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THE 


AMERICAN 
JOURNAL OF SCLENCE. 


Epiror: EDWARD S. DANA. 


ASSOCIATE EDITORS 


Proressorns GEORGE L. GOODALE, JOHN TROWBRIDGE, 
W. G. FARLOW ann WM. M. DAVIS, or Campripce, 


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


Proressor GEORGE F. BARKER, or PHILADELPHIA, 
Proressor HENRY S. WILLIAMS, or Irwaca, 
Proressor JOSEPH S. AMES, or Battimore, 
Mer. J. S. DILLER, or Wasuinerton. 


FOURTH SERIES 


VOL. XXIX—[WHOLE NUMBER, CLXXIX.] 


WITH FIVE PLATES. 


NEW HAVEN, CONNECTICUT. 


ok 0. 


ni2L84 


ee ee eel 


THE TUTTLE, MOREHOUSE & TAYLOR COMPANY, 
NEW HAVEN. 


oo 
Oe ee ee 


CONTENTS TO VOLUME XXIX. 
a 


SCIENTIFIC INTELLIGENCE. 


Chemistry and Physics—Relative Volatility of the Bromides of Barium and 
Radium, Stock and HEYNEMANN : Action of Light upon Hydrogen Chloride, 
CoEHN and WASSILIJEWA: Ratio between Uranium and Radium in Min- 
erals, Mile. GuEDITscH, 79.—Action of Radium Hmanation upon the 
Elements of the Carbon Group, Ramsay and UsHer: Quantitative Chem- 
ical Analysis, CLOWES and CoLEMAN, 80.—Positive Electricity, J. J. 
THomson : Doppler Effect in Positive Rays in Hydrogen, T. Royps, 81.— 
Magnetic Rotation of Plane of Polarization in the Ultra-red, U. MEYER: 
Instantaneous X-Ray Photography, F. DessavErR: Light and Sound, W. 
S. FRanxKuIN and B. Macnutr, 82.—Direct and Alternating Current Test- 
ing, F. BEDELL: Elements of Physics, H. Crew and F. T. Jonszs, 83. 

Geology.—Radio-activity and Geology, J. Jory, 85.—Geology and Ore 
Deposits of Goldfield, Nevada, F. L. Ransome, 85.—United States Geological 
Survey, 86.—Geological Survey of West Australia: Contribuzioni allo 

_ Studio Petrographico della Colonia Eritrea, EH. Manasse, 87.—Carboniferous 
Air-breathing Vertebrates of the United States National Museum, R. L. 

; Moopie: Cenozoic Mammal horizons cf Western North America, H. F. 

; OsBORN, with Faunal Lists of the Tertiary of the West, W. D. Martruew, 
88.—New Fossil Mammals from the Fayfim Oligocene. Egypt, H. F. 
OssBorn : New Carnivorous Mamma!s from the Faytim Oligocene, Egypt, 
H. F. Ossorn, 89.—New or little known Titanotheres from the Eocene and 

_ the Oligocene, H. F. Ossorn, 99. 

Miscellaneous Scientific Lntelligence.—The Autobiography of Nathaniel 
Southgate Shaler, 90.--Third Report of Wellcome Research Laboratories at 

the Gordon Memorial College, Khartoum, A. Barsour, 91.—lIllustrations of 

African Blood-sucking Flies other than Mosquitoes and Tsetse-flies, EH. E. 

. 


q 
Num ber 162: 
Page 
| Arr. I1.—Dinosaurian Distribution; by R. 8. Lunn. __-- ___- 1 
- IL—Origin of the Crinoidal Muscular Articulations ; by .A. 
: =. JTLUPID 2 Do Re eer 0) ie ae ones epee 40 
- if].—Substitution of Bromide and of Iodine for Chlorine in 
the Separation of Cerium from-the other Cerium Earths; 
fee he Srownine and K..J. Roperrs .._2..--.. 222 45 
| IV.— New Fossil Coleoptera from Florissant, with Notes on 
: fomc already described ; by H..F. WickHAM_2__-2 22-2 47 
V.—Feldspar from Linosa, and the existence of Soda 
Anorthite ; by H. 8S. Wasuineton and F. E. Wright. 52 
VY I.—Rare and Imperfectly Known Brachiopods from the Mis- 
Beemeeeeti by) DL) Ae GREGHR oe! See oe 
: Vil.—Descriptions of Tertiary Plants, HI; by T. D. A. 
‘ op SEEDER DIODE, Bn a lena 


Austin: The Cambridge Natural History, HaRmMeR and SHIPLEY: The 
Human Bodyand Health, A. Davison : International Congress of Radiology 
and Electricity, 92. 


lV CONTENTS. 


Number ao: 


Page 
Art. VIII.—Nitrogen Thermometer from Zinc to Palladium ; 
by A. L. Day and R. B. Sosman ; with an Investigation 
of; thesMetals, by HE. T. Alun 2222 72222 eee 93 
IX.—New Sclerometer; by A. l. Parsons _... ......_.2]23iiee 
X.—Dodecahedral Jointing due to Strain of Cooling ; by 
PE WARE aoe. 22 ou. ~ 2k ERE ES se oe 169 
XI.—Restoration of Paleolithic Man ; my RS. Lorn (Wis 
Plate Dio 2:25. aes eee Pees | | 


XII.—Bismite; by W. T. Scatter and F. L. Ransome’. 173 


XIII. S-ehite bution to the fe of Franklin Furnace, 
N.J.; by C. PavacnE.. 2...) 52 22. Lo! 


SCIENTIFIC INTELLIGENCE. 


Chemistry and Physics—Yormation of Colloidal Sclutions by the Action of 
Ultra-violet light upon Metals, SVEDBERG, 187: Potassium Percarbonate, 
RIESENFELD and ReEINHOLD: Practical Application of Radium, BaxtER 
and TinutEy, 188.—Volumetric Determination of Selenious Acid, L. 
Marino: Contract for Radium : Absolute Measurement of High Pressure 
with the Amagaet Manometer, P. P. Kocnw and KE. WaGner: Relation 
between Absorption and Phosphorescence, M. L. BRUNiInGHAUS: Mass of 
Moving Electrons, E. HupKa, 189.—Hertz’s Photo-Electric Effect, M. 
EK. Birocu: Influence of Thunder on Size of, Raindrops, V. J. Laine: 
Conduction of Electricity through Gases and Radio-activity, R. K. 
McCuiune, 190.-—Die Strahlen der positiven Elektrizitat, EK. GEHRCKE, 
191. 


Geology and Natural History—Thirtieth Annual Report United States Geo- 
logical Survey, G. O. Smita, 191.—Fifth Biennial Report State Geolog- 
ical Survey of North Dakota, A. G. Leonarp, 192.—Figure of the Earth 
and lsostacy from Measurements in the United States, J. F. Hayrorp, 
193.—Geological Survey Cape of Good Hope, A. W. Rocrers: Devonian 
_fauna of the Ouray limestone, KE. M. KinpLE : Lower Paleozoic Hyolithidz 
from Girvan, F. R. C. Reep: Dieasiatischen Fusulinen : Die Fusulinen von 
Darwas, G. DyHRzNFURTH, 194.—Paldozoiche Seesterne Deutschlands ; I. 
Die echten Asteriden der rheinischen Grauwacke, F. SCHONDORE : La Vallée 
de Binn (Valais); Etude géographique, géologique, minéralogique et pit- 
toresque, L. DESBuISSoNS: Catalogue of the Fossil Bryozoain the Depart- 
ment of Geology, British Museum of Natural History, J. W. GREGORY: 
Hand-List of the Genera and Species of Birds, R. BOWDLER SHARPE: 
Physiologische Pflanzen-Anatomie, G. HABERLANDT, 195. 


Miscellaneous Scientific Intelligence—Report of the Secretary of the Smith- 
sonian Institution, C. D. WaxcottT, 196.—Annual Report of the Board of 
Regents of the Smithsonian Institution, 197.—National Antarctic Expedi- 
tion, 1901-1904, Magnetic Observations, 198.—Evolution of Worlds, P. 
‘LoweLL: Hyperbolic Functions, G. F. Becker and C. E. Van ORSTRAND, 
199.—Robbins’ Plane Trigonometry, E. R. Roppins: Experimental Dairy 
Bacteriology, H. L. Russetut and EK. G. Hastines: Bref och Skirfvelser 
af och till Carl von Linné, Tu. M. Friss, 200. 


CONTENTS. V 
Numbers tek. 


- Art. XIV.—Armor of Stegosaurus ; by Ricwarp 8. Luti_. 201 
XV.—Times of Fall of Meteorites; by O. C. Farrineton. 211 
XVI.—Note on the Occurrence of Astrophyllite in the 
Granite at Quincy, Mass. ; by L. V. Pirsson.--_-. .----- 215 
XVII.—Crystallization of a Basaltic Magma from the 
Standpoint of Physical Chemistry ; by C. N. Fuenner_. 217 
XVIII.—Notes on Goethite ; by V. Gotvscumipr and A. L. 
PRES ON SURE ele cone ss ee ge 2 UE Ra 235 


X1X.—Velocities of Certain Reactions between Metals and 
Dissolved Halogens; by R. G. Van Name and G. 


ieee rs eer eter ES EL, Oe ee See 237 
XX.—New Cretaceous Bauhinia from Alabama; by E. W. 

Bere try ey area) Pe i ee OS SREY O56 
XXIi.—Anhydrite and Associated Minerals from the Salt 

Mines of Central Kansas ; by A. F. Rogers -__._----- 258 


SCIENTIFIC INTELLIGENCE. 


Chemistry and Physics—Purple Dye of the Ancients, P. FRIEDLAENDER, 
262.—Purification of Water Supplies by the use of Hypochlorites, W. P. 
Mason: Allen’s Commercial Organic Analyses, H. LEFFMANN and W. A. 
Davis, 263.—Introduction to Physical Chemistry, H. C. Jones: Change 
from Positive Reflection to Negative through Pressure, O. LUMMER and 
K. SorGE: Study of Gaseous Suspensions, M. DE BROGLIE: Constitution 
of the Electric Spark, T. Royps: Cadmium Amalgams and the Weston 
Normal Cell, F. HE. Smita, 264. 


Geology and Natural History—Florida State Geological Survey, E. H. 
SELLARDS, 260.—Report of Topographic and Geologic Survey Commission of 
Pennsylvania, 1906-1908, 266.—Virginia Geological Survey, I’. L. WATSON : 
Illinois State Geological Survey, H. F. Bain: Geology and Water 
Resources of the Northern Portion of the black Hills and Adjoining 
Regions in South Dakota and Wyoming, N. H. Darron, 267.—Biological 
Survey of Michigan: An Ecological Survey of Isle Royale, Lake Superior, 
C. C. Apams: The ee Geological Survey of Kansas, E. Haworru, 
268.—Das Antlitz der Erde, _ SUESS, 269.—Beitrage zur Flora der unteren 
Kreide Quedlinburgs, Teil it: Die Gattung Nathorstiana P. Richter und 
Cylindrites spongioides Goeppert, P. B. Ricater: Cave Vertebrates of 
America; a Study in Degenerative Evolution, C. B. Eigenmann, 270.— 
Die Saéugetierontogenese in ihrer Bedeutung ftir die Phylogenie der Wir- 
beltiere, A. A. W. HuBRECHT: Occurrence of Strepsicerine Antelopes in the 
Tertiary of Northwestern Nevada, J. C. Merriam, 271.—Recherches Géo- 
logiques et Pétrographiques sur lOural du Nord ; Le Bassin de la Haute 
Wichéra, L. Duparc: Laboratory pony for the High School, W. N. 
CLUTE, 272. 

Miscellaneous Scientific Intelligence—The Norwegian Aurozva Polaris Expedi- 
tion 1902-1903, 272.—Carnegie Institution of Washington, Highth Year 
Book: The Carnegie Foundation for the Advancement’ of “Teaching. 
Fourth Annual Report, H. S. PrircuetTr and T. M. Carnecir, 274.— 
Relief Maps: Report of the Librarian of Congress and Report of the 
Superintendent of the Library Building and Grounds, 275.—Harvard Col- 
lege Observatory, E. C. PICKERING, 276. 

Obituary—M. Srerce Nikitin; Dr. SHELFORD BIDWELL, 276. 


al CONTENTS. 


INT e eee 


Page 
Arr. XXII.—Studies on the General Circulation of the 
Earth’s Atmosphere; by Il. WH. Bigelow 2... 2232 eaee Ah 
x XU1.—Mixed Crystals of Silver Sulphate and Dichromate ; 
by R. G: Van Name and RS, Bosworrm -- eee 293 
XXIV.—Osteology and Affinities of the Genus Stenomylus ; 
by I, B. Loomis... 22222: vale 2 
XXV.—Refractive Index of Canada Balsam; by W. T. 
SCHALLER, -.- 34245. 255 gee eee ke 324 


XX VI.—Stratigraphy of the upper Carboniferous in West 
Texas and Southeast New Mexico; by G. B. RicHarpson 325 


X XVII.— Gravimetric Determination of Free Bromine and 
Chlorine, Combined Todine, and Oxidizing Reagents by 


means of. Metallic Silver ; by C. C. Perkins. -_-.._--- 338 
XXVIII.—Discharges of Electricity Through Hydrogen; 
by J. TROWBRIDGE: (2.22.02. 2) 2) 2 2 ee 


XXIX.—New Pennsylvania Meteorite; by O.C. Farrineron 350 
XX X.—Remarks on the Pentamerous Symmetry of the Cri- 


noidea s-by ADE Cram. 22.2.2 2 ee 353 
XX XI.— Association of Enargite, Covellite, and Pyrite from 
Ouray Co., Colorado ; by W. M. Tuornton, JR..__--._ 358 


SCIENTIFIC INTELLIGENCE. 


Chemistry and Physics—Detection of Sodium, Czesium, and Rubidium, W. C. 
Baux, 360.—Volumetric Determination of Sulphates, MircHrLi and SMITH: 
Action of Metals on Fused Caustic Soda, LEBLANC and BERGMANN, 361.— 
Transformation of Diamond into Graphite, VoGrEL and TAmMMann: The 
Johns Hopkins University Circular, No. 2: Meteorologische Optik, F. M. 
EXnNeEr, 362. 


Geology and Mineralogy-—Publications of the U.S. Geological Survey, G. O. 
Smita, 363.—Geological Survey Canada, Department of Mines, R. W. 
Brock, 365.—Kilauea and Mauna Loa, Hawaiian Volcanoes, W. T. 
BricHamM : Deviations from the Normal Order of Crystallization in Granite, 
Macktez, 366,—New Occurrence of Lujavrite: Mercury Minerals from Ter- 
lingua, Texas, HILLEBRAND and SCHALLER, 367.—The Rochester Collec- 
tion of Meteorites ; Descriptive List of Specimens, K. 5S. Howarp: A new 
Meteorite from Georgia, G. P. MERRILL, 368. 


Miscellaneous Scientific Intelligence.—Carnegie Institution of Washington : 
Publications of the Ailegheny Observatory of the University of a 
368. 


CONTENTS. Vil 


INGuanilo eng leita: 


Page 
Arr. XXXII.—Contributions to the Geology of the Grand 
Canyon, Arizona.—The Geology of the Shinumo Area ; 
BogleedNommis Mart: - ili 222 e ee ee eee 2. 369 
XX XUI.—Additions to the Pleistocene Flora of Alabama ; 
me ae igre ve oe hE ee ee ote 387 
XXXIV.—Application of Potassium Ferricyanide in Alka- 
line Solution to the Estimation of Arsenic, Antimony, 
Mee OY. lei. I ALMOR: 5 2.2 ee re oa. 399 
XXXV.—New Cystid from the Clinton Formation of Onta- 
rio—Lepadocystis clintonensis ; by W. A. Parks.--- -- 404 


XXXVI.---New Petrographic Microscope ; by F. E. Wrieur 407 
XXXVII—New Ocular for Use with the Petrographic Micro- 


Becerra pyeh: Me VWRIGHT 22S 5 Veil a ee 415 
XXXVIII.—Behavior of Crystals in Light Parallel to an 
Biers by Cn LRAVIS. Soe ee eta ek. 427 
XXXIX.—Some Simple Improvements for a Petrographical 
Microscope... by—A.- JIOHANNSEN. 2... 22-0202 -..-2.2-.- 485 
XL.—Natural Naphtha from the Province of Santa Clara, 
Cuba; by C. Ricuarpson and K. G. Mackenzixr ._-. -- 439 


XLI.—Intrusive Granites and Associated Metamorphic Sedi- » 
ments in Southwestern Rhode Island ; by G. F. Loucurin 447 


SCIENTIFIC INTELLIGENCE. 


Chemistry—Metallic Zirconium, Wertss and NruMANN, 457.—Gas-volumetric 
Determination of Hydrogen, Paat and HaRrTMANN : Theoretical Principles 
of the Methods of Analytical Chemistry, M. G. Coesnrau : Analyse Volu- 
métrique, L. Duparc et M. Basaponna, 408.—Solid Bitumens, S. F. 
PECKHAM, 459. 


Geology—lowa Geological Survey, S. Catvin: West Virginia Geological 
Survey. I. C. Warte, 459.—New Zealand Geological Survey, J. M. BELt, 
460.—Certain Jurassic (Lias-Oolite) Strata of South Dorset, and their Cor- 
relation, etc., S.S. Buckman, 461.—Palzontologia Universalis : Geologic 
Atlas of the United States: Folio 169, Watkins Glen-Catatonk, New 
York, 1909, H. S. Winuiams, R. S. Tarr, and E. M. Kinpie, 462.—Geol- 
ogy of the Auburn-Genoa Quadrangles, D. D. LuTHER, 463. 


Miscellaneous Scientific Intelligence—National Academy of Sciences, 463.— 
Ostwald’s Klassiker der Exakten Wissenschaften, 464. 


Obituary—ALEXANDER AGASSIZ: ROBERT PARR WHITFIELD: CHARLES REID 
BARNES : SAMUEL WARD LOPER. 


Vill CONTENTS. 


Number 174. 


Page. 

Art. XLII.—Experimental Investigation into the Flow of o 
Rocks, by Frank D. Avams, assisted by Ernest G, 
Coxrr. First Paper—The Flow of Marble. (With 

Plates.-LI-[V)). . 22.1 See 465 
XLIIT.—Heat of Formation of the Oxides of Moiybdenum, 
Selenium and Tellurium ; and fifth paper on the Heat of 
Combination of Acidic Oxides with Sodium Oxide; by 

WG. MIT BR oS 488 
XLIV.—Contributions to the Geology of the Grand Canyon, 

Arizona.—The Geology of the Shinumo Area (continued); 

by L.-F! Nosies-> (With Plate’V.) 22 222232.) ae oa 


XLV.—Effect of Certain Magnetic and Gravitational Forces 
on the Motion of the Moon ; by Ernest W. Brown-_.- 529 


XLVI.—Use of Silver in the Determination of Molybdenum, 
Vanadium, Selenium and Tellurium; by CraupE C. 


PERKINS (lo 2200502 Ol hey Spe 
XLVII.—Chemical Composition of Hulsite and Paigeite, by 
WArpmanel. SCHALLER 222505505 2 ee 543 


SCIENTIFIC INTELLIGENCE. 


Ohemistry—Gas containing Helium from the German Potash Deposit, H. 
ErpMANN, 549.—Detection of Methyl Alcohol, G. Denicks, 550.—A Sub- 
stitute for Platinum Wire for Use in Blowpipe Work, O. F. Kirsy : The 
Use of Sodium Hypobromite in the Separation of Certain Metals, Pozzi- 
Escort: Doppler Effect in Hydrogen, B. Strasser, 551.—Effect of Dust 
and Smoke on the Ionization of Air, A. S. Eve: Measurements in the 
Extreme Infra-Red Spectrum, H. Rupens and H. HOLLNAGEL, 592. 

Geology—Paleogeography of North America, C. SCHUCHERT, 552.— Virginia 
Geological Survey, T. L. Warson, 507.—-Geological and Archeological 
Notes on Orangia, J. P. Jounson : Handbuch der Regionalen Geologie 
G. STEINMANN and G. WILCKENS, 508. 

Miscellaneous Scientific Intelligence—United States Coast and Geodetic 
Survey, O. H. Tirrmann: Connecticut Geological and Natural History, 
Survey, 559.—Kraft das ist animalische, mechanische, soziale EKnergien 
und deren Bedeutung fiir die Machtenfaltung der Staaten, EH. REYER : 
Soziale Machte als Erganzung der Arbeit uber ‘‘Kraft,” E. Reyer: Pub- 
lications of the Allegheny Observatory of the University of Pittsburgh, F. 
ScHLESINGER and R. H. Baker: Bulletin of the University of Kansas, 
M. E. Rice and B. McCotivum, 560. 

Obituary. —ALEXANDER AGAssizZ, 561: Roprert PARR WHITFIELD, 060: SIR 
WituiamM Hueerns, Knut JoHan ANGSTROM, JULIEN FRatpont, H. 
Lanpo.ut, EH. Purnippr1, Richard ABEGG, 566. 


INDEX TO VoL. XXIX, 567. 


= 


4 


t 
\ 


yrus Si, 
ibrarian U. S. Nat. Museum. 


Sivop xx JANUARY, 1910. 


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 CamsBrmwngcz, 


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


Proressor GEORGE F. BARKER, or PHIvapenPen, 
Proresson HENRY S. WILLIAMS, or Irsaca, 

Proressor JOSEPH S. AMES, or Bautimore, 

Mr. J. S. DILLER, or Wasuineton. | 

| 

. 


FOURTH SERIES 
VOL. XXIX—[WHOLE NUMBER, CLXXIX.] 


No. 169—JANUARY, 1910. 


NEW HAVEN, CONNECTICUT. 


1910. a 


THE TUITLE, MOREHOUSE & TAYLOR CO., PRINTERS, 123 TEMPLE STREET. 
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Published monthly, Six dollars per year, in advance. $6. 
Postal Union ; $6.25 to Canada. Remittances should be made 


_ registered letters, or bank checks (preferably on New York ban S). JAN 3 1909 


We: tty? $ 
alignal Mys?* 4 


_— 


Announcement of New Arrivals. 


Iceland Minerals. 


I have just received after considerable delay a new lot of Iceland Zeolites 
consisting of one hundred specimens. The species represented are Heuland- 
ite, Stilbite, Epistilbite, Scolecite, Ptilolite and Quartz geodes in both 
Museum and cabinet size specimens, which I have priced at far below former 
values placed on, these choice trap rock minerals. Their beauty, brilliancy 
and the quality of the crystals is finer than any Be BERS lot bet 2 to this 
country. 


Minerals from Franklin Furnace, N. J 


I have also been fortunate in obtaining a very old collection from a gentle- 
man who specialized in Franklin Furnace minerals and which contains many 
duplicates of finely crystallized specimens. For instance, several of the ex- 
tremely rare crystallized Zincites as well as Franklinites, Rhodonites, Troost- 
ites in very large crystals; also Gahnite, Tourmaline, Calamine, Garnet and 
Spinel. An exceptional lot of choice Phlogopite in Calcite of the largest 
size found. 


Minerals from Colorado. 


Recent additions to my large stock of the desirable Cripple Creek Tellur- 
ides include specimens of the very best quality obtainable. such as Tellu- 
rium, Sylvanite, Calaverite, Gold, ete, With these came Amethyst in parallel 
growth of exquisite quality and a crystallized Calciovolborthite and Carno- 
tite from Telluride, Col. 


Minerals from New Mexico. 


A number of Vanadinites have been received from New Mexico, which 
show crystals distributed over Barite matrix forming desirable specimens of 
beautiful contrast. Also a number of fine native Silvers from the same 
locality. 

Desirable and timely gifts for Christmas of cut gems, gem crystals, antique 
cameos, opal carvings, with semi-precious stones cut and polished and adapt- 
able for mounting in pins, brooches, etc. 

The large stock carried places me in the best position to cater to ae many 
requirements of my patrons for either minerals, rare or common gems, as 
well as the highest quality of reconstructed Rubies, Sapphires, blue or white, 
and the beautiful new pink Topaz. 

I would be pleased to send on approval for inspection aud selection any- 
thing that would interest my patrons. 

Information as to special lists and prices of individual specimens cheer- 
fully furnished. 


ASH. PETEREII. 
81—83 Fulton Street, New York City. 


THE 


AMERICAN JOURNAL OF SCIENCE 


POU Ril, S Eas 3] 
ee Se 


Arr. 1.—Dinosaurian Distribution ; by Ricuarp 8. Lott. 


ehooutibaion from the Paleontological Laboratory, Peabody Museum, 
Yale University. | 


I. Introductory. 
II. Classification. 
Ill. Habitats and adaptations. 
IV. Geological distribution. 
V. Geographical distribution. 
VI. Summary of migrations and paleogeography. 
VII. Bibliography. 


Dinosaurian Distribution. 


I. InrropuctTory. 


Tue significance of terrestrial vertebrates of bygone days 
as aids to geological interpretation, and especially in throwing 
light upon the isolation and connection of continents, is becom- 
ing more and more appreciated. 

The dinosaurs, with their known geological range through- 
out nearly the entire Mesozoic period, and of almost world- 
wide distribution, are the most significant vertebrates of 
Secondary times. Add to this their great numbers both of 
individuals and kinds and the amazing range in their adapta- 
tions and one can appreciate the importance of the line of 
research of which this paper is the first fruit. It constitutes 
the further elaboration of a presidential address delivered 
before the American Society of Vertebrate Paleontologists 
at Baltimore, December, 1908. 

As such a work is of necessity to a certain extent a compila- 
tion, I can but express my indebtedness to the various authors 
listed in the Bibliography, of whom my confrere, Professor 
v. Huene, is the one to whom I owe the most. I am also 


Am. Jour. Sct.—FourtsH SEeRies, Vou. X XIX, No. 169.—January, 1910. 
a ; 


9 R.S. Lull—Dinosaurian Distribution. 


grateful to my colleagues Professors Schuchert and Barrell for 
helpful criticisms and suggestions. 


II. CLASSIFICATION. 


The dinosaurs, because of their great adaptive radiation 
throughout their long career, seem to be a very heterogeneous 
group, so much so that Baut (1891) emphatically denied any 
relationship on the part of the several orders which are 
included within the group. 

They exhibit two distinct lines of cleavage, dividing the 
super-order into three orders, of which two, the carnivorous, 
bipedal Theropoda and the herbivorous, quadrupedal Sauro- 
poda, may be grouped together, in spite of great adaptive dif- 
ferences ; while the herbivorous, bipedal or quadrupedal Ortho- 
peda stand more aloof and show a vastly greater range of 
intra-ordinal variation, To the first two orders collectively 
the name Saurischia has been given by Seeley (1888), while 
the Orthopoda have been designated by the corresponding title 
of Ornithischia. 

A further differentiation of the Theropoda points to two 
distinct races. The heavier megalosaurs, typified by Iegalosau- 
rus of Europe; Alloswwrus of the American Morrison, and 
culminating in the huge Zyrannosaurus of the Laramie, 
were the more conservative group, the evolution of which 
consists mainly in an increase in size, accompanying a relative 
diminution of the fore limbs, which were never used for loco- 
motion, and an assumption of the prehensile function by bine 
feet and mouth armament as in birds of prey. 

The other carnivores, the compsognathoid forms, were ne 
an aberrant nature, not increasing so markedly in size; but of 
a more agile character, better fitted to prey upon feebler rep- 
tiles, birds and mammals than upon other dinosaurs. Typical 
members of this sub-order are C ompsognathus from the litho- 
graphic stone of Bavaria and Ornitholestes of the American 
Morrison beds. 

The Sauropoda appear and disappear with startling sudden- 
ness in the northern hemisphere, though lingering in the 
southern until the close of the Mesozoic. During this time 
they undergo but little evolution, and that mainly in the line 
of a marvelous adaptation for lightness coupled with great 
strength, especially in the elongated vertebral column. Per- 
haps the best-known repr esentatives of this group are Apato- 
saurus (Brontosaurus), a huge, unwieldly beast, and Dzplo- 
docus, a lighter, more slender form; both from the Morrison 
of Wyoming and Colorado. It is a significant fact that the 
most generalized (Haplocanthosaurus) and the most specialized 


R.S. Lull—Dinosaurian Distribution. S 


(Diplodocus) among sauropods occur in the same quarry and 
were therefore contemporaneous. (Hatcher 1903, p. 57). 

Of the plant-feeding Orthopoda there are three main types, 
which have differentiated from the original stock; one, the 
unarmored Ornithopoda, paralleling the carnivores in general 
bodily contour and bipedal gait, though bringing the fore 
feet to the ground when occasion demanded. Like the car- 
nivores they too included a greater and a lesser race. The 
former, like gwanodon of the Wealden of Europe and Camp- 
tosaurus of the American Morrison, culminated in 7’ rachodon 
of the late Cretaceous ; while the latter are represented by the 
fleet Laosawrus of North America and fypsilophodon of 
Europe. 

On the other hand, two groups of armored, secondarily quad- 
rupedal dinosaurs arose, possibly derived from the same branch 
of the Orthopoda, possibly of independent origin. These 
were the Stegosauria, the defensive sort with small head and 
heavy body armor sometimes forming, over part of the body 
at least, a veritable cuirass or carapace ; and the more ageressive 
Ceratopsia with huge armored skull, but, so far as our knowl- 
edge goes, bereft of any special body mail. The first are 
represented by the British Polacanthus and the American 
Stegosaurus, while the last have a splendid representation in 
that most grotesque of dinosaurs, Zrzcerutops from the Ameri- 
can Laramie. 

V. Huene (1907-1908, p. 351) derives the Sauropoda from 
the early Theropod dinosaurs of the Trias, seeing in the genus 
Plateosaurus the annectant type. In his scheme of relation- 
ships (v. Huene 1909, p. 22), however, he seems to defer the 
divergence of the Sauropoda from the Plateosauridee until the 
Lias, which would hardly give time for the profound change 
shown by either Cetosaurus or Dystropheus of the Dogger. 
It is my impression that the divergence occurred earlier in 
Triassic time. 

Of annectant forms, lmking the Theropoda and Orthopoda, 
none is suggested by v. Huene among known types, as our 
known record of the latter does not go back far enough in 
time. Of the Stegosauria, Scelidosaurus of the English Lias 
seems to be the most primitive as it surely is the oldest; it is, 
however, still removed from the Ornithopoda and a common 
ancestor must again be sought in more remote strata. 

The Ceratopsia: may have their earliest representative in 
Stenopelix of the Wealden of Briickeburg. V. Huene (1907- 
1908, p. 374) has shown strong points of resemblance between 
the pelvis of Stenopelia and that of Triceratops. Whether, 
as he suggests, one can derive the phylum from the Scelido- 
sauridan stem, or whether the group represents an independ- 
ent offshoot from the Orthopod stock, is not quite clear. 


4 R.S. Lull—Dinosaurian Distribution. 


These relationships are expressed in the table (figure 1), 
which is largely compiled from lesser ones by v. Huene (1907— 
1908, pp. 340, 375, 877; 1909, p. 22). 


III. Haprrats and ADAPTATIONS. 


In order to comprehend the remarkable geographical distri- 
bution of the dinosaurs, it is necessary to investigate the 
character of their various habitats, the conditions they were 
forced to meet and the marvelous degree of adaptation to the 
environment which they underwent. 

I imagine the conditions which gave to the dinosaurs their 
initial evolutionary trend were such as are thought to have 
prevailed, beginning in the Permian, throughout Triassic 
time. This is well shown in the region now known as the 
Connecticut valley. The older notion of the estuarine origin 
of these deposits has been abandoned in favor of the idea that 
they were of terrestrial origin, the climatic conditions being 
those of semi-aridity with areas here and there which were 
subject to inundations occurring in times of torrential rains 
such as are observed to-day under similar climatie conditions 
in different portions of our globe. This lends color to the 
view that the early dinosaurs were truly terrestrial types, with 
marked cursorial adaptation, indicated in the free, bipedal 
stride and compact, bird-like foot which is shown by the fossil 
footprints. 

V. Huene (1907-1909, pp. 396-401) derives the Theropoda 
and Parasuchia from one stem, the supposition being that the 
distinguishing characteristics were developed during the oldest 
Trias through adaptation. Increasing aridity of climate would 
_render it necessary for an animal to go farther afield for water and 
possibly for food and thereby place a premium on good powers 
of locomotion, so that selection would be very active in weed- 
ing out the unfit or inadaptable lines. This locomotor adapta- 
tion in the quadrupedal stage is beautifully shown in the 
Parasuchian genus Stegomus (Lull 1904 B, pp. 147-148) from 
the Connecticut valley Trias (Rheetic), evidently a persistent 
type which, possibly because of the retention of armor, 
remained a “quadruped though long of limb and with the 
greater portion of the weight borne on the hinder extremities. 
Stegomus, I imagine, though belonging, morphologically, to a 
very different race, represents a stage in the adaptation of the 
dinosaurs which was reached early in the Trias. 

Many modern lizards are amazingly swift of movement, but 
their journeys are brief and the rapidly moving types are 
small. It is a well known fact that a number of lizards, nota- 
ably Chlamydosaurus, when startled, rise on the hinder limbs 


\ 


R.S. Lull—Dinosaurian Distribution. 5 


and run with a truly bipedal gait (Sayville-Kent 1898, p. 341). 
It is significant that the bipedal lizards, so far as my knowl- 
edge goes, are all found in semi-arid climates— Australia, 
Southwestern United States. This tendency toward bipedal- 
ism, with a consequent profound alteration of the hind limbs 
and pelvis, both in bone and musculature, seems therefore to 
have developed to meet the need of greater range of move- 
ment necessitated by increasing aridity, and was the prime factor 
in the early evolution of the dinosaurian race. 

So strongly was this feature impressed, that the main lines 
of dinosaurian evolution, whether plant or animal feeders, 
were cursorial, terrestrial types, though, as new conditions arose, 
or were met with during their forced migrations, aberrant 
types of marvelous complexity and range of specialization 
developed. These aberrant forms, from the fact that their 
remains were more readily preserved, are the ones best known 
to us and have colored our whole conception of the dinosaurian 
race. 

When the plant-feeding Orthopoda arose we do not know. 
Nanosaurus (v. Huene and Lull 1908) is known from the 
upper Trias (or lower Jurassic) of Colorado, while in the pos- 
sibly contemporaneons beds of the Connecticut valley there have 
been found many footprints which Lull (1904 A, pp. 499-509) 
has shown to belong to plant-feeding types of general propor- 
tions not unlike those of their theropod allies, but differing 
mainly in the feebly prehensile character of the little, blunt- 
toed manus, the imprint of which is sometimes seen. The 
Theropoda, on the other. hand, had a strong, grasping hallux, 
as a rule rotated to the rear of the foot so as to be in opposi- 
tion to the other toes, and a manus with powerful claws, which 
had already sacrificed fully the function of locomotion to that 
of prehension. The Orthopoda could give rise to secondarily 
quadrupedal (Dollo 1905) forms, the Stegosauria, the Ceratop- 
sia; the Theropoda, on the other hand, had cast the die in favor 
of absolute bipedalism and stalked on upon the hind limbs to 
the end of their career. 

While both small and large forms prevailed at the close of the 
Trias, the differentiation, if we except the character of the 
pubis, is largely owing to opposite habits, acquired apparently 
_ In the remote Trias, very early in the dinosaurian evolution. 

The carnivores, as has been said, are relatively conservative 
in their evolution, except for the differentiation into the 
greater megalosauroid forms and the lesser compsognathoid 
types. The Theropoda were evidently the most mobile of all 
dinosaurs, free to migrate wherever other creatures lived 
which could possibly be utilized for prey, for not only do we 
find them the world over, with the exception of Asia (vide 


6 R.S. Lall—Dinosaurian IMstribution. 


infra p. 81) north of India, but practically wherever dinosaurs 
of whatever sort are found. 


The Sauropoda. 


~ During the Triassic, the carnivores had spread to other 
conditions and had given rise to a new order, the Sauropoda, 
no longer truly terrestrial, but inhabiting the bayous and 
swamps S of the numerous deltas which fringed the continental 
shores. This change of habitat was far-reaching in its effects, 
for rapid locomotion was no longer necessary and a certain 
degeneracy resulted—whether the carnivorous ancestors had 
attained bipedalism or whether the Sauropoda were primi- 
tively quadrupedal I cannot say. Increase in size was accom-* 
panied by an elongation of the neck to get a greater range of 
feeding with as little bodily movement as possible and it 
necessitated as well a diametric change in diet, for with 
increasing bulk, no longer finding the animal food of their 
forbears “adequate or readily obtainable, they took to an 
herbivorous feeding habit which required but little change in 
the mouth armament. 

The modern Iguanidee show a certain parallelism with the 
Sauropoda, for while the primitive diet is carnivorous (insect- 
ivorous) ‘some of the most striking forms are herbivorous, e. g. 
Iguana, Amblyrhynchus, and Basiliscus.” (Gadow 1908, pp. 
528, 533.) Moreover, one finds within the family not only 
seml-aquatic adaptation, but even semi-marine. The iast is 
shown by Amblyrhynchus cristatus, which “inhabits the 
rocky and sandy strips of coast of most of the Galapagos 
Islands, feeding on certain kinds of algae, which it has to dive 
for, since these plants grow below tide-marks.” 

The precise food of the Sauropoda is a matter of doubt. 
Dr. Hay (1908, p. 674), in discussing that of Diplodocus, the 
most highly specialized member of the order, sums up the 
expressions of opinion as follows: “ Hatcher suggested that. 
the teeth might have been useful in detaching from the bot- 
toms and shores the succulent aquatic and semi-aquatic plants 
that must have grown there in abundance. Osborn [1889, p. 
ae says that the ‘ food probably consisted of some very large 
and nutritious species of water plant. ‘The anterior claws may 
have been used in uprooting such plants * * * The plants 
may have been drawn down the throat in large quantities 
without mastication” * * * Holland [1906, p. 240] thinks. 
that the teeth were better adapted for raking and tearing off 
from the rocks soft masses of clinging alge than for securing 
any other forms of vegetable food now represented in the 
waters of the world. 


RS. Lul—Dinosaurian Distribution. ¥( 


“To the present writer [Hay] the suggestion of Dr. Holland 
has in it more of probability than any of the others presented. 
If the food-plants sought by Diplodocus had been large and 
such as required uprooting by the great claws of the reptile, 
the prehension and manipulation of the masses would have 
been liable to break the slender teeth and would certainly have 
produced on them perceptible wear. * * * 

“Tt is more probable that the food consisted of floating algae 
than of plants that were loosely attached to the bottoms of 
stagnant bayous and ponds. .. . In addition to various algae 
were probably other floating plants.” 

The teeth of the Sauropoda, notably Moroswurus and Apto- 
saurus (Brontosaurus), are much more robust and frequently 
show decided wear. ‘This wear, however, is along the edges 
on either side of and sometimes including the apex; which 
could readily be accounted for by abrasion of the alternating 
teeth of the opposing jaw and which could not be due to 
scraping of vegetation from the rocks. The food of these 
animals may have been more in keeping with the character of 
that mentioned by Osborn. : 

It is interesting to note in this connection, a propos of the 
question of the digestibility of huge masses of unmasticated 
vegetation, the occurrence of “stomach stones” or “‘gastroliths”’ 
(Wieland 1906) which seem to have had an important 
.funetion in aiding in the-trituration of the food. Wieland 
records the occurrence of such polished flint pebbles in immedi- 
ate association with the remains of a large sauropod observed 
at the northern end of the Big Horn Mountains. Pebbles, 
_ presumably gastroliths, were also found by Wieland with the 
type of the Sauropod genus Barosaurus from near Piedmont, 
South Dakota. 

Dr. Hay (loc. cit., p. 673-674) further says: ‘“‘Hatcher has 
discussed at length the nature of the region in which the 
species of Diplodocus and their allies lived, as well as the 
habits of the Sauropoda in general; and the present writer 
[Hay] agrees with him on most points. Hatcher believed that 
the Atlantosaurus [ Morrison] beds were deposited, not in an 
immense freshwater lake, as held by some geologists, but over 
a comparatively low and level plain which was occupied by 
perhaps small lakes connected by an interlacing system of 
river channels. The climate was warm and the region was 
overspread by luxuriant forests and broad savannas. The 
area thus occupied included iarge parts of the present 
states of Colorado, New Mexico, Utah, Montana and the 
Dakotas. In his memoir on Diplodocus Hatcher compares 
the conditions prevailing in that region during the Upper 
Jurassic [Lower Oretaceous] to those now found about the 


8 R.S. Lull—Dinosaurian Distribution. 


mouth of the Amazon and over some of the more elevated 
plains of Western Brazil. 

“In such regions the rivers, fed from distant elevated lands, 
must have been subject to frequent inundations. The beds of 
the streams were continually shifting, and there existed 
numerous abandoned channels that were filled with stagnant 
water. An animal that lived in such a region would be com- 
pelled to adapt itself to a more or less aquatic life, and this 
adaptation would be reflected to a greater or less extent in 
the structure of the animal.” 

Through the courtesy of Dr. Holland, I have been able to 
study somewhat critically an undoubted sauropod footprint 
from the Morrison dinosaur quarry at Cafion City, Colorado. 
Hatcher figures a cast of this track in his memoir on the 
osteology of Haplocanthosaurus (1908, fig. 28, p. 161). The 
figure is somewhat deceptive, however, in that it was taken 
from a plaster cast of the specimen which in turn is a natural 
cast of the original impression made by the living animal and 
which is therefore in relief. .The surface of the specimen 
itself is covered with deep pits caused by a solution of the 
calcareous cement which bound the grains of sand together, 
thus allowing the latter to be washed out. In the photograph 
the casts of these pits, being in relief, give the impression of 
pebbles, whereas the rock in the quarry is a fine-grained, cross- 
bedded sandstone of uniform texture, without appreciable clay, 
and not gravelly at all. A microscopic study of the sand- 
grains themselves show them to be angular with slightly 
abraded corners, sand of aqueous deposit; but apparently laid 
down in a lake or bayou, rather than in a normal river as 
indicated by the absence of clay and the presence of a lime 
cement. The cross-bedding which the rock exhibits could 
readily have been made by wave action along the shores of a 
comparatively shallow delta-lake or bay, and the track, which 
is that of a very young animal, was evidently made under 
water. The character of the sediment does not give evidence 
of much vegetable matter at the particular point where the 
track was made. The footprint is that which one would 
expect from the known character of the sauropod foot, and is 
evenly impressed throughout as though the animal’s weight 
were borne equally over the entire sole, evidence in favor of a 
true walk rather than a sprawling er awl, at any rate when the 
body was partly water-borne. | 

I believe these animals to have been truly aquatic though — 
capable of coming ashore where the substratum was sufficiently 
firm to support the immense weight, and, while they show no 
trace of swimming appendages, they doubtless could swim as a 
hippopotamus does or, as Hay (1908, p. 667) has implied, like a 


R. S. Lull—Dinosaurian Mstribution. 9 


colubrid snake .“‘which makes fair progress in the water, not- 
withstanding the absence both of a compressed tail and of a 
vertical fin.” 

The Wealden formation of England is thus described by 
Geikie (1903, pp. 1180-1181). “The Purbeck beds bring 
before us evidence of a great change in the geography of 
England towards the close of the Jurassic period. They show 
how the floor of the sea, in which the thick and varied forma- 
tions of that period were deposited, came to be gradually 
elevated, and how into pools of fresh and brackish water the 
jand leaves, insects, and small marsupials of the adjacent land 
were washed down. ‘These evidences of terrestrial conditions 
are followed in the same region by a vast delta formation, that 
of the Weald, which accumulated over the south of England, 
while the marine strata were being deposited in the north. 
Hence two types of Lower Cretaceous sedimentation occur, 
one where the strata are fluviatile (Wealden), and the other 
where they are marine (Neocomian).” 

In Wyoming the Morrison beds lie directly upon the marine 
Baptanodon beds of Marsh in which Belemnites abound. 
Lying between this and the main dinosaur-bearing layer are 
about 156 feet (Loomis 1901, pp. 192-1938) of variegated sand- 
stones and clays, of which bed No. 13, 824 feet above that 
which contains Baptanodon itself, seems to represent the first 
of the freshwater (or brackish) series, as it contains an aban- 
doned dinosaur quarry in Como bluff. This would seem to 
fndicate that in the Morrison, conditions very similar to that 
of the Wealden prevailed and that in each instance access to 
the sea on the part of the sauropod inhabitants was not only 
possible but actually probable, as the littoral realm seems to 
have been the highway of immigration of this order of dino- 
saurs. 

The Morrison beds, lying as they do in a great synclinal 
trough, and at the time of their deposition but little above sea 
level, probably were drained, in the southern portion at least, 
into the sea, which lay some two hundred and fifty miles 
(Schuchert 1909, Late Upper Jurassic Chart) to the south- 
ward. This drainage outlet because of its very low gradient 
may again have given conditions similar to those of the 
Amazon (vide supra p. 8), so that the passage of the 
Sauropoda across the area included in the present state of 
New Mexico would appear to have been perfectly feasible. 
Evidence which may be corroborative is found in Madagascar, 
in a locality east of the bay of Narinda, wherein were dis- 
covered the remains of Zvtanosaurus in a matrix containing 
the marine Mytilus madagascarensis and foraminifera (Boule 
1896, p. 348). : 


»% 


10 R.S. Lull—Dinosaurian Distribution. 


Orthopoda. 


The Orthopod dinosaurs were adapted to a very different 
kind of food from that of the Sauropoda, developing in the 
course of their evolution a more and more perfect dental 
mechanism for chopping into short lengths the relatively firm 
terrestrial vegetation. The toothless anterior part of the 
mouth was sheathed in a leathery or horny beak which reached 
its highest perfection in the Ceratopsia and which constituted 
the prehensile, while the teeth, borne in the posterior por tion 
of the jaws, formed the masticatory part of the mouth ; best 
developed in the Ceratopsia (Hatcher 1907, pp. 48-46) on the 
one hand and the Trachodontidee (Brown 1908, pp. 52-53) on 
the other. 

The Sauropoda and Theropoda had only prehensile teeth 
and did not masticate their food at all. This shows quite 
clearly that, so far as feeding habits go, none of the three 
great groups of dinosaurs came into competition with each 
other, except that the carnivores did occasionally devour the 
others, and that, in so far as the Sauropoda and Orthopoda 
were concerned, the habitat was necessarily different; the 
latter being in the main terrestrial, the former amphibious. 
In no other way can we account for the marked differences in 
distribution of the two orders which, reduced to its final analy- 
sis, has gone so far that the two groups are rarely found in the 
same quarry even within the same region and geological forma- 
tion. | For example, “ Quarry 13” (Gilmore, 1909) pp zea 
in Como Bluff, Wie can from which several of Professor 
Marsh’s more important type specimens came, contains almost 
entirely the remains of Orthopoda, Camptosaurus, Pryosau- 
rus, Stegosaurus ; of Carnivores, Allosawrus and Ce lurus, 
while but a single Sauropod, the type of Morosaurus lentus, an 
extremely young individual, was found in association. On the 
other hand, the famous Bone Cabin Quarry, situated but a few 
miles distant, had yielded up to 1904 (Osborn, 1904, p. 694) 
sauropods, 44; stegosaurs, 3; smaller herbivorous dinosaurs, 4; 
large carnivorous dinosaurs, 6; small carnivorous dinosaurs, 3 ; 
showing the Sauropoda to be vastly more numerous than the 
other plant-feeding varieties, and evidently implying a distinet 
habitat from that repr esented by “Quarry 13.” 

Within the Orthopoda the marked differentiation into 
Ornithopoda, or unarmored types, and the Stegosauria and 
Ceratopsia, or armored forms, seems to have been due to their 
different modes of defence, presumably against the omnipresent 
carnivores, though the existence of enemies other than dinosaurs, 
such as the crocodile Goniopholis, is not unlikely. The 
Ornithopoda, which were the most conservative in their evolu- 


R. S. Lull—Dinosaurian Distribution. ee 


tion among the Orthopoda, retained the cursorial character of 
their ancestry, relying evidently upon celerity and speed rather 
than upon weapons or armor for defence against their san- 
guinary foes. The ideal of this type of dinosaur was perhaps 
Laosaurus of North American Morrison and its old world 
representative [ypsilophodon of the English Wealden. Later 
Trachodon, and probably its ancestor Claosaurus, the remains 
of which are found repeatedly in marine rocks, became in 
their turn semtaquatic, possibly in their sear ch for food 
because of competition with the great armored forms. They 
did not, however, rely on increasing bulk for immunity against 
attack as did the Sauropoda ; but, by means of a powerful, 
laterally compressed swimming tail may have been as active as 
erocodiles in the water while still retaining a means of com- 
paratively rapid locomotion on land. The defencelessness of 
these creatures, so far as armor is concerned, has been beauti- 
fully shown in the ‘‘mummitied” specimen of Zvachodon, 
discovered in 1908 by C. H. Sternberg, in Converse County, 
Wyoming, and now preserved in the American Museum of 
Natural History. Professor Osborn (1909, pp. 793-795) says 
of it: “The first and most surprising impression is that the 
epidermis is extremely thin, and that the markings are exces- 
sively fine and delicate for an animal of such lar ge dimensions. 
There is no evidence in any part of the epidermis either of 
coarse tubercles or of overlapping scales. In all parts of the 
body observed it is entirely composed of scales of two kinds: 
(1) larger pavement or non-imbricating scales, (2) smaller 
tubercular scales.” Osborn speaks not only of the « vigorous 
use of the tail as a balancing, and perhaps partly as a swim- 
ming organ,” but also tells us that the “ manus is completely 
encased in the integument, and was thus web-footed.” Evi- 
dence for aquatic or senii- aquatic life. 

The armored dinosaurs make their first appearance in Scel7- 
dosaurus of the English Lias, the possible ancestor of all of 
the subsequent mailed types. The earliest forms were proba- 
bly bipedal, but, as time went on, and the armor increased in. 
bulk and weight, we find these dinosaurs becoming secondarily 
quadrupedal (Dollo 1905), losing all celerity of movement and 
becoming sluggish, slow moving, living citadels of well-nigh 
impregnable character. In habitat they were doubtless terres- 
trial, as in the case of the earlier Ornithopoda with which their 
remains are found associated. A curious differentiation of 
armored dinosaurs occurred, correlated with a marked differ- 
ence in the mode of defence, in that the more aggressive, men- 
tally alert Ceratopsia used the head both for offence and 
defence, while the stegosaurs seem to have used the tail. Ste- 
gosaurus proper, which developed to an extreme this method 


12 R.S. Lull—Dinosaurian Distribution. 


of defence as well as a remarkable body armament of huge 
probably upstanding plates, became too highly specialized to 
survive and apparently died out early in the Lower Cretaceous. 
Its allies, however, still lived on until the close of the Mesozoic, 
developing over the rear of the body m Polacanthus of the 
English Wealden, and later in Ankylosaurus of the Laramie, 
a veritable cuirass, elyptodon-like in its perfection, covering 
what seemed to be the most vulnerable portion of the body. 

That the Ceratopsia were aggressive fighters among them- 
selves, as the cattle are to-day, is known from the frequent 
punctures of skull and frill, broken horn-cores, and such san- 
guinary evidences. That they held their own against the ter- 
rible carnivores of their time is shown by their survival until 
the close of dinosaurian history. 

The environment of the Cretaceous Orthopod dinosaurs and 
of the attendant carnivores is described by Stanton (1909, pp. 
280-282) as consisting of great areas but slightly elevated 
above the level of the sea and occasionally actually beneath it, 
wherein are found fresh-water, brackish water, or marine 
deposits. Upon these great marshes vegetation became estab- 
lished, and land animals, and those of the streams and lagoons 
as well as the bays and estuaries, sought their appropriate 
habitats. 

In speaking of the conditions prevailing toward the close of 
the Cretaceous, Hatcher (1893, p. 142; Hatcher, Marsh, Lull 
1907, p. 194) says: “ The Ceratops beds are thought to afford 
evidence in themselves of having been deposited not in a great: 
open lake, but in a vast swamp with occasional stretches of 
open waters, the whole presenting an appearance similar to 
that which now exists in the interior of the Everglades of 
Florida. This condition would account for the frequent 
changes from one material to another in the same horizon.* * * 

“The conditions that prevailed over this region during the - 
period in which the Ceratops beds were deposited were prob- 
ably those of a great swamp with numerous small open bodies 
of water connected by a network of water courses constantly 
changing their channels. The intervening spaces were but 
slightly elevated above the water level or at times submerged. 
The entire region where the waters were not too deep was 
covered by an abundant vegetation, and inhabited by the huge 
dinosaurs (Z7iceratops, Torosaurus, Claosaurus, etc.), as well 
as by the smaller crocodiles and turtles and the diminutive 
mammals, all of whose remains are now found embedded in 
the deposits.” 

For the terrestrial Orthopoda, such as Camptosaurus and 
Iquanodon, the cycads and ferns which grew in such profusion 
during their time would supply ample nourishment. Stegosau- 


R. §. Lull—Dinosaurian Distribution. 13 


rus, however, has relatively feeble teeth, and must have fed 
upon the most succulent of terrestrial plants. The Ceratopsia, 
living as they did toward the close of the Upper Cretaceous, 
were surrounded by a virtually modernized flora, and hence 
may have had feeding habits very similar to those of the sub- 
tropical browsing ungulates of to-day. 

Trachodon, however, presents more of a problem on account 
of its undoubted aquatic habits. Here the anterior, toothless 
part of the mouth in the most highly specialized types became 
broadened and depressed into a duck-like form, and, while 
undoubtedly sheathed with a horny or leathery integument, 
probably did not have the shearing mechanism so perfectly 
developed as in the true terrestrial plant-feeders. On the 
other hand, the dental battery reaches its greatest perfection 
in Zrachodon, consisting as it does of “from 45 to 60 vertical 
and from 10 to 14 horizontal rows of teeth, so that there were 
more than 2,000 teeth altogether in both jaws.” (Brown, 
1908, p. 53.) The immense number, especially of those in 
reserve, implies a very rapid wear and consequent replacement 
of the teeth ; which, together with the sharp, serrated, shear- 
ing edge which the collective teeth of a jaw present, argues 
strongly in favor of the idea as expressed by Brown (loc. cit., 
p- 55) that some species of Equesetze, the remains of which are 
- the most abundant among the plant relics entombed with these 
dinosaurs, supplied them with food. The broad duck-like 
muzzle would be admirable for dislodging the rhizomes from 
their resting place, while the abundance of silica in the cuticle 
of the plant would necessitate just such a dental battery as the 
Trachodonts possessed for its proper mastication. 


