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THE 


AMERICAN 
JOURNAL OF SCIENCE. 


Epiror: EDWARD S. DANA. 


ASSOCIATE EDITORS 


Proressorns GEORGE L. GOODALE, JOHN TROWBRIDGE, 
W. G. FARLOW anp WM. M. DAVIS, or Camsringe, 


Proressors ADDISON E. VERRILL, HORACE L. WELLS, 
L. V. PIRSSON anp H. E. GREGORY, or New Haven, 


Proressor HENRY S. WILLIAMS, or Irwaca, 
Proressor JOSEPH S. AMES, or Battimmore, 
Mr. J. S. DILLER, oF Wasuineton. 


FOURTH SERIES 


VOL. XXXI—[WHOLE NUMBER, CLXXXI.] 


WITH FOUR PLATES. 


NEW HAVEN, CONNECTICUT. 
iG etenlige 


28101 


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MEE iM agit 1) 
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CONTENTS TO VOLUME XXXI. 


Number 181. 


Page 

Arr. I.—Gravity Determinations at Sea; by L. A. Bauzr.- 1 
II.—Stratigraphy of a Deep Well at Waverly, Ohio; by R. 

She LSU NSS EHTEL <2 pS a ee ree 
III.—Solid Solution in Minerals with Special Reference to 

Nephelite; by H. W. Foorr and W. M. Brapuny--.--- 25 
IV.—Fossil Evidence of the Age of the Virginia Piedmont 

Slates; by T. L. Watsow and S. L. Powntt _--------- 33 
V.—Native Gold from Gold Harbour, Queen Charlotte 

lisllewngls; @ loyr dies Lei, 1B), Cor/g IN eieced ee Ses cee ee 45 


VI.—Natramblygonite, a New Mineral ; by W. T.Scaatiter 48 
VII.—New Emission Theory of Light; by J. TRowsripecE. 51 
VIII.—Origin and Peopling of the Deep Sea; by J. 


DNV WAGTISTSETINRCm Meee eee a armalner a anit 2 Ls SS ud rete A ee 55 
IX.—Camels of the Harrison Beds, with Three New Species ; 

loge 15 18, ILO IS e eee ate ee ane eee Se ee 65 
NVAIETANT EDN RM mRE ee 2 ke lh ase oo (Al 


SCIENTIFIC INTELLIGENCE. 


Chemistry and Physics—Preparation of Metallic Radium, KE. EBLER: Reduc- 
tion of Oxide of Iron by Solid Carbon, CHARPy and BoNNEROT, 70.— 
Action of Light upon an Hlectrie Cell, H. Panason : Sterilization of Large 
Quantities of Water by Ultra-violet Rays, HreLBROoNNER and RECKLING- 
HAUSEN, 76.—Refrigeration by Mixtures of Liquids, J. Ductaux: The 
Relations between Chemical Constitution and Some Physical Properties, 
S. Suites: Positive Rays, W. Wien, 77.—Deflections by Electrostatic 
and Magnetic Fields of Radium B after Recoil from Radium, A. S. 
Russ, etc.: Energy Distribution of Diffraction Gratings, A. TRow- 
BRIDGE and R. W. Woop: Modification in Magnetic Fields of Lines of 
the Light emitted by the Hlectric Spark, G. A. Hrmsatece: Electric 
Motors, H. M. Hopart, 78. 


Geology and Natural History—Grundziige der Paldontologie, K. A. v. 
ZirreL, 78.—Notes on Ordovician Trilobites, 11, Ill and IV, P. HE. Ray- 
MOND: Preliminary List of the Fauna of the Allegheny and Conemaugh 
Series in Western Pennsylvania, P. E. RaymMonp: The British Carbonif- 
erous Orthotetine, I. THomas, 79.—Geological Excursion in the Grand 
Canyon District, D. W. Jounson: Aufbau des Gebirges in der Umgebung 
der Strassburger Hiitte an der Scesaplana, W. v. SEIDLITZ: Granites of 
the Southeastern Atlantic States, T. L. Watson: The Volcanic Rocks of 
Victoria, E. W. Skrats, 80.—Analcite Rocks, G. W. TyRRELL : Morganite, 
a Rose-colored Beryl, G. Kunz, 81.—Tables for the Determination of 
Minerals by Physical Properties : The Subantarctic Islands of New Zea- 
land ; British Nudibranchiate Mollusca, with Figures of the Species ; 
Part viii, Supplementary, 82.—Medusae of the World, A. G. Mayzr: 
An Introduction to Zoology, R. W. Heener, 83.—Animal Study: with 
Directions for Laboratory and Field Work, W. H. D. Murer: Methods of 
Attracting Birds, G. H. TRarton: Second Report on the Hymeniales of 
Connecticut, EH. A. Waite, 84. 


iv CONTENTS. 


Number 182. 
Page 
Arr. X.—Adjustment for the Plane Grating Similar to 
Rowland’s Method for the Concave Grating ; by C. 


Barus and M,(BAmugieeesse peso. lon). eee 85 
XI.—Determination of the Hardness of Minerals, II; by 

bc Way A Gu ee ees ce ey 1g Ae Yee gen 96 
XII.—Photographing Fossils by Reflected Light ; by L. D. 

Buntang Johan NG itches ae 99 
XIII.—Synthesis of the Paleogeography of North America ; ; 

by -E. Swass 222.3. Sees ee ee 101 


XIV.—Estimation of Silver by Electro-Deposition from an 
Ammoniacal Solution of the Oxalate; by F. A. Gooca 
and Jo PS Winisnr 2k ee) See ee eee a eS ne 109 


XV.—Notes on the Armored Dinosauria; by G. R. WiELAND 112 
ie Manne Gneissoid Structure in the Cortlandt Series ; 


Dy Guts ROG WR hg peter ones ay etn ane es Men 125 
XVII.—Thaumasite from Beaver County, Utah; by B. S. 

Bouriur and- W.."PAScHAmiEME 2205 eee ten eer e 131 
XVIII.—Nomenclature of the Lower Paleozoic Rocks of 

New) York. byiH. PCusnine 2-95. 952- = 2 eee 135 


SCIENTIFIC INTELLIGENCE. 


Chemistry and Physics—Determination of Copper as Sulphate, Rrcoura : 
New Method for Determining Boiling Points and Vapor Pressures, SMITH 
and Menzies, 146.— Reactions of Nascent Hydrogen in the Dry Condition, 
Vournassos: Synthetic Sapphire, Verneutnt, 147.—Influence of Tem- 
perature on the Compressibility of Metals, E. GRUNEISEN : Ionization of 
the Atmosphere due to Radio-active Matter, A. S. Eve: Thomson Effect, 
P. Cermak: Velocity Measurement of Rontgen Rays, E. Marx, 148. 


Geology—Osteology of Pteranodon, G. F. Eaton, 148.—The Age of Mam- 
mals, H. F. Osporn, 150. —Tertiary Faunal Horizons in the Wind River 
Basin, Wyoming, with Descriptions of New Eocene Mammals, W. 
GRANGER, 151.—Geological Survey of New Jersey, Annual Report of the 
State Geologist, H. B. Ktmuet, 182. 


Astronomy—Transactions of the Astronomical Observatory of Yale Uni- 
versity, 152.—Determination of the Solar Parallax from photographs of 
Eros, 153.—Les Déterminations des Longitudes et l’Histoire des Chro- 
nométres, J. Mascart: Project for the Reform of the Calendar, C. A. 
Hesse, 154. 


Miscellaneous Scientific Intelligence—Report ot the Secretary of the Smith- 
sonian Institution, 155.—Report of the Librarian of Congress and Report 
of the Superintendent of the Library Buildings and Grounds : Academic 
and Industrial Efficiency, M. L. Cooxes, 156. 


CONTENTS. Vv 


Number 183. 


Page 
Art. XIX.—Transmission of Light through Transparent 
Inactive Crystal Plates, with Special Reference to 
Observations in Convergent Polarized Light ; by F. E. 
WitiGht? 3... 2a9e See See Se ere Eee aera 157 
XX.—Separation and Estimation of Barium Associated with 


Calcium and Magnesium, by the Action of Acetyl Chlo- 
ride in Acetone Upon the Mixed Chlorides ; by F. A. 


Gooner andeCr NisBOWNTON 6-2 5-5 so ce one secs =n 212 
XXI.—Feldspar Aggregate Occurring in Nelson Co., Vir- 

Pinay Me WetORNTON,, Iie J o22 2 epen yee aie ee 218 
XXII.—History of the Coconut Palm in America; by O. F. 

(CO CHE  o e  eee, ee e 
XXIII.—New Mink from the Shell Heaps of Maine ; by F. 

booming: 2o5 see ange i aie ie eee reset Mena epee 2247 


SCIENTIFIC INTELLIGENCE. 


Chemistry and Physics—Mesothorium, W. MarckwaLp, 230.—Combustion 
of Hydrocarbons, W. A. Bonn: Supposed Chemical Distinction between 
Orthoclase and Microcline, VARNADSKY and REvouTsKY, 231.—Preparation 
of Argon, G. CLaupE: Die Stellung der neueren Physik zur mechanischen 
Naturanschauung, M. Puanck: History of the Cavendish Laboratory, 
1871-1910, 232.—The Principles and Methods of Geometrical Optics, J. P. 
C. SouTHALL, 233.—Chemische Krystallographie, P. Groru, 2384. 


Geology and Natural History.—United States Geological Survey, 234.—Pub- 
lications of the U. S. Geological Survey, 235.—Bureau of Mines, J. A. 
Hotmes : Florida State Geological Survey, 236.—The Badland Formations 
of the Black Hills Region, C. C. O’Harra: West Virginia Geological Sur- 
vey, I. ©. WurtE: New Zealand Geological Survey, 237.—Geological 
Survey of Western Australia, 238.—Palzontological Contributions to the 
Geology of Western Australia, 239.—Report of the Vermont State Geolo- 
gist for 1909-1910, G. H. Perkins: Contribution to the Geologic History 
of the Floridian Plateau, T. W. VAUGHAN: Recent Discoveries Bearing on 
the Antiquity of Man in Hurope, G. G. MacCurpy, 240.—Fossil Faunas of 
St. Helen’s Breccias, H. S. Wintiams, 241.—Palzontologia Universalis, 
242.—Botanische Tropenreise, Indo-Malayische Vegetationsbilder und 
Reiseskizzen, G. HABERLANDT: Plant Anatomy, W.C. Strvens: A. Text- 
Book of Botany and Pharmacognosy, H. Krammrr, 243.—Biology, general 
and medical, J. McFaruanp, 244. 


Miscellaneous Scientific Intelligence—Carnegie Institution of Washington 

_ Year-Book, No, 9, 1910, 244.—Publications of the Carnegie Institution, 
245.—Annual Report of the Board of Regents of the Smithsonian Institu- 
tion, 246.—Publications of the Allegheny Observatory of the University 
of Pittsburgh, F. Scauesincer: Bref och Skrifvelser af och till Carl von 
Linné; Seismological Society of America, 247.—Das Hlectrokardiogramm 
des gesunden und kranken Menschen, F. Kraus und G. Niconar: Plane 
Trigonometry, E. R. RopBins : Shop Problems in Mathematics: Ostwald’s 
Klassiker der Exakten Wissenschaften, 248. 


Obituary—Sir FRANcIs Gatton; Dr. M. WitnELM Mrynr, 248. 


yi CONTENTS. 


' Number 184. 
Page 
Art. XXIV.—Ionization of Different Gases by the Alpha 
Particles from Polonium and the Relative Amounts of 
Energy Required to Produce an Ion; by T. 8. Taytor 249 
XXV.—Heat Generated by Radio-active Substances ; by 
W. DUANE 2. 502. 23 ie 
XXVI.—Contributions to the Geology of New Hampshire, 
IV. Geology of Tripyramid Mountain; by L: V. 


IPTRSSON ANG Vint. INFO er chai CL een ee 269 
XXVII.—Note on a Method in Teaching Optical Mineralogy; 

by FW... McN Are Se ne em 
XXVIII.—New Paleozoic Insects from the Vicinity of 

Mazon Creek, Illinois ; by A. HanpirrscH---- .------- 297 
XXIX.—Results of a Preliminary Study of the so-called 

Kenai Blora of Alaskac iby Aviioumcnemeee es. == anes 327 


SCIENTIFIC INTELLIGENCE: 


Chemistry and Physics—Use of Calcium Carbide for the Determination of 
Moisture, Masson : Action of Water upon Phosphorus Pentoxide, BaLa- 
REFF, 351.—Fractional Crystallization of Argon, F. Fiscurer and VY. 
FROBOXKSE: Qualitative Chemical Analysis, BASKERVILLE and CURTMAN : 
Die Verwertung des Luftstickstofts, J. ZenNEcK, 332.—Allen’s Commercial 
Organic Analysis: Absorption Spectra of Solutions, H. C. Jonrs and W. 
W. Strone, 333. 


Geology and Mineralogy—Thirty-fourth Annual Report Department of . 
Geology and Natural Resources, Indiana, 333.—West Virginia Geological 
Survey, Vol. 5, Forestry Wood Industries, A. B. Brooxs : Geological Sur- 
vey of Tennessee; Atlas Phographique des Formes du Relief Terrestre, 
334.—Illinois Oil Fields in 1910: Physical Notes on Meteor Crater, Ari- 
zona, 335.—Minéralogie de la France et de ses Colonies: Practical Min- 
eralcogy Simplified for Mining Students, Miners and Prospectors, J. P. 
Rowe: Calcites of New York, H. P. Wurttock: Minéraux des Pegmatites 
des Environs d’Antsirabé a Madagascar, L. Duparc, 337.—Production of 
Phosphate Rock in Florida during 1910: North Carolina Geological and 
Economic Survey, 338.—Note on the parietal crest of Centrosaurus apertus 

’ and a proposed new name for Stereocephalus tutus, L. M. Lames, 339. 


Miscellaneous Scientific Intelligence—Carnegie Foundation for the Advance- 
ment of Teaching, 339.—Text-Book of General Bacteriology, EH. O. JoRDAN: 
Catalogue of the Lepidoptera Phalenz in the British Museum, G, F. . 
Hampson, 340. es 


Obituary—H. P. Bowpircu : J. H. van’t Horr: J. W. BrUaL, 340. 


CONTENTS. vil 


Number 185. 
Page 
Arr. XXX.—Melting Points of Minerals in the Light of 
Recent Investigations on the Gas Thermometer; by A. 


DLeeWaveandpits by SOSMAN 25202. seen 2S s'Le oss ae 2 341 
XXXI.—Separation of Cerium by Potassium Permanganate ; 

ange imtebe bn OUST Se ete 2(2 7. cle oe can wien Se 350 
XXXII.—New Paleozoic Insects from the Vicinity of Mazon 

Creek, lilimois:;by A. HANDIIRSCH 525)... 22-2 22.2254 358 
XXXIII.—New Family of Reptiles from the Permian of 

INewnMexicaGiby S) Wee WiILLISTON, 2222 55).222 205508 378 


XX XIV.—New Elasmobranchs from Solenhofen in the Car- 
negie Museum ; by C. R. Hastwan. (With Plates I-III) 399 


XXXV.—Contributions to the Geology of New Hampshire, 
No. V ; Petrography of Tripyramid Mountain ; by L. V. 
IPATESSIORN regener cs cls Soe ee a | 405 


XXXVII—Geologic and Petrographic Notes on the Region 
about Caicara, Venezuela; by T. A. BeNDRAT..------- 443 


SCIENTIFIC INTELLIGENCE. 


Chemistry and Physics—Researches on Polonium, Mdme. Currie and A. 
DEBIERNE, 453.—Introduction to General Chemistry, J. T. Sropparp: Die 
Beziehungen zwischen Farbe und Konstitution bei organischen Verbin- 
dungen, H. Lay, 454.—Rays of Positive Electricity, J. J. Thomson, 455.— 
Focal Isolation of Long Heat-Waves, RuBprns and Woop, 456.—A Method 
of Calibrating Fine Capillary Tubes, T. R. Merron, 457.—An Intro- 
duction to Thermodynamics for Engineering Students, Jonn Mints, 468. 


Geology and Mineralogy—Denudation and Hrosion in the Southern Appa- 
lachian Region, L. C. Giunn, 458.—Preliminary Notes on the ‘‘ Chazy” 
Formation in the Vicinity of Ottawa, P. E. Raymonp, 459.—Die Fauna der 
Spiti-Schiefer des Himalaya, ihr geologisches Alter und ihre Weltstellung, 
VY. Unuic: Beitrage zur Geologie der Baren-Insel, Spitzbergens und des 
K6nig-Karl-Landes: Historical-Stratigraphical Review of the Silurian of 
Sweden, Jon. Cor. Mopere, 460.—Geologisch-petrographische Studien in 
der Patagonischen Cordillera, P. D. QuENSEL, 461.—Ueber einigige Japan- 
ische Vulkane, I. FRIEDLAENDER: Geological Survey of Ohio, 462.—Ele- 
ments of Geology, BLACKWELDER and BarRows: A Remarkable Crystal of 
Beryl, G. F. Kunz: The Mineralogy of Arizona, F. N. Guiip, 463.—Notes 
on a recent find of Zincite Crystals, A. H. Puriures, 464. 


Miscellaneous Scientific Intelligence—National Academy of Sciences, 465.— 
Bulletin of the Seismological Society of America, 466.—Commercial 
Geography, E. V. Ropinson, 467. 


Obituary—S. F. Emmons, 467: S. Catvin: J. M. Van BeMMELEN: Mrs. 
EK. H. Ricnarps: HE. E. Hows, 468. 


Vili _ CONTENTS. 


Number 186. 
; . Page 
Art. XXXVIII.—Podokesaurus holyokensis, a New Dino- 
saur from the Triassic of the Connecticut Valley ; by M. 
Parson, (With Plate GV.) e222 22k 469 
XXXIX.—Minerals Associated with Diamonds and Carbon- 
ados in the State of Bahia, Brazil ; by J. C. Branner.. 480 
XL.—An Engelhardtia from the American Eocene; by E.. 
W.. BER By ee RE Re oo geet en 8 cha 491 
XLI.—Use of Sodium Paratungstate in the Determination 
of Carbon Dioxide in Carbonates and Nitrogen Pent- 
oxide in Nitrates ; by F. A. Goocu and 8. B. Kuzirian 497 
XLII.—Influence of Pressure on the Melting Points of 


Certain Metals; by J. Jonnsron and L. H. Apams ..-- 501 
XLIII.—A New Occurrence of Pearceite; by F. B. Van 

Horniand Cx WicCoom a2 5. caer cee ae 
XLIV.—Mollugo verticillata L.; by T. Horm .--.---.---- 525 


XLV.—Composition and Crystallization of Parisite and 
Occurrence in the Granite-Pegmatites at Quincy, Mass., - 
U.S. A,, etc., by C. Panacue and C, H. Warren ----- 538 

XLVI.—Notes on the Absence of a Soil Bed at the Base of 


the Pennsylvanian of Southern Ohio ; by J. E. Hype __ 557 ' 


XLVII—A New Jolly Balance; by E. H. Kraus -----.--- 561 
XLVIII.—Independence of the Coronas of the Thickness of 
the Woe Waiver, siloyg, @. gly AS seat eee eee 564 


SCIENTIFIC INTELLIGENCE. 


Chemistry and Physics.—Radium Contents of some Uranium Minerals, 


MarckwaLp and RvussELL, 566.—Determination of Cane Sugar in the ~ 


presence of other Sugars, A. Jottes: Action of Sulphur Dioxide upon 
Ammonia, EPpHRam and ProrRowskt, 567.—Quantitative Chemical Analy- 
sis of Mixtures, H. FRIEDENTHAL: Metallic Coloring in Birds and 
Insects, A. A. MicHELson, 568.—Isolation of an Ion, a Precision Meas- 
urement of its Charge, and the correction of Stokes Law, R. A. MILLIKAN, 
5970.—Homogeneous Rontgen Radiation from Vapors, J. C. CHAPMAN, 


571.—Lehrbuch der Kristallphysik, W. Voter, 572.—Electrical Nature of 


Matter and Radioactivity, H. C. Jones, 573. 

Geology and Mineralogy.—Illinois State Geological Survey: New Zealand 
Geological Survey, 573.—Geological Survey of Western Australia: Geo- 
logical Survey of Canada, 574.—Mineral Production in the United States 
in 1909, 575.—Production of Gems and Precious Stones in 1909 : Production 
of Bauxite in 1909: Origin of the Thermal Waters in the Yellowstone 
National Park, 576.—Tables for the Determination of Minerals, H. H. 
Kraus and W. F. Hunt: Striiverite, R. C. WELxs, 577. 

Miscellaneous Scientific Intelligence.—Bulletin of the Bureau of Standards : 
Prehistoric Period in South Africa, J. P..Jonunson, 578.—Field Museum 
of Natural History : Astronomical and Astrophysical Society of America, 
580.—Harvard College Observatory : Cincinnati Observatory: Princeton 
University Observatory: R. Comitato Talassografico Italiano, 581.—Con- 
gress of the Applications of Electricity : Congress of Applied Chemistry : 
Anthropological Society : University of Bologna, 582. 

Obituary.—SAMUEL H. ScuppER; M. Epovarp Dupont: THomMas RUPERT 
Jones ; J. Bosscwa, 582. 

InDEx TO VOLUME XXXII, 583. 


> 7 


‘f VOL. XXXI. JANUARY, 1911. 


Established by BENJAMIN SILLIMAN in 1818. 


HT 


AMERICAN 
JOURNAL OF SCIENCE. 


Epiror: EDWARD S. DANA. — 


\ 


ASSOCIATE EDITORS 


Proressors GEORGE L. GOODALE, JOHN TROWBRIDGE, 
W. G. FARLOW ann WM: M. DAVIS,: or CampBrince, 


Proressorns ADDISON EB. VERRILL, HORACE L. WELLS, 
L. V. PIRSSON anp H. E. GREGORY, or New Haven, 


Proressor HENRY S. WILLIAMS, or Irwaca, 
Proressorn JOSEPH S. AMES, oF Bartimmore, 
Mr. J. S. DILLER, or Wasuinerton. 


FOURTH SERIES 


VOL. XXXI—[WHOLE NUMBER, CLXXXIJ]_ 


No. 181—JANUARY, 1911.9" : 


NEW HAVEN, CONNECTICUT. 


dL Oalsk 


THE TUTTLE, MOREHOUSE & TAYLOR ©O., PRINTERS, 123 TEMPLE STREET. 


Published monthly. Six dollars per year, in advance. $6.40 to countries in the 
either by money orders, 


Postal Union ; $6.25 to Canada. Remittances should be made 
registered letters, or bank checks (preferably on New York banks). 


food B 
ol 


IMPORTANT TO MINERATLOGISTS. 


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secured:a collection of remarkable old finds from exhausted localities, which 
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some of the finest crystallized minerals from well-known American localities 
some of which are not at present procurable. This collection will be placed 
on sale by January 15th. Full details of special list sent on request. 


I can safely state that no dealer has ever had at one time as many Zincites 


crystallized as there are in my present stock, at prices which will tempt any: 


collector not having these remarkable rare crystals ; also a good stock of all 
the well known Franklin Furnace minerals. 


COPPER AND SILVER FROM LAKE SUPERIOR. 


I have just received a large lot of excellent crystallized Silver and also 
Copper, Calcite enclosing Copper, Psilomelane, etc., in large and small sizes 
at very reasonable prices. 


COLORADO MINERALS. 


Recent additions to my already large stock of Colorado Minerals include 
the following: Native Tellurium, Sylvanite, Calaverite, Gold Pseudomorph, 
Smoky Quartz Crystals, Amazonite Crystals, Topaz, Aquamarine, Calciovol- 
borthite, Crystallized Carnotite, Pyrite, Rhodochrosite, Fluorite. 


CALIFORNIA MINERALS. 


In addition to my already large stock of California Tourmalines, I have 
made special connections with one of the large mining concerns for all their 
specimens and I have just received as fine an assortment as ever was found, 
all ranges of quality and color, at reasonable prices. 


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tors with rare stones in all sizes, shapes and colors. 


I have also added considerably to my stock of Reconstructed Gems and 
have the following to offer :. Rubies, sapphires, blue, yellow, pink and white ; 
in all sizes and shapes of the best quality. If you are interested in anything 
in Mineralogy send for my special lists or request me to send you a ship- 
ment for your selection, prepaid. 

Do not fail to send your name for my mailing list, mentioning AMERICAN 
JouRNAL OF SCIENCE. 


A. H. PETEREIT, 
81—83 Fulton Street, New York City. 


4 DS Oto) 


AMERICAN JOURNAL OF SCIENCE 


[FOURTH SERIES. ] 


Arr. I. — On Gravity Determinations at Sea;* by L. A. 
BaveEr. 


A etven mass changes its weight when transported over the 
Earth’s surface. How shall we determine these alterations ? 
It cannot be done with a balance; for a mass in one scale pan 
held in equilibrium by a set of weights in the other pan will 
remain in equilibrium all over the Earth, since the Earth’s 
gravitational force within our limits of measurement acts alike 
on all substances. The variations in gravity are composed of 
three parts: one called the ‘normal part,” varying simply with 
latitude; another the “anomaly,” a more or less irregularly 
distributed part, and the third part dependent upon altitude 
of station above sea-level. 

We might replace the beam of our balance by a pivoted 
magnetized steel bar or needle. Suppose we were to start out 
_ from Washington, where the magnetic dip is about 70°5°, with 
the beam made to le horizontal by suspending a suitable 
weight on its south end; we have thus balanced the earth’s 
gravitational force by the vertical component of the Earth’s 
magnetic force. Were we now to proceed with this balance 
to some distant point, the beam might no longer be truly hori- 
zontal but make instead an angle with the horizon, the magni- 
tude of which would depend upon the relation at that point 
between the earth’s magnetic and its gravitational force. 
Knowing the value of the vertical magnetic component, it is 
then possible to determine, within certain limits, from the 
inclination of the beam how much the suspended mass has 


i Presented before the Philosophical Society of Washington, November 5, 
0. 


Am. Jour. Sci.—FourtH Series, Vou. XXXI, No. 181.—January, 1911. 


2 L. A. Bauer—Gravity Determinations at Sea. 


altered its weight, or in turn find the change in gravitational 
force. We have in fact such an instrument as here described, 
viz., the dip circle used in determining the total magnetic force 
by Lloyd’ s method, one operation consisting of measuring the 
angle of dip of a suspended magnetic needle having a load on 
one end. Observations made thus on the ‘ Galilee” in the 
Pacific Ocean, covering a range in latitude from about 59° 
North to 42° South, showed that the variation in weight of the 
load over a large range in latitude might be taken into account. 
With such a dip circle, the latitude variation of gravity could 
just about be detected ; however, for smaller gravity variations 
the instrument would not be sensitive enough, both because of 
its construction and our inability to determine the magnetic 
force with sufficient precision. 

The method most commonly in use on land for determining 
the value of the linear acceleration of gravity, g, is by pendu- 
lum observations. But this method has not been found feasi- 
ble on board ship. If, then, it is desired to extend a gravity 
survey so as to include the oceans as well as the land, other 
experimental means than swinging pendulums must be devised. 
The method thus far used to disclose gravity anomalies at sea 
is that known as the “boiling point, mercurial barometer 
method.” The principle here is to measure the counterbalane- 
ing effect of the elastic pressure of a vapor on a column of mer- 
cur y, once by reading the height of the mercurial column, the 
counterbalancing vapor being the atmosphere ; next, by measur- 
ing the atmospheric pressure prevailing at the time by deter- 
mining the temperature ot the boiling point of pure water. 
Since the boiling point, other things being equal, depends 
solely upon the atmospheric pressure, it will not vary as we 
pass over the earth as long as the pressure is the same; how- 
ever, the height of the mercurial column, under the same con- 
ditions, changes with variationsin gravity. Hence the gray- 
ity anomaly is found by a direct comparison of the atmospheric 
pressure determined from the boilmg point with that read off 
on the mercurial barometer. Prior to the boiling-point method 
for measuring the prevailing atmospheric pressure inde- 
pendently of gravitational force, the use of the aneroid was 
proposed ; however, the latter instrument is found too variable 
and uncertain in its indications to possess the required sensi- 
tiveness. 

Guillaume in 1894 was led to suggest the use of boiling 
point thermometers in place of the aneroid, but Mohn* has 
the credit of having made the first practical use of the method, 

* Mohn, H.: Das Hypsometer als Luftdruckmesser und seine Anwendung 


zur Bestimmung der Schwerekorrektion. Christiania, Skr. Vid. Selsk. 
Math.-naturw. K1. I, 1899, No. 2 (1-69). 


L. A. Bauer—Gravity Determinations at Sea. 3 


in determining between 1896 and 1898 the gravity correction 
to observed barometric heights at various stations of the Mete- 
orological Service in Norway. It was Mohn’s suecess which 
led Helmert and Hecker to consider this method for ocean 
gravity observations. 

Hecker, working under the direction of Helmert, has thus 
far made three expeditions, chiefly at the expense of the Inter- 
national Geodetic Association,—the first in 1901, in the Atlan- 
tic from Hamburg to Rio de Janeiro and return to Lisbon ; 
next in 1904, a eruise extending over the Indian and Pacific 
Oceans, and finally in 1909 in the Black Sea. All of his work 
was executed in a most painstaking manner and a very elabo- 
rate instrumental outfit was used; the observations were made 
only on good-sized steamers of 5000 tons and upward. In his 
Black Sea eruise, of which the results have just appeared, the 
Russian cruiser “ Pruth,” of 5500 registered tonnage, was put at 
his disposal; his instrumental outfit consisted of six boiling 
point apparatuses, each provided with a thermometer and two 
sets of photographically registering barometers, one set having 
five mercurial barometers and the other four, or nine specially 
constructed barometers in all. The thermometers were read with 
a telescope magnifying twenty times, so that to the observer 
0°001° appeared of the length 0-4". The nine photo-baro- 
grams were independently read by two assistants and correc- 
tions for various sources of error were applied. Hecker also 
devised instruments for photographically recording the ship’s 
motions, with the aid of which further corrections were deter- 
mined. Finally, an elaborate adjustment by the method of 
least squares was made of the outstanding differences between 
the atmospheric pressure, A, derived from the boiling point 
work, and that, 6, resulting from the barometric readings 
referred to standard temperature and normal gravity for lati- 
tude 45°; there were thus determined further corrections, as 
explained later in this paper. 

The 1901 work was published in 1903, that of 1904 in 1908, 
and that of 1909 in 1910. In Hecker’s last publication are 
given, in addition to the Black Sea results, the revised results 
of the work done in 1901 and 1904, so that the previous publi- 
cations are superseded by this latest one. The revisions were 
made necessary by the correction pointed out by Baron Kétvos 
due to course and speed of vessel. Hecker’s work in the 
Black Sea was done partly for the very purpose of testing 
whether his methods were of sufficient accuracy to detect this 
theoretical correction; he reaches an affirmative conclusion and, 
accordingly, revises his previous reductions. He now also. 
excludes, in the least-square adjustments, observations in ports 


4 L. A. Bauer—Gravity Determinations at Sea. 


made on vessel at anchor; his present results for Ag differ at 
times from the previously published ones by 0°15°™, 

Suggestions have been received from various sources that it 
would be highly desirable to include, if possible, gravity work 
on the “Carnegie.” At the request of President Woodward, 
I consulted in 1905 Professor Helmert, Director of the Geo- 
detic Institute at Potsdam, as to the possibility of attempting 
the boiling-point method on the “Galilee,” which had just been 
chartered for magnetic work in the Pacific Ocean. As the 
result of Hecker’s experiences on vessels exceeding the ton- 
nage of the “Galilee” by eight times and more, Helmert did 
not feel warranted in advising the undertaking of similar work 
on our vessel; he thought it best under all circumstances to 
await the conclusion of Hecker’s labors. No attempt was 
accordingly made on the ‘ Galilee.” 

However, on the “Carnegie” it was decided to include 
determinations of the temperature of the boiling point of 
water in the regular routine work aboard, the prime purpose 
being to obtain data for controlling the corrections of our ane- 
roids. The instrumental equipment was in accordance with 
this aim; it consisted merely of two boiling apparatuses of the 
pattern described and figured in the British Antarctic Manual 
of 1901, p. 94, two specially constructed thermometers by 
Green, of Brooklyn, N. Y., graduated into one-hundredths of 
a degree centigrade from 97°6° to 107-7°, the length of one 
degree being about 40 millimeters, and one Green mercurial 
marine barometer. In all 106 determinations of the boiling 
point were secured on the First Cruise, between Sept. 1909 
and Feb. 1910, four of which had to be rejected because of 
manifest errors, leaving 102 values and representing 75 differ- 
ent points. While a few observations were made at the very 
beginning of the cruise, by Mr. J. P. Ault, the navigating 
officer, the work did not begin regularly until the vessel left 
Falmouth on November 6, 1909, but thereafter to Madeira, 
thence to parallel 20° North and return to Brooklyn via Ber- 
muda, the observations were made almost daily by Dr. C. C. 
Craft, and that too at times under very trying conditions of 
weather. A week’s series or more was obtained at each of the 
ports,—Brooklyn, Falmouth, Funchal (Madeira), and Hamilton 
(Bermuda). 

The two boiling-point thermometers were read visually, with 
the aid of a hand lens, to the nearest 0:001° by estimation of a 
tenth of a space 0°4"" long; and the mercurial barometer was 
read directly by vernier to 0-01 inch and by estimation to 0-005 
inch or less. The pumping of the barometer, which is of the 
ordinary marine type, amounted at times under the severe 
conditions of sea encountered on the return trips to as much as 


LI. A. Bauer—Gravity Determinations at Sea. 5 


5™™; several settings were made, and both the low and high 
readings were recorded. To reduce the pumping, Hecker had 
introduced a special capillary tube in about the middle part of 
his barometer, and, since his observations were made on large 
steamers, the pumping of his barometer was generally less than 
075". A eareful scrutiny of our observations has encouraged 
me in the belief that it may be worth while to attempt also 
gravity work on the “ Carnegie,” which in her various cruises 
will have opportunity of getting data in regions not yet coy- 
ered, and will also at times cut across Hecker’s trips. Atten- 
tion is accordingly being given to the question of refining the 
instrumental appliances and simplifying the method of reduc- 
tions. As the best preparation it was thought well to review 
carefully Hecker’s work in order that full advantage might 
be taken of his experiences in this pioneer work, as also to 
determine what were the various sources of error and their rela- 
tive importance. (Cf. Bestimmung der Schwerkraft auf 
dem Schwarzen Meere, etc., Berlin, 1910.) 


Hecker’s Ocean Gravity Observations. 


Let us begin with the formule used, and the theoretical 
treatment applied to the observations. 


Let A=atmospheric pressure deduced from the temperature of 
the boiling point of pure water with the aid of tables, 
as for example Wiebe’s, given in the “ Landolt—Boérn- 
stein Tabellen” for 1905 ; 

£=the simultaneously observed atmospheric pressure with 
a mercurial barometer, reduced to standard temper- 
ature, to sea-level and to normal gravity for latitude, 
p=4o° ; 


thenis @= A— Binmms. mercury. (1) 


Were there no errors of whatever kind attaching to A or B, 
then 8 would be the gravity anomaly sought. To convert 
into ems. of the acceleration of gravity, g, we must multiply 
equation (1) by the approximate factor, 980/760 = 1:29, 
hence 

Ag = 1:29 (A — B) in ems. per second. (2) 


The reduction of & to normal gravity is made with the aid 
of Helmert’s formula of 1901* : 


¢ = ( — 0002644 cos 26 + 0:000007 cos’ 26) B. (3) 


The coefficient of the second term was adopted by Helmert 
from the theoretical investigations of Wiechert and Darwin; 


* See note next page. 


6 L. A. Bauer—Gravity Determinations at Sea, 
however, the first coefficient, 0:002644, he deduced empirically* 
from a least-square discussion of nearly one-fourth of the 
available pendulum observations, selecting undisturbed coast 
and inland stations. This first coetticient gives for the ellip- 
ticity of the earth, 1/2983; the value adopted in the 
Smithsonian Meteorological Tables, 1907, is 0°002662 as 
obtained by Professor Harkness in his work “The Solar 
Parallax and its Related Constants, Washington, 1901.” 
For B = 760, for example, the first corrective term for a 
point on the equator would be, —2-0095™™"s for Helmert’s 
formula and —2-0231°™S for the Smithsonian Tables; the 
second term for 6 = 760™™ and the equator amounts to 
+0:0053, so that the total correction, according to Helmert, 
would be —2°0042"™"*. For the poles, the corrections would 
be, +2°0095 and +2°0231™™s. In order, therefore, to detect 
by ocean observations the difference between the two formule, 
it would be necessary to secure an accuracy of about 0:01™ 
mercury or 0:015"™ acceleration or about 1/100,000 part of g. 
This matter is mentioned here since one of the conclusions 
drawn by Hecker from his ocean observations is that they 
accord with Helmert’s formula, 

But A and & are subject to various sources of error, partly 
due to instrumental causes and observational errors and partly 
due to motion of the vessel. Of the disturbances caused by the 
vessel there are two which may readily be disposed of. First 
that due to tbe possible attractive effect of the mass of the 
vessel, since this even for a 100,000 ton vessel would only 
be on the order of 1/1,000,000 of g, is negligible; second, that 
due to the course and speed of the vessel. Only the motion 
in longitude counts—for a vessel sailing east along a certain 
par allel the instruments aboard are being transpor ‘ted around 
the axis of rotation of the Earth faster than is a fixed point 
in the same parallel and the force of gravity aboard is accord- 
ingly diminished and the mercury in the barometer made to 
stand correspondingly higher than it would were the vessel not 
moving. For a vessel sailing west, the effect is reversed. So 
that if at a certain point on the earth gravity is measured aboard 
a moving vehicle, once when moving eastwardly and next 
moving westwardly at the same rate of speed, the values of 
g at the two times would differ by twice an error, the exact 
amount of which may be computed from the following 
formula : 


*Helmert, F. R. Der normale Theil der Schwerkraft im Meeresniveau. 
Sitzber. Akad. Wiss., Berlin, xiv, 1901. There is a misprint in Hecker’s 
publication of 1908; at top of. table, p. 226, Helmert’s coefficient is given 
as 0:00244 instead of 0°002644. 


ih al 


LI. A. Bauer—Gravity Determinations at Sea. 7 


Let c’ = correction to an observed mercurial barometric 
height on account of speed and course of moving vessel, 


C= velocity of a point in the equator = 4:65 x 10° em. / see. 
y= “ * ship along a parallel of latitude. 
FR = earth’s mean radius — 6°38 X 10° em. 
then is 
Fa UOON AO rime. sane tec Ly Eau vind 
— 980 Bi s' 6=0'0146 cos’ ¢ inmm.mereury (4) 


— for vessel going east. + for vessel going west. 


To get the correction in ems. g, multiply the tabular quan- 
tities by 1:29. For a oe sailing east, for example, along 
the equator at. the rate of 7 degrees or 420 knots a day, the 
atmospheric pressure sheerved on board with a mercurial bar- 
ometer would have to be diminished by 0°:1™™. On the other 
hand, for the same vessel going west at the same speed, the 
barometer reading would have to be increased Oy Wee Lie 
the first case g would be too low by 0°15°" and im the second 
too high by the same amount, or the resulting error, if not 
taken into accouat between the two occasions, would be 0:30 
or 1/3300 part of g—a respectable quantity. "On the aver age, 
Hecker’s corrections for the vessels on which he made his 
observations was about + 007°" in g; for the “ Carnegie ” the 
correction would usualiy be less than + 9°03. Since the cor- 
rection is a perfectly definite one and can readily be coniputed, 
it is worth while applying. 

But there are more troublesome sources of disturbance 
arising from a moving vessel not so readily disposed of as the 
preceding one—arising from the actual motions of the vessel, 
such as rolling and yawing, vibration due to machinery, and 
worst of all, pitching and accompanying vertical motions. 
Hecker, as above stated, undertook to determine these sources 
of error instrumentally with the aid of devices recording the 
ship’s motions. He then determined the reducing coefficients 
for each effect by a least-square adjustment of all the observa- 
tions made on any one cruise. The manner of mounting, as 
compared with those of the barometers, as well as an examina- 
tion of the results of Hecker’s laborious least-square adjust- 
ments, leads one to question the effectiveness of his devices for 
the elimination of the ship’s effects. 

Next are the errors due to purely instrumental causes, such 
as changes in the corrections of the thermometers with which 
the boiling point of pure water is determined, furthermore the 
relation of the zero of the boiling-point atmospheric pressure 
to that of the mereury barometer, and the variations in this 
relation, etc., ete. 


8 L. A. Bauer—Gravity Determinations at Sea. 


Hecker’s final observation equation is of the following form : 


d B 


B+k,+a ae +bp+er+ds+e(t—t,) +h,=0. (5) 


I have substituted 8 for his quantity (Therm. —. Bar. — com- 
puted gravity reduction to 45° — correction due to speed and 
course of vessel); it is the same as the quantity in equation 
(1) after having had the correction ¢’ applied to B. 

k,, = relation of the two zeros above + constant part 
of other corrections. 
ad B 


ag bee correction to reduce the observations of boiling 
Me poimt and readings of barometer to same 
moment of time for any one set. 
bp = correction due to pumping, p, of barometer. 


cr = 6 “« © rolling of vessel. 
ds — ce oe 66 pitching oe 66 
e(t—t,) = ue «“ “ time changes in instruments 


supposed to progress linearly. 

k, = constant which enters into the equation only for 
deep sea observations, say for depths beginning 
with about 2000 meters. 


There are thus in Hecker’s complete equation seven unknowns, 
kn, a, 6, c, d, e, and &,, which he determines by the method of 
least squares. Substituting next in each observation equation, 
of which there is one for each station, the derived values of 
the unknowns, a residual quantity, v, is obtained, supposed to 
be the gravity anomaly sought. 

To get a clear understanding as to the assumption implied in 
his formula, let us suppose first that all the corrective terms 
in (5) except k, and #,, by a suitable scheme of observation 
and in a calm sea, reduce to negligible quantities, then we 
have for a shallow water station, s, 


8, = — = constant, (6) 
and for a deep water station, d, 

Ba= —k, — k, = constant, (7) 
or 8, — Bag =k, = constant. (8) 


The same result (8) is obtained if we suppose, in passing 
from s to d, the corrective terms for each station were the 
same in magnitude and sign. But the difference @s—d, 
under the conditions supposed, when multiplied by 1-29 (see 


equation 2) should be the difference in Ag at the two points, ’ 


which of course would not, in general, be a constant. In other 


L. A. Bauer —Gravity Determinations at Sea. 9 


words f is composed of two distinct quantities, one, Ay, repre- 
senting the gravity anomaly and the other the various sources 
of error, 2, “and so we have: 


Ag 
mag. 
Ag 
Oe > 09 oe (9) 


Comparing this equation with Hecker’s (5), it must be evi- 
dent that his corrective terms include the effects of the very 
quantities—the Ag’s—to be determined. Since he applies the 
method of least squares to his equation, Hecker must asswme 
that during a cruise the local gravit y anomalies, 1.¢., the 
Ag’s, partake of the nature of accidental errors—that they 
either balance out in the long run or oscillate about a mean 
constant value, which enters into the constant terms of (5). 
But is not the proving whether such distributions of gravity 
anomalies exist, or do not exist, the very purpose of gravity 
surveys ¢ 

Furthermore, since Hecker adjusts each cruise by itself, then 
by the theory of least squares alone, the sum of his residuals 
or outstanding gravity anomalies must reduce to zero, or prac- 
tically so, because of the presence of the constaut terms in (5); 
hence his average computed § tor the cruise must be ¢heoreti- 
cally equal to his average observed 8, or in other words, the 
average gravity anomaly of @ whole cruise would be zero. It 
must be evident then that as Hecker derives his unknowns they 
are not true values but are affected by the gravity anomalies 
over the areas for which the adjustment is made. They might 
be different, for example, for a cruise from New York to 
Liverpool than for one from Hamburg to Rio de Janeiro, even 
- though all conditions remained precisely the same except that 
of difference in route followed. Manifestly then Hecker’s 
method of adjustment is open to grave objections and it is a 
question as to how much of his resulting conclusions may not 
already be contained in his fundamental assumptions. Let us 
hope that the variations in the gravity anomalies at sea about 
an average value will be found to be of asufficiently accidental 
nature to vitiate Hecker’s main conclusions! 

Strictly speaking, the values of the unknowns entering into 
equation (5) can only be derived from stations where “there 
exist accurate gravity observations from which the anomaly 
Ag can be derived. This means, however, restriction to shore 
and harbor observation, but these are the very observations 
which above all Hecker has been unable to reduce satisfactorily 


10. LL. A. Bauer—Gravity Determinations at Sea. 


and hence either omits entirely in his final tables or brackets 
as doubtful. In the first place the coefficients, 6, c and d, can 
of course only be found from observation on a moving vessel. 
How poorly the Ag’s from the harbor observations agree, in 
general, with those resulting from shore pendulum observations 
when the former are computed with the values of the unknowns 
obtained from the observations on the moving vessel, is shown 
by a table which Hecker gives on p. 159 of his 1910 publica- 
tion. The differences amount at times to 1/6000 part of g. 
Hecker believes that the trouble arises chiefly from the fact 
that observations on a vessel moving and on one at rest are 
not comparable and, hence, require separate treatment, the 
difference arising chiefly from the dynamic conditions which 
enter in on the moving vessel. While he is undoubtedly in 
the main correct, still he does not appear to see that the un- 
knowns as he derives them are not strictly instrumental or ship 
constants, but depend, as has been shown above, upon the area 
(extent and geographic position) from which they are derived. 
In any case, beyond revealing the discrepancies, he does not 
make known any attempt at a satisfactory reduction of the 
harbor observations. This is doubly unfortunate, first, because 
the harbor observations ought to furnish the best criteria pos- 
sible of the absolute accuracy and possibilities of his method 
of observation, and secondly, since the connection of ocean 
results with land stations is correspondingly diminished in 
strength. 

Every series of observations made by Hecker on shore or in 
port has been investigated, and not a single case of satisfactory 
reduction or adjustment was found. On his first eruise in 
1901, in the Atlantic Ocean, from Hamburg to Rio de Janeiro 
and return to Lisbon, he made shore boiling-point observations 
at Rio de Janeiro and Lisbon at precisely the same places where 
he swung his pendulums. There was thus afforded a fine 
opportunity to test his boiling-point method and the behavior 
of his instrumental appliances. But he makes no attempt at 
such a comparison. Instead, he merely adjusts the series of 
shore observations at Rio de Janeiro o, Aug. 24—-Sept. 11, 1901, 
by itself and similarly the series at Lisbon, Oct. 12-17, 1901, 
again by itself. His observation equation is the same as (5) 
above with the omission of the terms involving J, ¢, d, and &,, 
which apply only to observations at sea. While his adjustment 
improves the ¢ndividual day’s results at each of the two stations, 
it leaves unaltered the actual mean gravity anomaly observed 
at each station—in brief, he does not adjust Rio de Janeiro 
and Lisbon together, and the labor of his painstaking adjust- 
ments is practically. for naught. Hence, if we take the 
quantities, as derived from Hecker’s adjustments (or from the 


L. A. Bauer—Gravity Determinations at Sea. 11 


direct observations), we may see what the extent of énstru- 
mental changes may be during even such a brief interval as 
six weeks, during which, thermometers are subjected to fre- 
quent and protr acted boiling. The mean Ag results for Rio de 
Janeiro—Lisbon derived from each of four barometers—two 
eye-reading ones and two photographically recording ones— 
differ from the pendulum value by —0-105 to +0: 200°", 
thus exhibiting a range of 0°3. Even the two visual barometers 
give results from shore observations differing by 0-1 and this 
in spite of Hecker’s laborious method of observation. The 
mean result here considered for any one barometer depended 
on 24 boiling point determinations and 8 barometric readings 
times the number of days, or for Rio de Janeiro, 360 B. Pts 
and 120 readings of each barometer and for Lisbon 216 B. Pts 
and 72 readings of each barometer ! 

Hecker made no shore observations by the B. P, method on 
any of his subsequent cruises, but he made a number in harbors 
on board vessels at anchor. These also exhibit most marked 
changes in but a few days, the effects of which if likewise 
experienced at sea, as must undoubtedly be the case, would 
exceed in impor tance the corrective terms in equation (5) due 
to motions of ship. 

Jn his Black Sea work, Hecker had repeated trouble with his 
thermometers so as to be obliged to discard some series entirely. 
The thermometers were made by Fuess of Steglitz of Jena 
borosilicate glass 59 III. Looking over Hecker’s scheme 
of observations, the suspicion is awakened that he ‘‘ boiled” too 
often and too protractedly —a fact he himself began to suspect 
in his later work. What accuracy was supposed to be 
gained by excessive observing was lost in resulting instability 
of his thermometers. he corrections jor Hecker’s thermom- 
eters were never re-determined after they had once been fur- 
nished by the German Pha ysihalische Reichsanstalt. Though 
some of the thermometers had been in use on the three cruises 
of 1901, 1904 and 1909, practically the same table of thermo- 
metric corrections is employed throughout. Three of them 
were provided with zero points but the zeros were never 
re-determined. Zhe corrections for the various barometers on 
a standard barometer for various barometric heights were 
never determined, or it so, they were not used, the observer 
supposing that all instrumental changes—both of thermometers 
and of barometers—would fully be taken account of by a con- 
stant term (#,, equation 5) and by a term, ¢ (¢—7,), progressing 
linearly with the elapsed time. Let it ‘be remembered that 
these two quantities #, and e were not derived from observa- 
tions at stations where Ag was known from pendulum work, 
but from the discussion of ocean observations for which a 
fictitious distribution of gravity anomalies had to be assumed 
in order that a least-square adjustment could be made. 


12 L. A. Bauer—Gravity Determinations at Sea. 


The first point to be made, therefore, on the instrumental 
side is, that in order to secure desired accuracy in gravity 
determinations from boiling-point observations, it is essential 
that a method of observing be adopted which will protect, as 
nearly as possible, the instruments from changes of whatever 
kind, and next that the boiling-point thermometers be provided 
with zero points, the variations of which may be determined in 
the field with melting ice once a week or as often as may be 
found necessary. The next point is that the method of 
observations be such that they can be quickly reduced and that 
too in such a perfectly definite manner as to admit of no ques- 
tion with respect to the logical method of reduction to be 
employed. Hecker, as shown aboye, did not lay sufficient 
stress upon these vital points. It is believed that equally 
good, if not indeed superior results, can be obtained with less 
equipment than used by Hecker, using a simpler method of 
observation as well as of reduction. Hecker’s cumbersome 
adjustments at times appear to have caused much needless 
labor. See, for example, his Black Sea adjustments, where he 
has attempted to derive his many unknowns from an insufh- 
cient range of conditions. 

Another very important point introducing a source of error 
not considered by Hecker is with regard to the possible errors 
in the vapor tension tables used to convert boiling-point tem- 
peratures into corresponding atmospheric pressure. The latest 
of these tables are those of Wiebe’s given in Landolt-Born- 
stein’s “Physikaliseh-Chemische Tabellen” for 1905. The 
most recent observations appear to be those of Holborn and 
Henning. For the purpose of gravity work, it is essential to 
be able to obtain accurately the atmospheric pressure for a com- 
paratively limited range extending below and above 100° C.; 
the observations on which the tables are based were made at 
larger intervals and the interpolation is accordingly somewhat 
uncertain. It is quite possible that the atmospheric pressure 
as taken from the tables may be out by -05 to 0:1", which 
corresponds to 0-065 to 0°135™ in g. When dealing with only 
differential results, as we are in our case, the tabular errors are 
somewhat eliminated, though not wholly. Zhe problem of 
most accurate vapor-tension tables for water between 99° and 
101° is here called to the attention of physicists. 


Hechers Gravity Results. 

From the explanatory statements on p. 150 of his 1910 pub- 
lication, it is seen that Hecker uses a different plane of refer- 
ence for the gravity anomalies, the Ag’s, over each ocean, and 
that the planes refer strictly only to the parts of the respective 
oceans traversed. No direct comparison can in consequence 
be made in passing from one ocean to another and 


il 


L. A. Bauer— Gravity Determinations at Sea. 18 


even for the same ocean, eg., the Atlantic, it would 
not be possible to compare directly gravity anomalies 
between New York and Hamburg, with Hecker’s between 
Hamburg, Rio de Janeiro and Lisbon. He does not 
explain completely how he actually connected ocean results 
with pendulum stations; for example, how he. distributed the 
correction from one land station to another. Why he did not 
refer his Atlantic Ocean results likewise to his pendulum 
stations, e.g., at Rio de Janeiro and Lisbon, he does not say. 
All this confusion has come about because of Hecker’s method 
of adjustment, as already explained, whereby he discards the 
shore and port boiling-point observations ab inztio and gets his 
unknown coefficients from a least-square adjustment of ocean 
observations. Having done that, he finds that the port 
observations computed with these coefficients give results not 
only very discordant among themselves but also with the 
pendulum observations. He then has the difficult problem of 
connecting his ocean results with land pendulum stations by 
means of more or less discordant port and shallow water 
stations. 

Tables I and II were drawn up from the figures in Hecker’s 
1910 publication ; a plus sign means that g at the place in ques- 
tion is greater than it would be did the local disturbing cause 
not exist, and a minus sign means, of course, the reverse. It 
must be recalled that the tabulated Ay’s are those as derived 
from Hecker’s adjustments ; if we may assume them correct, a 
mere glance shows at once that the disturbances in g are, in 
general, larger over the oceans than usually observed on land. 
Table I would show that the difference in Ag for two oceanic 
points may reach 0-4 and even 0°67. 


TaBLE I.—THE AVERAGE, THE MAXIMUM, AND THE MINIMUM VALUES OF 
GRAVITY DISTURBANCES AS SHOWN BY H&rCKER’S OCEAN OBSERVATIONS. 


(Revised figures 1910.) 


> |oA Ag 
Route = 168 
A |AO|Average |Maxi’um| Mini’um) Range 
em em em em 
Hamburg—Rio de Janeiro-___- 1901} 47 | +0-048 | +0:172 | —0:095 | 0-267 
Rio de Janeiro—Lisbon ___.__-_ 1901) 35 56 | +0°142 } —0-123 | 0°265 
Spain—Suez—Colombo ----.--- 1904) 33 83 | +0°289 | —0°106 | 0°395 
Colombo—Sydney -. .____....|1904/ 28 61 | +0°214 | —0-106 | 0°320 
Sydney—Honolulu—San Fran- 
CISCO. =: eee a ee ELS 1904| 41 106 | +0°393 | —0°273 | 0°666 
San Francisco—Honolulu—Yo- 
kohamla SS Sueeaee ese ee 1904) 33 54 | +0°310 | —0-067 | 0°377 
Black Sea (Odessa—Batum) ____/1909) 15 31 | +0:079 | —0-052 | 0:131 
Entire Work, 1901—1909___. 232 | +0:066 | +0°393 | —0-273 | 0-666 


14 L. A. Bauer—Gravity Determinations at Sea. 


TasLe II.—Some Larce Gravity Distursances Saown By Hecker’s OBSERVATIONS, 
1901-1909. mate riser figures 1910.) 


Cruise \Ye’r| Ag Lat. Long. | Depth Region 
| em m 
° ( | | + 0°172|35° 02’ N) 11°56’ W)| 3600 |Deep sea. 
ge a ee a )ig01/4 1488 36 S| 34 58 W| 40 [Nea Pernambuco. 
; | — 095/11 44 N) 26 59 W) 5600 |Deep sea. 
( \— 12311 35 S) 86 49 W) 3200 |Deep 2D) AnD 100 km. or 
Rio de Janeiro— J 4901 + 123) 6 238 S} 38 20 W) 5000 of move from Bra- 
Lisbon } |+ °142| 2 15 N| 29 38 Ww! 2000 «  \ zilian coast. 
L + 123) 1 04 N| 30 08 W) 2400 |Near St. Paul. 
{| + 289/48 34 N) 9 30 E) 200 |Med. Sea, N. of Corsica. 
| (+ °23512 34 N) 55 45 E) 3400 |Near Socotra. 
+ °214/35 49 N|129 64 E) 5400 |Steep gradient. 
| + °346/33 49 S/151 54 HE} 200 Bt 
D f + °393/384 17 S172 07 HE) . 150 |Near N. point N. Zealand. 
So even i 24 Wig0dl ms pe6di8 20 S178 27? E) 2700 |Tonga Plateau. 
{| + 161/27 15 S177 40? E| 2700 iN 
| | — ‘196/23 12 S174 47 E) 8000 |Tonga Deep. 
| — 273/22 07 S|174 13 | 6500 ui 
— °245)17 09 S171 42 H 8500 re 
L + 26821 17 Nj157 50 KE) 20 |Roadstead of Honolulu. 
San Franciseco— ; 1904) + *310/21 18 N\157 387 E). 70 |Near Oahu. 
Yokohama + °304/21 17 N\158 17 | 1700 . 
| + ‘079/44 51 N| 82 46 E) 150 |Shallow water. 
BLISS ae i 1909)” -052/43 36 NI 35 50 El 2200 ‘Deep water. 


Table III gives a comparison between Hecker’s 1908 and 
1910 values of Ag for certain characteristic points in the Pacific 
Ocean selected by Prof. J. F. Hayford in his paper before the 
meeting of the International Geodetic Association of 1909.* 
The last two columns are the differences between Hecker’s 
values of g and those computed by Hayford with the aid of his 
new method; I have myself added the 1910 figures. 


TasLeE III.—ComMpariIson OF SOME OcEAN GRAVITY ANOMALIES OBSERVED BY HECKER IN 
THE PACIFIC OCEAN WITH THOSE RESULTING FROM HAYFORD’S COMPUTATIONS. 


Depth | Hecker’s Ag | Ee Se 

iS Name of Station in Lat. Long. : Hayford 

Fe ec Niners 1908 | 1910 | 1908 | 1910 

1/Between Honolulu and San cm cm em em 
Francisco, at sea -_-.___- 5100 |28° 10’ N|146° 35’ W|—0-001 —0-010) + 0.003) —0-006 
2\Tonga Plateau, at sea-__---- 2700 |28 20 S\178 27 W)+ 215) + -264)+ -207/+ -256 
3/Tonga Plateau, at sea______ 2700 27 15 S177 40 W/+ -135)+ +161)+ -124/+ +150 
4\Tonga Deep, at sea ------_- 6500 |22 07 S174 13 W/— -271)— -273)— -181/— -183 
5/Tonga Deep, at sea -. ___- 8500 17 09 S171 42 W\— -248/— -245/— -162)— -159 
6|Near Hawaiian Islands, atsea) 4000 |22 50 N\160 23 W\+ 034)+ -062)+ -023)+ -051 
7|Near Oahu, at sea _ ___---- 1700 21 17 Njl58 17 W/+ -278)+ -304)+ -203)+ -234 
Mean with regard to sign ___ | +0020) +.0-038) +.0:031) + 0-049 
Mean without regard to sign 0-168; 0:188| 0:129) 07148 


*Hayford, J. F. The Effect of Topography and Isostatic Compensation 
upon the Intensity of Gravity. Cf. Report of the Int. Geod. Association for 
1909, published in 1910, pp. 365-389. 


L. A. Bauer—Gravity Determinations at Sea. 15 


In the first place it is seen that Hecker’s mean Ag for the 
seven points here considered is larger for the 1910 figures than 
for the 1908 ones—whether the mean is taken with or without 
regard to sign. Next, the differences on Hayford are in every 
instance larger quantitatively for the 1910 figures than for the 
original ones of 1908 except for No. 5. 

Furthermore the difference, Hecker-Hayford for station No. 
2, viz., +0°207 for 1908 and +-256 for 1910, is greater than 
any residual thus far shown upon Hayford’s computed g’s. For 
56 pendulum stations in the United States Hayford’s computed 
values differed from the observed ones, on the average, by less 
than 0:02, the maximum difference being 0°094, this occur- 
ring at Seattle, known to be locally disturbed. Here are the 
differences for some very disturbed pendulum stations : 


TasLeE IV.—Some VERY DistuRBED LAND STATIONS. 


Height 
Station above Latitude | Longitude! g,-g. 
sea level 
m | cm 
lslom@lmllhn = 22.0 a Seaesensogee 6 21°18’ N |157° 52’ W, +0:0838 
Mauna Kea (voleano) -_-.---. 3981 19 49 N |155 29 W) + 184 
Hachinohe (Japan)____---.--- 21 40 31 N |141 30 EH) + ‘111 
St. Georges, Bermuda-------- 2 32 21 N | 64 40 W| + -019 
Jamestown, St. Helena_---- -- 10 15 58 S| 5 44 W) + -059 
Sorvaagen, Norway _____----- 19 67 54 N | 13 02 E) + 147 
Kala-i-Chumb, Turkestan ---- 1345 Bem Ne 0m Gm Ep 052 
Gornergrat, Switzerland _----- 3016 45 59 N| 7 46 EH + -050 
St. Maurice, Switzerland ___-- 419 46 13 N! 7 00 E| + -004 


It will be noted that only in the case of two very remark- 
able stations—the voleano Mauna Kea and Sorvaagen, Norway, 
Hayford’s computed g, differs from the observed g, by more 
than 0-11 and in both of these cases the differences are less than 
0-2. But Hecker’s revised figures of 1910 give five out of 
seven residuals over 0-1 and two above 0°2. Whether Hay- 
ford’s method fails for such deep sea stations as here considered 
or whether we have thus afforded an indication of the absolute 
error of Hecker’s values, it is not for me to say. It is curious, 
however, that Hecker’s supposedly most correct values (those 
for 1910) accentuate the differences on Hayford. 

Other detailed examinations made have not revealed any 
superiority of the 1910 method of adjustment over the pre- 
vious one. The difficulty with some of the port observations, 
e.g., at San Francisco, was found to be chiefly due to énstru- 
mental changes (change in thermometer corrections). If the 
port observations are omitted, as Hecker desires, then the mean 
difference in Ay between his two computations without regard 


16 LZ. A. Bauer—Gravity Determinations at Sea. 


to sign is 0:°022™. The individual differences occasionally 
amount to 015°". He finally s says: “All conclusions drawn 
in the previous publications remain unaltered.” These main 
conclusions are : 

“The acceleration of gravity over the oceans traversed is 
approximately normal and conforms with Helmert’s gravity 
formula of 1901. Pratt’s hypothesis of isostatic adjustment of 
the masses of the earth’s crust is thus, except for local anoma- 
lies, found to hold true generally. It can be regarded hence 
as proved that the lesser density of the water of the oceans is 
compensated for by the increased density of the masses below 
the ocean bottoms.” 

My contention is that this conclusion was already practically 
embodied in Hecker’s method of adjustment. The conclusion 
may be true, but it can not be considered as proved by his 
mode of attack. Since no attempt was made to test whether 
another formula for normal gravity might not still better con- 
form with the observations, ‘the statement at the close of the 
first sentence does not seem warranted. 


Observations on Hecker’s Ocean Gravity Work. 


1. No wholly satisfactory measure of the absolute accuracy 
of the existing ocean gravity results can be secured by a mere 
perusal of the publications. If an independent examination is 
made and such checks applied as are possible, and when all 
sources of error are considered, 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 01°, or about 1/10,000 
part of g. In view of the pioneer nature of the work, it would 
have been desirable to have repeated observations, under dif- 
ferent conditions, over all regions previously traversed. 

2. One of the chief sources of error is to be ascribed to in- 
constancy of the corrections of the boiling-point thermometers 
caused by their continued and protracted use; the error thus 
arising may at times transcend in importance all other ones, an 
error in the temperature of 0:01° C. corresponding to about 
0°35 in g. Insuflicient attention was paid to purely instru- 
mental changes and corrections. Thus, for example, correc- 
tions for the boiling-point thermometers of the Atlantic Ocean 
work of 1901 were used practically unaltered throughout the 
subsequent cruises of 1904 and 1909—after having once been 
supplied by the Physikalische Reichsanstalt, the corrections 
were never again redetermined. No separate examination of 
the barometers by comparison with standard barometers appears 
ever to have been made. The belief that such purely instru- 
mental changes would be fully taken account of im the adjust- 


DOr val Bauer—Gravity Determinations at Sea. 17 


ment is shown to be fallacious. A source of error also not 
considered is that due to possible imperfections of the vapor 
tension tables. 

3. Insufticient evidence has been given to prove that, in the 
reduction of the observations, it is best to omit those made on 
board vessels at anchor. A method of adjustment which 
must assume practically what is to be proved, and which 
necessitates the rejection of data secured under supposedly the 
best conditions, weakening thereby the connecting link between 
the ocean results and the shore pendulum stations, can hardly 
be regarded as the best possible one. Instead some logical 
method of observation and of adjustment must be striven for, 
which will take advantage to the fullest possible extent of the 
shore and harbor results. 

4, The problem of obtaining sufficiently reliable ocean grav- 
ity results still awaits solution. 


Method to be Tried on the “ Carnegie.” 

The method it is proposed to try on the “ Carnegie,” begin- 
ning, if possible, at Cape Town in about April of 1911, is 
practically the same as that employed in the magnetic work. 
At all ports visited there will be both shore and harbor 
observations, especially at those places where g has been 
observed with pendulums and where accordingly the anomaly 
Ag is known, thus permitting a logical determination of purely 
instrumental constants. Our provisional equation of condition 
for such stations will be of the followimg form, @ having the 
same significance as in equation (1) above : 


p— 9% —h + a(t-t,) + b(B-B,). (10) 

k=k,+ k’, = constant part (%,) of the relation between the 
zero otf the thermometer and the zero of the barometer plus 
the constant part k’, of the errors of the vapor tension tables. 
It is hoped also by zero point determinations of the thermom- 
eters and by comparisons of barometers with port stand- 
ards wherever there are such, to determine #, independently 
of &’, and thus gradually get some idea of the various errors. 

a (¢—t,) is to represent the change in instrumental constants 
with elapsed time from some mean epoch, ¢,; it may later be 
found necessary to introduce a quadratic term, a’ (t—2,)*, but it 
is believed that, with proper care of instruments and with 
sufficiently frequent zero determinations of the thermometers, 
this term may be avoided. 

b(L-—8,) is to take account of the variations not included 
in the time term, but dependent upon barometric height or upon 


Am. Jour. Sci.—Fourts Series, Vou. XX XI, No. 181.—January, 1911. 
2 


18 LZ. A. Bauer—Gravity Determinations at Sea. 


boiling point; we may possibly find that this term can be taken 
account of by the special observations for %, as mentioned 
above. 


Hecker’s term a = is to be eliminated partly by method 


of observation and partly by refinement of instrumental 
appliances. The three terms, bp +cr+ds of his equation 
(No. 5), supposed to represent the effects of the ship’s motions, 
we shall endeavor to make negligible as far as possible or reduce 
to one term, dp, partly by the manner and place of mounting 
and by construction of the barometers, and partly by the scheme 
of combination of the observations, so as to introduce varied 
conditions of motions of vessel. It is thus hoped to avoid any 
need of a laborious and time-consumizg adjustment of the 
ocean results, thereby enabling the observer to make as nearly 
a complete reduction of his observations aboard as may be 
possible, the determination of the effects from instrumental 
causes disclosed by the shore and harbor observations being 
left to the office computer. 

The various sources of instrumental error—thermometer and 
barometer—are at present being further examined. It is 
possible that the temperature of the boiling point will be deter- 
mined both with mercurial thermometers of special construe- 
tion and with electrical resistance thermometers. The chief 
difficulty now appears to be in the sufficient refinement of the 
barometric work. The hope is entertained, however, that the 
great importance of getting values of g within the accuracy 
demanded by geodosists—about 0:02 or 0:03°°—will lead some 
one to discover a method so superior as to eliminate the boiling 
point-barometer method altogether for ocean gravity work. 


R.S. Bassler—Deep Well at Wuverly, Ohio. 19 


Art. Il.—The Stratigraphy of a Deep Well at Waverly, 
Ohio ;* by R. 8S. Bassiur. 


Some months ago, in the course of routine work at the 
National Museum, the writer had occasion to identify a num- 
ber of characteristic Eden fossils from a set of photographs 
sent for determination by Mr. Peru Hutt, of Waverly, Ohio. 
The occurrence of this fauna at Waverly, in a region of Missis- 
sipian strata more than 60 miles from the nearest outcrops of 
the Eden formation, led to a correspondence with Mr. Hutt, in 
which it was learned that the originals of the photographs had 
been obtained from a deep well drilled for oil at that place. 
Mr. Hutt had carefully saved enough samples from all of the 
material resulting from the boring to prepare two very detailed 
logs, which he was kind enough to forward for study. He is 
to be commended for his zeal in the matter, for, without his 
eare, the following determinations, which are believed to be of 
some interest, concerning the underground stratigraphy could 
not have been made with any degree of accuracy. 

The notes resulting from the study of the two series of sam- 
ples were discussed with Dr. E. O. Ulrich at the time, and then 
set aside for future reference. Later the subject was mentioned 
by Dr. Ulrich to Professor Schuchert, who, in turn, deemed the 
section of sufficient importance to request a short article upon 
it for this Journal. 

The well was drilled to a depth of 3,320 feet. The upper 
1,100 feet were cased, so that the samples from this portion 
were little mixed and afforded an accurate idea of the various 
formations penetrated. The lower 2,220 feet, however, were 
left open, and the samples from this part required more careful 
study. Still, this latter portion was not difficult to decipher, 
since the predominating foreign material in the lowest samples 
was the blue limestone and shale of the Cincinnati group, 
which had fallen from above, and which, on account of litho- 
logic characters totally different from those of the white mag- 
nesian limestone and sandstone of the lower formations, could 
easily be eliminated. 

Instead of giving a detailed description of each of the many 
samples, the results of the study are arranged below in the 
form of a geologic section. Drilling commenced at a point 
100 feet below the top of the sandstone quarries of the town, 
and the first 35 feet of the well passed through the lower por- 
tion of this sandstone. Then in descending order came the 
black Ohio shale, the limestones and sandstones of Devonian 
and Silurian ages, a good representation of the various Cincin- 


* Published by permission of the Secretary of the Smithsonian Institution. 


20 R.S. Bassler— Deep Well at Waverly, Ohio. 


‘natian formations, a fair thickness of Trenton, Lowville, and 
Stones River, typical Saint Peter sandstone, and, finally, about 
300 feet of rocks assigned to the Canadian. The various thick- 
nesses given must be considered as only approximate, mainly 
because they were calculated from two distinct logs. For some 
reason the samples had been arranged in two sets, one measuring 
from the top to a depth of 2,020 feet, and the other from the 
bottom to a height of 2.200 feet. The two overlapping por- 
tions were correlated with little difficulty, because this part of 
the section was the most fossiliferous. The base of the well 
is of particular interest and will be discussed later. 


Geologic Section at Waverly, Ohio. 
Thickness 
in feet. Depth. 
Mississippian: 
(b) Fine grained, drab ‘‘ Waverly ” sand- 
stone exposed in hills of town above 


mouthviok well: p:2 44; ae te as ee same OO) 

Similar standstone forming lower part 

of Waverly, series yess pease ee 35 0- 35 
(a) Bituminous, fissile, black Ohio shale-. 450 35— 485 


Devonian and Silurian: 
Mainly white, fine-grained sandstone 
with traces of white limestone. This 
material is so ground up by the drill 
that the limestone which it may have 
contained in some quantity has been 
mainly pulverized and washed away. 
The sandy material is evidently mostly 
from the Obio Silurian formations. 
At the base of this portion are the red 
and brown calcareous sandstones of 
Clinton ager? 227 22a ae eee eres 415 485— 900 
Cincinnatian: 
(c) Blue shale with a few fragments of 
blue limestone. Fossils scarce, small 
portions of only Dalmanella jugosa 
being seen, but the strata are evidently 
of Richmond and Maysville age, with 
probably the Upper Eden shales rep- ; 
ReseNbe eee. oe oe 1065 900-1965 
(b) Blue shales containing rather numer- 
ous Middle Eden fossils. ‘The species 
identified are: Rafinesquina alternata 
(Eden variety), Plectambonites seri- 
ceus, Dalmanella multisecta, Trematis 
millepunctata, Pholidops cincinnati- 
ensis, Callopora sigillarioides, Clima- 
cograptus typicalis, Byssonychia vera, 
Protowarthia cancellatu, Ceratopsis 


R.S. Bassler—Deep Well at Waverly, Ohio. 21 


Thickness 
in feet. Depth. 


chaumbersi, Bythocypris cylindrica, 

Trinucleus concentricus, Calymene cal- 

licephala, Proetus? spurlocki, and 

Nereidavus varians. From this point 

to the bottom of the well, blue shale 

fragments holding this fauna were en- 

countered, but, eliminating them, the 

remaining formations were, for the 

main part, clearly represented in the 

SACOLOS arse ban Sear = ye ee 55 1965-2020 
(a) Unfossiliferous blue and greenish shale 

associated with the blue shale holding 

the overlying Middle Eden fauna. 

This portion probably represents the 

Lower Eden and Utica divisions... -- 80 2020-2100 

Mohawkian: 

Trenton formation. 

Blue clay and shale, with a few frag- 

ments of blue limestone. Zygospira 

recurvirostris, Trinucleus concentricus, 

and a species each of Khinidictya and 

Callopora, known elsewhere from the 

Lower Trenton, were noted. At the 

base of this formation a small amount 

of glauconitic grains were present in 

the*sanmples ey wae keen heh oe 125 2100-2225 
Lowville and Stones River formations. 

Each of these formations is probably 

represented, but their lithology is so 

similar that no distinction could be 

made in the samples, which consisted 

mainly of white, clayey, and dove un- 

fossiliferous limestone with blue argil- 


laceous limestone at the bottom __-.- 600 2225-2825 
St. Peter sandstone. 

White, saccharoidal sandstone ---- -- 175 2825-3000 
Canadian. 


This portion naturally contained the 
greatest mixture of materials, but after 
excluding all the rock formations of 
the overlying beds, a few fragments 
of white dolomitic limestone remained. 
These are quite similar to the Cana- 
dian rocks of the Appalachians, and for 
that reason and the absence of chert, 
which is more characteristic of the 
Ozarkian, as well as the stratigraphic 
position, the correlation was made as 
above. .At the very base of the well 
a few small fragments of an igneous 
rock were detectedinn - 98222 2225... 320 3000-3320 


92 Rk. 8. Bassler—Deep Well at Waverly, Ohio. 


This section presents no new facts regarding the rocks 
younger than the Trenton, for between Waverly and Cincin- 
nati, about 80 miles west, the same strata have been studied 
along numerous surface outcrops. The earlier Mohawkian 
formations are not exposed until central Kentucky, over 100 
miles distant, is reached, while the Saint Peter sandstone and 
Canadian limestone are not known at all by surface outcrops 
in the Ohio valley. 

The section of strata penetrated by a deep well at Oxford, 
Ohio, is of interest in this connection. A detailed description 
of the log of this well was given by Joseph F. James in vol- 
ume X of the Journal of the Cincinnati Society of Natural 
History, but for present purposes only the general section 
determined by him is of interest. Arranged in the same form 
as the one given aboye, this section, with the formations as 
identified by James, but with the correlations of the present 
day inserted in brackets by the present writer, is as follows : 


Geologic Section, Deep Well at Oxford, Ohio. 


Thickness 
in feet. 
Cincinnati group: 
Blue limestone and shale [Richmond and Maysville]-- 360 
Blue shale |[Maysvallevand ident] S25 ee = oe ae oer 380 
Dark limestone! | @remt om) = eS cae eon seen ae 


Trenton group: 
White limestone with magnesia [Lowville and Stones 


River | 2 oes eee e)e ep ere Ce ae ee BO os 
Calciferous sandrock: 
White, arenaceous limestone [Saint Peter] ._--.------- 40 


Unfortunately this well did not go deep enough to show the 
strata underlying the Saint Peter sandstone, nor did certain 
deep wells bored at Cincinnati pass beyond this formation. 
These Cincinnati wells showed the same stratigraphy and essen- 
tially the same thickness as in the Oxford well, so that the 
latter can be taken as typical for the region of. the Cincinnati 
axis. Comparing the Oxford and Waverly sections, the follow- 
ing conclusions may be drawn: 

(1) From observations on both sides of the Cincinnati axis, 
the Maysville and Richmond divisions of the Cincinnatian do 
not vary enough in thickness to suggest marked decrease of 
deposition across the apex of the axis. The Utica is seldom 
more than a few feet thick at Cincinnati. In northern Ohio 
it has become greatly thickened, as shown in the gas wells; it 
has likewise attained a considerable thickness in the Appala- 
chians. The increased thickness of the Cincinnatian as a whole 


a 


R. 8. Bassler—Deep Well at Waverly, Ohio. 23 


in the Waverly well is thus probably due to the presence of 
greater deposits of Utica shale. 

(2) The same eastward increase in thickness may be stated 
for the Trenton rocks with less doubt. At Cincinnati the 
lower 50 feet of the Trenton are exposed with the thin Utica 
shale resting upon its eroded surface. Proceeding southeast 
along the Ohio River, this thickness increases to over 100 feet, 
in a distance of 30 miles, by the addition of higher beds of the 
formation. The occurrence of 125 feet of Trenton strata at 
Waverly, 80 miles east, is therefore in line with the idea that 
the Trenton and the Utica are alike in having a minimum 
thickness along the Cincinnati axis. These same facts, among 
others, have convinced several of the students of Cincinnati 
geology that this axis did not pass along a northeast-southwest 
line 25 or 30 miles east of Cincinnati, as commonly believed, 
but close to the city itself. 

Allowing for a certain amount of error in determination, 
the Stones River—Lowville sequence is practically the same 
in cach section. At any rate, both the Stones River and Low- 
ville are among the most widespread Ordovician formations, 
extending from Oanada to Alabama, and from New York to the 
central Mississippi Valley. Both the Oxford and Waverly wells 
are interesting, therefore, in indicating the presence of both 
formations in the northern part of the Ohio Valley, where 
they have no surface outcrops. 

The presence of such a typical fauna of Middle Eden species, 
a hundred or more miles from the shores of the sea of the time, 
is evidence for the shallowness of the early Paleozoic continen- 
tal seas. Deep wells elsewhere have furnished abundant proof 
of this same fact, and the one at Waverly simply furnished an 
additional well-established example. This Eden fauna is well 
known in New York, in the Cincinnati uplift,and in the Appa- 
lachians, and not being pelagic, it could not have had such a 
eeeereipe had deep seas intervened between these several shore 
ines. 

The occurrence of glauconitic material in the samples from 
the base of the Trenton is likewise noteworthy in indicating 
the unconformity between this formation and the underlying 
Lowville strata. Detailed studies of the early Paleozoic rocks 
have shown glauconite to be a common ingredient of the basal 
sediments of several overlapping formations. 

Perhaps the most interesting fact brought out by this well is 
the presence of a few fragments of igneous rock at its very 
bottom. The importance of this occurrence was suggested at 
once by Doctor Ulrich, for the area about Waverly is on the 
northward extension of the uplift which he has named the Car- 
ter axis. The igneous nature of these fragments was verified 


24 RR. S. Bassler—Deep Well at Waverly, Ohio. 


by Dr. George P. Merrill, who determined them as peridotites 
which had become altered into serpentine. That the presence 
of this igneous rock is to be considered as indicating that the 
well passed through the base of the Paleozoic cannot be posi- 
tively determined from the facts at hand, as the material may 
possibly have been derived as a bowlder from above. However 
the facts so far as known are highly significant, and it may 
be tentatively suggested that the Canadian rocks rest upon pre- 
Cambrian. Whether this area was a part of an axis of uplift, 
such as the Carter axis, or was included in a broad southern 
extension of the Laurentian shield during Cambrian and Ozark- 
ian time, cannot be decided with the present evidence. 


U.S. National Museum, Washington, D. C. 


eX, 


ee ee eee ee ee 


Foote and Bradley—Solid Solution in Minerals. 25 


Arr. IL.—On Solid Solution in Minerals with Special 
Reference to Nephelite; by H. W. Foorm and W. M. 
BRADLEY. 


Ir is a fact well known to mineralogists that there are 
certain minerals to which no satisfactory chemical formule can 
be assigned which agree with the results of analysis. The 
reason for this in many eases, particularly where the mineral 
is rare and little investigated, is probably that the material is 
impure, containing included foreign matter, or else the 
analysis is incorrect. There appear to be cases, however, 
where the material has been so carefully selected that foreign 
matter could not be present except in traces, and where 
analyses have been made with the greatest care and still the 
formula cannot be definitely assigned. A case of this kind is 
that of the mineral nephelite, to which the formule NaAISiO, 
and Na,A1,Si,O,, besides others more complicated have been 
given. An examination of several good analyses of this 
mineral will show that the analytical data do not support any 
one formula, but that there are considerable variations from 
it which are greater than can be accounted for by the ordinary 
errors of analysis. 

In general the composition of a mineral as obtained in 
analysis varies from the composition of the ideal pure com- 
pound for two reasons, aside from errors of analysis. Either 
there is (a) isomorphous replacement of one element or radical 
by another, or (>) there are mechanical impurities present. 
Where there is merely isomorphous replacement, the formula 
of the pure compound can be derived from the analysis by the 
ordinary methods of caleulation, which need not be considered 
here. The presence of mechanical impurities can usually be 
determined by other means, for instance, by the use of heavy 
solutions or by microscopic examination. We wish to call 
attention to another influence which must probably be taken 
into account in cases like that of nephelite. It appears to us 
necessary to assume that in certain cases a substance on crystal- 
lyzing forms a solid homogeneous solution with foreign matter 
which cannot be assumed to be isomorphous with any constit- 
uent, and which is not to be regarded as a mechanical mixture. 
It can be compared to the solution of salt in water, in which 
the salt takes on the appearance and form of the water without 
taking any part in the formula of the water. A case of this 
kind in minerals would not be a mechanical: admixture of the 
foreign substance, comparable to the suspension of a solid in 
water, but would form a homogeneous mass with the rest of 


26 Foote and Bradley—Solid Solution in Minerals. 


the mineral comparable to the salt solution. If such an 
impurity were present in appreciable amount, it is obvious that 
the formula of the pure compound could not be caleulated 
correctly from the analysis. This type of solid solution must be 
clearly distinguished from isomorphous replacement, which is 
also commonly considered as solid solution. In the latter case, 
the formula of the compound can be derived directly from 
the analysis, as previously mentioned. 

Before considering the application of these statements to 
nephelite, we wish to mention a simple case of solid solution 
which is known in artificial crystals. It has been shown by 
Roozeboom* that when ammonium chloride crystallizes from a 
solution containing ferric chloride, the crystals deposited are 
colored and may contain as much as seven per cent of ferric 
chloride. Here there can be no question of isomorphous 
replacement, and on the other hand the ferric chloride is not 
mechanically enclosed by the ammonium chloride. The latter 
point is proved partly by the fact that the crystals appear 
pertectly homogeneous, and it is proved much more definitely 
by the fact that the solubility of such erystals varies with their 
composition. If a mechanical mixture were present, the solu- 
bility would not vary with the composition of the mixed crystals, 
but there would be a definite solubility at a given tempera- 
ture independent of the composition. The colored crystals 
are to be regarded as one homogeneous phase in which 
the ferric chloride is held in solid solution by the ammonium 
chloride. Similar occurrences have been noted in artificial 
minerals with a good deal of probability. Day and Shepherdt 
have observed an artificial calcium metasilicate crystallizing 
with tridymite which differs slightly in optical properties from 
the pure silicate. The variation appears to be due to the 
presence of silica taken up in solid solution by the metasilicate. 
The same metasilicate is also capable apparently of absorbing 
a considerable amount of the orthosilicate and still appear 
homogeneous. Again, Shepherd and Rankin{ have shown 
that artificial corundum may take up a limited amount of 
sillimanite (or silica) in solid solution and also a small quantity 
of calcium oxide. We believe such cases also exist in certain 
minerals such as nephelite. 

Several years ago, the late Prof. S. L. Penfield suggested to 
one of us (Bradley) that the reason for the variation in the 
composition of nephelite might be due to the presence of 
mechanical impurities and that if material of undoubted purity 


* Zeitschr. f. phys. Chem., x, 145, 1892. 
+ This Journal (4), xxii, 265, 1906. 
{This Journal (4), xxviii, 293, 1909. 


Foote and Bradley—Solid Solution in Minerals. 27 


could be obtained so far as mechanical admixture was con- 
cerned an analysis would show the correct formula of the 
mineral. A sample of nephelite from Eikaholmen, Norway, 
was chosen for analysis and freed from other minerals by use 
of acetylene tetrabromide. The sample used in analysis floated 
when the specific gravity of the liquid was 2°638 and sank 
when it was lowered to 2°632, so that variation in the density 
of the mineral was not more than -006. The resulting nephel- 
ite contained a minute amount of albite which was insoluble 
* in hydrochloric acid, but the quantity was so small thatit could 
be neglected. The material obtained was, we believe, as pure 
as it is possible to obtain nephelite by mechanical means, since 
observations under the microscope showed the sample to be of 
excellent quality and practically homogeneous. 

Two complete analyses and two other partial ones were 
made on this material with the greatest care (by Bradley). 
Only brief mention seems necessary of the methods employed 
im the chemical analysis. Silica was determined in the usual 
way, after dissolving the mineral in hydrochloric acid and by 
testing its purity traces of alumina were recovered. Alumina 
was precipitated as hydroxide and this was dissolved, repre- 
cipitated and weighed in the usual manner. The small per- 
centage of iron was determined volumetrically with potassium 
permanganate. A Smith’s fusion was made for the alkalies. 
The results in detail with the ratios obtained are given below. 


Taste I, 
Analyses of Nephelite (Bradley). 


Nephelite from Hikaholmen, Norway. 


perc 2 3 4 Average Ratio 
SiO, 44:59 44:31 44:37 44°59 44-46 -736 = 2:93 
BOR asso yn on 02 es ola Wari t 185 Wie 824 anes 
ier O: 96 “96 ‘96 sons 96 :006 ay 
KEOe (562) 5:62 . 155% 15:59. 5-61. -060 

BIG) Sy 

NO SiG Onn 1631 Gia W606, 16-325 263 tae” 
H,O emt cae ap asa cae 

101:43 100-60 100-29 100:84 


The above analyses were not published at the time they were 
made, as the formula derived from them was complex, and the 
results could not be regarded as establishing the formula. 


* Taken from anal. I. 


28 Foote and Bradley—Solid Solution in Minerals. 


The composition of nephelite was further investigated the 
following year by Morozewicz,* who also gives an excellent 
review of the literature on the subject. The author gives 
analyses of six different nephelites which were apparently 
made with the greatest care on carefully purified material. 
By his method of analysis, he was able to free his material 
from even a trace of albite. The results and the ratios 
derived are given below. 


Taste II. 
Analyses of Nephelite (Morozewicz). i 
II Tit 
Nephelite (Elezolite) from Mariupol. Nephelite (Elolite) from Mariupol. 
Porphyritic Crystals. Coarse and granular. 
Ratio Ratio 
SiO, occas oes RSTO Mere Sem 43-46 
TO. 61. ane 10 { 22 Oa oe 07 f Ae 
EAR O ae oes 33°12 ‘ AON eet ee 32°82 ; 
Re es bas) (200 Maney a ors} 100 
CAO ye ieeee 0°49 CaQ a2 ee 0°31 
EO yee 5°69 0799) 1) AS O Pee ee 5°55 0°99 
NaI O's eee 15°91 Nia: Oe see 16°12 
EE OS 0°74 AU Ress Meare 0°89 
100°18 99:97 
IV ; Vv 
Nephelite (Eleolite) Mariupol. Nephelite (Elzeolite) from Miask. 
Reddish Crystals. 
Ratio Ratio 
SiOmes ee 43°55 SlOve sg. eee 42°71 
: 9) sap . 
PHO, sone st 0 t ar OP ab 0-04 } gue 
INCOM eat 32°96 Poa Ni OhGuu at a: 33°83 
He Oe 0°66 t 100 ss tel) hy. Mena G A Bee 
CaO Sere ee 0°25 } CaOiee ser 0°32 
KP Ope oi 6°09 100 TE OL se 5°86 1:00 
Manan bee 16-00 J NaiOne ns 16-46 
YO ee ee ae 0°33 EO Peeires 0°18 
MgO Be ae trace 
Impurities -. 0°06 
99°86 99°86 


* Bull. Acad. Sciences Cracovie, 958, 1907. 


Foote and Bradley—Solid Solution in Mineratls. 29 


VI VII 
Nephelite from Vesuvius, Nephelite from Vesuvius. 
Different specimen from VI, 
Ratio Ratio 
Ste aes 49°53 SiOn so) ae 4334 
Ona eae 0-01 ; Serle TON - Neen at aie 
ALO Cee ae 33:92 AO yee 33°75 
Pome We ple? pots ray. 1200 
CaQ pas Sr. 1b9'7) CaQ ie tees 2°20 | 
is pe 0:07 | MeOus. 5. 0:24 | 
9 5 
iFe(O ue ela! eps @enn lc ik Omen cl. Aevinig 08 
Na,O meee Sate 15°12 | INEEOR See: 15°66 J 
EI Oye eepre ses 0°13 HORS ee 30 0528 
Impurities... 0°24 
100711 100'26 


We consider the seven analyses given above to be the best 
which have been made on nephelite. A considerable number 
of other analyses have been made, however, and we give 
below a summary of the ratios obtained from the analyses 
given in Dana’s Mineralogy, page 425. The numbers are the 
same as in the Mineralogy. 


Tasxe III. 
Ratios obtained from Analyses of Nephelite given in Dana’s Mineralogy. 
SiO, Al,O; etc. Na,O etc. 

No. 1. OM 1:00 1:00 
4 Oe 9°95 (45 “99 
OF BOUT o6 1:00 

4, 2-29 ss *95 

5. 2°20 sf “91 

6. 2°24 a 1°04 

7. 2°18 ‘6 1°02 

8. 2°24 ce 101 

9, 2°31 ‘s 97 

10. 2°60 “ 1°16 

11. 2°24. << 1°05 

UR, 2°06 oY °94. 

13. 9°14 6G *93 

14, 2°29 < “97 

15, 2°19 Se “98 


The summary of the ratios obtained in the seven analyses 
first given is as follows: 


30 Foote and Bradley—Solid Solution in Minerals. 


Taste IV. 
Summary of Ratios from Analyses by Bradley and Morozewicz. 
No. SiO, Al.O; ete. Na.O ete. 
It 2°93 1:00 0:98 
TT: Zroili ef 0°99 
1606 2°21 ee 0°99 
Ve 2°21 fs 1:00 
ais Pa as 1:00 
VI. 2-11 cs 1:02 
VIL. 2°15 re 1:03 


- 


In this table the ratio of Na,O: Al,O, is as nearly 1:1 as 
could be desired. There can be no question that soda and 
alumina are present in this proportion. The ratio for silica 
varies from 2°11 to 2°23, and this variation is greater than can 
be accounted for either froin errors of analysis, or from the 
presence of impurities. For imstance, analysis No. I contains 
more than two per cent excess of silica if the ratios were to be 
the same as in No. VI. There is no case known, we believe, 
where silica can be considered as replacing isomorphously 
either alumina or soda, and if it did in this case, the ratio 
between these two would not be simple. The same general 
conclusion as regards composition may be drawn from the 
ratios derived from older analyses given in Table III, though 
many of the analyses are probably not as good as the more 
recent ones. 

Morozewicz* has shown that the nephelites may be con- 
sidered as consisting of two series of compounds, a normal 
series and a basic one. The normal series should be repre- 
sented by the formula K,Na,Al,4.Si,43Oin410, in Which n=8, 9, 
10, and 11, and the basic series by the formula K,Na,,Al,,O,,. 
By this series of variable formule, the variation in composition 
can be expressed. This method of representing the com- 
position is open to the serious objection that a chemical com- 
pound, so far as we know, does not vary in type. Isomorphous 
replacement, for instance, varies the composition, but the type 
of compound remains the same. 

If nephelite be considered a solid solution, the case becomes 
very different. A solution may be defined as a homogeneous 
mixture of substances which cannot be separated by mechani- 
cal means and whose composition varies continuously within 
certain limits. This definition distinguishes a solution from a 
suspension on the one hand and from a chemical compound on 
the other. It characterizes a solution of a salt in water, and a 
solid solution of ferric chloride in ammonium chloride and we 


* Loc. cit. 


—— 


Foote and Bradley—Solid Solution in Minerals. 31 


can see no reason why nephelite should not be treated in the 
same class. This method of considering the composition of 
nephelite has the advantage of being much more simple than 
using a series of complicated formule, and it appears to us to 
agree with the facts. It need hardly be said that a chemical 
formula could be assigned to any solution but a different one 
would have to be used for each change in concentration of the 
solution, just as Moroscewiez uses a different formula for each 
nephelite. 

From what has been said, we think it fair to consider that 
nephelite as it occurs in nature is not a pure compound but a 
solid solution analogous to the solid solution of ferric chloride 
in ammonium chloride. It then becomes of interest to con- 
sider the probable formula of the pure compound which forms 
the basis of nephelite. This appears to be the orthosilicate 
NaAIlSiO,. This formula is supported in two ways: (1) Nephe- 
lite has the same crystalline form as eucryptite LiA1ISiO, and 
kaliophilite K AISiO, which are in the same group, making it 
very probable that the type of formula is the same in all three 
eases. (2) Artificial nephelites have been prepared by Doel- 
ter* which have the same general characteristics as natural 
nephelite and vary in composition from the formula NaAISiO, 
to compounds containing potash and an excess of silica corre- 
sponding to the mineral. 

Perhaps the point should be emphasized that nothing what- 
ever is known about the actual condition of the dissolved 
silica, whether it is present as dissolved albite or silica or 
leucite or in any other form, just as very little is known about 
the condition of dissolved substances in liquids as to whether 
they are combined with the solvent. It is certain, however, 
that the dissolved silica does not have the properties of either 
ordinary quartz or albite, since it is soluble in hydrochloric 
acid. In the same way, the properties of a dissolved salt are 
entirely different from the properties of the solid. 

The excess of silica which can be taken up by nephelite to 
form a saturated solution can apparently be determined from 
the data given by Morozewicz and ourselves. Where albite is 
found intimately mixed with nephelite it is evident that the 
nephelite must be saturated with silica and the excess of the 
latter has formed albite. 

In this case, therefore, the nephelite should have a constant 
ratio of silica to alumina, and these nephelites should contain 
the maximum amount of silica that ean be taken up. The 
influence of temperature in determining the composition of 
the saturated solution can apparently be neglected. In our 


* Zeitschr, f. Kryst., ix, 321, 1884. 


32 Foote and Bradley—Solid Solution in Minerals. 


own specimen, albite was associated with the nephelite, and 
Morozewicz states that albite was present in the specimens con- 
taining the nephelites of analyses II and III and microcline- 
microperthite, which would have a similar effect, in analysis 
IV. The ratio for silica in these four cases is 2°23, 2°21, 2°21 
and 2°21, which is as nearly constant as could be desired. In 
analysis V, where the ratio for silica is only 2°12, the mineral 
is stated to be exceptionally pure, with biotite crystals on the 
outside. In VI or VII, where the ratios are 2°11 and 2-15, 
sanidine was present which might have the effect of albite, 
tending to raise the ratio to the saturation point, but in just 
these two cases (from Vesuvius) the nephelite appears to be a 
later growth on the sanidine and not intimately mixed with it. 
In these cases, then, where albite or its equivalent was not 
formed with nephelite, the ratio of silica to alumina shows that 
the nephelite has not taken up the maximum amount of silica. 
The most basic rock containing nephelite with which we are 
acquainted is an iolite described by Hackman.* This rock 
contains essentially pyroxene and nephelite with smaller 
amounts of titanite, apatite and ivaarite. There is no albite, 
quartz or feldspar present. The nephelite in this rock had the 
following composition and ratios: 


Ratio 
si0, BOO 2 ps wee ee 43°98 O13 
Al,O, a AY Aa 34°93 1°00 
CaO pea laa ties ee 0.36 
INaiOR: Sacre ee 16 mf 0°94 
K,O Eres Das eae Sh Meta 3°83 


99°86 


Here, again, the silica is below what we may call the 
“saturation ratio” of 2°21. 

It would be of considerable interest if nephelites could be 
found which closely approximated the formula NaAISiO,,. 
From what has been said above, such an occurrence could only 
be expected where crystallization had taken place from a 
magma so deficient in silica that albite did not form. 

In conclusion, the authors consider that the arguments 
advanced in the present article may be applicable to other 
minerals. Work has already been begun on the mineral 
pyrrhotite with the hope that similar deductions may be 
applied to this mineral. 

Chemical and Mineralogical Laboratories of the Sheffield Scientific School 


of Yale University. 
New Haven, Conn., October, 1910. 


* Bull. de la Commis. Geol. de Finlande, 1900, p. 9. 


Watson and Powell— Age of Virginia Piedmont Slates. 33 


Arr. [V.—Fossil Evidence of the Age of the Virginia 
Piedmont Slates; by Tuomas L. Warson and 8. L. 
Pow tu. 


CoNTENTS: 
Introduction. 
Virginia Piedmont Province. 
Slate areas of the crystalline region. 
Quantico slate belt. 
Fossils. 
Arvonia slate belt. 


Introduction. 


Recent detailed field study of the slate areas in the crystal- 
line (Piedmont) region of Virginia by the State Geological 
Survey has resulted in much important information bearing 
on the lithologice characters, structural and age relations of the 
rocks, and on the sulphide ore-bodies (veins) associated with 
the slates of the northeastern belt. Of especial interest are: 
(1) discovery of fossils in the easternmost one of the slate areas ; 
(2) recognition of voleano-sedimentary beds intimately associ- 
ated with the slates in several of the areas; and (3) evidence of - 
the age relations of a part at least of the sulphide veins in the 
northeastern portion of the crystalline region, which hitherto 
have been assumed to be pre-Cambrian. 

The present paper treats only of the discovery of fossils in 
the Quantico slate belt, with a brief statement of its strati- 
graphic position, and of that of the other slate belts in the Vir- 
ginia crystalline region. Discussion of the age relations of the 
sulphide veins and of the volcano-sedimentary beds associated 
with the slates will be treated in another paper, now in pre- 
paration. 


Virginia Piedmont Province. 


The Virginia Piedmont province (crystalline area) lies be- 
tween the Coastal Plain and the Appalachian Mountains. It 
extends from the Blue Ridge eastward to the western margin 
of the Coastal Plain, and it widens southward (map, fig. 1). 
Its width increases from 40 miles in the northern portion 
along the Potomac River to nearly 175 miles along the Virginia— 
Carolina boundary. The rocks of this region are the oldest in 
the state, and, excepting the areas of Triassic rocks, they are 
all erystalline. They comprise both igneous and sedimentary 
masses, in many places so altered from metamorphism, chiefly 
pressure and recrystallization, that their original character is 
indistinguishable. 

The region is made up of a complex of schists, gneisses, and 
granites, with which are associated some slates, quartzites and 


Am. JOUR. Sct.—FourtH SERIES, VOL, XX XI, No. 181.—January, 1911. 
>) 


Aa ee 


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a Se STS “ol -= 

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5 iG oe i 
S er, ae 
S | 

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r= <p 

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= eainae U 

2s C samquaudy 7 

aS Z "s) 

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Age of 


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> aN INP VSS : (09 ajewaqyy) “3184 3uoWs| NVINEWWS 
aN ‘ ; p . A 
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nN é (seg e1uerjAsq}0ds 
= f Z pue “paojyers “wWeIj|!AA e2Ul4d) HEGoruenh B | i. oquo 
Ss : /. ; (sop euueAn|4 pue Wweysulyong) “}ieq eluoniy 
~ QN3931 
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T ‘OL 


34 


Watson and Powell—Age of Virginia Picdmont Slates. 35 


conglomerates, and crystalline limestones. These are metamor- 
phosed and intruded by dikes and masses of diabase, diorite, 
and gabbro. Over parts of the eastern and central portions of 
the region are areas of altered voleano-sedimentary rocks, which 
extend southward into North Carolina. 


Slate Areas of the Crystalline Region. 


There are five principal slate areas occurring within the 
limits of the erystalline region of Virginia. These are shown 
on the accompanying map, figure 1. Named in the order of 
their present importance, the areas are: (1) the Arvonia belt 
in Buckingham and Fluvanna counties; (2) the Keswick— 
Esmont belt in Albemarle County ; (8) the Snowden belt in 
Amherst and Bedford counties; (4) the Warrenton belt in 
Fauquier and Culpeper counties; and (5) the Quantico belt 
in Prince William, Stafford, and Spottsylvania counties. 

The discovery of fossils in three of the areas (Snowden, 
Aryonia, and Quantico) has definitely determined their age— 
the Snowden area as Cambrian, and the Arvonia and Quantico 
areas as Ordovician. Fossils have not been found in either of 
the other two areas, Warrenton and Keswick—Esmont, but the 
relations of the slates to associated rocks of known age in or 
near these areas fix the age of the slates beyond reasonable 
doubt as Cambrian. 

The Snowden slate area, flanking the southeast slope of the 
Blue Ridge m Amherst and Bedford counties, includes a series 
of beds of conglomerates, sandstones, and slate resting uncon- 
formably on a basement of igneous rocks. The sedimentary 
beds are in a highly metamorphosed condition, and were 
regarded by Rogers as Huronian, and by J. L. and H. D. 
Campbell as pre-Cambrian, but the discovery of fossils in them 
has definitely determined their age as Cambrian.* The sand- 
stones of this series contain fossil borings of Scolithus linearis, 
which with the other data marks them as Cambrian in age. 
No fossils have been found in the slates of this series, but the 
Scolithus sandstone is observed to dip under the slates, which 
indicates that the latter cannot be older than Cambrian.t 

The Warrenton slate area in Fauquier and Culpeper counties 
comprises a sedimentary series of rocks of Cambrian age 
(Loudoun) in close association with a pre-Cambrian (Algon- 
kian) series of basie voleaniec rocks (Catoctin schist) and their 
equivalent pyroclastics (tuffs). The sedimentary series (Lou- 
doun formation) includes coarse arkoses, sandstones, quartzites, 


* Pre-Cambrian Geology of North America; Bull. No. 360, U.S. Geol. 
Survey, 1909, p. 675. + Ibid., p. 694. 


36 Watson and Powell—Age of Virginia Piedmont Slates. 


schists, conglomerates, and slates. No fossils have been found 
in the sedimentary rocks of this area, but their correlation with 
the Loudoun is conclusive, although the evidence cannot be 
presented here. ; 

The Keswick—Esmont slate area in Albemarle County in- 
cludes in its northern portion the following succession of rocks 
extending eastward from Charlottesville: Monticello schist 
(Catoctin schist of Keith), derived chiefly from a basic voleanie 
rock, basalt, of Algonkian age, followed by a series of sedi- 
mentary beds of fine and coarse conglomerate, sandstone, slates, 


LEGEND 


| Granites and Sneisses chiefly 
Probably pre-Cambrian 


Quantico slates 
Ordovician 


LM 


| Coastal Plain formations 
Cretaceous and Tertiary 


AT 


7 
| 
| 


apeene 


() ‘ 2 3 MILES — 


~— 


hin 


Fie, 2. Geologic map of northeastern Virginia, showing the northern - 
half of the Quantico slate belt. 


and limestones of Cambrian age. No fossils have been found 
in these beds, but the evidence strongly favors their being Cam- 
brian in age, and they have been so mapped and described.* 


Quantico Slate Belt. 


The Quantico slate belt is so named from Quantico Creek in 
the southern part of Prince William County. It has been 
traced as a narrow belt averaging about one mile in thickness 


*Lambeth, W. A. Notes on the Geology of the Monticello Area, Virginia. 
A Thesis, University of Virginia, June, 1901. 


Watson and Powell—Age of Virginia Piedmont Slates. 37 


for a distance of 40 miles, extending in a southwest direction 
from Lorton, Prince William County, where it passes beneath 
the Coastal Plain formations, to Shady Grove, Spottsylvania 
County, five miles south of the Orange and Fredericksburg 
railroad. It lies partly in the three following counties: Prince 
William, Stafford, and Spottsylvania. The slates have not 
been traced continuously on the surface between the extreme 
limits given above, because of their concealment beneath the 
Coastal Plain sediments in the northern half of the belt, but 
they have been recognized in every section measured along the 
streams which cross from the crystalline rocks of the Piedmont 
onto the Coastal Plain sediments (map, fig. 2). The principal 
streams have carved narrow canyon-like gorges in the crystalline 
rocks of the northeastern Virginia Piedmont region, and they 
usually afford excellent exposures along their courses. North 
of Accakeek Creek the slates are concealed on the interstream 
areas by the Coastal Plain cover (inap, fig. 2). 

The slate belt varies from less than one mile to about 2 niles 
in width, with a probable average of about one mile. It isa 
part of the crystalline rocks of the Piedmont region, and north- 
eastward from Accakeek Creek, Stafford County, it is the east- 
ernmost representative of the Piedmont crystallines. This 
part of the belt is bordered on the west by gneisses and gran- 
ites, and on the east it is concealed beneath the cover of Coastal 
Plain sediments. Southwestward from Accakeek Creek the 
gneisses and granites are the limiting rocks on the east and 
west sides of the belt. 

Structurally the slates show considerable variation in places 
both in dip andstrike. With but few exceptions the dip is 
to the northwest, usually from 70° to vertical (see fig. 4); and 
the strike ranges from N. 20° E. to N. 60° E. The strike and 
dip are given below for the sections measured. They are: 


Name of Section. Strike. Dip. Remarks. 
Occoquan Creek N. 40°—45° EK. 70° N.W. to vertical. 
Maruinsco Creek WN. 35°—42° EK. Nearly vertical. Variable. 
Powells Creek INS 207 Ee: 50°-70° N.W. to vertical. 
Quantico Creek N. 30°-—35° K. 175° N.W. to vertical. 
Aquia Creek N. 25°-40° KE. 70° N.W. to‘vertical. 
Austin Run N. 30° —45° E. 80° N.W. to vertical. Variable. 
Accakeek Creek N. 38°-—6v° E. 80° N.W. to vertical. 
Potomac Creek N. 50° E. 35°—59° N.W. 
Wilderness, one 

mile west IN: 202K. Nearly vertical. 

Brock Station N. 38° E. Vertical. 


Shady Grove IN. 25° Hi. Vertical. 


38 Watson and Powell-—Age of Virginia Piedmont Slates. 


In several sections, especially those of Occoquan and Quantico 
creeks, occasional steep southeasterly dips are observed. The 
general structure of the rocks suggests a series of closely com- 
pressed folds, probably of the isoclinal type. 


The slates are not lithologically alike for the entire thickness - 


of the belt in any section measured, but a variety of types 


Fie. 3. 


Fic. 3. Alternating light- and dark-gray slates, about 34 mile S.E. of 
Occoquan village, on Occoquan Creek, The position of the slates is ver- 
tical. Some beds are tufaceous. 


Fie. 4. 


Fic. 4. Alternating light- and dark-gray slates, partly tufaceous, show- 
ing a steep dip to the southeast. About 14 mile 8.E. of Occoquan village, 
on Occoquan Creek. 


——— = 


Watson and Powell—Age of Virginia Piedmont Slates. 39 


occur, grading one into the other. The belt comprises a prob- 
able average thickness of about one mile of alternating beds of 
gray to dark gray and black slates, with beds of green and ma- 
roon slates shown in some sections. Slaty cleavage is promi- 
nently developed in all the rocks of the belt. Variation is from 
dense, homogeneous, black graphitic slates of exceeding fine 
texture, having smooth cleavage surfaces, to rocks of fine gran- 
ular texture having more or less curved or crumpled cleavage 
surfaces, and closely resembling phyllites. 


Fie. 5. 


Fie. 5. Granite falls in Occoquan Creek immediately west of Occoquan 
village, and about 14 mile west of granite-slate contact. 


The black graphitic slates near Dumfries in the Quantico 
section are reported to contain on analysis 3 per cent of graph- 
ite. These slates have been exploited for graphite in the 
Quantico Creek and Potomac Oreek sections. In the Potomac 
Creek section the slates are considerably puckered and twisted. 

The tufaceous character of a part of the beds for a consider- 
able thickness of many of the sections is apparent to the naked 
eye. Beds of tufaceous character associated with the slates of 
the Arvonia district, further southwestward in Buckingham and 
Fluvanna counties, are even more conspicuously developed in 
places than in some sections of the Quantico belt. 

The slates proper usually grade northwestward into true 
phyllites and schists, and are in contact with granites and 
gneisses which are in part at least of pre-Cambrian age. More 
or less pyrite in small and large crystals and in shapeless grains 
is disseminated through the slates, and frequently forms thin 


40 Watson and Powell—Age of Virginia Piedmont Slates. 


Fia. 6. 


East 


West 


o 
Cc 
_ ig} 
N 
i) 
n 
le} 
res 


from old telegraph road northwestward about one 


, dense-textured, altered rhyolite ; c, Coastal Plain sediments. 


~ 


Geologie section along Powells Creek, Prince William County, Virginia 


a, dark gray to black graphitic slates ; b, light-colored 


films or veinlets in the cleavage. Ina 
number of places the pyrite in the 
slates is sufficiently concentrated to 
encourage mining. Much quartz is 
present in the slates in places, occur- 
ring chiefly as eyes and _ stringers, 
sometimes as veins, which may coin- 
cide in direction with that of cleavage 
or may cut across it. 

In several of the measured sections, 
Marumsco and Powells creeks in the 
Quantico slate belt, and south of James 
River in the Arvonia slate belt, a light 
gray, hard and dense-textured rock, 
which has been identified microscop- 
ically as an altered (metamorphosed) 
rhyolite, occurs interbedded with the 
slates (fig. 6). Thin sections of the 
rock show the following minerals: 
Quartz, sericite, biotite, chlorite, mag- 
netite, tourmaline, apatite, zircon, and 
yellow glass. The exact thickness of 
this rock in the Quantico belt could 
not be ascertained because of lack of 
exposures, but in the Arvonia belt it 
is about 18 feet. It is strikingly uni- 
form in lithology at every point ob- 
served. Except for small parallel 
elongated yellow specks and areas, 
which are identified as feldspathic (?) 
glass under the microscope, the fresh 
rock appears more massive than schis- 
tose, but partially weathered speci- 
mens of the rock invariably show 
pronounced schistosity. The longer 
axis of the yellow glass areas and the 
direction of schistosity are oriented in 
the same plane. 

Occasional dikes of both basic and 
acid igneous rocks are intruded in the 
slates, as observed in the Occoquan 
and Quantico creeks sections (tig. 7). 

Fossils.— During the summer of 
1909, while studying the Powells 
Creek section, 3 miles north of Dum- 
fries in Prince William County, the 
junior author found fossils in the 
smooth black graphitic slates, exposed 


Watson and Powell—Age of Virginia Piedmont Slates. 41 


Bre. 7. 


Fie. 7. Dike of igneous rock intruding slates parallel to the cleavage, 
_ west of Dumfries on Quantico Creek. 


Fic, 8. 


Fic. 8. Granite-gneiss exposed in Austin Run near contact of the slates 
on the northwest. 


42 Watson and Powell—Age of Virginia Piedmont Slates. 


in a steep bluff on the south side of the stream one mile west 
of the old telegraph road (figs. 2 and 6). Figure 6 is a section 
along Powells Creek, in which the position of the fossiliferous 
beds is designated. 

The specimens of slate containing organic remains collected 
from this locality were submitted to Dr. R. 8. Bassler, of the 
U. 8S. National Museum, for identification, who kindly fur- 
nished the following statement regarding them: “ The slates 
from northeastern Virginia contain numerous examples of a 
fairly well preserved pelecypod, closely related to the Cinein- 
natian forms of Pterinea, such as ?. demissa Conrad. Asso- 
ciated with these are very imperfect remains of what may have 
been a linguloid shell, possibly a Pholidops or Leptobolus. 
The horizon is certainly Cincinnatian and most probably mid- 
dle Cincinnatian.” 

It is a little disappointing not to have found definite evi- 
dence of the same species in the two slate areas (Quantico and 
Arvonia), and it is not improbable that more diligent search 
for fossils in the Quantico belt will be rewarded. It was 
thought at first that there was one species in common to the 
two areas, but after an examination of the U. S. National 
Museum collections from Arvonia, Bassler decided that the 
Arvonia species was not well enough defined for the most aceu- 
rate determination. Concerning the correlation of the two 
areas on the basis of organic remains, Bassler says: “Although 
the present collections from the slates at Arvonia and from 
northeastern Virginia (Quantico slate belt) show no fossils in 
common, it appears most probable that the fossiliferous portion 
of each is of approximately the same age, indeed that the two 
slate belts themselves are synchronous.” 

The authors made a brief visit to the same locality during 
the past summer, but the conditions were such that no deter- 
minable organisms different from those collected in 1909 were 
found. : 

The same fossiliferous beds were exposed in a recent open- 
ing for pyrite near Marumsco Oreek, 3 miles north of Powells 
Creek. Fossils were likewise noted here, chiefly replaced by 
pyrite, but the material was so disintegrated from weathering 
that no collections preserving them could be made. 

The resemblance of the Quantico slates to the roofing slates 
of the Arvonia district on James River was noted by Darton 
as early as 1894,* but fossils had been found at that time only 
in the latter district (Arvonia). The two belts are aligned in 
the same direction of strike, similar lithologice types and asso- 
ciations are observed, and the metamorphic and structural rela- 


*Fredericksburg Folio, No. 13, U. S. Geol. Survey, 1884. 


Watson and Powell—Age of Virginia Piedmont Slates. 43 


tions of the slates are the same. Moreover, the slates in the 
two belts are alike in composition in being both graphitic and 
maenetitic. 

There is in Louisa County and a part of Spottsylvania an 
area between the two belts, representing a distance of about 35 
miles in direction of strike, in which the very dark gray to 
black graphitic slates have not been observed. °While the true 
slates of this lithologic type have not been found in the small 
area between the two belts, the phyllites and schists, into which 
the slates of the Quantico belt grade, are traced continuously 
from the Quantico belt to the Arvonia belt, without change 
of structural relations indicated. It seems most likely there- 
fore that the basin in which terrigenous and pyroclastic sedi- 
ments were deposited during Or dovician times was a continuous 
one, and, so far as traced in Virginia, extended from the south- 
ern part ‘of Buckingham County i in a northeasterly direction to 
within 10 miles southeast of Alexandria, where the rocks pass 
beneath the Coastal Plain sediments of Cretaceous and Ter- 
tlary age. 

The slates of these two belts, Quantico and Arvonia, in which 
upper Ordovician fossils have been found, represent the east- 
ernmost extension in Virginia of sedimentation during Ordo- 
vician time. West of the Blue Ridge the extensive areas of 
Martinsburg shale were laid down about the same time and 
are regarded as the probable equivalent of the Piedmont slates 
of the Quantico and Arvonia belts. Differential metamorph- 
ism has emphasized a fundamental difference in the eastern 
Piedmont slates and their equivalent Martinsburg shale, west 
of the Blue Ridge. 


Arvonia Slate Belt. 


In 1892,* Mr. N. H. Darton announced the discovery of 
organic remains in the roofing slate at Arvonia, Buckingham 
County, Virginia. The slabs collected by Mr. Darton were 
submitted to Dr. Walcott, who made the following statement 
regarding them :} “I have studied the specimens of slate show- 
ing crinoidal remains and come to the conclusion that they 
belong to the Trenton—Lorraine or upper portion of the Ordo- 
vician fauna. One of the large columns is closely allied to 
Schizocrinus nodosus, and some of the heads, although indis- 
tinct, approach closely to Heterocrinus and Poterocrinus. If 
these suggestions are correct, the slates are to be correlated 
with Lorraine or Hudson series and in the same horizon with 
the Peach Bottom slates of Pennsylvania.” 


* Darton, N. H. Fossils in the ‘‘Archean” Rocks of Central Piedmont, 
Virginia. This Journal, vol. xliv, pp. 50, 52. {Ibid., p. 52. 


44 Watson and Powetll—Age of Virginia Piedmont Slates. 


Doctor R.S. Bassler furnishes the following statement of 
the fossils from the slates at Arvonia in the collections of the 
U.S. National Museum: “The collections of the U.S. National 
Museum contain twelve species of fossils from the slates at 
Aryonia, Buckingham Oounty, Virginia. These.are from the 
same horizon as the crinoid remains which resulted in Dr. Wal- 
cott referring the strata to either the Trenton or Hudson (Cin- 
cinnatian). The additional species make up an assemblage of 
forms which seems to be of middle Cincinnatian age. Most of 
the fossils are so distorted that their specific identification is 
necessarily uncertain. Many of the Lafinesquinas, for exam- 
ple, have a diameter of six inches, although the original shells 
were undoubtedly not more than two inches wide. The three 
species of echinoderms are numerously represented, a fact 
which is most unusual for Ordovician faunas. Indeed, if this 
fauna could be found well preserved, the general association of 
species would probably be very different from that of any Ordo- 
vician strata west of the Blue Ridge.” The list follows: 


Cyclocystoides sp. (one-third to one-half inch in 
Me and with twelve to fourteen plates). 
‘otaster ? sp. 
lyptocrinus cfr. decadactylus. - 
Ya alymene callicephala. 
Trail resembling A saphoidichnus. 
\afinesquina alternata (cfr. var. ponderosa). 
lectorthis cfr. plicatella. 
“a otelus cfr. gigas. 
Tentaculites sp. 
Buthotrephis cfr. gracilis. 
Buthotrephis cfr. succulens. 
An indeterminable ramose bryozoan. 


Five drawings of crinoids from these slates are reproduced 
by Darton in the paper published in 1892.* 

There are several specimens of a trilobite Calymene callice- 
phala (Green) and an indeterminable crinoid, probably Protas- 
ter n. sp., in the collections of the University of Virginia, made 
by the senior author from the slates at Arvonia. 


Brooks Museum, University of Virginia, October 18, 1910. 


*This Journal, vol. xliv, p. 51. 


Graham—Nuative Gold from Gold Harbour. 45, 


Art. V.— Native Gold From Gold Harbour, Queen 
Charlotte Islands; by R. P. D. Granam, Lecturer in 
Mineralogy, McGill University. 


A BEAUTIFUL example of the crystallization of native gold 
has recently been presented to the MeGill University Museum 
by Wm. Fleet Robertson, Esq., the Provincial Mineralogist of 
British Columbia, and on account of the comparative rarity of 
sharply defined crystals of this mineral it was thought that the 
occurrence merited a short note. The specimen is additionally 
interesting owing to the fact that it comes from Gold Harbour 
on Moresby Island, one of the Queen Charlotte Islands, which 


locality, as Mr. Robertson informs me, was the scene of the 
very first gold excitement in British Columbia. 

The gold, in the specimen examined, occurs as a cluster of 
erystals attached to colorless crystals of quartz, which also 
enclose specks of gold. With one exception the crystals are 
quite small, having a diameter of about 1”, but the remaining 
erystal stands out very prominently on the specimen and meas- 
ures 4X3™", the elongation being along a trigonal axis ; all are 
remarkably brilliant, and, both in luster and in the sharpness 
of their edges, they compare with even the brightest crystals of 
pyrite, from which mineral, however, they can at once be dis- 
tinguished by the characteristic golden yellow color. 


46 Graham—Nuative Gold from Gold Harbour. 


The form exhibited by the crystals is not at first sight obvi- 
ous; the most striking feature of the habit is the arrangement 
of a number of almost square, four-faced pyramids, which lie 
very nearly, though not quite, in zones encircling the crystal. 
Parallel to the bases of these the faces are heavily striated, and 
in a great many cases there is a step-like structure; the occur- 
rence of the accompanying reéntrant angles at the "junction of 
neighboring pyramids causes these to stand out from one 
another more prominently, and is largely responsible for the 
pronounced “ pyramidal” appearance. 

From an inspection of the striae it is easily possible to locate 
the various axes of symmetry and orientate the crystals; meas- 
urement of the large crystal on the telescope goniometer showed 
it to possess all the faces of the six-faced octahedron {421}, 
uncombined with any other form. ~The smaller crystals were 
not measured, but they are similar, so far as can be seen with- 

out removing ‘them from the specimen ; one was noticed which 
bore small faces of the dodecahedron, replacing the summits 
of the ‘‘four-faced pyramids” referred ‘to above, and also of the 
eube. The general habit of the crystals is shown in the figure. 

From the nature and distribution of the reéntrant angles, it 
was at first thought that the crystals might possibly be twinned, 
in which case they would have to be regarded as supplement. 
ary twins of some hemihedral form, such as the. pentagonal 
icositetrahedron. As is well known, the holohedral symmetry 
of gold has been called in question by Helmhacker* and K. 
Martin,t who have described apparently tetrahedral forms of 
this substance: but, apart from this, it has been found that the 
erystals, however much distorted and misshapen, can always 
be referred to some form or combination of the holohedral class 
of the cubic system, and this is generally accepted as being the 
true symmetry of gold. 

Although the evidence furnished by the reéntrant angles 
in the present erystals is suggestive, it is not, in itself, strong 
enough to warrant the assumption that they are hemihedral 
and twinned. Prof. E. 8. Dana has very kindly examined the 
specimen, and is of opinion that the striz and reéntrant angles 
are best to be regarded as the result, only, of an oscillatory 
repetition of the faces of the normal six-faced octahedron. 

The specimen was collected by Mr. John McLennan, A.R.8.M., 
‘of Skidegate, from a quartz vein on his claim at, Gold Harbour, 
and Mr. Robertson has kindly furnished the following partie. 
ulars of the occurrence of gold in this neighborhood (see his 
Report for 1909, p. 76). 

Gold (or Mitchell) Harbour is situated on the west coast of 


*Tscherm. Min, Mitth., 1877, 1. 
+ Groth’s Zeitschr., xxix, 278. 


, ee 


Graham—WNative Gold from Gold Harbour. 47 


Moresby Island, which is the more southerly of the two prin- 
cipal members of the Queen Charlotte Islands. The discovery 
of gold in this locality would appear to have been originally 
made by Indians, since it was their possession of pieces of this 
metal that excited the curiosity of the Hudson Bay Company’s 
traders, who induced the Indians to disclose the source ; and 
this led to the prospecting expedition under the auspices of the 
H. B. Co. in 1852. Varying accounts have been given of the 
results of this expedition, but Major Wm. Downie, who exam- 
ined the spot seven years later, states that he could not tind 
anything worth working. 

Since that date prospectors have been attracted to the vicinity 
at various times, and in 1906 McLennan discovered a new vein 
within about one hundred yards of the original H. B. Co.’s 
mine. 

Mr. Robertson, who paid a visit to this locality in 1909, states 
in regard to the H. B. Co.’s mine, that “a trap dyke was found 
eutting through a diabase country rock in a N. 45° W. direc- 
tion, with a nearly vertical dip. Following alongside the dyke 
is a erushed zone about 2 feet in width in which occurs a small 
vein of quartz, from one to four inches wide, somewhat irree- 
ular but quite persistent.” The McLennan vein is similar, and 
being inclined to the other would intersect it under the harbour ; 
both carry free gold in the form of small specks. A consider- 
able amount of development work has recently been carried 
out on the property, and a stamp mill is now being erected for 
the treatment of the ore. 


Geological Department, McGill University, 
Montreal, Canada. 


48 W. 7. Schaller—Natrambiygonite, a New Mineral. 


Arr. VI.—WNatramblygonite, a New Mineral; by 
Watpemar T. ScHaier. 


NATRAMBLYGONITE is, as the name indicates, a:soda ambly- 
gonite, or a hydroflno-phosphate of alumina and soda, with the 
soda in part replaced by lithia. 

Occurrence.—The new mineral described in this paper was 
collected by me in 1908 in a large pegmatite mass four miles 
northwest of Canon City, Colorado. ‘The presence of lithia 
minerals—lepidolite and pink tourmaline—had been noted in 
this pegmatite by Sterrett,* and it is owing to his favor and 
kindness, as well as to that of Mr. J. D. Endicott of Canon 
City that I was enabled to visit the locality and collect a suite 
of specimens from the pegmatite. As described by Sterreté, 
the occurrence of the tourmaline and associated minerals is on 
alow oval hill composed of pegmatite inclosed in contorted 
biotite and hornblende gneiss. Pink tourmaline and lepido- 
lite are abundant though no cavities or pockets affording gem 
tourmaline were seen, the mineral being found only in “the 
solid pegmatite. 

A ssociation.—The minerals associated with natramblygonite 
are few in number and do not possess any unusual properties. 
Tourmaline is abundant in black, pink or green erystals 
though no faces except those in the prism zone were seen on 
any of the erystals collected. A dark green, nearly black core 
with a pink shell seems to be a common color association for 
this locality. Small masses of minute bluish crystals and some 
larger green ones imbedded in muscovite were also noted. 
Most of the tourmaline is opaque and partly altered. The 
micas, muscovite and lepidolite, are also abundant. Lepidolite 
occurs in scaly pink masses, also as larger plates and in indefi- 
nite crystalline aggregates of pink or purplish colors. Albite 
generally is tabular in platy masses or in groupings of small 
crystals. The quartz and potash feldspars are massive and 
the single piece of natramblygonite found is also massive. 

Deser “uption of new mineral.—The specimen of the new 
mineral measures about 7*538°™8 and consists of a mass of 
cleavable natramblygonite surrounded by feldspar and lepido- 
lite. Small veins and isolated masses of lepidolite are found 
scattered through the new mineral. Small amounts of pink 
tourmaline and of albite were also detected imbedded therein. 

Three directions of cleavage can be detected, one more 
prominent than the other two. A section of the mineral cut 
_ parallel to the most prominent cleavage showed the other two 


* Sterrett, D. B. te Production of Precious Stones in 1908; Mineral 
Resources 1908, U.S. Geol. Survey, 1909, p. 44. 


—— 


W. 7. Schaller—Natramblygonite, a New Mineral. 49 


cleavages intersecting at about 70°. In its general appearance 
the mineral very much resembles massive amblygonite. The 
hardness is 5°5 and the specific gravity lies between 3:01 and 
3°06 with an average value of about 3°04. The luster is vitre- 
ous inclining slightly to greasy. The color is greyish white 
to white. In the hand specimen, it is translucent to opaque. 

Examined in thin section under the microscope, inclusions 
of quartz, feldspar and mica were seen and also an irregular 
distribution of a kaolin-like dust. Two directions of polysyn- 
thetic twinning lamellee intersecting at about 86° are promi- 
nent and lie at an angle against the cleavage cracks. The 
best cleavage is nearly normal to a bisectrix, and the section 
parallel to ‘this cleavage shows a biaxial interference figure 
with a large angle. Its sign is negative. 

Heated in a blowpipe flame, the mineral easily fuses, with- 
out decrepitation but with slight intumescence, to an opaque 
white enamel. The flame is colored yellow with no indication 
of red, due to lithium. In this particular, natramblygonite 
differs markedly from amblygonite and can thereby be distin- 
guished from the common mineral. It would be well to test 
amblygonite from different localities by this flame test. 
Heated in a closed tube, water is given off and the mineral 
then quietly fuses without decrepitation to a blebby enamel 
firmly fused onto the glass tube. 

Chemical composition.—Analysis of a selected sample of 
natramblygonite gave the values shown below. The sample 
was finely crushed and all visible impurities and doubtful look- 
ing pieces picked out by hand under a magnifying glass. The 
final sample all sank in Thoulet solution of density 301+ and 
all floated in solution of density 3:06. Beryllium was tested 
for but could not be detected. The mineral is difficultly solu- 
ble in H,SO,, in which solution no calcium could be found. 


Analysis and ratios of natramblygonite. 


dP Ot oe aaa ne a 44°35 "312 1:00 
EO ete as 33°59 "3.29 1:06 
Owe ee 3-21 107 
INSLO ute eo fe 11-23 Tet) 2898 | 298 
EON A aN S 14 ‘001 
ROP aaa ee 2b c4ei78 266 CBee: 
1) (a UC ees a 5°63 296 ATE, { 
¥ 
102-93 
hess Omion: Hye ss 22 2:37 
100°56 


Am, JOUR. ooh eee SERIES, VoL. XX XI, No. 181.—January, 1911. 


50 = W. 2. Schaller—Natramblygonite, a New Mineral. 


The ratios yield the formula P,O,.A1,0,.(Na,Li),O.(H,0,F,), 
which may be written more simply AlNa(OH)PO,, ‘with the 
Na partly replaced by Li and the (OH) by F. The ‘ratios for 
water and fluorine are a little high, but this is probably to be 
ascribed to the difficulty of the fluorine determination. It is 
worthy of note, however, that the ratios for water and fluorine 
are also all high in Penfield’s analyses of amblygonite.* The 
relations of natr amblygonite to amblygonite are clear, the first 
being essentially the soda mineral and the second the lithia 
one. 

Natramblygonite, Na[Al(OH,F)]PO,. 

Amblygonite, Li[ Al(OH, F)]PO,. 
Nothing was seen which would indicate that the new mineral 
here described was originally the lithium compound which 
was afterwards changed to the sodium one. The alteration of 
ambly gonite,. described by Carnot and Lacroix+, yielded the 
mineral morinite which contains lime and soda without any 
lithia and much more water and fluorine than was present in 
the amblygonite. 


Chemical Laboratory, 
U.S. Geological Survey. 


* Penfield, S. L. On the Chemical Composition of Amblygonite; this 
Journal, 3d ser., vol. xviii, pp. 295, 1879. 

+ Carnot, A., and Lacroix, A. The Chemical Composition of Morinite ; 
Bull. Soc. franc. mineral, vol. xxxi, 1908, p. 149. 


Trowbridge—New Emission Theory of Light. 51 


Arr. VII.—A New Emission Theory of Light; by Jonn 


TROWBRIDGE. 


Ir is interesting to imagine how Sir Isaac Newton would 
have rehabilitated his cor puseular Theory of Light if the Elec- 
tron Theory had been enunciated during his lifetime. Might 
he not have answered the objection to his theory that light 
travels slower in fluids than in air by the assumption that the 
infinitely small electrons could pass between the atoms of the 
fiuid and in so doing give up a portion of their energy to these 
atoms by setting them in vibration, thus producing absorp- 
tion spectra which arise in all fluids on the transmission of 
light. Might he not, also, if the vortex theory of motion had 
engaged the attention of the mathematicians of his time, have 
provided his corpuscles with a whirling or vortical motion ? 
In the periodic motion of the negative electron along a helical 
path, he could have supposed an “apparent wave motion ; and 
in the repulsion of neighboring vortices perhaps he could have 
abolished the conception of an elastic ether. 

In thus imagining a new light dawning upon a mind which 
was capable of penetrating oreat secrets of the universe, I am 
emboldened to offer a hypothesis which may serve to lead us 
back to an emission theory of light, and at the same time 
enable us to relegate the ether to the phlogiston, the caloric, 
and the two fluid theories of electricity. 

In the rough this theory supposes that negative electrons are 
shot forth from the sun’ in helical vortices, and in their pro- 
gression provide an apparent periodic wave motion, giving, 
according to Maxwell’s Electrodynamic Theory of Light, a 
pressure in the line of propagation and a tension at right 

angles to this line. A magnetic effect is a plane at right angles 
to the electrostatic effect, a repulsion between neighboring 
vortices which would simulate the supposed elasticity of an 
ether. The circular helices might become elliptical helices in 
passing through doubly refracting substances, and interference 
of light could be provided for. In support of this theory it 
may be urged that vortical motion ds as common as rectilinear 
motion. The observer of the sun’s surface is as conscious of 
vortex motion in the sun’s spots as of the rectilinear uprush in 
the protuberances. The atomic theories are being recast to 
embrace the effect of supposed vortical motions. Speculation 
has gone so far as to suppose that atoms are mere whirls in a 
supposititious ether. A recent distinguished physicist has sup- 
posed that the negative electron is not matter and is provided 
with a vortex tail or tails to account for electrical lines of force. 
In this hypothesis, we appear to have two intangible essences 


52 Trowbridge—New Emission Theory of Light. 


tied together. Can we blame the metaphysicians for smiling, 
and saying “ You physicists are coming into our ranks” But 
are we not supplanting the hypothesis. of a fluid which fills all 
space, a fluid which is thinner than any gas, 4 something which 
has no resemblance to anything of which we have cognizance 
and which is more elastic than steel, by another fantastic 
hypothesis? We have, however, g riven up the fluid theories 
in electricity and instead of media we have motions of elec- 
trons. Light is an electro- -dynamie phenomenon, and the 
hypothesis I frame extends the motion of electrons from the 
confines of electrical circuits to the extent of space. : 

I have said that we have abandoned the fluid theories of 
electricity. This is true of the two fluid theories; but we see 
some merits still in Benjamin Franklin’s one fluid theory, in 
the light of the electron theory. Franklin accounted for 
attraction and repulsion by an excess or diminution of a fluid. 
His theory could become an electron theory if instead of an 
excess or deficit of a fluid we read excess or deficit of negative 
electrons. The attachment or detachment of the negative 
electrons explain in a plausible manner the fundamental 
experiment of the attraction or repulsion of electrified pith- 
balls. Can we extend the moditied Franklin theory to account 
for magnetism and diamagnetism? We should be able to do 
this, for as Maxwell remarks: “ Every phenomenon in electro- 
statics has its analogy in magnetism.” 

To answer this question I am led to the subject of canal 
rays, which has greatly interested me;* for in this phenome- 
non we are brought into close consideration of what is perhaps 
the most important question in the theory of electricity: 
“ W hat is positive electricity ‘” 

The negative electron has been identified in the discharge 
from the negative cathode in Geissler tubes and the positive 
rays proceeding from orifices in the cathode—the so-called 
canal rays—are supposed to be a phenomenon of the positive 
electrons. To account for the positive rays we have a multi- 
tude of theories of combination and neutralization of single 
entities and doublets. From the cathode in a Geissler tube, at a 
suitable exhaustion, proceed negative electrons from every ‘anit 
of surface both toward the positive terminal of the tube and 
toward or into the region where the canal rays manitest them- 
selves, that is away from the positive terminal and back of the 
cathode. The canal rays appear to emanate from the canals 
or perforations in the cathode, and also proceed in both direc- 
tions, one toward the positive terminal and the other in the 
direction away from the terminal. 


*Proc. Am. Acad., xlv, No. 19. Ibid., xliii, No. 20, 


eel 


Trowbridge—New Emission Theory of Light. 58 


We find that the negative electrons exhibit the greatest 
penetrating and impulsive effects. They are extraordinarily 
sensitive to a magnetic field; whereas, the positive rays are 
comparatively insensitive and require a strong magnetic field 
to affect them, which is in the opposite direction to that taken 
by the cathode rays or streams of negative electrons. 

If we adopt Franklin’s hypothesis of excess and ceticit and 
make the assumption that all space is filled with negative 
electrons, which pass through matter, modifying atomic move- 
ments, we might suppose that the positive discharge in a 
Geissler tube is due to an effort of the electrons of space to re- 
establish an electrical equilibrium disturbed by chemical action 
of a battery or the motion of a dynamo. This disturbance 
appears to be shown in more Protean ways at the cathode than 
at the anode. The stream of negative electrons in passing 
through the glass of the Geissler tube communicate some of 
their energy to the atoms of the rarified gas, aiding perhaps 
the cathode electrons in driving the atoms in both directions 
from the perforations in the cathode, thus causing the Doppler 
effect, and transforming their ultra-violet radiations into longer 
wave lengths, and the diminished velocity of the wave lengths 
of the visible spectrum. The positive column of the discharge 
in Geissler tubes may also be regarded as the effect on the 
atoms of the gas of the electrons. entering from outer space to 
reéstablish the electrical equilibrium, disturbed by the agency 
which produced the electric discharge in the tube. 

But how shall we explain the effect of a magnetic field on 
the positive rays? The electrons of the cathode do not appear 
to affect the canal rays, although the directions of both the 
retrograde canal rays and the direct canal rays coincide with 
the directions of the cathode rays from the two surfaces of the 
cathode. Experimenters have always been careful to drive the 
cathode rays out of the field before applying a magnetic field to 
the positive rays. Is it not possible, however, that negative elec- 
trons can be so entangled among the atoms of the gas that the 
effect of a magnetic field on the motion of these atoms and the 
effect on the electrons of the environment which come from outer 
space, and not from the local electrical disturbance, might pro- 
duce a deflection of the atoms in a direction opposite from that 
taken by the cathode rays? We appear to have an analogy in 
magnetism and dia-magnetism. We can suppose that the mag- 
netic metals afford a greater receptivity to the vortical motion 
of the negative electron of space than the non-magnetic metals, 
or that the energy of the electrons is less consumed in iron than 
in copper. The strong magnetic effect necessary to produce 
an apparent effect in deflecting non-magnetic metals may be 


Or 


4 Trowbridge—New Emission Theory of Light. 


regarded, asin the case of the canal rays, of a balance between 
the effect on the atomic motions and the effect on the environ- 
ment. The difference of phosphorescent effect of cathode and 
positive* rays is mainly a question of energy and not a differ- 
ence in kind. 7 

As I have previously remarked, our experiments on electrons 
in Geissler tubes are conducted in an environment filled, on my 
hypothesis, with electrons. The magnetism of the field is also 
an exhibition of a certain selectivity of path of the electrons 
of outer space. 

If the sun is constantly throwing forth negative electrons, it 
is, according to Franklin’s hypothesis, being ‘positively charged 
every instant, and recharged, perhaps from the electrons of 
outer space. Every flame throws off negative electrons and is 
constantly being reduced to a positive state. Perhaps in this 
interchange we can trace the intermittent action, amounting to 
billows of pulses, of the waves of light. If we examine the 
tendencies of Physical Science from the time of Sir Isaac 
Newton, we see a tendency to abandon intangible media and 
to base all phenomena upon the motion ot matter. Indeed, I 
am tempted to paraphrase Tyndall’s much-quoted remark, that 
we may be led to discern ‘‘in matter the promise and potency 
of all terrestrial life’ + by substituting motion and matter for 
“in matter.” It has become a serious question, how the phys- 
icist, in entertaining a belief in an intangible ether, the whirls 
of which constitute matter,—a belief that electricity is another 
intangible something not matter, in an electron which is an 
essence with an essential tail tied to it by a knot of something 
thinner than any gas,—can escape being welcomed into the 
ranks of the metaphysician and philosopher. To escape this 
suppression of his identity, E believe the physicist must reso- 
lutely cling to a belief in both motion and matter. 


*TIt may be suggested that the effect of magnetic fields on non-magnetic 
metals is feebler than that on the positive rays. An atom of gas, however, 
has a finer suspension than any we can accomplish in the case of a metallic 
filament. 

+ Belfast address. 


Walther—Origin and Peopling of the Deep Sea. 55 


Art. VIII.—TZhe Origin and Peopling of the Deep Sea; by 
Prof. Dr. Jonannes W ALTHER.* 


Tue ocean covers two-thirds of the earth’s surface. Five 
continents and numberless islands rise out of it and divide the 
ocean into separate parts, but nowhere is there to be found a 
barrier which can permanently prevent the intermingling of 
the waters. The ever-moving and restlessly intermingling sea 
water shows therefore a very marked uniformity in its chemi- 
cal composition. At Pole as at Equator, in the upper surface 
as in the depth of the sea, the salt content amounts to about 
3°5 per cent and the proportion of chloride, sulphate and car- 
bonate remains on an average the same in brackish bays or at 
the mouths of great rivers. 

It is known that the astronomical position of the earth with 
relation to the sun causes marked climatic zones which are 
arranged in almost parallel girdles perpendicular to the earth’s 
axis, and we notice on the mainland a steady decrease of 
organic life the farther we proceed from the warm equatorial 
region toward the cold polar circle. 

The surface of the sea is also girt about with climatic zones, 
which, corresponding to the continental temperature belts, 
reach from one coast to the other. In the equatorial region, 
the water has a warmth of 30° C.; toward the poles its tempera- 
ture sinks, and since salt water first freezes at —2°5° C., the 
polar shores are laved by very cold water. One would then 
believe that hand in hand with this decrease in temperature a 
diminishing of the organic life in the sea would be noted, but 
quite the opposite is the case. In the polar seas, the plankton 
net is filled with a veritable jelly of floating plants and ani- 
mals which serve as food for the numberless fish swarms and 
the giant whales, and if the naturalist has drawn the dragnet 
over the sea bottom, it is filled with a vast multitude of echino- 
derms, mollusks and crabs. 

In order to understand this striking fact, we must keep 
clearly in mind that almost all sea animals belong to cold- 
blooded forms whose own warmth changes as the temperature 
of their surroundings changes. Pecten islandicus thrives as 
well in a sea temperature of zero centigrade as does Pecten 
jacobeus in 10° C., or as the tropical Pecten sanguinolentus 
in the water of the coral seas with a temperature of 25° C. 
Consequently, the absolute degree of temperature is of no influ- 
ence on the richness in forms of the sea fauna. 

We know that the climate of a continent undergoes very 


* Translated from the German (Naturwissenschaftliche Wochenschrift, 1904) 
by Clara Mae LeVene, Peabody Museum, Yale University. 


56 Walther—Ovrigin and Peopling of the Deep Sea. 


noticeable changes in the same geographical latitude if the 
land is raised into mountains. Kilimanjaro lies in the tropical 
zone and still its peak is covered with eternal snow and “polar” 
glaciers. 

Just as the climate of the continent with inereasing topo- 
graphical altitude becomes more like polar climate, so we 
notice in the sea with increasing depth a constant lowering of 
temperature. Even at 120 meters* the daily and yearly fluctu- 
ations of the warmth of the water cease as a rule, and under 
the surface water, with a warmth of 30° C. in the equatorial 
region, we find even at 200 meters a temperature of 12° C.and 
at 1200 meters one of 5° C. From here to the bottom reigns 
an unvarying temperature of zero to 5° C., which in the south- 
ern Atlantic sinks even to —2° C. 

But while on the land the colder regions oceupy only scanty 
space, the contrary condition rules in the sea bottom. For 
even in the equatorial regions, the warm water is restricted to 
very narrow zones parallel to the coasts and the whole expanse 
of the true deep sea bottom is covered with ice-cold water. 
A gigantic but im measurably slow stream of cold south polar 
water flows toward the equatorial region in the depths and 
projects the thermal characteristics of the southern ice seas 
to the deep sea bottom. 

By examination of a world chart, we do not get the correct 
impression of the relation of the sea to the continents, because 
the border region of the continental mass is washed over by 
the sea, and consequently around almost all coasts extends a 
broad shallow-water zone, whose depth very slowly sinks to 
200 to 300 meters. The whole North sea, the Irish sea and 
the ocean for 300 kilometers west of Ireland belong to this 
so-called continental shelf, and not until beyond them ‘does the 
sea bottom sink suddenly to 4000 meters. 

But even if we consider the continental shelf as the sub- 
merged edges of the continents, still half the earth’s surface 
belongs to the area of the deep sea, with an average depth of 
4000 meters and a maximum depth of 8 to 10 kilometers. 
This vast region, embracing half of the globe, is so significant 
in the natural history of the earth to- day that one can well 
understand the important role it has also played in the geo- 
logic past. But in order to disceru the past history of the deep 
sea, we must point out still another important characteristie of 
the present deep sea. 

Waves and currents were produced by passing or periodical 
winds and set in motion only the upper water strata. In a 
depth of 1000 meters, even the Gulf Streain is scarcely notice- 
able and farther down all measurable water movements cease. 


* For the sake of simplicity the figures are given in round numbers. 


Walther— Origin and Peopling of the Deep Sea. 57 


Only imperceptibly slow diffusion streams constantly mix the 
waters. 

Just as the sun’s heat can only warm the upper water strata, 
so the sunlight, even in clear water, penetrates only to a 
depth of about 400 meters. Photographie plates which were 
exposed at such a depth at Nice show no influence of light. 
Only the delicate shimmer of phosphorescent animals lights 
the dark abyss. The consumption of carbon dioxide, so 
important for the life of plants, is only possible in sunlight ; 
therefore we need not wonder that the deep sea harbors no 
single plant and that with their absence fail also the plant- 
eating animals. 

To. sum up the characteristics of the abyssal region so far 
noted,—a uniformly low temperature, quiet water of normal 
salinity disturbed by no noticeable movement, no light and no 
plant life: these are the bionomically important characteristics 
of the deep sea. 

These conditions of existence are, moreover, very constant 
over vast areas and cause the world-wide distribution of most 
of the deep-sea dwellers. The fauna of the deep sea is 
undoubtedly poorer than that of the shallower parts of the sea, 
but if we consider that all light-hungry and _ plant-eating 
animals are lacking there as well as all inhabitants of the 
moving and warm sea water, we are still astonished at the 
animal world of the abyss. For each dragnet brings up deep 
sea animals and even the small bottom samples of the sounding 
apparatus have afforded traces of organic life at the maximum 
depth of more than 8000 meters. 

Ten years ago, Sir John Murray gathered the results of the 
earlier deep sea expeditions and thereby showed that 


down to 200 meters about 4200 kinds of bottom- dwelling animals exist 
down to 2000 ‘‘ 600 

at 4000 ce ce 400 “ce ce (a9 “ce oe e 
below 5000 “ce a3 150 ee ee (79 (79 6c (74 


To this must be added the great number of animals floating 
and swimming in the deeper water strata. but, while in 
shallow water a great number of individuals of each species 
are captured in each cast of the net, the deeper strata are rich 
in species, but poor in individuals. A cast of the dragnet in 
1000 meters depth still gave 100 examples of the same ani- 
mal, but in greater depths there were often in a net only 2 
examples each of 10 different species. 

It is difficult to point out a peculiar characteristic of the 
known deep-sea animals without giving a specific description 
of individual forms. but one can safely state that they 
mostly possess very weak structures. Their hard parts are 


58 Walther—Origin and Peopling of the Deep Sea. 


rare or very frail. Some are blind, others distinguished by 
telescopic eyes or wonderful concave mirror-like sight organs. 
Many live on decaying deep sea ooze and have therefore lost 
their organs for the mastication of food, others are robbers 
with strongly developed jaws. Many forms show wonderful 
contrivances for the care of the young, while others seem to 
multiply with extraordinary rapidity ; but almost all are pro- 
vided with phosphorescent light organs which unite with their 
gay, soft radiance, that in some cases can be photographed after 
capture, to transform the dark depths into a magic garden. 

If we inquire into the conditions of existence of this ani- 
mal world so rich in forms, a peculiar problem arises : we know 
that organic life is only maintained by the constant introduc- 
tion of inorganic elements into the cycle of life and that the 
force which in great measure is able to maintain life is the car- 
bon dioxide consumption by the plants. Only when sunlight 
falls on brightly colored plant parts are carbonic acid and 
water separated into their elements and from these the com- 
plex protoplasmic molecule built up. Where sunlight and 
green plants are wanting, there can no new life arise and no 
organic life be maintained. So the animal life in the deep sea 
of to-day could not be maintained if a stream of cold south 
polar water did not pour oxygen and food down into the 
abyssal depths. 

The deep sea resembles, speaking in terms of national ecol- 
ogy, a purely industrial state without agriculture dependent 
for its existence upon lands pursting agriculture and stock- 
raising. Hence it follows as a necessary consequence that 
the fauna of the deep sea cannot have originated there, but 
must have wandered down into the dark depths from the sun- 
lit strata rich in plants. 

‘As soon as we have made clear this indisputable fact, a very 
significant geological problem confronts us. We ask, When 
did the deep sea become peopled? and when did the deep sea 
basin originate ? 

To be able to solve these questions, we must describe in few 
words the character of the sediments of the present deep sea, 
for only by knowing these well is it possible to examine an 
old rock as to the history of its origin. 

All deposits of the coast region and the shallow continental 
shelf had their origin on the mainland of the continental areas. 
The bowlders on the rocky shore, the sand of the dune regions, 
and the blue or green ooze of the shallow sea are either 
washed from the strand by the sea waves or borne into the 
ocean by rivers. The mighty delta masses of the Nile, Ganges 
or Mississippi bear witness to the vast quantities of continental 
muds that are carried into the sea. 


Walther— Origin and Peopling of the Deep Sea. 59 


But the salty sea water has the peculiar property of clarify- 
ing muddy river water in a short time and of precipitating all 
ooze to the bottom. In this way all the river mud is deposited 
in the shallow sea region and no fragment of quartz reaches 
the abyss. 

Sir John Murray, after the completion of the Challenger 
expedition, examined all the known samples of deep-sea bot- 
tom and showed that in these depths sediments of a very pecu- 
liar character exist. The mightiest rdle in their composition 
is played by the floating organisms of the sea. The chalky 
shells of frail Globigerina cement together the main mass of 
the so-called Globigerina ooze, which covers about half of the 
entire deep sea bottom: This cream-yellow when fresh, soft, 
liquid lime-ooze is connected with the continental muds of the 
coast zones by transition stages, and passes, by decrease of its 
chalk content, into the so-called Red Clay of the deep sea, 
which covers about one-fourth of the earth’s surface. To it 
are joined isolated areas which are completely strewn over by 
the delicate microscopic siliceous tests of Radiolaria. The 
Red Clay of the deep sea originates from transformed vol- 
canic ashes and through the solution of organic calcareous 
skeletons. | 

With certain exceptions the above named deep sea sedi- 
ments and other associated deposits of the abyssal regions are 
distinguished by the following characteristics : 

1. They contain neither quartz nor other fragments of 
* continental rocks. 

2. They contain no plant residue which is brown or black 
in color. 

3. They are piled in horizontal layers and are spread over 
marvelous distances. 

4. They contain no remains of shallow sea animals or 
plant-eaters. 

5. By very slow and gradual transitions they are connected 
with the shallow water sediments of another origin. 

The geologic examination of the continental masses has 
given the remarkable result that from the oldest times of earth 
history to the present day almost every part was repeatedly 
sea bottom. The present position and limits of the ocean are 
a transitory appearance, and while it was formerly believed 
that it was possible to measure and gauge the height of the land 
by the fixed level of the sea surface, it has been known for 
twenty-five years that the sea level is variable. Now, if each 
part of the present dry land was one or more times sea bottom, 
we must first ask whether we know deposits in the earth crust 
which by their lithologie and faunal character can be con- 
sidered as formerly sea bottom. 


60 Walther—Ovigin and Peopling of the Deep Sea. 


IT have busied myself much with recent deep sea sediments, 
have studied those of the Challenger expedition, and in my 
geologic studies have considered again and again whether any- 
where a fossil rock possesses abyssal characteristics, and can 
state that nowhere have I met with a rock either from Paleo- 
zoic or Mesozoic deposits that by its structure and nature of 
deposition corresponds to the present sediments of the deep 
sea. Even the radiolarian rocks made known through Dr. 
Riist’s careful studies contain no likeness to the radiolarian 
ooze of the present deep sea. Their coal wealth, the mass of 
terrigenous material, and their stratigraphic connection -with 
undoubted littoral sediments make it impossible to see in them 
the deposits of the deep sea. We are much more reminded 
of the tripoli of Sicily and the oceanographic conditions in the 
straits of Messina. Here rushes upward a mighty stream of cold 
deep sea water, bringing deep sea fishes, crabs and radiolarians 
to the surface of the sea where they, mingled with the dwellers 
of the upper water strata, give rise to the richness of the 
sea fauna here so well known to all zoologists. John Murray 
attained the same result:after he had applied to a number of 
veologists with the request to send him fossil “deep sea rocks.” 
The microscopic examination showed that only on a few small 
islands like Malta, Barbados, and Christmas island occurs true 
Tertiary deep sea ooze, and the local distribution of these 
unmistakably indicates that local upheavals of former deep 
sea bottom formed the nuclei of these islands. Although 
almost the entire areas of the continents of to-day have been 
wholly or partly and repeatedly overflowed by the ocean since 
the Cambrian, yet we know here only such deposits as are now 
forming in the shallow seas or in depths not below 1000 to 
2000 meters. 

Herewith we confirm by geologic proof a view which has 
long been asserted on the ground of theoretical speculations 
and which centers in the statement: the deep sea of to-day has 
been deep sea for a long period and it has not essentially shifted 
its place on the earth’s sphere since its origin. The deep sea 
basins appear to us as the original regions of ocean origin, 
from which the sea periodically transgresses upon the con- 
tinents, only to flow back again into the gigantic gathering- 
reservoir. 

Geologically it can be shown with certainty that former 
continents have been sea bottom. Thus, we find in Devonian 
time on both sides of the Atlantic ocean, in North America 
and Spitzbergen as well as in Scotland and Russia, deposits of 
great fresh-water basins with a very characteristic fish fauna. 
In the Carboniferous as well as in the Jurassic and Oretaceous 
the same land and plant animals lived in North America as in 


_ 


Walther—Origin and Peopling of the Deep Sea. 61 


North Europe. All this points to the conclusion that during 
these long periods an Atlantic land connection existed between 
both continents which to-day is in part deep sea bottom. 
Similar facts force the acceptance of the opinion that the 
present Indian ocean throughout long periods possessed a land 
bridge from Africa to India and Australia. Finally, how can 
we explain the occurrence of entire skeletons of hippopotamus 
and African elephants in very ancient bone caverns at Palermo 
except by the conclusion that Sicily was once joined with 
Africa, althongh now a deep sea exists between the two shores ? 
For a passive transportation of these gigantic animals is not to 
be considered. 

Aside from a few local exceptions where deep sea bottom 
has again become land, there are numerous cases in all parts 
of the earth where we can show that great portions of the 
firm earth crust through sinking have become changed into 
sea bottom. In other words, the deep sea has grown at the 
expense of the shallow sea and the mainland. 

The great interest of geologists in the investigation of the 
deep sea arose when the elder Sars discovered in the Lofotens 
at a depth of 1000 meters a small sea lily, 2ehizocrinus lofo- 
tensis. The stalked sea lilies up to this time had been held as 
an entirely extinct group which in the geologic past had pos- 
sessed a great significance, inhabiting the former seas in hun- 
dreds of genera now extinct. Out of the deep sea there was 
then drawn such an ancient animal still living and at once then 
arose the hope of obtaining by methodical dredging of the 
deep sea bottom other animal species also believed to be 
extinct. It was one of the more important tasks of the Chal- 
lenger expedition to seek after these very ancient types. 

A number of expeditions have now explored the bottom of 
the deep sea and we know very well the systematic interrela- 
tion of the present deep sea fauna and its characteristics 
acquired by adaptation to the peculiar environmental condi- 
tions; and it seems a praiseworthy task to prove the geologic 
age of this fauna, just as paleontologists do in determining 
the age of an extinct fauna. It is well known that in each 
period of the earth’s history different sea animals have lived ; 
let us now compare the present deep sea fauna with the chron- 
ologically arranged: faunas of the past. 

To this end we must first point out that not a single animal 
characteristic of the Paleozoic is found in the present deep sea. 
The Archeeocyathide, Tetracoralla, Tabulata, Stromatopora, 
Spiriferidee, Graptolithids, Cystidea, Blastoidea, Paleocrinoi- 
dea, Orthoceratidee, and Trilobite are completely lacking. We 
might then perhaps surmise that in general no Paleozoic forms 


62 Walther— Origin and Peopling of the Deep Sea. 


still live. Therefore we must also point out that in the 
present shallow sea there actually live a number of uncom- 
monly long enduring Paleozoic genera: 

Of brachiopods, Lingula, Rhynchonella 

Of bivalves, Arca, Avicula, Astarte, Leda, Mytilus 

Of univalves, Capulus, Pleurotomaria 

Of cephalopods, Mautilus 

Of worms, Serpula 

Of starfishes, Astropecten. 

Limulus, the last representative of Silurian horseshoe crabs, 
is a coast dweller, and Ceratodus, rooted in the Devonian, still 
lives in Australian rivers. 

We must thereto also add a number of forms without skele- 
tons which are phylogenetically very old and which must have 
had their origin in the pre-Cambrian faunas. /Zydra and 
Amphioxus as well as the Asconia sponges, Planarians and 
Holothurians are mostly dwellers in very shallow water, and 
all these forms reach back into the oldest part of the earth’s 
history. 

Only the Cambrian genus Discina, some Silurian bivalves 
such as Avca and NVucula, univalves such as Dentaliwm and 
the Devonian Zerebratula, have descended into the deep sea, 
but it is naturally very easy to suppose that they first began 
this migration at a later time. Mustering now the remaining 
animals with skeletons living below 2000 meters and with a 
clear understanding as to their paleontologic position, there can 
be no doubt that the oldest genera date from the Triassic and 
Jurassic periods. 

The Euretide among the hexactinellid siliceous sponges, the 
turbinolids among the corals, Pentacrinus among the crinoids, 
Ophioglypha and <Asterias among the starfishes, Hcehinus 
among the sea urchins and Penwws among the crabs are forms 
whose oldest kin belong to the Mesozoic age. Their migra- 
tion into the deep sea can therefore at best date from the Tri- 
assic. 

Very close is the relationship of the present deep sea fauna 
to the animal world of the Jurassic and Cretaceous periods. 
The German Valdivia expedition found the nearest kin of the 
upper Jurassic Hryon in the characteristic deep sea crabs 
Pentacheles, Willemasia and Polycheles, and A. Agassiz has 
shown that most of the deep sea urchins are related to Creta- 
ceous genera. 

The deep sea corals belong almost entirely to Cretaceous gen- 
era. It is further noteworthy that typical Tertiary forms are 
very rare in the deep sea. The migration must therefore in 
general have ceased in the Tertiary. 

Were the present deep sea fauna laid before a paleontologist 
“without designation of locality,’ he would on the basis of 


Walther—Origin and Peopling of the Deep Sea. 68 


the more fundamental relationships have to consider it as Mes- 
ozoic and would refer the majority of the forms to Cretaceous 
and Jurassic genera and others to genera of the Triassic. The 
few Paleozoic genera occurring at all water depths would 
thereby gain no significance because all specific forms of Paleo- 
zoic time are wanting in the deep sea, whereas, on the other 
hand, many representatives of the same are found living in the 
present shallow sea. 

General considerations as to the life habitats of the deep 
sea have led us to the conviction that its fauna must have 
migrated from the shallow sea ; the comparison of the deep sea 
fauna with the fossil faunas has shown us that it has a Meso- 
zoie character; therefrom the conclusion necessarily follows 
that the peopling of the deep sea can be traced at the earliest 
to the Triassic. 

The deep sea basins represent the greatest inequalities of the 
earth’s crust. While the average height of the mainland 
amounts to only 700 meters, the average depth of the oceans 
is 83500 meters, but the average depth of the deep sea basins 
amounts to about 5000 meters. It is only the Tibetan high- 
land that rises to this amount above the mainland, while one- 
half of the entire earth’s surface is depressed below this level. 

In different periods of the eartlh’s history great land areas 
have sunk beneath the surface of the sea to be united to the 
deep sea; into the new depressions the water flowed and left 
the former shallow sea regions. Since the Jurassic, North 
America and Europe have in this way gained land, and even 
in Asia we see the land growing at the expense of the shallow 
sea. The intensive development of mammals, birds and 
insects since the Eocene seems to stand in the closest causal 
connection thereto. 

The fact, recurring in all great sea basins, that the greatest 
depths occur nearest the coasts, can be explained only by the 
assumption that these deep channels represent local exagger- 
ated deepenings of a general deepening process. 

From the study of newer and older mountains it is now seen 
that hand in hand with the elevation of the mountain chains 
extensive depressions have occurred. The Alpine folding con- 
tinues into the depressed plain of Lombardy just as the chains 
of the Himalayas are connected with the Bengal depression 
and the South American Cordillera finds in the bottom of the 
Pacific ocean its downward-directed compensation. With the 
elevation of the Black Forest and Vosges the plain of the 
Rhine valley sank into the depths, and the sinking of the Dead 
Sea corresponds to the elevation of the Lebanon. 

We must also expect the beginnings of those immense 
depression areas to be connected with the powerful processes 


64 Walther—Origin and Peopling of the Deep Sea. 


manifested in mountain-building, and have to examine as well 
whether in the earth’s history there is discernible an increased 
folding of the crust at the end of the Paleozoie.. 

Everyone who is at all familiar with the events of that 
epoch knows that at no other period did there arise anything 
eyualling the extent and grandeur of the mountain ranges of 
the time between the Carboniferous and Triassic periods. A 
gigantic range of mountain folds can be traced from Ireland 
through all of France to the banks of the Rhone; a second 
range extended from the Rhine northeast through Germany 
to the Car pathians. The eastern Alps were mountain land 
and in Switzerland as well are to be seen undoubted traces of 
a former mountain range. In the same epoch arose the Urals 
and simultaneously the Appalachians were thrust together in 
North America. In the Sudan there probably arose a moun- 
tain fold with great granite stocks at the termination of the 
Paleozoic and in South America the Permian age of extensive 
mountain folding was definitely established ! Even in eastern 
Asia keen scientific a have been able to trace a Per- 
mian period of folding from China to Japan and through the 
interior of India to Sumatra. 

But where are to be sought the complementary movements 
of this same time directed toward the center of the earth ? 

An answer to these questions is not difficult to find. For if 
the present deep sea fauna contains predominantly Mesozoic 
types and in accordance with its whole character must be con- 
sidered as a migration from the shallow sea; if therein almost 
all Paleozoic elements are lacking although such are repre- 
sented rather numerously in the present shallow sea; then the 
deep sea must have originated at the end of Paleozoic time. 

And if in the same period of time we find that mighty 
mountains have arisen almost everywhere on the earth, then it 
is easy to bring the depressions of the deep sea basins into 
direct connection with these folding processes. 

General biological grounds, the stratigraphic position of the 
present deep sea ; fauna as well as tectonic investigations, force 
us to the conclusion that the deep sea as a life-region is not a 
characteristic of the earth in its oldest periods, ‘and that its 
origin falls in the time when in all parts of the present conti- 
nents began tectonic folding movements which so decidedly 
changed the relief of the earth’s surface. 


Loomis—Oamels of the Harrison Beds. 65 


Arr. [X.—TZhe Camels of the Harrison Beds, with Three 
New Species; by F. B. Looms. 


Durine the deposition of the Upper and Lower Harrison 
beds of Lower Miocene age there was probably no more 
abundant or varied group of vertebrates in that region than 
the camels. Already six species belonging to two genera have 
been described, and in this paper three more will be added to 
the number; but even then the collectors in that region, judg- 
ing from the varied toe bones, etc., are confident that there are 
yet several species to be added. The deposits are typically 
those of an upland country, those of the Lower Harrison being 
finviatile, and those of the Upper Harrison, in a considerable 
proportion at least, eolian. The fauna points in the same 
direction, being entirely composed of plains types and river- 
frequenting animals, like the rhinoceroses, Diceratheri ium and 
Aceratherium. 

In 1908 both Yale University and Amherst College had 
parties working together along Muddy Oreek and in the 
“breaks ” to the south of the Raw Hide Buttes in Converse 
Co., Wyo.; and it is the camel] material of these two expedi- 
tions which is the basis of this paper, the authorities of the 
Yale Museum having generously loaned all of theirs for this 
purpose. 

In the Lower Harrison beds the camels which are most 
abundant belong to the genus Stenomylus, forms characterized 
by their very hypsodont dentition and slender build. Of these - 
there are three species as differentiated further on. Then one 
species of Oxydactylus has been described by Mr. Cook from 
these beds, making four known species. It is in these horizons 
that there are doubtless several more species. In the Upper 
Harrison beds two species of Oxydactylus have been described 
by Peterson, the genus being characterized by a brachyodont 
complete dentition and elongated limbs. To these will be 
added two more species of Oxydactyius and one of Protomeryx, 
which differs from the foregoing by not having the excessive 
development of limbs and still retaining the brachyodont denti- 
tion. In both divisions of the Harrison it will be seen that the 
camels are specialized and further that they are of the open 
country or plains types. The more generalized genus Pro- 
tomeryx is strikingly scarce, being only represented by the one 
species, which in its turn is the slenderest representative of 
the genus. 

