco,
Peru, 297, 306, 325.

Maryland geol. survey, 598.

Membrane, semi-permeable,
ton, 377.

Metals, purity of commercial, Myl-
ius, 586

Metamorphism, etc... Narragansett
Basin, Lahee, 249, 354, 447.

Trou-

Metecrites, stone, analyses, Far-
rington, 65. .
Microscopy, modern, Cross and
Cole, 379.

Microseismic motion, Burbank, 470.

Microseisms caused by frost, Bur-
bank, 474.

Mineral nomenclature, Washington,
137.

Mineralogy, Hatch, 595; Sommer-
feldt; 67.

— of Pennsylvania, Eyerman, 67.

Minerals, solid solution in, Allen,
Crenshaw and Johnston, 169;
Foote and Bradley, 433; Bowen,
ddl.

MINERALS.

Analcite, composition, 483. Anor-
thite, 564. Apatite,-475.

Baddeleyite, Montana, 54.

Carnegieite, 564. Carnotite, Penn.,
574. Chromitite, Servia, 294.

Dahllite, Nevada, 475.

Eichbergite, Austria, 295.

INDEX.

Fermorite, India, 294.
Hydrocarbon, Bahia, Brazil, 25.
Ilmenite, chem. composition, 500.

Lorandite, Wyoming, 105. Losite, -
69.

Marcasite, composition, etce., 170,
218. Muthmannite, Transyl-
vania, 293. :

Nephelite, composition, 49, 439,
564.

Pyrite, composition, etc., 170, 218.
Pyrrhotite, composition, etc.,
193, 222.

Rutile, Quebec, 263. _

Sapphirine, Quebec, 263. Silliman-
ite, with native gold, 241. Spo-
dumene, melting point, 499.

Thorveitite, Norway, 294. Troilite,
relation to pyrrhotite, 212. Tur-
quoise, crystallized, Virginia, 39.

Uraninite, East Africa, 67.

Veelckerite, 475. Villiaumite, 69.

Yttrofluorite, Norway, 293.

Mines, Bureau of, 63.
Mixter, W. G., heat of formation of

titanium dioxide, 49.

Morse, H. W., Storage Batteries,

380.

Mykologie, Kossowicz, 295.

N

Narragansett Basin, R. I., geolog-
ical structure, Lahee, 249, 304, 447.

Nephelite-anorthite series, Bowen,
49, 551.

Newfoundland,
Twenhofel, 1.

New Jersey geol. survey, 64, 382.

New Zealand botanical notes, Aston,
163.

Nichols, E. I., Physics, 380.

Nitrogen tetroxide, in electric dis-
charge, Zenneck, 379.

— thermometer scale, Day and Sos-
man, d17.

Nuclei, rate of decay, Barus, 107.

Nutrition, Human, Jordan, 299.

physiography of,

O
OBITUARY.

Bornet, J. B. E., 296. Borup, G.,
598. Brush, G. J., 296, 389.

Davison, G., 72. Divers, E., 598.
Dutton, C. E., 168, 387.

Hooker, J. D., 72.

Lebedew, P. N., 598. Lister, Sir
Joseph, 296.

Montgomery, T. H., Jr., 388.

INDEX.

Reynolds, O., 516. Rotch, A. L.,
516

Smith, J. B., 388. Spezia, G., 72.
Sutherland, W., 72.

iimtcett. Os, 060, OL, Lopler, A.;
598.
Wheeler, C. G., 296.
Observatory, Allegheny, publica-
tions, 586.

— Harvard College, 386.

Olsson, A., new genus of Palchin-
oidea, 442.

Optics, Physical, Wood, 61.

Ore deposits, types of, Bain, 292.

Osmotic pressure, determination,
Trouton, 377.

Ostwald’s Klassiker
Wissenschaften, 296.

der exacten

P

Paddle-Wheels, Photometric, Milne,
157.

Paleontologia Universalis, 511.

Patten, W., Evolution of Vertebrates,
590.

Peat, uses of, Davis, 388.

Peru, pre-historic human remains
from Cuzco, Bingham, 297; Bow-
man, 306; Eaton, 325.

Petrographic methods, Weinschenk
and Clark, 511.

— Microscopic Research, Wright, 512.

Physics, Hawkins, 589; Jones and
Tatnall, 379; Mann, 590; Nichols
and Blaker, 380; Reed and Guthe,
285 ; Spinney, 157.

Physiography of
Twenhofel, 1.