IV. GroitocicaL DistrRiBuTion. 


Both geologically and geographically the dinosaurs show a 
peculiar discontinuous distribution, due in large measure to the 
imperfection of our records, but also to the fact that they were 
principally terrestrial types and that the preservation of their 
remains in water-laid rocks is largely the result of accident. 


Theropoda. 
Geologically the Theropoda have the greatest range, as they 
are first found in the Lower Muschelkalk of Europe and con- 
tinue on until the end of the Mesozoic. 


Triassic. 


Of the Triassic forms, a very complete series is found in 
central Europe, of which one of the most primitive genera is 
Thecodontosaurus, which also had the widest distribution both 
geographically and in time (see fig 2). From the Zhecodonto- 


14 Frais: Tul Dinosaurian Distribution. 


saurus stem are derived, as side lines, the Newark dinosaurs 
Anchisaurus and Ammosaurus of the Connecticut valley ; 
while the first known of these, d/egadactylus polyzelus from 
Springfield, Massachusetts, v. Huene (1906, pp. 115-118) 
refers to the genus 7) hecodontoswurus itself, J anystropheus, 
ancestral to the delicate, hollow-boned Oceluridee, begins also in 
the Muschelkalk, and while differing widely from Zhecodonto- 
saurus, its successor Celophysis, from beds in Colorado equiva- 
lent to the Upper Keuper of Europe, converges again toward 
the Thecodontoid phylum, so that the later representatives, 

Celurus on the one hand and the Compsognathoid forms on 
the other, are closely approximated. 

In the Lower Keuper a new genus, Zanclodon, appears in 
Europe, of greater size than its contemporaries, and from 
which v. Huene (1909, p. 20) would derive Ceratosaurus of the 
Morrison with no annectant forms, There are, however, among 
the Connecticut valley footprints (Rheetic), besides numerous 
ones referable to the Thecodontoid types (Anchesauripus 
Lull—1904, p. 468), those of a large carnivore with powerful 
anterior claws but witha relatively feeble hallux. This track 
which Hitchcock called Gigandipus (Lull, loc. cit., p. 492) 
because of its great size, may well have been made by a mem- 
ber of the Zanclodon phylum, the bones of which are as yet 
unknown in these deposits. 

The Middle Keuper ushers in another genus in the form of 
Leratosaurus; giving rise, in the Rheetic, according to v. 
Huene, to two main branches, from one of which arose, through 
Gressylosaur us and Euskelosaurus, the great Megalosaurian 
line, the other giving rise, through Plateosaurus, to the Sau- 
ropoda. This seems to me, however, to place the divergence 
of the Sauropoda somewhat too late in time; to the imply 
phylogeny I take no exception. 

The Connecticut valley forms, which had reached great 
profusion, to judge from the abundance and variety of their 
footprints, are contemporaneous with the European Rheetic. 
Footprints apparently of equivalent age and character are 
found in New Mexico as well. | 

The lower Keuper beds contain Thecodontosaurus and 
possibly dassospondylus in India (Lydekker 1890, p. 22), 
while the Upper Keuper entombed the fermer genus in 
Australia. 

The Upper Karoo beds: of Africa, rorerned by v. Huene to 
the Rheetic and by Broom (1907, p. 161) to the Lower Jura 
(Stormberg Beds), contain Thecodontosaurus, Husxelosaurus 
and Massospondylus, all Triassic types. 


R.S. Lull—Dinosaurian Mstribution. 15 


Jurassic. 


During Jurassic time the record is confined practically to 
England and the adjacent parts of France until the ushering in 
of the North American Morrison and Potomac toward its 
close. 

_ While several species of carnivores are found in England 

and France during this period, they are all referred to the 
genus Megalosauvrus with the exception of the Kimmeridgian 
Streptospondylus of England and Compsognathus of equiva- 
lent age from the lithographic limestone of Solenhofen, 
Bavaria. | 

Dr. A. Smith Woodward (1906, pp. 1-3) has recently 
deseribed a Megalosaurian ungual phalanx from the Lower 
Jurassic of Victoria, Australia. He does not, however, sug- 
gest a more precise correlation of the beds with those of 
Europe. 


Lower Cretaceous. 


The American Morrison in the West and the basal Potomac 
(Patuxent—Arundel) in the Kast have yielded a number of 
Theropoda; from the Potomac, Ad/osaurus, the American 
representative of Megalosaurus and Celurus ; while the Mor- 
rison has produced, in addition to these forms, Creosawrus and 
Labrosaurus, the horned carnivore Ceratosaurus, and the 
agile “ bird-cateching ” dinosaur Ornitholestes. 

In Europe the Wealden, probable equivalent in part to the 
American Morrison, has produced numerous remains of 
Megalosaurus. This genus is also reported from the Albian 
or Gault of Franceand from the Bellasien of Portugal, considered 
by Chaffat to be midway between the Aptian and Cenomanian. 


Upper Cretaceous. 


“In the Upper Cretaceous, ushered in by the Cenomanian, 
the European species of Ther opoda are, almost without excep- 
tion, referred to the genus Megalosaurus, a well-nigh incredible 
range, Lias to Danian, for a single genus, even of a relatively 
conservative type. Depéret (1899, -p. 692) has referred a 
carnivore from the Danian (Rognac) of Montagne-Noire, 
France, to the genus Dryptosaurus, first made known from the 
Upper Cretaceous of New Jer sey. 

The New World carnivores, on the other hand, have been 
given various names ; of these the principal types are Drypto- 
saurus of the New Jersey Greensand and the Judith River 
(Senonian) of Montana and Alberta and Tyrannosaurus of the 
Laramie (Danian; among the huge Megalosaurs; while the 
lesser race is represented by Ornithomimus of the Judith 
River beds, a probable derivative from. Ornitholestes of the 


16 R. 8. Lull—Dinosaurian Distribution. 


Morrison. From the Guaranitic beds (Danian) of Patagonia 
two genera of carnivores, Genyodectes (Woodward 1901) and 
Loncosaurus (Ameghino 1900, p. 61), both similar to dLegalo- 
saurus, have been described. 


The Sauropoda. 


The oldest undoubted Sauropod dinosaur thus far recorded 
is Dystropheus, described by Cope (1877), from the Red beds 
of the Painted Canyon in southeast Utah, which he refers to the 
Trias, but which v. Huene (1904, pp. 320) 321), upon the evi- 
dence offered by Whitman Cross, ‘believes to be the equivalent 
to the Dogger. Doubtless owing to the dearth of Jurassic 
continental deposits, the American record is a blank from this 
time until the Morrison and its equivalent, the Lower Potomac 
of Maryland. Sauropoda appear in England with the 
Bathonian (Great Odlite) in the form of the generalized 
Cetrosaurus. 

The Oxfordian has produced Orndthopsis, the Kimmeridgian _ 
Ornithopsis, Bothriospondylus and Pelorosaurus; the 
Portlandian, the first of these; while in the Lower Cretaceous 
Wealden we find Cetiosaurus, Pelorosaurus, Morosaurus and 
Titanosaurus (Lydekker non Marsh). ‘Cetiosaurus and 
Pelorosaurus, v. Huene believes, represent parallel phyla 
giving rise, in the first instance, to the aberrant American 
Brachiosaurus and Haplocanthosaurus of the Morrison, 
while Pelorosaurus, through an early Morosaurus as a central 
type, gives rise to Atlantosaurus and Apatosaurus (Bron- 
tosaurus) on the one hand, and Dzplodocus on the other, 
being succeeded in time by “Titan osaurus (Lydekker) which 
ranges as high as the uppermost Cretaceous. 

The American basal Potomac beds have produced Pleuro- 
celus, which is also found in the Wealden of England and 
Purbeckian of France. The Trinity sands of Texas, of prob- 
able equivalent age.to the upper Aptian, contain the remains 
of Morosaurus, a » typical Morrison genus. 

In the southern hemisphere, in Africa, Madagascar and 
India, in beds of an age approximately ‘equivalent to the 
Cenomanian, there have been found Titanosaurus and allied 
genera, such as Gigantosaurus, Bothriospondylus and, in 
Patagonia in the Guaranitic beds, 7itanosaurus, Argyrosaurus 
and the relatively small aberr ant Microsaurus. 

Depéret (1889, p. 692) has also described 7ttanosaurus from 
the Rognac, Danian, of Saint Chinian in the south of France, 
the last record of the Sauropoda in Europe. 


Orthopoda— Ornithopoda. 


The Ornithopod dinosaurs, which exclude the armored 
types, make their first appearance in the North American 


R.S. Lull—Dinosaurian Distribution. IG 


Upper Triassic, the possible equivalent of the Rheetic, being 
represented in the bone by Vanosaurus, of the Hallopus beds 
near Cafion City, Colorado, described by Marsh as a carnivore, 
but which v. Huene and Lull (1908, p. 148) have lately 
referred to this order. This type comes from the Upper Trias 
or Lower Jura of Colorado and is absolutely unique. 

Williston, in a letter to the author dated Cafion City, Colo- 
rado, July 11, 1909, says: “‘ After a careful study of the locality 
and region the conclusions [ reach are: Nothing more definite 
as to the age of the Hallopus beds can be said than was given 
by Marsh. In my opinion they are either uppermost Trias or 
Lower Jurassic, though possibly of Middle Jurassic age. No 
fossils of any kind have ever been found below them in the 
Cation City region. The type [of Hallopus| was found 
between 60 and 70 feet above the Red beds, doubtless of 
Triassic age. The intervening strata are distinctly conformable 
with the Red beds. All the known Morrison fossils from 
Cafion City are from above the Hallopus horizon, from one to 
three hundred feet, though numerous fragments of sauropods 
in the hillside suggest the possibility of less interval between 
them. There is no persistent red sandstone stratum in the 
Hallopus horizon. * * * my conclusion is that, until other 
fossils are found to fix more definitely their age, it is unwise to 
assign definitely either Triassic or Jurassic age to them. Jura- 
Trias will express this uncertainty.” 

Impressed upon the rocks of the Newark system, the equiva- 
lent of the Old World Rhetic, m the Connecticut valley and 
New Jersey are numerous footprints which Lull (1904, p. 499) 
has shown to pertain to ornithopod forms, the genus Ano- 
mepus unquestionably. Two other genera may also belong 
to the Ornithopoda, Hubrontes of larger size and the aberrant 
Otozowm, the bipedal tracks of which indicate a foot unlike 
that of any known dinosaur. The footprints included under 
the genus Anomepus show a considerable range in size but 
are all such as could have been made by forms like WVano- 
saurus and Hypsilophodon. 

England again gives us the only record of Jurassic types, if 
we eliminate Vanosawrus and the Morrison forms, Campto. 
saurus prestwichii described as Jguanodon being found in the 
Kimmeridge clay. The other Jurassic types which have been 
referred to Camptosaurus Gilmore (1909, pp. 289-292) con- 
siders as invalid so far as the genus is concerned. The 
Oxfordian has yielded Cryptodraco (Cryptosaurus) which v. 
Huene (1909, p. 21) considers as ancestral to Camptosaurus, 
the central type of this group. 

From the American Morrison are Camptosaurus, and a lesser 
form Laosauvrus and its relative Dryosaurus, which, together 


Am. Jour. Sct.—FourtH SERiEs, Vou. X XIX, No. 169.—Janvary, 1910. 
2 ; 


18 R.S. Lull—Dinosaurian Distribution. 


with the persistently primitive Wealden /Zypsilophodon, v. 
Huene derives from the Colorado Wanosaurus. Lull (1910) 
will report Dryosaurus also from the basal Potomac beds 
of Maryland, and Gilmore (1909, pp. 892-895) has described 
a Camptosaurus from the Lakota in South Dakota. 

The Wealden of England and especially of Belgium has 
yielded remarkably preserved specimens of Jguanodon, the 
successor of Camptosaurus. ILyuanodon is in turn succeeded 
in the Cenomanian of England by a type referred to the. Ameri- 
ean genus Zrachodon, but somewhat questionably. 

In America, the Niobrara, the equivalent of the European 
Turonian, has yielded the type of Claosaurus agilis, which is 
followed in the New Jersey Greensand and in probably 
equivalent beds of North Carolina by Zvrachodon (Hadro- 
SOUTUS)\s oe 

In the West, Zvachodon is found in the Judith River beds 
and again in the Laramie, where it lingers on until the final 
extinction of the dinosaurian race at the close of the Mesozoic. 

The European Cenomanian has produced Craspedodon in 
Belgium and JMJochlodon from the Gosau formations of Aus- 
tria. L2habdodon, found in Rognac of southern France and 
in the Meestricht beds of Belgium and Hoiland, both of the 
Danian period, is probably the closing member of the race in 
Europe. 


Armored Orthopoda—Stegosauria. 


The Stegosaurs have their first known representative in 
Scelidosaurus of the English Lias, beyond which the record is 
blank until we come to Dacentrus (Omosaurus) of the Kimme- 
ridgian, which appears to be the central type in the evolution of 
this group. The Morrison yields Stegosaurus, which some 
authors have identified with the European Dacentrus, but 
which appears to be an aberrant side branch derived also from 
the Scelidosaurian stem. In the basal Potomac beds of Mary- 
land several teeth and more questionably a vertebrum (Lull 
1910) are described as Przconodon and referred to the 
Stegosauria. 

The Purbeckian of England has also yielded Przconodon, 
while from the Wealden come Polacanthus and Hyclosaurus, 


the latter bemg found in Belgium as well as in England. | 


Acanthopholis, from the English Cenomanian, v. Huene makes 
the connecting link with Ankylosaurus of the Laramie. 
Intervening forms in the series, however, are probably repre- 
sented by Vodosaurus from the Pierre (Turonian) of Colorado, 
while Stegopelta, recently described by Williston (1905, pp. 
503-505) from the Lower Benton of Wyoming, and Paleo- 
scincus of the Judith River are closely related if not identical 


LR. 8. Lull—Dinosaurian Distribution. 19 


with Ankylosaurus of the Laramie. All three, according to 
Williston, were derived from Polacanthus of the Wealden of 
Europe. 7 

The Gosau beds of Wiener Neustedt near Vienna, probably 
equivalent to our Judith River, contain a number of armored 
forms such as Struthiosaurus (Nopesa 1902) and Acanthopho- 
lis (Nopesa 1902) some of which, at least, probably pertain to 
the same race. 


Ceratopsia. 


The Ceratopsia have a relatively brief career,—Stenopelia, . 
the pelvis of which resembles that of Z7rzceratops, being the 
earliest possible representative among known forms. It is 
found in the Neocomian of Germany. The remains described 
by Seeley (1881, pl. xxviii, fig. 4) from the Gosan formation 
under the name of Cratwomus (=Struthiosaurus ; Nopesa 
1902) contain what appears to be a ceratopsian left supra- 
orbital horn-core which would seem to represent a stage of 
evolution equivalent to Ceratops of the American Judith 
River. Nopesa (1902, p. 7) is of the opinion, however, that 
the horn-like bone in question represents a dorsal spine after 
the manner of those of Polacanthus. This, together with 
the total absence of two-rooted teeth of the ceratopsian sort 
among the number preserved at Vienna, casts grave doubt upon 
the existence in Europe of this remarkable group. 

The American Judith River (= Belly River of Canada) 
contains two stages in the evolution of the Ceratopsia, JZono- 
clonius and Ceratops, as well as the somewhat aberrant 
Centrosaurus described, by Lambe (1904). The Laramie 
deposits which follow later after a hiatus of some 2,000 or 
more feet of marine strata contain the terminal members of 
this race, Triceratops and Torosaurus. The geological distri- 
bution and phylogenies are shown in figure 1. 


V. GrocrapHicaL DisrripuTion. 
Theropoda. 


The geographical distribution of dinosaurs presents some 
very interesting problems, some of which, at first sight, are 
difficult to explain. 

By far the widest spread forms are the carnivorous Theropoda 
(fir. 2), evidently the most adaptable and of a nature not so 
subservient to a peculiar kind of food, which was apt to be 
local in distribution, as in the case of the plant-feeding forms. 
These carnivores are reported in practically every locality 
where herbivorous dinosaurs have been found, as they seem to 


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ene ee 2 eee 


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ton. 


ShaNDSOUN 
Quisdyoos)sndawu0Uuly 


Lhistribut 


C2OSMULPTEAN 


(Snanvsojd 
O2vUpoyd hag 


Fie. 1. 


ES. Latl—D 


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S sdoqv4e9 snunvsopon uopoyrD4) 


Quiadjeos) (snarpsojeysa3) 
2sndipuvbis Sn4rrsojhssaay 


snus) WOUqU4o 


Snwwoy;u4O 


snanvsojd hag 


snanveouu vahy 


SNAMVSO9AD]| 4 


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R. S. Lull—Dinosaurian Distribution. 21 


have accompanied the latter in all of their wanderings. In 
addition to this they had, during Triassic times, deployed 
rapidly before our records give us evidence of the existence of 
the herbivores. 

The oldest recorded Theropoda, those of the Lower Muschel- 
kalk, are found in Germany, but we have no proof that this 
was the center of dispersal. Indeed v. Huene (1908, pp. 100- 
101) is of the opinion that one must go farther west, where a 
ereat continent extended from England to America, to find the 
conditions which, we have imagined, must have given rise to 
the dinosaurian race. During the Keuper, particularly, “a 
brackish sea and swamp extended from England to Eastern 
Germany as far as the Scandinavian, East Prussian and Bohe- 
mian borders, where another great northern continent began 
and extended eastward.” 

The semi-arid continent of Triassic time would doubtless be 
the chosen habitat, the swamp regions the place where the 
remains of wandering individuals might more readily be 
preserved. 

During the Trias, the Theropoda spread in one direction 
through Germany, France, England, and in the other to east- 
ern and finally to western ‘North Ameri ica, which was reached 
not later than the Upper Keuper. On the other hand, they 
migrated southward in the Old World to the Gondwana con- 
tinent, for in the Lettenkohle time we find them in India, in 
the Upper Keuper in Australia, while South Africa was 
reached at least by Rheetic time. 

What the precise line of march was is somewhat doubtful— 
I imagine, however, it was southward to what is now northern 
Africa, thence east to India and Australia, and south to the 
Cape Colony. We have no recorded evidence of Triassic 
dinosaurs in South America or in New Zealand. I should 
hesitate to infer that they. had not reached South America 
during this period, though, as we shall see, the first remains to be 
found are not older than the Wealden. New Zealand, however, 
has yielded a rich Triassic flora, together with the remains of 
labyrinthodonts, implying extensive terrestrial deposits though 
not the ideal dinosaurian habitat; but as Theropoda are found 
in all sorts of deposits, even marine, that feature is not espe- 

cially significant. The total absence of the dinosaurs from 
New Zealand deposits of any age; the presence in the Permian 
and Trias of laby rinthodonts ; the presence to-day of the abso- 
lutely unique Hatteria, the sole survivor of its order, dating 
its ancestry also from the Permian; the presenée of no tailed 
amphibia, of one rare species of frog, of a few lizards, which 
Heilprin tells us cannot pass the sea as adults, but do in the 
egg as they are found on remote oceanic islands to which they 


22 R. 8. Lull—Dinosaurian Distribution. 


Fie. 2. 


Upper Rhdatic 


Muschel- 


Ammosaurus, Manchester,Conn. 

Anchisaurus as " 

Thecodontosaurus, Springfield, 
Mass. 


Gresyllosaurus, Wedmore Hill, 
- Somersetshire. 


Plateosaurus, Brigend, Glamor- 


ganshire. 
Plateosaurus, Leicester 
Thecodontosaurus, |Warwick; Durdham Down; Bristol, 


Plateosaurus, Provenchere,Hte. 
Marne; Buerre and Domblans n. 
Besancon; Bois de Chassagne, 
Polisny,Jura; Fechaux n. 
Lons-le-Saunier. 

Gresyllosaurus, Provenchére, 

Hte.Marne; Bois de Chassagne, 

Poligny, Jura; Lons-le-Saunier 


Luneville. 


GERMANY 
Plateosaurus, n.Gottingen, n. 
Hedeper Schlosslesmiihle in 
Sch6nhuch, n. Tubingen. 
Plateosaurus, n.Katzenhof, Pegnitgthal, 
Unterfranken, n.Nuremberg, n.Bayreuth, 
n.Tiibingen, n.Stuttgart, Balingen. 
Gresyllosaurus, n.Nuremberg, n.Tiihingen, | 
n, Stuttgart. 
Pachysaurus, n.Tibingen, n.Rottweil, n. 
Gmiind, n.Lowenstein. 
Teratosaurus, n.Rottweil, n.Stuttgart, n.Brack- 
enheim, n.Nuremberg. 
Sellosaurus, n.Stuttdart, n.Brackenhein. 
Tanystropheus, n.Stuttgart. 
Thecodontosaurus, n.Stuttgart. 
Zanclodon, n.Ludwigsburg, n.Stuttgart, n.Hall. 
[hecodontosaurus, Bayreuth, n.Crailshein. 
Tanystropheus, Bayreuth, n.Crailsheim, Hall, QOberbronn, Alsatia. 
Thecodontosaurus, GSogolin, Upper Silesia. 
Tanystropheus, Gogolin, Krappita. 


Paar 
pri | isang tees rr n. Basel 


soi AFRICA 
Thecodontosaurus, Barkley-East 
(Stormberg beds), Aliwal 
North. 
Buskelosaurus, Aliwal North. 
Massospondylus, n.Harrismith, 
Drakensberg. 


INDIA 
Thecodontosaurus, |? Ranigansch. 


ae oe a 


Figure 2. Distribution of the Triassic Theropoda Cena from v. Huene). 


Thecodontosaurus, 


North-east Coast. 


R. S. Lull—Dinosaurian Distribution. 23 


Me Gy 


Fullonianl os Uxfordian| Coral li- Paecensl Soon Purbeckian 


a a a 


ENGLAND 


Nuthetes, Swanage, 


Megalosaurus, Yorkshire. 
Megalosaurus, Reymouth. | 


FRANCE 


Megalosaurus, Boulogne-sur-Mer, 

Megalosaurus(Streptospondylus), Le davre, 

Devizes, Boulogne, Cape-de-la-Heve. 
ok wee Calvados. | 

ee gaurus, Caen in Calvados, Saint-Gaulthier. 


Megalosaurus, Mont Lambert. 
Megalosaurus(Lusitanien), Pombal,environs of 


Se aa a 


Dystrophdeus, Painted Ganon S: Aautan: 


ENGLAND 


of Portland.. 
Pelorosaurus, Strethag, Cambridgeshire. 
Pelorosaurts(Bothriospondy lug), Swindon, 
Bradford, Wiltshire. 
Pelorosaurus(Qrnithopsis), feymouth, Ely. 
Pelorosaurus, Peterborough. | | 
Pelorosaurus(Ornithopsis), Byebury, Oxfordshire. 
etiosaurus, Peterborough. 
Cetiosaurus, Oxford, Stonesfield, Blismorth, Bilbury, &nslow, Cogenhoe. 
FRANCE 


Bou- 

logne-sur-Mer. 

Pelorogaurug, Rimille n. Eou- 
logne. 


Pelorosaurus(Pothriospondylus), n.Havre. 


Pelorosaurus, 


Vestaria. 


Fic. 3. Distribution of the Jurassic Theropoda and Sauropoda (original). 


94 R.S. Lull—Dinosaurian Distribution. 


may have found means of introduction by floating timber ; the 
absence of any indigenous mammals other than bats, a rat, and 
the Maori dog, the introduction of which may be as readily 
accounted for ;—all of these evidences seem to me to point to an 
utter isolation geographically on the part of New Zealand since 
the close of the Permian. De Lapparent’s maps (1906) indicate 
a continuous New Zealand-Australian connection into the basal 
Eocene—long after the breaking up of the Gondwana conti- 
nent. The biological evidence which I have given strongly 
opposes this view. 

During Jurassic times the record of Theropoda (fig. 3) is 
practically continuous in England and Europe, and one Megalo- 
saur has been described by Smith Woodward (1906) from the 
Lower Jurassic of Cape Patterson, Victoria, Australia, about 
the nearest point toward the unattainable New Zealand. 

For Africa, South America, and most strikingly for North 
America, the known Theropod record is a perfect blank 
throughout the Jurassic, though the remains of other dinosaurs 
are sparingly known. This is unquestionably due to dearth of 
known terrestrial deposits in Africa and North America, for 
the few which exist have thus far yielded no dinosaur remains: 
As for South America, it may be that the migrant dinosaurs 
did not arrive until the beginning of Lower Cretaceous time. 

The Lower Cretaceous (fig. 4; saw the Theropoda at their 
widest extent, the Wealden of England and the Morrison 
and basal Potomac of North America having yielded a mar- 
velous assemblage of types. In Europe their record is seen 
somewhat scatteringly throughout the Lower and Upper Creta- 
ceous, indicating that they inhabited the whole area through- 
out the period. In North America, while there are extensive 
breaks in the continuity of the record, the great numbers and 
wide distribution at the beginning and end imply an equally 
extensive distribution in time and space. Central Africa, near 
the Tchad See, yields theropod remains during the Cenoma- 
nian; Madagascar, India and Australia as well in beds of 
approximately equivalent age; while in the neighborhood of 
Bahia, Brazil, in beds of an age equivalent to the Wealden, is 
found the first positive indication that these forms had reached 
South America. Having once found a foothold in South 
America, the Theropoda lingered on until the close of the Cre- 
taceous, as their remains are reported from several localities in 
Patagonia in the Guaranitic (Danian) strata. 


Sauropoda. 


The Sauropoda (fig. 5) are also very widespread though 
evidently local in distribution owing to necessary peculiarities 
in habitat and food. Their appearance in time is startling, as 


R.S. Lull—Dinosaurian Distribution. - 2 


Hie. 4; 


Wealden | Aptian Albian |Cenomani-j Turonian j Senonian| Danian 
Morrison an 


NOR[H AMERICA 


pyrannossurus, Hell Creek, 
Mont.;E.Fork of Little Pow- 
der R.,Mant.;O0jo Alamo,N.M.; 
Converse Co., Nyo. 
Ornithomimug, Converse Co., 
Wyo.;n.Denver, Col. 
Ornithomimus, Red Deer River, Alberta, 
Can.;Mont. 
Aublysodon, Judith,Yont.:Red Deer Riv- 
er, Alberta. 
Deinodon, Judith,Mont.;Red Deer River, 
Alberta. 
Dryptosaurus, Red Deer River, Alberta; 
Haddonfield,N.J,° 
Colosaurus, Haddonfield, N.J. 
PAllosaurus, Kansas. 
Allosaurus, Como, fyo.;Bone Cahin n.Nedicine Bon, Wyo.; Canyon City,Col.;Prince George Co., 
Ud. (Potomac). 
Labrosaurus, Gomo, Wyo.;Canyon City,Col. 
€reosaurus, Como, Wyo. 
Ceratosaurus, Como, liyo.;Canyon City,Col. 
Qrnitholestes, Bone Cabin, fyo. | 
Coelurus, Como, Wyo.;Prince George Co.,\d. 


ENGLAND 
degalosaurus, Hastings,Cuckfield,Isle of Wight. 


Calamospondylus, Isle of Wight. 
Coelurus, Isle of Wight. 


FRANCE 


: Dryptosaurus, Saint Chinian. 
Megalosaurus, Boulonnais,Grand Pré,Louppy. 


PORTUGAL 


Mesalosaurus, Vizo. 


Megalosaurus, Boco do Chapin,Cap d'Bspichel. 


ee. BELGIUM and HOLLAND 


Yesalossurus, North Germany. | 


AUSTRIA and HUNGARY 
Megalosaurus, n.Vienna(Nene Pelt )Sie- 


benhirgen. 


Mesgalosaurus, Maestricht. 


® 


INDIA 

2a ee Yegalosaurus, Trichinipoli. Sia 
AUSTRALIA 

Wo. | Megalosaurus, New South Wales(Geol.level not siven) 


E SOUTH AMERICA 
Loncosaurus, Rio Rehuen, Pata- 
gonia. 
Genyodectes, Patagonia. 
Megalossurus, Bahia, Brazil. 


Fic. 4. Distribution of the Cretaceous Theropoda (original). 


26 R.S. Lull—Dinosaurian Distribution. 


they are found in strata which v. Huene refers in each ease to 
the Dogger but at points far removed geographically, in Eng- 
land, in Utah, and in Madagascar (v. Huene, 1909, p. 14). If 
v. Huene is correct in his derivation of the group from the 
Theropod genus Plateosaurus, I should look to this swamp- 
land extending during the late Trias from England to Eastern 
Germany, before alluded to (vide supra p. 21) as the place of 
origin of the race. That they reached such remote places 
before their very existence is indicated in our records points to 
the incompleteness of the latter and good powers of migration 
along the swamp and delta formations which fringed the con- 
tinental shores. 

The Sauropoda are abundant in England from the Bathonian 
(Dogger) to the Wealden, in France from the Bathonian until 
the Aptian, and then, if Depéret (1899) is right, after a lapse 
of time during which no Sauropoda left their records else- 
where in the northern hemisphere, they appear again in the 
form of Titanosawrus at Saint Chinian and Languedoe in 
southern France in beds referable to the Danian—the very 
close of the Cretaceous period! 

In America, with the exception of Dystropheus of the 
Dogger of Utah and an unnamed Sauropod reported by Gil 
more (1909, p. 300) from the Lakota (Aptian) of Buffalo Gap, 
South Dakota, the Sauropoda are confined entirely to the Mor- 
rison and its eastern equivalent, the basal Potomac, and in the 
South, to the Trinity sandstones of Texas and Oklahoma. A 
remarkable feature of the career of the American types is that, 
with the exception of the ill-known Dystropheus, the most 
generalized aplocanthosaurus and the most specialized 
Diplodocus have been found associated in the same quarry, 
although Riggs (1904, p. 246) argues for LHaplocanthosaurus 
a terrestrial habitat, on account of the similarity in length of 
fore and hind limb and the apparent inflexibility of the verte- 
bral column; while Diplodocus shows the highest degree of 
aquatic adaptation known within the group. 

In the southern hemisphere one finds sauropod remains 
from India across Madagascar and East Africa to Patagonia, 
almost the entire length from East to West around the south 
shore of the old Gondwana continent. There is, however, no 
record of their occurrence in Australia, a piece of negative 
evidence which can hardly be weighed heavily in view of the 
meagerness of the known dinosaur remains in that quarter of. 
our globe. 

The principal southern genus is 7?tanosaurus (Lydekker 
non Marsh), the remains of which are found also in the Eng- 
lish Wealden. The beds wherein the southern Sauropods 
are found are, curiously enough, Upper Cretaceous, probably 


R. S. Lull—Dinosaurian IMstribution. DANK 


HIGGS oD: 


Cenomani 

ee paa 
NORTH AMERICA 

Atlantosaurus, Canyon Baer cule were igus. Coie 


Morrison 


Apatosaurus(Brontosaurus), Como, N"yo.;Bons Cabin, Wyo.;Medicine Bow, Ryo., Sheep Creek, Wyo.; 
) 


Grand River Valley n.Fruita,Col.;Freeze Out Hills, ¥yo.;Morrison,Col.; Webster Park,Col. 
Worosaurus, Oklahoma(Trinity Sands). 
Worosaurus, Como, Wyo.;Canyon City,Col.;Grand River Valley,Col.;Freeze Out Hills, Wyo. 


Camerasaurus, Canyon City,Col | 


Pleurocoelus, Prince George Co.,Md.( Potomac): Como, Wyo. 
Diplodocus, Bone Cabin, Nyo.;Sheep Creek, Wyo.;Canyon City,Col.;n.Worrison,Col. 
Barosaurus, Piedmont, S.D. | 

Brachiosaurus, Grand River Valley,Col. 
Haplocanthosaurus, Canyon City,Col. 
"Sauropod"(Lakota), Buffalo Gap,S.D. 
ENGLAND 
Cetiosaurus, Isle of oy eee ee lGra es: 
Pelorosaurus, Isle of Wisht, Sandown, Cuckfield, Sussex. 
Pelorosaurus(Ornithopsis), Cowden. 
Titanosaurus, Isle of Wight. 
Morosaurus, Cuckfield, Sussex. 
Pleurocdelus, Hastings,Cuckfield,Isle of Wight. 


Hoplosaurus, Isle of Wight. 


FRANCE 
n urugs, Saint Chinian, 


Languedoc, 


Aepysaurus Mont Ventoux(Vaucluse)Perigord. 


Pleuroccelus, Caen. 


PORTUGAL 


| 
Pleurocoelus, Boca do Chapin,Cap d’BEspichel. 


AFRICA 
' 
Algoasaurus, Port Blizabeth(precise level doubtful). 


Titanosaurus, Tendaguru, Fast Africa. 
Gigantosaurus, Tendaguru, Fast Africa. 


MADAGASCAR 
I 


Titanosaurus, Nevarana. 
Pelorosaurug(Bothriospondylus), n.Bay of Narinda. 


| ; 
itanosaurus(may be Albian), Maleri,Pisdura, 


SOUTH AMERICA E 


Titanosaurus, Neuquen, Rio Che— 
but, Patagonia. 

Argyrosagurus,Rio Chehut, Pat- 
agonia. 

Microsaurus, Neuquen, Pata- 


gonia. 


8 R.S. Lull—Dinosaurian Distribution. 


Fie. 6. 


Jura-Trias and Jurassic 


Pe Peers race 
ridgian 


Dal ae Rae ae 


NORTH a 


Nanossurug, n.Canyon City,Col. 
AnomoéSpus( Footprints), Wass.,Conn.,N.J. 
Otogoump( Footprints), Mass.,Conn. 


ENGLAND 
guanodop 
Camptosaurus(Iguanodon), Cumnor Hurst, 
Oxfordshire. | 
Lguanodon(Camptosaurus), Peterhorough. 
yptodraco, (loc. unknown) 


Seer a ae 


a 


Echinodon, Swanage. 
Qmosaurus, Swindon, Nootton Bassett, 
Wiltshire. 


ji guanodon( Camptosau- 
rug), Soulogne-sur- 
Mer 


Scelidosaurua, Charmouth, Dorset: 


Cretaceous 


so 


Tigh Th ne a 


NORTH AMERICA 


achodon( Laramie), Hell 
Creek,n. Forsyth, Chalk 
Buttes 20 mi.¥.of Elblaka, 
E.Fork Little Powder R.,n. 
Glendive, Mont. ;Converse 
Co.,N.Platte R.mouth of 
Medicine Bow, Wyo.;Grand 
River,S.D. 
Trachodon, Red Deer River, Alberta;S. 
Fork Cheyenne,S.D.;Judith,Missouri 
R.;Hell Creek(Pierre Musselshell Ba- 
gin,Sweet Grass Co.,Mont.;Cape Fear 
R.,N.C.; Georgia; Haddonfield, N.J. 
Claosaurus(Niobrara)Smoky Hill Valley,Kan 
Camptosaurus(Lakota), Buffalo Gap,S.D. 
Camptosaurus, Como, Bone Cahin, Albany Co.,Garbon Co.,Wyo.;Canyon City,Garden of the Gods, 
Col.;Custer Co.,S.D. 
Laosaurus, Como,Bone Cabin, Wyo. 
Dryosaurus, Como, Wyo. ;Bladensburg, Md.( Potomac). 
ENGLAND 
2?Trachodon 
Isuanodon, Isle of Wight, Sussex; Maidstone, Kent. 
g@uanodon, Bradfordshire(Neocomian), Hastings, Cuckfield, Isle of Wight. 
guanodon(Camptosaurus), Isle of Wight. |- 
lypsilophodon, Cuckfield,Isle of Wight,n.Brixton. 


1 aoe 


PORTUGAL 
Suanodon(Bellasien Infer.), Boco do Chapin, Capd'Bspichel. 


AUSTRIA-HUNGARY 
Mochlogon,n. Vienna, Siebenhirgen. 
saurus)Siehenhiirgen 


Fr Ic. 6. Dicerioution of the Jura-Trias and Jurassic Orthopoda and 
of the Cretaceous Ornithopoda (original). 


Craspedodon, Maeatricht, 
Orthomerus, Maestricht. 


Rhabdodon, Rognac n. Provence 


?Hypselosaurus, Rognac. 


R.S. Lull —Dinosaurian Distribution. 29 


not older than Cenomanian time, and, with the exception of 
the questionable Wacrourosaurus of the English Cenomanian 
and the 7?%tanosaurus reported by Depéret (vide supra) from 
the Danian of Southern France, the contained dinosaurs repre- 
sent by far the latest appearance of the Sauropod group any- 
where recorded on the face of the globe. 

The last stand of these huge creatures, so far as our present 
knowledge goes, and again excepting Depéret’s Z2tanosaurus 
(vide supra, p. 26), was in Patagonia, where the remains of 
three genera, Z?tanosaurus, Argyrosaurus and the small 
aberrant J/icrosaurus are found in the Guaranitic beds corre- 
lated by Hatcher (1900, p. 95) with the Laramie (Danian) of 
North America. 


Orthopoda. 


Geographically the Orthopoda (figs. 6 and 7) as a whole, 
with the exception of the Ceratopsia, which are apparently 
eonfined to western North America, have a common distribu- 
tion; and, while paralleling that of the other dinosaurs in the 
northern hemisphere, are unique in their entire absence from 
the southern. It can hardly be said that the paucity of our 
records is responsible for this apparent lack of southern forms, 
for their preservation and discovery should surely have brought 
some to hght when the Theropoda and Sauropoda are relatively 
so abundant. 

America seems to have been the original home of the 
orthopod dinosaurs, the first recorded type the bones of which 
are known being Vanosaurus of the Jura-Trias of Utah. In the 
upper series of the Newark (Rheetic) beds in Massachusetts, 
Connecticut and New Jersey are indications of numerous species 
of these plant-feeding forms, so that it is evident that by the 
beginning of Jurassic time not only were they widespread in 
North America but they had reached a considerable degree of 
variation as well, implying a long though unrecorded career. 
During the Jurassic the record is again a blank as with the 
American Theropoda, but with the ushermg in of Lower 
Cretaceous time by the great Morrison deposits in the West 
and the Potomac in the East we find a marvelous assemblage 
of types, small and large, armored and unarmored. This is 
especially true in the West, since the Potomac dinosaurs, coming 
as they do from few localities which are all of one character, 
reflect the Sauropod rather than the Orthopod habitat, so that 
while an armored dinosaur, Priconodon, and an unarmored 
Dryosaurus (Lull 1910) only have been found in Mary- 
land, others doubtless existed and may some day be brought to 
light. 

Pan through Upper Cretaceous time the American record is 
quite complete, especially in the West, though New Jersey, 


30 R.S. Lull—Dinosaurian Distribution. 
WIG SH: 


is 


| | 


NORTH AMERICA 


Ankylogaurus, Hell Creek, 
Mont. 

Ankylosaurus(Stereocephalus), Red Deer 
River, Alberta. 

Paléeoscincus, Red Deer River, Alberta; 
Judith River,Mont. 

Nodosaurus, n.Como, Wyo. 

egopelta, Lander, fyo. 

erosaurus(Niobrara), Gove Co.,Kan. 

Hoplitosaurus(Lakota), Buffalo Gap,S.D. | 

Stesosaurus, Como,n.Medicine Bon,Bone Cabin, Sheep Creek, Ryo. 

Stesosaurus(Diracodon), Como, Myo. 

Priconodon( Potomac), Prince George Co.,Md. 

ENGLAND 

Acanthopholis, Folkstone. 

Acanthopholis, Cambridge. 

Polacanthus, Hastings,Isle of Wight. | 

Hydélosaurus, Hastings, Tilgate, Cuckfield. 


Vectisaurus, Isle of Wight. 


FRANCE 


Struthiosaurus( Cratdéomus)St.Chinian. 
Hyd@losaurus, Boulonnais,Grand Pré. 
GERMANY 


Hyaelosaurus, North Germany. 
Steno opelix, Briickebursg. 


AUSTRIA-HUNGARY 
Struthiosaurus, n.Vienna(Neue felt). 
Hoplosaurus, n.Vienna(Neue Welt). 


a ae = 


|| 


Fic. 7. Distribution of the Cretaceous Stegosauria and Ceratopsia (original). 


Triceratops, Converse Co., 
N.Platte River opposite 
mouth of Medicine Bop, fyo.; 
Hell Creek, Powder River, 
Chalk Buttes 20 mi.¥.of 
Slklaka,&.Fork Little Pow- 
der River,n.Glendive,n. 
Rosebud, Mont.; Yule, Billings 
Co.,N.D.;@jo Alamo,N.M.; 
n.Denver,Col. 

Diceratops, Converse Co.,Wyo 

Torosaurus, Converse Co.,fyo. 

Agathaumas, Black Buttes, Ryo. 

Ceratops(Judith River), n.Judith, Mis- 
souri River,Mont.;Red Deer River, Al- 
berta. 

Monoclonius(Judith River), n.Juditn, 
Mont.;Red Deer River, Alberta. 

entrosaurus(Judith River), Red Deer 
River, Alherta. 

"Ceratopsians", Musselshell River Ba- 
sin, Sweet Grass Co., Wont. 


R. S. Lull—Dinosaurian Distribution. 31 


North Carolina and Georgia have yielded Trachodons of 
Magothy (Senonian) age. ee 

The great culmination of the group, in which the older types 
were joined by the remarkable Ceratopsia, occurred toward the 
close of the Cretaceous in the area lying just eastward of the 
Rocky Mountains and extending from New Mexico on the 
south to Aiberta on the north, perhaps beyond. 

In the Old World I have searched in vain for traces of 
Orthopoda before the Lias. Beasley, Sollas and others have 
described many fossil footprints from beds ranging from the 
Bunter to the Upper Keuper, including some undoubted 
dinosaurian tracks (Sollas 1879, pp. 511-516) resembling those of 
Anchisauripus (Brontozoum, part) (Lull 1904, p. 486) of the 
Connecticut formation. There is none among them in any wa 
comparable with Anomepus (Lull 1904, p. 500) of the New 
World. Beasley (1907, p. 167-168) is inclined to think that he 
has in Chirotherium storetonense trom near Liverpool the foot- 
print of an herbivore. That one may readily consent to, but the 
foot in no way resembles that of a dinosaur and the tracks are 
generally referred to unknown labyrinthodonts. 

In the English Lias the first Orthopod appears in the form 
of the armored Scelidosaurus followed in the Oxfordian by 
Omosaurus and later by Echinodon. Recorded specimens of 
armored forms are entirely confined to England during Jurassic 
time and not until the Wealden do we find their remains on the 
continent. With the Cenomanian they apparently forsake their 
earlier home entirely for the continent, culminating in 
Struthiosaurus and Hoplosaurus of Austro-Hungary and 
southern France. 

The unarmored Orthopoda, the Ornithopoda, begin their 
Old World career simultaneously in England and Portugal in 
beds of Oxfordian age, but are not numerous during the 
Jurassic. The Wealden, however, brings in a great many 
species, some in wonderful preservation. Their subsequent 
history is much like that of the armored types, culminating 
in Austro-Hungary, France and Belgium. 

It will be observed that no mention is made of the Asian 
continent north of India—the ancient Angara-land. Thus far ,, 
our records show absolutely no trace of dinosaurian remains 
from any part of this vast area. Professor Marsh (1897, pp. 
413-414) says: “In St Petersburg I hoped to find many dino- 
saurlan remains, as here had been brought together an 
abundance of fossil treasures from various parts of the Russian 
Empire, which I knew must contain many forms of this group. 
In the four principal museums of the city, however, I could 
find no bones of Dinosaurs on exhibition, nor could I learn 
from any of the museum authorities that such remains had 


Ya Ak _ 


Rd” 
S 
\N 


iia AWN 
w ae 


34 R.S. Lull—Dinosaurian Distribution. 


been recognized among the specimens received, neither could 
I find any such fossils myself among the debris of the collec- 
tions, so often a rich repository for new or inconspicuous 
specimens. This was true, also, of the smaller collections 
visited, and I was at last forced to admit that here, at least, the 
Dinosaurs of Russia like the snakes of Ireland, were conspicuous 
only by their absence. 

“This opinion was not changed by a visit to the rich geolog- 
ical collections of Moscow, which J examined with care; although 
other fossil vertebrates, including many reptiles, were abun- 
dantly represented. I was assured, moreover, by various 
Russian paleontologists, that in other museums of the empire 
or in the known localities they had seen no dinosaurian 
remains.” , 

This evidence can be interpreted again in the light of the 
fact that Asia is so largely a terra incognita from the paleon- 
tologist’s point of view, or in that of the physical isolation of © 
Angara during the whole dinosaurian epoch. 


VI. Summary or MIGRATIONS AND PaLEOGEOGRAPHY. 


The probable center of evolution and course of migration of 
the Theropoda has already been sketched. Having their 
‘origin apparently somewhere in the northern continent of 
Laurentia, they deployed southward and westward, covering 
not only the confines of western Europe but extending into 
Gondwana, the southern land mass, during Triassic times. 
New Zealand they never reached and they may have been 
retarded in their passage to South America until the begining 
of the Lower Oretaceous (see fig. 8). The Sauropoda 
probably had their origin in Europe, migrating early in 
Jurassic time to the sonthern as well as to the western continent. 
Thence in the southern hemisphere both east, south, and west 
until their range was almost as great as that of their carnivorous 
allies. Whether the Danian Titanosaur of southern France 
was a returned migrant or whether suitable conditions caused 
it to linger long after the death of all of its neighboring allies, 
like the Steller’s sea cow in Behring Sea, I cannot say. The 
second idea seems the more probable (fig. 9). 

The Orthopoda (fig. 10) present at first sight a much more 
serious difficulty in their entire absence from the southern 
hemisphere. It would seem as though we had here a group 
the center of whose dispersal was North America. They were 
truly terrestrial types, many of marked cursorial adaptation, 
which should be as capable of migration as the Theropoda. 
They were, however, dependent upon a peculiar sort of 
food which was in turn dependent upon certain climatic 


\\ 
“ N W a 
e ¢ 


Ni 
KS YY “al ee SS ~ 
> 9 4 WS ie 
K S Ne 
NS IE Ne eC \ KC 
eee SSNs WAS \ Ys \ NSS : i 
gf SEQ NE NS 2p | x 


S 
: 
- a5 fv : 


ey 


02 


Wa ; ” 


36 R.S. Lull—Dinosaurian Distribution. 


conditions and necessarily went where food was abundant and 
were checked where it failed. The opportunity for migration 
to Gondwana Land from Europe by a dry land route may 
readily have ceased before the Orthopoda reached the Old 
World. The Sauropoda, on the other hand, being amphibious 
could cross broken land connections provided the water were 
not of too great an extent. It is a significant feature that only 
Theropods, Sauropods and the late Cretaceous Orthopods, 
Claosaurus and Tyrachodon, have been found in marine 
deposits, indicating a semi-aquatic life on the part of the latter 
two and at least a fearlessness of water when necessity arose upon 
that of the carnivores. By the time the Trachodont dinosaurs 
reached the Old World the opportunity for southern migration 
even for an amphibious animal had apparently ceased. . 

A comparison may well be made with living mammals, the 
deer on the one hand, the hippopotamus on the other. The 
former are world-wide in their distribution except for 
Australasia, the Arabian peninsula and Africa, save for a sin- 
gle species, Cervus barbarus, which inhabits the Mediterranean 
coast from Tunis to the slopes of the Atlas range. Schillings 
(1906, p. 261) says: “In 1896 hippopotamuses were still plentiful 
in the Nzoia River and the Athi River in British East Africa; 
they were to be found, too, along the coast between Dar-es- 
Salaam and Pangani. I saw them on several occasions in the 
surf, and I shall never forget my astonishment once, on get- 
ting out of a clump of cocoanut palms, to see what I had 
imagined to be an uprooted tree trunk on the sands suddenly 
change into a hippopotamus and make its way into the sea. 

‘“Hippopotamuses travel by sea to get from one estuary to 
another, no doubt ridding themselves at the same time of 
certain parasites in the salt water.” 

Hippopotamuses show no more aquatic adaptation than the 
sauropod dinosaur, Diplodocus, if as much. Hippopotamuses 
are confined in their present range to Africa south of the 
Sahara, being found in the Nile only above Khartum. In 
former times they extended to Madagascar, northwest 
India and practically the whole of western Europe including 
southwest England (Murray 1866, map X XIX). This shows 
that certain barriers exist which prove effective against such 
extremely mobile creatures as the deer and which have 
debarred them from the Ethiopian realm. These barriers, 
however, were not prohibitive in the case of the less mobile 
hippopotamus. A similar contrast of conditions might readily 
have limited the distribution of the Orthopod dinosaurs, while 
the Sauropoda, as in the case of the hippopotamuses, could 
easily migrate. 


R.S. Lull—Dinosaurian Distribution. Bil 


e 


Why the Sauropoda lingered so long in the southern hemi- 
sphere after their apparent extinction in the North, is difficult to 
answer unless it were because of the limitations of food and 
climate in the North which did not at once prevail in the South. 
Even though the Trachodontide gradually assumed aquatic 
habits, they were too late to be brought into active competition 
with the Sauropoda in the northern Jand mass. 

The carnivores being always present doubtless served at 
first only to limit the plant-feeding forms ; they may, however, 
have been responsible for the final blotting out of the Sauro- 
poda when weakened in numbers and by the burden of racial 
old age. 

I believe that, all things considered, the degree of moisture, 
whether atmospheric in accelerating or limiting plant growth, 
or in the form of actual water barriers, was the most potent 
factor in the origin, evolution, migrations, and final extinction 
of the dinosaurian race. 

Williston (1909, p. 401) is inclined to think that “there must 
have been free communication during part or all of the Meso- 
zoic time between North and South America, proof of which 
is seen in the dinosaurs, mosasaurs, and crocodiles, some of 
them being, according to competent observers, identical generic- 
ally even with North American forms.” This may be true of 
the crocodiles and mosasaurs and yet imply no land bridge 
over which dinosaurs could pass. True, fragmentary remains 
from Patagonia have been referred to Allosaurus so character- 
istic of the American Morrison, but I seriously question the 
generic identity of any of the dinosaurs with North American 
forms. The presence of the earliest recorded remains near 
Bahia, on the line of march from the East, may be taken at its 
apparent value. [have found no evidence in favor of a north 
and south migration in the western hemisphere. 

These studies only serve to verify for the most part the 
paleogeographical maps of de Lapparent and Schuchert, for. 
in every instance, with the exception of Patagonia and where 
the dinosaur was found in salt water deposits, the locality fell 
upon a land area as indicated upon the maps. I would, how- 
ever, differ from de Lapparent in his inclusion of New Zealand 
in the Gondwana continent after the beginning of the Trias. 
The finding of similar dinosaurs on either side of the Mozam- 
bique Channel during the Cenomanian, after the cleavage of 
Gondwana Land into an Indo-Madagascar and an Africo- 
Brazilian mass, has been explained by Depéret (1909, p. 303), 
who assumes that a temporary closure of the gap occurred. As 
the Madagascar types are mainly Sauropod, one of which was 
found associated with Mytilus and Foraminifera, the closure 
may not have been complete. It is not, however, necessary 


38 R.S. Lull—Dinosaurian Distribution. 


to assume even a partial closure, as my map (fig. 9) will 
show. De Lapparent’s maps show no connection between 
Gondwana Land and Patagonia until the Basal Eocene, which 
is too late for the migration of the Patagonian (Danian) dino- 
saurs from the northeast. The closure may have occurred 
not long before, however, so far as dinosaurian evidence is 
concerned. | 


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R.S. Lull—Dinosaurian Distribution. 39 


von Huene, F. and Lull, R. S.—1908. Neubeschreibung des Originals von 
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40 Clark—Origin of Crinoidal Muscular Articulations. 


Arr. I1.—The Origin of the Crinoidal Muscular Artic- 
ulations ; by Austin Hoparr Criark. 


Tue peculiarly complicated type of muscular articulation by 
which the post-radial ossicles of the crinoids are joined together 
is generally supposed to have been derived from the so-called 
loose suture, the connective tissue of which has gradually 
become differentiated into two different types of ligaments 
and also into true muscle. The steps by which this process 
has come about have never been satisfactorily shown. 

While there appears to be in the crinoids a direct continuity 
between the connective tissue through various types of liga- 
mentous attachment to true muscle, yet it does not seem 
probable that the differentiation of the connective tissue 
between two adjacent ossicles could ever have progressed so far 
as to produce the conditions found in the crinoids, where two 
bundles of highly specialized muscle fibers occur, histologically, 
as well as in their location, sharply differentiated from the 
ligaments. 

A comparison of the crinoids with the two most nearly related 
recent classes, the Echinoidea and the Holothuroidea (Bohad- 
schoidea), offers, however, an easy solution of the problem of 
the origin of the complex crinoidal muscular articulations. 

In the Echinoidea the plates are united more or less closely 
by connective tissue, just as are the interradials and the 
secondary perisomic plates generally in the recent crinoids, and 
this was probably the original mode of union for the primary 
ambulacral ossicles of the crinoids as well, Now im all the 
heteroradiate Echinodermata (which include the Pelmatozoa, 
Echinoidea, and Holothuroidea) wherever the ambulacral ossi- 
cles or body wall are at all flexible, as occurs in the crinoids, in 
the holothurians, and in the echinothurids among the echinoids, 
each ambulacrum possesses a pair of longitudinal muscles one 
of which runs along either outer border, and may extend itself 
more or less inward. No definite homology has ever been 
proved between these five longitudinal ambulacral muscle pairs 
which are so constant in all the recent heteroradiate Echino- 
dermata possessing the possibility of ambulacral motion ; but 
from the uniform presence and location of these muscles it 
seems most probable that such homology actually exists. 