The genus Oxydactylus is the dominant one, containing five 
different species, the representatives of which are also among 


Am, Jour. Scr.—FourtTs SERIES, Vot. XX XI, No. 181.—January, 1911. 
5 


66 Loomis— Camels of the Harrison Beds. 


the most frequently found. It is characterized by i. 3/3 ¢. 1/1 
pm. 4/4 m. 3/3 brachyodont teeth, the upper incisors being 
but little reduced, the third incisor being caniniform and 
often of consider able size, occasionally larger than the canine. 
The first premolar in both upper and lower jaw is double- 
rooted. Limbs are long and metacarpals free, metatarsals also 
separate except at the palmar process. The skull is usually: 
small and specific variations are perhaps best seen in the rela- 
tive development of the snout as shown by the spacing either 
side of the canine and first premolar. The relative size of the 
canine and third incisor are also characteristic. O. longipes 
is the largest of the known species and most fully described so 
that it can conveniently be used as a standard for comparisons. 


Oxydactylus longipes Peterson 

Ann. Carnegie Museum, vol. ii, pp. 435-468, 1904. 

This largest species of the genus is also comparatively abund- 
ant in the Upper Harrison beds; and is characterized by a 
moderately short snout, and by the third incisor being equal 
to or slightly larger than the canine. 


Oxydactylus brachyodontus Peterson 

Ann. Carnegie Museum, vol. ii, pp. 469-471, 1904. 

This species is the most abundant of the Upper Harrison 
camels, is slightly smaller than O. longipes, and has a much 
more elongated and narrower snout, the third incisor being 
smaller than the canine. 


Oxydactylus lulli sp. nov. 

The type of this species is number 10327 of the Yale 
Museum, found by Prof. R. S. Lull in the “ breaks,” about 
five miles south of the Raw Hide Buttes, Converse Co. , Wyo. 
The type consists of a skull complete as to the jaws and 
dentition, but lacking the major part of the brain case and 
being considerably crushed laterally, and also of incomplete 
limb and foot bones. Beside the type there are three other speci- 
mens, all from the Upper Harrison beds, but none showing the 
brain case. This species is nearest to O. brachyodontus but is 
smaller and of very different proportions. The facial portion 
of the skull is as long as that of O. brachyodontus but much 
lower throughout. The back part of the skull, especially in 
the region of the premolar and molar series of. teeth, is con- 
siderably shorter than the foregoing. The third upper incisor 
is much smaller than the canine, though caniniform in shape. 
In the upper jaw the diastema between incisor 3 and the 
canine is only 12™", which makes the canine seem very far 
forward. Similarly in the lower jaw the first premolar is placed 


Loomis— Camels of the Harrison Beds. 67 


well forward, being but 15™" from the canine. This first 
premolar is unusually stocky and two-rooted. Premolars 2-4 
in the lower jaw are entirely simple and do not resemble the 


molars. 


Fie. 1. 


Fic. 1. Type of Oxydactylus lulli. Dotted outlines are put in from a 
second specimen. Nat. size. 


Oxydactylus gibbi sp. nov. 

The type of this species is number 10328 in the Yale 
Museum, found by Mr. Hugh Gibb on Muddy Creek, about 
opposite the spring associated with the “Spanish diggings.” 
The type consists of the palate and lower jaws with complete 
dentition, except that the third molar is lacking in each jaw. 
In the measurements given it is estimated as being of the same 


Fic. 2. Upper and lower jaws used as type of Oxydactylus gibbi. Half 
nat. size. 


proportions as that of the other members of the genus. Beside 
the type there are two other specimens from the same general 


68 Loomis—Camels of the Harrison Beds. 


‘ 
region, all from the Upper Harrison beds. One of the two 
accompanying specimens consists of the major portion of the 
skull and some limb bones, but the individual is so young as 
to still be using the milk dentition although molars 1 and 2 
are up in the jaw. : 

This species is smaller than the preceding one, in fact is 
the smallest Oxydactylus yet described. Its snout is moder- 
ately long and the species is easily distinguished by the great 
size of upper incisor 8, which is nearly twice the size of the 
reduced canine. The first premolar is also a large, strong 
tooth, and less reduced than in other species. The lower-jaw 
is stocky, the canine being much enlarged. The first premolar 
stands considerably nearer to the canine than to the second 
premolar. The skull of the young individual shows wide 
projecting arches over the orbits and a rather wide but short 
_ brain case. The limb material is only complete enough to 
show that the form had long limbs typical of the genus. 


Oxydactylus campestris H. J. Cook 

Amer, Naturalist, xliii, p. 188, 1909. 

This species occurs in the Lower Harrison beds, is interme- 
diate in size between QO. brachyodontus and O. lulli, and 
clearly distinguished by the very short snout, and by the large 
size of upper incisor 3, which is larger than the canine. The 
short snout would indicate a less advanced type than those in 
the Upper Harrison beds. 


Protomeryx leonardi sp. nov. 


The type of this species is number 2004 in the Amherst 
College Museum, and was found in the Upper Harrison beds — 
on Muddy Creek, about three miles below the ‘Spanish 
Diggings” spring, by Mr. E. N. Leonard. Part of the skull 
of a very young individual was also found in the same beds 
some five miles further up the Muddy Creek and is 10326 of 
the Yale Museum. Heretofore this genus has not been 
reported from the Harrison beds. This species is characterized 
by the slender proportions of the lower jaw, which is all that 
was found of the adult animal. The full set of teeth is present 
in the lower jaw, the teeth being rather high crowned, but not 
enough so to be designated hypsodont. In the lower jaw there 
is a short diastema behind the third incisor (as shown by the 
young jaw). The canine is a slender, compressed tooth which 
rises to an unusual height and projects somewhat forward. 
The first premolar is reduced, being but 44™" wide, the dias- 
tema between it and the canine being 15™", while the interval 
behind it, i. e. between premolar 1 and premolar 2, is very 


Loomis— Camels of the Harrison Beds. 69 


considerable, 17™". The premolar series is simple, there being 
no crescent on any of the teeth, and premolars 2-4 measuring 
23™", The three molars are those typical of the genus, but’ 
rather high crowned, and together extending 45™™, The jaw 
is very slender and with a short coronoid process. It measures 
but 125”™ in depth under the first premolar, and 17™" under 
the second molar. 


Fig. 3. 


Fic. 3. Lower jaw used as type of Protomeryx leonardi. Nat. sizé. 


The following table is arranged to show the relative size of 
the different species of Oxydactylus, and especially to show 
the variations in the proportions of the snout and in the posi- 
tions of the canine and first premolar teeth: 


ae E o/ 4 a, Aol ‘q A yh, eS 12 

ole Mele be Nee bre Viet 

Sale lB ole © HBR le lS Bale 
O. longipes_-_--- lv. Harrison | 340 | 18 | 14) 18 | 102 | 17 | 17 | 104 
O. brachyodontus|U. Harrison | __- | 14*| 18*) 19*| 93 | 17*| 22%) 100 
ON Cult ae ae U. Harrison | 275 | 12 | 19 | 19 | 85 | 15 | 20) 91 
O, gibbt .2...-.- U. Harrison | --. | 10 | 16| 18 | 72+) 12 | 24] 77+ 
O. campestris ---|L. Harrison | 290 | _- rem |e ose Wea Os lapse td ee 


The genus Stenomylus contains the other Harrison camels 
and is distinguished by having a complete dentition of very 
hypsodont teeth, by the upper canines being partly and the 
lower wholly incisiform, and by the slender build. Three 


* These measurements are taken from the figure. 
+ The last molar being absent, it is estimated as being normal to the genus. 


70 — Loomis—Camels of the Harrison Beds. 


species are described, of which S. Aztchcocki is commonest and 
known by the most complete material, so may be used for a 
standard for comparisons. 


Stenomylus hitchcocki Loomis 

This Journal, vol. xxix, 298-318, 1910. 

This species, known by several complete skeletons, has so far 
been found only at one point, in a quarry near Agate, Neb., 
in the Lower Harrison beds. It is characterized by the small 
size, narrow molars, lower canine completely incisiform, lower 
jaw deep, metacarpals separated the entire length. c 


Stenomylus gracilis Peterson 

Ann. Carnegie Museum, vol. iv, p. 41, 1906, and p. 286, 1906. 

A larger species, rather rare, with narrow upper molars, 
lower canine less incisiform, lower jaw slenderer, and meta- 
carpals codssified a part of their length. Occurs in the Lower 
Harrison beds. 


Stenomylus crassipes Loomis 

This Journal, vol. xxix, p. 319, 1910. 

About the size of the preceding, but with lower canine com- 
pletely incisiform, and the limbs much shorter and the skeleton 
throughout much heavier. This form occurs in the uppermost 
beds of the Lower Harrison. _ - 


William Henry Brewer. 71 


WILLIAM HENRY BREWER. 


Professor William Henry Brewer was born September 14, 
1828, at Poughkeepsie, N. Y., and while he was still an infant 
his family moved to Enfield, about six miles from Ithaca. 
Here Brewer’s childhood and youth were spent on his father’s 
prosperous farm, where the boy took his part in all kinds of 
farm work, from the clearing of the forest to the marketing of 
special crops. He went to the village school and later to a 
private academy in Ithaca, intending after his “schooling ” was 
done to follow his father’s business. 

Early in life he had a strong taste for natural science, par- 
ticularly botany and chemistry. The published letters of Prof. 
J. P. Norton, who was studying with Johnstone, the Scotch 
agricultural chemist, and of Prof. Horsford, a student of 
Liebig’s, fixed his attention on the application of chemistry to 
agriculture, and the reading of Liebig’s letters on the subject 
determined his career. It was the spark that fired him, that 
“educated him away from the farm,” and though he left it 
for a year to prepare himself to be a better farmer, with no 
thought but to live and die there, he was drawn to the ends of 
the earth,—as a botanist, a chemist, a sanitarian and an ex- 
plorer, the servant of all men and friend of all the world. 

In 1848 he came to New Haven, to learn from Prof. J. P. 
Norton, of Yale College, how to analyze the soils of that hill- 
top farm near Oayuga Lake and by it to learn how to make 
them more productive. On the same day that Brewer reached 
New Haven there also came George J. Brush, and then began 
between these two an acquaintance which ripened into a com- 
panionship for many years in the work of the Sheffield Scien- 
tific School, and into a friendship which was lifelong. 

Just when young Brewer definitely decided to leave the 
farm for the work of study and teaching is uncertain. After 
study in Yale College and two years of teaching natural sci- 
ence in the state of New York, he came again to New Haven, 
passed his examinations and received his degree with the class 
of 1852, the first to be graduated by the Sheftield Scientific 
School. 

After some further time spent in teaching 
and studied in Paris, Heidelberg and Munich. 


, he went abroad 


72 William Henry Brewer. 


In 1858 he became professor of natural science in Washing- 
ton College, Pa. From 1860 to 1864 he was first assistant on 
the California State Survey and in the last of these years was 
a professor of natural science in the University of California. 
In 1864 he was appointed professor of agriculture in the Shef- 
field Scientific School of Yale and served in this position until 
1903, when he became professor emeritus. 

A catalogue of Professor Brewer’s publications and a sum- 
mary of the strictly scientific work which he did is left for 
some fuller biographic notice than can be given here. We 
choose rather to notice some of the public services which Pro- 
fessor Brewer rendered freely and often at personal sacrifice,— 
services which needed a man scrupulously honest, with scienti- 
fic training, a careful observer, with strong common sense and 
‘willingness to give time and strength freely to the public ser- 
vice. Such aman was Brewer. He was of the noble race of 
scientific men who were the forerunners of specialists in sci- 
ence,—men with a clear knowledge of the scientific method, 
inspired with the scientific spirit and not being called to the 
profound study of some narrow specialty, yet were the apos- 
tles of science and justified it by showing its help in practical 
matters. No one connected with Yale University within the 
last forty years has been called so continuously and in so many 
ways for service outside the college world as Professor Brewer; 
and he has met these various calls with a mixture of scientific 
knowledge and common sense which has commended science 
to the laity and common sense to the specialist. 

Thus for seventeen years he was a member of the local 
health board and for twelve years its president. 

For thirty-one years he was on the State Board of Health, 
from the time it was organized until he resigned because of 
failing strength, and for sixteen years he presided over the 
Board. 

This Board began its duties when the public had very little 
understanding of the value of public health work. Violent 
opposition developed throngh ignorance, as well as through 
evil intent, There was little help at that time to be got from 
the experience of other states. Brewer’s knowledge. of sani- 
tary science, his vast fund of information on many related. 
matters, his ‘influence as a public speaker and his common 
sense were never more helpful than in guiding the growth of 
a state health board from a distrusted experiment into an 
indispensable public service. 

He was chairman of the Commission which managed the 
topographical survey of Connecticut, from 1889 to its ‘comple- 
tion in 1895. His experience as a zeographer in the survey 
of California fitted him for this work and the popular knowl- 


William Henry Brewer. 73 


edge of his character and ability left no room for the criticism 
of those who, with more or less reason, always suspect that a 
public commission will be made a private graft. 

He was a member of the United States For estry Commission 
in 1896, which visited and reported upon forest conditions in 
the west. 

At the age of 66 he joined an exploring expedition on the 
steamer Mir anda, which went up the coast of Greenland and 
was wrecked near the Arctic Circle. After much danger and 
great exposure and discomfort, the party was rescued by a 
small schooner “built to accommodate 18, that could carry 22, 
but came back with 90 people on board,” who were forced to 
sail the North Atlantic in her for fifteen days. 

Interested in the problems of animal breeding, he made 
special researches in the evolution of the horse, par ticularly i in 
the matter of speed, gathering and discussing ‘the very volu- 
minous data which had never been thus treated. His predic- 
tion from this discussion, of the time of the coming of the 
two-minute racing horse, was verified. 

He was fond of travel, not for rest, but for the recreation 
which he found in careful observation and record of facts in 
all departments of human interest. To observe and gather 
- was his delight all the days of his life. Even the signs of 
waning strength and the coming of old age interested him as a 
new class of facts to be studied and noted. Afraid of nothing, 
he observed in himself these things in the detached way that a 
physician might watch a hospital patient. It is the one regret 
of those who knew him that to arrange, diseuss and publish 
his work was hard and almost impossible for him. 

“Hducated away from the farm” in his youth, his sympathy 
with farm interests was always active. He was a professor of 
agriculture, not only in the Sheffield School, but throughout 
the state. His addresses at farm meetings, through many 
years, which were published in the reports of the State Board 
of Agriculture, did much to make its early reports sought 
after everywhere as an encyclopedia of farming. All the 
various work of the farm was familiar to him. On practical 
matters he spoke to practical men as one having authority, 
in homely language and with that kind of humor which is 
indigenous to countr y life. 

He labored, with his associate and friend, Prof. S. W. John- 
son, for the establishment of an agricultural experiment sta- 
tion in Connecticut, and saw it established, the first one to be 
organized in the United States. He was a member of its 
Board of Control from 1877 until he died, and his last public 
appearance was at a meeting of this Board a few days 
before his death. 


74 William Henry Brewer. 


He was a member of the Connecticut Academy of Sciences, 
the American Public Health Association and the National 
Academy of Sciences. 

From Washington and Jefferson College he received the 
degree of Ph.D., in 1880; the degree of LL.D. from Yale, 
in 1903, and the same degree from the University of Califor- 
nia, at its fiftieth anniversary, in 1910. 

He was married twice and leaves a daughter and three sons. 
After a brief illness he died at his home in New Haven, Nov. 
2, 1910. 

By the public he will be remembered for his public service. 
To those who knew him well a memory better and more use- 
ful than that of the things which he did will be the recollec- 
tion of his genial companionship, his broad, unselfish nature, 
and his clean, helpful life. 

Epwarp H. Jenkins. 


Chemistry and Physics. 75 


SCIENTIFIC INTELLIGENCE. 


J. Curmistry AnD Prystcs. 


1. The Preparation of Metallic Radium.—The successful pre- 
paration by Mme. Curie of a small quantity of this metal was 
noticed in the last number of this Journal, but, nevertheless, the 
preparation of barium-radium metal by a different method appears 
to be worthy of mention. E. Exsimr considered the preparation 
of the metal an important matter, as he conceived the possibility 
that radium might not be an element at all, but a comparatively 
stable radical, possibly a radical containing helium, and that the 
salts of this radical resemble barium salts in the same way that 
ammonium salts resemble those of potassium. It was his view 
also that the preparation of radium amalgam, which had been 
effected by Coehn, did not contradict this radical theory on 
account of the well-known formation of ammonium amaloam. 
Ebler’s method of preparing the metal was by slowly heating the 
mixed barium and radium azides, Ba(N,), and Ra(N,),, since it 
had been shown by Curtius and eae that the metals ‘calcium, 
strontium and barium may thus be produced from their azides. 
The method appears to be preferable to that used by Mme. Curie, 
as the azide is stable and, as Ebler has shown, it does not appear 
to be decomposed by the radium radioactivity. Ebler found that 
the mixture of metals produced in this way gave the same y radia- 
tion as the original salt, and he concludes that metallic radium is 
capable of existence, and is analogous to metallic barium,— 
Berichte, xliii, 2613. H. L. W. 

2. The Reduction of Owide of Iron by Solid Carbon.— 
Cuarpy and Bonneror have studied the interesting question 
concerning the action of the solids under consideration in the 
absence of gases. They employed carefully purified ferric oxide 
and graphide which had been heated separately to 1000°. The 
materials were then finely pulverized and mixed in an agate mor- 
tar, and the mixture was agglomerated at a pressure of several 
thousand atmospheres. Since it appeared to be impossible to heat 
the mixture in the absence of every trace of gas, even by the use 
of a mercury pump, the matter was studied by observing the 
rapidity of the reaction, measured by the amount of gas given off, 
at varying, very low pressures. As an example, a series of ex- 
periments carried on at 950° C. gave the following results : 


Pressure in Volume of gas 
millimeters given off per 
of mereury hour, cem. 

ORO) Mires ies eR 2s SST a Ea) ede na a De aS 0°10 

COE sts 2 2a Bal a ge a OO RNR i A pC Pe 0-14 

TUS Ts TS ch 3k a pk eee no Bp DR ap 0°3) 

WE Ss es ee AN aR EE ae gd a Ge 0°56 

UNTO hy il, RN sa a un SCM 0°80 

Sich Pelee iss aac a ) weconee saasoses Shack 1:07 


76 Scientific Intelligence. 


From these results the conclusion is reached, since the rapidity | 
of the reaction diminishes rapidly with the pressure of the gas in 
the apparatus, that solid carbon does not reduce oxide of iron, at 
least at 950° C., although it has been previously supposed that this 
reduction commences at 450°.— Comptes Rendus, cli, 644. 

H. L. W. 

8. Action of Light upon an Electric Cell_—H. Piiapon has 
observed that if two rods, one of pure antimony and the other 
of an alloy of antimony and selenium, are plunged into a hydro- 
chloric acid solution of antimony trichloride, a cell is obtained in 
which the pure antimony acts as the negative pole. This cell 
has curious properties. If it is kept in darkness its electromotive 
force, in open circuit, attains a constant value in a few days, 
provided that the temperature remains constant. Upon suddenly 
illuminating the positive pole, the electromotive force, originally 
H,, increases at once to a much higher value, E,, and then, the 
illumination being maintained, it diminishes, and in the course of 
about 20 minutes reaches the original value E,, which remains 
constant under these conditions. Then when the illumination 
is cut off the electromotive force diminishes to a value E,, when 
it increases slowly and in about an hour reaches the original value 
E,, which is maintained continuously in darkness. The same 
phenomenon is observed, whatever may be the proportion of 
selenium in the positive electrode, but alloys low in selenium 
appear to be the most sensitive. Tellurium and sulphur when 
alloyed with antimony do not give this behavior. The nature of 
the metal influences enormously the delicacy of this phenomenon. 
Almost all the metals with their selenides give cells which are 
sensitive to light.— Comptes Rendus, cli, 641. H. L. w. 

4, Sterilization of Large Quantities of Water by Ultra-violet 
Rays.—HuLBRONNER and ReCKLINGHAUSEN have devised an 
apparatus for the treatment of water on a large scale with the 
rays of the quartz-mercury-vapor lamp. The lamp is placed in 
a box, three sides of which are composed of quartz plates, and the 
current of water in the apparatus flows against each of these 
plates in succession. In this way more than three-quarters of 
the rays emitted by the lamp are utilized. It was found that the 
transparency of the treated water is of the greatest importance 
and that it is desirable to filter the water to clarify it before the 
treatment. The authors have installed a practical apparatus 
treating about 160,000 gallons per day, which gave most satisfac- 
tory results for a period of six weeks. Before passing through the 
apparatus the water contained from 30 to 300 germs per cubic 
centimeter, including 50 to 1000 of bacillus coli per liter. After 
the treatment the water contained an average of one germ per 
cubic centimeter, and not a single bacillus coli, The lamp 
employed was of the Westinghouse-Cooper-Hewitt type of 220 
volts and 3 amperes, so that the electricity employed amounted 
only to about 100 watts-hour per 1000 gallons.— Comptes Ren- 
dus, cli, 677. H, L: W. 


Chemistry and Physics. 77 


5. Refrigeration by Mixtures of Liquids —The mixture of 
two liquids is often accompanied by a lowering of temperature. 
For instance, with carbon bisulphide and methyl formate the 
variation of temperature is 16° C. For practical refrigeration 
such mixtures have never been used on account of their cost and 
low effect in comparison with the solution of a salt, such as 
ammonium nitrate, in water. J. Ductaux has devised an inge- 
nious application of the two liquids method for the production 
of very low and nearly constant temperatures. He allows the 
liquids to flow through two long tubes, and after mixing they 
flow back around the exterior of the tubes. In this way the 
cooling effect is accumulated. The tubes used were very small, 
about 1™™ in diameter, delivering one or two drops of liquid per 
second. The most satisfactory liquids employed, on account of 
economy and ease of recovery, are carbon bisulphide and acetone. 
which produce quickly a temperature of —48° C. by this method, 
When the apparatus is protected by a double-walled, silvered tu be 
it is easy to produce a practically constant low temperature for 
along time. It is a simple matter to recover the liquids nearly 
pure by shaking the mixture three times with half its volume of 
water and distilling the products.— Comptes Rendus, cli, 715. 

H. L. W. 

6. The Relations between Chemical Constitution and Some 
Physical Properties ; by Samurt Sites, D.Sc. 12mo, pp. 583. 
London, 1910 (Longmans, Green & Co.).—This is one of the 
text books of physical chemistry edited by Sir William Ramsay. 
As the title indicates, the aim has been to show the relations that 
exist between certain physical properties and the chemical con- 
stitution of compounds, particularly of organic compounds. The 
various properties are dealt with under the general headings of 
mechanical, thermal, optical and electrical properties and these 
are further subdivided. Under mechanical properties, for in- 
stance, are included capillarity, viscosity and volume relations. 
There is a short historical introduction to each property, followed 
by the common methods of determination and ending with a dis- 
cussion of the results obtained. References to the literature ap- 
pear to be excellent and the book will be found useful as a work 
of reference. H. W. F. 

7. Positive Rays.—W. Wi=N contributes a very full paper on 
this subject accompanied by many diagrams. His previous inves- 
tigations had shown that the manifestations of canal rays are 
dependent not only upon conditions of immediate excitation 
but also upon length of path pursued and upon the conditions of 
voltage and other circumstances in the escape of the positive ions 
from one receptacle to another. The author does not agree with 
Sir J. J. Thomson in regard to the non-dependence of the devia- 
tion of the rays under magnetic and electric fields, upon voltage, 
nor with the latter’s assumption that the velocity of the rays 
depends on the atomic energy or upon cathode rays instead of 
upon the voltage.—Ann. der Physik, No. 15, 1910, pp. 871-927. 

Jee 


~y 
Lo 6) 


Scientific Intelligence. 


8. Deflections by Electrostatic and Magnetic Fields of Radium 
B after Recoil from Radium A.—These deflections have been 
measured—the electrostatics, by Stpney Russ and WaALTeRr 
Maxower ; the magnetic by W. Maxower and E. F. Evans, 


aia ‘ e ; ; 
and estimations of the value of — and the atomic weight of 
mM 


radium were made. The value of 194 was obtained for the latter, 
which the authors regard as good agreement with the theoretical 
value 214.—Phil. Mag., No. 15, 1910, pp. 875-886. a Late 
9, Energy Distribution of Diffraction Gratings.—Professors 
Aveustus TRowBripGE and R. W. Woop continue their investi- 
gations on the energy of distribution from definite forms of 
grooves—wedge shaped—in gratings with few rulings which are 
called echelettes. They show that these gratings give the highest 
resolving power that has yet been brought to bear upon the 
infra-red.— Phil. Mag., Nov. 1910, pp. 886-901. Bye 
10. Modification in Magnetic Fields of Lines of the Light 
emitted by the Electric Spark.—G. A. Hemsaxecu finds that mag- 
netic fields modify the intensity of light. On the sun such fields 
may produce a diminution of light, showing thus an apparent 
absorption of light coming from the photosphere and a reinforce- 
ment of certain lines in the solar spots.— Comptes Rendus, Nov. 
21, 1910, pp. 938-941. J. T. 
11. Electric Motors ; by Henry M. Hogparr. Pp. xxiv, 748, 
with 798 illustrations. New York, 1910 (The Macmillan Co.).—— 
This is the second edition, entirely rewritten and enlarged, of a 
volume which first appeared in 1904. It treats the theory and 
construction of continuous, polyphase and single phase motors; 
the section on the latter accounting in large part for the increased 
size of the present edition. A useful table of the properties of 
copper wire for standard wire gauge is given in the Appendix. 
as) SAL aIKS 


II. Gronrogy anp Narurar History. 


1. Grundziige der Paldontologie; by Karu A. von Zirren, 
1, Abteilung, third edition, revised by F. Broili, 1414 text figs., - 
607 pages with an index. Munich, 1910 (Oldenbourg).—This 
well known German text-book, the classic of Invertebrate Paleon- 
tology by a great past master, is here revised by one of his 
students. The reviser has added about 70 new figures and on 
many of the old ones letters have been affixed permitting of 
more direct descriptions of the structural parts. There are 
about 90 pages of new matter over the first edition, and about 
50 pages more than in the second edition, 

The revision and additions are chiefly important in matter of 
detail and the classification adopted is practically that of the 
former editions. Even Treptostomata Bryozoa or the monticuli- 


Geology and Natural History. — (ie 


porids still remain here as in former editions with the Tabulate 
corals. Beecher’s classification of the Brachiopoda and Trilobita, 
while mentioned, are not accepted. This conservatism is also 
seen in the geological colunin and particularly in the Paleozoic, 
where Silurian system is retained for the Ordovician and Silurian, 
and the Carbon system embraces our Pennsylvanian and Missis- 
sippian systems. The book is nevertheless the best so far in the 
German language and should be used by teachers of paleontology 
in connection with the Zittel-Eastman English translation of the 
first edition, entitled Text-Book of Paleontology. Cc. Ss. 

2. Notes on Ordovician Trilobites, parts II, IIL and IV; by 
Percy E. Raymonp. Annals Carnegie Mus., vol. VII, No. il 
1910; 35-80, pls. x1v—x1x.—The author, now a member of the 
Geological Survey of Canada, revises the trilobites of the New 
York-Vermont Chazy, and the Asaphide of the Beekmantown, 
Lowville and Black River formations bordering the Adirondacks. 
A number of new species are described along with the following 
new genera or subgenera,—Tsoteloides, Hemigyraspis, and Vog- 
desia. 

The following European genera are for the first time recog- 
nized in this country,—Asaphellus, Basilicus, and Onchometopus. 

Two new subfamilies of Asaphide are erected,—(1) Ogygine 
for Ogygia, Niobe, Asaphellus, Symphysurus, Nileus, Vogdesia, 
Illenurus, Megalaspis, and Megalaspides ; and (2) Asaphine for 
Basilicus, Ptychopyge, Pseudasaphus, Asaphus, Onchometopus, 
Tsotelus, and Isoteloides. The author is well acquainted with 
the European literature and is making decided efforts to get 
entire specimens so that even fragments may be of ee in 
stratigraphy. 

3. A Preliminary List of the Fauna of the Maes y au 
Conemaugh Series in Western Pennsylvania; by Prrcy E. 
Raymonp. Annals Carnegie Mus., Vol. VII, No.1, 1910: 144— 
158, pls. xx1v—xxvui.—For several years the author has been 
gathering the marine fossils in the Pennsylvanian of central 
western Pennsylvania, resulting in 97 species here listed accord- 
ing to the various zones from which they were taken. Of these 
28 are restricted to the Allegheny series and 52 to the Cone- 
maugh. ‘Three new species are described and a new chiton 
genus Glaphurochiton. Cc. S. 

4. The British Carboniferous Orthotetinae ; by Ivor Tuomas. 
Mem. Geol. Surv. Great Britain, Pal. I, 1910 ; ; 83-134, pl. 13.— 
A very important revision of the various brachiopod genera of 
this subfamily and of the British Carboniferous species. The 
author recognizes two groups of genera, (1) having a ventral sep- 
tum in the muscular area as in Orthotetes, Derbyia (has not the 
same generic characters as Orthotetes as "heretofore supposed), 
and Geyerella; and (2) without such a septum as in Schucher- 
tella, Streptorhynchus, and Meekella (Places here both plicate 
and non-plicate species). As the genus is based on plicate forms 
having a very different general aspect from the two new English 


80 Scientific Intelligence. 


non-plicate species, these had best be restored to Orthothetina, a 
name here abandoned), and Schellwienella (new, genotype Spi- 
rifera crenistria Phillips, heretofore thought to have the internal 
characters of Orthotetes). Six new’ species are described. 
CS; 
5. Geological Hucursion in the Grand Canyon District ; by 
D W. Jounson, Proc. Bost. Soc. Nat. Hist., vol. xxxiv, p. 155— 
161, 1909.—This presents a study of faulting in a part of the 
Grand Canyon district and is of considerable interest in showing 
for how long a period movements have continued in the region. 
Thus the author finds that three periods of faulting are shown i in 
the area of the San Francisco Plateau, along the same plane; the 
first and second periods separated by a long era of base-levelling 
while the second and third were divided “by a shorter, but yet 
distinct, interval of erosion. In the main the faults of the region 
are of ancient date. The paper is illustrated by a number of ex- 
cellent half-tone cuts of photographs. L. Vv. P. 
6. Aufbau des Gebirges in der Umgebung der Strassburger 
LETiitte an der Scesaplana ; von W. von SxEipurrz. Festschr. 25- 
jabr. Best. d, Sekt. Strass. i. E. d. deut. u. 6sterreich. Alpenver. 
Pp. 45-68, 1910, Strassburg.—This is a small geological guide, 
well planned and excellently carried out. It describes the geol- 
ogy surrounding an elevated point in the Raetikon Alps, on the 
border between the Tyrol and Switzerland. It is an excellent 
lessou in tectonics, folding, faulting, and thrusting being visible 
on a gigantic s¢ ale. A large panorama, well drawn and geolog- 
ically color ed, is a prominent feature of the work, which is also 
illustrated by a number of sections and photogravure plates of 
the scenery. Wil 
7. Granites of the Southeastern Atlantic States; by T. L. 
Warson. Bull. 246 U.S. Geol. Surv., pp. 282, 1910.—The author 
has given in this work a general description of the granite areas 
in the region mentioned, extending from Maine to Georgia, and 
including “Tennessee and Alabama. The petrographic, physical, 
and chemical properties of the varied occurrences are stated, and 
especial emphasis is laid upon their technical exploitation and 
use. The work is illustrated with many maps, diagrams, and pho- 
tographs, the latter chiefly of granite quarries. While its value is 
mostly on the economic side, and it should prove of great service 
in the granite quarrying industr y, it has none the less scientific 
interest and is a useful work of reference for geologists and 
petrographers. Te VersPa 
8. Lhe Volcanic Rocks of Victoria ; by EH. W. Sxnars. 
Address by the Pres. Sec. C, Aust. Assoc. Adv. Sci., 1909.--This 
paper contains a general account (and a full bibliography) of the 
igneous rocks in this part of Australia ; it will undoubtedly prove 
of considerable local service, and to the general reader it empha- 
sizes once more what a wide distribution the alkalic rocks have in 
Australia, The brief descriptions are materially aided by the 
considerable number of analyses which are quoted. The article 
is accompanied by several sections and a map, Tie NIaD 


Geology and Natural [istory. 81 


9. Analcite Rocks.—In a recent paper Mr, G. W. Tyrretr of 
Glasgow University has shown that among the numerous intru- 
sions of igneous rocks that penetrate the Paleozoic strata of the 
west and south of Scotland there are numerous types of alkalic 
nature, which are of interest to petrologists. Thus he describes 
teschenites of several types, essexites, trachytes, etc., along with 
other varieties. Among these in the south of Scotland are rocks 
containing much analcite which, for several reasons, he considers 
as a primary constituent. In a letter to the reviewer he says, in 
addition, that “the group contains rocks of the analcite series 
corresponding to the nepheline series,—from nephelite-syenite to 
ijolite. The analcite syenite is a remarkably fresh rock composed 
principally of soda-orthoclase, albite, and analcite, with purple 
titanaugite, barkevikite, and aegirine. The latter is inclosed in 
the analcite, which is very abundant. Another remarkable rock 
is one composed principally of analcite, with a little nepheline, 
crowded with perfect euhedral barkevikite, sometimes with a 
little titanaugite and plagioclase.” These appear to be remark- 
able and novel rock types, and Mr. Tyrrell’s forthcoming paper 
upon them, in which full details are promised, will be awaited 
with much interest by petrologists.—7Zrans. Geol. Soc. Glasgow, 
vol. xili, Pt. ILI, p. 299, 1909. ity We les 

10. Morganite, a Rose-colored Beryl.—In a paper read before 
the New York Academy of Science on December 5th, 1910, Dr. 
Grorce Kunz described some new and remarkable gems which 
had been cut from a rose-colored beryl found in Madagascar. 
He proposed the name morganite for them in honor of Mr. John 
Pierpont Morgan of New York City. 

The beryl, together with other gem minerals, is found at 
Maharita in the valley of Sahatony, an affluent of the Manandora 
which passes along the western slope of Mount Bity, Madagascar. 
The minerals occur in numerous veins of pegmatite which 
penetrate the alternating layers of limestone, mica schist, and 
quartzite. The vems often attain a thickness of nearly one 
hundred feet and consist of quartz, amazonite often in fine colors, 
albite, lithia, tourmaline, lepidolite in deep shades, etc. In these 
veins magnificent crystals of tourmaline, beryl, and kunzite have 
been found. 

The pink beryl, morganite, has also been found associated 
with kunzite at Pala, San Diego Co., California, in large but 
pale crystals and sometimes more of a salmon color. At the 
Madagascar locality, however, it is found in magnificent speci- 
mens of gem quality, some which weighed 984 carats. Its color is 
a true rose-pink, a pure, clear color with less of the magenta tint 
than is found in even a pale tourmaline and lacking the lilac of 
the kunzite. It is obtained in larger, finer stones than any other 
pink gem mineral we have ever had. 

When exposed to the Réntgen rays the new beryl assumed 
a brilliant cerise color under a tube of moderately low vacuum 
with about twelve or fifteen amperes through the tube. When 


Am. JOUR. pene roueae SERIES, Vou. XXXI, No. 181.—January, 1911. 


82 Scientific Intelligence. 


the current was increased the brilliancy of the stones increased 
accordingly. Under the mercury light it became a pale lilac. 

This beryl has been found by Ford* to contain 4°98 per cent 
of alkalies, distributed as follows: Na,O, 1°60; Li,O, 1°68; Cs,O, 
1:70. Along with this unusual amount of alkalies goes a slightly 
higher specific gravity (2°79) and an increase in the mean refrac- 
tive index and the amount of birefringence. W. EF, 

11. Zables for the Determination of Minerals by Physical 
Properties, ascertainable with the aid of a few Field Instruments, 
based on the system of the late Prof. Dr. A. Wetssacu ; by 
Prerstror Frazer and Amos PrAsteE Brown. Sixth edition. 
Pp. xiii, 125. Philadelphia, 1910 (J. B. Lippincott Co.).—This is 
a new edition of a well-known work, which has filled a highly 
useful place, both in Germany and as translated into English. 

12. The Subantarctic Islands of New Zealand: Reports on 
the Geo-physics, Geology, Zoology, and Botany of the Islands 
lying to the South of New Zealand, based mainly on Observa- 
tions and Collections made during an Expedition in the Govern- 
ment Steamer ‘‘ Hinemoa” (Captain J. Bollons) in November, 
1907. Edited by Cuas. Cuirron. Published by the Philosophi- 
cal Institute of Canterbury. Twovolumes: Vol. I, pp. xxxv, 388, 
with 20 plates and many figures. Vol. II, pp. 389-848, with 
numerous illustrations (John Mackay, Wellington, N. Z., 1909).— 
This work consists of thirty-five separate articles, written by spec- 
jalists in various parts of the world, and based on the collections 
obtained by the members of the scientific staff which accompanied 
the magnetic survey expedition to Auckland and Campbell 
Islands. Three of the papers relate to geo-physics, 3 to geology, 
22 to the various groups of animals, 6 to plants; while the conclud- 
ing article, by the editor, presents asummary of the results and dis- 
cusses the biological relations of the islands. Many new species 
of invertebrates were discovered, and are here described and 
figured. The only mammals found about the islands are seals 
and cetaceans. There are no reptiles of any kind. Seabirds, of 
which the species of albatross and penguin are most conspicuous, 
are abundant. Of these there are several excellent reproductions 
of photographs showing the nesting habits. There are a few kinds 
of land birds, in addition to: several species of British birds, 
including the English sparrow, goldfinch, starling, thrush and 
blackbird which have reached the islands from New Zealand. A 
comparison of the animals and plants found on tbese islands 
offers strong evidecne of a former connection with the Antarctic 
continent. W. R. C. 

13. British Nudibranchiate Mollusca, with Figures of the 
Species ; Part viii, Supplementary. Figures by the late Josuua 
ApEr and the late ALsany Hancock and Others, text by Sir 
Cuartes Exior. Quarto, 197 pp., with 8 colored plates. 
London, 1910 (Ray Society).— This supplementary volume to 
Alder and Hancock’s classic monograph, published in 1845-1855, 


* This Journal, xxx, 128, 1910, 


Geology and Natural History. 83 


consists in part of the drawings and notes which they had made 
some years ago with a view to issuing a supplementary volume 
to include such rare, inconspicuous, or little known species as had 
been found on the British coast during the many years that had 
elapsed since the publication of their monograph. After their 
death Sir Charles Eliot undertook the preparation of the volume, 
and the great value of the work is largely due to the lucid dis- 
cussion of the general anatomical features and relationships of 
this group of animals from his pen. The chapters on variation 
and distribution, bionomics, embryology and larval stages, and 
classification, are treated on such broad biological lines as to be of 
general interest, while the concluding chapter contains a synopsis 
of the families, genera and species which occur in the Northeast- 
ern Atlantic region, and brings up to date the nomenclature of 
the forms which have been recorded during the more than half 
century since the publication of the first seven parts of the work. 
Of the 68 figures, 45 are reproduced from the drawings of Alder 
and Hancock, while the remaining 23 have been drawn, mainly 
from living animals, especially for the present volume. w. R. c. 
14, Medusae of the World; by Atrrep GoLpsporouen 
Mayer. 38 volumes, quarto. Washington, 1910. (Published 
by the Carnegie Institution.)— Volume I, pp. 230 + xv, with 29 
colored plates and 119 text figures, and Volume II, pp. 231 to 
498 + xv, with 26 plates and 208 text figures, contain descrip- 
tions of all the known Hydromedusae of the world and of such 
hydroids as are known to produce medusae. Volume III, on the 
Scyphomedusae, contains pp. 499-735, with 21 plates and 101 text 
figures. This splendid monograph is by no means a systematic 
treatise only, for it includes a discussion of all known facts 
regarding the embryology, cytology and physiology of each 
species. The large number of beautifully executed drawings on 
the colored plates illustrate alike the artistic ability and tireless 
energy of the author. Wie Rou. 
15. An Introduction to Zoology ; by Rosperr W. Hrener. 
Pp. xii, 350, with 161 figures. New York, 1910 (Macmillan 
Company).—This book represents a wide departure from the 
customary plan of an elementary book in zoology in that its aim 
is to illustrate the important biological principles by a compara- 
tively thorough study of a very few types rather than by a super- 
ficial study of a representative of each of the principal phyla. A 
general discussion of the principles of biology, the phenomena of 
life, the cell, and cell theory is followed by a comprehensive 
study of the structure and life processes of Amoeba and Para- 
mecium, with reference to certain other protozoa. The hydra, 
worms, crayfish, and the honeybee represent the metazoa and are 
treated with a special reference to the physiological peculiarities 
of their various organ systems. An interesting chapter on the 
history of zoology, with portraits of several of the earlier inves- 
tigators, and a final chapter on the more important zoological 
theories and the facts on which they are based, emphasize the 


S84 Scientific Intelligence. 


bearing of zoology on human thought and progress. The book 
is cordially recommended as giving a thorough preparation for 
oT oo courses in the subject. W. RB. C. 
Animal Study : with Directions for Laboratory and Field 
Work ; by W. H. D. Meier. Boston and New York, 1910 
(Ginn & Co.).—A loose-leaf laboratory note book of convenient 
size, and well arranged for the use of elementary classes in Zool- 
ogy. The type system, for both invertebrates and vertebrates, 
is employed. The directions for work and questions to be 
answered are printed on the top of each sheet, with blank space 
for drawings beneath. Additional sheets of drawing and note 
paper are provided to be inserted in place as required. “The 
directions for work are at once clear and suggestive and the 
questions stimulative of interest outside the classroom. 
W. R. C. 
Methods of Attracting Birds ; by Gitzerv H. Trarron. 
With illustrations; pp. xv, 171. Boston and New York, 1910 
(Houghton Mifflin Company).—The desirability of encouraging 
the feeding and nesting of birds around the home, garden, or 
orchard is here discussed, and such methods of accomplishing 
this end as have been found practicable either in this or other 
countries are described and illustrated. Suggestions are made 
for the protection of our native birds from the rigors of winter, 
from cats and other enemies, and especially from their arch 
enemy, the English sparrow. Ww. R. €. 

18. Second Report on the Hymeniales of Connecticut ; by 
Epwarp Alpert Wuirtr, Pp. 70, with 28 plates. State of 
Connecticut, Geological and Natural History Survey. Bulle- 
tin No. 15, Hartford, Conn., 1910.—This is properly a sup- 
plement to Bulletin No. 3 of the Survey, containing a preliminary 
report, by the same author, on the fleshy and woody fungi of the 
State. Some of these are edible mushrooms, while others are 
extremely poisonous. The first part of the present Bulletin gives 
analytical keys for the identification of Connecticut species of 
Agaricacee. This is accompanied by a series of excellent half- 
tone plates from original photographs by the author. The second 
part describes the edible species of the group, while the third 
gives a list of the species reported since July, 1905, and hence 
not included in Bulletin No. 3. 

Copies of this Bulletin may be obtained from the State Librarian, 
Geo. 8. Godard ; the price, including postage, is 35 cents, but it 
will be sent gratuitously to scientific men, teachers, and others, 
particularly citizens of the State, who require it for their special 
use. 


i til | FEBRUARY, 1911. 


Established by BENJAMIN SILLIMAN in 1818. 


= <tr ey 
eau 1% 


AMERICAN 
JOURNAL OF SCIENCE. 


Epirorn: EDWARD 8S. DANA. 


e 


ASSOCIATE EDITORS * 


Proressors GEORGE L. GOODALE, JOHN TROWBRIDGE, 
W. G. FARLOW anp WM. M. DAVIS, or Camsrincez, 


Proressors ADDISON E. VERRILL, HORACE L. WELLS, 
L. V. PIRSSON anp H. E. GREGORY, or New Haven, 


Proressor HENRY S. WILLIAMS, or Iruaca, 
Proressor JOSEPH S. AMES, or Battrore, 
Mr. J. S. DILLER, or Wasuiveron. 


FOURTH SERIES 
VOL. XXXI—[WHOLE NUMBER, CLXXXI] 


No. 182—FEBRUARY, 1911. 


NEW HAVEN, CONNECTICUT. 


Gusti Pd bo 


THE TUTTLE, MOREHOUSE & TAYLOR CO., PRINTERS, 123 TEMPLE STREET, 


ee ee SS a 


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 
registered letters, or bank checks (preferably on New York banks). 


y 

oC 

i 

q a 
eae 


SPECIAL ANNOUNCEMENT. 


MORGANITE. 

I beg to advise my numerous patrons that after considerable difficulty I 
have secured a small lot, in the rough state, of this very rare and new gem 
from-Madagascar; this is the first opportunity ever offered collectors to 
purchase this unique variety of Beryl in this country. 


REMARKABLE RUBY GEM CRYSTALS IN MATRIX 
FROM BURMA. 

These I have just secured from a mining engineer, who has returned from a 
visit to this celebrated locality, and was fortunate in securing the lot; the 
crystals are of the very finest quality in color and shape and are of the 
pigeon-blood quality ; prices and further particulars on application. 


REMARKABLE COLLECTION. 
I have received a remarkable collection of crystallized minerals of the 
finest quality, representing old finds and very rare examples of recent locali- 
ties which I have just placed on sale. 


HERKIMER QUARTZ. 

Just secured a good lot of crystallized quartz in Bituminous limestone, the 
finest I ever saw, and in the same box were a fine lot of quartz on matrix” 
from Amsterdam, N. Y. It is known that specimens are not obtainable 
now ; as this locality is all built over their value will be appreciated. Prices 
range from 20 cents to $1.50. 

Have received a very remarkable Amethyst from Port Arthur, China, 
9x10, beautiful color: would make an exceptionally good museum specimen. 
Must be seen to be appreciated. _ 


A FEW REMARKABLE GOLD SPECIMENS. 

One consisting of one inch solid vein of gold, very rich, contains 2034 
ounces ; the matrix itself is a rich ore of gold. One side of the specimen is 
polished ; it is 31g x 28¢ x 214 inchesin size. I am selling this at a sacrifice ; 
former value $500, as announced in the JouRNAL oF Screnoz, July, 1909; 
will be disposed of now for $300, the actual value of the gold in the specimen. 

IRIDESCENT PYRITES. 

A recent trip of a local mineralogist awarded him a small lot of the 
finest quality of pyrites from South River, N. J. They are of the iridescent 
quality, the finest from this locality I have ever seen. Do not fail to secure 
one of these brilliant specimens. 

I shall be pleased to send anyone on request, an assortment, prepaid, for 
selection, and guarantee satisfaction. 


A. H. PETEREIT, 
81—83 Fulton Street, New York ae 


Phone Beekman 1856, 


THE 


AMERICAN JOURNAL OF SCIENCE 


[FOURTH SERIES.] 


Arr. X.—On an Adjustment for the Plane Grating Simi- 
lav to Rowland’s Method for the Concave Grating ;* by 
Cart Barus and Maxweti Barts. 


1. Apparatus.—The remarkable refinement which has been 
attained (notably by Mr. Ives and others) in the construction of 
celluloid replicas of the plane grating, makes it desirable to 
construct a simple apparatus whereby the spectrum may be 
shown and the measurement of wave-length made, in a way 
that does justice to the astonishing performance of the grating. 
We have, therefore, thought it not superfluous to devise the 
following inexpensive contrivance, in which the wave-length 
is strictly proportional to the shift of the carriage at the eye- 
piece; which, for the case of a good 2-meter scale divided into 
centimeters, admits of a measurement of wave-length to a few 

ngstr6m units and with a millimeter scale should go much 
further. 

Observations are throughout made on both sides of the 
_ineident rays and from the mean result most of the usual errors 
should be eliminated by symmetry. It is also shown that the 
symmetrical method may be adapted to the concave grating. 

In fig. 1, A and B are two double slides, like a lathe bed, 
155™ long and 11°" apart, which happened to be available for 
optical purposes, in the laboratory. They were, therefore, 
used, although single slides at right angles to each other, 
similar to Rowland’s, would have been preferable. The car- 
riages C and D, 30™ long, kept at a fixed distance apart by 
the rod afb, are in practice a length of +inch gas pipe, 

*The greater part of this work was done by my son and myself and con- 
tributed to the Proceedings of the American Philosophical Society, April 


24, 1909, from which the present paper is abridged. I have since added 
some other matter at the end.—C. B. 


Am. JouR. Scl.—Fovurts Smrins, Vou. XX XI, No. 182.—Frsruary, 1911. 
7 


86 OC. Barus and M. Barus—Plane Grating Similar to 


swivelled at a and 6, 169'4 centimeters apart, and capable of 

sliding right and left and to and fro, normally to each other. 
The swivelling joint, which functioned excellently, is made 

very simply of +-inch gas pipe 'T’s and nipples, as shown in 


Fie, 1. 


Fic. 1. Plan of apparatus. AA, BB, slides; CD, carriages ; 
R, connecting rod. 


fig. 2. The lower nipple JV is screwed tight into the T, 
but all but tight into the carriage D, so that the rod ad turns 
in the screw JV, kept oiled. Similarly the nipple JV” is either 
screwed tight into the T (in one method, revoluble grating), 


Rowland’s Method for the Concave Grating. 87 


or all but tight (in another method, stationary grating), so that 
the table ¢¢, which carries the grating g, may be fixed while 
the nipple WV’ swivels in the T. Any ordinary laboratory 
clamp and a similar one on the upright ¢ (screwed into the 
earriage S) secures a small rod & for this purpose. Again, a 
hole may be drilled through the standards at A and ¢ and 
provided with set screws to fix a horizontal rod & or check. 
The rod & should be long enough to similarly fix the standard 
on the slide S carrying the slit and be prolonged further 
toward the rear to carry the flame or Geissler tube apparatus. 


Hie. 2. 


Fie. 2. Elevation of the grating (g) and the eye-piece (#) standards. 


The table ¢ is revoluble on a brass rod fitting within the gas 
pipe, which has been slotted across so that the conical nut 
may hold it firmly. The axis passes through the middle of the 
grating, which is fastened centrally to the table ¢¢ with the 
usual tripod adjustment. 4-14 

2. Single Focusing Lens in Front of Grating.—T1 shall 
describe three methods in succession, beginning with the first. 
Here a large lens, Z, of about 56° focal distance and about 
10 in diameter, is placed just in front of the grating, 
properly screened and throwing an image of the slit S upon 
the cross-hairs of the eye-piece Z, the line of sight of which is 
always parallel to the rod ad, the end 6 swivelled in the car- 
riage C, as stated (see fig. 2). An ordinary lens of 5 to 10™ 


88 C0. Barus and M. Barus—Plane Grating Similar to 


focal distance, with an appropriate diaphragm, is adequate and 

in many ways preferable to stronger eye-pieces. The slit S, 
carried on its own slide and capable of being clamped to e 
when necessary, as stated, is additionally provided with a long 
rod hA lying underneath the carriage, so that the slit S may be 
put accurately in focus by the observer at C. /’is a carriage 
for the mirror or the flame or other source of light whose 


Fias. 3, 4, 5. 


Fies. 3, 4,5. Diagrams. 


spectrum is to be examined; or the source may be adjustable 
on the rear of the rod by which D and S are locked together. 

Finally the slide AB is provided with a scale ss and the 
position of the carriage C read off by aid of the vernier v. A 
good wooden scale graduated in centimeters happened to be 
available, the vernier reading to within one millimeter. For 
more accurate work a brass scale in millimeters with an 
appropriate vernier should of course be used. 

Eye-piece F, slit S, flame J, ete., may be raised and lowered 
by the split tube device shown as at J/ and W/’ in fig. 2. 


Rowland’s Method for the Concave Grating. 89 


3. Adjustments.—The first general test which places slit, 
erating and its spectra and the two positions of the eye-piece 
in one plane, is preferably made with a narrow beam of sun- 
light, though lamplight suffices in the dark. Thereafter let 
the slit be focused with the eye-piece on the right marking the 
position of the slit; next focus the slit for the eye-piece on the 
left; then place the slit midway between these positions and 
now focus by slowly rotating the grating. The slit will then 
be found in focus for both positions and the grating, which acts 
as a concave lens counteracting Z, will be symmetrical with 
respect to both positions. 

Let the grating be thus adjusted when fixed normally to the 
slide B or parallel to A. Then for the first order of the 
spectra the wave-length X=d sin 0, where d is the grating 
space and @ the angle of diffraction. The angle of incidence ¢ 
is zero. 

Again let the grating, adjusted for symmetry, be free to 
rotate with the rod a). Then @ is zero and A=d sin 7. 

In both cases however if 2 be the distance apart of the car- 
riage C, measured on the scale ss, for the effective length of 
rod ab=r between axis and axis, 


N=dza/r or (d/2r) 2a, 


so that in either case X and # are proportional quantities. 

The whole spectrum is not however clearly in focus at one 
time, though the focusing by aid of the rod AA is not difficult. 
For extreme positions a pulley adjustment operating on the ends 
of / is a convenience, the cords running around the slide AA. 
In fact if the slit is in focus when the eye-piece is at the cen- 
ter (@=0, 1=0) at a distance a from the grating, then for the 
fixed grating, fic. 4, 
a'=a- 


D} o? 
Tr —o" 


where a’ is the distance between grating and slit for the dif- 
fraction corresponding to . Hence the focal distance of the 
grating regarded as a concave lens is /=ar'/a*. For the fixed 
grating and a given color, it frequently happens that the 
undeviated ray and the diffracted rays of the same color are 
simultaneously in focus, though this does not follow from the 
equation. 

Again for the rotating gratin 
between slit and grating 


Ck aA 
g, fig. 3, if a” is the distance 
Yr — 7 


eS 
o SI , 


so that its focal distance is 


ae eee 
vi =. 
x 


90 C. Barus and M. Barus— Plane Grating Similar to 


It follows also that a xa” =a. For a=80™ and sodium 
light, the adjustment showed roughly 7’ = 650, £” = 570, 
the behavior being that of weak concave lenses. The same 
a= 80 and sodium light showed furthermore a = 91 and 
a’ =70°3. 

Finally there is a correction needed for the lateral shift of 
rays, due to the fact that the grating film is enclosed between 
two moderately thick plates of glass (total thickness ¢=-99™) of 
the index of refraction n. Moreover, since this shift is on the 
rear side of the lens Z, its effect on the eye-piece beyond will 
be (if f is the principal focal distance and 4 the conjugate focal 
distance between lens and eye-piece, remembering that the 
shift,smust be resolved parallel to the scale ss) 


<r aeae yecee) ($?) 


where the correction ¢ is to be added to 2a, and is positive for 
the rotating grating and negative for the stationary grating. 
Hence in the mean values of 2x for stationary and rotating 
grating the effect of ¢ is eliminated. For a given lens at a 
fixed distance from the eye-piece (6/ /—1) is constant. 
4. Data for Single Lens in Front of Grating.—In conelu- 
sion we select a few results taken at random from the notes. 


TABLE I. 
Grating Line Observed 2x’ Shift Corrected 2x. 

Stationary C 132°60 — ‘26 132°34 
eID 118-90 — "23 118°67 
Tt 98°23 —'19 98°04 
Hydrogen 87°87 —‘16 87°71 

Violet 3 
Rotating C 132710 +°26 132°36 
D, 118°45 23 118°68 
F 97°90 “19) 98°09 
H. Violet 87°50 ‘16 87°66 


The real test is to be songht in the corresponding values of 
2” for the stationary and rotating cases, and these are very 
satisfactory, remembering that a centimeter scale on wood and 
a vernier reading to millimeters only was used for measure- 
ment. 

5. Single Focusing Lens Behind the Grating.—The lens 
LI’, which should be achromatic, is placed in the standard 
behind g. The light which passes through the grating is now 
convergent, whereas it was divergent in §2. Hence the focal 
points at distances a’, a” lie in front of the grating; but in 


Rowland’s Method for the Concave Grating. Bl 


other respects the conditions are similar but reversed. Apart 
from signs, for the stationary grating 


alae 2 
a=a peers 


, 


and for the rotating grating 
Gf 
Nees 
ee 


The correction for shift loses the factor (6//—1) and becomes 


tx ( 1 1 
Tas V1 =a" |r? ey Va) 

As intimated, it is negative for the rotating grating and posi- 
tive for the stationary ¢ erating. It is eliminated in the mean 
values. 

6. Data. Single Lens Behind the Grating.—An example 
of the results will suffice. Different parts of the spectrum 
require focusing. 


Grating Line Rac! Shift Qa 
Stationary = -.---- D, 118°40 +°13 118°53 
Rotating se e= = D, 118°65 =>18 -118°52 


The values of 27, remembering that a centimeter scale was 
used, are again surprisingly good. The shift is computed by 
the above equation. It may be eliminated in the mean of the 
two methods. The lens Z’ may be more easily and firmly 
fixed than Z. 

7. Collimator Method.—The objection to the above single- 
lens methods is the fact that the whole spectrum is not in 
sharp focus at once. Their advantage is the simplicity of the 
means employed. If a lens at LZ’ and at Z are used together, 
the former as a collimator (achromatic) and with a focal dis- 
tanee of about 50°, and the latter (focal distance to be large, 
say 150°") as the objective of a telescope, all the above diffi- 
culties disappear and the magnification may be made even 
excessively large. The whole spectrum is brilliantly in focus 
at once and the corrections for the shift of lines due to the 
plates of the grating vanish. Both methods for stationary and 
rotating gratings give identical results. The adjustments are 
easy and certain, for with sunlight (or lamplight in the dark) 
the image of the slit may be reflected back from the plate of 
the ovating on the plane of the slit itself, while at the same 
time the transmitted image may be equally sharply adjusted 
on the focal plane of the eye-piece. It is, therefore, merely 
necessary to place the plane of spectra horizontal. Clearly a’ 
and @” are all infinite. 


92 OC. Barus and M. Barus—Plane Grating Similar to 


In this method the slide Sand D are clamped at the focal 
distance apart, so that flame, ete., slit, collimator lens and grat- 
ing move together. The grating may or may not be revoluble 
with the lens Z on the axis a. 

8. Data for the Collimator Method.—The following data 
chosen at random may be discussed. The results were obtained 
at different times and under different conditions. The grating 
nominally contained about 15,050 lines per inch. The efticient 
rod length ab was R=169'4™. Hence if 1/C=15,050~x 
3937 X 338°8, the wave-length A = C-2x. 


Grating Lines Qa! 2a cs 
Stationary es eee DD. 118°30 118'19 
Rotate eso .. -eae D, 118-08 118719 
Stationary) suse e ese D, 118:27 118716 
Rotate eles ae D 118-05 118°16 


Rowland’s value of D, is 58°92X10-°™; the mean of the 
two values of 2x just stated will give 58° 8710-2, The dif- 
ference may be due either to the assumed grating space, or to 
the value of # inserted, neither of which were reliable abso- 
lutely to much within 1 per cent. 

Curious enough an apparent shift effect remains in the 
values of 2x for stationary and rotating grating, as if the colli- 
mation were imperfect. The reason for this is not clear, 
though it must in any case be eliminated in the mean result. 
Possibly the friction involved in the simultaneous motion of 
three slides is not negligible and may leave the system under 
slight strain equivalent to a small lateral shift of the slit. 

9. Discussion.—The chief discrepancy is the difference of 
values for 2v in the single lens system (for D,, 118-7 and 
118'5°", respectively) as compared with a double lens system 
(for D,, 118-2°") amounting to *2 to ‘4 per cent. For any 
given method this difference is consistently maintained. It 
does not, therefore, seem to be mere chance. The detailed 
investigation, which must be omitted here,* made it clear that 
the effect of focusing is without influence on the diffraction 
angle and much within the limits of observation. It is, there- 
fore, probable that the residual discrepancy in the three 
methods is referable to a lateral motion of the slit itself due to 
insufficient symmetry of the slides AA and BL in the above 
adjustment. This agrees, moreover, with the residual shift 
observed in the case of parallel rays in § 8. 

10. Reflecting Grating—The adjustment of the plane grat- 
ing if cut on specular metal is nearly identical to the above, 
except that the collimator is fixed as a whole in front of the 
grating, either to the slide carrying the standard of the grating, 
B, or else quite in front of the cross slide AA, fig. 5 above, 


* See Proc, Am. Phil. Soc., 1. ¢. 


Rowland’s Method for the Concave Grating. nos 


so as to give clearance for the to and fro motion of the rail, /2. 
This admits of measurement of w on both sides of the slit, so 
that 2v, the distance apart of the two symmetrical positions for 
a given spectrum line, is again observed. 

11. Rowland’s Concave Grating.—For the case of the con- 
cave grating, the accurate adjustment for symmetrical meas- 
urement on both sides of the slit is not feasible, because the 
slit and eye-piece would have to pass through each other. It 
is possible, however, to find conjugate foci at different distances » 
from the grating in the normal position, which approximately 
answer the purposes of measurement. Rowland’s equation 


(cosz/p — 1/ &) cost + (cos 6/p’ — 1/p') cos 6 = 0 
where p and p’ are the conjugate focal distances for angles of 
incidence and deviation ¢ and @, may for 0 = 0 be written 

1 lpm aligeecs 
a CIO ~ Th CIs Say FI 
where p, is the normal distance of the eyepiece, so that 
1 1 2 


If in figure 6, the slit S is put at p’ > & from the grating 
G (normal position), the image is at Hat the end of p, from 
G, where p, < H <p’. If p, be used as a rail instead of R 
and put at an angle of incidence @, for the eye-piece at Z’ or EL”, 
Po cost > p. But this excess need not be so large as to inter- 
fere with adequately sharp focusing. 

The following table gives an example, in which the difference 
of p, and p,’ in the normal position is even over 1 foot, an 
excessive amount, as the distance necessary for clearance need 
not be more than a few inches. The grating has 14436 lines 
to the inch and a radius about R = 191. 


TABLE II. 


Conjugate foci of the concave grating. R=191°™, 14436 lines to inch, 
5683 lines to em. D= ‘000,176. 

po=166™,. p=198™, p—po=32™. 1/p.—1/R= 000788. 6=0, sin 
i=A/D. 


Fraunhofer 
ae p Po cos t Diff. (p/cos i)? Lines a 
em. em. 
0° 166°0 166:0 0 27500 B 99° 59! 
5 165°3 165°3 0) 27500 C 91° 54! 
10 163°2 163°5 c=) 93} 27400 D 19° 34’ 
15 159°6 160°3 — "7 27300 EH 17° 26° 
! 20 154°7 156°0 —1°3 97100 Ji 16° 02’ 
25 148°5 150°4 —1°9 26800 G 14° 10’ 
30 140:9 143'7 —2°8 26500 
35 132°2 136°0 --3°8 26000 


40 122°3 12771 —4'8 25500 


94 CO. Barus and M. Barus—Plane Grating Similar to 


The greater part of the visible spectrum is thus contained 
between 7 = 15° and ¢ = 20°. It follows that the excess of 
Po CoS 7 — p lies between 7 and 13"". Hence the eye-piece 
may be placed at a mean position corresponding to 10™™" and 
give very good definition of the whole spectrum without 
refocusing, as I found by actual trial. Within 1™ the focus 
is sharp enough for most practical purposes. If the distances 
po and p,’ are selected so that eye-piece and slit just clear each 
other the definition is quite sharp. 

The diffraction equation is not modified and if 2a corre- 
sponds to the positions + ¢ and — ¢ for the same spectrum line, 


De (D/f) Phos 


It is, therefore, not necessary to touch the eye-piece, and this 
is contributory to accuracy. 


Fic. 6. 


If Rowland’s equation is differentiated relatively to p and p’ 


—dp = (—* / dp, , where the dp,’/p,’ factor is constant. 
Po COS 7% 


Hence — dp varies as (p/cos 2)’, given in the table. If further- 
more a comparison is made between dp, and dp this equation 
reduces to 


a/dp,/dp = |(R—p,)(i—cos 7) |/F# cos z 
which becomes unity either for 7=0 or for p, = (Rowland’s 
case). 
12. Summary.—By using two slides symmetrically normal 
to each other and observing on both sides of the point of 


————— 


Rowlands Method for the Concave Grating. 95 


interference, it is shown that many of the errors are elimi- 
nated by the symmetrical adjustments in question. The slide 
carrying the grating may be provided with a focusing lens in 
front or again behind it, if the means are at hand for actuat- 
ing the slit which is not shar ply in focus on the plane of the 
eye-piece carried by a second slide throughout the spectrum at 
a given time. It is thus best to use both lenses conjointly, 
the latter as a collimator and the former as an objective of the 
telescope in connection with the eye-piece. It is shown that a 
centimeter scale parallel to the eye-piece slide with a vernier 
reading to millimeters is sufficient to measure the wave lengths 
of light to few Angstrom units, while the wave lengths are 
throughout strictly proportional to the displacements along 
the scale. The errorsof the three available methods and their 


counterparts are discussed in detail. The method is applica- 


ble both to the transparent and the reflecting grating. 

It is furthermore shown that in case of Rowland’s concave 
grating observation may be made symmetrically on both sides 
of the slit, or for reasonable clearance of slit and eye-piece 
passing across each other, although one conjugate focal dis- 
tance is now not quite the projection of the other. 


Brown University, Providence, R. I. 


% HH. Z. Kip—Determination of the Hardness of Minerals. 


Arr. XI.— Determination of the Hardness of Minerals, IT ; 
by H. Z. Kier. 


In the issue of this Journal for July, 1907, an article by the 
writer on the subject of mineral hardness appeared, whose 
threefold object was outlined as follows: 1. To invite general 
acceptance of a single definition of hardness. 2. To establish 
theoretically in conformity with the definition the best method 
of investigation. 38. To put this method in practice by means 
of suitable apparatus and adequate mathematical calculation. 

Inasmuch as it is my present purpose to act as my own critic 
as well as to publish the results obtained in carrying out the 
investigations indicated above under 3, it will be found excuse- 
able, perhaps, if I depart from the general practice of contribu- 
tors to the extent of speaking in the first person instead of the 
third.* 

In regard to the formula for determining hardness, estab- 
lished in my previous paper, H=~/a’+y’, I may say that no 
mineralogist or physicist who has favored me with his opinion 
has taken exception to this equation. Indeed so long as the 
generally accepted definition of hardness prevails (resistance to 
abrasion) this is, and ean be, the only adequate formula. 

If in what follows I appear to view my own results with 
some scepticism, I wish it to be understood that this is not the 
result of a lack of faith in the method employed, but merely 
an acknowledgment of the difficulty of dealing accurately 
with molecular forces by mechanical means, such means, at 
least, as I have had at my disposal. 

The apparatus employed was described in its general prin- 
ciples in my previous paper. As actually constructed it dif- 
fered from the description given in two points only. <A pulley 
and weight were substituted for the spring scale (see fig. 3, 
loc. cit.) in determining y (lateral force), the mineral and car- 
riage, meanwhile, remaining immovable. This made it nec- 
essary to determine x (vertical force) and y in two separate 
operations, which, however, proved to be rather an advantage 
than a disadvantage. Likewise two arms were substituted for 
four in the frame carrying the diamond point. These arms 
were bent and continued down beneath the level of the sur- 
face of the mineral so that the frame and point remained in 
equilibrium even when no weight was attached. The method 

*This is rendered the more necessary by the fact that it is my duty, no 
less than my privilege, to make due acknowledgment in this place to the 
trustees of the Elizabeth Thompson Science Fund (Boston) for the appro- 


priation (Grant No. 136) without which these investigations would hardly 
have been undertaken. 


H. Z. Kip—Determination of the Hardness of Minerals. 97 


of applying the vertical force by means of a weight suspended 
beneath the diamond point, with the necessary consequence 
that this force, at least, is expended solely in the abrasion of 
the mineral, proved itself to be even more efficacious than was 
anticipated, and while experimenters are notoriously devoted 
to their own mechanical devices, I cannot but believe that this 
feature will be adopted in the sclerometer of the future, pro- 
vided this instrument is ever standardized. 

The values obtained for x, y, and H for Nos. 3 to 9, inelu- 
sive, in Mohs’s scale are given in the subjoined table. Values 
for tale and selenite could not be obtained for the reason that 
these two minerals yielded to the diamond point even when 
the latter was balanced merely by the weight of the frame in 
which it was mounted. 


x y H 
Calcite 1870 me. 250 mg. 1887 mg. 
Fluorite 3300 1180 350d 
Apatite 5010 500 5035 
Orthoclase: 13566 1292 13627 
Quartz 22135 2128 292937 
‘Topaz 20197 1539 20255 
Corundum 94130 Q774. 24289 


Two diamond points were used in these tests, the first weigh- 
ing in its frame 784 mg., and the second 2723 mg. The 
former was used on calcite, fluorite and apatite; the second, 
and sharper, point on apatite and the remaining members of the 
seale up to and including corundum. It was found that the 
force required to produce abrasion on apatite with point No. 1 
was 3°8 times that required with pot No. 2. The values 
obtained, therefore, with point No. 2 for orthoclase, quartz, 
topaz and corundum were raised in this proportion and so 
appear in the table. ; 

It would, of course, give more reliable results if one and the 
same abrading instrument were used throughout. But neither 
of the diamond points prepared at my request by Messrs. 
Richard Miller-Uri & Cie. (Braunschweig) seemed suited for 
all of the minerals tested, and with the time and funds at my 
disposal it was not possible to reconstruct the apparatus and 
repeat the tests. Future experimenters, it is hoped, will avoid 
this error from the start. The relatively high value for y on 
fluorite is doubtless due to the fact that a polished specimen of 
this mineral was used, no cleavage surface being found among 
the specimens at hand suttciently smooth to be available. 
For the other minerals only natural cleavage or crystalline 
faces were tested. A polished surface is an artificial product 
and has, in my opinion, no place in investigations which deal 
solely with surface phenomena. 


98 HH. Z. Kip—Determination of the Hardness of Minerals. 


While I do not claim or consider the values given in the 
above table as final, I wish to call particular attention to the 
fact that the hardness value shown for quartz is greater than 
that for topaz. Similar values for these two minerals were 
obtained by Rosiwal in 1892; quartz, 149: topaz, 138 (corun- 
dum being placed at 1000), although his unsupported testimony 
seems to have failed to shake the traditional faith of mineralo- 
gists in the infallibility of Mohs’s scale. As a result of my 
experiments I am fully convinced that Rosiwal is correct in 
stating that quartz is harder than topaz, but that the difference 
between the two minerals in this regard is comparatively slight. 
It should be observed that Pfaff, Prof. Jaggar and others who 
have arrived at the opposite conclusion have failed to eliminate 
the factor of density in carrying out their tests. In other 
words, while regarding hardness as resistance to abrasion they 
have sought to determine its value on the theory that it was 
to be measured in terms of resistance to excavation. This 
fact, of course, should also be borne in mind in comparing all 
the values presented by Rosiwal and the writer with those 
obtained by investigators who are satisfied to measure only 
one of the forces employed in producing abrasion and who 
disregard density as a possible factor in the problem. The 
idea that the minerals at the upper end of Mohs’s scale are 
almost infinitely harder than those at the lower end is, in my 
opinion, erroneous. They may appear so when tested by the 
method usually employed in the laboratory, in which the hard- 
ness of the constantly changing abrading agent is perhaps not 
greatly superior to that of the mineral under investigation. 
The nearer the rigidity and hardness of the instrument of 
abrasion approaches the ideal, the less will the differences in 
hardness of the various minerals be found to be. 


Vanderbilt University, Nashville, Tenn. 


Burling—Photographing Fossils by Reflected Light. 99 


Arr. XIIl.— Photographing Fossils by Reflected Light; by 
Lancaster D. Bururne. 


Tae successful photography of fossil organisms is not easy, 
and when the specimens have no relief and are hardly to be 
distinguished, except by ‘reflected light, from the rock on 
which they rest, the problem becomes one of great difficulty. 
Several thousand such specimens were collected by Dr. Chas. 
D. Walcott in the Canadian Rockies, and Dr. R. S. Bassler, 
Mr. J. M. Jessup, and the writer have been working upon a 
method of photographing them by reflected light. The 


Fie. 1. 


scheme developed seems to yield excellent results, is believed 
to be new, and may be generally valuable in photographic 
reproduction. 

The back of an ordinary enlarging and reducing camera was 
pivoted so that it would revolve about a vertical line passing 
through the center of the groundglass or plate, and the rack 
upon which the specimens are mounted was made to revolve 
about a vertical line passing through the center of the speci- 
men. Suitable scales were so attached to both the specimen 
rack and the back of the camera that each might be clamped 
at any desired angle. In practice the specimen is placed in 
position, the lens is removed, and the relative position of the 
light and the angular position of the specimen are manipulated 
to secure the most favorable illumination.* . In order to elimi- 

* Hxperience has shown that variations in the intensity of the reflected 
light are necessary to bring out the particular features of different speci- 


mens and that the degree of illumination required can best be determined 
by direct observation through the camera, rather than upon the groundglass. 


100 Burling—Photographing Hossils by Reflected Light. 


nate distortion, the back of the camera is then revolved through 
an angle corresponding to that indicated by the scale on the 
specimen rack, the lens is replaced, and. the specimen is focused 
and photographed. The best results have been obtained with 
lenses having a focal length of at least six or seven inches, or 
long enough to eliminate any errors arising in the adjustment 
of the camera. , 

Figure 1 is a plan of the camera showing its arrangement. 
The light used is a screened arc lamp, suspended by a pulley 
from the ceiling, the camera stand is movable, and the speci- 
men rack and the back of the camera are each free to move 
through an are of 60 degrees. The box-like projection mto 
which the bellows may be compressed has been cut away to 
increase the angle through which the back of the camera may 
be revolved. 


EF. Suess—Paleogeography of North America. 101 


Arr. XIII.—Synthesis of the Paleogeography of North 
America; by Epwarp Svzss.* 


Ir is only now, after more than four months of fatigue, that 
I can sit down to answer your kind letter of April 20 and 
thank you for the transmittal of your great paleogeographic 
memoir [The Paleogeography of North America] and the 
honour of haying my name on the title page beside that of 
your illustrious Dana. I believe I cannot express my deep 
feeling of gratitude better, than by trying to enter into a can- 
did comparison of the existing differences of views as they 
result on both sides of the Atlantic from differences of per- 
sonal experience, and differences in nature; further, from those 
variances that are caused by different systems of classification 
or nomenclature, and which, as results from your memoir, are 
all governed by the indisputable fact, that great eustatic move- 
ments of the strand-line have taken place. 

J intend first to write of tectonic influences on the distribu- 
tion of seas, second to compare several great eustatic phenom- 
ena, and third to discuss the difficulties in finding an explain- 
ing hypothesis. 


1. Tectonic movements influencing the distribution of seas. 


First, 1 must confess myself a heretic in all regarding isos- 
tasy. I have in my last volume given the facts [IV, 1909: 
608—]| which cause me to doubt anything like a deficit in gray- 
ity beneath the mountains. Faye has always doubted it and, 
if [am not wrong, Professor Gilbert seems also to partake of 
this view. There is not sufficient space here to enter into this 
question and I only permit myself to doubt likewise whether 
any sinking can be caused by loading. All these loads seem 
trifles in comparison to the magnitude of the planet. 

The ideas of Dana on mountain-making were the concep- 
tion of a great genius. Experience tells us now, that caution 
is necessary in the use of terms like syncline, synclinorium, ete. 
I formerly used these terms for structures that are produced 


* This very valuable contribution came in the form of a letter dated Marz 
(Méreztalva), Hungary, September 2, 1910, and addressed to the undersigned. 
The subject matter is of so much importance to geologists that it should 
have wider circulation than that of a personal letter, and it is here published 
with the author’s consent. It will be seen that as yet geologists cannot 
explain several of the more fundamental characteristics on The Face of the 
HKarth but that we are approaching a determined synthesis. This desidera- 
tum will come all the sooner through the life work of Professor Suess in 
making accessible the garnered geologic knowledge of all lands, printed in a 
multitude of languages, in his ‘‘ Antlitz der Erde,” or in the English transla- 
tion by Sollas and Sollas, ‘‘ The Face of the Earth.’””-—CHARLES SCHUCHERT. 


Am. Jour. Sci1.—Fourta Serius, Vou. XXXI, No. 182.—Frsruary, 1911. 
8 


102 E. Suess—Pualeogeography of North America. 


by folding, of which both halves or sides form parts of the 
same tectonic unity. This is not the case with the great ‘‘syn- 
clinoria” in front of the mountain chains, the “Vortiefen” or 
“fore-depths” [see zb¢d., LV ; 626]. 

The great Pacitic fore- depths of 7,000 to more than 9,000™ 
are evidently not caused by folding , as one side is’ formed by 
the foreland (mostly covered by ‘the ocean here) while the 
other is the front of a folded chain. This is clearly visible 
wherever such a fore-depth enters the continent, as for exam- 
ple in the valley of the Ganges, where one side is the Penin- 
sula (=Gondwana land), and the other the Himalaya, or the 
valley of Guadalquivir in Spain between the old foreland of 
the Meseta in the north and the young folded cordillera (Betic) 
in the south. It is clear that the Pacific Asiatic voleanoes 
have nothing to do with these depths; they always remain 
inside the more or less arched chain of mountains. The folds 
of the cordilleras advance towards the depths and seem to 
reach them. Sometimes the depths are filled with very thick 
masses of terrestrial sediments, coming from the new-born 
cordilleras, sometimes with deep-sea sediments having Radio- 
laria, as in front of the Carpathians and parts of the Eastern 
Alps. I regard the thousands of feet of Carboniferous sedi- 
ments, partly marine and partly continental, which accompany 
the front of our pre-Permian chains extending from Silesia to 
southern England as the filling of such a fore- -depth. Marcel 
Bertrand was right in drawing a line from the Bretagne to 
Newfoundland and in regarding the Appalachian coal fields as 
the continuation of those of southern England, Belgium, ete. 
_ Ali this is in harmony with the remarkable words of Dana on 
the existence of a greater trough or deeper channel on either 
side of the Azoic nucleus and “perhaps also gives a hint as to 
the northern limit of your Poseidon ocean. But this trough 
is no synclinorium and no anticlinorium exists.* 

It will be too great a digression for me to describe here the 
great Asiatic depths and I prefer to write briefly of the diffi- 
culty which arises from the fact, that a tr anser essing sea enters 
a fore-depth in one case and an extended river valley in an- 
other. Then, too, the contour may be very similar, but the 
thickness of the deposits is by far greater in the fore- -depth. 
The Cretaceous Flysch with Fucoides and Inoceramus has 

* “The region toward the Atlantic border, afterward raised into the Appa- 
lachians, was already then, even before the Lower Silurian era closed, the 
higher part of the land’ (319). ‘‘We hence learn that in the evolution of 
the continental germ, after the appearance of the Azoic nucleus, there were 
two prominent lines of development, one along the Appalachian region, the 
other along the Rocky Mountain region—one, therefore, parallel with either 
ocean. Landward, beyond each of these developing areas, there was a great 


trough or channel of deeper ocean waters, separating either from the Azoic 
area”’ (344), Dana, this Journal, vol.’xxii, 1856. 


Ef. Suess 


Paleogeography of North America. 108 


tilled a great part of the fore-depth of the eastern Alps, Car- 
pathians, and Apennines, and it is very curious that similar 
beds occur on the external (southern) side of the Alaskan 
(Aleutides) arch [described fully in “ Face of the Earth,” IV: 
376-378]. Your Coloradoan Sea with the posthumous folding 
of the Laramide Range and the pressure from the Pacific 
agrees perfectly with European experience. 

Other examples are not so definite. Take the Middle Juras- 
sic. A transgression of this age appears on Franz Josef land 
and other islands of that part of the Atlantic, attains the north- 
ern coast of Russia, forms a broad strip on the west side of 
the Ural Mountains, attains the Caspian, mixes with Tethys, 
but lies in transgression beyond: the borders of this sea in east- 
ern Bayaria, and at the same time, with very similar fossils, 
appears in the Argentinian Andes, spreads farther than the 
southern borders of Tethys beyond Damascus, lies on Gond- 
wana beds in German East Africa, also in transgression on old 
rocks in Khach (East India), as well as in western Australia, 
southern New Guinea, etc. This same transgression is met 
with in different parts of northern Siberia as a wide flat series 
of beds. It is the Enochkin and Naknek of the Alaskan 
peninsula and your Sundance transgression (Logan Sea). 

In some places the middle Lias has left traces in the regions 
beyond Tethys, as in Madagascar; Ammonites amaltheus of 
the Lias has been found beneath this transgression in arctic 
Siberia (1 believe on the lower Anabar but have no books 
here), but with these few exceptions the transgression of 
about Kelloway age everywhere rests on by far older rocks. 

It is the strip along the west or front side of the Urals 
which connects the Arctie with Tethys, and eminent Russian 
geologists thought that a syncline was formed in front of the 
Urals. But curiously enough, transgression also proceeds from 
Tethys far to the south, and I am inclined to believe that the 
strip along the west side of the Urals was simply due to the 
sea entering a river system, let us sav of a pre-Jurassic Voiga. 

I do not know enough about the relations of yonr Logan 
Sea to the Oregon Jurassics and of these to the Franciscan 
Jurassic Radiolaria to speak about them and only desire-to 
point out the necessity of comparison and the difficulties. 
The evident entrance of fore-depths into the area of the exist- 
ing continents, as for instance the one in front of the Carpa- 
thians and Alps extending through the middle of Europe and 
depositing Jurassic Radiolaria even in the suburbs of Vienna, 
always has prevented me from acceding to the opinion, that 
only “epi-continental seas” had entered the present conti- 
nents. In Europe north of the Alps mountain-making ended 
before the upper Carboniferous or upper Permian, and coin- 


104 =F. Suess—Paleogeography of North America. 


cides very nearly with what you say about the fixing of the 
broader relations by the Appalachian Revolution of the Atlan- 
tie realm. Only sinking of regions seems to have occurred 
since that time in northern Europe. 


2. Comparison of several great eustatic movements. 


It has long been known that the stratigraphic series of the 
Alps is more complete by far than that of its foreland. Within 
this foreland the pre-Permian mountains (which I compare 
to your Appalachians) are to be separated from those regions 
in which no orogenetic process is known since the beginnin 
of the Cambrian. Such I once named Archeboles, but the 
name is bad, because pre-Cambrian folds are well known in 
these same regions. The environs of Saint Petersburg and the 
rim of the Baltic shield are types of horizontal Cambrian. 

This difference between the less extensive marine series of 
the foreland and the more complete series of the folded chains 
seems to exist all over the world with few exceptions (south- 
eastern Himalaya where the fore-depth cuts off part of the 
foreland, Mackenzie district and Argentina where the folds 
enter the less complete series of the foreland, the Jura Moun- 
tains which form a sort of complicated parma with a transi- 
tional series). In seeking to compare the marine series of the 
United States with that of Eur ope, I believe I ought to divide 
the immense array of facts offered by your maps into three 
groups or regions, as defined by Dana in 1859, viz., (1) the so 
called Azoic nucleus or Laurentia, (2) the Appalachians and 
(3) the western mountains. To these I add as a fourth area 
the United States Range of Ellesmere land which is thrust on 
Laurentia from the north and adds a new example of the com- 
pletion of the marine series as soon as a folded region is 
entered. 

Of these four regions Laurentia presents the imperfect ma- 
rine series of an undisturbed nucleus or shield and has much 
in common with Gondwana land; Appalachia may be regarded 
as the continuation of the pre-Permian mountains of Eurasia 
(A]taides) ; the United States Range seems to be an Asiatic 
fragment; while the Mesozoic and upper Paleozoic of your 

western mountains has decided relations to Tethys. In this 
I believe I am not in contradiction with your results. 

Europe cannot boast of a Paleozoic series comparable in 
completeness with that of the United States. I have read 
with great interest what you write regarding the interr elation 
of Atlantic biota such as that of the Paradoxides fauna, but I 
fear I am not able to say more about the older palzeozoics 
than I have already said in my “ Face of the Earth;” perhaps 


ee es ee nn ee 


E.. Suess—Paleogeography of North America. 105 


other information will be found in the last volume, which was 
not at your disposal. I will restrict my remarks to the undis- 
turbed region extending to Texas and the western mountains. 

These undisturbed regions (those in which Cambrian is not 
folded) not only show the clearest marks of the negative peri- 
ods, but also the slow creeping upon them of the transgressions. 
The negative marks of the strand-line are found more rarely 
and with difficulty in the folded regions with their rich marine 
series. 

A great negative phase appears at the limit of Jurassic and 
Cretaceous (Comanchie). This is the Wealden, extending cer- 
tainly from Poland across Hanover, southern England, Spain, 
Portland, to the Potomac beds of Maryland, Texas, and Colo- ' 
rado to Alberta, ete. If no other case were known, this one 
would be sufficient to prove the wide extension of similar 
movements. The contrast is given by the Spiti beds of the 
Himalayas, as described a short time ago. In England the 
Jurassic ends with oscillations in the Purbeck, then follows 
the Wealden as the time-equivalent of lower Neocomian 
(Berriasien) and then the marine Cretaceous series. In Hima- 
laya all is marine and difficulties exist in separating the latest 
Jurassic (upper Tithonian) from the Berriasien. At this time 
climatic differences seem to have existed in the seas (Knox- 
ville?). 

I do not think that lower Neocomian exists in Texas; the 
oldest forms from Trinity seem to me to be Gault, according 
to Kilian’s determination, and although it may seem daring on 
my part, I venture to state that the “equivalents of the Euro- 
pean Cenomanian (upper Greensand) begin within the Freder- 
icksburg. This is the introduction to the great transgression 
known to me (your Coloradoan Sea is a part of it). The full 
series exists with lower Neocomian in the southern Andes as 
well as in the Alps, but in leaving these one sees the Gault 
creeping over older rocks in northern France while the Ceno- 
manian transgression spreads from the United States through 
Europe, covering the Sahara from the Atlantic to the Nile, 
then passing sortrihvermn Russia and attaining even the Jesens 
near Kashgar. Then there seems to appear a pause or even 
a small regression during the Turonian, perhaps coinciding 
with your “remarks about. Pierre, and after this the maximum 
of the transgression is attained in the Senonian with outliers 
in the Arctic (central western Greenland) as well as in the 
Antarctic (Scott). 

Next appears the great and probably rapid negative move- 
ment of the strand-line, which forms’ the limit “between the 
Mesozoic and Cenozoic. North America indeed possesses 
extremely little lower Eocene. This absence seems to occur 


106 E. Suess 


Paleogeography of North America. 


all over the world in the undisturbed regions except parts of 
the Sahara. 

I will try to point out but two peculiarities of the upper 
Cretaceous tr anseression : 

a. The great inundation does not, as far as I know, attain 
the northernmost coasts and islands of Eurasia. Here, on the 
contrary, transgressions appear in undisturbed (only faulted) 
regions, a condition which we are not accustomed to see in 
these areas. Such are the upper Carboniferous and Triassic 
marine beds of Bear Island, ete.; the Kelloway, ete., which has 
been described ; then Lias at one locality in northeastern Sibe- 
ria; the Volga ‘beds of lower Cretaceous age in northern Rus- 
sia; the coast of Siberia, also spreading to the center of Russia ; 
and finally the circumpolar late Champlain transgression. It 
seems almost as if in certain Mesozoic phases the transgres- 
sions in undisturbed regions were complementary to those in 
lower latitudes. The upper Cretaceous inundation is traceable 
to Scotland, attains Scania and Moscow, but is not known far- 
ther in the north. Angara land (eastern Siberia) and China 
have as yet not given a sign of this transgression. You 
know by far better than I that North America shows the con- 
trary. The upper Cretaceous transgression clearly extends to 
Yesso and Sakhalin, in northern Alaska along the, arctic 
coasts about Colville River to the delta of the Mackenzie 
and thence southward into the United States. The undis- 
turbed arctic and subarctic coasts therefore show quite a differ- 
ent marine series in Eurasia and in America. 

b. The wide inundation of so many continents and the 
succeeding probably rather rapid retreat of the marine waters 
also dissipated the land waters, resulting in the destruction of 
the large dinosaurs, the inhabitants of swamps, rivers and 
lowlands, and retaining only those types of Reptilia which 
exist unto the present day. The freshwater fauna was driven 
into the upper reaches of the rivers. The Pyrgulifera from 
Bear River have a very remarkable aftinity with the forms 
from the upper Cretaceous beds of the Gosau of Hungary and 
similar forms from southern France. The Pyrgulifera living 
in Tanganyika lake resemble them so much that I am willing 
to believe that this African freshwater fauna is not a relict 
of the Cretaceous transgression which seems not to have 
attained to that part of Africa, but the descendants of the 
habitants of higher parts of an upper Cretaceous river trom 
the time of the transgression, exactly as Baikal preserves some 
species of Levantine : age. 

I will dwell a little longer on the most important question of 
fluviatile faune about which more is said in the last chapter of 
wy book. The development of lungs preceded by gills teaches 


EF. Suess—Paleogeography of North America. 107 


that life has proceeded from the ocean to fresh water and land. 
In other cases of animal life no considerable change is visible ; 
examples are the Medusa of Tanganyika, Victoria and the lower 
_Niger. In a like way the marine pelecypods Myside in the 
upper Volga, now separated by twelve degrees of latitude from 
the Caspian, are probably older than the separation of the 
Caspian from the Mediterranean. Another example is the 
sirenian Phoca baikalensis. In Pyrgulifera a Cretaceous 
freshwater gastropod has been preserved and f regard this as 
a relict from the head of a Cretaceous river, because the marine 
Cretaceous trangression and indeed every later marine inun- 
dation seems in the center of Africa not to have extended far 
beyond the southern limit of Sahara. In this way only can 
we understand that Nile, Niger, Gambia, Senegal, Kongo, 
Zambesi and lake Tchad (Boulanger’s Megapontic sub-region) 
possess a very uniform fluviatile fauna. Further, the oldest 
types of fluviatile fishes exist in the oldest continents, Amia 
and Lepidosteus in Laurentia, Lepidosiren in Brazil, Polypterus 
and Protopterus in Africa, Ceratodus in Australia. 


3. Difficulties in finding a satisfactory hypothesis as to the 
causes of transgressions. 


When I wrote of eustatic movements in 1883 [** Face of the 
Earth,” vol. I] I confessed that I did not understand the trans- 
gressions. I thought that variations in rotation might some- 
how have influence. I also believed and still think that the 
accumulation of sediment was a vera causa, but hardly suf- 
ficient. Now, after twenty-seven years I cannot offer you 
more than a loose heap of doubts regarding the explanation. 
I have learnt more and know less abont it. 

Regarding rotation, we must ask: Where was the pole ? and 
has it alwavs been fixed? Many years ago Oswald Heer said 
that its position was variable, as plants of a warmer climate are 
known from the Devonian or lower Carboniferous through the 
whole succeeding stratigraphic series and that signs of refrig- 
eration begin to appear for the first time in the middle Tertiary. 
Now, the Jurassic ferns from the Antarctic teach a similar 
lesson and all these plants demand not only a warmer climate 
but more light than the polar nights afford. Further, the 
repeated glacial periods in different latitudes seem to hint of 
great displacements of the poles; several theories have been 
proposed but none is adequate. 

It is quite true, as you remark, that the-sinking of part of 
an ocean’s base or part of a continent must increase the rapidity 
of rotation. The question remains, however, whether the 
phenomenon is not accompanied by a displacement of the 
planetary center of gravity. 


108). Suess— Paleogeography of North America. 

All measurements of the polar applanation of the globe are 
executed on the base of the actual strand-line. The result of 
these measurements therefore, does not represent the ap- 
planation of the lithosphere but of the hydrosphere, and the 
high terraces or strand-lines in high latitudes prove the vari- 
ability of the hydrosphere’s shape. It is very improbable that 
the quantity of water has greatly increased, and this increase 
was probably not more than the volume of juvenile waters 
issued by volcanoes. 

The terraces of the north are very distinct, as well as those 
of a great number of islands iw low latitudes of the Pacific; 
but I cannot with certainty see whether these two sets of 
phenomena are synchronous and continuous or complementary. 
I believe in the formation of negative eustatic strand-lines 
through the sinking of ocean bottoms; therefore I suppose 
them to be synchronous. Rotation would give complementary 
lines (better complementary phases, as plus in polar regions 
and minus at equator), but synchronous negative lines might 
interrupt them. 

What I wrote in 1883 about the considerable attraction of 
the continents and islands on the adjacent waters was then 
regarded as fully ascertained by our first authorities. Later 
on doubts arose and the question seems not yet fully settled. 

Nature is parsimonious on occasions in allowing us to follow 

the actual facts in arctic, antarctic and in tropical regions. 
What we know is principally the northern temperate zone. 
In Mesozoic times the American and the Euro-Asiatic-Arctic 
transgression seem to be different. Of real peri-arctic trans- 
gression, that is, actual heaping of water about the north pole, 
the last inundation (Champlain) offers most proof and still 
holds as the best evidence for a rotatory hypothesis. On the 
other hand, the sharpness of all negative lines speaks decidedly 
against their formation by rotatory phenomena. Therefore I 
accepted the formation of the elevated strand-lines as due to 
the making of new depths, and left the cause of transgressions 
in doubt. Even now I cannot go farther. 
I must close. Writing to a fellow geologist from whom I 
have learnt so much is such a treat to me that I must beg you 
to forgive the great length of this letter. What I offer you is 
little more than a number of questions; but questions are the. 
buds on the tree of knowledge. 


Gooch and Feiser—Silver by Electro-Deposition. 109 


Art. XIV.—The Estimation of Silver by Hlectro-Deposition 
From an Ammoniacal Solution of the Oxalate; by F. A 
Goocw and J. P. Friser. 


[Contributions from the Kent Chemical Laboratory of Yale Univ.—cexvii.] 


Ty a recent paper from this laboratory an account is given 
of tests upon the efficiency of a silver anode in the fixation 
of chlorine derived from hydrochloric acid by electrolysis. It 
was found in these tests that when the silver anode was made 
by plating platinum gauze with silver in a solution of the 
double cyanide of silver and potassium the silver deposit 
invariably included some of the potassium salt. To secure 
purity of the silver anode an ammoniacal solution of silver 
oxalate was substituted for the double cyanide solution in 
the plating process, for the reason that nothing of a non-volatile 
nature can then be included in the deposit which after ignition 
consists of pure silver. The present paper describes the 
adaptation of this process to the quantitative estimation of 
silver. 

The solutions of silver nitrate used in testing this process 
were carefully standardized by precipitating silver chloride 
from the hot solution by hydrochloric acid, cooling, digesting 
over-night, and weighing the silver chloride upon asbestos after 
heating gently without melting. Depositions were made upon 
a rotating cathode of platinum—the ordinary crucible,* the 
double disk of gauzey and a gauze cone set point downward 
upon the axis of rotation. In the experiments of Table I, 
measured amounts of the silver nitrate solution (25°™* or 50°™*) 
were drawn from a burette into a small beaker and treated 
with ammoniuin oxalate to complete precipitation. The silver 
oxalate was dissolved in a slight excess of ammonia, and this 
solution, diluted to 100%™*, was electrolyzed with a current of 
0°25—1°5 amp. and 4—7 volts. The cathode with the deposited 
silver was dried cautiously over a low flame and thereafter 
ignited to incipient redness. ‘The details of individual experi- 
ments are given in the table. 

These results show plainly that the process of depositing 
silver from the ammoniacal solution of the oxalate, precipitated 
from the nitrate, is capable of yielding good analytical results. 
Under the conditions of these experiments the electrolysis 
should be continued from twenty-tive to, thirty minutes in 
order to make sure that the deposition is complete. The 


* Gooch and Medway : this Journal, xv, 320 (1908). 
{Hildebrand : Jour. Amer. Chem. Soc., xxix, 450 (1907). 


110 = Gooch and Leiser—Silver by Electro-Deposition 


TaBLeE I, 
The Electrolysis of Silver Nitrate dissolved in Ammonium Oxalate and 
Ammonia, 
Ag in Current Revolu- 
taken found Error Approx. ' Time per 
grm. grm. grm. Amp. N.D. Volt min. min. 
A crucible used as cathode. 
(1) 0°2687 0°2685 —0-0002 x 1°5-1 5-3°3 6-7 25 500 
(2) 02687 0°2687 +0-0000 x 1°5-1 5-3°3 6-7 30 500 
(8) 02687 0:2684 —0-0003 x 1-0°5 33-17 6-7 30 450 
(4) 0°2687 0:2685 —0-0002 x 1-0°5 33-17 4-6 30 450 
(5) 0°3183 0°3181 —0-0002 x 1°5-1 5-3°3 4-6 20 450 
(6) 0°3183 0°3178 ase nee 1°5-1 5-3" 4-6 10 450 


0°3183 03179 —0:0004 x 1-0°5 0-50-25 4-6 20 400 
0°3183 0°3182 —0-:0001 x 1-0°25 0:5-0°10 6-8 
(9) 0°3183 0°318L —0-0002 x 10:25 = 0°85 5-8 2 
(10) 0°3183 0°3180 —0-0003= 0°75-0°25 0°4-0°10 5-7 40 450 
(11) 0°3183 03180 —0-0003x 1° -0°25 0° 4-6 
6 


(12) 0°3183 0°3176 —0°0007+ 0°75-0°25 0:4-0:10 20 450 
Gauze cone used as cathode. 
(13) 0°2687 0:2686 —0-0001x 1°5 -1 3-2 4-6 25 500 
(14) 0°2687 0°2683 —0:0004x 1: -25 2-0°5 6-7 30 450 
(15) 0°2687 0:2684 —0°0003=x 1: -5 2-1 4-6 25 450 
(16) 0°2687 0°2686 —00001=« 1: -0°25 2-05 46 25 450 
(17) 0°5875 0538738 —0:0002=« 1°5 -1 3-2 6-7 25 450 
(18) 0°5375 05371 —0-0004x 1:5 -1 3-2 6-7 25 500 


x Deposition complete, as shown by H.S test. 
+ Deposition incomplete, as shown by HS test. 


deposit is naturally more adherent when the cathode surface 
is relatively large and the current density low. When the 
current density is high the deposit is apt to be voluminous, 
shrinking considerably upon drying, and this phenomenon 
was especially notable in the case of the deposits upon 
a comparatively small and smooth surface of the crucible. The 
best form of apparatus appears to be the gauze cone set point- 
downward and so placed with relation to an annular platinum 
band used as the anode that the end of the axis where the 
centrifugal effect of rotation is least shall not receive much of 
the deposit. Experiments made with stationary gauze elec- 
trodes were not successful nor were those made with a dish 
cathode and stirring anode. 

Other experiments in which the silver was first precipitated 
as silver chloride and then deposited from the solution in 
ammonia and ammonium oxalate are given in Table Il. In 


these experiments, in which the solutions were more strongly - 


ammoniacal than those of the experiments of the preceding 
series, the deposits were dark and spongy, but they became 
lighter in color and more compact upon drying. 


a 


st alas 


From en Ammoniacal Solution of the Oxalate. VG 


TABLE IT. 
The Electrolysis of Silver Chloride dissolved in Ammonium Oxalate and 
Ammonia, 
Ag in Current Revolu- 
AgNO; Ag (Fa a tions 
taken found Error Approx. Time per 
erm. grm. erm. Amp. N.D. Volt min. min, 
A crucible used as cathode, 
(1) 03191 0°3187 —0:0004 — 1:5-1 5-38 5-7 20 500 
(2) 0°3191 0°3189 —0-0002 1°5-1 5-33 4-6 30 500 


Gauze discs used as cathode. 
(8) 0°3191 0°3185 —0-0006* 1:6-1 0:°75-0°5 = 5-7 15 500 
(4) 0°3191 0°3189 —0-0002 15-1 0:75-0:55 5-7 25 500 
(5) 0°3191 0:3190 —0-0001 15-1. 0°'75-0°5 4-6 35 500 
*Time of electrolysis short. 


It appears, therefore, that silver may be deposited from an 
ammoniacal solution of the oxalate, in presence of ammonium 
nitrate or ammonium chloride, in pure condition and in form 
suitable for quantitative estimation. 


112 G. R. Wieland—WNotes on the Armored Dinosauria. 


Arr. XV—Wotes on the Armored Dinosauria; by G. R. 
WIELAND. 


[Contributions from the Paleontological Laboratory of Yale University. ] 


Wiru the progress of exploration in many fields it becomes 
more and more evident that an interesting parallel must exist 
between the long-persistent Testudinata and the shorter-lived 
armored Dinosauria, a group which plainly constituted a 
numerous and varied cosmopolitan race with its dermogene 
bones always as distinctly ranged in keels as in any turtles. 
For, as insisted upon several years since,* not only is a pri- 
mary comparison afforded by the keels, but secondarily as well, 
the lumbar-hip carapace, present in the Nodosanridee though 
not in the Stegosauride, finds its analogy i in the osteodermal 
mosaic of Dermochelys. 


Nevertheless, despite the cumulative evidence for the exist- 
euce of a race of keeled saurians of world-wide distribution, 
and despite the frequent occurrence of more or less isolated 
plates from these keels, only the median dorsal line of Stego- 
saurus and the lumbar-hip carapace of Polacanthus (with 
Stegopelta Willistont), are so far known with any degree of sat- . 
isfying exactness. Indeed it appears that collectors, in both 
Europe and America, have been so little fortunate in finding 
the keeled Dinosaurs with their plates more or less naturally 
aligned in sitw as to long leave the existence of such a great 

group obscure, although ‘field work has but recently reached a 
far point in the collection of integumented skeletons of the un- 
armored, switt-footed Laramie Hadrosaurs. Nor was it known 
until three years ago that in that most explored of all verte- 
brate yielding horizons of North America, the Niobrara chalk, - 
typical armored saurians occur. Then, as described in this 
Journal,{ the plates assigned to the new genus Hierosaurus 
(with dermal plates characterized by deep and broad horn 
shield sulci), were found by the fossil hunter Sternberg. 

As it transpired, the interest of these fossils had not been 
fully recognized by their collector. In consequence, as was 
later learned on the occasion of a visit by Mr. Sternberg at the 
writer’s home, many much weathered and broken fragments 
of the type had been left behind. But for tunately, as found 
so desirable by us both, Mr. Sternberg was able to make the 
needed reéxamination of the locality before the frosts of 
another winter had set in, securing and sending every last 
remaining fragment. 

*A new Armored Saurian from the Niobrara; by G. R. Wieland. This 
Journal, vol. xxvii, March, 1909, p. 250-252. 

+ A new Armored Dinosaur from the Upper Cretaceous of Wyoming; by 
S. W. Williston, Science, N. S., vol. xxii, No. 564, October 20, 1905, p. 503- 


540. [Preliminary note on Stegopelta landerensis, from the Fort Benton. 
An illustrated description is not yet published. | t Loe. cit. 


G. R. Wieland—Notes on the Armored Dinosauria. 113 


And indeed from this second instalment of the type much 
more has been learned than might have been anticipated. In 
it, as enumerated below, nearly every part of the skeleton is rep- 
resented. In fact, after careful search and reuniting of many 
separated fragments, it is found that although much of the 
new material, especially of the limb bones, is too much weath- 
ered and broken to permit restoration, there are present far 
more than twice as many complete elements as were first 
secured; while taking both collections together, quite one- 
third of the entire armor is directly indicated, and inferentially, 
more than half. To the description of this new material we 
may now turn with the remark that the recovery of such a 
large part of the armor in intimate association with the skele- 
ton assures us that the Niobrara must in time yield finely con- 
served armored saurians. 


Further Structures of Hierosaurus. 
Figures 1-3da. : 

The additional portions of the skeleton of Mierosaurus 
described herein have the same general surface characters and 
features of weathering as the plates first collected, and are to 
be regarded as part of one and the same type. They come 
from the same locality, and so far as I can determine represent 
but a single animal, with the exception of the caudal bands 
shown in the first description (cf. figures 7, 7a, loc. cit.). 

_ As forwarded by Mr. Sternberg, this second instalment 
includes the following skeletal parts: 


(a). One large flat caudal spine of isosceles triangular form 15 
centimeters high with a base 13+ cm. long. Base some- 
what crushed but showing clearly outlined surface of 
attachment about 4 cm. wide. (Cf. fig. 3, 3a.) 

(5). Distal half of a somewhat lower spine than the preceding. 

(c). Two portions of summits of spines of moderate to large size. 

(d). A low set spine strictly intermediate in form between the 
preceding and following (fig. 14). 

(e). One elliptical and ridged dermal plate 10x15 cm. (fig. 1c). 

(f). A subrhombic dermal plate like e, 9x15 cm. 

(g). Four oblong elliptical elements ranging from 9 to 11 cm. 
long and from 3 to 5 broad, and having a submedian ridge 
varying from a shallow sigmoid (fig. 2e) to a crescent 
(fig. 24, g), the latter form being doubtless one of the 
most anterior in which the tendency to form a poste- 
riorly set spine is clearly marked. 

(i). Three smaller oblong ridged elliptical elements about 
83 em. (fig. 2, a—-c). 

(2). Series of twenty-five incomplete plates like the two pre- 
ceding groups. Length average 8 to 10 em. 

(j). About fifty additional fragments of smaller elongate ridged 
plates, less than 10 cm, in length. Some must be portions 


114. G. R. Wieland—Notes on the Armored Dinosauria. 


of one and the same plate, the group doubtless represent- 
ing about twenty-five plates. Average length under 10 cm. 
(4). Six much crushed dorsal (?) centra 6 em. long. Nearly 
platyan or slightly coeloplatyan. 
(2). Four toe bones 42 em. (may include a caudal vertebra). 
(m). Fragments of ribs of T-shaped section with the top very 
heavy, breadth 3 cm. 


Fig. 1. 


Figure 1.—Hierosaurus Sternbergii Wieland. Cranial and dermal ele- 
ments referred to the original type. x 0°37. 

s, s, lower outer portion of right squamosal with series of fused epijugals 
(s, s) indicating the presence of a Triceratops-like frill of considerable size if 
correctly identified (comparison is primarily to be made with the “‘ posteranial 
scutes” of Stereocephalus tutus Lambe) ;— 

e, inner side of a characteristic cranial element supposed to be the right 
jugal with the free concave side (at e) forming part of the orbital border ;— 

6, dermal element, rising into a large posterior spine with the suggestion 
of a possible bifid condition. (The rugose crescentiform base is shown 
below) ;— 

ec, dermal plate traversed throughout by a strong ridge not rising into a 
spine, 


G. P. Wieland—Notes on the Armored Dinosauria. 115 


(n). A portion of post cranial band—cf. figure 1, s. s—as well 
as larger parts of same rugose surface character, with heavy 
sulci. All may be supra-cranial plates. 

(0). A cranial element (jugal)—ef. figure le. 

(p). Many fragments of limb bones and other parts of skeleton 
not determinable but bulking up as great as the parts 
determinable, 


The principal anatomical features readily determinable from 
this type, as in part illustrated in my previous description (cf. 
loe. cit. figures 1-7@) and by the accompanying figures 1-3a, 
are :— 

1. That the length of the animal was about four meters, 
being perhaps less than half the size of Stegosaurus, and dis- 
tinetly smaller than Stegopelta ;—whence the length of a spine 
series measured from near the skull over the lumbar-hip eara- 
pace, and including the anterior three-fourths of the tail, would 
be three meters more or less. 

2. The dermal elements present in whole or part now num- 
ber nearly 70. Hence if all were arbitrarily placed end to end 
with an allowance of say one-fourth their actual size as abut- 
ting space, a length of from 9 to 10 meters on keel lines or the 
equivalent of three full keel lengths is present. Or counting 
off space for the lumbar-hip carapace, fully four keels. 

3. Since the dermal elements no doubt fairly represent all 
the keels and yet include no strictly bilateral members, it is 
not likely that there was a true median keel, whence five to six 
keels are arbitrarily demonstrated as present. 

To make an estimate of the maximum number of keels is 
however seen to be impracticable. One can only say that 
there appear to have been at least as many as on the turtles 
with a neural, two pleural, two supra-marginal, and two mar- 
ginal keels, or seven in all. 

4. Since a few cranial bones are present, but no portion of 
the lumbar-hip carapace which was no doubt well developed, 
it is likely that the dermal elements recovered are mainly of 
the anterior dorsal region. 

5. The complex character of the armor is striking, combin- 
ing as it does a system of free keels which lose their identity 
in a lumbar-hip carapace and must then reappear in the caudal 
rings. No less too is the ¢owt ensemble one of the most ornate 
that has ever been demonstrated. For as we see the elements 
of the keels vary regularly in shape from tubercles through 
rounded, oblong, elliptical, subrhombic and crescentic forms, 
with regularly increasing elevations passing from points to 
ridges both straight and sigmoid, low bifid, and at last huge 
caudal spines. 


116 G. R. Wieland— Notes on the Armored Dinosauria. 


The specific isolation of JZierosaurus Sternbergii is be- 
lieved to be clearly established, since the nearest form with 
which it can be compared is Stegopelta of Williston (loc. cit.) 
from a different horizon however, the Fort Benton. Not as 
yet clearly illustrated, that genus is described as having mainly 
rounded dermal elements, whereas those of the present fossil 


Fie. 2. 


FicureE 2.—Hierosaurus Sternbergii Wieland, x 0°37. Characteristic 
dermal elements showing variation from the straight keeled forms a-c, to 
the crescent keeled forms, f, g, and the sigmoid keel e. In all these instances 
(except c, incomplete) it can readily be determined by inspection of the 
specimen which is the anterior end. [That of e is below. ] 


cannot be so described. But in other respects these forms are 
so near as to make it possible that a fuller knowledge of both 
will warrant bringing the Niobrara saurian within the genus 
Stegopelta ; while the next nearest relation is doubtless the 
slightly older Stercocephalus of Lambe* from the Belly River 
series of the Red Deer River, Alberta.+ 


* New Genera and Species from the Belly River Series (Mid-Cretaceous) ; 
by Lawrence M. Lambe. Contributions to Canadian Paleontology, vol. lii, 
Ottawa, 1902, p. 25. 

+ Since penning these lines I have shown the type material of Hierosawrus 
to Professor Williston, who says he believes the form generically distinct 
from Stegopelta, and calls attention to the fact that in the latter many of the 
dermal plates bear a large shallow pitting whereas no such markings are 
present in any of the Hierosawrus plates, though so many have been recoy- 
ered, 


G. R. Wieland—Notes on the Armored Dinosauria. 117 


Fig. 3. Wie. 3a. 


Figures 3, 3a.—Hilerosaurus Sternbergii Wieland, x 55. Large broad- 
based caudal spine of the type, 20 centimeters long. Figure 3 shows the 
slightly fluted intero-superior side, and figure 3a the rather flat extero-infe- 
rior surface. The base was broad and heavy, the apex ornately outcurved 
and sharp. 


The family attribution of both genera along with Polacan- 
thus Hulke, Nodosaurus Marsh, Palwoscincus Leidy, Stereo- 
cephalus Lambe, and Ankylosaurus Brown, we think surely 
lies within the Nodosauridee of Marsh. 

It is thus seen that the type of Hzerosaurus, though promis- 
ing but little of its true interest when first noted in fragments 
weathered, broken and scattered in the Kansas chalk hills, 
shows students as well as collectors that exhausted fossil-bear- 
ing horizons are as yet unknown. As enumerated, the ele- 
ments recovered indicate that approximately an entire skeleton 
was present when erosion of the matrix began. Evidently 
future search in the Niobrara cannot fail to reveal other com- 
plete examples, mayhap with their keels fairly in place. 

But for the present the evidence available for even tenta- 
tively illustrated restorations of mail-clad Dinosaurs remains 
too battling. Perhaps if one were in ignorance of both Pola- 
canthus and Stegopelta it would be possible to produce a 
plausible generalized restoration of the armor of our Niobrara 
form, seeing that it has quite the longest series of finely con- 


Am. Jour. Sc1.—FourtH Smries, VoL. XX XI, No. 182.—Frsruary, 1911. 
@) 


118) G. Rk. Wieland—WNotes on the Armored Dinosauria. 


served plates of any specimen so far obtained. Indeed Brown,* 
overlooking Polacanthus entirely, has attempted with far less 
material to restore the keels of his Any ylosaurus. But as 
Williston+ has rightly said of this restoration, “It is based on 
too scanty material to serve as a satisfactory basis for a restora- 
tion * * since the form must be included in the same family 
as Polacanthus Hulke.” Whence it is pertinent to remark that 
vertebrate paleontologists have reached the time when it is 
well to realize that even though what is more a surmise or a 
guess prove fortunate, its value both present and future must 
depend on the concrete evidence which lies behind it, as we 
have learned from severe experience. 

We may pass on to a brief notice of some further structures 
of the mail-coated Dinosauria of much present interest. 


Pleural Armor of Stegosaurus. 


So far, the startlingly strange, complex, and ornate aspect at 
once indicated by even lesser portions of the mail-clad Dino- 
saurs, has naturally led to so called ‘new families.” Not to 
mention a long series of genera of convenience, we thus have 
the Scelidosauridee, Polacanthidee, Stegosauridee, Nodosauride, 
Ankylosauridee, ete., ete. 

Now while this iommenclatane of expediency may really 
foreshadow the degree of complexity the mailed saurians will 
‘ultimately be found to exhibit, they are none the less to be 
regarded as a compact and homogeneous series. And in all 
likelihood this series displayed as much uniformity in the gen- 
eral alignment of its keels as might be observed in a similar 
array of Oretaceous Testudinate families. From our view- 
point we hence hold it safe to predict that buttressing pleural 
keels will certainly be found in addition to the two great and 
tirmly set dorsal Stegosaurian keels recovered. On both 
anatomical grounds and relationship this must be the conclusion; 
though it is very clear that such pleural keels would be low, 
since the mid-line armor had become the dominant means of 
defense, or at least region of accelerated growth. . Even so 
there is in the nearly rigid back a most curious parallel to the 
turtles, and we believe that restorations should take more cog- 
nizance of this fact in dealing with the leg flexion than they 
have so far. 

That pleural keels have not been so far recovered, or recog- 
nized must be explained away as due to accidents of preserva- 
tion and collection—even to paucity in field observations or 
notes. At best the chance to find more or less loose peripheral 

*The Ankylosauride, a new family of Armored Dinosaurs from the 
Upper Cretaceous, by Barnum Brown. Bull. Am. Mus. Nat. Hist., vol. xxiv, 


Feb, 13, 1908, pp. 187-201. 
+ American. Naturalist, vol. xlii, Sept., 1908, p. 629. 


G. R. Wieland—Notes on the Armored Dinosauria. 119 


elements is always most precarious, as we know from the fre- 
quent dissociation of testudinate marginals. 
Dinosaur Mail from the Ceratopsia Beds. 
Figures 4-7, 


There is strong reason to believe that owing to accidents of 
preservation, fer course of erosion from their ‘matrix, and even 


Fie. 4. 


Se 


Figure 4.—Oblong dermal Le of Nedaneanides or fue from 
the Ceratops beds of Converse County, Wyoming. x+. Forms illustrat- 
ing extreme displacement of the spinal node. In the upper figure s is the 
inner, and s’ the outer view of a plate, the inner left basal angle of which 
rises as a distinct triangular spinal elevation ss’, 3 centimeters high. 
Which is the major axis, remains uncertain. 

{n the lower figures, the spinal node is at the mavaeile of the upper edge at 
the end of the transverse axis aa’, although the trifaced feature is as distinct 
as before, The entire form is shown by the transverse and longitudinal 
sections aa’ and bb’ respectively, n being the upper inner face of the plate, 
and its node. 


120 G. R. Wieland—WNotes on the Armored Dinosauria. 


to the fortunes of collection, the bony plates thus far found 
more or less closely associated with the reptiles of the Ceratops 
beds do not represent the true abundance and proportion of 


Fig. 5. 


Figure 5.—Rounded, elliptical and subrhombic dermal plates of Nodo- 
sauride or Ceratopside, furtner illustrating the great variety of form and 
the changing development and position of the spinal node. All are from 
the Ceratops beds of Converse County, Wyoming, and at least in part 
from the same individual as the plates shown in figure 4. 

1-v form a series passing from a rounded flattened tubercle (1) to a form 
with a low node (11), to a ridyed form (111), and then a form with a heavy 
spinal node sv (17). In v the spinal node sn lies near to the posterior border. 

All are of heavy and comparatively dense bone, upper surfaces usually 
showing nutrition canals. 


armored saurians in that horizon. Such armor is as a rule 


found at some distance from the skeletons to which it belongs, 


and yet it cannot serve as a satisfactory basis for new species. 
There may, therefore, be far more of it in the various collec- 


oe 


G@. R. Wieland—Notes on the Armored Dinosauria. 121 


tions than one might suppose from the minor mention it 
receives in all accounts of Dinosaurian material from the 
Ceratops beds of the Laramie and Belly River series. 

The plain fact is that we have been entirely misled by a 
seeming paucity of such armor not in accord with the existence 
in the Laramie of numerous representatives of the armored 
race, each bearing, as one may readily calculate, anywhere from 
200 to 800 dermal elements varying from mere tubercles up to 
huge staked plates. Indeed it would be of very considerable 
interest to know the actual number and proportion of these 


Fie. 6. 


FiguRE 6.—Subrhomboidal Nodosaurid or Ceratopsid dermal element 
from the Ceratops beds of Converse County, Wyoming. x4. (Thickness 
1°5 centimeters. ) . 

The upper surface, showing the large nutrition canals radiating from the 
subcentral and little elevated nodal area. The under surface is distinctly 
convex and shows the Nodosaurus textilis type of striated surface. A 
frequent and typical form. - 


elements in the collections, and especially their associations ; 
thotgh it is, we repeat, greatly to be feared that field notes sufti- 
cient to reveal the full cumulative value of this evidence may 
be lacking. The more are we impressed with this idea because 
of the fact that the discovery of the armored saurians has been 
late, is only beginning now. Furthermore we can add very 
tangible evidence to these views, having but recently secured 
from Mr. Sternberg a collection from the Laramie of some 
thirty most interesting dermal elements, the chief forms of 


122) G. Le. Wieland---Notes on the Armored Dinosauria. 


which are figured herewith. These are supposedly from two 
individuals and may represent Ankylosaurus, or an ally; though 
it is, as we must insist, by no means proven that some of these 
forms did not pertain to Ceratopsia, just as Professor Marsh 
supposed they did. Forms like these were found near Cera- 
topsians by Hatcher, and Sternberg @ says he found one of these 
plates accompanying ‘the Tricer atops skull he sent to the Brit- 
ish Museum two years ago. 

As readily seen from inspection of the figures, these elements 
present far more variety of form than do those of Wierosaurus. 
They also vary all the way from tubercles to plates of large 
size, and from mere knots of bone to armor with the most 


ornate ridging. Taking the elements as 
a whole there is in fact a notably small 
number with flat upper surfaces, the ten- 
dency being to rise first as a point, then 
as amore or less rounded elevation, and 
more often into a keel. Finally, there is 
the backward projection and elevation 
into a free spine. 

The figures 4-7 taken in conjunction 
with those illustrating Hierosaurus give 
a fair idea of form-range in Dinosaurian 
dermal armature where passing beyond 
the stage of minor patternless ossifications 
such as may have’been present in various 
heavy-skinned Dinosaurs and have been 
pointed out to me as accompanying Pelo- 
rosaurus. But they by no means show 
the range in these types characterized by 
a dominant linear arrangement of the ele- 
ments, on which these studies are based. 
In particular one notes that the spinal 
node, as we term that point, line or area 
which tends to project, whether pro- 
nounced or not, may occupy any portion 
of the face. Usnally the spine once it be- 


Fie. 7, 


Fieurn %.—Thick 
strongly rugose Cera- 
topsid or Nodosaurid 
dermal element from 
the Ceratops beds of 
Converse County, Wy- 
oming. 

Ath a strong horn- 
shield groove appears, 
not to be confused with 
the nutrition canals, 
and showing further 
evidence of a high de- 
velopment of horn- 
shield systems in many 
of these forms. 


comes pronounced of course rises from the posterior half. But 
as a ridge the node may even rise to form the edge of a meats 


as in fioure 4, 


%* % % * * * 


* * 


In all the armored saurians there is the constant variation in 
general form of the plates and spines suggesting close abutment 
to suit the different body areas, but yet producing no doubt a 
rigidity of body in most of the later forms approaching that of 


testudinates. 


Indeed these animals in the larger sense started 


in the direction of testudinate armoring but ran off to bizarre 


i it i i 


G. R. Wieland— Notes on the Armored Dinosauria. 123 


patterns. As a rule, however, the transition from low, flat or 
erect plates to large spines does not appear so abrupt as in the 
ease of the more or less fluted caudal spines of Stegosaurus ; 
but taken ali in all, it is evident enough that there was present 
throughout an entire armored race a most ornate keeled armo- 
rial pattern. And while the complexity of this pattern as yet 
bafiles exact restoration, it is now seen to be most likely that 
forms with their armor in place will soon be discovered, reveal- 
ing in full the structure and number of the keels, the degree of 
carapacial and hornshield development, the extent of possible 
comparison with the armor of the Testudinata, the correlated 
skeletal structures, and finally following anatomical features, 
the extent and the nature of the -antithetic course of evolution 
which must be involved in the development of the late Creta- 
ceous carnivorous and mailed and horned Dinosauria. 

Indeed so extended has already become the evidence here 
added to, that a further brief word of interpretation is perti- 
nent. At first sight ail development of dermal armature may 
appear to be mainly a senile feature, due even to inertia—the 
' general life movement of the individual andthe race.* But it 
is also evident that the development of dermal ossicles in series 
finally resulting in a protective osteodermal armature or cara- 
pace is a most profound change codrdinated with striking endo- 
skeletal alteration. Used with less suecess by the Dinosauria, 
as already much specialized, the accomplishment of this change 
however appears to have given the Testudinata an exceedingly 
long lease of life. 

It is hence in our view most probable that not so much 
bathmic courses and tendencies as ordinary exigencies of lite 
and environment were really primary factors in the origin of 
armored reptilian races. At least ever since the discovery that 
races of formidable carnivores like Megalosaurus and Lelaps 
developed side by side with such strongly armored herbivores 
as Scelidosaurus, HTyleosaurus and Stegosaurus, it has seemed 
reasonable to believe that a completer knowledge of Dino- 
saurian faunze must finally reveal some of the modes of adjust- 
ment to a life of attack and defense in these dominant but 
comparatively short-lived apposite lines. For if ever the ver- 
tebrate paleontologist might hope to detect boundaries between 
the direct origin of organs to meet obvious necessities, and 
their appearance with the aging of races as secondarily used 
senile features, here where all the characters are writ large 

*On page 106 of this Journal, Aug., 1902, the parallel modification of cer- 
vicals in long separated Testudinate races was cited by the writer as a case 
of evolutionary inertia. It is a conspicuous one, and is correctly named 
inertia, whereas the term momentum, now used by some, implies a knowl- 
edge of rates of evolution we do not as yet possess. The general term is 
certainly preferable. 


‘ 


124 G. R. Wieland—Notes on the Armored Dinosauria. 


must be the point. Though in the simple relations of attack 
and defense involved in spines, bony plates, horns and teeth, 
nothing we can to-day observe in the reptiles or the mammals of 
the land or sea could have quite prepared us for that veritable 
apotheosis of force finally involved in the juxtaposition of 
Tyrannosaurus with the Ceratopsia as justly included mem- 
bers of the great group of keel-armored saurians here hypothe- 
sized. 

Certainly then one can not bring himself to seek an explana- 
tion of the evident parallel development of these structurally 
antithetic series, and their brief culmination in the latest Cre- 
taceous, as a chronological accident, explicable in terms of 
senility and bathmism, or of mere developmental inertia. 

That one or the other of these opposed series could so arise 
as an aging race during continental and climatic evolution is 
thinkable. But that both the carnivorous and horned and mail- 
coated herbivorous Dinosaurian lines so developed their formid- 
able array of structures of attack and defense synchronously, 
appears improbable. Such equal rates of evolution have never 
been demonstrated ; though in any aiternative one is surely led 
to believe that when once the Dinosaurian lines are known in 
approximate paleontologic totality, the sequence and cause of 
-complementary development in these groups, whether simple 
as it now seems, or obscure, may not only be largely under- 
stood, but that the facts will aid us notably in gaining very 
definite conceptions of fundamental biologic factors involved. 
Indeed it is most evident that any idea that the study of the 
Dinosauria can be in the least barren must be wholly erro- 
neous, and that contrariwise, this group is destined to yield in 
largesse evolutionary testimony of everyday bearing that can 
be learned nowhere else. 


G. 8. Rogers—Original Gneissoid Structure. 125 


Arr. XVI.— Original Gneissoid Structure in the Cortlandt 
Series ; by G. 8. Rogers. 


In the course of a rather detailed investigation of the Cort- 
landt Series the attention of the writer was attracted by a 
peculiar structure occasionally occurring in these rocks, which 
seems to be undoubtedly of an original gneissoid character. 
By way of introduction a word of review about the Cortlandt 
Series itself may not be ont of place. The rocks cover an area 
of about 25 square miles, and are situated just southeast of 
Peekskill or about 35 miles north of New York City. They 
constitute a small but rather complete igneous complex, con- 
taining examples of all of the main varieties from granite to 
peridotite. Although hitherto they have been thought of as a 
wholly basic group of rocks, more careful work reveals the 
fact that nearly a third of the whole series consists of granite, 
syenite, and a diorite often acid enough to be called monzon- 
ite. Pyroxenites, often chrysolitic, make up somewhat less 
than a third, while several varieties of norite comprise most of 
the remaining types. Trachyte, sodalite-syenite, gabbro, and 
many dike rocks are also represented, and there are moreover 
several contact developments of very peculiar and abnormal 
composition. Finally, emery has been mined for the last 30 
years, chiefly along the borders of the district. 

The Cortlandt Series is rather well known from the work 
already done on it by two eminent geologists, Professors J. D. 
Dana and G. H. Williams. Professor Dana* described the 
rocks in connection with his work on the limestone belts of 
Westchester County. He directed his attention especially to 
the origin of the rocks, giving only a brief general description 
of their petrographic characters. He noticed, however, that 
on Montrose Point:several very different kinds of rock are 
associated in the most intricate way, generally as successive 
bands; and cites one case in which norite and pyroxenite are 
found in alternate layers of constant grain only three or four 
inches wide. There are also other less pronounced cases; and 
from these phenomena, as well as from the occasional streaked 
appearance of the rocks, Dana concludes that they were orig- 
inally volcanic ashes or tufts, which, on being subjected to 
intense local metamorphism, lost most of their bedded struc- 
ture and became pseudo-massive. In his last paper, however, 
which is based on the revelations of the new railroad cut 


* Geological Relations of the Limestone Belts of Westchester Co., N. Y., 
this Journal (8), xx, 194. Also, Origin of the Rock of the Cortlandt Series, 
idem (8), xxii, 103; and Note on the Cortlandt and Stony Point Hornblendic 
and Augitic Rock, idem (3), xxviii, 384. 


126 G. 8. Rogers—Original Gneissoid Structure 


through Stony Point. he abandoned,his former explanation and 
pronouneed the rocks truly igneous. In 1886 Professor G. H. 
Williams * published his first paper on the Series, and in it 
treats the rocks as unquestionably igneous. He also mentions 
their occasional streaked appearance, and points out that this 
is just what would be expected in igneous rocks which had 
undergone some regional metamorphism. 

The present paper is theretore not the first to describe the 
structure, although it is the first to interpret it as originally 
igneous. Recognizing the existence of such an original gneiss- 
oid structure in other parts of the world, it becomes evident 
that Professor Dana has described several rather obvious exam- 
ples of it. The northern part of Montrose Point, where these 
cases occur, is a complicated mixture of a biotite. augite nor- 
ite + and an olivine pyroxenite, the latter lying mainly to the 
south and west. These varieties appear to interpenetrate very 
intricately, and occasionally a structure such as Professor 
Dana describes is to be found. The writer noticed in one case 
a streak, about four feet wide, of the coarse dark pink norite 
in a cliff of black pyroxenite. This comparatively narrow 
strip was coarser, if anything, than the pyroxenite, and was 
coarse moreover to its very edge, having thus none of the char- 
acteristics of a dike. Analyses of these two types, given 
below, show their great chemical differences. 

It is in the various norites, however, that the structure is 
best shown. It may be stated first, as a general rule, that the 
finer grained a norite is, the simpler it is, i.e., a very fine- 
grained norite is composed chiefly of feldspar, with consider- 
able hypersthene, while the coarser varieties carry in addition 
either hornblende or biotite and augite. The fine-grained 
simple norite is never found in large areas, but always as inclu- 
sions in the coarser and therefore more complex varieties. 
It often occurs in biotite norite, for example, as small, 
rounded flow-like patches, or again as streaks; or it may be 
banded with the coarser rock. In this case the chemical dif- 
ference is not so great, as the accompanying analyses show 

A. Biotite augite norite, from Montrose Point. Analysis by 
Nee DS Minne for). 510: Dana, this Journal (3), xxii, p. 104, 


* The principal papers are: Peridotites of the Cortlandt Series, this Jour- 
nal (3), xxxi, 26; Norites of the Cortlandt Series, idem (3), Xxxiii, p. 
135 and p. 191; and Gabbros and Diorites of the Cortlandt Series, idem (8), 
xxxv, p. 438. 

+The names used to denote the different rocks are, it is believed, suffi- 
ciently explicit to obviate, for the purposes of this paper, a more detailed 
petrographic description. The analyses given serve the purpose; Professor 
Williams, in the papers cited above, gives very minute descriptions should 
these be desired. 


in the Cortlandt Series. 127 


1881, Contains andesine, augite, hypersthene, biotite, apatite 
and magnetite. Symbol, IT. 5.3.4. Andose. 

B. Augite peridotite (olivine pyroxenite) from Montrose 
Point. Analysis by W. H. Emerson, for G. H Williams, this 
Journal (8), xxxi, p. 40, 1886. Contains augite, hypersthene, 
hornblende, olivine, magnetite and pyrrhotite. Symbol, IV. 2.1.2. 

C. Norite, from 13 miles soutg of Peekskill. Analysis by G. 
8. Rogers. Contains orthoclase, andesine, hypersthene, a little 
biotite, apatite, ilmenite and magnetite. Symbol, I. 5.3.4. 
Andose. 

D. Biotite norite, 2 miles east of Montrose Point. Analysis 
by G. 8. Rogers. Contains orthoclase, labradorite, biotite, 
hypersthene, apatite, ilmenite and magnetite. Symbol, II. 5.4.3. 
Hessose. 


A, B. @: D. 
SiO, 55°34 47°41 51°49 46°10 
Al,O, 16°37 6°39 20°72 18°66 
Fe,0O, Hil 7:06 1:80 3°00 
FeO 754 4°80 7:28 9°58 
MeO 5°05 15°34 3°82 6°71 
CaO 751 14°32 6°71 8°26 
Na,O 4:06 69 3°70 Daa Ti 
Keo 9°08 1°40 9-14 1°59 
H,O+ 58 2°10 “31 ‘18 
H,O— Ss ee ‘10 10 
TiO, pans Seea 2°26 2°88 
EO: teas epee “15 70 
MnO 40 Prego 13 tiie 
BaO as sree tr tl 
tS) mee “49 11 18 
Sum 99°65 100-00 100°72 100°51 

Norms. 

As B. Cc. D. 
or 12:2 8:3 12°2 94 
ab 34°] 5 30°9 21°5 
an 20°3 10°6 32°5 34°8 
C Siete ieee 5 Ree 
di 14:0 479 Bettas 5:0 
hy 11:4 6°7 13°8 3°0 
ol 5:3 86 29 15°9 
mt 12 10°2 2-6 4-4 
il ie ses ie i 4°9 5:3 
ap See etre “4 1:2 


Now if the simpler norite be not quite so fine-grained it will 
not be entirely pure; and this is the case in most places. 
In fig. 1 the mass of the rock is a biotite-augite norite, while 


128 G. S. Rogers—Original Gneissoid Structure 


the white streak is merely a finer and therefore simpler facies, 
containing only small amounts of biotite and augite. In one 
place it shows an included patch of the coarser rock. Fig. 2 
shows the same relations on a smaller scale, but in better 


Iie 1) 


Fic. 2. 


Figs. 1, 2. Original gneissoid structure in the Cortlandt Series. 


development, so that the rock might easily be mistaken for a 
real metamorphic gneiss. A number of other equally good 
instances might be shown, for the structure is quite commen ; 
but these suffice to show its general aspect. It may be added 


that none of the rocks of this series exhibit any great amount 


in the Cortlandt Series. 129 


of shearing; and that in all the cases examined which show 
this flow structure, it is absent, even in thin section. The phe- 
nomenon could not, therefore, be due to ordinary regional 
metamorphism. 

The classic locality for this structure is on the Isle of Skye, 
in Tertiary gabbro, where it was first described as such by Sir 
Archibald’ Geikie and Professor Teall.* From their photo- 
graphs it appears to be little, if any, better developed than 
in the Cortlandt. The same structure, however, has been 
described in wonderful perfection by Professor A. G. Hégbom * 
from the Island of Ornd, just south of Stockholm. Here the 
black and white bands are narrow and numerous, and may be 
traced for 60-80 meters with the utmost ease. The zone in 
which this development occurs constitutes the periphery of an 
igneous (dioritic) complex. It is also found strikingly devel- 
oped near Montreal; this occurrence will be described by 
Professor Frank D. Adams in a forthcoming work. 

The explanation now accorded this phenomenon is simple 
and plausible. Eliminating Dana’s idea of worked-over vol- 
eanic ashes, and Williams’ ‘suggestion of the ordinary regional 
metamor phism of igneous rocks, we are thrown back on some 
force concomitant in its action with the cooling of the rock. 
Since the several layers or streaks are always quite different 
in mineralogical composition, and more or less so in chemical, 
it is evidently a question of magmatic differentiation. It is 
inconceivable that the structure be due to the differentiation 
of a magma én sitw—after it has reached its present position 

—since the differentiation is into bands which bear no definite 
relation to the borders of the magma; and the idea of success- 
ive intrusions —first of a light band and then of a dark—is equally 
inapplicable, since even when there is a sharp line of demar- 
cation separating two bands, the individual grains seem to 
interlock across the line. The only remaining hypothesis, 
therefore, is that of the intrusion of a molten mass already 
heterogeneous. Professors Geikie and Teall + push their con- 
clusions thus far; Mr. Harker § goes a bit fur ther. He appears 
to favor the view that the structure is due to the approxi- 
mately simultaneous intrusion of two different magmas, which 
would give rise to a thorough interpenetration of the two. 
This would explain why the banded structure, which always 
shows evidence of flowage, is seldom str aight and clear-cut. 
The assumption would be then that the mass must have 


*On the Banded Structure of some Tertiary Gabbro on the Isle of Skye. 
Quar. Journ, Geol. Soc., Nov. 1894, i, 646. 
tae Petrographie von Ornd Hufvud, Bull. Geol. Instit. Upsala, x, 150. 
p. cit. 
§ Natural History of Igneous Rocks, New York, 1909. 


130) G. S. Rogers—Original Gneissoid Structure. 


promptly begun to cool and harden while resting quietly, as 
otherwise the two magmas might combine to form a third and 
homogeneous one. Mr. Harker’s alternative view is that the 
mass was intruded as a unit, already heterogeneous, the two 
different magmas haying been partly mixed ‘before intrusion. 
Whichever be the correct theory, it is evident that in the Cort- 
landt Series the simple norite magma was very small in com- 
parison with the more complex norite magmas, since the former 
always appears as included bands in the others, while these 
latter cover extensive areas. 

It is interesting to note that here, as in most of the other 
examples of this structure, there have been distinct changes in 
our conception of its sioniticance. The old school of Ameri- 
can geologists, of which Professor Dana was the last great 
disciple, were very prone to consider as worked-over ‘sedi- 
ments what are now called true igneous masses; and he there- 
fore even adduced this structure to prove the sedimentary 
origin of the rocks. Dr. Williams, on the other hand, was one 
of the early exponents of the school which has laid great stress 
on metamorphic action in igneous rocks, and he accordingly 
passed it over without concern, as being merely an evidence 
of regional metamorphism. To-day we are passing—or perhaps 
have passed—through yet another change; Vogt, Hégbom, 
Harker, Adams, Pirsson, Kemp and others are now, in the 
light of our present greater knowledge, reading into igneous 
action many attributes, for the manifestation of whieh an 
entirely different origin had hitherto been postulated. The for- 
mation of this original eneissoid structure is a case in point. 
Up to the present it has not been recognized in many localities ; 
should it be found to be more common than is now thought, 
however, it may prove illuminating (as Sir Archibald Geikie 
suggests) in connection with some of the puzzling structures 
of the ancient and obscure igneous gneisses. 


Columbia University, New York. 


———— ee eee ee 


Butler and Schaller— Thawmasite. 131 


Arr. XVII.—Thaumasite from Beaver County, Utah ;* by 
B.S. Burrer and W. T. Scwarier. 


Introduction. 


Tue interesting mineral thaumasite was first described in 
1878 by Baron von Nordenskidldt from material collected at 
the copper mines of Areskuta, Jemtland, Sweden. Since that 
time it has been noted from other localities in Sweden and in 
1896 it was described by S. L. Penfield and J. H. Pratt, from 
Berger’s quarry, West Paterson, New Jersey. The latter 
locality is the only one where it had been noted outside of 
Sweden, previous to the one here’ described. 

During the summer of 1909 one of the authors (B. S. Butler) 
while engaged in a geological survey of the Frisco district, 
Beaver County, Utah, found a mineral of unusual appearance 
which on examination in the office proved to be thaumasite. 
The mineral was found in the Old Hickory mine of the Majes- 
tie Copper Company, located in the Rocky Range, Rocky dis- 
trict, Beaver County, Utah, about four miles northwest of the 
town of Milford on the Salt Lake, Los Angeles and San Pedro 
Railroad. 


Geological Occurrence. 


The Rocky Range is built up at the southern end, where 
the mine is located, of a series of interbedded dolomitic lime- 
stones and quartzites of probably Carboniferous age which 
have been intruded by monzonite. The intrusion of the mon- 
zonite has produced typical contact alteration of the limestone, 
resulting in the formation of magnetite, garnet and pyroxene 
with some pyrite and chalcopyrite. At the Old Hickory mine 
the limestone for several feet from the contact has been largely 
replaced by magnetite, with a small percentage of the contact 
silicates, and sulphides of iron and copper. As the distance 
from the contact increases the amount of magnetite decreases 
and the contact silicates become correspondingly more abun- 
dant, and these in turn give place to the carbonates composing 
the limestone. The zone of magnetite carrying copper values 
as chalcopyrite and secondary alterations of this mineral 
(covellite, chaleocite and copper carbonate) has furnished the 
ore that has been shipped from the mine. In the general 
vicinity of the mine and especially to the north and northwest, 
there are veins in the limestone from a fraction of an inch to 
upwards of a foot in width, composed of a dense white mate- 


* Published by permission of the Director of the U.S. Geological Survey. 
+ Comptes Rendus, vol. 1xxxvii, p. 313, 1878. 


132 Butler and Schaller—Thaumasite. 


rial with conchoidal fracture that on analysis proved to be 
composed largely of magnesium carbonate with some ealcium 
carbonate. These magnesite veins, however, were not observed 
in the Old Hickory mine. 

The Old Hickory mine has been developed to a depth of 
about 300 feet and four levels have been opened. <A vertical 
shaft extends to the lowest level while the second level, about 
100 feet deep at the shaft, is connected with the surface by a 
tunnel. The first level is about 80 feet below the surface and 
about 20 feet above the tunnel level. On this level the mag- 
netite body has been opened for a distance along the strike of 
about 125 feet. To the east of this, from 10 to 25 feet from 
the magnetite body, a parallel drift has been run in the altered 
limestone. One hundred feet south of the shaft a crosscut 
from this drift extends to the east about 25 feet, where it 
encounters quartzite. Throughout this eastern drift and cross- 
cut are a great number of veins of white material varying 
from the thickness of paper to upwards of two inches. To 
the north of the crosseut many of the veins are open with 
erystals projecting into the openings while others are composed 
of a dense white substance completely filling the space. The 
material from these veins proved on examination to be a mix- 
ture of quartz and carbonate, the latter probably largely calcite. 
In the east crosscut just east of the drift and extending across 
the drift to a crosseut on the opposite side, is a zone of veins 
having a general northeast-southwest direction, though the 
individual veins vary in direction and are connected by cross- 
veins making a network. These are composed of thaumasite 
completely filling the fissures. 

The tissuring occurred later than the contact metamorphism 
of the limestone and the filling of the fissures with thaumasite 
of course occurred at a still later period. The thaumasite was 
not found associated with the quartz and carbonates in the 
same veins and the relative age of the minerals was not deter- 
mined. At the Paterson, New Jersey, occurrence of thauma- 
site, the mineral is in trap associated with heulandite, apophyl- 
lite, laumontite, pectolite, chabazite, scolecite, and natrolite, the 
thaumasite er ystallizing later than the zeolites. No zeolites 
were found associated with the thaumasite at the Old Hickory 
mine, though these were especially looked for. It seems prob- 
able, however, that the mineral was found under physical con- 
ditions similar to those favorable to the formation of zeolites. 


Physical Characters. 


In the hand specimen the thaumasite from Beaver County 
is a nearly pure, white mineral with silky luster due to its 


Butler and Schaller— Thaumasite. 133 


fibrous character. It is readily recognized in the field as an 
unusual mineral by its silky luster and lightness (specific grav- 
ity 1°84). Under the microscope it is seen to be composed of 
minute slender prisms, none of which showed terminal faces. 
Microscopically it is most readily distinguished by its low 
index of refraction and rather high double refraction ; o=1°507, 
e—1'468, as determined by Lévy and Lacroix. The indices 
of refraction for the Beaver County mineral were approxi- 
mately determined by immersion in solutions of known index 
as @=1°500+, e=1:464+. The mineral extinguishes parallel 
to the elongation cf the prisms and is probably hexagonal, as 
it has been found to be in the previously described occur- 
rences. Orystals suitable for measurement and exact deter- 
mination of the refractive indices were not found. 


Chemical Composition. 


A determination of the density of the thanmasite by means 
of the Joly balance gave the value 1:84. A second determi- 
nation, using the Thoulet solution and small fragments of the 
mineral, gave the value 1:85. These figures are slightly lower 
than those found by Penfield (1°88) on the New Jersey thau- 
masite. 

The analyses of the Utah thaumasite, with the ratios 
deduced therefrom, are shown below. 


Analyses and ratios of thaumasite, Utah. 


SiOwtetie ae 10°14 "169 1:06 1 
SO as ee: eee 2G “156 98 ll 
COl eee he 6°98 159 1:00 1 
(CODES 2 set ae 26°81 479 3°00 3 

UO sees We 42:97 2°387 14:95 15 
(CANIS) {Oe ae ee 20 002 05 
MaOgp ences. 23 006 
ugh Olson are inace 

99°93 


The ratios agree very closely with the established formula 
3CaO.Si0,.SO,.CO,.15H,O and the mineral is very pure, only 
a trace of some foreign matter, probably a silicate, being 
present. 

A comparison of the analyses of the mineral from Utah, 
from New Jersey and from Sweden (the average of the three 
original analyses given by Lindstrém), strikingly shows the 
uniform composition of this rare mineral. 

Am. Jour. ae nee SERIES, Vou. XX XI, No, 182.—Frsruary, 1911. 


134 Butler and Schaller —Thawmasite. 


Comparison of analyses of thaumasite. 


Jemtland, New Jersey. Utah. Theory. 

Sweden. 
ROS 2 see 9°70 9°26 10°14 9°64 
DOF ke acre 13°02 13°44 12°60 12°86 
CO peeps fe 6°86 6°82 6:98 7-08 
CaO haere 27°28 23 26°81 27°01 
OR ones 42°20 42°77 42°97 43°41 
(ALF) COM Watte ae 0:20 ne 
MsQl eas see pias meee 0°23 peers 
Nas ee cieae “ital 0°39 Le 
KOM ee ‘08 0-18 vn ae 
BOR scueee on pes a tr. eee 
Cheyer ass 12 Wy eal Ege phd 

99°53 99599 99°93 100°00 


_ The new locality in Utah makes the third general locality 
in which this mineral has been found, or the fifth distinet mine, 
the three localities in Sweden being fairly close together. 


Bibliography. 


Backstrom, H. Geol. For. Forh., vol. xix, p. 307, 1897. 

Bertrand, E. Bull. soc. minéral., vol. 111, p. 159, 1880. Ibid., vol. 
iv, p. 8, 1881. Ibid., vol. xix, p. 88, 1896. Geol. For. 
Forb., vol. ix, p. 131, 1887. 

Cohen, E. Jahrb. Mineral., vol. ii, p. 22, 1881. 

Lacroix, A. Geol. For. Forh., vol. ix, p. 35, 1887. , 

Lévy, A. M. and Lacroix, A. Minéral. des Roches, p. 286, 1888. 

Lindstrom, G. Oefv. Ak. Stockholm, vol. xxxv (No. 9), p. 43, 
1878. 

Nordenskiold, A. E. Comptes rendus, vol. lxxxvii, p. 313, 1878. 
Geol. For. Forh., vol. v, p. 270, 1880. Ibid., vol. viii, 
p. 146, 1886. 

Penfield, 8. L. and Pratt, J. H. This Journal (4), vol. i, p.229, 
1896. 

Pisani, F. Bull. soc. minéral., vol. xix, p. 85, 1896. 

Widman, O. Geol. For. Forh., vol. xii, p. 20, 1890. 

Zambonini, F. Mem. Acc. Sci. Napoli, vol. xiv, p. 11, 1908. 


U.S. Geological Survey, Washington, D. C. 


H. P. Cushing—Lower Paleozoic Rocks of New York. 135 


Arr. X VIIl.— Nomenclature of the Lower Paleozoic Rocks of 
New York; by H. P. Cusutne.* 


Introduction.—W ork on the early Paleozoic rocks of north- 
ern New York during the past few years has not only added 
materially to our knowledge concerning them, but has empha- 
sized the necessity of certain modifications and certain ampli- 
fications of the nomenclature. Since these results are scattered 
through various official publications, it is believed that a sum- 
mary of them will be a convenience to many. 

Though begun by Cushing, the work has been actively par- 
ticipated in by Drs. Ulrich and Ruedemann. We have been 
so closely associated, and have so freely shared ideas, both in 
the field and in correspondence, that it is now an utter impos- 
sibility to assign to each his appropriate share. The writer 
therefore appears here merely as the scribe, and not at all as 
the sole author. 


The Saratogan Formations. 


Ulrich and Cushing have, in a recent paper, presented the 
detailed evidence which has led to the belief that the Little 
Falls dolomite, formerly classed with the Beekmantown, belongs 
rather in the same group with the Potsdam sandstone. It is 
not the intention to repeat the discussion here, but merely, for 
the sake of completeness, to note the matter.t The Saratogan 
in New York consists of the Potsdam sandstone below and 
Little Falls dolomite above, with a series of passage beds be- 
tween named the Theresa formation. The Little Falls dolo- 
mite is shown to be the equivalent of the basal division and a 
half of what was formerly classed as Beekmantown in the 
Champlain valley. It comprises division A and the lower 
half of division B. In the Mohawk valley the Potsdam dis- 
appears because of overlap and the Little Falls rests on the 
Precambrian. In the Black river valley both disappear and 
still younger beds lie on the Precambrian. 

The fossiliferous limestone which overlies the Potsdam at 
Saratoga and which furnished the fauna described by Walcott 
and determined by him to be upper Cambrian, was named the 
Greenfield limestone by Clarke and Schuchert.t This name 
was preoccupied, having been applied by Grabau to an Ohio 
formation of Monroe age. We propose to call it the Hoyt 
limestone, and we regard it as a local, calcareous phase of the 
basal portion of the Little Falls dolomite, of which it becomes 
a member. It is exceedingly local, being confined, so far as 


* Published by permission of the State Geologist of New York. 
+ Bull. 140, N. Y. S. M., pp. 97-140. t{ Science, Dec. 15, 1899. 


136 H. P. Cushing—Lower Paleozoic Rocks of New York. 


surface exposures are concerned, to the immediate vicinity of 
Saratoga. 

The Potsdam and Little Falls are the only two absolutely 
conformable formations in the entire early Paleozoic section 
of New York. In all other cases there is an unconformity 
between formations and frequently between subformations. 
To draw the line between Cambrian and Ordovician at this 
horizon is thus to draw it at the one place where there was 
continuous deposition between two formations. Structurally 
and faunally the Potsdam and the Little Falls belong to the 
same system and group. Their normal affiliations are with 
one another. And there is no diastrophic warrant whatever 
for putting a systemic boundary between them. 


The Beekmantown Group. 


In this paper just cited, Ulrich and Cushing separated from 
the Little Falls dolomite the upper division, heretofore classed 
with it, which Vanuxem called the “fucoidal beds,” and which 
careful reading of his report shows that he would himself have 
separated as a distinet formation, had his district alone been in 
question. The name proposed for this new division is the 
Tribes Hill limestone. It is much more calcareous and more 
fossiliferous than the Little Falls, and there is a distinct and 
widespread break between the two. Ulrich regards the fauna 
as of earliest Beekmantown age, and on the basis of his deter- 
mination the line between the Beekmantown and Saratogan is 
drawn at this break. This formation is the only representa- 
tive of the Beekmantown which occurs on the south and west 
sides of the Adirondack shield. 

In the Champlain valley Brainard and Seely some years ago 
divided the Beekmantown into five subdivisions, which they 
lettered from A to E.* The equivalence of division A and 
the lower half of B with the Little Falls dolomite, and the 
impropriety of classing them as Beekmantown at all, having 
now been shown, there yet remain the upper three and one- 
half divisions, with a thickness of from 1300 to 1400 feet. 
The thorough faunal study of this formation, and its proper 
subdivision and naming, constitute the most important problem 
be awaits the investigator of the early Paleozoic rocks of 
New York. It is reasonably certain that the four lithologic 
aon of Brainard and Seely will require much readjust- 
ment, when the faunas are collected and studied, and it would 
be folly therefore to give them names as at present constituted. 

It is not known whether the Tribes Hill limestone is pres- 
ent in the Champlain valley or not. If it be, it is represented 


* Bull. Am. Mus, Nat. Hist., vol. iii, pp. 1-28. 


H. P. Cushing—Lower Paleozoic Rocks of New York. 137 


in the dove limestones of division B; but up to the present 
these have furnished no fossils and precise correlation cannot 
be made until these are forthcoming. We greatly doubt its 
presence; we doubt if the Beekmantown of the Champlain 
. valley has asingle member in common with that of the Mohawk. 
And certainly, with the exception of the Tribes Hill, Beek- 
mantown deposition in New York was confined to the Cham- 
plain trough and to its prolongation southward; and to a 
branch trough extending up the St. Lawrence valley. The 
Mohawk and Black river valleys were unsubmerged. And, 
during Tribes Hill time on the other hand the Mohawk and 
lower Black river valleys were submerged, the Champlain 
valley probably not. This contrasted distribution might seem 
to support the recent suggestion of Raymond that the Tribes 
Hill should be classed with the Little Falls dolomite beneath 
rather than with the Beekmantown.* Raymond’s argument 
is wholly paleontologic, and must be answered by a paleontolo- 
gist. There was oscillation both preceding and succeeding the 
Tribes Hill, and the relative importance of the two breaks can- 
not be determined in New York. To be able to class the 
Tribes Hill with the Little Falls would much simplify areal 
mapping in the Watertown region, where the Saratogan has 
comparatively meager representation. The thinned western 
edge of the Potsdam is present, followed by some 25 feet of 
passage beds (Theresa). These are directly overlaid by a simi- 
lar small thickness of impure limestones with the Tribes Hill 
fauna. The Tribes Hill beds are so like the calcareous mem- 
bers of the passage beds beneath that Cushing was constrained 
to map the two together as a single lithologic unit. And yet, 
according to our results, the boundary between two systems 
must lie midway in that thin, lithologic unit. But Ulrich is 
positive in his correlation of the faunas and, in reply to the 
incongruity of distribution between the Tribes Hill and the 
remainder of the Beekmantown, points out that the early 
Devonian was characterized by similar incongruity, the distri- 
bution of the Helderberg and Oriskany rocks contrasting 
sharply with that of the Onondaga and its successors. 


The Chazy Group. 


There is an unconformity between the Beekmantown and 
Chazy groups which marks a time of extensive withdrawal of 
the sea from the New York region. Like their Beekmantown 
predecessors the Chazy rocks in New York are chiefly restricted 

to the Champlain trough. They do not however run south- 
ward along that trough as the Beekmantown rocks do, but 


* This Journal, Nov., 1910. 


138 H. P. Cushing—Lower Paleozoic Rocks of New York. 


pinch out before the upper end of Lake Champlain is reached ; 
and are wholly absent at Ticonderoga and all points south of 
that within the State. 

In the Champlain valley the group is separable into three 
well-marked formations,as Brainard and Seely were the first 
to show.* These were named by Cushing the Day Point, 
Crown Point and Valcour limestones.t More recently a for- 
mation of supposed Chazy age has been recognized and de- 
scribed in the Watertown region and named by Cushing the 
Pamelia limestone.t It has a length of outcrop of some 70 
miles in the State of New York, and probably an even greater 
extent across the border in Canada. In this district it rests 
either on Tribes Hill, Theresa or Potsdam, or else on the Pre- 
cambrian, and is overlain unconformably by the Lowyille. It 
cannot be successfully correlated with any of the Champlain 
Chazy, either lithologically or faunally, and seems to repre- 
sent a deposit in a wholly separate basin; and therefore evi- 
dence as to its precise position must be obtained from without 
the State. ; 

In 1896 Winchell and Ulrich revived Safford’s name Stones 
ftiver group for the deposits of the interior basin, or basins, 
representing the Chazy interval; or more strictly speaking, the 
lower and middle Chazy interval (Day Point and Crown Point) 
of the Champlain section. The Chazy and the Stones River 
basins of deposit were for the most part separate, with but 
slight and interrupted opportunity for commingling of faunas. 
The Pamelia limestone is the New York representative of the 
Stones River group, but represents only its extreme upper 
portion. 

The southern Pennsylvania section which has recently been 
described by Stose seems to furnish the evidence desired for 
closer correlation of the Pamelia.| Ulrich studied the faunas 
and furnished the correlation statements for that folio, and the 
correlation with the New York formations, as here given, is 
due to him. The Beekmantown of the Chambersburg region 
is overlaid by the Stones River formation, with a maximum 
thickness of 1050’; and this by the Chambersburg limestone, 
of 750’ maximum thickness. Ulrich regards the Pamelia as 
the equivalent of the upper part of the upper division of the 
Stones River of the Chambersburg section. The middle divi- 
sion, which carries Maclurea magna and other fossils is re- 
garded as the equivalent of the New York middle Chazy 
(Crown Point limestone). 

* Am. Geol., vol. ii, pp. 323-330. 

} Bull. 95, N. Y. 8. M., p. 368. 

{ Bull. G. S. A., vol. xix, p. 161; Bull. 145, N. Y. S. M., pp. 68-79. 


§ Geol. Sury..Minn., vol. iii, p. xc. 
|| Mercersburg-Chambersburg Quadrangles, Folio 170, U. S. G. S. 


H. P. Oushing—Lower Paleozoic Rocks of New York. 189 


On the Mercersburg quadrangle the basal 150-170’ of the 
Chambersburg limestone earries a fauna which, on the basis of 
several identical species, among them Lhynchonellu plena, 
Ulrich correlates with the upper Chazy (Valcour limestone) 
of the New York section. This directly overlies the upper 
Stones River (Pamelia), and just above it the Lowville fauna 
comes in. Hence it follows that the New York Pamelia is, in 
age, intermediate between the middle and the upper Chazy of 
the Champlain Valley, and that there must be a break there 
between those divisions. Also that the New York Chazy con- 
sists of four divisions, Day Point, Crown Point, Pamelia and 
Valcour limestones. And further, that Chazy deposition was 
confined to the Champlain trough until Pamelia time; that 
then the northwest border was overlapped by the sea which 
withdrew, at the same time, from the Champlain trough ; and 
that, at the close of the Pamelia, the reverse oscillation took 
place, the sea returning to the Champlain trough and with- 
drawing on the northwest. 


Lowville and Black River Limestones. 


In their readjustment of the nomenclature of the New York 
formations in 1899, Clarke and Schuchert gave the name 
Lowville limestone to the formation previously called the 
Birdseye.* Also, following the custom which had gradually 
grown up in the State, they classed the darker-colored lime- 
stones between the Lowville and the Trenton as Black River 
limestone. This usage of Black River did not at all accord 
with that of the early New York geologists, but was con- 
venient and had gradually become customary. However, the 
type sections of neither had received detailed study, and hence 
they had not been precisely defined. 

In their areal mapping in the Watertown region in 1907-08 
Cushing and Ruedemann found the typical, thin-bedded, dove 
limestones of the Lowville to be overlaid by a thickness of 
25-30’ of thick-bedded, black, blocky limestone, above which 
followed the Trenton. An uncomformity was also detected 
between the black bedsand the dove limestones. The black 
limestones constituted a natural, lithologic unit, and we so 
mapped them and called them Black River, this being the type 
region of the formation. Subsequent study of the section in 
company with Ulrich disclosed another break midway in the 
black limestones, separating them into a lower portion with 
much chert, and an upper in which chert was chiefly lacking, 
and whose chief member is the massive, chertless bed known 
as the 7 foot ter. That this upper break was a more con- 


* Science, Dec. 15, 1899. 


140 A. P. Cushing—Lower Paleozoic Rocks of New York. 


siderable one than that between the black and dove limestones 
was suggested by the limited distribution of the 7 foot tier as 
compared with that of the chert beds beneath, the latter 
accompanying the Lowville all the way up the Black River 
valley and also across into Ontario, while the 7 foot tier was 
restricted to the immediate vicinity of Watertown. Ulrich 
also urged that, in many localities without the State where he 
had studied the sections, the lower break was bridged by 
deposit, so that the dove limestone Lowville graded upward 
into the cherty beds; and that the sharp lithologic difference 
between the two in the Watertown region was local, rather 
than the general rule. He conceded that at Watertown the 
natural method for areal mapping purposes was to class the 
two black limestones, the chert beds and the 7 foot tier, together 
as we had done. But he emphasized the fact that this was 
not the usual rule, that in many districts no separation of the 
chert beds from the Lowville was possible, and that the name 
Lowville limestone was capable of vastly more extensive appli- 
cation as a formational name were the chert beds included in 
the formation at the type locality. 

Ruedemann, Ulrich and Cushing had also, during 1907, 
1908 and 1909, carefully studied the beds, latterly called Black 
River, in many localities on all sides of the Adirondack region. 
These beds are mostly thin, and often of patchy distribution, 
especially in the Mohawk valley, and we found that they were 
of quite various age, representing the thin, shoreward edges of 
embayment deposits, with repeated and quite local oscilla- 
tions of level. Plainly a considerable time interval] was repre- 
sented, and the term Black River was one of very loose 
application. 

In the final reports of the four geologists of the early survey 
(1842) the name Black River limestone was somewhat vari- 
ously used by the different men, though the statements of 
Vanuxem, Mather and Hall in regard to it do not greatly vary. 
They make it include the interval between the Calciferous and 
the Trenton. Vanuxem heads his chapter on the group as 
follows : 

“Black River limestone. Synonyms—Birdseye limestone, 
Mohawk limestone, base of the Trenton limestone, as used in 
the reports of the Third District. Black marble of Isle la 
Motte, Seven-foot-tier, and Chazy limestone of Dr. Emmons, 
the latter mass connecting the Birdseye with the Calciferous 
sandrock proper.”* 

The formation was chiefly confined to the Second and Third 
Districts, and Mather and Hall, in their reports, apparently 
simply followed Vanuxem. 


* Geol. 3d Dist., p. 38. 


Ee 


H. P. Cushing—Lower Paleozoic Rocks of New York. 141 


Emmons did not use the term Black River at all, though 
the Chazy was practically contined to his district, and the 
remainder of the formation was as fully shown as in the Third 
district. It is, however, quite differently shown. He plainly 
did not sympathize with the term, and probably objected to 
the inclusion of Chazy init. The above quotation also indi- 
cates that Vanuxem did not feel sure of the propriety of 
extending the term to cover the Chazy. Emmons used instead 
the terms Chazy limestone, Birdseye limestone, and Isle la 
Motte marble, and did not sanction the use of a group term 
to include the three. HEmmons correlates the 7 foot tier at 
Watertown with the black limestone at Glens Falls, Chazy, 
and Isle la Motte. But the Glens Falls, Chazy and Isle la 
Motte occurrences represent the horizon of the chert beds 
rather than that of the 7 foot tier. 

Vanuxem’s broad use of the term Black River has been con- 
sistently followed by some writers since, and notably so by the 
Geological Survey of Canada. 

In the first volume of the Paleontology (1847) Hall seems to 
‘advocate a quite different use of the term, though he nowhere 
makes an explicit statement to that effect and there is little 
evidence that he had any detailed acquaintance with the Water- 
town section. The most specific statement made is at the bottom 
of p. 41, where he says that Wurchisonia perangulata “ occurs 
in a siliceous, cherty mass of the Birdseye limestone . . 
near the upper termination of the rock at Watertown.” Now 
there is little or no chert in the Lowville proper and it seems 
that the reference here can only be to the cherty beds just 
under the 7 foot tier, which Cushing and Ruedemann mapped 
with it as a single lithologic unit. If Hall regarded the chert 
beds as Birdseye he must have restricted the use of Black River 
substantially to the 7 foot tier. 

Since the appearance of Hall’s report there has been no use 
of the term Black River in New York in the comprehensive 
Vanuxem sense. A usage has grown up however which is not 
so sharply restrictive as that of Hall, namely that of calling 
everything Black River which lies between the Lowville and 
the Trenton. As thus used the term had no precision, since it 
had not been determined just what was included in the Low- 
ville. Our recent work about Watertown, which we extended 
so as to include study of the type section at Lowville, gave pre- 
cise definition to the Lowville formation for the first time.* 
At the same time a very complicated and ditticult nomencla- 
torial problem was presented. If we included the chert beds 
with the 7 foot tier as Black River, in accord with present 
New York usage, and excluded them from the Lowville, as 
the Watertown sections seemed to suggest we should do, difti- 


* Bull. 145, N. Y. S. M., pp. 79-86. 


142 HT. P. Cushing—Lower Paleozoic Rocks of New York. 


culties arose in the Champlain sections, and Ulrich urged 
difficulties without the State, which rendered it impossible to 
give either of the names Lowville and Black River as wide 
application as they might otherwise secure. If we adopted 
Hall’s restricted use of Black River we practically wiped it 
out as a New York name, since the 7 foot tier is thin and 
occurs only about Watertown. It was finally decided, there- 
fore, that it would be best to revert to Vanuxem’s usage 
(except for the inclusion of the Chazy) and to apply the name 
Black River to the entire rock group between the Trenton 
and the Chazy, the usage which the Geological Survey of 
Canada has consistently followed. The Lowville thus becomes 
the lower division of the Black River group. The black, cherty 
beds of the Watertown region, between which and the typical 
Lowville an unconformity exists, we class provisionally as the 
uppermost member of the Lowville, and name it the Leray 
formation, from the river exposures in Leray township, Jeffer- 
son county. The section there is, however, not complete. At 
Lowville, for example, is a thickness of 5’6” of cherty lime- 
stone with Columnaria halli and Stromatocerium rugosum 
not seen at Watertown. And to the south, at Newport, in the 
valley of West Canada creek, this Stromatocerium bed is the 
sole representative of the formation, the remainder having 
disappeared. 

The Champlain valley seems a wholly separate trough of 
deposit for these beds. There is present a trifling thickness 
only of Lowville proper, followed by black, massive beds in 
much greater thickness than elsewhere in New York. The 
upper portion of these black beds seems to represent the Leray 
horizon, and the remainder to bridge the interval represented 
by the break between the Lowville and Leray in the Water- 
town sections. The Champlain succession seems unbroken, 
but deposit did not commence there till late in Lowville time. 

The upper subdivision of the Black river group in New 
York (the Lowville being the lower) is nowhere represented 
by any considerable thickness of deposit, with the possible 
exception of the extreme east, where the shales of the Levis 
channel, overthrust to the west, are met with. Otherwise the 
deposits are thin, scattered, and of quite varying age, indicat- 
ing repeated oscillations and prevalence of near shore condi- 
tions throughout. In the Watertown sections we group with 
the 7 foot tier the massive bed below, and the thin one above, 
into a formation of 13’ thickness which we call the Watertown 
limestone. It occurs only in the immediate vicinity; and other- 
wise there is no representative of the upper Black River on 
the western side of the Adirondack region. 