Planeten, das Schicksal der, Arr-
henius, 167.

Platinum, production in 1910, 67.

Postma, G. E., analysis of dahllite,
veelckerite, etc., 475.

Potash in the United States, 69.

Newfoundland,

R

Radio-active disintegration, effect of
temperature, Russell, 587.

Radio-activity of Diirkheim Waters,
Ebler and Fellner, 59.

-— measurements, Barss, 546.

Radiotelegraphy, experiments, Aus-
tin, 59.

Radium, deposit in electric field,
Wellisch and Bronson, 48.

—magenetic spectra of ~-rays, von
Baeyer, Meitner and Hahn, 281.

Reed, J. O., College Physics, 285.

Roberts, E., Famous Chemists, 156.

603

ROCKS.

Anorthosite, Quebec, 268.

Granites of Connecticut, Dale and
Gregory, 160.

Ilmenite rocks near St, Urbain,
Quebec, Warren, 263.

Nephelite-syenite of Los, Lacroix,
68.

Pegmatites, etc., of Narragansett
Basin, Lahee, 447; pelites, psam-
mites, psephites of, 354.

Rocks of Mt. McKinley region,
Alaska, Brooks and Prindle, 161.

Topsailite, 68.

Urbainite, Quebec, 276.

Rogers, A. F., baddeleyite, Montana,

04; lorandite, Wyoming, 105.

Roéntgen radiation, production of,

Whiddington, 282.

S

Saturn’s ring, optical
Todd, 152.

Schaller, W. T., crystallized tur-
quoise from Virginia, 35.

See, T. J. J., Capture Theory of
Cosmical Evolution, 167.

Seismological Society of America,
bulletin, 161.

Sismologie moderne, de Ballore, 288.

Smith, D. C., Geometry, 168.

Smith, J. P., coral reefs in Triassic,
of No. America, 92.

Smithsonian Institution, annual re-
port, 71, 165.

Soil solution, Cameron, 512.

Solid solution in minerals, 169, 433,
551.

Sosman, R. B., nitrogen thermom-
eter scale, with boiling point of
sulphur, 517.

Spectra, magnetic, of 6-rays of ra-
dium, 281 ; of thorium, 588.

Spectrum of iron, wave-lengths, 283.

Spinney, L. B., Physics, 157.

Standards, Bureau of, bulletin, 59,
515.

Starlit sky,
Fabry, 280.

Sulphur, boiling point, Day and Sos-
man, 517.

Sun, Abbot, 61.

Sun’s energy-spectrum, Abbot, 285.

resolution,

intrinsic brightness,

Ao
Tatnall, R. R., Physics Problems,
279.

Taylor, G., Australia, 289.

604

Temperatures, nitrogen-thermome-
ter scale, Day and Sosman, 517;

standard scale of, Adams and
Johnston, 934.
Terrestrial relief forms, Atlas, 168.

Thorium, magnetic spectra of -rays,
von Baeyer, ete., 588.

Thorndike, E. L., Animal Intelli-
gence, 70.

Thorpe, E., Dictionary of Applied
Chemistry, 500.

Todd, D., optical resolution of the
Saturnian ring, 102.

Tohoku Imperial University, Science |

reports, 597.
Trisection of angles, Uhler, 506.
Trotter, A. P., Illumination, 61.
Twenhofel, W. H., physiography of
Newfoundland, 1.

U

Uhler, H. S., notes on Maskelyne’s |

‘‘ trisection of an angle,”’ 506.
United States Bureau of Mines, 63.
— Geol. Survey, 62, 159, 507.

V

Vermont, Sudbury, Ordovician out-
lier, Dale, 97.

Vertebrates, Amer. Permian, Wil-
liston, 65, 592.

— Evolution, Patten, 590; Jaekel,
592.

Virginia geol. survey, 594.

Vortex rings in liquids, Northrup,
504.

Ww

Walcott, C. D., Cambro-Ordovician
in British Columbia, 508 ; Olenopsis
in America, 509: middle Cambrian
Branchiopoda, etc., 509.

|
|
}

|

INDEX.

Ward, H. L., estimations of lead,
nickel, and zinc, 334; oxalate per-
manganate process, 428.

Warren, C. H., ilmenite rocks of St.
Urbain, Quebec, 262

Washington, H. S., mineral nomen-
clature, 187.

Watson, T. L., association of gold
with sillimanite, 241.

Weinschenk, E., Petrographic Meth-
ods, 511.

Wellcome Tropical Research Labo-
ratory, fourth report, 294, 597.