Now if the ancestral crinoids possessed a longitudinal muscle ~ 
along each border of the ambulacral series, as we must infer 
from analogy with the echinothurids and the holothurians, 
their closest recent relatives, we may assume an ambulacral 
structure something like that of the former—a series of 


& 


Olark— Origin of Crinoidai Muscular Articulations. 41 


ambulacral ossicles united by connective tissue with a longitu- 
dinal muscle band running interiorly along either side of the 
ambulacral series as a whole. It is easy to imagine that at 
first the muscle bands were fanlike in arrangement. and broad 
as in the echinothurids, but later, with increased flexibility 
of the test, became narrow, and finally resolved themselves 
into longitudinal muscles more like those of the holothurians. 
With increased scope of motion between the ambulacral 
ossicles, beveling was induced, whereby the apposed faces of 
adjacent ossicles were in close apposition in the median line 
(perpendicular to the line between the center of the ossicle 
and the center of the calyx) but sloped away from each other 
both imwardly and outwardly. The connective tissue along 
this median line, the prototype of the so-called transverse 
ridge, now became very short and dense, forming what is 
practically a very narrowly linear close suture; while the 
connective tissue on the remainder of the articular surfaces 
was more or less lengthened, and gradually became ligament- 
ous in nature, at the same time, through the separation of the 
internal edges of adjacent ossicles, the Jongitudinal muscle 
bands were, by pressure from within the calyx, pushed in 
between them, and certain of the fibers came to be inserted on 
the apposed faces of the ossicles instead of only on the ventral 
(interior) surface. This would give the ambulacral ossicles a 
joint face consisting of two equal oblong ligament fosse, 
separated by a narrow transverse ridge, with a small muscular 
fossa at each outer corner of the inner ligament fossa. Now 
the calyx of the ecrinoids is remarkable for its very small 
size, and hence in the development of the race we may assume 
that this decrease in size has caused it to press more or less 
upon the internal organs. This pressure would not be equal 
at all points on the inner surface of the ossicles because of the 
existence of various radial vessels which run along the center 
of the ambulacra, chief among which is the axial nerve cord. 
These vessels would, by this pressure, encroach upon the area 
of the inner ligament fossa, and would tend to excavate it in 
the form of a more or less broad V, at the apex of which 
would be the axial nerve cord; at the same time the muscles 
would encroach more and more upon the articular face, and 
the part of the original muscular band which originally ran 
along the inner side of each individual ossicle, having now 
become useless, would disappear. The ventral ligament fibers, 
as a result of the decrease in the area of the fossa occupied by 
them through the encroachment of the “soft parts,” not being 
able to migrate past the close suture along the transverse ridge, 
would come to lie more and more closely together, and would 
form two masses each more dense and compact than that of 


42. Clark—Origin of Crinoidal Muscular Articulations. 


the outer (dorsal) ligament mass, which remains unchanged. 
The muscles, unable to penetrate into the area occupied by the 
two resultants from the originally single inner (ventral) liga- 
ment mass, would gradually creep inward along their outer 
edge toward the center of the joint face. When the encroach- 
ment of the “soft parts” had progressed so far as to cause the 
axial nerve cord to lie upon the transverse ridge, we would 
find a condition as follows: first a large undivided dorsal 
ligament fossa occupied by more or less scattered contractile 
ligament, and bounded ventrally by the transverse ridge; just 
ventral to the transverse ridge would be found two triangular 
fossee, one on either side, lying with their apices just under 
the center of the axial cord and one of their sides coinciding 
with the transverse ridge; these fossze would lodge ligament 
masses similar to the dorsal ligament mass, but much more 
dense; on the outer distal corners of each of these two trian- 
gular fosse would be found muscular fosse, which would 
extend more or less inward toward the-center of the joimt 
face, but which would never meet in the median line. ‘Thus 
we have arrived at the type of muscular articulation charac- 
teristic of the crinoid arm, comprising a single dorsal ligament 
fossa, two interarticular muscular fosse, and two ventral 
muscular fosse. This theory of the genesis of the crinoidal 
muscular articulations (1) explains the peculiar denseness of 
the interarticular ligament masses, and (2) does away with 
the necessity of assuming that the muscles are the specialized 
connective tissue of an original loose suture. 

I have already shown how the peculiarly modified non- 
muscular articulations, the syzygy and the synarthry, are 
derived from the muscular type of articulation; so that now 
we are enabled to derive every known type of union between 
the ossicles of the crinoid crown from the simple connective 
tissue union known as the loose suture. 

A few words in regard to the syzygy may not be out of 
place. Minckert, like all his predecessors except Sars, believes 
that the syzygies are joints of especial weakness in the crinoid 
arm where fracture takes place in case the arm is seized, due 
to this especial weakness. He also believes that in adolescent 
autotomy the arm is voluntarily cast off by the animal at the 
first syzygy. My experience with living crinoids has led me 
to agree with Sars; the syzygy is at least as strong as the mus- 
cular articulations, as anyone may prove for himself by break- 
ing up crinoid arms. Under certain conditions, however, the 
syzygy becomes peculiarly weak, and often breaks of itself. I 
believe that this is susceptible of ready physiological explana- 
tion. Bosshard has shown that the fibers of the dorsal liga- 
ment and of the syzygy are histologically the same, the only 


Clark—Origin of Crinoidal Muscular Articulations. 48 


difference being that the latter are extremely short. Now 
since the fibers of the dorsal ligament and of the syzygy are 
identical except in length, we should expect that they both 
would possess the same physiological characteristics, and, there- 
fore, that the fibers of the syzygy would be contractile in the 
same way that those of the dorsal ligament are, though their 
possible loss or gain in length, owing to their shortness, would 
be very slight. As the fibers of the syzygy are continuous in 
substance through the organic base of the ossicles with those 
of the dorsal ligaments preceding and succeeding, it is probable 


Fies. 1-5. 


3 ) 


Diagrams illustrating the origin of the muscular articulations of Crinoids. 


Fic. 1. The primitive joint face, with connective tissue binding; the 
two longitudinal ambulacral muscles are seen on the outer angles. 

Fic. 2. A joint face differentiated by the development of a transverse 
ridge ; the connective tissue on either side has become ligamentous, and the 
museles have increased in size. 

Fic. 5. A joint face showing reduction of the internal fossa by pressure 
of the ‘‘ soft parts ;” the ligament of the internal fossa is becoming denser ; 
the muscles have increased in size. 

Fic. 4. The internal fossa has now become divided into two interarticu- 
lar ligament fosse, lodging dense ligament bundles; the muscles have 
become still larger. > 

Fic. 5. Radial face of one of the Zygometride. 


that they act in sympathy with them, expanding and contract- 
ing, in their small way as they do. It may be readily sup- 
posed that the tension of the fibers in the syzygy is adjusted to 
the ordinary movements of the crinoid arm. The dorsal lga- 
ments are normally always antagonized more or less by the 
powerful ventral musculature and ordinarily never contract to 
their furthest capacity. If for any reason the ventral muscles 
are rendered inert, as by the panic incident to capture, then 


44. Clark—Origin of Crinoidal Muscular Articulations. 


the dorsal ligament would contract to the farthest limit, and 
the fibers in the syzygies, through sympathetic action, would — 
also contract, but, being normally under more or less tension, 
would not be able to take up this contraction within them- 
selves, but would be pulled apart, thus breaking off the arm at 
the syzygy. Fracture of the arms at the syzygies, then, would 
appear to be an entirely involuntary act on the part of the eri- 
noid, due solely to the physiological effects of panic; this 
panic may, of course, be more or less general, or localized, so 
that stimulus of the calyx would induce fracture at the first 
brachial syzygy, stimulus on the arms at the neighboring 
syzygies. 

During the growth of most of the oligophreate comatulids 
the ten original arms are cast off, often at the first syzygy, and 
from the stumps axillaries arise bearing severalarms. Minckert 
supposed that this was a voluntary action; but it is noticeable 
that all the comatulids which have more than ten arms have 
short brachials which are correlated with a corresponding 
shortness in the muscle fibers and dorsal hgament fibers unit- _ 
ing them. Now it seems probable that during growth the 
dorsal ligament fibers are able to accommodate themselves 


gradually to their decreasing length through their contractile 


power; but this would have exactly the same effect upon the 
syzygies as panic—they would be torn apart—so that the cast- 
ing off of the arms of the ten armed young of the oligophreate 
comatulids appears to be, not a voluntary action, but a direct 
result of the gradual change from the juvenile to the adult 
type of brachial. 


Browning and Roberts—Separation of Cerium. 45, 


Arr. Ill.—On the Substitution of Bromine and of Lodine 
For Chlorine in the Separation of Cerrvum from the other 
Cerium Harths; by Puitie E. Browntne and. Epwin J. 
RopeRts. 


[Contributions from the Kent Chemical Laboratory of Yale Univ.—cevi. | 


One of the best known processes for the separation of 
cerium from lanthanum and didymium is that of Mosander.* 
This process consists in passing chlorine gas into a mixture of 
the hydroxides suspended in a distinct excess of a fixed alkali 
hydroxide, until the solution is saturated and the reaction of 
the liquid is no longer alkaline to litmus. Under these con- 
ditions nearly all the cerium remains undissolved as the ceric 
hydroxide, while the other cerium earths go largely into 
solution. In treating mixed material the residue of ceric 
hydroxide generally retains some of the cerium earths so that 
_ the treatment with chlorine must be repeated. Two disad- 
vantages associated with this method therefore are, the prepa- 
ration and use of chlorine gas, and the solvent action of the 
hydrochloric acid formed in the reaction upon the ceric 
hydroxide _ 

2Ce(OH), + Cl, = 2CeO, + 2HC1+4 2H,0. 


The work to be described was undertaken to study the 
effect of substituting bromine or iodine for chlorine in this 
process. A preliminary experiment was made by suspending 
a precipitate of the washed hydroxides of the cerium earths in 
water, adding a little liquid bromine, and allowing the action 
to go on for several hours with occasional stirring. The pre- 
cipitate took on the color of the ceric hydroxide, and on filter- 
ing the filtrate was found to contain a considerable amount of 
cerium earths free from cerium. 

In the-followmg experiments solutions of known amounts 
of the mixed oxides, composed of about 50 per cent of cerium 
and 50 per cent of the cerium earth oxides other than cerium, 
were treated with a slight excess of sodium or potassium 
hydroxide. To these hydroxides suspended in the alkaline 
solution, liquid bromine or bromine water was added in dis- 
tinct excess, and the mixture was placed upon a steam bath 
until the greater part of the free bromine was expelled. The 
residue was then filtered off, washed, and treated as before. 
This process was repeated twice, and the filtrate after each 
treatment was found to contain the amounts of cerium earth 
oxides, free from cerium, indicated in the table. The residue 
from the last treatment on being dissolved in acid showed only 


* J. prakt. Chem., xxx, 267. 


46 Browning and Roberts—Separation of Cerium. 


faint didymium bands. In experiment (6) the indication of 
the presence of didymium was very faint. In another experi- 
ment the same amount of material used in (5) and (6), 10 grams, 
was subjected to a fourth and fifth treatment with bromine, 
the fourth treatment yielding a small fraction of a gram of the 
oxides, and the fifth only a few milligrams. In both cases 
these oxides were free from cerium. The oxides from the first 
filtrates were much lighter in color than those obtained from 
the last, which, of course, indicates that the lanthanum is 
dissolved by the action of the bromine more readily than the 

didymium. The results follow in the table: : 


Mixed oxides Oxides found Oxides found Oxides found Total 


taken in first in second in third oxides 
filtrate filtrate filtrate . found 
grm. erm. erm. grm. erm. 

(1) 1°0000 0°3310 0:0720 0:0190 0°4420 
(2) 1°0000 0°2900 0°1010 0:0420 © 6°4330 
(3) 1°:0000 0°2250 0°1290 0°0640 0°4180 
(4) 1°0000 | 0°2750 0°0860 0°:0740 0°4350 
(5) 10°0000 3°1360 1°:0050 0°5930 4°7340 
(6) 10°0000 3°4590 0°5240 0°8560 4°8390 


So it has been shown that by substituting bromine for chlo- 
rine in the Mosander process about 50 per cent of the other 
cerium earths can be separated from ceric hydroxide in one 
treatment, and that after three treatments practically all the 
other cerium earths are removed without any solvent action 
upon the ceric hydroxide. The advantages of the method are, 
the convenience in the use of the bromine, and the apparent 
lack of tendency of the hydrobromie acid to dissolve the 
ceric hydroxide. 

An experiment was made, using iodine in place of bromine, 
as follows: The precipitated and suspended hydroxides from 2 
grams of the mixed oxides were treated with 1 gram of solid 
iodine. After standing for about two hours on a steam bath, 
the excess of iodine was removed by boiling, and the residue of 
hydroxides was filtered off. The filtrate gave 0:0980 orm. of 
oxides, free from cerium, and of a slight brown color. This 
shows that the action of iodine is the same, in a general way, 
as that of chlorine and bromine, but is too incomplete to be of 
any practical value. 


Wickham— New Fossil Coleoptera from Florissant. 47 


Art. 1V.—WNew Fossil Coleoptera from Florissant, with 
Notes on some already described; by H. F. Wicknam. 


Calosoma Web. 


C. cockerella nu. sp. A piece of a wing cover lacking both 
base and apex is referred to this genus. It represents a species 
about the size of C. calvini m., from the same shales. The 
elytron is marked with sixteen well impressed punctured strie, 
besides an indeterminate number (perhaps two) closer to the 
outer margin. ‘The interspaces are nearly four times as wide as 
the diameter of the punctures in most parts of the area, but in the 
neighborhood of the apex of the tenth and eleventh strize the 
punctures are much larger than elsewhere and are equal in 
diameter to the interstitial width. In general, the punctures 
are rounded or slightly elongate and they are separated longi- 
tudinally by spaces about equal to their own diameters. The 
elytral surface shows no indication’ of the coarse imbricate 
seabrosity of the interstrial spaces which is evident in our 
recent North American C. calidum, nor are any series of inter- 
stitial punctures visible. The interspaces are apparently 
slightly convex. Length of fragment about 9°25™™, greatest 
width 6°15™". 

Station number not given. Collection number 232, Florissant 
Expedition 1906. Received from Prof. Cockerell. Holotype 
in Peabody Museum of Yale University. Cat. No. 10. 


Pierostichus Bon. 


P. pumpellyz Scudder. An elytron showing obverse and 
reverse is referred here with fair certainty. The elytral strize 
are nine in number and are more clearly exhibited on the 
reverse. They are fine, sharp, fairly deep, perfectly smooth, 
the interspaces moderately convex. The scutellar stria joins 
fe. rst at about 1-75" from the base. Length 9-75™™, 
width 3-40". 

Station number 13. Collection number, obverse 87, reverse 
65, Florissant Expedition 1906. Received from Prof. 
Cockerell. 


Platynus Bon. 


A specimen in obverse and reverse, believed to belong to 
this genus, is among the material sent by Prof. Cockerell. 
The elytra are 6°20" in length, and have a conjoint width of 
4-10™™ at middle. They are finely striate, about as in our 
recent P. placidus, and are apparently almost or quite impunc- 


48 Wickham—New Fossil Coleoptera from Florissant. 


tate. Compared with P. tartareus Scudder, from the Floris- 
sant shales, the specimen in hand has the humeral angles less 
rounded and the elytral apices decidedly less truncate. The 
remainder of the body is too poorly preserved for study, and - 
it seems scarcely wise to impose a specific name. 

Station number 13a. Collection numbers 114 and 155, 
Florissant Expedition 1906. Collected by Mrs. W. P. 
Cockerell, and received from Professor Cockerell. Specimen 
in the Peabody Museu of Yale University, Cat. No. 11. 


Peltis Wliger. 


P. laminata n. sp. Form oblong-elliptical, similar to that ~ 
of the recent North American P. pipingskeldi. Head larger 
than in that species, somewhat dilated by pressure. Prothorax, 
as preserved, broader shortly in front of the base, sides arcu- 
ately narrowed to apex which is broadly emarginate, front 
angles a little greater than right, hind angles obscure but — 
apparently obtuse and rounding, a faint basal marginal line 
somewhat as in Colorado specimens of the recent P. ferruginea. 
Elytra slightly broadest at base, where they are a little wider 
than the prothorax, scarcely perceptibly narrower to a point 
behind the middle, thence rapidly arcuately narrowéd to the 
apices, which are nearly pointed and (through distortion) 
dehiscent. The disk shows traces of having been finely striate 
but the sculpture of the entire surface is now scabrous and 
obscure. ‘The sexual organs are protruded from the tip of the 
body but show no definite structure. Length, including 
extruded sex organ, 12°50™"; of prothorax along median line, 
2°25™™ ; of elytra, 6°60"; width of prothorax, 5™™; of elytra 
conjoined, 6°25™™. | 

In outline, this inseet quite closely recalls several recent 
species of Peltis, though the form of the thorax is slightly 
nearer that of Ca alitys scabra. However, the thoracic and 
elytral margins are perfectly clear-cut and entire as in Peltzs, 
while in our Calitys they are coarsely serrate. The antenne 
and legs are not shown. 

Station number R. 4. Collection number 145, Florissant 
Expedition 1906. Received from Prof. Cockerell. Holotype 
in the Peabody Museum of Yale University, Cat. No. 12. 


Atenius Harold. 


A. putescens Scudder. One specimen, in reverse, exceeding 
Scudder’s measurements by about °50™™, is included in the 
collection. The state of preservation is only fair and no 
important characters can be added to the original description. 

Station number 14. Collection number 207, Florissant 
Expedition 1906. Received from Prof. Cockerell. 


), ee 


Wickham—New Fossil Coleoptera from Florissant. 49 


Aphodius Mlliger. 


A. laminicola n. sp. Form stout, evidently a little more so 
than in the recent A. fimetarius, head narrowed anteriorly, 
elypeus almost squarely truncate at middle, the angles rounded. 
Prothorax broadest about the middle, sides apparently regularly 
arcuate but not alike in the specimen and therefore incapable 
of exact definition. The appearance is that the base was 
distinetly broader than the apex. Sculpture obliterated by the 
impressions of the underside, which show through. Scutel- 
lum (?) large, almost equilaterally triangular, the basal (anterior) 
angles obliquely truncate, basal region rugosely punctate, 
middle finely carinate. Elytra subparallel to an indeterminate 
distance behind the middle, regularly conjointly rounded at tip, 
striz fine, single, finely and not closely punctured, interspaces 
broad and very nearly or quite flat with a few scattered fine 
punctures, sutural interval narrower than the next. Legs 
stout, middle tibia slightly bent at base, tip moderately ex- 
panded, median oblique ridge faintly indicated. Length 9°70", 
of elytra 5-75™™, of middle femur about 1°70™™, of middle tibia 
1:35", of middle tarsus about 1°35™", conjoimt width of elytra 
about middle 4:80"™. 

Station number 14. Collection number 231, Florissant 
Expedition 1906. Received from Prof. Cockerell. The type 
is in the Peabody Museum of Yale University (Cat. N®. 13); 
a second, poorer specimen, a reverse, from the same station 
and with the catalogue number 140, is in the Museum of the 
University of Colorado. 

The type specimen is very puzzling, on account of the 
peculiar state of preservation; the parts of the under side are 
largely shown through and interfere with the view of the 
upper surface. Thus [I am not sure whether the structure 
described as the scutellum may not be the mesosternum, and 
on account of similar confusion [I have not tried to give 
measurements for the head and prothorax. Of the legs, the 
two middle femora show plainly, the front and hind ones 
indistinctly. One middle tibia and the tarsus of the opposite 
leg are distinct. 

Amphicoma Latr. 


A. defuncta n. sp. The specimen shows only the tips of 
the elytra, with ill-defined exposed portions of the abdominal 
apex, some traces of hind wings, a well preserved hind tibia 
and tarsus and poorly indicated portions of the other leg of 
this pair. Elytra strongly dehiscent and tapering to the tip, 
which is rounded, surface clothed with hairs which are appar- 
ently longer and sparser than in the recent California A. ursind. 
The outer edge of each elytron shows a fine marginal bead, as 
in that species; the sutural bead is less strongly marked. No 


Am. Jour. Sct.—Fourtu SERIES, Vou. X XIX, No. 169.—January, 1910. 
4 


50 Wickham—New Fossil Coleoptera from Florissant. 


indication of discal sculpture, aside from the fine piligerous 
punctures, can be seen. The exposed tibia of the hind leg is 
perhaps a trifle stouter than in A. wrsina, about equally 
broadened to the tip, the lateral margins (perhaps accidentally) 
irregular; one terminal spur shows, which is more than half as 
long as the first tarsal joint, but the extreme apex is con- 
cealed so that the exact length cannot be determined. Tarsi 
rather stout for this genus, the first joint longest (about one 
third longer than the one following) third and fourth joints 
nearly equal to each other and slightly longer than the second, 
claw joint again longer but ill defined, lee not in conden 
for study. Apparently, the first, second and third tarsal joints 
were finely longitudinally carinate above, a feature that I can- 
not detect in any recent Amphicoma at my disposal. ‘Neither 
do I find any certain evidence that the legs were hairy, though 
I believe that certain sculpturings on the tibia represent pilig- 
erous punctures. The tarsal joints surely bore short stiff hairs 
on their margins, as in the recent A. vulpena from the New 
England coast. Width of elytral fragment, at 5™" from tip, 
37"; length of tibia, 4°‘75™™5 of tarsus, entire, 1-25" =sonmnmer 
joint about 1°75™™. 

Station number 14. Collection number 186, Florissant 
Expedition 1906. Received from Prof. Cockerell. The holo- 
type is in the Peabody Museum of Yale University, Cat. 
No. 14. 

Lema FEabr. 


L. evanescens n. sp. Form similar to that of the recent 
L. collaris and equally stout. As the type is largely in pro- 
file, it is not possible to give comparative measurements 
of the length and breadth of different parts of the body, 
though the head, with greater portions of the eyes and antenne, 
the prothorax, elytra, abdomen, and parts of the lees are more 
or less clearly shown. The antennze are very nearly approxi- 
mate at base and are stout, the intermediate jomts but very 
little longer than broad ; the eyes are large and prominent, legs 
stout. The specimen isa reverse, and lines of small elevations 
indicate that the elytra were punctured in rows similarly to 
most of our recent North American species. Total length, 

560°" = on elytron, o;b0rs. 

Station number not given. Collection number 86, Florissant 
Expedition 1906. Received from Prof. Cockerell. Type in 
Peabody Museum of Yale University, Cat. No. 15. 

A second specimen, collected at Florissant in 1906 but ith 
no station designated though bearing the collection number 
107, is less in profile than the first and indicates that the pro- 
thoracic constriction was shghtly antemedian and fairly deep. 
In this the broader elytron is 3°65" in length and about 
1°30" in width. 


Wickham—New Fossil Coleoptera from Florissant. 51 


Ologlyptus Lacordaire. 


O. primus n. sp. The rather poorly preserved specimen 
indicates a species of moderate size and probably flattened 
form, approximating that of our recent O. anastomosis. The 
prothorax is broadest near the middle, sides regularly round- 
ing, apex considerably narrower than the base but owing to 
incompleteness of the specimen the exact proportions cannot 
be given. Head obscured, antennee with the median joints 
about as broad as long. Elytral sculpture apparently rough, 
but no details can be made out. Legs wanting. Length of 
specimen, which lacks a small portion of the tip of the elytra, 
7-25" ; of prothorax about 2°15"; width of elytra, conjoint, 
3°65™™ ; of prothorax (distorted ?), 2°75™™. 

Station number 13. Collection number 154, Florissant 
Expedition 1906. Received from Prof. Cockerell. Holotype 
in the Peabody Museum of Yale University, Cat. No. 16. 

The generic reference is not made with any great certainty, 
but the facies is decidedly that of several recent species of 
Ologlyptus, with which it has been directly compared. The 
prothorax appears to have the basal margin extending farther 
backwards than the points of the hind angles, much as in the 
Mexican O. sinuaticollis but to an even greater degree. 


Macratria Newm. 


M. gigantea n. sp. Form elongate, head small, short, 
prothorax very long and narrow, elytra conjointly much broader 
than the prothorax, sides subparallel, apices rounded, surface 
finely, distinctly and rather closely striate, the strie finely, not 
closely punctured, interspaces flat. Middle leg not elongate 
and only moderately stout. Antenne showing only a few 
intermediate joints which are sufficiently. well preserved to 
indicate that they are longer than wide, but not greatly 
elongate. Length from front of head to tip of elytra, but 
exclusive of projecting abdominal organs, 8". Length of 
head, as preserved, 1™; of prothorax, 2° 10"; of elytra, a LORE: 
Width ot prothorax about 1: Orns) Ob, el yang conjointly, 2 OMe. 
The articulations of the leg joints are not well enough defined 
to permit of accurate measurements. 

Station number 14. Collection number 9, Florissant Expedi- 
tion 1906. Received from Prof. Cockerell. Holotype in the 
Peabody Museum of Yale University, Cat. No. 17. 

The specimen has a decidedly Anthicide look, and in build 
as well as sculpture resembles our recent North American 
species of Macratria though far exceeding them in size. 
Possibly it may represent an- extinct allied genus, but no 
characters are evident upon which to base a separation. 


Iowa City, Lowa. 


52 Washington and Wright—Feldspar from Linosa. 


Art. V.—A Feldspar from Linosa and the Existence of — 
Soda Anorthite (Carnegicite) ; by Henry S. Wasnineton 
and Frep. Eugene WricuHr. 


Tue mineral described in this paper was found as loose 
crystals, together with crystals of kaersutite, at a small parasitic, 
einder cone of the volcano Monte Rosso, on the island of 
Linosa; east of Tunis.* -The chemical investigation was under- 
taken by the senior author and the optical by the junior. 


Physical Characters. 


‘The dark brown, pumiceous, basaltic lava clings so tenaciously 
to the erystal faces that it was not possible to obtain satisfac- 
tory material for crystallographic measurements. The crystals 
vary much in size, the largest one measuring 3:5 in length 
and about 2 in width. While some are fragmentary, others 
are wholly bounded by erystal faces. They are elongated 
parallel to the @ axis, and are of simple crystal habit, bemg 
bounded by the forms (001), (010), (110), and (110), on the 
assumption that the mineral is a triclinic feldspar. 

Although the crystal faces do not lend themselves to gonio- 
metric measurement, the basal cleavage is highly perfect, and 
albite twinning lamelle are occasionally well developed. On 
such a cleavage flake the angle between the basal cleavage 
planes of two adjacent albite jamellee was measured on a two- 
circle goniometer with ee attachment, and found to be 
_ 8° 3’. From this the angle (001), (010) — 85° 59’ can be 
deduced, this angle for albite being 86° 24’, for anorthite 
BH 200, ‘and for labradorite 86° 12’. The cleavage after (010) 
is very imperfect, as is often the case with the soda-lime feld- 
spars, and only indications of cleavage after the prism faces 
(110) and (110) were noted. When the cleavage does not 
control, the fracture is highly conchoidal. Viewed along cer- 
tain directions, especially about normal to the front pinacoid, a 
peculiar, milky, opalescent sheen, resembling that of moon- 
stone, can be seen in some of the erystals. 

Fine polysynthetic twinning lamelle after the albite law are 
not uncommon, and occasionally cross polysynthetic twinning 
lamellee, probably after the pericline law, were observed. On 
a plate nearly normal to the obtuse bisectrix the angle between 
the albite and the pericline twinning lamelle was found 
to be 94°. 

The specific gravity was determined (by H. S. W.) with the 
pycnometer on two separate portions of the carota selected 


* Cf. H. S. Washington, Jour. Geol., vol. xvi, p. 10, 1908 ; and Washington 
and Wright, this Journal, vol, xxvi, p. 187, 1908. 


Washington and Wright—feldspar from Linosa. 58 


material used for the chemical analyses, and was found to be 
Zoom at 5, and 2;°693 at 17°. The latter may, therefore, be 
considered to be the specific gravity of the mineral, or, rather, 
correcting for about 0°75 weight per cent, or 0°35 volume per 
cent, of included magnetite, the true specific gravity of the 
mineral would be 2°684. The hardness is slightly less than 
that of adularia, but not far from 6. 

Except for ferruginous stains derived from the inclosing 
basaltic scoria on the exterior portions of the crystals, and the 
very small and rare inclusions of magnetite to be described 
later, and which did not interfere with the optic determina- 
tions, the material is remarkably fresh, colorless and trans- 
parent, and admirably adapted for optic work. Zonal structure 
was not evident. 

The refractive indices were measured in sodium light on an 
Abbe—Pulfrich total refractometer, the probable error of the 
values being less than + ‘001, with the following results: 

@ ya 1°5549, B yz=1°5587, y na=1°5634, 
y—a=0°0085, y—B=0°0047, B—a=0°'0038 

According to these values the measured crystal plate was 
optically positive and 2Vy,—82° 48’. On a second, less per- 
fect plate slightly higher values were obtained, but the observed 


differences were only a little greater than the probable error. 


The optic axial angle was measured directly on a Wiilfing 
axial angle apparatus in sodium light, the plates being im- 
mersed in a liquid of the refractive index 1: 559, the observed 
readings giving, therefore, at once the true optic axial angle 
2Vxa- Five plates normal to the bisectrix ¢ and one plate 
normal to a were measured. ‘The values thus obtained did not 
agree well, and several of the plates were remeasured with 
practically the same results.* The probable error of the values 
in the following table is certainly less than +30’. 


Crystal Optical Extinction 
plate 2VNa Dispersion character angle,t aaa 

it 78° 0’ p>v + 28°0° 

2 is aes). Bcaged + 12°0- 

3 84° 99’ p>v = G2 

4} areal a ISERe “ir 33.0. 

5) 89° 27,8 ene = 11°9° 

6 88° 59’ | eres — BHO 


* We are indebted to Mr. E. S. Larsen, jr., of the Geophysical Laboratory, 
for an independent measurement of the optic axial angles of the entire set. 
His results are practically the same as those in the table, the greatest differ- 
ences being 20’ on a less favorable plate. 

+ Too much stress cannot be placed on these extinction angles, since the 
plates were cut only approximately normal to the bisectrices and were out a 
number of degrees in certain instances. 

{ Plate cut normal to the obtuse bisectrix. 94° 18’ measured. 

$ 90° 33’ measured. | 91° 1’ measured, 


54. Washington and Wright—Feldspar from Linosa. 


These variations are of considerable magnitude and the 
values seem to differ from crystal to erystal rather than within 
a single crystal. This phenomenon of variation in optic axial 
angle: might possibly be explained as a result of unequal cooling 
of the different er ystals, as is the case with orthoclase and sani- 
dine; but other evidence, particularly that of the extinction 
angles, shows that the composition probably varies slightly 
from crystal to erystal. 

The extinction angles were measured both on cleavage flakes 
after (O01) and on (010). In each case the angles were 
measured as accurately as possible, with the aid of the cireularly 
polarizing bi-quartz wedge,* and the probable error is less 
than 15’. 

On (001) the values for axa ranged from —0°6° to —4°5°, 
and on basal cleavage flakes from one crystal the angles averaged 
—2-0°, and from a second —4:5°. Other pieces showing poly- — 
syuthetic lamelle were observed occasionally with very high 
extinction angles; but the examination in convergent light, 
and also the determination of the ellipsoidal axis, whether 
a or c, proved that either the cleavage fragment was not 
parallel to the base or that pericline lamelle were bemg 
examined.t 

Extinction angles were also measured on the brachypinacoid 
(010), both on the rhomb-shaped cleavage flakes and also on a 
section ground parallel to the brachypinacoid. Different values 
were obtained for different flakes, although in the larger 
ground plates no marked indications of wavy extinction or 
zonal structure were observed. The values ranged from 
ana= —2°5° to —11°. Since, however, the cleavage parallel to 
(010) is not perfect, it is possible that part of this variation was 
due to the fact that the surfaces were not precisely parallel to 
(010) at the place of measurement, but were inclined because 
of minute irregularities of the cleavage. Flakes parallel to 
(010) often show in white lght the peculiar interference 
phenomena characteristic of minerals with shght dispersion of 
the bisectrices. 

In convergent polarized light the optic normal emerges near 
the center of the field on plates parallel to (001); while the 
bisectrix cis nearly normal to the brachypinaoid, and appears 
near the center of the field on flakes parallel to (010). 

Taken collectively, these results indicate that the present 
material is a plagioclase feldspar, of somewhat variable com-_ 
position and with slightly modified characters. Taken alone, 

*Cf. F. E. Wright, this Journal, vol. xxvi, p 391, 1908. 

}+ A series of measurements on 12 different cleavage flakes from one of the 
crystals was also made by Mr. E. 8S. Larsen, with the result a . a=2° 2'+6, 
a value well in accord with Wright’s observations. 


Washington and Wright—Feldspar from Linosa. 55 


the extinction angles on (001) would indicate a feldspar com- 
position ranging from about Ab,,An, to Ab,,An,,, while from 
those on (010) a composition from Ab,,An, to Ab,,An,, and 
higher might be inferred. The values,of the optic axial angle 
alone indicate variations from Ab,,An,, to Ab,An,, according to 
the most accurate measurements of the different members of 
the plagioclase series. As a whole, therefore, the optic charac- : 
ters would show that we have an andesine feldspar of a composi- 
tion somewhat more sodic than Ab,An,, on an average about 
Ab,An,, while the specific gravity is almost exactly that of a 
labradorite of the composition Ab,An,, or (corrected) of an 
andesine Ab,An,,. 


Chemical Composition. 


_ The material used for the chemical analyses was obtained by 
coarsely crushing several of the crystals and fragments and 
very careful hand-picking under the lens. It was found to be 
impossible to separate the portions contaminated with adherent 
basaltic scoria by means of heavy solutions. Because of the 
similar specific gravities, particles with and without attached 
scoria floated and sank together. In the heavy solution the 
material used for analysis seemed to be homogeneous. 

All the material analyzed was perfectly fresh, colorless, and 
water-clear, and consisted of but one mineral, so far as could be 
ascertained by examination under the microscope. While the 
greater portion was entirely free from inclusions, it was 
impracticable not to use some fragments containing inclusions, 
and as these have a bearing on the chemical discussion, they 
may be briefly described here. Apart from them the material 
was perfectly pure and admirably suitable for chemical 
analysis. 

The inclusions are never very abundant, especially in the 
fragments used for the analyses. They are very minute in 
size, the largest being 0°5"™ long by 0°1™™ wide, and the great 
majority are much smaller. They are of uniform character, 
in the form of narrow, spindle-shaped bodies or thin cylinders 
with rounded ends. They are black, with metallic luster, and 
perfectly opaque, so that they may be regarded as essentially 
magnetite, a conclusion also indicated by the results of the 
analyses. 

The feldspathic mineral is only slightly acted on by hot, 
dilute hydrochloric acid, even after prolonged treatment, so 
that the main portion was brought into solution by fusion with 
mixed sodium and potassium carbonates. In this, as in other 
respects, the analyses were made by the methods advocated by 
Hillebrand and by Washington, the alkalies being determined 
by the Smith method. 


56 Washington and Wright—Feldspar from Linosa. 


An analysis was made in duplicate (except for FeO, the 
alkalies and H,O) on one lot of selected fragments, portions of 
which also served for the specitic gravity determinations, the 
material being dried at@10°. As the results were decidedly 
unexpected, especially in view of the preliminary optic work, 
a second lot of fragments was analyzed, special care being 
taken to select, so far as possible, only those showing cleavage 
surfaces, so as to exclude any possible nephelite. The results 
of the three analyses, with the average and the molecular 
ratios of this last, are given below. 


I II III Average 

S10, Sra te & NOS SOS 52°83 DEAT "874 
Ti@:e ates trace trace trace trace | 
AOne oy 29°34 29:54 29°68 2950 -290 
UNS Oo ac ay OGY 0°75 0°53 0°65 004 
HeOyr tia O17 (0:17) 17): 7 Oa aa 
MeO af rete aoe, 0°03 0°05 0°07 ~ 0°05 ‘001 
CAO ees OTS 10°59 10°67 10°66 °190 
Na,O...2.) 5:40. (540) | °(640) ~ 5 40) ene 
KO? shih 0-74 (0-74) (0-74) 0-74 noe 
1,0 CS 0°38 (0°38) 0°34 —~60°36 


100°19 100°37 100°38 100°30 


The very small amounts of iron oxides and magnesia are 
evidently derived from the small, opaque inclusions. Ferrie 
oxide is in excess of ferrous, but in the determination of such 
small amounts the fact is not of much significance, so that the 
fizures bear out the microscopic examination in the conclusion 
that the inclusions are of a (non-titaniferous) magnetite. They 
also probably contain the magnesia. We may, therefore, sately 
reject the small amounts of ferric and ferrous oxides, magnesia 
and water, which last is to be ascribed to adsorption of 
atmospheric moisturet by the powder. On this basis the 
composition deduced from the analysis will be as follows: 


Linosa mineral (4Nao#Ca)AI1,Sis01. Abi:An, Abs;Anz 


S10, 53°26 °882 9:09 52°84 55:67 58:24 
AOR 29:78 429 aor 00 29°94 28:26 26°53 
CaO 10°76 °192 1:98 10°96 10°34 8°32 
Na,O 545 +088 lo: 99 6°26 5°73 6-91 
K,O O75) 008 0°00 0:00 0°00 

100-00 10000 100°00  100°00 


* The color produced by H,O, in the solution used for the titration of iron 
as Fe.O; was barely perceptible, so that only faint traces of titanium can be 
present, 

+ Cf. Day and Allen, Carnegie Publication, No. 31, 1905, p. 57, 


Washington and Wright—Feldspar from Linosa. 57 


The ratios of the Linosa mineral are very close to whole 
numbers, though there is a slight excess of silica. Calculating 
the small amount of potash with the soda, the figures of the 
analysis correspond to the formula Na,O.2Ca0.3A1,0,.9Si0,, 
which, simplified, becomes ($Na,,3Ca)A1,Si,0,,.. The percent- 
age composition of this molecule is given above. 

No anhydrous silicates with formulas corresponding to this 
appear to be known independently, but several zeolites are 
analogous, namely: wellsite, (K,,Ca,Ba)AI,8i,0,,+3H,O; eding- 
tonite, BaAJ,Si,0O,,+3H,O; natrolite, Na,Al,Si,0,,+2H,O; 
and a potassium natrolite observed by Pirsson* in missourite 
with the approximate composition (K,Ca)A1,Si,0,,+2H,O. 
Indeed, the composition of the Linosa mineral is exactly that 
of a mesolite, (mNa,A1,Si,O,,.2H,O +nCaAl,8i,0,,.3H,O), with 
Na,O: CaO = 1:2, and lacking the water. 

Compounds of this type can be regarded as salts of the 
alumo-trisilicie acid (H,A1,Si,O,,) of Morozewiez,} the potas- 
sium salt of which he considers as present in nephelite, 
with varying proportions of the sodium alumo-disilicate, 
(Na,A1,Si,0,). Reduced to still simpler terms they would be 
salts of the acid H,Si,O,,, for which Vogtt proposes the name 
pyrosilicic acid. He refers akermanite and gehlenite to this 
simple formula, as does T’schermak§ the mineral melilite. 

Comparing the composition of our mineral with those of the 
two plagioclases, Ab, An, and Ab,An,, which it closely resembles 
in its physical properties, it will be seen from the table above 
that Ab,An, shows closely concordant figures for lime and 
soda, while silica is distinetly higher and alumina lower; and 
that, on the other hand, Ab,An, shows much higher silica and 
slightly higher soda, but lower lime and alumina. In fact a 
composition satisfactorily close to that of the Linosa mineral 
as regards all the constituents, and furnishing like ratios, 
cannot be calculated from mixtures of the albite and anorthite 
molecules. 

The relations may be better seen in the respective ratios, as 
shown when the formulas are compared, as follows: 


Linosa mineral - = Na,O.2Ca0.3Al,0,.9Si0,. 

Labradorite (Ab,An,) = Na,O.2Ca0.3Al1,0,.10Si0,,. 

Andesine (Ab,An,) =3Na,0.4Ca0.7AI,0,.225i0,. 
Discussion. 


The data given in the preceding pages make it clear that the 
physical and chemical characters of our mineral are at variance. 
The crystal system, twinning laws, cleavage, and hardness are 

* Weed and Pirsson, this Journal, ii, p. 320, 1896. 
+ Morozewicz, Bull. Acad. Sci. Cracov., p. 999, 1907. 


t Vogt, Mineralbildung in Schmelzmassen, p. 162, 1892. 
$ Tschermak, Lehrbuch der Mineralogie, p. 523, 1905. 


58 Washington and Wright—Feldspar from Linosa. 


those of the lime-soda feldspars. The specific gravity, the 
crystallographic angles measured and the birefringences are 
those of a labradorite of about the composition Ab,An,. 
Although the optic axial angle and the extinctions are decid- 
edly variable, they correspond to those of andesines somewhat 
more sodic than Ab,An,, on the average about Ab,An,. On 
the other hand, the chemical composition is not that of any 
possible member of the normal plagioclase series, or mixtures 
of albite and anorthite. The ratios of Al,O,, CaO and Na,O 
are those of Ab,An,, but the amount of SiO, is lower than that 
demanded for these by the known feldspar formulas, and the 
mutual ratios of this with those of the other constituents indi- 
eate a composition which corresponds to that of an anhydrous 
mesolite, or a salt of the acid H,A1,Si,O,,, with Na:Ca-= 1:1. 
Our mineral is, therefore, physically closely allied to labrado- 
rite and andesine, but chemical distinctly different in the ratios 
of the constituents. 

The possibility that the material analyzed was a mechanical 
mixture of particles of two minerals, such as labradorite and 
nephelite, and that only fragments of the former were subjected 
to optic investigation, is rendered untenable by the following 
facts. Careful examination of the unbroken crystals, as well 
as microscopic study of the crushed tragments and cleavage 
flakes, by both of the authors independently, revealed the 
presence of but one mineral, colorless, transparent, cleavable 
and feldspar-like. Apart from the small, opaque inclusions, 
each crystal appeared to be homogeneous, and all appeared to 
be of identical material, except for the optic variations. The 
action of hydrochloric acid showed that no readily decom- 
posable mineral was present as separate individuals. The very 
close agreement between separate portions in specific gravity 
and in chemical composition renders the mathematical chances 
against the hypothesis of a mechanical mixture of particles of 
two minerals so great that it may be safely eliminated from 
consideration. Finally, the lavas of Linosa are all typical 
feldspar basalts, and only a few very small amounts of nephe- 
lite possibly existent as a glassy base. . Assuming, therefore, 
that the material was homogeneous, two hypotheses present 
themselves to account for the anomalies observed. 

One is that the Linosa mineral is to be regarded as a distinet 
species, chemically, of the formula Na,Ca,AJ1,Si,O,,, but with 
physical properties which correspond very closely to those of — 
a plagioclase of the composition Ab,An, to Ab,An,. The 
uniformity of the material as shown by the specific gravity 
and the chemical analyses and, above all, the very close approach 
to exact rationality of all the ratios, are in favor of this view. 
But the pecutiarities of chemical composition are explicable in 


Washington and Wright—Feldspar from Linosa. 59 


another way, and as it would be contrary to our notions of the 
definitions of mineral species to consider two chemically similar 
minerals as distinct which possess essentially identical crystallo- 
graphic form and physical and optic properties in so many 
respects, we may also disregard this hypothesis. 

The alternative view is that the mineral is a labradorite of 
abnormal optic characters and chemical composition, due to the 
presence of another mineral in intimate molecular mixture as a 
mixed crystal or solid solution. The amount of this must be 
small, and in its optic characters the subordinate mineral should 
presumably resemble a plagioclase, since the optic constants of 
the Linosa mineral are essentially those of a lhme-soda feldspar, 
but indicate a composition somewhat more sodic than that 
indicated by the specific gravity. 

The range of possibilities as to the mineral molecule which 
may be supposed to be admixed molecularly with the labrado- 
rite is very limited, as it must be, chemically, an alumino- 
silicate of either soda or lime, or of both of these, with alumina 
equal molecularly to the basic oxide or oxides, ‘and with the 
ratio of silica to bases less than in labradorite. Furthermore, 
it seems necessary to assume that the base is soda alone, because 
if the subordinate mineral is purely calcie, all the soda entering 
albite, the lime must be equally distributed between the mole- 
eules CaO.A1,O,.2SiO, (anorthite) and CaQ.Al],O,.SiO,, to 
obtain the ratios and percentages shown by our mineral. This 
ealcic subsilicate is not known to occur either in nature or 
artificially, its nearest analogue being kornerupine, MgO.A1]1,0,.- 
SiO,, and its existence does not seem probable. Also no 
mineral in which CaO+Na,O = Al,O, is known which suits 
the requirements of the case. 

The sodium-aluminum metasilicate, Na,O.A],O,.4810,, occurs 
in nature as jadeite, and might also presumably exist as an 
isometric and isotropic soda-leucite. The presence of this 
molecule would yield a composition identical with that of our 
mineral, if soda is equally distributed between this and albite, the 
whole forming the mixture: Na,O.A1,O,.6S8i0,+ Na,O.A1l,O,.- 
48i0,+4(CaO.Al,O,.28i0,). But the presence of either of these 
mineral molecules may be considered as impossible here, on 
crystallographic as well as on optic grounds. 

The most probable mineral molecule, therefore, is the ortho- 
silicate Na,O.A1,O,.28i0,. Assuming this to be present, the 
composition of the Linosa mineral in terms of mineral mole- 
cules can be calculated to be as follows : 


WAIST e 1-016)". : . Pals) 
NaAlSi,O,... °137 vas Le 36:16 
Cy cis cae 192 9°84 53-7 
Ne AIO Ge. -019>..- 1-00 5-5 


60 Washington and Wright—Ffeldspar from Linosa. 


Reckoning the small amount of potash as orthoclase with 
the albite molecule, the ratios of albite, anorthite and sodium 
alumino-metasilicate approximate closely to whole numbers, and 
are almost exactly 8:10: 1. The labradorite would thus have 
the composition Ab,An,, while we have seen that the optic 
data indicate that the mineral is actually somewhat more sodic, 
from about Ab,An, to Ab,An,. 

The molecule Na, Al, Si ,O, 1s that of potash-free nephelite, 
which does not seem to occur in nature, but which has been 
made artificially in small hexagonal crystals, much like those 
of nephelite, and with a specific gravity of 2°555.* If this 
mineral were present it would necessarily be as a mechanical 
mixture or as what has been termed + an “anomalous solid 
solution,” since it is not crystallographically isomorphous 
with the triclinic albite and anorthite, and true solid solution or 
a mixed erystal, containing such an amount of the subordinate 
mineral as shown above, would hardly be expected in such 
dissimilar minerals. 

True solid solution could take place, however, if the mole- 
cule Na, Al,Si,O, is dimorphous, and a second form exists whose 
symmetry relations approximate those of anorthite and albite. 
The two formulas 


Anorthite, CaO.A1,O, 2510, 
Nephelite, Na,O.A1,O,.28i0, 


are identical, except that in the second Na,O replaces the CaO 
of the first, and it is not out of the range of possibility that 
a soda anorthite should exist. This mineral is not yet: 
known to occur in nature, but its presumable characters 
would harmonize the conflicting data. Thus, it should be’ 
triclinic and isomorphous with albite and anorthite, and there- 
fore capable of forming mixed crystals with these analogous to 
the ordinary plagioclase series. Similarly, it would presumably - 
possess optic characters more sodic, that is, more like those of 
a soda-lime feldspar, than those of purely ecalcic anorthite; so 
that we would thus have an explanation of the fact that, while 
the relations of CaO and Na,O in our mineral are those of 
Ab,An,, certain of the optic characters are those of a more 
sodic plagioclase. Since the specific gravity of nephelite, and 
presumably also of the soda anorthite, is less than that of 
anorthite, the density of the mixed crystal should be less than 
that of the equivalent plagioclase in which no soda anorthite 
occurs, and we have seen that, while the normal plagioclase 
present is about Ab,An,, which would have a density of 2°698, 
the density of our mineral is that of Ab, An, or Ab,An,. 


* Cf. Hintze, Mineralogie, vol. ii, p. 97. 
+ A. Johnsen, Neues Jahrbuch, 1903, ii, p. 93. 


Washington and Wright—Feldspar from Linosa. 61 


From the above data on the percentage composition in terms 
of the different mineral molecules (Or, Ab, An, Ne), the 
specific gravity of the mineral can be calculated on the assuinp- 
tion that no great volume change in the component molecules 
has taken place, a condition which experience has shown to 
hold true for practically all cases of solid solution. The weight 
per cent of each molecule present, divided by its density in 
erystallized condition, furnishes its speciiic volume or its 
volume compared with water of esnal weight. The sum of 
these specific volume values for all the molecules present 
denotes in turn the specific volume of the substance, the 
reciprocal of which is the density required. In this calculation 
the most accurate density determinations of the components 
were used, namely: Or = 2°55, Ab = 2°605, An = 2°765, and 
Ne = 2-571 (the last determined on artificial triclinic Na, Al.,- 
Si,0,). The resulting density, 2°685, approximates very closely 
the measured density, 2°693, and is almost identical with this 
as corrected for the magnetite inclusions, 2°684. This in itself 
is a strong proof that the Linosa mineral is a mixed crystal of 
feldspar and soda anorthite. 

This complex mineral would belong logically to the group 
of feldspars, just as do the barium-bearimg members of the 
orthoclase-celsian series, some intermediate members of which 
are called hyalophane, and which contain the molecule 
BaAl,Si,O0,. In this connection it is interesting to note that 
a sodium-barium plagioclase, described by Des Cloiseaux,* was 
erystallographically similar to albite-oligoclase, optically like a 
labradorite, and with the oxygen ratios of andesine. Mention- 
ing this mineral, Rosenbusch}+ points out that, as celsian is 
monoclinic, the barium alumino-silicate must be. dimorphous. 

The Linosa mineral would thus be a representative of a dis- 
tinct and hitherto unrecognized triclinic feldspar series, char- 
acterized by the joint presence of molecules of albite, lime 
anorthite, and soda anorthite. Reckoning in with the soda 
the small amount of potash present, and distinguishing the 
lime and soda anorthites as Can and Nan respectively, our 
feldspar would have the composition Ab,Can,, Nan,. 

Regarded as a feldspar of such abnormal character, and 
especially if the assumption is verified that soda anorthite is 
present and that we are dealing with a representative of a new 
feldspar series, the Linosa mineral is deserving of a new name. 
For this we propose anemousite, after the ancient Greek name 
of the island. The term anemousite would imply, of course, 
not only a feldspar with the exact composition given above, 
but, like hyalophane, oligoclase, labradorite, etc., couid be 

* Tscherm. Min. Mitth., p. 99, 1877. 
+ Mikr. Phys., vol. i, part ii, p. 313, 1905. 


62 Washington and Wright—Feldspar from Linosa. 


applied to feldspars composed of the three molecules men- 
tioned in somewhat varying ratios. If more representatives of 
the series are discovered, these limits might be more sharply 
defined, centering round the composition of the present ease. 

The very close approach to stoichiometric ratios of the 
oxides may seem to be inconsistent with the view that the 
mineral is an isomorphous mixture or solid solution. It is, 
however, in harmony with the well known fact that solid solu- 
tions tend to form with their elements in simple ratios, in 
which case they possess greater stability, giving rise to the sub- 
stances known as molecular compounds. This is exemplified 
in many mineral groups, such as the plagioclases, pyroxenes, 
olivines, nephelite, and the calcite group, the intermediate 
members of which are very apt to show simple ratios of the 
end components. 

The tact that soda anorthite is not known to occur inde- 
pendently in nature cannot be brought up against the hypoth- 
esis of its presence in this case, as the assumption of the 
presence of a molecule unrepresented by itself in nature is not 
uncommon in explaining the constitution of many complex — 
mineral groups. Its non-existence as a mineral may be best 
explained on the ground that the conditions necessary to its 
formation seldom obtain, the physical conditions being gen- 
erally such that the more stable nephelite is formed in its 
stead. 

Assuming the presence of the soda-anorthite molecule, it is 
certainly remarkable that it does not appear to have been 
detected as yet among the hundreds of chemical analyses 
which have been made of the feldspars. It would seem to be 
certain, at least, that it does not enter into the composition of 
many of these, so far as known, and that, if present at all, it 
forms only a very small percentage of the feldspar substance, 
so that its effect in altering the silica ratios would either be 
overlooked or attributed to impurities or analytical error. 

It is a plausible, and indeed reasonable, supposition that we 
have to do here with a case of imperfect isodimorphism or 
limited miscibility, as it is termed,* instances of which have 
been investigated by Retgers and others. As stated by Groth: 
“Tf the temperature intervals for the stability of the indi- 
vidual modifications of two substances differ so widely that, 
under the conditions ruling during the crystallization, the cor- 
responding state of the one substance is metastable, then as a 
rule this substance can crystallize along with the other in the 
form which is stable for it [the other], but only to a limited 
extent.” This is illustrated by monoclinic FeSO,7H,O and 


*Cf. P. Groth, Introduction to Chemical Crystallography, New York, 
1906, p. 92. 


Washington and Wright—feldspar from Linosa. 68 


orthorhombic MgSO,.7H,O. Monoclinic mixed erystals with 
the form of the former can be obtained with up to 54 per cent 
of magnesium sulphate, indicating the existence of a mono- 
elinie form of this salt. Then a gap occurs, until we obtain 
orthorhombic mixed crystals with 81 to 100 per cent of the 
magnesium salt, showing the existence of an orthorhombic 
ferrous sulphate. Very. unstable monoclinic crystals of the 
magnesium salt have been prepared, but orthorhombic ferrous 
sulphate is as yet unknown in the free state. An analogous 
ease is that of rhombohedral sodium nitrate and. orthorhombic 
silver nitrate. Rhombohedral mixed crystals have been pre- 
pared containing up to 52°5 per cent of silver nitrate, while 
orthorhombic erystals containing only up to 4:5 per cent of 
sodium nitrate have been obtained. In accordance with these 
results, no orthorhombic modification of sodium nitrate is 
known, but the pure rhombohedral silver salt is formed from 
fusion on cooling. 

Analogously we can suppose that Na, Al,Si,O, and CaA1,Si,O, 
are isodimorphous, each forming hexagonal and triclinic modi- 
fications. Of these, however, only the hexagonal form of the 
sodium salt and the triclinic form of the calcium salt are stable 
under ordinary pyrogenetic conditions, while the converse 
forms are metastable and capable of existence in mixed er ystals 
with the other only in small amount. and within a very narrow 
range of temperature or other physical conditions. The eal- 
cium almost always present in nephelite, up to about two per 
cent, may be thus regarded as existent as hexagonal calcium 
nephelite,* which must possess a_very limited degree of stabil- 
ity, while the stability of the triclinic modification of the 
sodium salt is apparently somewhat greater, to judge from the 
percentage shown by anemousite. 

It is obvious that the existence of soda anorthite and its 

presence in the lime-soda feldspars, or the possibility of the 
assumption by these of other molecules in solid solution, would 
have a very important influence on determinative miner alogy 
and petrography. The optic characters of such an abnormal 
feldspar would not indicate its true chemical composition in 
accordance with the tables and diagrams in use at present, as 
the feldspar would be apparently more sodic than it is in reality. 
The optic determination of the soda-lime feldspars in thin sec- 
tion would thus not be the comparatively simple and unerring 
matter that itis now supposedsto be, as the possibility of the 
presence of soda anorthite and its influence on the optic con- 
stants would have to be taken into consideration. The recogni- 
tion of celsian introduces a similar uncertainty. 