H. P. Cushing—Lower Paleozoic Rocks of New York. 148 


Amsterdam limestone.—There is present in the eastern Mo- 
hawk sections and the Saratoga region a limestone of 'Trenton- 
ish aspect, which the early geologists were clear-sighted enough 
to distinguish from the typical Trenton. Conrad called it the 
Mohawk limestone; but this term was variously used by the 
different geologists, was hence abandoned in the final reports, 
and instead the formation was referred to as “ base of the Tren- 
ton” limestone. The rock is chiefly in the third district, and 
that most excellent geologist, Vanuxem, discusses it in his 
chapter on the Black River limestone, with which he classes it 
notwithstanding the name used.* We propose to call it the 
Amsterdam limestone. It has of late years been usually refer- 
red to as Trenton, both along the Mohawk and at Saratoga, 
but is older than anything in the type section at Trenton Falls, 
and is properly referable to the Black River, forming the 
youngest division of the group in New York. It is also a de- 
posit in a different trough from that of the type Trenton and, 
during Amsterdam time, the entire western border of the Adi- 
rondacks was unsubmerged. The Amsterdam is emphatically 
a deposit of the eastern and southeastern border only. On 
the southeast (eastern Mohawk and Saratoga) it rests on the 
Tribes Hill or Little Falls and is followed by shaly limestones 
and shales, or simply by shales. In the Champlain valley true 
Trenton limestone overlies the Amsterdam, though even here 
only the lower Trenton consists of limestone. In the lower 
Mohawk region the bulk of the true Trenton consists of shale, 
with some thin, intercalated limestone bands in the lower por- 
tion. 

The view here urged in regard to this formation is nothing 
but the old view of Conrad and Vanuxem, and a new term is 
proposed for the formation because of the confusion attending 
the use of the term Mohawk limestone in the Annual Reports, 
and its ultimate abandonment by the proposers; and also to 
avoid conflict with Clarke and Schuchert’s useful and more 
comprehensive term Mohawkian.t The type sections are 
along the Mohawk in the vicinity of Amsterdam. 

The shales—Above the Black River or the Trenton lime- 
stones black shales follow, in all the New York sections. In 
the Champlain region limestone deposit continued through 
the lower Trenton, but the upper Trenton is represented by 
shales, with occasional thin limestone bands; in the eastern Mo- 
hawk and Saratoga sections the shales follow the Amsterdam, 
and the entire Trenton consists of shales except for the imme- 
diate base which consists of alternating, shale and thin lime- 
stone bands; in the western Mohawk sections there is again a 


* Geol. 3d Dist., pp. 43-5. + Science, Dec. 15, 1899. 


144. H. P. Cushing—Lower Paleozoic Rocks of New York. 


limestone of lower Trenton age followed by shales and thin 
limestone bands; only in the western border sections (West 
Canada creek and Black river) did limestone deposition con- 
tinue through to the end of the Trenton. Much of shaly 
Trenton has heretofore been called Utica. As the result of 
recent work Ruedemann has the problem of the age of these 
shales well in hand, and with most important results. 


Paleozoic Submergence of the Adirondack Region. 


Some years ago Cushing expressed the view that the entire 
Adirondack region was submerged during Utica time, basing 
the opinion on the thickness of the Champlain Paleozoic sec- 
tion (Potsdam-Utica) and the present altitudes of the Precam- 
brian summits of the Adirondacks. The assumption was that 
the successive seas overlapped ever more extensively on the 
oldland, without extensive downwarping of the marine troughs. 
It was further thought that the Utica shale was found on all 
sides of the region.* Shortly afterwards, and independently, 
Ruedemann expressed the same view, his argument being that 
the orientation of the graptolites in the shales indicates cur- 
rents clear across the region. 

Our recent results cast much doubt on the correctness of 
these previous views. As the evidence accumulates it points 
more and more strongly to deposit in downwarping troughs, in 
which large depth of deposit by no means implies extensive 
overlap on the shores. Usually also deposit on the east side 
of the region was coincident with sea-withdrawal on the west, 
and vice versa. Even when submerged at the same time, as in 
the Trenton, the deposits on the two sides are so different, 
both lithologically and faunally, as to indicate that the two 
basins had no very direct connection. Entire submergence of 
the Adirondack tract during the Utica appears unlikely. It 
follows that there has been no complete submergence of the 
area since the earliest Precambrian. 

Chart.—In order to present more concisely the nomenclature 
modifications suggested in this paper, the chart below is here- 
appended. It makes no pretence of completeness so far as the 
major division are concerned, giving simply the chief groups 
into which the rocks present are divided, their subdivisions, 
and the general sections of the northwest, southwest, south, 
southeast and northeast borders of the Adirondacks. 


*18th Rep., N. Y. State Geol., pp. 76-7. 
+ Am. Geol., Feb. 1898, p. 75. 


145 


EH. P. Oushing—Lower Paleozoic Rocks of New York. 


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auojspues TULps}og 
UOMeUILO, Vsa.1oyy, 


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UWOMVULLOZ Vsotet J, 


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146 Scientific Intelligence. 


SCIENTIFIC INTELLIGENCE. 


Il. Curmistry anp Puystcs. 


1. The Determination of Copper as Sulphate.-—Rrcoura 
states that he has made a practice of weighing copper as anhy- 
drous sulphate and finds the method extremely simple and accu- 
rate, although it does not appear that the method has been 
previously recommended. When a neutral solution of copper 
sulphate is evaporated to dryness and the residue is heated-in the 
oven to 180-200° C., it loses the last traces of water with con- 
siderable difficulty, and this fact is undoubtedly the reason why 
the determination of copper in the form of the sulphate has not 
been used. But Recoura has found that such is not the case 
when a solution of copper sulphate containing free sulphuric acid 
is thus evaporated and heated. Even when the amount of sul- 
phurie acid is small, the salt when heated a short time at 180—200° 
contains neither water nor sulphuric acid and reaches a constant 
weight. The following results are given where exactly 1 g. of 
copper sulphate was taken in each case : 


Time of heating Neutral solution Acid solution 
at 190° Residue Residue 
1 hour 1°0045 1°0005 
2 hours 1:0040 1°0001 
4 « 170022 
48 “ 170006 


It appears, therefore, that the method is satisfactory, and that 
it is to be preferable to the method of weighing cuprous sulphide, 
at least in many cases. Many compounds of copper which con- 
tain nothing that is not volatile at 200° may be treated with 
dilute sulphuric acid in a platinum capsule, and then simply 
evaporated, heated to 180-200° for two hours and weighed. 
Other compounds of copper which are not directly soluble in 
dilute sulphuric acid may be first dissolved in a little concen- 
trated nitric acid, and then treated as before. The sulphide 
requires roasting in a porcelain crucible over a good burner 
before dissolving in nitric acid.— Bulletin, IV, vii, 832. 

H. L. Ws 

2. A New Method for Determining Boiling Points and Vapor 
Pressures.—Swuitnh and Menzies of Chicago University have 
devised an important method for making these determinations in 
a very simple way with the use of very small quantities of sub- 
stances. The substance is placed in a small glass bulb having a 
capillary tube which is bent in a semi-circle just above the bulb, 
so that its straight, open end is directed downward. The bulb 
tube is then attached to a thermometer, and placed in a heated 
liquid bath according to the usual manner of making melting- 


Chemistry and Physics. 147 


point determinations. When the boiling point is reached vapor 
escapes from the capillary tube, and this may rise through the 
liquid of the bath as bubbles or be absorbed by it according to 
circumstances of solubility. In determining the boiling point 
the temperature is raised somewhat above “the required tem- 
perature, then by cooling the point is found where the bubbles 
cease to be given off, or r the liquid recedes in the capillary tube. 
For taking vapor pressures the apparatus is modified so that the 
heating is carried out in a test-tube containing some of the liquid 
used as a bath, and this in turn is placed in a beaker containing 
the same liquid. The test tube is closed with a stopper through 
which passes the thermometer as well as a glass tube connecting 
with a manometer and also with suction or compression appa- 
ratus. With this arrangement boiling points may be taken at 
various pressures, and of course these give the vapor pressures. 
The quantity of substance required for these determinations is 
only about 0-1 g, and it is important to notice that the boiling 
points of solids which do not melt, as well as liquids, may be 
taken in this way. The liquids recommended for use as a bath 
are, besides water, sulphuric acid of 92°75 per cent, paraffine of 
M. P. 53°, a two nitrate mixture with KNO, and NaNO, in the 
proportion 54°55 to 44:5, and a three nitrate mixture with NaNO,: 
KNO, : LINO, :: 18°18: 54°54: 27:27. A correction for the pres- 
sure of the liquid of the bath above the opening of the capillary 
tube is required, and tables are given showing the specific gravi- 
ties of the different liquids mentioned above at various tempera- 
tures. The authors give very satisfactory results of determina- 
tions made by the new method, and it is their opinion that the 
boiling points thus determined are more accurate than by the old 
methods, because there can be no difference in the temperature of 
the liquid, the vapor and the thermometer.—Jour. Amer. Chem. 
Soc., Xxxii, 897. H. L. W. 
3. The Reactions of Nascent Hydrogen in the Dry Condition. 
—Vournassos has found that the nascent hydrogen produced by 
heating dry sodium formate is capable of combining with various 
simple | substances which do not combine with hydrogen directly, 
but which form hydrogen compounds indirectly. Thus by heat- 
ing sodium formate with phosphorus, or with sodium phosphites 
or phosphates, PH, is obtained; likewise H,S is obtained by 
heating the formate with sulphur, sodium sulphite, or a sulphide 
of mercury, lead or tin. With arsenic AsH, is produced. Anti- 
mony gives a little SbH,. Silicon does not ‘react, but SiCl, and 
SiS, give a little SiH,. *B 20, heated with metallic sodium and 
the formate gives a gas which appears to be BH,. ‘The nitrides 
give NH,, the cyanides HON, and the alkaline carbides Clete, 
‘Comptes Rendus, cl, 464. H. 1. W. 
4. Synthetic Sapphire. —VERNEUIL has obtained artificial sap- 
phires by HESS before the oxyhydrogen blowpipe alumina 
mixed with 1:5 per cent of magnetic oxide of iron and 0:005 per 
cent of titanium dioxide. Vhe ovoid masses obtained gave a 


148 Scientific Intelligence. 


beautiful sapphire color, and had the same optical properties as 
the natural mineral. It is remarkable that the oxides employed 
should give a blue color.— Comptes Rendus, cl, 391. a. L. W. 

5. Influence of Temperature on the Compr essibility of Metals. 
—E. GRUNEISEN’s experiments on this subject extended over a 
range of temperatures of —190° to 166°. He used a Cailletet 
pump for high temperatures and bombs filled with hydrogen gas 
for low temperatures. He, therefore, did not go above a pres- 
sure of 500 atmospheres. He finds that the compressibility 
increases with the temperature, or in other words the expansion 
coefficient diminishes with increasing pressure. Apparently with 
a linear expansion one must have a linear compressibility.—Ann. 
der Physik, No. 16, 1910, pp. 1239-1274, Ir T. 

6. Ionization of the Atmosphere due to Radio-active Matter.— 
This subject is of importance in regard to the observed difference 
between the case of transmission of wireless signals at night and 
in the daytime. A. 8S. Eve, McGill University, gives a table 
which indicates a decreasing ionization with altitude which can 
be detected at an elevation of 100 meters, and also that at 1000 
meters the penetrating rays from the earth are ineffective 
ionizers.— Phil. Mag., Jan., 1911, pp. 26-39. die it 

7. Thomson Effect.—This has been measured by P. Cermak 
in lead, mercury, tin, zinc, cadmium, and aluminium ; the effect 
has been found extremely small, but never constantly nothing. In 
the transition from the solid to the liquid state the curve repre- 
senting the Thomson effect is a continuous one ; while that repre- 
senting the change in resistance is a broken one,— Ann. der 
Physik, No. 16, 1910, pp. 1195-1215. Te as 

8. Velocity Measurement of Réntgen Rays.—A very volumi- 
nous paper on this subject has been published by E. Marx. He 
discusses various method-causes of error; maxima and minima 
in the bundle of rays, phase differences and other conditions. 
Various wave lengths were found, which depend so much upon 
these conditions that a definite wave length is apparently not 
reached. The paper concludes with a discussion of Bragg’s the- 
ory, corpuscular theory of neutrals and doublets, and the bearing 
of the impulse theory on the existence of an ether.—Ann. der 
Physik, No. 16, 1910, pp. 1305-1391. Jap Le 


II. Groxoey. 


1. Osteology of Pieranodon ; by Grorce F. Eaton, Pu.D. 
Memoirs of the Connecticut Academy of Arts and Sciences, vol. 
II, pp. 1-38 and pls. i-xxxi, July 1910.—In this volume Dr. 
Eaton discusses the morphology of the American pterodactyl genus 
Pteranodon, basing his descriptions upon material in the Peabody 
Museum of Yale University assembled by Professor Marsh and 
numbering in all no fewer than 465 individuals. Of this mate- 
rial but seven specimens, including the types of the three species 


Geology. 149 


Pteranodon ingens, P. longiceps, and P. occidentalis, were sufti- 
ciently complete to form the immediate basis for research. No 
attempt is made to amplify specific descriptions and the author 
plunges at once into the osteology of the genus, during which 
certain details of specific distinction are mentioned. 

The skull shows a complete obliteration of sutures, and in its 
extremely narrow proportions and the extension of the great supra- 
occipital crest and of the toothless jaw is utterly unique among 
vertebrates. The curious spirally grooved jaw articulation, resem- 
bling that of the pelican, though developed to a higher degree, 
the effect of which is to bow outward the rami of the lower jaws, 
together with the apparent presence during life of a gular pouch, 
is suggestive of fish-eating habits. The supraoccipital crest is 
compared with that of Phalacrocorax, Chelydra, and Chameleo 
and its initial development is accounted for by the necessity 
for increased origin of the powerful temporal muscles. How 
far these spread over the crest is not *«nown, but it is supposed 
that a secondary function of the crest must have arisen to account 
for its extreme development. In this connection a counterpoise 
for the long jaws and the effect of the crest as a vertical aéro- 
plane cannot be entirely disregarded. 

The cervical vertebre, while apparently massive, are of 
extreme lightness of construction. As in certain birds the ante- 
rior: dorsals are fused into a rigid notarium, then, after an inter- 
val of three or four free vertebra, the long synsacrum of nine 
or ten codssified vertebra appears, again very bird-like in struc- 
ture. The tail was evidently very short and of little value in 
flight. 

The shoulder girdle is very massive, the scapule articulating 
with a very distinct facet on either side of the fused dorsal spines 
of the notarium. There is a powerful sternum, somewhat keeled 
for the origin of the great muscles of flight. 

The limb bones have been well described by earlier authors 
but note is taken of the various ways in which they may be 
modified by the crushing to which they have been subjected and 
which renders specific distinctions based upon these elements of 
little value. The phalangeal formula of the manus is correctly 
stated for the first time and shows the ordinary reptilian sequence 
of bones. 

Two admirable restorations are given which are, however, 
composite, in that elements from more than one species had to be 
used in their construction. One shows the animal from the side,, 
the other from below with wings broadly expanded as in the 
plaster replicas preserved in the Yale and U.S. National Museums 
and in the British Museum of Natural History, all of which were 
made under Dr. Katon’s supervision. 

Dimensions of the various specimens under consideration are 
given, the most interesting being the alar expanse, conservatively 
estimated in that the bones were given their natural angulation. 
They range from Pteranodon sp. (Cat. No. 1181) with 3:390™ 


Am. Jour. Sc1.—Fourts Serins, Vou. XXXI, No. 182.—Frpruary, 1911. 
11 


150 Scientific Intelligence. 


(=11 ft. 1 in.) to P. ingens type (Cat. No. 1175) with 6:803™ 
(=22 ft. 3 in.). Still another individual (Cat. No. 2514), if the 
proportions of the known bones were carried out, would have the 
tremendous expanse of 8:°163™ or 26 feet 9 inches! 

The geologic and geographic localities of the seven described 
specimens are given — all from the Niobrara chalk of Wallace 
and Trego counties or from the Smoky river in western Kansas. 

It is’ to be regretted that a specific summary was deemed 
inadvisable, for the author was certainly better fitted than any 
one else to attempt such revision. Nothing is said as to relation- 
ships with other Pterosaurs or of the life conditions other than 
the following brief suggestion on page 13: 

“The occurrence of Pteranodon remains in the chalk deposited 
in a shallow sea and at a distance of not less than one hundred 
miles from the probable shore line, also the shape and proportion- 
ate size of the jaws, have given rise to the supposition that this 
pterodactyl lived principally upon small fish taken at the surface 
in a manner somewhat similar to that adopted by the Skimmer, 
Rhynchops.” 

The only suggestion in the way of a cause of extinction is the 
danger of parturition, owing to the development of crest and 
wing bones “the immoderate proportions of which, however, were 
probably due entirely to postnatal growth.” 

Mr. Eaton has done an excellent piece of descriptive work and 
the plates, prepared from photographs and pen drawings, are 
admirable. R. 8, L, 

2. The Age of Mammals; by Henry Fatrrir~tp Osporn. 
Pp. 1-xvil, 1-635, with 220 text figures. New York, 1910 (The 
Macmillan Company). Price $4.50 net.—This admirable book in 
its present form is the outcome of the series of Harris lectures 
delivered in 1908 before the students of Northwestern University. 
Many of the facts set forth are of course known to men of sci- 
ence, especially to such as have had the privilege of being 
Osborn’s pupils, but the assembling of the great array of truths 
to find which one would have to go far afield or delve into various 
sources, often in foreign tongues, is a work of the utmost value 
to the student and teacher of mammalian life and likewise to the 
serious reader. The problems discussed are not those of the 
evolution and descent of the various phyla, but rather the sources 
of origin of the various mammalian groups, their wanderings 
over the face of the globe and the final extinctions of the races 
which have passed away, together with the competition of the 
elements of the successive faunas in time and space. 

Paleogeography, the climatic changes and the consequent evo- 
lution of plant life, which form the fundamental factors influenc- 
ing animal change, are fully discussed, illustrated by excellent 
geologic and geographic charts. Of the mammals themselves, 
the great array of fossil skeletons in the American Museum 
together with the well-known restorations in the flesh by Charles 
R. Knight form most ample and admirable illustrations. Espe- 


Geology. 151 


cially interesting are the outline sketches of the associated ani- 
mals of the various faunas. 

In the introduction Osborn discusses the North Polar theory 
of the origin of land mammals near the North Pole, whence they 
spread southward, ascribing the idea to Haacke in 1886. It is 
but just to state that an earlier writer, G. H. Seribner, advanced 
a similar thesis as to the origin of the flora and fauna of the 
earth in his little monograph entitled “ Where did Life Begin ?” 
and published in 1883. Except for this the bibliograpby is 
apparently very complete and the appendix also contains a new 
and copious classification of the mammalian genera, living and 
extinct. 

The volume is an excellent example of bookmaking and the 
type clear and legible, the principal room for criticism being the 
half-tones, many of which, notably those of Knight’s drawings, 
do not do justice to the originals. R. 8. L. 

3. Tertiary Faunal Horizons in the Wind River Basin, 
Wyoming, with Descriptions of New Eocene Mammals ; by 
WaLteR GrancerR. Bull. Amer. Mus. Nat. Hist., Vol. xxvii, 
Art. xxi, 1910, pp. 235-251, with 6 text figs. and 3 pls.—This 
excellent little bulletin by Mr. Granger summarizes his work of 
exploration in the Wind River Basin as follows :— 

“1. The Wind River Basin is covered throughout the greater 
part of its area with beds of the Wind River group, pertaining 
to the Lambdotherium Zone. 

“9. Mammalian remains are extremely rare or absent from 
these beds except in two localities in the northern and north- 
eastern part of the basin, viz., along Alkali Creek and between 
Muddy Creek and the Owl Creek Mountains. 

“3. Lying along the northern border of the Tertiary deposits 
in the northeastern corner of the basin, between the foothills and 
the Lambdotherium beds, apparently older than the latter and 
with the best exposures along Cottonwood Creek, is a series of 
350 feet or more, containing a fauna intermediate between the 
Lambdotherium Zone and the Coryphodon Zone of the Big Horn 
Wasatch, the genera being all common to both zones. 

“4, Along the southern border of the basin, on the divide 
between Sweetwater River and Beaver Creek, there is exposed a 
thickness of 1,100 feet of Tertiary, a remnant of deposits which 
undoubtedly extended over a large part of the basin at one time. 
Three distinct faunal levels, as indicated by mammalian fossils, 
are exhibited, Lower Eocene, Upper Eocene, and Lower Oligo- 
cene, the levels being correlated with (1) the ?Coryphodon Zone 
of the Wasatch, (2) the ? Diplacodon Zone of the Uinta, and (3) 
the Titanotherium Zone of the White River. An unconformity 
exists between the Eocene and Oligocene, but no break in sedi- 
mentation was detected in the Kocene series. 

“5. Between the Coryphodon and Diplacodon levels are sey- 
eral hundred feet of unfossiliferous beds, the lower part of 
which pertain probably to the Lambdotherium Zone of the White 


152 Scientific Intelligence. 


River group, and the upper part possibly to the Middle Eocene 
faunal zones of the Bridger Basin.” R. 8. L. 
4. Geological Survey of New Jersey. Annual Report of the 
State Geologist, Hmnry B. Kimet, for 1909. Pp. 123. ‘Tren- 
ton, 1910.—The latest volume from the New Jersey State Survey 
contains, in addition to the Administrative Report by the State 
Geologist, three detailed papers upon “ Development of the 
Passaic Watershed by Small Storage Reservoirs,” by C. C. Ver- 
meule ; “ Records of Wells in New Jersey, 1905-1909,” by Henry 
B. Kiimmel and Howard M. Poland ; and “ Notes on the Mineral 
Industry,” by Henry B. Kiimmel. The first of these reports is 
accompanied by a large folded may. 


- 


III. Asrronomy. 


1. Zransactions of the Astronomical Observatory of Yale 
University. Vol. II, Part II, pp. 213-325. Published by the 
Observatory, 1910.—Part I of this publication ranks among the 
foremost of contributions to the world’s knowledge of stellar 
distances by reason of the number of star measures recorded, the 
high character of the work and the important deductions made 
from it. The present publication is of less importance only 
because of the smaller number of parallax measures in it. The 
character of the work is the same. 

Part If gives the work of the Observatory on 35 stars, per- 
formed by Dr. Chase with the collaboration of Dr. Elkin and 
Mr. Smith. The stars discussed are grouped in five classes, as 
follows : 

A—6 stars with remarkably large proper motions. 

B—6 second magnitude stars not previously tested by reliable 
methods. 

C—7 stars from Part I which showed either exceptionally large 
parallax or appreciable negative results. 

D-—Additional stars from Vol. I, of large proper motion, re- 
measured. 

E—Certain stars in the Pleiades which might furnish evidence 
of the parallax of the group as a whole. 

The most elaborate discussion is that of Arcturus, the earlier 
measures of which, by Elkin, gave a parallax so small as com- 
pared with what might be expected from its brightness and proper 
motion that a remeasurement seemed called for. 

The present discussion covers everything that has been done on 
this star at the Winchester Observatory during twenty-three 
years, by Elkin, Chase and Smith. The groups of measures by 
each observer are all reduced independently by three different 
methods, each based on a different hypothesis as to the weighting 
of the observations; and the conclusions reached as to the paral- 
lax of Arcturus may well be regarded as final. (t= +0."066+ 
0.”006.) 


: Astronomy. 153 


At the end of the volume the results presented in it are col- 
lated with those of the previous volume, thereby exhibiting the 
results of all the work of the Winchester Observatory in parallax 
from its establishment to the present time. 

The conclusions reached as to the relation of parallax to dis- 
tance and proper motion appear in the following table : 


Proper Motion} 0.//00 to 0.734. 0.//41 to 0.754. 0.55 to 0./’65. 0./’66 to 0.//96. 1.//01 to 7,//07. 


. 0:0-2°5) + 0:031 13 stars} +0°100 2stars}+0°113 3 stars 0 stars} +0°200 2stars 
“ 3°0-5:0) + 0'026 9 .** |40:024 7 “* |407114 5 “ |/4+0°091 8 “** |+0°162 6 ‘“* 
5°1-7°0/—0:010 7 ‘ |+0°08414 ‘“ |+0:06416 ‘* |+0°08620 ‘ |4+07111 8 * 
7:1-9°0 0 ‘ |+0°04023 ‘ |+0°08228 ‘ |4+0°:01819 ‘* |4+0:12812 <“ 


“ While the groups are small there is, with slight exception, 
manifest a very decided sequence of values both with respect to 
magnitude and size of proper motion such as one might expect. 
This is very gratifying in that it shows, in our opinion, as well 
as does the comparison of different series upon the same stars, 
that on the whole the work is comparatively free from systematic 
error.” W. B. 

2. Determination of the Solar Parallax from photographs of 
Eros made with the Crossley Reflector of the Lick Observatory, 
under direction of Coaries D. Perrine. Pp. 98. Washington, 
1910. Published by the Carnegie Institution —The photographs 
from which this parallax determination has been made were 
taken at the opposition of Eros in 1900. Owing to the remote- 
ness of the Lick Observatory from the others engaged in the 
work, its measurements were arranged so as to admit of inde- 
pendent reduction, and consisted of sets at large hour angles 
east and west of the meridian, together with meridian observa- 
tions of the planet for correction of the ephemeris. In the reduc- 
tion most elaborate precautions have been used to detect all 
systematic errors, with the result that everything except an insig- 
nificant item of this sort has been satisfactorily accounted for. 

As a final check 20 of the plates showing the largest discrep- 
ancies were remeasured and an independent determination of the 
parallax made from them, and, almost as a work of supererogation, 
even a third independent determination from the five most dis- 
crepant of the former 20 plates was also carried through. 

The fact that neither of these determinations differs appre- 
ciably from the full result is taken as a convincing test of the 
absence of every source of appreciable error from measurements 
and reductions. 

The correction deduced for the assumed parallax of 8°80” is 
+0067” +0025". 

The probable error here given is estimated from the probable 
errors derived in the following ways: 


154 Scientific Intelligence. 


PE 126 :equations'. esse ee eee +0°0027”" 
O6 ‘equations.c0 2. SUA GaT sl eeeeee 18 

18 daily meansis sone ce Aare eer 52 

15 daily means (omitting 3 largest values) 34 

8 results used in final combination .--- -- 18 

Ww. B 


3. Les Déterminations des Longitudes et ? Histoire des Chro- 
nometres ; par JEAN Mascarrt, Astronomer at the Observatory of 
Paris, pp. 62. (Extrait des Journal, “ L’Horologier”).—This is 
an account of the development that took place from about 1760 
to 1780 in methods of determining longitude and time, especially 
at sea, and more particularly in making marine chronometers-and 
testing them on long voyages. The expedition of the Flora, 
which was one of several chronometer-testing expeditions under- 
taken for the first time at this epoch, and the most important of 
them, is described at length. The transits of Venus which occurred 
in 1761 and 1769 gave an impetus to progress in these lines, from 
the demands which they made for accurate chronometers to be 
taken to the widely separated stations at which the transits were 
observed. W. B. 

4, Project for the Reform of the Calendar; by Cartos A, 
Hess, Iquique. Presented to the Fourth (Pan-American) Scien- 
tific Congress.—The author would divide the year into 13 months 
of 28 days each, the last month to be called Trecember, and the 
odd day Jan. 0, and at leap year, 00. The numerous advantages 
that would attend such an orderly arrangement are forcibly pre- 
sented. 

The abstract proposition can hardly be contradicted, but the 
irrational obstacles of tradition and mental inertia are pretty 
certain to be insurmountable to this, as to other such attempted 
revisions, for an indefinite period to come. 

The revised calendar, which would be perpetual, and which the 
author would like to see introduced in 1912, would be as follows; 
and “future generations would learn it by heart from earliest 


infancy.” W. B. 
2 
a = 3 z b = a 
Bee | dst dea loco ae ea atte 
Soe eames te) 
1 2 3 4 5 6 7 APRIL 
Boaewe 10 11 12 13 14 | JuLy 
15 16 17 18 | 19 20 21 Oona: 
Wh No BB ; 24 25 26 24 28 Teena 


Miscellaneous Intelligence. oon 


LTV. Misceruanxous Screntiric INTELLIGENCE. 


1. Report of the Secretary of the Smithsonian Institution for 
the year ending June 30, 1910. Pp. 89. Washington, 1910.— 
The report of Dr. Walcott, recently issued, gives an interesting 
summary of the work of the Smithsonian Institution in its many 
lines of activity. Although the Institution is already committed 
to so much, it is interesting to note that the Secretary is planning 
to further extend its usefulness. He calls attention to the import- 
ance of a national seismological laboratory, observations at which 
would not only serve to give a large mass of important scientific 
data, but might also serve to predict occurrences as serious as 
that at San Francisco in 1906. A number of similar laboratories 
are now being conducted in different parts of the world, and it is 
a reproach to this country that it has taken no steps in this 
direction hitherto. The estimate of initial expense involved is 
moderate, amounting to some $20,000 for the equipment of the 
laboratory and the expense of the first year. It ismuch to be 
hoped that it will be found practicable to undertake this work at 
an early date, although it is intimated that it may be necessary 
to look for a special gift; such gifts have already been made 
effective in other lines of research. 

The total permanent fund of the Institution amounts to nearly 
one million dollars, and the appropriations for the year covered 
in this report amounted to $720,500. 'The Secretary remarks 
with some detail upon the large and valuable collections made by 
the Roosevelt expedition, the work of which was comprised 
between April, 1909, and March, 1910. It is stated that the series 
of large and small mammals from Hast Africa is probably more 
valuable than is to be found in any other museum in the world. 
The series of birds, reptiles and plants, is also of great import- 
ance. Of the special investigations now being carried on or 
planned for the near future, may be mentioned that of Dr. Wal- 
cott on the Cambrian and pre-Cambrian rocks in Western Canada ; 
also the biological survey of the Panama Canal zone to be under- 
taken in the winter of 1910-1911; and the work of Dr. A. 
Hrdliéka on the antiquity of man in South Africa. These last 
researches, carried on for two months in the spring of 1910, fail 
to substantiate a large part of the claims that have been made. 
The specimens, both human and archeological, agree with those 
of the American Indian, and, so far as observed, bear only intru- 
sive relations to the Quaternary or Tertiary deposits with which 
they are associated. It is noted that the new museum building is 
practically completed in essential respects, and the transfer of 
collections and laboratories is going on rapidly. 

The results of the work of the Astrophysical Observatory are 
summarized by the Director, C. G. Abbott, as follows : “ The work 
of the year is notable for the determination of the absolute scale 
of pyrheliometry and for the success of spectrobolometric observa- 
tions of the solar constant of radiation on Mount Whitney. 
These agree with simultaneous observations of the same kind on 


156 Scientific Intelligence. 


Mount Wilson. Reducing these and other results to the absolute 
scale of pyrheliometry, we may fix the average value of the solar 
constant of radiation at 1°925 calories per square centimeter per 
minute for the epoch 1905-1909. Making allowance for the 
higher values which must prevail at sun-spot minimum, the solar 
constant may be estimated at 1°95 calories as an average value 
for a sun-spot cycle. No reason has been found for departing 
from the view heretofore held that short-interval variations of 5 
per cent or more from this value occur, The energy distribution 
in the solar spectrum outside the atmosphere has been determined 
with the bolometer on Mount Whitney between wave lengths 
0°294 in the ultra violet and 3:0u in the infra-red. This region 
appears to contain full 99 per cent of all the solar energy outside 
the atmosphere. The apparent temperature of the sun as com- 
puted by three different methods comes out 6430°, 5840° and 
6200° of the absolute scale. Researches on the transmission of 
moist columns of air for long-wave rays such as the earth emits, 
have been continued to wave lengths beyond 15, and for col- 
umns of air 800 feetin length. Secondary pyrheliometers, stand- 
ardized to the absolute scale, have been sent to Russia, France, 
and Italy, and also furnished to the United States Weather 
Bureau and Department of Agriculture.” 

2. Library of Congress. Report of the Librarian of Con- 
gress and Report of the Superintendent of the Library Buildings 
and Grounds, for the fiscal year ending June 80, 1910. Pp. 305, 
with 7 plates. Washington, 1910.—All of those immediately 
interested in the important matter of library administration will 
welcome this annual volume from Mr. Putnam, since the Con- 
gressional Library, of which he has charge, rightfully serves 
as a model to the other large libraries in the country. It is 
interesting to note that the total appropriations for the Washing- 
ton Library and associated copyright office for 1911 amount to 
about half a million. The accessions to the Library, including 
pamphlets, are about 90,000. Among the various appendixes is 
to be noted that which enumerates the important series of manu- 
scripts and transcripts which have been received during the year. 

3. Academic and Industrial Efficiency. A Report to the 
Carnegie Foundation for the Advancement of Teaching ; by 
Morris LuewrEittyn Cooker. Bulletin Number Five. Pp. vi, 
134. New York City, 1910.—The investigation detailed in this 
Bulletin was carried on by Mr. Cooke of the American Society of 
Mechanical Engineers, under the direction of the Carnegie Founda- 
tion. Eight institutions served as the object of investigation, the 
effort being to obtain an estimate of the cost and output in teach- 
ing and.in research in the department of Physics. The data 
have evidently been obtained with all possible fulness and aceu- 
racy, and although the results are presented with some frankness 
of criticism, and although the suggestions made as to the proper 
place of research in an educational institution of the first rank, 
will not meet with universal approval, there can be no question 
of the value of having information of this kind brought together 
and presented to the interested public. 


COE EEE OO 
| SENN EASA AL. MARCH, 1911. 
J 


Established by BENJAMIN SILLIMAN in 1818. 


THE 


AMERICAN 
JOURNAL OF SCIENCE. 


Epirorn: EDWARD S. DANA. 


ASSOCIATE EDITORS 


Prorgessors GEORGE L. GOODALE, JOHN TROWBRIDGE, 
W. G. FARLOW ann WM. M. DAVIS, or Camprince, 


Proressors ADDISON E. VERRILL, HORACE L. WELLS, 
L. V. PIRSSON ann H. E. GREGORY, or New Haven, 


Proressork HENRY S. WILLIAMS, or Iruaca, 
Proressor JOSEPH S. AMES, or Bautimore, 
Mr. J. S. DILLER, oF Wasuineton. 


FOURTH SERIES 


VOL. XXXI—[WHOLE NUMBER, CLXXXI.] 


No. 183—MARCH, 1911. 


' s ale 
sxhison ian if q t 7 Uf, 
© “op 


rm 
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THE TUTTLE, MOREHOUSE & TAYLOR CO., PRINTERS, 123 TEMPLE STREET. 


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Published monthly. Six dollars per year, in advance 6.40 t ies i 
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Postal Union ; $6.25 to Canada. Remittances should be a eave caer usr aie 
registered letters, or bank checks (preferably on New York banks). : 


*- 


SPECIAL ANNOUNCEMENT. 


MORGANITE. 

I beg to advise my numerous patrons that after considerable difficulty 
have sectired a small lot, in the rough state, of this very rare‘and new gem 
from Madagascar; this is the first opportunity ever offered collectors to 
purchase this unique variety of Beryl in this country. 


REMARKABLE RUBY GEM CRYSTALS IN MATRIX 
FROM BURMA. 

’ These I have just secured from a mining engineer, who has returned from a 
visit to this celebrated locality, and was fortunate in securing the lot ; the 
crystals ave of the very finest quality in color and shape and are of the 
pigeon-blood quality ; prices and further particulars on application. 


REMARKABLE COLLECTION. 
I have received a remarkable collection of crystallized minerals of the 
finest quality, representing old finds and very rare examples of recent locali- 
ties which I have just placed on sale. 


HERKIMER QUARTZ. 

Just secured a good lot of crystallized quartz in Bituminous limestone, the 
finest I ever saw, and in the same box were a fine lot of quartz on matrix 
from Amsterdam, N. Y.. It is known that specimens are not obtainable 
now ; as this locality is all built over their value will be appreciated. Prices 
range from 25 cents to $1.50. 

Have received a very remarkable Amethyst from Port Arthur, China, 
9x10, beautiful color : would make an exceptionally good museum specimen. 
Must be seen to be appreciated. 


A FEW REMARKABLE GOLD SPECIMENS. 


/ 


One consisting of one inch solid vein of gold, very rich, contains 2034 


ounces ; the matrix itself is a rich ore of gold. One side of the specimen is 
polished ; it is 314 x 234 x 214 inchesin size. I am selling this at a sacrifice ; 
former value $500, as announced in the JouRNAL oF ScrencE, July, 1909; 
will be disposed of now for $300, the actual value of the gold in the specimen. 


IRIDESCENT PYRITES. 


A recent trip of a local mineralogist awarded him a small lot of the 
finest quality of pyrites from South River, N. J. They are of the iridescent 
quality, the finest from this locality I have ever seen. Do not fail to secure 
one of these brilliant specimens. 

I shall be pleased to send anyone on request, an assortment, prepaid, for 
selection, and guarantee satisfaction. 


A. H. PETEREIT, 
81—83 Fulton Street, New York City. 


Phone Beekman 1856. 


‘ 


THE 


AMERICAN JOURNAL OF SCIENCE 


eo Urn FHS RH S:..] 
—++>—_—__. 


Arr. XIX.—The Transmission of Light through Transparent 
Inactive Crystal Plates, with Special Reference to Observa- 
tions in Convergent Polarized Light; by Frep. EvcEnr 
Wricu'. 


Introduction. 


Tue problem of the refraction and reflection of light on 
inactive, transparent crystal plates has long attracted the atten- 
tion of physicists and crystallographers, and has proved a 
fruitful field of investigation from the standpoints both of 
theory and of applied physical optics. The general problem 
was first successfully attacked in 1835 by F. Neumann’ in Ger- 
many and by J. MacCullagh’ in Ireland, Neumann using 
strictly analytic methods; MacCullagh, on the other hand, 
inclining rather to geometric methods and attaining thereby 
greater simplicity in his treatment of the whole. Both Neu- 
mann and MacOullagh showed keen mathematical insight and 
judgment in overcoming the inherent difficulties of this prob- 
lem; their work, moreover, was remarkably thorough and 
comprehensive, and has served as the foundation on which all 
subsequent investigations have been based. Their general 
conclusions have remained intact and valid to the present day, 
even though their methods of calculation have been superseded 
by simpler and more effective methods and their fundamental 
assumptions have been modified to some extent and expressed 
in terms more nearly in accord with modern views on the 
nature of light. , 

1 Theoretische Untersuchungen der Gesetze, nach welchen das Licht an 
der Grenze zweier vollkommen durchsichtiger Medien reflektiert und gebro- 
chen wird, Berliner Akad. Abh. 1835, Math. Abt. p. 1-160; also Poggen- 
dorf’s Annalen. xlii, 1-37, 1837. 

? Phil. Mag. (3), viii, 103, 18385; x, 42,1837; On the Laws of Crystalline 
Reflexion and Refraction, Trans. Roy. Irish Acad. xviii, p. 31, 1887; Col- 
lected Works, 1880. 


Am. JouR. Sci.—FourtH SrrRizs, Vout. XX XI, No. 183.—Marcz, 1911. 
12 


158) FE. Wright—Transmission of Light through 


Besides the papers by Neumann and MacOullagh, the most 


important contributions to this subject have been made by D. 
Brewster’ (1819), A. Seebeck’ (1831), A. Cauchy® (1836), C. G. 
Stokes* (1852), J. Grailich® (1855), A. Cornu’ (1867), G. Kireh- 
hoff’ (1876), H. A. Lorentz* (1877), F. Kohlrausch’ (1878), R. 
T. Glazebrook” (1882), Th. Liebisch” (1885), J. Danker" (1885), 
J. Conroy” (1886), C. Spurge™ (1886), J. Norrenberg”’ (1888), 
Lord Rayleigh” (1888), P. Drude’ (1889), C. Pulfrich* (1890), 
A. Potier’® (1891), W. Voigt” (1896), C. Viola” (1899), A. Ost- 
hoff” (1905), P. Kaemmerer* (1905), F. Pockels™ (1906). 

In all these investigations, interest has centered in the 
reflected rather than in the refracted waves. The phenoniena, 
however, resulting from the transmission of light through 
crystal plates are of great importance in practical microscopic 
diagnosis and merit detailed consideration, from the standpoint 
both of general theory and of observation. The present inves- 
tigation was undertaken primarily to determine the influence 


1Phil, Trans., 1819, p. 145. 

BS Pogg. Ann., xxi, 290, 1831; xxii, 126, 1831; xxxviii, 276, 1836; x1, 462, 
1837. 

3Compt. Rend., ii, 364, 1836. 

4On the composition and resolution of streams of polarized light, etc., 
Cambridge Trans. ix, 399; Phil. Mag. (4), ii, 316, 1852. 

®'Wien Sitzungsber. (II), xi, 817, 1853; xii, 280, 1854; xv, 311, 1855; 
xix, 226, 1856; Denkschr. Math. Nat. K1 ix, 57, 1805; xi, 41, 1856; Pogg, 
Ann. xcviii, 205, 1856. 

® Recherches sur la reflexion cristalline. Thése fac. Science. Paris, 1867; 
Ann, Chim. Phys. (4), xi, 1867. 

1 Uber die reflexion u. Brechung des Lichtes an der Grenze krystalliner 
Mittel., Abh. Berliner Akad., 1876. 

8Uber die Theorie der Reflexion u. Refraction d. Lichtes, Schlémilch’s 
Zeitschr. xxii, 1, 1877. 

9Wied. Ann., iv, 1, 1878. 

10On the Refraction of plane polarized Light at the Surface of a uniaxial 
Crystal. Phil. Trans. clxxiii, 595, 1882. 

1Uber Totalreflexion an doppeltbrechenden Krystalien. Neues Jahrb. 
i, 245, 1885 ; ii, 47, 1886 ; Lehrb. d. Physik. Kryst., 1891. 

12 Neues Jahrbuch, Beil. Bd. iv. 241, 1885. 

13 Proc. Roy. Soc., xl, 173, 1886. 

4 Proc. Roy. Soc., xli, 468, 1886; xlii, 242, 1887. 

15 Uber Totalreflexion an doppeltbrechenden Krystallen. Wied. Ann., xxxiv, 
843, 1888. : 

16 Phil, Mag. (5), xxvi, 241, 1888. 

“Wied. Ann., xxxvi, 532, 865, 1889; xxxviii, 265, 1889. Physik. d. 
Aethers, 1894. Lehrbuch d. Optik (2d edition), 1906. 

18 Das Totalreflectometer, 1890. 

19 Sur la principe du Retour des rayons et de la Reflexion cristalline, Journ. 
de Phys. (2), x, 349, 1891. 

*0Compend. d. theoret. Phys. ii, 622, 1896. 

1 Zeitschr. Kryst., xxxi, 40, 1899; xxxvi, 245, 1902. 

22 Uber die Reflexion u. Brechung des Lichtes an Zwillingsebenen volkom- 
men durchsichtiger inaktiver, einachsiger Krystalle. Neues Jahrb., Beil. 
Bd. xx, 1, 1905. 

23 Uber die Reflexion und Brechung des Lichtes an inactiver, durchsichti- 
gen Krystallplatten, Erster Teil. Neues Jahrb., Beil. Bd. xx, 159, 1905. 

24 Lehrbuch d. Kristalloptik, 1906. 


Transparent Inactive Crystal Plates. 159 


of certain factors which underlie the methods for the measure- 
ment of the optic axial angles, especially the method of Pro- 
fessor Becke’ and the writer’s modification*® of the same.° 

These methods are based on the degree of curvature of the 
dark hyperbolas or zero isogyres of the interference figure and 
depend, therefore, on the polarization directions of waves 
transmitted along ‘different paths. In microscopic work, the 
influence of the boundary surfaces, not only of the crystal 
plate, but also of the intervening glass plates, on these waves 
enters the problem and tends to render it more complicated. 
In the following pages the general mathematical treatment of 
the problem of ‘ight transmission through transparent inactive 
erystal plates is given in. Part 1 and ‘several important and 
apparently new yelations are deduced which simplify the 
presentation materially. In Part 2 results of calculation are 
checked by series of observations with apparatus specially 
designed for the purpose. 

The results of the investigation show that the methods pro- 
posed by Professor Becke and by the writer are approximate 
methods only; both furnish results of about the same order of 
accuracy, the one advantage of the writer’s method being that 
of slightly greater simplicity. They show, furthermore, that 
a theoretically correct method is not attainable because of 
many factors, each of only slight intluence, which enter the 
problem and complicate the relations seriously. 


Part 1.’— Theoretical. 
The Boundary Conditions.’ 


Light waves, in passing through a erystal plate, encounter 
peculiar conditions, both on entering the plate and emerging 
from it. At the limiting surfaces of the plate, the crystalline 
material ends abruptly and the system of forces which result 
from the erystal strueture are suddenly cut off from further 
action. On emerging from the plate the light waves pass from 
the influence of these forces to that of an entirely different 


1 Tschermak’s Mitteil., xxiv, 35, 1905; xxviii, 290, 1909. 

This Journal (4), xxiv, 332-338, 1907; Tschermak’s Mitteil., xxvii, 
293, 1908. 

*In the course of this investigation the writer has corresponded frequently 
with Professor Becke and is indebted to him for several suggestions and for 
his open consideration of the points in question. 

“In the preparation of this section the following books and papers have 
been consulted especially: Drude, Lehrbuch d. Optik; also Drude in Win- 
kelmann’s Handbuch d. Physik; Liebisch, Lehrbuch d. Kristalloptik ; 
Pockels’s Lehrbuch d. Kristalloptik ; and P. Kaemmerer, Uber die Reflexion 
u. Brechung des Lichtes an inaktiver, durchsichtigen Kristallplatten, Neues 
Jahrb., Beil. Bd. xx, 159, 1905. 

5 The subject of boundary conditions is thoroughly treated by P. Drude in 
Winkelmann’s Handbuch der Physik, vi, 1169, 1906; also in Drude’s Physik 
d. Aethers, 511, 1894. 


160 FL E. Wright—Transmission of Light through 


system, but this passage from the one set of conditions to the 
second, although very rapid, is a continuous process, since, 
physically speaking, there are no discontinuities in nature. On 
the one side of the surface the light waves are entirely within 
the influence of the crystal forces; on the other, within that of 
the second medium; at the boundary surface, the transition 
from the one sphere of influence to the second is accomplished. 
There the two sets of forces meet and the result is a continuous 
passage of the one set to the second, so far as their influence 
on external forces is concerned. Whatever theory or hypothe- 
sis of light is adopted to explain the phenomena, this contin- 
uity must be taken into account. In the electromagnetic 
theory of light a “ boundary’ surface between two substances 
of dielectric constants e, and e, must be considered an inhomo- 
geneous surface in which the dielectric constant passes contin- 
uously though very rapidly from the value e, to e, in the 
direction of the normal to the surface.” The general equations 
of the electromagnetic theory are valid even in this film: 


4r , Ow NA _ ou Ow 47, Ow dou 


Gn” Foy! Gee? oom be) del ice) a co 
Gy * 10a. soy! 2 ee Ok ios ate ~ meno i umnro ne 


In these equations of Maxwell, u, v, and w are the compo- 
nents after the a’, y’, 2’ axes of the magnetic force (the 2’ 
axis being normal to the surface and the ~’ axis in the plane of 
incidence); X, Y, Z the components of the electric force; 
Jx's Jy Juy the components of the electric density in electro- 
static units ; Ss, ., Sy, S,, the components of the magnetic current, 
and ¢ a constant, expressing the ratio between the electrostatic 
and electromagnetic units. The components of the electric 
and magnetic currents, 7., Jy, J, and s,., sy, 8, are finite quanti- 
ties. The right hand side of the equations with differential 
quotients must therefore also be finite, even when the thickness 
of the film approaches 0, and the components of the electric 
and magnetic forces parallel with the boundary surface must 
_ be continuous on passage through the boundary surface. This 
condition is realized mathematically by stating that on either 
side of an infinitely thin film the two forces are equal. 


(@),. = @),6°(%), =(@), (C2 =o, 1), = eee) 


These conditions are perfectly general and must always be 
fulfilled at boundary surfaces. 


'P. Drude in Winkelmann’s Handbuch der Physik, vi, 1169-1170, 1906. 


Transparent Inactive Crystal Plates. 161 


Boundary Conditions Applied to Transparent Inactive Crystal 
Plates. 


A erystal is distinguished electromagnetically from an iso- 
tropic body by the variation of its specific inductive capacity 
with the direction. If «€,, €,, «,, be the three principal dielec- 
tric constants of a crystal and mw the magnetic permeability, 
= |, as is practically the case in all known dielectrics, then the 
general differential equations, referred to any codrdinate sys- 
tem, for the electromagnetic field in a crystal, are: 


Dea a0) es 20S 
e en ot + €, ot ar 13 a) ay Bev 


| Ox era ot) _ 9 Jw (4) 


= —— Sih de = = _ —= 
ec 1 ot ap or ot 4 €o3 Ot dz! Ox! Y] 


Mv OX en Ov OZ Oo Ou 
Cc («: at E50 ot + €,, =] 


Ty Ghee Vo 
Lau _9¥_ 9% 180 _ 9% 9X 1dw_ dX OY 


aero cnon mon) O20. ue OF Oy’ 1 Oz! 


In these equations, €),—=€xn ('). 

If the magnetic force be taken as light vector, the compo- 
nents X, Y, Z, of the electric force can be eliminated from (4) 
and (5) by differentiating equations (5) with respect to ¢: 


Ohh 6 (ey 9 ear 1 . A ee 9 @); 


Goin Oe NOt) MeOu Not) 6 Ot Onl ob) m2) \ an) 2 
Idi 2 0 /oX do /dY (6) 
e Ot a) cal ae 
IX IY OZ 


and substituting the values from equations (4) which 


Ot? dt? dt 


are linear functions of these quantities. If, for abbreviation, the 
right hand side of the equations (4) be made equal respect- 


: OX JY OZ : 
ively to &, 7, & then Dt? on? oe Can be expressed as linear 


functions of &, », €, thus: 


‘A simple proof of this relation is given in Drude, Lehrbuch der Optik, 
294, 1906. 


1620 FL EB. Wright—Transmission of Light through 


Oxia dl 

on = Cc (4,,€+4,,9+4,,0) 

Vesa 

Ot = Cc (4,,€ + 49 + Aa6) (7) 

Amel 

Ot a Cc (45, + G9 +4,,) 
in which the so-called polarization constants @,,...,a,,..., 
@,,. + . 5 aresimple determinate functions of ¢,...,6,.. 


€,--., and ¢’ and for which the relations a, = dy, hold 
true just as €,, == €,. These equations indicate that a function 
of the second degree is possible whose partial differential 
quotients with respect to & 7», ¢, are equal, respectively, to 


aX oY 97 
ot? dt? Ot” 
2cG = 4,6 +4,,4' +4,,0 + 20,6 + 2a,,CE+2a,,€) = constant. (8) 


From energy considerations it is evident that this equation (8) 
must represent an ellipsoid; and if, in it, the constant be 
2¢G=1, the equation is then that of a triaxial ellipsoid referred 
to a coérdinate system of any position. This ellipsoid is the 
“index ellipsoid” of MacCullagh, or “ellipsoid of elasticity ” 
of Kirchhoff, or the “indicatrix”’ of Fletcher. The codrdi- 
nate axes can be brought to coincide with the principal 
ellipsoidal axes by use of the usual transformation equations : 


This function is 


ap + Bp", +p’, = 0. 


2,2 22 2,2 ae 
OP POG, Vegan =a 

2,42 PLP) taza =: 

OT OTS Ci 9 =e 

2 r 2 a : 42 a 

a le OOP +e 9,1; ap, Ws (9) 


wT Dp, ar br, DP, 3 CT, Dp, = 4,, 
WPT, + OG. + OPI, = % 


in which 7, Py Doo Yrs Yoo Yon And 7,, 7,, 7,, ave the direction 
cosines between the new coordinate axes #, y, 2, and the w’, v’, 2’ 
of the old system respectively. Referred to the principal 
ellipsoidal axes equation (9) becomes a*&’+6'n’+c*O* = 1, in 
which a, 6, c, are the principal light velocities of the erystal. 
The symmetry axes of this index ellipsoid are the reciprocals 
of a, 6, ¢, or directly the principal refractive indices of the 
crystal. In geometric problems of reflection and refraction, 
the index ellipsoid and the index surface derived from it are 
specially useful. 


Transparent Inactive Crystal Plates. 163 


On substituting the values of Bae ae Ze of equation (7) 
in (6) we obtain a system of partial differential equations : 
ae = = (Qe Gant 2.56) — 5 (14,8 + 529 + Ua06) 

oe 3s = (Gygé + Gag + 4.6) — S (4,,€+@,.9+4,,6) (10) 
ce = iu (a,,€+4,.n+4,€) — ee (4,,E + U9 + 4,06) 


which are free from the components of the electric force and 
of the electric current. 5: 

Equations (4) and (5) are of general validity and obtain 
therefore, even at the boundary surface of a crystal plate." alt 
is apparent from the last equation of (5) that, as (X),= (X),, 
(Y),=(Y), at the boundary, (3 i) = in or (w),=(w), for 
periodic vibrations. The boundary conditions for a crystal 
plate may therefore be written : 


(0, = Hy =v (= oe (FE) = (Ge), 


(ar), (5), 


of which only four are independent. The last equation of 
the set may accordingly be discarded. The fourth equation 


a) = (Fe) can be expanded by means of (7) and (4) and 


becomes for the general case of two adjoining crystal plates : 


Pee) io aa, (2 Se 
tu 50) — 5p +4,,(55— 5a T ys aay) = 


, fow — ov’ Bay (Oi an os fou why 
a le a oa) + a aCe Ox! ) +a da a (12) 

These boundary equations, together with equation (8), are 
of general validity for transparent, inactive plates, and form 
the basis on which all detailed work rests. 

The partial differential equations (10) representing the move- 
ment of the magnetic vector are satisfied by the components 
u, v, w of the vibration of a plane polarized, advancing wave 
of constant amplitude. This vibration is defined by the usual 
equations of the general form : 


164 FL EL Wright—Transmission of Light through 


U / / 
“= Al cos aC Siw) 
T q 
if / ' 
v = Am cos all (« = ee (13) 
T q 
t J / 
w = An cos p(e—-S ts) 
T q 


in which A is the amplitude of the vibration or magnetic 
force; 7, m, n, the direction cosines of the line of vibration 7, 
which in this case is that of the magnetic light vector and also 
the polarization direction; T, the period of vibration; A, #, v 
the direction cosines of the normal N of the wave propagated 
with the velocity g. To simplify these equations, let the 
boundary surface of the plate be the a’, y’ plane, fig. 1; the 


AE 


plane of incidence, the «’ 2’ plane; the angle between the 
normal of the advancing wave N, and the 2’ axis, 7, the positive 
direction of z’ being on the crystal side of the boundary 
surface; let also the polarization azimuth yw be the angle 
between the plane of incidence (the «’z’ plane) and the plane 
of polarization (the angle Kz, fig. 1) counting from the 2’ axis 
in the direction of the +7’ axis and passing beyond this axis 
if necessary. In this case, 


= cos 7 


| 
oS 
_ 


== sin i 
t= —cosrcosy, m=siny, n= sin? cos y. 


and the equations (13) reduce to 


Transparent Inactive Crystal Plates. 165 


a x’ sin 7 +2! cos } 
u= — A cosy cosr cos — —- 
i qY 
, 2 a'sin 7 + 2’ cos7r 
Qs A sin y cos a(t — (14) 
i q 
: Qn a’ sin r + 2’ cosr 
2o= Acosysinr cos —(t — 
T q 


For 2’ = 0 it is evident from the boundary conditions, 
(wv), =(w),, (v), = (v), of equations (11) and (14), that for all pos- 
sible reflected or refracted waves at the limiting surface, T, the 
period of vibration (color) remains constant (T, = T,); also 
oF By BS = fs , which is the sine law of wave normals; while 


# =O signifies that all wave normals lie in the plane of 
incidence. 

By means of equations (14), the general differential equations 
(10) can be solved and the fundamental formulas obtained for 
the refraction, reflection, and polarization of light waves in 
erystals. Thus from equations (4) and (14) 


ow ow 
é Syme: sin yw cos 7 
Ou Ow 
ee acme ping. ha COSY 
dv ou , : 
= gi Dy! = K sin wy sin 7. 


W herein 


9 i D) i I SI “4 I a 
eS es sin sp (¢— CaS eas o*) 
T.g T qd 
From these expressions, we find: 
p ; 
) 
Oz! (2,, 5 a Ayo) a Aes é) = 
| a cos 7 (—a@,, Sin ¥ Cos 7 —a,, cos y +4a,, sin y sin 7’) 
) 
Ox’ (a,,€ oF a, ate Ass é) = 


Cae : ; A 
ee sin 7 (— @,, sin y cos 7 — @,, Cos + Q,, Sin W sin 7) 


} 
Oz! (4, g — a). SUE a,, é) = 

C ; : ; 
ae cos r (— a@,, sin y cosr — @,, COS Y + @,, Sin y sin 7) 


166 FF. EB. Wright—Transmission of Light through 


4) 


° 


Ox" (4, 3 ai; 4 tr Ms é) == 


—; sin 7 (— @,, sin y cos 7 — a,, cos y + @,, sin y sin 7) 


Wherein 
Cay all ie Qa (+ a! sin 7 + 2’ cos 7 
T de q 
similarly from (14) 
Ou 
>A atari Cosh tan Ns 3 
ov ‘ ; 
oF = C sin y 
ow é 
cava ae C cos wy sin 7 


Substituting the values from these last two sets of equations 
in (10), we obtain the two equations 


1 4 “ 4 
—cos Ye Phe sin y cos 7—a@,, cos W+a,, Sin ysin”) and 


; sin r 4 : F | 
sin y= Fe (—a,, sin Y cos r—a,, cos Y+@,, Sin y sin 7) — | 


cos 7 6 ; 
(—a,, sin Wy cosr—a@,, cosy+a,, sin y sin 7) 


2 


which, on rearrangement, become 

(a) cos y (¢’—a,,)=sin wp (a,, cos r—a,, sin 7) (15) 

(0) cosy (a,, cos r—a,, sin 7) = 

sin y (¢°—a,, sin’r7—a,, cos’r+ 2a,, sin 7 cos 7) 
By division of 15 (a) by 15 (6) an expression results which is 
free from y; 
(7’—4a,,)(¢°—4,, cos’*”r—a,, sin’*r +2a,, sin r cos 7)= (16) 
(@,, COS 7—a,, Sin 7)” 

and which reduces to’ 


[4, 1 a 20,19 ui a (4s, —k'/ig’r | [Go ar (Go —k*)tg’r| — (16a) 
; (@,,— A, .9 ry(1 +t9*r) 
if & be substituted for the constant value = which, by reason 


of the sine law of refraction, is equal, for all possible waves, to 
es where g, is the velocity of light in the isotropic medium 
enveloping the crystal and 7 the angle of incidence. By means 
of this standard formula, which can be derived in different . 


1G. Kirchhoff, Uber die Reflexion und Brechung an der’ Grenze Krist. 
Medien, Berliner Akad. Abh., 1876.—Th. Liebisch, Neues Jahrbuch, II, 191, 
1885. 


Transparent Inactive Crystal Plates. 167 


ways, the angle of refraction or reflection of any light waves 
in the erystal can be calculated. 
From 15 (a), the following equation is readily derived : 


t/a 
gw= q 22 


@,, COS T—A,, SIN 7 
which may be written 
(°—a,,)tg’r—4a,, 
(@y.— Ayal 1) 4/1 tg" age r (17) 


wherein & = 2 as in (16). From (17) the azimuth of the 


plane of polarization can be determined, provided 7 be known. 

Equation (16) is biquadratic and indicates that in a er ystal 
there are four possible waves, of equal significance,—-two 
reflected and two refracted waves,—which must be taken into 
account in the general boundary conditions for the erystal. 
The general equations (11), (12) and (14) for the magnetic 
light vector on passage through the boundary between two 
inactive, transparent crystal plates may therefore be written :' 


gv 


4 4 

> A, cos 7, cos y, = > A’, cos 7’, cos wy’, (from (w),=(u),) 
4 

> A, sin y, = > A’, sin W’, (from (¢),=(),) (18) 


4 
= A, sin 7, cos y, = > A’, sin 7’, cos y’, (from (w),=(w),) 


eH Me »# Men 


4 A, sin 7, 


> 


(sin ¥. (@,, COS 7,—G,, SIN 7) +a,, COS Y,) = 


ATS Sim en . 
—*—__*(sin y',(#’,, cos7,—@’,, sin 7",) +.a',, cos ’x) 


(tm (=) =(3),) 


In the last equation of this set both sides of the equation 
sin TAS sin 7’, 


have been multiplied by the equality —— ee 
k k 


In the first three equations, the factors of the amplitudes, 
A,..A,, are the direction cosines, J, m, nm, of the line of 
vibration 7 with the axes 2’, y’, 2’; if the factors of the 
amplitudes in the fourth equation be indicated by p, the 
equations can be written in the abbreviated form,” 

1G. Kirchhoff, Ges. Abhandlungen,. 367-370, 1882. 


2A. Potier, Journ, Phys. (2), x, 300, 1891. P. Kaemmerer, N. J., Beil. 
Bd. xx, 174, 190 


1 
4 
> 
1 


168) FE. Wright—Transmission of Light through 
S4.,= 5 4107 
1 1 


4 4 
Ayn, = ¥ Alm! 
> erga > ok (18a) 


4 4 
SA, = > Ain, 
at 1 


4 4 
LAAs A’ p's 
1 1 


In case the crystal plate is surrounded by an isotropic 
medium, these general equations become simpler; the index 
ellipsoid for the isotropic medium is a sphere and its coeffi- 
cients are @’,,—= @',,= @,,.—=q, anda’,,=a,,=a',,=0. For the 
passage of light from the isotropic medium to the crystal plate, 
there are, in general, one incident wave (I), one reflected wave 
(Rt) and two refracted waves, W,, W, (fig. 2); the boundary 
equations are, then, 

Fig. 2. 
I R 


Wu; ~W, 
D, cos 0, cos r, + D, cos 0, cos 7, = (E cos e—R cos p) cos 7 
D, sin 0, +D, sin 0, = E sine+Rsinp 
D, cos 0, sin7,+D, cos 0, sin 7, = (E cos «+R cos p) sin 7 
sin 7,,. : 
iD), 7 *[sin 0, (a,, cos 7,—a@,, sin7,)+4,, cos 0,]+ 
1 
D SU 5 ; 3 ; 
. 7p [sin 0,(a,, cos 7,—a@,, sin 7,) +a,, cos 0,|= (19) 


2 
(E sin e—R sin p) sin @ cos 7 


wherein, for the incident wave (1), the reflected wave (R), the 
faster refracted wave W, and the slower refracted wave W.,, 
respectively, E, R, D,, D,, are the amplitudes; «¢, p, 6,, 6,, the 
polarization azimuths; g,, g,, @,, d,, the normal velocities of 
the wave; 7, 7—17, 7,, 7,, the angles of the wave normals with 


Transparent Inactive Crystal Plates. 169 
z'. In these equations 2, E, ¢, g, of the incident wave are 
known ; also by calculation (equations (16) and (17)), 7,, 7, and 
05:05 of the refracted waves; and 7, g, of the reflected wave; 
unknowns are R, p of the reflected wave and DD, ot the 
refracted waves W, Woe 

In abbreviated form, corresponding to (18a), these equations 

may be written :' 

D/, +DJ, = (E cos e—R cos p) cos 7 

Dm, +D,m, = E sin e+R cos p 

Dy», +D,n, = (E cos e+ Ros p) sin z 

Dp, +D,p, = (E sin e—R sin p) siné cost (19) 


At the second boundary surface where the two refracted 
waves emerge from the crystal plate into the isotropic medium, 
two sets of boundary equations obtain, one for each refracted 
wave, W,and W,. At this surface, there are for each incident 
wave, W, and W.,, two reflected waves and one refracted wave 
as indicated in fig. 2. 

For the refracted wave W, the boundry conditions reduce to 


D, cos 6, cos 7,+R’, cos p’, cos 7’, +R”, cos p", cos 7”, = 
IDINCos) 0) cos) 7 
‘ PW Ie 1 View ee Ti whe. 
D, sin 6, +R’, sin p’, +R’, sin p”, ee 
: D’ sin 0’. 
Heaps aes ! if yak ,! Tse WS a 7 ae 
D, cos 8, sin7, +R’, cos p’, sin 7’, +R’, cos p sine = 
D’, cos 8’, sin ¢. (20) 
SUD PAT os : 
D, 7 | sin 8, (4,, cos 7,-a,, Sin 7,) +4,, Cos 3, | + 


1 


R’, sin 7! 
1 =o ’ ‘ / = ! 2 I 
ese | sin p, (@,, cos? —a@,, sin r,)+-a,, Cosi p,) + 
1 
R”, sin 7” 
1 1 is etd : a7 Picante te 
apn [sin p’, (a,, cos 7”,—-a,, sin 7”,) +a,, cos r’,) = 
1 


D’, sin 0’, cos @ sin 7. 


wherein, for the incident wave W, the faster reflected wave 
W.,, the slower reflected wave W,,, and the refracted wave WwW"; 
respectively, D,, R’, R”, D’, aie the amplitudes; 6,, p’,, p”, 0; 
the polarization azimuths ; PT Pte a the inclination of the 
wave normals with 2’; and I Gs Fy Yo the wave normal 
velocities. 

Similarly, for the slower refracted wave W, the boundary 
equations are 
D, cos 6, cos 7, +R’, cos p’, cos 7’, + R”, cos p”, cos 7” 

De cos ‘yy cos 7 
D, sin 6, +I’, sin p’, +R", sin p’, Ett eu) 
D', sin 6’, 
1P,. Kaemmerer, Neues Jahrb., Beil. Bd. xx, 176, 1905. 


170 EL EL Wright—Transmission of Light through 


D, cos 6, sin 7, +R’, cos p’, sin 2, +R”, cos p, sin 7”) = (21) 
cos p, sin 7”, = IDE veos! a sin 2 


Sankey ple ; . 
De (sin 8, (4,, COS 7,—a,, Sin 7,)+4a,, cos oy) + 
Vs ; 


R 5 sin ae J, Sey 1 as 1 f , 
—2___—+*| sin p, (@,, cos 7’,—@,, Sin 7”) + @,, COBip’, | 4. 


Yu 

p sibel : ” ay wv beet) 

R’, oR sin p”,(a,, cos 7”,—a,,sin 7”,)+ a,, Cos p”,. | = 
2 

D’, sin 0’, cos @ sin @. 


- 


/ 


These equations (19), (20), (21), agree with the fundamental 
equations of Neuman, MacCullagh and Kirchhoff derived from 
the mechanical theory of light. They are, however, exceed- 
ingly complicated, and in their solution certain auxiliary geo- 
metric and analytic relations are used which simplify and 
facilitate the practical calculations considerably. The most 
important of these aids are the index surface introduced by 
MacCullagh ('), Potier’s (7) generalization of the Neumann- 
MacCullagh relation, and the conception of the uniradial azi- 
muth as given by MacOullagh(*) and Neumann.(‘) 


The Newman-Mae Cullagh-Potier relation. 


The index surface, whose radii vectors are proportional to 
the reciprocal wave normal velocities or directly to the refrac- 
tive indices for the direction of propagation, is best adapted to 


Fig. 3. 


present graphically the relations between refracted and re- 
flected waves. Itis derived from the index ellipsoid in the same 
manner that the ray surface is derived from Fresnel’s ellip- 
soid. The index surface (1) of a crystal is the reciprocal of its 
ray surface (2), just as the index ellipsoid (I) is the reciprocal 
1J. MacCullagh, Trans. Roy. Irish Acad., xvii, 252, 1833. 
* Jour. Phys. (2), x, 349, 1891. 


3 Trans. Roy. Irish Acad., xviii, 31, 1837. 
4 Berliner Akad. Abh., Math. Abt. 144, 1835; Pogg. Ann., xlii, 9, 1837. 


Transparent Inactive Crystal Plates. 171 


of Fresnel’s ellipsoid (Ff). Each point S of the ray surface (2) 
defines a ray direction; the normal OQ to the tangent plane 
SQ through § of the ray surface is then the radius vector of 
the normal tu the wave producing the ray, 8. (Fig. 3.) The 
extension of this wave normal vector to its reciprocal length 
ON determines a point N on the index surface. The two points 
N and § are said to be corresponding points, and the plane 
NOS is normal to the polarization direction. 

Similarly, a point p of the index ellipsoid (I) is the corre- 
sponding point P of Fresnel’s ellipsoid (F), (fig. 4), if its radius 
vector coincides in direction with the normal op’ to the tan- 
gent plane Pp’ through P and is equal in length to the recip- 
rocal of the normal Op’=g. The radius vector, OP repre- 


sents a ray of velocity s (fig. 4) while the radius vector Op = Lis 
g 


the reciprocal of the corresponding wave normal velocity g. The 
normal to the plane Pop is then the polar- rey, 

ization direction. By obtaining the codr- a tk 
dinates of such corresponding points on the 
two ellipsoids (F) and (1), Potier discovered 
a simple relation between the expressions 
l,m, n, p, of equations (18a) which has 
proved of great value in the solution of B 
problems of reflection and refraction. 

For the sake of simplicity, let the equa- 
tion of Fresnel’s ellipsoid and the index 
ellipsoid be referred to the principal axes; 
Fresnel’s ellipsoid is then represented by 


Fa eto; the index ellipsoid by 
(22) 


MWe w+ yy +e 2=1 (23) 


If the codrdinates of a point P on Fresnel’s ellipsoid be 2°, 
y°,, 2°, then the equation of the tangent planes through P is: 


5 (ok ile or WOE ey) oe 
(x x 1 Gas ats y yY Aa)ye, + (2 & (Fn )e = 


The equations of the normal to this plane are 
az Yy @ 


2) = e = eo (24) 
By definition, the point p is common both to the normal and 


the index surface and its codrdinates, 2,, y,, 2,, are readily 
found by means of (22), (23), and (24), to be: 


1720 EF. EB. Wright—Transmission of Light through 


2 =O, © 
Oa ]xe, oy]y®, ; d2 2°, 


Similarly it can be shown that 


Fee) AS) Bll, OL ay ful (25a) 
(ae) aie ees 


This reciprocal relation of polar quadries obtains for all posi- 
tions of the codrdinate system, as can be readily proved by 
adopting general coérdinates in the above equations.’ 


oe 4 i : 
In case two pairs of corresponding points be taken, p, P, 
and p, P,, then, in general codrdinates, 2 


gi! aie, p(s) f= (5 
PO Out! a, ? D3 dy! y', FS aioe Ba 


,/0 = f=(— = (2 
27 Oa’ com > Y= ahh ? ona ai 


The general form of 21=a,,v"+a,,y" + ,,2” +2a,,y'2' + 2a,,2'x' 
+2a,,x'y'=1 is that of a homogeneous equation of the second 
degree, from which it follows that 


! ol , ol Tr ol Tg oelt . t ! ib pot 
x, Ox’ ae Oy’ tia PE gt gy Y gH yg? 24 + 
A +Yy'2',) ar a, (2,2", +2 @ ,) ar A, (2',Y'o ae wy’) 


ol aol TREN Sos 
=0(57) pee ay),* ee x) i 


tat PET ae eRe SAW cee Bell's 8K) fF aati r lO 
Ce YY -+e 2 ee FY DY , +22 He (26) 
Fig, 5. 
Y! 
Pp 
S 
ao 
3 
! 
».¢ 
K 


1MacCullagh, Geometrical Propositions applied to the wave theory of 
light, Trans. Roy. Irish Acad., xvi, pt. 2, 67; also xvii (1833); Coll. Works, 
p. 20-22, 1880. 


Transparent Inactive Crystal Plates. 173 


To apply this relation, discovered by Potier, between two 
pairs of corresponding points on the two ellipsoids (F) and (1), 
it is necessary to obtain the codrdinates of the points. In the 
stereographie projection (fig. 5), let y and P be the projections 
of the two corresponding points p and P, Ky’ the wave front, 
x'z’ the plane of incidence, N the wave normal, 7 the angle of 
inclination of N with 2’, the azimuth of the plane of polari- 
zation, and s the angle pOP (O being the center of the sphere). 

The coordinates of p are then: 


'—O Iyosd 1 G 7) 
a Bee sin w, cos 7, 
1 


1 
DOCS BY Coe (27) 


1 
' Ets ol ee : 
z,=Op cos pz a sin y, sin 7, 


1 
and the codrdinates of P are 
oe ees c Sal a feo 
x'° =OP cos Pa' =OP (sin s, sin 7,—Ccos s, cos 7, sin y,) 


y,=OP cos Py’=—OP cos s, cos y, (28) 
z' =OP cos Pz’ =OP(sin s, cos 7,+¢os s, sin 7, sin y,) 
Op" qs 


But from fig. 4, OP= and equations (28) ean 


cos POp' cos s, 
be written: 
x’ =9,(t7 s, sin 7, — cos 7, sin y,) 
Y 49. COSY (28a) 
2 =q,(tg7s, cos 7,+sin 7, sin y,) 

In fig. 5, P is situated between N and p; in case P lies 
beyond p, tg s, in (28a) changes sign and becomes negative. 
If the sign + be placed before tg s,, therefore, all possible 
relations are taken into account; for each particular case, the 
proper sign must be determined. 

On substituting these codrdinate values (27) (28a) in the 
Potier relation (26) for two sets of corresponding points p,, P., 
P., P, of the waves W,,W, whose normals lie in the plane of 
incidence az’, we obtain, 


q : : : : 
~ | sin y, cos 7, sin y, cos 7,—sin y, cos 7, tg s,sin7, + 
1 
cos , cos Y, +sin y, sin”, tg s, cos 7, +Sin y, sin”, sin W, sin 7, ] 
q, 
q, 


[ sin y, cos7, Sin y, cosr,—sin y, cos 7, tg s, sin 7, + 
cos Y, cos Y,+sin y, sin”, tgs, cos7r,+sin y, sin 7, sin y, sin 7, | 
This equation may be rearranged to read 


(7, —¢’,)[sin YW, sin YW, COS (7,—7,) + cos W, Cos v|— (29) 
(g 1 tg $, Sin Word 2 tg s, Sin ,) sin (7,—7,)=0 
Am. Jour. pets uEre SERIES, VoL. XX XI, No. 183.—Marcg, 1911. 
1 


174 FE. Wright—Transmission of Light through 


This general relation of MacCullagh-Neumann-Potier exists 
between any two of the four possible waves, W,, W,, W,, W,, 
within a erystal plate for each of which the sine law 
g, sin 7, q, Sin 7, qg, Sin 7, 

SS Tc ae hg Sentara rh. 

POT) Sete Mens Ses Nei) sin é 

is valid. These values introduced into (29) give after division 

by sin (7,—7,) the equation 

sin (7,+7,)[sin y, sin y, cos (7,—7,)+cos y, cos y,]— (29a) 
sin’ 7, tg s, sin y,—sin’ 7, tg s, sin y,=0 

Six different equations of this general form are possible, as six 

combinations of two can be obtained from the four different 

waves. 

Equation (29a) can be simplified by substituting for ty s, an 
expression containing g,, 7,, ¥,, and three constants, @,,, d,.) Us.) 
of the index ellipsoid. In fig. 4, the coordinates of P are 


rope BIN oI 
ah al (e (equation (25@)) and the length 
d1\? BNE Ol\2 


Oz 
Accordingly 


Op' q 
PO '— a —— u 
cos J) =COS S, OP Vy nie a O1L\? (30) 
V (5.),+ (5;),+ (a) 
The direction cosines of the radius vector OP are propor- 
tional to the codrdinates of P and therefore from (29) and (29a) 


ol 
Cos baaae ee (=). _tg s, sin r,—cos 7, sin y, 
COS Py) Tn ole ae —cos tp, 
(33), 
from which 
(5 ) =(3,) —cas yy, 
Oy), \dx/, tg s, sin r,—cos 7, sin y, 

Similarly (81) 


OLN | tg s, cos7r,+sin 7, sin y, 
& a \e ,tg Ss, sin 7,—cos7 sin y, 
On substituting these values from (31) in (30) we find 

Lee. q% 
Se I Le 
/1+tg’s, (5) Vitis’ 8, 


“/, tg 8, sin 7,—cos 7, sin y, 


COs S$, = 


Transparent Inactive Crystal Plates. 175 


or tg s, sin 7, = ~(5) +cos 7, sin y, 
AM), 


ol / / 
But (Fe) Oa Cb Yb A 
which from (27) 


il : : ; 
= @ ( —d,, cosr,siny,—d,, cos ¥, + a@,, sm 7, sin ) 
1 

7 1 

Accordingly 
2 S te oe 2 
Fes (97, —4@,,)cos ”, sin ¥,—a,, cosy, +a,, sin 7, sin y, (*) (32) 
1 


q°, sin 7, 
On eliminating tg s from (29a) by means of (32) we find 
sin (r,+7,)[sin y, sin y, cos (7,—7,) + cos y, cos y,]+ 
sin 7, sin Wy, 
q 
sin 7, sin y, 
q, 
which on rearrangement becomes 


[a,,—7',) cosr, sin y,—4,, sin 7, sin W,+a,, cos y,]+ 


(a,,— q,)° cos 7, sin W,—4,, Sin 7, Sin Y,+a,, cos y,]=0 


1This expression was first derived by P. Kaemmerer (Neues Jahrb., Beil. 
Bd. xx, 206, 1905), though by a method different from the above. 

2From the equations (80) and (81) the following relations can also be 
derived: 


—cos P= It (5) = 1 —@i2 COS 7; SIN Y;—Aeo COS J, + G13 SiN 7 Sin a) 
qi \dy/» 


2 
—a 
or tg y= Osim 2aa Be (82a) 
G12 COS 71 —Ao3 SIN 1} 


an equation identical with (17). 


— % 
mee ae Vixntg s, 
0z ; tg si cos7; +sin 7; sin yp, 


Also 


—@13 COS 7; SiN W;— 3 COS 1 +(As3—Q"1) SiN 71 Sin W, (32b) 
@*1 Cos 1, 
an expression for fg s, which is apparently novel. On equating (82) and 
(320) we find 
a 12 COS 7; —Ao3 SiN 1; 
tg i= 5 a - D) 
@?1— M11 COS’; —G33 Sin? 7; + 2ai3 SiN 7; COS 11 ) 
From (82a) and (32c), we have 
(q?1 —@22)(q?1 — G11 COS? 71] — M35 Sin? 7; +2 a3 SiN 1; COS T;) 
=(die COS 7; —Ag3 Sin 71)? 
an expression free from wp and identical with (16). . 


or tg = 


176 FL EB. Wright—Transmission of Light through 


cos 7, cosy, sin 7, cos w,+ cos 7, cos , sin 7, cos y, + 
sin 7, sin W, 


j [sin y,(a,, cos 7,—a,, sin 7,)+a@,, cos ,]+ (33) 
q, 
sin 7, sin ; f 
ea a [sin w, (@,, CoS 7,—@,, Sin 7,)+a,, cos w,] = 0 
To i 


an equation, which, like 18¢, can be written in the abbreviated 
form 

Ln tln,+p,m,+p,m, = 0 (33a) 
This equation is the general Potier relation’ and is applicable 
to any two of the four possible waves within the crystal. 


Uniradial azimuths. 


At the boundary surface of a crystal plate with an envelop- 
ing isotropic medium, an incident plane polarized, monochro- 
matic light wave furnishes, in general, one reflected wave in the 
isotropic medium and two refracted waves, W,, W,, within the 
erystal. The directions and azimuths of the two refracted 
waves are definitely fixed by equations (16) and (17) and a 
rotation of the plane of polarization of the incident wave can 
produce a change in the amplitudes only of the two refracted 
waves. Fora certain value of the azimuth, the amplitude of 
either W, or W, becomes zero, and but one refracted wave is 
transmitted. Such azimuths, e,, of the plane of polarization 
of the incident wave, for which only one refracted wave 
results, are called uniradial azimuths, and were first inves- 
tigated by MacOullagh* and Neumann.’ For D, = 0 in equa- 
tion (19) we find 


(a) (E cos e,—R cos p) cosz ==) 

(6) Esin e, +R sin p == DN simso), 
(c) (E cos «, +R cos p) sin 7. = D) cos 0, sin 7, |. (34) 
(d) (E sin e,—R sin p) sin? cos? = 


D, sinv « 
1 1 = a 
eee [sin 0,(@,, cos 7, —a,, sin 7,)+4a,, cos 0,] 
L 


The last equation of this set can be readily reduced by means 
of (32) to the form 


(d’) (EK sin e,—R sin p) sin 7 cos7 = 
D, sin*’r,(cot 7, sin 0,—¢g s,) 


By multiplying the first of these equations with sin ?, the third 
with cos 7 and adding; also the second with cos 7 sin 2, and 
adding to the fourth, we obtain 

1 Potier, Jour. de Phys. (2), x, 352, 1891. 


2Trans. Roy. Irish Acad., xviii, 31, 1837. Collected Works, p. 110, 1880. 
2 Berliner Akad. Abh., Math. Abt. 144, 1835; Poge. Ann., xlii, 9, 1837. 


Transparent Inactive Crystal Plates. diving 


. (a) E cos «,(2 cos ¢ sin 7) = D, cos 0, sin (¢+7,) 
(6) Esin «(2 cos¢sinz)= 
D, (sin 0, sin 7 cos 7+sin’ 7 (cot 7, sin 0, —¢g s,) 
On division of (0) by (a) 4 
sin 0,(sin 7 cos7+sin r, cos 7,)--sin’ 7, tg s, 
cos 0, sin(¢+7,) 


ge= 
sin’ 7, tg s, 


or tg «, = tg 6, cos (t—7,) - ane an Ol 
1 1 


(35a) 


a 
sin 7, tg S, 
cos 0, sin(#+7,) 


Similarly, tg «, = tg 0, cos(t—r,) — 


By means of these formulas the uniradial azimuths for the 
refracted waves W, and W, can be calculated. At the second 
boundary surface of the crystal plate, the refracted wave W, 
produces two reflected waves W,,, W,, and one emergent wave 
W’.. (fig. 2). To caleulate the azimuth of the plane of polari- 
zation of this emergent wave, the relations of -Potier are 
important. The general boundary conditions for this surface 
and wave W, are defined by equations (20), which, after the 
manner of (18a) can be written in the abbreviated form: 

DL © BP, = RB’. =D’ cos 0! cosé 


Dim,+ Rm’ + Rm’ = De sin o”, 

Dan, + Rin’, + Rn’, = D’, cos 0", sin? (20a) 
Dp, + Rp’, + R’ p’, = D’, sin 0’, sin 7 cos 7 

On multiplying the first of these equations by n,, the second 
by p,, the third by Z,, the fourth by m,, and adding, we find 


D,(n,J,+m,p,+1,n,+m,p,) +R’ (nv +pm',+1,n',+m,p',) + 

R! (fn, +m, p",+4,m"_ +m,p",) = 
D’,(n, cos 4’, cos i+p, sin 0’, +0, cos 0’, sin ¢+m, sin 0’ sin 7 cos @) 
In this equation the coefiicients of D, R’, R’, are=0 by 


virtue of the Potier relation (83a), and as the amplitude D’ is 
not in general zero, the equation reduces to 


n, CoS 7+/, sin @ 
Pp, +m, Sin 7 Cosz 
On replacing 7,, Z,,9,, m, in this expression by their respective 


tg Os = 


values from (19), we obtain 
lg W =_— 
cos 0, sin 7, cos 7+cos 0, cos 7, sin 7 (36) 


Ringe 5 : ‘ vote ; 
P [sin 0,(@,, cos7,—a,, sin 7,) + @,, cos 0,] + sind, sin @ cos ¢ 
2 


178 EB. Wright—Transmission of Light through 


This Bapree eH can be simplified, as was (84), by the intro- 
duction of tg s, 

cos 0, sin(? +7,) 
sin* 7,(cot 7, sin 0,—¢g s,)+ sin 0, sin Z cos 7 


tg O” =— 


cos 0, sin(¢+7,) 
sin 0, sin(¢+7,) cos (¢—7,)— sin’ ”, tg s, 


(36a) 


or tg 0" =— 


On comparing this relation with (350), it is evident that 


1 
Te 
g 1 tg €, 
oe = 6 aE 90° (37) 
also Of Nemo Oe 


This apparently new and important relation greatly simpli- 
fies the labor of calculating the azimuths of the planes of 
polarization of waves transmitted through a crystal plate. In 
form it is similar to the relation deduced by Potier,’ that in 
case a wave W, within a crystal plate emerges into an isotropic 
medium, the emergent wave is polarized at right angles to that 
wave which, entering the crystal plate in the opposite direc- 
tion, produces the so-called “Hilfswelle W’” of W’. The 
above relation states that the azimuth of the plane of polariza- 
tion of the emergent wave W’, from W,, is at right angles to 
the uniradial azimuth e, of the wave W,. To calculate the 
azimuths of the emergent waves W’,, W’,, it is only necessary, 
therefore, to calculate the uniradial azimuths e,, e, of the inci- 
dent waves which produce the refracted waves W, and W,,. 


Uniaxial Crystals. 


In the preceding pages the formulas for the transmission of 
light through crystal plates have been developed for the most 
general case, that of biaxial crystals. When applied to uni- 
axial plates, these formulas become somewhat simpler, and 
deserve brief consideration as they will be used in the observa- 
tional part of this paper. The equation of the index surface 
for uniaxial crystals referred to general codrdinates is 


[0° (ae? +4" +2’) —1][@,,2" an U e +, ze 14-20, WV 2 ate 
2a, ge! +2a,,0'y' —1]=0. 
If, as usual, the plane of incidence be the «’ 2’ plane, (y’=0), 
and the zg’ axis the normal to the plate, the positive direction 
of z' being within the crystal plate, this equation can be written 


1 Journ. de Phys. (2), x, 354, 1891. 
2H. HE, Neumann, Berliner Akad. Abh., Math. Abt., 1835. 


Transparent Inactive Crystal Plates. 179 


[o°(a’? +2") —1][a, ,v" +a,,2° + 2a,,2'x’—1]=0. (38) 
In this formula w’ and 2’ can, by virtue of the sine law, be 
readily expressed in polar coérdinates; if 7 be the angle of 
incidence and 7 the angle of refraction and m, the refractive 
index of the isotropic medium, then v =n, sin 2, and 
sin @ : 
Zo== aa . With these values (38) reduces to 
WL 
[o’n,” sin? ¢ (1 +ég’r) —tg’r][(@,,2. sin® ¢—1)tg’r + 
2a,,2,' Sin” ttgr+a,,n, sin? i]=0, (38a) 
From the first half of this equation (88a) 
sin 7,=7, O Sin 2@. 


To evaluate the coefficients of tg 7 in the second half of the 
equation (38a), let the plane @’ y’ in fig. 6 be the boundary 


surface of the crystal plate; a’ 2’, the plane of incidence, the 
positive direction of 2’ being on the crystal side of the bound- 
ary surface; «, y, 2, the principal ellipsoidal axes of the erys- 
tal; @ the polar angle zz’, and », the azimuth of the principal 
plane 22’; let also the angles of inclination of the wave normals, 
Q., Q., with the 2’ axis be Q,2’=7, Q.2’=7.; with the 2 axis, 
be Q.2=¢,, Q.2=¢.. In this case the direction cosines of wv’, 
y', 2 with x, y, 2, are respectively 


P, = — Cos 8 cos w Pp, = Sino P, = sin 6 cos w 
7, = — cos sin w 7, = — Cos w q7, = sin 0 sin w 
ri sin a) ii, == GOS (uy 


also, inequations|(9)i@: = er. nbs )6' ce = 07, 


180 Ff. EL Wright—Transmission of Light through 


Substituting these values in equation (9), we obtain the 
usual equations 
a,, =e +{o°—e’) sin’ 6 cos’ w 
A,,=e +(0°—e’*) sin’ 6 sin® w 
a@,,=€ sin* 6 + 0° cos’ 6 (39) 
,,=(0°—e*) cos @ sin @ sin w 
d,,=(0°—e*) cos 6 sin 6 cos w 
a,,=(0*—e’) sin’ @ cos w sin 
and the coefficients of tg 7 in the second half of (88) become 
@,,%) Sin* i—1=n,° sin’ 7 [e’+ (0’—e’) sin? 6 cos’ w]—1 
2a,,m0° sin® 4=2n," sin’ 7 (o"—e") cos sin Ocosw (40) 
U,,%) Sin® t=n, sin* 7 (e’ sin” 6+ 0? cos? 6). < 
From equations (88a) and 40), 7, for the extraordinary wave 
can be calculated. If n,=1, as is practically the case when 
the crystal plate is surrounded by air, equation (38a) can be 
written in the following form, which is logarithmically con- 
venient : 
sin 7,=0 sin 7; (41) 


uf 1 
Bcos wo + Y B’ cos’ o + c( ; sat A cos? w — ¢) 
sin? ¢ 
tg — 1 
e — A cos?’ wo — —,. 
sin® 7 
wherein A = (e’—0o’) sin’ 0 


B = (e’—o’) sin @ cos 6 
C = e’ sin’ 6 + 0’ cos’ 6. 
To find the azimuths 6,, 6, of the planes of polarization of 
the refracted waves W,, W,, fig. 6.is again useful. In the 
spherical triangle Q, 2 2’, the relation obtains 


sin 7, cot 6 — cos 7, cos w 


cot 0, = a (42a) 
while in the spherical triangle Q, 2 2’ 
iq bee cos 7, COS w — sin r, cot 6 (428) 


sin w 

The uniradial azimuths e, and e, are calculated from equa- 
tions (35a). For the ordinary wave the wave normal and ray 
direction coincide and the angle s,—0. 

Accordingly 

tg €,==tg 9, cos (t—1,). (43) 

In the analogous expression for #9 €,, 

sin’? 7, tg 8, 
cos 0, sin (¢+7,) ee) 
tq 8, occurs but can be expressed in terms of known angles.’ 


1 MacCullagh, Coll. Works, 1880. Trans. Roy. Irish Acad., xvii, 1833. 
Pockels, F., Lehrbuch der Kristalloptik, 194-195, 1906. 


tg «, = tg 9, cos (t—r.) — 


Transparent Inactive Crystal Plates. 181 


In uniaxial crystals the usual formula for tg s, is 
2 2 
is = a cos ¢, sin ¢, (a) 
where ¢, is the angle Q,.z of fig. 6. From the spherical tri- 
angle Q, 2 2’, fig. 6, 
cos 7, sin 0, — cot w cos 0, | 


(2) 


cot ¢, = 


sin 7, 
cos 0, 


also cot ¢. = — (cot 6 cos 7, + CoS w sin ”,). (0’) 


sin w 
Furthermore, in the principal section through Q, and z 
Je = 0 cos’ d + e’ sin’ ¢, 


from which expression, we find (c) 

e—o’ ., ; O° 4 sin’ 7”, sin (7,—7,) sin (7,+7,) 

- Sino, == fo = ws : 
Oe $e Yo sin’? 7, sin’ 7, 


By means of the three equations (a), (0), (c), equation (44) 

becomes 
sin (7,—7,) sin (7, +7.) (cot o—cos r, tg 0.) 
sin (¢+7.) sin 7, (44a) 


tg «, = tg 9, cos (i—r,) + 
or from equations (a), (0’), (¢) 
tg «. = tg 9, cos (i—r,.) + 


sin (7,—7,) sin (7,.+7,)(cot 8 cos r,+ Cos w sin 7.) 
sin (¢+7,) SIN w (44d) 


Having thus found e, and e¢,, the azimuths 6’, and 6’, are 
readily obtained by the use of equations (37). 


0’, =€.+90° 0’, =e+90- (45) 


e 


Isotropic Plates. 


In the case of isotropic plates, the index ellipsoid reduces 
to a sphere and the constants of the equation become 
a,, = ,, = a. — Y 


Ay5 = A, aa a, = 0 


Equations (16), (85a), (86a), then reduce (if the surrounding 
medium be air g,=1) 
sin @ 
VW 
(0) tg «, = tg 0, cos (t — 1) 


(a) Sin 7) 19 7sin? = 


(0) tg 0, = 00h: 
cos (t—7) (46) 


182. Fk. EL Wright—Transmission of Light through 


In these last two equations, (4) and (¢), the azimuth 6, may 
assume any value, since the structure of isotropic substances 
does not prescribe definite planes of polarization for transmitted 
waves, as do anisotropic substances; but if 6, be once given, 
6, is then = 6, + 90° 
and the last equation, (¢), may be written 

tg 6, ig €, 
ey cos (t¢—7) cos (i— 7)? (46c’) 

From this formula, the angle 8’ can be caleulated, provided 
e,, «@ and 7 be given. The difference (e,—8’,) is.then the 
amount of rotation which the plane of polarization of incident, 
monochromatic light suffers on transmission through the 
isotropic plate. 

In case the light wave passes through several plates, 
cemented together as in a thin section mount where n, is the 
refractive index of the object glass, , that of the Canada 
balsam, and , that of the cover slip, an incident wave 2 


; similarly, 


becomes 7, in the object glass, where sin 7, =~ 

nN, 
7, and 7, are the angles of refraction in m, and n, and can be 
calculated by the general sine formula above. From formula 
(460) and (46c) it is evident that the total rotation of the plane 
of polarization of a transmitted wave under these conditions is 


cot 0’ = cot € cos(t—r,) cos(7,—7,) cos(7,—7r,) cos(¢—7,) 


Summary.—In the foregoing pages the formulas have been 
developed which are especially useful in a consideration of the 
phenomena observed on mounted crystal plates in convergent 
polarized light. In this discussion, the effects of the plates on 
reflected light waves have not been treated in detail, nor has a 
study been made of the relative amplitudes of the reflected 
and refracted waves; attention has been directed rather to the 
effects of transparent, inactive plates on the planes of polariza- 
tion of transmitted light. In the calculation of these effects, 
four steps are necessary; (1) if. the angle of incidence 7 of the 
entering light wave be given, the angles of refraction 7,, 7, of 
the two transmitted waves are found by means of formula 
(16) in the case of biaxial plates, or by (41) for uniaxial plates, 
or by (46a) for the single transmitted wave in isotropic plates. 
(2) The azimuths of the planes of polarization of the two 
refracted waves are then found by use of equations (17) for 
biaxial plates, or (42) for uniaxial plates. In the case of iso- 
tropic plates the plane of polarization of transmitted waves 
may have any azimuth, so far as such azimuths are dependent 
on the structure of the material. (3) Having given the angle of 


Transparent Inactive Crystal Plates. 183 


refraction and the azimuth of the plane of polarization of a 
trausmitted wave, the azimuth of the plane of polarization of 
the incident wave which produced it is obtained by use of equa- 
tions (35) for biaxial plates, (48) or (44) for uniaxial plates, and 
(460) for isotropic plates. (4) To find the azimuth of the plane 
of polarization of the emergent wave, provided that of the 
incident wave which produced the refracted wave be known, 
equation (37) is useful. This last equation, which is apparently 
new, states that the azimuth of the plane of polarization of 
an emergent wave 0’,, resulting from the refracted wave W.,, is 
90° from the uniradial azimuth of the incident wave e, which ~ 
produced the refracted wave W,. 

A detailed discussion of the above formulas is deemed 
unnecessary in this summary, as they are in large measure 
standard and the effects of the different factors will appear 
more clearly in the discussion of the data of observation. 

In the development of these formulas, no account has been 
taken of the effects of surface films on the rotation of the 
planes of polarization of transmitted waves. These films have 
been shown by P. Drude’ and others to be occasionally of great 
influence, especially on plates which have been highly polished, 
while on freshly cleaved plates they are practically absent. 
The observations listed in the following pages were made 
largely on cleavage plates, which, however, were usually ex- 
posed for a month or more before the observations were finished 
and may have accordingly suffered some deterioration. 


Parr 2. 
Observations. 


Apparatus.—All observations recorded below were made in 
sodium light, the crystal plate being mounted on a universal 
stage on the new model petrographic microscope recently 
described by the writer.’ To insure accuracy, the microscope 
was carefully adjusted and its adjustment tested at intervals in 
the course of the measurements. The nicol prisms were 
of the square end Glan-Thompson type and were crossed by 
pointing the microscope, from which all lenses had been 
removed, directly toward the sun whose rays are parallel and 
so intense that a rotation of less than 1’ of are from the posi- 
tion of exact crossing of the nicols is readily discerned. By 
means of the iris diaphragms the sun’s rays were sent through 
the microscope centrally so that no rotatory effect of the nicol 
surfaces on the planes of polarization of the transmitted waves 
was possible. The ordinary type of nicol prism with oblique 

1 Wied. Ann., xxxvi, 532, 865, 1888; xxxviii, 265, 1889; xliii, 146, 1891. 

? This Journal (4), xxix, 407-414, 1910. P 


184 OE. EL Wright— Transmission of Light through 


ends was first used, but was soon discarded because of the 
effect of its oblique surfaces on the plane of polarization of the 
transmitted waves. For exact work in extinction angles, the 
ordinary type of nicol prism is much inferior to the Glan- 
Thompson type with square ends. Having thus crossed the 
nicols accurately, the crosshairs of the ocular were adjusted by 
using the ocular and Bertrand lens as a microscope and focus- 
ing on a mounted anhydrite cleavage plate through which par- 
allel sun’s rays were passed centrally. Here again the sun’s 
rays are so intense that the position of total extinction of the 
anhydrite plate can readily be fixed within 1’ of are. By 
means of the anhydrite plate which extinguishes parallel with 
its cleavage edges, the principal sections of the nicols and the 
ocular crosshairs were brought to coincidence. The universal 
stage was then attached to the microscope stage and its hori- 
zontal axis of rotation brought to coincidence with the hori- 
zontal crosshair of the ocular, by use of the lines engraved on 
the glass disk of the universal stage. This glass disk, together 
with its supporting ring, was then remoyed and in its place a 
second ring of precisely the same dimensions substituted, on 
which a strip of thin glass plate was cemented, and to which 
in turn one corner of the crystal plate was cemented, the glass 
plate serving merely as a support for the erystal plate whose 
major part was left free and exposed on both sides to air. 
The surface of the crystal plate was then brought to approxi- 
mate parallelism with the horizontal circle of the universal 
stage ; it was adjusted to exact parallelism by viewing, through 
a mounted telescope, the image of a distant light source as 
reflected from the surface of the crystal plate. The horizontal 
circle H, of the universal stage’ was then rotated and the erys- 
tal plate tilted and turned by means of the horizontal circle H, 
and the vertical circle V, until the reflected image remained 
stationary on rotation of H,. The circles on the universal 
stage could be read to 5’ by means of the vernier, while on the 
microscope stage the vernier intervals were 3’. In neither 
case, however, were the lines on the circles and verniers suffi- 
ciently fine to insure greater accuracy in reading than the 3’ or 
5’ intervals on the vernier. In actual work each position of 
total extinction was determined 10 times and the average 
taken. On sharp extinctions it was found that the different 
settings were usually within 10’ of the average. 

In the earliest preparations measured, the positions of total 
extinction were determined by use of the bi-quartz wedge 
plate,’ but the fact that, in making the observations with this 
plate, it was necessary to use the objective and ocular, the 
glass surfaces of which in turn influence the plane of polar- 


1See page 186 below. ? This Journal (4), xxvi, 391, 1908. 


Transparent Inactive Crystal Plates. 185 


ization of transmitted waves, was sufficient reason to discard it. 
In the final arrangement adopted, no glass surfaces intervened 
between the nicols and the erystal plate. An enlarged image 
of the plate was obtained by means of a weakly magnifying 
microscope consisting of the Bertrand lens and ocular, above 
the upper nicol. 

Intense sodium light flame.—To increase the intensity of 
the sodium light flame, and with it the accuracy of the observa- 
tions, an arrangement was adopted which in practice has proved 
entirely satisfactory. A 25° platinum crucible was filled with 
a mixture of sodium chloride and sodium carbonate and 
heated over a Bunsen burner, a special mounting of thick 
platinum wire having been made for the 
erucible as indicated in the diagram. <A 
wick of fine platmum wires carried the 
molten salts from the base of the eruci- 
ble out into a strong and constant blast 
lamp flame, the high temperature of 
which produced an intense sodium flame 
which lasted for days, until the salts in 
the crucible were exhausted. An oxy- 
hydrogen blast was also tried, and 
although it gave a much more intense 
flame, its regulation proved troublesome 
and there was danger that the platinum wick might melt down 
unless the flame was constantly regulated. The fumes from 
the salts were carried off under a hood. The microscope was 
placed in a horizontal position and pointed directly at the flame 
without intervening reflector. 


Results. 


Isotropic Plates.—Plane polarized light waves, in passing 
obliquely through a mounted erystal plate, encounter not only 
the boundary surfaces of the crystal plate, but also those of the 
object glass, the cover slip and the Canada balsam in which the 
plate is mounted. Each surface exerts a certain rotatory in- 
fluence on the plane of polarization of the transmitted light 
wave. In order to obtain an idea of the effect of the glass 
plates and Oanada balsam alone on the rotation of the plane of 
polarization of a transmitted light wave, a blank glass slide 
was prepared consisting of an object glass (my, = 1°511) and a 
cover glass (my, = 1°520) cemented together with Canada bal- 
sam (yx, = 1°5387). ‘This slide was mounted on the universal 
stage’ whose different circles may be designated as follows’ : 

1This effect has been considered in some detail by G. Cesaro in the Bull. 


' de ’Acad. roy. de Belgique, Classe d. Sciences, No. 7, Juillet, 1906. 
2 See this Journal (4), xxiv, 348, 1907. 


186 Ft. EB. Wrighi—Transmission of Light through 


H, = circle on stage of microscope supporting universal stage. 
H, = outer horizontal circle of universal stage. 

H, = inner and smaller horizontal circle of universal stage. 

= large vertical circle of universal stage. 

V, = small vertical leaf circles on modified form of universal 

stage. 

The source of light used in this instance was a Nernst light, 
at the focus of a large condensing lens. The Abbe con- 
densor lens system was removed from the microscope, so that 
the entering light waves were as nearly parallel as possible. 
For the exact location of the position of total extinction the 
bi-quartz wedge plate was used. The upper nicol remained 
fixed while the lower nicol was rotated to determine the 
amount of rotation of the plane of polarization. 

The results of the observations are included in Table I, in 
which the probable error of the average angles H is less than 

‘10’. These measurements may be summarized by stating that 


1 
2 
3 
1 
2 


TABLE I. 


Caleu- ran 


i | 3) 0 ea Readings 


22°30! | | 22°80’ 22°50'| 22°53’ 0°20’ 22°50! 50") 51 48”) 51’) 517| 52"| 517| 527! 52’ 
“© | 45 00 | 45 87 | 45 33 | 0 37 | 45 388 |35 |37 | 35 | 36 | 38 | 38 | 39 | 39 | 39 
+ 67 30 | 68 00 | 67 53 | 0 30 | 68 00 |58 ot 01 | 00 | 02 | 00 | 00 | 01 | 01 
45 00 22 30 | 2419 | 24 25 | 1 49 | 2419 |16 21 17 | 17 | 20 | 20 | 20 | 21 | 21 
re 45 00 | 47 35 | 47 37 | 2 35 | 47 82 |33 [36 | 32 37 | 387 | 36 | 38 | 34 
Bs | 67 30 | 69 24 | 69 18 | 1 54 | 69 19 |20 25 28 | 20 | 21 | 28 | 25 | 26 | 20 


for low angles of inclination of the glass plate, originally plane 
polarized light is, after transmission, still practically plane 
polarized, although its plane of polarization has been rotated 
slightly, the amount of rotation increasing with the angle of 
inclination. On each boundar y surface a ‘certain part of the 
incident light is reflected and a certain part refracted. For an 
isotropic body, as an object glass, there is a definite angle 
(Brewster’s angle) for which all reflected light is plane polar- 
ized, while the refracted waves are partially polarized. In 
fact, for every angle of incidence reflected natural light is par- 
tially polarized in the plane of incidence. The refracted light 
must, therefore, also be partially polarized normal to the plane 
of incidence, as no light disappears. In this manner the 
polarizing effect of a set of plates may be explained. If the 
incident ‘light be plane polarized, its plane of polarization is 
rotated on refraction and the amount of rotation can be calen- 
lated from Fresnel’s reflection and refraction formulas (46), 
These formulas have been tested by numerous observers. 


Transparent Inactive Crystal Plates. 187 


especially Jamin,’ and found to be valid except for light 
waves incident at Brewster’s angle, in which case the light is 
not perfectly plane polarized, but shows elliptic polarization. 
In convergent polarized light, therefore, all waves except 
those near the center of the field and along the principal sec- 
tions of the nicols suffer from the rotating effect of the glass 
surfaces of the crystal mount on the planes of polarization. 
This effect increases in amount as the margin of the field is 
approached, where total extinction under crossed nicols is 
noticeably imperfect in the diagonal positions. The glass 
surfaces of the lenses, both of the condenser and the objec- 
tive, moreover, exert also a rotatory influence on transmitted 
plane polarized waves, and for this reason, in convergent polar- 
ized light, the field appears to be divided by a dark cross into 
four less dark quadrants even when no crystal plate intervenes. 
The amount of rotation and consequent intensity of illumina- 
tion is greatest for waves contained in planes at 45° from the 
principal nicol sections. The amount of rotation varies also 
with the refractive indices of the isotropic substances exam- 
ined and the enveloping media as indicated by equation (47). 
It is, however, obviously impossible in practical work to take 
into account the rotatory effects of all glass surfaces interven- 
ing between the two nicols, and all methods based on the exact 
measurement of extinction angles of obliquely transmitted 
waves must suffer from this defect and can only give approxi- 
mate results. This applies both to methods involving con- 
vergent polarized light and to the universal stage methods. 
The error produced from this cause alone is not great (in 
unfavorable instances, 2° to 4°), but it precludes results of a 
high degree of accuracy. In the universal stage methods the 
use of the small hemisphere as recommended by Fedorow 
materially decreases the rotatory effect both of the glass mount 
and of the erystal plate, and tends toward greater accuracy as 
well as increasing the angle of view of the field. The greater 
the difference in refractive index between the two media, the 
greater the amount of rotation as indicated by equation (46). 
The glass sphere not only tends to offer more nearly horizontal 
surfaces to the entering light wave than the inclined glass 
mount, but at the same time renders the boundary surface of 
the glass mount practically inert in its action; the glass mount 
in turn decreases materially the amount of rotation which the 
surfaces of the crystal plate exert when unmounted. These 
facts justify the application of Fresnel’s rule for finding the 
directions of total extinction in a tilted crystal plate to the 
universal stage methods, as a close approximation to the truth, 


1 Ann, Chim. Phys. (8), xxix, 263, 1850; xxxi, 165, 1850. 


188 FL BE. Wright—Transmission of Light through 


the error incurred thereby being of a comparatively low order 
of magnitude and usually not over L°. 


Uniaxial Crystals. 


Of the uniaxial crystals, calcite and nephelite were chosen 
for measurement; apatite plates were also tried, but they 
proved to be inhomogeneous and, therefore, unsuitable for 
accurate work. 


Calcite. 
On cleavage aes: of calcite several different sets of observa- 
tions were mad (1) The uniradial azimuths of monochro- 


matic light waves emerging from bare cleavage surfaces were 
determined for different positions of the crystal plate. (2) 
For these same positions of the plate the points of minimum 
illumination (maximum extinetion) under crossed nicols were 
ascertained. (8) The same cleavage plate was then mounted 
in Canada balsam (ny, = 1°537) between object glass (my, = 
1-511) and cover slip (my, = 1°520), and the positions of mini- 
mum illumination were determined between crossed nicols, 
both with and without the use of the bi-quartz wedge plate. 
(4) These observational data were compared with the values 
obtained by calculation from the formulas (41), (42), (48), (44), 
(87) of the preceding section for the same positions of the 
erystal plate. (5) Although not strictly comparable with the 
other angles, the azimuths of the radius OD (fig. 12) for both 
the ordinary and extraordinary waves were determined graph- 
ically. 

In Table II, the results of these observations and calcula- 
tions are assembled; in this table, 2 = angle of incidence, or, 
more correctly, the angle of tilting of the crystal plate; r = 
angle of refraction (horizontal line No. 1 of the table); o = 
azimuth of the section z 2’ with the plane of incidence (head 
line of table); 6= azimuth of plane of polarization either of 
extraordinary wave (E) or of ordinary wave (O) (horizontal 
line No. 2); €,==uniradial azimuth of entering wave (hori- 
zontal line No. 3); 6’ = azimuth of emergent wave correspond- 
ing to refractive waye 6 (horizontal line No. 4). 

Oniradial azimuths of emergent waves.—On the horizontal 
line No. 5 the observed azimuths of the emergent waves O and 
E are listed. The observations were made in strong sodium 
light and each azimuth was determined ten times. In the 
table each angle listed is the average of 40 readings, 10 for the 
position of the plate +72, +@, (5 of each set of 10 readings 
being made on turning the stage clockwise, and 5, counter- 

1Tn these calculations, the values o = 1°6585, «= 1°4864, and 6 = 44° 37’ 
were adopted. 


189 


Transparent Inactive Crystal Plates. 


96 6T | PG OL | 90 8E | FS Ig | FS Le | 00 SE | FE OL | 98 eT | O€ T8 | SLL | BF Lg | 98 Te | ST Og | FE gc | D | OT 

2 SES oi7' UE AOE RG NGS ee ae al Ra Sees pees — | «| 8G 2g | 6 EE | OF O€ | 0G 09 | H | 6 

OG 8ST | 00 Th | IG LE | Ge SS | FO 4G | 6G SE | GE 94 | TL GL | eG 18 | 9¢9 | Sg Le | 6¢ ee | FT OE | e209) a | 8 

OS ST | OF GL | OF LE | E% GE | 10 LE | OG SE | OG LL | OF GI | OS O8 | 82 8 | OF 9S | FE SE | OF Gz | F209 | a | L 

Pc St | 90 TL | PE LE | GH GE | Sh 9 | 0G GE | GE OL | GS SI |x80 C8 |xI€ 8 |x EL LG |x IS x90 Te |xLO Ge | w | 9 

9 St | Ty TL | OF LE | GG SF | 98 9 | GF SE | LZ OL | VE SI xO G8 |x9l 8 | 7 — |xVE TS |xS 09 | P | 

Ly SI | SE TL | OF LE | GG GE | Te 9G | OE SE | Sh OL | 0S SI | HF I8 | 688 | SF LE | GO GE | AT OS | #609 | @ | F 

46 81 | €f 1L | 80 LE | 0% GE | Fe 9G | 60 GE | OF OL | SI EI | 16 18 | 9L 8 | 4e 9G | et se | 9e Gz | SP 6G | * | e 

OY SI | VS Th | 6G LE | BS GS | HH 9G | OC gE | OG OL | LE EL | 8S 18 | PHL | LI LG | FO Be | ce 62 | ev Ec |e |e. 
0GoET | OS OPE | OFT | MGoFT | OST | CLoHL | 0GET | TL PT |, OC €T |,20.FT | 06.81 | FOE | OSE | 8Poel |” | LT | 08.8 
8h 8ST | 90 TL | 08 9E | GI PS | BF GC | SF LE | 9E 89 | BI ez | 0G GB | BFE | 00 GL | HS EI | SF OF | FE SF! DO | OT 

CO) IE | UGG Oy GE) CIE Oe = a= ees Bes ire oe eae a ~ &¢ PL | ve ST | PL ve | OG LF | HW | 6 

pS LT | Te &L | 00 SE | 1% Lg | ST O€ | 9G 6E | HH 99 | 60 Fe | OF G8 | eo | PH PL | LG OT | 18 GF | Bo LP | a | 8 

6G OT | 0 €L | OF SE | GE OE | 00 OS | OT OF | GI G9 | Ig Se | HH G8 | He F | BH CL | OP LT | GO GE | OF LH) A I L 

80 4T | IG pL | GG FE | TS BE | EC GE | Te TF | OT LO | Te FZ |xCO FB \x9F G |xGS PL lxCh LIL |x6T SF |x68 Le | 0 | 9 

96 LT | PI PL | Fo PE | 86 8S | TH OS | LO GF | BE 99 | TO GS /xLS $8 |x10 9 |xT@ OL |x8P GT |xdT GE \x97 LP | 0 | ¢ 

LG LI | 80 PL | OF FE | OT 82 | ET TS | OS Tr | Le L9 | OF FZ | 9 78 | GES | 68 FL | GE LT | Et ce | GL ST | 0 | F 

6S ST | SE GL | OF TE | OE C4 | OT BF | LE BE | 0S G9 | EE oe | 16 8) FES | Ih GL | 16 G1 | Gh IF | Ly PP | | e 

8h 91 | OF GL | Go SE | GT LG | SC GF | ST IF | 8E 99 | OS Fe | 1h F8 | PG 9 | GE GL | BG FI | 63 EF | FPar |e |e 
PERG | 0.86 | PES | SELB | PIGS | LE LS | PLLS | OTL | PLGS | LE.98 | PLCS | 90.98 | FIGS | SF.e% | 4 | T .| 00.87 

) a o - a ) a 0 a 0 a ty) a 0) a ‘ON | 2 
OS LGT 000S8T OS .6LT 00.06 08049 00.7 0€ 066 Y) 


Il @IdvVi 


Am. Jour. Scl.—FourtH Sreries, Vou. XX XI, No. 183.—Manrcna, 1911. 


14 


190 FE. Wright—Transmission of Light through 


clockwise); 10 for the position +2, +; 10 for the position 
+7, 180° —@; 10 for the position +2, 180°+@. In averaging 
the readings, all these positions should, with the exception of 
the sign, furnish identical results. This was found to be the 
ease for all positions of the plate for which good positions of 
darkness were attainable. Occasionally, however, differences 
of 20’ or even 30’ between the positions were obtained, even 
on good plates. The observations were made on bare cleavage 
plates, 1 to 8"™ thick, on which the two refracted waves from 
a single incident wave were appreciably separated after trans- 
mission. A large area of the front surface of each plate was 
blackened by means of a dull lacquer and rendered opaque 
(shaded part of fig. 8a). When viewed through the plate after 


Fic. 8a. Fic. 8b. 


rotation through 180° about the horizontal axis, the exposed 
area of fig. 8a appeared as in 8b. Two images were observed, 
one from the ordinary wave O and the second from the extra- 
ordinary, E. These two images overlapped to a large extent, 
but along the margins of the bright part of the plate the image 
of the extraordinary wave E extended on the left beyond that 
of the ordinary wave, while on the right and at the top a nar- 
row strip, due entirely to the ordinary wave O, appeared as 
indicated in fig. 84. The azimuth of the plane of polarization 
of one of these emergent waves, E or O, was then ascertained 
by rotating the microscopic stage H, until the margin in ques- 
tion disappeared completely. It was found that within the 
limits of error each edge became completely dark (1) when the 
azimuth of the plane of polarization of the entering waves 
was such that the amplitude of its refracted wave was zero 
(uniradial azimuth of second entering wave); and (2) when the 
plane of polarization of the emergent wave coincided pre- 
cisely with the extinguishing plane of the analyzer. These 
two positions were, within the limits of error, precisely 90° 
apart, thus proving experimentally the relation (37) deduced 
from theory; in other words, the uniradial azimuth of an 
entering wave W, is 90° from that of the second emergent 
wave, W’,. The doubly shaded portion of fig. 8b is the area 
over which the two images overlap. The positions of extinc- 


Transparent Inactive Crystal Plates. 191 


tion of these two images do not coincide exactly and there is, 
therefore, no position of total extinction for this area. Ina 
thin or weakly birefracting plate, the margins indicated in fig. 
8b become very narrow and all observations are practically 
confined to this area of overlap. In the microscopic examina- 
tion of thin sections this is always the case; it is evident, 
therefore, that in tilted, thin crystal plates there is no position 
of total extinetion, strictly speaking, but a region of minimum 
illumination which may extend over several degrees. The 
emergent light is not strictly plane polarized but shows ellipti- 
eal polarization and cannot, therefore, be totally extinguished 
by the upper nicol in any position. 

Still another feature deserves mention. In the actual deter- 
mination of the uniradial azimuths outlined above, it was 
often noted that for certain positions of the plate, even the 
margins of fig. 8b did not extinguish properly because of 
repeated internal reflexions. A wave, I (fig. 2), entering at the 
uniradial azimuth produces a single refracted wave, W,; from 
this wave, in turn, one emergent wave, W’, and two reflected 
waves, W,,, W,, are formed. Each of these reflected waves 
produces one refracted wave R,, and two reflected waves W’,,, 
W”,; of these W’,, is parallel with the first refracted wave 
W,, while W”,, is parallel with the second possible refracted 
wave W,, which would result from the initial wave J if the 
azimuth of its plane of polarization were not uniradial. The 
first wave W’,, produces an emergent wave (not indicated in 
fig. 2), the azimuth of whose plane of polarization is parallel 
with that of W’,; from the second wave W’’,, a second emerg- 
ent wave is produced, whose line of propagation is parallel with 
that of the first, but whose plane of polarization coincides with 
that of W’, and not with that of W’,. In this case the effect 
produced is precisely that of an overlap of the two images ; 
there is no position of total extinction but only a region of 
minimum illumination occasionally covering several degrees. 
Accurate measurements under such conditions are impossible. 

If thin plates be used for the observations, as in thin section 
work, this effect must always be present, and consequently 
there are under these conditions no points of total extinction 
for obliquely transmitted light waves, but only regions of 
minimum illumination which may extend over several degrees 
and on which only approximate measurements can then be 
made. In the thick plates employed in the present experi- 
ments, a portion of the exposed area was usually free from the 
effects of total reflexion and on these portions the positions of 
extinction were determined. And even there an abrupt shift 
of the faint margin due to a weak, repeatedly reflected wave, 
was often observed near the positions of total extinction of one 


192 FE. Wright—Transmission of Light through 


of the waves. Ifthe plate be placed in the position of total 
extinction for one of the edges in the image under crossed 
nicols, the edge produced by the second wave, and with it the 
entire plate, can then be extinguished by rotating either the 
analyzer, in case the second wave enters at uniradial azimuth, 
or the polarizer, in case the line of vibration of the emergent 
first wave is contained in the extinguishing plane of the 
analyzer. This method of first determining the position of 
extinction for the one wave and then rotating the polarizer 
was adopted in many of the above measurements, as the edge 
produced by the second wave generally extinguished imperfectly 
because of internal reflexions. Usnally, however, internal 
reflexion did not extend across the entire plate; the area free 
from it was then observed to became completely dark for a 
certain position of the polarizer. In this case the nicols were 
not crossed but included an angle which differed from 90° by 
exactly the angle of rotation which the entering, plane-polarized 
waves suffered on transmission through the two boundary 
surfaces of the crystal plate. The waves entered at their uni- 
radial azimuth and emerged vibrating in the extinguishing 
plane of the analyzer, and were therefore totally reflected in 
the nicol. From lines 3 and 4, Table II, it is evident that the 
total amount of rotation (€,—6’) of the plane of polarization 
is the same for both the ordinary and the extraordinary wave. 

In case the crystal plate is tilted so that the optic axis makes 
only a small angle with the line of propagation of the refracted 
waves, it is not possible to obtain satisfactory total extinction. 
The entering waves, although approximately parallel, are never 
precisely so, and for a slight difference in direction of pro- 
pagation, a considerable variation in the azimuth of the 
planes of polarization of the transmitted waves results. This 
effect is most pronounced near the optic axis’ but it is still 
perceptible on refracted waves, making angles of 20° or even 
25° with the optic axis. In the table these positions of im- 
perfect extinction are indicated by an asterisk. On line No. 6 
of the table a series of readings on a second cleavage plate is 
recorded, each angle listed being the average of 20 readings, 
10 for the position +2,+, and 10 for the position +7,—o. 

In the measurement of these uniradial azimuths, the observer 
was unfortunately unable, because of other duties, to finish 
each series of readings as rapidly as could be desired, a month 
or more often intervening before a series, once begun, was 
finally completed. This gave opportunity for the effects of 
surface films to enter the problem, which, as noted by Drude, 
nay seriously affect the accuracy of the values obtained. It is 


1Compare W. Voigt, Wied. Ann. d. Phys. u. Chemie (4), xviii, 676, 1905. 


Transparent Inactive Crystal Plates. 193 


probable that the recorded differences between calculated and 
observed values are in part due to the effects of such surface 
films. 

Previous measurements.—F. E. Neumann’ measured the 
uniradial azimuths of light waves, entering a calcite cleavage 
plate at different angles, and found that his results of observa- 
tion agreed closely with those of ealeulation. His observations 
were made in white light and through a prism which separated 
the two images E and O so that each could be studied alone. 
Although Neumann’s measurements were repeated 40 times 
and should therefore be very accurate, the use of white light, 
and also of intervening glass surfaces, introduced sources of 
probable error which might, under certain conditions, prove 
serious. 

Later, in 1852, R. T. Glazebrook’ undertook a more elaborate 
series of determinations of the uniradial azimuths of transmitted 
waves. His apparatus and method for determining the 
positions of total extinction were more accurate and refined 
than those of Neumann, but the agreement between his 
observed values and those of calculation was only approximate, 
and less satisfactory than Neumann’s values. Glazebrook’s 
measurements, however, were made for the most part on 
polished plates on which surface films may have been especially 
active and may have modified the results accordingly. As 
Drude has shown, an exceedingly thin surface is sufficient to 
produce marked elliptic polarization in the reflected waves. 

Extinction positions of an unmounted plate—(Line No. 7, 
Table II.) A series of readings in sodium light was taken to 
determine, if possible, the positions of maximum extinction of 
the central part (E and O overlapping) of a calcite cleavage 
plate. The angles listed are the average of two sets of 10 
readings each; the first for +, the second for —w. It was 
found that the individual settings often varied a degree or more ; 
their average, moreover, was not midway between 6, and 6,+ 
90° or vice versa. In short, accurate determinations under 
such conditions are not possible, and the different positions of 
extinction were rarely found to be precisely 90° apart. 

Extinction positions of mounted plate.—On lines No. 8 and 
No. 9, Table IJ, the results of the determinations of the ex- 
tinction position of a mounted cleavage plate of calcite are 
listed, in which the measurements were made in Nernst light, 
(1) with the aid of the bi-quartz wedge (line No. 8) and (2) 
without it (line No. 9), each angle being the average of 10 
settings. In the strong Nernst light, the individual settings 
agreed more closely, but their averages agree neither with the 
uniradial azimuths. observed or calculated, nor with the other 


1 Pogg. Ann., xlii, 11-12, 1837. *Proc. Roy. Soc., clxxiii, 617, 1882. 


194 FE. Wright—Transmission of Light through 


observations, differences of a degree or more being not uncom- 
mon. The rotatory effects of the glass mounts and lenses are 
included in these results, and indicate that in actual micro- 
scopic work with tilted slides or with interference figures, the 
observed azimuths of the planes of polarization of any given 
transmitted wave may differ several degrees from the actual 
azimuth of the refracted wave within the crystal. This, how- 
ever, is the azimuth songht for in such observations. The 
measurements prove that for such tilted thin plates there is no 
position of total extinction, but rather a region of minimum 
illumination. Methods based on such phenomena can there- 
fore furnish only approximate results. " 

On the horizontal line 10 of Table II, the values obtained by 
graphical construction of the azimuths of the plane 2’ D (fig. 12) 
for different positions of the plate are listed. These will be 
considered in a later section. 


Nephelite. 


In nephelite the birefringence is weak and the two refracted 
waves, resulting from a single plane polarized incident wave, 
follow approximately the same direction of propagation. A 
sutisfactory determination of the uniradial azimuths on thin 
plates of nephelite is, in consequence, not possible, and has not 
been attempted. The positions of maximum extinction of the 
plate tilted at different angles were, however, determined and 
are listed in Table III. For these measurements a polished 
plate of nephelite, so cut that the optic axis included an angle of 
27° 18’ with the normal to the plate, was mounted (7, of object 
glass 1°511, of cover slip, 1°520) in Canada balsam (my, = 1°537) 
and readings made in strong sodium light. On the horizontal 
lines, 1 to 4, of Table III, the calculated values of 7, 6, « and 6’ 
are listed; on line 5 the positions of extinction are recorded, 
as determined by direct observations on rotating the plate 
until the maximum darkness was attained. Each angle given 
is the average of 20 readings, 10 for +72, +@, and 10 for 
+z, —o. The individual settings agreed only fairly well, 
and even for the average values a high order of accuracy can- 
not be claimed. For these measurements the ordinary micro- 
scope lens system was used with the exception of the condensor, 
which had been removed. On line No. 6, Table III, the results 
of settings made with the aid of the bi-quartz wedge plate and 
strong sodium light are recorded, each angle listed being the 
average of 10 readings, 5 for the position + 2, + @, and 5 for 
the position + 7, — @. Since in the case of tilted plates the 
emergent light is not strictly plane polarized and there is con- 
sequently no position of total extinction, the positions of mini- 
mum illumination as determined by simple rotation under 


195 


Transparent Inactive Crystal Plates. 


“pas e19M 8] L=M PUL ‘OLEC.T=2 ‘9TFE.[=o senTeA oyg eTqe} STUY JO 9 's 'p ‘uw SonTYA oY} SuLye[MoTwo Uy , 


OT 91 | 00 FL | OF IE | SF 8S | 0G 0G | 00 OF | OF FO | 00 9Z | OF GB | OGL | SE HL | 00 OT | OF GF | 00 8F | D| 4 » 
GG CT | 1G GL | 8 TE | 9G OE | FE GF | LF GE | SF LO | CE Te | 66 48 | GEE | 6689 | OF GE] | a | 9 ” 
LG 91 | GO FL | ST SE | 9S AG | 8G OG | SP GE | 00 89 | 90 GZ | TH4B | STG | | fap ener a |G ” 
IF ST | 98 FL | GE TE | 10 GE | LE LH | Lo SF | GE F9 | GS Ge | LE EB | CS 9 | GO PL | CI OT | 00 EF | CEL) MF | » 
FG CT | 6 FL | GE 0 | TE 8E | GO LF | SS GE | GO F9 | 8G Ge | 80 8 | GF 9 | Gh Sh | BC GT | 86 GF | OO LF | 2) & 
S€ GT | 66 FL | PE IE | SP 8S | 0G LH | Sh GE | GE F9 | Gh Le | SE SB | SP 9 | HS SL | ST OL | GP GE | FE LH | P| w ” 
BBoPE | LGoPE | COPE | MGoPL | GGL | PovL | GOPL | COPE | GEHL | FGovE | COPE | OGHE | CO.rE | GLP. | “| FT | 08.66 
OE IT | SF LL | 00 9% | 00 99 | OF 8E | 00 FE | 00 OS | 0G GF | 00 09 | Go GE | 0E 99 | OF Te | GG Lk | GOTL|) DO] 4 ” 
ST SI | 6E 9L | 48 9% | LT 89 | GO OF | FT GF | 8G GG | OE OE | OE V9 | 9L Se | | {a3 Fa a | 9 ” 
TS SL | 9E OL | ST LZ | 80 E9 | 6S OF | GF GE | 00 FE | GE 9E | F699 | COE | = | a| ” 
ST €T | 8¢ LL | 20 96 | FO 99 | OT 8S | So HE | SP GF | 10 SF | TE 09 | 9G TE | Sh OL , 80 Te | TE 08) IE OL | P| F | » 
GO GI | Lh 9L | 9S SS | 8G G9 | LE CE | HH TS | 6S OF | GT OF | FO 8G | 6S 62 | GS 89 | BI GI | 66 64 | 6 & 2B hig 
LE GI | GB LL | 6S FS | GO G9 | 92 9E | 80 SE | BS SF | GE TE | BT 6G | OE OF | LH 69 | LV GI | 8S 64 | WH 8 QA ile t5o 
BILLS | GELS | BTAS | OS LT | ST LG | GGL | STAG | OGLG | STAS | PEL | BTLS | 80 LG | BLE | POLE | v4 | T | 00.7 
0 a 0 a 0 a oO a 0 a 0) a 0) a "ON 2 
OE LET 00.81 OS .6ET 00.06 60049 100 0&F 0€ 066 @ | 


Til WId VL 


196 FL EL Wright—Transmission of Light through 


erossed nicols may not coincide precisely with the positions for 
which the two sides of the inserted bi-quartz wedge plate 
appear equally lighted: the angles listed in lines 5 and 6, 
Table ILI, bear out this inference. 1n column 7, the positions of 
the direction D (fig. 12, p. 200) determined eraphically, are 
listed and will be discussed in a later section. From the above 
observations it is evident that parallel, plane-polarized light 
waves transmitted obliquely through a crystal plate do not 
emerge as strictly plane polarized waves. There is, conse- 
quently, no position of total extinction, but a region of mini- 
mum illumination which may extend over several degrees and 
which, of course, precludes accurate determinations. 

The two positions of approximate extinction, determined by 
observation, may differ by a degree or more from 90°, The 
unequal rotation of the planes of polarization by the glass sur- 
faces of the mount is an important factor in this connection. 

For positions of the plate in which the direction of ths 
transmitted light waves made a relatively acute angle with the 
optic axis, the lack of parallelism of the transmitted waves was 
keenly felt, and a position of even approximate extinction was 
not attainable. In such instances the determination was not 
attempted. 


Biaxial Minerals. 


Of the biaxial minerals, muscovite and aragonite were 
selected for measurement, but only a short set of readings was 
made on each, the object being primarily to determine the 
positions of maximum extinction as well as possible with the 
bi-quartz wedge plate. The observations were made in sodium 
light and with the aid of the usual microscope lens system, 
except that the condensor had been removed, 

Muscovite.—A fresh, bare, cleavage flake was used, and 12 
readings were recorded ‘for each position of the crystal plate. 
The effects of elliptic polarization were not especially notice- 
able except for the position 7 = 22° 30’, » = 22° 30’. Not- 
withstanding this, the measured positions of extinction are not 
in general 90° apart, but differ from 90° by several degrees in 
some positions, as shown in Table IV. 


TABLE IV. 
a oO a b Diff. 
45°00’ 60°00’ 10°48 78° 54’ 89° 42’ 
ee 45 00 14 14 73 82 87 46 
as 22 30 15 44 71 40 87 24 
22 30 45 00 32 41 56 31 89 12 
gs 22 380 54 46 34 081 88 54 


1 Hlliptie polarization pronounced. 


Transparent Inactive Crystal Plates. 107, 


Aragonite.—The polished plate used was nearly normal to 
the acute bisectrix. The observations were made in sodium 
light with the aid of the bi-quartz wedge plate, and the usual 
microscope lens system without condensor. The bare plate 
was mounted as usual on the universal stage and the positions 
of extinction for each position of the plate determined 12 
times. The individual readings thus obtained agreed fairly 


TABLE V. 
a o a b Diff. 
50°00’ 90° 00’ 87°36 3°18" 90° 54’ 
sf 0 00 93 19 1 01 92 18 
30 00 90 00 86 59 5 07 92 06 
ny 75 00 84 34 7 26 92 00 
ee 60 00 83 03 9 18 92 21 
af 45 00 82 16 7 16 89 32 
if 30 00 81 15 7 OF 89 12 
ae 15 00 87 36 2 24 90 00 
be 0 00 94 57 0 07 95 04 
30 00 ue 86 53 0 14 87 07 
25 00 ne 95 38 1 30 94 08 
40 00 oY 87 07 0 07 87 00 
19 30 oo Optic axis A. 
12 00 us Optic axis B. 


well, the upper and lower limits of each set of 12 readings 
being usually about 30’ apart, but a high degree of accuracy 
cannot be claimed for the angles listed in Table V, the prob- 
able error being possibly 15’. The different positions of ex- 
tinction thus observed are not precisely 90° apart, and often 
differ from it by several degrees, again emphasizing the diti- 
culty of an accurate determination of the plane of polarization 
of a light wave transmitted obliquely through a erystal plate. 


To find the direction of vibration for a dark point H on an 
interference figure. 


An interference figure is obtained by passing a cone of con- 
vergent polarized light waves through a crystal plate and 
observing the interference phenomena as they appear in the 
rear focal plane of an objective of short focus when examined 
through an analyzer. In the course of their passage through 
the microscope, the light waves emerging from the lower nicol 
(polarizer) may be considered practically parallel, plane polar- 
ized waves. On transmission through the condensor lens sys- 
tem, their directions of propagation are changed and they 
emerge from it in a sharply convergent cone; but their line of 
vibration has remained in the same plane except for the slight 


198 LE. Wright—Transmission of Light through 


rotatory effects of the surfaces of the condensor lenses, which, 
for the moment, may be disregarded. That this is the ease, is 
tacitly assumed in all microscopic work since the rotatory 
effects produced by the condensor and objective lens systems 
alone, on the plane of polarization of transmitted light waves, 
are practically negligible and the field appears approximately 
dark under crossed nicols. Thus, in fig. 9, if the direction Z’ 
be the axis of the optical system of the Eee Y’Z’ the 


plane of vibration of the entering waves, and P the direction 
of propagation of one of these waves after refraction, its direc- 
tion of vibration will then be along T, at right angles to P and 
in the original plane of vibration. This same direction of vibra- 
tion, OT, obtains for any other point, P’, in the polar plane to 
T. A wave propagated along P’, but still vibrating along OT 
in the original plane of vibration, will be destroyed by the total 
reflexion in the analyzer, just as is the wave OP. Since the 
entire field may be covered with waves similar to OP’, whose 
directions of vibration are contained in the plane of vibration 
Y’Z’, all the waves of the converging cone from the condensor 
and objective systems are extinguished by the analyzer and the 
field appears dark between crossed nicols, provided no bire- 
fracting crystal plate intervenes. The effect of the lens system 
of the microscope is, therefore, to change the directions of pro- 
pagation of transmitted light waves, but not seriously to affect 
the plane in which their ‘Vibrations take place.’ Conversely, 

‘That there is some effect on the planes of polarization of transmitted 
light waves is at once evident, even without accurate measurements, from 
the lack of uniformity in illumination of the field when viewed under crossed 
nicols in convergent polarized light. A dark cross divides the field into quad- 
rants which are “perceptibly lighter than the bars of the cross. This cross is 


visible in every microscope and is not always due to faulty construction of 
the objectives nor to strains in the glass. 


Transparent Inactive Crystal Plates. 199 


if Z’Y’ (fig. 10) be the extinguishing plane of the analyzer, and 
H any dark point in the field of the interference figure, the 
direction of vibration for this light wave H must be contained 
in the plane Z’Y’ and also in the polar plane to H’; it is accord- 
ingly the direction D. If its direction of vibration be not in 


Fie. 10. 


y! 


the plane Y’Z’, it will not be totally extinguished in the upper 
nicol and the point H will not appear completely dark. Briefly 
stated, for any dark point H of the interference figure, the 
direction of vibration is the intersection OD of the extinguish- 
ing plane X’Z’ of the upper nicol and the polar plane of H. 
This is the rule of construction given by the writer for finding 
the plane of vibration of any dark poimt in the interference 


200 FEL Wright—Transmission of Light through 


figure. As noted above, the rotatory effects of the surfaces, 
both of the erystal plate itself and of the glass mounts and 
lenses, are disregarded in this construction. “These effects are 
small but still noticeable, and the method in consequence is 
only an approximate method. 

Professor Becke' has described another method for finding 
the direction of vibration for a dark point P of the interference 
figure. His method consists in drawing, in stereographic pro- 
jection, the great circle which is tangent to a line through H 
parallel _w ith the plane of vibration Y’ Z’ (fig. 11). The inter- 
section F of this great circle with the polar circle of H is then 
the desired direction. The point can also be found, as Profes- 


sor Becke has shown recently,’ by noting that it is at the inter- 


section of the straight line H F Y’ (fig. 12) and the polar circle 
to H. This direction of vibration F is not, however, contained 
in the plane Y’Z’ (fig. 12), the extinguishing plane of the upper 
nicol, in which case the point H cannot be perfectly dark, if the 
above reasoning be correct. If the extinguishing plane ‘of the 
nicol were Z’' X’ instead of Y’ Z’, the point C would be the 
direction of vibration for a dark poimt H, while G would be 

1 Tschermak’s Min. Petr. Mitteil., xxiv, 39-40, 1905. 

* Tschermak’s Min. Petr. Mitteil., xxviii, 293, 1907. 

3 It may be of interest to note that in this figure the line HY’ cuts the 
great circle HL at F, as Professor Becke has shown; also that the line HD 
intersects the horizontal circle at L; that the angles LM, X’Y’, KN, are 


right angles; and that the angle CD is equal to KL, the angle between the 
lines of projection of the lines OF and OG on the horizontal plane. In fig. 


13, the angle X’M is equal to the angle DI, and also to the angle ZHX’ or 
180 —6 of the spherical triangle ZHZ’. 


Transparent Inactive Crystal Plates. 201 


the equivalent point determined by the method of Professor 
Becke. According to the writer’s method of construction, the 
directions of vibration of any dark point of the interference 
figure, as viewed through the upper nicol, must lie in the ~ 
extinguishing plane of the upper nicol. The directions found 
by Professor Becke’s method are not in general contained in 
this plane, and appear, therefore, to be incorrectly lccated. 
Objection has been made by Professor Becke to the writer’s 
method because the lines D and C (fig. 12) are not 90° apart 
while the points F and G are precisely so. In answer to this it 
may be stated that in any direction within a crystal plate, as H. 
in the uniaxial crystal plate of fig. 13, Z being the optic axis, 


Fie. 18. 


two waves are possible whose directions of vibration D and C 
(fig. 13) are strictly normal to each other and to the line of 
propagation H. In the interference figure, however, these 
directions are not observed along the line of propagation H 
but as they appear in projection; and in the plane of this pro- 
jection the lines of vibration are not 90° apart. To assume, 
therefore, that the planes of polarization of the two possible 
waves as observed in the interference figure are tangent to 
the two lines parallel with Y Z through H in stereographic 
projection, obviously introduces an error. If the point appears 
dark in the interference figure, its direction of vibration must | 
be contained in the extinguishing plane of the analyzer, and it 
is with such points alone that the present problem has to do. 
Along the line of propagation OH (fig. 12), a second direction 
of vibration is possible at right angles to OD and normal to 
OH, this direction OC is in general not contained in the plane 


202 FL EB. Wright—Transmission of Light through 


X’ Z’ at right angles to Y’Z’; but with this direction the 
present problem is not concerned, its object being solely to find 
the direction of vibration of an observed dark point in their 
interference figure, the extinguishing plane of the upper nicol 
being given. 

In the last paragraph, one factor which has profound influ- 
ence on the phenomena actually observed, has been purposely 
held in abeyance, and must now be considered in detail. Let P 
be a direction on the axial bar in an interference figure along 
which plane polarized light waves enter at uniradial azimuth. 
At the upper and lower surfaces of the crystal plate the plane 
of polarization of these waves suffers a slight rotation and as a 
result the emergent waves no longer vibrate in their original 
plane and are consequently not totally extinguished by the 
upper nicol. The point P is not completely dark. Similarly, 
let H be a point, adjacent to P on the axial bar of the inter- 
ference figure, for which one of the emergent waves vibrates in 
the extinguishing plane of the upper nicol. If this wave alone 
were considered, the point H would appear completely dark, 
but along H a second wave is possible whose plane of vibra- 
tion after emergence neither coincides nor is at right angles 
with the first; it is not completely extinguished by the upper 
nicol and accordingly illuminates H slightly. The two adja- 
cent points P and H appear, therefore, only approximately 
dark, and the narrow fringe between them is of about the 
same degree of darkness. There is, in short, no point of abso- 
lute extinction on the bar. The width of the bar increases as 
the margin of the field is approached (fig. 15). As the posi- 
tious of extinction of the two possible waves emerging in one 
given direction in air do not coincide precisely, and are not 
exactly 90° apart, there is evidently a range of weak illumina- 
tion between the positions of uniradial total extinction. For 
each of the two possible waves, however, the positions of extinc- 
tion are precisely 90° apart, and if the crossed nicols be rotated 
through 90°, there will be only a slight change, due to surface 
film effects, in the position of the axial bars in the interference 
figure from an unmounted plate. On mounted erystal plates 
the rotary effects of the surfaces of the glass mount enter the 
problem and there a rotation of the crossed nicols through 90° 
often produces a small though perceptible shift in the position 
of the axial bars, as is evident from the series of measurements 
- on interference figures, represented by (figs. 14a, b, 17a, 0.) 

Observations in convergent polarized light.—The measure- 
ments were made in strong sodium light on clear mounted and 
unmounted cleavage flakes of muscovite and anhydrite. The 
petrographic microscope was first accurately adjusted, a cap 
nicol being used whose vernier divisions read directly to 3’, 


Transparent Inactive Crystal Plates. 203 


Fie. 14a. 


204 FB. Wright— Transmission of Light through 


which was also the interval of the vernier of the lower nicol ; 
with this arrangement both nicols were situated outside the 
optical system, and during each set of observations neither the 
optical system nor the crystal plate were touched. Experience 
showed that if the upper nicol remained in the tube, as is 
ordinarily the case, and then rotated, a shift of the optical cen- 
ter resulted, and although almost negligible, was still distinetly 
noticeable. The cross grating ocular’ served to locate acct- 
rately the different points in the field. The axial bars of the 
interference figure were plotted directly on cross section paper 
as they appeared for different angles of rotation of the crossed 


rd 


Fie. 15. 


nicols. The interference figures were sharp and the dark, 
axial bars clearly defined, although not perfectly dark, and 
reaaings could be made to one half of one division (about 1° 
in angular coordinates ) of the coordinate scale of the ocular. 
Muscovite.—Several fresh cleavage flakes of this mineral 
were observed in convergent polarized light and the positions 
of the axial bars determined for different’ angles of rotation of 
the crossed nicols. The results are plotted in the stereographic 
projections (figs. 14a, >), in which the axial bars are drawn 
for the two positions of the extinguishing plane of the upper 
nicol (—10° and +15° ) as indicated by the dotted lines. The 


1 This Journal (4), xxix, 423, 1910. 


Transparent Inactive Crystal Plates. 205 


observations were made by using the cross grating ocular as 
shown in the microphotograph fig. 15. The observed codrdi- 
nated values were reduced to their angular equivalents by use 
of the apertometer and these in turn reduced to the corre- 
sponding erystal angles by means of the sine formula and the 
refractive index 8. The use of the refractive index 8 for all 
direction introduces an error, but experience has shown that 
this error is not great and in general may be disregarded. 

Points were located as accurately as possible along each 
axial bar and then plotted in projection (indicated by small 
circles, figs. 14a, 146). Although the axial bars were not 
perfectly sharp they were well detined and the points were 
taken along the central line of the bar, the position of each 
point being determinable to within about 1°, or less for certain 
positions. In fig. 14a, the results which were obtained from 
an unmounted cleavage plate are represented ; in fig. 140, the 
interference figure is that from the same plate mounted in 
Canada balsam between cover glass and object glass. In each 
of these figures, the positions of the line of vibration were 
determined graphically, both by the method of Professor 
Becke (indicated by small crosses) and by that of the writer 
(indicated by small circles). A comparison of the relative 
positions of these small circles and crosses relative to the dot- 
ted line which represents the position of extmguishing plane 
of the upper nicol shows that in a few instances the points 
as determined by Professor Becke’s method are slightly 
more accurate than the equivalent points of the writer’s 
method; in the majority of instances, however, the small 
circles are more nearly correct than the small crosses. 
As a general] rule, it may be stated that the order of accuracy 
of the two methods is about the same, the writer’s method 
having the single advantage of greater simplicity. 

A critical comparison of the results of observation on 
mounted flakes with those on unmounted flakes show clearly 
the effect of rotation by the glass surface, causing the axial 
bars and axes to shift slightly, so that the direct reading of the 
optic axial angle is not quite the same in the two cases. The 
difference is not great, but it is noticeable, and is sufficient to 
make it advisable to use unmounted plates wherever possible, in 
optic axial measurements, if results of the highest accuracy are 
desired. Ordinarily, however, this precaution is unnecessary, 
since such accuracy is not required. 

A rotation of the crossed nicols through 90° also generally 
produces a slight shift of the axial bars from mounted plates, 
as indicated by fig. 16, which is a direct record to scale of the 
observed phenomena. In each case the points along the cen- 
tral line of the axial bar were plotted. The position of this 


Am. JOUR. Sch SE oree SERIES, VoL. XX XI, No. 1838.—Marcgu, 1911. 
1 


206 =F. EL Wright—Transmission of Light through 


central line for an angle of rotation of 15° of the crossed nicols 
is indicated by the curve I, fig. 16; it sposition for an angle of 
rotation of 105° is shown by curve II. These two curves do 
not coincide, and although such measurements cannot be made 
very accurately, they show that a rotation of the crossed nicols 


Fie. 16. 


causes a slight shift of the axial bars of the interference figure 
of a mounted crystal plate. The amount of shifting rarely 
exceeds several degrees and is usually less, but it is often sufii- 
cient to be perceptible and shows the importance of referring 
the data, when plotting, to the correct position of the extin- 
guishing plane of the upper nicol. It is, therefore, not imma- 
terial which one of the principal nicol sections be chosen. If 
the observations themselves were of a higher order of accu- 
racy, this fact would be a serious objection to Professor Becke’s 
method. 

Anhydrite.—A series of observations (figs. 17a, 6) on a cleay- 
age plate of anhydrite, unmounted (17a) and mounted (176), cor- 
roborates the conclusions stated in the last paragraph. The 
degree of accuracy of the two methods in question is about the 
same here as in muscovite. A rotation of the crossed nicols 
through 90° also produced a slight shift of the axial bars on 
mounted plates, as in muscovite, and it is important, therefore, 
that the plotting be done with reference to the correct prin- 
cipal nicol section. 


Transparent Inactive Crystal Plates. 207 


Fie. 17a. 


Fie. 170. 


208 EE. Wright—Transmission of Light through 


A device to aid in the graphical solution of optical problems 
involving the use of the stereographic projection. 

In the measurement of optic axial angles in convergent polar- 
ized light,’ and also in all measurements by means of the uni- 
versal stage methods, the stereographie projection plat of 
Prof. Wulff has proved a useful and necessary adjunct, the 
angular values of observation being plotted directly on thin 
transparent paper placed above the plat and held in the center 
by means of a needle. This needle, however, is not entirely 
satisfactory, since it does not hold its place rigidly and tends 
thereby to injure the stereographic plat below. To overcome 
this dithculty the writer has constructed the device of fig 18 


Fic. 18. 


C D 


(one-eighth actual size). A heavy brass bar fits into two end 
blocks of brass, A and B; at its center a small hollow brass rod, 
C, containing a needle backed by a spring is introduced. By 
this device the needle is rigidly supported in a vertical posi- 
tion, and as the distance between the end blocks A and B is 
44, there is more then sufficient space available for the pro- 
jection plat and the overlying drawing. The writer has used 
this device for several years and has found it satistactory and 
a time saver.” 


Summary. 


Minerals are determined under the microscope by the effects 
they produce on transmitted light waves. Plane polarized 
light waves are ordinarily used and examinations are made 


1 For determining the Mallard constant of the microsope, whichis required 
in the measurement of optic axial angles by means of the microscope, Dr. J. 
S. Flett of London uses a Zeiss Abbe apertometer. His method is simple 
and accurate and is superior to any method yet suggested. He introduces 
the micrometer scale in the ocular as usual and then determines the divi- 
sions covered by the different angles of the apertometer. Since with this 
device any angle can be instantly set off, an objective can be calibrated 
rapidly for all possible angles within the field of vision, and an empirical, 
correct table prepared which is independent of the Mallard formula, thus 
obviating all errors due to a lack of correction in the objective lenses. 

* Recently, Prof. Nikitin has had constructed a graduated porcelain hemi- 
sphere (made by R. Fuess, Steglitz, Berlin, Germany) which the writer has 
found very satisfactory in optic axial angle projections and slightly more 
accurate than the projection plats. chiefly because of its lack of distortion 
toward the margin and consequent acute angled intersections of great circles. 
This hemisphere has the advantage of serving as amodel in the study of 
optical phenomena and is a useful piece of apparatus for the petrological 
laboratory. 


Transparent Inactive Crystal Plates. 209 


partly with and partly without the aid of the upper nicol (ana- 
lyzer). In anisotropic erystals the planes of polarization of 
light waves, transmitted along a given direction within the 
erystal, are prescribed by the crystal structure. On entering 
or emerging from a crystal plate, plane polarized light waves 
transmitted obliquely usually suffer a slight rotation of the 
azimuth of their plane of polarization. The amount of this 
rotation is rarely more than a few degrees. In practical micro- 
scope work but little attention has been given to this 
phenomenon, but in accurate work it is a factor which must 
be considered. 

In the foregoing pages the attempt has been made in Part 
1 to present, in terms of the electromagnetic theory of light, 
the general mathematical treatment of the transmission ot 
light waves through a transparent inactive crystal plate, spe- 
cial attention being given to the rotatory effects of the boun- 
dary surfaces of the crystal plate on the plane of polarization 
of a transmitted wave. This problem was first solved in 1835 
by J. MacCullagh and also by F. E. Neumann; since their time 
a number of investigators have made important contribu- 
tions to its solution. Interest, however, has centered chiefly in 
the reflexion of light waves by erystal surfaces and no con- 
nected presentation of the mathematics covermg the phenom- 
ena of refraction in crystal plates appears to have been made. 
This has been essayed in Part 1. The greater part of the 
ground covered therein is familiar, but several of the formu- 
las derived appear to be new, notably (326) and (87). Of 
these (87) is important and states that the uniradial azimuths 
of the plane of polarization of the emergent waves W’, and W’, 
are 90° from the uniradial azimuths of the entering waves 
whieh, on refraction, produce the waves W, and W,. In other 
words, the positions of extinction on emergence for either one 
of the two possible refracted waves, W, or W,, resulting from 
a single plane polarized light wave, incident at the surface of 
a crystal plate, are precisely 90° apart. The positions of 
extinction for the two waves do not, however, coincide and 
there is in general, therefore, no position of total extinction 
for waves transmitted obliquely through a crystal plate. 

Both theory and the observations of Part 2 show that as a 
general rule, a uniradial, plane polarized light wave, after 
transmission through a bare crystal plate (preferably a cleav- 
age plate so that the disturbing effects of surface films caused 
by polishing are not serious), is still plane polarized, but its 
plane of polarization has suffered a slight rotation depending 
on the direction of transmission, and if examined under crossed 
nicols does not appear perfectly dark in consequence. In thin 
crystal plates the two refracted waves W, and W, overlap to a 


210 Ff. EB. Wright—Transmission of Light through 


large extent and there is no position of total extinction for the 
tilted crystal plate even if the upper nicol be rotated alone. 
In general it may be stated that from an incident plane polar- 
ized wave two refracted waves are formed, which on emerg- 
ence from the plate are each still plane polarized, but their 
planes of polarization are not precisely 90° apart. The result- 
ant light as observed through the analyzer is consequently 
elliptically polarized and there is no possible position of total 
extinction of the plate, but rather a region of minimum illumi- 
nation which may extend over several degrees. 

These relations have an important bearing on methods based 
on the determination of the positions of extinction of obliquely 
transmitted waves, and preclude at once a high order of accu- 
racy in the measurements. If the observed crystal plates are 
mounted in Canada balsam, the rotatory influence of the sur- 
faces of the glass and Canada balsam mount enter the problem 
and tend to complicate the phenomena still further. 

The measurements of Part 2 show: (1) That a tilted glass 
plate may rotate the plane polarization of a transmitted plane 
polarized light wave several degrees, and that the amount of 
rotation increases with the angle of tilting; (2) that the 
observed uniradial azimuths of tilted cleavage plates of calcite 
agree closely with the calculated values; (8) that for the central 
areas of tilted plates of calcite, nephelite, muscovite, and ara- 
gonite, there are no positions of total extinction. It settings 
be made at the apparently darkest positions of the plate during 
the rotation of the microscope stage, these positions are often 
several degrees from 90° apart, and if the observed azimuths 
of the plane of polarization be taken as the azimuth of the 
refracted waves within the crystal, errors of several degrees 
are easily possible. (4) An obliquely transmitted wave will 
be extinguished provided its direction of vibration after emerg- 
ence is contained in the extinguishing plane of the analyzer. 
The direction of vibration of an observed dark point on the 
axial bar of an interference figure is therefore the line of 
intersection of the extinguishing plane of the upper nicol with 
the polar plane of the given point. This construction, sug- 
gested by the writer, does not take into consideration the rotatory 
effects of the surfaces of crystal plate and glass mount, and is 
accordingly only an approximate method. Prof. Becke has 
suggested another method, which is, in effect, to find the inter- 
section of the polar plane with the great circle in stereo- 
graphic projection, which is tangent to a line parallel with the 
principal section of one of the nicols. The points obtained by 
Prof. Becke’s method are slightly different from those obtained 
by the writer’s method, but not sufficiently different to affect 
the degree of approximation obtainable by such methods. In 


Transparent Inactive Crystal Plates. 211 


principle, however, the two methods are fundamentally differ- 
ent, and a detailed discussion, together with a series of meas- 
urements on interference figures of muscovite and anhydrate, 
indicate the general validity of the principle on which the 
method proposed by the writer is based; in this method the 
rotatory effects of all boundary surfaces are disregarded and for 
this reason the results obtained by its use are only approxi- 
mately correct. 

Several devices are described which have been found ser- 
viceable in connection with this work: (1) An apparatus for 
securing an intense and constant sodium light. (2) A simple 
and accurate method for adjusting the petrographic micro- 
scope. (8) A device to aid in the work with the stereo- 
graphic projection plat. 

Geophysical Laboratory, 


Carnegie Institution of Washington, 
Washington, D. C., November, 1910. 


212 Gooch and Boynton—Estimation of Barium 


Art. XX.—The Separation and Estimation of Barium 
Associated with Calcium and Magnesium, by the Action of 
Acetyl Chloride in Acetone Upon the Mixed Chlorides ; by 
F. A. Goocs and O. N. Boynton. 


[Contributions from the Kent Chemical Laboratory of Yale Univ.—cexviii.] 


In former papers from this laboratory* it has been shown 
that certain chlorides may be quantitatively precipitated for 
purposes of analysis by treating their water solutions with’ 
aqueous or gaseous hydrochloric acid and ether. 

The present paper is an account of procedure for the pre- 
cipitation of barium chloride from water solution and its sepa- 
ration from calcium and magnesium by the use of acetyl chloride 
to decompose the water of the solution according to the reac- 
tion CH,COCl + H,O = CH,COOH + HCl, inconvenient vio- 
lence of reaction being moderated by the addition of acetone 
which mixes in all pr oportions with both acetyl chloride and 
water and by itself exerts no appreciable solvent action upon 
barium chloride. 

When a mixture of acetone and acetyl chloride, preferably 
4:1, is added slowly to a very concentrated solution of barium 
chloride in water, the water is attacked at once, hydrogen 

chloride is liber ated, and precipitation begins immediately. Gi 

the temperature is kepi down during the process by immers- 
ing in cool running water the vessel in which reaction takes 
place, no more than a mere trace of barium can be detected by 
sulphuric acid in the residue left after evaporating the liquid 
separated from the precipitate by filtration through asbestos. 
When, however, the temperature is allowed to rise, in conse- 
quence of the heat liberated in the reaction, an appreciable 
amount of barium may be found by sulphuric acid in the 
filtrate. Below are given the data of experiments in which 
the residue obtained (a) by treating a solution of barium 
chloride in 1 of water with 30°? of a 4:1 acetone- -acety| 
chloride mixture and collecting the precipitate upon asbestos 
in a perforated crucible, washing with acetone and with ether, 
was weighed after drying in air, then (0) treated on the asbes- 
tos for ten minutes with 15-20 of acetyl chloride, washed 
with acetone and with ether, dried in the air and weighed, 
then (¢) digested for ten minutes with 20-25°* of 2:1 ace- 
tone-acetyl chloride mixture, washed with acetone and with 
ether, dried in the air and weighed, and then (d@) heated in the 
air-bath, or to low redness, and weighed. 

* Mar, this Journal [8], xliii, 521; Havens, this Journal [4], ii, 416; iv, 
111; vi, 45; vi, 396. 


Associated with Calcium and Magnesium. 213 


Experiment I PLE ae II 
—_——_-+7~ —— 
Weight Loss Weight Loss 
grm. grm. grm. grm. 
BaC],.2H,0O taken ..-- -_-- OghOM 2M ee OULOOO a eee 


(a) Residue after precipitation, 
washing, and drying in air, 071008 0:0004 0:0996 0:0004 


(b) Residue after treatment with 
acetyl chloride, washing, 
andl dyamereim a, 2-1 071006 0:0002 90:0996 0:0000 


(c) Residue after treatment with 
acetone-acetyl chloride mix- 
ture, washing, and drying 
Maas SO las 0:0985 0:0021 0°0981 0-0015 


(d) Residue after heating, BaCl, 0:0846* .... 00839 © .--- 
BaCl,.2H,O corresponding to 
ba@ le Townde easy: = sans OOO 35) oe Ser COLO9SD ein. cae. 
‘Loss of BaCl,.2H,O due to 
solubility and dehydration ---. 00027 ---.- 0°0019 


Loss of BaCl,.2H,O due to 
solubility, calculated from 
BaCl,.2H,O taken and BaCl, 


OUMKC ee  a tes eee eee TS ES ff OLOOLINE |. era =z 0'0015 
Wosspby, dehivdiratione jae =)t ae. 010008) "2-3-1" 020004 
* Heated to low redness. + Heated to 135° for 114 hrs. 


From these results it appears (a) that when the acetone- 
acetyl chloride mixture (4:1) acts upon the cooled concen- 
trated water solution of barium chloride the precipitate is the 
hydrous chloride, BaCl,.2H,O, only the water in excess of that 
needed to form the hy drous salt being immediately attacked ; 
(6) that acetyl chloride by itself pr oduces only slight dehydra- 
tion of the salt without marked solubility ; and ‘(e) that pro- 
longed action of the acetone-acetyl chloride mixture (2:1) 
results in appreciable dehydration and considerably increased 
solubility of the salt. By fnrther experimentation it was 
shown that when the acetone-acetyl chloride mixture is added 
without cooling to the water solution of barium chloride the 
heat of reaction favors dehydration of the hydrous salt, and 
the anhydrous salt may go into solution to the amount of 
several milligrams in 10° of the precipitating mixture. Upon 
filtering the mixture and treating the filtrate with acetone, 
with acetyl chloride, or with the acetone-acetyl chloride mix- 
ture the dissolved anhydrous salt is not thrown out of solution, 


214 Gooch and Boynton— Estimation of Barium 


but the addition of a drop of water is sufficient to induce 
immediate precipitation in the form of the hydrous salt. 

Incidentally it is interesting to note that when water acts 
upon the colorless mixture of acetone and acetyl chloride the 
solution becomes yellow, and then reddish, and develops a 
distinetly fruity odor, condensation taking place between the 
acetone and acetyl chloride. The boiling points of the col- 
lected filtrates from a series of barium chloride precipitations 
after standing about a week ranged from 50:5° to 250°, and 
left a resinous residue at that temperature. 

From the results of the experiments described, it may be 
inferred that the best conditions for the quantitative precipita- 
tion of barium chloride by the acetone-acetyl chloride mixture 
should be found in the use of minimum amounts of water, the 
preservation of ordinarily low temperature, a liberal propor- 
tion of acetone, and not too prolonged digestion of the precipi- 
tate in the excess of the precipitant. These conditions have 
been complied with in the quantitative tests. 

Barium chloride was prepared for the work by precipitating 
it with strong hydrochloric acid from a water solution of the 
presumably pure salt, recrystallizing twice from water, and 
drying in the air. On gentle ignition the salt lost water cor- 
responding to the ideal composition of the hydrous chloride, 
- BaCl,.2H,O. In each test a portion of this salt was weighed 
out into a small beaker and dissolved in 1°™° of water. The 
beaker was cooled by immersion in a water-bath preferably 
supplied with running water at a temperature of about 15°. 
To the cooled solution, constantly shaken, the acetone-acety] 
chloride mixture was added from a dropping funnel at the 
rate of five drops to the second. Other data of the experi- 
ments with barium chloride are given in Table I. The pre- 
cipitate was filtered off upon asbestos in a perforated crucible, 
dried, or ignited, and weighed as the anhydrous chloride, BaCl.,,. 
From these results it appears that the best of the conditions 
studied for the handling of 0-1 grm. of hydrous barium chlo- 
ride are the solution of the salt in 1°° of water, treatment 
with 30° of the 4:1 mixture of acetone and acetyl chloride, 
washing with acetone, and drying in the air-bath at 135° or 
at low redness. 

' The application of these conditions to the separation of 
barium from moderate amounts of calcium and magnesium 
proves to be easily feasible. When acetone is added to the 
concentrated solution of calcium chloride or magnesium chlo- 
ride in water two liquid layers are formed, the acetone above 
and the aqueous layer below; but the addition of a few drops 
of acetyl chloride renders the liquids miscible while further 
addition causes no precipitation. When the 4:1 mixture of 


Associated with Calcium and Magnesium. 215 


TABLE J. 


The Estimation of Barium. 
Amount of mixture and 


BaCly Water to composition by volume 
taken as BaCl, dissolve ———_—_—— tH 
BaCl,.2H,0 found Error BaCl,.2H.O To precipitate To wash 

grm. grm. grm. 

1-0°0859  0:0859 —0-0000t ems Get eal OGL 
2-0:0861  0:0854 —0-0007t ES RE Oe TOE 
3-0°0861 0°0858 —0:0003f ss aE oil HOSP et 
4-0°0862 0:°0854 —0-0008* ee Ge! Weil LOPE Bei 
5-0°0857 0:0854 —0-0003* sf ecm? 931 UIE Weil 
6-0°0858 0:0860 +0:°0002* ve (HOE BT, i Oto abe 
7-0°0860 0:0859 —0-:0001* © § Ge! Beil SO Za 
8-0°0853 0°0850 —0:0003* WY Ger acetone 
9-0°0854 0:0848 —0:0006* fs Gone 2 il y 
10-0°0852 0°0851 —0-:0001* “s 6cem® 221 ss 
11-0°0857 0:°0856 —0-0001t oo Ge Beil a 
12-0:0852 0°0845 —0-0007+ os Goat) Beil ce 
13-0°0855 0°0852 —0-0003+ oe Gore o a Hy 
14-0°0862  0:0862 —0-0000t He SOc es 
15-0°0868  0:0868 —0-0000t ee BOY Zep ss 

* Ignited at low redness. + Dried at 185° for 144 hrs. 


acetone and acetyl chloride is added at the rate of five drops 
in the second to the solution containing no more than 0°5 grm. 
of the calcium and magnesium salts, barium chloride is pre- 
cipitated and calcium chloride aud magnesium chloride are 
dissolved ; but when the soluble chloride is present in the pro- 
portion of 1-0 erm. to 0'1 grm. of the barium chloride, the 
rate of addition of the precipitating mixture should not be 
greater than two drops in the second at the start in order to 
avoid inclusion of the soluble salt in the insoluble barium salt. 
Even in such cases the mixture may be added at the rate of 
tive drops in the second, after the greater part of the barium 
is down. Tables II and III contain the data of experiments 
upon the separation of barium from calcium and magnesium. 
The results obtained in the separation of 0-1 grm. of the 
barium salt from 0°5 grin. of calcium and magnesium salts are 
excellent. 

The separation of barium from strontium proves not to be so 
simple. When the 4:1 mixture of acetone and acetyl chloride 
is added to the concentrated water solution of 0-1 grm. of 
strontium chloride a partial precipitation takes place. When 
the precipitate thus produced was filtered: off, washed with ace- 
tone and with ether, and dried in air, it lost SET amounting 
to 19°93 per cent and 20-00 per cent of its weight on heating 


216 Gooch and Boynton—LKstimation of Bariwm 


TABLE II, 


The Separation of Barium from Calcium. 