Wellisch, E. M., deposit of radium
in electric field, 483.

Wells, H. L., color-effect of isomor-
phous mixture, 103.

West Australia geol. survey, 583.

baba Virginia geol. survey, 381,
594.

ee E. T., carnotite in Penn.,
O74.

Wieland, G. R., American fossil

| eycads, Part vi, 73.

Williston, S. W., Amer. Permian
| Vertebrates, 65, 592; reptilian
skulls, 539.
|Wirbeltiere, Jaekel, 592.
| Wisconsin geol. survey, 582, 595.

— inland lakes, Birge and Juday, 71.

| Wood, R. W.., Physical Optics, 61.

Wright, F. E., Petrographic-Micro-

| seopic Research, 512.

| Writing, Technical, Earle, 386.

ee

| Zerfallprozesse in der Natur, Engler,

590

New Circulars.

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rare and showy minerals.

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blowpipe and laboratory work.

86: Minerals and Rocks for Working Collections: List of
common minerals and rocks for study specimens; prices
from 1% cents up.

Catalogue 26: Biological Supplies: New illustrated price list
of material for dissection; study and display specimens;
special dissections; models, etc. Szxth edition.

Any or all of the above lists will be sent free on request. We are
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76-104 College Ave., Rochester, New York, U.S. A.

CONTENTS. ee

ne

Art. XLITI.—Nitrogen Thermometer Scale from ee ‘teers & <a
630°, with a Direct Determination of the Boiling Point aa
of Sulphur; by Ar'L. Day and R. B. Sosmans- S2e= es ae ESs

XLIV.—Note on the clang Scale of Temperatures howe a |
tween 200° and 1100°; by L. H. Apams and J. Joun- =
STON Si 2 US See ee ee

XLV.—Note on Measurements of Radio- -activity by Means
of Aipha Rays; “by W-*Hh.*Dinss: <= 2 eee (546

XLVI.—The Binary System: Na, Al ‘Si, O, (Nephelite, Car-_

negieite)—CaAl, Si, 0. (Anorthite) ; by "N. L, BowEn..- 551

XLVIL—New Occurrence of Carnotite; by E. T. WuErry 574 | Sa

XLVHI.—Age of the Cleveland Shale of Ohio; by H. P.

CER BING 3 ra ee Sent a err 581.

SCIENTIFIC INTELLIGENCE.

Chemisty and Paysics—Ultra-filtration in Chemical Analysis, DOrFuRT and
GALECKI: Magnesia Rods as a Substitute for Platinum Wire, E. WADE-
KIND, 585.—Combustion of Carbon Monoxide, WIELAND: Purity of Com-

mercial Metals, F. Myxivs, 086.—Effect of Temperature upon Radio-activo

Disintegration, A. ‘S. RussELL, 587.—Das Magnetische Spektrum der [-
Strahlen des Thoriums, von BAEYER, Haun, and Merrrner, 588.—Applied
Physics for Secondary Schools, V. D. Hawkins: Die Messung vertikaler
Luftstrémungen, P. LupEwiG, 589.—Teaching of Physics for Purposes of
General Education, C. R. Mann: . Uber Zerfallprozesse in der Natur,
C. EnevEr, 590.

Geology—Evolution of the Vertebrates and their Kin, W. PATTEN, 590.—

Die Wirbeltiere: eine Ubersicht tiber die fossilen und lebenden Formen, ~
O. JABKEL ; American Permian Vertebrates, S. W. WuLListon, 592.—
Maryland Geological Survey: Method of Remov ing Tests from Fossils,
S. S. BuckMAN, 593. —Virginia Geological Survey : West Virginia Geolog-
ical Survey, 594, — Wisconsin Geological and Natural History Survey:
Building Stones and Clays, E. C. ECKEL : Mineralogy, F. H. Hatcn, 595.

Miscellaneous Scientific Intelligence—Annals of the Association of American — in|

Geographers, R. E. Dopge: Annual Report of the Director of the Field
Museum of Natural History, 596.—Science Reports of the Tohoku Imperial
University, Sendai, Japan: Fourth Report of the Wellcome Tropical Re-
search Laboratory, 597.--Life and Love of the Insect, J. H. FABRE ;
Evolution of Animal Intelligence, S. J. Hotmss, 598.

Obituary—P. N. Lepeppw: A. TopLer: HE. Divers: G. Borup, 598.
INDEX To VOLUME XXXITI, 599-604,

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