* Morozewicz (op. cit., p. 988) and others consider the calcium as replac- 
ing the sodium in nephelite. 


64 Washington and Wright—Ffeldspar from Linosa. 


Again, assuming the possibility of existence of soda anorth- 
ite, it would presumably depend on the conditions controlling 
during crystallization, whether the sodium-alumino orthosili- 
eate would crystallize as nephelite in separate individuals, or 
as soda anurthite im mixed erystals with albite and anorthite. 
With identical chemical composition of the rock, we would 
have in the one case a nephelite tephrite, and in the other a 
feldspar basalt, but the norms of both would be the same and 
would show normative nephelite, since nephelite and soda 
anorthite are normatively the same molecule. We might 
explain in this way the anomaly of certain holocrystalline 
rocks containing plagioclase, the norms of which show considera- 
ble nephelite, though none of this mineral is present in the 
mode; and this may be applied to the normatively nephelitic 
feldspar basalts of Linosa itself. In some cases, of course, the 
discrepancy is to be attributed to the readjustments of the ~ 
normative molecules due to the formation of other modal 
minerals. and the case is mentioned as illustratmg some of the 
petrographic possibilities consequent on the existence of soda 
anorthite. 


The points brought out in the preceding paragraphs indicate 
the importance and necessity of the verification of the assumed 
existence of soda anorthite, before any modification is called 
for of our ideas in regard to the composition and constitution 
of the soda-lime feldspars, based as these are on the large 
amount of accurate work by Tschermak, Schuster, Fouqué, 
Michel Lévy, Fedorow, and others. The very general agree- 
ment of the observations of all these workers with the theory 
that only mixtures of NaAISi,O, (albite) and CaA1,Si,0, 
(anorthite) are involved is strong evidence in favor of its gen- 
eral truth, and points to the conclusion that, if present at all, 
the amount of soda anorthite must be very small in most feld- 
spars so far examined. On the other hand, the occasional very 
notable divergences from the figures demanded by the pre- 
mises and the variability of the feldspars optically, indicate 
the possibility of the presence of some modifying constituents 
one of which might well be the molecule suggested by us. 


The Formation of Soda Anorthite. 

Fouqué and Michel Lévy* succeeded in 1880 in producing 
oligoclase, labradorite, and anorthite containing strontium, — 
barium and lead, instead of calcium, but they did not appar- 
ently attempt the formation of soda anorthite. 

* Synthése des Minéraux et des Roches, Paris, 1888, p. 145. 


Washington and Wright—Feldspar from Linosa. — 65 


The possibility of the existence of this mineral seems to have 
been first pointed out by Lemberg,* though he did not succeed 
in preparing it, and he remarks on its probable instability 
under ordinary conditions. 

Soda anorthite seems to have been actually formed by 8. J. 
Thuguttt by heating artificial “nephelite hydrate” to a white 
heat, followed by rapid cooling. A erystalline melt was 
obtained which contained lath-shaped sections of an apparently 
triclinic mineral, which showed numerous polysynthetic twin- 
ning lamelle, with extinction angles of about 386°. The pho- 
tomicrographs in Thugutt’s paper show clearly sections of this 
twinned plagioclase-like substance. . 

E. Escht describes a nephelite in the nephelinite from the 
Etinde volcano in German Kamerun. This nephelite shows 
extraordinary optic properties, and in all probability is tri- 
clinic, the crystals being intricately twinned so as to resemble 
an apparently simple nephelite crystal. The individuals are 
biaxial, with small optic axial angle, optically negative, and so 
twinned that basal sections are often divided into sextants, one 
of which may be normal to a negative acute bisectrix, while 
the opposite sextant is then about normal to the positive obtuse 
bisectrix. From this behavior, combined with large extinction 
angles, Esch considers the mineral to be triclinic. 

It may also be noted, as germane to the present subject, that 
the corresponding potassium alumino-silicate, K,A1,Si,O,, has 
been produced artificially in several modifications which differ 
erystallographically from the natural mineral kaliophilite.§ 
One of these, formed by Lemberg and examined by Lagorio, 
was in aragonite-like twins, resembling those of the Etinde 
nephelite. Another was isometric, while those formed by 
Weyberg were prismatic and possibly tetragonal. 

In the Geophysical Laboratory, soda anorthite was first 
obtained in 1905 by Dr. Allen by fusing together the com- 
ponent oxides in proper proportions. The resulting glass was 
clear and brilliant| but contained bubbles here and there, and 
although it softened gradually at high temperatures it was not 
as viscous as albite glass. The power of crystallization of 
this substance from the pure melt is not so great as that of 
many silicates, owing to its high viscosity. The glass was 
erystallized by heating it to 1080°, and was examined by 

* Zeitschr. deutsch. geol. Ges., vol. xl, p. 641, 1888. 

+ Neues Jahrb., Beil. Bd. ix, p. 561, 1894. 

t Sitzb. Berl. Akad., vol. xviii, p. 400, 1891. 

§$ Cf. Z. Weyberg, Centralblatt Min. etc., p. 395, 1908. 

| For a determination of the refractive indices of this glass, the writers 
are indebted to Mr. E. S. Larsen, of the Geophysical Laboratory. His 


values were obtained by the minimum deviation method with a polished prism 
of the glass. The results were: n,, = 1°5181, n,, = 1°5148, n,, = 10208. 


Am. Jour Sci.—Fourts Srerizs, VoL. X XIX, No. 169.—Janvary, 1910. 
5 


66 Washington and Wright—Feldspar From Linosa. 


Wright at the time. It varied in granularity and, except for 
occasional patches of more crystalline material, was too fine 
for optic determinative work. No separate crystals were 
obtained and no goniometric measurements could therefore be 
made. Since 1905 repeated experiments have been made with 
the crystallization of this substance from the melt, and also 
by heating the glass at different temperatures, but the results 
of the optic examinations have been practically the same in 
each case, and the different experiments need not be con- 
sidered in detail here. 


Fie. 1. 


Fic. 1. Polysynthetic albite-like twinning on artificial soda anorthite. 
Nicols crossed. Magnification 85 diameters. 

The most characteristic feature of this form of Na,A1,Si,O, 
is its polysynthetic twinning, which in many instances closely 
resembles that of the plagioclases (fig. 1). On other sections 
the cross grating twinning of microcline is developed, and if 
encountered in a rock section might easily be mistaken for this 
(figs. 2 and 3). The extinction angles on such polysyntheti- 
cally twinned individuals ranged up to 44° on symmetrically 
extinguishing sections, the angles between the (c) ellipsoidal 
axes of adjacent lamelle being 88°. As in the plagioclase 


Washington and Wright—Ffeldspar from Linosa. 67 


lamellee, the extinction angles in the zone of symmetry varied 
with the position of the sections, and the symmetrical extinc- 
tion angles most commonly observed ranged between 35° and 
40°, the ellipsoidal axis c being next the twinning junction line 
in each case. 

In many of the sections showing apparently albite twinning 
lamellee, a second set of polysynthetie lamellee often appeared, 
making ‘usually angles of 57° to 63° with the first, and so dis- 
tributed in the lamellee of the first set as to be sy mmetrical to 


Hic. 2. 


Fic. 2 . Polysynthetic microcline-like twinning on soda anorthite. Nicols 
exossed. Mag. 75 diameters. 


its planes of twinning. Thus, if the lamelle of the first set 
(albite lamellee) are placed in a north-south direction, then in 
Jamella No. 1 of this set the lamellee of the second set trend N. 
60° E. approximately, while im the adjacent lamella No. 2 of vo 
first set the lamellee of the second set trend N. 60° W., the N.- 

direction acting as a plane of symmetry. The positions i 
extinction of the interposed lamellae in any given twinning 
band of the first set agree closely with the extinction positions 
of the immediately adjoining second lamelle of the first set. 


68 Washington and Wright—Ffeldspar from Linosa. 


The general tendency of this involved twinning is to produce 
a hexagonal network of interpenetrating lamellee, but ordi- 
narily one set predominates and the other sets appear only 
dimly outlined in the background. 

As aresult of this complicated twinning, single individual 
grains suitable for optical work were rarely observed, and were 
then too small for accurate measurements. Optic axial angle 
determinations were influenced particularly by this condition, 
and although much time was spent in searching for suitable 


Iie. 3), 


Fie. 3. Polysynthetic twinning on artificial soda anorthite. Nicols 
crossed. Magnification 75 diameters. 
sections, the angular values obtained varied considerably. The 
most probable value for 2V is about 36°45°. The optie 
character is negative. The refractive indices were determined 
by the immersion method: a = 1:516+£:003, y = 1°520+-003. 
The birefringence is weak and was measured on several sec- 
tions, the highest value for a-y being 0°0042. 

The specitic gravity of soda anorthite was determined by 
the pycnometer method of Day and Allen, and the value 
2-571 at 25° was obtained. 


Washington and Wright---Keldspar from Linosa. 69 


Experiments on the melting temperature of soda anorthite 
have been made, and also on the relation between soda 
anorthite and nephelite, whether they are monotropic or enan- 
tiotropic, but the results are not yet decisive, and mention of 
them will be deferred until more definite information is at 
hand. 

In one of the preparations crystallized at about 1100°, single 
grains free from twinning were observed, which proved to be 
uniaxial and optically negative, and similar to nephelite in 
other properties, except that the refractive indices were very 
shghtly lower. Artificial nephelite has been produced by 
several workers.* 

The effect of an impurity, or of the presence of other sub- 
stances, on the stability of soda anorthite has not yet been 
determined. It is, however, of interest to note that, while soda 
anorthite crystallizes invariably out of the pure Na,Al,8i,0, 
melt, crystals obtained by melting down natural nephelite from 
Magnet Cove, Arkansas, and then allowing it to crystallize, 
were uniaxial and optically negative, and agreed in optic 
properties with the original nephelite. Natural nephelite is 
not the pure sodium salt, contains but notable but varying 
amounts of potassium as ever-present and essential constitu- 
ent, and from its melt not a trace of the triclinic form was 
observed to crystallize out. 

It is to be hoped that eventually well-developed crystals of 
soda anorthite will be obtained suitable for precise optic and 
goniometric work, because then its relation to the plagioclase 
feldspars, whether isomorphous or not, can be positively 
determined. ‘ihe fact of its notable solid solution in the Linosa 
plagioclase, the similarity in twinning phenomena, refrac- 
tive indices, birefringence, specific gravity, triclinic symmetry 
relations, and also in the chemical formulas, are strong argu- 
ments in favor of close crystallographic resemblance and 
probable isomorphous relations between soda anorthite and 
the plagioclase feldspars. 

In the preceding pages the name soda anorthite has been 
applied to the triclinic phase of Na,A1,Si,O,, this having been 
used previously by Lemberg and Thueutt. "While this name 
has some justification by analogy, and might serve as a pro- 
visional designation, yet it is open to serious objections. In 
the first place it is not in harmony with the usual nomencla- 
ture of the feldspars, soda orthoclase, for stance, signifying 

* Fouqué and Michél Levy, C. R., Ixxxvii, p. 961, 1878; xc, p. 698, 1880 ; 
and Bull. Soc. Min. Fr., ii, p. 116, 1879; and iii, p. 118, 1880; Hautefeuille, 
Ann. de l’Ecole Monn. Supér., ix, 1880: Bourgeois, Ann. Phys. Chim., 1885, 


p. 19: Doelter, Zeitschr. Kryst., ix, p. 321, 1884; C. and G. Friedel, Bull. 
Soc. Min. Fr., xiii, p. 129, 1890. 


70 Washington and Wright—feldspar from. Linosa. 


not a purely sodie monoclinic feldspar, but an orthoclase in 
which sodium partially replaces potassium. Also if, as is prob- 
able, the presence of this Na,AI,8i,O, molecule is verified in 
other feldspars, the use of the term soda anorthite will be apt 
to lead to awkwardness and ambiguity. The compound name, 
furthermore, does not lend itself to the formation of an appro- 
priate symbol, as Ab, An, and Or, for use in feldspar formulas ; 
and finally the new triclinic feldspar, which has been actually 
formed in a pure state, and which we have shown to be capa- 
ble of existence in nature in mixed crystals, is of such practical 
and theoretical importance as to deserve a special and distine- 
tive designation. For these reasons we propose to substitute 
for the earlier and essentially descriptive term soda anorthite, 
applied to the triclinic form of Na,AI,Si,O,, the name Carne- 
gierte (symbol Cg), in honor of the founder of the Institution 
under whose auspices the mineral was collected and the present 
investigations were undertaken. 
Locust, New Jersey, and 


Geophysical Laboratory of the 
Carnegie Institution of Washington, D. C., October, 1909. 


Greger—Lare and Imperfectly Known Brachiopods. 71 


Art. Vi.—Some Rare and Imperfectly Known Brachio- 
pods from the Mississippian; by Dariine K. Greeer. 


Tue four species of Brachiopoda which are figured here 
have caused not a little confusion to collectors of Mississippian 
fossils, the writer having frequently observed them severally 
labeled as the Phynchonella ringens of Swallow, in local col- 
lections. That the shell described by Prof. Swallow under 
the name above referred to may be definitely known, and that 
a distinctive appellation may be had for the forms long con- 
fused with it, is the object of the present paper. 


Camarophoria ringens (Swallow). Figs. 7, 8. 


Rhynchonella ringens Swallow, 1860, Trans. Acad. Sci. St. L., Vol. I, 

page 653. 

Original description. Shell large, thick, triangular, pli- 
cated, truncated and flattened in front. Ventral valve flat- 
tened, triangular; the anterior and the posterior lateral margins 
abruptly turned up to meet the dorsal valve: the anterior lat- 
eral margins curved downin the opposite direction; beak acu- 
minate; sinus wide and_ shallow, containing about eight 
plications. Dorsal valve more convex ; anterior and posterior 
lateral margins abruptly turned down to meet the opposite 
valve; strongly arched towards the anterior lateral margins. 
The juncture of the valves is sharply and deeply serrated. 
Surface marked with about fourteen large plications on each 
valve. Length, 1:90; breadth, 1°48 ; thickness, 0°99.” 

The plications all have their origin at orenear the beak and 
increase in size as they approach the front, the number occupy- 
ing the sinus and fold being quite variable; their number is 
never increased either by implantation or bifurcation over the 
body of the shell. 

The specimen we figure is from the Boyce collection and 
bears a label written by the late Prof. Swallow ; and while it is 
not so large as the type, we have no reason to ‘doubt its being 
the species to which his description applies, since we have col- 
lected from the Burlington cherts of Callaway county numer- 
ous single valves that equal the dimensions given by the 
author. Locality and horizon of the figured specimen, and a 
number of others in our collection—East of New Bloomfield, 
Callaway county, Mo., in residual cherts of the Burlington 
limestone. 

That the shell figured by Dr. Girty* from the Madison 


* Monograph U.S. G.S., vol. xxxii, pt. 2, 1899, p. 587, pl. lxix, figs. 1°, 
fr Te: 


72 Greger+Rare and Imperfectly Known Brachiopods. 


limestone is not conspecific with Camarophoria ringens is 
obvious if one follows the description with care, but whether 
Dr. Girty’s shell should be referred to our Paraphorhynchus 


Kies, 112: 


// 
gibbosum, or to the species described by Dr. White* under 
the name Lehynchonella caput-testudinis, we are not in a posi- 
tion to state, nor are we willing to risk the placing of either in 


the genus Paraphorhynchus, since practically nothing is 
known of their internal structure. However, Dr. White’s 


* Proc. Boston Soc. Nat. Hist., 1862, vol. ix, p. 28. 


Greger— Rare and Imperfectly Known Brachiopods. 73 


description of the exterior of his shell would suggest a species 
of Paraphorhynchus; he says “* * * surface marked by 
from sixteen to eighteen distinct somewhat rounded plications 
on each valve, which mostly reach the beak with some distinct- 
ness, but are occasionally increased both by implantation and 
bifureation ; they are traversed by fine radiatiug lines and 
erossed by fine concentric lines of growth.” 


Camarophoria arctirostrata (Swallow). Figs. 11, 12. 


Rhynchonella arctirostrata Swallow, 1868, Trans. Acad. Sci. St. L., Vol. II, 
page 34. 

This species was described by Prof. Swallow from material 
collected at Boonville, Mo., from the Keokuk limestone. The 
original description reads as follows: “Shell triangular or 
cuneate, valves nearly equal, costate, striate. Ventral valve 
most convex towards the beak, which is long, pointed, and 
strongly incurved. Dorsal valve most convex in front; beak 
small, pointed, and strongly incurved. Both valves flattened 
in the middle, and bent abruptly near the margins, forming 
perpendicular subrectangular faces on the sides and one more 
or less convex and rounded on the front. Each valve marked 
with from fourteen to sixteen rounded, radiating, plications, 
which extend to the beak—two or three implanted—and are 
ornamented by fine longitudinal striee, and by obsolete concen- 
tric folds. The angle at the beak very variable.” 

Our figures are from specimens collected at the type locality 
and labeled by Prof. Swallow, being a part of the Boyce col- 
lection. Average measurements are as follows: length, 15™™; 
breadth, 15°"; thickness, 12™™. 

The general outline of this species at once recalls Camaro- 
phoria subcuneata Hall, which fact was noticed by Prof. Swal- 
low, but the peculiar, interrupted, hair-like lines on the plications 
at once removes the possibility of its belonging to Hall’s 
species. Prof. Swallow’s statement that the ribs are orna- 
mented by longitudinal striz is correct only in a sense, since 
the striz are not only interrupted but are also inclined to 
curve down to the interradial grooves. Sinus and fold obso- 
lete or wanting in this species. : 


Paraphorhynchus gibbosum sp. nov. Figs. 1-6. 
Rhynchonella sv. Keyes, 1894, Mo. Geol. Surv., Vol. V, pl. xli, figs. 8 a—b. 


Shell elongate-ovate, very gibbous, greatest width at or 
anterior to the median line, fold and sinus obsolete or wanting 
in most examples. Valves ornamented with a few coarse ribs, 
irregular in number and position, increased by implantation 


74 = Greger—Lare and Imperfectly Known Brachiopods. 


and bifureation, entire surface covered with fine longitudinal 
striz, valve margins sharply serrate. Pedicle valve inflated, 
flattened in the middle, gently curved upwards in the anterior 
and posterior regions with the posterio-lateral margins inflected, 
beak somewhat prominent and pointed. Brachial valve 
decidedly more gibbous than the former, beak less prominent 
and obscured by that of the opposite valve, posterio-lateral 
margins inflected or flattened, corresponding with the opposite 
valve. 

This is one of the very rare brachiopods of the Burlington 
limestone and well preserved specimens are seldom met with ; 
it is only in specimens retaining the exterior uninjured that 
the delicate longitudinal striz are to be observed. 

Our collection contains specimens from Louisiana, Mo., and 
Hannibal, Mo., the last being the locality from which Dr. 
Keyes obtained his specimens. Figures 1, 3, and 4 are of the 
largest so far observed, measuring: length, 39"™; breadth, 25™™; 
thickness, 28™™. 


Paraphorhynchus ovatum sp. nov. Figs. 9-10. 


Shell elongate-ovate, greatest width anterior to the median 
line, vertically compressed, the transverse diameter always 
greater than the vertical, fold and sinus obscure, producing 
only a slight sinuosity in the marginal line. Surface orna- 
mented with eighteen to twenty low rounded ribs, which have 
their origin near the beak, growing constantly larger as they 
approach the front; the surface is further ornamented by fine ~ 
longitudinal striz, three or four in the space of one milli- 
meter. 

Pedicle valve but slightly inflated, sloping gently from the 
center to the anterior and anterio-lateral margins and some-_ 
what more abruptly to the posterior end; posterio-lateral mar- 
gins inflected, beak not prominent, incurved. Brachial valve 
with less depth than the former, subequally sloping and 
inflected in the posterio-lateral region; beak small and blunt. 
Average dimensions of the specimens in our collection: 35™™ 
long, 27™™ broad and 16™" in thickness, the greatest thickness 
being in the umbonal region. 

Horizon and locality—Chouteau limestone, Kiesenger Bluff, 
Warsaw, Benton County, Mo. 


Greger—Rare and Imperfectly Known Brachiopods. 


D> OTs 0 0 


Sale! 


an 
Be 


EXPLANATION OF FIGURES. 


Paraphorhynchus gibbosum sp. nov. 


Brachial view of specimen from Hannibal, Mo. 
Profile view of specimen from Hannibal, Mo. 
Brachial view of large specimen from Louisiana, Mo. 
Profile view of specimen from Louisiana, Mo. 
Brachial view of young specimen from Hannibal, Mo. 
Brachial view of specimen from Hannibal, Mo. 


Camarophoria ringens (Swallow). 
Posterior view of specimen from New Bloomfield, Mo. 
Anterior view of same. 
Paraphorhynchus ovatum sp. nov. 
Brachial view of specimen from Warsaw, Mo. 
Profile view of specimen from Warsaw, Mo. — 


Camarophoria arctirostrata (Swallow). 


Brachial view of specimen from type locality, Boonville, Mo. 


75 


Pedicle view of somewhat smaller specimen from same locatity. 


Figures ? natural size. 


Fulton, Missouri. 


76 T. D. A. Cockerell— Descriptions of Tertiary Plants. 


Arr. VIl.—Descriptions of Tertiary Plants, IIT; by 
T. D. A. CockERE Lt. 


A SorBus FROM FLORISSANT, CONSIDERED TO BE A HYBRID. 


Sorbus diversifolia (Lx.), fig. 1. 


Myrica diversifolia Lx., Cret. and Tert. Flora (1883), p. 148, pl. 
xxv, f. 6 (not Crateequs diversifolia Steud.; not Pyrus diver- 
sifolia Bong.). 

Crategus acerifolia Lx., Cret. and Tert. Flora, p. 198, pl. xxxvi, 
f. 10 (not C. acerifolia Moench). 

Orategus lesquereuxt Ckll., Bull. Torr. Bot. Club, 33 (1906), p 
311 (not Sorbus lesquereuxti Nath.). 

Onoclea reducta Ckll., Bull. Am. Mus. Nat. Hist., 24 (1908), p. 76 
and 108, pl. vi, f. A, 


TueE extraordinarily variable plant to which the above names 
have been applied is quite common in the Miocene shales of 
Florissant, at Station 14. A good leaf was also found by my 
wife at Station 20. In Knowlton’s Catalogue (Buil. U.S. 
Geol. Surv. No. 152) Myrica diversifolia is referred as a 
synonym to Crategus flavescens Newberry (newberryz Ckll.) ; 
but in his Fossil Flora of the John Day Basin, p. 66, 
Knowlton recognizes that while the John Day specimen 
referred to Myrica diversifolia by Lesquereux is undoubtedly 
C’. flavescens, the Florissant specimens are doubtfully identical. 
There occurs at Florissant (Station 14, W. P. Cockerell), a 
species of Crategus which I have provisionally referred to 
CU. newberryt, although the leaf is less deeply lobed, and it is 
not unlikely that the plant is distinct. This, however, has 
nothing to do with the true Myrica diversifolia, which is 
evidently identical with Crategus lesquereuar. A comparison 
of numerous specimens had convinced me that this well-named 
“ diver ee was a Pyrus in the broad sense, and probably 
a Sorbus; but I possessed no material exactly comparable, 
although I distinctly remembered having seen a similar living 
plant. During the past summer I was permitted to gather 
leaves in Kew ‘Gardens, and there at length I found what I had 
been looking for, labelled Pyrus pinnatifida var. fastigiata, 
and Pyrus newillyensis. These trees are hybrids between the 
Aucuparia and Aria sections of Sorbus. P. pinnatifida 
Ehrh. is properly called Sorbus hybrida Linne. It has the 
apical half of the leaf like Sorbus intermedia Pers. (Pyrus 
entermedia Ehrh.), while the basal half is variably cut into 
leaflets in the manner of the Aucuparia group. This occurs 
in Europe as a natural hybrid (¢utermedia K aucuparia). 


T. D. A. Cockerell— Descriptions of Tertiary Plants. TT 


There is a variety known as decurrens Koehne, in which only 
three to five of the upper leaflets are connate in a terminal 
lobe, which, like the separate leaflets, is decurrent at the base. 
Another variety is S. hybrida var. newillyensis (Dippel), 
(Pyrus newillyensis Hort.), of garden origin, having about 
four pairs of separate leaflets, those of about the apical third 
connate, but the leaflets not at all decurrent at the base. 

A related hybrid is Sorbus thuringiaca (Ilse) = Pyrus 
thuringiaca Ilse, with shorter leaves, as might be expected 
from the parentage, S. aucuparia X aria. In the fossils, the 
characters of these hybrids are reproduced with astonishing 
exactitude. The more common form is similar to S. hybrida, 


ine le Fie. 2: 


Fic. 1.—Sorbus diversifolia. Fig. 2.—Sorbus nupta. 


but narrower, and as in var. decurrens, the divisions are 
strongly decurrent at the bases, so much so that the leaflets are 
not wholly separated. In a form which I collected at Station 
14 (fig. 1), the lobing extends far toward the apex of the leaf. 
The form of the petiole, as well as the structure of the blade, 
is extremely similar in the fossil and recent leaves. Being 
thus wholly convinced that Sorbus diversifolia is a hybrid, I 
naturally sought for the parents. It was necessary to find in 
the shale species of the compound-leafed or Aucuparia type, 
and also the dentate, or slightly lobed Aria type. The first 
has already been published as Sorbus megaphylla Ckll., Bull. 
Am, Mus. Nat. Hist. 1908, p. 95, pl. 1x, f. 20.. The second, 
at first regarded as a mere variety of S. diversifolia, may be 
described as follows: 


78 TL. D. A. Cockerell—Descriptions of Tertiary Plants. 


Sorbus nupta sp. nov., fig. 2. 


Leaf-blade about 67™™ long, and nearly as broad, with short 
triangular lobes, the margin also sharply dentate. Structure 
and appearance of leaf exceedingly like that of the Italian 
S. crategifolia (Targ.-Tozz.) Wenzig, except that the Italian 
plant has the base of the leaf strongly cordate, whereas in 
the fossil it is strongly though narrowly decurrent on the 
petiole, extending for a distance of at least 10™™. The strong 
lateral veins are five or six pairs, as in S. crategifolia. The 
sharp teeth are perhaps a little more in the manner of S. dati- 
folia Syme (rotundifolia Auctt.). There is a strong resem- 
blance to S. entermedia in the lobing and toothing, but the 
shape of the leaf is different. 

Florissant, in the Miocene shales, Station 13 B (1908). 

S. dwersifolia is thus considered to be S. megaphylla X 
nupta. The only objection to this parentage appears to le in 
the fact that deversifolia leaves are normally narrower than 
those of hybrida, whereas from the breadth of S. nwpta one 
would expect them to be broader. 

There is reason to believe that the decurrent base of the 
leaf is a primitive character; the earliest form of leaf in the 
Pyrus group may perhaps have been narrow-lanceolate, like 
the living P. salicifolia Pall. from the Caucasus, which I had 
an opportunity of examining in the Cambridge Botanical 
Garden. From this, P. amygdaliformis Vill. (S. Europe) 
affords a transition to the more ordinary types. The extreme 
limit of modification is seen in Sorbus aucuparia var. laciniata 
(Pyrus aucuparia var. laciniata Hort. Kew.), in which the 
leaflets themselves are deeply lobed. 


Chemistry and Physics. 79 


SCIENTIFIC INTELLIGENCE. 


I. Curmistry AND Puysics. 


1. The Relative Volatility of the Bromides of Barium and 
Radium.—Stock and HeyNnEMANN have determined the temper- 
atures at which the bromides of calcium, strontium and barium 
begin to sublime in a quartz tube exhausted by the mercury pump 
as follows: 

Calcium bromide, about 720° C. 
Strontium bromide, “ 770 
Barium bromide, See?) 


These results showed that the temperature of sublimation rises 
with the atomtic weight of the metal in these cases, and it was 
inferred that barium bromide would sublime more readily than 
radium bromide. This was found to be the case by fraction- 
ally subliming several samples of barium bromide containing 
varying quantities of radium and determining the radium in the 
products by theelectroscopic method. For instance, a sample gave 
8°8 per cent of a sublimate containing 0:008 per cent of radium, 
while the residue, 88°2 per cent, contained 0°015 per cent of radi- 
um. In another case 17 per cent of sublimate contained 4°8 per 
cent of radium, while the 83 per cent of residue contained 6:6 
per cent of radium. The authors are of the opinion that frac- 
tional sublimation may be of practical use in the preparation of 
pure radium salts— Berichte, xlii, 4088. H. L. W. 

2. The Action of Light upon Hydrogen Chloride.—The 
action of light in causing the combination of hydrogen and 
chlorine gases is very familiar, hence it is suprising to find from 
the experiments of CozHN and WassiisEwa that ultra-violet 
light is capable of decomposing hydrochloric acid gas to some 
extent into hydrogen and chlorine gases. ‘These investigators, 
having previously found a similar decomposition of SO, into SO, 
and O,, passed pure HC! gas through a quartz tube, where it was 
exposed to the hight of a quartz-mercury=vapor lamp. The gas 
was then led through a blackened glass tube into potassium iodide 
solution where the liberation of iodine indicated the formation of 
chlorine, and the unabsorbed gas, collected in a eudiometer, was 
shown to be hydrogen. The decomposition of the hydrogen 
chloride in this way amounted to 0:25 per cent. No decomposi- 
tion was obtained when tubes of glass, instead of quartz, were 
used. Any suspicion that the liberation of chlorine here was 
due to the presence of atmospheric oxygen, which might give the 
reaction of the Deacon process, 4HC1+0,=2H,0+2Cl,, was 
shown to be without foundation since hydrogen was shown to be 
present.— Berichte, xlii, 3183. H. L. W. 

3. The Ratio between Urunium and Radium in Minerals.— 
Miz. Guepitscu has studied this question, which is important in 


80 Scientifie Intelligence. 


connection with the theory of the production of radium by ura- 
nium. Other investigators have concluded that this ratio is 
practically constant, but she has obtained the following results 
after making corrections for certain sources of error in her method: 


Radium : Uranium 


Krexnch-autumites:-= ae en ee 9°35 SC eae 
Joachimsthal pitchblende, ..---_-._-- 3°58 5c LOme 
Ceylon thorianite; 2° - == 222222525 2219) Gave 


While these results show magnitudes of the same order, they do 
not agree closely, and the author concludes that the determina- 
tion of the mean life of radium based upon the existence of a 
constant ratio between the uranium and radium in minerals can- 
not be considered exact. 

It may be observed in regard to this conclusion that the author 
does not appear to take into consideration the possible removal 
by solution of a part of the radium from the minerals. H. L. w. 

4. The Action of Radium Hmanation upon the Elements of 
the Carbon Group.—Ramsay and User, using the emanation 
produced in about a week from 1°2111¢. of metallic radium, have 
caused this to act upon solutions of silicon, titanium, zirconium, 
thorium, and lead compounds for periods of about four weeks, 
with the result that they believe that they have proven the pro- 
duction of carbon by this action. The following table shows the 
amounts of carbon found per cubic millimeter of emanation : 


Solution of Carbon, mg. 
ERSIR 2 22 a 
TSO) co. Coe eee 0-d82 
BESO Dn hs i cack Sale es ee 
Lee Se ea ee eee 2°93 
Th(NO,), rae SAL Re ee a 0°968 
Pb(ClO:) 5 2 


The carbon was found in the form of the dioxide, or as a mixture 
of this with the monoxide. The amount of CO, measured amounted 
in one case to more than 0°5°. ‘The authors state that mercurous 
nitrate gave no trace of carbon dioxide or monoxide, and that 
similar experiments are being performed with the compounds of 
other elements, 

It is probable that the statement in regard to this production 
of carbon from other elements will be received with much 
incredulity, because Sir William Ramsay’s previous assertion of 
the production of lithium from copper in a similar manner was 
not confirmed.— Berichte, xlii, 2930. H. L. W. 

5. Quantitative Chemical Analysis ; by CLowxEs and COLEMAN. 
8vo, pp. 564. Philadelphia, 1909 (P. Blakiston’s Son & Co.).— 
This English book, which is also issued in America, has passed 
through eight editions, with continual improvement and enlarge- 
ment, since its first appearance in .1891. It gives an introduction 


Chemistry and Physics. 81 


to the subject by describing the general processes and giving an 
extensive series of simple gravimetric determinations (here called 
estimations according to the British custom) suitable for the 
practice of beginners. The more important methods of volu- 
metric analysis are then taken up. The general yuantitative 
analysis covers a wide range of subjects, largely technical in 
character; the analysis of ores, metals, alloys, fuels, fertilizers 
and other products. It takes up also fire assaying, sanitary 
water analysis, the analysis of milk, butter, alcoholic beverages, 
sugar, tea, tanning materials, soap, oils, fats and waxes, and 
technical gas analysis. One section of the book is devoted to 
ultimate organic analysis and molecular weight determinations. 
Although some of the topics are necessarily treated rather 
briefly and incompletely, the book is an excellent one for giving 
the student practice in nearly all of the usual work of the analy- 
tical chemist. The methods are generally well selected and 
clearly described, but there are naturally some variations be- 
tween the British practice here given and what may be called the 
best American practice in analysis. The book has found extensive 
use as a text-book, and the new edition will doubtless be still 
more popular. HY EW? 
6. Positive lectricity—Sir J. J. THomson asks: — (1) 
Does a definite unit of positive electricity exist? (2) If so, 
what is the size of the unit ? This paper introduces a discussion 
upon these questions at the Winnipeg meeting of the British 
Association and therefore contains matter previously printed. 
There are, however, some new experiments upon the effect of 
magnetic fields on positive and negative rays, which led the 
author to elaborate theories in regard to neutral doublets. He 
concludes that even at the start from the cathode the “canal 
strahlen” include a large number of neutral doublets, if indeed 
they do not wholly consist of them. Much space is given to 
discussion of the neutral doublets, both in canal strahlen and 
retrograde rays, which proceed from the cathode toward the 
anode. It is supposed that these doublets are of the same 
character from whatever kind of gas they originate. Thomson 
refers to a former paper in which he showed that if a vessel was 
exhausted until the pressure was so low that the discharge 
would not pass, and small quantities of hydrogen, helium, air, 
oxygen, carbonic acid or argon were introduced so as_ to 
raise the pressure sufficiently to produce a discharge, the velocities 
of the particles were the same for all the gases. The paper 
closes with description of a method of measuring the effective 
magnetic field in the magnetic deflection of canal strahlen.— Phii. 
Mag., Dec. 1909, pp. 821-845. OTe 
7. Doppler Effect in Positive Rays in Hydrogen.—T. Royps 
has studied this effect, both in front and behind the cathode. He 
believes that the canal rays mostly start from the negative glow, and 
believes that the commencement of the cathode glow corresponds 
to the minimum Doppler effect when the cathode is viewed from 
AM. eg nets SERIES, VOL. XXIX, No. 169.—Janvuary, 1910. 


82 Screntific Intelligence. 


the anode side. After twenty hours exposure with a cathode fall 
of 2800 volts, he obtained a marked Doppler effect corresponding | 
to the positive rays approaching the cathode. This minimum 
velocity is not constant for different wave lengths, but is approx- 
imately inversely proportional to the square root of the wave 
length.— Phil. Mag., Dec. 1909, pp. 895-900. 571m 
g. Magnetic Rotation of Plane of Polarisation in the Ultra- 
ved.—Many investigations have been undertaken to put Fara- 
day’s experiment on a sound theoretical basis. Voigt has placed all 
such investigations in two classes, and the author of this paper, 
Ulfilas Meyer, discusses Drude’s theories, which are largely based 
upon the electron theory. He finds that with crystals of fluorspar, 
sylvin and rock salt, the amount of the turning of the plane of 
polarization diminishes with increasing wave length. At 8°85 p it 
is less than a minute for a thickness of the crystal of 1™ and a field 
strength of 10,000 Gauss units. The influence of ions on this turn- 
ing is very small in comparison to that of the ions. This con- 
clusion is reached from the ground of Drude’s view of the elec- 
tron theory, according to which ultra-red absorbtion arises from 
vibrating ions, while ultra-violet is excited by resonance of 
rotating electrons.— Ann. der Physik, No. 132, 1909, pp. 607-630. 
Spe 
9. Instantaneous X-ray photography.—FRieprich DussavER 
states the desirability of shortening the time of exposure to 
X-rays, and describes a powerful apparatus which he has devised 
for this purpose. It consists of a very large induction coil, fed by 
a powerful current which on arising to a proper value is quickly 
broken by a peculiarly constructed fuse. This fuse is a calibrated 
piece of wire which is surrounded by a moist covering consisting 
of a mixture of earths. When the wire heats, the water vapor 
is formed quickly under pressure and the fuse explodes with 
violence, breaking the current. The author recommends his 
method to physicians and has obtained Réntgen cinematographs 
of the movement of the heart.— Physikalische Zeitschrift, Nov. 
10, 1909, pp. 859-860. Leta 
10. Light and Sound; by Wm. 8. Franxuin and Barry 
Macnoutr. Pp. vill, 344. New York, 1909 (The Macmillan 
Co.).—This volume is a part of a series of elementary texts ; 
practically a revision of Nichols and Franklin’s Elements of 
Physics, which it is doubtless designed to replace. The pres- 
ent volume is the third of the new set: Mechanics having 
appeared in 1907, Electricity and Magnetism in 1908 and Heat 
being in course ‘of preparation. Improvement is noted in the 
relegation to an appendix of the more detailed discussion of lens 
systems, of radiation and the addition of 86 problems as exercises | 
on the several chapters. An excellent discussion of wave motion 
in general is illustrated by particular waves in water. A total of 
143 pages have been added. Much of the additional matter 
pertains to practical applications, on the importance of which to 
elementary students the authors express their opinion in the 


Geology. 83 


following words:—“A so called knowledge of elementary 
science which does not relate to some actual physical condition 
or thing is superlatively contemptible.” Dep Ag 
11. Direct and Alternating Current Testing ; by FREDERICK 
BeEDELL ; assisted by CLraRENCE A. Pierce. Pp. x, 265. New 
York, 1909 (D. Van Nostrand Co.).—To call this book a labora- 
tory manual of tests on direct and alternating currents, would 
not be doing it justice. The consideration given to the under- 
lying principles of the experiments, as well as to the significance 
of the results, places it both in the category of reference and of 
text books. It is not offered as an exhaustive treatment of the 
subject but is sufficiently comprehensive to give the student a 
good working knowledge. It presupposes only the usual college 
courses in physical and electrical measurements. The subjects of 
the seven chapters are :— D.C. generators; D.C. motors; synchron- 
ous alternators ; single phase currents ; transformers ; polyphase 
currents ; phase changers, potential regulators, etc. Other chap- 
ters on A.C. motors and converters are promised in a later 
edition. D. A. K. 
(12. Elements of Physics; by Henry Crew. Revised by 
Frankuin T. Jones. Pp. xiv, 435. New York 1909 (The 
Macmillan Co.).—This high school text is a revision of Crew’s 
original Elements of Physics and embodies much of his more 
recent General Physics. The insides of the covers contain the 
English and Metric systems of weights and measures, with tables 
of their equivalents. In the appendix are given 370 questions 
reproduced from examination papers of various high schools 
throughout the country. Definitions and leading statements are 
emphasised by bold-faced type, and numerous problems are 
embodied in the text. It is to be hoped that in the next edition 
the authors may eliminate such slips as ‘“‘knots per hr.,” “attraction 
of gravity, g,” “in physics rate always means ‘divided by time’ ”, 
and revise the somewhat misleading discussion of harmonic 
motion. Diy AK, 


Il. Gronocy 


1. Radio-activity and Geology. An account of the influence 
of radio-active energy on terrestrial history ; by J. Jory. Pp. 
287. London, 1909 (Archibald Constable & Co., Ltd.).—This 
book is an outgrowth of the author’s presidential address to Sec- 
tion C of the British Association and brings into one volume the 
present information regarding radio-activity in its bearings on 
geology. Geologists will consequently find it a most welcome 
volume since but few have the time or opportunity to follow in 
the physical journals the rapidly accumulating results of recent 
investigations. 

The first larger subject treated is that of radium in the earth’s 
surface materials. Many measurements have now been made on 


84 Scientific Intelligence. 


‘igneous and sedimentary rocks. The amount of radium varies, 
however, within wide limits, the abyssal radiolarian ooze and red 
clay being especially high. As radium loses half its mass in 1760 
years while its ultimate parent uranium takes five billion years for 
the same loss, it is seen that the radium in the rocks is really a 
measure of the contained uranium. Strutt, extending the work of 
Rutherford, has shown that the radio-active materials in the crust 
exist in sufficient abundance so that a crustal layer less than 100 
miles in thickness would continually supply the quantity of heat 
which the earth loses to space (45 miles in the original estimate). 
Joly argues, therefore, that the uraninm must be concentrated in 
the outer crust of the earth. Consequently where this concen- 
trated zone is depressed by the accumulating sediments of a geo- 
syncline, the loss by conduction being lessened, the temperature 
must rise. Local excesses as in the Simplon tunnel are also 
thought to play an important part in determining local tempera- 
ture gradients. Joly further argues that the instability of the 
earth’s crust and the ocean floor are also due chiefly to uranium 
and radium becoming more deeply buried. 

Another chapter of great geological interest is that on uranium 
and the age of the earth. Considering helium and lead as the 
ultimate disintegration products of uranium, measurements of 
their amounts in uranium minerals, while varying among them- 
selves and pointing to the need of further research, agree in givy- 
ing much larger values to geological time than estimates based 
upon denudation and sedimentation. 

Throughout the volume, the author, while arguing for the 
large influence of radio-activity, shows a spirit of fairness and 
caution. But there is room for so many possibilities in the 
underearth, which he does not discuss, that a large degree of 
skepticism may be maintained toward many of his conclusions. 
Of the geological importance of radio-activity there can be no 
doubt and it seems adequate to more than account for the tem- 
perature gradient, so that instead of a cooling earth we may come 
to face the possibility of a heating earth. But the deep-seated 
distributions of energy, pressure and mass traceable to earth 
origin, whatever that may be, seem able to play the chief part in 
terrestrial dynamics without invoking the radio-activity of the 
outer crust as a controlling cause. The contributions of various 
writers, but more notably Chamberlin, show the weakness of the 
outer zone to generate compressive movements, which seem, on 
the contrary, to be initiated by shrinkage of the centrosphere, 
periodically producing collapse of a thick outer shell of the earth. 
The great vertical movements, on the other hand, as shown by 
investigations on isostacy, seem to be in their origin largely inde- - 
pendent of denudation and sedimentation, but dependent upon 
differential volume changes in the outer hundred miles. The 
isostatic adjustments are further without doubt modified by sur- 
face unloading and loading. ‘These considerations are not ade- 
quately discussed by Joly. 


Geology. 85 


To make the foregoing criticisms specific by citing an illustra- 
tive point: it is inferred by Joly that uranium is concentrated in 
the outer hundred miles of the crust because if it extended indefi- 
nitely downward in the same amount, the energy liberated would 
be more than sufficient to maintain the temperature gradient. 
This inference, however, has no supporting evidence and leads in 
turn to some assumption as to the manner in. which uranium 
could be so concentrated and yet remain in its extremely diffused 
state. On this inference of the subsurface concentration is never- 
theless based an explanation of the making of mountains and of 
continental and oceanic movements. As other allowable infer- 
ences which would meet the same condition of a subsurface 
excess in radio-activity, it may be suggested that in the deep body 
of the earth the pressures and temperatures, greater than any 
attainable in the laboratory, may partially or completely inhibit 
‘the radio-active degradation of uranium, or offsetting heat- 
absorbing reactions in other materials may take place, or igneous 
activity may serve as a safety valve to reduce the excess of 
internal energy transmuted from subatomic to atomic form. 
These are all speculations which have not been disproved. None 
of them may be true, but they indicate the danger of arriving at 
conclusions supported on a complicated superstructure of reason- 
ing when the stability of the foundation premises is open to 
serious question. In considering the problems connected with 
internal terrestrial activities the field of the unknown is so large 
that the method of multiple working hypotheses should be more 
largely employed than is done in this volume. Nevertheless 
much is brought out which is stimulating and suggestive. J.B. 

2. The Geology and Ore Deposits of Goldfield, Nevada ; 
by F. L. Raysomze. U.S. G. 8., Prof. Paper No. 66, pp. 253, 
35 plates, 34 text fig. Washington, 1909.—The Goldfield district 
consists essentially of a low, domical uplift of Tertiary lavas and 
lake sediments resting upon a foundation of ancient granite and . 
metamorphic rocks. The erosion of this flat dome has exposed 
the pre-Tertiary rocks at a number of places in the central part 
of the district, and these outcrops are surrounded by wide con- 
centric zones of successively younger formations. Some of the 
later lavas were erupted after the dome had been elevated and 
truncated. The pre-Tertiary rocks consist to-day of quartz rocks 
intruded by masses of a granitic rock like that to which the name 
alaskite has been given. The Tertiary lavas include dolerite, 
rhyolite, basalt, andesite and latite. Most of these are found in 
different flows of different periods and lying between them are 
various fragmental rocks. 

The sulphide ores of the Goldfield district are of complex miner- 
alogical character, native gold and pyrite being accompanied by 
minerals containing copper, silver, antimony, arsenic, bismuth, 
tellurium, and other elements. In some ores the gold occurs free 
in ine particles, which, as a rule, are aggregated together to form 
yellow bands or blotches. The associated minerals are pyrite, 


(0 6) 


6 | Screntific Intelligence. 


marecasite, bismuthinite, perhaps famatinite, and a new cupric 
sulphantimonite, which has been named goldfieldite. (See below.) 

The most notable features of these ore bodies are their remarkable 
richness and their equally remarkable irregularity. The ores are 
associated with craggy outcrops of silicified volcanic rock. 
Associated with the silicification other processes of locally intense 
alteration, especially the formation of alunite, have also been 
active. The deposits have formed along irregular and branching 
zones of fissuring. The surface ores were oxidized and furnished 
a large part of the gold during the first years of exploitation. 

GOLDFIELDITE occurs aS a gray material in a dark telluric 
crust found at the Mohawk mine. The material was crushed and 
picked over under a lens. The gray portion appeared homo- 
geneous, with the exception of a few minute specks of gold. 
Color, dark lead-gray, with a high metallic luster. Brittle’ Con- 
choidal fracture. Hardness = 3 — 3°5. No crystal faces noted. 
Analysis by Palmer on small amount of material gave : 


Cu S Te Sb As Bi Au Ag Gangue 
33°49 21°54 17:00 19°26 0°68 6°91 0°51 .0°18 - 2°00 == soi 


The mineral is considered to be a cupric sulphantimonite, in 
which part of the antimony is replaced by arsenic and _ bis- 
muth and part of the sulphur by tellurium. Formula derived 1 1s 
5CuS.(Sb, Bi, As), (5, Te),. 

It would seem, in view of the facts presented concerning this 
substance, that the giving to the material a name and rank as a 
new species is hardly warranted. The material was intimately 
mingled with other minerals and had to be crushed and picked 
over by hand, so that the purity of the material analyzed must be 
somewhat questioned. It showed no crystal forms. The analysis 
was made on a small amount of material, and shows a high sum- 
mation, and the formula derived is only approximately justified 
by the analysis. It would seem desirable that more positive 
proof should be given before we can assume the existence of 
such an unusual compound as a cupric sulphantimonite. 

WwW. E. F. 

3. United States Geological Survey ; Issue of Geologic Folios 
in pocket form.—The Geological Survey has recently inaugurated 
the publication of an edition of the Folios of the Geologic Atlas 
of the United States in octavo form convenient for field use. 
The maps are folded and enclosed in a pocket so that the whole, 
including the accompanying text, forms a pamphlet of about 
6 x 9 inches. The folio form will also be continued, as it is most 
satisfactory for office and library use, but the new pocket edition 
will be welcomed by those at work in the field. The Folio now ~ 
received is No. 167 of the series, and describes the Trenton, New 
Jersey-Pennsylvania Quadrangle ; it is stated that the five folios, 
No. 164-168, have been printed and are ready for distribution in 
this new form. It is also to be noted that henceforth the 
separate maps, unfolded, showing the areal geology of the 


Geology. 87 


Quadrangle, will be, when desired, furnished separately at the 
nominal cost of five cents each. 

4. Geological Survey of West Australia.—The following 
publications have recently been received : 

Annual Progress Report for the year 1908. Pp. 19, 3 maps. 

Bulletin No. 32, containing: Greenbushes Tinfield, by A. Gibb 
Maitland, A. Montgomery, W. D. Campbell, and Mr. E. 8. Simp- 
son. Pp. 75, 2 maps, 2 plates, and 7 photos. Mount Malcolm 
Copper Mine, by Harry P. Woodward. Pp. 8,1 plate. Fraser’s 
Gold Mine, Southern Cross, by Harry P. Woodward. Pp. 6, 1 
map, l plate. 

Bulletin No. 35, containing Geological Report upon the Gold 
and Copper Deposits of the Phillips River Goldfield, by Harry P. 
Woodward. Pp. 104, 2 maps, 8 plates, 7 photos. 

Phosphate deposits have been discovered near Christmas Island, 
where a layer of phosphatic travertine 153,600 square yards in 
area and with a thickness of two feet has been investigated. The 
travertine is believed to owe its origin to capillary attraction, 
drawing up ground water from the lime contained in the under- | 
lying sands. In an investigation of the Green Bushes Tinfield 
(Bulletin 32) examination was necessarily made of the laterite of 
this region, which has a wide distribution and varies in composition 
from solid and pure limonite to aluminous rocks almost destitute 
of iron and often so tough that explosives have little effect. The 
distribution and character of the laterite in the Green Bushes 
region “clearly indicates periodic and zonal changes in the climatic 
conditions.” {n connection with the petrographic description of 
the crystalline rocks of the Phillips River (Bulletin 35) analyses 
were made of the following types: soda-granite, spodumene, 
albite, and eclogite. H. E. G. 

5. Uontribuziont allo Studio Petrographico della Colonia 
Eritrea ; by H. Manassz. 4°, pp. 168, 8 plates and map. Siena, 
s made by 
Profs. G. Dainelli and O. Marinelli during their geological 
researches in the Italian colony of Erythrea, Kast Africa, in 
1905-1906. After a brief sketch of the geology of the area 
visited, the main body of the work is devoted to a detailed report 
of the results of a thorough petrographical study of the 
specimens. ‘The author first describes, rather briefly, a series of 
schists of various kinds, including some porphyroid, mica schists, 
amphibolites, gneisses, etc. Then the igneous rocks are treated, 
and these were found to consist of granites, some of which, as 
shown by the analyses, are of alkalic character with predominant 
soda ; diorites of several types; a hornblendite which is a local 
facies of diorite, and two specimens of teschenite. There are also 
dike rocks, granite and diorite prophyries, aplites, paisanite, 
bostonite, tinguaite, malchites and among the lamprophyres, 
kersantites and camptonites. The effusive rocks or lavas are also 
not wanting and include quartz porphyry, rhyolite and rhyolitic 
tuffs, obsidians and pumices. Dacite and a great variety of 


88 Scientific Intelligence. 


basalts close the list. In the sedimentary rocks are found sand- 
stones, argillites, limestones, travertine, etc. The work closes with 
a chapter dealing with various generalizations on the results 
obtained. It is illustrated by a large number of excellent photo- 
gravures made from microphotographs of the thin sections 
studied. Its value is also much enhanced by a large number of 
excellent chemical analyses of the various rocks, which are the 
result of much patient labor in the laboratory. 

The work is an excellent contribution to our knowledge of Kast 
African petrology, and it is interesting to observe that the nature 
of the rocks isin harmony with the general alkalic character of 
the Kast African petrological province, as shown by a number of 
investigators during the last few years. ie he 12. 

6. Carboniferous Air-breathing Vertebrates of the United 
States National Museum ; by Roy L.Moopir. Proce. U.S. Nat. 
Mus., vol. 37, pp. 11-28, with pls. 4-10.—This paper, the fifth of 
Dr. Moodie’s contributions to our knowledge of the early Am- 
phibia, is a result of the study of a small collection in the National 
Museum ; but one which is of great interest in that it contains 
the only known examples of scaled Amphibia from North Amer- 
ica, as well as the only known specimen of a Carboniferous reptile 
from the Allegheny series. This reptile, Zsodectes punctulatus 
Cope, Doctor Moodie thinks, shows certain aquatic as well as ter- 
restrial adaptations ; the former being the broad-surfaced foot, 
such as MacGregor has described in MMesosaurus brasiliensis. 
The affinities of Isodectes are close to the Microsauria among the 
Amphibia ; to what group of reptiles it is related is not known. 

Of the Microsauria, Moodie describes some 17 species and 15 
genera, of which 3 of the former and 1 of the latter are new. 
The material comes in part from Linton, Ohio, and Cannelton, 
Pennsylvania. RLS. 

7. Cenozoic Mammal horizons of Western North America, 
by Henry Farrrietp Ossorn; with Launal Lists of the Tertiary 
of the West, by Winitiam Dinter Matruew. Bull. U.S. Geol. 
Survey No. 361, 1909, pp. 1-138, with 15 text figs. and 3 plates.— 
For the student of faunal paleontology as well as the stratigraph- 
ical geologist this paper is of the utmost importance, containing 
as it does a bibliography, a general discussion of the geologic and 
climatic history of the Tertiary, a careful description of the 
successive faunal phases, and most comprehensive faunal lists of 
the Tertiary mammals. 

The principal facts established are the two great natural 
divisions of geologic deposition and of habitat, the mountains 
and the plains; the progressive aridity of the climate during 
the Cenozoic with its consequent soil denudation and deforesta- 
tion, and the destruction of most of the larger forms of life during 
the lower Pleistocene glacial epoch. The contrast of the moun- 
tain and plains regions are no less striking than their resemblances. 
In the mountain region, with some exceptions, the drainage sys- 
tems are the same to-day as in the Tertiary, while on the plains 


Geology. 89 


the rivers are comparatively modern. In the mountains from the 
Basal Eocene to the John Day the rocks are not worked over, as 
erosion was retarded by the heavy cappings of lava in the John 
Day basin of Oregon, in the Bridger basin by a dense Pleistocene 
(?) conglomerate and in the Washakie by a fine conglomerate. 

In the plains region, by contrast, the very extensive Oligocene 
strata were in part worked over to form the Miocene and these in 
turn to form the Pliocene; all three contributed to the Pleis- 
tocene, and all four are now contributing to the alluvium of the 
Great Plains. 

The successive faunal phases are :— 

1, Archaic Mesozoic mammals with partly South American, 
partly European affinities. Basal Eocene. 