» Ba), Water used Amount of 
takenas CaCl,.2H.O BaCl, to dissolve mixture 
BaCly.2H;0 taken found Error salts (4:1) used 
grm. erm. grm grm. em?, em?, 
1-0-0859 01000 0:0859 0°0000* hs ae 30 
2—0:0867 071040 0°0867 0:0000* 1 S30) 
3—0°0868 0°1022 0:0868 0:0000* il 30 
4-0:°0865 0°1020 00865 0°0000* 1 30 
5-0°'0868 01017 0°0869 +0:0001* 1 30 
6—0°0864 071016 0:0861 —0:0003* 1 30 
7—-0°0866° 0°3025 0°0867 +0:0001*. 14 30 
8—0:0859 075025 0:0859 0:0000* 2 30 
9-0°0860 1:0020 0:0878 +0:0018* 3 30 
10—0°0859 10020 0:0855 — 00004 2 30 
11-0°0864 1°00385 0:0867 + 0°0003F 2 30 


* The precipitant was added at first at the rate of five drops in the second. 
+ The precipitant was added at the rate of two drops in the second at the 
outset and later of five drops in the second. 


TaBLeE Lil. 


The Separation of Barium from Magnesium. 


BaCl, Water used Amount of 
taken as MgCl..6H.0 BaCl, to dissolve mixture 
BaCl..2H.,0 taken found Error salts (4:1) used 
grm. germ. grm. germ, cm’. em’, 
1—0°0858 071000 0°0857 —0-:0001* u 30 
2—0°0869 0'1025 0:0870 + 0°0001* i 30 
3-0°0858 0°1025 0°0858 0:0000* 1 30 
4—0°0862 0°1010 0:08638  =+0°0001* h 30 
5-0'0858 071006 ~=—- 00860 +0:0002* 1 30 
6—0'0860 0°1020 0°0859 —(:0001* i 30 
7—0:0860 0'1010 = 0:0862 “+ 0:0002* 1 30 
8—0'0865 0°3010 0°0867 +0°0002* 14 30 
9-0°0864 0°5000 =0°0867 +0:0003* 2 30 
10—0°0868 1:0015 = 0°0878 +0°0010* 3 30 
11-—0°0853 10010 0:0854 . +0:0001t 3 30 


* The precipitant was added at the rate of five drops in the second, 
+The precipitant was added at first at the rate of two drops in the second 
and later of five drops in the second. 


to 185°. Obviously the salt was essentially SrCl,.2H,O, which 
should contain theoretically 18°51 per cent of water. This 
precipitate of SrCl,.2H,O when treated with a mixture of ace- 
tone and acetyl chloride containing a larger proportion of the 
latter, goes into solution and is again partially precipitated upon 
increasing the proportion of «cetone, essentially as SrCl,.2H,O. 


Associated with Caleium and Magnesium. 217 


When a mixture richer in acetyl chloride, the 2:1 mixture of 
acetone-acetyl chloride, is added to the concentrated water solu- 
tion of strontium chloride, the precipitate first formed is slowly 
redissolved in a sufficient excess of the mixture and again 
partially precipitated upon the addition of more acetone. This 
second precipitate of SrCl,.2H,O is not completely soluble, 
however, when the proportion of acetyl chloride is again 
increased, but will dissolve upon the addition of an acetone- 
acetyl chloride mixture to which a few drops of water have 
been previously added and which is, therefore, charged with 
hydrogen chloride. So it appears that the solubility of the 
strontium chloride, SrCl,.2H,O, depends to a very large extent 
upon the concentration of hydrogen chloride in the mixture. 

In attempting the separation of barium from strontium, 
therefore, it was the 2:1 mixture of acetone with acetyl choride 
which, on account of its higher power as a solvent for 
SrCl,.2H,O, was added to the concentrated water solution of 
* the barium chloride and strontium chloride, though this mix- 
ture has been shown to be somewhat less favorable to the com- 
plete precipitation of barium chloride than the (4:1) mixture 
containing the larger proportion of acetone, and the addition 
was made at the rate not greater than two drops in the second 
or 30 in ten minutes. ‘The precipitate, filtered upon asbestos 
and washed with acetone, was dried at 135°. The data of 
these experiments are recorded in the table. 

The separation of barium from strontium by the process 


TABLE IV. 
The Separation of Barium from Strontium. 
BaCl, Water used Amount of 
taken as SrCl, BaCl. to dissolve mixture 
BaCl,.2H,0 taken found Error salt (2:1) used 
grm. grm. grm. grm. em?, em?, 
1-0°0867 0°0385 0:0923 + 0°0056 1 30 
2—0'0866 0°0304 0°0857 —0°0009 1 30 
3—0:0860 0°0320 0°0861 +0°0001 1 30 
4—0°0856 0:0315 00840 —0°0016 1 30 
5—0°0856 0°0307 0°'0848 — 0°0008 1 30 
6-0'0859 0°0304 0:0839 —0°0020 ] 30 
7—0:0862 0:0307 0:0859 —0°0003 1 30 
8—0°0857 0:03815 0'1160 + 0:0303 0°5 30 
9-0°0857 0:0317 01058 +0:0201 0°5 30 
10-0°0853 0°0315 0'1083 + 0°0230 0°5 30 
11-0:'0869 0°6305 0'1043 +0°0174 0°5 30 
12—0°0863 0°0307 0:0906 + 0:0043 0°5 30 
13—0°0859 0'0808 0:0849 —0:0010 0°5 30 
14-0:°0869 0°0108 0:0870 +0:0001 1 30 
15—0°0865 0°0110 0°0858 —0:0007 1 30 
16—0°0853 0°0115 0°08538 + 0°0000 1 30 
17-0:0861 0:0109 0:0870 + 0:0009 1 30 


218 Gooch and Boynton—Estimation of Barium. 


described is obviously only approximate, some barium chloride 
going into solution in the 2:1 mixture of acetone and acetyl 
chloride, while the solubility of the strontium chloride turns 
upon the amount of water originally present—that is, upon the 
development of hydrogen chloride: 

It appears, therefore, that the method which rests upon the 
action of a 4:1 mixture of acetone and acetyl chloride upon the 
concentrated solution of the chlorides affords easy and exact 
means for the separation and estimation of barium associated 
with calcium and magnesium. It is not recommended for the 
separation of barium from strontium. : 


— ee = = 


Arr. XXI.—A Feldspar Aggregate Occurring in Nelson 
Co., Virginia; by Witt1am M. Tuornton, Jr. 


Near Rose’s Mill in Nelson Co., Virginia, the General - 
Electric Company recently carried on some mining operations 
with the view of obtaining rutile, where it occurs as a rock- 
forming mineral in the unique rock type ‘‘nelsonite.”* To give 
some idea of the nature of this peculiar rock, an analysis of the 
rutile phase is here inserted : 


Analysis of Nelsonite.—General Electric Company’s mine? 
14 miles northwest of Rose’s Mill. Essential minerals :—Rutile 
(TiO,) and apatite (Ca,FP,O,,). Accessory minerals :—Ilmen- 
ite (FeTiO,), pyrite (FeS,), and yuartz (Si0,). 


SION SOLER ene ho feta bene eee 0°67 per cent 
Bei O) rae SR NGhe oe wets serene tae EOI ee 
HeOr.=_ a es wie aD ee lke La ee aes ema) () fy ss 
MeO re aye oo 2 eae ae eee eae OmlaeD es 
CaO See ee eee eee He “ 
HO! (ab 110° Cpe ee ae Oe 
EVOy(above 110 21@:) Gee sens ae 0-1] a 
DiO ie eo), aie ge 6967“ 
Pe io be Oe au L Seed eee ote RON ee Aa ee 
(Cleese Ben ies ate Ss ENS : 
AE eimai age em (10) Fe 
SS eee ie Ur Se ne Ree eee 0°34 ce 
101°21 
Dp (orejfsy OM ae veered Hayy 8 0°39 
SUD EMIT AO 11 —— an ye 100°82 


At this place the narrow, well-defined dike of nelsonite 
intersects a metamorphosed pegmatite. The pegmatite is 


*Name proposed by T. L. Watson, Director Virginia Geological Survey. 
Seve Mineral Resources of Virginia, 1907, p. 300. 


W. MW. Thornton, Jr—A Feldspar Aggregate. 219 


composed essentially of feldspar and blue quartz and in places 
much hornblende. The accessory minerals ilmenite and pyrite 
and apatite are also present. The feldspar is by far the domi- 
nant portion of the rock; and, since it presents some unusual 
features, it was thought by the author that a study of its com- 
position would prove of some interest. Of course the natural 
procedure would be to isolate mechanically the feldspathic por- 
tion and to analyze the most homogeneous material obtainable. 
But three analyses of the pegmatite were required for geolog- 
ical purposes; and since time was lacking in which to make a 
fourth of the feldspar alone, it was decided to employ the 
analysis of the extreme acidic phase for calculating the compo- 
sition of the feldspar. 

The color of the feldspar is light bluish gray. Under a 
magnifier of twenty diameters it appears decidedly transparent 
and glassy. The texture is one of very close crystalline 
aggregation. Specific gravity = 2°68. From all outward 
appearances one would suppose it to be a definite species; but 
the analysis and portioning of the molecules to form the respec- 
tive feldspars in the accompanying table shows it to be a 
mixture of orthoclase and plagioclase, and that the plagioclase 
is made up of albite and anorthite in the ratio of 10 to 7. 
This is also confirmed by microscopic examination of thin 
sections. * 


Pegmatite (feldspathic facies) near Rose’s Mill, Nelson Co., Virginia. 
Per Mo. Rel. no. 


cent wt. mos. Rel. no. feldspar mos. 
SLO Smee se ean ae ae 59°92 = 60 = 0:9987 2K AISi;0, = 0°08117 
Als Oy eee Sea ee a eal 24°23 +102 = 0°2375 2NaAl1Sis0, = 0:081 
Hie) © seeks Sytner aa 0:29 CaAl.Si,0, = +1137 
LSE Os SR Da ee aN 0°24 [CasP20,; = -0006] 
Mie Oia cee a IS Soars as 0:23 
Cia Os Sra eh ais as ek 6°47 = 56= 01155 .-. NaAISi;0; : CaAl.Si.0, = 
Nias OE ee ae a le Fe 5°03 + 62 = 0:081 Ql == LON 7 
NEG Os Sa TS eS Ne a 2°93 + 94 = 0:03117 
HeOlat T07C:) 222255 0-08 
H.O (above 110° C.)_.-_- 0°28 
(CLO) Sts ae lars eee mee trace 
AUTO Pps Gee eR Sis aeetee ea  ae 0:22 
To O) plete ie ye leet eos 0-09 +142 = 0:0006 
SC eee Pees Me eo trace 
IVErn Ocha ely apn see Re trace 
100°01 
Pegmatite: = .*. orthoclase — 17°337 per cent, plagioclase (Ab;,An;) 


74:057 per cent. 
Composition of feldspar, aggregate : orthoclase 18°96 per cent ; plagioclase 
(Ab,.An7) 81:04 per cent = 100°00. 


* Bull. 430-D, U. S. Geological Survey, p. 57. ‘‘The Virginia Rutile 
Deposits,” by T. L. Watson and S. Taber. 


220 =W. M. Thornton, Jr.—A Feldspar Aggregate. 


After combining all the potash molecules with alumina and 
silica to form orthoclase and likewise all the soda molecules to 
form albite and all the lime molecules (except enough to satisfy 
the phosphoric anhydride to form apatite) to form anorthite, 
there is a little alumina in excess. This can be accounted for 
by assuming the hornblende to contain some alumina, which 
is probably the case, or by errors in the determinations. 

In general the methods of analysis employed were those in 
use by chemists of the U. S. Geological Survey. In the 
determination of the alkalis the purest reagents of Dr. T. 
Schuchardt were used, and the filtrate from the first lime 
precipitation was concentrated in a silver basin; glass and 
porcelain vessels were avoided where any error might arise 
from their use. 


Virginia Geological Survey, 
University of Virginia, January 16, 1911. 


O. F. Cook—History of the Coconut Palm in America. 221 


Arr. XXII.—Wistory of the Coconut Palm in America ; by 
O. F. Coox.* 


Many scientific text-books and works of reference support 
the popular idea that the coconut palm is specially adapted to 
tropical seacoasts and is confined to maritime regions. No 
other example of special adaptations of plants to their environ- 
ments has had longer currency or more confident belief. 
Nevertheless, it seems that the botanical romance of the coco- 
nut, protected by its thick husk and floated from island to 
island in advance of human habitation, must go the way of 
many other pleasing traditions. What natural agencies have 
been supposed to do for the coconut is now to be recognized 
as the work of primitive man. The truth proves again to be 
stranger than the fiction. 

The coconut exists in the lowland tropics only as a product 
of cultivation. It does not plant or maintain or distribute 
itself on tropical seacoasts, and would entirely disappear from 
maritime localities if human care were withdrawn. The 
habits of the palm from the botanical standpoint, its signifi- 
cance in human history, and even its agricultural possibilities 
are misunderstood unless we are able to lay aside the maritime 
traditions. 

An outline of the evidence for the American origin of the 
coconut palm and of its distribution by human agencies has 
been published in a previous number of the Contributions.+ 
The present study carries the subject further in two principal 
directions. It brings additional facts to show that the coco- 
nut palm was already widely distributed in the New World 
before the arrival of the Europeans, and that it is not naturally 
a maritime or humid tropical species, but a native of drier and 
more temperate platean regions in South America. A com- 
parison of the habits of germination of the coconut with those 
of other related American palms shows other and very differ- 
ent uses for the characters that have been looked upon as 
special adaptations for maritime dissemination. 

The huge seed with its immense store of food materials and 
its thick fibrous husk make it possible for the coconut to 
propagate itself im the relatively dry interior localities where 
it appears to have originated. The inability of the palm to 
withstand shade explains why it has been unable to establish 

* Extracted from Contributions from the U. S. National Herbarium, vol. 
xiv, pt. 2, pp. 271-342, 1910. The portions here given are from the intro- 


duction and summary. 
+ The Origin and Distribution of the Cocoa Palm, Cont. Nat. Herb., vol. vii, 


pp. 257-298, (1901.) 
Am. Jour. Sci.—FourtH SERIES, Vor. XX XI, No. 183.—Marcga, 1911. 
16 


222 O. F. Cook— History of the Coconut Palm in America. 


itself as a wild plant on any tropical seacoast. The application 
of these facts to cultural problems shows that the possibilities 
of an extratropical extension of the coconut palm are not to be 
realized on seacoasts, but in interior desert regions where 
larger amounts of heat and sunlight are to be obtained. 

Though the biological evidence of the American origin of 
the coconut palm appears complete and adequate, recent years 
have brought to light several additional facts which may be of 
use to those whose training and habits of thought lead them to 
attach great weight to the historical arguments of De Candolle 
and other writers who believed in the Old World origin of 
this palm and its dissemination by the sea. The reader is 
impressed by De Candolle’s references to many old and rare 
books, and will naturally remain loth to believe that so eminent 
an authority could have come to an erroneous conclusion, 
unless all the foundations of his opinions are carefully reex- 
amined. 

It is important to trace and clear away any mistakes or false 
deductions which obscure the early history of cultivated plants. 
Misconceptions regarding the origin and dissemination of any 
important economic species tend to distort human history as 
well as to mislead botanical and agricultural investigation. It 
is only when we view the past with the right perspective that 
we gain correct ideas of the factors which control our present 
interests and our future progress. Civilization itself is based 
on cultivated plants, and history may be written with as much 
propriety from the agricultural standpoint as from the mili- 
tary, political, or commercial. 


SuMMARY OF RESULTS. 


The history of the coconut palm has relation to several 
different kinds of scientific questions, so that the facts require 
to be summarized from several different standpoints. 


Botanical Conclusions. 


All the palms that are related to the coconut, comprising 
about 20 genera and 200 species, are natives of America, with 
the possible exception of a single species, the West African oil 
palm. All the species of the genus Cocos and of the closely 
allied genera are natives of South America. The species of 
Cocos that are most related to the coconut are natives of the 
interior valleys and plateaus of the Andes, where the coconut 
also thrives, remote from the sea. 

Comparison of the structure of the fruit and the method of 
germination of the coconut with those of the related palms 
indicates a high degree of specialization, but not for purposes 
of maritime distribution. The unusually large, heavy seed and 


O. F. Cook—LHistory of the Coconut Palm in America. 223 


the thick, fibrous husk are to be considered as adaptations for 
protecting the embryo, assisting in germination, and establish- 
ing the young plants in the dry climates of interior localities, 
the only conditions where this palm could be expected to 
maintain its existence in a wild state. 

The habits of the coconut palm afford no indication that its 
original habitat was on the seacoast, and none of its closer 
relatives have maritime habits or maritime distribution. The 
coconut palm does not appear to be able to maintain itself 
under littoral conditions without the assistance of man. Though 
carried by man to all of the warmer parts of the earth, it has 
not been able to establish itself as a wild plant on any tropical 
coast, but. is always crowded out by other vegetation after 
human care is withdrawn. 

Wafer’s circumstantial account of the existence of large 
numbers of coconut palms on the Cocos Islands, 300 miles 
west of Panama, in 1685, taken together with their almost 
complete disappearance at the present day, affords a striking 
illustration of the dependence of the coconut upon human 
assistance, not only for distribution, but for its continued exist- 
ence on oceanic islands. 

The dissemination of the coco palm along the tropical coasts 
is to be ascribed to the agency of primitive man, as with the 
sweet potato, banana, and other domesticated plants which 
were widely distributed in prehistoric times. The theory that 
it has been disseminated by ocean currents is gratuitous, 
unproved, and improbable. 

The development of distinct varieties of the coconut has not 
been confined to the Polynesian and Malayan islands. Dis- 
tinct varieties are also to be found in isolated localities in 
America, such as the Soconusco region of Mexico and the 
island of Porto Rico. 

The existence of many and diverse varieties in the Malay 
region does not indicate that the species is native there, but the 
opposite, since the proximity of the wild stock of a species is 
likely to hinder the appearance and preservation of mutations 
among its cultivated representatives. The relative uniformity 
of the coconuts of America is in accord with the probability of 
an origin in this hemisphere. The discovery of distinct varie- 
ties in isolated localities in America accords with the proba- 
bility that the Malayan varieties have arisen, like other culti- 
vated varieties, through segregation and mutation rather than 
by gradual evolution and natural selection. 


Historical Conclusions. 


At the time of the discovery of America the coconut was 
not confined to the Pacific side of the Isthmus of Panama, as 


224 O. F. Cook—Tistory of the Coconut Palm in America. 


De Candolle believed, but was already widely distributed along 
the Atlantic side of the American tropics. Early records show 
its presence in Cuba, Porto Rico, Brazil, and Colombia at dates 
so early as to preclude the idea of introduction by the Spaniards, 

The statement of Pickering, frequently quoted in works of 
reference, to the effect that coconuts were reported by Columbus 
on the coast of Central America during his fourth voyage, 
proves to be erroneous. On the other hand, there appears to 
be a definite reference to the coconut in Cuba in the journal 
of the first voyage of Columbus. 

De Candolle’s inference from Acosta’s report of coconuts in 
Porto Rico at the end of the sixteenth century, that they had 
recently been introduced by the Spaniards, proves to have no 
warrant in history and is directly opposed by the more extended 
reference to the coconut in Porto Rico by the Duke of Cum- 
berland’s chaplain, who visited the island only a few years after 
Acosta. 

De Candoile’s use of the testimony of Piso and Marcerave 
to support the idea of the introduction of the coconut into 
Brazil by Europeans is also unwarranted, since those writers 
only indicated that the plant was cultivated. An earlier and 
more explicit record, unknown to De Candolle, gives an 
account of the coconut as one of the native products of Brazil. 

The journal of Cieza de Leon, who accompanied the first 
Spanish expedition to the interior of Colombia, indicates the 
presence of the coconut palm in localities where it still con- 
tinues to exist, as shown by the accounts of Velasco, Humboldt, 
and more recent travelers, down to the present decade. 


Ethnological Conclusions. 


The American origin of the coconut palm and the strict 
limitation of its status in maritime tropics to that of a culti- 
vated plant are facts of ethnological significance. The wide 
distribution of the coconut in prehistoric times is evidence of 
the antiquity of agriculture in America and of very early 
communication across the Pacific. 

The American origin of the coconut palm, along with its 
inability to maintain itself on tropical seacoasts without human 
assistance, compels us to believe that its trans-Pacific distribu- 
tion was the work of primitive man. The dependency of the 
Pacific islanders upon the coconut may be taken to show that 
these islands could not have been occupied without the pre- 
vious domestication and dissemination of the coconut. 

In view of the fact that several other palms of unquestioned 
American origin have been domesticated by aborigines of the 
American tropics, no ethnological objection can be raised to 


O. F. Cook—History of the Coconut Palm in America. 225 


the idea that the coconut palm was originally domesticated in 
ancient America. 

The name “coco” does not appear to have been applied to 
the “Indian nut” till after the discovery of America and is to 
be considered as a word derived from the natives of the West 
Indies. Other native names for the coconut are found among 
primitive tribes of Costa Rica, as well as in Brazil. 

The presence of large numbers of coconuts on Cocos Island 
in the time of Wafer (1685) and their subsequent disappearance 
should be considered as evidence that the island was formerly 
inhabited, or at least regularly visited, by the maritime natives 
of the adjacent mainland. 

The fact that the coconut is largely restricted to islands and 
tropical countries of low elevation explains its importance 
among the preéminently maritime people of the Old World 
tropics and its relatively slight importance among the nonmari- 
time natives of the lowland tropics of America. 

The evidence of the prehistoric dissemination of the coconut 
and other American cultivated plants across the Pacific Ocean 
is such as to warrant a careful consideration of other indica- 
tions that agricultural civilization developed originally in 
America and was distributed to the shores of the Pacitie and 
Indian oceans by a primitive people with agricultural and 
maritime habits, like those of the Polynesians and Malays. 

The existence of a distinct tribe of frizzle-haired people near 
the Isthmus of Panama at the time of the discovery does not 
rest alone on Peter Martyr’s casual mention of the finding of 
negroes, but is supported by Oviedo’s contemporary history 
written directly from the testimony of Balboa and other mem- 
bers of his expedition, just after their return to Darien. The 
facts are not to be explained reasonably by assuming a chance 
arrival of African negroes, but indicate that prehistoric com- 
munication across the Pacific continued after the frizzle-haired 
Melanesian race had spread westward in the Pacitic. 

Such communication would account for the existence of the 
banana plant in America previous to the arrival of the Span- 
jards, as well as for the Old World distribution of the coconut 
palm and other cultivated plants of American origin. The 
banana plant is as evidently a native of the eastern continent 
as the coconut palm of the western. Evidence of these facts 
appears very definite and concrete from the biological stand- 
point, and is worthy of careful consideration by ethnologists. 


Agricultural Conclusions. 


The coconut is confined to seacoasts only in the humid low- 
lands of the Tropics; in dry regions it is not restricted to 
coasts, but thrives in many districts remote from the sea. The 


226 O. F. Cook—History of the Coconut Palm in America. 


fact that it received scientific study only as a maritime plant 
should not longer obscure the fact that it is also adapted to 
interior localities with saline soils. The cultural problems of 
the coconut palm should be investigated quite apart from the 
idea of maritime habits and distribution. 

The possibility of raising coconuts in frost-free localities out- 
side the Tropics is not to be tested along the seacoast, but in 
interior districts where larger amounts of sunlight and heat are 
available, as in the valleys of southern California and Arizona. 
The coconut, like many other plants, is not tolerant of shade 
nor of long-continued cool and cloudy weather. Other species 
of Cocos that are less exacting in their requirements of sun- 
light and heat have been found to do well along the California 
coast. 

The possibility of introducing coconut palms into southern 
California is not disproved by the absence of these palms from 
Egypt and Palestine. Though the climatic conditions are 
probably favorable, it does not appear that any adequate effort 
has been made to introduce the palms in those countries. 

The ability of the coconut to thrive on seacoasts shows that 
its requirements of heat are not as great as those of the date 
palm. Though probably less hardy than the date palm, it is 
not impossible that the coconut may be able to exist in frost- 
free localities that have not enough heat for the ripening of 
dates. 

The possibility of introducing the coconut palm into southern 
California and Arizona can not be fairly tested by the planting 
of the maritime varieties. The chances of success will be very 
much greater with the varieties that are adapted to the dry 
interior localities of the temperate plateaus of the Andes. 


Loomis—New Mink from the Shelt Heaps of Maine. 227 


Arr. XXTIL—A New Mink from the Shell Heaps of Maine ; 
by F. B. Loomis. 


Dorine the summer of 1909 the Amherst Biological Expe- 
dition collecting in the shell heaps along the Maine coast, 
opened the heap on the east side of Flagg Island in Casco Bay, 
near South Harpswell. This heap is distinct from any of the 
others in several features, but especially in having large num- 
bers of mink bones in it, the mink being, however, larger than 
any species now living in New England and markedly different 
from any that are known. It is as large as the largest species 
from Alaska.* In the course of the week spent in the Flage 
Island heap no less than 45 individuals were found in which 
there were 10 upper and 34 lower jaws of males, and 2 upper 
and 11 lower jaws of females. Beside these 3 lower jaws 
of the same species were found in the heap on Sawyers Island 
near Boothbay, 2 in the Seward Island heap in Frenchman’s 
bay, and one in the Winter Harbor heap. The other localities 
worked did not offer any of this mink; so that it would appear 
that Flagg Island was more or less overrun with these minks 
during the shell heap period, while they occurred also in small 
numbers along the coast to the east and north. 

The exact time when they lived is difficult to estimate, but 
the heaps contain nothing of European origin, so they were 
accumulated before 1627 and are probably as much older as it 
took to build them up, perhaps 200 to 400 years more. The 
mink is not confined to any one level on Flage Island but 
occurred all through the heap; so that it is to be thought of as 
having lived on the Maine coast for some hundreds of years. 

None of the skeletons were found associated, nor were any 
of the skulls perfect. In every case the mink had served as 
food for the aboriginal campers, so that the carcass had been 
pulled to pieces and the bones thrown away in various direc- 
tions. Every skull has the brain case broken and lost, the 
brain having apparently been used for food. The facial por- 
tion of each skull is, however, pretty much intact, indicating 
that the meat was simply picked off it. Many of the lower 
jaws are marked with tool scratches (see fig. 2) apparently 
made while removing the meat from the bones. 

This form is much larger than any of the living New 
England species, being all of 25 per cent larger than Lutreola 
(weson) lutreocephalus* Harlan, the large brown mink, and 

*N. American Fauna, Dept. Agriculture, No. 19, 1900, p. 42. 


+ Bangs, North American Minks, Boston Soc. Nat. Hist., Proceedings, 
vol. xxvii, 1897, p. 1-6. ‘ 


228 Loomis—New Mink from the Shell Heaps of Maine. 


equal in size to the Alaskan Z. vison ingens Osgood. This 
new form may be described as follows: 


Fie. 1. 


Fic. 1. A, the upper dental series of the type specimen, nat. size. B, the 
skull seen from above, nat. size. 


Lutreola vison antiquus sp. nov. 


The type is a male skull lacking the brain case together 
with an associated right lower jaw, numbered M 1401 in the 


Fie. 2. 


Fie. 2. 6 lower jaw, nat. size; a is scratch made by aboriginal tool in 
removing the flesh. ¢? lower jaw of female, showing relative size. 


Amherst Collections: and also a right lower jaw of a female 
numbered M 1402, both from Flage Island shell heap. 


Loomis — New Mink from the Shell Heaps of Maine. 229 


The form is large and heavily built, the skull with a low 
sagittal crest and short wide postorbital processes. The frontal 
region is slightly arched between the orbits. The teeth are 
those typical of the genus but rather stouter and heavier than 
usual. The inner tubercle of the upper carnassial is single and 
rather small. 

With this larger and typical form occur numerous individuals 
about 20 per cent smaller, but otherwise with the same char- 
acteristics, which I take to be the females, as there is in the 
family usually about this difference in size between the sexes. 

The following measurements give the data for comparisons: 


CG uppermental’ series). 22. 8222 2 es 99) 1 /2mm 
fe) T3 75 Oi A na he eR LE Warts ee SON Bs 95mm 
& lower dental series...-._-..--...-. -. 30™™ 
Q “ “cc CA Awe ao ene Oe mmM 
eG uuppen Catnassiple:t of paar tek es 8 1/47™ 
fe) “e ce ey gcie swe MUTE AS RIOR aS eR aey ee! 7 3/4m™ 
2 width between the orbits.._.____._-- _ 20mm 


For other measurements see figures, which are drawn to 
scale. 


‘Amherst, Mass. 


230 Scientific Intelligence. 


SCIENTIFIC INTELLIGENCE, 


I. Cnemisrry Ann Purysics. 


1. Mesothoriwn.—The existence of this radio-active element as 
one of the products of thorium was established in 1907 by Hahn, 
who showed that its half decomposition period was about 54 
years, and that it was separated from thorium in the commercial 
extraction of the latter from its ores. Later, Hahn was able to 
find this substance in the residues from the extraction just men- 
tioned, and he showed that it is not directly transformed into 
radiothorium, but that there is an intermediate product with a 
half-period of 6-9 hours, which he called mesothorium II. Hahn 
has recently been able to concentrate this last substance to such 
an extent that the radio-activity of the product is several times 
greater than that of pure radium salts. 

W. Marcxwatp bas now made some interesting observations 
in regard to these substances, for it appears that nothing has been 
published concerning the chemical properties of mesothorium I. 
He had occasion to examine a “radium preparation” which had 
been manufactured from the residues of uranium and thorium 
ores. This preparation, consisting chiefly of barium chloride, 
gave a y-ray radiation corresponding to more than 1 per cent of 
radium chloride, but the radium emanation obtained from it 
corresponded to only about 0°2 per cent of radium. A further 
study of the product showed that about 80 per cent of the y-radi- 
ation came from mesothorium II, for when an aqueous solution of 
the salt was treated with a trace of ferric chloride and made 
ammoniacal the mesothorium II was precipitated with the ferric 
hydroxide. The precipitate gave a strong y-radiation, while the 
barium chloride recovered from the filtrate by evaporation had 
lost almost the whole of this radiation. However, while the pre- 
cipitate lost its activity at the rate of one-half in about 6 hours, 
the salt regained the greater part of its activity within a day. 
The precipitate by ammonia must have contained also the 
radiothorium produced by the mesothorium, and in fact this was 
found to be the case, as the precipitate gave the a-rays of the 
thorium emanation after the disappearance of the mesothorium II. 
Mesothorium is evidently entirely analogous to radium in its 
chemical behavior, for Marckwald has been unable to find any 
means of separating the two. This is interesting in connection 
with the fact that no chemical method is known for separating 
the four elements, thorium, radiothorium, ionium and uranium X, 
and it appears that radium and mesothorium form a similar group, 
which possibly may contain other members also. It is evident 
that radium preparations are liable to be contaminated with meso- 
thorium, and since radium has a period of existence about 300 
times as long as the other, this contamination is of much import- 


Chemistry and Physies. 231 


ance. There is a possibility, not only of accidental contamina- 
tion, but of wilful adulteration. The best means for testing 
radium preparations for mesothorium is to remove the radium 
emanation either by heating or by solution and evaporation ; 
then the presence of y-rays after a few hours shows the presence 
of mesothorium. The proportion of y-rays before and after this 
treatment gives an indication of the amounts of the two radio- 
active substances present. — Berichte, xliii, 3420. H. L. W. 

2. The Combustion of Hydrocarbons.—In a recent lecture 
before the British Association, W. A. Bonz has given a review 
of the present knowledge of gaseous combustion, much of which 
is due to his own important researches. The opinion which 
formerly prevailed among chemists that in combustion the hydro- 
gen of hydrocarbons is first attacked by oxygen with the forma- 
tion of steam is incorrect. It has been known for a long time 
that when ethylene and acetylene are exploded with equal vol- 
umes of oxygen, carbon monoxide and hydrogen are practically | 
the only products, as follows : 


C,H, +0, = 2C0+2H, 
C,H, +0, =2CO+ H 


Bone has shown that the oxidation of the hydrocarbons at com- 
paratively low temperatures proceeds by addition of oxygen 
to the molecule and the successive formation of hydroxyl prod- 
ucts—alcohols, aldehydes, formic acid and finally carbonic acid. 
It appears that combustion at higher temperatures goes on in 
the same way, and it has been found that oxygen has a much 
greater affinity for the hydrocarbons than for hydrogen and car- 
bon monoxide. For example, when detonating gas is exploded 
with acetylene in the proportion O,H,+2H,+0O,, there is abso- 
lutely no separation of carbon nor formation of steam, and practi- 
cally the same thing holds good in the case of a mixture of 
ethylene, hydrogen and oxygen corresponding to C,H, +H,+0.,. 
In the presence of a hydrocarbon, carbon monoxide is attacked 
by oxygen even less readily than is hydrogen. These observations 
have an important bearing on the chemistry of flames. Hitherto 
hydrogen has been considered as one of the most combustible of 
gases, but in reality it is very much less so than the hydrocarbons. 
It is probably not so much th eoriginal hydrocarbon as its hydrox- 
ylated molecule which decomposes in ordinary flames, and experi- 
mental evidence does not warrant the view, so often encountered 
in scientific literature, that hydrocarbons are resolved into their 
elements prior to being burnt.— Chem. News, cii, 809. Hu. L. w. 

3. Supposed Chemical Distinction between Orthoclase and 
Microcline.—Two ov three years ago the view was advanced by 
Barbier that orthoclase differs from microcline in the fact that 
the former contains traces of lithium and rubidium, while these 
elements are not found in the latter. It appears, however, that 
Ramage had previously found these alkali metals in a microcline 
from Dalkley in Ireland, and that Vernadsky, somewhat later, 


2 


232 Scientific Intelligence. 


found both rubidium and cesium in the bluish-green microcline 
from Miask in the IImen mountains. In order to examine the 
matter more thoroughly, Virnapsky and Revoutsky have now 
examined a number of samples of microcline spectroscopically, 
and have found the following elements present: 


Miask, Iussian, K, Na, Rb, Li. 
Arendal, Norway, Ba, K, Na, Rb. 
Pike’s Peak, Colorado, K, Na, Rb, Li, Cs. 
Hunttila, Finland, K, Na, Ba, Rb, Li. 
Lojo, Finland, K, Na, Ca, Li (Rb?). 


These results were obtained by heating fragments of the mineral 
directly before the gas-oxygen blowpipe and observing~ the 
spectrum of the flame. The results show that Barbier’s view is 
evidently incorrect.— Comptes Rendus, cli, 1372. H. L. W. 

4, Preparation of Argon.—G. CLauDE has found a convenient 
way to prepare large quantities of argon. As a starting point he 
uses the oxygen produced by the liquefaction of air, which 
may be obtained 95 per cent pure, and with argon as its prin- 
cipal impurity, amounting to about 3 per cent. This oxygen is, 
therefore, about three times richer in argon than ordinary air. 
The oxygen is absorbed by hot copper, and the nitrogen by hot 
magnesium, only a small amount of the latter being required. 
_A tube of hot copper oxide serves finally to oxidize any hydro- 
gen that may have been formed from moisture present in the 
materials employed.— Comptes Rendus, cli, 752. H. L. W. 

5. Die Stellung der neueren Physik zur mechanischen Natur- 
anschauung ; von Dr. Max Piano. Pp. 33. Leipzig, 1910 (8. 
Hirzel).—This pamphlet contains a lecture given before the 
eighty-second meeting of the German Scientists and Physicians, 
held in Koénigsberg, last September. It deals with the Theory of 
Relativity and with the philosophical views to which it leads in 
the minds of many German mathematicians and physicists. To 
the Anglo-Saxon mind, these views appear to touch the limits 
of philosophical idealism. Ether and matter, in fact all substance, 
is apparently discarded, and the physical universe consists of a 
vacuum mitigated by the presence of the Principle of Least 
Action, and Maxwell’s Equations; the “building stones,” of 
which the physical world is constructed, are no longer material 
particles but the so-called universal constants: the velocity of 
light, the charge and mass of the electron, the “elementare Wir- 
kungsquantum, ” etc. H. A. B. 

6. History of the Cavendish Laboratory, 1871-1910. Pp. 
x, 842. London, 1910 (Longmans, Green & Co.).—This volume 
has been prepared in commemoration of the twenty-fifth anniver- 
sary of Sir J. J. Thomson’s election to the Cavendish Professor- 
ship of Physics in the University of Cambridge. It is the work 
of several different authors, each period of the history of the 
laboratory being treated by one who was intimately connected 
with it during the time in question. Messrs. Fitzpatrick and 


Chemistry and Physics. 233 


Whetham deal with the building of the laboratory ; Professor 
Schuster, with the Clerk Maxwell period ; Mr. Glazebrook, with 
the years during which Lord Rayleigh was professor ; and Sir 
J. J. Thomson, himself, gives a general survey of the past twenty- 
five years. In chapters V to VIII the activities of the labora- 
tory during these twenty-five years, are discussed in greater 
detail. Professor Newall gives an account of the researches 
conducted between 1885 and 1894 : Professor Rutherford recounts 
the memorable achievements which marked the years 1895-1898 : 
C. T. R. Wilson deals with the period from 1899 to 1902, and 
N. R. Campbell completes the record to 1909. Chapter IX by 
Professor Wilberforce of the University of Liverpool deals with 
the development of the teaching of physics in Cambridge, a 
development which has had great influence upon physics teach- 
ing throughout the world. The volume closes with a list of 
memoirs containing accounts of research performed in the Caven- 
dish Laboratory, and a list of those who have worked there. 

The volume cannot fail to be of great interest to all students 
of physies ; it is a valuable contribution to the recent history of 
the science, and a more appropriate way of celebrating Sir J. J. 
Thomson’s twenty-fifth anniversary could scarcely have been 
found. H. A. B. 

7. The Principles and Methods of Geometrical Optics, espe- 
cially as applied to the theory of Optical Instruments . by 
Jamus P. C. Sourmany. Pp. xxiii, 626, with 169 figures. New 
York, 1910 (The Macmillan Company).—This is a notable book 
which surpasses all others in the English language treating of the 
same subjects. The very great number of propositions in geo- 
metrical optics are presented clearly, in a carefully studied 
notation, which is, except in a few cases where other consider- 
ations are of greater weight, consistent and lucid. The diagrams 
are sufficient in number and very clear, with the too rare quality 
of good taste in respect to all the details which determine the 
character of such illustrations. Most excellent features of the 
book are its bibliography and historical notes, which are very 
complete. The only striking omission observed is that of the 
admirably convenient—perhaps the most convenient of all—col- 
lection of formulas for rigid computation of the constants of a 
system of centered lenses by P. A. Hansen. These features 
make the volume invaluable to one who seeks a knowledge of 
what has been accomplished in this field during the three cen- 
turies in which the problems of geometrical optics have been 
continuously increasing in importance. 

When we come, however, to consider the utility of the methods 
and equations deduced in the text to the designer of optical 
apparatus, we must give more restricted praise, since they empha- 
size what is relatively unimportant in practice and thrust more or 
less into the background those features which are essential. 
Excellent examples in support of this assertion are afforded by 
the only numerical calculations in the book, namely, the calcula- 


234 Scientific Intelligence. 


tions of some of the optical constants of a 12-inch Taylor tele- 
scope objective. The geometrical data are given to three-figure 
accuracy and are susceptible, perhaps, to a maximum of ten times 
this precision. The calculations of focal lengths are carried out 
to seven-figure accuracy, that is to some 1000 times the precision 
warranted by the data; it is three or four hundred thousand 
times as great precision as is deemed important by the designer 
himself, if we infer that he expected to make the ratio of focal 
length to aperture the standard for telescopes of this size. Never- 
theless, this incommensurate labor of calculations is necessary in 
order to deduce a sufficient value, to two figures only, of the 
spherical aberration. 

The other case is equally striking. The spherical aberration of 
the same objective is calculated to a two-figure precision, which 
is all that is of practical significance, by a tedious computation 
with seven-figure logarithms by application of Seidel’s analysis 
and with the disappointing error of one hundred per cent. These 
considerations are enough to show that there is some radical 
defect in a method which demands such efforts for such meager 
returns. Probably there is no hope of material improvement 
until the mathematician informs himself thoroughly as to the 
relative importance of the magnitudes which enter his analysis 
and then deals with the physical realities of wave surfaces and 
refracting surfaces instead of the unnecessary fictions of rays 
and of radii of lens surfaces. Cc. 8. H. 

8. Chemische Krystallographie; von P.Grotu. Dritter Teil. 
Aliphatische und Hydroaromatische Kohlenstoff-verbindungen. 
Pp. iv, 804, mit 648. Text figuren. Leipzig, 1910 (Wilhelm 
Engelmann).—This monumental work on Chemical Crystallog- 
raphy begun in 1906 has now reached its third part, or as esti- 
mated, three-quarters of the whole. It is devoted to the aliphatic 
and hydroaromatic hydrocarbons. ‘The whole makes a work of 
800 pages, with perhaps 1200 or more individual compounds, 
whose crystallographic and optical constants are given with great 
thoroughness. In a large number of cases the crystal form is 
illustrated by figures. The congratulations of those immediately 
interested are due to the veteran author for his success in carry- 
ing through a work of such magnitude and importance. 


II. Gerortoay anp Naturat History. 


1. United States Geological Survey, Thirty-first Annual Re- 
port (1909-1910) of the Director, GrorcEe O. Suite. Pp. 131 
with two plates. Washington, 1911.—This report contains a 
statement of the work done by the various divisions of the 
Survey during the fiscal year ending June 30, 1910. The pro- 
gress in land classification consisted in, first, the preparation of 
withdrawals covering power sites and coal, oil, gas, and phos- 
phate lands ; second, the classification of withdrawn lands and 


Geology and Natural History. 235 


restoration of such as were found to be not underlaid by valuable 
deposits. The work involves also the performance of various 
executive and advisory functions connected with the classification 
and valuation of the public lands. 

The mining and technologic work of the Survey, which in the 
last few years has assumed large importance, was transferred on 
July 1, 1910, to the newly established Bureau of Mines (see v. xxx, 
pp. 292, 419). Thus another child of the Geological Survey, 
having grown to adult proportions and demonstrated its useful- 
ness, has been launched on an independent career. No small part 
of the great value which the Survey has been to the nation con- 
sists in the foresight, efficiency, and high scientific grade with 
which new branches of government work have been developed 
under the care of that organization. The increase in the corre- 
spondence of the Geological Survey and in the distribution of its 
publications is a measure of the increasing appreciation by the 
people of the work which is done. The correspondence increased 
more than 20 per cent over that of the previous year and the 
total number of reports and maps distributed has increased more 
than 13 per cent. The publications of the Survey during the 
year measure a part of its returns for the money expended. 
They consisted of 4 professional papers, 47 bulletins, 18 water 
supply papers, one volume on mineral resources, 6 geologic folios 
and 94 topographic maps. J. B. 

2. Publications of the U. 8S. Geological Survey.—Recent 
publications of the U. 8. Geological Survey are noted in the fol- 
lowing list (continued from vol. xxx, p. 417). The thirty-first 
Annual Report of the Director is noticed above. 

Torocraruic ATLAS.—Seventy-three sheets. 

Fouro, No. 174. Johnstown Folio, Pennsylvania; by W. C. 
PuatEen. Pp. 15, with 1 columnar section, and 3 maps. 

Sacramento Folio, California; by W. LinpGren. Pp. 3, 4 
maps. 

ProFreEssionAL Parser, No. 72. Denudation and Erosion in 
the Southern Appalachian Basin ; by Leontpas C. Gurenn. Pp. 
137, 21 plates, 1 figure. 

Buxtietins.—No. 430. Contributions to Economic Geology 
(Short Papers and Preliminary Reports, in part earlier issued as 
separates.) 1909. Part I. Metals and Nonmetals except Fuels. 
C. W. Hayrs and Watpremar LinpereEn, geologists in charge. 
Pp. 653, 14 plates, 75 figures. 

No. 431—A. Advance Chapter from Contributions to Eco- 
nomic Geology, 1909. Petroleum and Natural Gas; by A. G. 
Lronarp, H. E. Grecory, C. W. Wasnpurne, and RosBertr 
ANDERSON. Pp. 83, 3 plates, 1 figure. 

No. 433. Geology and Mineral Resources of the Solomon and 
Casadepaga Quadrangles, Seward Peninsula, Alaska ; by Puivie 
S. Smiru. Pp. 234, 16 plates, 26 figures. 

No. 436. The Fauna of the Phosphate Beds of the Park City 
Formation in Idaho, Wyoming, and Utah; by Groner H. Girry. 
Pp. 82, 7 plates. 


236 Scientific Intelligence. 


No. 440. Results of Triangulation and Primary Traverse for 
the years 1906, 1907, and 1908. R. B. Marsuarn, chief geog- 
rapher. Pp. 688, 1 plate. 

No. 441. Results of Spirit Leveling in Alabama, Georgia, 
North Carolina, South Carolina, and Tennessee, 1896 to 1909, 
inclusive. R. B. Marsuatt, chief geographer. Work done in 
cooperation with the State of Alabama during 1899 to 1905, 
inclusive ; with the State of North Carolina during 1896 and 
from 1902 to 1909, inclusive. Pp. 145. 

No. 442. Mineral Resources of Alaska. Report on Progress 
of Investigations in 1909; by Atrrep H. Brooke and others. 
Pp. 426, 7 plates, 8 figures. 

No. 470-A. Advance Chapter from Contributions to Eco- 
nomic Geology, 1910. Phosphates in Montana; by Hoyt S. 
GatE. Pp. 9, 2 figures. 

Warer Suppty Parers.—No. 254. The Underground Waters 
of North-Central Indiana ; by SrepHen R. Capps, with a chap- 
ter on The Chemical Character of the Water, by R. B. Doux. 
Pp. 279, 7 plates, 12 figures. 

Nos. 262, 264.—Surface Water Supply of the United States, 1909 
[prepared under the direction of M. O. Lerentron]. No. 262. 
Part II, South Atlantic and Eastern Gulf of Mexico; by M. R. 
Hatt and R. H. Botster. Pp. 150, 5 plates. No. 264. Part 
IV, St. Lawrence River Basin ; by C. C. Covert, A. H. Horton 
and R. H. BotstErr. Pp. 130, 5 plates. 

3. Bureau of Mines, Joseru A. Hormes, Director.—Four 
additional bulletins have been recently issued ; these are as fol- 
lows: Bulletin 2, North Dakota Lignite as a Fuel for power- 
plant Boilers ; by D. T. Ranpati and Henry Kreisincrer. Pp. 
42, 1 plate, 7 figures. Bulletin 3, The Coke Industry of the 
United States as related tothe Foundry; by Richarp MoLtpENKE, 
Pp. 32. Bulletin 4, Features of Producer-Gas Power—Plant 
Development in Europe; by R. H. Fernarp. Pp. 27, 4 plates, 
7 figures. Bulletin 5, Washing and Coking Tests of Coal, at the 
Fuel-Testing Plant, Denver, Colorado, July 1, 1908, to June 30, 
1909 ; by A. W. Berpen, G. R. Detamarsr, J. W. Grovus, and 
K. M. Way. Pp. 62, 1 figure. 

Miners’ Circulars Nos. 1 and 2 have also just been issued ; they 
are the first of a series to be written in plain, non-technical language 
for the benefit of the miner. They contain the names of the per- 
missible explosives tested by the bureau at its Pittsburg station 
up to November 15, 1910, and gives precautions as to their use. 

4. Florida State Geological Survey. Third Annual Report, 
1909-1910, EK. H. Srtiarps, State Geologist. Pp. 397 with 
numerous plates and figures. Tallahassee, Fla., 1910.—This 
report, like the preceding of the series, is of high scientific 
as well as practical value. ‘The scientific interest lies in the 
unique character of the geologic province of Florida as com- 
pared with other portions of the United States and the way in 
which the subjects have been treated. The value to the citizens 


Geology and Natural History. 237 


of Florida lies in the information which it contains on the mineral 
and water resources of the State. The volume contains, besides 
the administrative report and index, the following papers: A 
Preliminary Paper on the Florida Phosphate Deposits, by E. H. 
Sellards ; Some Florida Lakes and Lake Basins, by E. H. Sel- 
lards ; The Artesian Water Supply of Eastern Florida, by E. H. 
Sellards and Herman Gunter; A Preliminary Report on the 
Florida Peat Deposits, by Roland M. Harper. J.B: 

5. The Badland Formations of the Black Hills Region ; by 
Crropnas C. O?Harra. 144 pp., 50 pls., 20 figs. South Dakota 
School of Mines, Bulletin No. 9, Department of Geology. Rapid 
City, South Dakota, November, 1910.—The “ badlands” of South 
Dakota form one of the most interesting physiographic sub- 
provinces in the world, and taken in connection with the Black 
Hills, forms a type area which in many respects is unique. While 
the structure and stratigraphy are not complicated, yet the details 
are so important as to fully justify the prominent place given to 
this area in the literature. Heretofore students have had to 
search through widely scattered technical reports in order to 
obtain information regarding the origin and topographic develop- 
ment of the badlands, as well as of the large and interesting col- 
lection of fossils. Thanks to Professor O’Harra, we now have a 
single volume accessible to students and amateurs wishing to 
become acquainted with this country,—a volume which does not 
require advanced scientific training to understand. From an 
educational standpoint the publication is, therefore, abundantly 
justified in spite of the absence of essential facts and interpreta- 
tions new to science. 

6. West Virginia Geological Survey, I. C. Wuirr, State 
Geologist. Bulletin 2. Pp. 358. Morgantown, 1911.—Follow- 
ing Bulletin No. 1, which gives a bibliography of the state, the 
West Virginia Survey has now issued a volume containing tables 
of levels and distances, and also coal and coke analyses. The 
levels are compiled from records of the State and Federal Sur- 
veys, and have been supplemented by data collected by the vari- 
ous West Virginia railways. The analytical tables contain 
results of tests of coal made from all the economic horizons of 
importance,—namely, the Pottsville, Kanawha, Allegheny, Cone- 
maugh, Monongahela, and Dunkard series. The estimated coal 
production for 1910 is 65,000,000 short tons. H. E. G. 

7. New Zealand Geological Survey, J. M. Bell, Director. 
Bulletin No. 9 (New Series), The Geology of the Whatatutu 
Subdivision, Raukumara Division, Poverty Bay ; by Jamus 
Henry Apams. 1910. Pp. ili and 46, 3 ills., 5 maps.—In age 
the rocks included within this subdivision are upper Miocene and 
consist of shales, argillites, sandstones, with coarse sandstones 
and conglomerates in the upper portion. Pumiceous deposits, 
possibly of Pliocene age, also occur. An interesting problem is 
presented by the fact that many of the igneous pebbles in the 
conglomerate are unlike any rocks thus far discovered in the 


Am. Jour. Sci.—FourtTH SERIES, VoL. XX XI, No. 183.—Marcu, 1911. 
17 


238 Scientific Intelligence. 


north island of New Zealand. The fossils collected in this area 
have been studied by Professor Marshall of Otago University. 
He finds that out of a total of forty-four species of mollusca 
recent species number twelve, and the conclusion is reached that 
the strata are. Upper Miocene in age rather than partly Cretace- 
ous, aS previously assumed. In the Whatatutu area the terraces 
developed along the streams at 200 and 400 feet give a clue as to 
the amount of elevation since the end of Miocene time. A much 
dissected coastal plain at an elevation of 3000 feet is indicated by 
the structure and attitude of Tutamoe ridge. Owing to the 
economic importance of this field the structure has been studied 
in detail. It is found that the rocks have been folded into broad 
anticlines and that accompanying the folds are faults of slight dis- 
location. The existence of fourteen oil seeps attracted attention 
to the Waitangi hill as early as 1874, but later developments have 
not led to discoveries of oil or gas in quantities sufficiently large 
to be of commercial importance. 

Bulletin No, 10 (New Series), The Geology of the Thames 
Subdivisions, Hauraki, Auckland ; by Coun FRAsER. 1910. 
Pp. ii and 129, 9 ills., 19 maps and sections.—The Thames section 
in the northern island of New Zealand was brought into promi- 
nence by the discovery of gold in 1865. By 1871 the production 
had reached about $5,940,000, and this largely from one bonanza. 
The production at the present time is below the $500,000 mark, 
and the main hope is in exploiting lower levels. The oldest 
rocks of the area, the Tokatea Hill series, consist of argillites and 
graywackes of pre-Jurassic age. The Manaia Hill series (Jurassic) 
overlies uncomformably the older terranes. A long interval, dur- 
ing which folding and faulting occurred and a submarine topog- 
raphy was developed, elapsed between the Jurassic and the Eocene. 
Three periods of volcanic eruptions are revealed by an examina- 
tion of the Tertiary strata. The upper Eocene and Miocene 
volcanics consist of andesitic and dacitic tuffs, breccias, con- 
glomerates and lavas, while the Pliocene eruptions were rhyolitic 
in nature. Large and small folds have been observed in the dis- 
trict, and have been found to be of direct economic importance. 
The great Moanataiari fault with a down-thrust of 595 feet is 
represented topographically by a partially dissected fault scarp. 
Pages 50-115 of this report are devoted to detailed descriptions 
of existing mines and mining areas. ; H. E. G. 

8. Geological Survey of Western Australia, Bulletin No. 
33, Geological Investigations in parts of the Gascoyne, Ashbur- 
ton and West Pilbara Goldfields ; by A. Gipp Marrianp. 1909. 
Pp. 77, 13 maps and 65 figures.—The area covered by this report 
is the extreme western portion of Australia including the coast 
line from Port Hedland to the mouth of the Wooramel River. 
The geological sketch-map shows the Gascoyne beds (Carbonifer- 
ous) well developed in the lower Gascoyne River ; the Bangemall 
beds (Nullagine ?) from Frederick River to Mount Flora; and 
the Ashburton beds (age undetermined), chiefly in the neighbor- 
hood of Ashburton and Hardey Rivers. There are also small 


Geology and Natural History. 239 


areas of pre-Carboniferous granite and gneiss. The relations and 
character of the formations near the coast line are revealed by a 
3011 foot well at Carnarvon, which shows 1211 feet of Mesozoic, 
1650 feet of Carboniferons. ‘The Carboniferous section in the 
Arthur River valley consists of (1) grits and fine conglomerate, 
(2) fossiliferous limestone, (3) limestone conglomerate, (4) gla- 
cial bowlder bed, (5) sandy and flaggy limestones. This glacial 
bowlder bed is well exposed at a number of localities and in the 
Wyndham River valley contains Spirifera, Productus, Polyzoa, 
and Aviculopecten. The Carboniferous series as a whole rests 
upon metamorphosed sedimentary rocks of unknown age. Owing 
to the economic importance of this part of West Australia some- 
what detailed studies of structural relations were made. In the 
vicinity of Bangemall slates, limestones, quartzites and diabase 
are arranged in a denuded anticlinal fold and are intersected by 
numerous quartz reefs. Mount Augustus, one of the most con- 
spicuous scenic features of West Australia, was found to be a 
sharp monoclinal fold of schist and conglomerate. Both normal 
and thrust faulting are revealed at Coorabooka Gap, and the 
position of this gap as well as the arrangement of the drainage 
lines suggests interesting physiographic studies. In the Uaroo 
copper district of Ashburton the rocks are sedimentaries of 
unknown age and have undergone deformation since mineraliza- 
tion. 

A chapter on petrography by J. Allan Thomas contains a dis- 
cussion of dolomite and cherts, pyroxenites and amphibolites, 
together with conclusions regarding magmatic sequence. Sixty- 
nine slides are described in detail accompanied by a list of eighteen 
analyses. While this bulletin is chiefly devoted to economic 
studies, it adds considerable to the meager information regarding 
the ceology of this interesting country. 

Bulletin 38, The Irwin River Coalfield ; by W. D. Came- 
BELL, 1910. Pp. 101, 7 plates and 53 figures.—The pre-Car- 
boniferous rocks of the Irwin River district are gneisses and 
granites “traversed by dikes of diabase, basalt, and norite, and 
lodes of lead and copper in addition to quartz veins.” This 
crystalline complex was greatly eroded before the deposition of 
extensive beds of quartz conglomerates and submarine tuffs of 
pre-Carboniferous age. The Carboniferous rocks are fossiliferous 
and consist of clays, shales, sandstones and limestones. One 
important stratum is the glacial bewlder bed which has been 
recognized at several localities in Western Australia. In the area 
under discussion this bowlder bed is found within the Carbonifer- 
ous and not at its base. Jurassic strata, 300 feet in thickness and 
containing lignite, rest upon the denuded surface of the Car- 
boniferous. ‘Tertiary limestones and sandstones seems to overlie 
unconformably the Jurassic rocks of the Hutt River district. 

H. E. G. 

9. Paleontological Contributions to the Geology of Western 
Australia. Geol. Surv. Western Australia, Bull. 36, Pt. III, 
pp. 133 and 12 pls. 1910.—A series of eight papers is here 


240 Scientific Intelligence. 


included, as follows :—(1) Hinde on isolated sponge spicules 
that are “newer than the Cretaceous”; (2) Arber on some Juras- 
sic plants; (3) Etheridge on 19 Oolitic invertebrates ; (4) Glau- 
bert on a fossil cave marsupial, Sthenwrus occidentalis, (5) on a 
list of West Australian pre-Tertiary fossils known to the end 
of 1908, (6) on Paleozoic fossil plants, (7) on peel fossils, 
and (8), on Cretaceous chalk and fossils. c. 8. 

10. Report of the Vermont State Geologist for 1909-1910 ; 
by Grorer H. Perkins. Pp. xii, 361, pls. 71. 1910 [Jan. 1911]. 
—The volume opens with an account of the History and Condi- 
tions of the State Cabinet, by the State Geologist. The granites 
of the state are described by T. Nelson Dale, in an ar ticle which 
is practically a reprint of a bulletin of the U. 8. Geological Sur- 
vey. C. H. Hitchcock has a chapter on the Surfacial Geology of 
the Champlain Basin and Percy E. Raymond brings together all 
that is known about the trilobites of the Chazy formation in 
Vermont. The latter comprise 36 species, all of which are illus- 
trated. Professor Perkins describes the geology of the Burling- 
ton Quadrangle and Professor Seely has a preliminary report on 
the Geology of Addison County. Asbestos in Vermont is treated 
by C. H. Richardson and the mineral resources by the State 
Geologist. oS} 

11. A Contribution to the Geologic History of the Floridian 
Plateau ; by Tuomas Waytanp Vaucuan. Carnegie Institution 
of Washington, Publication 133, pp. 99-185, 15 pls., 6 text figs. 
:910.—This well written and very interesting work should be 
studied by all stratigraphers and geologists because here we have 
worked out with care the present conditions of deposition and 
geologic work now going on in the Floridian region as a basis 
toward a proper interpretation of the Tertiary history of the 
peninsula. The author first describes the topography of the 
Floridian Plateau and then goes into considerable detail in regard 
to the marine bottom deposits forming in the bays and sounds 
behind the keys. Limestones are here being made by precipita- 
tion from the sea water as amorphous calcium carbonate and are 
apparently not of detrital origin. It is a soft ooze into which a 
rod can be forced down ten feet or more ; in fact, the depth of 
this soft material has not been determined. 

Vaughan then discusses the transporting agents (currents and 
winds) of the Florida coast and their effects. The smaller half 
of the work treats of the geologic history of the Floridian Pla- 
teau. The history is worked out in some detail and the book is 
abundantly illustrated by maps, one of which presents the geolo- 
gic formations of the state. There are also many photogravures 
of vegetation, sea shores, and geological deposits. ©. Ss. 

12. Recent Discoveries Bearing on the Antiquity of Man in 
Europe ; by Gnorck Grant MacCurpy. Smithsonian Report 
for 1909, pages 531-583, pls. 1-18. 1910.—The author brings 
together here the accounts of the many wonderful discoveries 
that have been made in the past ten years bearing upon the 


Geology and Natural History. 241 


antiquity of man in Europe. It seems that the oldest undisputed 
flint implements of man go back to the Upper Miocene and the 
oldest bone, a jaw (Homo heidelbergensis), has been found near 
the base of the Quaternary. Man, as man, has lived, therefore, in 
western Europe at least throughout the entire Glacial period, 
developing into Homo primigenius, a stocky robust type, of low 
stature, and with relatively short arms and legs much as in the 
Eskimo. In the Upper Quaternary, or at least 30,000 years ago, 
there came into western Europe, probably from the East, a more 
intellectual race of men, the Aurignacians, and it is these people 
who sculptured, engraved, and frescoed the walls of the caverns 
and their tools and ornaments. Their descendants, the Magda- 
lenians, introduced the rudiments of writing, and this seemingly 
was more than 10,000 years ago, if we may judge by the time 
standards accepted by geologists for the duration of time since 
the last glacial climate. The negroid people also passed into 
western Europe, possibly by way of Gibraltar, probably soon 
after the arrival of the Aurignacians. It is also becoming more 
and more certain that man did not originate out of any of the 
existing ape stocks, but rather that the human stock is as old as 
any of the tailless primates. According to Professor Klaatsch, 
Homo primigenius is more closely related to the gorilla of 
Africa, while Homo aurignacensis bas closer affinities with the 
chimpanzee of Asia. All of these stocks had their origin in the 
far distant past, certainly not less than one million years ago. 
C.us! 

13. On the Fossil Faunas of St. Helen’s Breccias ; by HENRY 
S. Wittrams. Trans. Royal Soc. Canada, III, pp. 205-246, pls. 
1-4, 1910.—The Devonian faunas of St. Helen’s island near Mon- 
treal have long perplexed students of fossils as to the exact age 
of these fossil horizons when compared with similar formations 
in New York. Professor Adams of McGill University had quar- 
ried out from three isolated limestone masses underlying the 
agglomerates of the island about three-fourths of a ton of mate- 
rial which Williams has here subjected to a detailed study. The 
author, therefore, has had far greater advantages than any other 
paleontologist studying these early Devonian biotas. 

The older fauna of about 30 species is of Helderbergian age 
and apparently of about Becraft time. Williams names it the 
Gypidula pseudogaleata fauna. The age is clearly seen in the 
following species: Schizophoria multistriata, Stropheodonta 
planulata, Gypidula pseudogaleata, Camaroteechia ventricosa, 
Spirifer concinnus, and Meristella princeps. The faunal rela- 
tions are clearly with New York and nothing exactly like it is 
known farther northeast in the Gaspé region. 

The younger fauna is from another isolated limestone mass, 
and is the one furnishing much new information. Williams calls 
it the Spirifer arenosus fauna and ascribes to it 25 species. The 
more striking forms are: 1 Dalmanella subcarinata, 2 Hodevo- 
naria hudsonicus gaspensis, 3 Chonetes striatissimus (near C. can- 


242 Scientific Intelligence. 


adensis), 4 Rhynchonellu eminens, 5 Eatonia peculiaris, 6 &. cf. 
whitfieldi, 7 Spirifer arenosus, 8 S. gaspensis, 9 S. montrealensis 
n. sp. (look almost like genuine S. granulosus), 10 S. cumber- 
landice, 1\ 8S. pennatus helene, 12 Metaplasia pyxidata, and 13 
Cyrtina rostrata. To these must be added 14 Chonostrophia 
montrealensis described by Schuchert but not seen by Williams. 
In the light of our American Devonian assemblages we see here 
a very much mixed fauna. Numbers 1 and 4 are Helderbergian 
forms, while 9 and 11 are decided early Hamilton reminders. 
The remainder of the fauna suggests later Oriskanian. In the 
Oriskany of Cumberland, Md., the reviewer has also collected 
shells of the type of 8S. montrealensis, but these are by no means 
so near the Hamilton S. granulosus as seemingly are the~St. 
Helen’s specimens. Further, the reviewer, while collecting on 
the island in 1900, noted that the two species 9 and 11 occurred 
together, but he then saw no other forms in the “flat block of 
limestone” in the agglomerate. For this reason he held their 
age to be Onondaga. It was Mr. Ardley who directed him to 
these fossils and associations and Williams’ S. arenosus fauna of 
25 species has since been quarried out of this same block. The 
majority of the fauna is undoubtedly Oriskanian and yet the 
aspect is more recent than any fauna of this series in the Appa- 
lachian—New York area. 

Williams clearly recognizes that the St. Helen’s Spirifer are- 
nosus fauna is unique and believes it to be somewhat younger 
than any Oriskanian fauna of New York but older than the 
Onondaga. Faunas of the same age as that of St. Helen’s but of 
another basin, linking more directly with the European Coblen- 
zian, he holds are those of Nictaux, Nova Scotia, York river, 
Gaspé, and Moose river, Maine, in which “ are seen traces of the 

Hamiltonian magnafauna.” He further holds that the 
Onondaga fauna came in along the western side of the Cincin- 
nati axis, finally spreading to the St. Lawrence valley and there 
met and mixed with the northern Atlantic fauna “ on the Ameri- 
can border at the time of the departure of the Oriskanian ele- 
ment rather than at the opening of the Hamilton epoch. This 
interpretation is in harmony with the mingling of these same two 
magnafaunas [lower Devonian and Hamilton] in the lower 
Devonian (Coblenzian) of Europe.” 

The reviewer agrees with Williams that the Oriskanian faunas 
of the maritime “province of eastern Canada are considerably 
Coblenzian in faunal aspect and that the Hamilton aspect appears 
earlier in this European assemblage, but he still believes that the 
York river fauna near the base of the Gaspé sandstone as 
described by Clarke (1908) is considerably younger than the 
Spirifer arenosus fauna, for the reason that the latter assemblage 
at Gaspé occurs at a very much lower horizon, in fact, at the 
base of the Grande Gréve limestone. C. SCHUCHERT. 

14. Paleontologia Universalis, ser. JI, fasc. II, 46 sheets, 
July 26, 1910.—In this new part of the Palzontologia Univer- 


Geology and Natural History. 243 


salis there are redescribed and well figured 20 Lamarckian species 
of mollusks and corals described by him between 1801-1819. 
The studies were made by Dollfus, Boussac, Pervinquiére, 
Cossmann, Lemoine, and Germain. CS: 
15. Hine Botanische Tropenreise, Indo-Malayische Vegetations- 
bilder und Reiseskizzen ; by Prof. Dr.G. Hasmrianpr. Second 
edition. Pp. viii, 296; 12 plates and 48 text-figures. Leipzig, 1910 
(Wilhelm Engelmann).—The first edition of Professor Haber- 
landt’s book appeared in 1893 and soon became widely and favora- 
bly known on account of its graphic and satisfactory descriptions 
of various types of tropical vegetation. The work is based on the 
autbor’s personal observations, most of which were made during 
a visit to the famous botanical garden at Buitenzorg in Java. 
Among the many interesting chapters those dealing with tropical 
trees, tropical leaves, vines, epiphytes, and mangroves should per- 
haps be especially mentioned, although several of the others treat 
subjects of equal importance. The twelve plates in the second 
edition are all new; nine are made from photographs, while the 
three others, in color, are reproduced from water-color sketches 
by the author. A. W. E. 
16. Plant Anatomy, from the Standpoint of the Development 
of the Tissues, and Handbook of Micro-technic; by Wittiam 
Cuase Srevens, Professor of Botany in the University of 
Kansas. Second edition. Pp. xv, 379, with 152 text-figures. 
Philadelphia, 1910 (P. Blakiston’s Son & Co.).—The first edition 
of this excellent work appeared in 1907, and was reviewed in 
this Journal for April, 1908 (xxv, 363). The most important 
new matter in the second edition is the, chapter on reproduction, 
which includes discussions of the following topics : the reduction 
of chromosomes, the behavior of hybrids interpreted according to 
Mendel’s Laws, the bearers of hereditary characters, and the 
theory of pangeneic exchange. A. W. E. 
17. A Text-Book of Botany and Pharmacognosy ; by Henry 
KrarmMeEr, Ph.D., Professor of Botany and Pharmacognosy in the 
Philadelphia College of Pharmacy. Fourth edition. Pp. viii, 
888, with 344 figures, mostly in the text. Philadelphia and Lon- 
don, 1910 (J. B. Lippincott Company, price $5.00 net).—The first 
edition of the present text-book appeared in 1902 and contained 
384 pages ; the second edition, of 1907, had already been enlarged 
to 840 pages; while the third edition, of 1908, numbered 850 
pages. The rapid succession of new editions proves conclusively 
that there is a strong demand for a work of this character by 
students of pharmacognosy and that the book in question is well 
fitted to their needs. In the first part, entitled ‘‘ Botany,” the 
morphology and classification of plants are clearly treated, with 
special reference to medicinal plants. In the second part, “ Phar- 
macognosy,” detailed descriptions of important drugs are given, 
their minute structure being fully illustrated by figures. The 
third and fourth parts are much shorter than the others. The 
third deals with “Reagents and Microtechnic,” and the fourth, 


244 Scientific Intelligence. 


which is new to this edition, discusses “ Micro-Analysis.” The 
eighteen figures illustrating the fourth part are reproduced from 
microphotographs of erystals, A.W. EB. 

18. Biology: general and medical; by Joseru McFaruann, 
M.D. Pp. 440, with 160 illustrations, Philadelphia and Lon- 
don, 1910 (W. B. Saunders Company).—This book differs widely 
from most of the other elementary text-books in biology, which 
have recently appeared, in subordinating the morphological 
almost entirely to the physiological aspects of the subject. It is 
essentially a treatise on general physiology, with such descrip- 
tions of the anatomical structures as are absolutely necessary for 
the understanding of the processes concerned. For elementary 
courses in colleges and universities where large numbers of-stu- 
dents elect biology as a general culture study, and where the 
laboratory work is necessarily confined mainly to the morpholog- 
ical side of the subject, the book forms an admirable supplement 
to the laboratory and lecture portions of the course. 

The immediate adoption of this book by some of our largest 
universities shows the need that has been felt for a work of this 
kind. There are, however, certain defects which appear when 
the book is subjected to the test of the classroom. Numerous 
instances of statements that are misleading or actually erroneous 
are brought to light, and complaint is made that an unnecessarily 
formidable array of technical medical terms is introduced. The 
general excellence of the plan of treatment, however, more than 
compensates for such emendations as the experienced teacher is ~ 
required to make in the classroom. 

The properties of living matter, cells, and their arrangement 
in different groups of organisms, reproduction, ontogenesis, con- 
formity to type, divergence, structural and blood relationships, 
parasitism, infection and immunity, mutilation and regeneration, 
grafting, senescence, decadence and death, indicate the subjects 
of the principal chapters into which the book is divided. 

W. Rs,.0. 


Ill. Miscernanrous Sorentiric InreLLicENoE. 


1. Carnegie Institution of Washington. Year-Book, No. 9. 
1910. Pp. xvi, 258, 5 plates. Washington, January, 1911.— 
Especial interest is connected with the appearance of the ninth 
Year-Book of the Carnegie Institution because of the recent gift © 
by Mr. Carnegie of an additional $10,000,000 to the Institution, 
making its total fund equal to $25,000,000. This addition to its 
resources is particularly opportune at this time, since in the pres- 
ent volume Dr. Woodward calls attention to the serious effect 
of increase of prices as limiting the future income available for 
promoting research. The Institution was organized in 1902 and 
since that time the magnitude and importance of the work it has 
accomplished are truly remarkable. The total amount of money 


Miscellaneous Intelligence. 245 


expended up to date is $4,590,000, of which a little more than 
one-half has been applied directly to the prosecution of research, 
and about one-third is represented in land, buildings, and other 
permanent forms; about 8 per cent has been used for expenses 
of administration and somewhat less for publications. Twelve 
hundred individuals have contributed towards the researches and 
publications undertaken by it. The volumes already published are 
167 in number, and aggregate more than 40,000 printed pages. 
Twenty-five additional volumes are now in press : further, some 
1200 shorter papers have been contributed to current scientific 
periodicals by those working under the Carnegie foundation. 

Of particular importance in the work of the past year is the 
occupation of the new administration building, which was dedi- 
cated in December, 1909, and has proved in all respects a thor- 
oughly satisfactory and dignified permanent home for the 
Institution. During 1910, also, the non-magnetic ship Carnegie 
completed its first voyage of 8,000 miles with important results, 
and a second cruise, planned to last three years, was begun on 
June 29th : at present the vessel is off the coast of Brazil. As 
is now generally known, there are ten departments, to the sup- 
port of which the income of the Institution is chiefly devoted, 
the total sum appropriated towards them amounting to $450,000. 
A considerable number of minor grants have been made in addi- 
tion, although these are few as compared with the situation 
earlier in the history of the Institution. For these last, the 
ageregate amount allotted was about $70,000. In the opening 
pages of the present volume, Dr. Woodward gives a very interest- 
ing résumé of the investigations of the present year, particularly 
in connection with the ten lines of work already alluded to. This 
same subject is discussed in detail on pages 53-204 by the 
Directors of the different departments. It is impossible here to 
go into details in regard to these special lines. Some of the 
most interesting concern the work of the Geophysical Labora- 
tory, under Dr. A. L, Day; the Department of Marine Biology 
at Tortugas, Florida, under Dr. A. G. Mayer; and the Solar 
Observatory at Mt. Wilson, California, now represented by W.S. 
Adams, Acting Director during the absence of Professor Hale. 
Dr. Bauer also gives a summary of the work accomplished in ter- 
restrial magnetism, with a chart showing the projected cruise of 
the “ Carnegie ” alluded to above. The volume closes with brief 
statements, thirty-four in number, as to the results accomplished 
in the various lines of investigation represented by the minor 
grants. 

2. Publications of the Carnegie Institution.—Recent publica- 
tions of the Carnegie Institution are noted in the following list 
(continued from vol. xxx, 295): 

No. 74. The Vulgate Version of the Arthurian Romances, 
edited from manuscripts in the British Museum; by H. Oskar 
Sommer. Volume III. Le Livre de Lancelot del Lac. Part I. 
Pp. 430. 


246 Scientific Intelligence. 


No. 88. Dynamic Meteorology and Hydrography; by V. 
BserKNES and different collaborators. Part I, Statics by V. 
Bserknes and J. W. Sanpstrém. Pp. 146 and appendixes, 31 
figures. 

No. 119. Determination of the Solar Parallax, from photo- 
graphs of Eros made with the Crossley Reflector of the Lick 
Observatory, University of California ; by Cuartes D. Perrine, 
Harotp K. Patmer, Freperic C. Moorr, Apretarwe M. Hose. 
Pp:98.- See ip. 153. 

No. 120. The Symmetric Function Tables of the Fifteenthic 
including an Historical Summary of Symmetric Functions as relat- 
ing to Symmetric Function Tables; by Froyp Fiskr Decker, 
Pp. 16, 5 large tables. 

No. 127. Superheated Steam in Locomotive Service; by 
WiturAm F. M. Goss. Pp. 144, 1 plate, 108 figures. i 

No. 130. A Study of the Absorption Spectra of Solutions of 
Certain Salts of Potassium, Cobalt, Nickel, Copper, Chromium, 
Erbium, Proseodymium, Neodymium, and Uranium as affected 
by Chemical Agents and by Temperature ; by Harry C. Jones 
and W. W. Srrone. Pp. ix, 159, 98 plates. 

No. 132. Department of Marine Biology, ALrrep G. Mayer, 
Director. Papers from the Tortugas Laboratory. Volume III, 
pp- 1-152, 17 plates, 38 figures. Contains twelve papers by dif- 
ferent authors. 

No. 132. Department of Marine Biology, ALFrep G. Mayer, 
Director. Papers from the Tortugas Laboratory. Volume IV, 
pp. 1-186, 43 plates, 17 figures. Contains three papers by Henry 
S. Pratt, Epwin Linton and T. W. Vaueuan. Pp. 185. 

No. 185. Researches upon the Atomic Weights of Cadmium, 
Manganese, Bromine, Lead, Arsenic, Iodine, Silver, Chromium, 
and Phosphorus ; by Grecory Pav Baxter, in collaboration 
with M. A. Hines, H. L. Frevert, et al. 

No. 136. Metabolism in Diabetes Mellitus ; by Francis G. 
Benepict and Erxriotr P. Josuin. Pp. vi, 234. 

No. 141. The Water Balance of Succulent Plants; by D. T. 
Macpoueat and E. 8. Spatpine. Pp. iii, 77, 8 plates. 

3. Annual Report of the Board of Regents of the Smith- 
sonian Institution, showing the operations, expenditures and 
condition of the Institution for the year ending June 30, 1909. 
Pp. x, 751, 73 plates, 1 map. Washington, 1910.—The Annual 
Volume of the Smithsonian Institution for 1909 opens with the 
Report of the Secretary, Dr. Walcott, issued in advance about a 
vear since, and at that time noticed in this Journal (vol. xxix, 196). 
It also contains, in the General Appendix (pp. 119-751), the usual 
series of well-selected papers devoted to a wide range of subjects, 
many of them republished from foreign journals. These papers are 
all more or less popular in method of presentation, so that they 
appeal to the intelligent public, which finds here a remarkable 
résumé of recent scientific progress not to be found in so con- 
venient a form elsewhere. Among them may be mentioned one 
on Radio-telegraphy by J. A. Fleming ; another by Marchis on 


Miscellaneous Intelligence. 247 


the production of Low Temperatures and Refrigeration ; on the 
return of Halley’s Comet, by W. W.Campbell ; on the British 
Antarctic Expedition of 1909, by Lieut. Shackleton; on the 
Antiquity of Man in Europe, by G. G. MacCurdy ; on Panama 
and its People, by Eleanor Y. Bell; on the Natural Resistance 
to Disease, by Simon Flexner. 

The following are recent Bulletins issued by the Bureau of 
Ethnology of the Smithsonian Institution: 

No. 30. Handbook of American Indians North of Mexico ; 
edited by Freprrick Wess Hopner. In two parts. Part 2, 
N-Z. Pp. iv, 1221. See vol. xxiv, p. 91. 

No. 37. Antiquities of Central and Southeastern Missouri, by 
GERARD Fowxer. (Report on Explorations made in 1906-07 
under the auspices of the Archzological Institute of America.) 
Pp. vii, 116, 19 plates, 20 figures. 

No. 45. Chippewa Music; by Frances Densmore. Pp. xix, 
216, 12 plates, 8 figures. 

No. 49. List of Publications of the Bureau of American 
Ethnology with Index to Authors and Titles. Pp. 32. 

4. Publications of the Allegheny Observatory of the Univer- 
sity of Pittsburgh ; edited by Frank ScuLesincEer.—The follow- 
ing have recently been issued : 

Vol. I, No. 23. The Orbits of the Spectroscopic Components 
of v Andromede; by Frank C. Jorpan. Pp. 191-201. Also 
title page and contents of volume I. 

Vol. If. No.1. A Description of the Mellon Spectrograph ; 
by Frank Scuiesincer. Pp. 1-12, two figs. No. 2. On the 
Relative Motions in 61 Cygni and similar Stars; by Frank 
ScHLESINGER and Dinsmore Atrer. Pp. 13-16. No. 3. The 
Orbits of the Spectroscopic Components of « Herculis ; by Ropurr 
H. Baxer. Pp. 17-23. No, 4. The Orbit of I H. Cassiopeiz ; 
by Roxserr H. Baker. Pp. 25-28. No. 5. The Orbit of 30 H. 
Urs Majoris; by Rosrerr H. Baker. No. 6. The Orbits of the 
Spectroscopic Components of 57 Cygni; by Roprerr H. Baker. 
No. 7. Further Observations of 9 Aquile ; by Roperr H. Baker. 
No. 8. The Orbit of 7 Andromede ; by Frank C. Jorpan. No. 
9. The Hclipsing Variable « Herculis; by Frank ScuLesincEeR 
and Rosrerr H. Baker. Pp. 51-62. No. 10. The Spectrum and 
Orbit of o Persei ; by Frank C. Jorpan. Pp. 63-71. 

5. Bref och Skrifvelser af och till Carl'von Linné. Part 1V. 
Pp. iv, 365. Stockholm, 1910.—The fourth part of the corre- 
spondence of Linnzeus (see vol. xxix, 200), published under the 
auspices of the Upsala University, contains a very interesting 
series of letters to and from Abraham Bick, dating from 1741 to 
1755. 

6. Seismological Society of America.—The Seismological 
society, of which Prof. J. C. Branner is president, has decided 
to issue a Bulletin, the first number of which is about to be 
issued ; it will be sent to all members. The dues of the society 
are $2.00 per year ; life membership, $25.00. 

7. Das Electrokardiogramm des gesunden und Kranken Men- 
- schen ; von Prof. Dr. Frrmprica Kraus und Prof. Dr. Grore 


248 Scientific Intelligence. 


Nicotar Pp, xxii, 322. Leipzig, 1910 (Veit & Co.),—This 
volume represents the first more elaborate attempt at a syste- 
matic presentation of the scientific basis and latest technic of 
the electrocardiographic method applied to the study of heart 
functions in animals and man. The authors have particularly 
emphasized the possibilities of the electrocardiogram as an aid 
in clinical diagnosis, and have furnished a review of the rapidly 
growing literature on the subject. Such pioneer work deserves 
commendatory mention and will assist many physiologists and 
clinicians in orienting themselves in the newer methods of 
research. L. B. M. 

8. Plane Trigonometry ; by Epwarv R. Rosstrys, Senior 
Mathematical Master in the William Penn Charter School. Pp. 
166. New York, 1910 (The American Book Company).—The 
only valid excuse for an addition to the multitude of text-books 
in ‘Trigonometry is that it be written by a teacher of Trigonome- 
try in order to minimize his labor of teaching by giving to his 
pupils his own methods in print instead of by dictation. Mr. 
Robbins has in this way recorded the economies that he has 
secured by 15 years’ experience. He seems to have systematized 
the work in elementary plane Trigonometry a little better than 
any of his predecessors, and thereby in so much diminished the 
labor of thinking for his pupils. w. B. 

9, Shop Problems in Mathematies ; by W. E. BRECKENRIDGE, 
S. F. Mersereav, and ©. F, Moorn. Pp. 280. Boston (Ginn & 
Co.).—This volume is designed for students in trade schools. It 
discusses materials and machines for both wood and metal work, 
and outlines construction work of various kinds. Mathematics, 
including trigonometry, is also reviewed with particular refer- 
ence to usefulness in shop practice. A large number of problems 
drawn from practical work are given. D. A. K. 

10. Ostwald’s Klassiker der Hxakten Wissenschaften. Leipzig, 
1910 (Wilhelm Engelmann).—Recent volumes in this important 
series are the following: Nr. 176. Mikroskopische Unter- 
suchungen uber die Ubereinstimmung in der Struktur und dem 
Wachstume der Tiere und Pflanzen, von Ta. Scuwann. Heraus- 
gegeben von F. Htnsever. Pp. 242. 

Nr. 177. Untersuchungen tiber Gegenstiinde der hdéheren 
Geodisie ; von Cart Friepricu Gauss. Herausgegeben von J. 
Friscuaur. Pp, 111. 

Nr. 178. Physikalisch-chemische Abhandlungen; M. W. 
Lomonossows, 1741-1752. Aus dem Lateinischen und Russischen 
mit Anmerkungen herausgegeben von B. N. MenscnuTKin und 
Max Sreter. Pp. 61. 

OBITUARY. 


Sir Francis Garon, the veteran English explorer and con- 
tributor to many departments of science, died on January 17 at 
the age of seventy-nine years. His most important writings were 
those on Heredity, but his activities extended into a remarkable 
number of different fields involving the application of quantita- 
tive methods to science. 

Dr. M. Wiruerm Meyer, the German astronomer, died two 
months since, at Meran, at the age of fifty-eight years. 


VOL. XXXL ? APRIL, 1911. 


Established by BENJAMIN SILLIMAN in 1818. 


THE 


AMERICAN 
JOURNAL OF SCIENCE. 


Epitor: EDWARD S. DANA. 


ASSOCIATE EDITORS 


Proressors GEORGE L. GOODALE, JOHN TROWBRIDGE, 
W. G. FARLOW ann WM. M. DAVIS, or Camsringe, 


Proressors ADDISON E. VERRILL, HORACE L. WELLS, 
L. V. PIRSSON anp H. E. GREGORY, or New Haven, 


Proressork HENRY S. WILLIAMS, or Irwaca, 

Prorressorn JOSEPH S. AMES, or Bautimore, Si 
Mr. J. S. DILLER, or Wasuineron. 

RUREAU GF 


neem ant EF THNO! OGY 
Ak Rail e] ; Vd he ! 


VOL. XXXI—[W HOLE NUMBER, CLXXXI.] 


No. 184—APRIL, 1911. 


“ansonian Ins P 
/ os ity b 
NEW HAVEN, CONNECTICUT. APR 29191] | 


ore National Muse ; 


a 


‘J 


THE TUTTLE, MOREHOUSE & TAYLOR O©O., 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, 
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as 


Of Especial Interest to Mineralogists. 


HIDDENITE FROM NORTH CAROLINA. 


It has been some years since this rare gem mineral was procurable at the 
mineral dealers; through very fortunate circumstances I procured a large 
lot of these crystals at a remarkably low price; they range in size from 14 
to 84 in. of very good color and quality. No doubt many collectors will be 
glad to have the opportunity to procure a representative of this variety 
of Spodumene, with a deep emerald green color; they range in price 
from 50 cents to $2.00. 


KUNZITE FROM CALIFORNIA. 


I also received a large lot of Kunzite crystals, showing remarkable nat- 
ural etchings; I am. now in a position to furnish a series of these etched 
crystals which should be in every collection; they range in color from 
white to deep lilac; former lots of this beautiful gem crystal were beyond ~ 
the average price for regular collectors; the present prices are far below 
any material of this quality ever offered before; crystals range in size from 
34 in. to 2144 in. long, from 75 cents to $5.00; will send a series of these 
crystals for selection to anyone. 


OTHER CALIFORNIA MINERALS. 


Can safely state that my stock of California minerals is the largest in 
the country, considering their quality; the following will suggest a few 
of the additions to my present stock; Stibiotantalite, which is at present 
extremely rare, both loose xls. and in matrix, prices ranging from $2.50- 
$15.00. 

Pink Beryl, good crystals, fair color, from $2.00-$12.00; Tourmalines, 
all colors, loose and in matrix, from $2.00-$25.00. Awaruite, a new lot of 
these interesting metallic pebbles, from the Smith River; their appearance 
is something like Platinum nuggets; price from 25 cents to $1.50; from 
the above locality I have also a fine lot of black and red Obsidian and 
brown: polished from 214 in. to 344 inches, prices from $1.50-$2.00. 

In addition to the above I also received quite a number of other minerals 
too numerous to mention, from this state. 


COLORADO. 


Recent shipments have brought a large lot of Amazonstone, in groups 
and loose crystals, single and twins, some of which are remarkable; also a 
number of the celebrated Cripple Creek Tellurides, such as Tellurium, 
Calaverite, Sylvanite, Gold Pseudo after Calaverite ; Calciovolborthite 
crystallized, Carnotite, Amethystsin parallel growths, Topaz, Smoky 
Quartz, Pyrites, Rhodochrosite quartz, with Fluorite and other well known 
minerals at remarkably low figures. 

I shall be pleased to send anyone on request an assortment, prepaid, for 
selection, and guarantee satisfaction. 


A. H. PETEREIT, 
81—83 Fulton Street, New York City. 


Phone Beekman 1856. 


THE 


AMERICAN JOURNAL OF SCIENCE 


[FOURTH SERIES.] 


Art. XXIV.—On the Ionization of Different Gases by the 
Alpha Particles from Polonium and the Relatwe Amounts 
of Energy Required to Produce an lon; by T. 8S. Taytor. 


Introduction. 


Iy previous papers,* the writer has shown that the air-equiv- 
alents + of metal foils decrease with the speed of the alpha par- 
ticles entering the foils. For sheets of different metals of 
equal air-equivalents, the rates of decrease are approximately 
proportional to the square roots of the respective atomic 
weights. On the contrary, the air-equivalents of hydrogen 
sheets increase while the hydrogen-equivalents of air sheets 
decrease with the speed of the entering alpha particles, and at 
such a rate as to be in agreement with the square-root law ob- 
served for the decrease of the air-equivalents of the metal 
sheets. 

A comparison of the Bragg ionization curves, obtained in 
atmospheres of air and hydrogen, when the pressure of the air ~ 
was so reduced that the range of the alpha particles from polo- 
nium was the same in air as it was in hydrogen at atmospheric 
pressure, showed differences which are sufficient to account for 
the variations in the air-equivalents of the hydrogen sheets 
with the speed of the alpha particles. These differences be- 
tween the Bragg ionization curves in air and hydrogen sug- 
gested that some such differences might be found between the 
ionization curves obtained in other gases, and it was for the 
purpose of making a detailed comparison of the ionization 

* This Journal, vol. xxvi, pp. 169-179, Sept. 1908; ibid., vol. xxviii, pp. 
307-372, Oct. 1909. Phil. Mag., vol. xviii, p. 604, Oct. 1909. 


+ By air-equivalent is meant the amount by which the range of the alpha 
particle is cut down by its passage through the foil. 


Am. Jour. Sct.—FourtH SERIES, VoL, XXXI, No. 184.—Aprin, 1911. 
18 


250 Taylor--- Ionization of Different Gases by the 


curves obtained in different gases that the present experiments 
were begun. 


Continuation of Experiments. 


The apparatus used was the same as had been used in the 
previous experiments.* The sheet iron case, enclosing the 
apparatus proper, was replaced by a solid iron case which could 
be readily exhausted. Polonium was used as the source of 
rays and was placed in a brass cylinder of such dimensions 
that the rays emerging from the cylinder fell well within the 
limits of the ionization chamber for all available distances of 
the source of rays from the ionization chamber. 

In the determination of the ionization curve in any gas, the 
vessel enclosing the apparatus was first evacuated and then the 
gas admitted very slowly till the pressure it exerted was such 
that the range of the alpha particles was exactly 1171 centi- 


Fie. 1. 


weer" 


0 / e 3 4 5 6 7 8 9 Jo Ww 


Fic. 1. The ordinates are the deflections in millimeters of the electrome- 
ter needle per second. The abscissas are the distances in centimeters of the 
polonium from the ionization chamber. Curves I, II, and III were obtained 
when the maximum range of the alpha particle was exactly 11°1 centime- 
ters in hydrogen, air, and methy] iodide, respectively. 


meters, which was the maximum range available with the 
apparatus. The Bragg ionization curve was then obtained in 
the usual manner by observing the deflection of the needle of 
the Dolezalek electrometer in scale divisions per second for 


* Loc. cit. 


Alpha Particles from Polonium. 251 


various distances of the source of rays from the ionization 
chamber. In this manner, the Bragg ionization curves were 
obtained in the gases and vapors given in Table I. The curves 


Fie. 2. 


0 / % 3 4 5 6 7 8 9 10 


Fic. 2. The ordinates are the deflections in millimeters of the electrome- 
ter needle per second. The abscissas are the distances in centimeters of the 
polonium from the ionization chamber. Curves I, II, and III were obtained 
when the maximum range of the alpha particle was exactly 11:1 centimeters 
in methane, ethyl chloride, and carbon disulphide, respectively. 


in figures 1 and 2 and the dotted ones in figure 3 represent the 
ionization curves obtained in the above manner in the gases 
as indicated below the figures, respectively. The dotted por- 
tion of each curve in figures 1 and 2 is assumed to be the form 
it would take were it possible to move the polonium entirely 
up to the ionization chamber. At any rate, such assumed por- 
tions of the curves can differ but little from the actual curves. 
It is to be noted, that the ionization curves shown in figures 1 
and 2 are plotted differently from the regular Bragg ioni- 
zation curve in that the values of ionization are taken as ordi- 
nates and distances of the source of rays from the chamber as 
abscissas, instead of vice versa as is usually done. 

Although the curves in figures 1,2, and 3 represent some 
differences from one another in regard to the relative amounts 
of ionization for corresponding distances of the source of rays 
from the ionization chamber, all of them are of the same general 
form. From a re-determination of the velocity of the alpha 
particle at different points in its path, and the assumption that 


252 Taylor—Ionization of Different Gases by the 


the ionization produced at any point in the path of the particle 
is proportional to the energy consumed, Geiger * has shown that 
the ionization Z at any point in the path is given by the rela- 
tion 


ee ae 
(r—a) 4% 


where ¢c and 7 are constants and « is the distance from the 
source of rays. By comparing this theoretical ionization 
eurve with the experimental curve obtained in hydrogen for a 
pencil of rays, Geiger found the two to agree very closely: 

This theoretical curve has been compared with the experi- 
mental curves obtained in each of the gases and vapors given 
in Table I and a very close agreement between theoretical 
and experimental curves was found for each gas. To make 
this comparison, it was necessary to determine the constants 7 
and ¢ for each gas. For the value of 7, Geiger used the aver- 
age range of the alpha particles in the pencil of rays. Since 
the maximum range of the alpha particles in the cone of rays 
used in the present experiments was always 11'1 centimeters, 
the average range of the alpha particles in this cone of rays 
emerging from the cylinder containing the polonium was 
slightly less than 11:1 centimeters. Consequently 10°8 centi- 
meters were taken as the value of the average range of the 
alpha particle, that is, 10-8 centimeters are supposed to repre- 
sent the average distance the alpha particles traveled in each 
gas before losing their power of producing ions. In order to 
determine c for any one gas, the ionization (ordinate of the 
ionization curve figures 1, 2, and 3) and the corresponding dis- 
tance x of the source of rays from the ionization chamber 
(abscissa of curve) were substituted in the equation 


zal c 
~ (10°8—2x) 4 


and the equation solved for c. Separate values of ¢ were thus 
obtained for various distances of the source of rays from the 
ionization chamber between «—0O and 9°5 centimeters, and 
the mean value of these separate determinations found for 
each gas. The mean values of ¢ as found in the above man- 
ner for all the gases and vapors used are recorded in column 
2, Table I. 


* Proc. Royal Society, Series A, vol. Ixxxili, No. A 565, p. 505. 


Alpha Particles from Polonium. 


Fie. 3. 


4 


r¢) 
(0) / 2 3 4 5 


Gly Meera tin Se, hy Ot 
Fie. 3. The full line curves I, II, and III are the theoretical ionization 
curves for nitrogen, sulphur dioxide, and ether, respectively, as obtained by 
substituting the corresponding values of ¢ given in column 2, Table I, in 
the equation 


= as “ where r = 10°8. 
r—x 


The dotted curves I, II, and III are the experimental ionization curves for 
nitrogen, sulphur dioxide, and ether, respectively, and are plotted similarly 
to the curves in figures 1 and 2 


The full line curves, I, II, and III in figure 3 represent the 
theoretical curves for nitrogen, sulphur dioxide, and ether, 
respectively, as obtained by using the values of ¢ as recorded 
in column 2, Table I, for the respective gases. The dotted 
curves are the corresponding experimental curves and, as can 
be seen, agree very well with the theoretical curves. The 
agreement “petween the theoretical and the experimental 
eurves for the other gases was equally as good as it was for 
those given in fioure 3. In some cases the agreement was 
much closer. This agreement between theoretical and experi- 
mental curves confirms the assumption that the energy 
assumed is proportional to the ionization produced 


The ionization at any point of the path of the particle being 
given by the relation 


G 


a (r—a) % ‘ 


253 


254 Taylor—TLonization of Different Gases by the 


the total area under this theoretical curve is a measure of the 
total ionization produced by the alpha particle in the gas. If 
A, represents the area under the theoretical curve, then 


A ye dx = ve ea 
(r—a)4 
0) 


ro) 


= 3/2 c(r)% = 7°33 ¢ 


(7 being equal to 10°8 centimeters). Hence c is 3/22 of the 
area under the theoretical curve when the average range of 


TABLE JI, ic 

¢ der expe. anetee Relative 

Gaston or area under) rimental under ex-|2atio of the total ioni-) energy re- 

Vapor theoretical | curve as perimen- zation in the gasto | quired to 

eurve divid- measured | al METS that in air. produce an 
ed by 7°33. jwith plan- fray ion. 

| imeter. | ; Taylor. Bragg. 

Air 11:24 980 | 87 ms on 1:00 
ic 10°00 966 9€ 0:99 1-00 101 
CH,I 14°73 1301 88 1°38 1°33 0°75 
CH, 12°65 1156 91 118 0°85 
C,H,Cl 14:05 1251 |) 89 1°29 1°32 0-77 
CS, 15°60 B50) Me Sa 1°38 1:37 0°78 
Air 14°64 1249 85 Pe: ae 1°00 
N, 1381) 1) 0206 87 0:96 0:96 1-04 
CO, 15°01 1262 84 1-01 1:08 0°99 
O, 16°72 | 1415 | 85 1:13 1:09 0°88 
C,H,,0 19-42 | 1702 88 1°36 1°33 0-74 
Air SO 82 89 ae ac 1:00 
so, 15°30 1223 80 1'03 aa 0:97 
HCl 17°70 1530 86 1:29 ae 0:77 
HBr 18732 po a 27 83 1:29 ae 0-77 
Air 13°36 | 1190 89 Ae, aS 1:00 
HI 17°68 | 1535 87 1°29 Se 0-77 


the alpha particle is 10°8 centimeters in any gas whatever. 
The values of ¢ recorded in column 2 of Table I are then 3/22 
of the area under the theoretical ionization curves in the 
respective gases. 

The areas under the ionization curves being proportional to 
the energies consumed in the production of ions in the respec- 
tive gases, the value of ¢ in any one gas depends upon the total 
ionization produced in the gas, and consequently upon the 
energy required to produce an ion in the gas. Then the ratio 
of the area under the experimental curve to ¢ should be a 
constant. By dividing the areas under the experimental 


Alpha Particles from Poloniwm. 255 


curves as measured with a planimeter and recorded in column 
3, Table I, by the values of ¢ for the corresponding gases, 
the values recorded in column 4 were obtained and, as can be 
seen, are approximately constant. 

The areas under the ionization curves being the measures of 
the relative ionizations produced in the gases, the ratios of the 
total ionization produced in the gases to that produced in air 
were determined by finding the ratio under each curve to the 
area under the corresponding comparison air curve. After 
the determination of the ionization curve in each gas, the ioni- 
zation curve was always obtained in air to be used as a basis of 
comparison. The ratios of the ionizations produced in the 
different gases to that produced in air are recorded in column 
5 of Table I. Bragg,* by a less direct process, determined the 
ratio of the total ionizations in gases to that in air and his values 
are recorded in column 6. There is a fairly good agreement 
between the values as found by Bragg and those found by a 
_ more direct process of measurement of the area enclosed by 
the axes of references and the ionization curve for each gas. 

Since the energy of the alpha particle is entirely consumed 
before it ceases to produce ions, the energy required to pro- 
duce an ion in any given substance will vary inversely as the 
ratio of the total ionization in the substance to the total ioniza- 
tion in air if the energy required to produce an ion in air is 
always taken as the basis of comparison. The values of col- 
umn 5 of the table are the ratios of the total ionizations pro- 
duced in the gases as compared with the total ionization 
produced in air. Consequently the reciprocals of these ratios 
are the relative amounts of energy required to produce an ion 
in the substance as compared with the energy required to pro- 
duce anion in air. The values recorded in column 7 are these 
reciprocals of the values in column 5, and hence are the rela- 
tive amounts of energy required to produce an ion in the gases 
as compared with that required to produce an ion in air. 
These values indicate a considerable variation of the energy 
required to produce an ion. The heavier and more complex 
molecules are apparently more readily ionized than the lighter 
and less complex ones. This is probably due to the electrons 
in the heavier and more complex molecules being in a less 
stable arrangement than they are in the lighter and less com- 
plex molecules and hence more readily drawn out. 

In conclusion, I wish to express my thanks to Professor 
Bumstead for his valuable suggestions in connection with the 
work and for loaning me the apparatus. I am also indebted 
to Professor Boltwood for furnishing me the preparation of 
polonium. 


* Bragg, Phil. Mag., vol. xiii, pp. 8383-357, March, 1907. 


256 Taylor—Ionization of Gases by the Alpha Particles. 


Results. 


1. The ionization curve obtained in various gases and 
vapors with polonium as the source of rays is of the general 
form 

e 
(72) 
where J is the ionization; ¢ is a constant for any one gas 
depending upon the total ionization produced, and conse- 
quently upon the energy required to produce an ion in the 
given gas; 7 is the average range of the alpha particles in the 
cone of rays ; and z is the distance from the source of rays. 

2. The agreement between the theoretical and the experi- 
mental curves confirms the assumption made in previous papers 
by the writer* and by Geiger,t that the ionization produced by 
the alpha particle is proportional to the energy consumed. 

3. The values of the ratio of the total ionization produced 
by the alpha particle in different gases to the total ionization 
produced in air as found by Bragg have been confirmed by a 
more direct process. 

4. The energy of the alpha particle consumed in the pro- 
duction of an ion depends upon the nature of the molecule 
ionized. It apparently requires less energy to produce an ion 
in the gases or vapors which have heavy or relatively complex 
molecules than it does in those gases of lighter or less complex 
molecules. 


i= y% 


Laboratory of Physics, University of Illinois, 
Urbana, Illinois, January 28, 1911. 


* Loe cit. + Loe cit. 


Duane— Heat Generated by Radio-active Substances. 257 


Art. XXV.—On the Heat Generated by Radio-active Sub- 
stances ; by Witt1am Duane. 


Since the discovery of radio-activity questions relating to 
the source and the transformations of the energy involved in 
the processes have been considered of prime importance. 
Early in the history of the subject Curie and Laborde* dis- 
covered that radium generates heat continually, and also that 
the heat effect increases as the emanation accumulates. A 
little later Rutherford and Barnest found that the emanation 
and the first few products of radium that form its induced 
activity produce their shares of heat, and more recently still 
Pegram and Webb¢ have succeeded in detecting a small heat 
effect in a large mass (about four kilograms) of thorium oxide. 

The ordinary methods of measuring heat (an ice calorimeter 
for instance) are sufficiently sensitive to detect and measure 
the heat generated by the quantities of radium, its emanation 
and its induced activity now at our disposal. I have made 
recently a number of experiments on the heat effects of other 
radio-active substances, and in these I have had to use special 
methods. At first I employed a modification of the differen- 
tial air calorimeter devised by Rutherford and Barnes (1. ¢.), 
but this was not sensitive enough and I then constructed a 
new instrument which is considerably more sensitive than the 
differential air calorimeter. The method is based on the rapid 
increase in the vapor tension of a very volatile liquid when 
the temperature rises. A and A’ (fig. 1) represent two glass 
vessels, which are joined by the capillary tube B. The vessels 
are half filled with the volatile liquid, and almost all the air 
is pumped out by means of a water aspirator through the tube 
C, which is then sealed off. A small bubble formed out of 
the residual air left in the vessels is inserted in the tube B, 
and the displacement of this bubble is observed by means of 
a reading telescope or by projection with a lamp, lens and 
seale. I usually employ the latter method, and the displace- 
ment of the image on the scale is about eight times that of the 
bubble in the tube. 

It is not difficult to place a bubble of any desired length 
in the tube B. It is sufficient to turn the apparatus upside 
down, and let the liquid run out of the tube. Then 
on replacing the apparatus right side up one finds the 
tube more or less completely filled with air. The bubble is 

* Comptes rendus, cxxxvi, p. 673, 1903. 


+ Nature, Oct. 29, 1903; Phil. Mag., Feb., 1904. 
tScience, 1904; Le Radium, 1908. 


258 Duane—Heat Generated by Radio-active Substances. 


usually much too long, and to reduce its length all that is 
necessary is to tilt the apparatus up a little so as to cause a 
current of the liquid to pass through the tube. This current 
pushes the bubble down into the portion of tube below and at 
the side, which is larger than the capillary portion. The 
bubble remains in this portion of the tube, and the current of 
the liquid passing it carries along the air little by little, thus 
reducing the bubble’s volume. On repeating this process, | 


Fie. 1. 


SN 
Se 


causing the current to flow first in one direction and then in 
the other, one can reduce the bubble to any desired length. 

After the bubble has been replaced in the tube, and the 
apparatus has been prepared for the experiment, the bubble 
remains in the horizontal part of the tube. It never descends 
into the large portion, no matter how much the temperature 
of the room may vary: but it slowly disappears. The air in 
the bubble dissolves in the liquid more or less rapidly accord- 
ing to the nature of the liquid, the pressure of the air and the 
dimensions of the apparatus. In my experiments it is neces- 
sary to renew the bubble once in two or three weeks: and this 
is a process requiring about five minutes time. 

The form and dimensions of the capillary tube B have been 
carefully studied. The length of the horizontal part is 44™ 


Duane—Heat Generated by Radio-active Substances. 259 


and the internal diameter is a little more than -5"™. The 
internal diameter of the two large parts is about 8™", and the 
yertical parts joining the horizontal with the larger parts 
should not have a larger diameter than the horizontal capillary 
part. It is easier to control the movement of the bubble, 
while placing it in the tube and reducing its size, if the capil- 
lary tube is not joined to the ends of the larger parts, but to 
the tops as indicated in the figure. 

The volume of each vessel is about 50°. 

The interior of the vessels and of the tube must be cleaned 
most carefully. The least dirt or grease stops the bubble, and 
in the experiments it is well to choose the part of the tube 
where the bubble moves most freely. 

If a source generating heat is introduced into the tube D, 
the vapor tension is increased and the liquid pushes the bub- 
ble toward the vessel A’. The instrument is very sensitive. 
In my experiment I found that 1:5 10-* gram-calorie of 
heat displaced the image of the bubble 1™ on the scale. 
This sensitiveness is due to the rapid increase of the vapor 
tension with the temperature. Among the liquids I have 
tried, ether seems to be the best. Ether cleans and wets the 
surface of the glass well, it has very little viscosity and its 
vapor tension increases rapidly with the temperature, about 
17™™ of mercury per degree centigrade at ordinary tempera- 
tures. Ethel chloride works well also but is much less easily 
manipulated. 

The sensitiveness of the instrument varies a great deal with 
the quantity of air in the vessels. If there is very little air the 
displacement of the liquid does not change the pressure of the 
gas much (saturated vapor tensions depending only on the tem- 
perature), and an increase of pressure in A due to a slight pro- 
duction of heat is opposed only by a change of level of the liquid 
in A and A’. As ether is a light liquid, this change of level 
opposes only a slight force to the displacement of the bubble. 
For great sensitiveness, therefore, one must remove almost all 
the air from the vessels, leaving only enough to form the 
bubble. The sensitiveness depends also upon the ratio of the 
eross-section of the capillary tube to the surface of the liquid 
in the vessels. A decrease in the cross-section increases the 
sensitiveness. I have found, however, that (if the liquid is 
ether) a tube of less than °5™™ internal diameter does not work 
well on account of the capillary forces. 

Further, the displacement of the image of the bubble is 
increased by the lens (or reading telescope). It is not desir- 
able, however, to multiply the displacement more than eight 
or ten times, as the loss in sharpness of image counterbalances 
the advantage of increased displacement. 


260 Duane—Heat Generated by Radio-active Substances. 


In actual practice the protection of the instrument against 
outside thermal disturbances is just as important as great sen- 
sitiveness. In my earlier experiments Damibedden the two 
vessels in a block, E (fig. 1), of lead (weighing 25 kilograms). 
The vessels were held in place by a layer of paraffine, which 
filled the space between them and the lead at the bottom. At 
the top this space was filled with cotton wool. Two metal 
rods, F (normal to the plane of the figure) support the block 
of lead inside a brass box, G. These rods serve as axles 
about which the lead can be turned, and thus the bubble of 
air shifted to any desired position in the capillary tube. The 
box G was completely enveloped in cotton wool contained in 
a second box of zine (not represented in the figure). This 
system of good conducting metal screens separated by spaces 
filled with non-conducting material furnished excellent pro- 
tection against thermal disturbances, but was not sufficient 
where the greatest sensitiveness was required. The whole 
apparatus, therefore, was placed in an electrical thermostat 
similar to the one described some years ago in this Journal.* 

In my later experiments I have replaced the cotton wool 
with eider down, and I have added two large blocks of lead 
on top of the box G. These blocks equalize the variations of 
temperature coming from above. They are placed one beside 
the other, leaving just enough space between them for the 
tubes by which the substances to be examined are lowered into 
the calorimeter. With these modifications I have found it 
unnecessary to set the thermostat going, except on those days 
when the temperature of the room undergoes wide fluctuations. 

Very often the heat due to the radio-active processes is pro- 
duced in relatively large masses of matter. In these cases it 
is necessary to leave the substance to be examined for a long 
time in the upper part of the tube by which it enters the calor- 
imeter, in order to be sure that its temperature is as nearly 
equal to that of the calorimeter as possible. This part of the 
tube should lie between the two large blocks of lead, and 
should be of metal to facilitate the equalization of temperatures. 

If the generation of heat by the source is relatively large, 
an appreciable quantity of it may be conducted down the 
column of air into the calorimeter. In order to avoid this a 
small quantity of eider down fastened to the end of a very 
fine glass rod may be inserted into the tube just above the 
calorimeter. In making an experiment the eider down is 
removed, the substance to be examined lowered into the 
calorimeter and the eider down quickly replaced. 

Any one of several methods may be used in measuring the 
heat generated by the source. On lowering the source into 
the calorimeter one can wait until a sort of thermal equilib- 


* Duane and Lory, this Journal, 1900. 


Duane—Heat Generated by Radio-active Substances. 261 


rium is reached, when the heat conducted away from the 
calorimeter equals that given it per second by the source, and 
observe the maximum displacement of the bubble of air. This 
method works well provided the instrument is not arranged 
for very great sensitiveness. 

If, however, the apparatus is very sensitive it is better to 
take the velocity of the bubble as a measure of the heat 
generated per second. Although the instrument is well pro- 
tected against thermal disturbances from the outside, yet the 
bubble does not stay in the same place. The zero of the 
instrument is not fixed. Nevertheless, if the apparatus has 
remained undisturbed for a long time, and the temperature 
throughout has become as nearly equalized as possible, the 
natural drift of the bubble is slow and regular, and the change 
in its velocity due to the heat from the source, when it is 
lowered into the calorimeter, can be measured with consider- 
able precision. 

A third method is to compensate the effect of the heat 
generated in the tube D by generating a known quantity of 
heat in the corresponding tube D’ (figure 1). 

The best method, however, is to compensate the heat effect 
by absorbing the heat in the tube D itself as fast as it is 
generated. This can be done by means of a current of 
electricity flowing across the junction of two metals. Peltier 
discovered that if the current passes in one direction heat is 
generated, and if in the opposite direction heat is absorbed at 
the junction. 

In my earlier experiments I inserted a thermo-couple P of 
iron and nickel wires into the tube D, and I determined the 
current that absorbed the heat as fast as it was generated, by 
varying the strength of the current until the velocity of the 
bubble was the same as its natural drift. In the later experi- 
ments I have replaced the simple thermo-couple by a metal 
tube. The walls of the tube are 1™™ thick, and its external 
diameter is just enough less than the diameter of the tube D 
to allow of its being inserted easily into the latter. The length 
of the metal tube is about 4°, so that the entire tube lies 
inside the calorimeter. Half of the tube is of iron and the 
other half of nickel, the two surfaces between the two metals 
being vertical and parallel to the axis of the tube. An iron 
wire is soldered to the outer edge of the iron half of the tube 
and a nickel wire to that of the nickel half, so that a current 
of electricity descending by the iron wire into the iron half of 
the tube can pass across the joints into the nickel half and 
ascend by the nickel wire. With this arrangement, when a 
source of heat is lowered into the middle of the iron-nickel 
tube, it is surrounded by a good conductor of heat, and the 
distribution and compensation of the heat takes place easily 


262 Duane—Heat Generated by Radio-active Substances. 


and quickly. Thus the thermal equilibrium of the apparatus 
is not disturbed much by the heat generated by the source. 

This method is capable of considerable precision and can 
be used, without changing the apparatus, to measure heat 
effects varying from ‘001 gram-calorie to 2 gram-calories per 
hour. Larger heat effects could be measured by increasing 
the thickness of the iron-nickel tube and iron and nickel wires 
so as to decrease their electrical resistance and the heat gen- 
erated in them according to Joule’s law. 

The iron-nickel tube has been carefully standardized by 
inserting a small coil of manganine wire of known resistance 
into the tube, by heating this with a known electric current, 
and by determining the current in the tube that would exactly 
absorb the heat produced. 

The electric currents were produced by small storage 
batteries, and their intensities were varied by changing the 
resistances in plug resistance boxes contained in the circuits. 
The resistances in these boxes, as well as the other resistances 
in the cirenits, were carefully measured by a standard Wheat- 
stone’s bridge. The electric currents were measured by com- 
paring the electromotive forces of the storage cells with that 
of a standard Weston cell by the potentiometer method, and by 
dividing these electromotive forces by the total resistance in 
the circuits. 

The following table contains the data obtained in standard- 
izing the iron-nickel tube. The resistance of the small coil 
inserted into the calorimeter was 9°20 ohms, and that of the 
lead wires attached to it was negligible. The electromotive 
force of the standard Weston cell was 1,018 volts, and that 
of the two cells forming the storage battery 4,153 volts. 


TABLE 1. 
Total resistance Heat produced Current iniron- Heat absorbed 
in heating cir- in heating cir- nickel tube. per hour per 
cuit. cuit calories . Ampere ampere 
Ohms per hour —_—_- 

Observed Corrected 
480 "593 0716 0716 § 29 
550 ‘450 *0540 °0542 8°30 
650 "324 “0392 "0393 8°25 
910 165 “0200 0197 8°37 


The compensations were not always exact, and a small cor- 
rection was made in the values of the current in the iron- 
nickel tube. This correction was determined by observing 
the velocity of the bubble of air. 

The heat effect in the iron-nickel tube is due to two causes. 
Firstly, the heat generated or absorbed at the junctions of the 
metals according to the direction of the current (Peltier effect), 
and, secondly, the heat generated according to Joule’s law, 


Duane— Heat Generated by Radio-active Substances. 268 


which is proportional to the square of the current and to the 
resistance. ‘The fifth column in the table contains the heat 
absorbed per hour and per ampere by the tube, and it appears 
that this quantity is independent of the current in the tube. 
This means that the absorption of heat is proportional to the 
intensity of the cooling current, i. e., the resistance of the tube 
is so small that the heat generated according to Joule’s law is 
inappreciable, if the cooling is no larger than -6 calorie per 
hour. 

The mean value of the heat absorbed (or generated) per 
hour and per ampere in the iron-nickel tube is 83 gram- 
calories. I found 8-2 calories for the couple used in the earlier 
experiments. 

It is interesting to note that the electromotive force in the 


Fig. 2. 


Centimeters 


Minutes 


surface between the iron and the nickel must be about -00055 
volt to produce this effect. 

In order to determine the sensitiveness of the instrument I 
sent a very small current through the iron-nickel tube, and 
observed the change in the velocity of the bubble due to the 
heat absorbed or generated. The curves in figure 2 represent 
the displacements of the image of the bubble. The lines ad 
and ed represent the bubble’s natural drift. The abscissas of 
the points 6 are the instants at which the electric current 
commenced to flow through the tube, and the abscissas of the 
points ¢ are those at which the current was broken. For the 
first curve the direction of the current was such as to generate 

heat, and for the second to absorb it. It appears that the dis- 
placement of the bubble due to the current was about the same 
in the two cases but in opposite directions. This confirms 
Peltier’s law, and indicates that the Joule effect is negligible. 


264 Duane—Heat Generated by Radio-active Substances. 


The strength of the electric current was ‘00019 ampere, and 
the heat generated or absorbed *0016 calorie per hour. In ten 
minutes ‘00027 calorie was generated or absorbed and _ this 
quantity of heat displaced the image of the bubble about 
1-6". It follows that one millimeter displacement of the 
image corresponds with :00017 calorie of heat absorbed or 
generated. 

In some other experiments I have found that the displace- 
ment of the bubble is proportional to the quantity of heat 
absorbed or generated, provzded that the absorption or genera- 
tion is not too rapid. 

These results are used in estimating the small correction that 
must be applied, if the value of the current that exactly 
absorbs the heat generated by a source has been determined 
only approximately. 


Centimeters 


Minutes 


I have measured the heat generated by radiothorium and by 
polonium. These experiments were described in two notes 
presented to the Paris Academy of Sciences on June 1 and 
June 21, 1909. 

Since the first experiments I have measured the heat gen- 
erated by the polonium several times to see if the heat effect 
decreased with the time according to the law of decay of 
polonium. Half a given quantity of polonium disappears in 
about 142 days. 

The curves in figure 3 represent the displacement of the 
bubble in these experiments, the dates being for curve 1 the 
4th of May; for curve 2 the 4th of June, and for curve 3 the 
25th of June. In each case the lines ab and fg represent 
the natural drift of the bubble. The abscissas of the points 6 
are the instants at which the polonium was lowered into the 


Duane—Heat Generated by Radio-active Substances. 265 


calorimeter, and the abscissas of the points / are the instants at 
which the polonium was raised again. The numbers written 
near the lines cd and de are the electric currents in amperes 
which were flowing through the iron-nickel thermo-couple dur- 
ing the corresponding intervals of time. 

Between the points ) and eI was searching for the proper 
value of the current to counterbalance the heat effect, and 
between the points e and 7 I was reducing the current to zero. 
The last experiment was not as good as the others, because the 
natural drift of the bubble was large and changed a little dur- 
ing the experiment. 

I compared the ionization due to the polonium when spread 
out in a thin layer on a disk of platinum (4 ¢) with that due to 
a thin layer of radium. The results of the experiments appear 
in Table 2. 

TABLE 2. 
Heat 
Weight of effect 
RaBr~ that of this 


Date of Current that Heat pro- Ionization hassame quantity 
experiment compensated duced cal- current due activityas of radium 


1909 heat effect. orie per topolonium polonium calorie 
Ampere hour g. per hour 

May 4 00143 012 Mes} Se Or" 75 °0110 

June 4 “00110 ‘009 119+ 107 66 0095 

June 25 ‘00100 008 "99 X10)" “Bil 0084 


It is evident that the generation of heat and the ionization 
current due to the polonium decrease with the time. The 
ionization current decreases at a rate indicating decay to half 
value in 136 days, which is very close to the value previously 
found by other experimenters. The heat effect decays a trifle 
faster than this, but the differences are not greater than one 
would expect considering the magnitude of the quantities of 
heat evolved. It follows from this that the heat effect was 
certainly due to the polonium. . 

On account of the difficulty of obtaining saturation in 
measuring the ionization of the radium and of the polonium, 
the method of comparing the activities of the two substances 
must be regarded as approximate only. Remembering this. 
it appears that the heat generated by the polonium is ver 
close to that generated by the quantity of radium that would 
produce the same ionization as the polonium. 

I have made «a number of experiments on phosphorescent 
salts to see if they generate heat when in the phosphorescent 
state. Every time I examined such a salt one or two hours 
after it had been withdrawn from the light of the sun (or of an 
ultra-violet ray are lamp), I found a small but measurable 
generation of heat. Twenty-four hours later not the slightest 
effect could be detected in the majority of cases, but a few 
times I observed a small generation of heat and on withdraw- 


Am. JOUR. Poteau Series, Vou. XX XI, No. 184.—Apnrin, 1911. 
ell 


266 Duane—LHeat Generated by Radio-active Substances. 


ing the salt from the calorimeter found that the phosphorescent 
light had disappeared. It is impossible to affirm, therefore, 
that the heat effect is directly related to the emission of vzscble 
phosphorescent light. It may be due to the emission of visi- 
ble and invisible rays together, or it may be caused by some 
reaction of a secondary nature. 

These researches, however, have suggested to me the follow- 
ing question: if a quantity of radium is mixed with a phos- 
phorescent salt, causing it to phosphoresce brilliantly, does the 
mixture generate the same quantity of heat as the radium 
would generate alone? There appear to be three possibilities : 
(a) the ener gy of the rays is absorbed (at least in part) in pro- 
ducing chemical reactions in the phosphorescent salt. In this 
case the heat effect of the mixture should be less than that of 
the radium alone, at least at first. (0) the radium rays acting 
on the atoms and molecules of the salt liberate a part of their 
chemical or subatomic energy. In this case the heat produced 
by the mixture should be larger than that produced by the 
radium alone. (¢) the energy of the radium rays is rapidly 
transformed (in part) into the energy of the phosphorescent 
light without producing other reactions, and in this case, if all 
the light is absorbed in the vessel containing the mixture, the 
heat produced should be the same as that due to the radium 
alone. 

In order to investigate this question I made the following 
experiments. On December 3d, 1909, a certain quantity of 
a salt containing finely pulverized radium chloride and barium 
chloride was divided into two parts. One part, A, weighed 
"0314 gram and was sealed into a small glass tube. The other 
part, B, weighing :0206 gram, was thoroughly mixed with 
‘267 gram of phosphorescent zine sulphide, and then sealed in 
a second glass tube similar to the first. 

Several times during the five weeks following the sealing 
of the tubes I measured the heat effects of each of them, and 
I also compared the intensity of the y-radiation emitted by 
them with that due to a standard tube containing 26°5 grams 
of radium chloride. The following table (3) contains the 
results of these experiments : 


TABLE 3. 

Date of Quantity of RaCl-? Production of Ratio 

of that produces the heat calories A 
experiment same y-rays per hour Tay 

= a => = Si => 
A B A B 

December 7 1°66 1:07 Be is pir 1°55 
December 7 se: deen sales 2 +098 5S 
December 21 DAVY 1°57 nae eM tinh 153 
December 21 ere eee 199 129 1:54 
January 5-- 2°39 1°56 oe Be 1°53 


January 6.. Bese sits = 201 “2 1°58 


Duane—Heat Generated by Radio-active Substances. 267 


The y-radiation and the generation of heat increased 
between the 7th and the 21st of December, but after that no 
increase was perceptible. This was due to the accumulation 
of the emanation and the induced activity, which after three 
weeks attained approximately their saturation values. 

The sixth column contains the ratios between the tubes A 
and B. It appears that these ratios are the same no matter 
what the date of the experiment was and no matter whether 
the y-rays or the heat effect was measured. It follows that 
the presence of the phosphorescent salt does not appreciably 
change the rate of generation of heat by the radium. 

The following facts may be noticed in passing: The phos- 
phorescence of the mixture has become less imtense than at 
first but is still brilliant. The hght has also changed its color, 
becoming more orange. 

In order to investigate the heat effect in the case where the 
phosphorescence is produced by the 8 and ¥ rays in willemite 
and in platinum-barium cyanide, I arranged the following 
experiment: A long, fine tube is inserted into tube B of the 
calorimeter and around the end of this tube is packed the 
phosphorescent salt. A very small glass capsule hermetically 
sealed containing radium can be lowered down the fine tube 
to the center of the salt. The walls of the tube and capsule 
are so thin that under these conditions the salt phosphoresces 
brilliantly. 

I compared twice the y-rays from the capsule with those 
from the standard and found that the quantity of radium in 
the capsule corresponded with 1:91 and 1:92 mg. of RaOl,. 

The heat effects observed on lowering the radium to the 
center of the phosphorescent salt were the following : 


TABLE 4, 
Heat 
calorie 
Salt used per hour 

67 gr Platinum-barium cyanide -_-------- 170 
DONG) Ore Aan Nieves 5 5 ey oes ee wee ca Nie 
No phosphorescent salt -_....--.--- Styl 

No phosphorescent salt _--- .-- ee MAlG 


It is evident that the generation of heat is the same whether 
the phosphorescent salt is present or not. It follows from 
these two series of experiments that there is no appreciable 
absorption of energy in producing chemical reactions, and that 
the rays do not liberate an appreciable amount of chemical 
_ subatomic energy. 

These results are interesting from the point of view of 
the amount of energy necessary to effect the organs of sight. 


268 Dwane—Heat Generated by Radio-active Substances. 

In the first series of experiments the phosphorescence was 
produced for the most part by the a-rays of the radium. We 
know that each a-particle that strikes the phosphorescent zine 
sulphide produces enough light to affect the eye, and it follows 
from the experiments described above that the energy of this 
light is no larger than the energy of the a-particle. The smallest 
velocity of an a-particle that has been measured and at the 


same time detected by its scintillation is 510° —— , and the 
kinetic energy of the a-particle at this velocity is 8107 erg. 


. ; : 6 1 : . 
This energy is about that required to raise G0 of a mille- 


1 : sas 
gram 3559 of a millimeter. The energy necessary to pro- 


duce the sensation of sight is less than the above quantity, 
since only a part of the total light energy enters the eye, and 
since probably the whole energy of the a-particle is not trans- 
formed into luminous energy. 

The heat generated by one gram of pure radium can be 
calculated from the data of Table 3. It is for tube A 110 and 
for tube B 108 calories per hour. The difference between these 
two numbers is not greater than the errors of experiment. 

The heat effect of one gram of radium calculated from 
the data of Table 4 is 117 calories per hour, a value considerably 
larger than the preceding values. This difference cannot be 
explained by errors of experiment. It is probably due to the - 
fact that the radium employed in the second series of experi- 
ments is several years older than that employed in the first 
series, and contains, therefore, more of the disintegration 
products of the radium, especially polonium, which generate 
heat. 

I have made a number of attempts to measure the heat pro- 
duced by the rays from radium at a distance from their source. 
In the first experiments a thermopile, a bolometer, and a 
radiometer were tried, but none of these instruments gave 
satisfactory results. A modified form of differential gas ther- 
mometer gave positive indications of a heating effect, but the 
only instrument that proved satisfactory was the differential 
calorimeter described in the present paper. I hope shortly to 
publish some details of these experiments, but will state here 
simply that the problem is somewhat different from that 
of measuring the energy of ordinary radiations (at least as 
far as the penetrating radium rays is concerned), because a 
relatively large amount of matter is required to stop these 
penetrating rays, and the heat is generated throughout the 
mass of this matter. 


Pirsson and Rice—Geology of Tripyramid Mountain. 269 


Arr. XX VI.— Contributions to the Geology of New Hamp- 
shire, IV. Geology of Tripyramid Mountain; by L. V- 
Prrsson and Wm. Norru Ricr.* 


Introductory.—Tripyramid Mountain is in the southern 
part of the White Mountains in New Hampshire. The point 
formed by the intersection of 44° N. and 71° 30’ W. is about 
two miles northwest of its northwest lower slope. It is entirely 
within the township of Waterville and a little east of its cen- 
ter. Surrounded by other mountains, Osceola, Kancamagus, 
Passaconaway, Whiteface, Sandwich Dome and Tecumseh, 
peaks which rise 3-6 miles distant, it is much concealed, and 
there are not many places where it can be observed in its full 
proportions from below. ‘The retired character of its situation 
is much enhanced by the wild and heavily wooded nature of 
the region in which it stands, the only habitations in the upper 
valley of Mad River, which drains the township, being a sum- 
mer resort hotel and a few scattered farm houses. The east- 
ern slopes of the mountain are drained by headwater branches 
of Swift River, whose upper basin is a similarly wild and 
heavily for ested region. Consequently its summit is not easily 
accessible and is little visited by tourists, especially as the view 
is largely circumscribed by the neighboring peaks and obscured 
by the thick growth of spruce serub covering it. The best 
point to reach it from is the hotel at Waterville, which is 12 
miles from the railway at Campton. A walk of about four 
miles, partly on trails through the forest and partly a scramble 
up rough and overgrown mountain brook beds, brings one to 
the lower slopes and the slides described beyond. 

Topography.—Tripyramid Mountain is a roughly oval mass 
which rises about 2000 feet above the floors of the valleys 
about it. It is crested by three peaks with saddles between, 
called the North, Mid, and South Pyramids, to which it owes 
its name. Its appearance from the west is seen in the 
accompanying view, which we owe to the kindness of Mr. 
A. L. Goodrich. It was taken looking across the mead- 
ows above the old lumber dam at a place on Slide Brook 
called Swazeytown, below the junction with it of Cascade 
Brook. 

On the north the mountain is connected with the peaks of 
Kancamagus by a high ridge with an intervening point upon 

*Some years since one of us (L. V. P.) went to Waterville, N. H., to see 
the occurrence of the ‘‘ossipite”” mentioned in this paper and to collect 
material. While engaged in this hefound W.N. R. had also studied the Tri- 
pyramid rocks in the field. We joined forces and the present paper is the 


result. It is proposed to follow this with one dealing with the petrology of 
the rocks. 


270 = Pirsson and Rice— Geology of Tripyramid Mountain. 


it, sometimes called Fourth Pyramid. On the south it 
descends to a bench, or roughly level area, known as Flat 
Mountain, whose elevation is about 2500 feet above sea level 
and which in tur again descends into the valley of Cold 
River. North Pyramid is about 4200 feet above the sea, the 
other pyramids are a little lower. The mass, as thus defined, 
is over two miles long, by about one and a half broad; the 


Fie. 1. 


Fie. 1. View of Tripyramid Mountain. 


Looking east from above the Swazeytown Dam. The North Slide and 
Ravine of Avalanches are seen to the left, the South Slide on the right. 


distance between the North and South Pyramids about a mile 
along the crest. The details of the topography are shown on 
the accompanying map, which has been compiled from various 
sources, the approximate expression of the topography of the 
older map of the Hitchcock Geological State Survey being cor- 
rected in details by later maps of parts of the area made by 
the Yale School of Forestry under the direction of Mr. Henry 
Gannett and Prof. Il. H. Chapman, by Mr. C. W. Blood, and 
one of trails and stream courses by Mr. A. L. Goodrich, and to 


Pirsson and Rice—Geology of Tripyramid Mountain. 271 


these gentlemen we desire to express our indebtedness for the 
use of this material. The western two-thirds of the map has 
been made chiefly from these sources, the eastern third is from 
the older state map. We have added a few corrections of our 
own. 

Nearly everywhere the mountain, and also for the most part 
the surrounding area, are covered with a dense forest growth. 
On the slopes of the mountain and on its top this is composed 
of a thicket of small spruce trees which rise through a floor 
mat composed of intermingled dead and fallen tree trunks, 
more or Jess decayed, accumulations of spruce needles, shrubs 
and moss, into which one often sinks to the waist, and through 
which progress is extremely difficult. On the lower slopes the 
kinds of vegetation are somewhat different but the character 
of the thicket remains the same and the mantle is often 
swampy in addition. Were it not for the slides and the chan- 
nels of the streams running from them, the underlying rocks, 
except on the summit, would be completely concealed by this 
vegetable growth and deposit, which on a rainy day, to one 
immersed in it, calls to mind Darwin’s description of Terra 
del Fuego. 

The Slides.—The most interesting features of the mountain 
are what are locally known as the “slides.” These are two tre- 
mendous landslides, or avalanches, which have occurred, one 
on its north, the other on its south slope. The North Slide has 
left a bare face of underlying rock extending from the narrow 
Ravine of Avalanches, which separates the mountain from the 
next peak to the north, upward for half a mile along the slope 
and with over a thousand feet of elevation, with an average 
angle to the horizontal of 30°. Starting at a point not far 
below the summit, it gradually widens until at its base nearly 
the whole north face of the mountain, up into the head of the 
Ravine of Avalanches, is exposed. The naked rock surface left 
by this, which is about as steep and smooth as one can comfort- 
ably climb upon, is interrupted here and there by piles and 
trains of rock débris and lines of small trees and shrubs grow- 
ing in crevices. The most conspicuous lanes of rock face 
exposed are separated from several minor similar ones east of 
them on the north slope and these from each other, by long 
strips of soil and forest. The exposed rock of these smaller 
eastern lanes appears quite weathered. Minor slides have also 
occurred from the opposite slope of the neighboring elevation 
into the Ravine of Avalanches, which appears to be well named; 
see fig 1. A view of the chief double lane of sliding of 1885 
is seen in fig. 3, taken from the opposite mountain side by 
Prof. E. L. Rice. Small drainages pass down these lanes and 
empty into Avalanche Brook, which heads below. 


“ay MOZMOT, “S@]IJ JO e[vog 


779, 
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Pirsson and Rice—Geology of Tripyramid Mountain. 273 


Fie. 3. 


Fie. 3. View of the North Slide from the south slope of Fourth Pyramid. 


274 = =Pirsson and Rice—Geology of Tripyramid Mountain. 


small amount of débris spread down the ravine below, com- 
pared with the extent of surface denuded. 

The condition which has caused the slides appears to be the 
steep and smooth rock surfaces on which the accumulating lay- 
ers of largely organic deposits rested. When these became 
heavy enough, at a time when they were saturated with water 
after long and torrential rains, which also lubricated the under- 
lying rock surface, they broke away and slid down. The steep- 
ness and smoothness of the bed rock is occasioned by a certain 
sheeting which it possesses and which is discussed later. Judg- 
ing from the conditions, and from what has occurred, it seems 
possible that other slides may occur in the future. The South 
Slide is in essential respects, as to size, height, ete., quite com- 
parable to the North one, only in this case the thickness of 
the débris of soil, rocks, ete., which moved, was apparently 
greater. Thus the underlying rock i is exposed only at the upper 
part of the slide, the earth mantles the middle part and 
increases in thickness as one descends, while the glen below in 
which the Slide Brook heads is choked with the accumulated 
material that moved down into it. This lower part has the 
hummocky surface characteristic of landslides and is furrowed 
by shallow ravines which the drainage has cut into it. Many 
large blocks of rock, some of them 8-10 feet long, are exposed 
in these ravines ; most of them are of syenite from the mountain 
above, but others are of black trap, porphyritic granite, dark 
gabbro, ete., and are evidently transported glacial erratics. This 
avalanche occurred on Oct. 4th, 1869, and a second one on 
Aug. 18th, 1885, as a sequence to the terrible downpour which 
also caused the largest North Slide. It can be just seen in 
fig. 1 to the right as a white line showing through the dark 
forest. An admirable account of these slides and the causes 
which produced them has been given by Mr. A. A. Butler.* 

Listory.—The first mention of the geology of Tripyramid 
Mountain that we have been able to tind is in a description 
of the South Slide by Prof. G. H. Perkins+ written shortly 
after its occurrence. The mountain is called by him Passa- 
conaway ; there appears at that time to have been some. con- 
fusion in regard to the use of this name, and later it became 
fixed to the mountain east of Tripyr amid, which now bears it. 
In his description of the slide he states that the upper part of 
the mountain is composed of a gray syenite. As this term 
was then used it bore reference to the fact that the rock 
contained hornblende, it did not mean that it was free from 
quartz, or nearly so. The name, however, proves correct as 


* Appalachia, vol. iv, No. 3, p. 177, 1886. 
+ This Journal (2), vol. xlix, p. 158, 1870. 


-7 


Pirsson and Rice—Geology of Tripyramid Mountain. 275 
used in the former, or in the later, petrographic sense, as will 
be shown later. He speaks also of the presence of trap dikes 
in it from an inch or two up to a foot in thickness. He does 
not mention their color, so it is uncertain whether this refers to 
aplitic or lamprophyrie dikes, or to both, but the use of the 
word trap suggests the latter. He speaks also of extensive 
layers of black hornblendic rock a mile below the slide on the 
stream ; this evidently refers to the gabbro mentioned later. 
The next account bearing on Tripyramid is found in Hitch- 
cock’s Geology of New Hampshire.* In this, references to 
the mountain, to its rocks and geology, are made in a number 
of places, and in vol. II, p. 211 and following, a general de- 
scription of its geology is given. As weshall have occasion in 


s sy 
<Ossipile / ~s 2 _Gray--- 4 oo" Conway 
Por Grn s=._-- 3 yore? Granite 


Fie. 4. Generalized section of Tripyramid according to Hitchcock 
(fig. 19). 


several places to refer more specifically to Hitchcock’s work 
we shall content ourselves here with a brief summary otf his 
account. It should be borne in mind that in the seventies, 
when this was written, certain views in regard to the origin and 
relations of rocks that we now regar das unquestionably 
igneous, such as granite, were then prevalent, and had great in- 
finence in his inter pretation of the geology of the White Moun- 
tains. We may add also, that where thr ough a knowledge of the 
local geology we are able to disentangle the facts, observed in 
the field by Hitchcock himself, from these hypothetical views 
and from the observations and views of other people, not infre- 
quently incorrect, with which they are more or Jess mingled, they 
are generally confirmed by our own studies. Hitchcock’s under- 
standing of its geology is most easily explained by the aid of 
the generalized section which he gives and which we have repro- 
duced in fig. 4. His results were obtained by a traverse up 
Slide Brook, whose rock bed had been largely laid bare by 
the then recent avalanche. This stream he calls Nor way 
Brook, for a reason mentioned later. He found the porphy ritie 
granite of the lower valley floor succeeded by an area of a labra- 
dorite feldspar rock, which is called “ossipite”’; this is succeeded 
by “syenite,’ which changes in character as one proceeds 


* The Geology of New Hampshire, by C. H. Hitchcock, 3 vols, 1877. 


276 =Pirsson and Rice—Geology of Tripyramid Mountain. 


upward according to the arrangement shown in fig. 4. On the 
east side of the mountain the rocks occur in the same order 
ascending from Sabba Day Brook. Labradorite rock occurs 
on this stream Blo: on the authority of his assistant, Prof. J. H. 
Huntington, and is in contact with granite of the Conway 
type. 

The occurrences and contacts as seen -Appealen to Hitchcock 
as irruptive ones and he suggests clearly that the syenite is an 
eruptive mass; but, influenced by the theoretical views pre- 
viously mentioned, he attempts to classify ossipite (gaobro) and 
porphyritic eranite as “formations” with the equivalence of sed- 
imentary beds.* Through, and upon these, if we understand 
his view correctly, successive layers of syenite were poured out 
and the whole then slightly folded. Thus the section is drawn as 
given and he considers the mountain to be a syneline in its 
structure. Leaving aside this interpretation, which in light of 
our present knowledge i is impossible, and with a minor change, 
we shall show later that Hitchcock’s idea of the general struc- 
ture of the mountain isa possible one which must be consid- 
ered in any discussion of its geology. 


Geology. 


Our geological field work within the area shown on the map 
has been confined to the western two-thirds,. including the 
north and south slopes of Tripyramid, traverses of its crest line 
and exploration generally of the western half of the area. 
The ridge leading southeast from Tripyramid to Whiteface 
Mountain, beyond the limits of the map, has also been traversed ; 
but combinations of want of time, bad weather and lack of 
camping equipage have prevented us from exploring the lower 
eastern slopes of the mountain in the valley of Sabba Day 
Brook and we have here been obliged to fall back on the obser- 
vations of Prof. J. H. Huntington, as given in Hitchcock’s 
report and mentioned later. The manner in which the geology 
is concealed and the difficulty of traversing parts of the area 
have been already alluded to, and one might say here that the 
true petrological history of lar ge areas of ‘the White Mountains 
cannot, under existing conditions, be adequately deciphered, the 
covering of glacial drift, débris and vegetation is so complete. 
Most interesting problems are suggested by many exposures and 
occurrences, but the data for their solution cannot be obtained. 

What we have learned concerning the area covered by the 
map is put down upon it and the conclusions we have drawn 

* Later (op. cit., vol. IJ, p. 667) Hitchcock appears to have considered it 


possible that the gabbro was eruptive and that the ‘‘Labrador formation” 
may not exist in New Hampshire. 


Pirsson and Rice—Geology of Tripyramid Mountain. 277 


will be given later. With this preliminary statement the 
details of the local geology follow. 

The Granite.—In the western half of the mapped area, 
wherever we have been able to find the underlying country 
rock exposed, it proves always to be of granite. Thus in the 
“Ledges” above the hotel at Waterville and along the ridge ; 
in Snow’s Mountain; in the cascades on Cascade Brook; in 
the areas of bed-rock exposed in the lower course of Slide 
Brook, as at Norway Rapids; in the exposures at the Scaur 
and in the Flume this is always the case. We infer from this 
that the western part of the mapped area is underlain by 
granite. This is only part of the great granite mass which 
extends northward into the peaks of Osceola and Kancamagus, 
southward into Sandwich Dome as far as Noon Peak and Jen- 
nings Peak, and westward to the base of Mount Tecumseh* 
where it is succeeded by mica schists not yet eroded. It isa 
part ef what we consider the great batholith which forms this 
southern part of the White Mountains, and it seems to us a 
reasonable conjecture that upon its descending southern slope 
the mica schists still rest in irregular manner, and represent the 
upturned beds, which, by folding, metamorphism, and the intru- 
sion of the granite, have been converted into gneisses and schists. 

The granite itself is of a common type, a coarse-grained 
mixture of flesh-colored alkalic feldspar and gray quartz with 
a little biotite, and it is usually more or less altered in the visible 
exposures. In places, as at Norway Rapids, the granite is por- 
phyritie with larger distinct phenocrysts of orthoclase feldspar, 
and in Snow’s Mountain to the southern edge of the map and 
beyond this character is persistent. Hitchcock on his geolog- 
ical map makes a distinct boundary between the two varieties 
of granite, but we do not feel that the amount of evidence we 
could obtain warrants this. We do not know whether the por- 
phyritic variety is a textural phase of the batholith, or whether 
there are two granites of different periods of invasion present, 
and, if so, which is the younger. Either assumption appears a 
possible one. On the eastern edge of the area covered by the 
map Prof. Huntington found that the falls on Sabba Day 
Brook are cut in granite of the “Conway” type and that this 
is the “common rock of the country.” It extends upward for 
a mile and is succeeded by gabbro, as discussed later. From 
this survey then it appears that the general mass of Tripyra- 
mid is known to be surrounded on all sides by granite, except 
on the southeast, where possibly there may be a continuation 
of its igneous rock into Mt. Whiteface, which is also a syenite. 

* The map accompanying the Hitchcock report shows Mount Tecumseh 


as composed of granite, but this is wrong, for certainly the greater part of 
it is mica schist. 


278 ~=Pirsson and Leice—Geology of Tripyramid Mountain. 


The actual contact of its rocks with the granite has, however, 
nowhere been seen by us. It is also notable that topographic- 
ally the mass rises everywhere high above the granite imme- 
diately about it, though elsewhere the granite, as in Mt. Osce- 
ola a few miles to the northwest, rises to similar elevations. 

Avalanche Brook and the North Slide.—The narrow valley 
of Avalanche brook is in general cut in glacial drift and the 
narrow stream bed is of transported blocks and pebbles. But 
about a mile above its mouth there is exposed a very heavy 
ledge of coarse black gabbro, sloping down stream, over which 
the brook descends. The length of the exposed area is about 
100 feet. It shows a thick heavy sheeting with strike approx- 
imately N. 70° E. and a dip of 25° NW. Theslope of the sur- 
face is about parallel to the sheet jointing, which apparently 
conditions it. The rock is identical in all respects with the 
gabbro, or “ossipite” of Hitchcock, from the Black Cascade 
on Slide Brook, mentioned later. It also appears as a ledge in 
the wood road south of the stream on the bench above, but in 
the woods no outcrops have been observed. 

Above this for a quarter of a mile, or less, there are no 
exposures until the foot of the North Slide is reached. From 
here almost to the very top of the North Pyramid is a contin- 
uous surface of naked rock which extends far up to the head 
of the gulch and also shows in massive outcrops on the lower 
slopes of the opposite Fourth Pyramid. 

The rock forming the lower portion of the exposed mass is 
a moderately coarse-grained, yellowish gray monzonite, which 
is more or less altered; the biotite which it contains resists 
weathering somewhat better than the hornblende, the latter 
being dull in luster, or even converted into earthy spots of 
iron oxide. This rock persists up the Slide to an elevation of 
about 400 feet above the stream, as determined by the aneroid, 
where it gives place to a flesh-colored syenite which extends 
from here to the top of the peak. 

The contact between the two rock types runs E. and W. 
magnetic across the slope, and thus descends from a higher 
point on the eastern side diagonally downward to a lower one 
on the western, a fact whose significance will be considered 
later. The contact plane appears nearly vertical, so far down 
as it can be seen. In the years immediately following the 
slide and the exposure of the fresh rock surface, this contact, 
or rather the contrast in color of the red syenite above and 
the gray monzonite below, as seen in mass at a distance, was 
a very noticeable feature. Since then weathering has dulled 
the colors and the growth of mosses and lichens upon the rocks 
renders them much alike in appearance. When close at hand, 
however, the contact was then, and is now, discovered with dif- 


Pirsson and Rice—Geology of Tripyramid Mountain. 279 


fieulty. As traced along the slope it shows little or no endo- 
morphie effect in either type of rock, except that in the syenite 
there is a narrow zone of two or three inches in thickness in 
which the grain is a little finer and in which it is enriched in 
spots with hornblende. Apart from this there is no change in 
texture, nor anything that would indicate a contact except the 
abrupt change in mineral composition. Another interesting 
feature in this connection is that the great mass exposed in the 
Slide shows everywhere a sheet jointing, similar to that seen in 
the gabbro previously described, and this sheeting, sometimes 
thick and heavy, sometimes thin and shelly, passes through both 
rock varieties and across the contact, as if it were in a unit mass 
of ove rock type. The apparent significance of this is discussed 
later. This sheeting, which is seen in fig. 2, conditions the 
naked rock slopes seen on the Slide, which for long distances 
are parallel to it, with a dip of about 25°-30°. It is also of 
interest that the monzonite in the higher exposures in the head 
of the Ravine of Avalanches and on the south slopes of 
Fourth Pyramid, where it appears in massive outcrops, is quite 
fine-textured. 

Above the monzonite, the syenite, as already mentioned, 
extends to the top of the pyramid. Along the surface of the 
Slide the rock is fairly fresh and solid, but the top consists of 
broken blocks and débris in place, and is more altered. 
The three pyramids and the whole top of the mountain are 
composed of this flesh-colored svenite, always in this state of 
broken blocks and débris, and everywhere covered with a more 
or less dense thicket of spruce. These conditions make its 
lower limit uncertain, but it pretty surely extends down as far 
as the 3500 contour line and is thus shown on the map. 

South Slide and Brook.—On Slide Brook and above its 
junction with Avalanche Brook the first rock in place is found 
at the Black Cascade, a very short distance above the mouth 
of Cold Brook. Here the stream pours over a low cliff of 
gabbro, forming a fall some 15-20 feet high. The gabbro 
is a black, heavy, very coarse-grained rock, quite similar to 
that seen on Avalanche Brook, but of somewhat coarser tex- 
ture. This is the original “ossipite” of Hitcheock,* which 
because of its containing labradorite was placed in the “ Labra- 
dor System” in the New Hampshire report (according to 
Sterry Hunt’s classification of the Azoic formations, which 
was followed by Hitchcock at that time, but later considered 
by him as doubtful). A chemical study of the rock was made 
by E. 8S. Dana,t who deduced that it consisted chiefly of 
labradorite, with some olivine, and a little ilmenite; and as it 


* Op. cit., vol. i, pp. 387-40, vol. ii, pp. 213 et seq. 
+ This Journal, 3d series, vol. iii, pp. 48-50, 1872. 


280 =Pirsson and Rice—Geology of Tripyramid Mountain. 


was thought to be a new rock kind the above name was given 
to it. This was before the microscope had been used to study 
thin rock sections in this country and the presence of pyroxene 
in the rock remained undetected. Thus it is actually a gabbro, 
though a very feldspathic one, as will be shown in the later 
paper on the petrography of the area. : 

The rock formed part of the “ Norian system” of Hitchcock, 
a term that was later supplanted by “ Labrador systein,’”’ and 
from the name “ Norian” the stream was called “Norway 
Brook” by him. 

This black gabbro extends up stream, forming an exposure 
about 500 feet long in the brook bed, where it is found-in a 
massive, sloping, smooth-surfaced outcrop in contact with a 
rock of very different appearance. This is brownish to reddish 
gray in color, and, on a freshly fractured surface, is evenly 
mottled light and dark with feldspathic and ferromagnesian 
constituents, and is of medium granular texture. The petro- 
graphical study shows it to consist chiefly of plagioclase, 
hypersthene and iron ore, with some augite and biotite. It is, 
therefore, a norite, and chemically is closely related to the 
adjoining gabbro, but the contrast between the two in color 
and appearance is striking. 

The contact of the two types is clearly shown for many yards 
on a smooth surface, kept clean and bright by the stream 
washing over it. Its general course is about N. and 8. It is 
not an even line but a broken one with offsets. The contact 
appears at first sight irruptive and it seems that one of the 
masses must have broken through the other. But on close 
study it is found difficult to say definitely which is the older. 
The contact is firmly welded, and both types come up to it 
without change in texture or minerals, so no endomorphic 
effects are visible. Nor does careful search show clearly 
definite fragments of the one type enciosed in the other. In 
one place the gabbro is penetrated by light-colored material in 
a small dikelet which may be norite or aplite, its altered condi- 
tion making it difficult to decide which. In addition the rock- 
mass has a massive sheet-jointing which passes through both 
and crosses the contact as if in a rock of uniform composition. 
It has a northerly dip varying from N. 45° W. to N. 25° E. 
Both kinds have been much cracked and the cracks healed by a 
later pneumatolytic deposit which shows as fine, whitish aplitic 
stringers, often as thin as cardboard, but sometimes widening 
out to narrow dikes and then in some cases assuming a pegmatitic 
aspect. In one place for a number of feet a crack has occurred 
along the contact, or closely adjacent, and this is filled like the 
rest. 


Pirsson and Rice—Geology of Tripyramid Mountain. 281 


While one cannot pronounce with the certainty that is 
desirable which is the younger of the two rocks, the study 
leaves a feeling and belief that the norite is, and this is con- 
firmed in considerable measure by the micro-study of the 
norite, given in detail later, which shows its feldspar crystals 
bent and broken near the contact from movement under pres- 
sure along the gabbro boundary, while crystallizing. If this is 
so, then the eabbro must have been still very hot when the 
norite came against it, and yet sutticiently stiff, or solidified, to 
retain after the movement the broken angular border which 
characterizes it. 

Ascending the stream bed from here the outcrops of norite 
after a short distance give place to exposures of monzonite. 
This monzonite is precisely similar to that found at the base 
of the North Slide, as previously mentioned. It is usually 
moderately coarse-grained but varies in places to rather fine 
grain; weathers brownish, but on a fresh fracture is rather 
thickly mottled with ferromagnesian minerals which are dull 
in luster and more or less altered. It resembles surprisingly a 
specimen of the more feldspathic monzonite from Monzoni in 
appearance and texture. It is composed of about equal parts 
of orthoclase and plagioclase, with hornblende, some augite 
and biotite, and a little quartz. 

No contact between the norite and monzonite is visible ; if 
such exists it is covered with débris. We are uncertain, there- 
fore, whether there is a sharp contact, as between the gabbro 
and norite, or whether the norite grades into the monzonite. 

Outcrops of monzonite are seen at intervals following up the 
stream, the best exposures being at the little gorge known as 
the “V.” As in the other types of rocks, it has a heavy sheet 
jointing which dips away from the mountain mass. The 
stream, following along the strike of this, has cut away the 
rock so that one wall is made by the jointing planes, the other 
by cross erosion, and this makes a steeply descending gorge. 
Long surfaces of naked rock are exposed over which the stream 
descends and into which it has cut pot-holes. 

Above this no rock in place is seen until the South Slide is 
reached. The stream bed is in débris and drift material and 
filled with bowlders of many rock types, the syenite and mon- 
zonite of the mountain being mixed with glacial erratics. 
Among them some blocks of black gabbro were noticed, and it 
is thought that these may have been brought over the western 
slope of the mountain from the direction of Avalanche Brook 
by the southward movement of the ice. 

The lowest outcrops of rock on the South Slide are about 
half-way up, and are of syenite similar to that of the North 

lide and it is all syenite from here to the top of the South 
Pyramid. 


Am. Jour. Sct.—Fourts Series, Vou. XX XI, No. 184.—Aprin, 1911. 
20 


282 Pirsson and Rice—Geology of Tripyramid Mountain. 


Eastern Side of the Mountain.—The lower eastern slope 
of Tripyramid and the valley of Sabba Day Brook were not 
visited by us for reasons stated, and we are here compelled to 
fall back on. the observations of Huntington and Hitcheock. 
They state that at the falls on Sabba Day Brook, as previously 
mentioned, the exposures are of granite of the Conway type, 
which is the common rock of the country.* It appears on the 
brook, but about a mile higher up it is replaced by an area of 
“labrador” rock. This is stated to have the large cleavable 
feldspars which show the opalescence characteristic of this 
variety. As both Hitchcock and Huntington had visited 
the gabbro (ossipite) locality on Slide Brook and were well 
acquainted with that rock, there can be no reasonable doubt 
but that this area is composed of gabbro similar to the areas 
of it on the western side of the mountain. Apparently the 
reason why Hitchcock did not name it ossipite was because, 
as he states, chrysolite (olivine) was not visible in it (megascop- 
ically of course). We have, therefore, shown an area of it on 
the geological map similar in a general way to that given in 
the atlas accompanying his report. According to his statement 
this area is bounded to the southeast, south, and southwest by 
the porphyritic granite, or gneiss, as he calls it; as no exposures 
are specified we have not attempted to show this on the map. 
In the same place Hitchcock says that on the North Tripyramid 
the syenitic rocks appear in the same order as on Slide Brook, 
“apparently cutting the labradorites.” Though he does not — 
mention specific exposures, it seems clear from this that he 
means that the monzonite (his gray syenite) occurs also on this 
side of the mountain, and his section, previously given, is drawn 
in accordance with this idea. 

Dikes.—No very large or important dikes have been seen 
by us in the areas of exposed bed-rock. The largest are two 
black dikes of altered camptonite, about 6—8 feet thick, which, 
at right angles to one another, eut the porphyritic granite at 
Norway Rapids, and whose presence in fact conditions the 
small fall in Slide Brook to which this name has been given. 
On the other hand, small dikes and dikelets are very common. 
Thus the gabbro at the Black Cascade is cut by a number of 
dikes of a gray-black, dense trap, varying from a few inches to 
a foot in thickness. One of these is exposed for a hundred 
feet or thereabouts in the rock bed of the stream. The petro- 
graphic study shows these are micro-gabbros. A short distance 
above the contact of the norite with the gabbro the bed-rock 
in the brook is cut by a dike of syenite about 6 feet in thickness 
with trend N. 70° W. In minerals, texture, and appearance 


* Op. cit., vol. ii, p. 217. 


Pirsson and Rice—Geology of Tripyramid Mountain. 288 


this dike is quite similar to the main mass of syenite. On the 
south wall, against the monzonite, there is no special evidence 
of endomorphie result from the contact, but on the north side 
there is a definite fine-grained band, about two feet wide, 
appearing like aplite. The two rocks seem to grade into each 
other. This dike is of importance in considering the genesis 
of the Tripyramid complex, as will be seen later. 

Narrow dikes of aplite consisting of alkalic feldspar and 
quartz, with a small quantity of biotite, are very common and 
eut all the other rocks of the complex. When of some thick- 
ness, that is from a few inches up to two feet, they have the 
sugar-granular texture of ordinary aplites ; when less than this 
they may become quite dense and felsitic. The coarser ones 
may be grayish or brownish white, but usually they are a 
strong flesh-pink. One of these, about 6 inches thick, cuts both 
gabbro and norite at the contact on Slide Brook, and another 
of two feet in width traverses the monzonite in the rock bed 
of the stream just above the “V.” Narrow stringers and 
dikelets are very numerous and may be seen traversing the 
surface of the North Slide. 

No general system of trend has been observed among the 
dikes, only in limited areas the parallel and reticulated arrange- © 
ment of aplitic stringers shows quite clearly that they fill joint 
systems, which have been cemented and healed by them, as in 
the norite and gabbro exposed at the contact on Slide Brook. 

Jointing.—The jointing of the rock masses composing the 
complex of Tripyramid has been alluded to in several places. It 
is a matter of importance because, when considered in general. 
it is seen that, except locally near the Black Cascade, it follows 
the surface of an oval dome, considerably eroded, of which the 
Pyramids may be considered the present highest points. This 
ovate sheeting, or onion-like structure, is one not infrequently 
seen in granitic stocks and massifs, and is one often referred ° 
to initial stages of weathering, that is to the shearing effect of 
alternate contraction and expansion produced by exposure 
of bare rock surfaces to the cold of winter and the heat of 
summer. We do not, in the present case, believe it has been 
produced in this way, because it is too regular and massive, 
and because it is just as well developed under heavy coatings 
of glacial till as on exposed surfaces, as may be seen on Ava- 
lanche and Slide brooks. During the period of the ice invasion 
all the superficial effects of pre-glacial weathering must have 
been swept away, and the rock surfaces bitten into rather 
deeply, and at its close certain areas were left exposed to 
weathering, while others were protected by heavy mantles of 
till left upon them. It is suggested that the upper part of 
the mountain was comparatively bare and the glacial deposits 


284 = Pirsson and Rice—Geology of Tripyramid Mountain. 


mostly left upon the lower slopes; and, in accordance with 
this, we find the syenite, although appearing firm and solid in 
the material on the Slides, yet somewhat affected by weather. 
ing when seen under the microscope, and the monzonite very 
much more altered, while the gabbro and norite are very fresh 
and unchanged. 

For these reasons we do not ascribe the sheet jointing to 
exposure, but believe that the explanation for it is to be 
sought in the jointing phenomena incident to the cooling and 
contraction of an intruded igneous mass. In a dome-surfaced 
intrusion, as the planes of cooling descend into the mass, the 
ensuing contraction would produce a sheet jointing, or 
onion-like structure, parallel to its surface. That this is so 
is well shown in some of the more massive of the laccoliths of 
the west. It is not our purpose here to discuss the jointing 
phenomena which ensue in various kinds of intrusions and 
under various conditions, for the subject is too extensive for 
treatment in this place; we merely wish to point out that this 
is one type of jointing which characterizes such intrusions, the 
proof being not merely theoretical, but actual.* And on the 
other hand, the possession of this kind of jointing by an igne- 
ous mass may be legitimately used to help in deducing the 
original form of the intrusion. 


Structure and Origin. 


From what has been said in the foregoing and by reference 
to the geologic map, it will be seen that, accepting the field 
observations of Hitchcock and Huntington on the eastern side, 
we have three sections up the mountain, one on the north- 
northwest slope, one on the south-southwest slope, and one on 
the east; that is roughly, in a general way, at 120° from one 
another. Disregarding the narrow norite phase on Slide 
Brook, each of these gives the same sequence of rock types, 
as follows: first, the general granite of the region, which at 
about 2,500 teet elevation is succeeded by a coarse-grained 
black gabbro; this gives way to monzonite, which at 3,500 feet 
(on the North Slide) is in turn replaced by the syenite which 
forms the upper part of Tripyramid. Thus the succession 
reads granite, gabbro, monzonite, syenite. It is this succession 
which led Hitchcock to draw the section we have previously 
given and to consider the mountain as of synclinal structure. 
It is evident from his remarks that his observations led him 
to consider it, aside from the gabbro, as aneruptive mass. Dis- 
regarding the views about stratification in the gabbro and syn_ 

* As in Square Butte in the Highwood Mts. of Montana, referred to later. 
Conf. also Ramsay, Das Nephelinsyenitgebiet auf der Halbinsel Kola, 
Fennia, xi, No. 2, p. 81, 1894. 


Pirsson and Rice—Geology of Tripyramid Mountain. 285 


clinal folding, Hitcheock’s section suggests one interpretation 
for the structure of Tripyramid which at first thought appears 
possible, that is, it may consist of successive layers of gabbro, 
monzonite and syenite erupted through the granite and on 
top of one another in the order named, and beneath some cover 
which has since disappeared, with the semblance to a sedimen- 
tary succession. 

We do not believe this view is tenable; it is negatived by 
the character of the contacts, which where visible are vertical 
or approximately so, by the dome-jointing, and by the direc- 
tion of the contact between the monzonite and syenite on the 
North Slide, which in this case, instead of striking diagonally 


Fie. 5. 


Fic. 5. Inferred geological map of Tripyramid intrusion. Legend as 
before. 


down the slope to the west, as it does, should follow round the 
mountain on a contour line. 

The sequences referred to suggest very naturally that Tri- 
pyramid is a differentiated mass of igneous rock, and, as has been 
found to be so commonly the case elsewhere, it begins with an 
outer basic border, succeeded by a less basic inner part which 
in turn gives way to an acid interior core. If we take into 
account the facts as observed and imagine to ourselves the 
geology of bed-rock that would be exposed if all the overlying 
material should be removed, we should have the relations shown 
in fig. 5, adjoining. In this, the southeast corner has been left 
indefinite for the reason, previously stated, that we do not know 
whether the Tripyramid mass is definitely cut off from that of 
Mt. Whiteface by the granite, or not. It is to be understood 
that these boundaries are not to be taken in a hard and fast 
way, as representing everywhere what we believe to be the 
exact location of definite geological contact lines. They only 
show in a general, or diagrammatic, manner what we believe 


286 =Pirsson and Rice—Geology of Tripyramid Mountain. 


best accords with the ascertained facts. It is, of course, possi- 
ble that the monzonite is entirely surrounded by gabbro, but 
we have no proof of this and have thus shown it only on the 
two sides where the outcrops have been seen, or are reported. 
The relative sizes of the different areas may vary considerably 
from what we have shown, but this is a detail which does not 
affect in principle the correct understanding of the structure 
and petrologic relations of the complex. 

Concentrically arranged complexes of igneous rocks similar 
to this have been described from numerous localities, and of 
alkalie types. Confining exampies to North America, 1 they 
have been shown to be common among the linear groups of 
elevations running southwardly from Montreal and termed the 
Monteregian Hills by Professor Adams, which have been 
described by him and other Canadian geologists.* _Washing- 
ton has shown this arrangement exists at Magnet Cove, Arkan- 
sas, and also in the complex in Essex County, Mass.t Other 
examples have been described from several localities in 
Montana.t Still others might be mentioned, but the dozen 
here cited are sufficient to illustrate this mode of occurrence 
and serve as a basis for discussion. 

On the grounds of the field evidence obtained the authors 
cited have in some of these cases considered the occurrence as a 
laccolith within which subsequent differentiation has produced 
the concentric complex; in others they have held them to be 
stocks, or voleanic necks, i in which differentiation has occurred, 
sometimes with subsequent movement of the differentiated 
bodies of magma. At Square Butte and the Shonkin Sag the 
field evidence as to the laccolithic character of the intrusions 
is ample and decisive, as it seems to be also that Mt. Johnson 
is a volcanic neck and Yogo Peak an intrusive stock. In other 
cases the evidence is less clear, and the nature of the intrusion 
is largely inferred; thus Harker§ questions Washington’s 
interpretation of Magnet Cove as a single differentiated lacco- 
lith, and suggests the alternative view “that it may consist of 
two thin, superposed laccoliths of different composition, which 

* Adams, F. D., The Monteregian Hills, Jour. Geol., xi, p. 239, 1903. 
Dresser, T. A., Geology and Petrog. of Shefford Mt., Quebec, Ann. Rep. 
Canad. Geol. Sury., xtii, pt. L, 1902. Geology of Brome Mt., this Journal, 
xvii, p. 347, 1904. Young, G. A., Geology and Petrog. of Mt. Yamaska, 
Quebec ; Ann. Rep. Canad. Geol. Sury., xvi, pt. H, 1906. 

+ Washington, H. S., Igneous Complex at Magnet Cove, Bull. Geol. Soc. 
Amer., xl, p. 389, 1900. Foyaite-Iolite Series of Magnet Cove, Jour. Geol., 
ix, p. 607, 1901. Petrog. Province of Essex Co., Mass., ibid., viii, p. 473, 1899. 

t Weed and Pirsson, Highwood Mts. of Montana, Geol. Soc. Bull. Amer., 
vi, p. 400, 1895. Igneous Rocks of Yogo Peak, Montana, this Journal, 
1, p. 467, 1895; 20th Ann. Rep. U.S. Geol. Surv., pt. III, p. 563, 1900. 
Bearpaw Mts. of Montana, this Journal, i, p. 3951, 1896. Shonkin Sag and 


Palisade Butte Laccoliths, ibid., xii, p. 1, 1901. 
§ Geol. Mag., Dec. iv, vol, 1X, p. 17, 1902, 


Pirsson and Rice— Geology of Tripyramid Mountain. 287 


have been subsequently domed by quaquaversal uplift and then 
eroded, thus producing the concentric arrangement. 