2, The first modernization, invasion of the archaic by the 
modern fauna—whence is not surely known, but Osborn favors a 
North American-Asiatic or Holarctic origin ; the severance of the 
South American land connection—Initial elimination of the 
archaic fauna in competition with the modern. Wasatch. 

3, Absence of fresh Kurasiatic migration, descendants of archaic 
and modern mammals slowly evolving and competing, with the 
gradual elimination of the archaic. Establishment of the North 
American Artiodactyla. Wind River to close of Mocene. 

4, Second modernization—First knowledge of the plains’fauna 
—Absence of all archaic mammalia except the Hyznodontide— 
Reéstablishment of faunal resemblances with western Europe. 
Oligocene and Lower Miocene. 

5, Fresh migrations from Europe. First proboscidians and 
true Feline. Middle Miocene to Lower Pliocene. 

6, Land connection with South America. Intermigration of 
North and South American mammals. Middle and Upper 
Pliocene. 

7 Increasing cold, moisture and forestation. Third moderniza- 
tion by EHurasiatic invasion—Gradual extinction of larger 
Ungulata. Pleistocene. 

Conclusion :—North America promises to give us a nearly 
complete and unbroken history of the Tertiary in certain regions, 
which are, after all, comparatively restricted. Middle and Upper 
Eocene are approaching solution ; Lower and Basal Eocene still 
require additional surveys. The chief remaining gap is now in 
the Pliocene stratigraphy, materials being at hand for an estab- 
lishment of the Pleistocene sequence. RS. Ls 

8. New Fossil Mammals from the Haytiim Oligocene, Egypt ; 
by Henry Fairrietp Osporn. Bull. Amer. Mus. Nat. Hist., 
vol. xxiv, 1908, pp. 265-272, with 6 text figures. 

New Carnivorous Mammals Jrom the Kaytim Oligocene, 
Eigypt ; by H. F. Osporn. Ibid., vol. xxvi, 1909, pp. 415-424. 
and 9 text figures.—In these two papers Professor Osborn 
describes part of the remarkable wealth of material collected in the 
Fayaim by the expedition from the American Museum sent out 
during the winter of 1906-1907. The first paper contains descrip- 


90 Scientific Intelligence. 


tions of two new genera of uncertain ordinal position as well as 
two new genera of rodents, including in all an equal number of 
species. In the second paper a number of creodont genera and 
species are described, all referable to the Hyznodontide, the last 
surviving family of the order. | Re, Soule 

9. New or little known Titanotheres from the Hocene and the 
Oligocene; by Henry Farrrietp Osporn, Bull. Amer. Mus. 
Nat. Hist., vol. xxiv, 1908, pp. 599-617 with 21 figures in the 
text. 

“In the preparation of the U. 8. Geological Survey monograph 
‘The Titanotheres’ the collections of Kocene and Oligocene 
materials in the larger museums of the country have been 
reviewed with care. Like the Oligocene titanotheres previously 
reviewed, the Eocene titanotheres prove to be in a high degree 
polyphyletic.” From the Wind River formation are two: genera 
and three species ; from the Lower Bridger one genus and three 
species; from the Upper Bridger and Lower Washakie three 
genera and five species; from the Upper Washakie and Lower 
Uinta two genera and four species; from the Upper Uinta two 
genera and three species, and finally from the White River 
Oligocene two new genera, each with a single species, are 
described. : 

Dolichorinus hyognathus, of which the more familiar name, 
Telmatotherium cornutum, is a synonym, is restored in the skele- 
ton and gives a good idea of the appearance of one of these 
ancestral titanotheres. . dos. as 


III. MisceLtuanrous Screntiric INTELLIGENCE. 


1. The Autobiography of Nathaniel Southgate Shaler, with 
a supplementary Memoir by his wife. Pp. 481, with 16 illustra- 
tions. Boston and New York, 1909 (The Houghton Mifflin 
Company ).—The six or seven thousand students who heard Shaler’s 
lectures at Harvard during his forty years service were always 
deeply impressed with his personality, his wide experience of men 
and the world, and his vivid presentation of the principles of geo- 
logy, enlivened by ever-flowing narrative of pertinent incidents, all 
the more entertaining from being phrased in picturesque language. 
The personality of the man is strikingly presented in this volume, 
of which the first half, descriptive of his youth up to the begin- 
ning of the Civil War, comes from Shaler’s own pencil—for it 
was his habit to prepare manuscript with pencil rather than with 
pen—while the second half, descriptive of his more mature years, 
is written by his wife. The picture that we gain of the way in — 
which science was studied at Harvard under Agassiz is particu- 
larly interesting ; a way that was well fitted for youths of the 
strong individuality that Shaler possessed. Several chapters on 
excursions along the coast of Maine and farther down east, with 
Hyatt, Stimpson, Verrill and others, are of special interest as 


Miscellaneous Intelligence. 91 


illustrating the delightfully primitive conditions of scientific 
exploration in the early sixties; they show the richness of 
happenings even ona near-by coast, if one only has the knack of 
meeting them as Shaler always had. 

The memoir by Mrs. Shaler exhibits the extraordinary variety 
of relations into which Shaler entered after his return to Harvard 
at the close of the war. It includes accounts of his several 
journeys abroad, where he made personal acquaintance with the 
leading geologists of the time; of his work on the Kentucky State 
Geological Survey and on the Coast Survey; of his occasional 
westward journeys chiefly in connection with mining interests ; 
of his wide excursions in literary fields, reflected again in the 
list of publications at the end of the volume ; and above all of the 
innumerable activities at Harvard which made him, as William 
James put it, “the myriad-minded and multiple-personalitied 
embodiment of all academic and extra-academic /enntnisse and 
Gemiithsbewegungen.” The real worth of this book les in the 
deep impression that it gives of the value df personality as com- 
pared to mere learning. Ww. M. D. 

2. Third Report of the Wellcome Research Laboratories at 
the Gordon Memorial College, Khartoum; ANDREW BaLrour, 
Director. Published for the Department of Education, Sudan 
Government, Khartoum. Pp. 477, with 28 colored plates, 413 
reproductions of drawings and photographs, and 19 maps and 
plans. London, 1908 (Bailliére, Tindall & Cox); New York 
(Toga Publishing Co., 45 Lafayette St.).—This handsome vol- 
ume shows the latest work of the enthusiastic investigators at 
this now famous tropical laboratory. As in the earlier reports, 
noticed in this Journal, the work covers a wide field of inves- 
tigation, although such biological topics as concern the health of 
the natives are given a prominent position. 

The blood parasites of man, domestic animals, rats, birds, 
reptiles, and fishes of the region have been subjected to extensive 
investigations by the director of the laboratory, and by Dr. 
Wenyon, both of whom contribute several beautifully illustrated 
reports, which form important contributions to the knowledge of 
these important parasites. The sanitary conditions existing in 
Khartoum are discussed, and further observations on sleeping 
sickness, kala-azar, and other diseases reported. Poisonous 
snakes and other reptiles have been studied by specialists, the 
parasitic worms investigated, and the insects of economic import- 
ance discussed and illustrated by colored plates. 

The later chapters deal with well illustrated articles on the 
healing art as practiced by the dervishes, the physical characters 
of certain negroid tribes, and notes on ethnographical specimens, 
while the reports of chemical investigations at the laboratory 
conclude the work. The floating laboratory on the Jurriver has 
proved a marked success. 

The admirable courage shown by those who have made these 
investigations, under the most trying climatic conditions, has been , 


92 Scientific Intelligence. 


further tested by a recent fire which destroyed many of the 
important preparations and documents at the laboratory. W. R. ©. 

3. Illustrations of African Blood-sucking Flies other than 
Mosquitoes and Tsetse-flies ; by EKrnest Epwarp Austin. Pp. 
xy, 221, with 13 colored plates. London, 1909 (British Museum 
of Natural History).—Since the discovery that many of the most 
fatal diseases of man and animals are disseminated by means of 
the bites of blood-sucking flies, the British Museum has published 
a number of handsomely illustrated monographs on various 
groups of these insects. Belonging to this series is the present 
volume, which gives general and non-technical descriptions and 
excellent colored figures of 103 African species, all of which have 
blood-sucking habits, although it is not yet known which of them 
may serve in spreading diseases. | Ww. RB. C. 

4. The Cambridge Natural History ; edited by Harmer and 
Saipcry. Vol. IV. Crustacea and Arachnida. Pp. xviii, 566, 
with 286 figures. London 1909 (Macmillan & Co.).—The 
series of ten volumes of excellent treatises by specialists in the 
different groups of the animal kingdom is now complete, and 
forms perhaps the most convenient and generally useful work of 
reference on the subject that has appeared in the English 
language in recent years. 

The present volume is quite up to the high standard of the 
others of the series, and treats of the Crustacea, and the widely 
divergent forms, as king crabs, spiders, scorpions, ticks, mites, 
water-bears, pycnogonids, and other animals, both fossil and 
living, which are now generally grouped together as Arachnida. 
The contributors for this volume are Geoffrey Smith, Henry 
Woods, A. E. Shipley, Cecil Warburton and D’Arcy W. "Thomp- 
son. The general excellence of the text is shared by the 
numerous illustrations. W. Ra C, 

5. The Human Body and Health: An Intermediate Text- 
Book of Essential Physiology, Applied Hygiene, and Practical 
Sanitation for Schools ; by Auvin Davison. Pp. 223, with 150 
illustrations. New York, 1909 (American Book Company).— 
The aim of this little book is to give the pupil in the public 
school a general knowledge of the principles of personal and 
public hygiene. Such of the essentials of the anatomy and 
physiology of the human body as it is necessary to introduce are 
clearly described and illustrated. WwW. R. C. 

6. International Congress of Radiology and Klectricity.—It 
is announced that an International Congress of Radiology and 
Electricity will be held in Brussels in 1910 under the patronage 
of the Belgian government and of the French Physical Society. 
A provisional program has been issued ; the address of the Gen- 
eral Secretary is | Rue de la Prévoété, Brussels. 


brarian U. S. Nat. Museum. 


4 
ar FEBRUARY, 1910. 


oa 


Established by BENJAMIN SILLIMAN in 1818. 


* | AMERICAN 
| || JOURNAL OF SCIENCE. 


“2 Eprrorn; EDWARD S. DANA. 


a ASSOCIATE EDITORS 3 
ay: Proressors GEORGE L. GOODALE, JOHN TROWBRIDGE, 


Bs W. G. FARLOW anv WM. M. DAVIS, or Campnince, 

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

a | Proressor GEORGE F. BARKER, or PumapeLput, 

Bi) Proressor HENRY S. WILLIAMS, or Iruaca, 

a Proressor JOSEPH S. AMES, or Battrore, 

eg) Mr. J. S. DILLER, or Wasurneton. 

se FOURTH SERIES 

aS VOL. XXIX—[WHOLE NUMBER, CLXXIX] 

% No. 170—FEBRUARY, 1910. 


WITH PLATE I, 
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BRIEF 
ANNOUNCHMENTS: 


Recent pressure of business has hindered me from compiling a detailed list 
of new minerals arrived. I wish to mention, however, a new lot of the 
metallic Awaruite from Smith River, California, ranging in sizes from 4 
inch-to linch. These interesting metallic pebbles are of scientific value 
on account of the nickel being associated with the iron in the metallic state. 


Considering the great amount of attrition which they received from stream 


action, I find them very well preserved and deserving a place in every © 


collector’s cabinet. These range in.price from 25 cents to $2,00. 

Although the finest of the recent Iceland Zeolites and Franklin Furnace 
minerals have been sold off rapidly, I still have choice examples of these 
splendid specimens at reasonable prices. 

Having received some excellent shipments representing chiefly Hungary, 
Saxony and other celebrated German localities, of which specimens I was 
unable to prepare a list in time for this issue, I shall be pleased to furnish 
further data on request. JI noted in these shipments several specimens of 


the rare Argyrodite ahd other silver minerals too numerous to mention. 


I recently received additional minerals from Colorado and can now supply 
any reasonable demand in Tellurides, native Tellurium, Amethystin- 
Quartz, Calciovolborthite and Carnotites. Prices on request. 

Lhave also considerably increased my stock of the celebrated California 
Tourmalines so that I now feel that no dealer has ever had the quality and 
quantity of these specimens that I have, while the prices of same have 
been somewhat lowered, considering their value, as compared with former 
prices. 

Have also made a recent addition to my stock of the Reconstructed 
Rubies, Sapphires and Pink Topaz, which places me in the best position for 
supplying the demands of my customers. 

It would be advisable for those interested in the shore to have their 
names on my mailing list, and I shall be pleased to send on approval for 


inspection and selection anything that may interest my patrons. 


Information as to special lists and prices of individual specimens cheer-— 


fully given. 


A. Ae PEE REVE, 
- 81—83 Fulton Street, New York City. 


dts Ls, 


AMERICAN JOURNAL OF SCIENCE 


[FOURTH SERIES.] 


of 


Art. VIII.— The Nitrogen Thermometer from Zinc to Palla- 
dium ; by Antuur L. Day and Rozserr B. Sosman; with 
an Investigation of the Metals, by Eucrnr T. Aten. 


CONTENTS: 


Introduction and Plan. 
Apparatus. 
Details, Errors, and Corrections. 
A. Temperature of Gas in Bulb. 
B. Definition of Temperature by Measurement of Pressure. 
C. Transference of Temperature by the Thermoelement. 
D. The Fixed Points. 
4, Experimental Data and Calculated Results. 
A. Hxpansion Coefficient. 
B. Gas Thermometer Data and Fixed Points, 
Interpolation between the Fixed Points. 
Analysis of Metals. (By E. T. Allen.) 
Cone¢ijusion. 


Peer. 


aad ah 


1. Introduction and Plan. 


THE measurements of absolute temperature here offered 
were undertaken in direct continuation of those published 
from the Geophysical Laboratory two years ago,* with the 
purpose of extending the gas scale to 1600°, or as near it as 
might prove practicable. Except in explanations of new or 
particularly important features, descriptive details have accord- 
ingly been omitted here and must be sought in the first paper. 
Substantially the same methods and apparatus have been 
employed throughout. 

One conclusion in particular which was brought out at that 
time is entitled to even greater emphasis, namely, that the 
existing uncertainties in the absolute temperature scale at 
1000° and above are the result of experimental limitations and 
not of any failure of the principles involved. The experi- 
mental conditions were scrutinized with great care throughout 
the first investigation, and not only were the known correction 
factors all redetermined, but their total magnitude was reduced 
nearly 75 per cent. This success, after so long and painstak- 


* Arthur L. Day and J. K. Clement, this Journal (4), xxvi, 405-463, 1908. 
Am. Jour. Sci.—FourtaH Series, Vout. XXIX, No. 170.—Frsrvuary, 1910. 
7 


94 A. L. Day and f. B. Sosman— 


ing a study of the correction factors, led the authors to believe 
that the upper end of the existing gas scale (melting point of 
pure copper), which has been vacillating in a somewhat irregu- 
lar way in various hands for three-quarters of a century, had 
been finally confined to the limits + 0°5°, or within 1°. 
Although this ideal had been affectionately cherished for a 
good many years, its triumph has been shortlived. The present 
investigation has discovered a source of error which appears to 
have passsed unnoticed before, which operates to raise the 
temperature scale at the copper point about 1°4°. This kind 
of history has repeated itself with remarkable persistence all 
through the record of high temperature research, and may, of 
course, do so again, but the limits of uncertainty are continu- 
ally becoming narrower, and it appears to the authors unlikely 
that further investigation will again reveal errors ageregat- 
ayee 

On the other hand, the detailed study of temperature distri- 
bution about the bulb (page 102) in which the present error | 
was discovered, cannot but convince an experienced observer 
that the limit of refinement in an electrically heated air bath 
has been practically attained, and that higher accuracy in gas 
thermometry must be sought in a liquid bath which can be 
stirred. 

Since the publication of the Reichsanstalt scale* in 1900, it 
has remained the standard for all temperature measurements 
between 400° and 1100°. Its limit of accuracy as an absolute 
scale was estimated to be about 3° at 1000°. 

The work of Day and Clement was mainly directed to the 
following essential features of the problem of absolute meas- 
urement with a constant volume gas thermometer: (1) An 
absolutely gas-tight bulb of definite volume; (2) uniform dis- 
tribution of temperature over the bulb surface during the 
measurements; (3) the reduction of the error due to the 
unheated capillary tube connecting the bulb with the mano- 
meter; (4) a more accurate determination of the expansion 
coefficient of the bulb itself. 

The results accomplished by them in these directions may 
be outlined seriatim as follows: (1) The bulb chosen (90 parts 
platinum, 10 parts iridium) is quite rugged enough for meas- 
urements as high as 1500°, and no difficulty was experi- 
enced in maintaining a nitrogen atmosphere in it without loss 
by diffusion or leakage. At high temperatures the material 
becomes considerably softer, but with the help of a gas-tight. 
furnace in which nitrogen could be maintained at the same 
pressure outside the bulb as within, neither diffusion through 
the bulb walls nor mechanical strain was encountered. Varia- 
tions in the zero point of the thermometer, which have been 


*L, Holborn and A. L. Day, Ann. d. Phys. (4), ii, 505, 1900; this Journal, 
(4), x, 171, 1900. 


Jitrogen Thermometer from Zinc to Palladium. 95 


very persistent and inaccessible errors throughout the history 
of gas thermometry, have therefore now become practically 
negligible. This gas-tight furnace possessed the further advan- 
tage that the initial pressure of the gas, and consequently the 
sensitiveness of the instrument, could be varied within con- 
siderable limits. A sensitiveness as great as 1™™ of the mano- 
meter scale per degree was regularly employed. The iridium 
alloy has the disadvantage that platinum thermoelements, 
which are necessary for recording variations in the tempera- 
ture over the surface of the bulb, and for transferring the gas 
thermometer temperatures to standard melting points, become 
contaminated in the presence of iridium at all temperatures 
above 900° ©.; the higher the temperature and the longer the 
time of exposure, the greater the degree of contamination. 

(2) It was sought to obtain a uniform temperature over the 
surface of the bulb by winding the (pure platinum) furnace 
coil on the inside of a refractory magnesia tube which contained 
sufficient iron oxide and other impurities to be a fairly good 
conductor of heat. The winding was somewhat closer at the 
ends than in the middle. This was further supplemented by sec- 
ondary coils of smaller wire extending a few centimeters into 
the tube from each end. The current in the three coils could 
be independently regulated with the help of thermoelements 
attached to the bulb and giving its temperature at the middle 
and upon each shoulder (positions 2, 4, and 6, fig. 1). When 
these temperatures had been adjusted so that the differences 
between them were smaller than 0°5°, it was assuined that the 
temperature over the whole surface of the bulb was constant 
within those limits. (For the oversight in this assumption, 
see pages 99 and 102.) 

(8) The platinum capillary and connections between the 
bulb and the manometer were much diminished in volume. 
Compared with the total volume of the bulb (195-7°) this con- 
necting volume amounted to ‘0015 in their instrument, and 
reduced the total correction for the “unheated space” to less 
than 5° at 1100°, a correction factor not more than one-fourth 
as large as the best previous attainment in this direction. The 
uncertainty of the temperature distribution in the ‘‘ unheated 
space” was perhaps 10 per cent, making the probable error 
from this source about 0°50°. 

(4) A special bar 25 in length, made up from the same 
alloy as the bulb, was provided with a scale and its length 
measured in a special form of comparator at temperature 
intervals of 50° up to 1000°. The expansion was found to be 
10°8=—8°84+0°00131¢, with an error of about 0°5 percent. An 
irregularity was detected both in the expansion and subsequent 
contraction in the region below 300°, which appeared variable 
with the rate of cooling or heating, and in character resembled 
the hysteresis which appears in a. bar which has been subjected 


96 A. L. Day and k. B. Sosman— 


to stress. If the bar was cooled down very slowly, it returned 
nearly to its initial length; if cooled rapidly, it required sey- 
eral days to return to its original dimensions. This irregularity 
makes up most of the 0°5 per cent uncertainty mentioned 
above. 

Plan.—Above 1100° considerable uncertainty has existed 
in the temperatures of various fixed points. The melting 
point of nickel, considered as 1484°,* has been frequently 
employed. The curve of the platinum-rhodium thermoele- 
ment, extrapolated beyond the copper-point, has been still 
more generally used, but like any extrapolation, may lead to 
quite erroneous results. The only gas thermometer compari- 
son that has been made in this region is that of Holborn and 
Valentiner,t but by their own estimaté the accuracy of the 
upper portion of their scale is not greater than + 10°. The 
chief purpose of our work was, therefore, to establish the tem- 
perature of several fixed points between 1100° and 1600° and 
to find what curve is followed by the platinum-rhodium ther- 
moelement in this region, with an accuracy comparable to that 
obtained in the lower portion. 

The plan of the work is simple. It consists, first, in select- 
ing certain fixed thermometric points, usually melting points 
of metals, and in determining their reproducibility ; second, 
in making a measurement of the true temperature on the 
nitrogen scale at or close by one of these fixed points; third, 
in transferring this known temperature by means of a thermo- 
element over to the fixed point in question. This transference 
by the thermoelement is necessary because the thermometer 
bulb cannot be put directly into melting or solidifying sub- 
stances at high temperatures. The relation of electromotive 
force to temperature for any particular kind of thermoelement 
does not enter into the problem when the temperatures 
measured are close to the fixed points; a linear correction is 
then abundantly accurate. The interpolation curve, for any 
element, between the fixed points established by the gas ther- 
mometer, is therefore a separate matter. 

The questions which remain to be answered are, then: (1) 
How exact and uniform can the temperature of the gas in the 
bulb be made (independently of any effort to measure this 
temperature)? (2) How accurately can its pressure be meas- 
ured in order to establish that temperature on the nitrogen 
scale? (3) How accurately can this temperature be transferred 
from the thermometer and compared with the fixed melting 
point? (4) How accurately can the fixed points be reproduced 
for purposes of calibration of secondary measuring devices ¢ 

As has been stated, our experience has convinced us that 
the most of the variations in the gas scale temperatures of the 


* Holborn and Wien, Wied. Ann., xlvii, 107, 1892 ; and lvi, 360, 1899. 
{Amn deschys.1(4). x00 too 7 


Nitrogen Thermometer from Zinc to Palladium. 97 


fixed points commonly in use, as given by various observers, 
are due, not to differences in the properties of different gases 
used, nor to differences in pressure, nor to differences between 
the constant-volume and constant-pressure scales, all of which 
have been frequently discussed from the theoretical stand- 
point; but to systematic errors residing in the apparatus and 
the methods employed. <A large portion of the present work 
has therefore been devoted to finding out experimentally the 
effect of variations in all those conditions which might affect 
the results systematically. 


2. Apparatus. 


In all essential particulars the gas thermometer apparatus is 
that developed by Day and Clement and already described by 
them in detail (loc. cit.). It consists of four principal parts: 
(1) bulb, (2) furnace, (3) furnace jacket, and (4) manometer. 

(1) Zhe Bulb.—A great deal depends upon the material of 
which the bulb is made. Primarily and obviously, the bulb 
must be able to hold the expanding gas without absorbing or 
losing any portion of it throughout the temperature range of 
the measurements. 

A secondary requirement, the importance of which increases 
rapidly when high accuracy is sought, is that it shall be possi- 
ble to use several thermoelements in the furnace with the bulb 
without their readings being endangered by contamination 
from the bulb material. As long as this intermediary role of 
the thermoelement remains a necessary one and alloys of 
platinum continue to provide the only successful bulb material, 
the contamination®* of the platinum wire of the element by 
the alloyed iridium or other platinum metal in the bulb will 
remain a serious consideration in all temperature measurement 
above 900°. 

Although the platin-iridium bulb served well as a gas con- 
tainer, the contaminating effect of the iridium upon the ther- 
moelements made the life of the latter, for measurements of 
such extreme accuracy, very short. Accordingly, at the close 
of the first series of experiments, a change was made from the 
platin-iridium bulb to one of platin-rhodium (80 parts platinum, 
20 parts rhodium) 160°" long and 47™™ in diameter. Inas- 
much as one of the wires of the thermoelement itself contains 
10 per cent of rhodium to which the platinum wire is always 
exposed (and which gradually contaminates it, too, although 
very slowly), it was thought that the substitution of a rhodium 
alloy in the bulb might serve to retain the necessary qualities 
of stiffness and regularity of expansion with a minimum of 
disadvantage in the matter of contamination. These expecta- 


* For a detailed account of the behavior and treatment of contaminated 
thermoelements, see Walter P. White, Phys. Rev., xxiii, 449, 1906. 


98 A. LI. Day and Rh. B. Sosman— 


tions have been completely realized. Although the rhodium 
alloy is less rigid at temperatures of 1000° and beyond than 
the iridium alloy, and requires more careful adjustment for 
equal pressure within and without, no sagging of the bulb 
walls or deformation from the gas pressure has appeared up 
to 1550°. Meanwhile, the contamination of the thermoele- 
ments in the presence of the rhodium alloy is now reduced in 
magnitude about 80 per cent for a given temperature and time 
of exposure. 

(2) The Furnace-—The common practice of recent obsery- 
ers (Callendar, Harker, Holborn and Day, Jacquerod and 
Perrot, Day and Clement) has been to use a cylindrical bulb 
in which the length was three or four times the diameter, 
enclosed in a concentric furnace tube (air bath) heated by the 
electrical resistance of a coil of wire wound upon or ‘within 
it. To this bulb the heat is applied radially over its eylindri- 
cal surface, but no heat is supphed at the ends. The furnace 
tube itself and the winding of the coils have been changed at 
different times and in a variety of ways in order to vary the 
distribution of the heat supply. The arrangement used in 
most of our experiments consisted of one main coil of platinum — 
wire 1:°2™" in diameter, wound on the inside of a refractory 
magnesia tube 86 long and 2° thick. As has been our 
habit for some years, the windings near the ends of the coil 
are somewhat closer together than those at the middle, but 
this device is not of itself sufticient* to compensate for dif- 
ferences of temperature along the bulb at all temperatures. 
In a particular case a favorable arrangement will provide an 
almost perfect temperature distribution at 500°, but will over- 
compensate the ends at 1000° sufficiently to spoil the meas- 
urements. ‘The conductivity of the bulb metal is wholly 
inadequate to help out this overcompensation by conveying 
surplus heat from the ends to the middle of the bulb. On the 
other hand, a change in the winding which will correct the 
overcompensation at 1000° provides insufficient compensation 
at 500°. The arrangement which has become usual with us 
is therefore to wind the coil somewhat more closely at the ends 
than in the middle, with the idea of providing partial com- 
pensation for the inevitable heat losses at the ends of the fur- 
nace in this way, and in addition, to insert supplementary coils 
of smaller wire in the ends of the furnace tube in order to 
provide a small, independently regulated heat supply which 
can be superposed upon that of the main coil and give the 
desired uniformity at any temperature likely to be employ ed. 
A furnace tube arranged in this way, except for accidental 
variations, caused, for example, by the flaking off of the fur- 

* Day and Clement, loc. cit., p. 411. 


Nitrogen. Thermometer from Zinc to Palladium. 99 


nace lining, affords uniform temperature distribution over a 
length of 20° in the center of the tube for a range of tem- 
perature from 300° to 1550°, and no one temperature is more 
difficult to regulate than another. This arrangement contains 
a limitation, however, of considerably greater magnitude than 
was at first suspected. The ends of the bulb face the com- 
paratively cold ends of the furnace tube and radiate a sufficient 
quantity of heat toward these cold ends to reduce the tem- 
perature of the end surfaces of the bulb some 6 or 8° below 
the mean temperature of the cylindrical surface. 

In so far as this may appear to be a rather obvious condition 
to be overlooked, it may be remarked parenthetically that it 
is a common practice of physicists to assume that the tempera- 
ture is constant over a radial cross-section near the center of a 
cylindrical furnace which is reasonably long in comparison 
with its diameter. With this in mind, the probability is even 
greater that a metallic conductor only 4™ in diameter (the end 
surface of the bulb) perpendicular to the axis in such a furnace 
will have a uniform temperature between its center and _ peri- 
phery. The fact is that neither of these assumptions is justi- 
fied, even in furnaces as long as twenty times the diameter. 
This was shown in a number of actual measurements made 
under varied conditions, differences of several tenths of a 
degree being found as low as 300°, and of several degrees at 
1000° and higher. 7 

This situation demonstrates the futility of depending upon 
metallic conductivity (of platinum) to equalize a steep tem- 
perature gradient, and again emphasizes the fact, if further 
emphasis is necessary, that the air bath, or, more explicitly, 
the temperature distribution within the heating chamber, is 
the most uncertain factor remaining in gas thermometry. 

On account of difficulties in manipulation and accidental 
leakage into the thermoelement system, we preferred not to 
introduce additional heating coils into the furnace tube, and 
accordingly undertook to stop the loss of heat by inserting 
thin, platinum -covered diaframs opposite the ends of the 
bulb. The situation was still further safeguarded, in exchang- 
ing the platin-iridium for the platin-rhodium bulb by adding 
a reentrant tube at the lower end of the bulb, to enable us to 
measure the actual temperature prevailing at its center as well 
as over the surface. In this way, we thought to obtain a more 
representative integral of the surface temperature and a com- 
petent comparison of this integral with the temperature 
actually prevailing at the center of the bulb. 

(3) The Furnace Jacket.—The furnace jacket was water- 
cooled and could be closed air-tight around the furnace and 
bulb together, so that the pressure could be maintained the 
same within and without the bulb to avoid deformation. 


100 A. L. Day and R. B. Sosman— 


(4) Zhe Manometer.—The bulb communicated, by a capil- 
lary tube leading out through the furnace jacket, with the 
manometer, which consisted of two glass tubes communicat- 
ing through a steel reservoir. At the top of the shorter arm, 
where the capillary joined it, was a fixed reference point to 
which the mercury was brought for each measurement of the 
pressure. A detailed description of the manometer will be 
found in the previous paper.* 


3. Details, Hrrors and Corrections. 


The gas thermometer for high temperatures has now reached 
a stage of development where it becomes necessary to examine 
many small sources of error. These will be discussed in the 
succeeding paragraphs without attempting to classify separately 
the variable errors of observation, and the systematic errors 
which may arise from conditions of the measurements or from 
constant corrections. 

To bring out the plan of investigation of these errors, it 
will be well to recall the derivation of the gas thermometer 
formula. The gas scale, as is well known, is defined by the 
relation | 


OU ees. 
ee ae ae (1) 


in which K and a are constants and ¢ is a function of p and v, 
the pressure and volume of a fixed mass of the gas. K and a 
are determined by two further conventions : 

When p=p, and v=v, (at melting point of ice), t=0 (2) 
When p=p,,, and v=v,,, (at boiling point of water), 7=100 (3) 


100 100 


It is then evident that 


100 


v, =P 
100 p, 


which defines a as the mean pressure coefficient of the gas 
between 0° and 100° (when w,,, and v, are nearly equal); and 


Pr00 


Keo: 
The temperature, ¢, is therefore defined by the formula: 
v 
Fe ee (4) 
ie ee: 


the scale depending upon the gas chosen, the value of p,, and — 


the ratio s . In the theoretical constant-volume thermometer, 


* Loc. cit., p. 415, and this article, p. 107. 


Nitrogen Thermometer from Zine to Palladium. 101 


. e 10) . e . . 
this ratio — is unity, but in the experimental constant-volume 
v 


thermometer it always varies considerably from 1. We have 
preferred therefore to treat equation (4) as the fundaraental 


e . . . (3) 
equation, introducing in place of rae however, the proper 


0 
function of the expansion coefficient of the bulb material. 
Since apparatus designed for high-temperature work is not 
suited for the most accurate determination of a, a has been 
treated in this discussion as a separately determined constant. 
In the experimental gas thermometer, there is always a 
small space in the tube connecting with the manometer which 
is at various temperatures other than ¢ The pressure (p’ or 
p,) actually measured is not therefore the p or p, of ‘the for- 
mula. Imagine that this supplementary space is heated up to 
the uniform temperature ¢, without any change in its volume, 
and let the resulting corrected pressure be p (or p, as the case 
may be). Furthermore, let 
V = volume of bulb at @°. 
Ne 6é 6¢ 66 Oc 
ees “ unheated space” which is at tem- 
peratures other than ¢ (or than 0°). 
¢, = temperature of this space. 
8 = linear expansion coefficient of the bulb material. 


Under these conditions, formula (4) becomes: 


pike 1 V +24, 
Papal RU TV ee = 2 | 


3Bt * 


ve [alee lee] (5) 


mt) 


. v . s e 
In this formula Vv is a very small correction term; while the 
0 


important quantities to be measured are p,, p, a and 8. The 


es AY ; ; eke 
ratio v. becomes of importance, however, in determining the 


corrected pressure p from the measured pressure p’. The 
derivation of this correction is as follows: 
The mass of the gas In the unheated volume under the 


/ 


. . $ = Q 
actual conditions of measurement is proportional to ne > 
at 
1 

, we v1 “1 
* he —— + — i, ae 3Bt 2 == 

Viv, ox Vo Vo ost ge kewl 

eee ei, Se er | 

oT V1 ‘ 2 V1 1 + aus 1 a 


V. Te ey, 


LO2e A. L. Day and. RB. B. Sosman—- 


the mass of the gas within the bulb is propor tional to aan : 
Q 


If we now suppose the unheated space raised to the uniform 
temperature ¢ without change of volume, the pressure being 


thereby raised to p, the total mass is proportional to pity, 
Q 
Therefore, : 
LO PN: eee) 
1+al, l+at ae l+at 
whence 


1 


— eas ! — ~ z -- = 
tere p oS aes 


This correction is easily caleulated and tabulated ; or, better, 
the factor in parenthesis (in the second member of the equa- 
tion) is plotted against temperature. In practice, the volume 
v, 1s divided into three portions at temperatures ¢,’, ¢,’’, and ¢,” 
as explained on p. 109, and the corrections obtained from the 
curve for each of these portions are simply added together to 
obtain the total correction p—p’. With these corrected pres- 
sures, p, and p, the temperature ¢ is calculated by formula (5) 
on page 101. 

The discussion of errors and corrections will now be taken 
up under the general outline sketched on page 96. 

A. Temperature of the Gas in the Bulb. (a) Unt 
Jormity.—Above the temperatures where a liquid or vapor 
bath can be used to secure uniformity, the differences of tem- 
perature between different parts of a furnace has always been 
a serious limitation to the accuracy of the gas thermometer. 
This variation, even in a furnace containing well-conducting 
materials, is much larger than has usually been assumed, and the 
three equalizing factors of conductivity, radiation, and convec- 
tion by air-currents, are all credited with much greater influence 
in bringing about uniformity than they really possess. It 
sometimes happens that our faith in these factors is inversely 
proportional to our quantitative information. 

To remove this source of uncertainty, Day and Clement 
introduced two auxiliary heating coils in the furnace, one at 
each end, and by varying he three independent currents, 
brought the temperature at the middle and at both ends, on 
the outside of the bulb, to equality. 

In our first measurements with the new bulb, the end ele- 
ments were placed on the axis of the bulb, in positions 1 and 
9 (fig. 1), instead of on the outside surface. It became evi- 
dent at once that the supporting tube in the bottom of the 
furnace, used in the work of Day and Clement, had a consid- 


v al or, 


Nitrogen Thermometer from Zinc to Palladium. 108 


erable cooling influence on the central! portion of the bottom, an 
effect which would tend to make their results low. This effect 
was largely obviated by using, in place of the heavy magnesite 
tube, a thin Marquardt porcelain tube in the top of which 
was placed a Marquardt crucible, cut ont into a three-pronged 
support. The bottom of the crucible acted as a screen to pre- 
vent radiation from the bottom of the bulb, and the smaller 
thickness and thermal conductivity of the tube practically pre- 
vented the loss of heat from the bottom by conduction. Later, 
a second diafram was added, about 1™ lower down, primarily 


Mires 1 Fie. la. 


SECTION. 


Fig.1. Numbers indicate the positions of the thermoelements grouped 
about the bulb. 

Fic.1la. A photograph of the bulb made after the palladium- point deter- 
mination showing all the elements and the diaframs in position. 


for the purpose of centering the tube and bulb in the furnace, 
but without noticeable effect on the temperature distribution. 

In addition to the three thermoelements mentioned, a fourth 
was located inside the reentrant, in position 8.* Several trials 
under varied conditions confirmed the fact that this element, 
when the other three were set equal, was 2° to 3° hotter than 
the cone on the outside. A thorough exploration of the dis- 


* See fig. 1, and note, p. 104. 


104 A, L. Day and Le. B. Sosman— 


tribution of temperature over the surface of the bulb was 
therefore undertaken. 

Since the number of wires which could be led out through 
the packed joints was limited, the plan was adopted of using 
the bulb itself as a differential thermoelement, single platinum 
wires being tied to the bulb at points whose temperature was 
to be determined. Each of these wires formed, with the 
platinum of the standard element tied to the bulb at the mid- 
dle, a differential element which would read zero if the wires 
were alike and if no difference of temperature existed between 
the two points on the bulb. 

The relation of the wires was established by sealing each in 
turn to the platinum of the standard, and measuring their 
E.M.F. at various temperatures. The readings varied, accord- 
ing to the quality of the wire, from 0 to 40 microvolts.’ The 
method of evaluating differences of temperature, when such 
existed, is discussed on page 118. 

The distribution of temperature lengthwise of the bulb was 
first investigated, and auxiliary wires were placed at the levels 
1 (base of stem), 2 (top shoulder), 6 (bottom shoulder), 7 
(bottom, outside of funnel), in addition to thermoelements at 
4 (middle outside), 8 (nside reentrant), and 9 (bottom, just 
inside of funnel).* 

With this system of thermoelements, it was found that at 
1082°, when 9 was brought to equality with 4 and 1, the bot- 
tom of the bulb was superheated 6 to 8° at position 6, and 
about 4° at 7, due entirely to the fact that the thermoelement 
at 9, not being in contact with the bulb, lost sufficient heat by 
conduction and radiation downward to keep its temperature 
below that of the metal surrounding it. The element at 8, on 
the other hand, received heat by conduction up the reentrant 
tube and by radiation from below, which made it read higher 
than the element at the same level outside. The element at 
position 9 was therefore discarded and each setting of tem- 
perature made with reference only to the elements which were 
attached directly to the bulb. 

The temperature between the middle and the top shoulder 
was also examined in several experiments. The temperature 
at this position was found to be within 0°5° of the other two, 
with a tendency to be lower than these. 

Further experiments showed that in addition to the possi- 
bility of vertical variation of temperature, there was a varia- 

* The system of numbering the positions of elements on the bulb is shown 
in fig. 1. The figure before the decimal point indicates the horizontal level, 
the figure after the decimal indicates the orientation around the bulb. For 
instance, an element in position 3°5 would be about half way between the 


top and middle and on the side of the bulb away from the front of the 
apparatus. 


Nitrogen Thermometer from Zine to Palladium. 105 


tion around the circumference of the bulb. This amounted 
in the worst case (at 1450°) to a variation of 1°3° from the 
mean, four elements being used around the circumference to 
make the test. This variation seemed to be due either to 
unequal conductivity of the furnace material at different 
points or to the falling off of small portions of the furnace 
lining, leaving exposed places on the wire. Variations of 
this character are probably an unavoidable result of using a 
furnace where the heat supply is so near to the point where it 


Fig. 2. Fic. 38. 
oMG | ANNAN 
ENN Ge \ N Ne 
a | \\ N N 
a NN NN 
ce i NN N Ne | 
=. WY \ ENN Nets Ny Ne 
es 7 LA NN aN N33 
[V7 YF 


K/// 


Fic. 2. Sectionof furnace and bulb showing the arrangement of coils and 
diaframs about the bulb which gave the most uniform temperature distri- 
bution in the measurement of both high and low temperatures. The sup- 
plementary end coils were independently heated and regulated. 

Fie. 5. Aspecialarrangement of the heating coil and diaframs designed 
to give a very uniform temperature distribution about the bulb. The coil 
was heavily ballasted inward with a good heat conductor and outward with 
a poor conductor. The heating coil was also divided into three sections 
which could be independently regulated. This furnace was used at the 
copper point only. 


is measured, as is the case with the furnace which is wound 
on the inside. This form of winding is necessary, however, 
in order to reach the highest temperatures, so that absolute 
uniformity of temperature around the bulb had to be sacrificed 
to increased range of the instrument. 

After this variation was discovered, measurements were 
always made with four elements at equal distances around the 


106 A. L. Day and. R. B. Sosman— 


circumference of the bulb and the mean of their readings was 
taken. 

In order to be perfectly certain that no systematic error 
was being introduced by using this one form of furnace (fig. 2.) 
throughout, it was replaced temporarily by a furnace of plati- 
num wire wound on the owtside of a similar tube. In this 
way a heavy mass of good heat-conducting material was intro- 
duced between the source of heat and the bulb, with the 
expectation that a more uniform temperature might thereby 
be obtained in the inside space. The two types of furnace 
are shown in figs. 2.and 38. 

A measurement at the copper point with the outside-wound 
furnace gave as the melting point of copper 1082°6°, which 
differs only 0°4° from 1082°2°, the mean of the results obtained 
at the same pressure with the other furnace, and is identical 
with the final mean of all the results, thus proving that no 
systematic error was to be feared from the inside-wound type 
of furnace. The horizontal uniformity obtained in the outside- 
wound furnace was better than that in the inside-wound, but 
the furnace was more difficult to regulate and to hold at a 
given temperature. 

(0) Constancy of Conditions.—Several causes interfered 
with the establishment of a constant temperature for observa- 
tion. The three heating currents required constant observa- 
tion and readjustment with the gradual extension of the heated 
zone toward the outside of the furnace. This comes to equi- 
librium for a particular temperature after about half an hour, 
after which the bulb was held steady 15-80 minutes longer 
before readings of the pressure were taken. ‘The temperature 
thus established could be relied upon to remain constant to 
within 1 to 3 microvolts (0-1° to 0°3°) during the course of the 
pressure measurements. 

Above 1100° a noticeable leakage of current from the heat- 
ing coil into the bulb and thermoelements frequently appeared. 
This may have been due in part to conductivity across the 
narrow air space between bulb and coil, but was probably 
chiefly due to accidental contact between the protecting tube 
of one of the thermoelements and the furnace wall. ‘To obvi- 
ate any uncertainty from this cause, it was found necessary to 
use alternating current for all temperatures above 1100°. This 
was less easy to regulate than the direct current from storage 
batteries, but by careful regulation of the voltage of the motor 
generator supplying the alternating current, equally satisfac- 
tory results were obtained. 

The constancy and exactness of the temperature at 0° were 
beyond question. On several occasions pressure measurements 
at 0° were made at intervals of one-half to one hour and no 


Nitrogen Thermometer from Zine to Palladium. 107 


measurable difference found. Similarly, repacking the bulb 
in a fresh supply of ice gave exactly the same value. 

B. Definition of Temperature by Measurements of Pres- 
sure.—The procedure in measuring the pressure, p’, was as 
follows: First the three mereury thermometers on the mano- 
meter were read to determine the temperature of the mercury 
eolumn and scale; then three to four settings of the barometer 
were made, alternating with measurements of the manometer. 
The mercury thermometers were read again at the close. Dur- 
ing this interval the other observer made as many readings as 
possible of all the thermoelements. 

Before the manometer was connected to the bulb, the point 
on the scale corresponding to the reference point of the mano- 
meter* was determined once for all before the manometer was 
connected to the bulb, by connecting the two arms and raising 
the mercury to the point, as in a regular pressure measure- 
ment. Subsequent manometer readings were subtracted from 
this fixed level, and the resulting difference corrected for the 
temperature and calibration corrections of the scale and then 
reduced to 0°. The barometer reading was similarly corrected. 
The algebraic sum of the two gave the pressure p’, in terms of 
a centimeter of mercury at 0° and at the latitude and elevation 
of the laboratory. Since the absolute value of the pressure 
does not enter into the gas thermometer formula, corrections 
for altitude and latitude are superfluous. 

Errors and Corrections in p’.—The level of the fixed refer- 
ence point of the manometer varies with the temperature of 
the room because of the difference in expansion of the brass 
scale on the one hand and of the glass tube of the manometer 
which carries the fixed point on the other. This correction 
can be calculated from the expansion coeticients of the mate- 
rials and amounts to 0:04™™" per 5°. Its direction and amount 
were checked experimentally by determining the fixed point at 
two temperatures differing by about 10°, the room being open 
on acold day for the one case, and then closed and heated for 
the other. The difference found was 0:09™™, and that caleu- 
lated 0:08"™. 

The lengths of the divisions of the brass scale were corrected 
for change of temperature by a formula determined for this 
scale at the Normal-Aichungs-Kommission, the absolute length 
of the scale having been determined at 16°. In addition, cali- 
bration corrections, determined for each millimeter of the scale, 
were applied. The total scale correction was always less than 
0°15™™, hence the temperature measurement by the adjacent 
mercury thermometers was abundantly accurate for this pur- 


pose. 
5p. 100. 


108 A. L. Day and Rk. B. Sosman— 


The length of the mercury column was reduced to 0° by the 
expansion coefficient given in the Landolt-Bérnstein-Meyer- 
hofter Tabellen. This correction varied from 0 to about 3-00™™. 
As the mercury thermometers were calibrated and read to 0:1°, 
the uncertainty in this correction due to uncertainty in the 
room temperature may amount to 0°05"™". For the calibration 
the mercury thermometers were compared with a Richter 
standard thermometer calibrated at the Reichsanstalt. 

The barometer reading was corrected to 0° by the Landolt- 
Bornstein-Meyerhoffer table for barometer with brass scale. 
Two Fuess barometers were used. Both had been tested by 
the Bureau of Standards; one had an absolute correction of 
0-06"™, the other was exact. This was checked by direct com- 
parison of the two. The variable error in the barometer is 
probably about the same as in the manometer reading (0°05™"). 
On a very windy day or during the approach of a storm, the 
barometer was too unsteady to permit satisfactory measure- 
ments to be made. 

A further small correction to the barometer was necessary to 
allow for the weight of the air column between the cup of the 
barometer and the top of the mercury in the open manometer 
column. This correction was appreciable, amounting to 0:16™™ 
in the extreme case. 

To give some idea of the effect of these small corrections 
upon the final temperature measurement, it may be added that 
1:00" corresponds approximately to 1°. 

To determine the corrected pressure, p, from the measured 
pressure, p’ (see page 101), the volume of the unheated space, v,, 
connecting the bulb with the manometer, must be known.* 


Taste I.— Unheated Space. 


Max. effect 
Space Volume, c.c. Uncertainty | at Cu. pt. 
of errors 
Before | After |jof vol.jof temp. 
Apr. ’09 Apr. ’09 
Pt-Rh capillary, bulb to top | 
furnace (v;') 0:055 | 0°055 | 0°002) 100° 0°04° 
Pt-Rh capillary, top to out- | 
side furnace (v;") 0:086 | 0:°086 | 0-008 50° 020° 
Pt-Rh capillary to gold | 
capillary | 07102 | 0:054 ) 
Gold capillary i) OLUSEE Ua | 
Pt capillary and Ni Oe 0°015 | 0°5° 0:20" 
valve 0:025 0°025 | 
Space above meniscus J} 0-023 | 0°023 | 
Total 0385 | 0°309 | 0°45° 


* See discussion of this correction, Day and Clement, loc. cit., p. 410. 


Nitrogen Thermometer from Zine to Palladium. 109 


This was caleulated from the dimensions of the capillary. 
The figures are given in Table J. This volume was reduced in 
April, 1909, by bringing the manometer closer to the furnace, 
since the water jacket of the furnace cut off the heat so com- 
pletely that there was no risk in bringing the manometer as 
close as possible (85™). The volume v, was thereby reduced 


from 0°39% to 0°31°%, and the ratios! from 0°00187 to 0:00150. 


The volume, V, which enters into the correction term (see 
page 102) was "determined by weighing the bulb empty, and 
filled with distilled water at a known temperature. <A very 
accurate determination of this volume was not necessary, the 
important requirement being that the volume should not change 
during arun. A check on change of volume was obtained in 
the measurement of the value of p,. The volume of the bulb 
at 0°, up to the base of the capillary stem, was found to be: 


On-13 June; 1908 (new). ..-.- 2... 205°74° 
Onis. * tee (uber NA Onis 205) 7a 
Ore rA per I00 aa aoa en ZOD B26. 


The volume of the unheated space, v,, was arbitrarily divided 
into three portions for the convenient determination of its 
average temperature, ¢,. The first portion, v,’, extended from 
the base of the stem to the top of the upper brick of the fur- 
nace (see fig. 2); the second portion, v,”, included the capillary 
stem as far as the outside of the furnace ; the third portion, 
v,/’’, extended to the surface of the mer cury in the manometer 
and included all of that portion of the unheated space which 
remained at room temperature. 

The temperatures of the portions v,’ and »,’’ were deter- 
mined by placing a thermoelement at different points along the 
stem during severalof the runs. As this temperature does not 
need to be known accurately, a few measurements gave a 
sufficient indication of the distribution of temperature in the 
portion of the “ unheated space” within the furnace. 

A liberal estimate of the degree of uncertainty in the values 
of v, and #, has been made and is included in Table I, together 
with the effect which such errors would have on the calculated 
temperature, ¢, at the copper point. 

Errors and Corrections im p,’.—The same Ageeenmentell cor- 
rections apply to p,’ as to p’, but their proportional magnitude 
is, of course, larger. ‘The values of the uncertainty in ¢ due 
to these small errors will be found in Table LV. 

Changes in the value of p, (the ice point) after heating to 
high temperatures have always been disturbing factors in gas 
thermometer measurements and have introduced uncertainties 
of a very intangible kind. This was especially true of the 


Am. Jour. Sct.—FourtH Series, Vou. XX1X, No. 170.—Fesrvuary, 1910. 
8 


110 A. L. Day and f. B. Sosman— 


porcelain bulbs formerly used, where both changes of volume 
and emission or absorption of gases by the walls occurred. 
The restoration of the platinum metals to favor as materials 
for the gas thermometer bulb has practically eliminated this 
uncertainty. During the present work small changes in the 
value of p, have frequently occurred after heating to a high 
temperature, which seem not to be due to any change in volume, 
for the determinations of the volume, V,, given above (p. 109), 
show a total change after a year’s work cor responding to less 
than 0:1" in p,. Iu the early part of the work, the passage 
through the bulb wall of hydrogen or some other gas produced 
by the reducing action of wood fiber in an asbestos board insu- 
lator within the furnace, was suspected as being the cause of 
irregularity, particularly in view of the fact that Holborn and 
Valentiner had difficulties from this cause. Further, it was 
several times observed that heating the furnace and bulb to a 
higher temperature than they had reached before, caused a 
slight increase in the value of p,,—whether due to some gas 
passing in from the outside, or coming out of the wall of the 
bulb, is not known. Air dried over calcium chloride was 
used outside of the bulb in the furnace enclosure throughout 
the work, and no indication was ever obtained of the passage 
of either oxygen or nitrogen through the wall of the bulb, 
since measurements at a given temperature (after the first 
heating to that temperature) gave the same value of y, within 
the error of measurement. 

On one occasion an almost inappreciable leak in the mano- 
meter connection caused some uncertainty. All measurements 
affected by this error, when it was discovered, were rejected. 

a.—Since the gas thermometer apparatus as arranged for 
high temperature measurements is not suited toa determina- 
tion of the value of a (the pressure coefficient of the gas from 
0 to 100°) with an accuracy comparable to that attained by 
Chappuis,* the value of a was treated as a constant. The 
figures used were : 


For p, = 845 — 347™™, a = 3665°8 X 10° 
For Pp, = 217 — 2217", a = 36640 K 107 


A number of independent determinations of a for different 
pressures were made by Day and Clement} with the platin- 
iridium bulb, but they show no appreciable difference from 
those by Chappuis within the experimental error of the appara- 
tus. The probable error in Chappuis’ results is not great 
enough to affect the high temperature values. 


* Trav. Mem. Bur. Int., viand xii, 1888 and 1902. 
{Day and Clement, loc. cit., p. 442. 


Nitrogen Thermometer from Zinc to Palladium. 111 


Pure nitrogen was used throughout as the thermometric gas.* 
The storage tank was refilled several times so that not all the 
gas was from the same original supply; the filling of the bulb 
was also changed several times. The bulb was first. completely 
evacuated and heated to a high temperature, after which the 
connections and bulb were rinsed out several times with the 
purified gas before the final filling. 

Expansion Coefficient of the Bulb. (8).—The substitution 
of a new alloy in place of the platin-iridium made necessary a 
new determination of the expansion coefficient of the bulb 
material. The method of its determination and the comparator 
used for the purpose were fully described in the earlier articlet 
and do not require to be repeated here. 

Three additional precautions were taken in carrying out the 
measurements: The bar was increased in length to 0°5 meter, 
and in diameter to 6™”, in order to increase the sensitiveness of 
the determination and the uniformity of temperature along the 
bar respectively. In this case the bar was also made atthe 
same time and from the same alloy as the bulb itself, and was 
therefore identical with it in composition. t 

In ruling the bar, the lines were spaced 0°2™™ apart instead 
of 0°5™, as in the previous investigation. This enabled a 
greater number of observations to be made within a narrow 
region than heretofore, and has thus made it possible for us 
to avoid the error from parallax described in the previous 
paper.s 

The third precaution involved a slight change in the com- 
parator itself, and was made at the suggestion of Chappuis. 
Our custom had been to verify the distance between the fixed 
hairs of the microscopes before and after each heating by 
measuring this distance in terms of a standard brass bar cali- 
brated at the Bureau of Standards. The brass bar was then 
replaced by the platin-iridium bar before the heating began, 
and the length of the latter was measured in terms of the 
initial distance between the fixed hairs, at intervals of 50° or 

*TIt was prepared by dropping a solution of 200 grams of sodium nitrite 
dissolved in 250 grams of water, into a warm solution containing 350 grams 
of ammonium sulphate and 200 of potassium chromate in 600 of water. It 
was passed through a mixture of potassium bichromate and sulphuric acid 
and stored over water. For use in the gas thermometer it was purified by 
passing through calcium chloride, hot copper gauze, potassium bichromate 
in sulphuric acid, 2 bottles potassium pyrogallate solution, sulphuric acid, 
calcium chloride and phosphorous pentoxide. 

+ Day and Clement, loc. cit., p. 420. 

¢ The new bulb, as well as the bar, were made with the utmost care by Dr. 
Heraeus, of Hanau, Germany, for this investigation. We have had repeated 
occasion in the past to make public expression of our indebtedness to Dr. 
Heraeus for his interest and assistance in this work, and it is a pleasure to 


repeat this acknowledgment here. 
§ Day and Clement, loc. cit., p. 435. 


112 A. L. Day and FR. B. Sosman— 


100° up to1000°. This mode of procedure involved the assump- 
tion that the agreement of the measurements made before and 
after heating afforded adequate proof that no change had taken 
place during heating. The justification for this assumption 
lay in the fact that, (1) the furnace was completely water- 
jacketed to prevent any heat reaching the microscopes from 
the furnace ; (2) suitable insulating material introduced between 
the observer and the microscopes cut off any disturbing influ- 
ence from the near approach of the observer’s body; (3) the 
microscopes themselves, and the carriages upon which they 
were mounted, were connected by carefully selected invar bars 


Fic. 4. V 


Fic. 4. Section through furnace showing bar, thermoelements (EH, EH) and 
microscopes in position. A section through the arrow is shown in fig. 5. 


of negligible expansion coefficient, and, finally, (4) the faith- 
ful agreement of all the measurements before and atter the 
many heatings left no reason for suspecting a variation. 
Notwithstanding these conditions, it appeared to Chappuis 
that some positive proof should be offered that the distance 
between the cross-hairs remained unchanged while the heating 
was going on, inasmuch as all the measurements were made 
in terms of this distance. Accordingly, at his suggestion, 1t 
was arranged to retain a standard unheated bar in the field of 
the microscopes throughout the readings, so that the distance 
between the cross-hairs would be subject to check at any time 


Nitrogen Thermometer rom Zinc to Palladium. 118 


during the observations. The arrangement made for the pur- 
pose is very simple and effective, as can be seen from the 
neighboring diagrams (figs. 4 and 5). The last two series of 
measurements were made with this appliance, and the fixed 
distance was found to remain constant throughout the series 
to within 0:003™", although on first setting up the apparatus a 
gradual adjustment of strain, amounting to 0°012"", took 
place during the first two days. 

The determination of 8 is subject to two errors; the first 
is uncertainty of temperature, the second occurs in the measure- 


Fic. 5: 


%, 
ry 
AZ 


Fic. 5. A section through the furnace at one of the openings, showing 
the method of illumination of the heated bar and the standard cold bar (I) 
together with an arrangement for checking the distance apart of the cross 
hairs at each temperature. With a screen inserted at a only the hot bar is 
visible ; with the screen at 6 only the cold bar. 


ment of the change in length. It was impossible to wind the 
furnace (70 long and 2°" inside diameter, with two side open- 
ings) so as to give a perfectly uniform temperature along the 
bar; but as the furnace winding and consequent distribution 
of temperature were varied considerably for each run, the 
uncertainty from this cause was eliminated in the average of 
all the observations. The error in the temperature measure- 
ment itself was probably not over 2°, which would give an 
error of less than 0°2 per cent at the highest temperature. 
Two thermoelements with a common junction were used, one 
entering from each end of the furnace. This not only gave 
a second temperature reading in confirmation of the first, but 


114 A. L. Day and R. B. Sosman— 


a positive check upon the appearance of contamination in the 
thermoelements.* 

With a half meter bar and a temperature interval extending 
from zero to 1400°, the total expansion amounts to about 
78""™. The micrometers reading the expansion were read 
with an accuracy of 0-002". 

There was some indication of a very small hysteresis in the 
expansion and contraction. Although the amount was not 
much greater than the experimental error, the measurements 
indicate that the bar was slightly shorter after heating than 
before, and that it gradually regained its original length. _ 

The measurements at room temperature are given in Table 
IJ. The five measurements in this table which were made 


Taste Il.—Length of Platinum-Rhodium Bar. 


Max. preced- Max. preced- 
Date ing temper- i a Date ing temper- ee 
ature ature. 

1 July 1908) (New) 500°068 |/26 Sept. 1908 1150° 500°094 
Coes ne 900° DOO MAO el ial Oct ann. 20° 590°119 
9. SF a 28° 500°105 Gene SAE 1300° 500°034+ 
HG} eye a 900° DOO 09S a2 ee ees 900° 500°108* 
ie SOpta a. 900° DOOMOS a SOs. cea 1400° 500-096 
1S Ja ae 1200° 500°090 One O00 28° 500°103 
COs eae 20° S00 M007 sa ee ote 22. 500°108* 
Ge, 6 ate 1200° DOO OS iis eo 1000° 500°109 
ale aa gare 24° 5002096) Stan ae a 1400° 500-074+ 


* After interval of 4-7 days. 
+ Bent, after heating beyond last temperature at which measurements 
were made. 


within a few hours after the bar had cooled from a high tem- 
perature, excluding the two where the bar was bent, average 
500095; while the ten measurements (excluding the first) 
which were made two days or more after heating, average 
500°106. The difference is only 0:002 per cent of the total 
length, or 0°12 per cent of the total expansion to 1500°, or 
about 0:7 per cent of the expansion to 300°. This effect is, 
therefore, probably responsible for the observed irregularities 
between 0° and 300°, at which temperature most of the meas- 
urements were begun.t 

C. Transference of Temperature by the Thermoelement.— 
The electromotive forces of the elements attached to the bulb 
were measured by a Wolff potentiometer. The standard of 

* Day and Clement, loc. cit., p. 419. 

+Kammerlingh-Onnes (Konink. Ak. Wet. Amsterdam, Proc., x, 342, 


1907) has found the same effect after cooling platinum to very low tempera- 
tures. 


Nitrogen Thermometer from Zinc to Palladiun. 115 


electromotive force used was the true volt, in terms of which 
the E.M.F. of the Clark cell is 1°4328 at 15°, and of the satu- 
rated cadmium cell used, 1:01918 volts at 25°. 

Several small corrections are necessary in order to obtain 
the true E.M.F. of the thermoelement. The calibration cor- 
rections of the potentiometer (Reichsanstalt calibration) were 
all negligible except that for the fixed resistance to which the 
standard cell was attached. This correction amounted to 1°3 
microvolts in 10,000. ‘The correction for the change of resist- 
ance with temperature of the potentiometer was also negli- 
gible. The E.M.F. of the standard cell varies with the 
temperature; hence the temperature of the cell was read at 
each measurement and a small correction applied. ‘The read- 
ings were correct at 21°5°. For a variation of 5° from this 
temperature the correction was 2°2 microvolts in 10,000 micro- 
volts. The resistance of the contacts of the potentiometer, 
and the small E.M.F.’s existing at contact points in the circuit 
of the thermoelement, introduced another small error which 
was determined by placing the thermoelement in ice and read- 
ing the E.M.F. This correction varied for the different ele- 
ments from —1 to +4 microvolts. | 

As a check upon the absolute value, a Weston standard 
cadmium cell (calibration by the Bureau of Standards) whose 
E.M.F. was read directly on the potentiometer, was compared 
with the saturated cell each day. The agreement of the cor- 
rected values was usually within 0°5 microvolt. As in the 
case of the pressure measurement, the absolute value of the 
E.M.F. is not of importance, since it is used only for trans- 
ference from the fixed points to the gas thermometer; the 
above corrections were applied, however, to reduce the read- 
ings to a common standard. 

The effect of contamination of the thermoelement wires in 
furnace readings was much greater than the above mentioned 
errors.* Up to 1100° the contamination was not serious, but 
above that temperature the wires take up iridium together with 
some rhodium. It was hoped that the replacement of iridium 
in the bulb by rhodium, which is very much less volatile, 
would do away with this error, but there appeared still to be a 
very small percentage of iridium in the furnace wire, enough 
to affect the thermoelement wires appreciably, even though 
this furnace wire had been especially purified for this purpose. 

Although the task became much longer and more laborious, 
it was thought wise to make an effort to avoid the error from 
contamination, even of this diminished magnitude, rather than 
to attempt to compromise with it by any scheme of approxi- 


* For a more thorough discussion of this effect, see Day and Clement, loc. 
it., p. 419; and W. P. White, Phys. Rev., xxiii, 449, 1906. 


116 A. L. Day and R. B. Sosman— 


. 


mate evaluation. Accordingly, after every exposure of suffi- 
cient length to endanger the thermoelectric readings, ail the — 
thermoelements were removed from the furnace and their wires 
tested for homogeneity. Where contamination was found, 
the contaminated portion of the wire was at once cutoff This 
is the only absolutely safe method of avoiding errors from this 
cause, for it amounts to the use of new thermoelements exclu- 
sively in all the determinations of temperature distribution 
within the furnace as well as for establishing the absolute 
temperature of the metal melting points. 

A very simple method of testing the wires for contamina- 
tion has been developed which consists in connecting the junc- 
tion end of the wire to be tested, together with an uncontam1- 
nated wire, to the potentiometer and moving the free end of 
the standard wire along the wire to be tested, while heating 
the contact pomt of the two with a blast lamp.* The varia- 
tion of the E.M.F. produced at this junction indicates the 
degree of contamination of the wire; in the uncontaminated 
portion this E.M.F. is small and constant within 8myv. The 
temperature obtained by the blast lamp flame is sufficient] 
constant for the purpose and lies between 1460° and 1500°. 

The wires could be relied upon to give a constant E.M.F. 
within 2 my. at 1000° over a length of at least 50°, so that 
redeterminations of the fixed points were not necessary after 
cutting off each small portion of contaminated wire. Each 
test for contamination was continued over the 50°" of wire 
adjacent to the hot junction and so served as a test for the 
homogeneity of the new wire which replaced the portion cut 
off. In two cases a sudden change of E.M.F. along the unused 
wire amounting to about 10 mv. showed the probable presence 
of a junction point in the original sample from which the wire 
was drawn. Such a junction point was of course not intro- 
duced into the heated portion of the furnace. 

In this connection, it should be pointed ont that the relative 
weight to be given to the element inside the bulb, as compared 
with the outside elements, is greater at temperatures above 
1100° than at temperatures below, for two reasons: (1) The 
temperature at the middle of the bulb is not so much influenced 
above 1100° by the temperature of the lower part of the fur- 
nace, as it is below 1100°; (2) the outside elements are much 
more subject to contamination than the inside element by 
reason of the protection afforded by the intervening bulb walls 
against contaminating material from the heating coils. This 
is well shown by the data in Table VIII on the melting points 
of diopside, nickel and cobalt. In the first measurements of 
these temperatures, the elements were left on the bulb through 


*W.P. White, loc. cit. 


Nitrogen Thermometer from Zine to Palladium. 117 


several runs, in consequence of which the temperatures derived 
by the outside elements steadily increase through the series 
_ (i. e., the readings of the outside elements on the bulb steadily 
decreased), whereas the temperatures derived from the inside 
element are fairly constant. Its contamination was found to 
be less in amonnt and distributed over a region of more con- 
stant temperature. 

For insulating the thermoelement wires from the bulb and 
furnace, capillary tubes, both of Marquardt porcelain and of 
silica glass, were employed. The Marquardt tubes are open 
to the objection that they are very porous and offer little pro- 
tection against contamination. The silica glass capillaries pro- 
tected the wires very much better, but at 1100° and above 
they devitrified rapidly and at the end of a measurement at 
1400° or over fell from the wires in small fragments, so that 
the wires had to be taken off and reinsulated after a single run. 

.For the convenience of others who may confront similar 
problems, it may be added that such extreme precautions as 
cutting off the elements at the first sign of contamination are 
excessive for most purposes. The region of highest tempera- 
ture, and therefore of most rapid contamination in a good. 
turnace, is also a region of constant temperature. Contamina- 
tion would therefore produce little effect upon the reading of 
the thermoelement until it had crept out into the colder parts 
of the furnace, which it will do slowly during long exposures. 
The distribution of the contamination in an aggravated case is 
shown in the accompanying table, which is arranged in such 
a way that not only the magnitude of the contamination but 
also its distribution with respect to the bulb is roughly shown. 
The electromotive forces are determined, as has been 
explained, by bringing successive points of the contaminated 


Before After 
Heating. Heating. 
Microvolts Microvolts 


AQ? —4 —4 
35 —8 
Outside of furnace 30 : —"7 
25 5 
Bend of stem 20 —10 
15) —3 


—6 
—§ 
—9 
—6 
—5d 
rr —5 +2 
—5) 
Shoulder of bulb 8 —5 
—— 19) 
—6 
—6 
—8 


Middle of bulb 


118 A. L. Day and R. B. Sosman— 


wire into contact with an uncontaminated one in a biast flame 
(temperature, 1460—1500°), the cold junction being maintained 
constant at 0°. The absolute magnitude of the numbers in the 
column ‘before heating” represents the electromotive force 
between two uncontaminated platinum wires of (nominally) 
equal purity. Its constant value is a measure of the homo- 
geneity of the new wire. Its departure from this constant 
value ‘“‘ after heating” is a measure of the contamination it has 
received. Shght irregularities are the result of variations in 
the blast flame temperature. Such observations merely serve 
to furnish information about the distribution and approximate 
amount of contamination received by the element, but do not 
of themselves provide the data to correct its reading in a par- 
ticular furnace. 

Integration of Temperatures over the Bulb.—By the method 
which has been already described (p. 104) the differences of 
temperature between the ends of the bulb and the middle were 
determined differentially by means of platinum wires attached 
to the bulb itself. Temperatures about the circumference 
were measured by separate thermoelements, as it was not practi- 
cable to measure these differences differentially because of the 
necessity of passing a platinum binding wire around the bulb 
to hold the four elements in position. A check on the accu- 
racy of this differential method was obtained by using in one 
case a thermoelement at the top shoulder of the bulb and 
thus measuring the temperature at this point both directly . 
and differentially by means of the platinum wire of this ele- 
ment. The two temperatures agreed within 0°8° when the 
deviation from the middle was 6°; when the temperatures at 
the middle and top were nearly equal, the two methods agreed 
to, O'1°. 


Table III contains values of on the rate of change of E.M.F. 


with temperature at various temperatures from 400° to 1500°, 
both for the 10 per cent rhodium alloy and for the 20 per cent 


TasiLe IIL.— Values of AS for the alloys 90 Pt. 10 Rh. and 
80 Pt. 20 Rh. 


Temp. SO Pe elOUR he 80 Pt. 20 Rh. 
400° 9°4 11°5 
600° We LA) 
800° 10°8 14°2 
1000° 11°4 15°6 
1200° 1S 169 
1400° 12°2 175 


1500° 12°4 ies 


Nitrogen Thermometer from Zinc to Palladium. 119 


alloy of which the bulb was made. The data for the 20 per cent 
alloy (which need be only approximate) were obtained by two 
methods: (1) An element was made up by combining a plati- 
num wire with the 20 per cent rhodium bar used for the 
expansion coefiicient determination, and its readings compared 
directly with those of a 10 per cent rhodium element in the 
melting point furnace. (2) A platinum wire was connected 
from the stem of the gas thermometer bulb outside of the gas 
thermometer furnace to the ice box, and the E.M.F. deter- 
mined against the standard platinum wire attached to the 
middle of the bulb. In both cases, the E.M.F’. of the junction 
of platinum with the rhodium alloy at room temperature was 
applied as a correction. 

In order to obtain the true E.M.F. corresponding to the 
temperature as measured by the pressure of the gas in the bulb, 
it is necessary to integrate the various readings over the sur- 
face of the bulb. The following arbitrary weights were given 
to the different positions of elements on the surface : 


Top axis (position 1) 5 
Top shoulder Caress re 20 
Middle (owen as 55 
Bottom shoulder ( “ _ 6) 15 
Bottom axis (Biren alk) 5 


The elements on the axis at both top and bottom, although 
sometimes deviating rather widely from the others, have com- 
paratively small weight, as they affect only a small portion of 
the total volume. The element at the lower shoulder of the. 
bulb is given less weight than that at the top because of 
the smaller volume of the lower half, due to the presence of 
the reéntrant tube. . 

It was easy to show experimentally that it matters very little 
what these relative weights assigned to the different readings 
may be, since the total correction was usually small. Ina 
number of cases, two different settings of the temperature dis- 
tribution were made at each temperature, one in which the ele- 
ments at the top and bottom shoulders of the bulb were made 
equal to the middle, and one in which the elements at top and 
bottom on the axis of the cylinder were made equal to the 
middle. The pressures corresponding to these two settings, 
reduced to the same reading of the standard element, are 
shown for several typical cases in the table below. 


Pressure when 1, Pressure when 2, 
4, and 7 were 4, and 6 were 
Date Temp. equal equal 
22 Jan. 1909 1082° 1038°82™™ 1038°64™™ 
2 July 1909 1395° 1285°43 1285°17 


17 Sept. 1909 1489° 1331°40 1330°63 


120 A. L. Day and R. B. Sosman— 


It is evident that even without any correction for the dif- 
ferent distribution in the two eases, the readings agreed within 
0-2—0°8™", or about 0°2—-0°9°, so that the variation between any 
two arbitrary sets of weights which might be given to the dif- 
ferent readings must he well within this limit. 

The Transfer to the Fixed Points.—After the thermoele- 
ments are removed from the bulb, their E.M.F. at the fixed 
points must be determined by immersing them in melting or 
freezing metals or salts. The instrumental corrections to the 
readings so obtained were the same as in the case of the gas 
thermometer readings. The error due to contamination was 
also present above 1100°, just as in the gas thermometer fur- 
nace, and was a very disturbing factor in determining the melt- 
ing points of nickel, cobalt and palladium. Its source, how- 
ever, was not usually iridium vapor from the furnace or 
rhodium from the wire of the element, but was either vapor 
of the melting metal itself, or (when a hydrogen atmosphere 
was used) the products of reduction of silica. In the presence 
of hydrogen, silica rapidly deteriorates platinum wire by 
reduction and alloying, as has been shown in this laboratory 
by Shepherd,* and elsewhere by several observers. The con- 
tamination can be partly prevented by the use of a glazed 
porcelain tube surrounding the thermoelenient, instead of an 
unglazed magnesia tube; but an additional uncertainty is 
thereby introduced through the contamination of the melting 
metal by the melted glaze on the porcelain. For this reason 
nickel and cobalt did not prove to be as satisfactory fixed 
poits as had been hoped, since it was necessary to melt them 
in an atmosphere of hydrogen. Palladium, however, can be 
melted in the open air and serious contamination by silicon 
thus be avoided, although the palladium itself gradually con- 
taminates the wire. ! 

Above 1100° it is better to make direct comparisons of all 
the elements with one or two whose fixed points have been 
determined, rather than to contaminate them all by a direct 
determination. For making these comparisons, the plan first 
used was to bring a crucible of molten silver to a constant tem- 
perature and insert the elements (protected by a glazed Mar- 
quardt porcelain tube) successively into the silver bath. There 
is an uncertainty, however, in these measurements of 2 to 3 mv., 
caused by small differences of temperature within the tube 
and to the slight cooling produced by introducing cold wires 
into the furnace. A better method is to join together the two 
platinum wires and the two alloy wires of the elements to be 
compared, and determine the small E.M.F.’s of each pair at 
several temperatures, from which the difference between the 


* This Journal (4), xxviii, 300, 1909. 


Nitrogen Thermometer from Zinc to Palladium. 121 


elements at those temperatures can be obtained by algebraic 
addition. This method offers a great advantage in that the 
temperature need be only approximately constant and approxi- 
mately known, since the differences in most cases amount to 
only a few microvolts. By this method the comparison can be 
very quickly made at 1500° in the blast-lamp flame, which, 
with a little care, can be made to give a temperature constant 
to 20°. 

D. Fixed Points.—Considerable attention was given in the 
previous paper to the standard melting poimts which serve to 
establish the gas thermometer scale for general use. In parti- 
cular, a study was made of the purity of the zine, silver, gold, 
and copper used, and of the magnitude of the errors likely to 
arise with the ordinary metals obtainable in the market.* 
During the present work, attention has been more particularly 
directed to the technic of melting point determination itself.t+ 

All the metal melting points here described, except that of pal- 
ladium, were made in an upright cylindrical furnace through 
which passed a glazed porcelain tube which could be tightly 
closed above and below and therefore permitted the atmosphere 
about the melting metal to be perfectly controlled. An effort 
was first made to accomplish this by placing the entire furnace 
inside a gas-tight bomb in which the atmosphere could be 
similarly varied, but the persistent retention of gases by the 
various clay insulating materials used about the furnace made 
this method slow, cumbersome, and very uncertain in its results. 
The only success which these bomb furnaces attained was to 
permit melting points to be measured in an approximate vacuum 
(about 1™™ pressure). But it has since been found so much 
simpler to operate with a neutral or reducing atmosphere in 
the closed tube passing through the heated zone, that the 
vacuum furnace has not been used for this work. 

The chief disadvantage in the use of a tube of this kind is 
its effect upon the temperature gradient along the furnace axis. 
More heat is diverted toward the ends of the furnace and the 
central constant temperature zone becomes shorter. It offers 
no difficulty except that greater care must be taken in locating 
the crucible within the constant temperature region. 

The qualities desired in fixed thermometric points for estab- 
lishing and reproducing a scale are: 

(1) Exact reproducibility of the temperature in repeated 
determinations with the same charge of material and with a 
different charge independently obtained. This means that 
the metal or salt must be either perfectly pure or cbtainable 
with a constant amount and kind of impurity. 

*. T. Allen, in paper of Day and Clement, loc. cit., p. 454. 


+See also W. P. White, Melting Point Determination and Melting Point 
Methods, this Journal (4), xxviii, 453 and 474, 1909. 


122 A. L. Day and PR. B. Sosman— 


(2) Independence of particular experimental arrangements. 
The melting point of a metal, for instance, must be sharp and 
definite enough so that with different kinds of furnaces and 
different rates of heating, the same temperature will be 
obtained. 

(3) Convenience and safety of manipulation. A melting 
point which can only be obtained by the use of elaborate 
experimental arrangements is undesirable, even though it be 
reproducible and sharp. Furthermore, the substance must not 
injure the instrument to be calibrated. 

(1) Reproducibility.—No extensive experiments have been 
made in the present work to test a large number of samples of 
different origin. It appeared sufficient to assure ourselves 
that all of the metals here used are obtainable in such degree 
of purity, or with such a constant amount of impurity, that 
the variations in their melting points are well within the limits. 
of error in the scale itself. Waidner and Burgess* have 
recently made comparisons of various samples of pure zine, 
antimony, and copper, and have found no differences exceed- 
ing 0°3°.+ Our experience has been the same. All of the 
metals in the present investigation are readily obtainable from 
the ordinary sources of supply. They have been carefully 
analyzed in this laboratory by Dr. E. T. Allen, and the results 
are given in section 6. 

(2). Independence of Experimental Conditions.—A number 
of experiments were made to test the effect of different experi- 
mental arrangements on the points. Two different furnaces 
were tried, one 65™™ inside diameter and 150™™ long, the other 
55™™ inside diameter and 230" long. The region of constant 
temperature in the second furnace was longer than in the first 
and accordingly there was a larger range in which the erucible 
could be moved about without affecting the temperature. This 
furnace was used for all work after March 6, 1909. The ulti- 
mate test was always the agreement between the melting and 
freezing points. Any serious disagreement of these two 
shows that some influence is entering from without. 

The results of the study were briefly as follows: (1) The 
best dimensions for a charge of metal are about 25" diameter 
by 45™" deep. (2) The thermoelement tube should be about 
5%" above the bottom of the crucible. (3) There is a region 
within the furnace in which the melting and freezing points 
agree and are independent of the rate of heating or (within 
limits) of the depth of immersion of the thermoelement ; it is 
necessary to find this position of the crucible by trial. With 
this position once determined, the temperature of the zine, 
antimony, silver, gold, and copper points can be relied upon 


* Phys. Rev., xxviii, 467, 1909. Bull. Bur. Stds., vi, 149-230, 1909. 
+ In the case of antimony, this statement applies only to Kahlbaum’s metal. 


~~ 


Nitrogen Thermometer from Zinc to Palladium. 128 


within 0°-2°. With large charges and facilities for stirring the 
metal, Waidner and Burgess have found the zine point to be 
reproducible in a given furnace, with a given sample, within 
less than 0°1°. 

White* showed that the temperatures of the two silicate 
points used for the present scale are reproducible within 1-0° 
independently of the dimensions of the furnace or the rate of 
heating. For a mineral melting point, the charge should be 
small (about 3 grams), the heat should approach the thermal 
junction from the side and not from the ends, and a position 
in the furnace should be found in which the melting point, 
determined by a bare thermoelement, does not vary with the 
rate of heating. 

The possibility has been several times suggested that the 
temperature of the thermoelement inside of the tube might 
possibly be lower by a small constant amount than the tem- 
perature of the metal outside of the tube, and that this error 
might not be brought to light by such experiments as have 
been described. Several melting and freezing points of cop- 
per were, therefore, determined by enclosing the entire thermo- 
element wire in a thin eapillary of silica glass which was 
slipped over the wire, bent double, and melted down upon the 
wire at the junction by heating in the oxyhydrogen flame. 
This was dipped directly into the molten copper to within 5™™ 
of the bottom, so that there was practically no possibility that 
the temperature of the junction could be lowered by radiation 
or conduction upward. The melting point on element D 
obtained in this way was 10,473 microvolts as compared with 
10,473 microvolts in the closed glazed tube. There appears to 
be no error from this cause. : 

Convenience and Safety of Manipulation.—Zine and gold 
are the most convenient of manipulation, as they require no 
special atmosphere and the temperatures are easily reached. 
Antimony, silver, and copper require an atmosphere of car- 
bon monoxide and are somewhat less convenient. More care 
needs to be taken with copper than with silver and antimony 
because of the considerable effect of a very small amount of 
oxide. Antimony, silver, gold, and copper were all melted in 
carbon monoxide, made by dropping formic acid into warm 
sulphuric acid, and purified by passage through sodium 
‘hydroxide, lead nitrate, and sulphuric acid. The lead nitrate 
was introduced to make certain that no trace of hydrogen sul- 
phide, which might be formed if the acid became too dilute 
or too warm, could pass into the metal. 

The two silicates (diopside and anorthite) and palladium were 
melted in air. The silicate points are very convenient to 


* Diopside and its Relations to Calcium and Magnesium Metasilicates, this 
Journal (4), xxvii, p. 5, 1909. 


124 A. L. Day and k. B. Sosman— 


arrange and manipulate, provided the furnace is well insulated 
so that the temperature can be reached without difficulty. 
Palladium strains the platinum resistance furnace near to its 
limit of endurance on account of the high temperature, but 
has the great convenience of not requiring a reducing atmos- 
phere. Special pains need to be taken, however, in this case, 
to protect the thermoelement from contamination. 

Nickel and cobalt .were melted in an atmosphere of hydro- 
gen which was made by electrolysis in a large glass and earthen- 
ware generator, and purified by passage through potassium 
pyrogallate and sulphuric acid. Just before the thermoele- 
ment was introduced, the hydrogen was displaced by pure 
nitrogen drawn from a steel tank in which it was stored under 
pressure. The supply contained a trace of hydrogen and was, 
therefore, purified by passing over hot copper oxide and 
through calcium chloride and sulphuric acid. The extreme 
lightness of this gas compared with the outside air (especially 
when it is heated to 1450°) makes necessary special precau- 
tions in order to keep out any trace of air. Furthermore, 
hydrogen always caused contamination in the thermoelement, 
which was not prevented even when the hydrogen was replaced . 
for a short time during the melting by pure nitrogen. Nickel 
and cobalt are, therefore, not recommended for frequent use 
in the calibration of thermoelements, if the two points, diop- 
side and palladium (or diopside and anorthite), give a sutiicient 
calibration for the purpose in hand. 

The apparatus used for the melting points of nickel and 
cobalt is shown in section in fig. 6. The top of the large 
porcelain tube (Marquardt, glazed outside only) was closed by 
a sliding cup of brass in which the thermoelement tube and 
two others for introducing hydrogen were fastened by heat- 
ing the cup and pouring in molten solder. The porcelain tube 
extended far enough out of the furnace to keep the brass cup 
cool. A groove near the base of the cup carried a piece of 
asbestos cord which made a gas-tight joint with the porcelain 
tube and permitted the whole to be raised and lowered with- 
out moving the crucible or opening the top of the tube. Two 
diaframs of Marquardt porcelain above the crucible also pre- 
vented any considerable radiation upward to the brass cup. 

In zine, antimony, silver, gold, and copper, the thermoele- 
ment was protected by a glazed Marquardt tube of 5™™ inside 
and 8™™" outside diameter. In the case of antimony, the tube 
was further protected by a thin tube of graphite which fitted 
into the cover of the erucible. With diopside and anorthite, 
some contamination from iridium in the furnace may take place, 
but can be largely prevented by surrounding the tube with 
pure platinum. A glazed Marquardt tube cannot be used in 


Nitrogen Thermometer from Zine to Palladium. 125 


this case, for the glaze flows readily at these temperatures and 


may make its way into the charge. 


With nickel and cobalt, 


glazed Marquardt tubes and also pure magnesia tubes of the 
same size were used, but neither protects the element from 


contamination. In palladium only the 
pure magnesia tubes were used. 

Zine, antimony, silver, gold, and 
copper were melted in graphite cruci- 
bles 27™™ in diameter and 80™™ deep 
inside, and 37™™ in diameter and 
100°" high outside. The charge of 
metal was from 45™™ to 55™™ deep. 
Diopside and anorthite were melted 
in small platinum crucibles 10™ in 
diameter and 18”™™ deep, as described 
and illustrated in the paper already 
referred to.* Nickel was melted in 
an unglazed Marquardt porcelain 
crucible, lined with a paste con- 
sisting of about 90 per cent A1,O, 
and 10 per cent MgO; and also ina 
Berlin “pure magnesia” crucible. 
The charge was about 25" in diam- 
eter and 30™™ deep. Cobalt could not 
be melted in the alumina lined cruci- 
ble, as the metal penetrated through 
the lining and attacked the porcelain. 
It was, therefore, melted in a “ pure 
magnesia” crucible made by _ the 
Ko6nigliche Porzellan Manufaktur. 
The material of these crucibles prob- 
ably ecntains a small percentage of 
silica. Palladium was melted in a 
erucible made in this laboratory from 
a specially pure magnesia made by 
Baker and Adamson. The magnesia 
was first shrunk by heating to a tem- 
perature higher than that at which the 
crucible was to be used, and was then 
made into a paste with water and a 
little magnesium chloride, spun into 
form, and baked. 

Particular details regarding each of 


Hig. 6. 


Pe LIE L ALLELE EEE 


MRRALAREKRRRRLDMMRURERUM UW WUR WER ARE MKD 
AAS SSSA AAASS ASS SAS ASSIS ES SSS SSS SS SSS SSS SSS SSSSSSSSSSSSSSSS 


ZL 


DS ANUS Ss = 
WIZZ LLL 


Fic. 6. The furnace in 
which the standard metal 
melting points were made, 
showing the position of the 
metal with respect to the 
coil, the thermoelement (T) 
and the arrangement (H) for 
maintaining a hydrogen or 
nitrogen atmosphere. 


the substances used will now be taken up in the order of their 


temperatures.t 


*W. P. White, this Journal (4), xxviii, 477, 1909. 
+ See, also, E. T. Allen, in paper of Day and Clement, loc. cit., p. 454. 


Am. Jour. Sct.—FourtTH SERIES, VoL. X XIX, No.170.—Frsruary, 1910. 
9 


126 A. L. Day and R. B. Sosman— 


Zinc.—Two samples of “OC. P. sticks” were used, both 
from Eimer and Amend. No appreciable difference could be 
observed between their melting points. Both melting and 
freezing points were sharp and measurable to a fraction of a 
microvolt. Successive readings did not differ by more than 
one microvolt. The charge was about 200 grams. The analy- 
sis has been published.* 

Antimony.—Two samples of metal were used, both from 
Kahlbaum, and no appreciable difference was found between 
their melting points. An analysis of the first sample is given 
in section 6. The charge weighed about 150 grams. The 
melting point is sharp and does not differ from the freezing 
point by more than one microvolt, provided the undercooling 
which always precedes solidification does not exceed 15°. If 
the metal is undercooled too far to give an accurate freezing 
point, the fact is easily recognized by observing that the 
thermoelement does not return to a sustained constant tem- 
perature, but merely rises to a maximum, then falls again. The 
amount of undercooling is greater the higher the metal has 
been heated above its melting point after the melting is com- 

lete. 

Selver.—The charge weighed about 260 grams. Only one 
supply was used, a specially purified sample obtained from the 
Philadelphia Mint, of which an analysis is given in the previ- 
ous paper.* The melting and freezing points were sharp and 
agreed within one microvolt. 

Gold.—A new charge of gold was used, weighing 350 
grams. This was obtained from Dr. Eckfeldt of the Phila- 
deiphia Mint. No analysis was deemed necessary.* 

Copper._-The copper was obtained in the form known as 
“copper drops cooled in hydrogen” (EHimer and Amend). 
Only one supply was used. The melting and freezing points 
were not quite as sharp as was the case with silver, but always 
agreed within 1 microvolt. The temperature is very suscepti- 
ble to a trace of oxide, which not only lowers the temperature 
appreciably but makes it more uncertain, so that if a little 
oxidation has taken place it is recognizable at once. Waidner 
and Burgesst+ found that the best commercial electrolytic cop- 
per showed an average difference of 0°2° in the melting point ~ 
from the purified copper drops. Charge, about 210 gramp. 

Diopside.—Two samples of diopside were used, one from ~ 
the preparation of Allen and Whitet and the other made up in 
1909 by G. A. Rankin. No appreciable difference was found 

* H.T. Allen, in paper of Day and Clement, p. 454. 


+ Loc. cit., p. 469 (Phys. Rev.); p. 174 (Bull.). 
{ This Journal (4), xxvii, 1, 1909. 


Nitrogen Thermometer from Zine to Palladium. 127 


between the melting points. No freezing point can be obtained 
as the mineral undercools considerably. The charge used was 
3 grams. 

Nickel. A sample of specially purified electrolytic nickel 
was obtained from Kahlbaum. ‘The analysis showed less than 
0-2 per cent total impurities. Care must be taken in the case 
of nickel that no oxide forms, as a fairly sharp break can be 
observed about 10° below the melting point, which may repre-. 
sent the eutectic of nickel and nickel oxide. This break disap- 
peared when the nitrogen was replaced for a few minutes by 
hydrogen. This lower pomt may easily be mistaken for the 
melting point of the metal, and this mistake seems to have 
occurred in several of the published determinations of the 
melting point ofnickel. Nickel absorbs hydrogen aud possibly 
also nitrogen, and after cooling frequently showed excrescences 
and signs of “spitting” such as occur with silver in air. 

Cobalt.—Kahlbaum’s purest cobalt was used, containing less 
than 0:05 per cent total impurity. It was in the form of fine 
black powder, which was compressed into blocks for conveni- 
ence in handling. The results obtained were not quite as satis- 
factory as with nickel on account of the higher temperature 
and more rapid contamination of the thermoelement. The ab- 
sorption of gases seemed to be less than was the case with nickel. 

Samples of Eimer and Amend’s “98 to 99 per cent pure’ 
nickel and cobalt were also tried. The difference between the 
two samples of nickel was not greater than the uncertainty 
in the melting point caused by contamination of the ther- 
moelement. The “98-99 per cent pure” cobalt melted about 

5° lower than the pure sample. Since the impurities in 
nickel are usually chiefly iron and cobalt, and those of cobalt 
are chiefly iron and nickel, and since the melting points of all 
three are close together, the melting points of the slightly 
impure metals can not be expected to lie far from ee of the 
pure metals. 

Anorthite-—Only one preparation of anorthite was used, 
made by G. A. Rankin 1909. The charge was about 3 grams. 
The melting point is not quite as sharp as that of diopside. 
Only the melting point can be obtained, as the mineral under- 
cools considerably ; it may even cool to glass without crystal- 
lization, in which case of course no melting point will be 
obtained on the following heating. 

Palladium.—About 350 grams of pure palladium, in the 
form of sheet, was loaned to us by Dr. Heraeus. It melts and 
freezes quite sharply, making an excellent substance for a fixed 
thermometric point. The greatest uncertainty is caused by the 
vaporization of the metal and consequent contamination of the 
thermoelement wire. The charge used weighed 128-210 grams 


ae 
©) 
BD 


A. L. Day and Rf. B. Sosman— 


In addition to the fixed points which have just been 
described, two other metal melting points, cadmium and alu- 
minum, were incidentally determined. Only one measurement 
of the cadmium point was made on the gas thermometer, and 
this chiefly for the purpose of checking the extrapolation 
below the zine point. The conditions of melting were the same 
as for zinc. The sample was obtained from Eimer and Amend, 
and its analysis has been given in a paper by Day and Allen.* 
The charge weighed 215 grams. 

A sample of pure aluminum obtained from the Aluminum 
Company of America was melted in a graphite crucibie of the 
usual size in an atmosphere of carbon monoxide. On account 
of the sensitiveness of aluminum to silicon contamination, the 
tube carrying the thermoelement was also provided with a thin 
protecting cover of graphite so that the metal came in contact 
only with pure graphite. The freezing point was sharp and 
constant. The melting point was less sharp but lay within 
0°5° of the freezing point. 

The effect on the final temperature of all the errors and 
corrections which have been discussed in this section, is shown 
in summarized form in Table IV. 

The figures of Table LV serve to emphasize the statements 
already made, that the greatest present uncertainty in the high 
temperature gas scale arises from the lack of uniformity in an 
air bath, which not only leads to uncertainty as to what is the 
true temperature of the gas m the bulb, but also to errors in 
the transference by the thermoelement. The next largest 
uncertainty, due to the limitations of the materials used for 
fixed points, is not directly chargeable to the gas thermometer. 
In this connection, considerably more work needs to be done 
on the high thermometric points, comparable in thoroughness 
to the work in low temperature thermometry of Richards, 
Dickinson, and others, on the sodium sulphate transition point. 


4, Experimental Data and Calculated Results. 


A. Expansion Coefficient.—In Table V are given the experi- 
mental data cn the expansion coefficients of the alloy 80 per 
cent platinum, 20 per cent rhodium. In the first column is 
given the date of the series, in the second and third columns 
the readings of the thermoelements at the middle of the bar, 
corrected for zero error and the temperature of the cadmium 
ceil. The 12 other readings taken with each element at each 
temperature at different points along the bar cannot be given 
here, but the fourth and fifth columns contain the readings of 
the thermoelement corrected to represent the integrated tem- 


* Arthur L. Day and E. T. Allen, Phys. Reyv., xix, 180, 1904. 


Nitrogen Thermometer from Zinc to Palladium. 


129 


Taste 1V.—Estimated Errors and their Effect on the Value of t. 


Quantity 
affected 


(A) Temperature 
of gas 


Source of 
error 


Temperature 
differences 
over bulb 
surface 

Variability 


Reference 
point 
Manometer 
setting 
‘Seale correc- 
tions 
Temperature of 
mercury 
‘Barometer 
setting 
Temperature 
of barometer 
Variations 
in Po 


Reference 
point 
Manometer 
setting 
Seale correc- 
tions 
‘Temperature 
mercury 
‘Barometer 

| setting 
‘Barometer 

| temperature 


V1 


Unheated 


| space ty 


B Temperature 
“e 


(C) E.M.F. 


oe 


e 


(D) Fixed points Instrumental 


ce 


ce 


oe 


Expansion 
‘Hysteresis in 
| expansion 
Instrumental 
correction 
Contamination 
Integration 
over bulb 


corrections 
Contamination 
Variation in 
given charge| 
Variation be- 
tween differ-| 
ent charges | 


Amount of error Effect on t 
at 400° at 1500° | at 400°; at 1500° 
2mv 5 mv. Ora ey p= O74. 
0 1lmv 0 gz Gal 
0-02 002mm. {+ 0:04° |+ 0°15° 
002mm. | 0:02mm. | + 0:04° |+ 015° 
0-01 mm. 0:0 mime.) 002-1 =0:07- 
0-05 mm. 005mm. |+ 0°10° |+ 0°38° 
0:03 mm. 003mm. {+ 0:06° |+ 0°23° 
0:05 mm. 005mm. |+ 010° |+ 0°38° 
0 0--05 mm. 0 0 to +0°3 
0:02 mm 002mm. {+ 0:02° 0 
0:02 mm 002mm. |+0:02° | 0 
0°02 mm 0°02 mm + 0:02° 0 
0°07 mm 020mm. |+ 0-07° |+ 0.05° 
0-03 mm 003mm. |+ 0:03° |+ 0:01° 
0-05 mm 005mm. |+ 0°05° |+ 0°01° 
0-020 ce. 0:020 ce. |+ 0:07 |+ 0°5° 
0°5-50° Ore OOF ee ce Os 0K aes Ole 
10° 202 te Os02ee |e Ott? 
0°005 mm. | 0:008mm. | + 0°02° |+ 0°09 
0-01 mm. 0-Olmm. /|+0°04° /+ 0°10° 
1 my. 2mv. 2 Oto 1 -£ 0:28 
0 0-12 mv. 0 0 to +1:0° 
3 my. 12 my. Se O5d2) tae kOe 
1 mv 2 mv. + 071° |+ 0°2° 
0 0-10 my. 0 0 to -1°0° 
Specific 1-10 mv. Specific 0-1 - 1‘0° 
Specific 1 - 20 mv. Specific 0-1 - 20° 


130 A, L. Day and R. B. Sosman— 


perature along the bar. For convenience, the integration was 
made in terms of microvolts instead of degrees. The sixth 
and seventh columns contain the temperatures corresponding | 


Taste V.—- Observations of Hupansion Coefficient, B. 
? 


Thermoelements Temperature poe 
Date 
mm on 
W Z  |Weoor.|Z cor.| by W | by Z | Mean 500 mm 10°B 
1908 | 
Sept. 21, 2261) 2251) 2312) 2298) 301-47) 301-4") 301:4°| 1°404 9°32 
3197, 3187) 3278) 3258) 404°6 | 405-4 | 405-0 | 1°912 9°44 
4169) 4158) 4257) 4237) 506°0 | 507:1 | 506°6 | 2-434 | 9°61 
5157; 5140) 5287) 5212) 603°9 | 605-1 | 604°5 | 2°950 9°76 
6197) 6178) 6286) 6262) 705-4 | 707-2 | 706-3 | 3:500 9°91 
7264; 7238; 7362) 7333) 806°2 | 807°8 | 807:0 | 4:064 | 10°07 
8361) 8335) 8457) 8420] 905°9 | 906-7 | 906°3 | 4°640 | 10°24 
9509; 9470) 9599) 9552)1006°9 1006-8 |1006°8 | 5°241 | 10°41 
10662) 10611) 10733) 10675 |1104:5 |1103°4 |1104:°0 | 5°828 | 10°56 
11963} 11896) 12018) 11921 |1215°3 |1210°2 |1212°8 | 6°469 | 10°67 
Sept. 25) 1817; 1801; 1848) 1831! 248-7 | 248-4 | 248°6 | 1:154 | .9°28 
2756) 2785) 2791) 2768) 353-4 | 352-9 | 353°2 | 1°666 9°48 
3699 3674) 3726) . 3702) 451°8 | 452-0 | 451-°9 | 2°158 9°55 
4686, 4655) 4691) 4662) 549°7 | 550°3 | 550°0 | 2°668 9°70 
5711) 5679) 5691) 5660) 648°2 | 649:2 | 648°7 | 3191 9°84 
6820} 6788) 6772) 6742) 751°2 | 752-6 | 751°9 | 3°757 9-99 
7847| 7818) 7754) 7720) 842°2 | 843-2 | 842-7 | 4:262 | 10°11 
8980, 8945) 8845 8809) 940°8 | 941°4 | 941-1 | 4°827 | 10°26 
10140 10102; 9939 9901|1036°4 |1037-0 1036°8 | 9°408 | 10°42 
11368 11327) 11109) 11063 |1136-9 |11386°4 1136-7 | 6:°012 | 10°58 
Oct. 3 | 2291) 2272) 2302) 2283) 300°3 | 299°8 | 300-1 | 1384 | 9-22 
3228) 3205) 3250) 3228) 402°2 | 402-2 | 402°2 | 1°899 9°44 
4208) 4181) 4248 4215] 504°6 | 504°9 | 504°8 | 2°482 9°63 
5205, 5175) 5247) 5216) 604°8 | 605°5 | 605°2 | 2°964 9°79 
6238) 6206) 6281) 6249] 704:9 | 705-9 | 705-4 | 3°511 9°95 
7297, 7263) 7342) 7309) 804:4 | 805°5 | 805:0 | 4:069 | 10°11 
8401) 8365) 8446) 8408) 904:9 | 905°6 | 905°3 | 4°644 | 10°26 
9536, 9497) 9576) 9534|1004°9 |1005°2 |1005°1 | 5°231 | 10°41 
10675) 10647) 10710) 10670 /1102°6 |1103:0 |1102°8 | 5°8380 | 10°57 
11884) 11857) 11926) 11875 /1207°5 |1206°2 1206-8 | 6-466 | 10°71 
Oct. 29 | 8419} 8377) 8866) 8324) 897-4 | 898:°0 | 897-7 | 4°618 | 10°29 
9551| 9507) 9436) 9392) 992-6 | 992°8 | 992:7 | 5:169 | 10-41 
10706) 10663) 10539, 10496 |1088-0 |1088-2 1088°1 | 5°752 | 10°07 
11884) 11849) 11786) 11751/1195°6 |1195-7 |1195-7 | 6-401 | 10°70 
13137) 18104) 18134) 13101 /1309°9 |1809°8 1809°9 | 7-154 | 10°92 
1909 Tee, D_ |Weor.|D cor. |by W | by D 
Oct. 13 | 2304) 2301) 2235) 2232) 293-0 | 293-0 | 293-0 | 1:352 9°23 
| 6222) 6217] 6180) 6175) 695-2 | 695-9 | 695°6 | 3-402 | 9°92 
9501) 9494 9493) 9486) 997-6 | 998-1 | 997-9 | 5:190 | 10°40 
Oct. 14) 9540 9536) 9542) 9544)1001-9 |1003°1 1002°5 | 5:200 | 10°37 
10666) 10663) 10690) 10691 |1101-°9 |1102°5 (1102-2 | 5-811 | 10°54 
| 11839) 11836) 11783) 11783)1195-4 |1195°7 (1195-6 | 6-410 | 10°72 
12998 12993) 13121) 13120/1308-9 |13808°6 |13808°8 | 7-156 | 10°93 
14183) 14170, 14890) 14372 /1413°4 |1411°6 |1412°5 | 7°832 | 11:09 


Nitrogen Thermometer from Zinc to Palladium. 131 


to the readings in columns 4 and 5, and the eighth column, 
the mean of these two temperatures. The micrometer read- 
ings are not given, but in column 9 will be found the expansions 
reduced to millimeters for that portion of the bar lying between 
the 0 and 50™ marks on the ends. Each of these represents 
the mean of eight settings at each end of the bar. In the 
last column are given the values of the mean expansion coefi- 
cient from 0°, calculated by dividing the expansion by the 
length at 0 and by the temperature. : 

For convenience of comparison, the values of 8 at the 
nearest round temperatures were interpolated linearly between 
the observations in each series, and the results are given in 
Table VI. Values interpolated between these values are given 
in parentheses. 


Taste VI.— Values of 10° B at Round Temperatures for the 
alloy 80 Pt, 20 Rh. 


: 21 Sept. | 20 Sept.| 3 Oct. | 29 Oct. | 18 Oct. | 14 Oct. 
Temp. | “14908 1908 1908 1908 1909 |- 1909 | Mean 
250 9-28 
300 9°31 (9°36) 9-22 9-24 9-28 
350 (9°37) 9-43 (9°33) | (9°33) 9-36 
4006 9-43 (9°49) 9-44 (9°41) 9-44 
450 (9°52) 9°55 (9°58) (9°50) 9°52 
500 9-60 (9:62) 9-62 (9°58) 9-61 
550 (9°67) 9-70 (9:71) (9°67) 9-69 
600 9°75 (9°77 9-79 (9°76) 9-77 
650 (9:83) 9°84." (9°86) (9°84) 9-84 
700 9-90 (9°92) 9-94 9-93 9-92 
750 (9-98) 9-99 (10-02) (10°01) 10-00 
800 | 10-06 10-06 10:10 (10°09) | . 10:08 
850 | (10-14) 10°12 | (10°17) (10-16) 10°15 
900 | 10-28 (10°20) | 10°25 10:29 | (10-24) 10°24 
950 | (10:31) | 10-27 (10°32) | (10°36) | (10°32) 10°32 
1000 | 10-40 | (10-36) | 10-40 10°42 10:40 10°37 | 10-39 
1050 | (10-47) | 10:44 | (10-48) | (10°50) (10°45) | 10-47 
1100 | 10°55 | (10°52) | 10°57 10°59 10°54 | 10-55 
1150 | (10-60) | 10°60 | (10-64) | (10°65) (10-63) | 10°62 
1200 | 10°65 | (10°67) | 10°71 10°71 10-73 | 10°69 
1250 (10°81) (10°82) | 10°81 
1300 10°90 10:92 | 10-91 
1350 (10°99) (10°99) | 10:99 
1400 11:07 | 11:07 
1450 (11°15) 
1500 (11:23) 


The table shows that the percentage error at 300° is greater 
than that at 1200° and above, probably on account of the 
larger effect of the hysteresis in the expansion and contraction, 
already discussed on page 114. The agreement of the results 
is very satisfactory, particularly in view of the fact that each 


182 A. L. Day and R. B. Sosman— 


series represents an entirely different curve of temperature 
variation along the bar. In some cases the temperatures at 
the ends were lower than at the middle, in others higher than 
at the middle, and in one series one end was higher and the 
other lower. The mean of all, therefore, probably eliminates 
any error which might arise ‘from variation of temperature 
along the bar. 

The results are represented within the limits of error by the 
straight line equation : 

10°B = 8°79+0°00161¢. 

This may be compared kere with the expansion coefficients 
between 300° and 1000° determined by the authors for the 10 
per cent iridium alloy,* and of Holborn and Day+ for the 20 
per cent iridium alloy and for pure platinum : 

80 Pt. 20 Ir 10°B = 8°20 + 0:001422 
90 Pt. 10 Ir. 10°8 = 8°84 + 0:00131¢ 
Pt. 10°8 = 8:87 + 0:00132z. 

B. Gas Thermometer Data and Fixed Points.—In Table 
VI aregiven the observed gas thermometer data.{ In the first 
column is the date of the measurement. The measurements 
are numbered chronologically in the second column for con- 
venience of reference. In the third column is the measured 
pressure, p’ (or p,’) in millimeters of mercury at 0°, corrected 
as described on pages 107 and 108. The application of the 
correction for unheated space (see p. 108) gives the pressure 
p (or p,) which is found in the foun column. In the fifth 
column is the value of the temperature, ¢, calculated by formula 
(5) on page 101. In column 6 are given the readings of the 
standard thermoelements in microvolts, and in column 7 the 
positions of these elements on the bulb; for the significance of 
these figures see fig. 1 and note on page 104. In the last 
column are given the other elements which were used on the 
bulb, together with their positions designated in the same way. 
The italicized letters represent single platinum wires instead of 
thermoelements. 

A few measurements in which the value Me 10; chmod by 
more than 0-1 per cent have been omitted ; their position is 
shown by the absence of their corresponding serial numbers. 

* Published in paper of Day and Clement, loc. cit, pp. 420-441. 

+ This Journal (4), xi, 374, 1901. 

t For the measurements in the table, seven furnaces were employed, 
using three supplies of platinum wire of about 400 gramseach. One of these 
furnaces was wound on the outside, the other six on the inside of the tube. 
It was possible to rewind the wire at least once after the furnace had 
burned out. Failure always occurred several cms, away from the bulb in the 
end portions of the furnace, which, in order to secure uniformity of temper- 
ature over the bulb, had to be considerably superheated. Only one measure- 
ment was made at the palladium point, as this one rendered the furnace | 


unfit for further use ; the conditions of this measurement, were, however, 
perfect. 


Nitrogen Thermometer from Zinc to Palladium. 


133 


Taste VII— Observed Gas- Thermometer Data. 


No. 


p (or py) | p (OF po). 