In this connection the nature of the contacts, or of the tran- 
sition of one type of rock in the complex into another type, is 
of importance though generally little is said upon this matter. 
At first thought it might appear that, if the intrusion were a 
laceolith in which differentiation had taken place an sctu after 
the magma had come to rest, the transition of one type into 
another would be gradual and extended over some distance, 
while if the change of one kind of rock into another takes 
place abruptly, as in an ordinary contact, this would be 
evidence that the intrusions of magma were successive. The 
matter is not, however, so simple as might be inferred from 
the above statement. Oases of transition there undoubtedly 
are, but at Square Butte the transition zone reduces to a few 
inches, or even less, while in the Shonkin Sag laccolith, one of 
the most evident instances of differentiation in place that we 
know of, the change is very abrupt and quite like an ordinary con- 
tact, except, of course, that there are no endomorphie effects in 
either type. It is conceivable that differentiation in the liquid 
form may be so complete as to yield fluid masses which come 
together in contact with definite surfaces, like oil and water 
for example. And on the other hand, if the differentiation is due 
to fractional crystallization about the borders of a closed cham- 
ber, it might happen that a certain set of components would 
separate out until a definite relation, possibly eutectic, was 
established among those composing the rest of the fluid, where- 
upon an abrupt change in the crystallizing minerals would 
occur. 

Therefore, to our minds, the fact that the transitions from 
one rock type to the other in the Tripyramid complex are 
abrupt as in ordinary contacts is not in itself an absolute proof 
that the differentiation did not take place im sétw, or that there 
must have been successive intrusions of magmas of different 
composition from below upward, although they naturally sug- 
gest this. 

Considering first some of the hypotheses that have been 
offered to explain concentric igneous masses, it appears that 
Harker’s suggestion that this arrangement at Magnet Cove 
may be.due to the doming and erosion of superposed sheets is 
not applicable to Tripyramid for reasons already mentioned, 
namely, the attitude of the contact planes, and the common 
jointing, and also the following one. Accepting this view the 
gabbro would be the top sheet, next the monzonite and the 
syenite at the bottom. Now the gabbro is coarse-grained, the 
monzonite medium or fine-grained, the syenite, by comparison 
with the gabbro, fine-grained ; and we should thus be presented 


288 Pirsson and Rice—Geology of Tripyramid Mountain. 


with the anomaly that when the mass is deeply penetrated the 
grain becomes finer, which would be contrary to experience. 

It has been sometimes suggested that the zonal arrangement 
of different rock-types in an intruded mass may be due to the 
absorption and assimilation of the surrounding country rock. 
In the present case the enclosing rocks were of acidic types, 
granite below, mica-schists and perhaps gneisses above, while 
the border facies of the intrusion is the basic gabbro. We 
should, therefore, have to imagine that in some manner a body 
of gabbro was intruded which was not affected at its border, 
but which assimilated more and more foreign material towards 
its center, so that the gabbro became a monzonite and* the 
monzonite syenite. Apart from the mechanical difficulty of 
such an operation it is to be noted that the gabbro, as shown by 
analysis, contains 11°5 per cent of lime, the syenite 2°5; there- 
fore, even if we make the most favorable assumption that the 
granite, or schist, absorbed contained no lime, it would require 
that the gabbro should make a thorough absorption and mixing 
ot between four and five times its own weight of country rock 
to produce the syenite. In the upper (and outer) parts of the 
syenite we have observed in several places small areas from a 
few feet across down to several inches where the rock differs 
from the main type in finer grain, more ferromagnesian 
minerals and a streaky appearance, and it is possible that these 
may represent blocks from the roof which sank into the mass 
and have been mostly resorbed and charged with syenite 
magma; but the view that the whole body of syenite could 
have been made from the gabbro by such a process, the above 
considerations, it seems to us, are sufficient to refute. 

After a review of these alternative hypotheses it is now in 
order to seek one which will best fit all of the varied facts which 
have been presented concerning the geology of Tripyramid. 
Brietly stated the facts are as follows: First, the concentric 
arrangement with the most basic rock at the margin and the 
most acidic inside; second, the abrupt transition of one type 
into another, with angular broken contact line in places, and 
yet with very slight though perceptible evidences of contact 
metamorphic effects; third, probable intrusion of the gabbro by 
the norite and positive intrusion of the monzonite norite by the 
syenite as shown by the dikes above the contact on Slide 
Brook* ; fourth, the common sheet jointing which passes 
through contacts as in a unit mass; fifth, the final intrusion of 
aplite dikes. 

The concentric arrangement naturally suggests a differentia- 
tion of a body of magma in place, as at the Square Butte and 

* A bowlder of gabbro on Slide Brook was noticed to be cut apparently by 
a dike of fine-grained monzonite, about 10 inches wide. Not being in place 


it cannot be regarded as conclusive evidence but tends to confirm the view 
that the gabbro solidified first. 


Pirsson and Rice—Geology of Tripyramid Mountain. 289 


Shonkin Sag laccoliths, but this is negatived by the contacts 
and the syenite dike. The latter suggest a series of successive 
intrusions; but the zonal arrangement, the common sheet 
jointing and the small amount of endomorphic effect show that 
this could not have been of the ordinary character. 

Between the differentiation of a unitary body of injected 
magma at one extreme and a series of successive intrusions, as 
one ordinarily finds such a process evinced, at the other, which 
might give rise to an igneous complex, it is easily possible to 
imagine a whole chain of gradations. It appears to us that what 
best explains Tripyramid is a process of intermediate nature, 
in which both differentiation and repeated intrusions, separated 
by only short intervals, took place. We might imagine this to 
be somewhat as follows: First, the intrusion of a body of 
monzonitic magma through the granite and between it and a 
cover of schists; second, differentiation in the body with pro- 
duction of basic border masses, either by diffusion of the femic 
molecules to the margin, or by their crystallization at the 
edge, or both, with production of the gabbro and cooling in 
this region until the latter had acquired a certain solidity ; 
third, an upward movement of magma from below with 
ruptures along the inner border of the gabbro and the bringing 
of material of a somewhat different composition against it ; 
fourth, differentiation continuing with formation of the inner 
body of syenite and progressive solidification of the main 
monzonite body from the margins and from above inwardly ; 
fifth, further upward movement of magma from below, ruptur- 
ing along the edges of the solidified monzonite, bringing 
syenite magma against it with the injection in places of 
syenite dikes into it; sixth, cooling and solidification of the 
syenite, and, lastly, injection of the final, most highly differen- 
tiated and acid product from within and below, upward and 
outners into the consolidated parts with formation of aplite 

ikes. 

We therefore think that the two upward movements here 
indicated were not of sufficient amount, or volume, to destroy 
the zonal effects of differentiation, but sufficient to modify it in 
the manner indicated, and they must have produced a further 
doming of the upper surface of the intruded mass. We sug- 
gest that they occurred while the already solidified parts were 
still hot, and before jointing from contraction had taken place; 
this would explain the small amount of endomorphism seen 
and the fact that the subsequent jointing took place asin a unit 
rock body. It is possible that still another uplift of magma 
may be indicated by a contact between the norite and monzonite 
on Slide Brook, or they may grade into one another, but upon 
this point, for reasons previously stated, the evidence is 
wanting. 


290 Pérsson and Rice-—Geology of Tripyramid Mountain. 


The lamprophyrie dikes may be regarded as complementary 
to the syenite-aplite and their peripheral situation in the gab- 
bro and contiguous granite is the customary one. 

In regard to the roof of the intrusion, it is known that a few 
miles to the south and to the west the granite batholith gives 
place to mica schists beneath which it may reasonably be sup- 
posed to descend, as previously stated. We suggest that this 
roof had once a greater extension to the northward over the 
now exposed granite, and that the Tripyramid mass was, in 
large part, intruded between the uneven surface of the granite 
and the mica schists, doming up the latter, as indicated in 
fig. 6, in a purely diagrammatic way. 


pee < 
ee 
aE et eey ep 


athens gern 
+ 


Fic. 6. Diagrammatic section to illustrate the probable origin and struc- 
ture of Tripyramid Mt. 


This conception makes the intrusion laccolithic in its nature. 
We do not desire to insist too strongly on this point because 
we know so little of the relation of the igneous mass to the 
surrounding granite beyond the fact that at three different 
points on its edges the gabbro begins at about the same eleva- 
vation. And we are also uncertain concerning the boundary 
on the southeastern side. But it seems rather strongly indi- 
cated, from the present shape of the mass and its sheet jointing, 
that its upper surface had the domed form seen in laccoliths; 
and, as this view of its structure seems the one best fitted 
to bring into harmonious relation the varied parts and corre- 
late it with similar occurrences elsewhere, it seems natural to 
adopt it. According to this conception the sheeted jointing 
merely represents the effects of contraction, as the planes of 
cooling parallel to the domed surface descended into the solidi- 
fied but still heated mass, as has been already discussed. 

Weare quite conscious, in provisionally adopting this hypothe- 
sis and in fact endeavoring to elucidate the structure of Tri- 
pyramid, that more and better evidence would be desirable, but, 
considering the facts that we have been able to obtain, this on 
the whole seems the most accordant with them. 


Summary. 


Tripyramid Mountain is an igneous intrusion consisting of 
several rock types concentrically arranged. On the outer bor- 


Pirsson and Rice— Geology of Tripyramid Mountain. 291 


ders are masses of coarse-grained gabbro which are succeeded 
inwardly and above by monzonite and these by an inner core 
of syenite. Where these are seen to meet there is a sharp transi- 
tion line but only slight endomorphic evidence of contact. The 
mass is surrounded with granite, but no contacts with this have 
been found. It is characterized by a parting or sheet jointing, 
common to all the rock types parallel to a dome surface. The 
study has led to the conclusion that it is probably laccolithic 
and that the different rock types have been formed by a com- 
bination of differentiation and repeated upward movements of 
magma, a process intermediate between differentiation im s¢tw 
and successive separated intrusions. Finally a rather full dis- 
cussion of the bearing of the contacts and of the jointing on 
various hypotheses is given, not alone for the purpose of elu- 
cidating the origin and structure of the mountain, but also to 
invite consideration and discussion of these as criteria in judg- 
ing of the nature of complex intrusions. 


New Haven and Middletown, Conn., Dec. 1910. 


292 MeNair—A Method in Teaching Optical Mineralogy. 


Art. XX VII.—Wote on a Method in Teaching Optical Miner- 
alogy ; by F. W. McNair. 


Tue writer has for some years given a short non-mathemati- 
cal course in polarized light as related to crystals, for the pur- 
pose of preparing students to take up optical mineralogy, the 
latter being applied in turn to the study of rocks. The course 
has been necessarily very brief, non-mathematical, and confined 
to the bare essentials needed to develop its applications. Under 
these conditions an attempt has been made to give the student . 
a logical basis for his conclusions, to develop in him some 
ability to reason about observed phenomena, and so to render 
him as far as may be independent of mere rules of procedure. 

In the effort to condense the course, and to base its entire 
structure on the smallest possible number of new ideas, the 
form of the wave shell and the deductions therefrom have been 
rested as directly as possible upon the so-called reciprocal ellip- 
soid, as introduced by McCullagh. It will be remembered 
that this ellipsoid, whose equation is 


on" 2 2g? 
pe hts ee oi 
c 


a 6° 


is constructed on semi-axes proportional to the square roots of 
the elasticities in the three principal directions. In the usual 
notation, these axes are named so that a@>6>¢e and their direc- 
tions are labeled respectively A, Band ©. This ellipsoid gives 
the wave shell, or ray surface, by the following construction : 
if through the center perpendicular to a given ray direction a 
plane is passed, the section is an ellipse, and if on the ray 
direction, distances be laid off proportional to the semi-axes 
of the ellipse the locus of all points so determined is the 
wave shell. Furthermore, the vibration directions belonging 
to the given ray lie in planes determined by the ray and the 
axes of the elliptical section. 

If one may judge by the text books, the ellipsoid, whether 
that of Fresnel or this of McCullagh, is used in the non- 
mathematical presentations of this subject to obtain the wave 
shell, or rather its three principal sections, and is then imme- 
diately abandoned. The device which occurred to me some 
years since, and which I have found useful in obtaining results 
with my students, is to carry the use of the ellipsoid into a 
considerable number of the applications of the theory to the 
properties of crystals. The “section cut from the ellipsoid” 


McNair—A Method in Teaching Optical Mineralogy. 293 


is used at once in accounting for the phenomena exhibited by 
thin crystal plates between crossed nicols. It is applied next 
to the simple cases of superposition of plates of even thick- 
ness, then to those cases in which the plates are not of even 
thickness. By its use the average student gains some facility 
in predicting the phenomena which will be observed in a 
given case, such, say, as that of an even plate over one shaped 
like a convex lens. Afterward the method is applied to crys- 
tal plates in convergent plane polarized light and perhaps the 
most conspicuous example of its usefulness lies in its applica- 
tion to the distinction between positive and negative crystals 
in the convergent beam of plane polarized light. 


Fic. 1. 


Let fig. 1 represent a central section through the converg- 
ent cone which traverses a plate cut perpendicular to the 
acute bisectrix. If the crystal is positive, this acute bisectrix 
is C, the direction of minimum elasticity. If for each ray 
direction the ellipsoid is constructed, and the section perpen- 
dicular to the ray is cut, the elliptical sections will appear in 
this figure only as traces marked E,, E,, ete. If now a dia- 
grammatic plan be made on the assumption that the above 
section coincides with the axial plane, and, for brevity, with 
that plane in “the 45° position”, and if the ellipses be dia- 
grammed on this in their full area, that is, if each be tipped 
into the plane of the diagram before being drawn, we shall 
obtain something like fig. 2. On this figure lines represent- 
ing the position of the hyperbola have been drawn to enable 
it to be referred to the biaxial interference picture, and the 


294 McNair—Method in. Teaching Optical Mineralogy. 


ellipses have been numbered to correspond with those shown 
in fig. 1. The ellipse for the central ray of the cone being 
drawn perpendicular to the C direction has for its semi-axes 
a and 6. 

If now we consider the series of ellipses belonging to rays 
in the A-O, or axial, plane, represented in the section above, it 
will be seen that as we leave the central ray, passing outward 
to rays making a continually increasing angle with the central 
one, the axis perpendicular to the A—O plane remains constant 


Fic. 2. 


and of the value 2b, while the axis in the axial plane decreases 
from its maximum, 2a, toward the value 2c. Furthermore, 
when the ray has the direction of the ray axis of the crystal 
the ellipse obtained for it is a circle. Beyond this ray the axis 
in the A-C plane is the minor axis of the ellipse. Thus it 
appears that the ellipses on one side lie with the major axes at 
right angles to the major axes of those on the other side, the 


McNair—A Method in Teaching Optical Mineralogy. 295 


change occurring at the ray axis, which is close to the nose of 
the hyperbola of the picture. 

Proceeding now from the center of the figure at right angles 
to the axial plane, the ellipses undergo no such change, the 
major axis now remains constant at 2a while the minor axis 
erows smaller, reducing from 2b toward 2c. The major and 
minor axes of these ellipses represent the speeds of the two 
disturbances vibrating respectively in the planes of these axes. 
If we call the difference of these speeds A, as is convenient, it 
is easily seen that A near the nose of the hyperbola is zero, 
and that from this spot it increases toward the center of the 
figure, while at right angles to the trace of the axial plane it 
increases away from the center. Outside of the hyperbola and 
away from the center it increases in numerical value but is 
negative. 

Suppose now that the quartz wedge is pushed over the 
plate, thin edge first, with its vibration directions as indicated 
by the ellipse drawn in its corner. It will readily be seen that 
this ellipse lies parallel to that for the central ray of the cone, 
and to all others inside of the hyperbola. The faster ray in 
the plate will also be the faster in the wedge, and the slower 
in the plate will be slower in the wedge. The effects of 
plate and wedge will be added. Now the location of the color 
bands depends directly on the value of A, hence for a given 
position of the wedge a particular band will be found where 
the combined A of wedge and plate equals the A of the plate 
alone at the original location of the band before the super- 
position of the quartz wedge. As the wedge is advanced the 
combined A at any point of the plate is increased continuously, 
while any particular value of the combined A necessarily shifts 
toward that spot in the plate where A is least. Therefore, as 
the wedge is pushed over, the color fringes will travel from 
the center toward the nose of the hyperbola. Likewise, on 
the line at right angles to the axial plane they must travel in 
toward the center. 

Outside of the hyperbola, however, the ellipses are in crossed 
position, and the slower ray in the plate is now the faster in 
the wedge. <A difference of effects results, and a given color 
fringe will now travel toward a position in the plate where A 
is numerically greater. Therefore, outside of the hyperbola 
the color fringes will travel away from the nose. Of course, 
a reversal of the quartz wedge, either by turning it over to 
reverse the position of its ellipse or pushing it thick end first 
instead of thin, reverses the travel of the fringes. For a neg- 
ative crystal, the travel would be in each case in the opposite 
direction. 

There are approximations in the foregoing which have not 


296 MeNair—A Method in Teaching Optical Mineralogy. 


been pointed out, but which are sufficiently close to avoid the 
possibility of error in any practical application. I have used 
this device with many students, and its justification rests in 
the readiness with which a student who once comprehends the 
meaning of the ellipsoid becomes independent in his applica- 
tion of this test of the quartz wedge, applying the wedge in 
either position, and reasoning out his results with an assurance 
of correctness. If there were no other application I should 
consider that the results have justified my continued use of 
the scheme. It applies of course to the uniaxial crystal and 
the quarter wave-plate, or the first order red, as readily as to 
the biaxial case. 


Michigan College of Mines, Houghton, Michigan, ’ 
Jan, 14th, 1911. 


Handlirsch—New Paleozoic Insects. 297 


_ Art. XX VIUI.—WNew Paleozoic Insects from the Vicinity of 
Mazon Creek, Illinois ; by Anton Hanpuirscu, Imperial 
Natural History Museum, Vienna. 


Tur Carboniferous (Pennsylvanic) ironstone nodules found 
in and around the region of ‘Mazon Oreek, Illinois, form an 
inexhaustible source for our knowledge of the Paleozoic 
insect world. Each new series of these precious pebbles 
examined furnishes new and interesting forms of insects, but 
rarely has one and the same species been represented by more 
than a single specimen. This fact seems to indicate that the 
species hitherto discovered are but a small fraction of the 
whole insect fauna of these far remote times. The more grate- 
fully, then, must we acknowledge the courtesy of Professor 
Charles Schuchert, who has again supplied for study and 
description a rich series of fossils, preserved in the geological 
collections of Yale University. Some years ago he sent me 79 
specimens, all from the vicinity of Mazon Creek, Grundy 
County, Illinois, 11 of which have previously been described. 
Besides 1, which is a Scorpion, and 17, which I am absolutely 
unable to determine, I have been able to classify them all. 
Only 4 of the fossils not hitherto br ought to notice belong to 
known species (Hucenus ovalis Scudder, £. mazonus Melan- 
der and two Blattoidea) ; all the others are new to science. It 
was necessary to establish for these 40 new species, 23 new 
genera, 9 new families and even a new order. Nevertheless, 
the whole can be introduced into the scheme established in my 
“Fossil Insects.” All the new forms are evidently hetero- 
metabolic. With the exception of some Blattoidea there is 
not one type of a modern order to be found in the collection. 
The Paleodictyoptera are. well represented by 6 species; 
many of the other forms belong to the extinct intermediate 
orders which lead from the Palseodictyoptera to the modern 
types (1 Protodonata, 2 Megasecoptera, 19 Protorthoptera, 8 
Protoblattoidea, 1 Sypharopteroid). Only 3 of the new species 
belong to the Blattoidea. 

The fauna of Mazon Creek seems to have been of a similar 
character to that of Commentry, Belgium, and Saarbriicken 
of Europe. It was a fauna of giants in comparison with that 
of our day. 


Order PALAZODICTYOPTERA (Goldenberg). 
Family DICTYONEURID Handlirsch. 


This very archaic family, represented by 30 species in the 
middle productive Carboniferous deposits’ of Europe (Com- 
mentry, Saarbriicken, Hennegau, ete.), seems to be much less 


Am. Journ. Sci.—FourtH Smrins, Vou. XX XI, No. 184.—Aprit, 1911. 
21 


298 Handlirsch—New Paleozoic Lusects from the 


frequent in North America.’ Only 4 species have been 
recorded from America; a fifth one, contained in the Yale 


collection, the type of a new genus, is now added to this 
number. 


ATHYMODICTYA » hew genus. 


Athymodictya parva, new species. Figs. 1, 2. 


A small insect, measuring about 26™™. Wings 17™™. Head 
comparatively small with distinctly vaulted lateral eyes. Pro- 


Hie. 1. 


r--- ----4 


~ 
~ 

S 
F--- 


Fie. 1. Athymodictya parva. x3. 


thorax much shorter than the mesothorax, its body nearl 
twice as broad as long, provided with semicircular lateral lobes. 
Mesothorax robust, almost equal in length and _ breadth. 
Metathorax shorter, its breadth one and a half times greater 
than the length. Abdomen scarcely narrower than the thorax, 
its first segment shorter than the others, the second, the 


Vicinity of Mazon Creek, Illinois. 299 


longest of all, being somewhat broader than long. All the 
seven segments preserved are provided with narrow lateral 
lobes. 

Wings’ with very broad base, horizontally expanded. 
Anterior and posterior wings similar, the latter with distinctly 
dilated basal half. Costal area very narrow’; subcostal vein 
and radius very close together. Radial sector farther removed 
from the base in the anterior 
than in the posterior wing, sep- pe aE, 
arated by a rather broad space 
from the radius and probably pro- 
vided with a single branch, cleft S Rs 
into about 3 twigs. Medial vein SSMS 
split somewhat before the origin 
of the radial sector into a forked 
anterior branch and a_ posterior 
branch divided into 3. twigs. 

Anterior branch of the eubitus ms Ma 
rising ey eae the base, simple Fie. 2. angnnace parva 
in the anterior wing and forked (negative of left wing). x 2°5. 

in the posterior ; posterior branch 

of the eubitus split into a simple and a forked twig. Three 
to four short anal veins. All the spaces between the veins 
filled with a delicate irregular network, one of the character- 
istics of the Dictyoneuride. 

Holotype in Peabody Museum, Yale University, Cat. No. 18. 


Family SYNTONOPTERIDZ‘, new family. 


A splendid anterior wing of a more highly specialized 
Palzeodictyopteron induces me to establish a new family, which 
may be placed near the Mecynopteride and Lithomantide. 
The most striking characteristics of the new family are the 
division of the wing into four nearly equivalent triangular areas, 
occupied by the sector, the two halves of the media, and the 
eubitus; the S-shaped origin of most of the twigs; and the 
comparatively long-vaulted anal veins, provided with a rather 
great number of short branches. 


SYNTONOPTERA, new genus. 
Syntonoptera schucherti, new species. Fig. 3. 


Negative of a left anterior wing with broad base. Length 
about 90", of which 80™™ is preserved. Costal area broad 
near the base, with pointed apex. Costal.and subcostal vein 
convergent; radius nearly parallel with the subcosta and 
moderately far removed. Radial sector rising at about one- 
quarter of the length of the wing, separated from the radius 


300 Handlirsch—New Paleozoic Insects from the 


by a distance equal in breadth to the radio-subcostal space, 
with but (?)3 slightly vaulted branches, one of which (the 
proximal) forms a terminal fork. The space oceupied by the 
sector is comparatively small. The medial vein splits near its 
origin into 2 equivalent branches. Each of these forms a large 
fork in about the center of the wing. All their main branches 
run in regular arches to the border of the wing. From the 
anterior branch of the first fork rise, moreover, 4, from that of 
the second fork 3, S-shaped twigs, directed backward and out- 
ward. The posterior branch of the second fork sends forth 2 
short twigs directed forward and outward. The cubital vein 
splits near the base into 2 main branches; the posterior is split 


Fie. 3. 


------4+ 


—_>S>~ 


=e Sn eee ee ee Ne eee ie AR 

eee eS a a SIN 
gee rae TOS NN 

egress 17 a 
Boo \ 
Shee weleee Y SCY 
SSS e < Bi 

a ey 

~ Se 


Fic. 3. Syntonoptera schuchertt. 


no further, the anterior giving origin to 3 main twigs, the fore- 
most of these widely diverging and sending forth 4 S-shaped 
twigs directed backward. Each of the 2 other main twigs 
forms 3 short apical veinlets. The 2 long-vaulted anal veins, 
directed like the branches of the cubitus to the posterior mar- 
gin of the wing, send out 3 or 5 partly simple, partly forked 
S-shaped branches. Of a third anal vein there is but a frag- 
ment to be seen. 

By the peculiar distribution of the veins and by the parallel 
position of the last radial with the first medial branch, of the 
last medial with the first cubital branch and by the bipartition 
of the medial vein, the surface of the wing seems to be divided 
into 4 triangular areas almost equal in value. 

It is of great interest to see the manner in which the convex 
and concave veins alternate in this wing. We find here a 
proof that the position of the veins above or below merely 
follows mechanical rules and has nothing to do with the origin 
of the veins. The costa is convex, the subcosta concave; the 


Vicinity of Mazon Creek, Lllinois. 301 


radius convex, its sector concave ; of the sector branches, the 
first and the third are concave, the second convex; the first 
main fork of the media is convex, the second concave and their 
branches again alternate like those of the sector ; the anterior 
branch of the cubitus is convex, the posterior concave, the 
twigs like those of the media; first anal vein convex, second 
concave. 

The spaces between all the main branches and veins are 
traversed by cross veins, sometimes forming a diffuse net- 
work. 

Many of the twigs or branches of the longitudinal veins have 
the appearance of intercalary veins like those of Plectoptera 
and Odonata, but this is only a superficial resemblance caused 
by their strongly S-shaped curve 

Holotype in : Peabody Museum, Yale University, Cat. No. 19. 


Family uncertain. 
AMOUSUS, new genus. 


Amousus mazonus, new species. Fig. 4. 


The basal third, 50™™ long, of probably a posterior wing. 
There are to be seen the nearly straight costa, the moderately 
remote subcosta and the radius, whose sector evidently rose in 


Wie. 4. 


Fie. 4. Amousus mazonus. 


the second third of the wing. The medialis splits near the 
base, the anterior branch running for a short distance close 
together with the radius, the posterior braneh soon splitting 
into 2 twigs. The cubitus is divided immediately after its 


origin, its 2 forked branches running steeply to the posterior 


302 Handlirsch—New Paleozoic Insects from the 


margin. Farther backward follow 6 simple short anal veins, 
vaulted in the characteristic manner. Interstices filled with 
irregular network resembling that of the Dictyoneurida, to 
which family this fossil possibly may belong. 

Holotype in Peabody Museum, Yale University, Cat. No. 
20. 


Direxopvs, new genus. 
Diexodus debilis, new species. Fig. 5. 
The specimen consists of 21" of the basal half of a left 


(? posterior) wing. Costal area moderately broad, pointed. 
Costa and subcosta nearly straight, radius close to and parallel 


Fie. 5. 


Fic. 5. Diexodus debilis (negative). x 2°8. 


with the subcosta, sector rising at about a quarter of the length 
of the wing. The media sends forth its first branch somewhat 
distally of the origin of the sector and splits soon after into 
2 branches. Cubitus forked very near the base, the anterior 
main branch splitting into 2 branches, the first of which again 
splits into 3 twigs running in a long vanlt to the posterior 
margin, the second forming only a long fork. The second 
main branch remains undivided. Of the 5 anal veins to be 
seen, some may have a common stem. Cross veins widely 
spread. 

This species possibly may belong to the Lithomantide. 

Holotype in Peabody Museum, Yale University, Cat. No. 21. 


ScEPASMA, new genus. 
Scepasma gigas, new species. Fig. 6. 
A fragment, 60™" long, of the anal region of a posterior 


wing which had probably a length of 180™" and evidently was 
very broad. There are preserved: a strong vein, split into 3 


Vicinity of Mazon Creek, Illinois. 303 


branches, probably the cubitus ; 2 long forked anal veins strongly 
curved downward ; and 10 simple anal veins, joined together 
by delicate and irregular cross veins, forming a diffuse network. 
Though this anal area by the somewhat fan-like arrangement 
of the numerous anal veins recalls the anal areas of more highly 
specialized orders, there is no support for the opinion that it 
eould be folded. 
I am not able to say to which category this giant species may 
belong, but it is certainly a Paleeodiectyopteron. 
_ Holotype in Peabody Museum, Yale University, Cat. No. 
22. 


Fig. 6. 


Fig. 6. Scepasma gigas. 


AMETRETUS, new genus. 
Ametretus levis, new species. Fig. 7. 


A fragment of 37™™ from the base of a ? posterior wing 
measuring probably about 150™". Costa slightly vaulted, par- 
allel with and rather remote from the subcosta, which gives off 
oblique simple or forked veinlets in the costal space. The 
simple basal pieces of the radius and of the medialis are fol- 
lowed by the eubitus, which is curved downward, splitting into 
3 branches. Of the 8 anal veins, which I can distinguish, the 
first, fourth and sixth are forked, the fifth trichotomous, the 
others simple. I cannot see cross veins. 


304 Handlirsch—New Paleozoie Insects from the 


This wing seems to belong to one of the more highly special- 
ized Paleodictyoptera, having a narrower base and no network 
between the veins. 

Holotype in Peabody Museum, Yale University, Cat. No. 
23. 


“= 


Fie. 7. Ametretus levis. 


Order PROTORTHOPTERA Handlirsch. 
Family SPANIODERIDA Handlirsch. 
SpaNIoDERA Handlirsch. 


I have based this genus on a single species. Having now 
before me 7 other forms, it is possible to make a more exact 
description of the generic characters. 

Anterior wing generally with rounded apex. Costa marginal ; 
subcosta shortened, uniting with the radius; radins simple, not 
split at its apex; sector rising very near the base but never 
cleft before the middle of the wing, forming only a small 
number of branches; medial vein cleft near the base into 2 
main branches, remaining either simple or splitting into a few 
twigs. ‘The medialis is always free and never meets with the 
sector. Cubitus long, more or less S-shaped, with 3-6 simple 
or forked branches, bent downward to the posterior margin. 


Vicinity of Mazon Creek, L[llinois. 305 


Anal area limited, comparatively slender and filled by a moder- 
ate number of sinuate veins. Cross veins oblique in the costal 
area, stretched and diffuse in the other areas. Posterior wing 
similar to the anterior, but provided with a large folded anal 
lobe. Prothorax elongated. Head apparently with progna- 
thous mouth parts. Legs homonomous, moderately long. 


Fie. 8. 


ok 
FEN CAN 
fo of 
: Q 


SS 
EFA 


Tes} : 
| LLL 
Pore 
Sie 


Fie. 8. Spaniodera longicollis. x1°'8. 


Spaniodera longicollis, new species. Fig. 8. 


Prothorax very slender, 10™ long. Anterior wing 34™™. 
Very similar to S. ambulans Handlirsch, from which it may 
be distinguished by the longer neck and by some details in the 
wing venation. Apex of the wings broadly rounded ; space 
between the radius and its sector moderately narrow; sector 
cleft into 8 branches; media forked very near the base, its 


306 = Handlirsch—New Paleozoic Insects from the 


anterior branch forming a long fork with, in turn, forked 
branches in the right wing, a simple shorter fork in the left ; 
posterior main branch of the media simple; cubitus provided 
with 1 forked and 4 simple branches in the right, with 6 
simple branches in the left wing. Anal area containing 6 
veins. 


Holotype in Peabody Museum, Yale University, Cat. No. 24. 


Spaniodera lata, new species. Fig. 9. 


Anterior wing 30" long and comparatively broad. Sector 
very far removed from the radius, split into only 2 branches. 
Medial vein branched near the base; in the right wing the 


Fic. 9. 


a5 
— 
(rer aaa] 
She 


DLE 


! eras y 
hip | 

| A, ae | 
I | 

Sai GS-2 
Fic. 9. Spaniodera lata. x 2°6. 


anterior, in the left wing the posterior of these two main 
branches is forked. Cubitus giving rise to 4 branches, the first 
of which is forked in the left, the second in the right wing. 
Costal and subcostal area filled by numerous oblique cross veins ; 
the other cross veins far removed. Anal area showing about 7 
veius of a peculiar specialization. 

Holotype in Peabody Museum, Yale University, Cat. No. 25. 


Vicinity of Mazon Creek, Lllinois. 307 


Spaniodera elatior, new species. Fig. 10. 


Prothorax slender, measuring 8™. Anterior wings 38". 

Subcosta strongly shortened, scarcely reaching the outer half 
; gry renes Ns 

of the wing. Cross veins in the costal and subcostal area much 


Fie. 10. 


Wie. 10. Spaniodera elatior. x2. 


less numerous. Sector far removed from the radius, split into 
3 twigs. Media cleft near the base into an anterior forked and 
a posterior simple.branch. COubitus with 4 branches, the third 
of which is forked in the right wing. Anal area filled by 7-8 
simple veins. 

Holotype in Peabody Museum, Yale University, Cat. No. 26. 


308  Handlirsch—New Paleozoic Insects from the 


Spaniodera schucherti, new species. Fig. 11. 


Anterior wing quite elliptical, not so distinctly enlarged in 
the apical half as in the other species, 30" long. Sector twice 
forked. Medial vein cleft at a greater distance from the base, 
much nearer the middle of the wing, its twigs bent distinctly 
downward to the posterior margin of the wing, the anterior 


Hre. 11. Fie. 12. 


Rs 


Fic. 11. Spaniodera schucherti. x 2. Fie. 12. S. acutipennis. x 2°d. 


one split into 3 twigs, the posterior simple. Cubitus somewhat 
shortened, with but 4 simple branches. Avnal area less slender, 
provided with 7 simple veins. 

Holotype in Peabody Museum, Yale University, Cat. No. 27. 


Spaniodera acutipennis, new species. Fig. 12. 


Length of the anterior wing 33™". Avex distinctly pointed. 
Sector twice forked. Media cleft near the’ base, its anterior 
branch with a terminal fork, its posterior branch simple. Cubi- 
tus shortened, with but 3 branches. Only a few anal veins. 

Holotype in Peabody Museum, Yale University, Cat. No. 28. 


Vicinity of Mazon Creek, Illinois. 309 


Spaniodera parvula, new species. Fig. 13. 


The smallest of all known species; the wings are only 22™" 
in length. Prothorax 5™™. Sector forming only a simple 
fork. Anterior branch of the media trichotomous, posterior 
branch simple. Cubitus long, with 5 branches. Posterior leg 
very slender and comparatively long. 

Holotype in Peabody Museum, Yale Univer sity, Cat. No. 29. 


Fie. 18. Fie. 14. 


ai 


Fie. 138. Spaniodera parvula. x3. Fie, 14. S. angusta. x1°9. 


Spaniodera angusta, new species. Fig. 14. 


Of a very slender shape. Length of the anterior wing 38™", 
of the pronotum 7™™. Radial sector split into 3 or 4 twigs. 
Media cleft very near the base. 


Holotype in Peabody Museum, Yale University, Cat. No. 30. 


Note-——Some of the species described by Scudder and 
Melander may possibly belong to the genus Spaniodera. This 


310 = Handlirsch—New Paleozoic Insects from the 


would be the case with Propteticus infernus Scudder, if the 
drawing of the subcosta should prove to be wrong. The same 
thing is true of Camptophlebia clarinervis Melander and 
Paracheliphlebia extensa Melander, perhaps also of Miamia 
bronsoni and Dieconeurites rigidus Scudder. All these forms 
need careful reéxamination. 


DigrconruRA Scudder. 


Dieconeura mazona, new species. Fig. 15. | 


Body conspicuously long and slender. The 3 segments of 
the thorax nearly equal in length; prothorax narrow, about 


Fie. 15. 


Fic. 15. Dieconewra mazona. x 2°5. 


one and a half times as long as broad, 3°5™™ long. The head 
seems to have been short, with strongly vaulted lateral eyes. 
Abdomen narrower than the thorax, the segments becoming 
shorter from the first to the fourth, then increasing to the 
eighth and ninth. Apex of abdomen extending beyond the 
wings. . 


Vicinity of Mazon Oreek, Lltinors. 311 


Anterior wing slender, 25" in length, its apical border 
obliquely rounded. Subcosta shortened, united at its apex 
with the radius and with the costa. Radius reaching to the 
apex of the wing, not split; its sector rising at one-fourth of 
the wing length, giving off 3 simple and arched branches. 
Media cleft about in the middle of the wing, its anterior main 
branch uniting for a short distance with the sector, then remov- 
ing again and forming a terminal fork. The posterior main 
branch of the media simple. Cubitus strongly S-shaped, with 
3 or 74 simple branches, bent to the posterior margin. Anal 
area long. 

In the posterior wing the sector has 4 simple branches. The 
media is a long fork, quite independent of the sector. 

Holotype in Peabody Museum, Yale University, Cat. No. 31. 


Family SCHUCHERTIELLIDAL, new family. 


This family is based on a rather incomplete anterior wing, 
undoubtedly belonging to the Protorthoptera, but differing 
essentially from all the other types of this order. Protokol- 
laria alone affords a comparison. 


SCHUCHERTIELLA, new genus. 


Schuchertiella gracilis, new species. Fig. 16. 


A right anterior wing, reaching about 30™ in length, only 
19™™ of which is preserved. The form of the wing seems to 


Fie. 16. Schuchertiella gracilis (negative of right wing). x3. 


have been an elliptical one, with slightly arched anterior mar- 
gin. Costal area moderately broad, the subcosta very well 
developed, united with the marginal costa by oblique cross 
veins and certainly not very much shortened. Radius nearly 
parallel to the subcosta and no farther removed than the sub- 
costa from the costa. Radial sector rising at about a quarter 
of the length, splitting about the middle of the wing, probably 


312 Handlirsch—New Paleozoic Insects from the 


into a few branches only. Medial vein cleft somewhat after 
the origin of the sector into 2 main branches, which probably 
were forked again in the apical half of the wing. The media 
is followed by a long vein, slightly curved down toward the 
posterior margin and forked somewhat before the middle of 
the wing. This vein may be either the whole cubitus or the 
anterior branch of it and is attached to the media by an oblique 
bridge which we must suppose to be a proximal branch of the 
media, uniting for but a short space with the cubitus. This 
interpretation being correct, it would tend to reclaim the fol- 
lowing richly ramitied vein for the cubitus, for it is not to be 
assumed that the cubitus could be reduced to a simple vein. 
In the other case it would be possible to designate the above 
mentioned richly ramified vein as the first anal vein. As un- 
doubted anal veins we must acknowledge the 3 oblique veins 
provided with terminal forks, which close the venation at the 
posterior angle of the wing. I see no cross veins but many 
small folds, which induces me to suppose that this wing was a 
delicate and membranous one. 

Holotype in Peabody Museum, Yale University, Cat. No. 32. 


Family GERARIDA Handlirsch. 


The Yale collection contains several new forms evidently 
belonging to this family. The examination of these leads me 
to make some corrections in my first description. 

The prothorax is not, as I supposed, short and stout, but on 
the contrary forms a long neck, which I previously had held 
for a part of the head. The new material shows that this fam- 
ily has no close relationship to the Cidischiide, approaching 
rather to the Spanioderide, from which it principally differs 
by the much more expanded radial sector and the much more 
reduced cubitus. The subcosta shortened, but discharging into 
the costa, not into the radius. Costa marginal. 


GERARUS Scudder. 


Prothorax with a broad base, either provided with tubercles 
or smooth, but in every case produced into a long, neck-like 
part bearing the head. 


Gerarus latus, new species. Fig. 17. 


Anterior wing elliptical, nearly three times longer than 
broad, measuring 44™™. Subcosta not conspicuously shortened, 
with numerous oblique cross veins, and equally far removed 
from the costa and from the radius, the latter nearly reaching 
the apex of the wing. Sector rising very near the base, moving 


Vicinity of Mazon Creek, Illinois. 313 


far away from the radius and sending obliquely toward the 
apical border 6 partly simple, partly forked branches, the 
first of which rises quite in the basal half of the wing. Medial 
vein independent, not meeting with the sector and branched 
in a singular manner: beginning from the base, we first find 2 


Fic. 17. Fie. 18. 


| 


\ 
N\\ 


A 


Fie. 17. Gerarus latus. x1°8. Fie. 18. G. collaris. x 1:4. 


short branches directed backward and not reaching the mar- 
gin; the stem then bends obliquely to the posterior margin, 
emitting obliquely forward 4 branches which retain the primi- 
tive direction of the media. Cubitus comparatively little 
expanded, scarcely reaching the apical half of the wing and 
giving rise to but 3 short branches which are directed back- 
ward. The long and pointed anal area may have been pro- 
vided with-about 5 veins. Traces of the long neck are to be 
seen. 

Holotype in Peabody Museum, Yale University, Cat. No. 33. 

Am. JouR. Sct.—Fourts Serims, Vou. XXXI, No. 184.—Aprin, 1911. 


22 


314 Handlirsch—New Paleozoie Insects from the 


Gerarus colluris, new species. Fig. 18. 


This form seems to be very nearly related to G@. longus 
Handlirsch and may possibly be but a variety of this species. 
The anterior wings have a length of 52™™. Subeosta strongly 
shortened, extending only a little distance in the apical half of 
the wing and provided with numerous oblique veinlets very 
regularly arranged. Radial sector differing somewhat in both 
fore wings; with 5 branches in the right, the first of which 
forms a short apical fork, the second and third trichotomous, 
the fourth and fifth dichotomous; and with 6 branches in the 
left wing, the third of these being trichotomous, the fourth 
and fifth simple, the sixth forked. Media cleft into a long 
fork, the branches of which fork again. COubitus strongly 
reduced, probably with not more than 1 or 2 branches. Sec- 
tor, media and cubitus very close together near the base. 
Prothorax bottle-shaped, without tubercles, more than twice as 
long as broad at the base. 

Holotype in Peabody Museum, Yale University, Cat. No. 34. 


Gerarus (?) reductus, new species. Figs. 19, 20. 


As only fragments of the positive and negative of the right 
anterior wing and of the left anterior and posterior wing are 
preserved, I cannot be positive on the point of the generic 


Fie, 19. 


Fic. 19. Gerarus reductus (negative of two left wings). x 2°2. 


determination of this fossil. The total length of the wing 
may have surpassed 40™, the breadth about 12™™. Costal 
margin gently curved, subcosta shortened, cross veins of the 
costal area forming a network near the base, elsewhere far 
remote, simple and oblique. Radial sector rising very near 
the base, not very far removed from the radius and provided 
with about 6 very regular simple branches directed obliquely 
backward and outward. The media is cleft near the origin of 
the sector into 2 main branches, the anterior of these forming 
a large fork, the posterior cleft no farther. There are to be 
seen but two branches of the cubitus, the anterior of which is 


Fie. 20. 


Fie. 20. Gerarus reductus (negative of right fore wing), x22. 


united to the media by an S-shaped twig. ‘The cross veins are 
straight between subcosta, radius and sector, waved and some- 
times ramified in the medial and cubital region. 

Holotype in Peabody Museum, Yale University, Cat. No. 35. 


Gerarus longicollis, new species. Fig. 21. 


Prothorax 14™" in length, provided in the basal part with 
2 lateral tubercles and with another situated in the middle 
of the hind margin; the neck-like slender anterior portion 
of the prothorax conspicuously thinand long. Head evidently 
broader than the neck. Anterior wing 386" long. Costal 
area broad, subcosta extending about two-thirds of the wing. 
Radius conspicuously far removed from the costa in the apical 
third. Sector rising at a quarter of the length, first diverg- 
ing from and then converging with the radius; of its 4 
branches the first is forked. Media cleft somewhat below 
the origin of the sector, its posterior main branch simple, 
the anterior forked into 2 twigs, the anterior of these uniting 
for a short distance with the radial sector. Cubitus free, 
giving rise to probably but 2 branches directed backward. 

The posterior wing being very fragmentary, it is difficult to 
distinguish media and cubitus, but it is possible to see by the 
different arrangement of these veins that there was present a 
large anal lobe. 

Holotype in Peabody Museum, Yale University, Cat. No. 36. 


GERARULUS, new genus. 


Evidently related to Gerarus but distinguished by the 
strongly expanded apical half of the anterior wing and by the 
radius being branched before the end. Costa marginal ; sub- 
costa shortened, united with the costa. The space between the 
sector and the radius conspicuously enlarged, sector with 


316 Handlirsch—New Paleozoic Insects from the 


numerous branches, media cleft into 2 ramified main branches. 
Cubitus of the anterior wing cleft near the base into 2 forked 
main branches, the anterior of which unites for a short dis- 


Fie. 21. 


Fie. 21. Gerarus longicollis. x18. 


tance with the posterior branch of the media. Anal area of 
the anterior wing not distinctly limited, with but few partly 
ramified veins. Posterior wing with an anal fan. 


Gerarulus radialis, new species. Fig. 22. 


Length of the anterior wing about 30™™ (24"™ only being 
preserved). Costal area comparatively narrow, extending 
about two-thirds of the wing and filled by simple and very 
regularly distributed oblique cross veins. tadius very near 
the subcosta, provided in the apical third with branches 


Vicinity of Mazon Creek, Lllinois. 317 


directed toward the costa. Sector rising at about a quarter 
of the length, widely diverging and giving off about 9 very 
regular branches, the first of which is forked. Media cleft 
into 2 main branches, the anterior of which closely approaches 
the sector. Each of these main branches splits into 3 twigs. 
Cubitus cleft immediately after the origin, its long anterior 
branch touching for a moment the media and then splitting 


Fie. 22. 


Fie. 22. Gerarulus radialis. x2°2. 


into 2 twigs, the posterior branch forming a long fork. First 
anal vein sinuated, with 2 twigs directed ‘backward. In addi- 
tion, there are ? 3’short and simple anal veins to be seen. 

In the posterior wing the radius is ramified in a similar man- 
ner to that in the front wing. ‘The sector rises very near the 
base, does not diverge so far and gives off its branches much 
nearer the base. Media cleft very near the base into 2 rami- 
fied branches. Cubitus with a simple anterior branch approach- 
ing the media and with a waved posterior branch splitting into 
a few twigs. Anal veins simple and straight. 

Holotype in Peabody Museum, Yale University, Cat. No. 37. 


ANEPITEDIUS, new genus. 


The following species, which I consider the type of ies new 
genus, is likewise very closely related to Gerarus and shows a 
slender pear-shaped prothorax, forming a long neck. The 
long wings, with a strongly shortened subcosta, meeting with 
the costa. The radius in its apical portion sends forth some 
ramified S-shaped branches, directed forward. The sector 
rises near the base and appar ently gives off but a few branches. 


318 Handlirsch—New Paleozoic Insects Srom the 


The media likewise forms only few branches and unites in the 
anterior wing with the sector by a short cross vein but remains 
quite independent in the posterior wing. Anal area of the 
posterior wing enlarged and evidently fan-like. 


Fie. 23. 


Fic. 28. Anepitedius giraffa (negative). x 2°2. 


Anepitedius giraffa, new species. Figs. 23-25. 


Prothorax 14" long, somewhat more than twice as long as 
broad at the base, produced into a neck-like form, traversed 
by a ridge and evidently depressed on the sides of the basal 
half. 


Vicinity of Mazon Creek, Illinois. 319 


Wings long and slender, measuring about 40™, 33™" of 
which is preserved. By the superposition of all the four 
wings, the venation becomes very confused and difficult to 
decipher. Subcosta scarcely extending below the middle of 
the wing. Costal area comparatively narrow, traversed by 
about 8-10 regular oblique cross veins. Radius at the same 
distance from the subcosta as the latter is from the costa and 
giving rise to 2 S-shaped forked branches, directed toward the 


Fie. 24. 


Fic. 24. Anepitedius giraffa (anterior wing). x 2°2. 


costal margin. Sector rising near the base and separated from 
the radius by a broad interstice, traversed in the anterior wing 
by oblique, in the posterior by straight cross veins. The sec- 
tor seems to have had but few branches. Media cleft in the 
anterior wing not far above the middle, its anterior branch 


Fie. 25. 


Fic. 25. Anepitedius giraffa (posterior wing). x2"2. 


advancing in a blunt angle until near the sector, uniting with 
it by a short and strong cross vein; the posterior branch is 
forked. In the posterior wing the bifurcation of the media 
seems to take place quite near the base, the anterior branch 
being independent of the sector and forking again near the 
end, the posterior apparently remaining undivided. Oubitus 
forming in the anterior wing a quite free vein cleft into 2 long 
branches. Of the anal veins I cannot see more than 3, which 
are almost parallel. 

Holotype in Peabody Museum, Yale University, Cat. No. 38. 


320 Handlirsch—New Paleozoic Insects from the 


Family APITHANID AL, new family. 


A very singular slender insect, differing from all other groups 
of the Protorthoptera, induces me to establish a new family. 

The pear-shaped prothorax is of a moderate length; the meso- 
thorax somewhat enlarged, bearing the comparatively broad 
anterior wings, which show a singularly specialized venation 
and could be laid backward over the abdomen. The metatho- 
rax conspicuously shorter. Abdomen slender, its first segment 
being the shortest of all, nearly twice as broad as long, the 
second about quadrate, the following to the seventh much 
longer than broad. The end of the abdomen and the posterior 
wing not being preserved, I am not able to say anything 
regarding the appendages and the anal lobe. The (? anterior) 
legs were short and delicate. 

The venation of the anterior wing is a characteristic one: 
the costa marginal; subcosta shortened, united with the costa; 
radius with a short sector, rising outward from the middle of 
the wing and forming a simple fork. Media independent, 
cleft near the middle of the wing into 2 branches. Cubitus 
divided near the base into 2 main branches, the anterior strongly 
waved and making a short terminal fork, the posterior 
trichotomous. Anal area slender, reaching half the length of 
the wing and containing few veins. Cross veins simple and 
oblique in the costal and subcostal area, elsewhere evidently 
very rare. 


APITHANUS, new genus. 
Apithanus jocularis, new species. Figs. 26, 27. 


Prothorax 5™™ long, one and a half times longer than 
broad. Mesothorax nearly quadrate. Metathorax one and a 
half times broader than long. First segment twice as broad 
as long, shorter than the metathorax; second segment quadrate; 
the third to the seventh each longer than broad. The middle 
line of the abdomen showing tubercles on the base and apex 
of each segment. The femora of probably the fore legs short 
and delicate, doubtless not exceeding the length of the protho- 
rax. Anterior wings 30™", three and a fourth times longer 
than broad, dilated in the apical half. Apical margin obliquely 
rounded. Costa marginal, slightly waved. Subcosta extend- 
ing nearly two-thirds the length of the wing, uniting with 
the costa and giving off about 7 oblique veinlets. Radius 
very close to the subcosta in the basal third, farther outward 
more remote, the interstice being traversed by 5 oblique cross 
veins. Sector not rising before the middle of the radius, from 
which it is separated by a broad interstice, and forming only 
one broad fork. Media quite free, cleft somewhat before the 


Vicinity of Mazon Creek, Litinois. 321 


middle into 2 branches converging toward the margin, the 
anterior of these branches being attached to the posterior branch 
of the sector by a long, oblique cross vein. The cubitus run- 
ning nearly parallel with the posterior branch and with the 
stem of the media, splitting quite near the base into an ante- 
rior branch forming a short apical fork and into a posterior 
branch cleft into 8 long branches which descend to the poste- 
rior margin. Anal area long and lancet-shaped, showing dis- 


Fic. 26. 


Fie. 26. Apithanus jocularis. x 2. 


tinctly only 2 veins, but probably there were 2 more which are ° 
not preserved. 
Holotype in Peabody Museum, Yale University, Cat. No. 39. 


Family NARKEMID At, new family. 


Anterior wings laid backward over the abdomen, broad, 
elliptical, with a broad costal area; much shortened subcosta 
uniting with the radius and giving rise like the free end of the 
radius to very regular oblique veinlets reaching the costa and 
being themselves united by cross veins. Sector rising at 
about a quarter of the wing length, giving off a small number 
of branches which are directed toward the apical border. 
Media independent of the radius, simple and only provided 


322 Handlirsch—New Paleozoic Insects from the 


with a short apical fork. Cubitus very well developed, cleft 
near the base, the anterior main branch splitting by repeated 
forking into a greater uumber of twigs, one of which reaches 
the media, the others going parallel with the branches of the 


Fig. 27. 


Fig. 27. Apithanus jocularis. x 2°9. 


sector and with the media to the margin; the posterior main 
branch splits into a bundle of divergent twigs, falling obliquely 
to the posterior margin. Anal area broadly lancet-shaped, 
separated from the wing by an S-shaped waved vein. All the 
interstices between the main veins are bridged over by verti- 
cally arranged simple cross veins. 

It is a curious fact that original color patterns, consisting of 
a number of broad and very regular transverse bands, have 
resisted destruction through petrifaction. Similar patterns 
have been found in some fossils of Commentry, as in Cnemi- 
dolestes and Protophasma. Unfortunately the venation of 
the Cnemidolestide not being sufficiently known, it is at pres- 
ent impossible to suppose that any relation exists between the 
two groups because of their similar color patterns. 


NARKEMA, new genus. 


Narkema teniatum, new species. Fig. 28. 


Front wing elliptical, scarcely two and a half times as long 
as broad, about 43™" in length, 37™™ of which is preserved. 
Costal area very broad, subcosta extending but little beyond 
the middle of the wing, uniting with the radius. Radius 
not far removed from the subcosta, not reaching quite to 
the tip of the wing and sending forth, like the subcosta, a num- 
ber of very regular oblique and straight veinlets, directed for- 
ward and bridged over by delicate cross veins. 


Vicinity of Mazon Creek, Illinois. 328 


The sector rises at a quarter of the length, runs parallel to 
and not far from the radius and sends off 2 simple and 1 
forked branch, directed toward the margin. The media passes 
near the radius and sector without meeting with them and 
forms a great and wide bow, only forking near the end. A 
great deal of the wing is occupied by the cubitus, cleft near 
the base, the anterior main branch splitting into 2 twigs, the 
posterior end of which is not divided and attains the posterior 
margin, while the anterior approaches the media, sending a 
small branch to this vein, and then regaining the original direc- 


Fig. 28. 


Z 
FEEL 
Lat 


Fic. 28. Narkema teniatum. x 2. 


tion splits into 8 twigs, the first and third of these forming 
apical forks. ‘The posterior main branch splits into 3 divergent 
twigs, the hindmost of which again splits into 3 twigs. The 
first anal vein being gently S-shaped, allows us to suppose 
that. there was a lancet-shaped anal area, provided with a small 
number of veins. Oross veins have been present in a rather 
great number; they are vertically situated on the main veins. 

Both wings are equally decorated by 7 transverse bands ex- 
tending across the whole wing without regard to the venation. 

Holotype in Peabody Museum, Yale University, Cat. No. 40. 


Family CACURGID, new family. 


In this family, which I propose provisionally, are placed 
forms regarding which I cannot with certainty discern whether 
they are Protorthoptera or Protoblattoidea. They all agree in 
the sector rising at a greater distance from the base and in the 
presence of a short oblique vein, going from the stem of the 
media to the cubitus and forming a sort of basal cell. This vein 
evidently is a branch of the media, which unites with the cubi- 
tus for the entire distance or for a certain space only. The 


324 Handlirsch—New Paleozoic Insects from the 


cubitus being separated from the anal area by a comparatively 
large space occupies a great part of the wing. Costa marginal. 
Cross veins irregular, oblique and often ramified, the ram- 
ifications of the main veins never being very rich. 

I consider as the type of this family a new genus, Cacurgus, 
which is the best preserved of all. Besides this another new 
genus, Splomastax, is placed here, and of the previously 
described forms, Palwomustax Handlirsch from the Westpha- 
lian of Belgium, Avchimastax Handlirsch from Fayetteville, 
Arkansas, and Archwologus Handlirsch from Mazon Oreek. 
These latter I had described as genera of doubtful position. 
It is not impossible that Awiologus thoracicus Handlirsch may 
also belong in this family. 


CacurGus, new genus. 
Cacurgus spilopterus, new species. Figs. 29, 30. 


Both anterior wings are preserved, partly crossed over the 
abdomen in a quite natural position, so that there can be no 


Fic. 29. 


Fic. 29. Cacuwrgus spilopterus (right fore wing). x 1°29. 


doubt that they belong to the same individual. Nevertheless 
the venation seems to be rather different in both wings. 

The form of the wing probably has been an elliptical one, 
two and a half times longer than broad, measuring about 75™™ 
in length. Costa marginal. Costal area broad, with numerous 
oblique branches from the subcosta, bridged over by cross 
veins. Subcosta attaining three-quarters the length of the 
wing and uniting with the costa. Radial sector rising some- 
what before the middle and splitting into but 3 branches. 
The radius itself gives off 2 strongly ramified branches, 


Vicinity of Mazon Creek, Illinois. 325 


directed toward the costal margin. The media in its basal 
part bends closely toward the radius and is cleft before attain- 
ing the end of the first quarter of its length. Its anterior 
main branch continues in a normal way and splits in the apical 
half; the posterior has the aspect of an oblique cross vein 
uniting the media with the cubitus. At a certain distance 
from this point of fusion we see that in the right wing a new 
separation of the two veins takes place, the branch of the 
media forming a large terminal fork. In the left wing there is 
but a temporary separation of the fused veins, which then 
unite again and remain so to the end. Nevertheless it is pos- 
sible, but not determinable, that the last fork of the cubitus 
may take rise from this second medial branch. In this case 
we would be forced to assume a strong reduction of the cubitus 
in the left wing in comparison to the right, where this vein 


Fic. 30. 


Fie. 80. Cacwrgus spilopterus (left fore wing). x 1°25. 


with its 8 or 9 partly forked branches occupies the whole hind 
margin. There being only 8 branches in the left wing, their 
number would be reduced to 6 by counting the apical fork as 
belonging to the medial vein. 

The anal area is broadly lancet-shaped, limited by an 
S-shaped vein and seems to have been filled by only a few 
veins of a similar curve. Jn all the broader interstices the 
cross veins are twisted into a moderately regular and polygo- 
nal network. Irregularly spread about there are to be found 
in both wings shallow, more or less regular, round bodies of 
different sizes, situated in darker patches of the wing mem- 
brane and showing a small groove in the middle. These 
structures give the impression of membrane thickenings. I 
probably should have regarded them as extraneous and not 
pertaining to the insect if they had been observed only in this 


326 Tlandlirsch —New Paleozoic Insects. 


ease, but as they are also present in the wings of the related 
form Spilomastax, I think they will prove to be organie strue- 
tures of these insects. Dr. Reis has found similar but smaller 
structures on the wings of one of the Protodonata of Triassic 
age. Tubercles on the membrane have also been found in one 
of the Palsodictyoptera. 

Holotype in Peabody Museum, Yale University, Cat. No. 41. 


SPILOMA STAX, new genus. 


Spilomastax oligoneurus, new species. Fig. 31. 


Two fragments evidently appertaining to the left and right 
anterior wing of a comparatively small insect, whose wings can 
be estimated at 30-35". Subcosta far removed from the 
marginal costa and provided with regular oblique branches. 
Radius giving off its sector at about the middle. Media send- 
ing the typical short and oblique branch to the eubitus at about 
a quarter of its length and split into a large fork before attain- 


ing the middle of the wing. COubitus cleft immediately after its 


Fie. 31. Spilomastax oligoneurus. x2. 


origin, the anterior branch waved, sending 4 branches obliquely 
outward and backward, the first 2 of them not reaching the 
margin; but the posterior main branch running straight and 
undivided to the end. First anal vein gently curved, second 
swung forward toward the first. Cross veins irregular, here 
and there ramified but not twisted into a polygonal network. 

Both wings show numerous quite irregularly distributed 
shallow round bodies similar to those in Cacurgus. 

Holotype in Peabody Museum, Yale University, Cat. No. 42. 


[To be continued. ] 


A. Hollick—Kenwi Flora of Alaska. 327 


Arr. XX1IX.— Results of a Preliminary Study of the so-called 
Kenai Flora of Alaska; by Arraur HoxxtoK.* 


Introduction. 


Durie a recent preliminary study of a series of collections 
of fossil plants from Alaska Peninsula, especially from the vicin- 
ity of Herendeen Bay and Chignik Bay, tentatively assumed, 
for the most part, to represent the flora of deposits to which 
the name Kenai formation has been applied, a number of facts 
were brought to light which are of considerable biological 
interest and which may prove, after critical analysis, to be of 
vaiue from the standpoint of stratigraphy. 

The name Kenai was originally applied to a series of beds 
exposed in southeastern Alaska, particularly on the shores of 
Kachemak Bay, Kenai Peninsula,t which at that time were 
regarded as Miocene or Oligocene in age but are now generally 
recognized as Kocene. The results attained from the recent 
studies indicate that, if the use of the name is to be restricted 
to the beds of the type locality and their equivalents elsewhere, 
there is also a series of beds, more or less closely associated with 
them stratigraphically, which may or may not be included in 
the formation. The ultimate inclusion or exclusion of these 
latter, either in whole or in part, cannot be determined, how- 
ever, until all of the paleobotanical evidence has been carefully 
weighed and compared with whatever stratigraphic observa- 
tions may be available. 

For example, some of the collections contain only Tertiary 
species. In others, often from the same localities, there is a 
preponderance of Tertiary species and a minority of Cretaceous. 
In others the majority are Cretaceous, with certain genera 
which are identical with those of the Jurassic. The several 
collections appear to merge into each other without any abrupt 
break in the paleobotanical sequence, and further careful 
investigation will be necessary before attempting to draw any 
stratigraphic line intended to indicate a differentiation of the 
flora into one undoubtedly of Tertiary and another of Creta- 
ceous age; but the facts may, at least, be described and their 
biological significance discussed. 


Description of the Flora. 


The flora represented in the collections thus far studied, if 
regarded as a unit, is unique so far as North America is con- 
cerned. There is none other described from either the United 

* Published with the permission of the Director of the U. S. Geological 
Survey. 

+ Dall and Harris, Bull. U. S. Geol. Surv., No. 84 (Correlation Papers, 
Neocene), p. 233, 1892. 


328 A. Hollick—Kenai Flora of Alaska. 


States or Canada with which it may be satisfactorily correlated. 
It contains many species which are identical with those of cer- 
tain well-defined Teitiary horizons in the United States and, 
if these species were the only ones represented, the Tertiary 
age of the beds in which they occur would not be questioned : 
such species, for example, as Zaxodium distichum miocenum 
Heer, Populus arctica Heer, P. Richardsoni Heer, Corylus 
McQuarrii (Forbes) Heer, Carpinus grandis Ung., Betula 
Brongniartii Heer, Paliurus Colombi Heer, ete. 

Associated with these, however, not only in collections from 
a single locality but frequently in the same pieces of matrix, 
are species which elsewhere occur in strata of recognized Ore- 
taceous age, such as Adiantum formosum Heer, Sequoia rig- 
ida Heer, Sagenopteris elliptica Font., ete., and others which, 
if found by themselves, would almost certainly be considered 
as closely allied to certain Jurassic species, such as Pterophyl- 
lum concinnum Heer, Anomozamites Schmidtit Heer, Vils- 
sonia comtula Heer, etc.! 

When first examined ,it was thought that this association 
of undoubted Tertiary angiosperm species with apparently 
Mesozoic types of gymnosperms was impossible, and that col- 
lections from different geologic horizons must have somehow 
become mixed; but the fact that some of these diverse floral 
elements were often included in the same piece of matrix 
proved that they must have been synchronous. 


Discussion of the Flora. 


Unless all of our previous knowledge and experience in rela- 
tion to the beginning and subsequent evolution of the angio- 
sperms is at fault, it is evident that the presence of highly 
developed angiosperm species in any flora at once precludes 
the possibility of regarding it as Jurassic inage. Furthermore, 
the fact that certain of the angiosperms in the flora under con- 
sideration are undoubted Tertiary species makes it imperative 
to regard the apparent identity of certain of the associated 
cycads with Jurassic species as untenable and to regard such 
apparent identity as due to superficial resemblances only. The 
theory that a specific type could persist throughout such a 
great length of time as that implied could hardly be accepted 
on evidence based entirely upon such inconclusive factors. 
The genera in which the species belong, however, are unques- 
tionably identical with Jurassic generic types; but it is more 
logical to assume that such types could have continued into 
Tertiary times than to imagine that highly developed angio- 
sperms could have been in existence in the Jurassic period. 

While searching through paleobotanical literature for any 
possible description of, or reference to, a flora similar to ours, 


A. Hollick—Kenai Flora of Alaska. 329 


three papers were noted which have a bearing on the subject. 
Saporta* describes the discovery of a single species of a cycad, 
Zamites epibius Sap. (2. ¢. p. 322), in the middle Tertiary of 
Provence, France, associated with many of the same angio- 
sperm genera as those represented in the Alaskan flora. ‘He 
describes and figures it again in his “Wtudes sur la Végétation 
du Sud-Est de la France a PEpoque Tertiare, Part III eit 
compares it with Z. formosus Heer from the Jurassic of 
Switzerland, and says (J. ¢ p. 11):“....Zamites epibius, 
despite its analogy with the Jurassic genus, must necessarily 
be specitically distinct, especially when one realizes the vast 
time interval which separates them.” The interest and impor- 
tance which Saporta attached to this single specimen may be 
inferred from the lengthy discussion which he gives to it in 
each paper. lt is possibie that a small fragment in one of our 
collections, evidently a Zamites, may belong to Saporta’s spe- 
cles. 

The third paper is by Heer,t in which he describes and 
illustrates a Tertiary flora almost identical with ours, from the 
island of Saghalien, in northeastern Asia, where the same asso- 
ciation of angiosperms and cycads occur and in regard to 
which he remarks (/. ¢. p. 9): “The most striking....is the 
family of the Cycads..... There are two species, which dif- 
fer widely from all living ones, but which show a striking and 
unmistakable identity with Jurassic and Rhaetic forms.’ 
Two species of Wilssonia are described and figured (1. sero- 
tina and WV. pygmea). The former species is undoubtedly 
represented in our collections by a number of specimens, and 
it is interesting to note that one of his figures (J. ¢. fig. 1, pl. IT) 
depicts this species associated with a leaf of Populus arctica 
Heer on one and the same piece of matrix: an association of 
species which is duplicated in several of the fragments of 
matrix in the Alaskan collections. 


Significance of the Facts. 


To those who are familiar with the factors which influence 
the distribution of our living flora, the presence of cycads, 
representing a tropical type of vegetation, associated with spe- 
cies of Populus, Corylus, Carpinus, Betula, Juglans, ete., in 
far northern latitudes, will appear mcongruous; but the fact 
that such an association existed in those regions in the Terti- 
ary period cannot be questioned. It is evident, of course, that 
cycads must have continued their existence somewhere through- 
out both Tertiary and Quaternary times, otherwise they would 

* Bull. Soe. Géol. France, Ser. II, xxi, 314-328, pl. 5, f. 1-3, 1864. 


+ Annales Sci, Nat., Ser. V (Bot.), viii, pl. 1, £. 1, 1867 
t Fl. Foss. Arct., v (Mioc. Fl. Sachalin), 1878. 


Am. Jour. Sct.—Fourts Srmrigs, Vou. XX XI, No. 183-—Aprin, 1911. 
23 


330 A. Hollick—Kenai Flora of Alaska. 


not be represented in our living flora. Nevertheless, so far as 
the paleontologic record indicates, they apparently disappeared 
from the southern and central parts of the North American 
continent in the Tertiary period and were almost exterminated 
in similar European latitudes at the same time, but continued 
to exist in northwestern America and northeastern Asia, until 
their descendants were in part exterminated and the remainder 
driven southward by the advancing cold of the Quaternary 
period to where they are now growing. 

Their present range of distribution in the New World is 
between northern Mexico and Bolivia, which affords an approxi- 
mate indication of the possible extremes of climatic conditions 
which might have prevailed in Alaska at the time when this 
flora was growing there. The climate could not have been 
colder than that of northern Mexico or southern California at 
the present time, if the cycads are to be regarded as adequate 
climatic indicators; nor could it have been much warmer, if the 
associated angiosperm genera are to be regarded in the same 
light. The logical inference is, therefore, that the climate 
which was synchronous with this Alaskan flora was about the 
same as that of southern California and Florida at the present 
day. We may also be warranted, apparently, in assuming that, 
at the time when this flora flourished, either the climate of the 
northern Pacific region was warmer than that which prevailed 
in the mid-continental areas farther to the south, or else that 
their meteorological conditions were not identical, thus giving 
rise to floral differences similar to those which prevail at the 
present day in the coastal and interior regions of the West. 

Finally, the identity of the Tertiary floras of northwestern 
America and northeastern Asia is confirmatory evidence of a 
former land connection between the two continents in recent 
geologic times, which is so strongly indicated by the well recog- 
nized physiographic and topographic features.* 

* See ‘‘The Probable Tertiary Land Connection between Asia and North 


America,” Adolph Knopf. Univ. Calif. Pub., Bull. Dept. Geol., v, 413- 
420, 1910. 


Chemistry and Physics. 331 


SCIENTIFIC INTELLIGENCE. 


I. Cwemisrry And Puysics. 


1. Use of Calcium Carbide for the Determination of Moisture. 
—This application of calcium carbide has been discussed by 
Masson. Difficulties occur in the ordinary methods of determin- 
ing moisture from the fact that other vapors besides water may 
be given off by the substance, or that the substance is oxidized 
and gains weight when heated in the air to expel its moisture. 
Calcium carbide has the advantage that water is the only ordi- 
nary substance that will react with it, and the acetylene pro- 
duced by the reaction can be readily measured. Hygroscopic 
organic substances are mixed with an excess of finely powdered 
carbide, when the reaction takes place quickly without artificial 
heating, and the gas evolved may be measured or its pressure 
determined by means of a manometer. The method has been 
applied for the determination of moisture in wool, explosives, 
petroleum, etc. The author has studied the application of the 
method to the determination of water of crystallization in salts, 
and finds that salts may be roughly divided into four classes in 
respect to their behavior with calcium carbide. In the first are 
those, such as sodium carbonate and sodium sulphate, which 
react at once and completely. In the second class are those that 
react rapidly and completely only on heating, such as barium 
chloride. The third class, which includes such salts as copper 
sulphate and the alums, react, either in the cold or on heating, in 
such a way as to lose only a part of their water, leaving a 
hydrated residue which belongs to the fourth class, characterized 
by being quite stable towards carbide even at 170° C. Itisa 
noteworthy fact that ammonium salts do not lose ammonia, nor 
do crystalline acids react as such, when these are heated with the 
carbide and calcium hydroxide present as a result of the acety- 
lene production. This is to be attributed to the complete 
absence of free water. It is interesting to notice that various 
observers have found that 18™ of water corresponds to 10°5° of 
acetylene at standard conditions, while the theoretical volume is, 
of course, 11:2°°.— Chem. News, ciii, 37. H. L. W. 

2. Action of Water upon Phosphorus Pentoxide-—Various 
statements are found in the literature concerning the products of 
this reaction, that is, whether metaphosphoric acid, HPO,, the 
pyro- acid, H,P,O,, the ortho- acid, H,PO,, or mixtures of these 
are first formed. BatarerF has now investigated this matter by 
allowing pure sublimed P,O, to deliquesce very slowly, and more 
rapidly in more or less moist air, and also by throwing it directly 
into water. In every case where the product was examined imme- 
diately after deliquescence, only metaphosphoric acid, HPO,, 
could be detected. In about 18 hours some of these products 


332 Scientific Intelligence. 


were found to be completely converted into H,PO,, and the 
remarkable fact was noticed that HPO,, produced from P.O, as 
described, becomes hydrated to H,PO, much more rapidly than 
the same compound which has been produced by the dehydra- 
tion of H,PO, by heating.—Zeitschr. anorgan. Chem., \xix, 215. 
H. L. W. 
3. The Fractional Crystallization of Argon.—According to 
its position in the periodic system of the elements, argon should 
have an atomic weight of less than that of potassium, 39°10, 
instead of 39°88, the atomic weight now attributed to it. FRANZ 
Fiscurr and Vicror FRopoxrs® have attempted to fractionate it 
by freezing the liquid. Since argon has been purified previously 
by fr actional distillation, they reasoned that it might form a Gon- 
stant boiling mixture w ith some unknown i impur ity, as is the case, 
for instance, with hydrochloric acid and water. However, the 
results of fractional crystallization were negative, so that no evi- 
dence was found that the atomic weight is not exceptional, like that 
of tellurium, in the periodic system. — Berichte, xliv, 92. 
H, L. W. 
4, Qualitative Chemical Analysis ; by BASKERVILLE and Curt- 
MAN. 8vo, pp. 200. New York, 1910 (The Macmillan Company). 
—Nearly every teacher of qualitative analysis writes a book on 
the subject, because there are many variations in the course of 
analysis and also many ways of presenting the subject. The 
book under consideration appears to be a very good one. There 
is a suitable amount of description and theoretical matter, and 
equations are very fully supplied. The analytical processes, 
which are given in tabular form, with numerous notes, are in 
general well selected. An attempt is made to have the student 
distinguish qualitative reactions in a somewhat quantitative way 
by comparing his tests with tests of measured solutions of known 
strength. The authors say in regard to this plan, ‘“‘ The value of 
such training cannot be overestimated. Our students rarely find 
any difficulty in differentiating between a trace and a significant 
amount.” The last sentence is somewhat disappointing when 
compared with the preceding one, for as much might be expected 
of the student even without the special method of comparison. 
H. L. W. 
5. Die Verwertung des Luftstickstoffs ; von Prof. Dr. J. 
ZENNECK. 8vo, pp. 29. Leipzig, 1911 (Verlag von S. Hirzel).— 
This pamphlet gives a recent lecture on the production of air- 
saltpeter by the aid of the electric arc. The principles of the 
method and a description of the apparatus are described in a very 
interesting way, with the aid of many excellent illustrations. 
The development of this new industry in connection with Nor- 
wegian water-power is of the greatest significance for the ad- 
vancement of agriculture and other industries. It will be recalled 
that attempts to produce nitric acid commercially from the air 
were made in the United States anumber of years ago, apparently 
without complete success. H. L. W. 


— 


‘Geology and Mineralogy. - 333 


6. Allen’s Commercial Organic Analysis. Volume IV. 8vo, 
pp. 466. Philadelphia, 1911 (P. Blakiston’s Son & Co.).—This, 
the fourth volume, of the entirely rewritten fourth edition of 
“ Allen,” treats of Resins, India Rubber, Rubber Substitutes and 
Gutta-Percha, Hydrocarbons of Essential Oils, and Volatile or 
Essential Oils. The importance and excellence of the work are 
so well known that no comments in regard to details seem to be 
necessary, except the statement that the present volume appears 
to maintain the high standard of the preceding ones. H. L. w. 

7. The Absorption Spectra of Solutions ; by Harry C. Jones 
and W. W.Srrone. Pp. 159 with 98 plates. Publication No. 
130, Carnegie Institution of Washington, 1910.—This investi- 
gation is a continuation of the work of Jones and Uhler which 
was begun in 1905 and subsequently greatly extended by Jones 
and Anderson. (See Carnegie Publications Nos. 60 and 110; also 
this Journal, vol. xxviii, page 78.) 

The first chapter of this monograph is devoted to a brief but 
excellent classification of the various types of spectra, to some of 
the theories of spectra, and to the methods best suited for study- 
ing specific spectroscopic problems. Chapter II deals with the 
apparatus used in the present investigation. The remaining ten 
chapters give in detail the variations in the absorption spectra of 
solutions of certain salts of potassium, cobalt, nickel, copper, 
chromium, erbium, praseodymium, neodymium, and uranium 
which are caused by chemical agents and by changes of temper- 
ature. 

The quantity of work done is very great, since about 3000 
solutions were investigated. The quality of the work is of the 
first class, as can be readily seen both from the text and from the 
98 plates. The results obtained are too numerous to be recorded 
in a brief review. Suffice it to say that well-defined “ solvent- 
bands” have been discovered for water, the alcohols, acetone and 
glycerol, and that all of the results seem to confirm the hypoth- 
esis of solvation as developed and emphasized by Jones. 

Ei SsUr 


II. Grorocy anp Mrneraroey. 


1. Indiana. Department of Geology and Natural Resources. 
Thirty-fourth Annual Report. W. 8. Brarcuney, State Geol- 
ogist. 1909. Pp. 392, with numerous maps, photographs, tables, 
ete. Indianapolis, 1910.—The soil survey of Indiana, begun in 
1907, was continued during 1909 by A. E. Taylor and C. W. 
Shannon, and the statement of the important results of their work 
fills the larger part of the present volume. During the three 
seasons in which the work has been carried on, thirty-three 
counties in the southern part of the state have had their soils 
classified, mapped, and treated in detail. It is proposed to go on 
until the entire State has been similarly treated. The Survey 


334 - Scientific Intelligence. 


during 1909 also gathered detailed data in regard to undeveloped 
water-power sites of the larger streams ; this work has been 
under the charge of W. M. Tucker. The volume contains, 
further, a report in regard to the natural gas, by B. A. Kinney, 
and another by the State Inspector of Mines, J. Epperson. 

2. West Virginia Geological Survey. Volume Five, Forestry 
and Wood Industries ; by A. B. Brooxs. I. C. Wuire, State 
Geologist. Pp. xiv, 481, with an envelope map of West Virginia 
and numerous illustrations. Morgantown, 1910.—This fifth vol- 
ume of the West Virginia Geological Survey, carried on under 
the guidance of Professor I. C. White, is devoted to a discussion 
of forestry by A. B. Brooks. This is a subject of vital interest 
at the present time, and one which fortunately is attracting the 
attention of those whose political position is such as to enable 
them to improve the existing situation. In the early days, the 
State was covered by an almost unbroken forest of more than 
fifteen and a-half million acres in extent. Now the virgin forest 
has been reduced to one and a-half million acres. It is estimated 
that if the large number of saw mills engaged in the State were 
to continue in active operation as at present, they would cut all 
the timber in a little over sixteen years. This outlook is sufti- 
ciently serious ; but it is aggravated by the very large waste that 
comes in in various ways, particularly through loss by fire. The 
volume by Mr. Brooks discusses the subject thoroughly from vari- 
ous standpoints, showing the great importance of the forests in 
their indirect relations, as well as a source of usable timber. 
An interesting chapter is devoted to the agents destructive to 
trees, including a great variety of destructive fungi and insects. 
A summary is given of the forestry work now being carried for- 
ward in some twenty States; an exhaustive list of the native 
trees is also added. The volume is made attractive by a large 
number of excellent reproductions of photographs. 

The Survey has also recently issued a map of oil and gas fields, 
and the structural contour of Wood, Ritchie and Pleasants 
Counties. 

3. Geological Survey of Tennessee; Grorcn H. Asutey, 
State Geologist.—The State Geological Survey of Tennessee was 
established in 1909. The special purpose, scope and methods of 
the work planned are detailed by the State Geologist in a pam- 
phlet, 1—-A, of 33 pages, extracted from Bulletin No. 1, on Geo- 
logical work in Tennessee. Other pamphlets, recently issued, are 
2—A, giving an outline introduction to the Mineral Resources of 
Tennessee, and 3—A, on drainage problems ; these are taken from 
Bulletins No. 2 and No. 3, respectively. 

4. Atlas Phographique des Formes du Relief Terrestre.—At 
the ninth Geographical Congress, held in Geneva in 1908, it was 
voted to adopt the plan proposed by MM. J. Brunhes and E. 
Chaix for the preparation of a collection of views, showing the 
different forms of terrestrial relief. A commission of eleven 
was appointed to report a complete plan for this enterprise at the 


Geology and Mineralogy. 335 


next Congress and to take steps to inaugurate the work. A 
preliminary circular has been issued, giving the plan as thus 
far developed. The photographs are to be published in quarto 
form, as separate plates, with one to two views on each ; a leaf 
of the same form will accompany each plate, giving a brief expla- 
nation, a chart showing the point of view, etc. It is estimated that 
some 500 to 600 plates will be needed to print all the types of 
relief as classified according to the provisional scheme adopted. 
If, in addition to these, regional series are arranged for, the number 
may be increased two or threetimes. The price proposed is one 
frane for a single plate or half that sum when a series of 100 are 
‘subscribed for. Of the various series planned the Committee 
wishes to go forward first with those dealing with the forms 
determined by tectonic conditions (faults, folds, etc.) and those 
connected with glacial action. Photographs relating to these 
two subjects are solicited and at the same time subscriptions are 
asked for parts of the work. Communications may be sent to 
one of the Executive Committee: Prof. J. Brunhes, Fribourg, 
Switzerland ; Prof. K. Chaix, 25 Avenue du Mail, Geneva ; Prof. 
Em. de Martonne, 248 Boulevard Raspail, Paris. 

5. The Illinois Oil Fields in 1910 —R. 8. Buatcuitey, of the 
Illinois Geological Survey, has issued a circular giving an 
account of the production of oil in the state during 1910. The 
estimated amount produced for the year is 35,000,000 barrels, 
while that of 1909 was not quite 31,000,000 barrels. Extensive 
explorations by drilling have been conducted at numerous points. 

6. Physical Notes on Meteor Crater, Arizona.—The interest- 
ing but as yet unsolved problems connected with Meteor Crater 
in Arizona (see vol. xxx, 427) have been discussed in a paper by 
W. F. Maciz in the Proceedings of the American Philosophical 
Society (vol. xlix, pp. 41-48). After describing the locality and 
the general character of the specimens found, he goes on to give 
the results obtained from some magnetic experiments with a 
cylinder of the Canyon Diablo iron. Briefly stated, these showed 
it to have a magnetic permeability about one-half that of a cylin- 
der of Norway iron. Experiments were also made with the 
shale balls: one of these, nine inches in diameter and entirely 
oxidized, was examined as it lay in the pulverized sandstone of 
the outer rim of the crater. It showed strong local poles over 
the surface, with, in general, south polarity on top and north at 
bottom. Another piece of a shale ball, which at the crater 
showed distinct polarity somewhat irregularly distributed, after 
arriving at Princeton in a box with other specimens, had lost its 
polarity and behaved like soft iron. Much of the shale is so 
feebly magnetic as hardly to affect a needle even close to it. The 
observations of Baker in 1891 showed no evidence of a local 
magnetic field within the crater, while the whole variation in the 
dip of a vertical needle was such as might. have been due to 
errors of observation or perhaps to local conditions, such as the 
presence of iron pipes in the drill holes. Whether the size of the 


336 Scientific Intelligence. 


meteor, to which it is assumed that the crater is due, was 750 ft., 
or 250 ft., in diameter, it should, at a reasonable depth, seriously 
affect the magnetic field, and a difference of dip between extreme 
stations of 30’ should exist even for the smaller sized sphere. 
“That no such difference was found argues that the meteor 
was broken and scattered by the impact, or more probably, as 
Mr. Barringer strongly argues in his latest paper, was a cluster 
or swarm of small masses of iron, mostly of the shale ball variety. 
The possible intrinsic magnetism of these masses, coupled with 
the possibility that they have gradually oxidized in the depths of 
the crater, would account for the absence of any observed mag- 
netic field.” e 

The symmetry exhibited by the crater, both in the tilting of 
the strata of the rim and the distribution of ejected material, is 
such as can plausibly be referred to the impact of a body rather 
sharply inclined to the vertical. Some experiments were tried 
with a lead ball shot from a high-power rifle at an angle of 30° 
from the vertical into a level floor of smooth, densely packed 
silica. The distribution of ejected matter on either side of the 
surface was distinctly like that observed in the crater. 

An approximate estimate is made as follows of the energy with 
which the meteor may have struck the earth. The work done in 
the excavation of the crater involves the probable ejection of 
some 330 million short tons. To lift the mass up and clear of 
the hole would have required about 1610” foot-tons; while if 
allowance is made also for the work of tilting back the strata and 
lifting the unbroken rock masses around the rim, some 20x 10" 
foot-tons in all may have been required. The larger part of the 
energy, however, was spent in breaking up the rock and reduc- 
ing the sandstone grains to the condition of finely pulverized 
silica. It is estimated that over 500 million tons of rock were 
broken up, and one-fifth of this converted into the pulverized 
form. The work done against friction resulted in heat, but in 
general the temperature did not rise to a point sufficient to melt 
the quartz, as only a small amount of melted material is found. 
Taking 2500° C. as the outside limit of temperature, and suppos- 
ing all the silica heated to that extent, the heat developed would 
be equivalent to 9°25 x 10“ foot-tons. If, however, a general 
temperature of 625° is assumed, that is, below the point at which 
the Widmanstitten figures would disappear, the heat developed 
would be equivalent to 2°3 X 10° foot-tons. In addition to the 
work on the silica, a layer of hard limestone, 300 feet thick, was 
also broken up, and much of it pulverized. It is estimated finally 
that the total amount of energy expended may easily have been 
60 X 10” foot-tons. The velocity of the meteor may be put 
somewhere between the outside limits of 3 and 48 miles per 
second. If 18 to 20 miles per second be assumed as the most 
probable velocity, it is found that a mass of 400,000 tons would 
have had the amount of energy estimated as necessary for the 
work done in connection with the formation of the crater. 


Geology and Mineralogy. 337 


7. Minéralogie de la France et de ses Colonies. Description 
Physique et Chimique des Minéraux; Etude des Oonditions 
Géologiques de leurs Gisements; by A. Lacrorx. Vol. IV. 
Part I, pp. iii, 1-360; Part II, pp. 361-924. Paris, 1910 (Ch. 
Béranger).—The author is to be congratulated as well as the 
mineralogical public, in that the great work which he undertook 
some seventeen years since has now been brought to a successful 
conclusion. The four volumes which have been published give 
an admirable account of the minerals of france and the French 
Colonies. The work of the author is always thorough and orig- 
inal, and the description of species contains much that is import- 
ant and new. Volume four, which has recently been issued in 
two parts, is devoted for the most part to the sulphates, phos- 
phates, and related compounds. There is also a Supplement of 
more than two hundred pages, made necessary by the discoveries 
of recent years. The work is well printed and fully illustrated. 

8. Practical Mineralogy Simplified for Mining Students, 
Miners and Prospectors ; by Jessk Perry Rowe. First Hdition. 
Pp. 162. New York, 1911 (John Wiley & Sons).—This little 
book kas been prepared with the object of putting before practi- 
cal miners a simple and elementary description of the commonly 
occurring minerals and ores, with a means for their investigation. 
The species are grouped according to the prominent metals 
present, and two large tables give a summary of the characters 
for non-metallic and metallic minerals respectively. 

9. Caleites of New York ; by Herserr P. Wurtiock, Pp. 
190, 27 plates. New York State Museum, John M. Clarke. 
Director. Memoir 13. Albany, 1910.—The species calcite is an 
almost inexhaustible subject from the standpoint of the crystal- 
lographer, and many important monographs have been published 
describing the forms from different localities. The author has 
now taken up the calcites of New York, which have been obtained 
from a wide range of different. localities, among which that of 
Rossie has been famous for nearly 100 years. The thoroughness 
of this investigation will be appreciated from the fact that some 
twenty-five plates are needed to show the different types of crys- 
tals with their wide range of forms ; among these a considerable 
number of new ones are noted. 

10. Les Minéraux des Pegmatites des Environs d’ Antsirabé 
a Madagascar ; par li. Duparc. Mem. Soc. Phys. et d’Hist. Nat. 
de Genéve, xxxvi, fasc. 3, pp. 283-410, 1910.—In this work the 
author gives an account of his investigations of the pegmatite 
dikes of a part of Madagascar, which in recent years have fur- 
nished the markets of the world with beautiful gem-stones and 
fine crystals for mineral collections. In the laboratory study of 
the material collected the author was aided by his assistants, 
MM. Wunder and Sabot. A short sketch is given of the geology 
of the island ; there follows a general description of the occur- 
rence of the dikes, accompanied by a detailed account of the 
separate localities visited, where work of exploitation is going 


338 Seientifie Intelligence. 


on; the memoir closes with a chemical and physical study of 
the minerals collected. Some attention is also devoted to the 
occurrence and petrography of a number of basaltic cones and 
extrusions of lava encountered in his journey. 

The pegmatites occur as a series of seams, dikes, stringers, 
and lenses, penetrating granites, gneisses, and schists, and their 
general character appears to be quite similar to what has been 
observed elsewhere in such cases. Here also they often attain 
gigantic dimensions in the size of the individual crystals. 

The surface of the country, the hill slopes and ridges, as well 
as the valleys, is nearly everywhere covered by a thick deposit 
of laterite, resulting from decay of the rocks in place. The 
pegmatites are likewise changed on the surface, but their presence 
beneath is revealed by the large unaltered masses of quartz, 
which form lines of bowlders in the soil. Some of the gem 
material is found in the soil, but the best occurs in pockets, etc., 
in the yet unaltered dikes. The chief minerals accessory to the 
pegmatitic quartz, feldspar and mica which furnish the gems are 
tourmaline, beryl, and garnet with some spodumene. The tour- 
malines are mostly black, but splendid rubellites and green, 
yellow, and brown varieties occur, and, as in other localities, the 
same crystal often shows zones and bands of several colors. The 
beryls are sometimes of enormous size and furnish aquamarines 
as gems; sometimes they are of a sky-blue color; there occurs 
also more rarely a beryl of a peach-blossom color, with a different 
crystalline form, which makes fine gems (see this Journal, 
xxxl, 81). The garnet is a yellow variety of spessartite and has 
yielded some small gems. The spodumene is sometimes lilac 
(kunzite), sometimes yellowish green, or white. A large number 
of chemical analyses and determinations of the optical and phys- 
ical properties of these minerals have been made and the results 
are given. The whole is a valuable and extensive contribution 
to our knowledge of the mineralogy of. Madagascar. Ts avi tba 

11. Production of Phosphate Rock in Florida during 1910.— 
E..H. Settarps, State Geologist, states in a preliminary circular 
that the production of phosphate rock in Florida during 1910 
exceeded that of any preceding year, the output having for the 
first time exceeded 2,000,000 tons. The total production for 1909 
was 1,862,151 tons, while for 1910 the production was approxi- 
mately 2,029,797 tons. This amount includes a production of 
392,088 tons of hard phosphate rock and 1,637,709 of pebble 
rock ; the increase noted, therefore, is in the latter variety, the 
former having diminished from a total of 527,582 tons in 1909. 

12. North Carolina Geological and Economie Survey ; 
JosepH Hype Pratt, State Geologist.—The following publica- 
tions have been recently issued : 

Economic Paper No.19. Forest Fires in North Carolina during 
1909; by J. 8S. Hotmus, Forester. Pp. 52, with 9 plates. 

No. 20. Wood-Using Industries of North Carolina ; by RocER 
E. Srmmmons, under the direction of J. 8. Hoxumzs and H.S. _ 
SackEeTT. Pp. 74, with 6 plates. 


Miscellaneous Intelligence. 339 


13. Wote on the parietal crest of Centrosaurus apertus and a 
proposed new name for Stereocephalus tutus; by LawrEeNcE M. 
Lamer. The Ottawa Naturalist, vol. xxiv, pp. 149-151 with 
plate III, Dec, 1910.—Centrosaurus is one of the Ceratopsia from 
the Judith river (Belly river) formation of Alberta and was first 
described by Lambe in 1902 as Monoclonius dawsoni and in 1904 
made the type of a new genus and species. The remains con- 
sisted of a parietal frill and a supposed nasal horn core, but now 
the latter is discovered to be in reality a portion of the crest 
itself, being a curious projecting process of the parietal bar which 
forms the rear margin of the fontanelle on the right-hand side, 
extending obliquely forward and slightly upward over the fon- 
tanelle itself though not in contact with any of its forward border. 
Lambe supposes the entire structure to have been covered with 
a common integument. It seems from the drawing, however, to 
be a process similar to the curious hook-like projections from the 
rear of the frill and is probably an instance of the development 
of spinescence accompanying racial old age. So far as one may 
judge from such fragmentary remains, Centrosaurus does not seem 
to the reviewer to be antecedent to either of the Laramie ceratop-. 
sian genera, Triceratops or Torosaurus, but to represent the ter- 
minal member of a side branch of the Monoclonius-Triceratops 
phylum, occupying a place among the Ceratopsia similar to that 
of Stegosaurus among the armored dinosaurs. 

The proposal of the new name Euoplocephalus to replace Stereo- 
cephalus (preoccupied), which was also described by Lambe, is 
but natural, although, in view of the necessary revision of all of 
these genera in the Stegosauria monograph now under preparation 
by the reviewer, it may perhaps only add to the burden of an 
already great synonymy. R, S. L. 


III. Miscerzranxous Screntiric INTELLIGENCE. 


1. Lhe Carnegie Foundation for the Advancement of Teach- 
ing. Fifth Annual Report of the President, H. 8. Prircnerr, 
and of the Treasurer, R. A. Franks. Pp. vi, 113. New York 
City, October, 1910.—The Carnegie Foundation completed its 
fifth year on September 30th, 1910. At that time, the original 
gift of $10,000,000 had been increased by something more than 
$1,100,000, from the accumulated surplus. This increase obviously 
adds much to the extent of the work which can be accomplished ; 
the fact, however, that of the total income for the last year, 
$543,880, all but $5,700 was expended, seems to indicate that an 
increase of capital from this source is hardly to be looked for in 
the future. The list of accepted institutions is now seventy-one, 
having been increased the past year by the addition of the Uni- 
versity of California, indiana University, Purdue University, and 
Wesleyan University. Retiring allowances were given to sixty- 
four teachers, forty-six of whom were in accepted institutions 
and eighteen in institutions not on the accepted list. Twenty- 


340 Scientific Intelligence. 


three pensioners died during the year. It is interesting to note 
that two institutions not included in the Carnegie list have under- 
taken to provide a pension fund for themselves. 

The Second Part of the Report is devoted to an interesting 
discussion of the relations of colleges to the secondary schools. 
The difficulty of bringing the high school and the college into 
close relations is one that has been felt for many years, and the 
importance of it is especially recognized at the present time. Dr. 
Pritchett takes up the various points involved, and indicates 
what he would regard as a promising method of removing the 
difticulty. The closing g pages of the Report are devoted to “brief 
obituary notices of the teachers who have died during the past 
year. 

' 2. A Teat-Book of General Bacteriology ; by. Epwin O. 
Jorpan, Ph.D. Second revised edition, pp. 594, illustrated. 
Philadelphia and London, 1910 (W. B. Saunders Company).— 
While the book is adapted primarily to the needs of students of 
medicine, it is general in its scope, as indicated by the following 
subjects treated: Methods of studying bacteria, their structure 
and development ; effects of physical and chemical agents, effects 
produced by bacterial growth, the relations of bacteria to dis- 
eases of animals and plants, bacteria in milk, air, soil, water, etc., 
their importance in the arts and industries, and other topics. A 
good bibliography is given. 

The subject matter is presented clearly, the illustrations are 
good, and the book should be of much value to students of gen- 
eral bacteriology. L. F. R. 

3. Catalogue of the Lepidoptera Phalene in the British 
Museum, by Sir Grorce F..Hampson. Volume X. The Noc- 
tuidee. Pp. xix, 829, 214 figures.—The tenth volume of the British 
Museum Catalogue of Moths, earlier parts of which have been 
repeatedly noticed in this Journal, has recently appeared. It is 
devoted to the Noctuid subfamily Erastriane. This is represented 
here by 1222 species belonging to 136 genera. This sub-family 
is largely confined to the more arid districts of tropical and warm 
temperate regions, and has few species in the colder zones. The 
plates belonging to this volume are promised at an early date. 


Mécanique Sociale ; par Sprrvu C. Harer. Pp. 256. Paris (Gauthier— 
Villars); Bucarest (Ch. Gobl), 1910. 


OBITUARY. 


Dr. Henry Pickrer1nc Bownrrcu, Professor of Physiology in 
Harvard University, died on March 13 at the age of seventy-one 
years. 

Professor, J. H. van’r Horr, the distinguished Professor of 
Physical Chemistry at the University of Berlin, died on Febru- 
ary 1 in his fifth- pinth year. 

Professor Jutius Wituretm Brin, the German chemist, died 
at Heidelberg on February 5 at the age of sixty years, 


hes aera +: - f. _— 
ie VOL) XXX. MAY, 1911. 
ae 

Established by BENJAMIN SILLIMAN in 1818. 


THE 


AMERICAN 
JOURNAL OF SCIENCE. 


Epitrorn: EDWARD S. DANA. 


ASSOCIATE EDITORS 


Proressors GEORGE L. GOODALE, JOHN TROWBRIDGE, 
W. G. FARLOW anp WM. M. DAVIS, OF CAMBRIDGE, 


Proressors ADDISON E. VERRILL, HORACE L. WELLS, 
L. V. PIRSSON anp H. E. GREGORY, or New Haven, 


Proressor HENRY S. WILLIAMS, or Iruaca, 
Proressorn JOSEPH S. AMES, or Baurimore, 
Mr. J. S. DILLER, or Wasuineron. 


FOURTH SERIES 
VOL. XXXI-[WHOLE NUMBER, CLXXX1] 
No. 185—MAY, 1911. 


WITH PLATES I-IItl. 


NEW HAVEN, CONNECTICUT. 
PIO ak 


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, 
_ registered letters, or bank checks (preferably on New York banks). 


Important Announcement. 


NATRAMBLYGONITE. 


Having secured a small lot of this new mineral as described in this Jour- 
nal, No, 181, January 1911, by W. T. Schaller, I am now in a position to 
furnish desirable specimens of same, at very reasonable prices. 


RUBY CORUNDUM. 


It has been some years since the Buck Creek deposit has produced material 
of specimen quality; having been fortunate in securing a lot of these 
double terminated crystals, the result of considerable work which did not 
pay the miners for their trouble, the mines were again closed. This is 
an opportunity for collectors to secure very desirable crystals, single or in 
sets, showing the variety of occurrence of form and colors; prices very 
reasonable. — 


HIDDENITE. 


We have secured the balance of the former lot of Hiddenite crystals which 
sold so rapidly last month ; we are now in a better position to furnish sets 
showing the different effect of etchings, form and color. These specimens 
have the deep emerald green color so desired by all collectors. When made 
in sets mounted on sheet wax, they present a beautiful contrast for show 
and study and should have a place in every collector’s cabinet. 


RUTILE. 


From another source was received a lot of trilling in this most unique 
mineral, all of good crystal quality, a number of them quite transparent 
and possessing a very brilliant luster ; prices very low. 


PRECIOUS AND SEMI-PRECIOUS STONES. 


Having secured from a receiver’s sale a very large stock of cut stones all 
colors, size and qualities, I take this opportunity to offer same at 75 per 
cent of their real value, so as to dispose of them rapidly. 

This is the chance of a lifetime for anyone interested in precious and 
semi-precious stones, carvings, mosaics, cameos, etc. Ask for an assortment, 
which I will gladly send on approval prepaid, for your selection. You can 
return at my expense anything you do not desire. 


REMARKABLE COLLECTION. 


I have just received for sale a remarkable collection which was in the 
possession of a well known mineralogist, who’ was noted for the intense 
interest he had in fine, choice specimens ; this collection represents years of 
diligent and presevering collecting, the specimens representing nearly all 
he old localities and most of the recent ones. Some of the specimens are 
the finest found and this is an opportuuity which new collectors should take 
to get possession of some of the choice things of past localities. © 

Tam now ready to furnish a complete list of this collection to anyone 
upon request and will advise early correspondence on same. 


A. H. PETEREIT, 
81—83 Fulton Street, New York City. 


Phone Beekman 1856. 


THE 


AMERICAN JOURNAL OF SCIENCE 


[FOURTH SERIES. |] 


tos 


Arr. XXX.—The Melting Points of Minerals in the Light 
of Lecent Investigations on the Gas Ty hermometer ; by 
Arraur L, Day and Rozsrrt B. Sosmay. 


Wuew the work of the Geophysical Laboratory was begun, 
no temperatures above 1150° ©. had ever been accurately ~ 
measured with the nitrogen thermometer. It had been the 
custom of the Reichsanstalt to interpret the readings of a 
thermoelement above 1150° by first calculating the curve of 
temperature and thermal electromotive force of the element 
for the region between 400° and 1150°, and then extrapolating 
this curve. The fixed temperatures commonly printed on high- 
temperature measuring devices, like the Siemens and Halske 
direct-reading galvanometers, are based on this extrapolation. 

The absolute accuracy of the Reichsanstalt scale (400° to 
1150°) was estimated to be about 3° at 1150°, and the extra- 
polation above 1150° with the thermoelement is certainly in 
error by more than ten times this amount at the melting point 
of platinum. It was therefore deemed necessary to undertake 
a new investigation of the high temperature region with the 
gas ther mometer, and im particular to extend its range for a 
considerable interval above 1150°, in order that a sound basis 
might be established for the mineral work of this laboratory. 

Accordingly, such an investigation was begun in 1904, and 
the final results were published within the past year.* It 
proved possible not only to attain higher accuracy in the region 
between 400° and 1150°, but to extend the fundamental meas- 
urements to 1550° with an accuracy estimated at 2° at the 
latter temperature. 

In the meantime, the temperature measurements made in 
this laboratory with thermoelements had been interpreted in 

* Preliminary publication : Day and Clement, this Journal, xxvi, 405-463, 


1908. Final publications: Day and Sosman, this Journal, xxix, 93-161, 
1910; R. B. Sosman, ibid., xxx, 1-15, 1910. 


Am. Jour. Sc1.—FourtsH Series, VoL. XX XI, No. 185, —May, 1911. 
24 


342. Day and Sosman—Melting Points of Minerals. 


the old way, by extrapolating the curve of temperature and 
thermal electromotive force. These results now require to be 
corrected by the amount of the difference between the old tem- 
perature scale and the new, which makes it necessary to recal- 
culate the existing temperature data of this laboratory in terms 
of the new séale. This paper will present a summary of the 
values resulting from this recalculation. 


1. Melting and Inversion Points. 


The “ melting point” of a pure substance may be defined as 
the temperature at which the crystalline and liquid substance * 
can remain side by side in equilibrium ; an “inversion point,” 
as a temperature at which two different seni forms of 
the substance can remain side by side am egudlibriwm. Only 
the addition or withdrawal of a quantity of heat will cause the 
disappearance of one of the two forms in contact. Both melt- 
ing and inversion are therefore characterized by two concur- 
rent phenomena, the appearance or disappearance of a particular 
crystal structure and the appearance or asap pearance of a 
quantity of heat. 

2. Melting Intervals. 


The above definition applies to pure compounds. If the 
material is a mixture or a solid solution, it will have, not a 
melting point, but a melting eterval, with (theoretically) 
definite temperature limits. 

The so-called melting interval of slow melting compounds is 
of entirely different character. Tammann,* and more recently 
Dittler,+ have criticized certain of the melting-point determ1- 
nations made in this laboratory, more particularly those of 
anorthite and diopside, as being too high because of inade- 
quate furnace control and super rheating.. This is plainly due 
to oversight in the consideration (1) of the phenomenon of 
melting in silicates, and (2) of the records of our measurements. 
ieee substance always undercools before crystallizing, the tem- 
perature of crystallization will vary with the rate of cooling, 
1. e., will be a random temperature depending upon the condi- 
tions of experiment and not a physical constant characteristic 
of the substance. If the same substance mélts so slowly that 
it readily becomes superheated while melting, the temperature 
of complete liquefaction will vary with the rate of heating and 
is also a random temperature dependent solely upon the condi- 
tions of experiment. Pure quartz, albite and orthoclase are 
such substances, and no doubt others will be found. The 
temperature-time curve is not a competent method with which 
to determine the temperature of change of state of such sub- 
stances. 


* Zts. physikal. Chem., Ixviii, 257-269, 1909. 
+ Zts. anorg Chem., lxix, 273-304, 1911. 


Day and Sosman—Melting Points of Minerals. 348 


Tf, on the other hand, the substance yields the same constant 
melting temperature with widely different rates of heating, 
the melting temperature is a physical constant which is char- 
acteristic of the substance and does not depend upon the con- 
ditions of experiment. Diopside and anorthite are such 
substances, and the published melting points of pure anorthite 
and diopside to which criticism has been directed, were 
obtained in this way. (See references 1, 4, 32, 44, 46.) 

If it be contended (as has recently been done by Dittler) 
that the thermoelement does not give the true temperature of 
the mineral at any time during the heating, or that the energy 
change in the system is not “contemporaneous with the dis- 
appearance of crystal structure, experimental proof is readily 
obtainable with the “quenching” furnace, which fixes the 
matter beyond all doubt. 

Suppose the melting point of diopside, for example, to have 
been observed, in the manner described abov e,at 1391°. Place 
a portion (2 orams) of this erystalline charge in a quenching 
furnace, heat it slowly to 1388° and hold the temperature con- 
stant at that point for an hour, or until there can be no further 
question that the thermoelement and all parts of the charge 
have the same temperature ; then remove the bottom of the 
furnace and drop the crucible with the diopside suddenly into 
a basin of mercury, which has the effect of cooling it almost 
instantly without giving the slightest opportunity for any fur- 
ther change within the substance. If the crystalline structure 
of the diopside, upon examination, is found to be unchanged, 
1388° is below the melting temperature. Place the same mate- 
rial in the furnace once more, heat to 1396°, hold this temper- 
ature constant for some time and drop the charge quickly into 
mereury as before. If the diopside now appears as a clear 
glass, the change of state and all its attendant phenomena must 
have occurred between 1388° and 1396°. 

By way of offering a visible record of this particular case, 
this experiment has “been performed in this laboratory with 
both diopside and anorthite (chemically pure), and photographs 
of the substances as they appeared after removal from the 
furnace are reproduced in figs. 1 to 4. These photographs 
with their accompanying data give absolute proof that the 
melting point of the diopside was between 1388° and 1396°, 
and the melting point of the anorthite between 1547° and 1561° 
(new nitrogen-thermometer scale). 

The so-called melting interval of slow-melting compounds 
(quartz, albite, orthoclase) should be carefully distinguished 
from the we melting interval” of mixtures (lime-soda feldspars, 
impure natural minerals). The former melt and become amor- 
phous very slowly, but their melting interval is an interval of 
time, whereas the melting interval of mixtures is an inter val of 


B44 Day and Sosman-—-Melting Points of Minerals. 


Fie. 1. Fie. 2. 


eliiel, By, 


Fic. 1. Chemically pure diopside. Element R, 14100 microyults = 1388". 
Time, 1 hour. Crossed nicols. 200 diameters. Crystalline. The interfer- 
ence colors show in bands around the edges of the crystal fragments. 

Fic. 2. Chemically pure diopside. Klement R, 14200 microvolts = 
1396°. Time, 14 hour. Photo with crossed nicols. Magnified 52 diameters, 
Glass. 

Fig. 3. Chemically pure anorthite. Element R, 15950 microvolts = 1547°. 
Time, % hour. Crossed nicols. 200 diameters. Orystalline. The twin- 
ning shows distinctly. 

Fic. 4. Chemically pure anorthite. Hlement R, 16100 microvolts = 1561°. 
Time, 44 hour. Crossed nicols. 100 diameters. Glass. 


temperature. The pure soda feldspar (albite), if held at a tem- 
perature slightly above its melting point for a sufficient length 
of time, will melt completely ; the mixture, on the other hand, 
if held at a temperature within its melting interval, will melt 
in part, come to equilibrium, and remain indefinitely part erys- 
talline and part liquid. 


Day and Sosman—WMelting Points of Minerals, 345 


The solidifying points and intervals of silicates, unlike those 
of most metals, are not as accurately determinable as the me/t- 
ing points and intervals, because of the tendency to under- 
cooling. ‘The extent of the undercooling varies widely, and is 
affected by numerous incidental conditions. It may amount 
to only one or two degrees under one set of conditions; and 
for the same substance may become so great under other con- 
ditions that the material is obtained at ordinary temperatures 
in the form of glass, which will remain amorphous indefinitely. 


3. Principal Temperature Determinations at the Geophysical 
Laboratory, 1905-1910. 


In Table I the principal fixed temperatures that have 
been determined during the past five years in this labora- 
tory are summarized, and restated in terms of the revised 
temperature scale. Zhese are not new determinations. The 
original thermoelement or optical data have simply been inter- 
preted in terms of the Day and Sosman scale of 1910. 

All of the early thermoelectric measurements of this labora- 
tory were interpreted by calculating a curve of the form: 
e=a+bt+ct* from the melting points of zine, silver, and 
copper, and using this curve for extrapolation, as has been the 
general custom since the publication of the work of Holborn 
and Day in 1899. Occasionally a function of the form 
t=a + be + ce’ has also been employed. 

The curve ¢=/(¢) gives temperature values that are about 
16° low at 1500°, and the curve ¢=f(e) gives values that are 
about 33° low at 1500°. At 1100° the correction is only 1°5°, 
so that temperatures up to 1100° remain practically unchanged. 

The data of Shepherd and Rankin on Binary Systems of 
Alumina with Silica, Lime, and Magnesia, have already been 
revised and published inthe German translation of that article.* 
The revision of the other data is here published for the first 
time. 

The melting points which form the basis of reproduction of 
the present scale are as follows : + 


EGAN CREM tse Te Pe atin eee ect Oo Mea Naunt Ue ARGO 
ANNO MNOMWY ines Ben cE a eee es ee OOM 
Silivermeee cece phi Sekirei Mae OGIO: () 
GON ee ee eG oS es. 8 NO GOLA 
Coppel ie Aa ran aaah en NOSDG 
JDO DSCC] ieee ia eo) a eee == agile 
ieallaoituim = 25 Seen os re ae 1549° 
PAM ORtMIGC: eee en sees Ue ae OS 
2 Vavt imu eae en eA ole We 


* Zts. anorg. Chem., Ixviii, 370-420, 1910. 
+ Day and Sosman, loc. cit., p. 161. 


346 Day and Sosman—Melting Points of Minerals. 


TaBLE I,—Principal Temperature Determinations at the Geophysical 
Laboratory, 1905-1910. 


Substance Formula Transformation pera- | Observer | Reference 
ture 
a i a to @, and 65 Wright & |39, 64 
Quantz SiO. reverse 575" | Larsen (1909-10) 
Aluminum ’ , 
saan : lnraes Shepherd |41, 65 
Tatar onte) nes panos 1816 |e Rankin |(1909-10) 
: | Allen 
a-Magnesium | : “ ey 
STE evi ‘MgSiO; 1554 |Wright & 18 £1906) 
Clement 
& ==» |Allen & |. 
ue oe | 1557 White 32 (1909) 
a-Caleium | | 
metasilicate : sf Allen & |. 
(Pseudo- CaSiOs | 1540 | White G96) 
wollastonite) 
a-Calecium ; eg! >, |Day & 8, 11), 19 
orthosilicate  |C225!0« | 2130 Shepherd (1906-7) 
Eutectic between) | 
-calci : 
metasilicate CASO» 77 4** 146 |“ c 
and cristoba- SiO, 28 % 
lite 
Eutectic between 
a-caleium : 
metasilicate [CasiOs, 66 % do 1440 Ge Ob 
and a-calcium | CaxSiO. 34 % 
orthosilicate | 
Eutectic between) 
a-calcium 'CasSiO, 93 4 Viet. a és 
orthosilicate CaO 74% | 2065 
and lime | 
Tricaleium | ‘Dissociation into Shepherd 41, 65 
aluminate B20. A105 CaO and liquid) 1937 |& Rankin (1909-10) 
5:3 compound | | | 
v lime and 5CaO.3A1,05 \Melting 1382 ve a8 
alumina | 
= | 
Rees \Ca0.Al20s Ie ey eee Q a 
3:5 compound | \Dissociation into 
of lime and [|3Ca0.5A1.0O; Al,O; and 1700 ih i 
alumina liquid | 
Yel 
Eutectic Bree oahu 4 Melting 1378 * | ‘6 
F a of f 
Eutectic revauriee oe ss 1378 pe bc 
. \CaO. Al.05 1G) % ‘ ‘ 
Hates | 8Ca0.5A1,0,27¢ | | Selby & | : 
Magnesium-cal- | 
cium metasili- |MgSiO;.CaSiOs « 1391x/Pay © 46 (1910) 
cate, (Diopside) Syeesees | 
66 | Allen & . 
Bh Ob 1391 | Wite i (1909) 


** Percentages by weight. 


Day and Sosman—Melting Points of Minerals. 347 
TABLE I.—Continued. 
a= —— “= = = = == SSS ror — | —— 
Substance Formula Transformation pera- | Observer | Reference 
ture 
Eutectic between) | 
2 solid solu- 95.54 56) {62% diops. 
tions of diop- Ye 80 | 384M egSiOs : ,|Allen & |. 
side and Motel 49 diops. Melting 1385 White Be (1909) 
a-MgSiO, in rae. | 962M gsiO; 
each other 
Eutectic between) . : 
diopside and ne 60 & 66 1357 a 66 
a-CaSiOs Bomtan 1 | 
Calcium alumi- | j | 
ae CaAl.Si2O; or Day & \1, 4 
licate. | aaa Pra “ Me ? 
(saeethitey * | CaSiOs. AlsSiOs 1552 alien —_—(1905) 
i os “ 1550* 2oy & 46 (1910) 
; Albite, ‘Day & 1,4 
Bytownite meee “ 1516+ a then (1905) 
mae yities Albite; fs ie ‘ 
Labradorite Nnorthites : 1477+ : e 
Andesine- Albite; p ‘ 
Labradorite Anorthite; : 1430+ G ae 
Albites eeu ; 
ee Anorthite, hate 1375¢, 
Calcium Dissociation pres- 
carbonate CaCOs ssocratin Pre | 898 Johnston |56 (1910) 
, o . Day & 1,4 
is NE as meting 741 Vatien —_‘((1905) 
SOHEREE NaCl ss | 800 White 44 (1909) 
Sodium x ; : 
sulphate Na»SO. : 884 : § 


In the first column of Table I is the name of the compound 
or mineral; in the second, its molecular formula; in the third, 
the transformation or reaction which takes place at the tem- 
perature given in the fourth column. The last two columns 
contain the names of the observers, and the references. The 
numbers are those in the published list of papers of this labo- 
ratory, and the references are given at the end of this article. 

A number of melting and transition temperatures were only 
approximately determined, on account of the sluggishness or 
slow rate of the change. These are summarized in Table II. 


* Direct comparison with the nitrogen thermometer. 

} Being isomorphous mixtures of two compounds, these substances have 
no melting point, but a melting imterval. The temperature limits of this 
interval are probably narrow, and its existence is entirely covered up by the 
slowness with which these silicates reach equilibrium. See full discussion 
in paper 1 (pp. 60-69), or 4 (pp. 40-50). 


Day and Sosman—WMelting Points of Minerals. 


TaBiE Il.—Approwimate Temperature Determinations. 


Substance Formula Transformation Te Observer | Reference 
Cristobalite : : About Day & 8, 11, 19 
(from quartz) Sia Melting 1600 Shepherd (1906-7) 

Day & 8, 11, 19 
Quartz SiO Inversion to Above Shepherd |(1906-7) 
3 eristobalite 800 Wright & |39, 64 
Larsen (1909-10) 
Eutectic* : 
between cristo-|SiO. 80% Sree) A rite |Shepherd 41, 65 
balite and AlSiOs 20% el Foe 1600 |& Rankin (1909-10) 
sillimanite ; 
Hateoliy belmee AI Os 84 ere About  |Shepherd 41, 65 
CTT She | hd ORES LOR PON atl gaan tae 1810 | & Rankin (1909-10) 
sillimanite 
| Inversion a to | 
Magnesium | F B (clino- About Allen &  ja5 
metasilicate | MgSiOs enstatite), and| 1375 [White >» (1909) 
reverse 
Inversion to le 
B-Calcium a-CaSiOs B 6, 82 
metasilicate, CaSiO, (pseudo- 1190 * 4906-9) 
(Wollastonite) wollastonite), f 
and reverse Day & 8 11. 19 
Caleium : Inversion a to Sa alVeiayaya. 
orthosilicate Ca2Si0. 6 and reverse te Shepherd |(1906-7) 
Calcium ; Inversion ? to ye ‘ ; 
orthosilicate \CasSi0. y and reverse Blio , 
ns Nes | Formation of 2 Ser 
Ene '3C'a0.Si0; phases by | yeuyt (een ten ein cigtay 
| dissociation ete 
Eutectic of 41, 65 
spinel and peer Ee: poe Melting oe ee (1909-10) 
periclase peso ge | 
: : Below Day & 1,4 
aoe Ree 5 1200t Allen —(1905) 
igoclase- 1te3 ¢ 66 | “c 
Andesine Anorthite, : EAD) 
Microcline | KAISis0¢ “ erhin te) oy dager 
c | : Change to 1300 and |Shepherd 41, 65 
ee noe sillimanite above** & Rankin (1909-10) 
Cyanite or : 1300 and Z rj 
disthene ALSIOs i | above** 
a'-Magnesium Chane em : Allen, 
metusilicate, MgSiOs to BMocio,  (L800%*  |Wright & |13' (1906) 
(Enstatite Gi | to P-MgSiO; | Clement 
a (clino-enstatite) 
6'-Magnesium e 
mains esi aH eee 
amphibole$ 
y'-Magnesium | 
orthorhombic /M&SiO. 4 eee 
amphibole§ grape | 


* The eutectic compositions are given in percentages by weight of the two 
compounds named. 
+ See note (+) to Table I. 


Day and Sosman—NMelting Points of Minerals. 349 


{The purest natural albite showed signs of melting when heated a few 
minutes at 1200°, and again when heated for four hours at 1100°, Small 
amounts of certain impurities might, however, lower the melting point con- 
siderably, while others would raise it. No determinations of melting point 
on chemically pure albite or orthoclase have been made, The best statement 
that can be made, therefore, is to say that the melting point is probably 
below 1200°. The facts concerning microline are similar. 

** These temperatures differ from the others in the tables, in not being 
fixed physical points. The change is from an unstable into a stable form 
and is not reversible. The figures merely represent the temperatures at 
which the change is rapid enough to become observable within a reasonable 
length of time. 

§ Both of these have been called kupfierite by different authors. 


References. 


1. The Isomorphism and Thermal Properties of the Feldspars. I. Ther- 
mal Study ; by Arthur L. Day and E. T. Allen. II. Optical Study ; by J 
P. Iddings, with an introduction by George F. Becker. Publication No. 31, 
Carnegie Institution of Washington (1905). 

4. Der Isomorphismus und die thermischen Higenschaften der Feldspate. 
Arthur L. Day and E, T. Allen. Zts. physikal Chem., liv, 1-54, 1905. 

6. On Wollastonite and Pseudo-Wollastonite, Polymorphic Forms of Cal- 
cium Metasilicate. E, T. Allen and W. P. White, with Optical Study by 
Fred. Eugene Wright. This Journal (4), xxi, 89-108, 1906. 

te Quartz Glass. Arthur L. Day and E. S. Shepherd. Science, NSIS; 
Vol. xxiii, No. 591, pp. 670-672, 1906. 

8. The Lime-Silica Series of Minerals. Arthur L. Day and EK. 8. Shep- 
herd. Jour, Am. Chem. Soe., xxviii, 1089-1114, 1906. 

11. The Lime-Silica Series of Minerals. Arthur L. Day and EH. S. Shep- 
herd, with Optical Study by Fred. Eugene Wright. This Journal (4), xxii, 
265-302, 1906. 

13. Minerals of the Composition MgSiO;; a Case of Tetramorphism. 
H. T, Allen, Fred. Hugene Wright, and J. K. Clement. This Journal (4), 
xxii, 385-488, 1906. 

19. Die Kalkkieselreihe der Minerale. Arthur L. Day, E. T. Allen, E. S. 
Shepherd, W. P. White and Fred. Eugene Wright. Tschermak’s Min. 
Petr. Mitt., xxvi, 169-232, 1907. 

32. Diopside anc its Relations to Calcium and Magnesium Metasilicates. 
EK. T. Allen and W. P. White; with Optical Study by Fred. Hugene Wright 
and Esper S$. Larsen. This Journal (4), xxvii, 1-47, 1909. 

39. Quartz as a Geologic Thermometer. Fred. Eugene Wright and Esper 
S. Larsen. This Journal (4), xxvii, 421-447, 1909. 

41. The Binary Systems of Alumina with Silica, Lime, and Magnesia. 
H. S. Shepherd and G. A. Rankin; with Optical Study by Fred. Eugene 
Wright. This Journal (4), xxviii, 298-333, 1909. 

44. Melting Point Determination. Walter P. White. This Journal (4), 
xxviii, 403-473, 1909. Melting Point Methods at High Temperatures. 
Walter P. White. Ibid. (4), xxviii, 474-489, 1909. 

46. The Nitrogen Thermometer from Zinc to Palladium. Arthur L. Day 
and Robert B. Sosman; with an Investigation of the Metals by Eugene T. 
Allen. This Journal (4), xxix, 93-161, 1910. 

54. The Platinum-Rhodium Thermoelement from 0° to 1755°. Robert B. 
Sosman. This Journal (4), xxx, 1-15, 1910. 

06. The Thermal Dissociation of Calcium Carbonate. John Johnston. 
Jour. Amer. Chem. Soc., xxxii, 938-946, 1910. 

61. Preliminary Report on the Ternary System CaO- Al.0;-SiO.; a 
Study of the Constitution of Portland Cement Clinker. E. S. Shepherd and 
G. A. Rankin; with Optical Study by Fred. Eugene Wright. J. Ind. and 
Eng. Chem., iii, 211-227, 1911. : 

64. Quarz als geologisches Thermometer. F. E. Wright and E. S, Lar- 
sen. Zts. anorg. Chem., lxviii, 388-369, 1910. 

65. Die binairen Systeme von Tonerde mit Kieselsiure, Kalk, und Mag- 
nesia. H. S. Shepherd and G. A. Rankin. Nebst optischen Untersuchun- 
gen von fF. E. Wright. Zts. anorg. Chem., Ixviii, 370-420, 1910. 


(laa yee aca Tha) Nee bae, Alacra evetyay iene ee aes A900 Ys RO er ae Ve 1 Lo 


350. J. Roberts—Cerium by Potassium Permanganate. 


Arr. XXXI—On the Separation of Cerium by Potassium 
Permanganate ; by Evwin J. Roserrs. 
[Contributions from the Kent Chemical Laboratory of Yale Univ.—cexviii. ] 


Onx of the most useful methods for the separation of cerium 
from the rare earth metals which accompany it depends upon 
its oxidation by potassium permanganate according to the 
equation : 

3Ce,0,+2KMnO,+H,0 = 6CeO,+2KO0I+2Mn0,. 
This action takes place in a cerous nitrate solution provided 
some neutralizing agent is present to take up the nitric aeid 
set free. Stolba, in "1878, * used zine oxide for this purpose, 
and other investigatorst have since used the method. Dross- 
bach,t Bohm,§ Muthmann and Weiss,| Meyer‘ and others 
have used alkali hydroxides or carbonates in place of zine 
oxide. More recently, Meyer and Schweitzer** have studied 
this process, using sodium carbonate. They give the equation : 
30e(NO,), -+ K MnO, +4Na,CO, +8H,0 = 
3Ce(OH), + Mn(OH), +8NaNO, + KNO, +4€0,, 

and use two different solutions for the precipitation. One, for 
the complete removal of the cerium, contains one molecule of 
permanganate to nearly five of sodium carbonate; the other, 
for the purification of the cerium, contains one molecule of 
permanganate to less than three of sodium carbonate. It is 
obvious from the above equation that in the first case large 
amounts of other earths will be precipitated with the cerium by 
the excess of alkali, while in the second case the nitric acid 
will be in excess at the end of the process, leaving consider- 
able amounts of cerium in solution. The object of the present 
work was to study the process carefully and to produce, if 
possible, a sharper separation of the cerium. 

When a little potassium permanganate solution is added to 
a hot neutral solution containing cerous nitrate, the red color 
of the permanganate is instantly ‘pleached, and a brown precip- 
itate appears. If the addition of the permanganate 1s con- 
tinued, the color is bleached more and more slowly, the liquid 
becomes distinctly acid to litmus, and finally the red color 
becomes permanent. If a little alkali is now added, the color 
is again bleached, and if the liquid is kept neutral, or very 
nearly so, the red color will not be permanent until all the 
cerium is precipitated. The action seems to be as follows: 
the cerous nitrate is oxidized by the permanganate, probably 
according to the equation: 


* Jahreshber., 1878, 1059. 

+ Muthmann and Roélig, Ber. chem. Ges., xxxi, 1718; James, Jour. Am. 
Chem. Soc., xxx, 982. 

t Ber. chem. Ges., xxix, 2452. § Zeit. angew. Chem., 1903, 1129. 

|| Ann. Chem., cccxxxi, 9. “| Zeitschr. anorg. Chem., xxxvii, 378. 

** Zeitschr, anorg. Chem., liv, 104-120. 


E. J. Roberts— Cerium by Potassium Permanganate. 351 


3Ce(NO,),+ KMnO,+3H,0 = 
2Ce(NO,),+Ce(OH),+KNO,+H,MnO,. (1) 
The ceric nitrate formed then hydrolyzes: 
Ce(NO,),+4H,O =~ Ce(OH,) + 4HNO,. (2) 
If no alkali is added, the accumulation of nitric acid in the 
liquid checks the process by reversing the action in equation 
(2), and also in equation (1), for when a little of the mixed 
precipitate of hydrated ceric and manganese dioxides was 
treated, after washing, with dilute nitric acid and warmed, a 
strone permanganate color was produced. The addition of 
alkali at this point of course simply removes the free acid and 
allows the action to become complete. The fact that the 
oxidation and precipitation take place even in the presence of 
appreciable amounts of free nitric acid makes it possible to 
secure a better separation than would otherwise be the case, 
for if the liquid is kept perfectly neutral the small amounts of 
trivalent earths which are locally thrown down by the alkaline 
precipitating solution will not be re-dissolved, while if the 
liquid is distinctly acid during the whole process they will tend 
to re-dissolve on stirring. These considerations give the theo- 
retical conditions for the process. As to the choice of a 
neutralizing agent, it is of course desirable to use no compound 
of a metal which is precipitated by oxalic acid or which is not 
easily separated from the rare earths, as, for example, zinc 
oxide or calcium carbonate. Magnesium oxide was tried, but 
does not give as good results as the alkali carbonate, and is not 
so easily controlled. Sodium carbonate seems to be the simplest 
and most convenient neutralizing agent for the purpose. 

The solution used for the precipitation is made by dissolving 
15805 grams (one mol.) of potassium permanganate and 
424-00 grams (four mols.) of dry sodium carbonate in any con- 
venient amount of water. The solution should be kept in 
glass-stoppered bottles and should not be allowed to come in 
contact with organic matter. Solutions of pure permanganate 
amd of pure sodium carbonate, of any convenient strength, are 
also needed. The process is carried out as follows: The rare 
earth solution, which should not contain other salts than 
nitrates, is heated to boiling in a large porcelain dish, and, if 
not already neutral, is neutralized with the sodium carbonate 
solution. The solution of permanganate is added in small 
quantities, until the red color just begins to be permanent, and 
the mixed solution of permanganate and alkali is then added 
very slowly, with constant stirring, the liquid being kept nearly 
at the boiling point during the whole process. A faint color 
of permanganate is maintained all the time in the liquid, a 
little of the pure permanganate solution being added if at any 
time the color is entirely bleached. This is important, as the 
constant acidity of the liquid is thereby insured. When the 


352 LE. J. Roberts—Cerium by Potassium Permanganate. 


cerium is nearly all precipitated, the color is bleached more 
slowly after each addition of the precipitant, and the efferves- 
cence is less noticeable. The acidity of the liquid should now 
be tested from time to time, which may be done with litmus 
paper if only a slight excess of permanganate is present. Small 
amounts of the mixed solution or of sodium carbonate are 
added, until the liquid is nearly neutral to litmus, and still is 
faintly colored with permanganate. The whole is heated and 
stirred for about ten minutes, and filtered hot. The precipi- 
tate is washed with boiling water till the washings give no 
precipitate with ammonia. If the liquid at the end of the 
precipitation is faintly acid, the filtrate usually contains a 
trace of cerium giving a faint yellow color with ammonia and 
hydrogen peroxide, while from’ the precipitate a preparation of 
cerium chloride may readily be obtained which shows no 
absorption bands in a thickness of 15°" of very concentrated 
solution. The presence of a little cerium in the filtrate, where 
the earths in the latter are to be subjected to fractional erys- 
tallization, is usually not objectionable. 

To insure the complete removal of the cerium, the liquid at 
the end of the precipitation must be made absolutely neutral, 
when a filtrate is obtained which gives no test for cerium with 
hydrogen peroxide. Before testing, the excess of perman- 
ganate is removed from the filtrate by boiling with a few 
drops of alcohol. After re-filtering, the other earths are 
precipitated by oxalic acid. The precipitate of cerium and 
manganese hydroxides is dissolved in strong hydrochloric acid, 
the solution diluted and precipitated with oxalic acid and the 
cerium oxalate re-converted to nitrate. On repeating the pro- 
cess with this material, a pure cerium preparation is obtained, 
which gives an oxide of the characteristic pale yellow color. 
The process was thoroughly tested on several different kinds 
of material. A mixture containing as much as thirty-five to 
forty per cent of praseodymium and neodymium yielded pure 
cerium in two operations. 

Attempts were also made to extract the first cerium and 
manganese precipitate with dilute nitric acid, in order to 
remove the last traces of praseodymium and neodymium 
without recourse to a second permanganate treatment. Tho 
precipitate obtained in the usual manner was_ thoroughly 
washed on the filter, then transferred to a large dish and heated 
nearly to boiling with a large volume of water. Nitric acid 
was then added carefully until the liquid began to show the 
permanganate color. The whole was heated for about fifteen 
minutes, and the precipitate filtered off and washed. This 
cerium preparation, when freed from manganese, gave a pale 
reddish oxide, showing that the neodymium and praseodymium 
are not entirely removed from the first precipitate by extrac- 
tion with dilute nitric acid. 


Handlirsch—New Paleozoic Insects. 3538 


Arr. XXXI1.—WNew Paleozoic Insects from the Vicinity of 
Mazon Creech, Illinois; by Anron Hanpuirscu, Imperial 
Natural History Museum, Vienna. 

[Continued from p. 326.] 


Order PROTOBLATTOIDEA Handlirsch. 
Family EOBLATTIDA Handlirsch. 
ANEGERTUS, new genus. 
Anegertus cubitalis, new species. Fig, 32. 


An insect of about 60", the anterior wings of which measure 
45™™ and are nearly elliptical with a somewhat broadened 


Fie, 32. 


eat A mils 
bo we | ny 
V2 ey Dene 
Co Se ON 
Sl a muvee 


~ _— 


Fic. 32. Anegertus cubitalis (negative). x2. 


354 Handlirsch— New Paleozoic Insects from the 


apical half. Costa marginal and equally curved; subcosta 
long, nearly straight and reaching almost to the tip. The 
costal area comparatively broad, with numerous oblique, 
ramous veins, bridged over by cross veins. Radius straight, 
parallel to and very near the subcosta, its sector rising very 
near the base, diverging but little from the radius and sending 
off only 2 short branches near the end. The media is likewise 
somewhat reduced and cleft in the apical half into 2 branches. 
The cubitus on the contrary shows an extraordinary develop- 
ment occupying nearly half the wing and is cleft into 2 main 
branches at about a quarter of the wing length. ‘The anterior 
of these branches splits by repeated forking into 6-7 twigs; 
the posterior sends forth partly forward, partly backward, a 
number of forked twigs. The anal area, which occupies more 
than a third of the hind margin, is limited by a strongly curved 
vein and filled by about 6 veins which are sometimes forked 
and run in a regular vault toward the posterior margin. 
Cross veins numerous. 

Prothorax comparatively large and disciform; the head 
broad and free, with strongly vaulted lateral eyes. One of the 
legs, probably of the second pair, is preserved; it is compara- 
tively long and robust. If I am not mistaken, the posterior 
legs are directed backward in the middle line of the fossil, 
close together, a situation presupposing large and approxi- 
mated coxe. I have no doubt about the close relationship of 
this fossil to Hoblatta from Commentry, which has likewise a 
reduced sector and media and an expanded ecubitus. 

Holotype in Peabody Museum, Yale University, Cat. No. 43. 


Family ASYNCRITIDA, new family. 


Comparatively clumsy with a short, stout body, covered and 
exceeded in length by the singularly specialized wings, which 
are strongly dilated in their apical half. The small disk-like 
pronotum is pear-shaped. Meso- and metanotum fused to a 
solid complex, each of them broader than long. Coxz very 
large, femora and tibize of the posterior legs very short. The 
segments of the abdomen much broader than long. Anterior 
wings with a broadly rounded apical margin, a marginal costa 
and a long subcosta, fusing near the tip of the wing with the 
costa. Sector rising at a quarter of the wing length, diverg- 
ing widely from the radius and giving off but few branches, 
directed forward, parallel to the radius. Media free, forked 
only in the apical half. Cubitus free, with broken branches 
forming a polygonal network. The smaller interstices with 
straight cross veins, the broader ones, like the costal area, filled 
by a polygonal network. Anal area reaching nearly halt the 
length of the wing, containing a few veins regularly curved 


Vicinity of Mazon Creek, Illinois. 355 


backward toward the apical margin. The posterior wings 
seem to have been quite similar to the anterior pair with the 
exception of the fan-like anal area, which attains to about half 
their length. 


ASYNCRITUS, new genus. 
Asyncritus reticulatus, new species. Fig. 33. 


Length of the thorax and abdomen 28™™. Length of the 
wings 28". Pronotum but a little longer than broad. Pos- 
terior femora only as long as the pronotum. Anterior wings 


Fig. 33. 


Fie. 33. Asyneritus reticulatus. x 2°2. 


about two and a half times longer than broad, their greatest 
breadth falling in the third quarter. Sector running obliquely 
to the middle of the apical margin, sending forth but 2 
branches directed forward, their interstices being filled by an 
irregular network. Costal area with 2 rows of cells. Radio- 
medial space with 2 rows of large polygonal cells. Media with 
a simple fork. Oubitus split into about 8 branches, all angularly 
broken, some of them falling in the anal furrow. By the aid 
of the cross veins the whole cubital space takes on the aspect 
of a network. One sees only 4 anal veins, but 2 others may 
have existed. 


356 Handlirsch—New Paleozoic Insects from the 


By this singular specialization of the venation Asyneritus 
differs from all other Protoblattoidea. It is so characteristic 
that the establishment of a new family is justified. 

Holotype in Peabody Museum, Yale University, Cat. No. 44. 

Family EPIDEIGMATID A, new family. 


This family is based on a slender Protoblattoid with a nearly 
semi-elliptical disciform pronotum, long and somewhat waved 


Fig. 34. 


er, 


Fic. 34. Epideigma elegans (positive and negative combined). x3. 


anterior wings, the subcosta not uniting with the costa but 
with the radius as in some of the Protorthoptera. The anal 
area strongly shortened and limited by the characteristic 


Vicinity of Mazon Creek, Lllinois. 357 


strongly curved furrow. Costa marginal. Sector rising in the 
middle’ of the wing, giving off but a few branches, directed 
backward toward the apical margin. The media free, sending 
some branches obliquely backward, the last of which reaches 
the posterior margin: COubitus of a moderate development, 
splitting into numerous irregular branches which form, by the 
aid of cross veins, an irregular network and often take the 
character of intercalary veins. 


EpipEIeMA, new genus. 


Epideigma elegans, new species. Fig. 34. 


Prothorax somewhat longer than broad, of a nearly semi- 
elliptical shape. Head comparatively small, not quite con- 
cealed under the pronotum and bearing large, strongly vaulted, 
lateral eyes. Antennee long and slender. Anterior wings 
28"™™ long with a somewhat waved costal margin and with a 
broad costal area, filled by oblique branches of the subcosta 
and of the radius. Radius reaching nearly to the tip. Sec 
tor rising at about one-third of the length, diverging com- 
paratively far from the radius and giving rise to only 2 
branches. Media. independent of the radius and cubitus, 
slightly waved and traversing the middle of the wing. Of its 
3 branches, which extend obliquely backward, the first is 
forked and has, like the second, a few short apical veinlets 
with the aspect of intercalary veins. The cubitus is cleft near 
the base inte 2 main branches, both splitting into numerous 
twigs, running obliquely backward and taking part in the 
‘formation of a network. All main interstices are filled by a 
more or less regular polygonal network. The very short anal 
area hardly reaches one-fifth of the length of the wing and is 
limited by a sharply curved furrow. 

Holotype in Peabody Museum, Yale University, Cat. No. 45. 


Family CHELIPHLEBID At Handlirsch. 


By the discovery of a new species this family loses in some 
degree its provisional character and can with more certainty be 
added to the Protoblattoidea. It seems to be most nearly 
related to the Euceenide, having like those broad and short 
front wings with a broad costal area, the veins of which are 
not arranged in regular comb-like manner, but are irregular and 
ramified. The subcosta unites with the costa; the radius 
remains simple and its sector sends forth but few branches, 
directed obliquely backward. The media free and splitting 
into only few branches. The cubitus more richly ramified. 
Pronotum disciform and comparatively small, equal in length 
and breadth. 


Am. Jour. Scl.—FourtH SEries, Vou. XXXI, No. 185.—May, 1911. 
25 


3} 


or 
(os) 


Handlirsch—New Paleozoic Insects from the 


Cheliphlebia mazona, new species. Fig. 35. 


The only parts present are the nearly circular prothorax of 
about 8™" in length and a 34™" long portion of an anterior 
wing, which probably attained a length of 40™". Costa strongly 


Fie. 35. 


Fic. 35. . Cheliphlebia mazona. x1°8. 


curved ; subcosta nearly straight, with irregularly waved rami- 
fied branches that attain about three-quarters the length of the 
wing. Radius very near the subcosta and not reaching the tip 
of the wing, simple and uniting with the costa at a short dis- 
tance below the subcosta. Sector rising at one-third of the 
length, giving off only 2 oblique branches. Media cleft before 
the middle into an anterior simple and a posterior forked 
branch. Cubitus and anal area not preserved. 

Holotype in Peabody Museum, Yale University, Cat. No. 46. 


Family EHUCAXNID 4 Handlirsch. 


The finding of new specimens allows a more exact descrip- 
tion of this family to be given. What I had previously held 


Vicinity of Mazon Creek, Illinois. 359 


for the whole radial system is only the radius (s. str.) without 
the sector, giving off some branches forward. What I thought 
to be the media evidently is the long radial sector, rising near 
the base and sending forth some long branches, directed 
obliquely backward. A part of the veins designated by me 
as belonging to the cubitus must therefore be attributed to the 
media, which is not abundantly forked. The cubitus, too, 
does not show a conspicuously rich embranchment. In the 
posterior wing the sector seems to be much more expanded 
and in consequence of this the media and cubitus are strongly 
reduced ; the anal area is large and fan-like. Coxe of the 
hind legs very large. 


Kucanus Scudder. 


Euceenus ovalis Scudder. Figs. 36-39. 


The Yale collection contains a male and two females of this 
species which may be easily distinguished by the presence of 


Fig. 36. Fie. 37. 


~ 


Fie. 36. Hucenus ovalis.? x8. Fre. 37. Euceenus ovalis.2 x3. 


360 


Handlirsch—New Paleozoic Insects from the 


Fie. 38. 


Fic. 38. Euceenus ovalis. 6 x3 


Fie. 39. 


————— oot 


he 


R 


Fic. 39. Huccenus ovalis (reconstruction), x3. 


— 


Vicinity of Mazon Creek, Lllinois. 361 


an ovipositor. The cerciare short. The ninth segment of the 
male is of the same size as the preceding. All the segments 
are laterally produced into blunt lobes. Pronotum compara- 
tively smaller in the male than in the female. Coxee of the 
posterior legs large, the femora robust and short. Ovipositor 
extending but little beyond the end of the abdomen. 

Anterior wing of the ¢ 238™™ long, of the 9 24-25™™. 

Besides these three individuals, the collection contains 
another female which does not have the wings lying over the 
abdomen as is usually the case, but they are spread laterally, 
therefore permitting of a more exact determination of the 
veins. Unfortunately in this individual only the basal half 
of the wings is preserved. This specimen is somewhat smaller 
than usual, having a wing length of scarcely 22™™. As far as 
I can see, the cubitus is cleft in one of the wings into but 4 


Fie. 40. Fie. 41. 


Fie. 40. Eucenus minor 


(lof wing). @ 2-5, Fie. 41. Hucenus minor (negative of 


right wing). @ x2" 


Fie. 42. 


Fic. 42. Euccenus mazonus. x2°5. 


362 Handlirsch—New Paleozoic Insects from the 


branches and it seems possible that this individual may belong 
to a species distinct from ovalis Scudder or at least to a variety, 
for which I propose the name /. minor m, (figs. 40, 41). 

Plesiotypes in Peabody Museum, Yale University. Cat. 
Nos. 47-50. 


Eucenus mazonus Melander. Fig. 42. 


Much smaller than ovalis Scudder with a narrower pronotum 
and a very stout body. Length of thorax and abdomen 15™", 
equal to the anterior wing. Costal area of the anterior wing 
comparatively narrow. Radial sector of the posterior wing 
with 4 large branches, occupying nearly the whole anterior 
half of the wing, pushing to one side the media and cubitus, 
which are reduced to 3 parallel veins. The large anal area 
fan-like, with numerous veins. Pronotum one and two-thirds 
times longer than broad. Anterior leg delicate, the tibia as 
long as the pronotum. Probably a male. 

Plesiotype in Peabody Museum, Yale University, Cat. No.'51. 


Eucenus pusillus, new species. Fig. 43. 


Resembling /: mazonus, but of a smaller size. The abdomen 
more slender, the costal area of the anterior wing broader. 


Fie. 43. 


Fic. 48. Hucenus pusillus. x4. 


Radius cleft at the end, the sector with (?) 5 branches. Length 
of the pronotum nearly 5™™, of the wing 11™. 
Holotype in Peabody Museum, Yale University, Cat. No. 52. 
EHucenus rotundatus Handlirsch. Fig. 44. 


The experience gained by the study of the new material has 
led to another determination of the veins of /. rotundatus 


Vicinity of Mazon Creek, Lllinois. 363 


Handlirsch, as is shown in fig. 44. What I previously had 

called media evidently is the sector and the complex of veins 

formerly regarded as cubitus contains also the media. 
Holotype in the U. 8. National Museum. 


Fic. 44. 


Fie. 44. Eucenus rotundatus (new reconstruction). 


Family ANTHRACOTHREMMIDA) Handlirsch. 


Three of the fossils in the Yale collection seem to be of a 
near relationship with Anthracothremma Seudder. A com- 
mon characteristic of these forms is a greatly reduced and 
shortened anal area, a shortened subcosta and the tendency of 
all veins to stretch in the direction of the longitudinal axis of 
the wings. In all these species the media is of a comparatively 
small extent. 


PERICALYPHE, new genus. 
Pericalyphe longa, new species. Fig. 45. 


A slender insect with anterior wings 50™™ long which are 
at least four times longer than broad. The subcosta is strongly 
reduced and unites with the radius. Costal area narrow, 
traversed by short, stiff veinlets. The simple radius not quite 
attaining the apex; its sector rising beyond the first third of 
the length and sending off 9 simple and very regular parallel 
branches, directed toward the apical border. The quite inde- 
pendent mediai vein remains undivided. The cubitus, running 
in a large curve toward the end of the hind margin, sends off 
6 long branches, some of which are ramified. All of these 
take the direction of the sector branches and of the media. 
Only one or two short branches near the base run obliquely to 
the posterior margin. The anal area, limited by a curved 
furrow, reaches but one-fifth of the wing length. Very indis- 
tinct cross veins probably fill all the interstices. 

In the posterior wing the subcosta is produced almost to the 
tip but likewise unites with the radius. 

The disproportionately small pronotum forms a semicircular 
disk of scarcely 5™™ in length. Meso- and metathorax are of a 


364 Handlirsch—New Paleozoic Insects from the 


size proportional to that of the whole insect. The posterior 
leg is long and robust, its femur 15™" long and not thickened 
toward the base. 

This fossil seems to have its place very near <Anthraco- 
thremma, but it differs in having a simple medial vein and 
many more branches of the radial sector and cubitus. 

Holotype in Peabody Museum, Yale University, Cat. No. 54. 


Fie. 45, 


Fie. 45. Pericalyphe longa. x1°5. 


MELINOPHLEBIA, new genus. 


Melinophiebia analis, new species. Fig. 46. 


A single anterior wing, 22™" long, having the ‘apical half 
distinctly dilated, the anterior margin straight and the subcosta 
reduced to little more than half the length of the wing and 
uniting with the costa. Costal area comparatively broad with 
numerous short and oblique veins. Radius very near the 
subcosta, reaching not quite to the tip and not ramified. The 
sector originating but little before the middle of the wing, 
scarcely diverges from the radius and sends off 4 parallel 


Fie. 46. Melinophlebia analis.. x 2:7. 


branches that curve toward the apical margin, the first of them 
being forked. The media apparently forming but one fork, 
whose branches run parallel with those of the sector. The 
eubitus runs parallel with the media to the end of the posterior 
margin and its (about) 5 branches take the same direction. The 
anal area being limited by a strongly curved furrow extends 
about one-seventh of the wing length. Cross veins have 
probably been present but are not now discernible. 

This species shows how a wing of a blattoid type may have 
been transformed into a termite wing. 

Holotype in Peabody Museum, Yale University, Cat. No. 55. 


SILPHION, new genus. 
Silphion latipenne, new species. Fig. 47. 
Anterior wing 30™" long, 25™™ only being preserved. Apical 
half conspicuously enlarged. ‘Anterior margin nearly straight. 


Subcosta extending a little beyond the middle of the wing, 
uniting with the costa and giving off but 3 veinlets directed 


\ 
‘\ » 


Way iV 


\\\ 
\ 
| 
a 
1H 
{ 


r 
\ 
\\ 


\ 


Re (ees 


bea 


\ 


Fic. 47. Silphion latipenne. x22. 


obliquely toward the costa. Radius nearly straight and at a 
moderate distance from the subcosta. Sector rising somewhat 
before the middle of the wing, with 7 simple and parallel 
branches running toward the apical margin. Media forked 


366  Handlirsch—New Paleozoic Insects from the 


at a quarter of the length, each of the main branches again cleft 
into 2 branches. The anterior main branch gives off before 
its division 2 short branchlets, swinging forward and outward, 
the first of which unites with the base of the radial sector. 
The cubitus runs nearly straight toward the end of the apical 
margin, sending forth backward 8 branches, the first of which 
splits into 5, the second into 2 twigs. All these veins hold 
the same direction as the branches of sector and media and are 
bridged over by numerous cross veins. Anal area very short, 
but not so broad as in MMelinophlebia, and limited by a less 
strongly curved vein; it is filled by about 4 simple veins and 
reaches not quite a fifth of the length of the wing. 2 

I have no doubt of the close relation of this species with 
Melinophlebia. 

Holotype in Peabody Museum, Yale University, Cat. No. 56. 


Fie. 49. 


Fic. 48. (Protoblattoidea) minor. x3. Fie. 49. (P.) sellardsi. x2. 


(Protoblattoidea) minor and (P.) sellardsi Handlirsch. 
Figs. 48, 49. 


The Yale collection possesses the types of two larval forms, 
described by Sellards as belonging to the true Blattoidea but 
supposed by me (Fossil Insects, p. 152) to be members of the 
Protoblattoidea. Having now examined the types, I can ver- 
ify my opinion. j 

One of these larval forms, (Protoblattotdea) minor 


Vicinity of Mazon Creek, Illinois. 367 


Handlirsch (Fossil Insects, t. 15, f. 15), has a very singular organ 
at the apex of the abdomen (see fig. 48). A careful examina- 
tion shows that it reaches as far as the eighth segment and 
bears a longitudinal suture. There can be scarcely any doubt 
that it is a larval -ovipositor. On one side of this organ a 
distinct cereus is preserved. The sides of the segments are 
lobate, the wing cases somewhat spread outward and backward. 
The comparatively short and stout legs are inserted very near 
the middle line. The head with its large eyes lies free in 
front of the pronotum. Head, body and ovipositor together 
have a length of 22". 

It is very possible that this larva is of Hucenus or a 
related form. 

Another larva, contained in my work under the name (P7ro- 
toblattoidea) sellardst Handlirsch (p. 152, t. 15, f. 14), seems to 
be closely related to the above mentioned species, the stout 


Fic. 50. 


Fie. 50, Adeloblatta sellardsi. x 2°38. 


and short legs being very similar to Hucenus. This fossil 
(see fig. 49), with comparatively shorter wing cases than (P.) 
minor, is probably in a more juvenile stage but nevertheless 
much larger (somewhat more than 30™™), so that it must be 
considered as a distinct species. | 
Holotypes in Peabody Museum, Yale University, Cat. Nos. 

57, 58. 

Order BLATTOIDEA Handlirsch, 

Family ARCHIMYLACRIDA Handlirsch. 

ADELOBLATTA SELLARDsI (Handlirsch). Fig. 50. 


Ltoblattina hilliana? Sellards, Amer. Jour. Sci. (4), xviii, 
1904, p, 213, pl. 1, fig. 4. 
Phyloblatia sellardsi Handlirsch, Foss. Insects, 1906, p. 205, t. 21, 
fis 1B ; 
Sellards’ first figure did not show clearly enough the rami- 
fication of the media and so I was misled into placing the 


368 = Handlirsch—New Paleozoic Iasects From the 


species in my genus Phyloblatta. But now, having before me 
the type, I see that the 5 branches of the media rise from the 
posterior side of the main vein, The first of them splits into 
5 twigs, the following being no farther cleft. The cubitus is 
comparatively short and sends forth but 4 branches. The 
radius gives off 6 ramified branches and an apical fork. Sub- 
costa reaching about the middle of the nearly elliptical wing. 
Anal area of one-third of the wing length and filled by 6 reg- 
ular veins. The interstices are bridged over by rugous and 
twisted cross*veins. 

These characteristics induce me now to place the species in 
the genus Adeloblatta Handlirsch. - 

Holotype in Peabody Museum, Yale University, Cat. No. 59. 


Fie. 51. 


\, 


Fic. 51. Phyloblatta diversipennis (negative). x 2-9. 


Phyloblatta diversipennis, new species. Fig. 51. 


The two anterior wings, 24™™ long, of a rather large species, 
of a nearly elliptical shape. Subcosta reaching three-fifths 
of the length. Costal area comparatively broad, with more 
than 10 partly ramified veins, 8 of which are preserved. Ra- 
dius reaching to the apical margin and slightly waved. Of its 
4 or 5 branches only the first 2 or 3 are ramified. The media 
occupies a comparatively narrow space in the apical margin 


Vicinity of Mazon Creek, Illinois. 369 


and sends forth in the right wing (left of the negative) 2 very 
long forked branches, directed forward and outward. Cubitus 
attains the end of the apical margin and sends 8 oblique 
branches toward the posterior margin, few of them being ram- 
ified. In the left wing (right of the negative) there is a long 
forked branch, rising in front of the cubitus. Anal area two. 
fifths of the wing length and filled by 7 regular veins. I see 
nothing of cross veins. 

Holotype in ae Museum, Yale University, Cat. No. 60. 


Fie. 52. 


a 


Fic. 52. Orthomylacris contorta. x3. 


Family MYLACRIDAd Scudder. 
Orthomylacris contorta, new species. Fig. 52. 


An anterior wing of 23™™. Slender and of a pointed cordi- 
form shape, strongly vaulted. The costal and radial area on 
the one hand, and the medial, cubital and anal areas on the 
other, divide ‘the wing into two nearly symmetrical halves. 
The bundle of 4 or 5 subcostal branches éxtends beyond the 
middle of the anterior margin. The radius sends forth very 
obliquely 2 3-branched, a forked and a simple branch: the 
media 2 3-branched, a forked and a simple branch obliquely 
backward. The cubitus occupies about the middle third of 
the posterior margin and has a 38-branched and a forked 
branch. Anal area at least twice as long as broad. Structure 
leather-like. 

Holotype in Peabody Museum, Yale University, Cat. No. 61. 


PLATYMYLACRIS, new genus. 


A very broad form, the pronotum of which is nearly twice 
as broad as long. Anterior wing twice as long as broad, 
obliquely cordiform. Costal area reaching nearly three- 
quarters of the length. The subcosta and its branches not 


370 = Handlirsch—New Paleozoic Insects from the 


curved forward but backward. Radius composed of 3 long 
forks. Media giving rise to but 3 branches, directed back- 
ward. Cubitus with its 6 branches occupying the whole free 
posterior margin. Anal area very broad, its length only one 
and a half times its breadth, filled by numerous simple veins. 

This genus is sufficiently distinguished from all the Myla- 
erides known to me by the singular radius and the broad and 
short anal area. 


Fig. 53. 


Fie. 53. Platymylacris paucinervis. x1'9. 


Platymylacris paucinervis, new species. Fig. 53. 


Shoulder very much produced. Subcosta composed of 3 
branched veins, showing the tendency to curye toward the 
radius and being therefore posteriorly concave. The radius 
splits quite near the base into 3 long branches, forming short 
apical forks. The media traverses nearly the middle of the 
wing, and gives rise to but 3 main branches directed obliquely 
backward, the first of which rises very near the base and makes 
a long fork. The cubitus goes to the end of the posterior 
margin and bends near to the media in the basal part, its first 
branches being forked. The anal area is filled by about 12 
veins. Length of the fossil 37°", of the anterior wing 30”. 

Although the shape of this insect reminds one of Paro- 
mylacris rotunda Seudder, with which Sellards has attempted 
to identify it, the venation proves to be quite different. 

Holotype in Peabody Museum, Yale University, Cat. No. 62. 


Vicinity of Mazon Creek, Itinois. 371 


Larva of (Blattoidea) melanderi Handlirsch? Fig. 54. 


A larva, 17™™ long, belonging to the group designated by 
some authors as Dipeltis and probably referable to the Myla- 
cride. The comparatively short middle and posterior legs 
with their approximate coxe are easily to be distinguished. 
The lateral lobes of the segments are very clearly preserved. 

Plesiotype in Peabody Museum, Yale University, Cat. No. 63. 


Fic. 54. 


Fic. 54. (Blattoidea) melanderi? x2°6. 


Order SYPHAROPTEROIDEA, new order. 


This new order is based on a comparatively small insect 
which I am not able to place in any one of the other orders 
and which evidently represents an extinct offshoot of the Pale- 
odictyoptera. From it none of the more highly specialized 
groups of insects can be derived. 

Meso- and metathorax very similar, apparently not yet grown 
together. Abdomen slender, diminishing backward, its first 
segment being the largest, the eighth with an appendix, prob- 
ably an ovipositor. The two homonomous pairs of wings are 
of a quite equal shape and lie obliquely backward, not cover- 
ing the abdomen; the second pair being somewhat shorter but, 
like the first pair, nearly trigonal and apparently not provided 
with an anal fan. The costa marginal, the subcosta and radius 
strongly advanced toward the anterior margin. Subcosta 
reaching but half the length of the wings, uniting with the 
costa and sending forth some short oblique veinlets. Radius 
parallel to the subcosta and costa, reaching the tip of the wing 
and sending forth some short oblique veinlets toward the costa. 
The radial sector rises very near the base and diverges 
strongly from the radius, the interstice being bridged over by 


372 Handlirsch—New Paleozoic Insects from the 


4 or 5 straight and simple cross veins. The 5 (in the anterior 
wing) or 4 (in the posterior wing) simple branches of the 
sector run obliquely to the oblique apical margin and are 
united by a few straight cross veins. The media is reduced to 
a simple independent vein and likewise the cubitus, which has 
but a short strongly diverging branch near its apex. The first 
anal vein is moderately straight and apparently sends 2 
branches backward. Al] the main veins are united by isolated 
and widely spread cross veins. There is no doubt that the 
wings were of a delicate membranous texture. 

This fossil somewhat resembles certain Megasecoptera, but 
lacks certain characteristics of this order, such as the tempo- 
rary fusion of cubitus, media and radius, the shortened subcosta 
and the position of the wing being also quite different ; further, 
an ovipositor has never been found in the Megasecoptera. 
The want of intercalary veins and the strongly reduced media 
and cubitus do not allow this fossil to be put among the 
Ephemeroidea. 


Family SYPHAROPTERIDA,, new family. 
SYPHAROPTERA, new genus. 


Sypharoptera pneuma, new species. Figs. 55, 56, 57. 


Thorax and abdomen together having only a length of 13", 
the front wing of 12™™. Meso- and metathorax each somewhat 
broader than long, the first segment of the abdomen nearly 


Fic. 55. 


Fic. 55. Sypharoptera pneuma, x46. 


Vicinity of Mazon Creek, [llinois. 373 


quadrate, the second a little shorter, the third, fourth, and 
fifth again longer, and the eighth longer than broad. The ovi- 
positor is nearly as long as the eighth segment, onjthe apex of 


Fie. 56. 


Fie. 56. Sypharoptera pneuma (anterior wing). x4°6. 


Fic. 57. 


HA 


Fic. 57. Sypharoptera pneuma (posterior wing). x46. 


Fig. 58. 


Fic. 58. Paralogopsis longipes (posterior wing). x 2"3. 


which it is inserted. Unfortunately nothing is preserved of 
the terminal segments. The wings have their greatest breadth 
before the middle and are three times longer than broad. 
The first branch of the sector rises about in the middle of the 
wine. 

Holotype in Peabody Museum, Yale University, Cat. No. 64. 

Am. Jour. Sct.—Fourts SERIES, Vou. XX XI, No. 185.—May, 1911. 

26 


374 Handlirsch—-New Paleozoic Insects from the 


Order PROTODONATA (Brongniart). 
Family PARALOGID AS Handlirsch. 
PAaRALOGOPSIS, new genus. 
Paralogopsis longipes, new species. Fig. 58. 


An insect whose wings may have had a length of about 
100°". The basal parts only being preserved, it is difficult to 
give an exact description, but as this part is very similar to the 
American genus Pardlogus, described by Scudder, it becomes 
possible to “classify the fossil. 

The costa marginal, being separated from the subcosta by a 
single row of cells ; both veins are str ongly convergent, so that 
we can suppose that the subcosta was not very long. Going 
farther backward, we find a very thick vein which must be the 
radius, apparently fused with the basal portion of the media. 
On one and the same point of this vein rise 2 branches which 
1 suppose to be the sector and the media. The subcosta-radial 
space is filled by a single row of cells, just as is the space 
between the media and the next following waved vein, which 
I must call the first branch of the cubitus, Near the base we 
find an oblique bridge reaching the last main vein or analis. 
This bridge evidently is the second main branch of the eubitus, 
temporarily uniting with the anal vein; farther outward the 
cubitus again becomes independent. The interstices between 
the two cubital branches and the anal vein show but one row 
of cells. The anal vein sends off numerous more or less broken 
branches and intercalary veins toward the posterior margin, 
all being united by cross veins. 

The front wings are narrower than the hind wings (16"™ 
and 20™"), slightly reduced toward the base and not angular. 

One of the legs, probably of the posterior pair, is preserved ; 
its femur must be described like the tibia as very slender and 
reaches 24™", 

I cannot say whether my interpretation of the sector is right 
or not. Should the opinion of Mr. Sellards, who supposes that 
the crossing of sector and media was complete in the Paleo- 
zoic Protodonata, be ratified, the vein which I consider to be 
the sector should be added to the media. In any case we will 
await new discoveries before deciding this question. In the 
European Protodonata I have not seen a sigh of such a cross- 
ing and even Paralogus Scudder does not confirm Sellards’ 
opinion. 


Holotype in Peabody Museum, Yale University, Cat. No. 65. 


Order MEGASECOPTERA Handlirsch. 


Among the fossils now examined there is a very shadowy 
one showing nothing but the four wing cases of a nymph. 


Vicinity of Mazon Creek, I illinois. 375 


The very characteristic situation of these larval wings in the 
stone is due to their primitive position on the sides of the thorax 
and their being strongly spread outward. The base and gen- 
eral appearance is not that of wings which have been laid back 
over the abdomen. They are all nearly equal, and shape as 
well as venation—the subcosta and radius running parallel to 
the tip, the characteristic anal vein, ete.—points to a member 
of the Megasecoptera. 

I believe this discovery will confirm my opinion that the 
Megasecoptera have been heterometabolous msects, for the wing 


Ge 


\\\ 
i; We 
G Ny 


Fic. 59. Lameereites curvipennis (wing cases in situ). x18. 


Fic. 59. 


Fre. 60. 


———_____, 


(FEE 


Fic. 60. Lameereites curvipennis (wing case of first pair). x4°d. 


cases of a holometabolous form would hardly have been pre- 
served in such a manner and position. | 

This highly interesting fossil, certainly representing a new 
species and genus, may be called in honor of my highly estim- 
able opponent, Lameereites, new genus, curvipennis, new 
species (see figs. 59, 60). 

Holotype in Peabody Museum, Yale University, Cat. No. 66. 


? Family PROCHOROPTERIDAD, new family. 


The fossil inducing me to establish —though with some hesi- 
tation—a new family, probably will prove to be an aberrant 


376 Handlirsch— New Paleozoic Insects from the 


and somewhat more highly specialized member of the Megase- 
coptera, but it is possible that in the future we will be forced 
to consider it as the type of a peculiar order. 


PROCHOROPTERA, Kew genus. 
Prochoroptera calopteryx, new species. Figs. 61-63. 


The body is comparatively robust, but always slender. Head 
apparently small. The second of the three thoracic segments 
somewhat larger than the two others and distinctly limited. 
Prothorax about semicircular, mesothorax tun-like. The base 
of the abdomen as broad as the thorax, the first segment being 
twice as broad as long, the following segments becoming 
gradually shorter and, beginning with the sixth, also narrower. 


Fie. 61. 


| 


AS 
oe 
y 
a 


=< 
ae 
aoa 


ie 


es 


~ 


Fie. 61. Prochoroptera calopteryx. x3. 


The eighth segment comparatively small, the ninth elongated 
and provided beneath with a slit-like sexual organ, limited 
laterally by longitudinal ridges. Cerci not preserved. 

The two homonomonus wing pairs laid obliquely backward 
and apparently not to be folded over the abdomen. The 
anterior margin nearly straight, the posterior strongly curved. 


Vicinity of Mazon Creek, Illinois. B77 


The greatest breadth situated below the middle. Costa 
marginal. Subeosta produced somewhat beyond the middle 
and united with the radius, these two veins very near the 
anterior margin. Sector rising at about one-third of the 
length, moderately diverging fora the radius and giving off 2 


fon) 
eeamelice! The media sends a branch in the foam oi an 


Fic. 62. Prochoroptera calopteryx (fore wing). x93. 


Fie. 63. 


Fie. 68. Prochoroptera calopteryx (hind wing). x3. 


oblique cross vein to the sector, continuing its course as a 
branch of the latter. The stem of the media soon forks again 
and these forked branches are broken on the points of inser- 
tion of the cross veins. First cubital branch simple, free ; 
the second split into 3 twigs. Anal vein of the anterior wing 
forming a regular vault and giving rise to 3 oblique branches, 
directed backward. In the posterior wing the anal vein is 
broken and has also 3 branches. The whole medio-cubital 
and anal area, by the breaking of the veins at the insertion of 
the cross veins, chiefly in the hind wing, has a very singular 
aspect which recalls some Neur optera, for example, Raphidia. 
The small number of regularly arranged cross veins, the shape 
of the homonomous wings, the fusion of the sector with the 
media, seem to indicate a close relationship with the Megase- 
coptera. 

The length of the whole insect is 29™™, that of the 
anterior wing about 32™™, and of the posterior wing 28™™. 

Holotype in Peabody Museum, Yale University, Cat. No. 67. 


378 Williston— New Hamily of Reptiles from the 


Arr. XXXIII.—A New Family of Reptiles from the Per- 
mian of New Mexico; by 8. W. Witiston. 


Iv is now more than thirty years since the late Professor 
Marsh described in this Journal (May, 1878) three new genera 
and four new species of vertebrate fossils from the Permian 
of New Mexico. Three years later Professor Cope published 
a brief note on a small collection of vertebrate fossils from the 
same region, with descriptions of two new species.* The only 
other references to the New Mexico Permian deposits or fauna 
that I can find in the literature, either paleontological or geolog- 
ical, are brief descriptions by Professor Case of four new 
reptiles based upon the Cope collection, at present preserved 
in the American Museum of New York City. 

The collections of Permian vertebrates in the Yale Museum, 
inclusive of Marsh’s types, were made by the late David Bald- 
win of Farmington, New Mexico, in Rio Arriba County, in 
the interval between November 1877 and December 1880. 
Mr. Baldwin believed them all to be of Triassic age, and so 
labelled them. From 1880 to 1888 Mr. Baldwin was in the 
service of Professor Cope collecting fossils, chiefly from the 
adjacent Wasatch and Puerco formations; and sometime in the 
early part of this period made the relatively small collections 
of Permian fossils now in the American Museum, coming 
from the same horizons and localities as did his previous ones 
collected for Marsh. 