217°65 
1037°77 


217°45 
217°10 
948°81 
217°12 
217°08 
1088-50 


217°18 
1038 °57 


217:06 
217°49 
1242°38 
217°57 


1039-78 


1038°82 
1037-85 
217-36 


543°01 | 


942°27 
703°78 
70264 
949°56 


948-15 
1039-03 | 


1087°92 
217°33 


042°87 | 


42°07 
704°06 


| 


t 


| Standard 
| Elements 


Gas Firtuine No. 1 


217°63 
1042-72 


217°48 
217-08 
952°84 
217°10 
217-06 
1043°48 


217-16 
1043-56 


217:04 
217-47 
1249-71 
217°55 


1044-74 


1043-79 
1042°83 


217°34 
544:07 


543-32 
705-81 
704-67 
953-63 
952:23 
1044:05 
| 1042-93 


217°31 
543°92 


| 54a 44 


| 706°07 


] 


| 


° 


107987 
960-59 


1083°61 


0 
1083°77 


0 
0 

1365-71 
0 

1082:84 


1081°87 


1080°89 


0 
418-40 


417-43 
629°80 
628°34 
960°22 
958-41 
1083°01 
1081°56 


° 


418-30 
417-25 
650°21 


WwW 10443 
X 10491 


WwW 9061 
X 9100 


W10483 
X 10555 
w10473 
X 10512 


A 13866 
enue 


A 10502 
Y 10612 


A 10506 
Y 10584 
A 10498 
Y 10555 
3414 
3436 
3408 
3435 
5510 } 
5550 | 
) 


KEK PHP REE KD 


Posi- 
tion 


oom 


Orn On GO 


OO 


TT OO OT OU OE em 


OU Or or 


Other elements 
and positions 


Z (1), S (9) 
Z (1), S (9) 


Z (1), S (9) 


Z(1), S (9) 
¥ (1), 5 (9) 


Z (9), B (1:8) 
W (2°38), S (67) 
X (73 | 


134 A. L. Day and R. B. Sosman— 
Taste VII—( Continued) 
' | Standard | Posi- | Other elements 
Date (No. p'(or po')) p (or po) ) Elements | tion | and positions 
28 Jan. | 34) 703:35 | 705°37 | 629°31/A aay 45 |Z (9), B(13), W 
Y 5537f] 8  |(2°8),9(6°7)X(7°3) 
ef 30} 948:96 953°05 | 959:46|4 pia 4:5 Do. 
; Y 9142 8 
ae 36; 949-86 953°97 | 960°69 A 168 f 4:5 Do. 
Y 9168 8 
o 37| 1038°50 | 1048°57 |1082°23|A 10511 4:5 Do. 
Y 10576 ¢ 8 , 
— 38/ 103899 | 1044:06 AOS ey 10586 | 4:5 Do. 
Y 10585 8 
S 39| 1039°61 | 1044°68 pA aia 4°5 Do. 
Y 10617 §-| 8 5 
29 Jan. | 40) 217:°37 217°35 0° — 
de 41) 949°32 | 953°38 | 959-78|A ean 4-5 Do. 
Y 9156 8 
ya 42| 948:58 952°66 | 958°81 |A ae 4°5 Do. 
Nes lol 8 
- 43} 1039°29 | 1044:°34 |1083°15 ie 4°5 Do. 
Y 10595 8 
G6 44| 1038°49 | 1043-56 Be aaa 45 Do. 
Y 10568 8 
6 45| 1039°63 | 1044°71 |1083-58 ane 45 Do. 
Y 10617 8 
30 Jan. | 46] 217°39 217°37 0 Uae 
Gas Friuuine No. 2 
18 Feb. | 47| 346°74 346°70 0 eee 
22 Feb. | 48/ 3846:78 346°74 0 ain 
A 2487)| 4:5 |w (1:3), B (2-2), 
23 Feb. | 49| 745-09 746:19 | 319°55|D 2483 4°59 |X (6:2), S (73), 
z 2462)| 8 /[¥ (42) 
A 38414 4-5 Do. 
ts 50| 866°47 868:15 | 418°40|D 3406 AS 
Z 3385 8 
A 4451 4°5 Do. 
me 51} 995-97 998'°38 | 524:71/D 4439 4°5 
Z 4413\| 8 
A 5010 4°5 Do. 
ot 52| 1122°39 | 1125°61 | 629°37|/D 5495 4°5 
Z 5468 8 
24 Feb. | 58, 3846°67 346°63 |; 0 Rie 
26 Feb. | 59| 346°24 346°20 0 ue 
A 10508)| 4:5 |W (3:3), B (2:2), 
z 60| 1657-03 | 1665-07 ost D 1017 | 4:5 | X (6-2), S (7-2), 
7, 10499 \)) 8 We) 
27 Feb. | 61] 346°45 346°41 0 nye 
A 7895)| 4.5 | B (8-2), W (2:3), 
1 Mar. | 62| 1388-84 | 1394-18 | 853-76|D rs 4.5 | X (6-2), 8 (7°2,) 
7 7829\| 8 | Y (12) 
A 9086 4'5 Do. 
ss 63| 1513°67 | 1520°20 | 960°29|D aan | A'S 
Z 9010 8 
A 10265)| 4:5. Do. 
de 64} 1632°03 | 1689-78 106215) 10229 | 4:5 
ZA07s 8 


Nitrogen Thermometer from Zine to Palladium. 135 


Taste VII—( Continued) 


5 Mar. ! 71! 340°98 04594 0 Be? 


| 


No. ‘(or 1 | (or'n,))| -€ Standard} Posi- | Other elements 
| it Po i Po Elements| tion | and positions 
| A10511)| 45 | B(32), W@3), 
65| 1655°77 | 1663-81 |1082°84 D 10474 4°09 | X (6°2), S (72), 
Zz 10420); 8 | Y (42) 
66| 346-20 346°17 0 Be 
A 7885)| 4:5 |W (3-3), B (2-2) 
67); 1886°28 | 1891°55 | 852°44|/D 7861 4:0 | X (6°2), S (72) 
zZ 7820)| 8 |Z (), ¥ (12) 
A 9088)| 4:5 Do. 
68) 1511-95 | 1518°48 | 959°81/D 9059 A°d 
Z 9018 8 
A 10257 4°5 Do. 
69} 1628-71 | 1636°46 1060°24|D 10221 4°5 
Z 10169 8 
A 10511 45 Do. 
70| 1654°46 | 1662°50 1082-78 D ini 4°D 
Z 10444 8 


Gas Finuine No. 3 


A June | 72) 9840°31 340 :°27 Oi. 6 


5 June | 75| 345°31 345°27 0 


7 June | 79| 345-50 | 345-46) 0 ee 
10 June | 80 345°52 | 345-48 | 0 i 


3403 } 
3419 | 
3414 
3416 | 
3370 J |. 
5516 ) 
5585 | 
5528 
5529 | 
5461 | 
9090 } 
9114 | 
9099 | 
9108 | 
9002 J 
10258 } 
10285 | 
10266 $ 
10279 | 
10161 | 
10503 } 
10529 | 
10510 } 
10523 | 
10404 J 


Y (1), @ (2-4), 
b (6:4) 


73); 861°67 | 862°94 | 417-07 


74, 111850 | 1120°83 | 629-11 


NOW V@orcor 


Do. 


76) 1510°50 | 1515-27 | 959-77 


Do. 
77| 1628°08 | 1633°64 |1060°53 


Do. 
78) 1652°36 | 1658:10 |1081-28 


Co He He HS HS OO HS HSS He GOS HS HS HS CO HS HR HHO HSS 
Vow i VWooe Zsowre 3 cH ce 


NQ32EPNQHEPNQUE> NQPEPNQOE> 


1 a (1), 6 (2°4), 
EK c (6°4), e (7°38) 
18 June 81 1512°96 | 1517-69 | 961:21/A 9080 + 
| G 


VOW Waawre 


82) 1630:94 | 1636:53 1062°53/A 10252 } 
| G 10292 | 
7 AOtSit) 


N 
We} 
i) 
=n 
Or 


A. L. Day and R. B. Sosman— 


Standard 
Elements 


F 10584) 
E 10534 | 
A 10487 + 
G 10526 | 


1082-14 


Z 10403 
F 10536 } 
E 10534 | 

1082-91] A 10485 } 
G 10525 | 
Z 10426 J 


Gas Fituine No. 3a 


136 

Date |No.| p'(orpo')| p (or po) 
18 June | 83) 1608°61 | 1659°37 
a 84) 1654°51 | 1660°27 

19 June | 85; 340-51 345°47 
19 June | 86) 219°73 | 219-71 
os 87, 710°34 | 711°88 

? 88) 962°21 | 965°23 

“ 89) 1051-74 | 1055°41 

21 June | 90) 219°74 | 219-72 
22 June | 92) 220°65 | 220°63 
24 June | 93) 220°62 | 220°59 
25 June | 95) 220°56 | 220°58 
2 July | 96) 1288-36 | 1288°82 
i 97| 1285-43 | 1290°89 

3 July | 98) 221-02 | 220°99 
i 99) 1281°97 | 1287°45 

“« — |100} 1284-05 | 1289-54 

6 July |101| 220°62 | 220°60 


0 oe 


961°71 


1082-75 


Sorc 
1 
4 
1 
I 


H 14251 } 
E 14227 | 
F 14992 $ 
G 14245 | 
Z 14121 J 
H 14282} 
E 14247 | 
F 14241 $ 


1391°97 


1394-89 


G 14274 | 
ay! 14156 J 
H 14213) 
E 14214 | 
F 14196 } 
G 14216 | 
Z, 14099 | 
H 14264) 
E 14242 | 
F 14235 $ 
G 14259 | 
Z 14156 | 


1393°34 


13896°17 


Taste VIT—( Continued) 


Posi- 
tion 


Cb HW HS 0 HH HH 
“JF OU CD 2 O10) r+ 


3 C100 


Ob He He HH CO He HH > 0 HHH oe 
2 Ot CO 2 Or 00 


2 Ol Co r+ 2 Or Co 


Go He Ha HS OO HS We HSS GOSS HOO SH 
Soe Woore , 


Other elements 
and positions 


a (1), 6 (2°4) 
ce (6°4), e (7:3) 


a (1), e (2°3) 
c (6°3), f (73) 


Do. 


Do. 


Do. 


Do. 


Nitrogen Thermometer from Zinc to Palladium. 187 


TasLE VII—( Continued ) 


| | | | | 

Ra's r i | 'Standard Posi- | Other elements 
ais oe Gena ))P (OF Po) | t eaies es tion | and positions 
1 | | 

Gas Fiuuine No. 4 
8 July |102| 216-81 216°79 0 
a (1), e (2°38) 

¢ (6°3), f (73) 


1 
3 
ca 103) 1261°35 | 1266°80 |1391°15 |F 14209 + 5 
a 


Do. 


© — |104) 1263-13 | 1268°59 /1893°55 |F 14199 b | 
G 14236 | | 
Z 14155 | 


2 1 Co 


| H 14251 ) 
| E 14236 | 
< 106 1261-71 | 1267-15 1891-64 |F 14238 $| 
| G 14241 | | 
Z 14123 J 
H 14240) 
E 14236 | 


4: 
4: 
4: 
4: 
8 
4: 
4° 
4: 
4: 
8 
4- Do. 
4 
4: 
4: 
8 
4: 
4: 

107; 1263-01 | 1268°46 1393-44 |F 142254) 4: 
4: 
0 
4: 
4: 
4: 
4: 
8 
4: 
4- 
4: 
4: 
8 
A: 
4: 
4: 
4- 


Soe aoe 


G 14233 | | 
1Z 14152 | 


H 15019} 
E 15020 | 
1109) 1806-60 | 1312-52 |1455°37|F __.. $ 


~2 109 


Gyre 
| Z 14903 } 
12 July |110| 217°36 | 217-34 | 0 pes 
| H 14978} 

| E 14980 | 
« (114) 1805-53 | 1811-85 [1453-52 |F ___. 4 
| } G nha | 

Z 14867 | | 


Do. 


2 Oreo 


| | H 14980} 
oe | E 14960 | 
« 1112) 1305-46 | 1811-28 1453-31 |F 14947 }| 

| | GP ess | 
Z 14872) | 8 


31 0 


2) 


13 July 113) 217-40 | 217°38 | 0 
10 Sept. |114) 217-38 | 217-36 | 0 


| | a (1), ¢ (2°3) 
| Um E 15389 | | e(6°7), f (73) 
11 Sept. |115] 1328-68 | 1334-79 1484-70 F 15374 || 

eae 


peut 
art 
OU 


| ies 
| 


Hs 116) 1332°18 | 1338-32 1489: 60 \E 15417 } 
[A 15421 | 


SHO POT OD 
o 
S) 


OD HH He OD HH 


13 Sept. |117] 217-62 | 217-60 | 0 


138 


Date 


22 Sept. 


27 Nov.* 


29 Nov. 


9 Dec. 


No. 


129 


130 


131 


132 


A. L. Day and PR. B. Sosman— 


Taste VII—( Continued ) 


p' (or py’) 


1829-92 


217-51 


1331-40 
217-52 


1306°75 


1807-28 
217°45 
1045-80 
217-28 


1129°52 


1194°81 


1261-16 
217°30 


1125-92 


* Outside-wound furnace. 


Pp (OY Po) 
| 


1336°08 


217-49 


1335°78 


1837°51 


217°50 


1312-72 


1318°25 


217°43 


1049-49 


217°26 


1135°91 


1199-74 


1266°68 


217°28 


1180-29 


1487°36 


1486°95 


1489°34 


1454°83 


1459°60 


1090°59 


1206°63 


1298-01 


1391-45 


1201°50 


Standard 
Elements 


F 15376 \ 
G 15368 | 
A 15379 | 


14957 | 


14952 | 
14996 | 


H 10618 } 
EB 
F 
G 
C 
H 12002) 
12006 | 
12008 $ 
12010 | 
) 11914 J 
13106 } 
13112 | 
13107 $ 
13115 | 
13007 J 
14246 ) 
14250 | 
F 14248 | 
G 14256 | 
© 14146 | 
H 11940) 
E 11946 | 


F 11951 $ 
G 11949 | 


K 
r 
G 
C 
H 
i 
F 
G 
C 
H 
iy 


Posi- 
tion 


C 11887 | 


CoH HHH GOR SH CO CO RAR 0 HHH 


Other elements 
and positions 


4:1 | a (1), © (2°38) 
e(6°%) f(78) 


Do. 


Do. 


Do. 


a (1:5), J (2:4) 
c (62), e ('7°2) 


J OTC 


=? OU CD r+ “OU ce 


Do. 


Sade 


a (1), J 
c (6:2), 


(2°3), 
e (7°1) 


Io 


See page 106. 


Nitrogen Thermometer from Zinc to Palladium. 189 


TasLe VII—( Concluded ) 


| | | 

' ' | | |Standard | Posi- | Other eiements 
pee | NOL D (oF Pa) | NOE Po) |5a Elements tion | and positions 

'H 14950 } 
[EK 14958. | 
20 Dec. |138) 1802-40 | 1308°33 |1450-03 |F 14962 + 
G 14955 | 
IC 14882 J 
H 16156 | 
E 16160 | 
2 134) 1872°16 | 1878-78 |1550°15 |F 16170 } 
G 16148 | 
C 16075 | 


a(1), J (2°38) 
ce (6°72), e (71) 


Oo He HH HO HA 
2 C1 CO r+ 2 OU ce 
o 
(2) 


21 Dec. {135) 217-29 217-27 0 


(Continued from p. 132.) 


The melting and freezing points of the metals and salts, 
measured with the various thermoelements used during the 
investigation, as well as the frequent comparisons of thermo- 
elements with each other, are too numerous to be published here, 
especially as they are practically all summarized in Table VIII. 

Table VIII contains the final temperature of each thermo- 
metric point studied. In the first column is the number of the 
experiment corresponding to that in Table VII. In the second 
column is the correction in degrees to be applied to each of the 
thermoelement readings on the owtside of the bulb, integrated 
from the readings of the auxiliary elements as described on 
page 119; in the third column is given the corresponding cor- 
rection in microvolts. In the fourth column are the readings 
of the standard elements on the owts¢de of the bulb, corrected 
as above mentioned. In the fifth column are the readings of 
the same thermoelements at the fixed point in question, as 
obtained in the melting or freezing of metal or salt; these 
fisures usually represent the mean of a considerable number 
of determinations. 

In the sixth and seventh columns are the corresponding figures 
for the element zmside of the bulb. In this case, however, no 
correction has been applied to the reading of the element, 
since, being located practically at the center of the bulb, it 
might be expected to represent the mean temperature of the 
entire volume of the bulb. 

In the eighth and ninth columns are the temperatures of the 
fixed points derived from the preceding four columns. In the 
last column is given the weight assigned to each measurement. 
In assigning these weights the number of standard thermoele- 
ments used, the amount of variation in p,, and other incidental 
variables were taken into consideration. 

As has been pointed out on page 116, the relative weights to 
. be assigned to the inside and outside elements are different at 


140 A. L. Day and R. B. Sosman— 


different temperatures; (1) on account of the difference in 
contamination, and (2) on account of the fact that the inside 
element is subject to the influence of conduction and radiation 
from below. The weights assigned were as follows: 


Temperatures Outside Element Inside Element 
400-1100° oe il 

1100-1300° 2 if! 

1300-1550° 1 1 


The final weighted mean of the inside and outside elements is 
given at the head of each section of the table. 

In the last section of the table are given various points 
which were determined to aid in interpolating between the fixed 
points by means of the thermoelement. 

The only comment which need be made here on the data 
in Table VIII concerns the figures given under the heading 
“copper point.” In this section “of the table, the values derived 
at the two different initial pressures (217— 291™ and 346— 347™™) 
are quoted separately in order to bring out the fact that 
the difference between the temperatures obtained from these 
two pressures is less than the experimental error. In the other 
sections of the table the data obtained at the two pressures are 
not separately arranged. Above the copper point only the 
low pressure was used, as the high pressure would have 
exceeded the range of the manometer. 

The significance of the comparison between the inside-and 
outside-wound furnaces, which appears in the first half of the 
section on the copper point, has been commented on elsewhere 
(see p. 106). 

5. Interpolation Between the Fixed Points. 


The preparation of formulae to represent the relation between 
the temperature defined by the gas thermometer and the elec- 
tromotive force of a thermoelement has always been a cause of 
considerable dissatisfaction, both to the maker and the user. 
The chief reason for this is perhaps the fact that the formulae 
used have been applicable only to limited portions of the curve 
and have therefore given no suggestion of physical signifi- 
cance. In tho Reichsanstalt publication* the data extended 
from 300° to 1100° and included several good fixed points 
(melting points of pure metals) between which no interpolation, 
however rough, could go far astray. Accordingly, in so far as 
interpolation was concerned, but little attention required to be 
given to the formulation of this relation. It was sufiicient 
that a simple formula of the form 

EK = —-a+0bt+ct’ 


could be made to represent the observations between 300° and 
1100° within the limits of the errors of observation. 


* Holborn and Day, 1900, loc. cit. 


Nitrogen Thermometer from Zine to Palladiwn. 141 — 


TasLte VIII— Temperatures of the Fixed Points. 


Integrated Standard Elements Temperature 
correction | ae = 4 
Exp. t outside : ‘ nside ; yi ye : 
Ne. ne Ha ues | ie Tee Fixed OGuisde. inside Weight 
______~__|Correcte . rected * | Klement! Element 
Degr’s | M.V. | | 
Zine Point. 418°2° 
Tae 0-0° |A 3414 3411 /Y 3486 3436, 418°1°] 418°4° 


0 
3 A 8405 (8410°5 Y 3445 3435 | 418-0 4i8-4 
dL 00; 0 (A 3410 |3410°9 Y 5436 3435 | 418°3 418-2 
; 2 A 3402 3410 Y 3425 3434 | 418°0 418-1 


W W WO OO 


50 | —0-1 |—0-5/A 3413 [3411 418-2 
D 3405°3 13406 |Z 33845 | 3882 | 418-4 
, 498" | 418-9 | 3) 


# 


73 | —0°2 |—2 |A 3401 |3413°5 418°4 
BH 3417 [8429 418°3 
F 3412 = [8429 418°8 


G 3414 (38429 |Z 3370 3382 | 418°6 
418°5 418°3 + 


Weighted Mean, | 418-2°| 418-3° 
Antimony Point. 629°2° 


24) —01 |—1 |A 5509 5503 [¥ 5550 | 5546 | 629-2°| 629-4°| 2 
25 | —0°5 |—5 7A 5496 [5503 |¥ 5529 | 55451 629-0 | 629-9 2 
38 | —O-1 |—1 |A 5513 (5503 |¥ 5558 | 5544 | 629-2 | 629-3 2 
34| —0°5 |—5 |A 5505 [5503 |¥ 5537 | 5543 | 629-1 | 629-9 2 
52 | —0°5 |—5 |A 5505 (5508 629°6 

| | D 5490 5492 -Z 5463 | 5460 | 629-2 

| | 629°4 | 629-1 2 
74 | —0-2 |—-2 |A 5514 (5504 7 628-2 

| | |Z 5533 (55380 628°8 

| ‘F 5526 5530 629°5 


5) | 
| G5527 5580 Z 5461 0461 629°4 
| | 


| | is 629°0 | 629-1 4 


87 | —0°3 |—8 |F 5517 [5380 628-9 
| |B 5517 [5580 628:9 
1A 5481 (5504 | 629-9 


G 5513 55380 |Z 5437 | «5461 | 629-3 
| | 629°2 | 629-9 4 
Weighted Mean, 629-1°| 629°5° 


Silver Point. 960:°0° 


6) +08 /1+9 |W9070 (9057 |X 9100 9071 | 959°4°| 958-0° 
26 | —0°3 |—3 |A 9087 (9083 |Y 9159 9141 | 959-9 958°6 
27 | —08 |—9 |A 9066 (90838 |Y 9119 9141 | 959-9 960°4 
a0 |.—07 |—-8 |A 9079 (9082 |Y 9142 9141 | 959-7 959-4 
a6 | —O1 |—1 |A 9097 (9082 [Y 9163 9141 | 959-4 958°7 
41 —0°3 |—3 |A 90838 (9081 |Y 9156 9141 | 959-6 958-5 
42 | —0°8 |—9 |A 9076 (9081 |Y 9131 9141 | 959°3 959°7 


| 


WWORr KF OWwrH 


63 | —06 —7 |A 9079 9084 960-7 | 
| D 9048 9058 'Z 9010 | 9019 | 961-2 


| | | 960-9 | 9611! 2 


Am. Jour. Sci1.—Fourts SEeries, VoL. X XIX, No. 170.—FEpBruary, 1910. 
10 


142 A. L. Day and R. B. Sosman— 
Taste VIII—( Continued) 
| Integrated Standard Elements Temperature a 
correction : 2 ee 
Exp.) to outside a . Inside ; By By i 
No. | elements Out ee Fixed Uncor- Hee Outside Inside a 
| Se Pt. al Pt. ‘El t El t 
Degr’s | M.V.| recte eames | emen 
Silver Point—(Cont.) 
68 | —0°'7 |—8 |A 9080 (9085 960:3° 
D 9051 |9058 |Z 9013 |9019 960-4 
960°4 | 960°3° 2 
76 | —0°2.|—2 |A 9088 /|9082 959-2 
E 9112 = 9118 929-7 
EF 9097 9113 961-2 
G9106 |9111- |Z 9002 9018 960-2 
960-1 961225) et 
81 | +0°3 }+38 |F 9182 (9118 959°5 
E 9131 |9113 9596 
A 9088 — |9082 961°] 
G 9125 9111 |Z 9015 |9018 960-0 
960-0 961°5 4 
88 | +0°3 }4+38 |F 9148 (9118 959-0 
EK 9139 91138 959°4 
A 9993 |9082 960°7 
G 9135 (9112 |Z 9086 (9018 959°6 
959°7 | 9601 | 4 
Weighted Mean, 959:9° | 960:2° 
Gold Point. 1062°4° 
64 | —0°3 |—8 (A 10262 10265 | 1062-4° 
D 10226 {10233 |Z 10178 |10193 | 1062°8 
1062°6 | 1063°4° 2 
69 | —0°4 |—4 |A 10253 {10266 1061°4 
D 10217 |10234 |Z 10169 {10193 | 1061-7 
1061°6 | 1062°3 2 
77 | —0°3 |—3 |A 10255 |10263 1061°2 
E 10282 {10298 1061°6 
F 10263 {10296 1063-4 
G 10276 '10294 |Z 10161 '10198 | 1062:1 
106271 | 1063°3 t 
82 | +04 |)+4 |F 103038 |10296 1061-9 
E 10304 |10295 1061°8 
A 10256 |10263 1063°1 
G 10296 |10294 |Z 10181 10198 | 1062°4 
1062°3  1063°6 4 
Weighted Mean, | 1062:2°) 1063°2° 
Copper Point. 1082°6° (Lower Pressure. py=217—221™™) 
2) +1°2 )4+14 |wi0457 (10478 |X 10491 2 at OCTET ieee 1 
9} 4+1°0 |+12 (W 10495 10478 |X 10555 | ---. | 1082-2 iat 1 
1) 2 4 WA0487 0478s Xeno Sp ee OS sal one 1 
18 | +0°7 |+ 8 |A 10510 |10502 /¥ 10612 |10573 | 1082-2 ies 2 
19 | —0:4 |— 5 JA 10501 |10502 |Y 10584 |10573 | 1082-0 | 1081-0 3 


Nitrogen Thermometer from Zine to Palladium. 148 


Taste VITI—( Continued) 


| Integrated | Standard Elements Temperature | 
Ext correction | Tnsid B _ 
ue tsid : . nside : y y ep 
No. Pee eee aay Uncor- Fixed | Outside Inside | Weight 
Deor’s| MV. 4 | rected * |Klement | Klement 
fo) 3 alt 
Copper Point (Lower Pressure)—Cont. 
90 | —0°8 |— 9 |A 10488 [10502 ;Y 10555 10578 | 1082°1° , 1082°5° 3 
98 | —0°3 |— 4 |A 10512 (10501 |Y 10593 |10573 | 1082-1 | 1081-4 3 
99 | —0°9 |—10 |A 10494 {10501 |Y 10556 (10573 | 1082°2 | 1088-0 3 
37 | —06 — 7 A10504 (10501 -Y 10576 |10573 | 1082-0 | 1082-0 2 
388 | —0°3 |— 4 |A 10509 |10500 |Y 10585 (10573 | 1082°2 | 1081°9 2 
Bone O7 | SIA T0017 (10500 |Y 10617 |. -. | 1082°3 egecs 2 
43 | —0°3 |— 4 |A 10512 (10500 |Y 10595 (10578 | 1082°2 | 1081°3 3 
44 | —0°9 |—10 |A 10501 {10499 |¥ 10568 [10578 | 1082-0 | 1082°6 3 
45 | +06 /4+ 7 |A 10515 |10499 |Y 10617 | -.-- | 1082-3 uae: 2 
gg | +05 |+ 6 F 10546 [10534 1081°8 
E 10544 |10534 1081°9 
A 10496 |10508 10834 


a G10538 (10533 |Z 10428 |10482 | 1082-4 


| | 10824 | 1088-1 | 4 


126* | 40-4 /+ 5 @ 10631 |10534 1082-2 
F 10627 10534 1082°6 
G 10621 10538 1083-0 


H 10623 [10535 |C 10567 10470 | 1083-0 
1082°7 | 10825 | 4 


Weighted Mean ! 1082-2°| 1082:2° 


Copper Point—Oont. (Higher Pressure. p)=346-347™™) 
60 | —0-7 |— 8 |A 10500 |10502 1083°4° 
| D 10465 |10470 |Z 10422 |10482 | 1083-6 
| 1083°5 | 1084:1° il 
6) | —0-8 |— 9 |A 10502 |10503 1083°0 
D 10465 (10471 |Z 10420 |10482 | 1083-4 
| 1083°2 | 1083-9 
70 | —0-3 |— 4 |A 10508 [10504 | 1082-4 , 

| | D 10475 |10472 |Z 10444 10432 | 1082-6 

| 1082°5 | 1081°8 


CS) 


cy) 


7 | —0-1 |— 1 |A 10502 [10508 1081-4 
| | E 10528 |10534 1081°8 
F 10509 10534 1083°4 


G 10522 |10533 |Z 10404 |10432 | 1082-3 
1082°2 | 1083:7 4 


$3 +01 + 1 |F 10585 [10534 | 1082"1 


E 10535 10534 1082-1 | 
[A 10488 10503 | 1083°5 | 
10533 |Z 10403 /10432 | 1082-7 | 


G 10527 


| -1082°6 | 1084-6 4 
* Made with outside-wound furnace. See page 106. 


144 ats legs Day and R. B. Sosman— 


TasLE VITI—( Continued) 


Integrated | Standard Elements | Temperature 
Exp correction oe | By 
Now | to outside | Outside |Fixed Unser. Fixed | Outside mon Weight 
| elements (Corrected| Pt. has) Pt.) |Wlement esac 
Dep’rs| M.V.| recte Hlement 
Copper Point—Cont. (Higher Pressure) 
84 | +0°7 |+ 8 |F 10544 [10534 1082-0° 
E 10542 110554 1082°3 
A 10493 {10508 1083°8 4 
G 10583 {105383 |Z 10426 | 10482) 1083-0 
1082°8 | 1083°5 
‘Weighted Mean, | 1082°7°| 1083-7° 
Mean of 2 pressures, 1082°5° | 1082-9° 
Diopside Point. 13891°2° 
96 0-0 0 |E 14227 {14228 1392°1° 
F 14222 14229 1392°5 
G 14245 |14229 1390-7 
H 14251 |14231 |Z 14121 {14108 | 1390-4 
1891-4 | 1390°5° 1 
97 ; +1°0 |413 |E 14260 (14228 1892-4 
F 14254 |14229 1593:°0 
G 14287 |14229 1390-4 
H 14295 |14281 |Z 14156 |14103 | 1889-9 
1391°4 | 1890°5 i 
99 | —O71 |— 1 jE 14218 (14228 1894°5 
14195 |14229 1396:0 
G 14215 |14229 1394-4 
H 14212 |14231 |Z 14099 {14103 | 1394°8 
1394°9 | 1893‘7 il 
100 | +0°7 |+ 9 |K 14251 /|14228 1394-4 
IF 14244 |14229 1395-0 
IG 14268 14229 1393°1 
'H_ 14273 |14231 |Z 14156 (14108 | 1392-9 
1395°8 | 1891°8 il 
103 | —0°4 |— 9 |H 14211 |14228 ‘ 1392°5 
\F 14204 |14229 13931 
‘1G 14217 |14229 1392-1 
'H 14230 (14231 |Z 14124 |14103 | 1391-2 
| 1392°2 | 1889-4 3 
104 | +1:0 |+183 |B 14242 [14228 1392°5 
| F 14212 |14229 1394-9 
'G 14249 {14229 1392-0 
‘H14262 14231 |Z 14159 14103 | 1391-1 | 
| | 113926 | 1889°3 | 3 


Nitrogen Thermometer from Zinc to Palladium. 145 


TasLe VIII—( Continued) 


' | Integrated Standard Elements - | Temperature 


Exp. correction | ae By yd ae 
xp. | tsid : : i : ioht 
No. aie Ome foe Uncor- 5 ee Outside | Inside a 
ae | ECG : | rected * |Hlement|Element 
| Degr’s| M.V. | 
Diopside Point—(Cont.) 
106 | —0°6 |— 8 JE 14228 {14228 Tooley 
F 14225 = |14229 1392:°0 
G 14233 |14229 1391°3 
| H 14243 «|142381 |Z 14123 |14108 | 1390°7 | 13890-0° 9 
| 1891-4 
107 | +0°9 |4+12 JE 14248 |14228 1891-9 
EF 14237 . |14229 13892°8 
G 14245 (14229 1892°2 | 
H 14252 (14231 |Z 14152 (14108 | 1391-8 | 1389-4 9 
fo92s2 «| 
130 | —0°6 |— 7 |E 14248 /|14228 1390:2 
; IE 14241 |142380 1390-6 
G 14249 (14230 1389-9 
H 14239 14228 |C 14146 |14153 | 1390-6 
1390°3 | 1892-0 3 
| \ 
Weighted Mean, 13892°0° | 1890°4° 


Nickél Point. 1452°3° 


109 | +07 |+ 8 |E 15028 |14977 1451°2° 
H 18027 (14980 |Z 14903 |14850 | 1451-6 


1401°4 | 1451°1° 1 


q1! 0 0 E 14980- 14977 1453-2 
H 14978 (14980 |Z 14867 [14850 | 1453-7 


,| 1403°35 | 1452-1 2 


112 | +0°9 |}+11 'E 14971 |14977 1453°8 
F 14958 14978 1454°9 
H 14991 |14980 Z 14872 |14850 | 1452-4 
1453°7 | 1451-5 


coy) 


123 | —0-6 |— 7 |B 14984 [14977 | 1454-3 
'F 14989 |14978 |A 14982 |14945 | 1453-9 
| | 1454:1 | 1451:8 


coy) 


124 | +0:8 |+10 [BE 14989 |14977 1454:6 
F 14994 14978 |A 14996 14945 | 1454-3 


1454°5 | 1451°5 1 


133 —0°3 |— 4 E 14954 14977 : 1451-9 


F 14958 14976 1451°5 
G 14955 =|14981 1452-2 


H 14946 {14977 |C 14882 14898 | 1452-5 
| 1452-07) 1451-3°| : 4 
Weighted Mean, | 1453-0°| 1451-6° 


146 A. L. Day and R. B. Sosman— 
Taste VIII—( Continued) 
Integrated Standard Hlements eek | 
ak eck ee 

xp.| to outside . . nside ; 

No. | elements Aas ae Uncor- RIES oe ‘oneae 
| ; ho : rected Element Element 
| Degr’s | M.V.| 

Cobalt Point. 1489°8° 
115 | +01 |4+ 1 |E 15390 |15489 1488-7° 
| F 15875 |15485 |A 15857 (15409 | 1489-6 
1489-1 | 1488-9° 
116 | +1°4 }+17 |E 15428 |15439 1490°5 
F 154384 (15435 1489°7 
G 15435 (15441 |A 15421 §15409 | 1490-1 
| 1490-1 | 1488-6 
.118 | —0°5 |— 6 |E 15385 |15489 1491-7 
F 15383 /15485 1491°6 
G 153898 /15441 |A 153882 (15409 | 1491°3 
1491°5 | 1489-6 
120 | —0°4 |— 5 JE 15881 |15439 1491-7 
F 153871 |15435 1492°1 
G 15368 (15441 |A 15379 (15409 | 14938°3 | . 
1492°7 | 1489-4 
121 | +0°7 |+ 9 |/E 15406 |15489 1492°0 
F 15405 |15485 1491°8 
G 15898 (15441 |A 15412 /15409 | 1492°8 
1492°2 | 1489-1 
1490-6° | 1489-0° 
Palladium Point. 1549:2° 
134 | —O-7 |— 9 |E 16151 116143 1549°5° | 
F 16161 |161388 1548°3 
G 16139 {16145 1550°6 
| H 16147 (16145 |C 16075 16058 | 1550:1 
| | | 1549-6° | 1548-8° 
Anorthite Point. 1549°5° 

134 | —0°7 |— 9 /E 16151 16148 1549-9° 
| ‘R 16161 16141 1548°6 
| 'G 16139 16148 | 1550-9 
| (H 16147 16145 C 16075 |16060 | 1550°0 
| | | | | 1549-9° | 1549-0° | 

Interpolation Points. 

20) Salih fe ab pak Zabel | 22k) | | 320°2° | | 
| | D 2482 | 2486 |Z 2462 | 2465 | 320-0 | 
| Peay! | | 320-1 319-9° 

Mean for cadmium, 320°0° | 
51 0-0 | 0 |A 4451 4450 | 524°6 
D 4439 4442 |Z 4413 4417 | 525-0 
| | | §e48-] 825-1 
Mean for A = 4450, 524°9° 


Nitrogen Thermometer from Zine to Palladium. 147 
TasLte VIII—( Concluded) 
| Integrated Standard Elements Temperature 
Er correction Fe fe B = 
xp.| to outside : . _ Inside . y y : 
ee teeta | Outside Fixed’ Wncoe: Fixed Roe eeier ade Weight 
Corrected, Pt Pt 
i: |-skected: ’ | Element) Element 


| Degr’s M.V. | | 


Interpolation Points—(Cont.). 


21 0:01 0 {A 7895 | 7900 | | 854-22 | 
| 'D 7869 | 7881 |Z 7829 | 7848 | 854-9 
| | | | | 854°6 | 855-5° 
—0-2 | —2 [A 7883 | 7900 | | 854-0 
ID 7859 | 7881 Z 7820 | 7848 | 854:5 | 
| | | 8543. 855-0 
Mean for A = 7900, 854°7° 
—0-2 |— 2 |E 12004 |12000 1206°3 
F 12001 |12001 1206-7 
G 12008 |12001 | 1206-1 
H 12000 |12003 c 11914 (11928 | 1206 9 
| | | 1206°5 | 1207°8 
132 | +0-1 {+ 1 |E 11947 |12000 | 1206-0 
| | F 11952 |11097 1205 8 
| | G 11950 |12001 1205-8 
| | H 11941 |12003 |G 11887 (11928 | 1206-8 
| | 1206°0 | 1205-0 
Mean for E = 12000, 1206-4° 
129 | —0-6 |— 5 |E 18107 |13100 | 1297-4 
| | |F 13102 [13101 | 1297-9 
| G 13110 /13101 | 1297-2 
| | +H 13101 13103 c 13007 13028 | 1298-1 
| ee | | 12977 1299°3 
Mean for E = 18100, | 1298:5° | 


(Continued from p. 140.) 


If the investigator’s responsibility could be made to end 
with the representation of his own observations, no serious 
difficulty would arise, but such a formula when published is 
placed in the hands of many who do not realize that no physi- 
cal significance was attached to the formula by its author and 
that its extrapolation in either direction would be fraught with 
grave danger. A mere inspection of the equation is sufficient 
to show that the electromotive force does not become zero for 
zero temperature, thereby immediately proving that extrapola- 
tion downward does not correspond to the observed readings 
of the thermoelement. In the Reichsanstalt equation this 
constant term was in fact sufficiently large to lead to absurdi- 
ties if the extrapolation was continued far below 300°. 

Notwithstanding the warning contained in this situation, 
extrapolation upward of the thermoelectric curve has been 


148 A. L. Day and R. B. Sosman— 


employed almost universally for the determination of tempera- 
tures above 1100°, not only for direct determinations of tem- 
perature with the ‘thermoelement itself, but also for the cali- 
bration of optical pyrometric apparatus. The absence of 
absolute determinations in this region has left this practice in 
undisturbed security until recently, when some doubt has been 
thrown upon the validity of irresponsible upward extrapola-_ 
tion by various observations. (1) The increase in the accuracy 
now attainable with the optical pyrometer has given an inde- 
pendent thermal scale comparable with that of the thermoele- 
ment and overlapping the same region. The two curves have 
not been found to correspond. (2) Experimental determina- 
tions of the melting point of platinum by continuing observa- — 
tions of the thermoelement up to a point where a portion of 
its platinum wire melts, have been undertaken in the national 
laboratories of Germany, England and the United States, and 
have yielded a value measured upon the extrapolated thermo- 
electric curve of about 1710°. The agreement in the different 
determinations was good and the result found general accept- 
ance fora time. More recently, Holborn and Valentiner have 
made successful measurements with the gas thermometer at the 
temperature of melting palladium, and although high accuracy 
was not attempted; it “became clear that the “palladium point . 
obtained by extrapolating with the thermoelement was much 
too low and by inference the platinum point also, for the vari- 
ous optical methods give opportunity for a very good determi- 
nation of the temperature difference between the melting 
points of the two metals. The most recent estimates of the 
platinum melting point obtained in this way place it between 
1750° and 1775°, indicating that the upward extrapolation 
with the thermoelement has given rise to an error of about 
50° at the platinum point. 

The data obtained in the present investigation throw much 
light upon this situation. If we take the observations of our 
series over the range covered by the Reichsanstalt scale (500° to 
1100°) and write an equation for these of the same type as that 
used at the Reichsanstalt, it will read, 


EK = —302+ 8:2356¢+ "0016393¢° 


and this equation will reproduce the temperatures of the stand- 
ard melting points which fall in this region with a maximum 
error of 3 microvolts, an accuracy far within the errors of obser- 
vation. But if we extrapolate this curve in accordance with 
the general practice above described, and compare the resulting 
electromotive forces with our observations between 1100° and 


Nitrogen Thermometer from Zinc to Palladium. 149 


1550°, a somewhat startling surprise awaits us. Although the 
curve below the copper point is a practically perfect reproduc- 
tion of the observations, it diverges from the gas thermometer 
seale at the melting point of palladium by 245 microvolts, 
which represents a temperature error of nearly 20°. This 
comparison is made in the table below : 


Observed — 

; Observed Calculated Calculated 

Temperature Microvolts Microvolts Microvolts 
Wine ae 5 AVE 2 3429 3429 0 
Antimony ..- 629°2 5530 5530 0 
piver: is... '960:0 9113 9115 —2 
reer eh ent 1062°4 10295 10298 —3 
Mopper 2-22 1082°6 10534 10534 0 

Extrapolation. 

F201 12000 12027 —27 
1298°8 13100 15161 —61 
Miopside ~.2. 1391°2 14228 14338 —110 
Mickel. 205.2 1452°3 14945 15112 — 167 
Mertea lt es 1489°8 15439 15608 — 169 
Palladium ... 1549-2 16143 16388 © —245 


If, on the other hand, we follow Day and Clement, and 
represent ¢ as a function of E, using the same data as before, 
the equation will take the form 

t= 47-2 4°11297E—1-3946(10)—°K? 

This curve passes through the fixed points below 1100° nearly 
as accurately as the previous one, and is also quite competent 
to interpolate temperatures throughout the range of the old 
standard scale. Extrapolating this in turn up to the palladium 
point and comparing it with our gas thermometer measure- 
oe in the higher region leads to temperatures about 40° too 
ow. 


Observed — 
Observed Calculated Calculated 
7S TY ae ie a regs ATL B°O2 ALGO? Oe 
Antimony =... 629-2 629°3 —01 
30 960°0 960°9 = (2 
‘5536 eS aie 1062°4 1062°4 0 
Copper .__-.-.- 1082°6 1082°5 +0:1 
Extrapolation 
207-4 : 1202°0 +5°1 
1298°8 1287°8 +11°0 
Diopside ___. 1891-2 1372°0 +192 
Wi rekoh ss et-8 1452°3 1424:-0 ees 
Cabalis ss 1489°8 1459:0 + 30°8 


Palladium .__ 1549°2 1507-0 +492°9 


150 A. L. Day and R. B. Sosman— 


The untrustworthiness of the present practice of extending 
thermoelement values obtained below 1100° into the region 
above that temperature is therefore abundantly demonstrated.* 

We were unable to find a simple parabola with which to 
represent the whole series of observations between 300° and 
1550° within the errors of observation. The simplest proce- 
dure is therefore to divide the long curve into two parts. This 
plan is carried out below in the form in which it will probably 
be found most useful. A parabola passing through zine, anti- 
mony and copper reproduces the results over that temperature 
range within the errors of observation. A similar parabola 
through copper, diopside and palladium gives the upper tem- 
peratures as accurately as they were measured. These two 
equations offer a means of safe and convenient interpolation 
throughout the entire range of the gas thermometer measure- 
ments. In this series are included certain gas thermometer 
measurements given at the end of Table VIII which were 
made at temperatures between the fixed melting points, for 
the purpose of checking the interpolation formula, together 
with a single gas thermometer determination of the cadmium 
melting point. The temperature 854:1 appears here corrected 
by —0°6°, since the series, of which this measurement formed 
a part, showeda systematic difference of about this amount 
from the final average of antimony and silver, which lie on 
either side of this point. 


Cadmium to Copper 


EK = —302 + 8:°2356¢ + :0016393877 

Observed — 

Observed Calculated Caleulated 

Temperature Microvolts Microvolts Microvolts 
Cadmium. 2 322042 3210-0 % 2504 2501 +3 
ZAC es See a eA " . 8429 3429 O 
524°9 4470 4472 —2 
ANUHNINOS Sree hse.  GLOM 5530 5530 0 
854°1 7927 7928 —1 
Silver Vy eee 960°0 9113 9115 —9 
(old Ae eee 1062°4 10295 10298 —3 
Copper Zot Ses ESC MSI 1082°6 10534 10534 0) 

Copper to Palladiwm 
E = —1941 +11°1746¢+ 00032161? 

Copper eae 1082°6 10534 10534 0 
BONA 12000 12010 —10 
1298°8 13100 13112 —12 
Diopside 320) 1391°2 14228 14298 ®) 
NGG eet es 1452°3 14977 14967 +10 
Cobain ne) MAA ORs 15439 15421 +18 
Panladitnti oe 1549°2 16143 16143 0 


* For an account of some of the dangers of careless interpolation, see Day 
and Clement, loc. cit., p. 453. 


Nitrogen Thermometer from Zinc.to Palladium. 151 


It is possible to write a cubic equation which will reproduce 
the entire series from zinc to palladium without error greater 
than the normal accuracy of the observations themselves. The 
equation offered makes no pretensions to a least square solu- 
tion with balanced residuals, but is arranged so that the great- 
est uncertainties are found in that portion of the curve where 
the greatest experimental error lies. The coefficients were 
rounded off for convenience of computation. 


Cadmium to Palladium 


E = —169°+7°57¢ + 0:0026482? —0:0000004724¢° 

Observed — 

Observed Calculated Calculated 

Temperature Microvolts Microvolts Microvolts 
Se AOEUIN: ofS. 320-0, 2504 2509 —5 
mers ek 2 418°2 3429 3425 +4 
524°9 4470 4466 +4 
PAMEIMONY 2 =.= - 629°2 5530 5525 +5 
854°1 7929 7984 —9d 
Bene 960-0 9113 9121 —8 
5. Se ee 1062°4 10295 10296 —1 
Mipper 9 4..° 2: EO S226 10534 10530 +4 
1206°4 12000 11988 +12 
1298°5 13100 13091 +9 
DWiopside 2-2... 1391-2 14228 14215 +13 
TCI 3) a a ae 1452°3 14977 14963 +14 
Sowalt ioe elk 1489°8 15439 15424 +15 
EAladtum : 22 2. 1549°2 16143 16157 —14 


6. Analysis of Metals. (By £. T. Allen.) 


The object of these analyses was primarily, of course, to 
decide whether the metals should be used or rejected for the 
temperature scale, and those selected were examined very care- 
fully so that in the future, when more is known about the 
specific lowering which the various impurities produce on the 
melting point, corrections may be made if desirable. 

The accuracy of the determinations is problematical. There 
is of course the possibility of increased solubility of difficultly 
soluble compounds in the comparatively concentrated solutions 
of the metals from which the impurities have to be precipi- 
tated, viz., 5 to 6 g. in 250° volume. Also, when it is neces- 
sary to separate the bulk of the metal by precipitation from the 
impurities, as it sometimes is, one cannot be sure that the 
impurity sought is not occluded by the precipitates. In most 
cases, the latter source of error is probably the more serious. 
Only methods worked out synthetically with materials labori- 
ously prepared could decide these questions. Large quantities 
of metal, 25 to 100 g., were generally taken for analysis, and 


152 A. L. Day and R..B. Sosman— 


since the impurities were weighed to the tenth of a milligram, 
the results are generally stated to the ten-thousandth of a per 
cent. This does not mean that the results are considered accu- 
rate to this figure. The variation in successive determinations 
comes in the thousandths, so that the fourth decimal place 
may have about as much value as the second in an ordinary 
analysis. Great pains have been taken to purify precipitates, 
often by many precipitations, so that in all cases the figures given 
may be regarded as minima. In all cases, too, | have endeav- 
ored to avoid missing anything, by repeating every process, 
rejecting no precipitate or solution until it was decided that 
nothing more was to be gotten from it. In any reasonable 
ease of suspicion, blank determinations were made with the 
reagents.* 


Heraeus’ Palladium. 


The palladium was naturally suspected to contain other 
metals of the platinum group. It is well known that the sep- 
aration of these metals is a problem of unusual difficulty. The 
plan here was therefore to precipitate most of the palladium 
from solution as one of its characteristic compounds and, 
while the filtrate was reserved for impurities, to redissolve and 
again precipitate the metal as another characteristic compound. 
In this way it was hoped that those impurities which were 
retained by the first precipitate would not be occluded by the 
second. ‘The sheet metal was first cut into shavings on a mill- 
ing machine which was especially cleaned for the purpose. 
Then the shavings were boiled a short time with dilute hydro- 
chlorie acid to remove any iron from the surface, washed and 
dried. After an unsuccessful endeavor to dissolve the palla- 
dium in nitric acid (insoluble brown hydroxide (?) always 
formed), it was dissolved in aqua regia and rid of nitric acid 
by successive evaporations with excess of hydrochloric acid. 
It was then dissolved in dilute hydrochloric acid and diluted 
further to about 1]. Ammonia was added in excess.t <A pre- 
cipitate came down and redissolved on warming—all but a 
little ferric hydroxide which was filtered off. The filtrate was 
then evaporated again to about 250°, diluted and precipitated 
with stirring, by dilute hydrochloric acid. The voluminous 
precipitate of PdCl,.2NH, was now filtered and washed on a 
Biichner porcelain funnel, using suction. The filtrate we will 
call “solution A.” The precipitate was then dried and 

* After considerable experience in the examination of these ‘‘ pure”’ 
metals, the writer has reached the conclusion that a 10 g. portion, in the 
great majority of cases, will give as satisfactory results as a larger portion 


and with far less labor. 
+E. F. Smith and H. F. Keller, Amer. Chem. Jour., xiv, 423, 1892. 


Nitrogen Thermometer from Zinc to Palladium. 158 


ignited in a large porcelain crucible. The resulting metal was 
dissolved in aqua regia and freed of nitric acid. This solution 
was diluted and precipitated by potassium iodide, and the fil- 
trate—* solution B”—-removed as above. 

From solutions A and B, separately, the platinum metals 
were first removed by long oiling with ammonium formate. 
The metal—1 to 2 g. in weight, mostly palladium—was filtered 
and the filtrate and washings were examined further for other 
heavy metals by the usual methods. 

Separation of the Palladium from the Platinum Metals.— 
Considering now the ammonium formate precipitate, Erdmann 
and Makowka* have obtained satisfactory separations of palla- 
dium from platinum and iridium by treating the solution of 
the mixed chlorides with acetylene. Palladium comes down as 
acetylide and the other metals are unprecipitated. I found 
also that rhodium solutions even on heating were not precipi- 
tated by acetylene. As for osmium, the ease with which it 
oxidizes and the high volatility of its oxide makes its elimina- 
tion, in the process of preparing the palladium, fairly certain. 
Ruthenium, the rarest element among the platinum metals, 
need hardly be looked for; still it was sought for in the iri- 
dium found. The acetylene method was used, for lack of 
a safer one, though very tedious. In solutions at all con- 
centrated, I find the palladium ceases to precipitate long 
before it is entirely removed from solution. Perhaps this 
is due to the accumulation of acid liberated in the process. 
At least, when the solution is separated from the acetylide, 
evaporated and diluted again, acetylene brings down another 
portion. After five or six operations, a residual solution was 
obtained on which acetylene had no further action. The acety- 
lide was now carefully ignited with a little ammonium nitrate, 
the metal redissolved, and the whole process repeated. The 
residual solution was then added to the first and from it NH,Cl 
brought down platinum. In the chlor-platinate no iridium 
was found. It was ignited and the metal was entirely soluble 
in a few drops of aqua regia. It was again precipitated with 
NH,Cl and finally weighed as platinnm— Pt = 1°6 mg. = 0:007 
per cent. No rhodium was found in the filtrate. In the 
attempt to dissolve in aqua regia the several portions of metal 
formed by igniting the acetylide, tiny insoluble residues accu- 
mulated. These were fused with KHSO,, which, as is well 
known, dissolves palladium and rhodium but not iridium or 
platinum if the temperature is kept low. The soluble portion 
was dissolved in water and precipitated with ammonium for- 
mate. It turned out to be palladium, since it was precipitated 
by potassium iodide and no trace ‘of rhodium was found. 


* Zeitschr. anal. Chemie, xlvi, 146, 147, 1907. 


154 A. L. Day and R. B. Sosman— 


The portion insoluble in KHSO, was freed from silica 
(which came from the dish) by HCl+HF, ignited, and weighed. 
Ir + [Ru] = 1°9 mg. = 0:008 per cent. When fused) with 
K,CO, + KNO,, some blue insoluble IrO, was formed, but the 
fusion showed no yellow color, and in view of the minute quan- 
tity of material, it was not thought worth while to search more 
carefully for r uthenium. 

The final precipitate of palladium acetylide was changed to 
chloride, diluted, and saturated with SO, for gold, but none 
appeared. 

Nothing else was found in the metal except a trace of cop- 
per. The iron found earlier had to be. reprecipitated several 
times from chloride solution by ammonia to get rid of palla- 
dium. The precipitate was finally transformed into sulphate 
and determined volumetrically. Fe=2°6 mg.—-010 per cent. 


Analysis of Palladium. 


SAL ere Ee es ee A eed none 
RU ee ig fig) eh ere DSR aa none 
Ai 2 Ay ree tc aaa ies as eas none 
Bitsy EN ieee ee OOM 
1 eR eer Meee mee tea ten ce "008% 
Ci GIN ORO ng pele dale GN trace 
TS RN SURE Cone doubtful trace 
| Sune SoU Mman ates) Ges arn AU ys Les "010% 

025% 


Kahlbaum’s Electrolytic Nickel. 


Two 50 gram portions were dissolved separately in measured 
quantities of nitric acid and then carried to white fumes with 
excess of sulphuric acid. Both portions were then dissolved 
in water and filtered. There was a small dark residue which 
was washed thoroughly and extracted with aqua regia, leaving 
a little silica from the dish. The yellow chloride obtained 
was freed from nitric acid, saturated with SO, and left to stand. 
No gold. Changed to chloride again and tested with caustic 
soda and H,O,. Stzll no gold. Acidified and reprecipitated 
with NH,Cl, a characteristic yellow precipitate was obtained. 
Confirmed by dissolving the chlor-platinate in hot water and 
precipitating by hydrogen. Pt = 2°3 mg. = 0:0023 per cent. 
The main solution was then precipitated by H,S (wv = 2 1.). 
The small black precipitate obtained was worked over for gold 
and platinum with the above. 

Other heavy metals were tested ion in the ordinary way. 
0-2 mg. PbSO, = about 0-1 mg. Pb. Cu=52°3 mg. = 0:05238 
per cent. 

Ammonium Sulphide Group.—The voluminous solution 
was now freed from hydrogen sulphide by evaporation, some 


Nitrogen Thermometer from Zine to Palladiwm. 155 


ammonium persulphate was added and a stream of air passed 
through the solution for some time. Wo manganese. 
Fe,O, = 6:1 mg., after repeated precipitation. Fe = 4:2 mg. 
Repeated efforts were made to separate zinc with H,S on the 
principle of the lower solubility of ZnS in dilute acids, but 
without satisfaction. First I tried to precipitate a small fraction 
of the nickel, hoping to get all the zine with it. The volume 
of the solution was about 51. But unless so much acid was 
added that strong doubts were entertained of recovering any 
zine that might be present, the fraction of the nickel precipi- 
tate was far too great. Again, all the nickel was precipitated 
and the precipitate was digested with cold 10 per cent solution 
of hydrochloric acid. Here one had to fear either the failure 
to remove the zine or the removal of too much nickel to handle 
without so many precipitations that a small quantity of zine 
would probably be lost. It is doubtful whether we have any 
method which will give very small amounts of zinc in metallic 
nickel. 

The whole solution was now tested for cobalt as follows: 
It was freed from H,S by evaporation, acidulated with HCl 
and precipitated by a-nitroso-6-naphthol in 50 per cent acetic 
acid. ‘This was added in severai portions. After long stand- 
ing the precipitate was collected and washed. The voluminous 
precipitate was very cautiously burned in a capacious porce- 
lain crucible. Much tar was formed. The residual oxide was 
dissolved in nitric acid and the cobalt separated from nickel 
by KNO, in the usual way. The potassium cobalto-nitrite 
was finally decomposed by sulphuric acid and precipitated 
electrolytically from ammoniacal solution. Co=101°4 mg.+4°9 
mg. recovered from filtrate and weighed as sulphate. Total = 
0-°1063 per cent. Feand Co were also determined in a separate 
10 ©. portion of metal. Fe,O,—0-7 mg. Fe = 0-49 mg. = 
0:0049 per cent. Co=10°3 mg. = 071030 per cent. A 
separate 10 g. portion was taken for sulphur. It was dissolved 
in nitric and evaporated on the water bath. This solution was 
diluted and precipitated with a slight excess of sodium car- 
bonate. The filtrate was just acidulated, evaporated, and 
treated with barium chloride. No precipitate. 


Analysis of Nickel. 