The Yale collections have never been thoroughly studied 
till recently ; a part, indeed, including the type of the genus 
and species herein described, had never been unpacked from 
the boxes in which it was originally received so long ago. 
And it is unfortunate for science that these specimens have 
remained so long buried in the basement of Peabody Museum. 
Although I was an assistant of Professor Marsh at the time 
of their reception, I had no suspicion that the collections were . 
as extensive as they prove to be. 

By the kindness of Professor Schuchert I have recently had 
the privilege of studying this material, a privilege for which 1 
would here express my sincere thanks. Not only were all the 
Permian vertebrate fossils of the Yale collections brought 
together and placed at my disposal, but the full staff of pre- 
parators was engaged in their preparation for more than two 
months. 

The known New Mexico Permian deposits, so far as I can 
learn from the notes of Mr. Baldwin, are chiefly in the vicin- 


* American Naturalist, xv, 1020, 1881. 


Permian of New Mexico. 3879 


ity of the Gallinas mountains, east of the Nacimiento moun- 
tains, reaching as far east as the peak El Cobre north of the 
Chama river. They overlie the Carboniferous, apparently 
conformably, and are overlain by the Morrison beds of the 
Jura-Oretaceous, with more or less of the.Trias doubtless inter- 
vening. The Permian fossiliferous strata are in the lower part 
of the Red Beds and are several hundred feet in thickness. 
The matrix in which the fossils are enclosed is variable, con- 
sisting of red, white, and reddish brown sandstones, and red 
and black clay. There is an entire absence of all concretionary 
material and pebbly conglomerates, both of which are highly. 
characteristic of the Texas deposits. 

In the examination of these Permian fossils preserved in 
the Yale Museum I have distinguished with more or less assur- 
ance at least ten genera of amphibians and reptiles; J found 
no trace whatever of fish remains. These genera are: Votho- 
don Marsh, indistinguishable from Deadectes Cope, published 
ten days earlier; Sphenacodon Marsh, the type of which is 
indistinguishable from Dimetrodon Cope, published five days 
later ; Ophiacodon Marsh, closely allied to the genus which Case 
has called Zheroplewra Cope on somewhat questionable evi- 
dence; Hryops Cope, a species of which was described by 
Marsh as Ophiacodon grandis ; Clepsydrops Oope, represented 
by very characteristic limb bones; ““Dimetrodon” navajoicus 
Case, not a true Dimetrodon, but a short-spined Pelycosaur, 
probably belonging to a new genus ; Dimetrodon Cope, repre- 
sented by very characteristic specimens either closely allied to 
or identical with species from Texas; “Ctenosawrus” rugosus 
Case, which is not a real Ctenosaurus v. Huene from the Trias 
of Europe, but a new genus which I shall describe and figure 
later as Platyhistriz, gen. nov.; a pelycosaurian reptile with 
long flattened spines, probably new; one or two other reptiles 
which I cannot at present determine ; Aspidosaurus represented 
by a new species which I shall describe as novamexicanus ; and 
the genus Limnoscelis herein described. In addition, Case has 
named the genera Hicabrosawrus (melius Hlcobrosawrus) and 
Diasparactus from vertebree in the Cope collection. 

In this examination I was especially struck by the absence 
of forms characteristic of the Upper or Clear Forks division of 
the Texas Permian, such as the Pariotichids, and especially 
Labidosaurus, Diplocaulus, ete. Diplocaulus may not be a 
characteristic guide fossil, because of its occurrence in the 
Illinois beds that are probably lower than the Wichita division, 
but the Pariotichidee are reliable. Not only is there an absence 
ot forms characteristic of the Clear Fork division, but forms 
such as Diadectes and Clepsydrops have never been found in 
Texas in the upper beds. The evidence thus seems to indicate, 


380 Witliston—New Family of Reptiles from the 


almost conclusively, that the New Mexico beds are the strati- 
graphical equivalent of the lower or Wichita division of the 
Texas beds. The presence of certain forms, like those of 
Dimetrodon, either closely allied to or identical with Texas 
species, indicates a faunistic relationship between the New 
Mexico and Texas faunas. On the other hand, the majority of 
the New Mexico genera, and perhaps all the species, will be 
found to be distinct from those of Texas, indicating either 
interrupted communication between the two not very widely 
separated regions during these Permian times, or different 
environmental conditions. The latter conclusion seems the 
more probable one, since those forms most nearly allied~ are 
chiefly from the red clays and red sandstones quite like those 
of the Texas deposits, while most of the unlike forms come 
from sandstones or clays unlike anything in- Texas. Further- 
more, the entire absence of concretionary material, pessbly sand- 
stones, and apparently of all fish remains, may also indicate 
different environmental conditions. Remains of sharks and 
dipnoans are rather abundant in Texas deposits, and while they 
may not be absolutely characteristic of marine or brackish 
waters, they probably are. Of interest is the fact that there 
is not a single fragment in the New Mexico collections that is 
even suggestive of Vaosaurus. perhaps the most widely dis- 
tributed, and at the same time fragmentary and tantalizing of 
Texas fossils. 

A full discussion of the Yale collection of New Mexico 
Permian fossils would be beyond the limits of a single maga- 
zine article, and will be given elsewhere, with figures of some 
of the more characteristic specimens and of Marsh’s types. I 
restrict myself here to a description of a remarkable new family 
of reptiles, coming from the very base of the deposits in the 
vicinity of El Cobre. 


Limyoscerip2, family new. 
Limnoscelis paludis, genus and species new. (Figs. 1-7.) 


The description of this genus and species is based upon two 
specimens, both from the same immediate locality in Rio 
Arriba County, New Mexico, and both enclosed in a like matrix, 
a dark, rather fine-grained sandstone, in nodular form. These 
two specimens seem to be specifically identical, as the slight 
differences observed between them may well be due to age or 
conditions of fossilization. Of one of them (No. 809), there 
is 4 nearly complete skeleton save the skull and front feet, and 
a part of one of the hind feet; the preserved parts lie, for the 
most part, in orderly articulation. The second specimen 
(No. 811) is almost perfect, the only missing parts that I 


Permian of New Mewico. 381 


observe being the right hind foot, and perhaps a part of the 
left hind foot, both which had been more or less exposed and 
the bones somewhat weathered. This skeleton lies in the most 
orderly relations, with all its parts in close articulation, save 
such as had been disturbed by gravitation. It is without brealk, 
at least as far as the proximal third of the tail; some of the 
smaller caudal vertebra may be missing, but, fortunately, the tail 
seems to be quite complete in the other specimen. This more 
perfect specimen (No. 811), which may be considered the type 
of the species, was found among unpacked material only a few 
weeks before my departure from New Haven became neces- 
sary, and its preparation has not been quite completed. When 
fully worked out from the matrix and prepared for exhibition, 
it will be one of the most notable specimens of a reptile ever 
obtained from the Permian deposits of America. 

The skeleton is evidently that of an animal which had died 
peacefully in some pool or body of water undisturbed by waves or 
currents; nor does it show any indications of extraneous forces. 
The animal at death rested with its ventral side downward 
upon a hard bottom, since all the bones had fallen, so far as 
was possible with their natural articulations, to a level, as is 
the case with fossils preserved in marine deposits. The skull 
and limbs are in complete articulation, the vertebral column 
enrved gently to the left, the pectoral and pelvic girdles intact 
and in position, and with all the bones of the limbs closely 
articulated, so far as they are preserved, at least, save a few of 
the terminal phalanges. The sacral vertebra is attached to the 
ilia, but the vertebree immediately preceding and succeeding 
it had fallen to the level of the pubes and ischia. As the 
specimen lies in place it measures three feet and four inches to 
the hind end of the ischia, while the articulated or nearly artic- 
ulated tail of No. 809 has a length of forty inches to where 
the centra measure ten millimeters in diameter. Yet smaller, 
unarticnlated vertebree among the unassociated material indi- 
cate a possible length of the tail of forty-four or forty-five 
‘inches, or a total length for the skeleton of about eiohty-four 
inches. it 

Skull.—The skull of Limnoscelis paludis is remarkable in 
many respects, and fortunately this part of the specimen which 
serves as the type is remarkable for its completeness and perfec- 
tion of preservation. Like the remainder of the skeleton, with 
which it was in close articulation, it lay upon its ventral side, 
slightly depressed by its own weight in fossilization, and a little 
skewed to the right. As collected, it was broken in eight or ten 
pieces, the bone so firm that it permits the matrix to be removed 
very completely, which has been done by the skillful head 
preparator of the Yale Museum, Mr. Hugh Gibb; not quite 


382 Williston—New Family of Reptiles from the 


completely yet, the anterior palatal region being still invisible. 
Since the mandibles are clearly in natural relations with each 
other save for the slight twisting, and the upper part of the 


Fie. 1. 


Fic. 1. Limnoscelis paludis Will. Skull, from above two-fifths natural 
size. pm, premaxilla; n, nasal; J, lachrymal; /, frontal; pf, prefrontal ; 
pof, postfrontal ; po, postorbital; pa, parietal ; do, dermoccipital; t, tab- 
ulare. 


skull is undisturbed: the obliquity has been corrected in the 
drawings—a matter of no difficulty. In a later paper, a restora- 
tion of the skeleton and photographs of the skull and other 
parts will be given. Some facts of interest, especially the 
mandibular and maxillary teeth, were made out from the sepa- 
rated pieces before they were cemented together, characters 
which will again become visible when the preparation of the 


Permian of New Memxico. 383 


Fre. 2. Limnoseelis paludis, Skull, from side, two-fifths natural size. 
pm, premaxilla; n, nasal; 7, lachrymal; m, maxilla; pf, prefrontal ; pof, 
postfrontal ; po, postorbital; j, jugal, sq, squamosal; qj, quadratojugal ; 
q, quadrate; d, dentary ; swr, surangular; ang, angular. 


Fie. 3. 


\ 
\ 


Fic. 3. Limnoscelis paludis. Skull, from below, two-fifths natural size. 
sp, splenial ; pa, prearticular ; st, (?) stapes. ; 


384 Williston—New Family of Reptiles from the 


skull is completed. The surface of the skull is almost smooth, 
with feeble indications of small pits. 

The skull of Lemnoscelis is remarkable among terrestrial 
reptiles for its elongated form and highly developed incisor 
teeth. The upper surface is nearly in one plane from the 
margin of the occiput to near the extremity of the rostrum, 
somewhat convex above in front of the eyes, and the parietal 
region is moderately convex on the sides. Fortunately the 
sutures of the skull nearly everywhere are quite distinct, even 
visible in the photograph as serrated or zigzag lines. A few 
cracks are present, but they are not confusing save in a few 
cases, but those are in the most important part of the skuli; the 
posterior temporal and occipital region. The sides of the skull, 
with the mandibles in place, are of nearly uniform height, that 
at the nostrils being quite what it is at the temporal region, unless 
there has been a slight depression in the latter place. From 
just in front of the orbits the skull widens very rapidly, the 
orbits themselves being nearly wholly concealed in top view 
by the overhanging roof of the skull. In front of the orbits 
there is a rather deep depression on each side. Back of the 
orbits there seems to have been a nearly vertical wall for 
some distance, and then convex broadly outward. The nares 
are of considerable size, oval in shape and situated close to 
the anterior end of the skull. The orbits are relatively small 
and situated far back, the distance between orbits and nares 
being greater than the extent of the skull posteriorly. They 
are oval in outline, somewhat narrowed in the specimen, their 
planes nearly parallel to each other and nearly vertical, the 
posterior part turned a little outward. 

The premaxille are very massive bones, strongly protube- 
rant in front. The suture uniting them with the nasal is 
strongly digitative, beginning at ale front end of the nares. 
Each premaxilla has three large, conical and recurved teeth. 
In the specimen the interior one on the right side had been 
lost before fossilization, but its mate is complete; the second 
and third teeth are successively smaller, but of the same char- 
acter as the inner one, long, conical and recurved. The bases 
of two are present on one side, with indications in the matrix 
of their length. Doubtless when the skull is finally prepared, 
the missing parts will be found. The long tooth lies in the 
specimen as I have figured it, directed downward and back- 
ward, and closely applied to the end of the mandible. 

The maxilla has quite the same relations as in the other 
American cotylosaurs where it is known, a rather narrow bone 
united with the premaxilla below the nar es, with the lachrymal 
throughout nearly its whole length above, and with the jugal 
posteriorly below the orbit, which it joins by a long, oblique, 


Permian of New Mewico. 385 


serrated suture. The precise number of teeth I cannot be sure 
of. On the left side the teeth are hidden by the obliquely 
compressed mandibles from the outer side; on the right they 
are not perfect. Before the parts were cemented together, Mr. 
Gibb worked out the left maxillary and mandibular teeth from 
the inner side in large part, and these have been used to com- 
plete the figuresin the drawing. There are at least eighteen in 
the maxilla, and perhaps more. The anterior ones are longer 
’ and stouter, conical like the incisors, and somewhat recurved. 
Their attachment to the bone is more or less pleurodont. The 
posterior teeth are shorter, but are also nearly circular at their 
bases. There is but one row. The nasalsare very large bones, 
occupying nearly the whole of the upper surface of the skull 
in front of the orbits, and are gently convex or flat. The 
lachrymals, as in probably all cotylosaurians, are elongate, form- 
ing the posterior border of the nares and a part of the anterior 
border of the orbits. As in the Diadectide, and quite uniike 
the condition in the Pariotichide, the small frontals do not 
take any part in the orbital border, which is formed by the pre- 
frontals and postfrontals; as in the Diadectide, both these 
bones are short and broad, extending little beyond the orbit 
‘in front or behind. The parietals are short, broad bones form- 
ing most of the superior surface of the skull back of the orbits ; 
the parietal foramen is of the usual size, very unlike the enor- 
mous one of the Diadectidz. The sides of the skull back of 
the orbit are formed chiefly by the squamosal, very clearly dis- 
tinct from the small quadratojugal on the lower posterior 
margin, but not distinguishable at present from the postorbitals 
and epiotics quite to my satisfaction. Back of the parietals 
are the narrow transverse dermoccipitals, which seem to be 
quite distinct from a small bone at the outer angle, which 
doubtless is the tabulare (epiotic). The structure of the poste- 
vior part, the occipital region, is somewhat confusing, and I do 
not feel at all sure of my determinations. The discussion of 
this region I reserve for a later paper, hoping that additional 
material may be forthcoming. The structure of the palate, so 
far as it has been developed in the specimen, is most interest- 
ing, so closely resembling the “ rhynchocephalian” type, that a 
few years ago, had it been found without other parts of the 
skull it would have unhesitatingly been located in the “ Diap- 
sida” and “ Diaptosanria.” The specimen has not yet been 
thoroughly cleaned in the anterior part, so that I can say noth- 
ing of the vomers. The palatines and united pterygoids are, 
as in Labidosaurus and Pariotichus, separated by a more or 
less elongated interpterygoidal space. The eminence in the 
region of the transverse, if the bone be distinct as I think it is, 
is crowned by a row of five or six teeth, evidently more or 


386 Williston—New Family of Reptiles from the 


less conical in life, but unpreservable in the preparation of the 
skull. In front of these teeth I can find evidence of but a 
single tooth, located as I have marked ; I am not quite sure of 
it, but in all probability there were others. Opposite the front 
end of the basisphenoid, the pterygoid on each side articulates 
with a stout basipterygoid process of the basisphenoid, quite as 
in the lacertilians, the first evidence I have seen among the 
Permian vertebrates of a real articulation at this place. The 
pterygoid has a pit or depression on the inner side for the head 
of this large process. Back of these processes the pterygoids 
resemble remarkably the like processes of the lizards, or Sphen- 
odon, a not very wide, rather stout, obliquely placed process 
reaching backward to articulate with the lower inner side of 
the quadrate. In the middle the large basisphenoid is con- 
spicuous; unlike that of the Diadectide, itis stout and rounded 
below, where it gives off the basipterygoid processes. Ante- 
riorly it gives off the so-called parasphenoid. But the “ para- 
sphenoid” in this case is a thin vertical plate, thickened poste- 
riorly to join the anterior end of the basisphenoid, very much as 
in Zrinacromerum among the plesiosaurs.. In the specimen 
the front part les obliquely in the matrix an inch or more in 
width, with the lower margin, that visible in its normal posi- 
tion, narrow. Behind the rounded median convexity of the 
sphenoid, the bone is broadly concave in the middle, on either 
side of which the usual basisphenoid process is directed down- 
ward, backward and outward, to end in a rather stout projec- 
tion. In the middle of this concavity the sutural line for union 
with the basioccipital is evident. The occipital condyle is 
quite flat or even concave, as in Diadectes and Pareiasaurus, 
a strong indication of relationship. On either side of the basi- 
occipital I think I have interpreted the bones of the posterior 
palatal and occipital regions, but I prefer to wait before pub- 
lishing my conclusions in the hope of getting material of this 
form the coming season. 

The mandibles of Limnoscelis are very powerful, indicative 
of the carnivorous habits of the animal in life. They lie in 
perfect relation to each other, save that they are a little skewed 
to the right. They are broadly separated behind, with a long 
convexity on the sides, and again expanded at the front end. 
The teeth are only partly visible from without; the one or 
more large ones in front opposing the premaxillary teeth are 
wholly hidden, nor can the number be made out with certainty. 
The postarticular process is small, not extending back of the 
quadrate, or if so, but for a few millimeters only. Externally 
the suture separating the angular from the surangular passes 
forward near the middle of the bone, and backward nearly to 
the extremity, Ontheinner side of the mandible the structure 


Permian of New Memico. 387 


is peculiar. A broad flange is directed inward, nearly verti- 
cally, opposite the middle of the articular surface, concave in 
front. The suture separating the prearticular from the artic- 
ular is very conspicuous, passing back over the flange. In 
front the prearticular passes far forward, between the upper 
opening to the cavity of mandible and the elongated foramen 
near the middle of the inner side before the middle of the bone 
antero-posteriorly. A fracture of the mandible a little in 
front of the articular shows a large cavity with an elongated 
opening above back of the teeth. The elongated vacuity is 
bounded by the angular below, by the splenial in front, by the 
_ prearticular above behind, anteriorly apparently by the coro- 
noid. The splenial is very broadly visible on the under side 
of the mandible, the suture between it and the dentary begin- 
ning some distance in front of the posterior end of the median 
symphysis, and extending back nearly as far as the posterior 
end of the internal vacuity. On the left side a piece about 
two inches in extent of this bone has been peeled off from the 
dentary, showing the bone to be thin, not more than six or 
eight millimeters in thickness. In front, the splenial turns 
upward to cover the inner side of the mandible below the 
teeth and apparently partly covering the internal vacuity in 
front. Interesting is the fact that the existence of a separate 
prearticular is demonstrated beyond doubt in this specimen, 
and also that the splenials meet in a median symphysis in front 
as in Labidosawrus, and probably all the Cotylosauria. 
Vertebre.—Kighteen presacral vertebree have been cleared 
of the matrix in a continuous series curved to the left. The 
lengths of these vertebrze are almost exactly the same through- 
out; in front of them the vertebrae above the pectoral girdle 
have not yet been exposed ; the space in which they lie corre- 
sponds exactly with that of five vertebree following them, and 
that is doubtless the number hidden in the matrix. In front 
of these the atlas and axis have been partially exposed, giving 
twenty-five as the total number of presacral vertebre. The 
first of the series exposed below, the eighteenth presacral, has 
a shallow fossa or flattened surface on the under side in the 
middle, which fossa increases in depth posteriorly, a very char- 
acteristic feature which seems to separate this form from any- 
thing hitherto described and especially Diasparactus Case. 
The outline of the centra both on the sides and below, antero- 
posteriorly, is deeply concave. The arch has a marked resem- 
‘blance to that of D/adectes, so far as they have been worked 
out, save that there is no trace of a hyposphene anywhere in 
the series and the rib articulation is continuous from the arch 
to the centrum, as in Labidosaurus. All the observed ribs 
are single-headed, but expanded, that is without an emargina- 


388 Williston—New Family of Reptiles from the 


tion distinguishing the head from the tubercle. In Déadectes, or 
at least in such species as I have been able to study of this genus, 
the ribs anteriorly are distinctly double-headed. The transverse 
processes are short throughout the series, scarcely extending 
on the sides beyond the margin of the zygapophyses. This 
character has been given by Case as a distinctive one for his 
genus Diaspar actus, but, in a large species of Diadectes from 
Texas I do not find any ‘appreciable difference in the promi- 
nence of the processes, at least in the posterior presacral region. 
The spines are moderately elongate through the series, thick- 
ened and somewhat rugose at the upper end. There are large 
intercentra between the centra below, and as the vertebre lie 
in the matrix a considerable space is left between the adjacent 
vertebree for cartilage, indicating a very flexible, though not 
very firm spinal column. The spines, of the posterior part of 
the column at least, are about one inch in length. The first 
presacral spine is rather broad and expanded above, the second 
and more anterior ones are more slender. There is but one 
sacral vertebra, which has a very broad, stout, sacral rib on 
each side, turned directly downward so as to cover nearly the 
whole of the inner side of the ilium at its junction with the 
ischium and pubis, its antero-posterior width being 60™, its 
vertical width where it joins the ilium, 40". The ribs imme- 
diately in front and behind are small and slender and do not 
seem to touch the ilium ai all. Case has described Diadectes 
as having two sacral vertebrae, but in the specimen in the 
Chicago ‘collections, of a large species, the structure of the 
sacrum seems to be quite as in Limnoscelis ; and this is also 
the case in a new genus of Diadectide, which Professor Case 
will describe from a specimen in the University of Chicago 
collections, collected by Mr Miller. 

The first chevron occurs at the hind end of the third caudal 
vertebra, the first one visible above the ischia from below ; the 
first three or four of the caudal vertebree have short, free ribs, 
as in other genera of American Cotylosauria. The tail, as pre- 
served in specimen No. 908, is rather slender, with rather 
short spines and chevrons, rather precluding the idea that the 
animal was marked natatorial in habit. The terminal vertebree 
are a little elongated. 

Pectoral Girdle and Kxtremity.—The pectoral girdle lies 
in very orderly arrangement, with little if any distortion. 
Both clavicles are in articulation with the imterclavicle, scap- 
ule and cleithra. The clavicles have the usual cotylosaurian 
form, curving under the anterior end of the interclavicle and 
the anterior margin of the coracoid, curved and somewhat 
spoon-shaped below. The long, dilated, scapular part is curved 
upward in a vertical plane and | ‘obliquely backward in the artic- 


Permian of New Mexico. 389 


ulated skeleton, reaching nearly to the upper end of the scapula, 
flattened from side to side above. The cleithrum is small and 
vestigial, smaller than in Diadectes, a slender, cylindroid bone, 
reaching quite to the superior anterior angle of the scapula, 
but not expanded over the end, as in the temnospondyls. It 
is dilated at its lower end to articulate with the attenuated 
upper extremity of the clavicle, lying between the clavicle and 
the front margin of the scapula. It is only a little more than 


Fie. 4. 


Fie. 4. Limnoscelis paludis. Left pectoral girdle, two-fifths natural size. 
¢, cleithrum ; cl, clavicle; sc, scapula. 


two inches in length. The scapula is very short. The blade 
above is narrow, thinner and curved outward on its front part, 
thickened at its posterior superior border. Its upper end is 
truncated, and doubtless had a supra-scapular, cartilaginous 
continuation, possibly the representative unossified of the upper 
end of the cleithrum. The glenoid fossa is deep and large, the 
stout metacoracoid extending far back relatively. The poste- 
rior border of the scapula is curved nearly uniformly from the 
angle to the extremity of the preglenoid facet, which is large 
and flattened. There is a distinct supra-glenoid fossa a little 
below the middle of the bone, between the borders, which 
diverge nearly the middle of the length of the scapula; it is 


pierced in the usual temnospondyl way for the passage of the 


Am. Jour. Sct.—FourtH SERIES, VoL. XXXI, No. 185.—May, 1911. 
27 


390 Williston—New Kamily of Reptiles from the 


Fie. 5. Limnoscelis paludis. Right front leg, dorsal view, two-fifths 
natural size. re, radiale; 7, intermedium ; we, ulnare; p, pisiform. 


supraglenoid canal. I have observed this foramen in this posi- 
tion in scapulee which I refer to the genus Ophiacodon, but 
usually in the Pelycosauria the opening pierces the bone in front 
of the scapular margin. I had supposed that this foramen was 
characteristic of these old orders of reptiles, never having seen 
any reference to it in literature of other orders of vertebrates. 
But, Lam surprised to find that it is quite typical of certain 
lizards, and it perhaps occurs in other reptiles. In the present 
reptile I have observed for the first time in any form other 


Permian of New Mexico. 391 


than the amphibia, the inner opening of the foramen or canal 
back of the border of the subscapular fossa which I have called 
the glenoid foramen. That the canal perforates the bone to 
open in the glenoid fossa I am not prepared to affirm. I find, 
however, that the foramen is also present in the Diadectide, 
and perhaps in all cotylosaurians. Its presence removes the 
last distinguishing character between the temnospondyl and 
cotylosaurian pectoral girdles. One may distinguish them now 
only by the smaller size of the cleithrum in the reptiles. 

The suture separating the metacoracoid (coracoid auct.) is 
situated not far back of the supracoracoid foramen, which is 
unusually large. The limits of the coracoid (procoracoid auct.) 
are not distinguishable ; the bone is thinned, rounded on the 
anterior angle, which is slightly underlapped by the clavicle, 
and, with the metacoracoid, is curved inward nearly to a hori- 
zontal plane, approaching its mate of the opposite side, but 
separated by the stem of the interclavicle. ‘The interclavicle 
reaches a little further back than the hind angle of the meta- 
coracoid, and is of moderate width ; its front part is dilated and 
mostly hidden from view, as in the other Permian reptiles. 

In each skeleton there is a pair of bones found lying just 
back of the coracoids, and nearly below the vertebree, of the 
nature of which I am not fully satisfied, though there would 
seem to be little doubt but that they are unusually large hyoids. 
They are about three inches in length, greatly expanded on 
their distal, thin end, with a somewhat curved and narrowed 
shaft, deeply concave in outline on one side, less so on the 
other, thickened and truncate for articulation at the proximal 
end. The two bones in each specimen lie with the thin ends 
nearly in apposition, as though they had joined each other in 
lite. 

Humerus.—The humerus is a remarkably short and thickset 
bone, resembling that of Dzadectes more closely than that of 
any other genus that I know. The ectocondyle is more ex- 
panded and turned inward than in that genus, however, nor is 
the proximal expansion so much twisted from the plane of the 
entocondyle as is the case with the humeri of more terrestrial 
Permian reptiles. The entocondylar foramen is large, situ- 
ated not far from the lower extremity of the lateral process. 
The ulnar expansion is broad and flat, and occupies a plane 
divergent from that of the proximal inner side of about forty- 
five degrees. The capitellum is very large and rounded, situ- 
ated on the outer angle of the bone, as seen from the ventral 
side, and is remarkably close to the lateral process. The 
ectocondyle is remarkably stout and protuberant, and is directed 
almost rectangularly, or even at an acute angle backward, termi- 
nating very near the middle of the bone transversely, and above 


’ 


392 Williston—New Family of Reptiles from the 


the groove for the ulna on the dorsal side. It is an interest- 
ing fact that not only the structure of the humerus, but also 
the whole anterior limb, resembles, not only that of Diadectes, 
but also that of the amphibian “ryops, suggesting similar 
habits in all three animals, and possibly too genetic aflinities. 
There is a moderately stout ectepicondylar process, as in Des- 
mospondylus, Seymouria, Diadectes, EHryops, ete. It is situ- 
ated a little below the lateral process on the radial side.. 

Radius, Ulna.—The radius and ulna are very like those of 
Diadectes and Eryops, rather short and stout bones. The two 
lie in position on each side, as shown in the figure, the upper 
end of the radius partly lodged in the lower end of the sig- 
moid fossa, and the two are in ove plane. The radius has the 
eapitulum truncated and hollowed for articulation with the 
humerus, the extremity strongly convex on the dorsal, fiat- 
tened on the ventral side. The shaft of the bone is moderately 
narrowed, and its two borders are nearly symmetrically con- 
cave. The lower extremity is more expanded, with its end 
truneate and flattened for articulation with the radiale and 
intermedium, the inner side the thicker. Just above the inner 
distal angle there is a characteristic protuberance, which evi- 
dently came in close contact with the ulna. The ulna is a 
more slender bone and is a little longer; it is thick and mas- 
sive at its upper end, the shaft more slender than that of the 
radius, and the lower end moderately expanded. | Its radial 
border is deeply concave, its inner border nearly straight to 
the lower fifth. The sigmoid fossa is deep, winding obliquely 
about the bone, and fits accurately the curved trochlear sur- 
face on the distal and dorsal side of the humerus. Evidently 
the elbow joint was a strong and firm one. The distal extrem- 
ity of the ulna is subtruncate, its border somewhat oblique to 
that of the radius, but with the angle broadly rounded for 
articulation with the pisiform. Both radins and ulna have 
the dorsal side convex, the ventral more flattened. 

Front Foot.—Lying in close articulation with the radii and 
ulnz are the proximal carpal bones, four in number on each 
side, the radiale, intermedium, ulnare and pisiform. The pisi- 
form is a small bone, thinned along its free border and articu- 
lating in its usual position between the ulna and ulnare. The 
ulnare, the largest of the carpal elements, is an irregularly 
oval bone, articulating rather broadly with the ulna and the 
intermedium, but without distiuet facets for the other carpal 
elements. ‘he smaller intermedium is much thickened, artic- 
ulating with the ulna, ulnare and the radius, with a very small 
free border between the ulna and the radius. The radiale 
is the smallest of the three, almost vestigial in fact, elon- 
gate-ovate in shape, with the radial border straight and flat- 


Permian of New Mexico. 393 


tened, the outer and obtusely pointed; it merely touches the 
intermedium. The ventral surface of all three of these bones 
is flattened, the dorsal more rounded, that of the radiale obso- 
lete. Especially remarkable is the fact that all of these proxi- 
mal carpal bones save the ulnare are very small, smaller 
than in Diadectes even, and much smaller than in other known 
Permian reptiles. 

The remaining bones of the right foot were found nearly all 
connected, for the most part in the relations of the living ani- 
mal. The foot had been slightly twisted in fossilization, dis- 
turbing somewhat the relations of the metapodials. Of the 
phalanges all were found in association save two terminal ones, 
the distal phalanges somewhat confused in the three middle 
fingers. The three distal carpal bones were found in the posi- 
tions shown in the figure, but there were no traces of others, 
and they could have hardly escaped notice had they been fos- 
silized with the others. Evidently these nodular bones repre- 
sent the centrale and the third and fourth carpalia. Fertu- 
nately the bones of the left foot were found in the matrix in as 
natural relations as one could wish, and they will be so retained 
in the prepared skeleton. The block containing the distal 
earpals and the digital bones had been separated in collec- 
tion from that containing the fore-arm and proximal carpals, 
and was not accurately readjusted. The three carpal nodules 
are quite as in the other hand with no traces of others; from 
which facts I have no doubt that they were the only ones ossi- 
fied, and they but imperfectly. Of the digits the bones of the 
three middle toes were all in perfect articulation save the 
ungual phalanges of the second and fourth digits, which are miss- 
ing. Of the first digit, the ungual phalange is also missing and 
the phalanges of the fifth have not been adjusted to the meta- 
carpal. However, these digits were preserved in perfect artic- 
ulation in the right foot. From these facts, which I have 
given in detail because of their importance, it is certain that the 
phalangeal formula is, as is seen in the figure, 2, 3, 4, 5, 3, 
fixing for the first time the foot structure in an American 
cotylosaurian, and save for Procolophon, which has been 
referred (wrongly I believe) to another group, in a niember of 
the order. My figure was made by simply tracing the outlines 
of the various bones as they lie in position and transferring them. 
The only doubt that remains is the precise width of the space I 
have left for the carpal elements, it may be a trifle too broad. 
As is seen, the foot is remarkably broad and flat, lying in the 
matrix in nearly one plane, with the phalanges short, the 
ungual ones broad and hoof-like, as in Diadectes, and probably 
also Hryops. The foot resembles that of Diadectes somewhat 
save that the proximal carpal bones are large, and the distal 
row seems to be fully ossified in that genus. | 


394 Williston—New Family of Leptiles from the 


Three years ago I expressed the opinion that the phalangeal 
formula 2, 8, 4, 5, 3(4) was the primitive one for land reptiles, 
if not for land vertebrates, as observed in Hosawravus cope. 
Broom is of the opinion that this is the formula in Propappus 
and he has proven it to be that of Procolophon. Dromopus 
agilis Marsh, as figured by the author and Matthew, shows a 


Fic. 6, 


Fic. 6. Limnoscelis paludis. Pelvis, from below, two-fifths natural size, 
a, cross-section through pubes at a; b, cross-section through ischia at 6. 


similar phalangeal formula. These footprints are from near 
the upper part of the Coal measures in the vicinity of Osage, 
Kansas. Marsh thought that they were made by a lacertilian 
rather than an amphibian, a natural error considering the 
lacertilian form of the prints. They probably come from 
some microsaurian reptile uot unlike Hosawravus copet. 

_ Pelwie Girdle and Extremity.—The pelvic girdle lies in 
natural articulation, with but little disturbance; the right 
pubis is a trifle compressed, and the extremity of the left 


Permian of New Mewico. 395 
ilium had been broken off and turned aside before fossiliza- 
tion. Both femora are closely articulated in the acetabula, 
directed obliquely dorsad and cephalad. The pubes and ischia 
lie in a subhorizontal position, with a protuberant carina along 
the middle, deeper anteriorly. This keel, however, is not 
formed by the downward deflection of the margin of the 
bones, but by the increased depth of the symphysis, as will be 
seen from the cross sections of the figure, sections made at 
points of fracture in the specimen. The ischia have an 
angular margination in the middle, the sides curving outward 
and upward to the rounded posterior angle. The sutural 
division between ischium and pubis is at about two-fifths of 
the length from the front end of the pelvis. The pubic fora- 
men is remarkably large at the bottom of a rather deep fossa 
situated a little back of the ischio-pubic suture, and. not far 
from the acetabular border. The acetabulum is deep and 
large, with an overhanging, nearly horizontal roof-like pro- 
cess, at the upper posterior part. In life the cavity looked 
almost directly outward. The ilium is relatively small; it is 
flattened and thinned above and in front, with a rather stout, 
narrow process directed backwards and a little outward, nearly 
horizontal. Upon the whole, the structure of the pelvis is 
nearly identical with that of Diadectes and Pariotichide, and 
even of Hryops and Cacops, save in the form of the ilium; in 
Diadectes, broader above and not produced backward ; in the 
temnospondyls without iliac projections either in front or 
behind. While there is but a single sacral vertebra in Lemno- 
scelis and Diadectes, in Cacops there are two, a precise reverse 
of what has always been supposed to be diagnostic charac- 
ters of these two classes of vertebrates. The femur is of the 
characteristic Dzadectes type, short, stout, and expanded, with 
a heavy, protuberant trochanter, and a large digital fossa. 
The trochanter has a large facet, 20 or more millimeters in 
diameter, looking backward, and is rugose; the adductor ridge 
is pronounced and oblique. The tibia, like the femur, is short 
and stout, with a greatly expanded upper end, and a strong 
cnemial protuberance. The outer side is deeply concave in 
outline, the inner nearly straight. The lower extremity is much 
thickened. The fibula is a more slender bone than the tibia, 
and is longer. Its proximal end is thickened and subquadrate 
in shape; the lower end is thin and considerably expanded. 

Hind Foot.—As already stated, the foot bones of specimen 
No. 811 were more or less weathered. From the wash, numer- 
ous toe bones and the ends of the epipodials with attached 
tarsals had been gathered up by Mr. Baldwin, and some of — 
- them still retain enough of their original matrix to show their 
relationships, but how many of them are irretrievably lost 


396 Williston—New Family of Reptiles from the 


Fie. 7. 


Fic. 7. Limnoscelis paludis. 


Right hind leg, dorsal view, specimen No. 
809, two-fifths natural size. 


t-i, fused tibiale and intermedium ; /, fibulare. 


cannot be determined at present. Fortunately, however, in 
specimen No. 809, the tibize and fibule of both sides were 
preserved in position with the tarsal bones attached, fortu- 
nately so, since one would hardly have identitied the tarsal 
bones correctly had they been found isolated, so very different 
are they from the corresponding bones of the Pariotichida 


Permian of New Mexico. 397 


or Pelycosauria. The tibiale, or intermedium, is nearly 
cuboidal in shape, with a slight notch only between the articular 
faces for the tibia and fibula. Its outer facet is thickened for 
union with the fibulare, but I see no perforating foramen 
between the two bones. The distal and inner facets are also 
very broad, subquadrate in outline, with rounded angle. The 
fibulare is a larger bone, but much thinner than the tibiale ; its 
tibial side is the thickest. I identify these two bones as the usual 
fused tibiale and intermedium, and the fibulare, but it is not 
impossible that the tibiale has been entirely lost, after fusion, 
and what really remains are the intermedium and fibulare. 
I have so far found no evidence satisfactory to me that the 
tibiale and intermedium are ever present in adult reptiles as 
distinct bones. I am aware that Broom has provisionally 
recognized a separate intermedium in Howesia and that other 
instances have been cited, but 1 think they are all open to 
doubt. The separation of the intermedium of the hand is a 
very persistent character in the Amniota, Man, himself, even 
having the same bones that are found in the temnospondyls in 
the proximal row of the carpus. In the tarsus, however, there 
was an early specialization, as far back as early Oarboniferous 
times, and I do not think there was ever a reversion to the 
amphibian type. 

Of the left foot of specimen 908 only these two tarsal bones 
and a number of separated toe bones have been recovered. Of 
the right foot, however, all the bones of the toes were preserved 
in their natural relations in the matrix, or with but slight dis- 
tortions, the metatarsals all lying in one plane, apparently quite 
in the positions they occupied in life. The block containing 
them had the phalanges of the first toe, the first one of the sec- 
ond toe, the first two of the third toe and all four of the fifth 
toe in close articulation, those of the first and fifth toes strongly 
flexed. With this block, but separated, were the phalanges of 
the middle toes, the two each of the second and third and all 
five of the fourth toe severally connected by matrix, but not 
positively attachable to the basal bones of their respective dig- 
its, because of the effacement of the matrical surfaces in collect- 
ing. That they belong with these toes is, however, beyond 
doubt, both because of their perfect anatomical association and 
the peculiarities of the matrix. The formula as is thus seen is, 
like that of the front feet, the primitive one for reptiles, 2, 3, 
4,5,4. The phalanges, as of the front feet, are all remark- 
ably short and broad, and I may also add, relatively thin. The 
ungual phalanges, as have been described for Diadectes, which 
they reseinble, are short, broad and hoof-like rather than claw- 
like, with a thin rounded extremity, the bones possibly encased 
in a horny nail in life. I can hardly conceive of a foot of this 
character being used for burrowing, notwithstanding Case’s 


398 Williston— Reptiles from the Permian. 


comparison of the similar feet of Dvadectes with those of the 
gopher. The right front foot, as preserved in the matrix, had 
the tibia and fibula, with their attached proximal carpals, pressed 
downward somewhat below the proximal ends of the metatarsals, 
but not a vestige is preserved in the matrix of centrale or 
tarsalia, nor is there any tarsal bone preserved with either speci- 
men save the four sets of proximal ones. It is not at all impos- 
sible, however, that vestigial, nodular tarsalia may have been 
ossified, but it is not very probable that they were. Chondrifica- 
tion was evidently here a specialization, and in accordance with 
the almost universal rule among terrestrial vertebrates we 
should expect that the process would develop more rapidly in 
the hind than in the front feet. 

No indications whatever of ventral ribs are present in 
either specimen. In their place, however, the whole ventral 
region was covered by a sort of plastral sheath of imperfectly 
ossified or calcified material. Patches of this sheath were 
found scattered about in the matrix below the posterior verte- 
bree and adjacent regions, some of them two inches or more in 
diameter. I have not yet had an opportunity to examine the 
substance microscopically, but to the unaided eye it appears to 
be loose bone tissue. It is quite certain that the animal did 
not have distinct ventral ribs, or osseous dorsal scutes. 

Habits and Relationships of Limnoscelis.—It is almost 
superfluous for me to point out, so evident will it be to 
every one, that Lamnoscelis must have been a subaquatic or 
marsh-dwelling reptile. Of the poorly ossitied or cartila- 
ginous carpus and tarsus the evidence is almost positive, and 
there can be but one explanation, subaquatic habits. The limbs 
as a whole indeed are strongly suggestive of the turtles. The 
relationships of the genus are unquestionably closest with 
Diadeates of any forms that we know, from which it differs 
chiefly in the elongated skull, the conical, prehensile teeth, the 
absence of the ear cavity posteriorly, the small size of the 
parietal foramen, the smoothness of the skull surface, the non- 
expanded ribs, their apparently single-headedness throughout, 
the absence of hyposphenes, and the feebly ossified carpus and 
tarsus. It agrees with Dzadectes especially in the general 
structure of the limbs, the arrangement of the skull bones, 
especially the union of the prefrontal and postfrontal over the . 
orbit, the general structure of the vertebree, with the cylindric 
or prismatic spines, etc. It agrees with both Dadectes and 
Pareiasaurus in the very characteristic flattened occipital con- 
dyle; and I believe that when we know more of the structure 
of the skull of the latter genus, we shall also find more evi- 
dences of affinity in these groups, to such an extent that the 
three genera, and Propappus also, may perhaps be placed in 

the same suborder of reptiles. 


C. R. Hastman— New Hlasmobranchs from Solenhofen. 399 


Arr. XXXIV.— New EHlasmobranchs from Solenhofen im 
the Carnegie Museum ; by C. R. Eastman. (With Plates 
I-I1I.) 


SEVERAL years ago, through the generosity of Mr. Andrew 
Carnegie, the Museum founded by him in Pittsburgh received 
a notable enrichment of its collections illustrative of vertebrate 
and invertebrate paleontology, especially from European hori- 
zons and localities. By its acquisition of the famous Bayet Col- 
lection, through the gift of Mr. Carnegie in 1903, the Pitts- 
burgh "Museum was at one stroke placed i in the front rank of 
American institutions as regards representation of the ancient 
life-history of the globe in “Old World formations: Remark- 
able not only for its size and great wealth of fossil species, but 
also for the excellent character of the material, this collection 
is one of the largest and scientifically most important that has 
ever been brought together by a single individual, and in . cer- 
tain respects it stands unrivalled save by the larger public insti- 
tutions abroad. 

The great strength of the Bayet Collection may be said to 
lie in its magnificent series of vertebrate remains, especially | 
fishes, from European Mesozoic and Tertiary strata. Within 
this category is to be included first of all the splendid suite 
of fishes and flying reptiles from the Lithographic limestone 
(Upper Jura) of Solenhofen, Bavaria, and from the correspond- 
ing deposits of Cirin, France. Next in order of importance may 
be reckoned the fish and reptilian remains (including at least 
one complete Pterodactyl) from the Lias of central Europe, 
and “ blue Lias” of Dorsetshire. Nor would any mention of 
this collection be complete which failed to speak of the large 
variety of exquisitely preserved marine fishes, crocodiles, and 
plant remains from the Upper Eocene of Monte Bolea, Italy. 

So much by way of brief comment on the surprising rich- 
ness of the collection which has found a final resting-place in 
the Carnegie Museum, and which embraces the material about 
to be described in the following pages. For an opportunity to 
study the entire assortment of fossil fishes belonging to “the 
Carnegie Museum, and for many privileges and courtesies 
enjoyed during his "tempor ary connection with the institution, 
the writer is oreatly indebted to the kindness. of the Director, 
Dr. W. J. Holland, and desires hereby to express his hearty 
appreciation of the manner in which work upon the collections 
has been encouraged and facilitated by Dr. Holland and his 
assistants. 

It is not the purpose of the present article to notice all of the 
interesting specimens of sharks and rays from Solenhofen 


400 C. BR. Kastman—New Elasmobranchs from Solenhofen. 


belonging to the Carnegie Museum, but rather to signalize the 
characters of a few new or little known forms, reserving more 
detailed descriptions and a review of the entire Upper Juras- 
sic piscine fauna until some later season. The species to 
which special attention is directed are referable to four genera, 
as follows: Cestracion, Phorcynus, Squatina and Rhinobatus. 


Family CesTrRaciontTip &. 
Genus CrsTrracion Cuvier. 


To this existing genus, commonly known as the Port Jack- 
son shark, have been referred certain skeletal remains not as 
yet satisfactorily distinguished from it which occur in the 
Lithographic limestone of Bavaria. The holotype of the 
so-called ‘““Acrodus falcifer” (= Cestracion) of Wagner is pre- 
served in the Paleontological Museum at Munich, and other 
imperfect portions of the skeleton are to be seen in the collec- 
tions of the British Museum. None, however, exhibits the 
body outline and fin-characters at all satisfactorily. 


Cestracion fulcifer Wagner. 


(For reference to literature see Woodward’s Cat. Fossil 
Fishes British Museum, 1889, pt. 1, p. 332.) 


The typical example of this species shows every indication 
of being an adult individual, and is estimated to have had a 
total length of about 40™. In it the two dorsal fin-spines are 
seen to be of unequal size, both are gently recurved, and the one 
in advance of the anterior dorsal is inserted at a point about 
midway between the pectoral arch and the origin of the pos- 
terior dorsal fin. It would appear from the published fig- 
ures, also, that the pelvic fins arise opposite the first dorsal, and 
the shagreen granules are described by von Zittel as ‘‘schau- 
felformige oder kérnelige,” without being markedly differen- 
tiated in size. To this species has also been referred by von 
Zittel (Handb. Paleeont. vol. 3, p. 77) a smaller but better 
preserved individual, having a total length of only 12°5°, or 
less than one third as large as the type. According to the 
author just named, the smaller specimen, which he regards as 
the young of (. falcifer, has feebly striated lateral teeth, and 
is provided with enlarged stellate tubercles in the dorsal region. 
The description of this feature reads: ‘ Neben den schaufel- 
formig gestalteten Chagrinschuppen liegen in der Riickenregion 
kurze gekriimmte Stacheln, welche sich auf einer vierstrah- 
ligen Basis erheben.” 

It cannot escape notice that the smaller example just referred 
to presents characters in common with the well preserved 


CO, R. Eustman—New Elasmobranchs from Solenhofen. 401. 


specimen in the Carnegie Museum from the same horizon and 
locality, immediately to be described as the type of a new 
species ; and it seems proper to associate under the latter head 
the small shark which the late Geheimrath von Zittel regarded 
as the young of C. falcifer. 


Cestracion zitteli, sp. nov. 
(Plate I.) 


The example which is here regarded as typical of a distinct 
species merits special attention on account of its being proba. 
bly the most perfect post-Liassic Cestraciont shark which has 
thus far been discovered in the fossil state. Agreeing in prin- 
cipal characteristics with the small form described by von Zit- 
tel as the young of CO. falcifer, as above stated, its features are 
nevertheless judged to be sufficiently distinctive as to warrant 
a separation from that species. 

The more important differences relate to the position of the 
dorsal fins, form and relative size of the dorsal fin-spines, num- 
ber and size of the vertebral centra, and presence of a series of 
enlarged radially ridged and acutely conical shagreen tuber- 
cles along the back. A comparison of characters displayed by 
the dentition in the type specimen of C. falcezfer is impossible, 
as the teeth are unfortunately not preserved, but in the small 
Munich example, which may be with entire propriety associ- 
ated with the type now under description, the lateral teeth are 
said to be “mit eine Anzahl von Zacken versehen.” ‘This 
statement may be understood to mean that the oral surface is 
faintly rugose, transversely striated perhaps, or else that the 
coronal margin: is slightly indented. In any case, however, 
- the teeth must have been exceedingly minute. 

A summary of the chief features of interest presented by 
the type specimen may be given as follows: Form of body 
slender and elongate, total length from extremity of snout to 
that of the vertebral column about 15. Vertebral centra 
varying somewhat in length, being more compressed in a longi- 
tudinal direction underneath the second dorsal fin. About 25 
centra occupy the interval between the bases of the two dorsal 
fin-spines, and it is noteworthy that these latter abut almost 
directly against the column, as if they had been deeply implanted 
in the flesh. The spines themselves are of relatively large size, 
smooth, sharply pointed distally, and only slightly arcuate or 
recurved. 

Portions of the fin-membrane or shagreen covering of the pec- 
toral pair, as well as the greater part of the pelvic, anal, and 
caudal fins, are preserved. The anal is nearly opposite the pos- 


402 0. R. Eastman—New Elasmobranchs from Solenhofen. 


terior dorsal and, except for being more sharply pointed, resem- 
bles it in form and proportions. The pelvic pair is decidedly 
acuminate, and placed midway between the anal and pectoral 
pair. The pelvies slightly exceed the second dorsal in size, 
which latter is somewhat higher and longer than the first dor- 
sal; and the depth of the pectorals is about one-third greater 
than that of the pelvic pair. Nearly the entire front margin 
of the right pectoral fin is preserved, but the distal portion of 
the left pectoral is either concealed or broken away. The same 
is true of the terminal part of both lobes of the caudal. The 
general outline of body and position of all the fins is shown 
in the accompanying illustration (Plate I). In this the shaded 
area immediately behind the head indicates a piece broken 
away from the containing rock. 

The specific name is bestowed in honor of the memory of 
the late and deeply lamented Geheimrath Karl von Zittel, of 
Munich. 


Genus Puorcynus Thiolliére. 
Phoreynus catulinus Thiolliere. (Plate II.) 


Our knowledge of this species has depended hitherto solely 
upon the type specimen, which lacks the anal and is in other 
respects incomplete. It must be regarded, therefore, as an 
extremely fortunate occurrence that a second and more perfect 
example of this forerunner of modern Dogtishes should have 
been discovered a half-century after the first was found, and 
should provide the means of further enlightenment concerning 
this genus and species. 

The total length of the Carnegie Museum specimen, which 
bears the catalogue number 4780, is a trifle less than 40°. 

It is a little difficult to determine the exact length of the 
head, but it was apparently contained between five and six times 
in the total length. The outline of the cranial roof, including 
the orbits on either side, and that of the lower jaw, is clearly 
shown. In the ethmoidal region and elsewhere in the body, 
the rounded or polygonal tesserze of the endoskeletal cartilage 
are beautifully displayed, and the same remark apples to the 
fine shagreen granules occurring throughout the integument. 
Just beneath the orbital cavity are to be seen impressions of a 
few minute teeth, each provided with one principal and a pair 
of lateral cusps. 

The vertebral column is preserved intact almost to the 
extremity of the tail, being flexed upward to support the upper 
caudal lobe. Ninety-six vertebral centra are to be counted in 
continuous series, and it is probable that not more than five or 
six are missing from the posterior extremity. The centra are 


C. Rk. Eastman— New EHlasmobranchs from Solenhofen. 403 


of the usual hour-glass form, and do not call for any special 
comment. 

Both the median and paired fins are very well preserved. 
The pectorals are large, lappet-like, not abruptly truncated dis- 
tally as in modern representatives of Scyllium, but obtusely 
pointed, as is the case in Cretaceous species of Palzeoscyllium. 
The low pelvic fins arise at a point opposite the middle of the 
first dorsal. The endoskeletal supports consist of at least a 
dozen segmented radialia. The first dorsal arises at about the 
middle of the back, is of triangular form and moderate height, 
with twelve or more strong radialia. The second dorsal is sim- 
ilar to the first, but smaller, and the gently rounded anal lies 
directly beneath its posterior half. The taii is strongly hetero- 
cereal, in this respect differing from Paleeoscyllium and resem- 
bling the recent Ginglymostoma. 

A minor feature which deserves perhaps casual mention is 
the preservation within the intestinal tract, near the vent, of 
portions of undigested food, including small ganoid scales, frag- 
ments of a small finely striated dorsal fin-spine (doubtless the 
young of some Cestraciont shark), and a number of small 
Kehinoid spines, besides a few Foraminifera tests. 

An outline drawing of this highly interesting shark is given 
in the annexed illustration (Plate IT). 


Genus Squatina (Aldrovandi) Duméril. 
Squatina minor, sp. nov. (Plate III.) 


Type. Complete skeleton, Carnegie Museum (Cat. No. 4737). 

In general like the contemporary species of S. alifera, but 
distinguished from it by its smaller size (total length 49°), rela- 
tively narrower disk, and more posterior position of both dor- 
sal fins. The first dorsal arises at a point about one-third the 
distance between the hinder extremity of the pelvic fins and 
tip of the tail, the second dorsal midway between the latter 
point and origin of the first dorsal. Dentition and other char- 
acters as in the typical species. 

The differential characters given in the foregoing diagnosis 
are considered of sufficient weight to warrant a specific separa- 
tion between the form here described and its larger contem- 
porary which accompanies it in the same locality, S. alifera. 

Not more than two or three examples of the latter form have 
thus far been brought to light, so far as published information 
shows, and the holotype of the new species here made known is 
unique. Hence the genus Squatina must be regarded as repre- 
sented very sparsely, and by not more than three species, 
at the time of its advent in the Upper Jura of Solenhofen. 


404 C. LR. Hastman—New Elasmobranchs from Solenhofen. 


Genus Rutyosatus Bloch (Schneider). 
Rhinobatus bugesiacus (Thiolliere). 


As recognized by Dr. A. Smith Woodward, the type of 
Wagner’s so-called Spathobatis mirabilis is only a large 
variety of this species, which was founded by Thiolli¢re upon a 
complete skeleton from the Lithographic stone of Cirin (Ain), 
France.* The Bavarian specimen serving for the type of 
Wagner’s species is a magnificent example measuring 1°7™ in 
length, with well developed clasping organs, and preserved in 
counterpart. The original of Wagner’s and Zittel’s studies is 
in the Munich Museum, and the opposite half now forms~-part 
of the exhibition series ot the Carnegie Museum. It is note- 
worthy as being probably the largest and most perfect example 
of a fossil ray thus far discovered. 

* Thiolliére’s final work, a large folio published shortly before his death, 
bears the title: Description des Poissons Fossiles provenant des gisements 
coralliens du Jura dans le Bugey. Lyons, 1854. 

The close attinity between Phorcynus and the type of Wagner’s genus 
Palzoscyllium appears to have been overlooked by students of fossil fishes 


generally. The tormer is conjecturally associated with Squatina by Smith 
Woodward. 


Am. Jour. Sci., Vol. XXXI, 1911. Plate |. 


Cestracion zitleli, sp. nov, x'7/6, (Carnegie Museum Cat. No. 4423.) 


Plate II. 


Phorcynus catulinus Thiolliére. x 1/2. (Carnegie Museum Cat. No. 4780.) 


Am. Jour. Sci., Vol. XXXI, 1911. Plate Ill. 


Squatina minor, sp. noy. x1/3. (Carnegie Museum Cat. No. 4737.) 


Pirsson—Petrography of Tripyramid Mountain. 405 


Art. XXX V.—Contributions to the Geology of New Hamp- 
shire, No.V ; Petrography of Tripyramid Mountain ; by 
L. V. Pirsson. 


Introductory.—In a previous paper in this Journal* Prof. 
Wm. North Rice and the author have described the geology 
of Tripyramid Mountain and discussed its structure and prob- 
able origin. It was there shown that the mountain was prob- 
ably laccolithic in nature, and concentric in the arrangement of 
the different rock-types composing it. The outer border against 
the granite of the region is formed in considerable part of a 
gabbro, which is succeeded by a broad inner shell of monzonite, 
and this in turn encloses a core of syenite. In one place the 
gabbro is separated from the monzonite by a narrow zone of 
norite. In the gabbro and outer granite a few narrow dikes of 
lamprophyric character were observed, while with small aplite 
dikes and stringers all the rocks of the complex are reticulated. 
For further details the reader is referred to that article; the 
present paper is devoted to the description of the rock-types 
mentioned above, and to the consideration of their petrographic 
relations. Outside of various references to their mineral com- 
position and megascopi¢ appearance by Hitchcock,t the only 
investigations which have been made of these rocks appear to 
consist in a chemical study of the constituents of the gabbro b 
EK. S. Danat and an examination of it in thin section by G. W. 
Hawes,§ and these studies are referred to later. 

In this paper the rocks will be considered in the following 
ae syenite, monzonite, norite, gabbro, aplite and lampro- 
phyres. 


SYENITE, VAR. Umprexite (NORDMARKOSE). 


A comparison of specimens and of sections shows great uni- 
formity in this rock in all the exposures seen. The freshest 
material was found in a block which had fallen from the out- 
crops above down on the South Slide, and this was therefore 
selected as the type for description and analysis. 

Megascopic.—Phanerocrystalline; medium grained; pale 
flesh-colored ; dominantly feldspathic, but dotted with black 
anhedra and prismoids of hornblende 2-4™™ by 1™™ in size; 
feldspars mostly equidimensional, 1-5"; the great majority 
composed of flesh-colored orthoclase, but mingled with them a 
considerable quantity of grains of a white sodic feldspar ; gran- 

* Vol. xxxi, p. 269. 

+ Geology of New Hampshire, vols. i and ii. 

¢ Composition of the Labradorite Rocks of Waterville, this Jour. (3), 
vol, iii, p. 48. 

§ Geol. of New Hampshire, vol. iii, pt. 4, Mineralogy and Lithology, by 
G. W. Hawes, p. 166, 1878. 

Am. Jour. Sci.—FounrtH SERIES, VoL. XX XI, No. 185.—May, 1911. 

28 


406 Pirsson—Petrography of Tripyramid Mountain. 


ular fabric; fracture rather crumbly; luster dull and slightly 
earthy, showing incipient alteration. 

Mucroscopic.—The study of the thin sections proves the fol- 
lowing minerals to be present: apatite, iron ore, zircon, horn- 
blende, augite, biotite, labradorite, microperthite and quartz. 

The ton ore, in rather sparing grains, and the apatite, in 
small, relatively long prisms, present nothing unusual. The 
zircon, in rather short, thick prisms, bounded by 100 and 110, 
shows an unusually distinct cleavage parallel to 110, and the 
grains, though rare, are rather large. 

Augite was observed in only two cases; in one it was seen 
as a group of minute prismoids in one of the feldspars; these 
were well bounded in the prism zone by 100, 110, and 010; 
were of a pale yellow, had an extinction angle of 40°, and were 
twinned on 100. In the other case it formed the core of a 
hornblende crystal, as described below. 

The hornblende is the most interesting mineral in the sec- 
tion. It is an alkalic variety, occurring in short, thick, not 
very well-defined prisms. It consists mostly of a brown kind 
with the following properties, ¢ on c= 25°; a—c=0°018; ¢, 
yellow-brown; 6, yellow-brown; a, pale ocher-yellow, and 
absorption c>b>a. This is frequently capped by masses and 
tibrous tufts of a greenish blue variety, in which c>c= 18°: 
birefringence low, not over 0-010, and c, strong blue-green, a, very 
pale greenish gray. These quantities are of course not exact ; 

Fre. 1 they represent approximations which are 
oe the average from a number of sections. 
The relations of the two hornblendes to 
one another, and to augite, were well 
shown in a single crystal, a drawing of 
which is given in the adjoining figure, No. 
1. It consists of a core of colorless augite, 
around which the brown hornblende has 
grown in parallel position ; at the top and 
bottom are cappings of the bluish green 
hornblende terminating above in acicular 
tuftings; there are also some enclosed ore 
grains. Examination of this section in 
convergent light shows that it is not cut 
parallel to 010 but between that and 110, 
since the trace of an axial hyperbola 
crosses the field. The scheme of absorp- 
tion, with the strongest color in c, is like 
that of barkevikite ; the mineral is unlike 
it in the very wide extinction angle, while 
on the other hand this character agrees 
with Brégger’s kataphorite, whose absorp- 
tion is strongest in 6. It is thus intermediate between the two 


Fie. 1. Intergrown 
hornblende and pyrox- 
ene. 


Pirsson—Petrography of Tripyramid Mountain. 407 


and the colors have this intermediate character. The blue- 
green variety, which at first thought suggests arfvedsonite, 
differs from this in that c is nearest ¢ (18°) and the strongest 
absorption lies inc, while in arfvedsonite these properties lie 
ina. It appears to be in fact closely allied to the hastingsite 
of Adams and Harrington, which has c on ¢ = 25°, c and 6 deep 
blue-green, a, yellow-green. 

The biotite is not abundant, occurring in occasional small, 
well-formed tablets of the ordinary pleochroic brown variety. 

The feldspars consist of labradorite in small amount, associ- 
ated with much microperthite. The former is in relatively thin 
tables elongated parallel to 010, well twinned according to 
albite and Carlsbad laws, and having the composition Ab, An, ; 
these serve as cores to masses of much more highly sodic feld- 
spar, or anorthoclase, which have grown around them in par- 
allel orientation ; these masses as a whole have no definite 
outward form, and they constitute the white feldspar spots 
seen on the surface of the hand specimen. 

The microperthite is by far the most abundant mineral in 
the rock ; it presents no unusual features, being the ordinary 
intergrowth of orthoclase and albite; it is somewhat altered to 
kaolin, and this accounts for its lusterless surface in the speci- 
men, and the half per cent of water shown by the analysis. It 
is not intended by this to convey the idea that the rock is 
badly altered, for such is not the case; ouly that the feldspar 
is to some degree changed. 

A small amount of gwartz is present in the interstices between 
the feldspars; it has a distinct tendency in places to micro- 
graphic intergrowth with them. 

The order of crystallization is the normal one, beginning 
with apatite, zircon and iron ore, then hornblende, then labra- 
dorite followed by microperthite, whose final stage of consoli- 
dation was simultaneous with that of the small remnant of 
silica as quartz. 

Mode.—The mineral composition of the rock is essentially 
that shown by the calculated norm, and the mode is therefore 
normative. The differences between the mode and norm con- 
sist in that the greater part of the calculated pyroxene, with 
some of the iron ore and a little soda of the feldspar, is present 
as hornblende ; the hypersthene and a little orthoclase are 
represented by biotite; the adjustment of these differences 
frees enough silica to convert the small quantity of normative 
nephelite into albite and yield a little free quartz. 

The composition is then approximately : 


408 Pirsson—Petrography of Tripyramid Mountain. 


Apatite 2 see ule: 0°5 Texture. The rock has a thor- 
[rorivoren cere. os 2a 4:0 oughly normal granitoid texture, 
Biontere sis. sce 1:0 and shows no tendency to the 
UPI ei. 22a eR 1:0 trachytoid one so often exhib- 
Hornblende . ---~---- 6:0 ited by alkalic syenites. The fab- 
Labradorite -.-.-..- 65 rie is inequigranular-seriate, and 
Microperthite -- - - --- 80°0 consertal, composed of irregular 
Quartz <...4 ec 4522. 1:0 nearly equant grains. 
Totaly ==. 100-0 


Chemical Composition.—For the chemical analysis of this 
rock, and also of others given later, I am indebted to thelate 
Mr. C. J. Monahan, a promising young chemist, who at one 
time was assistant in the Sheffield Chemical Laboratory. It is 
given in the adjoining table, and the analyses of some other 
closely related syenites are quoted for comparison. 


ANALYSES OF SYENITES. 


I il III IV Vv VI VII 
SiO, 2225 62°12. 63°71... 62°99: 59:01. 63520, 60:60), 1085 
AV Ov 2s OMS T1675 9)s TAS RIBS iA: NG 70 lic 
Be 0; soy 26 72 De eo we leos t aA O al ty ce ee 
HeO -3.2)) 22999). O66) 5) (Sb SU 3565 2a Se Os 
MgO 2.2.) 10786 9. 307905 eds 0 1:05 = 0°75 2°14 021 
CaOncs (2°37), Sl” 2720 BAO pede mete 043 
NaOll 678) 826) 7 UA 86 le  i-Onee 26, 90mem el 110 
Oe #19. DD ~ 6°35) oe ep 8S eet 051 
HOF = 1048! 0°19)" /VONS a e050 BOL GHO:BiD a eee 
BO S82 0-09), ee Eee OS Se EE Be | MOMoret Tee 
TiO, .-- O84 086 “O-16° NO Sy 1046997000 010 
EO UE 10-23 WHO eee tr ed 0°28 001 
Ma Ser tr, 0°20" 1 OFLSN) MOTOS a) EE Sah OS eee 


ee _ — 


Total... 100°88 100°19 100°92 99:95 100°14 100°10 Rye ts 
* BaO. 


I. Syenite, var. Umptekite, Tripyramid Mt. C. J. Mona- 
han, analyst. 
II. Syenite, var. Umptekite. Shore of the Umpjavr, Kola 
Peninsula, Lapland. W. Ramsay, Fennia 11, No 2, 
p. 205, 1894. W. Petersson, anal. 
III. Syenite, var. Umptekite, Beverly, Mass. F. E. Wright, 
Tscher. Mitt. xix, p. 318. F. E. Wright, anal. 
IV. Syenite, var. Umptekite, Red Hill, New Hampshire. 
W. S. Bayley, Bull. Geol. Soc. Amer., ili, p. 243, 
1892. W. F. Hillebrand, anal. Total includes BaO 
0:08, Cl 0-12. 
V. Syenite, var. Nordmarkite, Tonsenaas, Norway. Brog- 
ger, Zeit. f. Kryst, xvi, p. 54,1890. G. Norsberg, anal. 
VI. Syenite, var. Plauenite, Plauen near Dresden, Saxony. 
Anal., H.S. Washington. This Journ., xxii, p. 129, 1906. 
VII. Molecular proportions of No. 1. 


Pirsson—Petrography of Tripyramid Mountain. 409 


These analyses show that the Tripyramid rock agrees in 
composition very closely with other syenites of alkalic type. 
The magnesia, lime and total alkalies have proportions very 
similar to those in the original umptekite of Ramsay, the chief 
difference being in the relative proportions of the alkalies. It 
is not very unlike one of Broégger’s nordmarkites. All of 
these are alkalic, and to emphasize this Washington’s analysis of 
the well-known syenite of Plauen, which is of subalkalic type, 
is introduced for comparison. The difference in proportions 
and amounts of the alkalies, lime and magnesia is striking. 

Classification.—Considering the fact that this is an alkaliec 
syenite, with an alkalic hornblende as the predominant ferro- 
magnesian mineral, it must be classed with those types which 
have been termed umptekite. This, notwithstanding the small 
amount of labradorite present, which is an unusual feature in 
these rocks, and which a somewhat higher percentage of mag- 
nesia might have prevented by uniting with the lime to form 
more hornblende, or pyroxene. 

In the quantitative system the position of the rock is shown 
in the following calculation of its norm and place from the 
analysis : 


Or 2422, 28:36) Sal 86-38 : 
Ab_... 55°54 Hemi 1DOa 7 3, Persalane 
ee ae ene a 
Ne... (14 —>—_<—, Canadare 
Di hte 6°37 F 87°94 Wl p 
Hy..-- 060 K,O’+Na,O’ 161 
Tis eee aeRO Gao’ Sot 13, Nordmarkase 
Ve te SES 
K U 
Ose 1 OSY! seer =0'46, Nordmarkose 


Na,O’ 110 


Total 99°46 


The rock is, therefore, persalic, perfelic, peralkalic, and doso- 
dic, and its codrdinates are 1, 5, 1, 4. The six per cent of 
hornblende is not sufficient to make the mode abnormative and 
it may therefore be termed grano-nordmarkose. 


MonzonitE (Monzonass). 


Megascopic.cAs exposed in the bare rock surfaces of the 
“Vv,” and fora long distance down Slide Brook, and corre- 
spondingly on Avalanche Brook up to the limits mentioned on 
the North Slide, this type has the following megascopie char- 
acters on a freshly fractured surface. Phanerocrystalline ; 
medium to coarse grain ; dominantly feldspathic; whitish, but 
dotted with blotches consisting of grouped anhedra of horn- 
blende and some biotite; feldspars generally anhedral to sub- 


410 Pirsson—Petrography of Tripyramid Mountain. 


tabular, white, sometimes pale pink, 1-5"™ in dimensions, 
generally dull and lusterless; hornblende blackish-brown, 
pitchy looking, altered ; fabric apparently equigranular ; frac- 
ture rather crumbly ; rock partly decomposed ; weathers pale 
brown. Except for the alteration of the ferromagnesian 
minerals the rock resembles strikingly in color, granularity, and 
fabric, including the grouping of the ferromagnesian minerals, 
a specimen of feldspathic monzonite from Monzoni, which I 
owe to the kindness of Dr. H. 8. Washington. 

Microscopic.—Under the microscope the following minerals 
are disclosed: Andesine, orthoclase, and hornblende essential ; 
iron ore, zircon, allanite, apatite, augite, biotite, and quartz 
accessory; with chlorite, epidote, muscovite, kaolin, and limonite 
as alteration products. 

Of the feldspars, the andesine has a pronounced tabular 
development, yielding elongated sections which commonly 
show both Carlsbad and albite twinning, the latter with very 
thin lamelle. Measurements showed it to have the composi- 
tion Ab,An,. These feldspars, which attain a length of 5™™, 
are rather thickly scattered in a divergent manner through the 
section, and are filled in between, and surrounded by, broader 
fields, or formless masses, of orthoclase, in the manner common 
in many monzonites. The orthoclase shows no perthite inter- 
growth with albite; it is considerably kaolinized, but not uni- 
formly so; the andesine does not show this but contains in 
places much sericitic white mica, and this is also sometimes 
seen in the orthoclase. 

The hornblende is almost entirely changed to masses of 
chlorite and grains of epidote, stained to a greater or lesser 
extent with limonite, but a few unchanged pieces were found 
which prove it to have been a brownish green variety of common 
hornblende, with pleochroism between that color and colorless. 
It surrounds cores of a colorless augite, or accompanies it. 

Iron ore appears occasionally in rather large grains, often 
associated with apatite ; the latter is rather abundant and the 
stout crystals are sometimes 0°5™™ long. Zzrcon is also abund- 
ant, in short thick crystals up to 0°5™" in length, well devel- 
oped and having the forms m(110) and p(111). One crystal of 
allanite was seen surrounded by epidote. A few shreds of 
brown dzotite in the chlorite point to a former greater abund- 
ance of this mineral. The guartz appears here and there, asso: 
ciated with the orthoclase ; as usual, it is the last mineral to 
crystallize, and a poor, but yet distinct, tendency to micro- 
graphic fabric shows that it is original and not secondary from 
alteration. Its total amount is small. 

Mode.—The rock is too altered and rather too coarse-grained 
to yield an accurate ratio of the relative quantities of the com- 


Pirsson—Petrography of Tripyramid Mountain. A411 


ponent minerals by the Rosiwal method, but a rough approx- 
imation, gained by study of a hand-specimen and the thin 
sections, is as follows: 


Alkalic feldspar .....---.--- 40 per cent. 
PAMCCSING ees sas ele ane a 2 ia diaey 
Hipmublenders. 25222022 batt ra ce 
WROMRICG Seen sae oe ce St. Banas 
Ouher minerals 22.2222 2! bs \ COMES 
Total 100 per cent. 


Chemical Composition.—Although the classification of the 
rock appears quite clear, a chemical analysis would be desira- 
ble for several reasons, especially for comparison with the asso- 
ciated types; but as all attempts to obtain material, which 
would be fresh enough to warrant the labor of a good analysis, 
were unavailing, it has not been undertaken. The actual min- 
eral composition shows, however, that it would not be essentially 
different from other monzonites, such as those of Monzoni and 
central Montana, if regard is paid to its more salic nature. 

Classvfication.—In the quantitative classification it is easily 
seen that this rock is dosalic but near to persalic, it is clearly 
perfelic and, from the feldspar relations mentioned above, it 1s 
also domalkalic. This would place it in the rang monzonase, 
but in which of the three middle subrangs it belongs is uncer- 
tain, though probably in monzonose. In any event it is on the 
edge of the group and very close to the persalic line, on 
account of the abundant feldspar. In this respect it is like the 
monzonose from Yogo Peak, which I described under the 
name of syenite,* and which has since been classified as a felds- 
pathic monzonite by Rosenbusch,t+ and included under mon- 
zonose by Washington.t 

In current classification this rock of Tripyramid Mountain 
is certainly a feldspathic monzonite, whether one uses this term 
according to the broad definition of Brdgger, or the more 
restricted one of Rosenbusch, since its genetic affinities are 
shown by its association with the syenite. 


Norirr (Anpose). 


The occurrence of this rock on Slide Brook, between the 
gabbro and monzonite, has been discussed in the foregoing 
paper. The material selected for investigation came from the 
slabs exposed in places in the brook bed, sufficiently far from 
the contact with the gabbro to be uninfluenced by it. 

* This Journal, 3d series, vol. v, 1895, p. 471. 


+ Mass. Gestein., 4th Aufi., 1907, p. 170. 
t Anal. of Igneous Rocks, p. 254, 1903. 


412 Pirsson—Petrography of Tripyramid Mountain. 


Megascopic.—Holoerystalline, medium-grained, 1-3"", mot- 
tled dark and light in color, average tone, gray; consists of 
formless, greenish, to greyish black, ferromagnesian mineral 
grains mingled with pale brownish-white feldspar ones. With 
the lens bronze-colored cleavages of biotite are occasionally 
seen and, on the feldspar cleavage, fine striations of albite twin- 
ning. Weathers brown, becoming stained by ferric oxide. 

Microscopic.—The microscope discloses in thin section the 
following component minerals; apatite, iron ore, biotite, hyper- 
sthene, augite, labradorite, andesine, orthoclase and quartz. 

The apatite is rather abundant for this mineral, in short to 
long prisms. The iron ore, which is titaniferous magnetite, is 
rather abundant, and, while sometimes showing crystal outlines, 
is often very irregular and encloses apatite and augite. The 
augite, in large crystals, is very irregular in form and then 
includes iron ore, apatite, biotite, and even labradorite. Small 
erystals are often quite automorphic, bounded in the prism 
zone by 100, 010 and 110 equally developed; these are quite 
free from inclusions, and often twinned on 100. The usual 
prismatic cleavage is good, the parting 100 was observed, but 
is not common. The color is a pale green; nonpleochroic. 
Maximum extinction angle 43°. 

The hypersthene is in rather long, columnar crystals, poorly 
terminated and of good size, though occasional rounded gran- 
ules also occur. It shows the usual parallel extinction and 
rather low birefringence. It is very distinctly, though not 
strongly, pleochroic, the ray parallel to c being green, while a 
is red. The rather faint pleochroism would tend to show a 
variety approaching bronzite in the content of iron. Along 
cracks there is a slight alteration to serpentine. It carries 
inclusions of apatite, iron ore, and biotite. 

The biotite, of the usual deep reddish-brown variety with 
strong absorption, is scattered through the rock in irregular 
flakes. It is apt to coat the’ iron ore, but also occurs inde- 
pendently, and, as noted above, is found as a frequent inclu- 
sion in the pyroxenes. Some large poikilitic crystals were 
observed which included all the other constituents, even labra- 
dorite. 

The plagioclase has the form of short, broad, book-— 
shaped masses, which yield columnar sections when parallel to 
the basal plane, but much of it is quite irregular in shape. It 
is quite clear, and fresh, and free from inclusions. It has both 
albite and Carlsbad twinning; the albite twinning also shows 
that the crystals in many cases are curved, or bent, or even 
faulted, pointing to movement under pressure, and, in connec- 
tion with this point the reader is referred to the discussion on 
the origin of Tripyramid in the preceding paper. In composi- 


Pirsson—Petrography of Tripyramid Mountuwin. 413 


tion the mineral varies in some crystals from Ab, An, to Ab,An,, 
that is from ecalcic andesine to rather basic labradorite. 
The average of these two is Ab,An,, while the average feld- 
spar caleulated from the analysis in obtaining the norm given 
below is Ab,An,, and this close approximation tends to show 
that the average feldspar must have about this composition. 
Only occasionally is it zonally built. 

The orthoclase and quartz are present in small amounts not 
exceeding two or three per cent each. They are not inter- 
grown, a8 is sometimes the case in rocks of this group, but 
occur independently, filling minute angular interspaces between 
the other minerals. In the calculated norm given below there 
is 10 per cent of orthoclase and 2 per cent of olivine and no 
quartz. This is because the biotite has been split up into oli- 
vine and kaliophilite, and the latter has used up the free silica 
of the quartz and become orthoclase. If we reverse this pro- 
cess and consider the biotite to have essentially the simple 
formula K,(Mg, Fe), Al,Si,O,,, this will split up into 2K. AlSi0,+ 
(Mg,Fe),SiO,, that isinto kaliophilite and olivine. With these 
data it may readily be calculated that the 10 per cent of ortho- 
clase and 2 per cent of olivine of the norm are equivalent to 
6-11 per cent biotite, 3°12 per cent quartz, and 2°78 per cent 
orthoclase = 12°02, which is what the rock modally contains. 

Mode.—By observation of the section and use of the data 
given above the actual mineral composition of the rock is as 
follows: 


Iironmiore sey 52222. 11-0 
PAWN AU Cet arate cen Aaya 4°4 
me ae haba © a Thus the percentage of feld- 
H a ees Pee eye OO spathic components, as compared 
Pee CRBS ers Bes with the ferromagnesian ones, is 
race qitwiacees Sap about two to one and thus clearly 
[oon aon f places the rock in the feldspathic 
ee te ese: : members of the gabbro family. 
Motal eas 2 -- 10050 


Textwre.—Although in the hand specimen the rock appears 
quite even-granular, in the section it is seen to be inequigranu- 
lar and seriate, and consertal in fabric. That is, while many of 
the grains are approximately equal in size, they grade down 
into much smaller ones, and all are closely fitted together, or con- 
serted. The most characteristic feature of the fabric is that 
produced by the rather long and large sections of the tabular 
feldspars diversely spread through the rock, with the other 
components and the smaller feldspars filling in the spaces 
between. 


414. Pirsson—Petrography of Tripyramid Mountain. 


Chemical Composition.—The rock was analyzed by Mr. C. 
J. Monahan with the result given in No. I. 


rm II III. IV. v. 

See 48°67 49°46 50°47 48-06 0-811 
AO... Tees 19°82 18°98 16°95 0°166 
MeO co. ape 5°69 4-29 4°78 0°031 
HeOe. 2-7 6°37 5°82 6°16 7°60 0-089 
MgO __.. 4°62 1:93 5°62 5°51 O°115 
Cx01t oe 8°63 10°62 11°72 779 0°154 
Na,O___-- 3°85 3°38 2°75 3°37 0°062 
KRiOontad eeos 0°74 0°56 1:42 0°018 
H.O+2...' 0°32 0°09 © 1:06 0°80 Eels 
HiQ=2 5620202 plore sea suas yok 
TO see a 2°19 0°69 0-12 2°57 0-026 
1 Oa OE ? ? 0°63 0:013 

Total... 99°57 99°84 101°78 99°48 


I. Norite, andose, Slide Brook, Waterville, N. H. C. J. 
Monahan, analyst. 

II. Norite, hessose, Near Ivrea, Piedmont. (Van Horn, Tscher. 
Mitt., xvii, p. 404, 1897.) M. Dittrich, analyst. 

III. Norite, Eperon du Cerebriansky, west side, Northern 
Urals. Duparc et Pearce, Mem. Soc. Phys. e. d’Hist. 
nat. de Genéve, p. 466, 1905. 

IV. Bronzite-kersantite (andose), Hovland, Laugendal, Nor- 
way. (Brégger, Erupt. Gest. Krist. geb. III, Ganggef 
der Laur. p. 75, 1899.) V. Schmelck, anal. 

V. Molecular proportions of No. I. 


In studying the analysis it is clear that since a very con- 
siderable proportion of the lime has been used to convert the 
excess of alumina over soda into plagioclase, there is not 
enough left to turn all the magnesia and the excess of the 
ferrous iron, not used in iron ore, into pyroxene. These extra 
magnesia and ferrous iron molecules have in this case formed 
hypersthene rather than olivine, because there was an excess 
of silica present, as the residential quartz shows. Thus a norite 
is formed, rather than an olivine gabbro. In this connection 
the reader may compare this analysis with that of the olivine 
gabbro on a succeeding page, where, under No. VI, the norite. 
is repeated for convenience. The gabbro differs chiefly in 
containing 3 per cent more of alumina and lime, and about that 
amount less of ferric iron. Since 3 per cent CaO = 0°59, and 
of Al,O, = 0°29, molecularly, a larger proportion of lime is 
able to combine in pyroxene, a metasilicate, and, since the 
lower ferric iron demands less ferrous to form iron ore, the 
result is that, with the lower silica content, olivine is found 
and not hypersthene, as in the present rock. 


Pirsson—Petrography of Tripyramid Mountain. 415 


For the sake of comparison analyses of two other norites are 
added. Unfortunately not many good reliable analyses of this 
rock, made by the latest approved methods, are available for 
this purpose. In this connection the reader is invited to com- 
pare Nos. land 1V ; Brogger’s rock is a lamprophyric dike- 
rock, one of the clan attendant upon the nephelite syenite 
(laurdalite) intrusions of South Norway. He gives the com- 
position as follows : plagioclase of the composition Ab,An,, 44°7 
per cent, augite 25°3 per cent, bronzite 8-6 per cent, lepido- 
melane (biotite) 14:6, iron ore 5:0 and apatite 1:5 per cent=99°7. 
Tt is to be noted that, while the minerals are essentially the same 
as those in our norite, their relative proportions are somewhat 
different. Chemically, the two magmas are similar ; save for 
the differences in the ferrous iron, magnesia, and the lime, 
they are remarkably alike. The bearing of this on genetic 
relationships is discussed in a later place. 

Classifecation.—In the quantitative system the position of 
this rock is shown by the calculation of its norm and place. 


Ore 10°01 Bal CO olla 

Ab ._.. 32°49 ion ae anes 22, osalane 

An -.-- 23°91 66°41 L+Q 

ees whe sae ems re manare 

ON ecces | GHOM Na,O’+K,0'_ 80 

Mit aves s19 Haeal es =—=0'9=3, Andase 
, ) 

ESS ee 3:95 CaO 86 

prea Arai 330355 KO! P18 

H,O .._ 0°34 NG Ol Ch oe Andose 


2 


Total 100:10 


It is, therefore, dosalic, perfelic, docaleic and dosodic, with 
cobrdinates 2.5.3.4. Comparing the norm with the mode pre- 
viously given, no critical mineral appears in notable amount ; 
the mode is therefore a normative one, and since the texture 
is granular it may be termed grano-andose. In qualitative sys- 
tems the rock is a norite, of feldspathic character. 


Gaxspro (HxEssose). 


The material selected for investigation is from the Black 
Caseade on Slide Brook. The gabbro on Avalanche Brook is 
of somewhat finer grain, but the sections show that it is petro- 
graphically similar. 

Megascopic.—Holocrystallne; medium. to coarse grain ; 
general color dark grayish to black; dominantly composed of 
feldspar of a deep smoky-gray color in roughly tabular crystals, 
10™™ across the cleavages of 6 (010) and lath shaped, 10™™ by 


416 Pirsson—Petrography of Tripyramid Mountain. 


2-3"™ on the ¢ (001) cleavage; the latter clearly striated by the 
albite twinning ; rarely the feldspar shows a blue opalescence ; 
occasional grains of dark greenish ferromagnesian minerals, 
black ones of iron ore, and glittering, bronzy specks of biotite 
are also seen. Resembles anorthosite from many Canadian 
and Adirondack occurrences. Weathers with a dark gray 
crust. 

Microscopic.—In thin sections the following minerals are 
found to be present; labradorite feldspar, pyroxene, olivine, 
iron ore, biotite, apatite. 

The feldspar is in the form of flat tables parallel to 6 (010) : 
it is unaltered and clear, save for swarms of slender ‘dark 
microlites orientated parallel to three different systems ; they 
appear as lines, dashes and dots. In places these microlites 
are somewhat larger, and it can then be seen that they are 
sometimes birefringent, have an index of refraction greater 
than the feldspar, and sometimes change in their length for 
short distances into black opaque bodies. They appear like 
the inclusions of a similar character found in the feldspars of 
gabbros and anorthosites from other localities, but their exact 
nature could not be determined. The feldspar is twinned 
according to the albite and pericline laws, but rarely according 
to the Carlsbad. It is sometimes zonally built and the opti- 
cal properties show in addition a feature sometimes, though 
rarely, seen in that one albite lamella has a different rela- 
tion of the Ab and An molecules which compose it from 
another twin lamella lying beside it. Such feldspars have been 
described by Michel Lévy,* Federofft and the writer.t The 
average composition of the feldspar as determined by optical 
methods is Ab,An,,, while that reckoned from the chemical 
analysis of the rock is Ab,An,—the first equals Ab,,An,,, the 
second Ab,,An,,. This feldspar was also analyzed by E. 8. 
Dana, and while made on material too impure to yield defi- 
nitely exact ratios, since at that time the later methods of 
obtaining pure material were unknown, the results also suffici- 
ently indicate it to be a basic labradorite. 

The pyroxene is of a very pale brown color ; in places filled 
with minute microlites like the feldspar, it does not show the 
diallagic parting parallel to a (100); it contains numerous grains 
of iron ore and scales of biotite but no feldspar ; its form is 
entirely irregular, filling spaces between the feldspars ; it shows 
no sign of alteration; the maximum angle of ¢ on c was meas- 
ured as 40°. 

* Mineraux des Roches, p. 84, 1888. 


+ Zeitschr. fiir Kryst, vol. xxiv, p. 180, 1894. 
t Bull. Geol. Soc. Amer., vol. vi, p. 412, 1895. 


Pirsson—Petrography of Tripyramid Mountain. 417 


The olivine is clear and colorless, unaltered save for a slight 
serpentinization along cracks; while at times it is shapeless, 
and fills spaces between other constituents which determine its 
form, in other cases it shows more distinct crystal outlines; it 
is often included in feldspar in minute grains; the only inclu- 
sions are occasional granules of iron ore and specks of biotite, 
but in some places shadowy spots under high powers reveal 
themselves to be thin sheets of magnetite, which when seen on 
end appear as lines, but viewed flatwise are found to be skele- 
ton erystals presenting remarkable patterns of grating struc- 
tures, such as have been described by petrographers in olivines 
from various localities.* 

The olivine of this rock was analyzed by E. 8. Danat on 
extracted grains with the following results : 


A. B. C. D. 

LON nee 38°85 0°647 0:050 0°597 0597 =1:04 
BeOveens.2 28°07 0°389 0°012 0°377 
WN O'S Saeco 1:24 0°017 Sate oor 0°1146=2-00 
Mo Oreene = 30°62 0°765 0°018 0°752 
CIO eee 1°43 0:025 0°025 
A Os aete tes trace 

Motale sss T0020 


Since the amount of alumina is practically nothing the lime 
must be due to a little admixed pyroxene. If, from the molec- 
ular ratios shown in B, a sufficient amount of iron, magnesia 
and silica be deducted, as in ©, to convert the lime into pyrox- 
ene, the final ratios available for olivine are given in D, which 
gives an excellent result for the olivine formula. There is an 
unusually large amount of iron present, the mineral being 
practically Fe,SiO,.3Mg,SiO,, and thus belonging to the variety 
hyalosiderite, which explains the presence of iron ore sepa- 
rated out along the cracks, where alteration has taken place, 
and thus confirms Rosenbusch’st view that in such cases the 
olivine of gabbro rocks is one with a large content of iron. 
The iron ore is shapeless, and only in one section was dis- 
tinct crystal outline seen, that of a hexagon. It is observed in 
relatively large masses and in small grains; the large masses, 
like those of the pyroxene, have their form conditioned by the 
surrounding minerals, and in a number of cases the ore was 
found completely enclosing automorphic labradorite. This 
shows that the period of crystallization for the ore lasted long 
after that of the basic labradorite, a phenomenon which Rosen- 


* Petrography of the Little Belt Mts., 20th Ann. Rep. U. S. Geol. Surv., 
(Pt. III, p. 481, 1900). 

+ Loe. cit. 

} Massigen Gesteine, 4te Aufl. 334, 1907. 


418 Pirsson—Petrography of Tripyramid Mountain. 


busch* likens to the structure of meteorites. The specks of 
metallic iron mentioned by Hawest I was not able to tind, but 
some pyrite was observed. 

The d2otite is of a deep red brown and very pleochroic ; 
while it occurs in isolated flakes it is usually seen as a mantle 
coating the ore grains. ; 

Apatite is not common, but is seen occasionally, often in 
slender prisms in feldspar. 

Mode.—The actual mineral composition, determined by 
observation of the sections and caleulation from the chemical 
analysis, is shown in the adjoining columns : 


Teeture. The texture is that 
of a typical gabbro, a granular 


Rabradorite’sss.9> a2. 63°0 one, conditioned by the short, 
BiOtite ewe, eee 5°0 broad laths of feldspar, with the 
Pyroxene ah. “eae 14:0 intermingled shapeless masses of 
Olivine: 22 ss Sa5-2 10:0 pyroxene, olivine and ores. There 
Tron! sorepeeey: Jae ae 6‘7 is no tendency to the ophitic tex- 
Apatite eae eee 1°3. ture by the enclosure of feldspar 
laths by pyroxene, indeed the only 

otal tae x Bee 100°0 case of this kind noted was where 


the feldspar in one or two cases 
was enclosed by iron ore as previ- 
ously stated. 


Chemical Composition.—For a chemical analysis of this 
rock, Iam indebted to Mr. CO. J. Monahan, whose results are 
given in No. I of the following table : 


No. i II. III. IV. ve VI. VII. 
SiO}. 47:82) | 47-88. 158-18) ts 522855 S:6nn ee oO Onno 
Al:O. 19799) 18:90). 93:25 ban 8, 20g ee lose Se Ogee 
BeOr eo 10 1°39 1:53 1-2 0:98 4:98 0°613 
ReO ete er sl Or4s i-BQbc aes 7°61 6°37 0-090 
MgO__. 4:94 7-10 2°60 4:8 1°57 4:62 07123 
CaO___. 11°65 8°36 11°18 12°9 9°16 8:63 0:208 
NavOlee Sco 2-75 3°97 3°0 3°33 3°85 0°056 
KON S067 0°81 0°86 0°5 1°61 1:26 0:007 
H,O+ _ 021 0°43 0°98 12 1:33 OSD bik eee 
H,O— _ 0:07 0-18 OS eee p ahh 0°02 shah! 
CO, ---- none 0°12 Ora Ae eae Saag eee fame 
TOS Leotae 1:20 0°45 0°5 ? 2°12  0°025 
PO) W42).. Gt0756 0°20 0:09 ? ? 1:85 0:004 
Seen ae geet 0:07 See A ees pat suns psec 
CriO ebials se tr Lik pets eect ais 
INGO ae 0:02 ie ee ee aes si fe epee 
WO) 2 fe, 0°16 OAL as tr igi 
Ba0__- tr. tr. tr air Se tr Be ee 


= 


10000 100°02 1001 99°5 100°01 99°57 ee 
Mass. Gesteine, 4'° Aufi., p. 336. + Loc. cit., p. 167. 


Pirsson—Petrography of Tripyramid Mountain. 419 


I. Olivine gabbro (hessose) “ossipite,” Black Cascade, Slide 
Brook, Waterville, N. H. C. J. Monahan, analyst. 
II. Gabbro (hessose), Split Rock Mine, Westport, Essex Co., 
N. Y., (Kemp, 19th Ann. Rep. U.S. Geol. Surv., Pt. 
III, p. 402, 1899). W. F. Hillebrand, analyst. 
III. Gabbro near anorthosite, Whiteface Mt., Adirondacks, 
N. Y. (Bull. 228, U.S. Geol. Surv.), G. Steiger, analyst. 
IV. Light band of Gabbro, Druim an Eidne, Isle of Skye, 
Hebrides (Geikie & Teall, Quart. Jour. Geol. Soc., 
vol. 1, p. 653, 1894). J. H. Player, analyst. 
V. Gabbro with predominant labradorite, Baste, Harzburg, 
Streng, Neues Jahrb., 1862, p. 963. 
VI. Norite (andose). Above the gabbro, Slide Brook, Water- 
ville, N.H. C. J. Monahan, analyst. 
VII. Molecular proportions of No. I. 


Gabbros, as is well known, are very variable rocks in the 
relative proportions of the feldspathic as compared with the 
ferromagnesian minerals; they can, therefore, be roughly 
divided into two groups, the feldspathic and the ferromagne- 
sian ones. In the latter the iron and magnesia are very large 
in amount, accounting for the predominance of ferromagnesian 
minerals. The analysis shows the rock under discussion to 
belong to the former class and this accounts for the agree- 
ment of the analyses with well known feldspathic types, as 
illustrated in the above table. Of the banded gabbros of Skye 
it has nearly the same composition as the light feldspathic 
bands. If all of the potash were present in biotite there 
would be some 8 per cent of this mineral in the rock; the 
actual amount estimated is not so large as this, and if correct, 
asmall amount (1°8 per cent) of orthoclase must also be in the 
rock. It has not been seen and may well be lost in submicro- 
scopic intermixtures in the other feldspars. The adjustment 
of molecules in the calculation of the following norm also pro- 
duces in it a little nephelite, which could not be found present 
in the rock. 

Classification.—The position of this rock in the quantitative 
system is seen in the following calculation of its place and 
norm : 


On eo oo Sal 68°53 


Ap Uuon68 Feim ain Dosalane 
ANAS 3629) Toe 
Ne --- 199 6853 ~~ *" —0.03=5, Germanare 
Di. 2214-08 Fo 66°54 
Ol Lease F893) K O'+Na,O' 63 
: 2 = =0°49=4, Hessase 
Mt.... 3°02 CaO’ 133 
ll Saas 3°80 K Q' q 
Ja Dee) IBY. BST 2-_ — —=0'12=3, Hessose 
H Oo ta) 28 Na,O 56 


Total 99:93 


420 Pirsson—Petrography of Tripyramid Mountain. 


It is, therefore, dosalic, perfelic, docaleic, and presodic, and 
its codrdinates are 2.5.4.3. The amount of biotite is negli- 
gible and hence the mode is a normative one. The texture 
being granular it is grano-hessose. In prevailing qualitative 
systems it is an olivine-gabbro of feldspathic type, or rather, 
one should say, it would be pronounced such if its association 
with the monzonite and syenite were unknown, or unsuspected. 
By those petrographers who hold rigidly to genetic lines in 
classification, if these facts concerning it became known, it 
would, supposedly, be classed as an essexite. 


QuARTZ-SYENITE APLITE (LIPARASE), < 


It has been previously mentioned that where the rock sur- 
faces of Tripyramid Mountain are well exposed they are found 
to be cut by narrow dikes, or dikelets, of aplitic character. 
While there is some variability in the relative proportions of the 
minerals composing these rocks, and in their texture, it is not 
so great but that they can all be placed in one well-defined 
group—they are quartz-syenite aplites. Also, they are rocks 
of such very simple composition that only a very brief descrip- 
tion of them is necessary. 

Megascopic.—Phanerocrystalline ; very fine-grained, but not 
dense; usually flesh-colored but varying from whitish to pale 
reddish brown; persalic and predominantly feldspathic ; 
faintly dotted at times with minute, blackish specks; appar- 
ently equigranular in texture and of firm habit; fracture not 
easy and hackly ; often rather weathered, 

Microscopie.—Alkalic feldspar essential, sometimes also 
quartz; iron ore, biotite and zircon accessory, sometimes also 

uartz. 

The alkalic feldspar is mostly orthoclase, with some micro- 
perthite intergrowth of albite; soda-lime feldspar was not 
observed. The feldspar appears in the slide in rather equi- 
dimensional sections, which tend to be square in outline, 
indicating a roughly cuboid habit. The interspaces are filled 
with quartz which is completely anhedral in consequence; in 
those cases where the quartz is more abundant it tends to a 
rudely micrographic fabric, in that the various interspaces 
between several feldspars are filled by a quartz mass of uniform 
orientation. An occasional grain of iron ore, sparsely sprinkled 
flakes of light brown biotite, generally altered to chlorite, and 
a rare crystal of zircon complete the list of minerals. So far 
as the feldspars, which are the predominant components, are 
concerned the fabric tends to be equigranular, and equant. If 
the quartz be also considered the fabric is seriate, consertal, 
tending in some cases to graphic. 


Pirsson—Petrography of Tripyramid Mountain. 421 


Classification.—The greatest amount of variation in any 
mineral is shown in the quartz; in some instances it is fairly 
abundant and these might be classed with granite aplites ; in 
others it sinks to a negligible quantity and such are syenite 
aplites; on the average the group contains much less of it than 
normal granite aplites and is, therefore, classed as quartz- 
syenite aplite. In the quantitative classification these rocks 
are very clearly persalic and peralkalic, and vary between 
liparase and nordmarkase ; the relation of soda to potash is not 
known, but the feldspars show so little evidence of being 
dosodic that it is probable the rocks vary in subrang from 
liparose to phlegrose. These dikes are closely allied to the 
syenite; they differ from it in being, on the whole, somewhat 
richer in quartz, and in their lack of hornblende. 


LAMPROPHYRE Dixes. 


Owing to the thick covering of glacial debris, soil and vege- 
tation on the lower slopes of Tripyramid and in the granite 
surrounding it, there are few places exposed in the outer zone, 
which would be the natural habitat of these rocks, where they 
can be sought for. They may, or may not, exist in consider- 
able numbers, but they have been found only in the granite at 
Norway Rapids as camptonite, and in very narrow dikes cutting 
the gabbro at the Black Cascade on Slide Brook, as previously 
mentioned. 


Black Cascade Dikes. 


Megascopic.—Holocrystalline; fine-grained, average much 
less than one millimeter, compact but perceptibly granular ; very 
dark greenish gray; shows a few rare occasional phenocrysts 
(perpatie fabric) of dark, smoky feldspar phenocrysts with 
nearly square to rectangular outlines 4 by 4 to 5 by 3", 
With the lens a fine intimate mixture of feldspar, sometimes 
in minute laths, and ferromagnesian minerals, indeterminate 
save for an occasional speck of biotite. Feldspar phenocrysts 
show fine albite twinning. Very tough, rings under the 
hammer, has a splintery fracture approaching conchoidal ; 
weathers dark green, turning brown. 

Microscopic.—In the section the following minerals are 
disclosed ; apatite, iron ore, biotite, olivine, augite, labradorite, 
orthoclase and nephelite and serpentine. 

The apatite is freely distributed in minute, very long, slen- 
der needles, which are enclosed in the other components and 
peg them together. It is inferred from the section that the 
amount of P,O, shown in the analysis is rather low and 
probably because the complete enclosure of the very minute 
apatite needles in other mineral grains prevented their going 

Am. Jour. Sc1.—FourtsH Serins, Vou. XX XI, No. 185.—May, 1911. 


29 


422 Pirsson—Petrography of Tripyramid Mountain. 


entirely into solution, a point emphasized by Hildebrand* and 
Washingtont in the determination of this oxide. 

The eon ore is also freely distributed in grains which are 
very small in size compared with those of the feldspar and aug- 
ite ; some is in the form of dust in the augite, and some appears 
secondary from olivine. One or two cases of larger grains 
were seen, and into them augite and feldspar projected, show- 
ing in this case a relatively late, or long-continued, period of 
erystallization. The analysis proves that the iron ore is very 
largely ilmenite. 

sZotite occurs in small flakes and shreds, which sink to sub- 
microscopic dimensions. It occurs in augite and feldspar. 
Only one instance of a larger flake, about 0:05"™ in diameter, 
was seen. As usual, it is apt to be attached to iron ore and 
olivine. It is a very pale-colored variety recalling phlogopite, 
and the pleochroism is not marked, between medium brown 
and almost colorless. Although rather generally sprinkled 
through the rock, the total amount is small, not more than two 
or three per cent of the total constituents. 

The olivine is the only mineral which is not fresh and unal- 
tered. It is mostly converted into masses of a yellowish-green 
serpentine, in which small unchanged fragments of the original 
mineral are still found. It was originally present in small 
irregular masses, or lumps, without good crystal form, averag- 
ing from 0:04-0:05". It is judged, from the character of the 
alteration product, and the iron ore separated out, to have been 
a variety rich in iron. 

The augite is of a pale brown color; the larger masses quite 
irregular in shape, sometimes wedged between feldspars, some- 
times indented by them, and thus showing here and there a 
tendency to ophitic fabric. The smaller grains, however, at 
times have a more distinct crystal form and approach short 
prismoids with the faces 010, 100, and 110 developed in the 
prismatic zone. It has the usual wide angle of extinction. It 
is very impure, filled with shreds of biotite, specks of iron ore 
and needles of apatite, and is frequently colored dark by iron 
ore dust peppered through it in irregular blotches. It is the 
most abundant ferromagnesian mineral. Although the masses, 
or grains, vary in size from 0-10—0:05"™ and from that down, 
no true phenocrysts of it were seen. 

The plagioclase, as previously mentioned, occurs in very 
rare, distinct phenocrysts, columnar on the @ axis and 4—-5™™ 
long. One of these was found, fortunately, to be cut perpen- 
dicular to the 6 (010) face, and having both albite and Carlsbad 
twinning, which permitted it to be determined as a labradorite 
of the composition Ab, An,. 


* Bull. U. S. Geol. Sury., 176, p. 78. 
+ Chem. Analysis of Rocks, p. 151. 


Pirsson—Petrography of Tripyramid Mountain. 428 


The plagioclase which composes the groundmass is much 
smaller, averaging 0:03 to 0:05™" in greatest dimensions. It is 
developed in rather thick tablets which tend to nearly square 
outlines on 6 (010) and which commonly exhibit both Carlsbad 
and albite twinning. The crystals are usually zonal in struc- 
ture, having a distinct, uniform, interior core consisting of 
Ab,An,, which passes into phases much richer in soda at the 
outer margins. Asshown by the calculations from the analysis, 
the average plagioclase present is approximately Ab,An,,. 

A moderate amount of orthoclase is also present in grains of 
about the same size as those of plagioclase and it frequently 
_ shows Carlsbad twins. 

In the angles between the feldspars there is seen, here and 
there, minute areas of a colorless substance which sometimes 
polarizes faintly, and sometimes does not. In some cases the 
latter sections yield a faint uniaxial negative cross. This is 
inferred to be nephelite and on testing with nitric acid the 
powdered rock was found to yield a definite, though not large, 
amount of gelatinous silica. Part of this must come from the 
olivine, but the amount seemed too large to be wholly derived 
from the small quantity of that mineral known to be present, 
and was thus held to be also indicative of nephelite. It is also 
possible that, in part, this interstitial material may be sodalite, as 
indicated somewhat by the distinct reaction for chlorine which 
the rock yields, though in this connection the possibility of a 
chlor-apatite must be considered. It may also, in part, be 
analcite, and in one or two cases this seemed possible, as a fairly 
good cubic cleavage was observed. At all events, a very small 
quantity of a feldspathoid is present, either wholly, or in part, 
nephelite, and this is also indicated in the calculation of the 
norm. 

Mode.—The mode of this rock is a normative one and the 
quantities of the minerals present are those shown in the cal- 
culated norm, the only essential deviation being that a small 
quantity of the caleulated orthoclase and olivine are really 
represented by the two or three per cent of biotite which the 
rock contains. 

Texture.—The fabric which this rock presents in the section 
is like that shown by many gabbros, but on a minute scale. It 
is produced by the short divergent feldspar laths, scattered 
through which are the grains and masses of augite, iron ore and 
olivine. A somewhat similar fabric is seen in diabases when they 
become deficient in augite, and lose the characteristic ophitic 
texture, and in some basalts. It appears in some lamprophyres, 
as in certain kersantites where biotite replaces augite, and in 
spessartites with hornblende. It is a quite different type of 
texture from the equigranular one observed in some dikes 


424 Pirsson—Petrography of Tripyramid Mountain. 


cutting gabbros, and which have been considered aplitie in 
character, like beerbachite for example. The fabric is that 
characteristic of lamprophyres, rather than of aplites. 

Chemical Composition.—A chemical analysis of the rock has 
been made for me by Dr. Ralph W. Langley, formerly assistant 
in the Sheffield Laboratory, and to whom my thanks are due 
in this connection. It is given in No. 1 of the following table 
and with it are also given analyses of some dike rocks which 
are of interest for comparison. 


Analyses of Dike Rocks. 


No. I II HET Pei v Waly | SVL) WL XS 
SiO, ---|50°75| 50°59) 52°95) 41°94) 50°50) 51-70/47-21/0'846|0°843 
Al,O, --|17°31| 17°74) 14:96} 15°36] 17°71) 19°89/20-52|0°170/0:174 
Fe,O, --| 2°08] 3°54) 2°44) 3:27] 5°41) 2°54) 7-48/0:013/0-022 
FeO ..-| 8:13] 7°45) 7:03) 9°89] 4:02) 6:44] 5°32/0°113]/0°104 
MgO.--.| 3°48! 3°92) 3°86! 5:01) 3°33! 4°64] 4°16!0:087|0-098 
CaO __-| 6°77) 6°85) 6°76) 9°47) 7:91) 8°95] 8°63/0:121/0'122 
Na,O _.| 4°14) 4:25) 4°95) 5°15) 5°52} 4-07] 5:17/0:066/0-068 
K,O _...| 2°87) 2°79! 1:64] 0:19! 3:02} 0:83! 0:33/0:031/0:030 
H,O-+ —| 0°56) 0°55) 0:55) 3:29] 0°45) 0°92) 0:34) __.|) —)_ 
H,O — iS Rae Hae eke ee was OPUS) OO) 222 hes 
OO. nINONG)| i rae | ace nea ae ees ee De al le lif i 
TiO, ---| 3°05| 2°60) 3:90) 4:15) 1:91) 0°14)" 2 10:0388)0-088 
LAOS SOG), | OL OSG ae 0°92) 0°37! 0:46} _-.|0°002 
MnO. _-_| tr tr tr 0:25) alee Salli cide 
Total ~~ |99°14/100°55/100°16/100-44|100°70/100°68|99-21| __.| __- 


I. (Andose), dike near the Black Cascade, Slide Brook, 
Waterville, N. H. R. W. Langley, analyst. 
II (Andose), dike at Norway Rapids, Slide Brook, Water- 
ville, N. H. C. J. Monahan, analyst. 
Ill. Spessartite? (hornblende akerose), Belknap Mts, N. H. 
(Pirsson & Washington, this Jour., vol. xxii, p. 455, 
1906). Washington, analyst. 
IV. Camptonite (camptonose), Livermore Falls, Campton, 
N.H. (G. W. Hawes, this Jour. (3), vol. xxvii,- 
p. 150, 1879). 
V. Essexite, Rongstock, Bohemia (Hibsch, Tscher. Mitt. 
xix, Heft I, 1899). RR. Pohl, analyst. 
VI. Luciite-porphyrite (beerbachose), Ernsthofen, Oden- 
wald, Hesse (Chelius, Notbl. f. Erdk., xviii, p. 15, 
1897). W. Sonne, analyst. 

VII. Beerbachite (beerbachose), Frankenstein, Odenwald, 
Hesse (Chelius & Klemm, Erl. z. Geol. Karte Hes- 
sen, x, p. 39, 1896). KR. Marzahn, analyst. 

VIII. Molecular proportions of No. I. 

IX. Molecular proportions of No. II. 


Pirsson—Petrography of Tripyramid Mountain. 425 


The discussion of the analysis really involves also the 
question of classification and is best considered under that 
heading. 

Classification.—In the quantitative system the norm of the 
rock and its position may be calculated as follows: 


Norm. Sal "0-44 

Or See lea at ou 2, Dosalane 
IN yee SNORE) Tatts ce 
ATT 20°29 : 

SS SS 1018}, & F a 
Ne.--- 1°99 70-44 F 68-45 sheer 
Di ---- 10°95 K,0’+Na,O'_ 97 } 
OlP ar 3"48 ash —— =— =1'3, 3, Andase 

CaO 73 

Mie. 3°02 | a 
aes ae 5°78 28°23 a — _ =0'49, 4, Andose 
Ore 56 Na,O’ 66 Wh oo 


Total 99:23 


That is, it is dosalic, perfelic, alkalicalcic and dosodic; its 
coordinates are 2.5.3.4 and, considering its texture, it is grano- 
andose. The attempt to classify this rock according to the 
general qualitative system meets with some difficulty. It 
shows some affinities to diabases, but the fabric is quite differ- 
ent from that of a typical diabase. It would be, perhaps, 
easiest to term it a micro-gabbro. If we consider genetic 
relations, and the fact that it is dike rock, the case becomes still 
more difficult. Does it belong to the alkalic clan of lampro- 
phyres, or to the alkalicaleic (sub-alkalic) group, and, if the 
latter, is it an aplite, or a lamprophyre? If we determine that 
the whole group of Tripyramid rocks is really an alkalic com- 
plex, and that the gabbro should be regarded as an essexite, 
then it is either micro-essexite or, clearly, a lamphrophyre, one 
probably complementary to the quartz-syenite aplite, and the 
small amount of nephelite it contains would be a natural 
feature. If a lamphrophyre we must class it as a new type, 
or one of those aberrant camptonites mentioned by Rosen- 
busch,* in which angite entirely replaces hornblende. In favor 
of this view it will be seen, by reference to the table, that it 
has an almost identical chemical composition with the dike 
at Norway Rapids, which is described as camptonite in the 
following section. On the other hand, the composition is quite 
different from typical camptonites, as seen by comparing 
with No. IV of the table; it does not agree with them, either 
in minerals, or chemically. From the standpoint of an alkalic 
rock, though wanting brown hornblende, it classifies best in 
minerals, fabric and chemical composition as a micro-essexite 


* Mass, Gesteine, 4te Aufl., p. 685. 


426 Pirsson—Petrography of Tripyramid Mountain. 


and the small amount of nephelite it contains would then be 
a natural feature. Compare analysis No. V. 

If we consider the gabbro as genuine gabbro and this as an 
attendant dike and, therefore, alkalicaleic, comparison with 
the analysis of the gabbro shows at once that this is aplitic (salic) 
rather than lamprophyrie in character. One must then com- 
pare it with luciite and beerbachite; it differs from these 
considerably in chemical composition, especially in potash. 
See analyses Nos. VI and VII. Thus it differs both in min- 
erals and in lacking the aplitice texture. 

On the whole, it is, perhaps, best considered as a very fine- 
grained essexite and it will be further treated in the discussion 
of the mutual relations of the rocks of the complex. 


Dike at Norway Rapids. 


Megascopic characters.—Holocrystalline; dark, greenish 
gray, dotted with dull whitish spots about 2™" in diameter ; 
megagranular, but fine; has a somewhat silky shimmer due to 
abundant minute, slender feldspar laths, 2-3" long, diversely 
scattered among the dark greenish granules of ferromagnesian 
minerals, suggesting a minute ophitic texture. The whitish 
spots are uniformly scattered, but have no definite boundaries, 
and are neither phenocrysts nor amygdules; they have a 
fibrous structure and are the scapolite mentioned later. Frac- 
ture rough and hackly; weathers brown. 

Microscopic.—The minerals observed in the section are: 
apatite, iron ore, hornblende, and plagioclase; these are 
original, while epidote, scapolite, garnet, chlorite, and titanite 
are present as alteration products. 

The hornblende was originally a rich brown, pleochroic 
variety similar to that found in normal camptonites and 
generally ascribed to barkevikite. It occurs in stoutly shaped 
prismoids several millimeters long. It was originally interwoven 
with compact laths of a plagioclase, apparently a labradorite, 
but now too much altered for definite determination. Between 
these, and also enclosed by them, were the grains of cron ore, 
rather small and sparse, and prisms and grains of apatite. In 
these respects the rock appears like a normal camptonite. 

From this condition the rock has been considerably altered, 
the brown hornblende, save for occasional remnants, has been 
bleached to a light green variety, and this has largely under- 
gone a still further alteration into masses of green chlorite, a 
pale epidote, and considerable titanite. : The occurrence of the 
titanite is similar to that observed by the writer in the altera- 
ation of a barkevikite-like hornblende in a dike rock from the 
Belknap Mts.* and points to a considerable amount of titanic 


* This Journal, vol. xxii, p. 503, 1906. 


Pirsson—Petrography of Tripyramid Mountain. 427 


acid in the original mineral. Shreds and grains of these 
secondary minerals are also spread through the rock fabric 
around the original hornblendes, producing confused aggre- 
gates which more or less conceal its original nature. 

The feldspar has been mostly changed to a colorless mineral 
of low single and moderate double refraction, a prismatic 
columnar aggregate in structure, with good cleavage, parallel 
extinction, uniaxial, negative character. This must be scapo- 
lite, a not uncommon alteration product of plagioclase. Sceat- 
tered about through this are grains and dodecahedrons of 
a colorless, isotropic mineral, with high index of refraction 
and without good cleavage, which is inferred to be a lime 
garnet. 

Chemical Composition.—The alteration which this rock has 
undergone is essentially one of molecular rearrangement, not 
ordinary weathering. Therefore the chemical composition in 
mass has not been materially changed, and analysis seemed 
desirable as affording the best means for judging its original 
nature. This has been carried out by Mr. C. J. Monahan with 
the results given in No. II of the previous table of analyses. 
It is considered under the discussion of the classification. 

Texture.—The general plan of the texture of this rock, 
when it was unaltered, is shown by the divergent, elongate 
prismoids of hornblende, intermingled with the tabular feld- 
spars and grains of iron ore and apatite, all varying considerably 
in dimensions. It is inequigranular seriate, multiform (tabular, 
prismoidal and equant, subhedral) divergent fabric. It is the 
panidiomorphic-granular structure of Rosenbusch. 

Classification.—In the quantitative system the position of 
this rock is shown by the following calculation of its norm and 
place : 


Norm. 

Oem ries 16°68 Sal 71°52 
Aa ee 31°44 Heme a Dosalane 
JT ieee 21°13 z : 

; 2-2 
ae eae ae Th Gos oe) Germanare 
OW esos: 8°74 
Mikes: 5°10 K,0'+Na,O’ _ 0:98 =1:3=3, And 
Live paar B02N i. COMM ONTCS . vienagt, 
Apres =ts 0°67 

KO" (0:30 

HL Of see 0°55 xe Oi = oa =0°44=4, Andose 


2 


Total 100°40 


It is dosalic, perfelic, alkalicalcic, and dosodic; its codrdinates 
are 2.5.3.4 and it is therefore andose. The original mode, 
which cannot now be quantitatively determined, was not a nor- 


428 Pirsson—Petrography of Tripyramid Mountain. 


mative one, since hornblende was present in large amount and 
is therefore a critical mineral. The texture, though fine, is 
megascopically granular. Hence the rock is a hornblende- 
yrano-andose. 

The classification of this rock, according to genetic qualitative 
system, meets with difficulty. In the fact that it consists essen- 
tially of brown hornblende and labradorite it at once suggests 
camptonite, so common a dike rock in this petrographic } prov- 
ince. Reference to the table of analyses shows that it differs 
considerably from the type given in No. IV. On the other 
hand, this rock has a chemical correspondence with a dike rock 
from the Belknap Mts., No. II, which was called by the author 
spessartite, because in mineral composition, texture, and mode 
of occurrence it agreed with that type as described by Rosen- 
busch, although chemically it corresponded only in a general 
way. From the genetic standpoint the Belknap rock, being a 
member of a clan of alkalic rocks, could not be spessartite, 
which should belong to the attendants of the common granite- 
diorite set of magmas. In the present case, however, the 
allegiance of the dike is less clear, but, all things considered, it 
may, perhaps, best be termed a camptonite. © It is of interest to 
observe that this dike, and the previous one, furnish a good 
example of how quite similar magmas may develop different 
mineral compositions according to different local conditions. 
The former consisted of augite, olivine, biotite, and plagioclase, 
this one of brown hornblende and plagioclase. A difference 
in the quantity and kind of mineralizing vapors may have 
determined the formation, of hornblende, rather than the other 
ferromagnesian minerals. 


GENERAL PETROLOGY. 


From the standpoint of general petrology there is noth- 
ing remarkable, or particularly novel, in the rocks of Tri- 
pyramid, so far as the individual types are concerned. Their 
interest centers chiefly in two features: the association which 
the rocks present, and their origin in relation to the surround- 
ing granite and gneisses. 

In regard to the association of types, this may be seen by the 
mention of them: umptekite (alkalic syenite), quartz-syenite- 
aplite, monzonite, norite, gabbro and camptonite. To the 
uninitiated there may seem nothing remarkable in this assem- 
blage, but to petrographers, who in “these later years have been 
considering the genetic relationships of rocks, especially as 
they are found associated in differentiated complexes, it is 
significant, and to many who hold very definite views on this 
matter it may seem unnatural. For, if the syenite, mon- 
zonite and camptonite come naturally together as an alkalic 


Pirsson—Petrography of Tripyramid Mountain. 429 


group, then they should not be associated with norite and gab- 
bro, for these are members of the alkalicaclic (or sub-alkalic) 
rock series. It is recognized, of course, that rocks consisting 
of ferromagnesian minerals and lime-soda feldspars occur in 
the alkalic rock series, and to one of these with certain min- 
eral and chemical features the name of essexite has been given. 
It is also understood that these rocks, of which essexite stands 
as a good example, show by the kinds of pyroxene and 
hornblendes they contain, by presence of more or less nephe- 
lite, or sodalite, and similar peculiarities, which may be regarded 
as tribal markings, their allegiance to the clan from which they 
have sprung. 

At this point the writer desires to say that with this view, 
recognizing the genetic relations existing between rock series, 
he is in hearty accord and that he believes the demonstration 
of it, made during the last fifteen or twenty years, to have 
been one of the most important results of petrologic research. 
But the question which the Tripyramid assemblage brings to 
mind is, how far can this be carried, and how invariable are 
the associations of given rock types? There are some perhaps 
who, insisting upon the law of invariability, would say that in 
this case the gabbro and norite are not really such, but are 
certain types, or aberrant forms, of essexite. But if we hold 
this view, then the definition of essexite becomes so broad and 
general as to lose any specific value. So far as one can see 
there are no chemical, or mineral, peculiarities about the Tri- 
pyramid gabbro which would differentiate it from the usually 
accepted types of that rock, or any grounds on which we could 
call it an essexite beyond the fact of its association. But if we 
do this and thus push the genetic view of classification to its 
limit, we shall have to admit that rocks (in some cases) are not 
to be classified as kinds according to the inherent properties 
which they possess, but by these and their associations. Thus 
we shall find rocks whose inherent properties are similar in two, 
or perhaps more, places in our classification. But what if we 
find such a type alone, by itself, without any associations, a 
not uncommon occurrence?: Then we shall be unable to 
classify it, or else we shall have to adopt the procedure 
of sometimes classifying rocks by one method and sometimes 
by another, a process which can scarcely commend itself as an 
orderly or logical one. ‘This, to the writer’s mind, is one of 
the chief difficulties of rock classification as based on genetic 
association and descent, and at present no practical way of 
solving it appears. It has also indirectly been brought for- 
ward by Whitman Cross* in a recent paper treating of this 
subject. 


* Natural Class. of Ign. Rocks, Quart. Jour. Geol. Soc., lxvi, p. 481, 1910. 


430 Pirsson—Petrography of Tripyramid Mountain. 


The geology of Tripyramid, as it is now known, indicates 
that a body of monzonitic magma, as this appears to be the 
main rock mass, after, or during intrusion, has so differentiated 
that the outer part has developed into ‘gabbro and an inner 
part into alkalic syenite. This does not seem illogical, for the 
intermediate position of monzonite with respect to-alkalie and 
sub-alkalic rocks has long been recognized, and its chemical 
similarity to the generalized earth magma of Clarke and Wash- 
ington clearly perceived. But if a monzonite magma is thus 
really intermediate, it cannot be expected to always differentiate 
in one direction alone, to the alkalic side. From it we must 
expect to get intermediate series, running in various directions 
and connecting the alkalic with the sub-alkalic rocks. Thus 


Alk. Granite—Alk. Syen.—Foyaite—Essexite—Shonkinite, ete. 
™~ 
SS 
Monzonite 


Common Gran. Quartz Diorite—Diorite—Gabbro—Peridotite 


in the present case our series runs diagonally as shown above. 
The norite is simply a phase between the monzonite and 
gabbro. It seems to realize the idea expressed by Cross in 
saying: “Given an intermediate monzonitic magma, is it not 
natural to suppose that its descendent magmas must be inter- 
mediate in many respects between the series from foyaitic and 
dioritic parent magmas and that a shifting of conditions may 
throw the dominance of characters one way or the other ?”* 
Considered from this point of view, the two dike rocks pre- 
viously described would be merely products of the monzonite 
magma, whose differentiation paths were towards essexite, 
rather than towards the gabbro, and whose complementary 
derivatives are to be seen in the quartz-syenite aplites. 

The other interesting feature of these rocks is their origin 
with respect to the surrounding older ones. Recently the view 
has been put forward that the alkalic rocks are due to the 
fusion and absorption of particular kinds of sediments by sub- 
alkalic magmas. Jensent regards these sediments as having 
been Archean saline beds, while Daly,t on the other hand, 
considers them to have been masses of carbonate rocks, and 
that juvenile carbonic acid assisted in the process. The latter 
also suggests that some alkalic rocks may have been formed by 
simple differentiation, by “splitting” of the magmas assisted 

* Op. cit. p. 484. 

+ Distribution, Origin and Relationships of Alk. Rocks, Proc. Linn. Soc. 


N.S. Wales, xxxiii, p. 491, 1908. 
t Origin of the Alk. Rocks, Bull. Geol. Soc, Amer., xxi, p. 87, 1910. 


Pirsson—Petrography of Tripyramid Mountain. 431 


by juvenile gases. Neither author offers a discussion of the 
chemical aspects of the case, the hypotheses being founded on 
geological and mineralogical occurrences and associations. 

It would be out of place to discuss these views in this place, 
but it may be pointed out that they can scarcely be appealed 
to for an explanation of the alkalic syenite of Tripyramid. 
For, since the magma was ejected through and into a granite 
bathylith with gneisses and acid schists above, there could have 
been neither saline beds nor carbonate masses operative upon 
it. It might be suggested that the syenite was formed by the 
action of such acid rocks on the monzonite or gabbro, but this 
has already been considered in the former paper. In this 
respect Tripyramid is like Red Hill and the Belknap Mts., 
occurrences of alkalic rocks to the southward, which have been 
studied and, in part, described by the writer.* In them also 
the intrusions have been through and into gneisses and schists 
and there is no evidence of saline beds or carbonate rocks 
having taken part. These cases seem to fall under the alterna- 
tive view suggested by Daly,t+ and it therefore appears that 
some alkalic magmas and rocks are formed without the aid of 
particular sediments. 

It has been suggested that the border zones of concentric 
masses have been produced by absorption of the enclosing 
rocks. This could not have been the case at Tripyramid, for it 
is clear that the gabbro could not have been made from the 
monzonite magma by the absorption of either granite, gneiss, 
or schist. It must be regarded either as a separate intrusion, 
or as a differentiation product. 


Summary. 


This article deals with the rocks of Tripyramid Mountain, 
which is shown to consist of alkalic syenite (umptekite), mon- 
zonite and gabbro with associated dikes of quartz-syenite aplite 
and lamprophyres allied to camptonite. These various types 
are described and, in most cases, chemical analyses of them 
given. The latter show in the case of the basic dikes that 
magmas of similar composition may produce rocks mineralog- 
ically different. The systematic positions of the various types 
are also discussed and in conclusion the bearing of the facts 
observed on the subjects of genetic classification, and on the 
origin of alkalic rocks, is treated. 

Sheffield Scientific School of Yale University, 

New Haven, Dec. 1910. 


*This Jour., xx, p. 344; xxii, pp. 489, 493, 1905-1906 ; xxiii, pp. 257, 433. 
+ Op. cit. p. 113. 


432 fess and Wells—Occurrence of Striwerite. 


ART. XXXVI. —An Occurrence of Striwverite ;* by PRANK 
L. Huss and Rogrr C. Wx 11s. 


Tue mineral described in this paper belongs to the tetragonal 
system, crystallizes like rutile and contains titanium, tantalum, 
columbium, iron and tin. It is apparently a new mineral and 
at one time we contemplated giving it a specific name in order 
to differentiate it from ilmenorutile and suggest its chemical 
composition, but this was not done for reasons which will be 
noted. In accordance with modern views, the mineral «may 
probably be regarded as a new member of an isomorphous 
series of minerals crystallizing like rutile and containing some 
or all of the metals named. 

In 1908 Prior and Zambonini described a mineral from Cra- 
veggia, Northern Piedmont, which differs from ilmenorutile 
in possessing’ a little more tantalum, in relation to columbium, 
than had been found in any ilmenorutile up to that time.+ 
After noting its crystallographic similarity to ilmenorutile and 
the possibility of considering it a solid solution of mossite and 
tapiolite in rutile, Prior says: ‘‘We propose to reserve the 
uame striiverite for those members of the series rich in tantalic 
acid and to keep the name ilmenorutile for those, like the Nor- 
wegian specimens, in which niobic is the prevailing acid.” 
Since the name ilmenorutile is reserved “for those minerals in 
which niobi¢ is the prevailing acid,” a fair inference would lead 
one to suppose that their mineral carried a preponderance of 
tantalum oxide, but as analyzed by Prior it showed Ta,O, and 
Cb,O, only “in about equal amounts,” — 23°5 per cent of each, — 
so that the columbium oxide is in molecular excess as 88:53. 
It is evident that their definition of striiverite does uot fit 
their mineral, although their mineral suggests the possibility 
of others haying more tantalum. In other words, they named 
a mineral which was yet to be found. 

The mineral described in this paper carries 35-7 per cent 
Ta,O, and 64 per cent Cb,O, and would seem to deserve a 
new name, but as it has been covered by the definition of 
striiverite we shall defer to that name in order to avoid over- 
burdening the literature of mineralogy. At the same time we 
hope that the custom of proposing names for unknown extra- 
polated members of a mineral series will not become general. 


* Published by permission of the Director of the United States Geological 
Survey. 

+ On Striiverite and its Relation to Ilmenorutile. Mineralogical Mag., xv, 
78-89, 1908. 


Hess and Wells—Occurrence of Striiwerite. 433 


Occurrence. (F. L. H.) 


The mineral is found in considerable abundance as an orig- 
inal constituent of the granite pegmatite dike on which the 
Etta claim is located, one and a half miles south of Keystone, 
in the Black Hills of South Dakota. While on a reconnais- 
sance trip for the United States Geological Survey in Septem- 
ber, 1908, I visited the claim and collected specimens. 

Since the early 1880’s the Etta dike has been famous as a 
storehouse of rare minerals. The claim which is located upon 
it was first worked for mica, and while being thus operated 
cassiterite was discovered. Out of the discovery grew the tin 
excitement of the Black Hills lasting through the late 80’s 
and early 90’s. Cassiterite did not prove to be in sufficient 
quantity to pay for mining, and latterly the dike has been 
worked for spodumene, which is used as an ore of lithium. 
The Etta dike is in some ways one of the most remarkable 
pegmatites known, and although it has been described in geo- 
logical literature a number of times, some of its features merit 
attention at this time. It has a roughly oval outline, and is 
about 150 by 200 feet in horizontal dimensions. Some of its 
component minerals are gigantic. The crystals of spodumene 
are probably unequaled in size by any other known occurrence, 
single crystals reaching 42 feet in length with a cross section 
of approximately 3 by 6 feet. It is said that 37 tons of spodu- 
mene were mined from one erystal. Cassiterite has been found 
in masses weighing from 50 to 60 pounds each,* and irregular 
ageregates of columbite weighing 600 pounds. 

In parts of the dike are finer-grained masses predominantly 
composed of honey-yellow muscovite and white feldspar, both 
microcline and albite. The microcline shows some crystal 
faces from one-half inch to several inches across, and is 
partly flesh-colored. The albite is pure white and occurs in 
thin plates which reach an inch or more in breadth. The 
muscovite is in flakes ranging from minute scales to plates 
three-fourths of an inch across. Through these masses are 
mixed other minerals in greater or less profusion, — white beryl, 
small spodumene crystals, cassiterite in small particles, quartz, 
secondary opal, and striiverite. 

Columbite occurs in considerable quantity, in most: places as 
individual crystals ranging from small ones up to those weigh- 
ing several pounds, with some larger aggregates such as those 
mentioned above. The crystals are tabular, in many speci- 
mens from one-third to one-half longer than wide, though some 

* Blake, W.P. Tin; Min. Res. of the United States for 1883-4. Geol. 


Surv. Washington, 1895, p. 607. 
+ Personal communication, A. M. Lane, Keystone, S. D. 


434 Hess and Wells—Occurrence of Striwerite. 


are nearly square, and the thickness ranges from about one- 
eighth to two-thirds of the length, Even in most of the very 
small erystals the tabular form may be distinguished. 

Near a point where columbite crystals were especially thickly 
sprinkled through the dike and where the general texture was 
comparatively fine-grained, little aggregates of a black, opaque 
metallic mineral whose luster and color were indistinguishable 
from columbite but whose crystal form was less distinct, were 
found rather thickly impregnating the dike for several feet. 
It was evidently an original mineral in the dike and oceurred 
completely imbedded in microcline, beryl, and muscovite. In 
the specimens examined none appeared to be entirely sur- 
rounded by quartz and none was found in spodumene. From . 
a hasty field examination the mineral was thought to be 
another form of columbite, but later the surrounding gangue, 
which in the piece used was mostly microcline, was dissolved 
with hydrofluoric and sulphuric acids and it was found that 
the crystals showed no resemblance to the crystal habit of 
columbite as it occurs in the Etta dike. A slight movement in 
the dike had crushed most of the crystals so that good speci 
mens for optical measurements were hard to obtain. The sep- 
arated crystals had been exposed to the action of the acids for 
about six weeks, and while to the unaided eye they were bright 
and smooth, W. T. Schaller, to whom they were referred for 
crystallographic determination, found them to be too badly 
etched to give a good reflection. He therefore extracted fresh 
crystals from the matrix and upon these made the crystallo- 
graphic determinations which are quoted in the next para- 
graph. The largest crystals collected are about 5™™ long by 
1-8 to 2™™ across the exposed cross sections. The largest 
ageregate is 16™™ across. The powder and streak are nearly 
black with a slightly greenish tinge. The hardness is 6—6°5 
and the specific gravity 5°25. The mineral is opaque in thin 
section and neither cassiterite nor rutile appears to be enclosed 
in it, although such a possibility was suggested by the analyses 
to be described. . 

Mr. Schaller remarks : 

“The small crystals, generally from 1 to 3 millimeters in 
length and hardly as thick, closely resemble twinned and dis- 
torted crystals of rutile, mossite, tapiolite, etc. They are 
tetragonal, twinned on the ¢ (101) face and elongated in the 
direction of the (111): (111) intersection edge. The crys- 
tals are very poorly adapted for measurement, the faces being 
rough and reflecting light poorly. The forms present are 
a§100}, e101}, s{111}. The habit of the crystals resembles 
very closely a so-called black rutile described by Headden and 


Hess and Wells—Occurrence of Striiwerite. 435 


Pirsson.* Their material was probably identical im character 
with that here described. 

In addition to the forms as illustrated by Pirsson, there is 
often present, on the crystals examined, a narrow face of ¢ 
between a and a. The measurements on which the identifica- 
tions are based follow. 


Measured. Calculated for rutile, 
é 9 = D7 — OBEO! 28°26’ 
€ -a@= 56 30 — 57 20 57 18 
Ss s’ = 55 57 — 56 50 56 52 
a a= 66 10 — 66 30 65 34 
a C= 10) Gi) 8 21” 


The mineral does not appear to be radioactive to any con- 
siderable degree, but after 15 days’ contact of a polished speci- 
men with the sensitive side of a photographic plate, the micro- 
cline surrounding the striiverite gave a distinct radiograph, 
the plate remaining unaffected under the striverite. 

Although it occurs in considerable quantity, the mineral 
gives little promise of having commercial value as an ore of 
tantalum, owing to the high titanium content. 


Chemical Analysis. (R. C. W.) 


The mineral was separated from the gangue almost com- 
pletely by crushing and panning. The resulting black grains 
were dried at 100°. Under the microscope there were visible 
only the black opaque mineral and a few grains of silica. 

Suitable tests showed that the essential constituents were 
titanium, tantalum, columbium, and iron. There were small 
amounts of tin and silica and a trace of aluminum. Phosphorus, 
calcium, manganese, molybdenum, rare earths, tungsten, and 
heavy metals were proved absent. It was concluded that 
zirconium was also absent because after repeated precipitations 
of the sulphates of the bases with hydrogen peroxide in the 
presence of a phosphate no residue finally remained.t With 
less than one per cent of sulphuric acid present in this last 
operation, much tantalum and titanium, and to a less extent 
columbium, are precipitated by the phosphate. But the separa- 
tion of zirconium is based on the fact that it is almost certainly 
precipitated in the presence of one per cent of sulphuric acid 
and possibly in the presence of even more. 

The density of the fragments was found by the pycnometer 
to be 5:25. Since the approximate density of titanium oxide is 
4-0, of iron titanate 4:8, of iron columbate 5:9 and of iron tanta- 

* Headden, W. P. and Pirsson, L. V. on Black Rutile from the Black Hills. 


This Jour., 3d ser., vol. xli, 1891, p. 249. 
{+ W. F. Hillebrand, Bull. 305 U. S. Geol. Survey, p. 141. 


436 Hess and Wells—Oceurrence of Striwverite. 


late 6°9, the mineral evidently contained a heavier constituent 
than titanium or iron and the presence of tantalum was thus 
first suggested. 

While the analysis of this mineral was in progress the paper 
by Prior and Zambonini appeared* and other suggestive papers 
upon the analysis of chemically similar minerals have recently 
been published. A method for analyzing columbite has been 
published by E. 8S. Simpson but is not intended to be used when 
titanium is present.t W. B. Giles has described the opening 
up of minerals containing colambium and tantalum.{ Weiss 
and Landecker,§ Hauser and Finckh| have worked on the sepa- 
ration of these elements. “ 

When it was desired simply to get the mineral into solution, 
fusion with acid sodium sulphate was employed. The melt 
was dissolved in 5 or 10 per cent sulphuric acid. 

The colorimetric determination of TiO, gave 45°8 per cent 
as an average of several experiments and readings, the series 
being 47-4, 44:2, 46-4, 45°3, 46°5, 45°3, 43-6, 45°6, and 47-6. 
All of the precautions mentioned by Merwin{ with regard to 
the influence of sodium sulphate, etc., were not considered, but 
about 5 per cent of sulphuric acid was present in the standard 
and sample compared. 

Since the mineral was not attacked by boiling with dilute 
sulphuric and hydrofluoric acids, a determination of the state 
of oxidation of the iron was abandoned. Calculated as ferrous 
oxide, the amount present was 7°5 per cent. 

By reducing the mineral in hydrogen and dissolving in hydro- 
chloric acid 0-6 per cent SnO, was obtained. More, however, 
was obtained by fusing with bisulphate, adding to the solution 
sodium hydroxide in excess, filtering and adding hydrogen 
sulphide. This treatment gave 1:09 and 1°14 per cent SnO, 
after correcting for platinum and other impurities. The method 
of attack recommended by Giles** for determining tin was also 
tried. He states that by fusing a columbite containing tin at 
a high temperature with potassium carbonate and digesting in 
warm citrie acid, the tin may be brought into solution as well 
as other constituents except titanium, zirconium and a little 
silica. From one gram after three fusions there remained 
only ‘0475 grm. of insoluble matter consisting of :0351 grm. 
Fe,O, and a little TiO, From the soluble part, however, 
there was obtained only 0-7 per cent SnO, by hydrogen sul- 
phide, which was less than that obtained in the previous way. 
In a wholly different way as much as 1:7 per cent SnO, was 


* Loe. cit. + Chem. News, xcix, 243, 1909. 
t Chem. News, xcix, 1,1909. §Zs. anorg. Chem. 64, 65. 
|| Ber., 1909, 2270. 4] This Journal (4), xxviii, 119. 


** Chem, News, xcix, 27, 1909. 


Hess and Wells—Occurrence of Striiwerite. 437 


obtained in one experiment. The mean of all was 1:3 per 
cent. 

A few words may be said upon the results of fusing the 
mineral with sodium carbonate. It was attempted to make a 
separation of titanium and other bases from tantalum and 
columbium by such a fusion and extracting the tantalate and 
columbate with hot water. After two fusions with sodium 
carbonate in one experiment, the insoluble portion (a) was 
found to be 83°8 per cent, the soluble portion (6) 16°5 per cent. 
But the separation was incomplete, for, after determining in 
portion (a) 7°8 per cent Fe,O,, 42°3 per cent TiO, and traces 
of other constituents, there remained 33°3 per cent unac- 
counted for, which was probably tantalum and columbium 
oxides, and in portion (6) there was found 4:5 per cent TiO,,. 
In another experiment one gram was fused with sodium 
carbonate and very thoroughly extracted with hot water. The 
residue was re-treated. Three such extractions brought 18 
per cent into solution, but of this a third or 6 per cent of 
the mineral was TiO,. Hence the columbium and tantalum 
carried titanium with them into the soluble portions, and it was 
not possible to extract nearly all the columbium and tantalum 
_ by even repeated treatments. 

With respect to this sodium carbonate treatment the experi- 
ments of Weiss and Landecker demand consideration.* They 
reasoned that the carrying into solution of titanium by colum- 
bium must be due to the formation of a compound of the two 
which they thought could be decomposed by adding a little 
niter during the sodium carbonate fusion. A trial of their 
method was made, but it was found that titanium passes into 
the soluble part with columbium and tantalum just as it does 
when no niter is used. In their description the method of 
freeing titanium from columbium and tantalum by hydrogen 
sulphide is not clear. In view of these facts the sodium 
carbonate attack was abandoned.t 

Another method of analysis was carried out as follows: 

After a bisulphate fusion, silica, tin, and iron were removed 
by the use of tartaric acid, ammonia, and hydrogen sulphide. 
The tartaric acid was destroyed by ignition, the total acid earths 
dissolved by bisulphate and eventually converted into the 
double fluorides of potassium. These were separated by the 
method of Marignac. The weight of crude Ta,O, thus obtained 
was corrected for the TiO, present. The total TiO, had 
already been determined. Cb,O, was computed by difference. 
Two such experiments gave the results below, in which are 
collected the data for the other constituents so far determined : 

* Chem. News, ci, 13, 1910. 
+ Compare Foote and Langley, this Journal, xxx, 401, 1910. 

Am. JOUR. peta Ouse Series, VoL. XXXI, No. 185.—May, 1911. 


438 Hess and Wells—Oceurrence of Striwerite. 


1 2 
HO. J. 25. Se eee ene eee 04 0°4 
SiO, ee eee 1°8 1°8 
TiO, aie UE ace Baa 458 45-8 
SnOLuere 124) weer DAA ies 1:3 
FeO sik. wes Sh eee aT. 75 
PasO “eters git, TANS feo ere 37°6 30°5 
Cb,O, (by difference)...-... 5°6 12°7 


Although these results give a fair idea of the composition, 
it was concluded that a separation of the chlorides by fractional 
distillation might be a more advantageous method of analysis. 
The separation of titanium from columbium and tantalum in 
this way was suggested by a method of separating titanium 
and iron occasionally employed in steel analysis,* although, of 
course, the quantities are not exactly comparable. 

Experiments were first made on known quantities of TiO, and 
Cb,O, using sugar carbon and dry chlorine to produce the 
chloride in a hot, hard, glass tube, and it was found that an 
approximate separation could be made. 

A mixture of titanium, columbium and tantalum oxides. 
obtained from the mineral under examination, and free from 
other elements, was subjected to treatments with carbon in 
chlorine. 


Taken =~. 2 0°2248 g. Homma Mi Oks eae= 0°1345 @. 
(Lah Ones == 0:0789 

Total found_.._.-- 0°2134'¢. 

Deficit 24/10 s wabe ‘0114 g. 


Applying the ratio of Ti to (Ta,Cb) here found to 89:1 per 
cent of the mineral (the total acid earths) gives TiO, 56-2, 
(Ta,Cb),O, 32°9 per cent. This is considerably more TiO, 
than found by the colorimetric method. 

Owing to the difficulty of completely converting the oxides 
into chlorides by the use of carbon, the apparatus was some- 
what modified and chloride of sulphur tried instead. It was 
found possible to convert nearly half of a gram of a mixture 
consisting of the oxides of titanium, tantalum or columbium 
into chlorides in two hours. A porcelain boat was used in a 
long, hard, glass tube. That portion of the tube used for the 
condensation of the less volatile chlorides was warmed uni- 
formly by a jacket of asbestos containing electrical resistance 
wire. Sufticient chloride of sulphur was introduced as vapor 
by merely passing the chlorine through a distilling flask in 
which sulphur chloride was kept gently warmed. Practically 


* Blair, The Chemical Analysis of Iron, 6th ed., p. 74. 


Hess and Wells—Occurrence of Striwerite. 439 


no titanium chloride or sulphur chloride condensed in the hard 
glass tube at a temperature of 70-80°. In fact a considerable 
number of wash bottles were required to collect all the vapors 
of titanium chloride, owing to the heat generated by the 
reactions which occurred with the water of the wash bottles. 
Unfortunately, however, a little of the columbium and tanta- 
lum chlorides passed over with the titanium, a difficulty which 
no style of condensing chamber seemed to wholly prevent. To 
decrease this loss as much as possible the condensing tube was 
inclined slightly so as to force the gases upward. - The titanium 
oxide, after collection, was treated a second time to recover the 
small fraction of tantalum and columbium which was carried 
over the first time. By such a repetition 2¢ was possible to 
separate nearly all the tantalum and columbium from the 
titanium. The sublimed columbium and tantalum chlorides 
are best washed out with concentrated hydrochloric acid and 
after nearly neutralizing with ammonia precipitated by boiling 
with sulphur dioxide. The oxides thus precipitated do not run 
through the filter. A slight residue, partly sulphate, forms in 
the boat, which is with difficulty converted into chloride. It 
is possible that the use of carbon tetrachloride vapor might 
be a better agent for converting the oxides of columbium, 
tantalum and titanium into chlorides than sulphur mono- 
chloride.* 

In analyzing the mineral it was found simpler to treat it 
directly in chlorine than to remove the tin and iron first. In 
this way three portions resulted,—a slight residue in the boat, 
a sublimate containing most of the tantalum, columbium and 
iron, and a dissolved portion containing titanium and tin. The 
titanium portion was nearly neutralized and precipitated by 
boiling with sulphur dioxide, leaving tin in solution. After 
ignition this precipitate was treated again in chlorine to obtain 
the little columbium and tantalum which escaped the first time. 
The columbium and tantalum oxides were precipitated together 
by sulphur dioxide, ignited and weighed. 

The tantalum and columbium oxides, finally freed from 
titanium, were next subjected to the method of Metzger and 
Taylor for determining columbium in which the columbium 
sulphate is reduced in a zine reductor and titrated with 
KMnO,.+ Metzger and Taylor found that on the average 
1 grm. KMnO, was equivalent to 2-232 grm. Cb,O,. As ina 
blank experiment 1 grm. KMnO, was found eqnivalent to 2°458 
erm. Cb,O,, the average 2°34 was used in computing the Cb. 
The results obtained by these methods were: 


* A. Demargay, Compt. rend., civ, 111-13. 
+ Columbia School Mines Quart., xxx, 323-24, 1909. 


440 Hess and Wells—Occurrence of Striwerite. 


Residueye oe ese 4:4 4°] 
TO, .-, pee tee eee CED 51:2 
Ta 0), ae ees 34:0 33-0 
Ob.) oe ae eee 2°6 4:3 
He Oe eee ee eee eee 6'8 


These results were corrected slightly for the residue in the 
boat. This residue was shown to be 50 per cent SiO, The 
remainder was computed as 90 per cent (Ta,Cb),O, and 10 per 
cent TiO,. With these corrections the results become: 


SiO iy ee aera 2D, 2°0 
PLOW ONGOR eS Dah 48-2 51:4 p 
ac! Wee Eig Ooe Bets 36°6 34°6 
CO. 822 BOL ee ee 2°8 4:5 
EOWA Mie Woe te Aye w ys eae 6°8 


An average of the results recorded on p. 436, with the results 
above gives the final average in the first coloamn below. On 
microscopic evidence the SiO, is considered to be gangue. The 
second column gives the composition of the anhydrous, gangue 
free material. The third and fourth columns give the molecu- 
lar ratios. 


AO) Lh. Ha 0-4 
DiOhMeL tis. GOR: 2°0 
TiO a oe 478 49-1 613 me 
SwO abet ay 1:3 1:3 ‘009 : 
He OGr: Sees see 7:3 75 104 104 
MacO ey ebony be 34:8 35°7 081 Rae 
ChiOhiass -e8te 6°2 6-4 024 

99°8 100-0 


These results are sufficient to establish the essential composi- 
tion of the mineral. In view of the fact that the determination 
of columbium by the Metzger and Taylor method is undoubt- 
edly better than by the first method used, it seems likely that 
the tantalum content should be a little higher and the colum- 
bium content a little lower than here stated, but the higher FeO 
content, by the first method, 7-5 per cent, probably deserves 
the greater weight. 

The mineral designated “black rutile” by Headden,* which 
was probably this mineral, was stated by him to consist of TiO, 
90-79 per cent, FeO 8:01, SnO, 1°35, MnO trace. If the tan- 
talum and columbium oxides determined above are added to 
the titanium oxide, the result is: Acid earths, 91:2, FeO 7-5, 
SnO, 1°3, a striking confirmation of the suspicion, raised by the 
density, that Headden weighed the tantalum and columbium 

* This Journal [3], xli, 249, 1891. 


Hess and Wells—Oceurrence of Striwerite. 441 


with his titanium. Owing to the unsatisfactory state of the 
analytical methods applicable to these elements, it seems likely 
that heretofore small amounts of tantalum or columbium may 
often have been overlooked in titanium minerals. 

The analysis yields no simple formula. Apparently one 
molecule of FeO is present to one molecule of (Ta,Cb),O,, but 
TiO, lies between 6 and 7 molecules. The formula approxi- 
mates roughly to Fe(Ta,Cb),O,.6Ti0,,. 


Classification of the mineral, (F. L, H. and R. C. W.) 


The tetragonal minerals containing titanium, tantalum, 
columbium and iron evidently form a series with a group at 
one end to which the name ilmenorutile is given and a group 
at the other end represented by the mineral described in this 
paper. Prior and Zambonini’s* mineral has a nearly medial 
composition, but really belongs to the ilmenorutile group. 
Iimenorutile, when first described by P. von Eremeyey,+} was 
supposed to be a rutile containing “up to 10 per cent, or more 
of Fe,O,.” Brogger,t in later analyses under improved con- 
ditions, found ilmenorutile to contain from 13°74 to 19°64 per 
cent of Cb,O,, and one specimen showed 0-43 per cent Ta,O,. 
He retains the name ilmenorutile, and it will probably stand 
for a columbium-iron-rich rutile. Prior§ reviewed Brégger’s 
results and found that the Cb,O, amounted to from 33:02 to 
33°50 per cent Cb,O,, but found no more Ta,O,. In an inde- 
pendent analysis of an ilmenorutile from the Ilmen Mountains, 
however, he found 21-73 per cent Cb,O, and 14°70 per cent 
Ta,O, (see table p. 442). 

The mineral from Craveggia, Northern Piedmont, is one 
which was first described by Zambonini| as bearing titanium, 
zirconium, tantalum and columbium, a mistake not unnatural 
owing to the difficulties of distinguishing in a chemical way 
between these elements. 

After the first publication by Zambonini, further work was 
done in collaboration with Prior and the mineral was shown to 
carry no zirconium but to have the composition (mean analy- 
sis)** indicated in column I of the table given below, with which 
are given for comparison an analysis of ilmenorutile (No. I]) 
from the Ilmen Mountains,{t+ and the mineral from the Black 
Hills (No. III), the analysis of which has been described. 


* Loe. cit. 

+ Quoted by J. Dana, System of Mineralogy, p. 238. 

{ Brogger, W. C., Die Mineralen der sidnorwegischen Granitpegmatitginge. 
Pt. 1, Niobate, Tantalate, Titanate and Titanniobate, p. 46. 

§ Op. cit. p. 87. 

| Zambonini, Ferruccio, Strtiverite, un nouvo minerale. Rend. R. Accad. 
Sci. Napoli, 1907, ser. 3, vol. xiii, pp. 35-44. 

S] Op. cit. ** Op. cit. p. 84. 

tt Op. cit. p. 87. 


449 Hess and Wells—Occurrence of Striiverite. 


Ilmen Black 
Craveggia. Mts. Hills. 
I II Til 
IO cs 2 ~ 2. eee 41°20 53°04 49°] 
Wp Oo col) See 23°48 * 21°73 6°4 
ey OOS Seca ere eee 23°48 14°70 35°7 
SHO. | .es Se ee Lake we a8 wanes 
BleQi;2 lates Abe dy 11°38 10°56 75 
MnO sc ate eee trace Eset Les 
CaO ee a cece “51 trace pale: 
MpOe ae hae Se O17 ane wise 
~ 100°22 100-03 100°00 - 
Dp, Shee 2 nes 5°59 5°14 5°25 


Summary. 


The occurrence and analysis of a mineral containing titanium, 
tantalum, iron, columbium and tin is described. Orystallo- 
graphically it belongs to the rutile group. Chemically it is 
essentially titanium oxide with iron tantalate and columbate, 
the tantalate being in excess of the columbate. Tin is an un- 
essential minor constituent. Its formula approximates to 
Fe(Ta,Cb),O.,6Ti0O,. It is considered to belong to a group 
of minerals whose members Prior and Zambonini designated 
striiverite. 


Bendrat—Notes on Region about Caicara, Venezuela. 443 


Art. XXXVII.—Geologie and Petrographic Notes on the 
Region about Caicara, Venezuela; by T. A. Brynrat, 
Turners Falls, Mass.* 


In the winter of 1908-09 the writer made some geographic 
and geologic studies in the interior of Venezuela, his field of 
investigation being the region immediately west of the El 
Caura district, at the famous bend of the Orinoco, an area of 
about 1500 square kilometers, that was hitherto very little 
known, being mapped. 

While the general results of this survey have been summed 
up elsewhere,t it is to the geologic and especially the petro- 
graphic features of the region that this paper relates. 


GENERAL GEOLOGY. 


The study of the geology of the region shows an underlying 
bedrock formation of gneisses and granites and on this the 
Sabana deposits. 


Tur GNEISS AND GRANITE BASEMENT. 


The bed rock consists of a series of granites and gneisses 
which, wherever they come to the surface, show a prevalence 
of gneiss over the granite. They rise from the bottom of the 
Orinoco channel, constituting the foundation of many of the 
islands; they are exposed in the banks of the river; they 
appear as cliffs above the water-level during the dry season, 
they also form the bulk of the so-called Cerros’ hills and ridges 
rising above the plain of the “Sabana,” and increasing in 
height in proportion to their distance from the Orinoco, and 
which may be regarded as the outliers of the Guyana mountain 
system in the south. These cerros are portions of the complex 
of granites and gneisses which have resisted the process of 
erosion partly because of a number of veins and dikes which 
traverse them in various directions, but mainly N.-S. E.—W., 
and N.W.-S.E. 

The Isla de Maria Luisa opposite Cabruta was not visited, 
but examination of the shores of Isla de Caicara, opposite the 
"village of Caicara, showed that its bed-rock is a purple weather- 
ing, drab-colored granite with N.-S. and E.-W. cleavage. 

* The writer desires to express in this place his high obligations to Prof. 
B. K. Emerson of Amherst College, who was kind enough to have the petro- 
exeunic microscopes at Smith College, Northampton, Mass., placed at his dis- 
posal. 


+ Petermann’s Geographische Mitteilungen, lvi, No. 5, 1910. Geographen 
Kalender, 1909, p. 221. 


444 Bendrat—Notes on Region about Caicara, Venezuela. 


The cliffs along the Caicara side of the Orinoco are evi- 
dently continuous with the rocks exposed in the southeastern 
bank and consist of medium-to fine-grained gneiss with lami- 


nation running N.N.E.-S.S.W. or “Ri, N.E. We S.W. Small 


quartz veins cut the gneiss in a general N.W.-S.E. direction. 


~~ : 


7, 


de Arinozal 


0 MG, ), J oe é 
Ba) | NEES ode Ae 
\ i 2 


ee J 


LATERITE 
ALLUVIUM 


UPPER LLanos 
DEPOSITS 


Seale = 1: 500,000. 


On the anool surface of these rocks, about one kilometer 
north of Caicara, the writer discovered three grooves about 
four to five inches long and one-eighth of an inch deep which 
run perfectly straight, one E. 10° N.E., and the two others E. 
10" 8B Whey, look exactly like glacial strie the writer has 
observed in various places in the United States. They may, 


Bendrat— Notes on Region about Caicara, Venezuela. 445 


however, have been produced by man, as in close proximity a 
series of so-called petroglyphics were found, the grooves of 
which, however, were considerably deeper and wider. 

The distribution of granite and gneiss in the hills and ridges 
north of Cabruta and south and southeast of Caicara also 
reveals a prevalence of gneiss over granite. For, with the 
exception of Cerro de Cabruta north of the Orinoco, and Cerro 
de los Spiritos, the lower portions of Cerro de Arinoza, and 
possible the whole of Pan de Azugar,* all the other cerros con- 
sist of gneiss. Pan de Azugar could not be visited and the 
nature of its rock ascertained because of the inaccessibility of 
the mountain from the land, while a planned ascent from the 
river side was not carried out because of the departure of the 
writer. Its outlines, however, are those characteristic of gran- 
ite hills. 

Rising abruptly with its southwestern terminus from the 
waters of the Orinoco to a height of about 290 meters above 
sea-level, the Cerro de Cabruta trends for a distance of about 
twelve kilometers in a northeastern direction and gradually 
falls off towards the llano-plateau. It is made up of a coarse- 
grained granite of a tan color weathering purple. Towards 
the top it becomes more quartzose, and is ent by quartz veins. 
A dike of felsite traverses the granite in a direction E.-W. on 
one of the smooth, facette-like cliffs of the cerro near the top. 
Exfoliation of the granites is strikingly exhibited. A vein of 
quartz cuts the granite in a direction N.N.W.-S.S.E., and 
probable determines the direction of the southwestern spur of 
the cerro in the process of erosion. 

The cerros on the east and southeast side of the Orinoco 
within the area begin with the Cerro de Caicara, which 
approaches the stream south of the village of Caicara and rises 
to a height of 127 meters above sea-level. It extends about 
two kilometers to the south along the stream and consists of a 
light-colored, fine-grained gneiss. The general strike of the 
lamination is N.—S. and the dip to the west, as is the case with 
ali the gneisses along the river. 

About three kilometers south of Caicara the Cerro de Ari- 
noza attains a height of 146 meters, while its foot is 71 meters 
above sea-level. Only the lowest levels of this hill consist of 
a coarse-grained quartzose granite, much the same as that 
encountered in the Cerro de Cabruta. The structure is at 
places pegmatite and the joint planes run N.—-S. and E.—-W. as do 
quartz and pegmatitic veins of various thickness. Higher up 
the granite yields to a medium-grained gneiss with lamination 
E. 70° S.E.; on the southeastern top apparently dipping 27° 
N.E. On this top occurs a similar coarse-grained and highly 
quartzose granite, like that found at the foot of the cerro, 


* Due south of the former. 


446 Bendrat—-Notes on Region about Caicara, Venezuela. 


which suggests a possible intrusion of the gneissie series by 
granites from the same magma. 

The Cerro de los Spiritos is situated about five kilometers 
east of Pan de Azugar and nearly eight kilometers 8.S.E. of 
the village of Caicara. About 200 feet high it trends in a 
general N.W.-S.E. direction for over five kilometers. With 
the possible exception of Pan de Azugar, as indicated above, 
it is the only cerro southeast of the Orinoco within the region 
which is entirely composed of granite. It is of a coarse- 
grained, feldspathic, rather hornblendic type and exhibits joint 
planes which run N.-S., H.-W. and N.W.-S.E. The backbone 
of the hill is a quartz vein from 53 to 54 feet wide. -In 
samples from this vein traces of gold were found by assays by 
a firm in New York City. Other quartz veins also occur, 
while near the top a dike of pink felsite, about two feet thick, 
stands out above the surrounding granite with K.-W. trend. 

While the flanks of the cerro exhibit gentle slopes, with only 
occasional steep cliffs, and are dissected by ravines, for the 
most part parallel to the main quartz veins, the top is flat and 
comparatively smooth. 

About 26 kilometers 8.S.E. of Caicara the Cerro de Morano 
rises above the plain of the sabana to a height of 375 and 396 
meters above sea-level. Its topographic outlines seem to be 
determined by two quartz veins, a minor one, running almost 
due E.-W., and a prominent one which constitutes the back- 
bone of the cerro and has apparently determined the N.S. 
direction of its longer axis. In approaching the cerro from 
the north one encounters knobs and cliffs emerging from the 
sabana which consist of coarse-grained feldspathic granite at 
places overlaid by limited beds of ferruginous coarse-grained 
sandstone. The bulk of the cerro is, however, made up of fine 
to coarse-grained hornblende-gneiss. It contains other quartz 
veins as well as dikes of amphibolitic gneiss, traversing the 
cerro in various directions. 


Tur Sapana Deposits. 


Dealing with the deposits of the sabana above which rise 
the isolated cerros just described, one must distinguish between 
the so-called “ Laterite”’ and what Dr. 8S. Passarge terms 
‘Upper Llanos” beds. 

Laterite.—This very peculiar deposit is apparently com- 
posed of a series of more or less fine and soft clays of a light 
gray color, which have been found by Dr. 8. Passarge along 
the banks of the Cuchivero, as well as the Caura, and, by the 
writer, overlying the gneisses on the banks of the Orinoco. 
As long as this clay is nnder water or still charged with moist- 


Bendrat— Notes on Region about Caicara, Venezuela. 447 


ure, after the streams have fallen during the dry season, it is 
exceedingly plastic. But as socn as it becomes dehydrated it 
turns extremely hard and becomes a clay ironstone, the lat- 
erite of the sabana, the river banks and the cerros: the German 
“zelliger Brauneisenstein.” It is, however, not continuons 
and is often replaced by a hard conglomerate cemented together 
by iron oxides. This is the case at Caicara, where the lower 
terrace on which the village is situated consists of the hard 
conglomerate. Also the level at which the laterite occurs is 
not uniform, and while at one point it may be seen to rise well 
above the stream, it disappears at another point below the 
level of the water. 

Not only along the Orinoco, but also inland on the plains of 
the sabana, wherever the granites or gneisses emerge from the 
younger deposits, even on the slopes of the cerros at consider- 
able heights, irregular, limited patches of this clay ironstone 
are found to fill to a greater or less extent the hollows in bed- 
rock, 

The general appearance of this laterite deposit in the Llanos 
of the Orinoco drainage basin, the sabana being only a “ floral” 
form of the Llano, has led Dr. 8. Passarge, who saw similar 
laterite formations in the Kalahari desert in southern Africa, 
to suggest a possible extended period of laterite formation by 
weathering from, perhaps, Tertiary time. 

This laterite deposit seems to determine the ground-water level 
in the sabana, carrying ground water over its surface to the sides 
and slopes of gullies, ravines and streams, as well as to the banks 
of the Orinoco, or allowing these waters to accumulate in more 
or less extended and comparatively shallow depressions, thus 
acting as a hardpan and giving rise to the formation of the 
“‘Jagunas” which in turn, where partially drained or when dry- 
ing up, to a certain extent during the dry season, may change 
into “ Potreros,’ swampy meadows, or into ‘“ Morichales,” 
swampy woods, in which the “ Mauritia” palm is the character- 
istic tree. Thus the laterite plays a not unimportant réle in 
the shaping of the features of the landscape. 

The Upper Llanos Beds——The Upper Llanos deposits, 
which, as a rule, unconformably overlie the laterite, wherever 
they have not been removed by subsequent erosion, or corra- 
sion, or both combined, may be said to consist of the following 
three members : 

A whitish or yellowish clay, rich in iron, which exhibits cell 
structure. 

Loams of various kinds. 

Sands of different fineness and color. 

Their relations to one another change with the locality and 
so also does their respective horizon. ‘ They constitute the 


448 Bendrat—Notes on Region about Caicara, Venezuela. 


upper portions of the islands, the upper terraces at an eleva- 
tion of about fifty feet above the average level of the lower 
terraces, and the sabana itself. They lie between the rocks of 
the granites and gneisses, wherever these come to the surface, 
filling in interspaces and fissures. The loam of the sabana 
becomes exceedingly plastic and soft during the rainy season, 
allowing turtles to dig furrows and ditches of from half a foot 
to one foot deep into it, and the torrents to carve deep 
channels, sometimes down to the underlying laterite. The 
walls of these ditches and channels become extremely indu- 
rated during the dry season, thus rendering traveling across 
the sabana under such conditions exceedingly difficult and tire- 
some, especially where there are no roads or paths available. 


PrrroGRAPHy. 


In describing the granites and gneisses of the cerros petro- 
graphically, the writer will describe them in a sequence that is 
determined by their genetic character, thus taking up the 
granites first and then the gneisses. 

The Granites.—The granites of the region are those of the 
Cerros de Cabruta and de los Spiritos and those that form the 
base of the Cerro de Arinoza. 

The microscopical study of thin sections from different 
places shows that there is essentially the same type of granite 
in all three cerros. This statement, however, has to be modi- 
fied in so far that at the two ends of this seemingly elliptic 
area, the granite shows a tendency to acidity at one and basid- 
ity at the other. For, while the Cerro de Cabruta consists of a 
granite rich in quartz in its upper levels and its top, the Cerro 
de los Spiritos has a predominance of the hornblende in the 
rock of its top. 

The petrographic features which characterize this granite 
are as follows : 

In a mass of angular or subangular grains of quartz and 
feldspar occur phenocrysts of the leading minerals, viz., the 
quartz orthoclase which is occasionally replaced by microcline 
as well as soda-lime feldspars, and lastly biotite, which is 
associated with hornblende, the latter sometimes replacing it 
entirely. 

A number of quartz and feldspar phenocrysts show en- 
largement by secondary growth, revealed by a faint ring of 
dark material, or by zonal extinction. 

The frequent occurrence of micro-pegmatitic texture suggests 
conditions in the eutectic magma favoring simultaneous crystal- 
lization of quartz and feldspar. 

Of the feldspathic minerals the soda-lime group prevails over 


, Bendrat—Notes on Region about Caicara, Venezuela. 449 


orthoclase (not so much over the microcline), and is chiefly 
labradorite. 

Biotite occurs in lath-shaped crystals, shreds and flakes: 
amphibole mostly in prismatic forms. 

An intergrowth of biotite and amphibole was observed, the 
former in the latter, demonstrating conditions in the magma 
that favored the contemporaneous development of these min- 
erals. Apatite and microlites of titanite occur as inclusions in 
the biotite, while the amphibole carries needles of apatite and 
grains of magnetite. Biotite has been observed in feldspar, 
and also apatite needles, while the quartz has dendrites of mag- 
netite, also apatite and occasionally zircon. Liquid inclusions 
are sometimes present in the quartz. ‘Titanite also occurs in 
free crystals. 

Secondary minerals are calcite, which might have been 
derived trom the feldspars, and chlorite, from the biotite, and 
last but not least, garnet, more or less idiomorphic. 

Wavy extinction in quartz and feldspar phenocrysts and 
microscopic grains; bending and breaking, as well as slicing, 
of feldspars and biotite; granulation in feldspar and quartz, 
and complete crushing of titanite crystals strongly suggest 
repeated katamorphism brought about by dynamic stress and 
shearing. 

The occurrence of more or less advanced decomposition and 
decoloration of considerable part of the biotite indicates the 
agency of descending waters, while the secondary growth of 
minerals, involving zonal structure, and the formation of vein- 
lets, where the crystals were broken, tell rather of ascending 
solutions. 

Lhe Gneisses.—The gneisses of the cerros in the sabana of 
Caicara comprise those of the Cerro de Caicara, Cerro de Ari- 
noza with the exception of its base, and those of the Cerro de 
Morano. 

The study of thin sections prepared from specimens taken 
from the foot, the top and sides of these cerros shows by the 
comparison of their composition, structure, texture, and fabric 
that they are essentially one and the same gneiss, as it was 
one type in the granites. This is, however, not intended to 
exclude local phases that represent gradation and variation. 

The petrographic description of these gneisses is as follows : 

In a groundmass of angular to subangular grains of quartz, 
with rather fringed and dentated outlines, and of microcline 
and plagioclase, arranged with their larger diameter either par- 
allel or more or less inclined to the plane of rock cleavage, are 
imbedded phenocrysts of pegmatite, microcline, and plagioclase, 
as well as biotite. All these minerals, with the exception of 
the biotite, exhibit more or less allotriomorphic forms. Micro- 


450 Bendrat—Notes on Region about Caicara, Venezuela. 


cline seems to replace the orthoclase to a great extent, wherever 
the latter is not Intergrown with quartz, and it is the predom- 
inance of microcline, together with that of pegmatite, that con- 
stitutes one of the main features of this gneiss. Feldspar is 
more abundant than quartz. 

So far as the ferromagnesian minerals are concerned, biotite 
occurs in phenocrysts of lath-shaped form, and in flakes. It 
seems to be almost the only representative of this group, as 
hornblende is very seldom encountered in allotriomorphie 
crystals. 

Of accessory minerals chlorite is present, most probably as a 
decomposition product from biotite and hornblende ; it is in 
scaly aggregates. Besides chlorite an occasional crystal of 
pyroxene is encountered, while magnetite in cubes, though 
rarely, and dodecahedrons and hematite in flakes, are more 
frequently met with.. Garnets are not uncommon, idiomorphic 
in form. 

As regards inclusions in the minerals, magnetite may be seen 
in feldspar, with a more or less parallel arrangement to the 
plane of parting ; other inclusions are zircon, chlorite, titanite 
and tourmaline (7) in quartz, actinolite in the feldspars, very 
fine glassy particles in the plagioclases, apatite in quartz and 
in pegmatite, the minute needles, or their fragments, being 
arranged in trains. 

To a greater extent than in the granites we meet in the 
gneisses with evidence of dynamic metamorphism. The evi- 
dences of katamorphism, due to stress and shearing, are: the 
wavy extinction in a number of quartz and feldspar grains ; 
the bending of lath-shaped biotite; the differential bending 
and anastomosing of the lamelle of feldspars; cracks and 
fractures parallel, or normal, to the plane of parting in bio- 
tite; the slicing of crystals of pegmatite and microcline; break- 
ing of crystals of feldspar and biotite, and displacement of 
the broken parts by miniature faulting; granulation zones 
about grains of pegmatite. 

The gneissoid structure of the rock is also shown in the sec- 
tions by the direction of the longer axis of a number of grains 
being parallel, or somewhat inclined, to the plane of schistosity. 

The Origin of the Gneiss—The question arises, whether 
the gneisses are of igneous or of sedimentary origin. 

Evidences in favor of the former are the following: the pres- 
ence of garnets, which are frequent in the granite of the region ; 
the regularity and fineness of the foliation, and the apparent 
uniformity of character of the gneiss both macroscopically and 
microscopically ; while as negative evidence in favor of it is 
the absence of minute variations in the thickness of the lamine, 
as well as the absence of minor plications, of widely dissemi- 
nated graphite and of any ferruginous beds within the gneiss. 


Bendrat— Notes on Region about Caicara, Venezuela. 451 


In favor of the other view, that the gneiss is sedimentary in 
origin, seems only the circumstance that the gneiss in all the 
different cerros is to some, and in that of the Cerro de Caicara 
to a remarkable, extent impregnated with iron oxides, although 
no pronounced ferruginous beds have been found. 

Consequently we may conclude that the gneiss is of igneous 
origin. From the pronounced similarity in composition of 
both granites and gneisses, we may further infer that the 
gneisses have probably been derived from the granites and 
might grade into them, although such gradation has not been 
observed by the writer. 

The Veins and Dikes wm the Granites and Gneisses.— The 
writer regrets not to have had time to examine more closely 
the veins and dikes of the cerros about Caicara, as a more de- 
tailed and special study of these would have brought out prob- 
ably different series of them, so far as strike and dip on the 
one hand, and composition on the other, are concerned, and the 
interrelation of these different series might have thrown some 
light upon the nature and succession of dynamic movements 
which the gneisses and granites have undergone. As time did 
not permit this, only specimens were taken and the strike deter- 
mined of the veins and dikes encountered in ascending the 
cerros. From notes taken in the field, and from the study of 
sections prepared from some of the specimens collected, the 
following may be of interest. 

While the writer is far from attaching any special signifi- 
cance to it and deducing any particular law of succession from 
it, because of the limited material at hand, it is nevertheless 
a peculiar fact that ail of the more prominent quartz veins 
encountered have a strike magnetic N.—-S., while all the peg- 
matite dikes of the region strike normal to this direction, viz., 
E-W. The writer also found near the summit of Cerro de 
Morano a vein of fine-grained amphibolitic gneiss that varied 
in thickness from two to three feet. A few feet below the top 
of Cerro de los Spiritos a felsite dike running E.-W. was met 
with, about one foot thick and standing out prominently two 
feet above the surrounding coarse-grained granite, so that from 
a distance it had the appearance of a wall. Microscopie inves- 
tigation showed that its main constituents are quartz and plagio- 
clase in nearly equal proportions, with some brown biotite in 
shreds and flakes. Also in the dike of pegmatite encountered 
midway between the foot and the summit of Cerro de Morano, 
and mentioned above, there are scattered through it a few small 
flakes of decomposing biotite. It might be mentioned in this 
connection that the dike cuts the foliation of the gneiss at right 
angles. Microscopical examination of the quartz veins shows 
that they are made up of small, interlocked grains of quartz 


452 Bendrat—Notes on Region about Caicara, Venezuela. 


with dentated margins; that amphibole of bronze brown to 
dark-green color occurs in irregular patches ; that tourmaline 
is occasionally met with in radiated aggregates: that garnets 
also occur and some magnetite. These facts point to the pneu- 
matolytic origin of these veins. The quartz has wavy extinc- 
tion, which goes to show that after the vein had been formed, 
together with the enclosing wall rock—in this case the granite, 
it was subjected to dynamic stress. 

In coneluding the writer wishes to remark, that it would be 
of great interest to ascertain the geologic and petrographic 
nature of other outliers in those waste plains that approach 
the Orinoco from the south and east, as well as the character 
of the rocks that make up the mass of the Guiana mountain 
system, in order to bring out facts that would bear on the rela- 
tions of those cerros to this area, which is probably Archean. 


Chemistry and Physics. 453 


SCLIN TIP TC erIN THLE GN CE. 


J. Cuemistry AND Purysics. 


1. Lesearches on Polonium.—This was the first of the new and 
strongly radio-active bodies to be discovered, but it has not yet 
been isolated and characterized as a chemical element. Accord- 
ing to the theory of radio-active transformation the relative 
proportions of the products are equal to the ratio of their mean 
lives, and since polonium is regarded as a descendant of radium, 
which has a life about 5300 times as long, a ton of pitchblende 
containing about 0°2 g. of radium could contain only about ‘04 mg. 
of polonium. Since polonium apparently represents the last 
unstable body in the series derived from radium, tt may be 
expected that polonium will produce an inactive element, which 
has been supposed to be lead, and a verification of this transforma- 
tion would be an important support to the theory. Mpmr. Curie 
and A. DEBIERNE have recently undertaken a chemical research 
with the view of preparing polonium in a concentrated state. 
They employed several tons of residues from the uranium mineral, 
first treating it with warm hydrochloric acid, which dissolved the 
polonium almost completely. The solution which contained no 
radium was submitted in a factory to a series of operations, the 
details of which are reserved for future description, and which 
yielded about 200 g. of a substance having a mean activity about 
3500 times that of uranium, and containing chiefly copper, bis- 
muth, uranium, lead and arsenic. This material was then treated 
in the laboratory by various chemical methods in order to con- 
centrate the polonium. Precipitation with hydrogen sulphide in 
acid and alkaline solution and precipitation by stannous chloride 
were found to be the most trustworthy reactions for the sub- 
stance. When the product was reduced to a few milligrams it 
was found by spectrum analysis to contain mercury, silver, tin, 
gold, palladium, rhodium, platinum, lead, zinc, barium, calcium 
and aluminium. Great difficulties were encountered in attempt- 
ing to make a further concentration, but it was found that polo- 
nium can be deposited completely by electrolysis from an acid 
solution, although other metals, such as gold, platinum, mercury, 
etc., are deposited at the same time. After many experiments 
the activity was concentrated in about 2 mg. of matter. From 
the activity of this product it was calculated that it contained 
about 0-1 mg. of polonium. A portion. of it was sacrificed for 
the study of the spark-spectrum, and several lines were obtained 
which may be attributed reasonably to polonium. The authors 
propose to examine the spectrum lines again after the polonium 
has disappeared, in order to make certain of the lines belonging 
to it. They hope to see also the spectrum of the element formed 
at the expense of polonium, which, according to theory, should be 


Am. Jour. Sct.—FourtH SEerigs, Vou. XXXI, No. 185.—May, 1911. 
31 


454 Scientifie Intelligence. 


lead ; lead is not entirely absent from the product, but its spec- 
trum is very faint. They observed that the active substance 
obtained does not give rise to induced radio-activity, nor to any 
appreciable emission of penetrating rays, but they noticed an 
extremely minute disengagement of radium emanation. <A por- 
tion of the solution was utilized for a study of the gases disen- 
gaged. Bubbles were observed to come off continuously from 
the decomposition of water by the a-rays of polonium, and the 
product given off in 100 days was purified from ordinary gases 
and found to consist of 1°3 cu. mm. of practically pure helium, an 
amount which agreed closely with the calculated quantity. This 
work establishes the production of helium from polonium, A 
curious effect of the rays was observed. The polonium product 
was kept dry in a small quartz capsule, and this was found to be 
cracked in a large number of places under the substance, pre- 
sumably 6n account of electric discharges. An abundant disen- 
gagement of ozone was noticed in the neighborhood of the sub- 
stance.— Comptes Rendus, cl, 386. H. L. W. 

2. Introduction to Generul Chemistry ; by Joun Tappan Stop- 
DARD. 12mo, pp. Xvili, 432. New York, 1910 (The Macmillan 
Company).—This is a text book of moderate scope, intended for 
a first year’s work in chemistry. ‘The author has endeavored to 
give the student a fair idea of the nature of chemical study, of 
the methods by which our chemical knowledge has been gained, 
and of the relations which chemistry bears to every-day experi- 
ences and to industrial activities. | He has aimed to develop the 
subject in a natural manner, introducing new facts and ideas 
gradually, and discussing their relations and the theoretical 
explanations at points where such discussions will be welcomed 
by the student as summing up and interpreting what has gone 
before. The quantitative relations of chemistry have been 
emphasized by frequent reference to a little book dealing with 
simple quantitative experiments, which the author has recently 
published. The synthesis of snlphuric acid and the study of its 
composition is made the basis for the study of other acid sub- 
stances, thus placing sulphuric acid, in the development of the 
subject, in a position which it occupies in actual practice, and in 
general, substances which are most familiar, or from which others 
are derived, are first described, and the other related substances 
follow somewhat in the order of their importance. 

The book appears to be an excellent one in its clear and interest- 
ing presentation of facts and theory. A noticeable feature is the 
entire absence of pictures and of detailed descriptions of experi- 
ments. Their equivalent is expected to be supplied in the lec- 
ture-room and the laboratory, or by means of the author’s little 
book, previously referred to. HL, We 

3. Die Beziehungen zwischen Farbe und Konstitution bei organ- 
ischen Verbindungen ; von Dr. H. Ley. 8vo, pp. 364, Leipzig, 
1911 (Verlag von 8. Hirzel).—This book discusses very fully and 
satisfactorily the present facts and theories in connection with the 


Chemistry and Physics. 455 


relations between color and constitution in organic compounds. 
The work will be of interest both to organic and physical chem- 
ists, for the chromophore theory, the effect of substituents, ultra- 
violet absorption, the recent electron theory of absorption, and 
many other topics are treated. A section at the end of the book 
deals with practical spectroscopic methods for the study of 
colored substances. H. L, W. 

4, Rays of Positive Hlectricity.—For the past several years 
Sir J. J. THomson has been studying the magnetic and electro- 
static deviation of positive rays of electricity by means of the 
phosphorescence excited in a willemite screen by the impact of 
the rays. Since this method did not give permanent records it 
was not very satisfactory to the observer and it was decidedly 
unsatisfactory, if not confusing, to the reader of the published 
accounts of the progress of the investigation. Fortunately, 
Thomson has worked out a photographic process which gives, of 
course, permanent records of the loci of impact. This process 
has the additional advantage of requiring a much shorter time of 
exposure than was possible with a willemite screen, for the reason 
that ordinary dry plates are much more sensitive to the rays 
than the phosphorescent screen ; in fact, an exposure of three 
minutes brings out, on the developed negative, curves which can- 
not be detected with the screen. In all cases, the photographic 
plate was placed inside the evacuated chamber and was manipu- 
lated by suitable rods which projected outside of the receiver. 
The ground-glass cones on the rods titted so well into the comple- 
mentary cones of the chamber that no leakage and consequent 
decrease of exhaustion took place. In the final form of appa- 
ratus employed, three independent exposures could be made by 
lowering a long photographic plate in such a manner as to bring 
three different areas of the plate successively in line with the 
rays. Vifteen typical negatives are reproduced on the plate 
accompanying the text. 

The rays after passing through the tubular cathode—in a 
direction away from the anode—were constrained to pass 
between the poles of a powerful electromagnet and also between 
two parallel, electrified, metallic plates before they reached the 
photographic plate. As usual, the directions of the magnetic 
and electric fields were at right angles to one another. In some 
cases .these fields were coterminous, and in others the center of 
the electric field was nearer the cathode than the axis of the 
magnetic field. In the reproductions of the negatives the hori- 
zontal and vertical directions uniformly correspond to the elec- 
trostatic and-magnetic deviations respectively. 

For convenience, the curves obtained on any one plate may be 
divided into two general classes. In one class the parabolic ares 
are short, of varying length, and are especially characterized by 
starting from different points of the same vertical, geometric line. 
This shows that the minimum electrostatic deflection suffered by 
the particles which gave rise to the photographic impressions 


456 Scientific Intelligence. 


was independent of the nature of the particles. From this fact, 
the conclusion is drawn that the maximum potential difference 
through which each set of particles had fallen is the same. These 
rays are called “ primary ” rays. 

The second type of curve is differentiated by the property of 
radiating from the point on the negative which is struck by rays 
which have experienced neither magnetic nor electric deflection. 
The portions of the curves near this “ origin” are straight lines 
when the magnetic and electric fields are coterminous. If the 
magnetic field overlaps the electric field on the side nearer the 
sensitive plate the curves are concave towards the horizontal 
axis. This fact is interpreted as meaning that the curves repre- 
sent “secondary” positive rays produced by the passage of pri- 
mary rays through the gas on the way to the photographic plate, 
and that the parts of the curve near the origin, which are pro- 
duced by particles which have suffered only small deflections, 
were produced by rays which had not traversed the whole of the 
magnetic and electric fields, but had been generated towards the 
ends of these fields. On the other hand, curves which are con- 
cave towards the vertical axis correspond to primary rays which, 
after passing’ through the cathode, have lost their charges as 
they were passing through the electric and magnetic fields. In 
this case, the parts of the curves near the origin would be due to 
rays which had /os¢ their charges near the beginning of the elec- 
tric and magnetic fields. 

For sake of brevity Thomson calls the ratio of m/e for any 
ray to the value of m/e for the atom of hydrogen, the “ electric 
atomic weight” of the particle forming the ray. Primary rays 
in hydrogen were found to have electric atomic weights 1 and 2 ; 
in oxygen, 16 and 32; in carbon dioxide, 12 and 47 ; in marsh 
gas, 16 and 28; in cyanogen, 26 ; etc. 

Many interesting and important facts concerning the secondary 
rays are recorded in the paper, but since an entire page is 
required for a synoptic table it will not be possible to quote the 
details in this place. Suffice it to say that the electric atomic 
weights have the following values: 1, 1°4, 2, 3, 6, 7, 12, 16, 26, 
36, 48, 72-78, 96, 100, 200 and 800. The last three numbers per- 
tain to mercury vapor.— Phil. Mag. (6), xxi, 225. H. S. U. 

5. Focal Isolation of Long Heat- Waves.—Rusens and 
Woop first tried to take advantage of the selective refraction of 
quartz in the manner described in 1899 by Rubens and Aschki- 
nass, which was to employ quartz prisms of small refracting 
angles in conjunction with a suitable spectrometer. The energy 
finally emergent in the apparatus was found to be too small a 
fraction of the incident radiation, and hence the experimenters 
were led to devise another and more efficient form of apparatus 
with which they were able to obtain heat waves of greater length 
than had ever been measured before. 

The source of energy, a Welsbach mantle, was placed in line 
with a circular aperture in a double screen of tin plate. This 


Chemistry and Physics. 457 


opening was situated on the optic axis of a double-convex quartz 
lens and at such a distance from the lens as to cause the ordinary 
light waves and shorter infra-red radiations—corresponding to 
refractive indices between 1°43 and 1:55—to form divergent 
beams after emerging from the lens. On the contrary, the very 
long heat waves were brought to a relatively sharp focus at a 
similar aperture in a second screen, By stopping out the central 
zone of the lens by means of a black paper disc, only the longest 
waves were allowed to enter the hole in the second screen. A 
second lens, similarly stopped and placed behind the last screen, 
completed the purification of the radiation and also brought the 
waves to a focus on the thermocouple of a radio-micrometer. 
The wave-lengths and distribution of energy in the isolated radia- 
tion were determined by means of a quartz interferometer placed 
close behind the second aperture. 

The mean wave-length was found to be about 108 and the 
existence of waves as long as 150u was established. The longest 
waves previously recorded had a length of 97p. 

Having determined the mean wave-length of the isolated radia- 
tion, the authors studied the absorbing and reflecting powers of 
various solids, liquids and vapors for this region of the spectrum. 
Only a few typical results may be mentioned here. Diamond 
was remarkably transparent, while fused quartz and water-glass 
were very opaque. Black paper and even black cardboard were 
partially transparent. A thin lamina of mica densely smoked 
was exceedingly transparent to waves of length 1084. As pointed 
out in the paper, this fact is of importance in the construction of 
radio-micrometers, etc. The reflecting power of water was found 
to be comparatively high, which is probably due to the presence 
of one or more absorption bands in the region under investiga- 
tion.— Phil. Mag. (6), xxi, 249. H. S. U. 

6. A Method of Calibrating Fine Capillary Tubes.—The 
usual method for the determination of the mean area of cross- 
section of the bore of a capillary tube decreases in precision as 
the radius becomes smaller because of the difficulty of weighing 
the thread of mercury employed to a sufficiently high degree of 
accuracy. For example, the mass of a column of mercury 10 
long contained in a capillary tube of 0:1™ internal diameter is 
about 0°01 gram, so that to obtain an accuracy of 1 per cent in 
the square of the radius the weighing must be correct to 0:1 mg. 

A very promising method, which depends primarily upon the 
determination of the electrical resistance of a thread of mercury, 
has been devised and tested by T. R. Merron. Each end of the 
capillary tube is fitted into a rubber stopper, and each stopper 
enters the shorter arm of a glass tube shaped like the letter L 
and of relatively large internal diameter. The longer arms of 
the L-tubes are vertical when the capillary is horizontal. The 
entire capillary bore and the greater part of the auxiliary end 
vessels are filled with pure mercury. By using a suitable air 
pump for evacuation, no difficulty is experienced in forcing the 


458 Scientific Intelligence. 


liquid into the capillary. During the determination of the elec- 
trical resistance of the thread of mercury in the capillary, the 
system of tubes is kept within 0:01° C, of a given temperature by 
means of a water-bath, toluene regulator, etc. 

The length of the capillary bore is easily measured by means 
of a comparator. From the numbers expressing the length of 
the capillary, the resistance of the thread of mercury, and the 
specific electrical conductivity of mercury, the square of the 
mean radius of the capillary bore can be calculated at once. A 
small correction was added to the length of the bore to allow for 
the curvature of the stream lines at each end of the capillary 
tube. The squares of the mean radii of three tubes were found 
to be respectively 0°002304™™, 0:004406™™*, and 0:004192™™’, with 
an error of about 0:000002™™. Thus the result obtained for a 
tube of 0°06474™™ radius is about 20 times as good as for the 
hypothetical case first cited for a radius of 0:05"™.— Phil. Mag. 
(6), xxi, 386. H. 8. U. 

7. An Introduction to Thermodynamics for Engineering 
Students ; by Joun Miuts. Pp. viii, 136; 61 figures. New York, 
1910 (Ginn & Co.).—This is a text written for the use of classes 
in engineering, and intended as a preparation for more advanced 
work in the application of thermodynamics to heat engines. It 
is divided into five chapters. The first contains a concise sum- 
mary of the general principles of thermodynamics, and the 
remaining four the applications to gases, water and saturated 
vapor, superheated steam, and the flow of steam and gases respec- 
tively. At the end of each of these last four chapters is appended 
a summary of the formulas which have been developed and a 
considerable number of graded problems with their solutions. 
This last feature frees the main. body of the text from the very 
necessary but cumbersome explanations of details, and allows the 
development of the theories involved to be shown in a truer per- 
spective than if such details were interpolated in the exposition. 
Graphical methods (the temperature-entropy, Boulvin, and other 
diagrams) are emphasized, but not to the exclusion of the analyti- 
cal methods. The ground covered is about that customary in 
first courses in this subject as given in most technical schools in 
this country. The subject matter is possibly too restricted in 
scope for a wide field of usefulness, and the discussion of the 
second law of thermodynamics is marred by a mistaken interpre- 
tation of Clausius’s statement of it. But on the whole, the end 
which the author had in mind in writing the book has been suc- 
cessfully attained. L. P. W. 


Tl. Gzwotogy Ann MiInERALOGY. 


1. Denudation and Erosion in the Southern. Appalachian 
Region ; by L. C. Guenn. Prof. Paper 72, U:S. Geol. Surv., 
1911. Pp. 137, 5 plates, 1 figure—A detailed study of the 
effects of deforestation, overgrazing, and “agricultural butchery” 


Geology and Mineralogy. 459. 


upon soil erosion. The paper is of timely interest, first, because 
of the new law providing for the creation of the Appalachian 
forest reserves, and, second, because it has recently been suspected 
in some quarters that the earlier pictures of soil destruction were 
overdrawn. The author finds about 74 per cent of the total area 
still forested. Even this amount, however, is considered too 
small. Under the given conditions of slope gradient, soil tex- 
ture, rainfall, etc., it is considered unsafe to have more than 18 
per cent to 20 per cent of the surface cleared. Clear-cut illustra- 
tions of soil erosion are supplied in a variety of situations: (1) 
on sodded “balds” where over-grazing and trampling by cattle 
have broken the turf and started landslides that quickly develop 
into gullies; (2) on all slopes where lumbering has removed the 
original protective covering and hastened the action of rain-wash; 
(3) on cleared and abandoned slopes once used for agriculture. 
In the last-named case the harm has been underestimated in the 
past. Undercutting and caving, once started in a cleared area, 
often extend upward into forested tracts, and the debris derived 
in this manner is washed downward into the forest below. Some 
porous soils were found to be erosion-resisting but their aggre- 
gate area is not relatively great. The allowable limit of steep- 
ness for cleared lands, 15°, is almost everywhere exceeded, and in 
many places greatly exceeded. ‘Terracing is practised on a 
wholly inadequate scale. There is increased silting on the flood 
plains and in the stream channels, a conclusion applied to all 
streams draining catchment areas that have been extensively 
cleared. One gains from the paper a clear and powerful impres- 
sion of destructive erosion on exposed mountain soils and of 
destructive sedimentation on the flood plains. It is with a feel- 
ing of great satisfaction that one contemplates the beneficent 
results that may flow from the recent action of Congress after so 
conclusive an argument against the further unguarded use of the 
soilits I. B. 

2. Preliminary Notes on the “ Chazy” Formation in the 
Vicinity of Ottawa; by Percy E. Raymonp. The Ottawa 
Naturalist, xxiv, Feb. 1911, pp. 189-197.—The following sum- 
mary is given: “The sections in the vicinity of Ottawa show 
about 250 feet of strata between the Beekmantown and the base 
of the Black River. These strata are characterized by two 
groups of species. The lower 125 to 135 feet contain a small 
fauna, some of whose species are found in the upper part of the 
Chazy formation of the Champlain Valley, and this portion is 
undoubtedly to be correlated with the Upper Chazy .. . 

“The upper portion of the section consists of 115 to 125 feet 
of limestone, sandstone and shale, with fossils more nearly akin 
to those found in the Black River and lacking the typical Chazy 
species. . . . This portion of the section . .. is capable of sub- 
division into two members, the lower of which contains most of 
the shale and sandstone, and the upper the pure limestone. The 
lower portion contains an immense number of small ostracods, 


460 . Scientific Intelligence. 


and, in the middle, great numbers of gastropods and other fossils. 
This member is from 65 to 75 feet in thickness. [It may be the 
equivalent of the Pamelia of New York. | 

“The upper member is composed mostly of pure limestone, has 
a larger fauna than either of the other formations, the upper 15 
feet being especially fossiliferous. This is the Lowville of the 
New York section and the thickness is about 50 feet.” Goi 

3. Die Fauna der Spiti-Schiefer des Himalaya, thr geolo- 
gisches Alter und thre Weltstellung ; by Vicror Unutie, Denkschr. 
d. Math-—Naturw. Klasse d. Kais. Akademie d. Wiss., Wien, 
Bd. Ixxxv, 1910, pp. 531-609.—There is here presented a sum- 
mary of the fauna found in the Spiti geode-bearing black shales 
having a thickness of about 500 feet. There are 218 species of 
ammonites, 4 belemnites, 35 bivalves and 2 gastropods. Evi- 
dently but little of the fauna is bottom mud dwelling as most of 
it is made up of swimming types. The specimens are as a rule 
preserved in geodes, or rather concretions, but unfortunately none 
of them were collected zonally. 

This fauna has no direct connection with the Kelloway biota 
as has been thought ; only a few forms point to the Oxfordian, 
there are certainly some Kimmeridgian species, while the Titho- 
nian and Valangian are best represented. The Spiti shales are, 
therefore, thought to hold the time of the Upper Jurassic and 
the early Lower Cretaceous. 

The Spiti fauna shows that it had no direct boreal connections, 
having only a single species each in Aucella and Simbirskites. 
On the other hand, there is positive faunal affinity with the 
Alpine region of Tethys. 

The author goes into a world-wide study of the Jurassic and 
Lower Cretaceous faunas that cannot be here detailed. His final 
conclusions regarding climatic zones are not at all in harmony 
with those of Neumayr, for the former states, ‘‘ All of these facts 
give the impression that the distribution of the marine faunas of 
the Jurassic and Lower Cretaceous was essentially independent 
of latitude and climatic zones” (609). Cc. §. 

4. Beitrage zur Geologie der Béren-Insel, Spitzbergens und 
des Kénig-Karl-Landes; by A. G. Natuorsr. Bull. Geol. 
Instit. Upsala, x, pages 261-416 with many illustrations and 
geological maps, 1910. The author here brings together all that 
is known regarding the geology and paleontology of these far 
northern lands, and one is surprised at the great amount of excel- 
lent work recorded. 

Biren Island is composed of Ordovician, Devonian (Ursa sand- 
stone probably of lagoon origin), three divisions of the Car- 
boniferous separated from one another by discordances, and 
Triassic. Spitzbergen has in addition to the above Permo- 
Carboniferous, Permian, Jurassic, Lower Cretaceous and Tertiary 
(? Miocene). C: 8. 

5. Historical-Stratigraphical Review of the Silurian of 
Sweden ; by Jou. Cur. Mosrerc. Arsbok 4, Sveriges Geol. 


er 


Geology and Mineralogy. 461 


Unders., No. 229, pages 210 and 1 map, 1910. Here is presented 
first a general and second a somewhat detailed statement of the 
Cambrian, Ordovician and Silurian or Gotlandian deposits of all 
Sweden. There is also a very extensive bibliography. It is one 
of the guides to the excursions given after the meetings of the 
Geological Congress at Stockholm last summer. The book is of 
great value to all students of early Paleozoic stratigraphy. 
C. 8. 
6. Geologisch-petrographische Studien in der Patagonischen 
Cordillera ; von P. D. QumnsELt. Bull. Geol. Inst. Upsala, vol. 
XI, 1-113, 1910, figs. and geol. map.—The writer during a period 
of two years, partly by land travel and partly by boat in the 
_fiords, has made a fairly general geological reconnaissance in the 
chains of the southern Andes, from Cape Horn northward to 41°S., 
a distance covering 15° of latitude. Availing himself of hitherto 
published material, which was rather scant, and his own obser- 
vations, he presents a geological map covering this stretch, and 
extending from the Pacific on the west to the pampas on the east. 
Although the work is chiefly devoted to presenting the results of the 
petrographical investigation of the material collected, these are 
accompanied by geological observations, which, taken together 
with a brief résumé of the geology of the area published by him in 
“ Geologische Rundschau ” (Band 1, p. 21, 1910), are sufficient to 
throw much light on the geology of this little known region. 
The western, or coast, cordillera, fronting on the Pacific, is 
composed of an enormous stretch of granular igneous rock, the 
andendiorite of Stelzner. This immense mass reaches from Cape 
Horn in nearly 56° §S. to 47°S8., and is deeply dissected by a 
remarkable system of fiords, comparable to those of Norway and 
Alaska. From 47° northward it swings more inland, and is 
replaced on the coast by islands of metamorphosed older sedi- 
ments. The author states that it has not the monotonous petro- 
graphic character formerly attributed to it, but shows much differ- 
entiation into types varying from acid potash granites, and quartz 
diorites, through syenites and augite-diorites, into gabbros, and is 
accompanied by systems of aplitic and lamprophyric dikes. Inland 
it is much covered by glaciers and seas of ice. The author is 
inclined to place the intrusion at the end of the Mesozoic; unfor- 
tunately no direct contacts with fossiliferous strata have been 
found, and this age is inferred from general considerations. In 
several places effusive masses of andesite and basalt were found. 
In regard to the central and east cordillera the geological for- 
mations and structure are very different from the foregoing, and 
also vary in the long stretch over which reconnaissance was made. 
Near the strait of Magellan the central chain is a folded range, 
consisting of sedimentary beds belonging to the Cretaceous, and 
against which the Tertiary of the pampas is gently inclined; 
there is probably an unconformity between them. in the north- 
ern part of this stretch great masses of quartz-porphyry occur 
with tuffs and breccias. 


462 Scientific Intelligence. 


North of 50° 8. two periods of folding were observed : the first 
probably Paleozoic, the second Tertiary. This part is also marked 
by the intrusion of large laccoliths, whose structures and rocks 
bear a marked resemblance to those of the western United States. 
North of 47°30’ the character of the southern Patagonian cor- 
dillera, as a folded range, changes, and at the Rio Aysen, where 
a complete tranverse profile was obtained, the greater part of the 
central chain consists of granitic igneous rocks, while the eastern 
chain is composed of masses of porphyries and tuffs. Between 
the two lies a band of sediments from which Belemnites and 
other fossils were obtained. On the eastern slopes, down toward 
the pampas, in several places immense fields of outpoured basalts 
occur. In the southern portion of the area several large vol- 
canoes were found, a southern continuation of the great series 
of volcanoes of middle Chile. They are andesitic in character, 
and their activity continued after the glacial period. 

A feature interesting to petrographers is the occurrence, at a 
number of places in the Andes of southern Patagonia, of alkalic 
rocks. These consist of intrusive masses of essexite, in stocks, 
exposed domes, etc. These rocks are composed of purple, pleo- 
chroic, titaniferous augite, brown barkevikite, labradorite and 
analcite, the latter regarded as secondary, perhaps after nephe- 
lite. They are accompanied by a series of dikes of bostonite and 
camptonite with essexite-porphyry, and the author parallels the 
occurrences with those of Southern Norway, made classic by the 
researches of Brégger. In other places aegirite-granite-porphyry 
is found with the essexite, while a trachydolerite is regarded 
as an effusive equivalent. The occurrence of these alkalic types 
in the sub-alkalic (alkalicalcic) province of the Andes is both 
interesting and significant. 1p Vig tet 

7. Ueber einigige Japanische Vulkane ; von 1. FrrepLaAENDER, 
II Theil. Mitt. d. deutsch. Gesell. f. Nat. u. Vélkerk. Ostasiens, xii, 
2. Tokio, 1910, with plates and map.—The author continues in this 
article his description of the Japanese volcanoes, basing his work 
upon his own observations, and upon those of others. It relates 
chiefly to the northern part of the island empire, and much of 
the material, drawn from Japanese sources, is now made available 
to western people. While it represents chiefly the observations 
of the geological traveler, and contains no detailed studies, the 
vulcanologist and geographer will find much to interest them, 
especially the records of periods of activity for certain volcanoes, 
which run back in some cases for over 1000 years. The article is 
accompanied by a number of half-tone plates of the volcanoes 
described, and by a map which shows their situations. L. v. P. 

8. Geological Survey of Ohio. J. A. Bownooxsr, State Geolo- 
gist. Fourth Series, Bulletin 11. The Manufacture of Roofing, 
Tiles ; by Wotsey G. Worcester; Epwarp Orton, Jr., Col- 
laborator and Editor. Pp. viii, 476 ; 187 Ulustrations.—The Ohio 
Survey has undertaken a series of Bulletins on the Clays and Clay 
Products of the State, and the fact that this industry is so promi- 


Geology and Mineralogy. 463 


nently developed in Ohio will give these Bulletins much value. 
The first report to be completed is that on the Manufacture of 
Roofing Tiles, an industry which thus far has been somewhat 
slow to develop in this country, although in the history of the 
subject we have to go back to 1814 for the time when tiles were 
first made use of in the state; this was at Germantown, a village 
some 30 miles northeast of Cincinnati. Roofing tiles have, aside 
from the non-permanent wooden roof, various rivals in the slates, 
corrugated iron, asbestos, and other artificial fabrics, and cement ; 
but the future is likely to see a larger development in the direc- 
tion which has had so much use in foreign countries. The author 
of the present work has been engaged in the practical industry 
for a number of years, and hence is able to discuss the various 
aspects of the subject with all needed fulness and accuracy. 

9, Hlements of Geology ; by Exrtot BhackWELDER and Haran 
H. Barrows. Pp. 467, 16 plates, 485 figures. New York, 1911 
(American Book Company).—No attempt is made in this book to 
present new material or to discuss controversial matter. It is a 
text-book pure and’simple and the selection of topics as well as 
the manner of presentation has been determined by that fact. 
The book shows clearly that its authors are experienced teachers 
and understand what is and what is not within the intellectual 
range of students who have not previously studied the subject. 
The text is rather too brief for use in colleges, but should find 
a place in institutions where short courses are given to students 
of elementary science. H. E, G. 

10. A Remarkable Crystal of Beryl; by Guorcr F. Kunz 
(from a paper read before the New York Academy of Sciences, 
April 3d, 1911).—On the 28th of March, 1910, in a pegmatite 
vein at Marambaya, a village in the vicinity of Arassuahy, on the 
Jequitinhonha River, in the State of Minas Geraes, Brazil, there 
was found a crystal of beryl, which was the largest crystal of 
precious beryl (aquamarine) ever found. In form it was a simple 
hexagonal prism with slight irregularities due to compression, and 
terminated with a simple basal plane at both ends., The crystal 
weighed 110°5 kilograms, was 48°5 centimeters high, and from 
40 to 42 centimeters in its different widths. It was so trans- 
parent that, looking down into the crystal through its basal 
termination it could be seen through from end to end. In color 
it was greenish-blue, absolutely free from included impurities but 
traversed by a number of fractures. 

This crystal was found by a Turk, who mined it in what is 
known as a primitive mine, at a depth of from five to six meters, 
and only with the greatest difficulty was it transported by canoe 
to the coast, by way of the Jequitinhonha River and then shipped 
to Bahia, where it is said that he realized $25,000 for it. It is 
estimated that this crystal would furnish at least 200,000 carats 
of aquamarines of various sizes. 

11. The Mineralogy of Arizona ; by F. N. Guitp. Pp. 99. 
’ Easton, Pa., 1910 (The Chemical Publishing Co.)—This is a useful 


464 Scientific Intelligence. 


account of the minerals thus far produced in a region which is 
unusually rich in variety and number of species, some of them of 
great rarity elsewhere. 

12. Notes on a recent find of Zincite Crystals; by A. H. 
Puiturrs.—During the past year a small stringer containing 
well crystallized and separate crystals of zincite was discovered 
in the Franklin Furnace mine. The vein, one-half inch in aver- 
age width, was surrounded by the ordinary mixture of frank- 
linite in a matrix of green willemite. Associated with the zincite 
are crystals of leucophoenicite, pyrochroite,* gageite, calcite and a 
very soft fibrous asbestos. The best crystals, fourteen of which 
are in the Princeton collection, the largest measuring 3°5°™ along 
its pyramid edge, were imbedded in this fibrous material, though 
some were broken out of the massive zincite. All the large crys- 
tals are apparently flattened, hexagonal pyramids. This apparent 
distortion is caused by the pyramid faces of one side being very 
short as compared to those of the opposite side of the crystal. 
The faces are rough, pitted, and generally crossed by two sets of 


Fie. 1. Fie. 2. 


Fic. 1. Zincite crystal showing striations and general termination. Nat. 
size. 

Fie. 2, Crystal in the matrix showing the upper base. Enlarged 62g 
diameters. 


striations; one parallel to the intersection of the pyramid and 
prism, the other parallel to the pyramid edge and caused by a 
parallel growth of the pyramid itself. This is so marked in one 
individual as to obliterate the pyramid edges and the crystal is 
then rounded and conical. 
Forms.—W hile accurate measurements, owing to the imperfec- 
tions of the faces, were impossible, they were, however, sufficiently 
accurate as to identify without doubt the crystal forms. All the 


*This pyrochroite is of new habit and it is hoped to publish a note on it 
in the future. 


— a 


Miscellaneous Intelligence. 465 


crystals which lie together in the larger vein gave measurements 
(pap’) varying from 48° 32’ to 49° 28'; this form thus corre- 
sponds to the hexagonal pyramid (4045) described by Grosser.* 
A single small crystal obtained from a small adjacent vein gave a 
measurement 55° 10’ for (pap’) and would, therefore, correspond 
to the pyramid (5054) described by Moses. 

The prism zone is represented by a single face only, the lower 
end of the crystals being as a rule rounded as shown in the illus- 
tration, or terminated by cleavage planes. 

Since zincite is dihexagonal polar in type, or hemimorphic, the 
base is represented by an upper (0001) and a lower (0091), each 
of which may occur independently. Both have been described 
as occurring on artificial zinc oxide crystals.{ Dana§ figures the 
lower base on a zincite crystal from this same locality ; while the 
lower base is not represented on any of the above crystals, one 
crystal, however, illustrated in fig. 2 shows the upper base (0001) 
very beautifully. This is, therefore, a new form not heretofore 
observed on zincite. All the other crystals are terminated 
sharply or are rough and rounded as if they were corroded. 

Guyot Hall, Princeton, N. J., Feb. 15, 1911. 


I. Miscerranerous Screntiric INTELLIGENCE. 

1. National Academy of Sciences.—The annual meeting of the 
National Academy was held in the new building of the National 
Museum at Washington on April 18 to 20. President Ira Rem- 
sen was in the chair and some forty-five members were present. 

The following new members were elected: Edwin E. Barnard, 
of the Yerkes Observatory ; Edward B. Van Vleck, of the Uni- 
versity of Wisconsin ; John F. Hayford, of Northwestern Uni- 
versity ; Edwin H. Hall, of Harvard University ; James F. Kemp, 
of Columbia University ; Arthur L. Day, of the Geophysical 
Laboratory of the Carnegie Institution; Julius O. Stieglitz, of 
the University of Chicago ; Bertram B. Boltwood, of Yale Uni- 
versity ; Robert A. Harper, of the University of Wisconsin. The 
following foreign associates were also elected: Prof. Ernest 
Rutherford, of the University of Manchester, England, and Prof. 
Vito Volterra, of the University of Rome, Italy. 

A lecture was delivered on Tuesday evening, under the aus- 
pices of the Washington Academy of Sciences and in honor of 
the National Academy, by Dr. John Murray, on “The Ocean.” 
At the dinner of the Academy, given at the Cosmos Club on 
Wednesday evening, the Henry Draper medal was presented to 
Mr. Charles G. Abbot, director of the Smithsonian Astrophysical 
Observatory, for his researches on the infra-red region of the 
solar spectrum and his accurate measurements, by improved 
devices, of the solar constant of radiation. 


* Zeitschr. Kryst., xx, 354, 1892. + School Mines, Q., xvi, 226, 1895. 
{Neues Jahrb. Min., 1884, ii, 164. § This Journal (8), xxxii, 389. 


466 Scientific Intelligence. 


The following is a list of the papers presented at the meeting: 


W. W. Campsety: On the motions of the brighter helium stars. Report 
of progress in spectrographic determinations of stellar motions. 

¥, R. Moutton: The evolution of periodic solutions of the problem of 
three bodies. 

G. F. Becker: Mechanical quadratures. 

W. M. Davis: Corollaries of the theory of isostasy. i 

Lynps P. WHrELER: Experimental investigation on reflection of light at 
certain metal-liquid surfaces. 

W. J. Humpureys: On the origin of the peaks of maximum pressure in 
the midst of the permanent tropical oceanic highs. 

E. F. Smita: A further study of columbic and tantalic oxides. 

J. P. Ippines : The outlook of petrology. 

WALDEMAR LINDGREN: The orogenic development of the northern Sierra 
Nevada. * 

H. F. Ossorn:: Biological conclusions drawn from the evolution of the 
Titanotheres. 

W. B. Scorr: A new reptile from the Newark beds. 

J. M. CuarKke: Restorations and ontogeny of the Hurypterids. 

Cuas. D. Watcorr: A geological reconnaissance in the Rocky Mountains 
of British Columbia. 

C. S. Minor: Comparative study of the early stages of vertebrates. 

Smion FLexneR: Infantile paralysis and its mode of transmission. 

E. G. Conxuin: Cell-size and nuclear-size. 

Jacques Lorzs : The cause of death of the unfertilized egg and the cause 
of the life-saving action of fertilization. 

Horatio Woop, Jr. : Studies of the pulmonary circulation. 

J. M. Courter : An American Lepidostrobus. 

THEO. GILL: Aristotle’s History of Animals. 

E. S. Morse: Notes on New England Mollusca. 

Franz Boas: Changes in bodily form of descendants of immigrants. 

C. Hart Merriam: Classification of Shoshonean tribes. The outside and 
the inside of the Yosemite Indian. 

E. 8S. Hotpen: Biographical memoir of W. H. C. Bartlett. 

H. L. Assor: Biographical memoir of C. B. Comstock. 

T. B. OsBorNE: Biographical Memoir of §. W. Johnson. 

A. W. Wricut: Biographical memoir of Benjamin Silliman, 1816-1885. 
Biographical memoir of James H. Trumbull. 

Wm. H. Dati: Biographical memoir of C. A. White. 

H. F. Osporn: Biographical memoir of Joseph Leidy. 


2. Bulletin of the Seismological Society of America. Publi- 
cation Committee: J. C. Branner, A. C. Lawson, 8. D. Town- 
LEY. Vol.I, No.1, pp. 32, Stanford University, 1911.—The open- 
ing number of the Bulletin of the Seismological Society, announced 
a month or two since (see vol.. xxxi, 247), has recently appeared, 
and inaugurates a movement which is sure to be of great impor- 
tance in the progress of this science in the country. ‘The leading 
article is by A. C. Lawson, and gives a brief review of the pres- 
ent condition of seismology in the country, with practical sugges- 
tions as to means for developing this further. This is followed 
by a paper on the seismological work on the Pacific coast, by J. 
C. Branner, and another by A. McAdie on the seismological 
observations of the future. The earthquakes in Central New 
Mexico of 1906 and 1907 are discussed at length by H. F. Reid. 
Other contributions give a list of seismographs in America, and a 
statement by J. B. Woodworth of the Gottingen nomenclature 


Obituary. 467 


of seismological reports furnished by Dr. Klotz of Ottawa. A 
series of reviews follow. In the following number it is proposed 
to give a list of earthquake records for a large number of Ameri- 
can stations in 1910. 

3. Commercial Geography ; by Enwarp VanDyxe Rosin- 
son. Pp. xlvili, 455. 252 illustrations, including 100 maps. 
New York and Chicago, 1910 (Rand, McNally & Co.).—A com- 
mercial geography by an economist is a book of unusual interest 
under any circumstances. ‘In this case the book possesses high 
distinction as well as interest and for,three main reasons. It is 
very carefully written ; it applies economic theory to commercial 
geography in a skillful and explanatory way and neither ignores 
nor overdoes the effects of natural environment ; it follows the 
regional method throughout with an evenness of treatment and a 
skill in the selection of topics that makes every page well-bal- 
anced and attractive. As a high-school text the book is far in 
advance of the older group of commercial geographies. None 
other has a style at once so vivacious and trenchant. In addition 
the book goes a long way toward solving a difficult high-school 
problem. Its combination of the physical, the commercial, and 
the regional will appeal to school men who wish a broad geog- 
raphy course and not a course in physiography alone or industry 
or commerce. I. B. 


OBITUARY. 


SamMuEL FRANKLIN Emmons, the geologist, died at his home 
in Washington, D. C., in the morning of March 28th. Although 
he had not been in. good health for some time, his death, from 
heart failure, was unexpected. 

He was born in Boston, Mass., on March 29, 1841 ; received 
his education at Harvard University, graduating in 1861 ; and 
then went abroad, where he remained for several years as a stu- 
dent at the Ecole des Mines in Paris and the Bergakademie at 
Freiberg in Saxony. 

Returning home in 1867, he joined the staff of the 40th Parallel 
Survey newly organized by Clarence King. The other members, 
as assistants to King, were J. D. Hague and Arnold Hague. 
With the forming of this organization, and with the beginning of 
its work in the field, it may be said, in a way, that a new epoch 
in American geology began; the former pioneer period, in 
which geology was carried on, partly by states and partly indi- 
vidually, by men largely self-trained, was henceforth to be suc- 
ceeded by one in which such work was to be supplemented, and 
largely replaced, by national organizations of men who, like 
Emmons, had been specially trained and fitted as professional 
geologists. From that time on Emmons remained continuously 
in the service of the Government with the exception of two years, 
1877-9, when he was engaged in managing a cattle ranch in 
Wyoming. When the present U. 8. Geological Survey was 


468 Scientific Intelligence. 


organized in 1879, he was appointed as one of the chief geolo- 
gists in charge of the division of the Rocky Mountains with 
headquarters at Denver. Although he had joined with Arnold 
Hague in writing the volume devoted to the descriptive geology 
of the 40th Parallel Survey, he had given much attention to the 
study of ore deposits. His bent in “this direction had undoubt- 
edly been stimulated by his European training, and by the inves- 
tigation of several mining districts while assisting J. D. Hague in 
the volume treating of the mining industry. His instructions, 
when the National Survey was organized, were to devote him- 
self to a study of the mineral wealth of the Rocky Mountains, 
and it was chiefly in this task that his life was spent. With the 
publication of his report on the geology and mining industry of 
Leadville, Colo., in 1886, a most important step forward was 
taken in economic geology in this country, in that it was then 
clearly perceived that the satisfactory economic development of 
mining regions must in future be based upon a thorough under- 
standing of the geologic structure and the conditions of the ore 
deposition. From that time Emmons, in the opinion of those 
qualified to judge, is held to have been the most prominent figure 
in this country in the development of the economic side of geol- 
ogy, especially as regards the metal mining industry in the west. 
The stimulus of his work has been felt in an ever increasing 
degree by the younger men who have succeeded him and who 
have given this country such a commanding position in this 
branch of geology. He published many papers in journals, 
otticial reports, and the proceedings of scientific societies, and 
mostly dealing with the particular field he had made his own. 
His services to science and to mining had been adequately recog- 
nized by his election to the National Academy of Science, and to 
many other scientific and technical societies. His loss will be 
strongly felt, not only in his especial field of work and by the 
organization of whose staff he was an honored member, but by a 
host of personal friends to whom his warm heart and genial 
character had greatly endeared him. ee fy es 

SamMvuEL Catxvin, Professor of Geology in the State University 
of Iowa and since 1892 State Geologist of Lowa, died on April 
17 at the age of seventy-one years. 

Professor Jaxon Maarren V'an BeEMMELEN, the distinguished 
chemist of the University of Leyden, died on March 13 in his 
eighty-first year. 

Mrs. Exten H. Ricuarns, head of the department of social 
economics at the Massachusetts Institute of Technology, and wife 
of Prof. Robert H. Richards of the department of mining engi- 
neering, died March 30 in Jamaica Plain, Mass. She published a 
work entitled ‘ First Lessons in Minerals” in 1885. 

Epwin E. Howe 1, mineralogist and maker of relief maps and 
models, died at his home, in Washington, on April 16, at the age 
of sixty-six years. 


WO XX XT. 


Established by BENJAMIN SILLIMAN in 1818. 


THE 


AMERICAN. 
JOURNAL OF SCIENCE. 


Epiror: EDWARD S. DANA. 


ASSOCIATE EDITORS 


Proressors GEORGE L. GOODALE, JOHN TROWBRIDGE, 
W. G. FARLOW anp WM. M. DAVIS, or Campriwer, 


Prorrssors ADDISON E. VERRILL, HORACE L. WELLS, 
L. V. PIRSSON anp H. E. GREGORY, or New Haven, 


Proressor HENRY S. WILLIAMS, or Irwaca, 


FOURTH SERIES 


VOL, XXXI—[WHOLE NUMBER, CLXXXTI.] 
No. 186—JUNE, 1911. 


WITH PLATE IV. 


~/ 
NEW HAVEN, CONNECTIOUIVUL g 1911 


lieu. 


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, 


registered letters, or bank checks (preferably on New York banks). 


JUNE, 1911. 


Hee ach 
ophykical Ohset'%e 


Important Announcement. 


NATRAMBLYGONITE, 


Having secured a small lot of this new mineral as described in this Jour- 
nal, No, 181, January 1911, by W. T. Schaller, I am now in a position to 
furnish desirable specimens of same, at very reasonable prices. 


RUBY CORUNDUM. 


It has been some years since the Buck Creek deposit has produced material 
of specimen quality; having been fortunate in securing a lot of these 
double terminated crystals, the result of considerable work which did not 
pay the miners for their trouble, the mines were again closed. This is 
an opportunity for collectors to secure very desirable crystals, single or in 
sets, showing the variety of occurrence of form and colors; prices very 
reasonable, 


HIDDENITE. 


We have secured the balance of the former lot of Hiddenite crystals which 
sold so rapidly last month ; we are now in a better position to furnish sets 
showing the different effect of etchings, form and color. These specimens 
have the deep emerald green color so desired by all collectors. When made _ 
in sets mounted on sheet wax, they present a beautiful contrast for show 
and study and should have a place in every collector’s cabinet. 


RUTILE, 


From another source was received a lot of trillings in this most unique 
mineral, all of good erystal quality, a number of them quite transparent 
and possessing a very brilliant luster ; prices very low. 


PRECIOUS AND SEMI-PRECIOUS STONES. 


Having secured from a receiver’s sale a very large stock of cut stones all 
colors, size and qualities, I take this opportunity to offer same at 75 per 
cent of their real value, so as to dispose of them rapidly. 

This is the chance of a lifetime for anyone interested in precious and 
semi-precious stones, carvings, mosaics, cameos, ete. Ask for an assortment, 
which I will gladly send on approval prepaid, for your selection, You can 
return at my expense anything you do not desire. 


REMARKABLE COLLECTION, 


I have just received for sale a remarkable collection which was in the 
possession of a well known wineralogist, who was noted for the intense 
interest he had in fine, choice specimens ; this collection represents years of 
diligent and persevering collecting, the specimens representing nearly all 
the old localities and most of the recent ones. Some of the specimens are 
the finest found and this is an opportuuity which new collectors should take 
to get possession of some of the choice things of past localities. 

Tam now ready to furnish a complete list of this collection to anyone 
upon request and will advise early correspondence on same. 


A. H. PETEREIT, 
81—83 Fulton Street, New York City. 


Phone Beekman 1856, 


Am. Jour, Sci , Vol. XXXI, 1911. Plate IV. 


Fig. 1. Fie. 2. 


Hie. 3. 


Fic. 1. Podokesaurus holyokensis, x 2/3. 
Fie. 2. Pelvic bones. x 3/2. 
Fie. 3. Skull bones (2). x 4/3. 


THE 


AMERICAN JOURNAL OF SCIENCE 


[FOURTH SERIES.] 
—__+++—__. 


Arr. XXXVIII.—Podokesaurus* holyokensis, a New Dino- 
saur from the Triassic of the Connecticut Valley ;+ by 
Micnon Tarzor. (With Plate IV.) 


Introduction. 


In a bowlder of Triassic sandstone which the glacier car- 
ried two or three miles, possibly, and deposited not far from 
the site of Mount Holyoke College, the writer recently found 
an excellently preserved skeleton of a small dinosaur the 
length of whose body is about 18°". The bowlder was split 
along the plane in which the fossil lies and part of the bones 
are in one half and part in the other. These bones are hollow 
and the whole framework is very light and delicate. 

As the fossil lies in the rock, most of the bones are in posi- 
tion, or nearly so, with the exception of the skull and the tail. 
A detached tail that probably belongs to this specimen lies a 
few centimeters from the rest of the skeleton and near it are 
three very thin bones that may belong to the skull (fig. 3, 
A, B, and C; Pl. IV, fig. 3). Two of these bones are bilat- 
erally symmetrical and one of them is broadly convex with 
a well-defined median suleus. They are all more or less 
embedded in the rock and cannot be described until the rock 


* From roddky¢ = swift-footed—an epithet commonly used in speaking of 
Achilles. 

+A paper giving a preliminary description of this fossil was read at the 
meeting of the Paleontological Society in Pittsburgh, in December, 1910. In 
that paper the conclusion reached was that the animal was a herbivorous 
dinosaur: but the work of developing, which is being done at Yale Uni- 
versity, has shown that the bone that was then described as the right fibula, 
displaced, cannot be a fibula. and, notwithstanding its great length, it is 
described in this paper as the pubis, in position. The bone that was 
thought then to be two bones, the pubis lying over the ischium, is probably 
the ischium with a well-developed ridge as is seen in. Compsognathus. 
There would be, therefore, no bone to call the postpubis and the form must 
be removed from the herbivorous group of dinosaurs. 


Am. Jour. Sci.—FourtH SERIES, VoL. XXXIJ, No. 186.—Juns, 1911. 
32 


M. Tathot— Podokesaurus holyokensis. 


470 


Fie. 1. 


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The other bones are better exposed and will be 


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M. Talbot—Podokesaurus holyokensis. 471 


Description. 


In the description which follows these features are to be 
noted: Light construction—hollow bones; slender, straight 
femur ; ; position of fourth trochanter ; position of fibula, lying 
close to the tibia; great length of tibia and metatarsals ; ; small 
humerus ; narrow shaft of ischium; great length of pubis; 
length of vertebrae. 

Foreimb.—The humerus (fig. 1, H.)* is a very delicately 
shaped bone, £2"™ long (not quite half the length of the femur), 
slender and well rounded, with high radial crest. The proxi- 
mal end shows a slight constr iction above the crest and below 
the bone tapers gradually to a diameter of 3™™ at the distal 
end. Measured through the crest itis 8™". There is a trace 
of the impression of the radius or ulna just beyond the distal 
end. 

In the scapular region is a broad, flat bone, lying vertically 
in the rock, but twisted on its long axis at a right angle, mid- 
way of its "length (fig. 1, S.). This bone has a length, as 
shown, of 20™™ ‘and a width of at least 3™, Lying near its 
pr oximal end is another flat bone, 8™™ long by 5™ wide. 
These may be three separate bones, more or less firmly united 
in the living animal. Further development is necessary, how- 
ever, to bring out their outlines and their relation to each 
other. 

Hindlimb.—The femur (fig. 1, R. F. and L. F.) is slender 
and nearly straight with thin walls. The bone is expanded on 
the back’ side at the distal end. The length is 86™™ and the 
diameter, just distalwards from the fourth trochanter, is 6°5'"™. 
The fourth trochanter (fig. 1, T.) is 18™" long and about 2™™ 
high and is situated just beyond the middle of the shaft, 
toward the distal end. 

Only the proximal end of the right tibia (fig. 1, R. T.) is 
exposed and there the bone is well rounded. This, however, 
may be only a small part of the proximal end, as the bone is 
embedded in the rock. The left tibia (fig. ik L. T.) is split 
lengthwise, part of the bone lying in each half of the bowlder. 
It is an almost straight, narrow shaft with the surface lying 
uppermost bent slightly at the proximal end, due, probably, to 
the expansion of the bone. In the position in which it lies, 
the bone is of nearly the same diameter throughout, about 7™™. 
Its length is 104", Lying close against ‘the tibia and of 
almost equal length is the extremely thin fibula (hoses: Unie): 

There is a small, convex bone, 4"™ by 6™™, lying where the 

*The first four text-figures have been drawn by Miss Clara Gould Mark 
of Mount Holyoke College. For the privilege of using the restorations of 


Professor Marsh I am indebted to the editor of this Journal. The photo- 
graphs were taken by Mr. Asa 8. Kinney of Mount, Holyoke College. 


472 M. Talbot—Podokesaurus holyokensis. 


right tibia and metatarsals should meet, that may be the astrag- 
alus (fig. 1, A.). It shows no sign of an ascending process. 
Two of the right metatarsals (fig. 1, Rt. Met.) lie in position. 
Their diameter is 2°5"" and 3°5™™, ‘respectively, along the shaft, 
but at the distal end there is an expansion to a diameter of 
5™". In position, at the distal end of the left tibia there is 
one metatarsal (fig. 1, L. Met.) slightly curved and 65™" long. 
Alongside are traces of a second. “One of the digits (fig. 1, D.), 
whose divisions are indistinctly shown, lies between two ribs 
not far from the right metatarsals. It is 20" long and 1:5™™ 
in diameter and is terminated by an ungual 7™™ long. Cross 
sections of two bones near this one look like unguals. < 
Pelvis.—The pelvic bones are partly covered by the right 
femur and their outline is not distinct. What is probably the 


Fic. 2 


Fic. 2. Pelvic bones. x1. 
F, Femur. Jl. lium. Js. Ischium. P. Pubis. 


pubs (fig. 1 and fig. 2, P.) is a remarkably long, thin bone, 

oo long, expanded at the distal end. The bone scems to be 
in position and makes an angle of about 40° with the line of 
the vertebral column. Its length is comparable with that of a 
new, undescribed form from northern Wirttemberg. 

The ischium (BI | fig. 2. fie cL vamd) sie 32, ‘Is.) is well 
rounded, anteriorly, aud “has a shaft 4™ wide of which a length 
of 30™™ is exposed.* The distal end is embedded in the rock. 

* The illustrations seem to indicate the presence of two bones but this 


may be due to the presence of a ridge on the ischium, as is seen in Comp- 
sognathus. 


M. Talbot—Podokesaurus holyokensis. 473 


The contact with the ilium and the acetabular edge is 
obscurely visible. 

There is a bone running posteriorly from the head of the 
right femur which may be the posterior process of the ilium 
(fig. 1 and tig. 2, I1.), the anterior process being covered by the 
femur. This posterior extension can be traced indistinetly for 
27™™ and either points upward or continues the line of the 
posterior part of the vertebral column. 

Vertebrw.—Of the vertebre there are visible seventeen pre- 
sacral (fig. 1, V.) and thirteen caudal (fig. 3, V.), all very hight 


Fie. 3. 


Fie. 3. Caudal vertebra and skull bones (?), x14. 


A, B. C. Bones of the skull (?). D, LE, F, G, V. Caudal vertebre. 


and hollow, and some, at least, slightly concave at each end. 
The presacral vertebree are slender, the measurements for the 
sixth presacral being 4™ through the middle of the centrum, 
6™™ at the ends and 15™" from.end to end. A strong, grace- 
fully curved neural spine (fig. 1, N.S.) rises from the vertebrze 
in the dorsal region, about 10™™ high and 12™™ long at the 
base. The first two or three presacrals are a little larger than 
the others and those at the anterior end of the column, much 
stronger. One of the latter measures 10"™ at the end and the 
diameter through the middle of the centrum is only a little 
less. They are not so long, however, measuring only from 12"™ 
to 13™". One of these vertebre is shown in cross section at a 
thin edge of the rock and has a transverse diameter through 


474 M. Tulbot—Podokesaurus holyokensis. 


the cavity of the centrum of 4" while the height of the cav- 
ity is 55mm (tig. 4). 

The caudal vertebre are only a little expanded at the ends and 
are very slender throughout their length. A typical one is 17"™ 
long witha diameter of 4™™ at the ends. The neural spines, if 
such they are (fig. 3, D.-G.), are of different shapes. These 
caudal vertebra are so nearly of a size, one with another, that 
there is no apparent tapering of the series and 
it is not clear which is the proximal end of 
the tail nor is it possible, as yet, to estimate 
its length. 

v2bs.—Quite a number of ribs (fig. 1, R.) 
are visible, all very slender and hollow, but 
the proximal end is not exposed save in one 
instance where the bone is so broken that the 
outline is not distinct. Near this proximal 
end, however, the bone is somewhat concave 
and expanded as if it might be bifurcate (fig. 

Hic. 2 Cross 7 RR’). he largest rib umcoveredais 925" 
section of cervical 1 Gomal orde tom ance Jopeiaeall eve 

ong and 2™" wide toward the proximal end, 


vertebra showing r F 3 
hollow construc- while in no place does the thickness seem to 


ee xe, i be more than 1™™. The most anterior of the 
trum. NV Neural cervical vertebrae preserved have long ribs. 
canal. These are on another piece of the bowlder 


and are not figured. 

Just anterior to the distal end of the pubis there is a small 
cluster of gently curved abdominal ribs (fig. 1, A. R.), exceed- 
ingly slender and dove-tailed as’ they lie in the rock, the 
position due, probably, to slipping. This mass of interlacing 
ribs covers a space of 40" by 23". There are at least eleven 
of these ribs on each side of the median line, the largest of 
which is 18" long and so small in diameter that the bone 
looks like a mere thread in the rock. Slender as are these ribs, 
they seem to be hollow. 

Sternal element (?).—In the center of this mass of abdominal 
ribs is a small body that responds to dilute hydrochlorie acid, 
as do’ all of the bones. The part exposed measures 5™™ by 
3™™. This may be one of the sternal elements displaced. 

Gastrolith.—Lying 10™™ away, and still among these ribs, is 
a small piece of quartz, a flat, well-rounded pebble, 1™" thick 
and 10°" long. The width exposed is 4™™, but more of the 
pebble is embedded in the rock. There are no other pieces of 
quartz larger than a grain of sand visible in the bowlder, and 
considering this fact, considering, also, its smooth, polished 
surface* and its position, the writer concludes that this must 


* Dinosaurian Gastroliths, G. R. Wieland, Science N. S., xxiii, pp. 819- 
821. 


M. Talbot—Podokesaurus holyokensis. 475 


be a gastrolith. This would seemingly be the first record of 
gastroliths found with carnivorous dinosaurian remains. 


Comparison with other forms. 


Herbivorous dinosaurs.—Compared with Vanosaurus agi- 
lis Marsh, the oldest known predentate dinosaur, the following 
points may be noted :* Points of similarity—The femur is 
shorter than the tibia, the ribs are very delicate, and the poste- 
rior extension of the ilium seems to have the same position. 
Points of dissimilarity—tIn this form the femur is more slen- 
der and is nearly straight, while in Vanosaurus it is distinctly 
eurved. In this form, too, the fourth trochanter is much nearer 
the distal end of the femur, the metatarsals are more slender 
and probably longer, the humerus is relatively much smaller, 
the shaft of the ischium is narrower, the pubis has a long ante- 
rior extension, and there is no postpubis. 

In Laosaurus consors Marsh,t from the Jurassic, the femur 
is much curved and is more nearly equal in length to the tibia, 
while the fourth trochanter is far up toward the proximal end ; 
the fibula is more bent, curving away from the tibia; the 
metatarsals are very much shorter; the prepubis is short and 
pointed ; and a postpubis is present. Laosauwrus has a short 
humerus as this form has but the shape is not the same. 

Hypsilophodon foxii Huxley (fig. 5), of the Wealden, Eng- 
land. Here we notice that the main points of difference are 
in the length and position of the pubis, and the presence of a 
postpubis in Hypsilophodon. In Hypsilophodon the femur is 
curved, but the fourth trochanter is situated more nearly as this 
one is, toward the distal end; the humerus is stouter and 
larger in every way with the radial crest much farther from the 
proximal end; the metatarsals are much shorter; the ribs are 
very much stronger; the neural spines are of an entirely dif- 
ferent shape. 

Carnivorous dinosaurs.—Anchisaurus colurus Marsh,t a 
very slender, long-limbed carnivore from the same Connecti- 
eut valley Triassic, with which this form seems to compare 
quite closely in general outline, shows the following differences. 
There is a decided difference in the relative lengths of the 
femur and tibia, the femur of the large form being much 
longer than the tibia. Marsh points out that the long femur 
is found in the larger animals of both carnivorous and herbivo- 
rous types, while the smaller birdlike forms of both types have 
the tibia longer than the femur.§ This small form certainly 

* Neubeschreibung des Originals von Nanosaurus agilis Marsh, F. von 
Huene and R. 8. Lull, fig. 1, p. 185. 


+ Dinosaurs of North America, O. C. Marsh, pl. Lv. 
t Ibid., pl. tv. §Ibid., p. 201. 


476 M. Talbot— Podokesaurus holyokensis. 


Fic. 5. 


Restoration of Hypsilophodon foxii Huxley, after Marsh. 
x1/8 natural size. 


Fic. 5. 


M. Talbot—Podokesaurus holyokensis. AV 


helps to confirm his observation. In Anchisaurus, the femur 
is much bent andthe fourth trochanter is high up toward the 
proximal end ; and all the limb bones are much stronger. The 
pubis of Anchisaurus is shorter, and runs at almost a right 
angle to the vertebral column; nor is it expanded at its distal 
end, as it is in this form. On the other hand, there is a general 
similarity in the size of the corresponding vertebra, though 
those of the caudal region of Anchisaurus are not quite so 
long and slender. 

Compsognathus longipes Wagner (fig. 6), from the Jurassic 
of Bavaria, corresponds quite closely with this form in length 
and general proportions of the limbs, in the shape of some of 
the neural spines, especially those just anterior to the scapu- 
lar region, and in the general shape of the ischium. The pubis 
of Compsoynathus is much shorter, proportionally, however, 
makes a larger angle with the vertebral column, and is much 
more expanded at its distal end. The shaft of the ischium 
is not so slender nor so uniform in width. 


Classification. 


No attempt at a definite placing of this fossil will be made 
in this paper, but certain conclusions reached by the foregoing 
study will be stated. The fossil is interpreted as that of a ~ 
carnivorous dinosaur because of the length, shape, and position 
of the pubis and the absence of a postpubis. Since no jaw 
has been found and there is no proof of the presence or absence 
of an ascending process from the astragalus, the determination 
of its position among the dinosaurs depends on the character 
of the pubis and the presence or absence of a postpubis. The 
position and length of the pubis are more nearly like those of 
the carnivores than those of the herbivores, and there seems to 
be no postpubis. The ischium is shaped somewhat like the 
bone in Scelidosaurus harrisont Owen, that von Huene 
describes as the ischium, with a query, however, stating that it 
may be the pubis, but not accepting that interpretation because 
he can find no obturator foramen.* 

The short, slender humerus and the long, straight hind- 
limb bones, together with the weil-developed fourth trochanter, 
are indicative of bipedalism. The length of the tibia, much 
greater than that of the femur, the extreme length of the meta- 
tarsals, over half that of the tibia, and the very light construc- 
tion of the skeleton, indicate rapid locomotion, which Lull 
uses as an indication of adaptation to climatic conditions, argu- 
ing that this animal must have been able to travel fast and 


* Ueber die Dincsaurier der Aussereuropzischen Trias, F, von Huene, p. 57. 


478 M. Talbot—Podokesaurus holyokensis. 


Fic. 6. 


Fic. 6. Restoration of Compsognathus longipes Wagner, after Marsh. 
x 1/4 natural size. ; 


M. Talbot—Podokesaurus holyokensis. 479 


far for water in a semi-arid climate. In support of this inter- 
pretation, also, may be added Barrell’s suggestion that the rock 
in which the fossil is embedded indicates deposition on a flood- 
plain in asemi-arid region. It is significant that many of these 
Connecticut valley sandstones that have dinosaur footprints 
have also raindrop impressions. 

Through the courtesy of Professor Schuchert the specimen 
has been sent to the Peabody Museum of Yale University 
for development, where further study will be given it by Pro- 
fessor Lull, to whom my thanks are due for many suggestions 
in regard to the interpretation of this fossil. 


Mount Holyoke College, April, 1911. 


480 Branner—Minerals Associated with Diamonds and 


Art. XXXIX.—The Minerals Associated with Diamonds 
and Carbonados in the State of Bahia, Brazil; by J. C. 
BRANNER. 


SEVERAL persons have already studied and written upon the 
minerals associated with diamonds in Brazil.* Most of the 
papers, however, have been based upon the concentrates found 
in washing for diamonds in the Diamantina district in the 
state of Minas Geraes. Comparatively little has been said of 
the general geology of the Brazilian diamond region, and that 
little has not always helped to clear up the questions that arise 
in connection with the origin of the diamonds. Indeed the 
geology of the diamond district of Minas Geraes is far from 
being simple, and no reconnaissance has yet been made that 
shows the general structure and relations of the rocks and 
minerals. The diamond district of Bahia is north and a little 
east of Diamantina and about 650 kilometers distant on an air 
line. 

The paper published by Damour in 1853, two by Gorceix 
published in 1884, and one by Hussak published in 1899, deal 
with the minerals found with the diamonds in Bahia, but none 
of these papers contains anything on the stratigraphy of that 
district. Indeed, up to the year 1905 practically nothing was 
known in regard to the general geology of the Bahia diamond 
region. In that year Professor Derby made a trip into the 
region for the state of Bahia, and prepared a short report to 
the government on its geology. That paper was published in 
Portuguese at Bahia, and, on account of its importance, it was 
translated into English and republished in Hconomic Geology 
(vol. I, pp. 1384-142, Dec., 1905), and again in the Smithson- 
ian Report for 1906 (pp. 215 to 221). 

The paper by Derby represents our knowledge of the 
geology and mineralogy of the diamond regions of Bahia 
up to 1907, when I visited and traveled through that region for 
some months. 

General geology of the diamond regions of Bahia.—I have 
already published brief sketches of the geology of the Cha- 
pada Diamantina of Bahia, + and only enough will be repeated 
in this place to give an idea of its broad features. 

* Boué, Bovet, Brongniart, Damour, Derby, Dufrenoy, Eschwege, Gorceix, 
Hussak, Moissan, and others. 

+The economic geology of the diamond-bearing highlands of the interior 
of the state of Bahia, Brazil. Engineering and Mining Journal, Ixxxvii, 
981, 1031. May, 1909. 


Outline of the geology of the black diamond region of Bahia, Brazil. 
Australasian Assoc. for Ady. Sci. 1908, 324-328. Brisbane, 1909. 


Carbonados in the State of Bahia, Brazil. 481 


The table following shows the order of the rocks, their 
approximate thickness, and ages, in so far as the ages are 
now known. In the adjoining state of Sergipe, Cretaceous 
fossils have been found in abundance, and some have been 
found in the vicinity of the city of Bahia, but below the Cre- 
taceous nothing has thus far been discovered that makes it 
possible to determine the ages of the beds with certainty.* 
The divisions mentioned in this paper are based solely upon 
stratigraphie and lithologic characters and physical breaks, 
and must therefore be regarded as tentative until something 
more trustworthy can be found. It should be added, however, 
that these divisions when put to the test in the field appear to 
be legitimate, and, for the most part, widespread. 


TABLE OF GEOLOGIC FORMATIONS IN THE INTERIOR OF BABTA. 


Names Thickness in meters Ages 
Ala g G as senlesmame x iepe gee tee SUE eS ie Ee Tertiary 
DELalperSerlese se eee Ss) eR is) Secs Cretaceous 
Salitverlimestomesss9- 22522 223505... 25 ace: Jura ? 
Estanciasred: beds 42-5222. 3.24 3 (0) Senter Mer seer cate Trias ? 
Lavras series (diamond bearing)700-_--.--------- Carboniferous 
Cambao quartzites __..----..-100-(possibly part of the Lavras). 
Caboclo shales (Paraguasst of 

Werby. Wess 2 Gaye Si DO Oe seep es Devonian ? 
JAcuIpS AMS a See: 100 (possibly part of the Caboclo). 
Tombador sandstones ---- ---- A Oe ae etre os Silurian ? 
Minas (or Jacobina) series ...1000......---.-.-. Cambrian ? 
Crystalline complex ..-. ------ a EMA Pre-Cambrian 

in part ? 


The Cambao quartzites and the Jacuipe flints appear to be 
local deposits that may belong to the larger divisions either 
above or below them. 

Attention is directed to the fact that the diamonds and car- 
bonados are found in the Lavras series, and to the further fact 
that the rocks of that series are everywhere of sedimentary 
origin, strongly false-bedded, and for the most part gently 
folded. The demarcation between the Lavras series and the 
rocks above and below is clear and well defined, with the pos- 
sible exception of piaces where the Cambao quartzites occur. 

Eruptives have been reported to me as occurring in the rocks 
of the Lavras series only in the region south of the Serra do 
Assurua about Fundao, and Guariba. These rocks I did not 
see personally, but they are reported by H. E. Williams, assist- 
ant of the Servicgo Geologico do Brasil, who, as my assistant, 
examined portions of the diamond regions. Mr. Williams says 

*JTt is reported that Carboniferous fossils were found in the interior of 


Pernambuco in 1910 by Dr. José Bach, but I have not been able thus far to 
get direct confirmation of the discovery. 


482 Branner—Minerals Associated with Diamonds and 


these eruptives are dikes of diabase and that they break through 
the Lavras quartzites. 

It should be noted in this connection that the principal dia- 
mond deposits extend over a wide area in the interior of Bahia, 
and that nowhere have eruptive rocks been found cutting the 
diamond-bearing sediments except at the places reported by 
Mr. Williams. 

In the erystaliine complex, however, that underlies all of the 
sedimentary beds of the interior of Bahia, there are many 
kinds of eruptive rocks. So far as observed, the eruptives in 
the crystalline series are all old; at least they have not been 
found to pass up into the sedimentary beds in which the-dia- 
monds are found, with only the exception just mentioned. 

Of the sedimentary rocks the Minas (or Jacobina) series, as 
shown in the Serra de Jacobina, has its beds generally stand- 
ing at a very high angle. Whether the position of these beds 
is due to folding or to faulting is not yet entirely clear, though 
the weight of evidence seems to be in favor of the theory of 
faulting. ‘4 

The Lavras quartzites.—Of the overlying Paleozoic beds 
the diamond-bearing Lavras series was most studied. The 
beds are usually more or less folded. The folds vary greatly: 
in some places they are so gentle as to be almost imperceptible, 
while in others they are highly distorted. In the mountains 
west of Gruna the beds are much contorted, broken, and 
faulted. Over most of the area, however, ane folds are not 
closely pressed, the dips varying from ten to forty degrees. 
This structure in connection with the sharp separation of the 
Lavras series from the underlying and overlying beds, makes 
the working out of the distribution of the diamond-bearing 
beds comparatively easy. 

The rocks of the Lavras series are nearly all pinkish quartz- 
itie sandstones and conglomerates. The pink color appears 
to be characteristic of the series everywhere except in places 
where weathering has permitted the leaching out of the color- 
ing matter. 


Analysis of the Lavras Quartzite 


Collected by J. C. Branner near Andarahy, State of Bahia. 
L. R. Lenox, analyst. 


sien (si\O))) 38 oo as ee pee SrA. SLOAN, 
Oxides of iron and alumina (Fe, 0, and Al 0 se = Aloe 
Lime (CaO) . Be ce in Do pe ee yee OG 
Magnesia (MgO) .- at A rages Smee ea Si! Sy SN trace 


99°92% 
* This Journal, xxx, 390-391, Dec. 1910. 


Carbonados in the State of Bahia, Brazil. 483 


The composition of the quartzite as shown by the analysis 
is about what might have been expected. The pink color is 
evidently due to the small percentage of iron present in a high 
state of oxidation. 

It has already been said that the beds are almost everywhere 
strongly false-bedded. It is a striking fact that the false dips 
are not variable in direction as we are accustomed to see them 
in such rocks, but they are remarkably constant. In the north- 
ern and eastern parts of the diamond district these false dips 
are almost invariably toward the north. So nearly universal 
is this rule that I venture to say that, in the region north and 
east of Morro do Chapeo, fully ninety-nine per cent of the 
false dips is toward the north. About Lengoes and south of 
there south dips are much more common. 

Occurrence of the diamonds.—Most of the diamond wash- 
ings in Bahia are in stream beds, either actual or abandoned. 
In other words, the diamonds are found chiefly in alluvial 
deposits. The position of these deposits, however, shows 
clearly that the diamonds come directly from the Lavras series. 
In a great many places the diamonds and carbonados are found 
in alluvial deposits along streams that flow over the Lavras 
beds only. Such is the case at and south of Morro do Chapeo 
and at Campinas. In some of the most productive areas the 
alluvial deposits have been long exhausted, and the miners now 
obtain the stones directly from the disintegr ating Lavras quartz- 
ites themselves. Between Lengoes and Andarahy the quartz- 
ites have been found so productive that the miners have 
removed the disintegrated rock down to where it is so hard 
that it cannot be removed with the hoes, mattocks, and almo- 
cafres used to scrape it away. 

At Ventura the diamonds and carbonados are found in grav- 
els that rest upon the Caboclo shales, but the valley is very 
narrow and the Lavras quartzites cap the hills to the north and 
west, while the stream itself rises in and flows for many kilo- 
meters over the Lavras beds, so that there seems to be no rea- 
sonable doubt that they have the same origin at Ventura as 
they do at Campinas, a few kilometers to the north, where they 
are taken directly from the disintegrated quartzites. 

Personally I have never seen a diamond or a carbonado in 
the original quartzite, but it seems to be a matter of common 
information that they have been so found. Professor Derby 
tells me that he himself has seen one such specimen. The evi- 
dence, therefore, all points to the Lavras sedimentary series as 
the immediate source of the diamonds and. carbonados in the 
state of Bahia. 

The minerals associated with the diamonds and carbonados. 
—The question naturally arises whether the diamond originated 


484. Branner—Minerals Associated with Diamonds and 


in the Lavras quartzites, or whether they originated elsewhere 
and were washed out of their original matrix and deposited 
along with the other sediments in the Lavras beds. Perhaps 
this question might be readily answered under ordinary cireum- 
stances, but in this case it is not so simple. 

It was hoped that a study of the minerals associated with 
the diamonds might settle the question definitely; and it was 
in this hope that the present examination was undertaken. 

In order to study the mineralogical association of diamonds 
and carbonados in the diamond region of Bahia, I have 
obtained thirty-five samples of the concentrates from different 
parts of the Bahia fields, and have had the minerals in them 
separated and identified. 

Some of the samples were collected by myself, but most of 
them were obtained for me through the kindness of my Bra- 
zilian friends, Dr. Alencar Lima of Bahia, Col. Dias Coelho 
of Morro do Chapeo, and of Mr. Arthur R. Turney of Lencoes. 
The samples consist of the fine heavy materials jeft in the bot- 
tom of the wooden bateas at the final “clean-up” in washing 
for diamonds at various places in the state of Bahia. The 
different minerals were separated by the use of Thoulet heavy 
solutions, and the percentages were determined by weighing 
before and after the separation. The weights are not alto- 
gether precise owing to slight losses, one of which came from 
the solubility of the gold in the solutions used. 

Notes on the mimerals.—The table shows that the minerals 
are unevenly distributed, some of them being very abundant 
in one locality and lacking at another. 

As was to have been expected, quartz is by far the most 
abundant at all localities. The quartz grains nearly all have 
secondary enlargement ; that is, the cementing material of the 
diamond-bearing quartzites is partly quartz in optical continu- 
ity with the original sand grains. 


* Samples 1 to 5, inclusive, are from Mosquitos near Lengoes, and were 
given me by Mr. Arthur R. Turney of Lengoes, Estado da Bahia. 

+Samples 6 to 14, inclusive, were obtained for me by Col. Dias Coelho of 
Morro do Chapeo. The precise localities are not stated, but it is under- 
stood that they are from washings about Morro do Chapeo, Campinas, and 
Ventura. 

+15, from Col. Dias Coelho, is marked Tres Moitas, Jacobina Nova, which 
is on the west side of the Salitre Valley about 130 kilometers west of Villa 
Nova. 

$16, from Col. Dias Coelho, is marked Rio Cambio, Jacobina Nova. The 
locality is within the Salitre drainage west of the Serra de Angico and 160 
kilometers west of Villa Nova. 

17, from Col. Dias Coelho, has no locality label. 

“| Nos. 18 to 35, inclusive, were sent me by Dr. Alencar Lima of Bahia. 
The exact localities are given in the table. The Chique-Chique mentioned 
is near Mucugé and should not be confused with a city of the same name on 
the Rio Sao Francisco. 


GOS. a Neg en een eee SOquIOg SOp oSe10g Gy 
CUT Gi | eee oe |e gee aca enbiyp-enbiypO ‘svriesueiey Fe 
EG Gled | Pin eaieect [see hte rae oe enbiyO-enbriyp ‘etieqis ¢e 
GIE| G& 8-09 | ~~ |" ~~enbryp-enbryp ‘eurp ep preg mog gg 
8 
8 


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SHHOSOHIOID 


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of ety sfi = 2 ESTP eral cl i ene | pcre [Pel | scale al eee leecher |u| hh a ee 


enbryQ-enbiyp ‘preg mog gz 
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ce 8-01 


=-|--|--|=-|--|--|--|--|--|--]----]----| x | ---|----]----]---- SBOE ial peso aller 9-18} -¢9 | ~~~ |“ onbryp-enbryp ‘oxteg op preg miog gg 
--|--|--|--|--|--]--|--|--]--|----]----|---- |----|----]----]---- |----|---+ SESS SSC Rea Borie = 00) Cal seit eae enbiyp-enbiy9 ‘vog esnoy gz 
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T 

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“eIlezesuy epuezeg ‘ouquiey ony 91S 

Fo | ese quay | ogee IJe= asses se. BAON vUIqooEr ‘sezIoyy Seay, Cyt 

|) PoRs e(R.6) |] Seno. pses=esccssaceecacs oadey) op ono FT 

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= re eee eae OO CeOG | 
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: B55 jlomacyooce Meg [ar olose=\i sess -00L -0g¢ Se: ee vinjueA pue seurduep 
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meiosis (2 |cs oe (08k 571g 16840. |= 61-0 l0¥-0 |-=-= | ¢2-0 | ---- | 08-96 | 29-c17 


a EE Relea | > |. -= 08:0 |SS-0 |" | | «6-0 6:86 | GSE-7&6 
os Scot is a8 en ane SP-0/40-0 |_| |_| 8 | |e H9 | GL-Gs 


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J 


<> &= 
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SN TS SE RS Bi) ORE RS SS OR Pee URES LOBES 


ee | 


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* 


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mcegayejeian core) 
‘oyrypoorg 


OJIZVUOT 
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Ten. 


Joule 
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m00 


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‘punog sjowamypy fo abnjuaowg—Uzvag ‘VIHVG JO DLVLG AHL NI SOGVNO@AVO GNV SGNONVI(] HLIM GALVIOOSSY SIVUGNI, 40 a1avy, 


.—FourtH Series, Vou. XX XI, No. 186.—June, 1911. 


33 


Am. Jour. Scr 


486 Branner—Minerals Associated with Diamonds and 


The corundum repor ted is of the ruby and sapphire varie- 
ties, and is of a pale gray color. 

The magnetite is sometimes found partly altered to hematite 
and the large amount of hematite and martite found with the 
diamonds is to be referred to this source. 

Metallic copper was found in several of the samples, but as 
the pieces are very small, and invariably curled up like filings, 
it is supposed that they came from the pieces of sheet copper 
often nailed in the bottom of the bateas to mend holes, and that 
these small fragments have been scratched off by the gravels 
while the washing was going on. 

Dr. Aw Rog ers gives me the following note upori the 
Savas and diamonds found in these concentrates : 

“ The phosphate ‘favas’ are rounded grains with faint greasy 
luster and pitted surfaces. The colors are quite variable, faint 
yellow, bluish gray, and dark brown. Under the microscope 
fragments are almost opaque, with a faint action on polarized 
light and have an aggregate structure. The index of refraction 
is about 1°62 and the hardness about 5. In composition the 
‘favas’ are hydrous phosphates of aluminum. They probably 
vary in composition as they do in specific gravity, some being 
a little greater than 3°3, and some a little less. 

“ Diamonds were found in two samples,—a single smoky 
cleavage in one sand, and thirty-five crystals and cleavages in 
another sample. These crystals are colorless, yellowish, green- 
ish, and pale wine-colored. The crystals are the common iso- 
metric forms, usually octahedral in habit, the faces being the 
octahedron, the dodecahedron, and the trisoctahedron, Some 
crystals are fairly sharp octahedrons with plane faces and 
grooved edges, but most of them have curved faces in oscilla- 
tory combination with each other. Several spinel twins of tri- 
angular shape were noticed. ‘The crystals vary in size from 1 
to 2"™ in diameter. One carbonado was found in this sample.” 

Four microscopic slides have been made from the diamond- 
bearing quartzites collected south of Lengoes for the purpose 
of ascertaining whether any of the minerals that are so charac- 
teristic of the metamorphic rocks oceur in them in such manner 
as to show that they originated in the quartzites themselves. 

Unfortunately the only minerals thus far found in the micro- 
scopic slides are quartz, chalcedony, and tourmaline: quartz 
forms the mass of the rock, the cementing material is partly 
quartz but largely chalcedony, while the tourmaline appears to 
have been carried in solution into small irregular cavities and 
there crystallized out. The dark greenish bands made by the 
tourmaline are quite visible to the naked eye in hand speci- 
mens. ‘This particular microscopic examination does not, there- 
fore, throw any positive light on the subject. But in view of 
the ‘scarcity of the diagnostic minerals, no other result was to 
have been expected from the examination of so few slides. 


Carbonados in the State of Bahia, Brazil. 487 


One other mineral which is not mentioned in the table is 
found in the diamond-bearing beds in Bahia. This mineral 
is a jet black, opaque, hydrocarbon having a lustrous conchoi- 
dal fracture, a hardness of 2°2, specific gravity of 1°51, and is 
related to asphaltum, but is not certainly identifiable with any 
known form. It was thought at first that this mineral might 
be especially interesting on account of its association with the 
diamonds and carbonados, but it occurs in large lumps and 
seems to have no apparent relation to them. 

Comparison of the minerals of Bahia and Minas.—In 
order to compare the minerals found in different districts I have 
brought together here the Bahia lists published by Damour, 
Goreceix, and Hussak,* and I have made up from various sources 
a list of all minerals reported from the diamond washings of 
Minas Geraes. 

In comparing the minerals from the Minas diamond wash 
ings with those at Bahia, it should be kept in mind that in 
Minas the diamords are found for the most part in river beds, 
either actual or abandoned, and that the minerals associated 
with them are the result of a long and high degree of concen- 
tration. In one instance to my own knowledge the Minas dia- 
monds were obtained from a metamorphosed rock that was 
broken up by weathering. In the Bahia region this long and 
complete concentration has occurred in some instances, but 
in others there has been practically no natural concentration 
since the minerals were set free from the quartzite matrix. 

Conclusion regarding the relations of the Bahia and Minas 
districts.—Taking the Bahia list of minerals as a whole and 
comparing it with the Minas list, we must conclude that the 
only difference between them that seems worthy of note is the 
presence of the carbonado in Bahia and its absence from Minas. 
The other differences, such as the finding of ilmenite, monazite, 
topaz, and spinel in the Bahia deposits, and the occurrence of 
tantalite, euclase, fibrolite, titanite, chrysoberyl, chromite, and 
klaprothine in the Minas gravels I regard as purely accidental, 
and lable to disappear with further search for those minerals 
in the regions from which they have not yet been reported. 
The tale and graphite in the Minas deposits may be regarded 
as purely local, as is that of asphaltum in the Bahia deposits. 

The diagnostic minerals—A study of this table at once 
shows that most of the minerals mentioned have no diagnostic 
value. Quartz, for example, may occur in rocks of any age, 
and in sedimentary, eruptive, deepseated, or metamorphic rocks, 
in pegmatites, or in ordinary veins. It cannot therefore be re- 

* Hugen Hussak.—Ein Beitrag zur Kenntnis der sogenannten ‘‘Favas” der 


brasilianischen Diamantsande. Tschermak’s Min. u. Petr. Mitteilungen, 
Xviii, 334-359, Vienna, 1899. 


488 Branner—Minerals Associated with Diamonds and 


Minerals associated with Diamonds and Carbonados in the 
States of Bahia and Minas Geraes, Brazil. 


Bahia, by Bahia, Minas Geraes, 
various by by various 
authors, Branner. authors. 

heeBery) te hea Oa HEE ae (0) 
De Brookite = 2s see Ol Due eee Oi FRET eae (0) 
8. Carbonado _-.--- On TER ed See Of ste Ree (0) 
4. Cassiterite ...-- fe) 
5. Chalcedony ---- ia de UE ee. 
6. Chioritesseoeeee 0) 
7. (Chromites sos see Pe Se A, Me ane my ce By oe Ce) 
8. Chrysobery] 2u-'50) Si Sed 3 ai eee ) 
9. Cinnebar.__..-- (0) - 
10. Columbite ....~- (0) 
11. Corundum -__.-.- OF sng sala hee ee ee ea Co) 
12. “Cy anNte eae ee Oat Sek he Say OF on, pee eee ) 
13. Diamond _____-_- Oi sete gare pee oe Ope ee ae (6) 
14. Diaspore 2... ) 
5s Huclase se] soe (6 ele So ees Rh A ae SE ot fo) 
16. “Favas” ee PIO TERE eee ek Se ORR: Wale Co) 
7 Ep rolite 2 ets oO. See aie ee BAM oe bse (6) 
1esiGarnet@e ests On : Ce Ole: BEG EUS a are 
TO. Goldeee es piss Ont, © BO ee ee ae ro) 
90. Hematite____--_- Spee s ee cee ho (Ovant te AL) Renee te) 
Ole imenitew sea OE ee ae oh at fe) 
po. Klaprothiney<.2.' \4). ii pede: teise win eee C) 
23. Limonite ._...-- COTES tet Ao ee ©. gtr eee fo) 
24, Magnetite ---- -- Onn cI ae eee Oy Aeon ete ) 
95. Manrtite ses. Ot Reet eee eee Oe eee eee fo) 
OG. Monazite s4-6,625), HOu jae ere Co) 
OH, INUOVINC ae sees oS es eee On Nato ees 
98° ‘Octahedrite. 55 00 22 ase Oi ih gee eet ae) 
29: Perovekite.--c8. 1 eee ee eee (0) 
SOME Vier =.= eee OL ee ge pare ee OF ae ce nee ) 
Sls QI aeons soe ON e as Sere see O) ae Uae ee (0) 
89. Rates See eS POT aR are oa ee eee One ne EO) 
33.) Spinel see CO Gort os ) 
34. Staurolite ___--- ORL. 2 ee ee (0) 
35) Mantalites eee O' UGE AR SES De eee ee ee (0) 
365 Hhitanitese ee ae 0} Se eee OGhS ANE to) 
37. Lopame eee re: Saud Wicesk sO ieee: Soir bile: co) 
384 Tourmahines 425 «Ou ce SO Wie ee Pe) 
39. Xenotime __-.--_- OF Gok se 5 Sa ed ee (0) 
AM), PAKEGOM 222 54 5-55 Opis coe eee OMS oo ae nO 
Minerals found in the rocks, but not generally in the concentrates. 
AT, -Asphaltnm eee aa | S22. peace 0 
AD: (Calcitesens eae MEA oe TG) 
AS) Heldspaneeaeee (0) a ce ae eee Meascrcs a: O) 
44, Graphite: 22.15.01 fap Wifie eee = SoA ere cea ) 
A5. Kao line eee OM Lee oct a fo) 
AG Mica) eee (oy ethos ee Ooo sect (0) 
Mig lesions sos O. sosscooascae O} og ans hs ee O 
48, Pyrolusite 22-22) 9) epee eee oO 


49, "Tale. 322 {oo ee oe eee 0) 


Carbonados in the State of Bahia, Brazil. 489 


garded as helpful in determining the Brazilian association of 
diamonds. x 

Omitting from the list all minerals of common or wide occur- 
rence, I have made up the following table of those which I 
regard as diagnostic in the state of Bahia, and the columns indi- 
cate their genetic rock associations : 


Table of Diagnostic Minerals associated with Diamonds 
and Carbondos in Bahia, 


Deep- 

Erup- seated Metamor- Pegma- 

tives granites phies tites 
Beye. tee ake 8 = ii x x 
IByRoOi® 25252552252 x x He ee 
Calssiterite: s2s. 20225” Ss Se re x 
Columbite..__....-.-- a re te x 
Corundum -_-_-_--_- ae ings Ks Ke os 
Cyanitersno sm ses a = x ae 
Diaspoves 2 22 s22- 2 - fh x ah 
WIOMEVATIO= 2. os oes aia Ke x od 
Octahedrite 25 22522 ie we x E 
Shiaimurolitk <2 2 55 ee ae - x? x ais 
Mambahiteers Ge owas ah oe ae x 
iganniterte ke 2 oi eo. a! x xX ep 
Nenotime:s sss 52 uae = Lae x we x 
ANE COME Mees ee ee a x x ae 


This table brings out the fact that the genetic relations of 
these minerals are plainly with deep-seated granites, metamor- 
phics, and pegmatites rather than with eruptives. 

In view of the widespread occurrence of diamonds in the 
Lavras quartzites in Bahia, and in view of the absence of 
eruptives from the vicinity of the diamond washings, one of 
the following conclusions seems to be warranted : 

First, either the Bahia diamonds or carbonados originated in 
the old granites and metamorphies that underlie the Paleozoic 
beds in Bahia and have passed down mechanically to their 
present position, or 

Second, they are one of the results of metamorphism of the 
quartzites themselves and have originated where we now find 
them. : 

Possible origin of the diagnostic minerals.—If the diamonds 
and their associated diagnostic minerals were derived from 
older metamorphic or eruptive rocks, where did they come 
from? Kast, west, and south of the diamond regions of Bahia 
are extensive areas of the crystalline rocks:mentioned at the 
beginning of this article, consisting of old, probably Archean, 
granites, gneisses, schists, and eruptives of many kinds, and 
similar to those upon which subsequent deposits have been laid 
down. If, therefore, such a source is assumed for the diamonds 


490 Branner—Diamonds and Carbonados, Brazil. 


and their associated minerals, there is no great geographic 
dithculty in accounting for them. 

But if they originated i in the ancient rocks and passed down 
with their associates through ages to the Lavras series, the 
hardness of the minerals must have been a factor of eonsider- 
able importance in their history. 

The associated diagnostic minerals, including the diamonds, 
are arranged with reference to hardness § in the following tables: : 


Table showing the Hardness of the Minerals associated 
with Diamonds in Bahia. 


Minerals ‘ Hardness 
1: Diamonds carbonados).: 44-225 acess: eae ele 
2° \Corm dina se ee Ae eee ae re 9 
34 ‘Beryl spinel)... 2) ied ee ene eee 8 
46  ZATCOMe 2. ee eee ee pee ee 75 
5. Cyanite, staurolite, cassiterite, diaspore be omen 7 
65 Mamntaliters. << <2) ea} eee re eee cu 6°5 
lee Broolstexscolumibitee sae a eee 6 
8. Monazite, octahedrite, titanite, “favas”_. ..-- 5'5 
Di, DRETIOTUENGHS Sel CANE MAE Nic isl eis ia ly att 5 


The hardness of the diamond (and carbonado) is a strong 
point in favor of the theory of the possibility of its having 
been passed down through several geologic ages, but the 
chances of the survival of a mineral having a hardness below 
6: seems rather small though not at all impossible. The value 
of this evidence, therefore, seems to be doubtful. 

Conclusion.—It is fully realized that the results of this 
study are mostly negative. There is no evidence, however, 
that the Brazilian diamonds are of eruptive origin. And they 
certainly were not brought into their present position in the 
Lavras quartzites by eruptive action of any kind. 

I am strongly inclined to believe that the diamonds of Bahia 
have their origin in the quartzites where they have been occa- 
sionally found in place, and that they are associated with min- 
erals characteristic of metamorphic rocks for the reason that 
those minerals also originated in the quartzites under the 
same conditions as the diamonds themselves.* 

*The occurrence of diamonds in place in South Africa and in Arkansas, 
and associated in both instances with peridotites, appears to have thrown 
the burden of proof upon any geologist who ventured to suggest any other 
than an igneous origin for diamonds in other parts of the world. But even 
this stronghold of the believers in the igneous origin of diamonds is seriously 
shaken by two important facts:— 

First, that diamonds are found in only a small percentage of the South 
African eruptive pipes. 

Second, that diamonds have been found in the garnets of the eclogites 
brought up into the diamond-bearing pipes by the eruptives. So that after 
all, a metamorphic rather than an eruptive origin of even the South African 
diamonds seems to be a possibility, if not a probability. 

[A. L. du Toit.—The diamond-bearing blue-ground and allied rocks of 
South Africa, Trans. Edin. Geol. Soc., 1x, 361-362, Edinburgh. | 


Berry—Engelhardtia from the American Eocene. 491 


Art. XL.—An Engelhardtia from the American Kocene ; 
by Epwarp W. Bzrry. 


Tue walnut family (Juglandacez), which in the popular 
mind is fully rounded out by the enumeration of the walnut, 
butternut, hickory and pignut, consists of six or seven genera 
and about forty species scattered throughout the warmer parts 
of the north temperate zone and penetrating some distance 
south of the equator along the Andes in South America and 
in the East Indies. The Juglandacez are of considerable 
interest for a variety of reasons, chief among which, aside from 
their great economic importance, are their line of ancestors 
reaching back to the mid-Oretaceous, and because of the much 
discussed question as to whether their morphological characters 
shall be interpreted as primitive or as mere simplifications of 
a more highly organized stock. 

All of the genera have not adopted the same methods of 
dissemination and certain tropical and sub-tropical genera 
have kept the seed part of their fruits comparatively small and 
light, thus enabling them to produce large nnmbers of seeds 
with the same expenditure of energy required for a single wal- 
nut. Furthermore, instead of depending upon chance for the 
distribution of their latent progeny, the bracts which are nor- 
mally present throughout the family have developed enor- 
mously and serve as wings. ‘This is especially true of the genus 
Engelhardtia, a recent addition to which is the occasion for the 
present brief note. 

The genus Engelhardtia was described by Leschen in 1825 
and contains about ten species of the southeastern Asiatic region. 
These range from the northwestern Himalayas through farther 
India and Burma to Java and the Philippines. The pistillate 
flowers are small and are grouped in paniculate spikes. They 
develop into small drupe-like fruits, each of which is connate 
at the base to a large expanded tri- alate inyoluere. 

A single little known species rarely represented in even the 
larger herbaria occurs in Central America and is the type and 
only species of the genus Oreomunnea of Oersted. This is 
much more restricted in its range than are its kin beyond the 
Pacific. Oreomunnea is very close to Engelhardtia, and for 
the purposes of the paleobotanist the two may be considered 
as identical since they represent the but slightly modified de- 
scendants of a common ancestry which was of cosmopolitan 
distribution during the early Tertiary. The present isolation 
of Oreomunnea furnishes a striking illustration of the enor- 
mous changes which have taken place i in the flora of the world 


492 Berry—Engelhardtia from the American Eocene. 


in the relatively short time, geologically speaking, which has 
elapsed since the close of the Cretaceous. 

The principle has frequently been enunciated that when 
closely related forms are found in the existing flora of the 
world, restricted in range and isolated from their nearest 
relatives, or when the existing genera are monotypic, it is quite 
safe to predict an interesting “and extended geological history. 
Engelhardtia proves to be another illustration of this princi- 
ple, for its peculiar three-winged fruits have been known in the 
fossil state for almost a century. They were long unrecog- 
nized, however, and the earlier students who described them 
compared them with the somewhat similar winged fruits of the 
genus Carpinus (Betulaceze). With the botanical exploration 
of distant lands in the early part of the 19th century, specimens 
of Engelhardtia began to be represented in the larger European 
herbaria, and Baron Ettingshausen,* that most sagacious of 
paleobotanists, as long ago as 1851 pointed out that certain 
supposed species of Carpinus were really fruits of Engelhard- 
tia. He returned to the subject in 1858+ without, however, 
actually changing the names of any of the supposed species of 
Carpinus nor does he seem to have been aware of the existence 
of a living species of Engelhardtia in Central America. 

Since Ettingshausen’s announcement a dozen or more fossil 
species have been described. The oldest known occurs in the 
upper Eocene or lower Oligocene (Ligurien) of France and the 
species become increasingly abundant throughout southern 
Europe especially toward the close of the Oligocene and the 
dawn of the Miocene, Saporta stating that the “slabs from the 
leaf-beds at Armissan in southeastern France are thickly strewn 
with their peculiar fruits. Fossil forms continue in Europe 
throughout the Miocene and Pliocene and specimens of late 
Miocene or early Pliocene age are recorded from Spain, France, 
Italy, Croatia and Hungary. 

The accompanying sketch map of the world (fig. 1) shows 
the existing distribution of Engelhardtia and Oreomunnea some- 
what generalized and exaggerated in order to be seen on so 
small a scale map. The Tertiary occurrences of Engelhardtia 
are indicated by stars, a single star covering all of the records 
in a single area, as for example, southeastern France, from 
which one Liourien, three Tongrien, five Aquitanien and one 
Pontien occurrences have been recorded. No fossil American 
species have been previously known with any degree of cer- 
tainty. Lesquereuxt in 1883 recorded Engelhardtia oxyptera 

* Ettingshausen, Die Tert. Fl. von Wien, Abhandl. k.k. geol. Reichsan- 
stalt, Wien, xi (8), p. 2, 1851. 

+ Ettingshausen, Beiter. z. Kennt. foss. Fl. von Sotzka, Sitzungsb. k. Akad. 
Wiss. Wien, xxviii, 1858, p. 12, pl. iv, fig. 4; pl. v, figs. 1-3. 
ie ee Cret. and Tert. FL, U.S. Geol. Surv, Terr., vol, viii, p. 192, 


Berry—Engelhardtia from the American Eocene. 493 


Saporta* from the Miocene of Florissant, Colorado. I have been 
unable to get track of this specimen and as no specimens of 
Engelhardtia have been detected in Professor Cockerell’s 
recent and extensive collections from this locality and as 
Carpinus is not at all uncommon, it seems probable that Les- 
quereux’s determination was based upon material of the lat- 
ter genus, particularly as the Florissant yen beds are consider- 
ably younger than the type locality for Hngelhardtia oxyptera, 


Fie. 1. 


0 reomunnea wth i 


Fic. 1. Sketch map showing the existing geographical distribution of 
Engelhardtia (vertical lining) and fossil occurrences (stars). 


which was Armissan, France. In any event the Florissant 
material differs markedly from the present species from Missis- 
sippi, having a different venation and being only half the size 
of the latter. 

With these introductory remarks we may proceed to the de- 
scription of an unmistakable species of Engelhardtia recently 
recognized from the Eocene deposits of northern Mississippi. 
The single specimen of the fruit shown in the accompanying 
text figure was collected in 1889 by W. J. McGee while 
engaged in his studies of the so-called Lafayette formation and 
has lain unstudied in the collections of the U. 8S. National 
Museum since that date. 


*Saporta, Etudes sur la Végét. du sud-est de la France & l’époque Ter- 
tiaire, xi, p. 344, pl. xii, fig. 2, 1866. 


494. Berry—Engelhardtia from the American Hocene. 


The writer has collected leaves of Engelhardtia in these 
deposits, but since their exact relationship with the fruit is 
unsettled they will not be considered at the present time. The 
species, which is new, may be called 


Engelhardtia (Oreomunnea) mississippiensis sp. nov. 


Description.—Involuere large, trilobate, somewhat reflexed. 
Ale widely spreading, the angle between the median and 


Fia. 2. 


n 
wry 
' 
' 
' 
' 
’ 
' 
' 
‘ 
o 


im - Ss Bh 5 } 
SSS Ss, ~> p 4 
8 SSE Yai 


oy =a or oa 
LS. fee eA a 
LEONA 


MOTT OY aril, 4, 
ey Aes. \ 
a 


UX 


ay 
aos 
« 


NY 
Ss) 
SS | 
YA Y 


Mee 
Rann 
A 
z 
os 


Fic. 2. Engelhardtia (Oreomunnea) mississippiensis, sp. nov. from the 
Eocene of Mississippi (nat. size). 
lateral wings being 70° to 80°. Sinuses correspondingly open, 
rather straight-sided, rounded at the angle, which is 1:5" from 
the extreme base of the specimen. The median wing is the 
longest of the three and is equilateral, spatulate or oblanceo- 
late in outline, expanding gradually distad from a basal width 
of 8™™ to a width of 18™", where the distal portion is broken 
off, 5°" above the base. Since this apical part is missing the 
total length is estimated at 6°5°", which is a minimum rather 
than amaximum estimate. Lateral wings slightly inequilateral, 
the outer part of the lamina being a trifle wider than the inner. 
Apex rounded. Length 5°". Greatest width, which is above 
the middle, 11™™. Least width proximad, 7™™. Primaries 
three in number, one median primary being present in each 
wing. The primaries are relatively very stout and continue 
with but slight attenuation to the tips of the wings. No sub- 
ordinate primaries or discordantly directed secondaries are 
present as in some of the European Tertiary species. 


Berry—LEngelhardtia from the American Eocene. 495 


Secondaries numerous, thin, more or less parallel, about twelve 
to fifteen pairs to each wing, alternate. The secondaries branch 
from the midvein at a wide angle which becomes progressively 
less distad, where they are placed at more frequent intervals 
and are more regularly curved, camptodrome throughout. Ter- 
tiaries extremely fine, forming small arches just inside the 
margin and more or less rectangular meshes within the spaces 
bounded by the secondaries. 

Margins strictly entire throughout. The essential portion 
of the fruit is poorly preserved and partially broken away, as 
is usually the case in the fossil species of this genus. It 
appears to have been of considerable consistency, and the 
whole fruit having fallen face downward the reflexed wings 
raised the peduncular portion, which either rotted away before 
fossilization or, what is more probable, was broken off when 
the specimen was collected. 

‘Among previously described Tertiary forms the present 
species is most similar to Engelhardtia Brongniurti Saporta, 
a species recorded from Spain, France, Italy, Germany, and 
Austria-Hungary and supposed to range from the Oligocene 
to the Pliocene. The American species is somewhat larger 
than the usual size of Hngelhardiia Brongniarti, although 
Unger has figured forms of the latter which do not differ much 
in size from Sotzka in Styria. The wings are more spreading 
and the outlines are much more elegant. In the European 
form the wings are rounded apically as in the American species 
but they are approximately the same width throughout and do 
not taper downward as they do in Engelhardtia mississippi- 
ensis. The secondaries, instead of being regular and camptdo- 
drome as in the latter, are less numerous and more irregular 
in position, several in each wing ascending from the base for 
considerable distances approximately parallel with the midvein. 

Among the existing species with which it has been compared 
Engelhardtia Mmississippiensis is very similar to most of the 
described oriental forms, perhaps resembling Hngelhardtia 
spicata Blume more closely than the others. The latter ranges 
from the northwestern Himalayan region through Burma to 
Java and other East Indian islands. Comparative material of 
Oreomunnea is very scarce. A single fruit in the National 
Herbarium is closer to the fossil than are any of the Asiatic 
species, but in the absence of more material the limits of vari- 
ation in Oreomunnea are unknown. 

In a general way Engelhardtia fruits are not unlike those of 
Carpinus, as has already been mentioned. There seems to be 
little occasion for confusion, however, even in poorly pre- 
served fossil material. The fruit proper is decidedly dif- 
ferent, although this is seldom well enough preserved in 


496 Berry—Engelhardtia from the American Eocene. 


fossils to be decisive. The involuere is also markedly differ- 
ent in the two genera. Carpinus involucres are usually 
smaller with the median wing much wider and longer than the 
lateral wings and with somewhat different venation. 

The margins are also toothed while in Engelhardtia they are 
always entire. Ihave examined fruits of all of the existing 
species of Carpinus and experience no difficulty in readily dis- 
tinguishing them from those of Engelhardtia, the American 
species of the former being especially different in appearance 
from those of Engelhardtia. I have seen involucres of the old 
world Carpinus betulus from trees cultivated in this country 
in which the wings had entire or nearly entire margins, 
but the aspect of the specimens as a whole, because of 
their different proportions and venation, was markedly unlike 
Engelhardtia, and if they had been found as fossils no com- 
petent paleobotanist would have been at a loss regarding their 
botanical attinity for a single instant. 

Engelhardtia mississippiensis was collected from a locality 
about one mile southeast of Early Grove in northeastern 
Marshall County, Mississippi, a few miles from the Tennessee 
border. The age of the beds is Wilcox Eocene, as indicated 
by the large flora associated with the present species. 


Johns Hopkins University, Baltimore. 


Gooch and Kuzirian— Use of Sodium Paratungstate. 497 


Arr. XLIL—The Use of Sodiwm Paratungstate in the Deter- 
mination of Carbon Dioxide in Carbonates and Nitrogen 
Pentowide in Nitrates by Loss on Ignition ; by F. A. Goocr 
and S. B. Kuzrrran. 


[Contributions from the Kent Chemical Laboratory of Yale Univ.—cexx. | 


From certain carbonates, like those of magnesium, zine and 
cadmium, carbon dioxide may be expelled by simple ignition 
at a moderate temperature, leaving an oxide in definite and 
weighable condition. In the case of calcium carbonate, this 
process of decomposition is completed only at the high heat 
of the blast lamp, and the reaction, being easily reversible in 
the atmosphere containing carbon dioxide evolved in the igni- 
tion or produced in the source of heat, may leave the oxide not 
quite pure. Strontium carbonate and barium carbonate are 
not entirely broken up by simple ignition under the conditions 
ordinarily available in analysis; nor are the alkali carbonates. 
For the decomposition of refractory carbonates it is customary 
to make use of a suitable flux which, by combining with the 
oxide, will aid in the expulsion of the carbon dioxide. Anhy- 
drous borax,* silicon dioxide,t potassium dichromate,t and 
recently, sodium metaphosphate§ have been thus used in the 
analysis of carbonates, and they are applicable similarly to the 
determination of nitrogen pentoxide in nitrates which leave 
definite oxides on ignition. Such fluxes, moreover, serve the 
very essential end of conserving the residual oxides in definite 
and stable form for weighing under the ordinary atmospheric 
condition of the balance room. Of those mentioned the first 
two, borax and silicon dioxide, require prolonged ignition to 
bring them to constant weight before making use of them to 
react with the carbonate or nitrate ; and generally they yield in 
the fusion process a pasty magma, so that prolonged heat at a 
high temperature is necessary to the complete expulsion of the 
gaseous product. Sodium metaphosphate, though more fluid 
in fusion, also demands prolonged care in the preparation. 
Potassium dichromate is too easily decomposed with loss of 
oxygen to be employed in exact processes demanding long con- 
tinued fusion or heating to temperatures much above its fusing 
point. 

These are points which have been sufficiently emphasized in 
the work to which reference has been made. 

* Fresenius : Zeitschr. anal. Chem., i, 181. 

+ Rose: Ann. Phys., exvi, 635. Fresenius: Zeitschr. anal. Chem., i, 184. 
Richards and Archibald, Proc. Am. Acad., xxxviii, 443. 

t¢ Rose: Ann. Phys., exvi, 131. Fresenius : Zeitschr. anal. Chem., i, 188. 


§ Lutz and Tschischikof: Chem. Zentralblatt, 1905, i, 564. Bdttger: 
Zeitschr. anal Chem., xlix, 487. 


498 Gooch and Kuzirian— Use of Sodium Paratungstate. 


In sodium paratungstate of composition corresponding 
approximately to the formule 5Na,0.12WO,, or Na,,W,,O,, 
we have material very easily prepared, stable in fusion, and 
well suited for use as a flux in the rapid determination of the 
loss of carbonates and nitrates on ignition. For the following 
experiments the sodium paratungstate was prepared by dehy- 
drating and fusing over the blast-lamp a known weight of 
normal sodium tungstate, Na,WO,.2H,O, adding an equal 
weight of tungsten trioxide, WO, (previously ignited with care 
to remove all ammonia and to insure complete oxidation), and 
heating to clear fusion. The cooled mass, which is very easily 
pulverized, was ground in a mortar and bottled. From this 
material kept in a desiccator over sulphuric acid (though not 
more than ordinarily hygroscopic), portions were weighed for 
the analytical determinations. Approximately half the weight 
of the paratungstate is tungsten trioxide (molecular weight 
232) and this should be capable of expelling carbon dioxide 
(molecular weight 44) to the amount of one-fifth its own 
weight, and of nitrogen pentoxide (molecular weight 108-02) 
to an amount one-half its own weight. The weights of 
paratunestate used were, therefore, always in excess of ten 
times the weight of carbon dioxide and four times the weight 
of nitrogen pentoxide to be expelled. In the following deter- 
minations it was the practice to weigh a platinum crucible, 
introduce the dried carbonate and weigh again, add a suita- 
ble amount of the prepared sodiuin paratungstate, stir carefully 
with a platinum wire with care to avoid mechanical loss, and 
weigh again. The crucible was heated over a bunsen burner, 
first at very low heat and then to fusion of the mixture for five 
minutes, cooled in a desiccator over sulphuric acid, weighed, 
and re-ignited to test the constancy of weight. ‘The constant 
weight was usually got in the first ignition. In Table I are 
given the results of the estimation of carbon dioxide in calcite. 


TasreE I. 
Analysis of Calcium Carbonate ( Calcite). 
CaCO; NasoWi201. Loss on Theory 
taken taken ignition for COz Error 
grim. erm. grm. erm. grm. 

0°5000 2°5 0°2195 0°2198 —0:0003 , 
075000 2°5 0°2206 0°2198 —0°0008 
0°5000 2°5 0°2200 0°2198 —0°0002 
05000 2°5 0°2203 0°2198 —0°0005 
0°5000 275 0°2200 0°2198 —0°0002 
0°5000 2°5 0°2204 0°2198 — 00006 
0°5000 2°5 0°2190 0°2198 —0'0002 
0°5000 2°5 0°2200 0°2198 —0'0002 


Gooch and Kuzirian— Use of Sodium Paratungstate. 499 


The strontium carbonate used in the experiments given 
below was prepared with great care. Strontium chloride, 
C. P., was partially precipitated by strong hydrochloric acid, 
washed with hydrochloric acid, dissolved in water and added 
in dilute solution drop by drop from a stoppered funnel to a 
saturated solution of ammonium carbonate heated to the point 
of decomposition. The precipitated carbonate was carefully 
washed, dried, washed again with ammonium carbonate and 
then with boiling water, and dried below red heat. In Table 
II are the results obtained with this preparation of strontium 
carbonate. 


Tasxe II. 


Analysis of Specially Precipitated Strontium Carbonate. 
NayoW12041 


SrCO3 taken Loss on Theory for 
taken (approx. ) ignition CO, Error 
grm., grm. grm. grm. grm. 
0°5000 2°5 01488 0'1490 —0°0002 
0°5000 2°5 0°1494 0°1490 + 0:0004 
0°5000 2°5 0°1494 0°1490 + 0°0004 
0°5000 2°5 0°1490 0°1490 00000 
0°5000 2°5 0°1496 0°1490 +0:0006 
0°5000 2°5 0°1486 0°1490 —0:0004 


With barium carbonate prepared from the chloride by par- 
tial precipitation with strong hydrochloric acid, solution of 
the precipitated chloride in water, gradual addition of the 
solution with constant stirring to a hot solution of ammonium 
carbonate, careful washing, and drying, the following results 
were obtained : 


Taste III. 


Analysis of Specially Precipitated Barium Carbonates. 
NayoW12041 


BaCOs taken Loss on Theory for 
taken (approx. ) ignition CO, Error 
erm, grm. grm. grm. grm. 
0°5000 2°5 01120 O°1115 + 0°0005 
0°5000 2°5 0°1125 071115 + 0°0010 
0°5000 2°5 0°1109 O'1ll15 — 00004 
0°5000 2'5 O°1113 O'1l1l15 —0°0002 
075000 2°5 0°1123 0-1115 — 00008 


The similar use of sodium paratungstate for the determina- 
tion of the nitrogen pentoxide in nitrates is shown in the 
following table : 


500 Gooch and Kuzirian— Use of Sodium Paratungstate. 


Tasie IV. 

Analysis of C. P. Nitrates of Commerce, after Drying. 

Nitrate NajoWi2041 Loss on Theory for 

taken taken ignition N20; Error 

grm. grm. grm, grm. ent, 
KNO, 

0°5000 1.5 0°2668 0°2670 — 00002 

075000 15 0°2678 0°2670 + 0°0008 

0°5000 1:5 0'2674 0°2670 +0°0004 

0°5000 15 0°2672 0°2670 +0°0002 

0'5000 15 0°2675 0°2670 +0°0005 
Sr(NO,), 

0:5000 2 0°2544 0:2543 +0:0001 

0°5000 3 0°2546 0°2543 +0°0003 
Ba(NO,), 

0°5000 3 0°2073 0°2067 + 0:0006 

0°5000 3 0°2076 0°2067 +0°'0009 


From the results of the experiments described above it is 
obvious that sodium paratungstate, easily prepared and stable, 
makes an excellent flux for use in the rapid determination of 
carbon dioxide and of nitrogen pentoxide by loss on ignition. 


Johnston and Adams—Melting Points of Metals. 501 


Arr. XLI1.—The Influence of Pressure on the Melting 
Points of Certain Metals; by Joan Jonnston and L. H. 
ADAMS. 


Tue authors have been engaged in developing methods and 
apparatus by means of which it will be possible to investigate the 
effect of high temperatures and pressures on certain systems and 
reactions, and especially those in which water plays an impor- 
tant part. The work has progressed until now we are able to 
introduce into the bomb current leads and thermoelement 
wires in such a manner that the wires are all thoroughly insu- 
lated electrically, and the joint remains absolutely pressure 
tight. Thus, it is possible to heat a substance to somewhat 
over 400°,* under pressures up to 2000 atmospheres ;+ and to 
measure both temperature and pressure with precision. More- 
over, the whole system, by reason of the special methods of 
construction adopted, is absolutely free from pressure leaks, 
even when the bomb is repeatedly closed and opened, discon- 
nected from, and reconnected with, the remainder of the high 
pressure system. or instance, on one occasion heating was 
continued for 30 hours continuously at a pressure of 1800 
atmospheres, without sensible loss of pressure in the whole 
interval. 

Before proceeding further in the main purpose of the work, 
it seemed desirable to make a rigorous test of the precision of 
temperature measurements under these conditions. For this 
purpose, determinations of metal melting points are suitable 
by reason of their definiteness. Accordingly it was resolved 
to investigate the effect of pressure upon the melting point of 
tin, bismuth, lead and cadmium, the four metals which lie 
within our present range of temperature. The results are 
eminently satisfactory, for, as we shall see, a precision in the 
temperature measurements of about 0:02° was reached, using 
a thermocouple of copper-constantan, for which an electro- 
motive force of one microvolt corresponds to about 002°. It 
may here be said that the results of this investigation are in 
entire accord with what was to be expected from the magnitude 
and direction of the heat change and volume change which 
accompany the process of melting; and that the small discrep- 
ancies between the observed and the calculated values are to be 
ascribed mainly or entirely to uncertainty in the experimental 
determinations of the latent heat of fusion and of the change 
of density on melting. 

* The highest temperature the oil will stand without serious charring. 

+ The limit of the present compression pump. 

Am. JouR. Se —Fourti Srerizs. Vou. XXXI, No. 186.—Junz, 1911. 


502 Johnston and Adams —Influence of Pressure on the 


Briefly, the method pursued in this investigation is as fol- 
lows: A charge of the metal to be investigated was placed in 
a suitable apparatus for heating it under pressure ; its freezing 
point or melting point was then determined, at constant 
pressure, using the Frankenheim method. A small electric 
resistance furnace supplied the heat; a thermocouple was used 
to measure the temperature of the metal; and a high boiling 
paraflin oil served to transmit the pressure. 


Description of the Apparatus. 


The essential parts of the apparatus are: the bomb, in which 
the substance to be heated under pressure is placed; the ptunp, 
with which to supply the pressure; and a gage for measuring 
it. In fig. 1 is shown the arrangement of these parts, together 
with the accessory apparatus consisting of valves, pressure- 
line connections, oil-reservoir, thermocouple, heating current 
wires, ete. In this diagram the bomb is drawn to seale but the 
remainder of the apparatus only approximately so. The bomb 
itself (the interior of which is shown in greater detail in fig. 3 
was built up of a cylinder of machine steel AX, on to which 
were shrunk a ring of nickel steel 47 and a number of thin- 
ner rings of boiler-plate separated from one another by a space 
of about4™™. Water enters at W,, circulates between the rings 
and around the central cylinder AX, and leaves at W,.* The 
bomb is closed by means of two hardened steel plugs, G and 
H, held in place by a 500 ton hydraulic press, the platens 
of which are shown at PP. On the shoulder (LZ, fig. 3), 
of either plug is turned a V-shaped ridge, and on the adjacent 
shoulder of the bomb a groove to correspond. Between the 
groove and ridge lies a ring or “ washer” of thick sheet cop- 
per; by maintaining with the press a force of about 20 tons in 
excess of that exerted on the inside surface of the plug by the 
internal pressure, the bomb is effectively and easily closed. 
Opening the bomb again—after it has been removed from the 
press—is effected with the aid of a large nut which fits the 
heavy screw thread cut on G. 

Experience has shown that without some device for center- 
ing the bomb and plugs with respect to the press platens, 
good and certain closure of the bomb is not possible, time 
atter time. The arrangement used for this purpose is worthy 
of mention; it is very simple and consists merely of the curved 
surfaces of A and G on the one end, and of A and #& on the 
other. By this arrangement practically perfect alignment is 

*This water-cooling device leaves nothing to be desired as regards effi- 
ciency, but is somewhat difficult to construct and to make water-tight. It is 


not of our own design. the bomb having been reconstructed from one which 
had been designed and built by Dr. A. Ludwig, 


Melting Points of Certain Metals. 503 


secured automatically, and a pressure-tight closure of the bomb 
thereby insured. 


Fie, 1. 


YZZZZZZLILE 
ZZZAUN 


4 
N 


PZZZZZZ2Z11k 
b WZZZZZZZZZ2 


Qay WY 
Yi 


Fie. 1. General arrangement of apparatus. The bomb is drawn to scale ; 
the rest of the apparatus only approximately so. Pressure is supplied by 
the pump D, and transmitted through the system by means of a paraffin oil 
which has at the same time a high boiling point and low viscosity. Fisa 
steel bottle of about one liter capacity; it serves to increase the volume of 
the system. The valve V (shown in detail in fig. 2), is used to lower the 
pressure in the system. MM is a Bourdon gage graduated to 3000 atm. in 
divisions of 50. The connection block CO affords a 4-way connection 
between pump, valve, gage, and bomb. The latter consists essentially of a 
ring of nickel-steel RR, and a number of rings of boiler plate shrunk on to 
a cylinder of steel KK. On the outside of the rings is shrunk a thin cylin- 
der. The cooling water enters at Wi and leaves at W2. The bomb is closed 
by means of the steel plugs G and H, which are held in place by a hydraulic 
press the platens of which are shown at PP. The curved surfaces of A and 
B on one end and of A and G on the other constitute the essential parts of 
the device used for securing alignment of bomb and plugs. JJ is the 
electric furnace (for details see fig. 3), and SS soapstone blocks for thermal 
insulation at the ends. Thermocouple wires are shown at TT, and heating 
current ‘wires at Z. 


504 Johnston and Adams—Influence of Pressure on the 


The electric furnace, depicted at //, and the arrangement 
of the interior of the bomb, will be described later on. 

The pressure in the system may be raised by means of the 
pump JP (fig. 1). It has a plunger 8™™ in diameter, and is of 
the type or rdinarily used with hydraulic presses. With this 
pump we have obtained without difficulty pressures up to 2000 
atmospheres. It communicates through the pipe O with the 
oil-supply tank (not shown in the diagram) and forces oil out 
through the steel bottle #’ and the connection block C into the 
bomb. The bottle F’, which has a capacity of about one liter, 
serves to increase the volume of the system, which otherwise 
would be less than 100°, and thus makes for greater constancy 
of pressure during heating and cooling and during changes 
such as occur when the material under - investigation melts or 
solidifies. 

The connection block C affords a 4-way connection between 
the pump, the bomb, the gage, and the release valve V. The 

gage M, of the Bourdon type, is a new one manufactured by 
Scheeffer and Budenberg, and was calibrated by them. It is 8 
in. in diameter and is graduated up to 8000 atmospheres in 
divisions of 50. The indications of Bourdon gages, as is well 
known, are subject to a hysteresis effect; that is, the reading 
corresponding to a certain pressure may vary slightly, depend- 
ing on whether the pressure is rising or fallmg. From various 
considerations, however, the writers are led to believe that the 
discrepancy in the present instance is small and that the readings 
of the gage are subject to a probable error no greater than + 5 
atmospheres,—an accuracy quite sufficient for the present 
purpose.* 

The valve V serves to lower the pressure in the system or 
to release it entirely; it is shown in greater detail in fig. 2, 
which is drawn exactly to scale. The valve-stem, which 
ends in a cone fitting into a conical depression in the valve 
block, is kept in place by the nut m. The packing consists of 
three layers of leather surmounted by a steel disk. The pitch 
of the screw between stem and nut is identical with that 
between nut and block; by this means the valve is not jammed 
down into its seat, when the nut m is tightened. 

Fig. 2 serves also to illustrate the type of high pressure 
connection which has proved uniformly satisfactory for mak- 
ing all the connections necessary in work, such as the present, 
where high pressures are employed. On account of its sim- 

* We have under construction an absolute gage, of the piston type 
described by P. W. Bridgman (Proc. Am. Acad., xliv, 119-251, 1909), by 
means of which we shall be able to measure pressures with an accuracy of 0°1 
per cent. In the present work its use was unnecessary by reason of the 


comparatively small influence of pressure on the melting points which we 
have investigated. 


Melting Points of Certain Metals. 505 


plicity of construction and certainty of operation, it seems 
desirable to describe it more fully. 

The end of the pipe p is turned off at an angle of 60°; a 
small round nut is put on, using a left-handed thread, and the 
whole is held in place by means of the larger nut », which is 
undercut to receive the smaller nut. The end of the pipe fits 
into a conical hole also turned accurately at an angle of 60°. 
An essential part of the procedure is that before the joint is 


Rie. 2. 


Fic. 2. Details of high pressure valve and connections, drawn to scale. 
The main body of the valve is of best quality nickel steel. The conical 
lower end of the valve spindle s fits into a conical depression. The leather 
packing around the spindle is held down by the nut m. On either side of 
valve is shown the type of high pressure connection which has been used for 
joining various parts of pressure apparatus. The end of the pressure pipe 
p is turned off at 60° and fits pressure-tight into a conical depression. A 
small round nut is screwed onto the end of the pipe and the whole is held 
down tight by means of the larger nut n. 


assembled for the first time, the pointed end of the pipe should 
be given a blow with a hammer squarely on its end. This 
treatment enlarges the tip slightly and has the effect of making 
certain that when the end of the pipe is forced into its seat by 
screwing up the nut it is the extreme tip that binds on the 
surrounding metal. This type of joint may occasionally leak 
when pressure is applied for the first time; increase of pres- 
sure, however, makes the joimt tight by expanding the tip of 


506 Johnston and Adams—Influence of Pressure on the 


the tube against its seat, and when this has once happened, it 
remains tight indefinitely. Joints such as this have been sub- 
jected to pressure up to 8,000 atmospheres, with both liquids 
and gases; when properly made, they show not the slightest 
leak whatever. This type of connection possesses the follow- 
ing distinct advantages over other types which have been used 
for high pressure work; (1) it may be taken apart and put 
together again repeatedly without impairing its efficiency ; 
(2) the joint is tight every time and thus there are avoided 
the troublesome delays so common in high pressure work ;* 
(3) the danger of the whole joint blowing out at high pres- 
sure—which may easily happen with ordinary butt joints—is 
practically obviated, because of the smallness of the bearing 
surface under all conditions. 

The tubing which has been used for all connections is of 
mild steel, cold-drawn, 12™™ in outside diameter and 2™™ inside 
diameter. It stands without rupture pressures of at least 8,000 
atmospheres and can easily be bent or twisted if heated to 
redness. 

We shall now proceed to describe the disposition of the 
interior of the bomb, comprising the arrangements for heating, 
and for measuring the temperature of, the charge of metal ; 
the details are shown in fig. 3, which is drawn to scale. 

The electric furnace JJ (fig. 3) was made by wrapping a 
thin sheet of asbestos paper around a copper tube 25™™ in diam- 
eter, and winding on this “nichrome” wire (B and § No. 16; 
1:°3"" in diameter), so that a coil 10° long with 5 turns per 
em. was formed. The whole was inserted in a cylinder of 
soapstone and the intervening space filled with “magnesite” 
mixture. Soapstone cylinders, SS, afford heat insulation at the 
ends of the furnace and also serve to fill up the space. One 
terminal of the heating coil is “grounded” onto the bomb 
through the brass ring 7; the other end is led through the 
lower soapstone plug 8, the steel plug A, and out along a slot 
cut in the top of the base plate 6. The thermocouple wires 
TT pass out through the top plug G. 

There are several ways in which good electrical connection 
may be made between the inside and the outside of the bomb. 
The method adopted in the present instance is as follows: a 
hole about 12™™ in diameter is bored in the steel part through 
which the wire is to pass and a cylinder of soapstone is turned 
to fit this hole. Through the soapstone is drilled a hole of the 
same diameter as the wire, which is then threaded through this 
hole. The soapstone cylinder is inserted in the steel, and 

*TIn this connection we desire to express our indebtedness to Mr. Geo, F. 
Nelson, to whom is principally due the success of this high-pressure joint, 


and without whose mechanical skill and ingenuity our work would not have 
been so far advanced. 


Melting Points of Certain Metals. 507 


rammed firmly into position by applying a force of twenty or 
thirty tons; this force is communicated through a small steel 
eylinder of the same diameter, which is properly drilled or 
grooved so as not to injure or interfere with the wire or wires. 
In order to prevent the wires being actually squirted out 
through the holes in the stone, two procedures may be followed. 


Fic. 3. Electric furnace and interior of bomb, drawn to scale. JJ is the 
furnace, SS soapstone blocks for thermal insulation of the ends, and G and 
H, the plugs which close the bomb. Freedom from leaks is insured by the 
use of the rings or “‘ washers” of sheet copper shown at LL. Thermocouple 
wires TT are led into the bomb through the upper steel plug G. One termi- 
nal of the heating circuit is grounded onto the bomb at J; the other passes 
out insulated through H. The graphite crucible with thermocouple tube 
in place is shown suspended from the upper plug. 


The soapstone cylinder may be made in two or more parts and 
the holes for the wires staggered; or the internal part of the 


508 Johnston and Adams—Influence of Pressure on the 


wire may be made somewhat larger than the outer part.* 
The latter method has been adopted i in the case of large wires, 
such as those of the heating circuit. The former method 
was used for the thermocouple and other small wires. The 
thermocouple wires are insulated in the horizontal portion of 
their path through the plug @ by sections of glass. tube, which 
are kept in place by short plugs of fibre. The heating current 
wire, after it has passed out through the soapstone, is ; likewise 
insulated from the steel plug H | by the insertion of a thin 
eylinder of fibre. 

The material to be investigated is contained in a graphite 
erucible of the form depicted in fig. 3. The erucible is held 
rigidly in position by small steel rods, which screw into the 
ends of larger steel rods, attached firmly to the plug G. The 
erucible lid, also of graphite, is held in place by means of a 
small screw-clip (not shown in the figure) fastened to one of 
the supporting wires. To the crucible lid is fastened by two 
steel pins the thermoelement jacket which is a porcelain tube, 
7™" in diameter. The thermocouple wires are separated from 
one another, as usual, by means of a small porcelain tube 
slipped over one of them. 

By these methods of construction, motion of the thermo- 
element, or of its jacket, with respect to the charge, is abso- 
lutely prevented, so that we could always be sure that the 
junction was in the proper position with respect to the crucible, 
viz., located axially and about 6™" from the bottom of the 
charge. 


Temperature Measurement. 


To determine the temperatures, thermoelements of cop- 
per-constantan were employed. Three lengths were cut off 
a reel of No. 30 (B and 8) constantan wire (0°25"") and were 
joined separately to lengths of copper wire of the same diam- 
eter. Two of these elements were preserved as standards, and 
gave readings at all temperatures not more than 2 microvolts 
apart ; the third element was fixed in the plunger @ in the 
way already described. The differences between this element 
and the standards amounted to 20-30 microvolts, probably 
owing to strains set up in it while it was being made pressure 
tight “through G. 

“Before proceeding to the measurements, it was, however, nec- 
essary to calibrate the standard elements, since so far as we are 
aware, no satisfactory calibration of such elements over the 
temperature range 0° to 400° has yet been made. For this 

* An equivalent method which may be used with some wires is to tie a 


knot which shall be too large to pass through the small hole drilled in the 
soapstone block. 


Melting Points of Certain Metals. 509 


purpose, we determined, on the standard element, the electro- 
motive force corresponding to the boiling points of water, 
naphthalene, benzophenone, and the melting point of. zinc ; 
while for the temperatures below 100° we compared it with a 
four-junction element belonging to Dr. W. P. White, the 
calibration of which is known with an accuracy of a few 
thousandths of a degree.* The values assigned to the standard 
temperatures are as follows :+ 


Naphthalene b.p.. ..-.------- 217°7°+0°057 (p—‘760) 
Benzophenonef (Merck) b.p..- 305°6° +0°063 (p—‘760) 
ZING MUNN eee Ss entre eRe ae ORD 


All temperatures given in the present paper are referred to 
the above fixed points; we also give the actual electromotive 
forces observed, so that the temperature may be easily cor- 
rected, if a change in the above reference points be rendered 
necessary by future work. 

In all the measurements, the cold junction was immersed in 
an ice-bath at 0°, and the electromotive force was measured by 
means of the usual potentiometric arrangement. By this means, 
an accuracy of 1 microvolt, corresponding to 0:02°, could be 
easily attained. The results thus obtained for the calibration 
of the standard element are: 


t e ue e 
(microvolts) ; (microvolts) 
0 (0) 100°0 4927 
24°92 975°7 ORV 10119 
50°00 ZONI 305°6 15007 
75°00 3096 418°2 21755 


Attempts were made to obtain a single equation which 
should pass through all the points; but without success. 
Accordingly, two cubic equatious of the form e= A+ Bt+ 
Ct + Dt’ were used to calculate the electromotive force corre- 
sponding to any given temperature ; ¢ was computed for every 
10° from 10° to 480°; the slight irregularities were evened 
out by adjustment of the successive differences. From the 


*See Phys. Rev., xxxi, 159. Its calibration curve is e = 155°311 ¢ + 
0183 # — 0:00014 #. 

+ Cf. Sosman, this Journal, xxx, 6, 1910; Day and Sosman, ibid, xxix, 98, 
1910. It is to be noted that up to the present there have been only two gas 
thermometer determinations of the boiling points of naphthalene and of 
benzophenone—one by Crafts (Bull. soc. chim., xxxix, 277-89, 1883) and one 
by Jacquerod and Wassmer; the former does not claim an accuracy better 
than 1°, so that the only accurate data at present available are those of 
Jacquerod and Wassmer. 

{The b.p. of benzophenone (Merck), according to Waidner and Burgess 
(Bull. Bureau of Standards, vii, 6), is 0°2° higher than that of benzophenone 
(Kahlbaum); the b.p. of the latter is 305°4, according to Jacquerod and 
Wassmer. 


510 Johnston and Adams—Influence of Pressure on the 


table thus obtained, giving e in terms of ¢, another and more 
convenient table was constructed, giving ¢ for each even 100 
microvolts. 

This table is presented in abridged form—for every, 500 
microvolts—in Table I, in which are also included the E.M.F.’s 
corresponding to the fixed reference points. Incidentally it may 
be noticed (1) that a quadratic equation will not express the 
relation between ¢ and e with sufficient accuracy; for such an 
equation when passed neuen the steam, benzophenone, and 
zine points misses the naphthalene point by 1°5°; (2) that 
the cubie equation of the above form fits the data with 
much greater accuracy than the inverse form of function, 
t=—Ae+ Be’ + Ce’. 

TABLE I, 
Abridged Standard Curve for Copper-constantan Elements. 


Microvolts t Diff. Microvolts t Diff, 
0 0 11500 243°19 
500 1298) 3525 PA@O00), | aeoawes a 
1000 25°53 Ds - 500 261°30 aoe 
500 37°77 ngs 13000 270:25 Aas 
2000 49°72 nee 500 27914 aa 
500 61°40 ue 14000 287°97 ere 
3000 72°83 “a0 500 296°75 axa 
500 84°05 ae 14.995 3054 
4000 95:07 15000 305°48 aa 
4227 10000 se 500 31415 eet 
500 105°88 oa 16000 322-76 ee 
5000 116°52 cee 500 331°31 aia 
500 127-00 ORS 17000 339°80 Bid 
6000 137°32 janie 500 348°24 ane 
500 147°50 ane 18000 356°62 2a5 
7000 157°55 age 500 364°95 aa 
500 167°48 er ep ee 373°24 ape 
8000 177°29 a0 500 381°49 oon 
500 186-99 ase 20000 389°70 ai 
9000 196°58 ANG 500 397°87 ate 
500 206-07 alia: 21000 40600 aan 
10000 215°47 500 41409 Bae 
10119 217-7 ane 21755 418-2 
500 224-79 924 22000 499°14 BD 
11000 234:03 aie 500 430°15 non 
500 243°19 23000 43812 


This table may be used for any element with the aid of its 
deviation curve, which is obtained by plotting at two or more 
known temperatures the differences between the readings of 
the element in question and the standard curve. Its use thus 
saves much calculation and recalculation of thermoelement 


Melting Points of Certain Metals. 511 


curves.* The uncertainty in the temperatures deduced in this 
way from the above table should, we believe, not exceed 0-1° 
on the temperature scale we have chosen ; and is much smaller 
than the present uncertainty in the absolute value of the 
temperature scale—an uncertainty which is about 1° at 450°. 
The readings may be immediately referred to any other scale 
of temperature by including in the deviation curve the differ- 
ences between the two scales. Temperature differences, how- 
ever, over a small range are probably accurate at least to 0:02°, 
regardless of slight discrepancies in the temperature scale, and 
of possible errors in the interpolation formula. For this reason 
the values of temperatures and differences in Table I are given 
to hundredths of degrees. 


Melting Point Determination. 


Briefly, the method pursued in the determination of the 
melting points of the various metals under pressure was as 
follows: A charge of the proper amount of metal having been 
placed in the graphite crucible, the whole was heated some- 
what above the melting point of the metal (a thin layer of oil on 
the surface of the metal prevented oxidation). The porcelain 
tube which serves to protect the thermocouple from the sur- 
rounding metal, attached to the crucible lid, was fitted into 
position. Crucible, steel plug (G, fig. 3), soapstone cylinder, 
etc., were then assembled and placed in the bomb, which was 
thereupon set in position on the lower platen of the press, and 
connected with the high pressure line (at Z) fig. 1). The 
upper press platen was forced down until the upper plug (@) 
slipped into place and centered itself; the electrical connections 
were made, the cooling watert turned on, and all was in readi- 
ness for the actual measurements. 

The pressure inszde the bomb was increased by means of the 
pump J), while simultaneously excess pressure in gradually 
increasing amount,{ was applied by means of the press, on the 
plugs G and H. When the desired pressure was attained, the 
freezing point of the metal was determined as usual by the 
Frankenheim method. 

No account was taken of the effect of pressure on the 
thermoelectric E.M.F. This influence is very slight in those 

* This matter is more fully treated in Sosman, loc. cit., q. v. 

+A supply of both hot and cold water was available; for most of our 
experiments hot water was used to ‘‘cool” the bomb. By the use of hot 
water in this connection a smaller heating current is required ; in addition, 
this plan makes for more uniform temperature distribution within the 


bomb. 
t¢ When the pressure was decreased again by releasing the valve V, a 


? 


corresponding diminution in the external pressure exerted by the press 
was effected by suitable manipulation of the proper valves. 


512 Johnston and Adams—Influence of Pressure on the 


cases which have been investigated: namely, for couples com- 
posed of platinum or other metals with mercury the difference 
of reading produced by a change of pressure of 1000 atmos- 
pheres is only about 0°2 microvolts.* It is therefore practi- 
cally certain that the error introduced by neglecting this 
variation does not exceed one or two microvolts, i. e., it is less, 
and probably much less, than 0:05°. 

It may be stated that we were able to get very sharp points ; 
it is obvious that the temperature did not stay long at the 
melting point, on account of the smallness of the charge and 
of the rapid rate of cooling, but the break in the curve was 
perfectly definite and reproducible. This is shown by the 
results, which have been brought together in chronological 
order in Table II, for the four metals investigated, namely, 
tin, lead, cadmium, and bismuth. 

In the second column is given the pressure in the system in 
atmospheres at the instant of freezing. The third column 
shows the observed reading of the thermoelectric E.M.F. at the 
freezing point; while in the last column these latter values are 
converted into degrees (uncorrected, that is, taken directly 
from Table I). Freezing points rather than melting points 
were taken since the former were with our apparatus much the 
sharper. Melting points were taken in a few cases, however, 
and found to agree well with the freezing point under the 
same pressure. 

A study of the results in Table II shows conclusively (1) that 
the melting point of a given metal under a given pressure is 
reproducible, since measurements made on different days, with 
different charges are in good agreement; and (2) that since the 
same results were obtained with increasing and decreasing 
pressure, the hysteresis effect of the gage was not large enough 
to interfere seriously with the accuracy of the measurements. 


Relation Between Melting Points and Pressures. 


It was expected that the change in melting point, Az, would 
be a linear function of the: pressure P. Accordingly, the 
straight line, ¢ = a@+bP, which best fits the data, was calcu- 
lated by the method of least squares, from the observations 
with each of the four metals used. The results of these caleu- 
lations are shown in Table III. In the first column of each 
table is given the pressure arranged in ascending order of 
magnitude. Columns 2 and 3 show respectively the observed 
change of melting point and that calculated from the 
least square curve. The differences between observed and 

*H. Wagner, Ann. d. Physik., xxvii, 955, 1908; Hérig, ibid., xxviii, 371, 
1909. 


Melting Points of Certain Metals. 513 


Tasue II. 
Direct Experimental Results. 
Freezing point 


(om =" 
Pressure in microvyolts in degrees* 
Date in atmospheres (uncorrected) 
TIN 
Ie te 
Diane ours ete 1000 10995 233°89 
750 10952 233°09 
2000 11174 237°18 
1490 11081 235°47 
1000 10994 233°87 
300 10904 232°20 
2000 11174 237°18 
Fant le. fe 22 500 10907 232°26 
1000 10999 233°96 
1995 11170 23711 
LEAD 
Yank lO ees = 2 500 16399 329°26 
1000 16641 333°38 
1490 16876 337°35 
2000 17114 341°38 
770 16536 331°59 
505 16409 329-43 
350 16332 328°12 
250 16293 3827°46 
150 16238 326°53 
CaDMIUM 
Alavi Gull eae Be Ss 1500 16331 32811 
1500 16333 328°14 
2000 16524 331°39 
2000 16526 331°42 
Mane Gee ee 1515 16352 3828°47 
1010 16162 325 24 
512 15976 322°06 
350 15912 320°97 
BISMUTH 
Deamon eae ss 22 500 12860 267°71 
1000 12746 265°67 
998 12748 265°71 
1550 12655 264:°04 
2010 12551 262°18 
1480 12662 264°17 


* These temperatures were read directly from the standard curve, no 
account being taken of the differences in electromotive force of the element 
actually used and the standard element. Since, however, these differences 
were always small and correspond to less than 1°0°, and since the standard 
eurve changes in curvature very slowly, no error is introduced thereby into 
the change of melting point caused by pressure, the quantity in which we 
are chiefly interested. 


514 Johnston and Adams—Influence of Pressure on the 


TasLE III. 
Change of Melting Points with Pressure. 
Change of melting point 


Pressure = a” = 
in atmospheres observed * calculated Difference 
IN 
P At=t’—230°61° dt=0:003275 P Ar—or 
500 1°59 1°64 — 0:05 
500 1°65 1°64 ae (Oil 
750 2°48 2°46 + 02 
1000 3°26 3°28 — 02 
1000 3°28 3°28 00 
1000 3°35 3°28 + 07 
1490 4°86 4°88 OZ, 
1995 6°50 6°54 — 04 
2000 6°57 6°55 + 02 
2000 6°57 6°55 + 02 
BIsMUTH 
At=269:°37—t’ 6t=0'003548 P 
500 1°66 ETT — 011 
998 3°66 3°54 + 12 
1000 3°70 3°55 + 15 
1480 5°20 5°25 — 05 
1550 5°33 5°50 eat la 
2010 7°19 7°12 + 07 
CADMIUM 
At=t' —318°81 6t=0-006288 P 
350 2°16 2°20 — 0°04 
512 3°25 3°22 + 03 
1010 6°43 6°35 + 08 
1500 9°30 9°43 — 183 
1500 9°33 9°43 — 10 
1515 9°66 9°53 + 138 
2000 12°58 - 12°58 00 
2000 12°61 12°58 + 03 
LEAD 
At=t' —325°35 6t=0-'008026 P 
150 1:18 1°20 — 0:02 
250 2 2°01 + 10 
350 DTT 2°81 — 04 
500 3°91 4:01 — 10 
505 4:08 4°05 + 03 
770 6°24 6°18 + 06 
1000 8°03 8°03 00 
1490 12°00 11°96 + 04 
2000 16°03 16°05 — 02 


calculated values, as may be seen by referring to the fourth 
column, are on the whole quite small; indeed the deviation 


Melting Points of Certain Metals. 515 


of the results from a straight line is no greater than the prob- 
able error of the observations. In other words, no indication of 
a tendency of the pressure-temperature curve to bend toward 
the pressure axis can be observed. This is confirmed by 
inspection of the graphs reproduced in fig. 4, which were 
obtained by plotting t or A¢ against P for each metal. 


TPREE 
ae Habe wld 


Oo 1000 2000 


Fie. 4. Diagram showing the relation of the change of melting point 
AT to the pressure P (in atmospheres) for each of the four metals studied. 
The relations between A T and P, it will be noted, are represented with great 
exactness by straight lines. The melting point of bismuth decreases with 
pressure while that of the other metals increases. 


It was thought that it would be of interest in this connection 
to calculate from the Clausius-Clapeyron equation the change 
of melting point with pressure. We may write the equation 

Diy ws tae LOGE Vache 
phon Was nee =! BIRO y 
where dé is the change in melting point for the change 
in pressure dp, ZT’ is the absolute temperature of melting Vi 


516 Johnston and Adams—Influence of Pressure on the 


and V, are the volumes of 1 gram of the metal at the melting 
point in the liquid and solid states respectively, and g is the 
latent heat of melting in calories per gram. 

A number of measurements not agreeing among themselves 
are recorded in the literature on the latent heat and volume 
change on melting of Cd, Pb, Bi, and Sn. We have made use 
of the data of Person* for the latent heat of melting, and of 
Vicentini and Omodeit for the change of volume at the melt- 
ing point, to calculate by means of the formula, the change 
of melting point per 1000 atmospheres for each of the four 
metals. These data were chosen for the sake of uniformity 
and because we believed them to be the best available. -The 
results of the calculation follow : 


I II Til IV Vv 


ott per 1000 
Latent Vol. change dt per 1000 atm. cale. from Probable 
heat: cal. onmelting atm.cale, from obs. change of error§ of 


per gram. ccpergram. vol.changeand wm.p. with coefficient 
Metal qd Vi-—V; latent heat pressure in col. IV 
Sn 14:25 0:003894 + 3°34 + 3°28 + 0:02 
Cd 13°7 0:00564 + 5°91 + 6°29 + 0°04 
Pb 5°37 =: 0003076 + 8°32 + 8°03 + 0:08 
Bi 12°6 0°00342 — — 8°56 — 3°55 + 0°08 


The agreement between the values given in columns III 
and IV is close—in fact, closer than might be expected when 
we consider the uncertainty in the latent heat and volume 
change of the metals involved. 

The change of melting point with pressure of tin and bismuth 
has been measured by Tammann.| He found for dt/dp per 
1000 kg / em’, 2°2 for tin and 3°9 for bismuth. His caleulated 
values (by the Clausius-Olapeyron equation and using, as it 
happens, the same data for latent heat and volume change as 
those we have employed) are 3°3 and 3°3 for tin and bismuth 
respectively.4] It is worth while noting that Tammann made 
his temperature measurements with a thermoelement of Pt— 
Pt Rhand a direct-reading galvanometer. This fact is sufficient 
to explain the discrepancy between his results for tin and bis- 
muth and ours for the same metals. 

* Ann. Physik, lxxv, 462; Ixxvi, 482, 596, 597. 

+Beibl. Ann. Physik, xii, 176. 

¢ These coefficients, are, of course, the dt (x 1000) of the third column 
of Table III. 

§ For calculation of probable error of the coefficient cf. Merriman, Method 
of Least Squares, 6th ed., Chapter on the Precision of Observations. 

| Zs. anorg. Chem., xl, 54, 1904. 

{ 3°3° per 1000 kg/cm? is equivalent to 3°4° per 1000 atm, Apparently, 
Tammann’s calculated value for bismuth is in error by about 2 units in the 
second significant figure. 


Melting Points of Certain Metals. oy 


Melting Point of the Metals at Atmospheric Pressure. 


The melting points of the samples of metals used in this 
investigation were determined with both copper-constantan 
and Pt—Pt Rh elements which were calibrated, as stated 
above, in steam, at the boiling points of naphthalene and ben- 
zophenone, and at the melting point of zine.* 


Metal Source Melting point* 
Sn Baker’s 231°0 
Bi BG 270°7 
Cd Kahlbaum’s 320°4 
Pb Baker’s 326°7 


These melting points are in very close agreement with those 
published by the Bureau of Standards, when the difference in 
temperature scale is taken into account. Incidentally, the 
melting points of Kahlbaum’s tin and lead were, measured. 
The result for tin was 230°5° and for lead, 326°7°. 


Summary. 


1. There has been designed and built an apparatus suitable 
for studying chemical and physical reactions at temperatures up 
to 400° and under pressures up to 2000 atmospheres. Both 
temperature and pressure in the reaction zone may be meas- 
ured with fair accuracy. 

2. The change with pressure of the melting point of tin, 
bismuth, lead, and cadmium has been measured; it was found 
to be a linear function of the pressure within the limits of 
experimental error. 

3. By substitution in the Clausius-Clapeyron equation of the 
data of Vicentini and Omodei on the volume change at the 
melting point, and of Person on the latent heat of fusion, 
dt /dp was calculated for each of the four metals. The caleu- 
lated values show satisfactory agreement with those observed. 

4, Incidentally, the melting points of tin, bismuth, cadmium, 
and lead were determined, and a standard curve for the cali- 
bration of copper-constantan elements at temperature from 0° 
to 425° is given. 

Geophysical Laboratory, — 


Carnegie Institution of Washington, 
March 25, 1911. 


*The values assumed for napht. bp., benzo. bp., Zn, mp. being 217°7, 
305°4 and 418°2 respectively. Cf. ante p. 509, foot-note. 


Am, Jour. Sci1.—FourtH Smries, Vou. XX XI, No. 186.—Junn, 1911, 
30 


518 Van Horn and Cook—New Occurrence of Pearceite. 


Art. XLITI.—A New Occurrence of Pearceite ; by Frank R. 
Van Horn and C. W. Cook. 


Introduction. 


In the summer of 1908, Mr. R. B. Cochran, formerly super- 
intendent of the Compania Metalurgica Mexicana at Sierra 
Mojada, Coahuila, Mexico, presented ‘the Department of Geol- 
ogy and Miner aloey at Case School of Applied Science with seve- 
ral specimens of silver, copper and lead minerals from the Veta 
Rica mine at the locality mentioned above. We wish to take 
this opportunity of thanking Mr. Cochran, both for speci- 
mens and much useful information concerning the district.* 
One of the minerals was recognized as polybasite, but blow- 
pipe tests showed that it contained chiefly arsenic with little if 
any antimony, and must, therefore, be pearceite. This in 
itself was interesting, since the mineral has been found previ- 
ously only at four other localities, namely: Schemnitz, Hun- 
gary in 1833,+ Arqueros, Chile, in 1879 »{ Aspen, Colorado, i in 
1892,§ and Marysville, Montana, in 1896. | The pearceite also 
occurred in well-defined crystal aggregates, and likewise 
appeared to be twinned, so that the specimens were sent to the 
University of Michigan, where their erystallographic proper- 
ties were investigated by the junior author. 


Geography and Local Geology. 


Sierra Mojada is the name of a town as well as that of a range 
of mountains which perhaps more properly might be called hills. 
The region is situated in the extreme western part of the 
State of Coahuila, Mexico. It is reached from Escalon on the 
Mexican Central railroad, a distance of 494 miles south of 
El Paso, Texas. From Escalon, the Mexican Northern railroad 
runs 78 miles northeast, and terminates at Sierra Mojada, which 
lies in a valley about three miles wide. This valley is bounded 
on the south by the range of hills called Sierra Mojada, and 
on the north by other hills called Sierra Planchada. Ore was 
first discovered in 1878, and is found for a distance of about 
three miles along near the base of Cretaceous limestone cliffs 

* A complete description of this region and geological occurrence of the 
ores was given at the Pittsburg meeting of the Geological Society of Amer- 
ica, Dec. 29, 1910, in the paper entitled ‘‘ The Occurrence of Silver, Copper 
and Lead Ores at the Veta Rica Mine, Sierra Mojada, Coahuila, Mexico,” by 
Frank R. Van Horn. 

+H. Rose, Pogg. Ann., xxxiii, 158, 1833. 

+ Domeyko, Min. 393, 1879 


& Penfield-Pearce, this Journal, xliv, 17, 1892. 
Penfield, ibid., ii, 18, 1896. 


Van Horn and Cook—New Occurrence of Pearceite. 519 


which constitute the Sierra. The ore occurs at or near the 
contact of the limestone with a rock which is locally called 
conglomerate, although others have named it a porphyritic 
breccia.* However, the rock seems to be either a decomposed 
rhyolite or a rhyolite tuff, since it consists chiefly of fine-grained 
quartz and orthoclase, much decomposed. Along the contact 
of the two rocks there are many indications of faulting, such 
as breccias, slickensides, and clay selvages. It seems not 
improbable that the valley was made by faulting, which has 
left the cliffs as a fault scarp. There are about 19 mines in the 
district, which, even in 1900, produced about 200,000 metric 
tons of ore. Up to 1893, it was a silver-lead camp in which 
the predominant ore was argentiferous cerussite with small 
amounts of galena. In 1893, however, in the western part of 
the region, large bodies of silver-copper ore were found in the 
San Jose mine in addition to the silver-lead ore bodies. Simi- 
lar silver-copper ores were afterward found on adjoining prop- 
erties, of which the Veta Rica mine is one. The latter has 
proven to be the richest if not quite the largest mine in the 
camp. 


Ores and Minerals Found at Veta Rica Mine. 


Although Sierra Mojada is still predominantly a silver-lead 
camp, nevertheless the chief output of the Veta Rica, which is 
one of the largest mines in the district, is known as a siliceous 
silver lime containing workable amounts of copper. The chief 
ore is either a red or dark gray magnesian limestone, impreg- 
nated with quartz, cerargyrite, native silver, and sometimes 
barite. In the specimens of this type which were subjected to 
investigation, no well-defined copper minerals were observed, 
although it is said to contain from 0-6 up to 2 per cent of 
copper. 

In another part of the mine, along a fissure in the limestone, 
copper minerals containing silver are found. A rather inter- 
esting fact is that on the same level along this fissure are two 
ore bodies of this type, but one consists of sulphides while the 
other is entirely oxidized. Specimens from the former presented 
by Mr. Cochran consist of massive chalcocite, chalcopyrite, 
and a little covellite. Also small amounts of galena and sphaler- 
ite are said to oceur at this point. About 120 meters west of 
this ore body, but at the same horizon and on the same fissure, 
is the oxidized body, which consists of native copper, cuprite, 
azurite, and malachite associated with gypsum. The water 
channel which caused the oxidation of this body has evidently 
been prevented in some manner from reaching the sulphides. 


*The Sierra Mojada, Coahuila, Mexico, and Its Ore Deposits, by James 
W. Malcolmson, Trans. Amer, Inst. of Min. Eng., xxxii, 105, 1902. 


520 Van Horn and Cook—New Occurrence of Pearceite. 


Occurrence of the Pearceite. 


In 1906, while working along the northern part of the silver- 
copper siliceous lime ore body, a fault was encountered having 
a displacement of about 40 feet. Following along the fault 
plane, silver-copper ores of great richness were discovered, 
along with considerable barite as gangue mineral. Minerals 
observed from this point were native silver, argentite, proust- 
ite, pearceite, and erythrite. The latter occurrence is rather 
peculiar, singe it is the only oxidation product, if native silver 
is excepted. Furthermore, there have been no other cobalt 
minerals noted either from this mine or the district as a whole, 
although it would seem as if some cobalt arsenides should be 
present. There were said to be about 200 pounds of pearceite 
erystals found, but on account of the heavier government tax 
on high grade ores, practically the entire amount was ground 
up and distributed through poorer grades. However, eight 
specimens were presented by Mr. Cochran, while a ninth aggre- 

ate was very kindly loaned to us by Senor Felipe Borrego, 
formerly with the Veta Rica mine, but at present foreman of 
the Guadalupe mine at Cerro de San Pedro, San Luis Potosi, 
Mexico. 
Crystallography. 

The crystallography of pearceite was studied first, in 1896, 
by Penfield,* who worked on crystals from the Drumlummon 
mine, Lewis and Clark County, Marysville, Montana. At this 
time he proposed the name pearceite for polybasites in which 
arsenic was in excess of antimony. He states that it crystal- 
lizes in the monoclinic system and possesses a rhombohedral sym- 
metry, due, in all probability, to twinning similar to that of 
the micas. On account of this rhombohedral symmetry, which 
was likewise exhibited by all the material under investigation, 
as well as the similarity on angles for several forms, and the 
imperfection of the crystals, definite orientation was found to 
be impossible. Also, an attempt to obtain etching figures, 
using nitric acid as the solvent, met with failure. Therefore, 
although several undoubtedly new forms are present, it is 
thought best to limit the present crystallographic report to a 
discussion of a new twinning law. : 

The pearceite occurs in aggregates of twin crystals, more or 
less perfectly developed, which show striations and vicinal 
planes. The individual crystals are tabular in habit with the 
basal pinacoid as the predominating form; the pyramids and 
domes occurring as very narrow faces. Unfortunately most of 
the edges of the crystals were broken off, as the mineral is very 
brittle. The basal pinacoid is characterized by the presence of 


*S. L. Penfield, this Journal, ii, 19, 1896. 


Van Horn and Cook—New Occurrence of Peareeite. 521 


triangular figures. According to Hintze* the sides of these, 
figures are parallel to the faces (111), (111), and (101). 

The new twinning plane, which is practically present on all of 
the specimens, is likewise parallel to one of the sides on the tri- 
angle. It must, therefore, lie in either the unit prism-basal pina- 
coid zone or the ortho-basal pinacoid zone and the twinning 
plane must be either a pyramid or an orthodome. 

The examination of the twinning planes of a large number 
of monoclinic minerals shows that twinning in the ortho-basal 
pinacoid zone is very common, whereas the pyramids function 
but rarely as twinning planes. The new twinning plane on 
pearceite has, therefore, been tentatively assumed to be par- 
allel to the orthodome (702) on the basis of the twinning angle, 
which is 34° 42’. The average of the measurements, made on 
a number of different crystals, gives for the angle between the 
basal pinacoid (100) and the orthodome (702) a value which 
agrees quite closely with the calculated value, as may be seen 
from the following : 


Observed Calculated 
(100) : (702) Se eS 72° 39’ HOO BBY 


Fig. 1 shows the general character of the crystal aggregates 
as well as the presence of reéntrant angles. The triangular 
striations on the basal pinacoid are seen on numbers 1, 2, and 
3. Parts of the best crystal measured are shown under 8, 9, 
and 10, but unfortunately the original was broken while deter- 
mining the specific gravity. Nevertheless the reéntrant angles 
are still visible on all three fragments. Number 7 is an aggre- 
eae of small thin plates and closely resembles some specular 

ematites in micaceous appearance. 


Chemical Composition. 


The empirical formula which was proposed in 1896 by Pen- 
field,t and was accepted, is (Ag,Cu),(As, Sb) S, or 9(Ag,Cu),S. 
(As, Sb),S,. This is analogous to the formula for polyba- 
site, (Ag,Cu),(Sb, As) S,, which was proposed by Heinrich Rose 
in 1829.t <A portion of one of the Sierra Mojada crystals which 
seemed free from all impurities was analyzed by Dr. N. A. 
Dubois of the Chemical Department of Case School of Applied 
Science with the following results : 

*C. Hintze, Handbuch der Mineralogie, 1904, p. 1167. 


+ Op. cit., page 18. 
t+ H. Rose, Pogg. Ann., xv, 575, 1829. 


522 Van Horn and Cook—New Occurrence of Pearceite. 


Pro- Pro- 

Pereentage Atomic Combining portion p’rt’n 

found weights weights Ratio found taken 

S 1746+ 32:07 = 5444 ='5444=:'1008 =5:°400K2=10°80= 11 

As 17:56 74:96 =:'1008 =1008+':1008 =1:000x2= 2:00= 2 

Sb 0:00 

Ag 59°22--(107°88 x 2)= 2744) _. a eae a ae 

Gi 1565 ( 63°57 X2)= 1981. 1 oe 3975—+'1008 =3'9438 x 2=7'886= 8 


99°89 


The International Atomie Weights for 1911 were employed in 
the calculations, and twice the atomic weights of silver and cop- 
per were used on the basis that these elements are isomorphous 


Fre. 1. 


Fic. 1. Pearceite crystals from Veta Rica Mine, Sierra Mojada, Mexico. 


in the compound (Ag,Cu),S. No antimony was found, so that 
evidently the pure pearceite molecule is present, as was also 
the case with the Montana occurrence mentioned at the begin- 


Van Horn and Cook—New Occurrence of Pearceite. 523 


ning of this article. At the three other localities cited a small 
amount of antimony was determined. Although iron was pres- 
ent in small amounts in three of the previous occurrences, and 
zine in one of them, neither of these elements was observed in 
the Veta Rica pearceite. A glance at the proportion of com- 
bining weights found in this analysis shows an extremely close 
ape ener to the formula (Ag,Cu,),As,S,, rather than to 
that of the accepted one, (Ag,Cu,), As,S,,. The theoretical 
composition of the Sierra Mojada pearceite was calculated for 
the latter formula on the basis that the ratio of silver to copper 
was 2744: 1231, as follows: 


Theo. 
Theo- Percent- percent, 
Atomic Molecular retical age ODiffer- of 
weights weights perc’tage found ence Ag AsS. 
Si 32:00 is = 384°84 17:27 17:46 +:°19.. 15°54 


As= 74:96 As, 149°92 6°73 7:56 +°83.. 6°05 


: | 

Ag—107'88 Ane of 10788 18=1339°92 60°12 59°22 —-90.. 78-41 
Ss MORN : 

Cu= 63°57 Cul?! of 63:57 18= 353°88 15°88 15°65 —-23.- 


3975 


2228°56 100°00 99°89 100°00 


It is seen that the differences between the theoretical com- 
position and that which was actually found are quite consid- 
erable, so that the theoretical composition required by the 
formula (Ag,Cu,),As,S,, was likewise calculated, using the pro- 
portion of silver to copper as above, with the following results: 


Theoretical 
Molecular Theoretical Percentage Differ- percentage of 

weights percentage found ence AgicsAs2Sir 
S, = 3852°77 17°56 17°46 —'10 15°84 
As, = 149°92 7°46 7°56 +°10 6°72 
LAG eS IGP OB 59°32 59°22 —'10 77°44 
Cu = 314°56 15°66 15°65 —'01 ge eee 
2009°17 100°00 99°89 100°00 


A comparison of the results obtained above shows that the 
analysis of Sierra Mojada pearceite conforms much more 
closely in all respects to the formula (Ag,Ou,),As,S,, or(AgCu),, 
As,S,, than to (Ag,Cu,), As,S,, or (AgCu),,As,S,,. A comparison 
of other analyses of pearceite and polybasite will follow this 
article, at a later date, in another paper by the senior author. 


524 Van Horn and Cook—New Occurrence of Pearceite. 


Physical Properties and Pyrognostics. 


The physical properties of the pearceite from the Veta Rica 
mine are very similar to those from the Drumlummon mine, 
Marysville, Montana, described by Penfield.* The mineral is 
black, and has a splendent metallic luster. It has a very 
pronounced conchoidal fracture, and is exceedingly brittle, 
which accounts for the fact that not enough erystal faces 
remained in the pyramid and prism zones to properly orientate 
the mineral and accurately determine the new twinning law. 
A specific gravity of 6°067 was obtained from the average 
of four determinations on two different crystals, in which the 
separate results were 6:01, 6°10, 6°02, and 614. A fifth 
result obtained was 6°33, which the writer feels is not accu- 
rate. However, if the average of all five were taken, the maxi- 
mum specific gravity possible would be 6:12. 

Although the streak is black, and the mineral is practically 
opaque, nevertheless if very small pieces are observed with a 
high power objective in convergent light, a brownish green 
color is apparent on the edges. No change of color is percept - 
ible if the mineral is rotated between crossed nicol prisms. 

In a closed tube in the flame ofa spirit lamp, the mineral 
decrepitates, fuses easily to a black globule, and deposits a 
white crystalline sublimate consisting of octahedrons of As,O,. 
The globule when heated with the blowpipe gives a yellow 
sublimate of As,S,. In the open tube it gives a sulphurous odor, 
and a white crystalline coating of As,O,. On charcoal, the 
mineral gives a faint white coating of As,O, and the odor of 
SO,. After continued blowing, a malleable bead is obtained. 
If this is treated with borax on platinum wire, it alloys with 
the wire but gives a bead which is green while hot but blue 
when cold, indicating copper. Continued fusion of the alloyed 
wire gave a bead which was dark green when cold. 


Geological-Mineralogical Laboratory, 
Case School of Applied Science, Cleveland, Ohio, February, 1911. 


* Op. eit., page 23. 


T. Holm—Mollugo verticiliata L. 525 


Art. XLIV.—WMolluyo verticilata L. ; by Taro. Hoim. (With 
nine figures drawn by the author.) 


In several respects our common Carpet-weed, Mollugo verti- 
cilluta L. is quite an interesting plant, and there are several 
points in its structure, external as well as internal, which have 
not been studied so far; as a matter of fact, a number of our 
commonest plants are actually but little known, and it so hap- 
pens that ene illustrates an excellent example of anisoph- 
ylly, beside that the internal structure, of the leaf especially, 
is somewhat anomalous when we compare the other members 
of the Hicoidew, to which the genus is now generally referred. 
For several reasons, which will be shown in the subsequent 
pages, Mollugo is somewhat out of place in this family, which 
contains so distinct and utterly different types as Zetragonia, 
Azzoon and Mesembryanthemum; moreover, Jussieu,* who 
established the family Picotdew, did not include Mollugo. - 

Now in regard to anisophylly, which is illustrated so very 
plainly in this species of AZollugo, the term was first proposed 
by Wiesner, and expresses the unequal size of leaves of plagio- 
tropic shoots in accordance with their position on the upper or 
lower face of the shoot; more frequently the leaves of the 
upper face are of a smaller size than those of the lower, but 
the opposite case is known also. Anisophylly occurs in very 
many plants, cryptogamous as well as phenogamous, herbs 
as well as trees; 1t may be characteristic of certain genera, or 
only of certain species within the same genus.+ It is readily 
appreciated that light must be one of the factors to produce 
anisophylly, especially when we consider the branches of a tree 
where the peripheral leaves are usually much larger than the 
inner ones, on account of their fuller exposure to the sun- 
light. However, this is not always the case, and, as stated 
by Goebel (I. ¢.) there may be several other factors, beside 
light and position to horizon, that produces anisophylly. 
Already in the buds of Aesculus anisophylly may be observed, 
thus a long time before they open, and etiolated specimens of 
Goldfussia and Hlatostemma exhibited the same degree of 
anisophylly as other specimens grown under normal conditions. 

Now in regard to Mollugo, the foliage is in the Synoptical 
Flora of North Americat described as “ pseudo-verticillate,” a 
term on linguistic grounds inadmissible; moreover the leaves 
are opposite, and very plainly so. The leaf-arrangement, as 

* Genera plantarum, Paris, 1789, p. 315. ; 

+ Compare Goebel: Organographie der Pflanzen, Jena, 1898, p. 85 seq., 


where several cases are described, and the most important literature cited. 
¢ 1895-1897, p. 257. 


526 T. Holm—WMollugo verticillata L. 


OY 


well as the anisophylly, may be observed already at the seed- 
ling-stage. Our figure 1 illustrates a seedling, in which we 
notice the primary root (R.), the erect hypocotyl (H.), the 
cotyledons (Cot.), and the first leaves proper. These leaves 
are represented by two pairs, the first (L’) being almost fully 


T. Holm—WMollugo verticillata L. 527 


developed, while only one (L’) is as yet visible of the second 
pair. It is now interesting to notice that the first two leaves 
(L’) are of unequal size, the posterior being the larger, thus 
demonstrating the fact that, in this case, the anisophylly is not 
produced by any difference in exposure to light; the little 
shoot is erect, and the leaves are equally exposed to the effect 
of the sunlight. Nevertheless, as shown in figure 3, three dis- 
tinct pairs of leaves develop in this way, with a remarkable 
tendency to attain a larger size on one side of the shoot than 
on the other. This plant (fig. 3) is, also, a young seedling 
with the cotyledons (Cot.) plainly visible, and we notice, 
furthermore, a very distinct, central internode which bears a 
few flowers and green leaves. At this stage the hypocotyl (11.) 
has become bent down toward the ground by the weight of 
the leafy rosette ; thus we have before us an indication of the 
future habit of the plant already illustrated by this very young 
specimen, viz.: a basal rosette of crowded, opposite leaves of 
unequal size, and a terminal shoot which begins with a stretched, 
plagiotropic internode terminated by an inflorescence, which is 
preceded by a few pairs of leaves. There is, thus, an alterna- 
tion of short and of long internodes, while the foliage shows 
the same anisophylly throughout, the leaves upon, or nearest, 
the upper face being distinctly smaller than those of the lower 
face of the shoot. No stipules are developed, but the leaves, 
the large as well as the small, bear pluricellular, glandular 
hairs (fig. 9) at the base, near the margin and along the dorsal 
face of the midrib. Very minute leaves occur, also, at the 
base of some of the flower-stalks and represent fore-leaves, as 
deseribed by Hichler.* The apical portion of a branch from a 
mature specimen is represented in figure 4. We notice in this 


branch the long internode -/, which bears four pairs of leaves, 
of which the first pair (L’) contains the smallest and largest of 
all the leaves developed, the inner pair (L*) show the gradual 
decrease in size when compared with the outer (L’-L*), and 
one of these is frequently completely suppressed. Further- 
more is to be noticed that the lateral shoot (S.) is developed 
from the axil of a large leaf (L*) on the outer face of the 
mother-shoot. 

The anisophylly illustrated by JZollwgo thus shows the much 
farther development of the leaves of the lower face of the 
stem, than of those of the upper. Furthermore, the ramification 
of the stem shows us, that the strongest lateral branches con- 
stantly develop from the axils of the largest leaves, rendering 
the complete growth of the plant horizontal, and more or less 
closely appressed to the ground. As already mentioned, this 


* Bliithendiagramme, vol. ii, Leipzig, 1878, p. 119. 


528 T. Holm—Mollugo verticillata L. 


particular habit of the species with the unequal development 
of the foliage and with the plagiotropic shoots, is noticeable at a 
very early stage of the plant, beside that it occurs in small, 
depauperate specimens where only two or three branches may 
be developed ; in other words, the species shows a typical exam- 
ple of what Goebel has designated as “ habituelle Anisophyllie” 
(Il. ¢. p. 93). This peculiar deviation in the development of 
foliage is not, however, characteristic of all herbs with prostrate 
stems; it does not, for instance, occur in such plants as Huphor- 
bia maculata, nor in Stellaria media, Callitriche Austinii 
and many others. It seems to be restricted to certain genera 
of widely different plants, as stated above, and we might-men- 
tion at this place, that it is exceedingly well represented by 
Abronia fragrans Nutt. In this plant the stems are prostrate 
with the leaves opposite, and the ramification is plainly sympo- 
dial. Each shoot is terminated by an inflorescence, and the size 
of the leaves in each pair is very unequal. Furthermore, it is 
from the axil of the larger leaf that the long shoot becomes devel- 
oped, which repeatedly terminates into an inflorescence and so 
on. From the axil of the smaller leaf, on the other hand, only a 
very short branch becomes developed, resulting in a very 
unequal structure of the whole shoot, a succession of branches, 
alternately to the right and left side of the main axis. Abro- 
nia micrantha Torr. shows exactly the same structure, but it 
is a smaller plant, thus the anisophylly and the sympodial 
ramification is less plainly to be observed. In the near ally 
Oxybaphus of much the same habit, the anisophylly is not to 
be observed, not even in the species with the leaves broad, 
although the ramification is the same, sympoidal. 

Another peculiarity possessed by Jollugo verticillata is the 
alternation of long and short internodes, as shown in figure 4 ; 
this type of structure is not very common, but represented by 
several monocotyledonous and dicotyledonous genera, viz: 
Munroa,* Eriochloa, Cynodon, Androsace, Chimaphila,t 
Erigeron (flagellaris Gr.), etc. In regard to the inflorescence, 
this is in the Synoptical Flora (1. ¢.), only deseribed as 
“ flowers 2-5 from each node, slender-pedicelled, subtended by 
foliaceous bracts”; it is, however, cymose, and represents a 
dichasium. The floral structure is rather peculiar, there being 
five free sepals, no petals, mostly three stamens, alternating 
with the three carpels; the fruit is a membranaceous, loculi- 
cidal capsule with several estrophiolate, rugose seeds. 

Now in respect to the internal structure of the vegetative 
organs very little seems to be known about Mollugo verticil- 
lata judging from the treatment of the #%cocdew in Solereder’s 


* Bot. Gazette, vol. xxxix, 1905, p. 123. 
+ Merck’s Report, vol. xviii, p. 148. New York, 1909. 


T. Holm —Mollugo verticillata L. 529 


Systematische Anatomie der Dicotyledonen.* A brief descrip- 
tion of the stem is given by Karl Christ.t In speaking of the 
roots of the /%coidew Solereder (1. c.) states that the anomalous 
structure of the stem generally recurs in the root-system ; 
however, the stem-structure of our Mollugo is anything but 
anomalous, and the root-structure is indeed very simple. At the 
seedling-stage the primary root has a hairy epidermis, and a 
thinwalled cortex of only two strata. Endodermis is, also, 
thinwalled, and the pericambium consists of a single layer of 
thinwalled cells; the stele is diarch with a diametric ray of 
vessels, and with two strands of leptome. Increase in thick- 
ness commences early, but only within the stele so long as the 
individual has not reached the flowering stage. In mature 
specimens the primary root is a little thicker, but relatively 
short, and sparingly branched ; epidermis and cortex with part 
of endodermis are now replaced by several strata of thinwalled 
cork developed from the pericambium, and the stele consists 
now of a dense mass of collateral mestome-strands. In other 
words, the structure agrees with that, which is the most common 
in roots of dicotyledonous ‘plants. 

In passing to describe the stem we might begin with the 
hypocotyl. This stem-portion shows, also, an early increase in 
thickness by the formation of pericyclic cork, and by the 
development of secondary mestome-strands between the pri- 
mordial, while the individual is a mere seedling bearing only 
the cotyledons and a minute vegetative shoot. At this stage 
epidermis is thinwalled, and the cortex is composed of onl 
two layers of very large cells surrounding a typical, thinwalled 
endodermis. Inside the cork is a continuous band of leptome, 
and hadrome of wide vessels extending to the center, and with 
thickwalled parenchyma between these. If we compare this 
structure with that of the hypocotyl of a mature specimen, we 
notice no difference except that it contains a little more cork, 
but even so, all the peripheral tissues from epidermis to endo- 
dermis are still present. 

In regard to the stem proper, and especially the stretched, 
prostrate internodes, these exhibit the structure as follows: 
They are cylindric, glabrous and perfectly smooth, covered 
with a very thin cuticle; the outer cell-walls of epidermis are 
slightly thickened, and the cortex is compact, but consists only 
of three strata with a little chlorophyl!, beside that many of the 
cells contain styloids of calcium oxalate. There is a distinct 
endodermis, which contains starch, and pericycle representing 
a closed sheath of stereome (S in fig. 5) in-one to two layers, 

* Stuttgart, 1899, p. 468. 


+ Beitrage zur vergleich. Anat. d. Laubstengels der Caryophyllinen. The- 
sis, Marburg, 1887. 


530 T. Holm—Mollugo verticillata L. 


beside a single stratum of thinwalled parenchyma bordering 
on the leptome (L. in fig. 5). We find in the stele about twenty, 
distinct, collateral mestome-strands separated from each other 
by narrow rays of thinwalled parenchyma, and enclosing a 
solid pith, which is not excentric; it is only in very thick stems 
that some of the internodes (but not all) may show an excentric 
structure so far as concerns the stele, but not the cortex. The 
structure of the fruiting pedicel agrees with that of the inter- 
node described above, but we notice here the presence of small, 
obtuse hairs (fig. 9) filled with a greenish brown, granular 
substance; moreover the stele contains only four mestome- 
strands. - 

Before leaving the stem we might mention that in vigorous 
specimens the basal nodes are frequently swollen, and distinctly 
so ; this is, however, not due to the presence of collenchynga, 
as was expected, but simply to an increase of strata in the cor- 
tex.—While thus the structure of root and stem is very simple, 
we observe in the leaf several points which are quite interest- 
ing. It is, for instance, strange that the leaves, although being 
held in a horizontal position, possess stomata on both faces, 
and, at the same time, the chlorenchyma illustrates a typical 
dorsiventral structure with palisade-cells on the ventral, and 
with a pneumatic tissue on the dorsal. 

The cuticle is thin, and the lumen of the thinwalled epidermis 
is wider on the ventral than on the dorsal face, but there are 
no papille ; viewed in superficial sections, the lateral walls of 
epidermis are undulate on the dorsal, but less so on the ven- 
tral. Stomata abound on both faces of the blade; they are 
level with epidermis, and lack subsidiary cells. Hairs like 
those observed on the pedicels (fig. 9) occur along the midrib 
on the dorsal face, and at the base of the leaf-blade. There 
are two strata of typical palisade-cells with single, quite large, 
rhombic crystals of calcium oxalate, besides styloids; spherie 
crystals were observed in material preserved in alcohol, and 
they were located beneath the stomata. No collenchyma and 
no stereome is developed, but the veins have large-celled paren- 
chyma-sheaths (P. in figs. 6-8); the midrib is the broadest of 
these (fig. 6); it is arch-shaped in cross-sections, and the hadrome 
contains several narrow spiral-vessels; the lateral veins are 
much thinner (figs. 7-8) and consist only of a few leptome-cells 
and a single spiral-vessel, or of leptome alone as shown in figure 
8, which represents the marginal mestome-strand. The water- 
storage tissue is very poorly developed as a few strata above 
the midrib, between the palisades and the parenchyma-sheath. 

From an anatomical point of view J/ollugo verticillata is 
very distinct from the ‘other’ members of /icoidew as 
described by Solereder (1. ¢.): Mesembryanthemum, Tetra- 


T. Holm—Mollugo verticillata L. 531 


gonia, Aizoon, Sesuvium, Galenia, ete., with their centric 
leaf-structure, abundance of water-storage-tissue, and papillose 
epidermis, not speaking of the frequent anomalous stem-struc- 
ture possessed by these, mostly xerophilous genera; in some of 
the other genera, the herbaceous Adenogramma, Cisekia, 
Limeum and Psammotropha, the stem-structure is normal, 
and, as stated by Solereder, these genera are now generally 
referred to other families, viz. Portulaceew and Phytolaccacec. 
Our Wollugo does not, from an anatomical viewpoint, show any 
relation to the Portulacewe, but to the Caryophyllacee ; in 
respect to the habit, it resembles the Adsenew, but the floral 
structure, and especially the fruit, is different. 

Let us now examine the various views that have been 
expressed in regard to the classification of J/ollugo based solely 
upon the floral characters. 

As stated in the preceding, Jussieu did not include Jollugo 
in the Yicoidee, but referred it to the Caryophyllee ; in accord- 
ance with him, the Ficoidew consisted of Seswviwm, Azzoon, 
Glinus, Orygia, Mesembryanthemum, Tetragonia, beside two 
other genera, Reaumuriaand Vitrarva, whichare now referred 
to Zamariscinee and Xygophyllee. With Bentham and 
Hooker, the family /%coidew is divided into three tribes: 
Mesembryew, Aizoidee and Molluginee; in the last of these 
we find Mollugo with Orygia, Pharnaceuwm, Gisekia, and a 
few others. <A similar classification is proposed by Pax,* who 
ealls the family Azzoacew, with two tribes, Molluginoidew and 
Ficoidew, the latter including, of course, Mollugo, Glinus, 
Pharnaceum, while Mesembryanthemum, Sesuvium and Te- 
tragonia are referred to the former. In other words, the 
extremely different habit, the floral structure: calyx, stamens 
and pistil free (Jfodlugo), or calyx and stamens united, the 
pistil free (Azzoon), or finally, calyx, stamens and pistil united 
(Mesembryanthemum and Tetragonia), not speaking of the 
fruit, which varies from a capsule with loculicidal dehiscence 
(Mollugo), or, at the same time, loculicidal and _ septicidal 
(Mesembryanthemum) to a pyxidium (Seswviwm) or a drupe 
(Letragonia), these very prominent characters are now con- 
sidered of no sufficient importance for arranging these genera 
into more than one single natural family. A different classifi- 
cation was, however, suggested by Fenzl, who at first placed 
Tetragonia and Aizoon as members of the family P%cordee, 
removing Mesembryanthemum from these, establishing the 
family Mesembryanthemew, and referring Mollugo with its 
igen und Prantl, Natiirliche Planzenfamilien, vol. iii, p. 38, Leipzig, 


+ Monographie der Mollugineen and Steudelieen (Ann. Wien Mus., vol. i, 
p. 337, 18385). 


oO 


32 T. Holm—Mollugo verticillata L. 


nearest allies to the Portulacew,; sectio Molluginew. But 
later on* Fenzl changed his views and transferred Zetragonia, 
Aizoon and Galenia to the Portulacew, tribes Tetragoniew 
and Aizoidea, leaving Mesembryanthemee intact. The segre- 
gation of Mesembryanthemum evidently rests on good founda- 
tion, but it seems unfortunate that the other genera should be 
considered allies of the Portulacee ; it also seems more nat- 
ural to keep Zetragonia and Aizoon in a family distinct from 
Mollugo, as was first proposed by Fenzl. According to Rohr- 
bach these genera might be referred to two families: JZollu- 
ginacee and Ficoidacee,t and he considered them as being 
somewhat related to the Portulaceew and Caryophyllew, beside 
the Phytolaccacew. As pointed out by Eichler,t this relation- 
ship is much more natural than that supposed by Bentham and 
rooker,§ who place them all as /2coidew between Cactew and 
Umbellifere, widely separated from the Caryophyllacew and 
Portulacee. It seems altogether as if the position of Mollugo 
is very difficult to define in the natural system; it surely does 
not belong to the same family as Zetragonia and Mesembry- 
anthemum, and especially not if we compare the internal 
structure. It represents evidently a little family of its own, 
allied in some respects to the Caryophyllew, but by no means 
to the Cactew. 


Brookland, D, C., Feb. 1911. 


EXPLANATION OF FIGURES (p. 826). 


Ficure i. Seedling of Mollugo verticillata L., showing the primary root 
(R.), the hypocotyl (H.), the two cotyledons (Cot.), and three normal leaves 
Li-L’, of which Li and L! are opposite, while the other leaf opposite L? is 
not visible ; magnified four times. 

Figure 2. Oneof the cotyledons; x6. 

Ficurr 3. A young plant with the cotyledons still attached, seen from 
above, showing three pairs of opposite leaves (L’—L’), but of which the one 
corresponding to L? is not visible; S is the first branch with a stretched 
internode and a few leaves; the other letters as above; x 4. 

Fieure 4. Part of a floral shoot ; for explanation see the text ; magnified 
about three times. 

Ficure 5. Cross-section of the stem. Ep.=epidermis ; C.=cortex ; End, 
=endodermis ; S.=stereomatic pericycle ; L.=leptome ; Camb.=cambium ; 
H.=hadrome; P.=pith; x 320. 

Ficure 6, Cross-section of midrib of leaf, showing the large-celled par- 
enchyma-sheath (P.), the leptome and the hadrome; x 320 

Fiagure 7-8. Two lateral veins of the leaf, of which fig, 8is from the 
marginal; P. =parenchyma-sheath ; x 320. 

Ficure 9. Hair fromthe leaf; x 320. 


* Ibidem, vol. ii, p. 279, 1839. 

+ Martius Flora Brasil, Fasc. 56, 1872. 

eee iat p. 119, Leipzig, 1878. 

§ Genera plantarum, vol. i, p. 51, London, 1862-1867. 


Palache—Warren—Chemical Composition of Parisite. 538 


Arr. XLV.—TZhe Chemical Composition and Crystalliza- 
tion of Parisite and a New Occurrence of it in_ the Gran- 
ate-Pegmatites at Quincy, Mass., U. 8. A. With Notes, 
on Microcline, Riebechite, Aegirite, Ilmenite, Octahedrite, 
Fluorite and Wulfenite from the same Locality; by 
Cuaries Paracueé and Onartes H. Warren. 


Parisite.—The rare fluo-carbonate of calcium and the cerium 
earths, parisite, was first discovered in 1835 at the emerald 
mines of Muso valley, U. 8. of Columbia, by J. J. Paris, after 
whom it was named. It was first described by Bunsen in 
1845.* Its erystallization was described by Des Cloizeaux,t 
who also gives the indices of refraction as determined by 
Senarmont. A paper relating to its crystallization was pub- 
lished by Vrba in 1886. The mineral was again described 
by Penfield and Warren,§ with chemical analyses, from a new 
locality in Ravyalli Co., Montana, U. S. A., where it occurred 
in the form of embedded erystals in what appeared to be a 
decomposed rhyolite. Crystals from Muso valley were also 
analyzed by them, and the chemical composition was shown to 
correspond to the formula (R’’’F),Ca(CO,),. In 1894 A. Nor- 
denskidld| described as parisite a mineral from Narsarsuk, 
Greenland. Later G. Flink§{ re-examined this mineral and 
showed that it differed from parisite in its rhombohedral crys- 
tallization, in the relative proportions of its cunstituents and in 
its indices of refraction as previously determined. Flink gave 
it the name synchisite and determined the formula to be 
(R’F),Ca,(CO,),. It occurred on the surfaces of feldspar or 
aegirite crystals, or in cavities in alkali granite pegmatite, and 
with it also occurred the barium-parisite, cordylite, described 
by Flink and later by Beeggild.** The new occurrence of pari- 
site at Quincy, Mass., at first thought to be synchisite from a 
preliminary crystallographic examination and so announced,tt is 
also in an aegerite-bearing-rock. Murgoci,{{ in a paper diseuss- 
ing the origin of riebeckite and riebeckite rocks, notes the pres- 
ence of rare earth carbonates (parisite?) with the riebeckite 
and aegirite. Tacconi also notes the presence of parisite in 

* Bunsen, Lieb. Ann., liii, 147, 1845. 

+ Min., ii, 162, 1874. 

t Ber. Boehm. Ges., 647, 1886, and Zs. Kr., xv, 210, 1888. 

§ This Journal, viii, 21, 1899, and Zs. Kr., xxxii, 1, 1899. 

|G. For, Forh., xvi, 338, 1894. 

{| Bull. G. Inst. Upsala, v, 81, 1901; see also Boeggild, Medd. om. Groen- 
land, xxiv, 29, 1901. 


** Medd. om Groenland, xiv, 236, 1898 ; xxiv, 42, 1901; xxxiii, 101, 1906. 
t+ This Journal, xxviii, 450, 1909. tt This Journal, xxx, 137, 1905. 


Am. Jour. Sct.—FourtsH Series, Vou. XX XI, No. 186.—June, 1911. 
36 


534 Palache and Warren—Chemical Composition and 


connection® with the riebeckite granite at Montorfano, N. 
Italy. It forms there thin hexagonal erystals several milli- 
meters long, generally embedded in a chloritie mass which is 
encrusted with stilbite and chabazite, and is associated with 
fluorite, pyrite and quartz. G. Tschernikt also describes the 
mineral from a Manchurian locality where it occurred in an 
erratic granite bowlder rich in pyrite and with accessory fluo- 
rite and zircon. He gives chemical analyses of three differ- 
ent phases of the mineral as found there, with an elaborate 
discussion of the same. 

It thus appears quite certain that parisite, or the closely 
related mineral synchisite and cordylite, are characteristic 
pneumatolitic minerals of the riebechite-aegirite rocks. 

The parisite to be described in the present article, as well 
as the other minerals, occurs in one part or another of the 
pegmatite-pipes of the Quincy granite located in the quarry 
of Fallon Brothers and the Ballou quarry, North Common 
Hill, Quincy, Mass. The granite, as is well known, is a rie- 
beckite- aegirite- bearing rock high in silica, ferrous and ferric 
oxides and the alkalies , but very low in lime and magnesia. 
The feldspar is almost wholly a microcline- -microperthite. 
These pegmatites have been described in a preliminary way in 
a short article which appeared in this Journal in November, 
1909, and are also described in considerable detail in a paper 
which will appear shortly in the proceedings of the American 
Academy of Arts and Sciences. The last paper will contain 
also a somewhat fuller description of the minerals of the peg- 
matites (with the exception of the parisite) than will be given 
here, and to this paper the reader is referred for further details. 

In the larger Fallon-quarry pegmatite the parisite is rela- 
tively abundant in all parts where open spaces are present, 
implanted on the surfaces of the microcline and aegirite crys- 
tals. It was particularly abundant along the immediate lining 
(consisting almost entirely of microcline and aegirite crystals) 
of the large central pocket, and was found to some extent on 
the surfaces of the many pegmatite fragments found in the 
open space of the pocket. Ina similar pipe, but without any 
central pocket, in the nearby Ballou quarry, it has been 
observed only as grains in the massive rock. It may also be 
noted that occasional grains have been identified in the Quincy 
granite in other parts of the area, but seem to be confined to such 
parts of the granite as show other undoubted evidences of 
pneumatolitic activity. In one instance it has been noted in 
close association with minute erystallizations of astrophyllite.t 

* Rend. Acc. Linc., xiv, 2, 88, 1905. 

+ Verh. Min. Ges. St. Petersburg, xliv, 1906, pp. 507-545. Reviewed in N. 
Jahrb. f. Min., etc., Band ii, p. 336, 1909. 


{On the Occurrence of Astrophyllite in the Quincy Granite, see Pirsson, 
this Journal, xxix, p. 215, March, 1910. 


Crystallization of Parisite. 535 


Crystallography.—Crystallographic data concerning pari- 
site are but scanty, and for that reason a rather full account of 
our observations on the Quincy crystals is here presented. 

Parisite was determined to be hexagonal by Des Cloizeaux* 
in 1874, and he found on the type crystals from Muso valley 
series of pyramids of both orders, the base and a prism. The 
value of ¢ calculated from his measurements was 3°2891. His 
erystals were doubtless the large and rather rough ones first 
found there and he describes them as badly striated. He sug- 
gests a rhombohedral interpretation of the crystals, but with 
no reason for its adoption. 

Vrbat in 1888 measured three crystals from Muso valley 
which gaye good readings for the form o from which he ealcu- 
lated the element ¢ = 3°3646. 

Penfield and Warrent in 1899 described a new occurrence 
of parisite from Montana, but the crystals were too badly stri- 
ated to give reliable measurements. 

Cesaro,$ in 1907, gave the results of measuring minute but 
brilliant crystals of parisite attached to quartz. The locality 
is Muso, but apparently from a deposit different from that 
which yielded the original crystals. He derives the value 
c=3'405, but makes no statement as to the number of crystals 
or faces measured. His crystals showed distinct rhombohedral 
development and Cesaro adopts a rhombohedral position with 
the pyramid #(1124) as the positive unit suggesting, however, 
a possible preference for the choice as unit of the steeper pyr- 
amid g(1123). The latter choice was independently arrived at 
by the study of the much more complex crystals of parisite 
from Quincey as shown below. 

Tschernik| found on erystals from Mukden, Manchuria 
forms and habit very like those of Montana erystals. 

The crystallographic data of these papers is collected in the 
following table which shows the forms previously found on 
parisite. Discussion of the relation of synchisite to parisite 
will be found on a later page. 

The parisite crystals found at Quincey are, on the whole, 
favorable to crystallographic study. They are mostly small; 
1 to 8™™ in length, with a maximum of about 2°" and for the 
most part very slender. Many hundreds of these tiny crystals 
and erystal fragments were found in the sand-like debris left 
after washing the large collection of specimens of pegma- 
tite; many crystals are also visible, of course, still attached to 
the matrix. The erystals vary enormously in habit and quality 

* Min, ii, 162, 1874. + Zs. Ky., xv, 210, 1888. 

t This Journal, viii, 21, 1899. § Bull. Ac. Belg., 321, 1907. 


| Vehr. Min. Ges. St, Petersb., xliv, 507-545, 1906, Abstract in N. Jahr. 
Min., 1909, ii. 


536 Palache and Warren—Chemical Composition and 


TABLE I, 
| SR Oo 
pa 2 | | E 
lhea eal sealer ales . g 
Dana al B 5 5 a as oO xg 
mee VS Ie ee ee 
s8 | 82 |28/82)e8 |) S38 | See | ze | 
S| Be NASial. oS oae Sas Skea 
SS Oy Sa eee alee ge iI FS | vl 
ball he komme Se yer |e 
¢ 0001p e | 0001 0001 0 e 
m 1010 | m m | 1120 1120 oc 
a 1120 | a | | 1010 1010 oc 
q 1012 | of | | 924 | 1159 3/2 0 
r 2023) b2 r | | 8.8.16.9 2243 20 r 
5053 be | 5053 | 10.10,30.5 | 5.5.10.6 | 5/2 0 
DeAOM aires | 4483 1121 30 
5056 bs | 5056  20.20.40.9 | 5.5.10.3 50 
o 2031 = | 9 | o | 20% | 88163 | 2241 60 5 
a 1138| a8 1012-1012 3038 3/8 
e 1136] af 2033 | 1012 1/2 
f 1124 at ! < d0nt 3034 3/4 
g 11233) a3 | 4043 1011 1 
2255 | ad 2255 | 0885 0665 —6/5 
h 1192) o@ 1152 0231 0332 3/2 
k 2253| a® 8083 2054 2 
s 1121 A es gS |} ala 4041 | 8031 3 s 
a 6395 | BSDeAS | 16.4.30.5 | 12.3.15.5 | 18/5 9/5 


of faces, so that of the hundred or more placed on the gonio- 
meter for trial, more than two-thirds had to be rejected. Some 
thirty crystals, however, proved to be measurable and the 
results of their study are here presented. 

The basal plane is almost always present, generally relatively 
large and always very brilliant, so that it served admirably for 
the adjustment of the crystals on the two-circle goniometer. 
Although of prismatic habit, the prism planes are rarely more 
than rudimentary, the prismatic appearance being produced by 
oscillatory combination of steep rhombohedrons or pyramids, 
as in other occurrences of parisite. 

Three types of combination may well be distinguished: (1) 
rhombohedral, a single rhombohedron of either position being 


Crystallization of Parisite. 537 


dominant (figures 1, 2); (2) pyramidal, the dominant forms 
being rhombohedrons of both positive and negative positions, 
so balanced, that without measurement, the rhombohedral 
character is not apparent; (8) pyramidal (corundum habit), 
showing a series of second order pyramids and the prism, the 
pinacoid always broad; rhombohedral planes, when present, 
slightly modify the basal edges. (Figure 3.) 


ZEN 


Fics. 1-3. Parisite. 


In all types the rhombohedral character is clearly demon- 
strable in almost every crystal, sometimes by simple inspection, 
more often only after study of the distribution of the meas- 
ured faces in vertical zones. In practically all cases it is safe 
to assume that the prism, rarely wholly absent, is of the second 
order, and this was made the basis of the general orientation 
of the crystals. The determination of the sign of the rhombo- 
hedrons is often difficult and sometimes impossible since many 
of them occur in both positions. The series chosen as positive 
is the more complex, not only as a whole, but on most crystals, 


538 Palache and Warren—Chemical Composition and 
* 


and it was generally only by a study of the form series of the 
whole crystal that decision could be reached as to position of 
the rhombohedral series. 

In the best erystals all the faces are brilliant and give sharp 
images of the goniometer signal when not too narrow; the 
steeper forms are often developed as mere lines and the signals 
are then apt to be dim. The frequent oscillatory striations, 
however, do not seem to produce false faces, the signals of a 
series of faces being generally quite distinct. All the crystals 
examined had been implanted by one end and were, therefore, 
but singly terminated, but occasionally faces of very steep 
forms belonging to the lower half of the crystal came within 
the range of measurement of the goniometer. 

Twinning on the basal pinacoid was to be expected (see syn- 
chisite below), but could not be established ; it would be more 
or less completely concealed by the striated character of the 
lateral surfaces of the crystal. 

Table II shows the forms found on the Quincey parisite. 
These forms include practically all those previously discovered 


TasLe II].—Forms found on Quincy Parisite. 


Bravis—Miller. Gold. G2 | Positive Rhombohedrons | ic eee 
¢ (0001) ) A (1014) 1/4 B (0.4.4.15) —4/15 
m (1010) oc B (4.0.4.15) 4/15 | y (0227) —2/7 
a (1120) <0 | © (8:0.8.11), 8/11 )-0(0.8,8910)) ao 
Pyramids | D (8.0.3.10) 3/10 | € (0.9.9.25) —9/25 
b (4.4.8.15) 4/5 0 | E (5.0.5.16) 5/16 | @ (0338) —83/8 
4 (1123) 10 F (1013) 1/3 | € (0112) =—1/2 
¢ (11.11-99,97) 11/9 0 | G (5.0:5.13) 5/13 | @ (0558) —85/8 
nm (5.5.10.12) 5/4 0 | H (2025) 2/5 | f (0334) —3/4 
t (4489) 4/3 0 | e (1012) 1/2 | » (0665) —6/5 
q (1122) 3/2 0 | 7 (8.0.8.11) 8/1 |X (0554) —85/4 
u (5.5.10.9) 5/3 0 | J (7078) 7/8 |p (0221) —2 
y (2243) 20 g (1011) 1 a (0552) —5/2 
v (5566) 5/2 0 | L (5054) 5A lo (0331) —3 
p (1121) 30 | M (4043) 4/3 | @ (0772) —7/2 
w (4483) 40 | Ah (8082 3/2 |p (0441) —4 
o (2241) 60 N (110.1156) 11/6} (551) 3 
Scalenohedron | & (2021) 2 wo (0661) —7 
y (4:26.11) Slt 2A |) Peo), sane 
| S (8031) Selig 
| Q (10.0.10.3) 10/3 | 
R (4041) 4 
T (5051) 5 
- | V (6061) 6. eal 


Crystallization of Parisite. 539 


elsewhere together with a much greater number of new ones. 
No explanation is attempted of the prevalence of complex 
symbols among these forms. ‘The choice of unit is clearly 
justified by the constant recurrence upon the crystals of the 
forms having the simplest symbols in the pyramid series; the 
infrequent occurrence of correspondingly simple symbols 
among the rhombohedral forms is curious and appears to be 
characteristic for at least this occurrence of parisite. The last 
two columns of Table III, in which the number of faces of each 
form is given forall crystals, gives better than words the relative 
abundance of the forms. It may be well to state in explana- 
tion of that table that where faces of any form are jess on a 
particular crystal than the full theoretical number, the lack 
may be from two causes: in case of the pyramid series and 
prism it is generally from the distortion of the crystal reduc- 
ing the size of some faces so that they are not measurable; in 
case of rhombohedrons it is more often due to faces of two or 
more forms near each other in inclination occurring together 
as though they composed a single form. 

Table III contains the data upon which the new forms are 
based, as well as that which served for the calculation of the 
axial ratio. For the latter there were used the readings from 
254 faces of 27 forms on 32 crystals, the value of the element 
derived from each form being given a weight proportional to the 
frequency of the readings for that form in making up the 
final average. The value adopted in this table is stated for 
comparison with those of other authors, recalculated to this 
new position and unit as follows: 


palaces sae sr 6=1:9368) ) p,—1 2912 
Des Cloizeaux ___-_- 1:899 1:266 
Washo eee. See alas 1:9425 1:295 
@esaro: o22 2522 5. 1:965 1°310 


It will be noted that the new value is in very close agree- 
ment with that of Vrba. 

Concerning the individual forms there is little to say in 
addition to the statistical information contained in the various 
tables. The single scalenohedron observed had two distinct 
but narrow faces in zone with the forms H and ¢ so that its 
symbol is well established. The scalenohedron « of Des Oloiz- 
eaux was not observed and is probably to be regarded as a 
doubtful form. 

Optical properties of Parisite— As seen under the micro- 
scope, very small crystals or fragments are very pale yellow to 
almost colorless and show a bar ely perceptible dichroism. For 
erystals 3™™ thick the ray is bright yellow, often with a 
brownish tone; thee ray is golden yellow. The absorption is 


540 


SR EGOS AIA TE MIA BNAP GRD GHWDORNNW TAT SNe GHe HOW HOWpPONe Bsc tearerwocags 


Palache and Warren—Chemical Composition and 


TaBLE III.—Caleulated and Observed Angles of Parisite, Quincy. 
c=1 : 1'9363 


a: 


Calculated 
Ge @ 


6 ce 
—18/5 9/5 19 06 
—8/11 2/11 10 53 


47 05 


po = 1:2912 


Measured, mean 


-$ 


30° 00 
00 00 


ce 
oe 
ce 
GG 
oe 
ce 
“e 
be 
ce 
(a3 


uc 


p 
00° 00 
90 00 
90 00 
45 47 


Limits 
Pp 


51° 45-52° 36 


ov 
58 
59 


30-57 
11-58 
34-60 


11-65 
36-69 
48-73 
59-75 
48-79 


07-29 
24-30 
30-31 
20-38 
20-35 


40-40 
20-41 
54-48 
18-58 
43-62 
48-65 


05-86 


43 


50 
00 


= a 
D>? DF DOW WOH CLOT OT CD 6 tO A 


ps es 


9 Cd 0 
BIO SS WH DWH CLOTW 


ps 


= 


. e 
SHAHIAW UW CUWMNDAWOPR OCH PW OWROWP 


ee ed 


we 
MEO HE OLE OO MOO ARO E 


Crystallization of Parisite. 541 


o>e slight. For erystals 1™™ thick the dichroism and absorp- 
tion are but slightly greater. Upon alteration the crystals 
become filled with a dusty product, are less transparent and 
often exhibit a brownish or brownish red stain of varying 
intensity. 

The indices of refraction were determined by the immersion 
method, using a barium-mercuric-iodide solution. The deter- 
minations were made on a number of perfectly clear, small 
erystals chosen on account of the uniform development of their 
prism zones; also upon one larger crystal (1"™ in diam.) ter- 
minated by a perfect basal plane which made it possible to 
orientate the crystal and cut a section parallel to the prismatic - 
axis. An attempt was made to measure the indices directly 
upon this crystal by means of the Abbe refractometer, but 
without suecess, owing to the small size of the section and its 
low degree of transparency. The fine striations parallel to the 
edge between the base and the prism stand out very sharply 
under the microscope and make it possible to orientate the 
erystals with great accuracy on the microscope stage. The 
values obtained with sodium light are given below, also those 
heretofore given for parisite as determined by Senarmont and 
those for synchisite according to Flink. 


Parisite, Quincy Parisite, Muso Synchisite, Greenland 
Warren Senarmont Flink 
e= 1757 1°670 1:7701 
w = 1°676(+0°002) 1569 16742 
eo = 0'081 0-103 0:0959 


The Montana parisite, analyzed and described by Penfield 
and Warren (loc. cit.), also crystals from Muso valley taken 
from the mineral collection of Harvard University, were tested 
by the immersion method and their indices were found to cor- 
respond to the values given for the Quincy mineral. The older 
values given for the Muso mineral appear to be quite wrong. 
The ordinary rays for parisite and synchisite are almost iden- 
tical. The extraordinary rays appear to differ by 0-0131. 
While the extraordinary ray for the Quincy mineral is prob- 
ably not as accurately determined as the value for the ordinary, 
the error can hardly be as great as 0-0131 and the difference 
between the two minerals for this constant may perhaps be a 
real one, 

Chemical composition of Puarisite—About a kilo of fine- 
grained material recovered from the fragile lining of the cen- 
tral pockets was carefully washed and fractioned by means of 
screens, an electro magnet, and heavy solutions until a fraction 
was obtained weighing about ten grams and consisting largely 
of parisite mixed with more or less aegirite, anatase, feldspar 
and quartz. From this about three grams of clear yellow or 
amber-colored crystals were separated by hand-picking under 


542 


a powerful lens. 


Palache and Warren—Chemical Composition and 


Aside from a slight stain in a few erystals, 


the only impurities visible under the microscope were minute 
adhering grains of anatase and aegirite, hardly amounting to 
more than a trace. 

A partial analysis was also made on a few carefully selected 
erystal fragments of parisite from Muso valley taken from the 
mineral collection of Harvard University, to serve as a check 
on the earlier analyses made by Warren on crystals of the 
Muso mineral from the Brush collection, in New Haven, Conn. 


| i] 
| | 
ea a eee ie a ies 3 | 4 0) 6 meen mete) 
Mon- | Muso | Muso} Quiney| Muso | Synchi-| Synchi- | Cordy- 
_ tana | 1899 | 1910 | 1910 | Damour, site site* lite 
1899 | & Fink Mauze|lius 
Warren anal yst | Deville Green- 
land 
Spee.Gr. | 41128 4:302 : 4°320| 4:358]) 3:902} 3°900] 4°358 
Oz | 22°93 | 24°22 | 24:34) 24:16 | 23°48 | 26:54 | 25:99 | 23:47 
Fluor, 590 | . 6°82 6°56 ya) 5°82 5°04 4°87] 
Ce205 | 2614 | 30°67 | 29°92) 30:94 | 44°21 | 28:14 | 21:98 3°72 
(LaDi)2O; 28:46 | 29°74 | 28°75] 27:31 | 18°00 | 22°88 | 28°67 | 25°67 
Yt.Os tr. if tr. 1:23 1:18 tr. 
Fe.O3 80 "25 32 
FeO rill 1°43 
CaO 10°98 | 10°70 |11°50] 11:40 | 10:10 | 17:13 | 16°63 1:91 
SrO tr. ¢ 
BaO | 17°30 
Na2O 69 20 30 “30 “19 | 
K,0 ‘19 ‘10 "22 20 12 | 
H.0 26 ‘10 tr. ald “80 
Gangue 6°13 |(diff.) 1:02 2°58 
102°48 | 102°65 102°21 | 101°34 | 102°05 | 102:00 | 102°05 
O = 2F. 2°48 2°87 2°76 2°34 2°45 2°12 2°05 
Totals 100:00 | 99-78 99°35 | 99:00 | 99-60 | 99:88 | 100-00 


* Material somewhat altered and impure. 
+ Material scanty, impure, and perhaps slightly altered. 


H.O 2°10; 1°56 expelled at 100°. 


The molecular ratios derived from the above analyses are as 


follows: 
CO, 
1. Montana, 0°550 
2. Muso, ’99, *D00 
3. Muso, 710, D8 
4, Quincy, B49 
5. Muso,(D. &D.)— +553 
6. Synchisite, 0) 
Flink : 
7. Synchisite, 390: 
Mauzelius : 
8. Cordylite, 580 | 


int, R.03 
0°310: 0°166: 
809: +183; 
‘178 : 
340: +178: 
292: +187: 
306: 160: 
260: ‘189: 
"256: ‘181: 


CaO or CO, 
0°196 =8: 1°79: 


‘191 =3: 1:96; 
2038 =3: 
‘205 =3: 1:88: 
180 =3: 1:65 
306 =38: 1°52 
=4; 2-02: 
298 =3: 1°34: 
412 117fe) 
148 =3; 1:44; 


ewes 
MPwmoaqacoe 
=e 


F, R203 CaO 


Crystallization of Parisite. 543 


The analyses were made in duplicate and agreed closely. 
Regarding the method of analysis it may be stated that the 
earths were separated from lime by precipitation with ammonia 
after the complete removal of fluorine by evaporations and 
fuming with sulphuric acid in order to ensure that no fluorides 
were precipitated with the earth-hydroxides. The cerium was 
separated from the lanthanum and didymium by precipitation 
of the cerium with chlorine in a potassium-hydroxide solution, 
a departure from the method employed in the earlier analyses 
of the Muso and Montana minerals. Care was taken to 
examine all filtrates from oxalate precipitations of the earths to 
recover, if present, any unprecipitated earths, a necessary pre- 
caution, as has been pointed out by Hillebrand and others. 
The results of these analyses are given above and in parallel 
columns are given for comparison the older analyses of pari- 
site ; also the analyses of synchisite and cordylite. 

For synehisite the ratios derived from Flink’s analyses are 
sharply—CO,: F:R,O,: CaO=4:2:1:2. This leads to the 
formula given by Flink, (RF),Ca,(OO,),. The analysis of Mauze- 
lins (7), though perhaps on less satisfactory material, leads to the 
same formula. From this it appears that the formula of synchi- 
site, as determined by Flink, differs from that of parisite in con- 
taining exactly one more molecule of calcium carbonate. To 
make the chemical compositions of parisite and synchisite iden- 
tical calls for a change of 2°3 per cent in the CO, and of 6-0 
per cent in the CaO. ‘These are very serious differences, for 
they involve unallowable errors in the determination of the 
two constituents whose determination can be made with great 
accuracy. Small differences in the proportions of the rare- 
earth oxides are to be expected in minerals from different 
localities, and, indeed, analytical errors in the determination of 
the earths, unless considerable, would not seriously affect the 
ratios on account of the large molecular weights of these 
oxides. The close agreement in the lime and carbon dioxide 
determinations of the Muso, Montana and Quincy parisites (in 
all ten determinations have been made) leads us to place great 
confidence in their correctness, as well as upon that of the 
formula derived for the mineral from these localities. 

In discussing the analyses by Tschernik on the Manchurian 
parisite we are at a disadvantage, as the discussion appears in 
full only in Russian. The ratios derived from these analyses, 
however, do not correspond, so far as we can see, with the 
ratios given above for either parisite or synchisite, being far 
more complex. The presence of considerable amounts of water 
in all three analyses, as well as the variable and zonal character 
of the crystals analyzed by Tschernik, suggests strongly that the 


544 Palache and Warren—Chemical Composition and 


material had undergone considerable alteration with consequent 
changes in composition. 

Ltelation of Synchisite to Parisite.—The synchisite of Flink 
differs in most respects but little from parisite, and was indeed, 
but on insufficient material, earlier described as such by Nor- 
denskidld. The present writers, in view of the results of 
this study of parisite, believe that no valid distinction exists 
between these substances, and that synechisite must stand as a 
synonym for parisite. 

Synchisite is rhombohedral with forms which permitted of 
only approximate measurement, on the basis of which they 
were interpreted in terms of the parisite axes. Most of these 
rhombohedral forms have now been found on parisite, but the 
new position chosen for the latter requires a readjustment of 
the symbols as given by Flink. This is made in the following 
table, it being understood that the angle given for synchisite 
forms, in each case, is that of the nearest then known form of 
parisite to the measured angle, none of the latter being given : 


Synchisite (Flink) Parisite equivalent 

(Palache) 

e (0001) ce (0001) 

m (1010) m (1010) 

m (1120) @ (1120) 

2 (1121) 81° 33’ Zoi s3)) aes lied 

t (2029) 40 48 d (0338) 39 59 

r (2023) 68 53 n (0665) 69 34 

v (3034) 71 04 xX (0554) KO a9 

p (1011) 75 34 (0553)) 74 59 
_ >} not found 

s. (4043) +79 05 (O73), = 279) 109 

a (3032) 80 13 ma (0552) 1A BO 

é (0115 Sipepil BY (013) 36 42 

u (0229) 40 48 G (5.0.5.13) 40 46 

q (0112) 62 46 J (7078) 62 56 

y (0334) 71 04 M = (4043) ees 

B (0332 80 13 P(E) e806 

y (0381) 85 06 I \(SS0510) 80 53 


It is evident that the form series of synchisite fits into that 
of parisite perfectly, and as both are rhombohedral no dis- 
tinction of form can be made. The new determination of the 
optical constants of parisite has shown that the two substances 
have sensibly the same values. Parisite has been shown to 
have the same cleavage property which Flink showed to be 
characteristic of synchisite; the basal cleavage of both is vis- 
ible only in altered specimens, the fresh minerals breaking with 
conchoidal fracture. 


Crystallization of Parisite. 545 


There remain but two sensible differences between the two 
substances; synchisite has a slightly lower specific gravity ; 
and its chemical composition shows the presence of exactly one 
molecule of CaCO, more than is present in parisite. It is 
hardly possible that this large difference in composition can 
rest in analytical errors; on the other hand, it is quite impos- 
sible for the writers to believe that two substances with such 
a profound chemical difference as this could be so nearly 
identical in all their physical properties. The following con- 
sideration is offered as a possible interpretation of the matter. 

In describing the crystals of synchisite Flink states that 
many of them show an enlarged central portion with forms 
and luster differing from the smaller crystals and with slightly 
altered optical character. This is a character common to the 
larger crystals. Now there is no statement in the paper of the 
quality of the analyzed crystals. Are we not justified in 
believing that the analysis material contained enough of this 
altered substance which might well be CaCO, to produce the 
differences found? The alteration would tend to lower the 
specific gravity, so that this difference too would be accounted 
for. A new analysis of perfectly fresh synchisite can alone 
settle the question. 

Microcline.—Microcline in well-formed crystals of orthoclase 
habit makes up the greater part of the porous material near 
the great central pocket. The crystals range from a diameter 
of two and a half centimeters downwards to mere crystal 
specks ; they are, however, very constant in habit, presenting a 
remarkably cuboid form due to the dominant development of 
the base, clinopinacoid and orthodome; prism and unit pyramid, 
the only other forms found, being very subordinate in size. 
The faces are smooth and give fairly good reflections of the 
goniometer signal. The albite twinning, shown by microscope 
study to be universally present, is not apparent on the exterior 
of the crystals; its presence makes the crystals sensibly mono- 
clinic however, and the measurements obtaimed approximate to 
those of orthoclase. Well-formed Baveno twins are seen in a 
few specimens, but most of the crystals are in clusters without 
apparent definite relation of the constituent individuals. The 
color of the microcline is white to pale ivory-yellow. On faces 
of the prism there is often a secondary coating of colorless 
glassy feldspar in parallel position to the main crystal, which 
the microscope shows to be also microcline, although its 
appearance strongly suggested the growths of albite so common 
on orthoclase from numerous localities. 

Orientated sections, cut from the freely developed erystals 
of the pocket lining and from some of the larger erystals with- 
out, show that the microcline is twinned after the albite law 


546 Palache and Warren—Chemical Composition and 


only and thus lacks the grating structure characteristic of 
microcline in general. In basal sections the twinning is seen 
to be very finely polysynthetic. The individual lamelle appear 
as short strips slightly elongated parallel to 010. Their bound- 
aries are as a rule not sharp. The two sets of lamelle extin- 
guished symmetrically on either side of the trace of the 
twinning plane at an angle of 16 degrees (average of 12 meas- 


Fie. 4. 


Fic. 4. Micro-photograph of a basal section of microcline cut from a 
freely developed crystal of the pocket lining, Fallon quarry pegmatite. 
Shows twinning after the albite law only. One set of twin lamelle is extin- 
guished at an angle of 16° with the trace of 010. 

Crossed nicols. Magnification about 300 diameters. 


urements). The clearer growths of later age are in parallel 
position to the older crystal and in them the twinning lamellee 
are often longer and more sharply defined. In the small 
microclines throughout the finer-grained portions of the pipe 
the twinning is usually more sharply defined. The extinction 
of 010 sections was found from the average of ten measure- 
ments to be 5°. Figure 4 is a micro-photograph, using 
polarized light, of a basal section of a small microcline 
erystal. 


Crystallization of Parisite. 547 


Riebeckite.—The riebeckite occurs in the form of elongated 
prismatic individuals, possessing a black color and a lustrous 
cleavage, scattered through the coarser-grained main portion of 
the pegmatite pipes. The associated minerals are quartz, 
microcline-albite-microperthite and aegirite with accessory zir- 


Fig. 9. 


Fic. 5. Micro-photograph of a basal section of a small microcline crystal 
in the fine-grained portion of pegmatite in the Fallon quarry. Shows twinning 
after the albite law only. One set of lamellz are extinguished at an angle 
of 16° with the trace of 010. 

Crossed nicols. Magnification about 250 diameters. 


con, fluorite and ilmenite. It varies in size from quite small 
individuals up to crystals one or two centimeters thick and ten 
or twelve long ; individuals a centimeter thick and five or six long 
being quite common. The erystals show a tendency toward a 
crystal outline consisting of the unit prism occasionally trun- 
cated by the clinopinacoid. The immediate boundaries are, 
however, always more or less intergrown with the surrounding 
minerals. Terminal planes are not observed. Measurements 
of the prismatic cleavage made on two individuals yielded 
identical values of 55° 05’, an angle considerably larger than 
that of common hornblende, which is 55° 49’, The mineral is 


548 Palache and Warren—Chemical Composition and 


always to a greater or less extent intergrown with aegirite. 
While the latter is frequently included in the body of the 
former, its most common position is about the outside, parti- 
cularly the ends of the crystal, and although the riebeckite con- 
tains unorientated grains of aegirite, the usual mode of inter- 
growth is with the prismatic axes of the two minerals parallel. 
As the sides and particularly the ends of the erystals are 
approached, narrow strips of aegirite are interlaminated with 
the riebeckite, the amount usually increasing until the latter 
is entirely replaced. The riebeckite usually contains consider- 
able amounts of black dust, often arranged in wavy lines, as 
well as larger grains of black oxides, mostly ilmenite. Occasional 
grains of feldspar, fluorite and zircon are also included, some- 
times singly and again forming patches of varying size. 

Optical.—The deep color and strong absorption of the min- 
eral makes the determination of its optical properties, with 
any precision, very difficult. This difficulty is increased by 
the fact that it has been found impossible after many trials to 
obtain altogether satisfactory sections of the mineral across 
the cleavage owing to its extreme brittleness. By the study of 
finely crushed material and thin sections the following char- 
acters have been made out :— 

Ray near c=a. For) Ray || tob=c. For| Rayneara=b. For 
sections 0:03™™ or under, 0°03™" thickness, very | thickness under 0:03™™ 
deep blue to bluish,|dark smoky green to| yellow. For 0:03 and 
smoky green. For over almost black. over brownish yellow 
0:03™™" nearly or quite | with a greenish shade. 
black. | | 

Absorption a<c much greater than 6. For many sections 
intermediate in position between the front and side pinacoids, 
a peculiar dull, grayish blue (some might call this a drab 
or even a violet tone of color) is seen. This is particularly 
true of thin cleavage fragments. In many sections parallel to 
the clinopinacoid it has been observed that the distribution of 
color is not uniform, the blue being seen in streaks parallel to 
the cleavage, or lying along lines crossing the cleavage, sug- 
gesting in appearance minute cracks along which there has 
been some slight chemical change. In such cases the remainder 
of the section has a dull bluish green colcr. In the riebeckite, 
from the pegmatites at least, such variation in color does not 
appear to be connected with any significant change in the 
chemical composition. Tests with the sensitive tint on very 
tbin cleavage fragments show always a negative elongation. 
The extinction in 010 sections does not exceed four or five 
degrees, measured on the prismatic cleavage. Its accurate 
determination is rendered difficult by the strong natural color 
and strong dispersion of the mineral. A single section perpen- 


Crystallization of Parisite. 549 


dicular to the prismatic axis which was sufficiently thin to 
yield, in convergent light, using a powerful illumination, a 
faint biaxial interference figure, was cut by the firm of Voigt 
and Hochgesang. The hyper bole move well out of the field 
on rotation of the preparation, indicating a large axial angle. 
The axial plane bisects the acute angle of the cleavages. This 
is substantiated by the interference figure obtained from the 
010 section, which is clearly that of an obtuse bisectrix with 
the axial-plane lying parallel to the cleavage direction. The 
hyperbole in figures from this section are faintly colored red 
and blue ; also interference brushes obtained from random sec- 
tions are strongly colored red or blue, indicating a strong dis- 
persion, the exact character of which has not been made out. 
From the above it appears that the axial-plane in this riebeck- 
ite lies perpendicular to b 010,an unusual relation for a horn- 
blende, while the acute bisectrix lies inclined by not over four 
or five degrees to c’, and is negative. A determination of thie 
index of refraction for the yellowish ray, by the immersion 
method, gave a value of 1°695 (sodium). 

Chemical composition.—Material for a chemical analysis 
was obtained from a single large crystal which appeared excep- 
tionally free from impurities. This was broken up and most 
carefully picked over by hand under a powerful glass. When 
examined under the microscope it appeared agreeably free 
from alteration and included grains, except some inevitable 
black dust and a few black oxide particles as well as traces of 
aegirite and microcline. The average of closely agreeing 
duplicates is as follows :— 


Per cent. Molec. ratios. 
poh Os ia ea age se 51°79 0°833 
Omer. yh U ie ene 0-015 
FAO)” SheNe ees eet et 68 pas th 
OMNIA. Lule shed 14°51 t oe 
2(0) 5 See ei OR 21°43 | 
IM iy QP stone oe aes tue 1°15 | } 
C2 Opes ult iI. ava 1:28 f oy 
IMiGOK 85. oa5 Agu mieeers 10 } 

INE 0 an aaa Par Ve 6:16 ao 
RO ith ci, cea 1710 
Sat ten Sy Sa eae ar 2 “20 

FO ps tb ani a ‘10 082 
RO Ee Al ee eee er 1°30 
Potaless ee we tee eet O8 
Less OS as cee ee 69 
101°17 
SPECMel eee see cae orl 


Am, Jour. Sct.—FourtH Series, Vou. XXXI, No, 186.—Junz, 1911. 
37 


550 Palache and Warren—Chemical Composition and 


The total of the analysis is a little high, a fault that is almost 

or quite unavoidable in a long silicate analysis made in a labo- 
ratory located in an excessively dusty part of a large city, par- 

ticularly in the summer when the windows have to be open. 
If the TiO, is deducted with a proportionate amount of FeO 
to form ilmenite, the ratios derived from the analysis are 
SiO, : R,O : (RO +R,O+H,O)=8 : 0:90 : 4:76. These may 
be apportioned between appropriate molecules as follows : Na, 
Fe, $i,0,, =0°582 : R,Si,O,,= 0:834 : SiO, left = 0-058. The 
excess of silica is considerable. The cause of this is not entirely 
clear. A little feldspar was present in the material analyzed, 
perhaps also unnoticed bits of quartz, and if the alumina in 
the analysis be taken out and combined with a proportion- 
ate amount of potash and silica to form microcline, the excess 
of silica is considerably reduced and the metasilicate ratios 
become more satisfactory. The potash seems rather high and 
may be in error. 

A comparison of the Quincy riebeckite with other varieties 
of the mineral has been made elsewhere* and need not be re- 
peated ere further than to call attention to the fact chat, owing 
to its relatively low ferric and high ferrous oxide, it contains 
only 42% of the Na, Fe,Si,O,, molecule, showing in this respect 
a rather close agr eement with the riebeckite from Colorado, 
described by Koenig,t that from Red Hill, New Hampshire, 
described by Pirsson and Washington,t which contains 43 and 
44 per cent respectively, but departs widely from the riebeck- 
ite from Socatra, analyzed by Sauer,§ which contains from 
68 to 69 per cent of this molecuie. The Quincy mineral also 
corresponds quite closely in the same way to several croci- 
dolites whose analyses are quoted by Dana.| This last 
resemblance is especially interesting im the present connec- 
tion because, in the central pocket of one of the pegmatites 
in which the riebeckite is found, there occurs an abundant 
crystallization of a black needle-like amphibole and crocidolite 
which seem to be, if not identical with the riebeckite in com- 
position, at least very nearly so. 

Aegirite.—The aegirite of the central pocket is also pris- 
matic in development, sometimes, and especially in the smaller 
crystals, showing distinct and measurable terminations. There 
is, however, even in the best crystals much facetting and curva- 
ture of part of the terminal planes, especially in those highly 
inclined to the vertical axis. ‘The faces of the prism zone are 

*The Pegmatites of the Quincy Granite, etc., Warren and Palache. Proc. 
Amer. Acad. Arts and Sciences, 1911. 

+ Zs. Kr., i, 430, 1877. {This Journal, xxxiii, 439, 1907. 

$ Zs. D. Geol. Ges., xl, 138, 1888. See also Dana’s System of Minera- 


logy, p. 400. 
|| Dana’s System of Mineralogy, p. 400. 


Crystallization of Parisite. 551 


generally plane and measurements of sufficient accuracy were 
obtained to make it clear that these crystals may be referred 
satisfactorily to the axial elements of aegirite as described by 
Brégger. As a rule the smaller the crystal the better the 
quality of its faces; the best ones were minute needles of clear 
green color. Larger crystals are dark green to blackish green 
in color and often occur in subparallel groups, sheaf or rosette 
forms; many show fractures more or less healed or extreme 
bending. 

Twinning on the orthopinacoid is common in larger crystals 
but is invariably associated with rounding and irregularity of the 
terminal planes to a degree that entirely precludes measure- 


Fie. 7. 


Kies. 6, 7. Aegirite. 


ments. The basal plane was not observed. The form series 
-as a whole is much more like that of augite than like that 
described as typical for either aegirite or acmite. None of the 
forms supposed by Brégger to be peculiar to those species 
were discovered. On this account and because several of the 
forms determined have not been recorded for aegirite ; since 
moreover, this aegirite is shown by the analysis to be nearer 
to the theoretical aegirite molecule Na,Fe,Si,O,, than any 
previously described, it was deemed advisable to calculate the 
angles of the forms found on the basis of the axial ratio 
derived from these measurements, and they are accordingly 
presented in the following table together with the observed 
angles : 


552. Palache and Warren—Chemical Composition and 


The axial ratio calculated from fifty faces of six forms on 
eight crystals gives the values of the first line below, with 
which may be. “compared the ratios of aegirite and acmite as 
determined by Brogger. 


a b ¢ 8 
Aegirite, Quincy 11044 1 > 6043 73°97? 
Aegirite, Norway, Brogger 1:0975 : 1 : 6009 73 09 
Acmite, 2 S09 96s sles mo Olio ical el 


Table of angles of Aegirite, Quincy. 
po=d472 go= 5762 e='3015 w= 72°27’ 


Calculated Measured Limits No. of 
ee aces Quality 
i) p Q p 


a 100 90°00' 90°00' 89°57’ §=90°00' 89°37'-90°04' 5 poor 

6010 0000 90 00 00 37 90 00 1 poor 

m110 4335 90 00 43 33 90 00 43 00-43 55 27 good 

f 310 7042 9000 |. 7026 90 00 69 56-70 56 5 poor 
willl 5550 47 06 55 54 647 08 55 17-56 16 

. 46 54-47 31 11 good 

s 111 -2315 3320 -2340 383 24 1 fair 
w 331 4821 69 52 48 29 69 50 47 45-49 13 

; 69 36-70 00 4 poor 

2 331 -38747 6627 -3746 66 42 1 poor 
6 551 4631 7710 44 46 77 57 44 02-45 31 

77 80-78 25 2 v. poor 


7 112 -5 32 1653 -5 51 16 50 516-6 19 
2 16 40-16 57 5 good 
A 311 -66 44 5650 -6640 56 45 66 37-66 44 2 v. poor 
d131 2609 63 39 26 40 63 48 26 19 -26 52 
63 34-64 03 3 good 


The forms w (831), (551), (112), and d(131) are new to 
aegirite although all are known on augite. The habit of the 
Quincy aegirite crystals is shown by figures 6 and 7. 

Optical.—Small crystals or crystal fragments show under 
the microscope the following pleochrism : 

a = pale to deep green, sometimes with a slight bluish tone. 
The color naturally varies with the thickness, but also varies 
quite widely in the same crystal. In fact portions of a erystal 
may be a very pale green to almost colorless, and the other 
portions medium to dark green, without there being, however, 
any other optical variation so far as can be told. 

b = pale yellowish green to almost colorless. 

= pale yellow to yellowish green ; almost colorless. 

In many crystals the whole or a part may show a brownish- 
yellow or even reddish-yellow color. This is often most pro- 
nounced about black oxide (ilmenite) grains and is believed to 
be a pigment stain of ferruginous character. There appears, 
at least, to be no regularity in the distribution of the brownish 
or reddish colorations. The, extinction, a A c’, is 6 degrees. 
Other optical characters appear to be as usual for aegirite. 


Crystallization of Parisite. 553 


Chemical composition.—The almost universal contamination 
of the aegirite with other minerals made the obtaining of suit- 
able material for chemical analysis very difficult. By means of 
magnetic and heavy solution separations combined with hand- 
picking under the microscope, about three grams of material 
were finally obtained which showed as impurities only a little 
ilmenite and traces of octahedrite and quartz. 

The analysis made in duplicate averaged as follows: Aegir- 
ite, Fallon Quarry, North Common Hill, Quincy, Mass., 
U.S. A. (analyst, Warren). 


Per cent. Molee. ratios. 

IS) Oe NE Bee ee ae St 51°73 0°862 0862 
NTO), Belo cel, ie Pen os “64 008 0-008 
INTRO) Mee Ba ay. RE 1°91 ‘018 

9) 
Fe,0, RR RAO MB 31°86 “199 Hee 
10) ee OMe eee 87 "012 | 
MOREE a) aN Es 60 “008 | 
CAO n= sin Gheie esau 87 “O15 | 

29 
Opel gee ob « 14 003 f oe 
INO) es os ata aes ol 11°43 "184 | 
EO ep ENS UD “40 “004 J 
NGL O ees Grice ee 2 Maree "20 
eae eee Pee enone 
Mogae Shee Wee =100°65 
Specwolaviat ton Cee eee bees =3°499 


Although a portion of the TiO, was probably present as 
TiO, (octahedrite), most of it is combined with RO as ilmenite, 
and after deducting the TiO, and the proportionate amount of 
RO as ilmenite, the combined ratios are: SiO,=0°838, R,O,= 
0-217, RO + R,O = 0-218; or very nearly SiO,: R,O,: RO+ 
R,O=4:1:1, leading to the formula (R’’,R) Fe,Si,O,,. So 
far as known to the writers, the ferrous iron is lower in this 
aegirite than in any other hitherto analyzed, and the compo- 
sition approaches very closely to the theoretical composition of 
the compound, Na,Fe,Si,O,,, which is SiO,, 52 per cent; Fe,O,. 
34-6 per cent; Na,O, 13°4 per cent. 


Fic. 8. Fre, 9. 


Fies. 8, 9. Ilmenite. 


Iimenite. — I\menite occurs in moderate abundance in 
both the Ballou and Fallon pegmatites. It appears to have 


554. Palache and Warren—-Chemical Composition and 


been of rather late formation and is particularly associated 
with aegirite; as embedded xenomorphie plates, and groups 
of tiny crystals implanted on crevices of fractured aegirite 
erystals (Ballou quarry); and as clusters of larger crystals upon 
the walls of cavities left by the destruction of such erystals b 
magmatic resorption (Fallon quarry). The crystals are anil 
not exceeding a diameter of 2", and are always very thin tab- 
ular in habit. A dull-black coating of manganese oxide com- 
monly gives them a lusterless appearance, but in two specimens 
brilliant crystals were obtained which, despite minute size, 
gave good measurements on the goniometer. Octahedrite is 
almost always sparingly present with ilmenite. fe 

The forms observed are as follows: ¢(0001), m(1010), 
@1120), (2130)* 6(1019), (1014), (2095), (1011), 
K(0.7.7.20), €(0112), A (0445)*, s(0221), »(0552)*, g (0.3.3.11)*, 
k(0.3.3.10)*, m (1123), (2248). 

The crystals from Ballou quarry showed the forms c¢, 7,a, 
6, 7, and 7,, the prism zone being well developed and the base 
large and very brilliant. The prism is new to ilmenite. 

Crystals from Fallon quarry are dominantly rhombohedral, 
prism faces being reduced to mere lines. The crystals meas- 
ured showed the following combinations : 

Feeney eee Shes 

Cr i 5 

CAT, is th, Ona 20. 
i, 


STS OT HR OO ND ES 
fo) 
. 
> 
2 
S 


Se eR 

As shown in the figures (figs, 8 and 9), flat positive rhombo- 
hedrons are largely developed on these crystals, recalling the 
description of one (the common) phase of ‘ Crichtonite” from 
Oisans by Des Cloizeaux.t That author considered the rhom- 
bohedrons which he measured (1015), and (1019), and (1.0.1.11) 
as negative, but left the determination of sign doubtful. The 
second of these forms is common to all the crystals from Fal- 
lon quarry and is certainly positive, so both the others should 
be likewise so considered. Several negative rhombohedrons 
new to ilmenite were observed and are based on the following 
data : 


Form Calculated Measured No. Limits of p. 
9g p o p 
g (0.3.3.11); 30°00’ 23°34’ 30°00’ 23°461 3) 23°28 to 24. Ob! 
k (0.3.3.10) es 235) Ai ee Dy 85 
A (0445 oe Dll -39 MG GL ye 2h) Vayil v8} uo) a2? (OKO) 
r (0552) pe easy ee w OG, ql 
0 (2130) 10 53 90 00 10 30 90 00 4 10 36 to 11 34 


* New forms. + Mineralogie, ii, 222, 1898. 


Crystallization of Parisite. 555 


The presence on one crystal of the form 7, observed before 
only by Solly on a Binnenthal crystal, confirms this form. All 
the forms present gave angles agreeing very closely with the 
values calculated from the axial ratio of Koksharow as used 
by Dana. 

Chemical tests on the ilmenite from both quarries revealed 
strong qualitative reactions for manganese ; an analysis would 
be interesting, but it was not possible to separate enough of 
the fresh mineral for this purpose. 

Octahedrite.—Octahedrite is found chiefly in the large cen- 
tral pocket of the Fallon pegmatite, generally in close associ- 


Fic. 10. Fie. 11. 


ia Lu 
sae 


ation with aegirite and often formed posterior to the alteration 
of that mineral, since it is not infrequently seen on the walls 
of hollow casts of aegirite crystals associated with fluorite and 
ilmenite. Isolated crystals were also found implanted on feld- 
spar crystals. The erystals of octahedrite are small, of a deep 
black color, and of very brilliant luster. They show only the 
forms ¢(001), m(110), p(i11), #(112), and 2 (113), the two last 
the least common. These crystals are marked by two pecu- 
liarities ; they are in large part of prismatic habit with the first 
order prism dominant, a habit not before described for this 
mineral, and causing the crystals to be at first mistaken for 


556 Palache and Warren—Chemical Composition and 


zircon ; and they occur in cruciform twin groups with the form 
(101) as twin plane. The twins are sometimes complete inter- 
penetrations of two equal crystals as shown in the figure ; some- 
times but one end of each is developed ; again a larger crystal 
has a much smaller one in twin relation to it. The groups are 
exquisitely sharp and leave no doubt as to the definiteness of 
the twinning since the two upper faces of the unit pyramid of 
each erystal : “and the two lower, parallel and opposite faces to 
these, reflect the signal simultaneously in pairs; thus the faces 
of (101) which are in zone with these unit pyramid faces must 
be parallel to the twin plane. 

This twin law has been observed but once before on this 
mineral, on erystals from the titaniferous calcite-quartz veins of 
Somerville, Mass.* There twins were extremely rare, while 
here they are sufticiently numerous to be considered as charac- 
teristic for the locality. Combinations of prism and unit pyra- 
mid are far the most common among these crystals. A few, 
however,’show the base as a tiny facet, and in a few the flatter 
pyr amids & or 2 replace the acute summit of the common form. 
Figs. 10 and 11 illustrate the habit of the octahedrite crystals. 

Fluorite.—Fluorite is distributed throughout all parts of the 
pegmatite masses. It is generally in small grains, but near the 
central pocket, especially in that part where crocidolite was 
abundant, the fluorite individuals were larger, one mass show- 
ing cleavage faces nine inches across having been found. 
Where wholly embedded in crocidolite the fluorite crystals are 
idiomorphic, octahedrons up to one inch in diameter thus 
occurring ; they are dull and somewhat rounded, the color a 
deep purple like all the fluorite of this locality, but occasion- 
ally there is a surface layer of bluish green color due to in- 
cluded fibers of the blue crocidolite. The hollow castes left 
by the solution of such crystals have already been described. 

In one or two cavities in the Fallon pegmatite there were 
seen tiny cubes of fluorite implanted on quartz, and in another 
such pocket, peculiar in containing also crystals of calcite, the 
cube was modified by two hexoctahedrons which appear to be 
new to fluorite. The measurements and derived symbols of 
these forms follow : 


No. of 
Calculated. Measured Limits read’gs 
¢ p ? p d p 
{ 3.10.16 16°42’ 33°07 15°45’ 33°20’ 
4 3.16.10 10 388 58 26 10 36 58 33 10°30’— 10°42’ 58°30’ —58°36' 2 
(10.16.38 32 00 80 58 32 04 81 05 31 52— 32 16 80 50 —81 20 4 
( 259 21 48 30 54 21 01 31 15 20 45— 21 18 3111 —3119 2 
+ 295 12 32 61 32 12 32 61 20 12 27— 12 37 61 23 —61 26 2 


| 592 29 03 79 00 


* On Octahedrite, Brookite, and Titanite from Somerville, Mass. C. 
Palache. Rosenbusch Festschrift, 1906, 511. 


Crystallization of Parisite. 557 


Wulfenite.— Thin coatings of light yellow color as well as 
tiny erystals of wulfenite were found on smoky quartz in the 
crocidolite pocket. The crystals are in part model-perfect 
combinations of first-order pyramid with third-order prism 
n (111), and 7 (320), (see fig. 6, p. 990, Dana, System), in part 
cube-like combinations of a prism and the base. The amount 
of wulfenite is very small, and its presence is easily accounted 
for by the association, in the same region of the pegmatite, of 
molybdenite and galena. 


Boston and Cambridge, Mass., 
February, 1911. 


Art. XLVI.—Wotes on the Absence of a Soil Bed at the 
Base of the Pennsylvanian of Southern Ohio ;* by JESSE 
KK. .Hyne. 


Baitey Wixtis has recently urged, as one of the fundamental 
principles of paleogeography, the theorem that the failure of 
representation of many horizons and formations in an area 
where sedimentation has otherwise apparently been continuous, 
is to be explained by submarine erosion or failure of deposition 
due to current action, and that it is unnecessary to assume 
subaérial erosion in order to explain such a break in sequence.t 
E. O. Ulrich has since seriously questioned the validity of the 
grounds for Willis’ stand, and his discussion with Willis’ reply 
are briefly abstracted in the minutes of two recent sessions of 
the Geological Society of Washington.t Although these 
remarks are not a formal presentation of either side, it is felt 
that they open up to discussion one of the most important 
points in paleogeography and one about which it is apparent 
much remains to be learned. John M. Clarke’s eloquent 
appeal for more facts to support scientific theory, appearing in 
the same number of Science with these abstracts, is as timely 
to the present instance as to any of the unproved propositions. 

One of the principal arguments cited by Willis to support 
this theorem is the absence of anything resembling a soil bed 
or in any way suggesting weathering due to exposure to the 
atmosphere at the plane which marks such an omission from 
the column. It is maintained that if the bed whose absence 
it is desired to explain had been eroded while the whole stood 

* By permission of the State Geologist of Ohio. 
+ Science, N. S., vol. xxxi, pp. 241-260, 1910. 
tScience, N. S., vol. xxxiii, pp. 312-316, 1911. 


558 J. BE. Hyde— Notes on the Absence of a Soil Bed. 


above sea-level, some trace of the subaérial exposure would be 
visible at the contact. 

The following facts concerning one erosion surface are 
presented solely as evidence against Willis’ interpretation of 
the significance of the absence of soil beds or other evidence 
of exposure. The point which it is desired to make is that 
there may be no evidence of such a period of exposure at a 
contact which undoubtedly stands for several hundred feet of 
erosion, apparently under conditions highly favorable for soil 
formation. The explanation of the absence in this case cannot 
possibly be the one given by Willis, but no reason is, as yet, 
to be assigned. iat 

The base of the Pennsylvanian series, or Coal-measures, 
along the outcrop belt in central and southern Ohio usually 
rests directly on the Logan formations whose general age is 
early Mississippian. The latter were subjected to erosion 
which removed an unknown thickness and a relief of 200 
to 800 feet was established before the Coal-measures were 
accumulated. At several points the Maxville limestone, late 
Mississippian in age, is found between the two, but it occurs 
only in patches. There was some erosion of the Waverly 
prior to the formation of this limestone, but it is very probable 
from the general field relations that by far the most of the 
erosion was in post-Maxville time. The irregularity in the 
distribution of this formation is to be explained, in large part 
at least, by the attitude of the post-Maxville erosion surface. 

This plane of disconformity extends entirely across Ohio. 
It has recently been followed in some detail from the center 
of the state to the Ohio river. In places, it cuts very abruptly 
into the fine-grained yellow sandstones of the Logan forma- 
tions, sometimes removing them entirely, and letting in coarse, 
massive Coal-measure sandstones, but usually the irregularities 
are gentle and observations of the contact may be necessary 
over a mile or more, in order to detect any considerable varia- 
tion. Differences in elevation of 100 feet are not uncommon, 
although most of them are less. Finally, it is the rule to find 
it standing uniformly high over considerable areas—several 
townships—and tending to be lower in adjacent townships. 
For example, in eastern Fairfield and southern Licking coun- 
ties it stands very high, about 300 feet of Logan being present 
at one point. To the northeastward and southwestward it sinks 
gradually until the Logan averages 60 or 80 feet and to the 
southwestward may be wanting entirely. At several points 
where the coarse Coal-measures sandstones are let into the 
Logan to a depth of 100 or even 200 feet, they take the form 
of a long, narrow mass which can be traced sometimes three 
or four miles, and clearly indicate the presence of a valley 
on the old Waverly surface. 


J. EL, Hyde— Notes on the Absence of a Soil Bed. 559 


The Pennsylvanian rocks consist usually of coarse sandstone, 
frequently feldspathic and sometimes pebbly. One or two 
coal horizons are present near the base, but the coal is usually 
thin. Shale beds are not infrequent, but they are usually 
found higher up in the series, those beds near the contact 
being commonly sandstones, the so-called “Sharon conglom- 
erate.” Usually the poor outcrops and the short time at hand 
have prevented the determination of the effect of the Logan 
hills on the strata of the basal OCoal-measures, but at one point 
in Vinton county and again in Perry county it can be shown 
that the hills were gradually covered by the Coal-measures 
and that the first coal swamps were broken by “islands” of 
Logan, which were later wholly covered by the coarse accumu- 
lations. Apparently none or, at most, very little of the material 
was obtained by the erosion of the Logan; it is much coarser 
and has come from some other source. 

There is no evidence of marine influence in these basal beds. 
It was not until later, until the Logan eminences had apparently 
been entirely covered, that the first marine beds, of which there 
are several, were formed. 

With the exception of the occasional marine beds which are 
intercalated, the Pennsylvanian formations of the Appalachian 
provinee, including eastern Ohio, are now quite generally held 
to be the result of some phase of continental deposition. Fol- 
lowing the post-Maxville period of erosion, which developed 
the sub-Pennsylvanian topography, the simplest interpretation 
is to suppose slight subsidence sufficient to cause the cessation 
of erosion and the initiation of deposition, or a climatic change 
leading to the same result. The area which had been land in 
post-Maxville time would so continue, except that the topog- 
raphy would gradually be buried beneath the plain of accumu- 
eating material, over which coal swamps were spread, even 
while the tops of some of these hills were yet visible. 

In connection with the discussion mentioned earlier, it is 
to be noted that there are few erosion contacts where one 
would look for an old soil bed with better reason than at this 
one. ‘The old land surface, gradually buried under supposedly 
continental deposits in a climate of at least moderate humidity, 
it would seem, ought to carry some trace of surface weather- 
ing if not a well-developed soil bed. The actual contact is 
seldom seen because of poor outcrops. However, it has been 
seen at several points and there is no suggestion of pre- 
Pennsylvanian weathering in the rocks below the erosion plane. 
In three places the Coal-measures sandstones and conglomer- 
ates are fused on to the Logan. The writer has in his posses- 
sion one small hand specimen, one side of which is Logan and 
the other side the coarse Pennsylvanian sandstone with the 


560 J.B. Hyde— Notes on the Absence of a Soil Bed. 


impression of a calamite stem. In this case, there was no ten- 
dency to break at the contact. At those localities where car- 
bonaceous shales or coals with their accompanying white clays 
rest on the Logan, the basal beds are clearly of the Coal- 
measures series and not a soil bed antedating the Pennsyl- 
vanian. 

It is not the purpose to here explain why there is no soil bed 
present. That seems to involve to a high degree the manner 
in which the basal Pennsylvanian beds were “formed, that is, 
whether they were truly continental or whether there was 
subsidence below a body of water and removal of the soil from 
the Logan hills by wave action. In support of the latter is the 
occasional occurrence in the basal beds of the Pennsylvanian 
sandstones of considerable numbers of fossiliferous limestone 
or chert pebbles which appear to have been derived from the 
breaking up of some part of the Maxville limestone, which is 
otherwise unrepresented in the immediate vicinity. However, 
the presence of the limestone pebbles and the absence of the 
soil beds are the only features which suggest that the basal 
Coal-measures are not truly continental or that the interval 
marked by the erosion plane has been one of greater com- 
plexity than simple subaérial erosion. 

Whatever may have been the intermediate stages, the 
occurrence is believed to show that a soil bed or evidence of 
weathering at an erosional contact is not essential to its inter- 
pretation as a plane of subaérial erosion, even when the next 
succeeding beds appear to be of continental origin, and that 
the absence of such a bed at such a contact may demand a 
much more complicated explanation than that of simple sub- 
marine or subaérial erosion. 


LE. A. Kraus—A New Jolly Balance. 561 


Art. XLVII—A New Jolly Balance; by Epwarp H. Kraus. 


Tue first important modification of the spiral spring balance, 
devised by Jolly, was introduced by Linebarger* in 1900, 
whose improved balance has since been used rather extensively. 
The balance to be described has several new features, of which 
the recording of the elongations of the spiral spring and the 
reducing of the number of readings necessary to determine 
the specific gravity are the most important. 

The balance consists of the square upright tube T to which 
the fixed vernier M and the movable graduated scale X are 
attached, as shown in the accompanying figure. A second 
tube Z is movable within T by means of the milled-head A. 
The movable vernier N is attached to Z by the arm E. The 
screw B controls the rod R, movable within the tube Z. From 
R the spiral spring S and scale pans O and D are suspended, 
the thin wire rods W and V connecting the spring and scale 
pans with the pointer P, which swings freely in front of a 
small circular mirror. 

In using the balance for the determination of the specific 
gravity of a solid, for example a mineral, it is necessary that 
the graduated scale X, the verniers M and N, and the pointer 
P all be at zero, the lower scale pan being immersed in water. 
Since the vernier M is fixed, the zero positions of N and X 
will be opposite M. The pointer P is brought to zero by 
being made to coincide with the index on the small cireular 
mirror, the adjustment being accomplished by the screw B. 
A fragment is now placed on the upper pan © and the elonga- 
tion of the spring determined by again bringing the pointer P to 
the zero position. This is now done by turning the mill-head 
A, which moves the tube Z, the graduated scale X and the 
vernier N, upward. After the zero position of the pointer is 
obtained, the scale X is clamped by the screw Y. It is 
obvious that the reading at M will give directly the elongation 
of the spring due to the weight of the specimen in air. The 
fragment is now transferred to the pan D under water. The 
pointer P is again, for the third time, brought to zero; this 
time by moving the tube Z and the vernier N downward by 
means of A, the scale X remaining fixed, having been clamped 
by the serew Y. The reading at N gives at once the loss in 
the elongation due to the immersion of the fragment in water. 
Henee, if the weight in air be represented by W, the read- 
ing at M, and the loss of weight when immersed in water by 


* Physical Review, xi, 110-111, 1900. 


F. H. Kraus—A New Jolly Balance. 563 


L, the reading at N, we have the simplified formula: Specific 
Bee) Aa 
gravity = 
The figure shows the balance* with the specimen immersed 
in water and indicates clearly that the chief advantages of 
this new form, over other balances in common use, are “to be 
found in the recording of the elongations so that they may be 
verified if necessary at the end of the operations, and further 
but two readings and a simple division are sufficient to deter- 
mine the specific gravity. 
I am under especial obligations to Mr. Ralph Miller, whose 
skill and experience as an instrument-maker were largely drawn 
upon in perfecting the balance. 


Mineralogical Laboratory, University of Michigan, 
February 15, 1911. 


* Made by Eberbach & Son Company, manufacturers and importers of 
scientific apparatus, Ann Arbor, Michigan. 


564 C. Barus—Coronas of the Fog Layer. 


Arr. XLV II.—The Independence of the Coronas of the Thick- 
ness of the Fog Layer ; by C. Barus. 


1. Lntroductory.—As an adequate theory of coronas is yet to 
be given, experiments with a definite bearing on the various 
features of the phenomenon are desirable. In my earlier work* 
I endeavored to elucidate the character of the interference phe- 
nomenon superimposed on the diffraction phenomenon, whereby 
the discs of coronas with white light eventually show a rhyth- 
mic succession of colors. A theory was suggested correspond- 
ing to that given by Verdet for the lamellar grating. Inferences 
so deduced were quantitatively in accord with facts. I showed 
that the reappearance of the same type of corona corresponds 
to a succession of diameters of fog particles in the order of the 
natural numbers n = 1, 2, 3, 4, etc. Finally, in a survey of 
coronas obtained with monochromatic light (mercury), it ap- 
peared that the disc and the first ring are alternately luminous 
in a way corresponding to the interference phenomenon in 
question. Finally, that in case of even the largest true coro- 
nas fog particles of an order of size greater than 10-** were 
in question, beyond which the corona degenerates into a 
mere fog. 

In another papert I touched upon the question of the inter- 
ference with each other of coronas due separately to two suc- 
cessive layers of fog particles normal to the line of sight, but 
the quantitative relations did not seem to be as promising as 
interferences inferred from the mere thickness of fog particles, 
already alluded to in comparison with the lamellar grating. 

2. Hffect of Thickness: Apparatus.—From the point of 
view ot the elementary theory the effect of the thickness of 
the fog layer should be negligible; but it does not by any 
means follow that this is actually the case. In very many 
experiments with coronas, the thickness of the fog layer is 
not at the observer’s disposal; or cases of different thicknesses 
have to be compared. Hence the following experiment was 
devised, with the object of detinitely testing the question. 

In the figure, 7” is a cross section of the tog chamber, 
along rectangular trough of wood, cloth-lined and provided 
with two glass plates, g and g’, on the broad sides of the trough. 
The pool of water is seen at w. Two mirrors, J/ and JZ’, of 
plate glass (their normals at 2, 7’), horizontally hinged at / and — 
/’ and capable of being displaced parallel to their own plane by 

*See Carnegie Publications, No. 96, Part I, 1908; ibid., Part II, 1910. 
This Journal, xxv, p. 224, 1908 (axial colors) : ibid., xxiv, pp. 309-12, 1907 


(cycles of coronas); ibid., xxvii, pp. 73-81, 1909 (mercury light). 
+ Proc. Am. Philos. Soc., April, 1911. 


CO. Barus—Coronas of the Fog Layer. 565 


virtue of the screw extension adjustment s and s’, are attached 
parallel to each other. The lower margin of JZ is somewhat 
above the upper margin of JZ’. Hence the observer on the 
left of the apparatus (in front) sees the direct rays AA’ from 
the source as well of the reflected rays 6 MW I'L’. By prop- 
erly adjusting the angle a, the small round distant source of 
white hght and its image in the mirrors (A’ and B’ respec- 
tively) may be made to coincide at the upper edge of AZ’. In 
such a case the corona due to the direct rays produced by a 
single thickness, d=15:5™ of fog layer, should exactly coincide 
with, i.e. be the complement of, the coronas due to the reflected 
rays and produced by a triple thickness d'=46'5™ of fog layer, 
if the variation of thickness in question is without effect. Other- 
wise the coronas should be dislocated at the margin of the 
mirrors. 


(7 


3. Results and Summary.—These experiments were carried 
through in regular series, both for the dust nuclei of ordinary 
air as well as for an artificial nucleation due to phosphorus. 
The exhaustions were made systematically, every two minutes. 
The coronas due both to the A rays (direct) and the B rays 
(reflected) were read off as quickly as possible, after which 
filtered air was introduced to dispel the coronas by evaporating 
the fog particles. In this way about twenty coronas were suc- 
cessively compared, from the largest easily observable having 
an aperture of about 34°, to the small ones of vanishing size, 
the nucleation ranging from about 10° to zero (particles per 


Am. JOUR. Scil.—FourTH SERIES, VoL. XX XI, No. 186.—Junn, 1911. 
38 


566 C. Barus—Coronas of the Fog Layer. 
eubie centimeter), and the fog particles from a diameter of 
about 2x10-*™ to 107. 

In no case was there any dislocation of coronas, or of color, 
detected, though naturally the coronas in case of reflection from 
the mirrors were somewhat more yellowish in color (due to the 
reflecting surfaces) and less vivid (due to the reflections and 
greater thickness of fog layer); for it is hardly probable that 
the fog particles are quite of asize. The continuity of corre- 
sponding colored rings, however, was exact within the limits of 
observation. Hence thicknesses of 15° and over 45 produce 
identical coronas identical in aperture ; or the thickness of the 
cloud layer is without influence on the coronas. " 


Brown University, Providence, R. I. 


SCIENTIFIC INTELLIGENCE, 


* 


I. CueEemistry anp Puystcs. 


1. The Radium Contents of some Uranium Minerals.—It has 
been shown by Boltwood and also by Strutt that in many miner- 
als a constant relation exists between the amounts of uranium and 
radium present, as would be expected from the theory of the 
formation of radium through the intermediate uranium-X and 
ionium. Recently Mlle. Gleditsch has found these relations to 
vary considerably (in the ratio 100 : 86: 68) in thorianite, Joachims- 
thal pitchblende, and autunite. Soddy and Pirret, while finding 
a constant ratio in thorianite and the pitchblende, have also found 
a deficiency of radium in autunite. MaArckwatp and RussELi 
have now confirmed the last mentioned result, and have made a 
further study of the autunite, which is a calcium-uranium phos- 
phate with the formula Ca(UO,),(PO,),.8H,O. This mineral, 
besides containing less than the expected amount of radium, is 
remarkable in containing no appreciable amount of lead as well 
as less helium than the required amount. From the amount of 
helium present, Soddy has calculated that the age of the mineral 
would be only about 30 years if none of this gas had been lost, 
whereas the radium corresponded to an age of many thousand 
years, so that he assumed that the radium in the mineral came 
from without and crystallized as an isomorphous replacement of 
calcium, instead of being a product of the uranium. This view 
of Soddy’s appeared improbable to Marckwald and Russell, so 
that they investigated the ionium contents of the mineral and 
found its amount to be only slightly less than normal in propor- 
tion to the uranium. Since ionium has an average life of not less 
than 30,000 years, it follows that the age of the ‘autunite must be 


Chemistry and Physics. 567 


at least hundreds of thousands of years. The facts thus found 
lead to the view that the porous structure of the autunite, in 
comparison with the dense oxides, has allowed the escape of helium, 
and also the leaching out of the lead and a part of the radium. 
From a consideration of this and other minerals it appears that 
lead is more easily removed than is radium.—erichte, xliv, 771. 
H. L. W. 

2. The Determination of Cane Sugar in the Presence of other 
Sugars.—Avo._F JoruEs has devised a new and very simple 
method for the determination of saccharose when other sugars 
are present. He finds that the other sugars, such as dextrose, 
levulose, maltose, mannose, galactose, arabinose, lactose, and 
rhamnose are readily decomposed by the action of dilute sodium 
hydroxide solution, while the saccharose may be left undecom- 
posed and may then be determined by the polariscope. <A one- 
tenth normal solution of sodium hydroxide is recommended, in 
which the cane sugar may be present in any convenient amount, 
but the contents of dextrose, levulose, invert-sugar, ete., should 
not exceed 2 per cent. The treatment may consist in boiling the 
liquid for three quarters of an hour in connection with an inverted 
condenser, or the liquid may be placed in a pressure-flask or sealed 
tube and heated in boiling water for the same length of time, or 
finally the solution may be allowed to stand in a closed flask at 
87° C. for 24 hours. The last treatment is preferred for exact 
work because it gives a minimal amount of discolorization, but 
the other methods give reliable results, and colored liquids may 
be treated with basic lead acetate. It seems probable that the 
method will be very useful in connection with food-analysis, 
etc.— Monatshefte, xxxil, 1. H. L. W. 

3. The Action of Sulphur Dioxide upon Ammonia.—The 
products of the reaction of these common gases have been fre- 
quently studied, and it seems remarkable that they have not been 
fully explained, but it appears from the recent work of Epuraim 
and Prorrowskti that such is not the case. These investigators 
have found that there are three different compounds formed instead 
of two as has previously been supposed. With an excess of sul- 
phur dioxide, amido-sulphinice acid, NH,.SO,.H is produced, while 
with an excess of ammonia, according to the temperature, there 
may be formed either the ammonium salt of the above acid, 
ammonium amido-sulphite, NH,.SO,.NH,, which is white, or a red 
compound haying the same empirical formula as the last, but 
with double its molecular weight. This has been found to be the 
tri-ammonium salt of imido-sulphuric acid, having the formula 

a ea 
(NH IN<§6: NH: This constitution was established by finding 
that one-quarter of the nitrogen was differently combined from 
the other three-fourths, so that at least four nitrogens must be 
present in it. By proper treatment it gives a silver salt, 
AgN<S6'4 which is rather unstable.— Berichte, xliv, 379. 


HE. Wis 


568 Scientific Intelligence. 


4. The Quantitative Chemical Analysis of Mixtures by Use of 
Differences in Specific Gravity.—Hans Frimepentuar has applied 
a method which, in a modified form, is well known to mineralogists 
to the analysis of complicated mixtures of organic and other ‘sub- 
stances. He states that in many cases the investigation of blood, 
milk, urine, gall, and other complex mixtures may be facilitated by 
removing the water ,grinding the residue very fine with a mechanical 
agate mortar, and then separating the ingredients by specific gray- 
ity. Asa liquid he uses bromoform diluted with toluol or xylol, 
whereby a range of specific gravities from 2°90 to 0°70 may be 
covered. A separator 'v funnel may be employed, or in certain 
cases a centrifugal machine. The statement is made that a solu- 
tion of a mixture of sodium chloride and potassium chloride may 
be evaporated to dryness, and the two salts separated quantita- 
tively by the use of a liquid of 2°04 specific gravity. No data are 
given in regard to the accuracy of any of the separations, so that 
an opinion cannot be advanced as to the value of the method.— 
Berichte, xliv, 904. H. L, W. 

5. On Metallic Colouring in Birds and Insects.—It has been 
thoroughly proved that the usual “flat,” “dead,” uniform color- 
ing, brilliant as this sometimes can be, e. g., in birds, butterflies, 
and flowers, finds its simple explanation in the existence of pig- 
ment cells. On the other hand, the lively, variable “ metallic” 
glitter of burnished copper or gold ; the reflection from certain 
aniline dyes ; the colors of certain pigeons, peacocks, humming- 
birds, as well as a number of butterflies, beetles, and other insects, 
require another explanation. 

After calling attention to the preceding facts, A. A. MicnEr- 
SON summarizes the distinguishing characteristics of “ metallic” 
reflection in the following sentences :— 

“1, The brightness of the reflected light is always a large frac- 
tion of the incident light, varying from 50 per cent to nearly 100 
per cent.” 

“9. The absorption is so intense that metal films are quite 
opaque even when their thickness is less than a thousandth of a 
millimeter.” 

“¢3. If the absorption varies with color, that color which is 
most copiously transmitted will be the part ‘of the incident white 
light which is least reflected—so that the transmitted light is 
complementary to the reflected.” 

“4. The change of color of the reflected light with changing 
incidence follows the invariable rule that the color always 
approaches the violet end of the spectrum as the incidence 
increases.” ‘If the color of the normal reflexion is violet the 
light vanishes (changing to ultra-violet), and if the normal radia- 
tion be infra-red it passes through red, orange, and yellow as the 
incidence increases.’ 

Since these four criteria are qualitative and necessary but not 
always sufficient, the author also makes use of the more refined 
quantitative optical tests which relate to the effects of reflection 


Chemistry and Physics. 569 


upon polarized light. In brief, he determines experimentally, for 
various angles of incidence, the ratio of the amplitudes and the 
difference in phase of the components of the elliptic vibrations 
resulting from reflection. The numerical data are plotted as 
“amplitude ” curves and “ phase ” curves. 

For sake of general orientation, the first figure contrasts the 
curves for silver, steel, graphite, selenium, flint glass, crown glass 
and quartz. Figure 2 relates to two typical aniline dyes, viz., fuch- 
sine and diamond green. ‘The third figure shows the modifications 
in the curves produced by changing from a thick film to a very 
thin film of magenta. The fourth and fifth figures present, side 
by side, the curves for two specimens of “ copper beetle ” and thin 
films of magenta. The correspondence between the two sets of 
curves is so remarkable that it leaves no room to doubt that in 
this case the metallic coppery color of the elytra is due to an 
extremely thin film of some substance closely analogous in its 
optical qualities to the associated aniline dye. For the first bee- 
tle and dye-film the thicknesses of the active layers were of the 
order of 0:00025™™, and for the second specimen and magenta 
film, about 0:00005™™. Figure 6 comprises the curves for a 
“oreen beetle” and for diamond green. These curves do not 
agree very well and, in fact, no aniline dye could be found to 
match this beetle. Nevertheless, the curves for the insect have 
all the characteristics pertaining to “ metallic ” reflection. 

The beetle wing-cases furnish in many instances a fairly smooth 
surface, and the difficulties attendant upon obtaining the necessary 
data are far less than when working with feathers of birds or 
with butterfly scales. The simple device of replacing the objec- 
tive of the collimator and of the observing telescope by low-power 
microscope objectives of small apertures removed these difficulties 
so far as to make it possible to obtain results which compare 
favorably with those found for the aniline films. “In some of 
the measurements it has been found possible to deal with a single 
butterfly scale ; and in these the irregularities of the surface were 
often insignificant, or of such a nature that they could be taken 
into account.” 

Figure 7 gives the curves for the green of a peacock feather, 
for a green humming-bird, for a red humming-bird, for a blue - 
humming-bird, and for the blue-winged butterfly Morpho alga. 
For all the feathers, except those belonging to the red humming- 
bird, the optical data were of such a nature as to lead to the con- 
clusion that the film which gives rise to the surface color is 
extremely thin. 

Michelson remarks: ‘The total number of specimens which 
have been examined is perhaps not so large as it should be 
to draw general conclusions, and it is clearly desirable that it 
be extended ; but so far the evidence for swrface film, as the 
effective source of the metallic colors in birds and insects, is 
entirely conclusive.” In this connection, reference should also 
be made to the essay of Dr. B. Walter entitled “ Die Oberflichen- 
oder Schiller: Farben.” 


+ ae 


570 Scientific Intelligence. 


The paper under review concludes with details of the optical 
peculiarities of some highly interesting eaceptional cases. Suttice 
it to say that these exceptions are afforded by the blue-winged 
buttertly, Morpho alga, by the “Diamond Beetle,” and by the 
coleopter Plustiotis resplendens.—Phil. Mag. (6), xxi, 554. 

ILS. U, 

6. Lhe Isolation of an Ion, a Precision Measurement of its 
Charge, and the Correction of Stokes’s Law,—In the earlier work 
of R. A. Mizircan the following sources of error introduced 
some uncertainty in the final results. (1) Lack of complete stag- 
nancy in the air through which the drop moved ; (2) lack of per- 
fect uniformity in the electrical field used; (3) the gradual 
evaporation of the drops, rendering it impossible to hold a given 
drop under observation for more than a minute, or to time the 
drop as it fell under gravity alone through a period of more than 
five or six seconds ; (4) the assumption of the exact validity of 
Stokes’s law for the drops, studied. The author says: “ The 
present moditication of the method is not only entirely free from 
all of these limitations, but it constitutes an entirely new way of 
studying ionization and one which seems to be capable of yield- 
ing important results in a considerable number of directions.” 

The essential modification of the method consists in replacing 
the droplet of water or alcohol by one of oil, mercury, or some 
other non-volatile substance, and in introducing it into the ioniza- 
tion chamber in a new way. By means of a commercial “ atom- 
izer” a cloud of fine droplets of oil is blown with the aid of 
dust-free air into a vertical, dust-free cylinder. The base of this 
chamber is made of a heavy, circular disc of brass which consti- 
tutes the upper plate of the electrical condenser and which is per- 
forated through its center by a vertical hole having about the 
same diameter as an ordinary pin. ‘This hole is provided with 
a trap-door or cover which is actuated electro-magnetically. 
This trap is kept open long enough to allow a few drops to fall 
through it into the condenser below and then the cover is closed. 
In this way it is possible to imprison droplets in a condenser con- 
taining dust-free air which is absolutely free from currents. The 
condenser plates were exactly 16™™ apart. A narrow, horizontal, 
parallel beam of light from an are lamp entered the condenser 
through one window, illuminated the droplets in its path, and 
then passed out through a diametrically opposite window. The 
illuminated drops were observed through a third window by 
means of a suitable telescope of short focus. The appearance of 
a drop is that of a brilliant star on a black background. The 
drop falls, of course, under the action of gravity, toward the 
lower condenser plate; but before it reaches the latter an electri- 
cal field of strength between 3,000 and 8,000 volts per centimeter 
is established between the plates by means of a battery. Hence, 
if the droplet had received a frictional charge of the proper sign 
and strength as it was blown out through the atomizer, it will be 
pulled up against gravity by this field, toward the upper condenser 


lad 


Chemistry and Physics. 571 


plate. The electric field is taken off before the droplet reaches 
the upper plate and then the droplet falls again. In this manner 
it is possible to keep the same droplet moving up and down in the 
field of view of the telescope for many consecutive hours. By 
observing the times taken by the same droplet to fall, and to rise 
respectively, through the distance corresponding to the distance 
between the horizontal cross-hairs in the telescope, it is easy to 
deduce the speeds attained under the action of gravity alone, and 
under the excess of the electric over the gravitational fields. This 
operation is repeated and the speeds checked an indefinite 
number of times, or until the droplet catches an ion either from 
among those which exist normally in air, or which have been pro- 
duced in the space between the plates by any of the usual ioniz- 
ing agents like radium or X-rays. The fact that an ion has been 
caught, and the exact instant at which the event happened, is sig- 
nalled to the observer by the change in the speed of the droplet 
under the influence of the field. From the sign and magnitude of 
this change in speed, taken in connection with the constant speed 
under gravity, the sign and the value of the charge carried by the 
captured ion are determined. 

“The experiment is particularly striking when, as often hap- 
pens, the droplet carries but one elementary charge and then by 
the capture of an ion of opposite sign is completely neutralized so 
that its speed is altogether unaffected by the field.” “In this 
case the computed charge is itself the charge on the captured ion.” 

The final value for the fundamental ionic charge is given as 
€= 4891 X10~™ electrostatic units. 

The paper contains many other facts which, for lack of space, 
must be omitted. 

The article closes with a complete list of the most important 
of the molecular magnitudes as recalculated frome = 4'891 107" 
K. 8..U., and with a table of “weights and diameters of mole- 
cules ” for 14 gases and vapors.— Phys. Fev., xxxti, 349. H. 8. U. 

7. Homogeneous Réintgen Radiation from Vapors.—When 
elements having atomic weights equal to, or greater than, that of 
chromium are exposed to Réntgen radiation, they emit chiefly 
homogeneous, secondary X-rays which are characteristic of the 
element used as radiator, and which are independent of the pene- 
trating power of the exciting primary beam. The homogeneity 
of this characteristic radiation causes 1t to suffer equal percentage 
absorptions when transmitted through equal thicknesses of alumi- 
nium. By determining these percentage absorptions the values of 


—, (where I=J,e-“” and p= density of aluminium), have been 


calculated for the elements of the group defined above. 

Since these elements had only been studied in the solid 
state, either pure or in the form of compounds, J. C. Cuapman 
has extended the investigation to the cases of the elements— 
small in number—which could also be experimented upon in the 
vapor state. 


572 ~ Seientific Intelligence. 


4 J MEN 
For the vapor of ethyl bromide ~— came out equal to 16-4. The 


values of this ratio for solid bromine, in the compounds sodium 
bromide and bromyl hydrate, were respectively 16-2 and 16:3. 


r 
The agreement between the value of — for the vapor and for the 


solid is about as good as could be expected from the nature of the 
experimental method. In the case of iodine in the solid condi- 
tion and as present in the molecules of the vapor of methy] iodide, 


Soe . : 
the ratio — was found to have the same value, viz., 2°3. 


Pp 

‘« Although it has only been proved in these two cases that ele- 
ments in the solid and vapor state emit the same type of radia- 
tion, yet it is safe to conclude that what applies here holds 
generally ; especially considering that the atomic weights of bro- 
mine and iodine are well separated.” “Tt is evident that this 
similarity of character in the radiations is what would follow 
from the fact that the phenomena of secondary X-rays are atomic 
in their nature.’ 

Some other experiments are described in the paper, which are 
interpreted as showing that the hypothesis which regards the 
characteristic secondary radiation as resulting from the subse- | 
quent bombardment of atoms by ejected corpuscles is quite 
untenable. However, for further details in this connection refer- 
ence must be made to the original article-—Phil. Mag. (6), xxi, 
446. H. S. U. 

8. Lehrbuch der Kristallphysik ; von Dr. WotpEMaR Voter. 
Pp. xxiv, 964; 213 text-figures, 1 plate. Leipzig and Berlin 
(B. G. Teubner, Sammlung von Lehrbiichern, Band xxxiv).—This 
is an encyclopedic work upon the physical properties of crystals, 
omitting, however, their optical properties. The first chapter 
deals with the ceometrical properties of crystals and the applica- 
tion of the pr inciples of symmetry ; the second and third chapters 
give an account of the vectorial analysis which is used by the 
author and of the mechanical and physical principles which find 
application later. The remaining tive chapters deal with physi- 
cal properties, such as pyro-electricity and pyro-magnetism, 
thermal expansion, conductivity for heat and electricity, thermo- 
electric and thermo-magnetic effects, elasticity and viscosity, 
piezo-electricity and piezo-magnetism. The classification of 
these effects is based upon their mathematical analogies—as to 
whether they involve a scalar and a vector, two vectors, ete. 

It would be difficult for any one who has not paid especial 
attention to this intricate and rather recondite branch of physics 
to give an intelligent opinion upon a work like the present, which 
is very voluminous and abounds in details. It is quite certain 
that there is no one better qualified than Prof. Voigt to write a 
treatise upon this subject, which he has long made his own ; 
and it is probable that this book will long remain the standard 
in its field. H. A. B. 


Geology and Mineralogy. 573 


9. The Electrical Nature of Matter and Radioactivity ; by 
Harry C. Jones. Second edition. 8vo, pp. 210. New York, 
1910 (D. Van Nostrand Co.),—The first edition of this work 
appeared five years ago (see vol. xxi, p. 465), and many advances 
have been made in our knowledge of the subject during the inter- 
vening period. It is, therefore, difficult to conceal the disap- 
pointment one feels on finding much of the older and now 
superseded data of the earlier edition still in evidence, and espe- 
cially so as one is led to believe from the title page and preface 
that a general revision of the subject matter has been carried out 
in the preparation of the present edition. The style of the writer 
is lucid, and his talent for the exposition of simple facts is par- 
ticularly noticeable’ in many instances. It is unfortunate, there- 
fore, that the value of the book as an elementary treatise should 
be somewhat impaired through what appears to be a certain lack 
of familiarity with the subject on the part of the author. B. B. B. 


Il. Gerotogy anp MINERALOGY. 


1. Illinois State Geological Survey, Bulletin No. 16, Year- 
book for 1909. Frank W. DeWorr, Acting Director. Pp. 
402; 37 plates, 9 figures, map in pocket. Urbana, 1910.— 
The reports of the Illinois Survey contain year by year the record 
of an unusual amount of work of a varied character, and indicate 
the advantages to be gained by codperation between the Federal 
and State organizations engaged in mapping, geologic work, 
reclamation surveys, and investigations of soil and water supply. 
The Survey has a generous appropriation, and the published 
results amply justify the expense. The Year-book for 1909 con- 
tains the following chapters, some of which have been separately 
published: Administrative Report ; Elizabeth sheet of the lead 
and zine district, by G. H. Cox ; Oil Resources of Illinois, by R. 
S. Blatchley ; Studies of Hlinois Coal, by F. W. DeWolf, A. 
Bement, 8S. W. Parr, G. H. Cady, T. E. Savage, KE. W. Shaw, R. 
G. Williams, Jon Udden ; Faunal Succession and Correlation of 
the Pre-Devonian formations of Southern Illinois, by T. E. Sav- 
age; The Occurrence of Structural Materials in Illinois, by Jon 
Udden and J. EH. Todd. H. E. G. 

2. New Zealand Geological Survey. A Geographical Report 
on the Franz Josef Glacier ; by J. M. Bett. With Topograph- 
ical Maps and Data by R. O. Grevitie, and Botanical Notes by 
Lronarp Cockayne. Pp. 14; 3 maps, 6 photographs. Welling- 
ton, 1910 (John Mackay).—Geographers are indebted to Dr. Bell 
for the first detailed report on one member of the interesting group 
of glaciers which occupy valleys in the Southern Alps of New Zea- 
land,—a series of glaciers unusually large in proportion to the 
height of the range and to latitude. The Franz Josef glacier is 
74 miles long, has a width at its terminus of 41 chains, while the 
snowfield at its head covers 4,758 acres. Owing to factors which 


Ke 


574 Scientifie Intelligence. 


control rainfall, the glacier descends to a point only 692 feet 
above sea level. Fluctuations in volume of ice are plainly indi- 
cated, and show that during Pleistocene time the glacier deployed 
on the Westland coastal plain as an extensive piedmont glacier. 
About 150 years ago the ice in the valley stood 250 feet above its 
present level ; then followed a period of retreat, succeeded by a sec- 
ond advance ; the amount of elongation from March, 1908, to April, 
1909, being 1382 to 162 feet. As an aid in determining future move- 
ments of the ice, observation stations have been established by 
the Survey. In addition to a discussion of glaciation, the report 
contains a brief account of the geology of the region and also a 
list of plants. H. E, G. 

3. Geological Survey of Western Australia, Bulletin No. 39. 
Geological Observations in the country between Wiluna, Hall’s 
Creck and Tanami; by H. W. B. Tatsor. Pp. 88; 3 maps, 
44 figures. Perth, 1910 (Fred. W. Simpson).—New and inter- 
esting information regarding the geology and geography 
of the great central Australian desert is being furnished as 
a result of the examination of coal, water, and mineral resources 
of West Australia. The present bulletin gives the results of a 
reconnaissance of a strip 150 miles in width, extending from 
Wiluna northeast to Hall’s Creek, covering a region in which no 
geological work has previously been done. Perhaps the most 
important discovery is the fact that sedimentary rocks extend 
through 7° of latitude and occupy an area previously assumed to 
be part of an Archean mass which had never been submerged. 
Metamorphosed sedimentaries are overlain by Devonian sand- 
stones, grits, and conglomerates, followed by Carboniferous 
quartzites, sandstones, and shales. No fossils were found, the 
age being determined by lithologic similarity and stratigraphic 
position. The surface cover includes alluvium from living and 
extinct streams, sand dunes, and extensive deposits of travertine. 
Asa geographic report the bulletin is valuable for its descriptions 
of desert scenery, wind erosion, conditions of life, and character of 
vegetation. Extinct lakes, abandoned channels, and other topo- 
graphic features, indicate that this region furnishes an unusual 
opportunity for the study of climatic changes in recent geologic 
time. H, E. G. 

4, Geological Survey of Canada ; Among the numerous publi- 
cations of the GEoLoGicAL Survey Brancu of the Canada Depart- 
ment of Mines, which have recently been issued (see vol. xxx, 
p. 357), are the following memoirs : 

No. 6. (1081.) Geology of the Haliburton and Bancroft Areas, 
Ontario; by Fraxx 8. Apams and Autrrep EH. Barrow. Pp. 
viii, 419; 70 plates, 7 figures, 2 maps. 

No. 1. (1091.) Geology of the Nipigon Basin, Ontario; by 
A. W.G. Witson. Pp. 152; 16 plates, 4 figures, 1 map. 

No. 2. (1093.) The Geology and Ore Deposits of Hedley Min- 
ing District, British Columbia, by Caartes CamsEtt, Pp. 218 ; 
20 plates, 8 figures, 4 maps. 


Geology and Mineralogy. 575 


‘ 

No. 5. (110.) Preliminary Memoir on the Lewes and Norden- 
skiéld Rivers Coal District, Yukon Territory; by D. D. Carrnes, 
Pp. 70; 8 plates, 2 maps. 

No. 8—H. (1115.) The Edmonton Coal Field, Alberta; by D. 
B. Dowrtne. Pp. 59; 5 plates, 2 figures, 2 maps. 

No. 12—P (1141). Canadian Paleontology. Part ILI, Vol. II; 
Fossil Insects; by Anron Hanpiirscw. Pp. viii, 93-129; 36 
figures. 

No. 14—N, (No. 1143.) New Species of Shetls Collected by Jonn 
Macovun at Barkley Sound, Vancouver: described by Wi11am 
H. Dati and Pavut Bartscu. Pp. 22; 2 plates. 

Report on a Part of the North West Territories drained by 
the Winisk and Attawapiskat Rivers; by Wiurtiam MolInnzs. 
Pp. 58; 5 plates, one map. Report on a Traverse from Lac Seul 
to Cat Lake in 1902; by A. W. G. Witson. Pp. 25. 

In the Mrnes Brancu, special papers have been published on 
the production of coal, iron, cement, and other products, for 
1909 ; another on peat bogs and the peat industry, ete. A pre- 
liminary report by Joun McLetsu (pp. 21) has also been issued 
giving a summary of production for 1910. The total value of all 
products amounts to 105 million dollars contrasted with 92 
millions for 1904, an increase of over 14 per cent, which gain is 
distributed throughout the whole list. The value of the gold 
produced was upwards of 10 millions, of silver 13 millions, of 
nickel and pig iron each 11 millions, and copper 7 millions. 
Among the non-metallic minerals, it may be noticed that the pro- 
duction of coal was nearly 30 millions and of asbestos 24 millions. 
The last subject is treated at length in a special volume by Fritz 
CirKkEL entitled : 

Chrysotile— Asbestos : its occurrence, exploitation, milling, and 
uses ; pp. 316, 66 plates, 88 figures. This is the second edition 
of a work first issued in 1895 (see vol. xxi, p. 255). The import- 
ance of the subject can be appreciated from the fact that 82 per 
_cent of the world’s supply of asbestos is now prodaced by Can- 
ada, while the value of the product has increased from $24,700, 
in 1880, to the total already noted above. The author notes 
further that at the Black Lake quarries, Quebec, there are some 
45 million tons of asbestos rock now in sight. The subject is 
treated in its various aspects with admirable fullness, and is 
illustrated by a large number of excellent plates. 

5. Mineral Production in the United States in 1909.—The divi- 
sion of Mineral Resources, United States Geological Survey, in 
charge of E. W. Parxer, has issued in rapid succession the indi- 
vidual chapters which will presently appear in the complete volume 
Mineral Resources for 1909, A comprehensive sheet has also 
been distributed, giving the quantity and value of each of the 
mineral products for the calendar years 1900-1909. The grand 
total valuation amounts to nearly 1900 million dollars, which has 
been exceeded only in the years 1906 and 1907. In 1900 the 
total value was only a little in excess of 1100 millions, while in 


a .  — 


lm I a ct le nt 


— a 


1 
1: 
oi 
if 
i 
M 


576 Scientific Intelligence. 

1890 it was 606 millions, and in 1880, 365 millions. The pro- 
duction of gold in 1909 reached a higher figure than ever before, 
very close to 100 million dollars. There was also a decided in- 
crease in the production of aluminum, but a falling off in the 
other metals as compared with 1906-7. In most of the other 
products, also, the total value for 1909 falls somewhat below the 
maximum already attained. A prominent exception is that of 
the clay products, the total value of which was 160 millions. 
Corresponding with the increase in aluminum there has also been 
an increase in the amount of bauxite, as noted below. 

6. The Production of Gems and Precious Stones in the United 
Stutes in 18S99.—A summary of the precious stones industry in 
1909 has recently been given by Dovcnas B. STERRETT, as an 
advance chapter of the ‘“ Mineral Resources of the United States.” 
The total valuation of the different kinds of precious stones amounts 
to about $534,000, which is an increase of 25 per cent over the 
preceding year. This increase is most conspicuous in the tur- 
quoise and turquoise matrix from Nevada, New Mexico, Arizona, 
and Colorado, especially in the first-named state. Variscite has 
also been produced in considerable amounts, particularly in 
Nevada, taking the place of the lower grades of the turquoise 
matrix. Other new points brought out are the occurrence of 
delicately-colored rhodonite in Siskiyou Co., California; a prom- 
ising emerald locality in Cleveland Co., North Carolina ; fine 
chrysoprase from Tulare Co., Cal. Serpentine, pseudomorphous 
after amphibole and somewhat resembling cat’s-eye, has been 
placed on the market under the name satelite. Some other similar 
names, having, however, no special claim to scientific recognition, 
are noted. The report contains many other facts of mineralog- 
ical interest. 

7. Production of Bauxite in 1909.—In an advance chapter 
by W. C. Puaten, from the Mineral Resources of the United 
States, itis stated that the production of bauxite in 1909 amounted 
to 129,101 long tons, valued at $679,447 ; this is an increase of 
23 p.¢. in quantity as compared with 1907. The states from 
which the bauxite is obtained are Arkansas, Georgia, Tennessee, 
and Alabama ; of these the first named shows an increase of 200 
p. ¢. as compared with 1908 and over 70 p. c. compared with 1907. 

8. Origin of the Thermal Watersin the Yellowstone National 
Park.—An interesting discussion on the hot springs of the Yel- 
lowstone Park was given before the Geological Society of Amer- 
ica at the annual meeting of December 27, 1910, by the President, 
Arnotp Hacuez. It closes with the following clear and concise 
summary: ‘‘In conclusion I may state that I have attempted to 
show: (1) that igneous activity was continued throughout Ter- 
tiary time ; (2) that this activity came to an end with the close of 
Pliocene time; (3) that during the Eocene and Miocene deep- 
seated waters were active geological agents, and that these waters 
were essentially primitive in their origin; (4) that in strong con- 
trast to the explosive, volcanic conditions of the Miocene, the 


Geology and Mineralogy. 577 


Pliocene lavas were emitted under far quieter conditions and built 
up the successive flows that formed the rhyolite plateau ; (5) that 
during the many thousand years since the withdrawal of glacial 
ice the Pliocene rhyolites have, since the beginning of Pleistocene 
time, been steadily undergoing progressive changes, brought 
about by the action of enormous volumes of superheated vadose 
waters; (6) that the gases contained in the thermal waters were 
in great measure derived from vadose sources ; (7) that the erup- 
tions and periodicity of geysers are phenomena due essentially 
to varying conditions of reservoirs and channels of superheated 
waters situated only short distances below the surface; (8) that 
the phenomena as seen to-day represent a phase in the evolution 
of thermal springs. 

9. Tables for the Determination of Minerals by means of 
their Physical Properties, Occurrences, and Associates; by 
Epwarp H. Kravs and Watrer F. Hunt. Pp. 254, New York, 
1911 (McGraw-Hill Book Company).—The determination of 
mineral species by means of their physical properties is particu- 
larly useful in the instruction of the science, since it calls 
the attention of the student to the characters with which it 1s 
most important that he should become thoroughly familiar. The 
tables of Weisbach, as translated into English by Frazer, have 
been before the public for many years, serving a useful purpose 
in many laboratories. We have now a new system of tables pre- 
pared with much completeness and based primarily upon the 
characters which appeal to the senses most directly: that is, 
(1) luster, (2) color, then streak, hardness, cleavage, and specific 
gravity. The fact that many minerals vary widely in color and 
sometimes also in luster leads to their being introduced in a 
variety of places in the successive tables ; this enlarges the work 
considerably, but does not necessarily make the task of the 
student more difficult. A useful feature of the work is the state- 
ment of special characteristics and of associated species, which 
is often important in the matter of identification, The work 
Opens with a concise explanation of physical properties and a 
glossary of mineral terms. 

10. Composition of Striverite; by KR. C. Writs (communi- 
cated).—In the paper upon striiverite in the May number of this 
Journal, pages 441 and 442, the formula Fe(Ta,Cb),O,.6Ti0, 
should read FeO.(Ta,Cb),O,.6Ti0, or expressed more simply 
Fe(Ta,Cb),(Ti0,),. 

Although it is stated on page 441 that “the analysis yields no 
simple formula” a better statement would be that too much sig- 
nificance shold not be attached to the simple formula deduced 
from the analysis, in view of the uncertainties of the analytical 
methods. 


D 


Scientific Intelligence. 


ou 
=I 


Ill. MuiscrLuaneous Sorentiric IntELLIGENCE. 


1. Bulletin of the Bureau of Standards, 8. W. Stratton, Direc- 
(or.—The results of the accurate work in many lines of the Bureau 
of Standards is presented from time to time in their Bulletin, of 
which No, 1 of Volume VII has recently appeared. Among the 
papers here included are two by C. W. Waidner and G, K. Bur- 
gess on the temperature scale between 100° and 500°, and on 
the constancy of the sulphur boiling point. J. H. Dellinger dis- 
cusses at length the temperature coefficient of resistance of copper, 
and with F. A. Wolff the electrical conductivity of commercial 
copper. A new form of candle-power scale and recording device 
for precision. photometers is described by G. W. Middlekauff. 
This has been in frequent use during the past year and has given 
excellent results, both as regards accuracy and economy of labor. 
P. G. Nutting and Orin Tugman discuss the intensities of some 
hydrogen, argon and helium lines in relation to current and 
pressure, 

2. The Prehistoric Period in South Africa; by J. P. Joun- 
son. Pp. 89, 6 pls., 47 figs. London, 1910 (Longmans, Green 
and Co.).—Believing that geological and archeological research 
has established a definite sequence in the primitive cultures of the 
Old World, the author has used the one generally accepted for 
Europe as a basis for his classification of South African antiqui- 
ties. In the introduction he emphasizes the importance of the 
data afforded by river terraces, citing as an example southern 
England, where a single section reveals the stratigraphic relation- 
ship of the main divisions of the entire stone age—eolithic, paleo- 
lithic, and neolithic, 

A chapter is devoted to eoliths from the Leijfontein farm, 
below Campbell Rand, near Cambell village, where patches of 
very old gravel, having no connection with any existing river, 
occur at the foot of the escarpment. Mixed with the gravel are 
much worn and highly glazed eoliths, a few of which are shaped 
from artificially produced splinters or flakes. As to paleoliths, 
the author is of the opinion that those of the Acheulian type are 
distributed throughont the whole of South Africa, he himself 
having found them in the valleys of the Zambesi, the Elands- 
Rustenberg, the Magalakwin, the Selati, the Olifants, the Komati, 
the Vaal, the Caledon, the Orange, and the Zwartkops, at Algoa 
Bay. Solutrean (paleolithic) sites are also widely distributed 
over South Africa, the Solutrean industry being distinctly more 
recent than the Acheulian; and as is also the case in Europe, 
characterized by a pronounced development of the artistic faculty. 
South African petroglyphs and rock-paintings of Solutrean age 
are distributed over the whole area in question. The pecked or 
incised figures are mostly found on bowlder-like outcrops of rock, 
either among kopjes or in the open veld, while the frescoes are 
chiefly met with at the back of rock-shelters. Some of these bear 
a remarkable resemblance to paleolithic frescoes recently found 


. 


Miscellaneous Intelligence. 579 


by Breuil near Cogul (Catalonia), Spain. The objects repre- 
sented are for the most part animals and men, generally in sil- 
houette only. Geometric figures are abundant. ‘The petroglyphs 
are disconnected units only, and usually larger than the paint- 
ings ; the latter frequently depict a scene, as, for example, a hunt 
or a fight. 

The petroglyphs are mostly peckings ranging from crude out- 
lines to veritable bas-reliefs. The most primitive series of petro- 
glyphs are those discovered by Leslie in the neighborhood of 
Vereeniging. ‘The principal animals illustrated are the eland, 
giraffe, rhinoceros, and elephant. Although the pecking is ver 
irregular, the general effect produced is good. All the groups 
appear to be of the same age and are weathered to the same color 
as the rest of the rock surface. At Biesjesfontein, some thirty 
kilometers southwest of the village of Koffyfontein, some of the 
figures are scraped instead of pecked on the rock. Here also are 
found two engravings; one of a hippotragus, the other of a 
quagga. Ina vast majority of rock paintings the outline is filled 
in with a uniform tint, either red or black, red predominating. 
In eastern Orangia and in the region south of the Orange river, 
polychrome paintings oceur, The eland, a great favorite with 
the Solutreans, is depicted in two or more colors, white ventrally 
and golden yellow, red, or dark brown dorsally. Some of the 
better polychrome examples “show distinct, though incipient, 
shading.” The figures of animals often show real merit ; those 
of men are always grotesque. 

The final chapter deals with the prehistoric Bantu, abundant 
proofs of whose activities are to be found throughout the now 
sparsely inhabited bush country of northeastern South Africa. 
The Steynsdorp valley, for instance, is everywhere dotted “ with 
remains of old kraals,” in and about which are mortars, pestles, 
rubbing stones, and other artifacts. Evidences of soil tilling are 
many ; also of mining and smelting operations in iron, copper, 
tin, and gold. The finest ruins occur between the Limpopo and the 
Zambesi, Of the smaller, more primitive ruins, the Inyanga fort 
is a good example. It is the prototype of the more imposing 
Zimbabwe type. The ruins are on commanding sites, taking 
their shape from the summit contours ; the walls were built of 
roughly rectangular blocks of granite laid in even courses. The 
best walls are solid throughout; many are merely faced with 
stone, the space between the faces being filled with rubble. No 
cement was placed between the blocks, The builders knew how 
to produce chessboard, cord, herring-bone, and chevron patterns. 
Courses of rock of a different color were also frequently inserted. 
Monoliths were placed upright on the walls of some of the build- 
ings. At Zimbabwe, which was the “fortified kraal of the head 
chief,” additional pillars of soapstone occur, “carved at the top 
to represent perched birds of prey.” All these ruins are the work 
of a Bantu race that reached a more advanced culture stage than 
their descendants. The objects found in the ruins are character- 
istically Bantu. 


580 Scientific Intelligence. 


The present work is the fourth on South Africa by the same 
author, three of which are archeological. His right, therefore, 
to be classed as an authority in this field can hardly be questioned. 

G. G. MACCURDY, 

3. Bield Museum of Natural History. Annual Report of the 
Director for the year 1910. Pp. 100, with 15 plates. Chicago, 
1911.—The Annual Report of Dr, F. J. V. Sxrrr shows'the pro- 
gress made by the Field Columbian Museum during the past year. 
This was particularly marked in anthropology through the collec- 
tions made by Dr. Laufer in China and Tibet. Several import- 
ant expeditions in the same line are now in the field in New 
Guinea, Borneo, the Philippines, Venezuela, and elsewhere. The 
total amount expended in 1910 from Museum funds was about 
$200,000, and nearly $21,000 in addition were subscribed by 
friends of the Museum for special purposes. The excellent plates 
show a number of interesting natural history groups recently 
installed. 

The Field Museum has also issued the following : Meteorite 
Studies III ; by Ottver Cummines Farrineron. Pp. 165-193, 
plates LV-LIX, Dr. Farrington gives here an account of the 
meteoric stone which fell at Leighton, Alabama, on January 12th, 
1907, weighing 850 grams; also of the remarkable Quinn Cafion 
iron, weighing 3,275 lbs., acquired by the Museum in April, 1909. 
A description of this iron was given by W. P. Jenney in this 
Journal (vol. xxvili, p. 431). Dr. Farrington also discusses 
further the subject of the times of fall of meteorites, earlier taken 
up by him in this Journal (vol. xxix, p. 211). A complete list of 
the meteorites of the United States, geographically arranged, 
closes the number. 

4. Publications of the Astronomical and Astrophysical 
Society of America, Vol. I. Organization, Membership and 


abstract of papers, 1897-1909. Pp. xxvil, 347, 4to, 1910.— 


The dedication of the Yerkes Observatory in 1897 was the occasion 
for a conference of scientists which led to the establishment of 
this society. The present volume is the complete record of 
its activities since its beginning, expressed in discussions and 
memoirs. Their range is wide and their number great. Many 
are of general interest. For example, a short article on the 
duration of twilight in the tropics, by S. I. Bailey, shows con- 
clusively from observations at Arequipa (altitude 8,000 feet) and 
at Vincocaya (altitude 14,000 feet) that the statements contained 
in text-books generally (even Young’s) as to the brevity of tropical 
twilight are as inaccurate as that of the ancient Mariner (“The 
sun’s rim dips, the stars rush out, at one stride comes the dark”). 
He says: ‘‘ While the tropical twilight i is somewhat shorter than 
occurs elsewhere and is still further lessened by favorable cireum- 
tances, such as great altitude and a specially pure air, it is never 
less, and gener ally much longer, than an hour.’ 

Simon Newcomb, it goes without saying, was the leading spirit 
in the society until his death, and an excellent portrait of him 
appropriately faces the title-page, followed by one of Charles 
Young. W.B, 


Miscellaneous Intelligence. 581 


5. Harvard College Observatory ; Epwarp C. PickERINe, 
Director. Recent publications are noted in the following list 
(continued from vol. xxix, p. 276). 

Annats. Vol. LIX, No. 6. Photographic Magnitudes of 153 
Stars ; by Epwarp 8. Kine. Pp. 157-186. 

Vol. LXV. Journals of Zones observed with the 8-inch 
Meridian Circle during the years 1888-1890; by ARTHUR 
SEARLE. Pp. 264. 

Vol. LXVI. Journal of Zones observed with the 8-inch Merid- 
ian Circle during the years 1890-1898; by ArTuuR SEARLE. 
Pip. 253. 

“all LXXI, No. 1. Standard Photographic Magnitudes of 
Bright Stars ; by Epwarp C. Pickrrine. Pp. 25. 

Crrcurars. No. 153. Opposition of Eros (433) in 1910. Pp. 3. 

No. 154. Determination of Absolute Wave-lengths with 
Objective Prisms. Pp. 4, 6 figures. 

No, 155. Accurate Measurements of Photographs. Pp. 3. 

No. 156. Comparison Stars for Halley’s Comet. Pp. 3. 

No. 157. Brightness of Halley’s Comet. Pp. 35; one figure. 

No. 158. Stars having Peculiar Spectra. 38 New Variable 
Stars. Pp. 3. 

No. 159. 15 New Variable Stars in Harvard Map, Nos. 7, 10, 
teyanide Wo pn a: 

No. 160. Photographic Magnitudes. Progress to July, 1910. 
Pp. 6. 

ae. 161. Curved Photographic Plates. Pp. 3, 2 figures. 

No. 162. 22 Variable Stars in Harvard Map, No. 52. Pp. 3. 

No. 163. 181,325. Nova Sagittarii, No. 3. H. V. 3306. Pp. 
3; one plate, 3 figures. 

Sixty-fifth Annual Report of the Director of the Astronomical 
Observatory of Harvard College for the year ending September 
30, 1910; by Epwarp O. Pickerine. Pp. 10. 

6. Publications of the Cincinnati Observatory.—The follow- 
ing memoir has recently appeared: No. 17. Micrometrical Meas- 
ures of Nebulz 1905 to 1910; by Jermain G. Porter, Director. 
Pp. 3-72. Cincinnati (Published by Authority of the Board of 
Directors of the University), 1910. 

7. Contributions from the Princeton University Observatory. 
—The following memoir from the Princeton Observatory has 
recently appeared: No. 1. Photometric Researches : The Algol- 
System Rt Persei; by Raymonp Suirn Duean. Pp. 47, with 
4 tables. Princeton, 1911. 

8. R. Comitato Talassografico Italiano.—A committee, hav- 
ing as its object the study of the Italian seas, was appointed in 
1909, and later it was formally established by act of the Italian 
government. This committee, of which the Marine minister is 
the president, has the task of making investigations of the Italian 
seas from the physical, chemical, and also biological point of 
view. The practical questions concerning the navigation and 


Am. Jour. Sct.—Fourtu SERins, Vou. XXXI, No. 186.—Junz, 1911. 
39 


t 


582 Scientifie Intelligence. 


the fisheries will also be considered, and, further, investigations of 
the high atmosphere will be made in connection with the airship 
navigation. An annual sum of 60,000 lire is appropriated by the 
government, which also supplies the ships needed from the Royal 
navy. Four cruises in the Adriatic sea have already taken place, 
and a fifth cruise will soon start. 

9. International Congress of the Applications of Electricity.— 
An International Congress of the Applications of Electricity will 
be held in Turin, from September 9 to 20,1911. A circular from 
the committee of organization has been issued. Communications 
to it should be sent to 10 Via San Paolo, Milan. 

10. International Congress of Applied Chemistry.—The eighth 
International Congress of Applied Chemistry will have its open- 
ing meeting in Washington on September 4, 1912; other meet- 
ings, business and scientific, will be held in New York from Sep- 
tember 6 to 13, The president is Dr. W. H. Nichols, and the 
secretary, Dr. B. C. Hesse of 25 Broad st., New York City. Dr. 
EK. W. Morley is honorary president. 

11. German Anthropological Society.—The forty-second meet- 
ing of the German Anthropological Society—the fifth combined 
meeting of Germany and Vienna—will be held in Heilbronn, 
from August 6 to 9, 1911. 

12. University of Bologna.—The University of Bologna will 
celebrate on the 12th of June the fiftieth anniversary of the ap- 
pointment of Professor Giovanni Capellini to the chair of Geology. 
His contributions to geological science and his work in inspiring 
others in the same line are so important that the occasion should 
be a highly notable one. The president of the committee is 
Professor Augusto Righi, and the secretaries are Professors Vit- 
torio Simonelli and Albano Sorbelli. 


OBITUARY. 


Dr. Samuet H. Scuppsr, the naturalist, died at his home in 
Cambridge, Mass., on May 17 at the age of seventy-four years. 
He was early (1862-4) active in connection with the Agassiz 
Museum of Comparative Zoology, and later with the Boston 
Society of Natural History. He was also assistant librarian of 
Harvard University in 1879-82 and paleontologist of the U.S. 
Geological Survey from 1886-92. He was the author of many 
original memoirs on insects, recent and fossil, and his valuable 
contribution to science brought him recognition from numerous 
scientific societies at home and abroad. 

M. Enovarp Dupont, the geologist and director of the Royal 
Museum of Natural History at Brussels, died March 31, at the 
age of seventy years. 

Tuomas Rupert Jones, F.R.S., the veteran English geologist, 
formerly Professor of Geology at Staff College, Sandhurst, died 
on April 13, in his 92d year. 

Prof. J. Bosscua, the Dutch physicist, died on April 15, at 
the age of seventy-nine years. 5; 


INDEX TO VOLUME XXXI.* 


A 
Academy, National, meeting at 
Washington, 465. 
Adams L. H., melting points of 


metals, 501. 
Alaska, Kenai flora, Hollick, 327. 
Allegheny Observatory, see OB- 
SERVATORY. 
Allen’s Organic Analysis, 333. 
Animal Study, Meier, 84. 


Anthropological Society, German, 
582. 
Arizona, Meteor Orater, physical 


notes, Magie, 335. 

— Minerals of, Guild, 463. 

Astronomical Society of America, 
publications, 580. 

Atlas photographique des formes du 
relief terrestre, 334. 


B 


Bacteriology, Jordan, 340. 

Barrows, H. H., Elements of Geol- 
ogy, 463. 

Barus, C., independence of coronas 
of thickness of fog layer, 564. 

Barus, C. and M., plane grating for 
spectrum measurements, 85. 

Baskerville, Qualitative Chemical 
Analysis, 382. 
Bassler, R. A., stratigraphy of a 
deep well at Waverly, Ohio, 19. 
Bauer, L. A., gravity determinations 
at sea, 1. 

Bendrat, T. A., geology of Caicara, 
Venezuela, 443. 

Berry, E. W., Engelhardtia from 
American Eocene, 491. 

Biology, McFarland, 244. 

Blackwelder, E., Elements of Geol- 
ogy, 463. 

Boiogna, University of, fiftieth anni- 
versary of Prof. Capellini, 582. 


BOTANY. 


Botanische 
landt, 243. 

Botany and Pharmacognosy, Krae- 
mer, 248. 

Caco palm in America, Cook, 
221. 

Buaiouales of Connecticut, White, 
4 


Tropenreise, Haber- 


Mullugo verticillata, Holm, 525. 
Plant Anatomy, Stevens, 243. 


Boynton, C. N., estimation of ba- 
rium, 212. 

Bradley, W. M., solid solution in 
minerals, 25. 

Branner, J. C., minerals associated 
with diamonds in Bahia, Brazil, 
480, 

Brazil, diamonds, 
Branner, 480. 
Brewer, William H., obituary no- 

tice, Jenkins, 71. 

British Museum Catalogues, Lepi- 
doptera Phalzenze, Hampson, 340. 

Brown, A. P., Mineral Tables, 82. 

Burling, L. D., photographing fos- 
sils by reflected light, 99. 

Butler, B. S., thaumasite from Utah, 
131. 


ete., in Bahia, 


C 


Calendar, reform of, Hesse, 154. 

Canada geol.'survey, 574. 

Capillary tubes, method of calibrat- 
ing, Merton, 457. 

Carnegie Foundation, fifth annual 
report, 339; report on academic 
efficiency, Cooke, 156. 

— Institution of Washington, Year- 
Book, 244: publications, 245. 

Cavendish Laboratory, 1871-1910, 
282. 

Chemical Analysis, Qualitative, Bas- 
kerville and Curtman, 332. 

— Constitution and Physical Proper- 
ties, Smiles, 77. 

Chemistry, Applied, International 
Congress, 582. 

— General, Stoddard, 454. 


CHEMISTRY. 


Argon, fractional crystallization, 
Fischer and Froboese, 382. 

— preparation, Claude, 282. 

Barium, estimation, Gooch and 
Boynton, 212. 

Boiling points, method for deter- 
mining, Smith and Menzies, 146. 

Calcium carbide for determination 
of moisture, Masson, 331. 

Cerium, separation by potassium 
permanganate, Roberts, 350. 

Copper, determination as sulphate, 
Recoura, 146. 

Hydrocarbons, combustion, Bone, 
231. 


*This Index contains the general heads, CHEMISTRY (inel. chem, physics) , GEOLOGY, 
MINERALS, OBITUARY, ROCKS, ZOOLOGY, and under each the titles of Articles referring 


thereto are mentioned. 


ly 


584+ INDEX. 


CHEMISTRY—continued. 
Hydrogen, nascent, reactions, Vour- 
nassos, 147. 
Tron, oxide of, reduction by solid 
carbon, Charpy and Bonnerot, 75. 
Mesothorium, Marekwald, 230. 
Mixtures, quantitative chemical 
analysis, 568. 
Phosphorus pentoxide, action of 
water on, Balareff, 331. 
Polonium, researches, Curie and 
Debierne, 453. 
Radium, preparation of metallic, 
Ebler, 75. 
Silver, estimation by electro-depo- 
sition, Gooch and Feiser, 109. 
Sodium paratungstate, use of, Gooch 
and Kuzirian, 497. 
Sugar cane, determination of, 
Jolles, 567. 
Sulphur dioxide, action upon am- 
monia, 567. 
Uranium minerals, radium contents 
of, Marckwala and Russell, 566. 
Chronometers, History of, Mascart, 
154. 
Cincinnati Observatory, see OB- 
SERVATORY. 
Cirkel, F., Chrysotile-Asbestos, 575. 
Colors of birds and insects, 568. 
Cook, C. W., new occurrence of 
pearceite, 518. 
Cook, O. F., coconut palm in Amer- 
ica, 221. 
Cooke, M. L., Academic and Indus- 
trial Efficiency, 156. 
Coronas and the fog layer, Barus, 
564. 
Curtman, Qualitative Chemical Anal- 
ysis, 332. 
Cushing, H. P., lower Paleozoic 
rocks of New York, 135. ¢ 


D 


Day, A. L., melting points of min- 
erals, 341. 

Diffraction gratings, distribution of 
energy, Trowbridge and Wood, 78. 

Duane, W., heat generated by radio- 
active substances, 257. 


E 


Eastman, C. R., new Elasmobranchs 
from Solenhofen, 399. 

Eaton, G. F., osteology of Pterano- 
don, 148. 

Electric cell, action of light on, Péla- 
bon, 76, 

— Motors, Hobart, 78. 


Electricity, Congress of Applications 
of, 582. 

— rays of positive, Thomson, 455. 

Eliot, C., British Nudibranchiate 
Mollusca, 82. 


F 


Feiser, J. P., estimation of silver by 
electro-deposition, 109, 

Field Museum Natural History, 579. 

Florida geol. survey, 236. 

— production of phosphate rock in 
1910, Sellards, 338. 

Foote, H. W., solid solution in min- 
erals, 25. 

France, Mineralogy, Lacroix, 337. 

Frazer, P., Mineral Tables, 82. 


G 


Gas thermometer, measurements 
with, Day and Sosman, 341. 

Geography, Commercial, Robinson, 
467. 


GEOLOGICAL REPORTS. 


Canada, 574. 
Florida, annual report, 236. 
Illinois, 335, 573. 
Indiana, 333. 
New Jersey, 152. 
New Zealand, 237, 573. 
North Carolina, 3388. 
Ohio, 462. 
Tennessee, 334, 
United States, 31st annual report, 
234; publications, 235. 
Vermont, 240. 
West Australia, 238, 239, 574. 
West Virginia, 237, 384. 
Geology, Elements, Blackwelder and 
Barrows, 463. 


GEOLOGY. 


Badlands formation of South Da- 
kota, O’Harra, 237. 

Baren Island and Spitzbergen geol- 
ogy, Nathorst, 460. 

Camels of the Harrison beds, 
Loomis, 65. 

Centrosaurus apertus, Lambe, 339. 

“Chazy” formation near Ottawa, 
Raymond, 459. 

Dinosaur, new, from the Connecti- 
cut Triassic, Talbot, 469. 

Dinosauria, armored, Wieland, 112. 

Elasmobranchs from Solenhofen, 
new, Hastman, 399. 

Engelhardtia from the American 
Eocene, Berry, 491. 


INDEX. 


Fauna of Allegheny and Cone- 
maugh Series, Pa., Raymond, 79. 

— der Spiti-Schiefer des Himalaya, 
Uhlig, 460. 

Floridian plateau, geologic history, 
Vaughan, 240. 

Fossil faunas of St. Helen’s brec- 
cias, Williams, 241. 

Fossils, photographing by reflected 
light, Burling, 99. 

Gneissoid structure in the Cortlandt 
series, Rogers, 125. 

Kenai flora of Alaska, Hollick, 327. 

Mammals, Age of, Osborn, 150. 

Man, antiquity of in Hurope, Mac- 
Curdy, 240. 

Mink, new, from shell heaps of 
Maine, Loomis, 227. 

Ortholetinz, British Carboniferous, 
Thomas, 79. 

Paliontologie, Grundztige der, von 
Zittel, 78. 

Paleogeography of North America, 
Suess, 101. 

Paleozoic insects, new, from Illinois, 
Handlirsch, 297, 353. 

— rocks of New York, Cushing, 135. 

Patagonischen Cordillera, Geolo- 
gisch-petrographische Studien in 
der, Quensel, 461. 

Pennsylvanian of Ohio, absence of 
soil bed at base of, Hyde, 557. 

Permian reptiles of New Mexico, 
Williston, 378. 

Podokesaurus holyokensis, Talbot, 
469. 

Pteranodon, osteology, Eaton, 148. 

Silurian of Sweden, Moberg, 460. 

Slates, age of Virginia Piedmont, 
Watson and Powell, 33. ~ 

Southern Appalachian region, de- 
nudation and erosion, 408. 

Tertiary faunal horizons, 
ming, Granger, 151. 

Thermal waters in the Yellowstone 
National Park, Hague, 576. 

Trilobites, Ordovician, Raymond, 
79. 

Voleanic rocks of Victoria, Skeats, 


Wyo- 


Well at Waverly, Ohio, stratigra- 
phy, Bassler, 19. 

Gold crystals, Graham, 45. 

Gooch, F. A., silver, estimation by 
electro-deposition, 109; estimation 
of barium, 212; use of sodium par- 
atungstate, 497. 

Graham, R. P. D., native gold from 
Queen Charlotte Islands, B. C., 45. 

Grand Canyon district, geological 
excursion, Johnson, 80. 

Grating, plane, for spectrum meas- 
urements, C. and M. Barus, 85. 


585 


Gravity determinations atsea, Bauer 
i 

Groth, P., 
graphy, 234. 

Guild, F. N., Mineralogy of Arizona, 
463, 


Chemical OCOrystallo- 


H 


Handlirsch, A., new Paleozoic in- 
sects from Illinois, 297, 353. 

Harvard College Observatory, see 
OBSERVATORY. 

Heat generated by radio-active sub- 
stances, Duane, 207. 

Heat-waves, focal isolation of long, 
Rubens and Wood, 456. 

Hegner, R. W., Zoology, 83. 

Hess, F.L., striiverite, 432, 577. 

Hobart, H. M., Electric Motors, 78. 

Hollick, A., Kenai flora of Alaska, 
327, 

Holm, I., Mullugo verticillata, 525. 

Hunt, W. F., Mineral Tables, 577. 

Hyde, J. E., absence of soil bed at 
base of Pennsylvanian of Ohio, 557. 


I 


Illinois, new Paleozoic insects, Hand- 
lirsch, 297, 3538. 

— geol. survey, 335, 573. 

— oil fields, 1910, Blatchley, 335. 

Indiana geol. survey, 333. 

Insects. new Paleozoic from Illinois, 
Handlirsch, 297, 353. 

Ion, isolation of an, Millikan, 570. 

Ionization of atmosphere by radio- 
active matter, Hve, 148. 

— of gases by a-particles from polo- 
nium, Taylor, 249. 

Italian seas, investigation of, 581. 


J 


Japanese Volcanoes, 
462. 

Jenkins, E. H., obituary notice of 
W. H. Brewer, 71. 

Johnson, J. P., Prehistoric Period of 
South Africa, 578. 

Johnston, J., melting 
metals, 501. 

Jolly balance, new, Kraus, 561. 

Jordan, E. O., Bacteriology, 346. 


Friedlander, 


points of 


K 


Kip, H. Z., determination of the 
hardness of minerals, 96. 

Kraemer, H., Botany and Pharma- 
cognosy, 243. 

Kraus, E. H., new Jolly balance; 
561 ; Mineral Tables, 577. 


SL A eee ==. 


A TY Py, 


586 INDEX. 


Krystallographie, Chemische, 
Groth, 284. 


Krystallphysik, Lehrbuch der, 
Voigt, 572. 

Kunz, G. F., morganite, a rose- 
colored beryl, 81; beryl from 


Brazil, 463, 
Kuzirian, S. B., 
tungstate, 497. 


use of scdium para- 


L 


Lacroix, A., Minéralogie de la 
France, etc., 337. 

Library of Congress, report, 156. 

Lick Observatory, see. OBSERVA- 
TORY. 


Light, new emission theory, Trow- 
bridge, 51. 
— transmission through crystal 


plates, Wright, 157. 
Linnzus, Carl, Correspondence, 247, 
Loomis, F. B., camels from the 
Harrison beds, 65 ; new mink from 
shell heaps of Maine, 227. 


Luftstickstoffs, Verwertung, Zen-} 


neck, 332. 


M 


MacCurdy, G. G., antiquity of Man 
in Europe, 240. 

Madagascar, Minéraux des Pegma- 
tites, Dupare, 337. 

Magie, W. F., physical notes on Me- 
teor Crater, Arizona, 339. 

Maine, new mink from shell heaps 
of, Loomis, 227. 

Mathematics, Shop Problems, Breck- 
enridge, Mersereau, and Moore, 248. 

Matter and radio- -activity, electricity 
of, Jones, 5738. 

Mayer, A. (ey Medusee of the World, 
88. 


McFarland, J., Biology, 244. 
McNair, F. W., method in teaching 
optical mineralogy, 292. 
Meier, W. H. D., Animal Study, 84. 
Melting points of metals under pres- 
sure, Johnston and Adams, 501. 
—of minerals, Day and Sosman, 341. 
Wane compressibility, Griineison, 
148. 
—melting points of, influence of pres- 
sure on, Johnston and Adams, 501. 
Meteor Crater, see Arizona. 
Meteorite Studies, Farrington, 580. 
Mills, J., Thermodynamics, 458. 
Mineral production in Canada, 1910, 
575; United States in 1909, 575, 576. 
Mineralogie de la France, etc., La- 
croix, 337. 
Mineralogy, Practical, Rowe, 337. 


Minerals of Arizona, Guild, 463. 

—determination of hardness, Kip, 96. 

sold solution in, Foote and Br adley, 
20. 

—Tables of, Frazer and Brown, 82; 
Kraus and Hunt, 577. 

—uranium, radium contents of, 
Marckwald and Russell, 566. 


MINERALS. 


Aegirite, 550. Asbestos, 575. 

Bauxite, 576. Beryl, 81, 463. 

Calcites, New York, 337. 

Diamond, Bahia, 480. ~ 

Fluorite, 556. 

Gold, crystals, 45. 

Ilmenite, 553. 

Microcline, 545. Morganite, 81. 

Natramblygonite, new, 49. Neph- 
elite, composition, 25. 

Octahedrite, 555. Orthoclase and 


microcline, supposed chemical 
distinction, 232. 

Parisite, Mass., 533. Pearceite, 
Mexico, 518. 


Riebeckite, 547. 
Sapphire, synthetic, 147. Striiver- 
ite, 432, 577. 
Thaumasite, Utah, 131. 
Wulfenite, 557. 
Zincite, crystals, 464. 
Mineraux des Pegmatites, Madagas- 
ear, Dupare, 337. 
Mines, U.S. Bureau, 236. 


N 

New Hampshire geology, Pirsson 
and Rice, 269; petrography, Pirs- 
son, 400. 

New ‘Jersey geol. survey, 152. 

New Mexico, Permian reptiles of, 
Williston, 378. 

New York, lower Paleozoic rocks, 
Cushing, 135. 

New Zealand geol. survey, 237, 573. 

— Subantarctic Islands, Chilton, 82. 

North America, Paleogeography, 
Suess, 101. 

North Carolina geol. survey, 388. 


O 
OBITUARY. 


Bowditch, H. P., 340. Bosscha, J., 
582. Brewer, W. H., 71. Brihl, 
J. W., 340. 

Calvin, S., 468. 

Dupont, H., 582. 

Emmons, S. F., 467. 


INDEX. 


Galton, F., 248. 
Howell, E. E., 468. 
Jones, T. R., 582. 
Meyer, M. W., 248. 
Richards, Mrs. E. H., 468. 
Scudder, Samuel H., 582. 
Van Bemmelen, J. M., 468. 
Van’t Hoff, J. H., 340. 

Observatory, Allegheny, 
tions, 247. 

— Cincinnati, publications, 581. 

— Harvard, publications, 581. 

— Lick, determination of Solar Paral- 
lax, 1538. 

— Princeton, publications, 581. 

— Yale, transactions, 152. 

Ocean, see Sea. 

Ohio geol. survey, 462. 

Optics, Geometrical, Southall, 238. 

Osborn, H. F., Age of Mammals, 150. 

Ostwald’s Klassiker der Exakten 
Wissenschaften, 248. 


publica- 


iz 


Palache, C., chemical composition of 
parisite., ete., 533. ; 

Palaeontologia Universalis, 242. 

Palaeontological contributions to 
the geology of West Australia, 289. 

Phillips, A. H., on zincite crystals, 
464. 

Photographic atlas of terrestrial re- 
lief, 334. 

Photography of fossils by reflected 
light, Burling, 99. 

Physik, die Stellung der neueren, 
Planck, 282. 

Pirsson, L. V., geology of Tripyra- 
mid Mountain, N. H., 269; petrog- 
raphy of Tripyramid Mountain, N. 
H., 405. 

Polonium, ionization by a-particles 
from, Taylor, 249. 

Positive electricity, Thomson, 455. 

— rays, Wien, 77. 

Powell, S. L., age of Virginia 
Piedmont slates, 33. 

Princeton Observatory, see OBSER- 
VATORY, 880. 


R 


Radio-active substances, heat gener- 
ated by, Duane, 257. 

Radium, deflections of electrostatic 
fields, etc., by, Russ, Makower, and 
Evans, 78. 

Rays, positive, Wien, 77. 

eee positive electricity, Thomson, 

Refrigeration by mixtures of liquids, 
Duclaux, 77. 


587 


Rice, W. N., geology of Tripyramid 
Mountain, N. H., 269. 


ROCKS. 


Analcite rocks, Tyrrell, 81. 

Granites of the southeastern Atlan- 
tic states, Watson, 80. 

Nelsonite, Virginia, 218. 

Petrography of Tripyramid Moun- 
tain, N. H., Pirsson, 405. 

Quartzite, Lavras, Brazil, 482. 

Robbins, E. R., Plane Trigonometry, 
248. 
Roberts, E. J., separation of cerium 
by potassium permanganate, 350. 
Robinson, E. van D., Geography, 
467. 

Rogers, G. S., gneissoid structure in 
the Cortlandt series, 125. 

Roentgen radiation from vapors, 
571. 

— rays, velocity measurement, Marx, 
148. 

Rowe, J. R., Practical Mineralogy, 
307. 


S 


St. Helen’s breccias, fossil faunas, 
Williams, 24. ? 

Schaller, W. T., natramblygonite, 
new mineral, 49; thaumasite from 
Utah, 131. 

Sea, deep, origin and peopling of, 
Walther, 50. 

Seas, investigation of Italian, 581. 

Seismological Society of America, 
247, 466. 

Smiles, S., Chemical Constitution 
and Physical Properties, 77. 

Smithsonian Institution, annual re- 
port, 155, 246. 

Solar parallax, determination, Per- 
rine, 153. 

Solenhofen, new Hlasmobranchs 
from, Eastman, 369. 

Sosman, R. B., melting points of 
minerals, 341. 

South Africa, Prehistoric Period, 
Johnson, 578. 

South Dakota, badlands formation, 
237. 

Southall, J. P. C., Geometrical Op- 
ties, 233. 

Standards, Bureau of, bulletin, 578. 

Stevens, W. C., Plant Anatomy, 243. 

Ee eee J. T., General Chemistry, 

04. 

Solutions, absorption spectra of, 
Jones and Strong, 333. 

Suess, E., paleogeography of North 
America, 101. 

Sweden, Silurian, Moberg, 460. 


or 
io 6) 
io 6) 


an 


Talbot, M., Podokesaurus holyo- 
kensis, 469. 

Taylor, T. S., ionization of gases by 
a-particles from polonium, 249. 

Tennessee geol. survey, 334. 

Thermodynamics, Mills, 458. 

Thomson effect, Cermak, 148. 

Thornton, W. M., Jr., feldspar ag- 
gregate of Virginia, 218. 

Trigonometry, Robbins, 248. 

Tripyramid Mountain, N. H., geol- 
ogy, Pirsson and Rice, 269 ; petrog- 
raphy, Pirsson, 405. 

Trowbridge. J., new emission theory 
of light, 51. 


U 


United States geol. survey, annual 
report, 234 ; publications, 235. 

— — production of minerals in 1909, 
Parker, 575; of gems and precious 
stones, Sterrett, 576. 


Vv 


Van Horn, F. R., new occurrence of 
pearceite, 518. 

Venezuela, geologic notes on, Ben- 
drat, 443. 

Vermont geol. survey, 240. 

Victoria, volcanic rocks, Skeats, 80. 

Virginia Piedmont slates, age, Wat- 
son and Powell, 33. 

Volcanoes of Japan, Friedlinder, 
462. 


Ww 


Walther, J., origin and peopling of 
the deep sea, 5d. ; 
Warren, C. H., chemical composi- 
tion of parisite, etc., 533. 

Water, sterilization by ultra-violet 
rays, Helbronner and Reckling- 
hausen, 76. 


INDEX. 


Watson, T. L., age of Virginia Pied- 
mont slates, 33. : 

Waverly, Ohio, deep well, strati- 
graphy, Bassler, 19. 

Wells, R. C., striiverite, 432, 5177. 

weet Australia geol. survey, 289, 
574, 

West Virginia geol. survey, 237, 334. 

Whitlock, H. P., Calcites of New 
York, 337, 

Wieland, G.R., notes on the armored 
Dinosauria, 112. 

Williams, H. S., fossil faunas of 
St. Helen’s breccias, 241. 

Williston, S. W., Permian reptiles 
of New Mexico, 378. % 

Wright, F. E., transmission of light 
through crystal plates, 157. 

Wyoming, Tertiary faunal horizons, 
Granger, 151. 


Y 


Yale Astronomical Observatory, see 
OBSERVATORY. 

Yellowstone Park, origin of thermal 
waters, Hague, 576. 


Z 


von Zittel, K. A., Grundziige der Pa- 
laontologie, 78. 
Zoology, Hegner, 83. 


ZOOLOGY. 


Birds, Methods of attracting, Traf- 
ton, 84. 

Birds and insects, metallic coloring, 
Michelson, 568. 

Lepidoptera, British Museum, Cata- 
logue, Hampson, 340. 

Medusz of the World, Mayer, 83. 

Mollusca, British Nudibranchiate, 
Eliot, 82. 


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 Spee nS 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. Sixth edition. 


j Any or all of the above lists will be sent free on request. We are 
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CONTENTS. 


Art. XXXVIII.—Podokesaurus holyokensis, a New Dino- 
saur from the Triassic of the Connecticut Valley ; by M. 
Tarror. (With Plate IV.) 

XXXIX.—Minerals Associated with Diamonds and Carbon- 
ados in the State of Bahia, Brazil ; by J. C. Branner- 

XL.—An Engelhardtia from the American Eocene; by E. 
W. Berpy 20): oo. Re eee 

XLI.—Use of Sodium Paratungstate in the Determination 
of Carbon Dioxide in Carbonates and Nitrogen Pent- 
oxide in Nitrates ; by F. A. Goocu and S. B. ‘Kuzirran 

XLII.—Influence of Pressure on the Melting Points of 
Certain Metals; by J. Jounsron and L. H. ‘ApAMS ..- 

XLIIL—A New Occurrence of Pearceite ; by F. B. Van 
eee and. CW. Cook s.c% 222. 22 en eg eat 

XLIV.—Mollugo verticillata L. ; by T. Horm 

XLV _—Composition and Crystallization of Parisite and 
Occurrence in the Granite- Pegmatites at Quincy, Mass., 
U.S. A., ete; by C. Pazacne and ©. H. Warren 

XLVI. = Notes on the Absence of a Soil Bed at the Base on 
the Pennsylvanian of Southern Ohio ; by J. E. Hypn -: 

XLVIIL—A New Jolly Balance ; by E. H. hop Anig oe alge. 

XLVIIL—Independence of the Coronas of the Thickness of 
the Fog Layer ; by C. Barus 


SCIENTIFIC INTELLIGENCE. 


Chemistry and Physics.—Radium Contents of some Uranium Minerals, 
MakcKWALD and RvssELL, 566.—Determination of Cane Sugar in the 
presence of other Sugars, A. Jotius: Action of Sulphur Dioxide upon 
Ammonia, EPHRAIM and PloTROWSKI, 567.—Quantitative Chemical Analy- 
sis of Mixtures, H. FRIepENTHAL: Metallic Coloring in Birds and 
Insects, A. A. Micnretson, 568.—TIsolation of an Ion, a Precision Meas- 
urement of its Charge, and the correction of Stokes Law, R. A. Mi_irKan, 
570.—Homogeneous Roéntgen Radiation from Vapors, J. C. CHAPMAN, 
571.—Lehrbuch der Kristallphysik, W. Voter, 572.—Eiectrical Nature of 
Matter and Radioactivity, H. C. Jongs, 573. ; 

Geology and Mineralogy.—Illinois State Geological Survey: New Zealand 
Geological Survey, 573.—Geological Survey of Western Australia: Geo- 
logical Survey of Canada, 574.—Mineral Production in the United States 
in 1909, 575.—Production of Gems and Precious Stones in 1909 : Production 
of Bauxite in 1909: Origin of the Thermal Waters in the Yellowstone 
National Park, 576.—Tables for the Determination of Minerals, E. H. 
Kraus and W. F. Hunt: Striiverite, R. C. WELLS, 577. 

Miscellaneous Scientific Intelligence.—Bulletin of the Bureau of Standards: 
Prehistoric Period in South Africa, J. P. Jounson, 57$.—Field Museum 
of Natural History: Astronomical and Astrophysical Society of America, 
580.—Harvard College Observatory ; Cincinnati Observatory: Princeton 
University Observatory: R. Comitato Talassografico Italiano, 581.—Con- 
gress of the Applications of Electricity : Congress of Applied Chemistry ; 
Anthropological Society : University of Bologna, 582. 

Obituary.—SamMugL H. ScuppErR; M. Epouarp Dvuront: Tuomas RvuPERT 
JONES ; J. Bossowa, 582. 


Om 
InDEx TO VoLuME XXXI, 583. ~3 ] 3 


ee a aed » * _ a 


AMICI 


3 9088 01298 5826