5) Cea none Bree weet none 

ae ee pea 00234 Cd syne! “ 

Baths waMt Se none Lis? oes * none found 
| Ue eee i Coie "10634 

3 bee hed aes a ee Vint e mone 
Pistia oe 0001% He, df oye, 004.2% 

6 eer Nee 0523% Si yee none 


1654 


156 A. L. Day and R. B. Sosman— 


Kahlbaum’s Cobalt. 


Two 25 g. portions of the metal in the form of powder 
were dissolved in 150° water+35° concentrated H,SO,. The 
analysis was quite similar to that of the nickel. In the H,S 
group were found: Cu=89 mg.=0°0178 per cent. PbSO,= 
12-9 mg. Pb =-0176 per cent. In the (NH,),S group man- 
ganese was tested for as in the nickel. None was found. 
Fe,O, = 0°9 mg. Fe = -0006 per cent. As the tests for Ni 
and Zn were unsatisfactory, another portion of 25 g. was dis- 
solved in dilute sulphuric acid and precipitated by H,S. The 
filtrate from the sulphides was filtered and freed from excess 
of H,S by evaporation. Then it was diluted to 1 liter and 
divided into two portions. Both were neutralized by sodium 
carbonate. In the one, manganese was sought for by ammonium 
persulphate. In the other nickel was looked for. <A little 
ammonia was added and then an alcoholic solution of dimethyl 
glyoxime. A precipitate containing much cobalt was obtained. 
This was worked over for nickel but none was found. For 
sulphur the method used in the analysis of nickel was followed. 
BaSO, = 144 mg., blank = 5:1 mg., difference = 9-3 me., 
S = 0-013 per cent. 


Analysis of Cobalt. 


aCe ar Ase none Cul. 22 oe Oe 
FANT gape ERE Me Bag re Poe none 
Pt ay Mea esa 66 Cd Th seme 66 
PAIS peusast cya, ee Liv ae eee 
i OPE peeeet ie as Nitec eee ae “< 
Saye Gee ae ec Ke 2.2.5. 00067 
] rd Opa ee 0176% Mime eee none 
Ware Se: 013% 
049% 
Aluminum. 


Owing to the difficulty of handling this metal, small portions 
(10 g.) only were taken for analysis. Heavy metals, except 
arsenic and antimony, were sought for in the hydrochlorie 
acid solution by ordinary methods. Only a trace of copper 
was found. 

Phosphorus, Arsenic, and Sulphur.—For these elements, a 
separate portion was dissolved in caustic alkali in a special appa- 
ratus entirely of glass. The vessel was first filled with purified 
hydrogen and then the alkali was introduced and the gases 
evolved were passed through silver nitrate solution. At the 
end, the gases remaining in the vessel were displaced by hydro- 
gen. The precipitated silver was worked over for the different 
elements. Wo As nor Sb. A separate portion was used for 
sulphur. BaSO, =14 mg. S =-002 per cent. 


Nitrogen Thermometer from Zine to Palladium. 157 


Silicon.—10 g. metal were dissolved in a mixture of nitric 
and sulphuric acids, using a platinum dish. With hydrochloric 
acid alone nearly all the silicon is lost as hydride. The brown 
amorphous residue was filtered, washed and fused with sodium 
carbonate. From the fusion silica was obtained in the usual 
way. SiO,=41-4meg. Si=0°194 per cent. Repetitions gave 
0°189 per cent and 0°190 per cent. 

Carbon.—10 g. metal were dissolved in NaOH. and filtered 
through glowed asbestos, washed first with water, theu with 
dilute acid and finally with water and dried at 105°. The 
asbestos and residue were then transferred to a combustion 
tube and burned in air free from CO,. The gases were passed 
through standard Ba(OH),. <A considerable precipitate was 
obtained, while a blank gave no trace. The excess of Ba(OH), 
was the ntitrated with standard acid using phenolphthalein as 
indicator.. 5°05 mg. CO, found. C = 0-014 per cent. A 
duplicate in which the metal was dissolved in KOH gave 
0-012 per cent. 

LIron.—10 g. metal were dissolved in hydr nonlent: acid, and 
to the solution was added tartaric acid free from iron. From 
this solution the iron was precipitated by colorless ammonium 
sulphide. The precipitate was finally changed to sulphate 
and determined volumetrically. Fe—46mg. Blank deter- 
mination gave 0:3 mg. Fe = 0-043 per cent. 

Calcium, Sodium, and Potassium were sought for in the 
hydrochloric acid solution, by precipitating with ammonia, 
washing the large pr ecipitate and testing the evaporated filtr ate. 
NVo Ca. Some alkaline chloride was found, but a blank showed 
that it came from the ammonia, as there was only a difference 
of 1°6 mg. between the chloride of the blank and that in the 
determination. Wo Wa or K. 


Analysis of Aluminum. 


7S Sage eeeeas none Cree eee 0°013% 
es eames oe See 020024 
| Phra ae aie & Cas sees none 
“OHITE aie Sas aa a 0°003% Naka see « 
Beene Py 282 0°043% Reg seen i 
Die 0°190% —— 

0:251% 

Antimony. 


25 g. metal were powdered in an agate mortar and treated 
with 35 per cent HNO, on the steam bath. Assoon as the reac- 
tion was practically complete, the antimonic acid was extracted 


Am. Jour. Sci1.—FourtH Srerizs, VoL. X XIX, No. 170.—Frsruary, 1910. 
11 


158 A. L. Day and R. B. Sosman— 


with hot dilute nitric acid, transferred to a filter and washed 
with water, The filtrate and washings were then evaporated 
to dryness with hydrochloric acid, while the antimonie acid 
was digested repeatedly with yellow sodium sulphide till the 
soluble portion was dissolved. The residue, after a little 
washing, was dissolved in nitric acid, evaporated to dryness, 
freed from nitrie by hydrochloric acid, and the chlorides united 
with the first extract. The whole was pr ecipitated by hydrogen 
sulphide. The washed sulphides were then extracted with 
colorless ammonium sulphide. From this solution the sulphides — 
were thrown down by acid, filtered and washed. Then they 
were dissolved in hot dilute caustic potash. The solution was 
boiled with perhydrol for complete oxidation, and arsenic 
sought for by Fischer’s method, viz., reducing by ferrous 
ammonium sulphate and distilling i in a current of hydrochloric 
acid gas. Vo As. 

A separate portion of 5 g. was taken for tin. McCay’s 
method was: tried.* SnO,— 1:3 mg. Sn — 1:0 mo. 02apen 
cent. 

A separate portion of 25 g. was used for sulphur. The 
metal was oxidized by nitric acid as before, and the soluble 
portion separated and evaporated. ‘The residue was then heated 
with a small excess of sodium carbonate and filtered. The 
residue was also boiled out several times with sodium carbonate 
solution. The two solutions were then acidified with hydro- 
chloric acid and treated with barium chloride. The portion 
soluble in nitric acid gave a slight precipitate,which was fur- 
ther purified, after the usual washing and dr ying, by fusion with 
sodium carbonate. The water extract containing the soluble 


sulphate was acidified and precipitated a second time. 
BaSO, = trace. 


Analysis of Antimony. 


INS ogee ce none Cdieu epee none 

Sneek) ote Stas 0:02 (?) INS Ee ao gs 

aaa CNV eas none Cotera ae $f 

] Be rest a Ne trace (?) Mire eet ee 

Cire eerie es 0:004 Ziti Mee ae ace S 

| ea a none ) Ree nee ee 0:007% 

Dele eden trace (?) 

081% 


In the following table, the results of these and previoust 
analyses of metals for the temperature scale are summarized : 


* Private communication. 
. + Day and Clement, loc. cit., p. 454. 


Nitrogen Thermometer from Zine to Palladium. 159 


Summarized Analyses of Metals.* 


Impurities Metals 
stated in 
eae Peat Cobalt Nickel Copper [Silver ee Antimony| Zine 

Pt 0-007 | none | -0023; 00114 | -0001 
Ir “008 
Rh none 
Ru ce 
Au Ks none |*none| none | :0005 
Se (a4 
Te ‘a4 
As none) none es none | none! none none 
Sb | (a z5 6é (5 6é "002 
Sn (a3 (75 6é | 66 “02 (2) 
Hg oe none 
Ag none} none 0006 - none 
Pb none | ‘0176; -0001; none | -0008 051 
Bi ‘*< | none} none gs none none none 
Cu trace | -01'78| -0523 trace | °008 “004 none 
Cd none | none} none! none | none none "004 
Ni ee ee (a4 (4 none 66 none 
Co ce °1063 ac cé (74 (a9 $e 
Fe 7010 | -0006| :0042| -00388 | :0011)| :048 007 "006 
Zn trace? none? none?) ‘0007 | none none 
Mn none | none ee 
Si none "190 none 
GS 0008} :013 
Ss "013 | none ‘0020 | -0004| -002 none 
N 2 none 
Ca ss 
Na | * 
KG | (a4 

Total “025 | -049 | 165 | -008 | -003 | -251 |  -031 063 


* A blank opposite any impurity means that it was not looked for. 
t Means platinum metals. 


7. Conclusion. 


It is now something over five years since the Geophysical 
Laboratory took up the task of redetermining the absolute 
temperature scale from 300° to 1100° with the nitrogen ther- 
mometer, and of extending it, if it should prove practicable to do 
so, to 1600° C., for it- isin this upper region-that most of the 
mineral relations which it is the chief purpose of the labora- 
tory to study are found. ‘T'wo preliminary publications have 
been made during the investigation. One, a brief summary 
of pr eliminary work up to 1100°, was given before the National 
Academy ot Sciences and the American Physical Society in 
April, 1907,* the second covered the same ground at con- 


* Abstract, Phys. Rev. xxiv, 531, 1907. 


160 A. L. Day and Rf. B. Sosman— 


siderable length in 1908.* The present paper extends the 
observations to 1550°, and completes the work contemplated 
under the original plan. 

No attempt will be made to offer an inclusive summary of 
the whole investigation. It is a record of experimental 
measurements covering an unusually wide range of details 
which do not admit of brief classification. The errors which 
have heretofore been present in measurements with the nitro- 
gen thermometer have been reduced by the present investiga- 
tion to about one-fourth their former magnitude and the 
certainty of their evaluation is at least proportionately increased. 

The chief source of present uncertainty is the temperature 
distribution over the surface of the bulb. in an air bath. No 
indication of a lmit to the temperature attainable with the 
nitrogen thermometer or to its ultimate accuracy was discovered 
during the present investigation. 

The magnitudes of the errors, and their effects on the tem- 
perature, are summarized in Table IV, page 129. The deter- 
minations of the expansion coefficient of the bulb material 
(80 Pt. 20 Rh) are summarized on pp. 131-132. 

The melting temperatures of the metals and salts which 
have been used as fixed points to establish the new scale 
are brought together in the table below, together with 
the conditions under which the determinations were made. 
The generally accepted Reichsanstalt scale is printed beside it 
for convenient comparison. The analyses of the metals are 
summarized on p. 159. 

To this table has been added a new estimate of the melting 
temperature of platinum, of which we could make no direct 
determination. its general acceptance and availability as a 
fixed point of reference, and the wide disagreement between 
the direct determinations heretofore made of it, form a suffi- 
cient reason for its inclusion. The estimate is arrived at in this 
way: There isa remarkably close agreement between inde- 
pendent determinations of the temperature interval between 
the melting points of palladium and platinum : 

Nernst and von Wartenbergt 204° 

Holborn and Valentiner (at the Reichsanstalt)f 207° 

Waidner and Burgess (at the Bureau of 

Standards) § 20aa 

If we therefore simply add 206° to our determination of the 
palladium point, we obtain 1755° as the melting point of pure 
platinum, with an absolute error of perhaps no more than 
+ 5°. The table follows: 

* This Journal (4), xxvi, 405, 1908. 

+ W. Nernst and H. von Wartenberg, Ber. d. Deutsch. phys. Ges., iv, pp. 
48, 146, 1906. 


as Holborn and §. Valentiner, Ann. d. Phys. (4), xxii, 1, 1907. 
$C. W. Waidner and G. K. Burgess, Bull. Buc. Standards, iii, p. 163, 1907. 


Nitrogen Thermometer from Zinc to Palladium. 161 
The Reich - 
Substance Point Atmosphere! Crucible |Temperature| sanstalt 
Scale 
Zine Melting and |Ain Graphite 418°2° +0°3) 419°0° 
freezing 
Antimony Do. Carbon Do. 629°2 +0°5) 630°6 
monoxide 
Silver Do. Do. Do. 960:°0 +0°7) 961°5 
Gold Do. Do. Do. 1062-4 +0°8} 1064:0 
Copper Do. Do. Do. 1082°6 +0°8) 108471 
Diopside {Melting Air Platinum 1391-2 +1:0 
(pure) 
Nickel Melting and |Hydrogen |Magnesia | 1452°3 +2°0 
freezing and Nitro-| and Magne- 
gen sium Alum- 
inate 
Cobalt Do. Do. Magnesia 1489°8 +2-0 
Palladium Do. Air Pure Mag- | 1549°2 +2:°0) 1575°* 
nesia 
Anorthite |Melting Do. Platinum 1549°5 +2°0 
(pure) 


In addition, the following temperatures were incidentally obtained : 


320°0 +0°3) 321°7 


Cadmium |Melting and |Air 


freezing 


Aluminum |F'reezing 


Platinum 


Melting 


Carbon 
monoxide 
Air 


Geophysical Laboratory, 
Carnegie institution of Washington, 
Washington, D. C., December 24, 1909. 


Graphite 
Do. 


658°0 +0°6) 657: 


1755: 


* Holborn and Valentiner, loc. cit. 


162 A: L. Parsons—New Sclerometer. 


Arr. IX.—A Wew Sclerometer; by A. L. Parsons (Uni- 
versity of Toronto). 


Tue physical properties of minerals and metals have for a 
long time been a subject for investigation, and among the first 
of these properties to be studied were hardness and tenacity, 
but although the tensile strength and crushing point of the 
various substances are easily measured, the determination of 
hardness or resistance which a substance offers to abrasion is 
not so well understood. The sclerometer which was devised 
by Seebeck and later improved by Grailich and Peckarek is 
the one which is best known, but it is little used because the 
length of time which is required for a single measurement 
prevents the common use of an instrument which should be 
of valuable assistance to the mineralogist and metallurgist. 

A bibliography of works on sclerometry is given by Jaggar* 
which includes the most important papers and outlines the 
principles employed by various investigators in using their 
own instruments or those devised by others. 

The new instrument differs from those of Seebeck, Grailich 
and Pekarek and others in that the force that is necessary to 
make a scratch is measured a means of a spring and not by 
weights. 


Description of the Instrument. 


The instrument consists of four working parts on a base, as 
follows (see fig. 1) :— 


1. Steel spring (F) with test-point holder (H) fastened to 
the column (8). 

2. Object holder (O) with divided horizontal circle (C), 
horizontal screw (1) for moving the object to be tested from 
side to side, and two vertical screws (2 and 3) to give the object 
the desired inclination. 

3. Carriage (7) with transport screw (4) and spring (5) to 
move the test object, while making the scratch, and a slide (6). 

4. Micrometer screw (E) and scale (8) to measure the eleva- 
tion, which is proportionate to the force necessary to make a 
scratch. 


5. Base (G) to hold the working parts together. 


1. The spring (F) consists of a strip of steel 120™ long, 
from the column (S) to the test point, 4-8°" wide and 0°75™™ 
thick. It is firmly fastened by a screw to the top of the 

* This Journal (4), iv, p. 399, 1897. 


+ Price of instrument, 80 marks from the mechanic, P. Stoe, Heidelberg, 
Germany, Jubilaeums Platz, 70. 


A. L. Parsons—New Sclerometer. 163 


column (S) and with this can be raised or lowered in the socket 
(B). The rod (St) behind the column prevents lateral move- 
ment of the spring in raising or lowering the same. On the 
free end of the spring is screwed the test point holder (H,, H.,, 
or H,) which carries the crystal point or metal point with 
which the test object is to be scratched. 

The following three poimt-holders seem desirable and are 
provided with the instrument: H, with diamond point. This 
is preferably a tetrahedral cleavage fragment, as this form gives 


Bree 


the sharpest cutting edge and is least liable to variations in 
hardness. H,, a holder in which a needle of steel or other 
metal can be fastened. Generally a sewing needle is used, as 
there is little variation in hardness in needles from the same 
packet. For very soft substances a brass pin or a copper point 
may be employ ed. H, , a holder with a cup-like depression in 
which a erystal or other substance may be fastened by means 
of wax “kit.’* This may be either a substance of known 
hardness with which another is to be compared or one of 
unknown hardness which is to be tested by scratching the sur- 
face of a substance whose hardness is known. 


* A piece of ‘‘ kit” is provided with each instrument. ; 


164 A. L. Parsons—New Sclerometer. 


2. The object carrier (O) holds the crystal or other test 
object firmly in the position desired for making the tests. 
The crystal is fastened by wax “kit” to a small plate which 
is set in a socket at the top of the carrier. 

The adjustment of the test object is as follows: 


1. To bring the surface under the test point the transport 
screw (4) and the screw (1) are used. The screw (1) has also 
the purpose of moving the test object from side to side so 
that duplicate measurements may be made in parallel positions. 

2. To give the face of the test object the desired inclination 
so that it forms with the slide (6) a wedge, it is tilted by means 
of the screw (2). The inclination will vary according to the 
hardness of the substance to be tested; very soft substances 
require only a slight inclination while harder materials require 
a greater one. This inclination of the surface to be tested is 
one of the most important features of the instrument, as it 
gives the measure of the pressure of the spring (I) when the 
crystal is moved by the transport screw (4). 

3. To level the test object from side to side a screw (83) on 
the rear of the instrument is employed. 

4, To test the hardness of the substance under investigation 
in different directions the graduated circle (C) is turned about 
itsaxis. This circle is divided into 36 parts so that each division 
gives 10°. 


3. The transport screw (4) and accompanying spring (5) 
move the test object under the test point. The inclination of 
the surface to be tested to the plane of the slide (6) forms a 
wedge which by the movement of the screw (4) raises the 
spring (F) until a scratch is made. 

4. The micrometer screw (E) raises or lowers the test object 
until it just touches the test point. Each division on the screw 
head measures an elevation of 0-01™™. 

5. The base (G) carries the different parts and needs no 
particular description. 


Measurement. 


The crystal or other test object is fastened to the top of the 
object holder (O) and inclined by means of the serew (2) so 
that the face to be investigated forms a wedge with the track 
(6). By the screw (8) it is made horizontal from side to side. 
By raising or lowering the column (8) the test point is brought 
to a position where it nearly touches the surface to be tested. 
By means of the micrometer screw the crystal is then raised 
until the test point just comes in contact with the face to be 
tested at the point a, fig 2. 


A. L. Parsons—New Sclerometer. 165 


Now by means of the transport screw (4) and the accom- 
panying spring (5) the crystal is moved in the direction indi- 
cated by the arrow points so that as the surface acts as a wedge 
the test point (H) is raised and the spring (F) is bent from 
position F, to position F,. By this movement a position is 
reached where the test point makes a scratch on the surface to 
be tested which is indicated in the figure as 6. By the move- 
ment of the test object from position I to position II this 
point 6 has been brought to the position 0’ and the point 6 has 
also been raised the distance a ’/=d. After the scratch has 
been made a reading is made on the micrometer screw IE. 
The erystal is then lowered by means of the micrometer screw 


Fig. 2. 


until the test point just touches the crystal or other substance 
at the point 6’, in other words at the beginning of the scratch, 
and a second reading is made on the micrometer screw which 
gives the distance ad’ in divisions on the micrometer screw. 
This distance gives a measure of the bending of the spring or 
of the pressure necessary to make a scratch on the crystal, 
that is, it is a measure of the hardness. 

In practice the lowering of the crystal by means of the 
micrometer screw gives a forward motion of the erystal in the 
direction of the arrow points in the figure and the beginning 
of the scratch must be brought under the test point by the 
transport screw (4). It is also found better in practice to 
lower the crystal or other test object so that the test point 
does not touch the surface, and then raise the test object again 
until the point just touches. 


Calibration. 


In this instrument the force that is necessary to make a 
scratch is measured by the strain on the spring (fF) and the 


166 os Win oe Parsons News Selcronietor: 


reading is made in divisions on the micrometer screw (E). In 
the instruments of Seebeck and others this same force is 
measured by the weights with which the test point is loaded. 
This measurement by weights has the advantage that the 
weights are constant, while the bending of the spring (F) is 
dependent upon the material and dimensions of the same, and 
with each instrument we get a different factor. In order to 
reach comparable results it is necessary to reduce the divisions 
on the micrometer screw to measures of weight This reduc- 
tion of elevation to weight is called the calzbration of the 
enstrument.* : 

The calibration of the instrument is made in this way. A 
glass plate is fastened to the object carrier and a scratch is 
made with the diamond point. The glass is now brought to 
the position where the test point just touches the beginning of 
the scratch. This point is determined when the test point just 
meets its reflection in the glass. The reading on the micro- 
meter screw (EK) is taken, the plate lowered by means of the 
micrometer screw and a weight placed on the test point holder 
(H) by which the spring is bent. The plate of glass is now 
raised until the test point just touches the beginning of the 
scratch and a second reading is made on the micrometer screw 
(EK). Subtracting the second reading from the first gives the 
number of divisions on the micrometer screw that corresponds 
to a given weight. ‘ 

By lowering the glass plate by means of the micrometer 
screws not only the plate but the track (6) and the object 
carrier (O) describe a small are of a circle about A so that the 
beginning of the scratch must be brought under the point by 
means of the transport screw (4).+ 

The deflection of the spring for various weights is measured 
and a table can be made for all. 

The results of the calibration are as follows: 


Deflection of 


needle in No. of Mean No. of 
Weight Reading divisions of | divisions divisions 
graduated equivalent equivalent to 
erm. circle to 1 grm. 1 grm. 
Parstetrial ae 20 183°0 0 
5 170°0 13 2°6 
10 159°0. 24 2°4 
20 134°5 4A8°5 2°425 
50 60°5 122°5 2°45 2°469 


* Every instrument is furnished with a calibration table so as to give the 
weight that corresponds to one division on the micrometer screw. 

+ A very slight error is thus introduced but in practice this can be neg- 
lected, as the determinations of hardness are made in the same way and the 
errors are comparable. 


A. L. Parsons—New Sclerometer. 167 


Deflection of 


needle in No. of Mean No. of 
Weight Reading divisions of divisions divisions 
graduated equivalent equivalent to 
erm, circle to 1 grm. 1 grm. 
Second trial. 0 Dantes 0 
5 199°0 12°5 2°5 
10 186°5 25°0 2°5 
20 162°5 49:0 2°48 
50 86°0 125°5 2°51 2°4975 
Third trial.. 0 135-0 0 
3) 123°0 12°0 2°4 
10 110°0 25'0 2°5 
20 85°0 50°0 2°5 
50 LO 128:°0 2°56 2°49 
Fourth trial. 0 193°5 0 
5 180°5 13°0 2°6 
10 168°5 25°0 225 
20 143°5 50:0 2°5 
DOE 67°0 126°5 2°55 2°5325 
MMeanieOimaliert mone rau me ye eee Oe 2A OD 


The results agree closely so that the elevation may be con- 
sidered proportional to the weight and in this instrument a 
load of 10 grams is equivalent to 25 divisions on the microm- 
eter screw. 


Results of Measurements. 


Plane and polished surfaces of glass, iron, copper, and brass 
were taken as test objects. A few trials were made with 
crystal faces, but further study is necessary before it can be 
stated that the instrument is suitable for determining the 
hardness of unpolished surfaces. 

Measurements with the diamond point (a tetrahedral cleay- 
age fragment) : 

Copper. 10 measurements: Pressure — 1:2, 1:2, 1°8, 
1:6, 1°6, 1:4, 1°6, 1°8, 2°0, 1-4 grm. Mean of first five meas- 
urements = 1°48 grm.; mean of second five measurements =. 
1-44 orm.; mean of all 1°46 grm. 

B. Brass. 10 measurements: Pressure = 1°6, 2°0, 2°2, 2°2, 
2°0, 2:2, 2°2, 2-2, 1°6, 1:‘7-grm. Mean of first five measure- 
ments = 2°00 grm.; mean of second five measurements = 
1°98 grm.; mean of all 1:99 grm. 

C. Iron (rolled). 10 measurements: Pressure = 2°2, 1:8, 
Ply eee eee lO. 2-0, 1°S orm, Mean, of first: five 
measurements=1'96 grm.; mean of second five measurements 
= 1:96 grm.; mean of.all 1:96 grm. 

D. Glass (object glass for microscope). 10 measurements: 
Pressure = 3°8, 4:0, 4:2, 4:0, 4:0, 3°8, 4:2, 4:2, 4:2, 4:4 orm. 


168 A. L. Parsons—New Sclerometer. 


Mean of first five measurements = 4:0 grm.; mean of second 
five measurements = 4°16 grm.; mean of all 4:08 grm. 

Measurements with steel point (sewing needle, number 5 
sharp) : 

E. LepeR 10 measurements: Pressure = 5-0, 4°8, 4-0, 4'8, 
4-0, 4:2, 3°8, 4:2, 4:2, 4:0 grm. Mean of first five measure- 
ments = 4:52 grm.; mean of second five measurements = 4:08 
grm.; mean of all 4°3 orm. 

F. Lrass. 10 measurements: Pressure = 16:4, 12:0, 10°4, 
10-4, 9°8, 14°0, 13-0, 10°8, 10°8, 10°-4 grm. Mean of first five 
measurements = 11°8 grm.; mean of second five measure- 
ments = 11:8 grm.; mean of all 11:8 grm. 

The ten measurements were made each time on the same 
piece of copper, brass, ete. with the same inclination of the 
surface and the same direction for the serateh. After each 
scratch the plate was moved a little to one side by means of 
the screw (1) so that the ten scratches were parallel and near 
each other. 

The beginning of the scratch with the diamond point was 
always sharp and easily seen and is a very distinet point. 
With the steel needle, however, the beginning of the scratch 
on steel was somewhat nneertain. The scratch did not have 
a sharp beginning but was microscopic and gradually increased 
in depth with the increase of pressure. 

In general a diamond point will probably give the best 
results for all substances except possibly for those which are 
extremely soft. Special study is being made to determine this 

oint. 

. The nearly equal results obtained by scratching iron and 
brass with diamond were surprising and the two were tested 
against each other. The iron made a scratch on the brass very 
easily and the brass made a scratch on the iron but apparently 
with greater difficulty, but the point on the iron was, however, 
sharper than the point on the brass. It would appear that in 
the determination of hardness other properties such as tenacity, 
elasticity, flexibility, ete. must be taken into consideration, and 
it is hoped that this instrument may be of assistance in the 
study of the relations between these properties. 

The results show a good determination when the mean of 
five measurements is taken. . 

The measurement is rapid and requires less than three 
minutes for a measurement when the test object is in position 
or for ten consecutive measurements less than a half hour. 

The advantages of the instrument above mentioned are 
rapidity of observations, compactness, and cheapness. So far as 
observations have been made up to the present time, the instru- 
ment gives good results for polished faces of glass and metal, but 
further study is necessary to show its availability for minerals. 


Heidelberg, Aug. 14, 1909. 


I. Hf, Lahee—Dodecahedral Jointing. 169 


Art. X.—Dodecahedral Jointing due to Strain of Cool- 
ing ; by Frep. H. Lawes. 


In the woods just south of Beacon St., and about a quarter 
of a mile west of Hammond St., Chestnut Hull, Mass., the 
Roxbury conglomerate is cut by a fine-grained, basaltic dike* 
which, in some parts, disintegrates into small (average dia- 
meter, € in.), polyhedral, often roughly dodecahedral, frag- 
ments. The dike has approximately plane-parallel sides, is 
four feet thick, strikes N. 20° E., and dips 78° E., its attitude 
being parallel to a prominent joint set of the country rock. 
That it entered a relatively cool rock is indicated by the fact 
that its texture, moderately fine in the middle, becomes very 
tine at the contact. It contains occasional large phenocrysts 
(xenocrysts) of apatite and biotite, both of which are well 
shaped, and of pink acid feldspar, which has outlines made irre- 
gular by the invasion of short tongues of the groundmass. 

Near the country rock, on each side, in a zone from four to 
ten inches wide, hexagonal columnar jointing is poorly devel- 
oped perpendicular to the contact surface. Inwards, the col- 
umns give place to the polyhedral blocks already mentioned as 
conspicuous in the disintegration of the rock. 

Obviously the jointst which give rise to such many-sided 
fragments are of small extent. Furthermore, they (the joints) 
often vary in direction, or may die out entirely; but in spite of 
this irregularity, it is not difficult to find blocks bounded by 
twelve rhombohedral faces that intersect one another at angles 
nearly equal to the similar angles of a perfect dodecahedron. 
The surfaces of the blocks are relatively coarsely granular, 
without a well-developed feather fracture, a feature not uncom- 
mon on the more finely textured hexagonal columns. Where 
the phenocrysts are in the path of fracture, the break either 
passes round the obstacle, or takes advantage of the mineral 
cleavage. These statements clearly point to the inference that 
the dodecahedral jointing, like the hexagonal, is an effect of 
tension due to cooling. 

_ Hexagonal columnar jointing has long been so interpreted. 
In the ideal case, according to the principles of least action, 
the columns begin their development as a series of three-way 
fractures (each fissure at an angle of 120° to the other two) 
radiating from equally spaced points in a surface which is per- 
pendicular to their (the columns’) direction of growth. This 
type of fracture is therefore a two-dimensional, or surface, 
phenomenon, and the extension of the columns may be regarded 

* The writer wishes to thank Mr. R. W. Sayles for bringing this dike to 
his notice, and Professor Chas. Palache and Professor J. B. Woodworth, 
who discovered the dodecahedral jointing, for valuable suggestions. 


+ Similar jointing has recently been seen by the writer in trap dikes on 
Ragged Island, Casco Bay, Maine. 


oy 
170 I. A. Lahee—Dodecahedral Jointing. 


as the result of the regular inward advance of successively 
cooler planes, for each of which the temperature is uniform 
throughout. 

If, on the other hand, we conceive of a soled which is losing 
heat equally in all directions and in such a way as to be sub- 
jected to a homogeneous strain, sia-way fracture will develop 
instead of the three- -Way fracture of the cooling swrface, and 
the resulting geometrical form will be a dodecahedron instead 
of a hexagon. 

As hexagonal fracture may be illustrated by considering a 
series of equal tangent circles compressed uniformly from all 
directions in the same plane, so dodecahedral jointing may be 
experimentally demonstrated by subjecting a group of equal 
tangent balls, arranged in superposed horizontal layers, to 
equal pressure from every direction. Those spheres which 
were originally in contact with twelve others will, it is true, 
be dodecahedral; but whether they become regular rhombic 
dodecahedra or forms which, to borrow from crystallography, 
resemble a regular rhombic dodecahedron twinned parallel to 
an octahedral face, will depend on whether the centers of the 
balls of a given horizontal layer were above the centers of the 
spaces, or of the spheres, of the second layer below. In either 
case, prior to the compression, the conditions of unoccupied 
space and of equal distance between the centers of spheres will 
be fulfilled. | 

The literature appears to be lacking in references to the par- 
ticular kind of jointing described. Much of the work on this 
subject was done several decades ago. At that time hexagonal 
jointing received considerable attention and was correctly 
explained as the result of uniform strain in a surface. Spher- 
oidal structure, which was shown by Bonney to be often unre- 
latedto fracture systems, was, however, held to be the analogous 
phenomenon in a solid, and perlitic structure was consigned to 
the same catagory. Bonney thus states his views:* “ A hexa- 
gon is the figure which will result from uniform contraction in 
two dimensions, a sphere from contraction in three dimen- 
sions.” ‘The case in point, however, leads to the conclusions : 
(1) that hexagonal columnar jointing is caused by equal tension 
in all directions in a surface at right angles to which the 
strain is differential; and (2) that uniform contraction in a 
solid must, under corresponding conditions of homogeneity, 
give rise to dodecahedral jointing. ‘The sphere cannot be the 
exact analogue of the hexagon. 

Cambridge, Mass. 

* Bonney, T. G., On Columnary Fissile, and Spheroidal Structure. Quart. 
Jour. Geol. Soc., Lond., xxxii, p. 152, 1876. On this subject see also 
Jukes, J. B., and Geikie, A., Student’s Manual of Geology, 3d ed., 1872, 
pp. 182, 183, 311; Mallet, R., Phil. Mag., Ser. 4, vol. i, pp. 122, 201; 
Scrope’s Volcanoes of Central France, p. 92; Iddings, J. P., The Columnar 
Structure in the Igneous Rock on Orange Mountain, New Jersey, this Jour- 


nal, (3), xxxi, p. 321, 1886, and Iddings, J. P., Igneous Rocks, N. Y., 820, 
1909. 


R.S. Lull— Restoration of Paleolithic Man. iat 


Art. XI.—Restoration of Paleolithic Man, by Ricuarp 
: Swann Loni. (With Plate I.) 


[Contribution from the Paleontological Laboratory, Peabody Museum, 
. Yale University. | 

AN attempt has recently been made by the writer to restore 
in plastic form the type of mankind dwelling in Europe dur- 
ing a portion of the Paleolithic period and variously known to 
science under the names of Homo primigenius, neanderthalensis 
or mousteriensis. The restoration, which is life size, is a tenta- 
tive one and will be kept in the clay for a time in order that 
authoritative criticism may be met before it is cast in plaster 
(ef. Plate I). 

The model is based mainly upon what is known as the “ Man 
of Spy No.1”; one of the two specimens found at Spy in 
Belgium, of which the museum contains excellent plaster casts. 
The illustrations of the remains of man found at Krapina in 
Croatia and described by Professor Gorjanovic-Kramberger in 
his “ Der Diluviale Mensch von Krapina in Kroatien” 1906, 
were largely used, together with certain other measurements, 
such as the estimate for total height, ete. For the use of the 
casts. and the assembling of data, together with kindly eriti- 
eism, I am indebted to Dr. George Grant MacOurdy, Curator 
of Anthropology in this museum, while to Professor Joseph 
Barrell, who has. taken a very lively interest in the work, I 
wish also to acknowledge my gratitude. 

My conception of Homo primigenius is that of a man of 
low stature, standing only five feet three inches in height, but 
of great physical prowess as indicated by the robustness of the 
limb-bones and especially of their articular ends. The great 
paunch of the higher anthropoid apes, which are almost exclu- 
sively vegetarians, is lacking and in its place is shown the 
clean-cut, athletic form of torso such as one sees in the typical 
North American Indians, for-I imagine food conditions were 
much the same. We have abundant evidence that Paleolithic 
man was a crafty hunter, for the remains of various animals 
which he slew for food are found in the bone breccias of the 
caverns wherein his own relics are entombed. Great power is 
indicated, however, in the upper portion of the trunk and in 
the arms, compensating this ancient type for his lack of ade- 
quate tools and weapons. 

The knees are somewhat flexed as the curved thigh bone 
would indicate, and probably should be more so, and the trunk 
is only partially erect, for the inward curves of the back bone, 
so characteristic of modern man, are but feebly developed, as 
in the case of babes of the present day or in individuals bowed 
down by the weight of years. The shin is relatively short, as 
with certain present-day races, and the great toe somewhat off- 
set though having long since lost its ape-like opposability. 


172 —-R. S. Lull— Restoration of Paleolithic Man. 


The head shows the prominent supra-orbital ridges above — 
the deep-set eyes; the low, flat forehead; the broad, concave, 
nasal bridge and the somewhat prognathous jaws. The lower 
jaw is deep and powerful, and lacks the characteristic chin 
prominence of modern man. Other restorations give a greater 
prognathism than mine, and it may be that here I am in error 
in showing too great a refinement of countenance as compared 
with the low type of calvarium. The contour of the jaw is 
based upon actual measurement of one of the Krapina speci- 
mens and one should bear in mind that the far older jaw 
recently brought to light at Heidelberg, though of a more 
brutal type than any yet known, shows less dental prognathism 
tban do the modern negroes, indicating a very great antiquity 
for the radiative evolution of the several human stocks. 

In all probability the men of that day were much more 
hairy than the model would indicate, as they had little or no 
clothing and the climate, during part of their racial career at 
least, was severe. They were, however, cave dwellers and 
knew the use of fire. I have purposely refrained from indi- 
cating this conjectural character, as 1t would, to a certain extent, 
conceal the conformation of the underlying parts. 

A jaw of the cave bear, Ursus speleus, a contemporary 
animal, though now long since extinct, is borne in the left 
hand, while the right contains a chipped stone implement from 
one of the typical stations, thus indicating the cultural plane 
of the race. 

This type dwelt in Europe before the last glacial period, 
estimated at from 100,000 to 200,000 years ago, and continued 
for a long period of time, for his remains are found entombed 
successively with both cold and warm climate animals. The 
relics are found within or near rock shelters and caves, the 
best known of which are those of Neanderthal, Germany ; 
Spy, Belgium; Krapina, Croatia; Le Moustier and La Cha- 
pelle-aux-Saints in France. As a race Homo priumigenius 1s 
to-day entirely extinct, though whether he was blotted out or 
absorbed by the invading horde of the superior Homo sapiens 
we have no certain knowledge. Occasionally, however, some- 
thing of his type appears in modern man, notably in St. 
Mausberg, a medieval Bishop of Toul, and in Lykke, a scien- . 
tific Dane of the eighteenth century, as well as among Austra- 
lians and Melanesians, the lowest living races of mankind. 
These may be looked upon as instances of atavistic reversion. 

The “ Man of Spy,” while showing more pithecoid charac- 
ters than his successor, was nevertheless eminently human, 
representing as he does the type just preceding modern man, 
and one far removed from a true ape-like ancestry. In the 
popular conception ‘‘ Prehistoric man ” should be gorilloid, or 
at any rate distinctly simian; against this misconception the 
model stands as a silent protest. » 


x Ara SOUP Sein xo 1S 10: Plate I. 


RESTORATION OF PALEOLITHIC MAN. 


* 


W. 7. Schaller anal FF. L. Ransome—bhismite. 173 


Arr. XII.—Bismite ; by W. T. Scuarier and 
F. L. Ransome. 


In the Goldfield district in Nevada, bismite occurs in the 
January, Combination, Sandstorm, and probably also in other 
mines, as minute, pearly scales with brilliant Inster and of 
silvery whiteness. The luster of the scales is almost metallic 
and suggests at first glance delicate and untarnished crystals of 
native silver. The mineral is limited to the oxidized zone, 
is usually accompanied by limonite and is frequently associated 
with rich ore. It occurs as single glittering scales or specks 
on the walls of cavities in spongy hmonite or rusty ledge- 
matter, as delicate frost-like films on the same materials and as 
spongy aggregates with quartz. In the last-named form it is 
clearly pseudomorphous after bismuthinite, the material having 
consisted originally of a mass of bismuthinite prisms held 
together by a siliceous gangue. The prismatic structure of 
the bismuthinite is retained as hollow casts in the quartz, lined 
or partly filled with scales of bismite. 

As natural crystals of bismite do not appear to have been 
found hitherto and as the mineral has been assigned to the 
orthorhombic system in Dana’s and Hintze’s mineralogies on the 
basis of Nordenskidld’s work on artificial crystals in 1860 and 
1861, considerable interest attaches to the Goldtield occur- 
rences on account of the crystallinity of the material. 

When examined under the microscope in gently powdered 
material the crystals appear as thin colorless scales, with occa- 
sionally a suggestion of hexagonal outline. On account of 
their tenuity, it is rare that an edge view of a scale is obtain- 
able. ‘he larger flat-flying scales are dark in all positions 
between crossed nicols and give a negative uniaxial figure with 
convergent light. There are no colored rings and the double 
refraction is apparently not great. The refractive index, on 
the other hand, is rather high, being greater than that of 
anorthite. The mineral has a perfect basal cleavage and the 
scales, viewed without the analyzing nicol, commonly show 
delicate interference colors due to the refraction and reflection 
at the surfaces of the exceedingly thin cleavage sheets. 

Some of the best material obtainable was analyzed with 
results as follows: 


Insol. in HCl, mostly 1 2 3 Average 
quartz sancue . 2. - 18-950 j SeSnea iio Olas 1 1.85 Oe 
pin aa ee nt ees", 129 17°00 16°84 17°04 
H .O (loss on ign.) Sagat ae 3°96 a oe Dan 3°96 
Fe,0, Beet, FS Aa ee 0°36 0°50 0°21 0°36 
100°30 


Am. Jour. Scit.—FourtH Series, Vout. X XIX, No. 170.—Frsruary, 1910. 


~ 


174 W. 7. Schaller and F.. L. Ransome— Bismite. 


The results show that the mineral is either bismite or else a 
hydrous oxide of bismuth. If the latter be the case, the min- 
eral is a new species (providing, of course, that Bi, O, is the 
correct formula for the bismuth ocher found in nature and 
called bismite). Attempts to isolate a sufficient quantity of 
the pearly scales from the gangue for separate analysis were 
not successful. 

The minute, tabular crystals are too incomplete to allow of 
a determination of their geometrical form by crystallographic 
measurements alone. From the uniaxiality of the crystals, 
their hexagonal outline, triangular markings on the base and 
distribution of the faces as far as seen, reference of them to 
the rhombohedral division of the hexagonal system appears 
to be justifiable. 

The value of the ¢ axis, derived in a manner presently to be 
described, is 0°5775. Seven faces are determined as present ; 
the base, tive positive and one negative rhombohedra. Besides 
these, there are indications of two more positive rhombohedra. 
A brief description of these forms follows. 


e {0001}. Always very large, even, and highly polished. 
Serene shows triangular markings or striz, the faces parallel 
to these markings being taken as positive. 

o {1016}. Occurs on two erystals, as broad faces giving, how- 
ever, poor reflections. One face was considerably striated, 
giving two signals a degree apart. 

g {1015}. Broad faces giving fairly good reflections. 

wu {1014}. Narrow faces, one striated wlth a fair reflection, 
and one as a line face giving a very poor reflection. 

k {1013} Usually as a line face, striated and giving a very 
poor reflection. 

? 12025}. <A doubtful face, narrow, giving no distinct signal. 

2d {1012'. Another doubtful face, broad, giving no distinet 
reflection. | 

y \2021'. Line faces, giving exceedingly faint reflections. 

z {0111;. The only negative rhombohedron observed. Very 
faint line faces, giving no ‘reflection, Its negative position could 
be determined only on crystal No. 6. 


The measurement of the forms are shown below. 


Meas. , Cale 

(0001) : (1016) Oar 6° 41’ Gee 
¥ 7 ( VOui)) (Gace BO 7-36 
. (1014) 9 31 9 31 928 
a (1013) Laan UP QE 12. 32m 

iets 12°-14° 

oa ; (2021) 54° 54° 53 08 
ee iige (Od 119) 35° 325° 33 42 


W. ZT. Schaller and F. L. Ransome— Bismite. ees 


Doubtful forms: Meas. Cale. 
(0001) : (2025), io Aes 6 
ete (LOA 2), 16" =207 18 26 


The value for the ¢ axis was obtained from three measure- 
ments that were considered as the most accurate. The others 
gave values agreeing fairly well with the one adopted, as is 
shown below. The crystals were measured on the two-circle 
goniometer and the p angle for these forms is the angle 
between that form and the base. 

The three best measurements are: 


petOro t=. 7°. 33' Pe. == 662i eryst. No. 1 

p {1015} = aes \ 6) eee os ar: 

ar POM 9 SL = OOO 2 
Av. p, = ‘6668 ; ¢ = 0°5775. 


An average of the other measurements gave values closely 
agreeing. Thus: 


pe oaG) == 6°37" Pea — 6960 -eryst. No. 3 

6¢ — 6 A] ia — “T7031 (74 (74 6 

pe, LULL = 59 31 & == 6106 ry ofa 

p {1013} == 12-11 = +6477 Ca TaN 

«= 12 26 “= +6614 cee ee) 4 

74 — 13 18 66 — “7102 66 66 1 
Ate ==6815 


The following measurements of faces giving no distinct 
reflections also showed close agreement : 


p 11013} = 12°-14° (av. 13°) Pe 09e F CLYSta NO. <! 
fe 2025) == 15° co GH Beceoeey Cente) 
p {1012 = 16°—20° (av. 18°) Seg ees 65) Corea OLR 
p {0111} a “¢ — -7Q¢ 66 eh unr 

66 — 324° 6 — +64 éé 66 6 
p {2021} = 54° & — +69 sence 7 

66 — 54° (i °69 66 66 6 


The values for p, just given show that the interpretation of 
the forms is the correct one. 

Of the six crystals (all incomplete) that were measured, only 
two need to be briefly described. 

Fig. 1a is an orthographic projection of a crystal (No. 1), 
showing the trigonal distribution of the rhombohedra, and the 
triangular markings on the base. 

Fig. 1b shows a similar projection of cryst. No. 6, with a 
negative rhombohedron. 


176 W. 7. Schuller and F. L. Ransome— Bismite. 


An odd feature of these crystals is that the development of 
the faces is so uneven, that no two faces of the same form are 
present on the upper half of a crystal, though this is in part 
due to the incompleteness of each crystal. 

From the foregoing observations it appears that the natural 
bismite is not orthorhombic but belongs to one of thé uniaxial 


Hac: la. Fic. 1b. 


systems, probably the hexagonal. Its presence in oxidized ore 
appears to be uniformly indicative of bismuthinite in the origi- 
nal sulphide ore. Some migration, however, has taken place 
during oxidation and the scales of bismite do not always 
occupy the exact positions of the parent needles of bismuth- 
inite. 


U. S. Geological Survey, 
Washington, D. C. 


C. Palache—Mineralogy of Franklin Furnace, N. J. 177 


Arr. XII1.— Contributions to the Mineralogy* of Franklin 
Furnace, NV. J.; by CHartes PaLacue. 


THE purpose of this paper is to present in brief form some 
of the more interesting results obtained in the study, con- 
tinued through several years, of the minerals of Franklin 
Furnace, New Jersey. The complete results of the study will, 
it is hoped, appear soon in monograph form, but it seems desir- 
able to place on record without further delay the chemical 
analyses made for the most part in the laboratory of the Geo- 
logical Survey. These analyses are either of minerals not 
before recorded from this locality or of species concerning 
which our information is incomplete. With these are also 
included crystallographic notes on a number of species and a 
list of additional minerals whose presence at Franklin Furnace 
has not hitherto been recorded. 


Arsenopyrite: Crystal Form, Composition. 


Brillant erystals of arsenopyrite up to an inch in length 
were found in several of the limestone quarries at Franklin 
Furnace in 1905. They are associated with pyrite, pyrrhotite, 
spinel, humite, tourmaline and phlogopite. The crystals are 
completely developed, showing besides known forms the new 
pyramids (532), (112), (1438), and (132), the first present on all 
erystals and characteristic for the locality. 

The following analysis by E. C. Sullivan, U. 8S. G.S., was 
made of selected crystal fragments: 


Ratio 
1 OEY Gee On eee oe 32°48 Stet) | l 
Care Bey 1°16 "02 
JM ge peg ao ay a 48°72 “650° 1-08 
Scere eee 18°80 587 "98 


The ratio shows a normal composition. The presence of 
cobalt is interesting; it has been shown by Kraus & Scottt to 
be present in about the same proportion in pyrite crystals in 
the same limestone. Tests for cobalt made on the associated 
pyrrhotite showed no trace of this element and hardly more 


than a trace of nickel. 


Fluorite: Composition. 
The following analysis of fluorite by G. Steiger, U.S. G. S., 
was made in the belief that it was a manganiferous variety. 


* Published by permission of the Director of the U. S. Geological Survey. 
+ Zeitschr. far Kryst., xliv, 144, 1907. 


178 C. Palache—Mineralegy of Franklin Furnace, lV. J. 


The material was pale red and granular, the matrix of frank- 
hinite grains. 


Oa ae tee Bie VANCES we he: 9, 0°18 
Vi oie 5 ours 0:24 AB ey yet) 45°85 
Hie ee 0°27 CC oe 2: none 
Via 0°09 

97°84 


Mr. Steiger remarks that the deficiency in the analysis is 
doubtless due to fluorine. | 

The Bie content is insignificant. If the total defici- 
ency, 2°16 per cent, is calculated as fluorine, there is still shghtly 
less than is required to form RF, with all bases, but almost 
exactly enough to satisfy the pallet. This suggests, but of 
course does not prove, that the bases other than calcium are 
present as impurities in the form of unknown compounds. 


Manganosite: Occurrence, Composition. 


This rare substance, known hitherto only from two Swedish 
_ localities, was found in a single specimen in the Harvard 
Mineralogical Museum. ‘The specimen consists of a granular 
ageregate of franklinite, zincite und manganosite. The latter 
is In irregular. grains showing cubic cleavage, dark green in the 
mass, emerald-green in thin fragments. The material analyzed 
contained traces of zincite and minute black films of manganese 
oxide. The specific gravity was 5°364. 

1. Manganosite: analysis by George Steiger, U. 8. G. BS. 

2. Same corrected for ZnO and MnO, known to be present. 


al 2 
Nin On ee eae 94°59 99°61 
Min Oxy si ears 1°30 Midian 
LD KO) Eero ee oat 3°41 tents 

FeO ~ : 
Fe,0, istgee Byte thc 0°26 O27 
MeO seca 0-11 0°12 
HO So eee 0°38 pel ae te 
LEO 42 A aie 0°40 ae 
100°45 100°00 


The material is thus shown to be very nearly of the theo- 
retical composition of manganosite, MnO. 


Zincite: Crystal Form. 


Measurements of natural crystals of zincite are very few and 
poor and the generally accepted axial ratio for the species is 
based on artificial crystals. The writer obtained measurements 


C. Palache—Mineralogy of Franklin Furnace, N. J. 179 


on one crystal of zincite from Franklin Furnace, however, 
which were very satisfactory; he has therefore calculated an 
axial ratio based on them and in the following table gives all 
the measurements made on natural crystals and the correspond- 
ing angles calculated from (1) the new ratio, (2) Dana’s ratio, 
(3) Traube’s ratio based on artificial crystals. The author’s 
measurements were on four faces of the pyramid (4045), the 
angle to the base (average) being 55° 42’ with deviation of but 
4’. A single reading (0001) to (1011) was also obtained, in 
close agreement. 


Calculated Measured 
Angle Dana ‘Traube Palache Dana | Grosser) Moses Eaipehe 

ae= c= | -0:6= 96 199 195 | Refle x- 

1:1°6219 1:1°6077 1:1°5870 Contact a 
eee G1 5461°41" 61°23'| -_- |. ..| 25) 62°00 69°22! 
1011 A 0111] 52 21 | 52 14 5204 Be Rh doo ame Seo OOK eee. 
D001 ~ 4045) 56.17/56 03/55 42) .__.| 55°88" 55°40", __..| 55°42" 
4045 , 0445/49 09 49 00 48 48 2 LUST) eta aia 6g A aa 
pew o4166 152/66 41166 25°) 65°20'|- 3222) be. |s eee | =e 
weeee0954) 54 46/54 40/54 33/53 538). 2. )54°42") 12] =--- 


Gahnite, variety Dysluite: Composition. 


Following is an analysis of a gahnite crystal supplied by Mr. 
Canfield from the locality at Sterling Hill which yielded the 
enormous crystals in the Canfield Collection. This is the type 
of the variety dysluite but has not been before analyzed. 
Specific gravity 4°56. , 

1. Analysis of dysluite, W. T. Schaller, U. 8. G. 8., 1906. 

2. Same omitting SiO,, CO, and equivalent of CaO, and H,0. 
State of oxidation of iron and manganese not known. 


1 2 Mol. Ratio 

150 keg eae 47-97 48°81 HEB EA ce | 
2, (6 epee eniies 9°90 0322 064 
RIO FLO 38°31 ‘472 | 
Jt 0) Glee ea 0°93 0:97 PO WSs 
MeO 8k. 1-09 1:12 UO eee es 
AO Fs 1:01 O57 Ode. 
LO ea pe ae 0°38 brat 
PEO) eee ait Ie. 1°47 See 
15 10 Deane eae ae 2A aoe 

100°36 100-00 


The composition of dysluite is very like that of the gahnite 
from Franklin Furnace analyzed by Brush, both being very 
high in zine. 


180 ©. Palache— Mineralogy of Franklin Furnace, NV. J. 


Franklinite: Form, Composition. 


Small implanted crystals of franklinite of quite abnormal 
appearance were seen in two specimens believed to have come 
from the Hamburgh mine, Franklin Furnace. The crystals 
are of adamantine luster and on edges or where splintered 
show a deep red color. The prevailing habit is cubo-octahe- 
dral with occasional planes of the forms (101), (311), (211) and 
(310). The unique color and habit of these crystals suggested 
a new type of the spinel group, but the analysis below by W. 
T. Shaller, U. 8. G. S., shows them to be of ordinary frank- 
linite composition. Specific gravity 5:09. 


oh 6 O72 aes 66°58 CaO ese. sas 0°43 
nO) ie eee 9°96 MoOv a ake 0°34 
LOOR aes he OR ds IG Fae ayer 0-7 
99°51 


Fletcerolite: Form, Composition. 


Reéxamination of this mineral, which has been a doubtful 
species because of Moore’s incomplete description, establishes 
the correctness of his characterization as a zinc hausmannite. 

Tetragonal, shown by optical behavior of the fibers under the » 
microscope. Indistinct prismatic cleavage, specific gravity 4°85. 

Composition ZnO.Mn,O,, as shown by the following analysis 
of material furnished by E. P. Hancock: 

1. Heterolite, analysis by W. T. Schaller, U.S. G.S., 1906. 

2. Same corrected for the small amount of SiO, and for 
water probably contained in a slight admixture of chal- 
cophanite. 


il 2 Ratio. 
MnO jane ees 60°44 63°85 405 1 
Ve, Oe hier tae “aa 0°83 "005 
LUO ae Soe 33°43 35°32 "435 1:06 
SIO 2. ake eae ile7h 
EL Os ee ee 2°47 
HO a eee 1°42 

100°24 100-00 


Hausmannite, MnO.Mn,0O, 
Heterolite, ZnO.Mn,O, 


Pyroxenes: Composition. 


Manganese- and zine-bearing varieties of pyroxene are char- 
acteristic both of the granite and of the intruded rocks near 
the contacts at Franklin Furnace and Stirling Hill. The dis 


* State of oxidation of iron and manganese not known. 


C. Palache—Mineralogy of Franklin Furnace, VN. J. 181 


tinctions between these pyroxenes are not sharply defined. 
Jeffersonite, the most abundant of them, contains manganese 
zine and iron in addition to lime and very little magnesium. 
Zine schefferite differs in the practical absence of iron and in 
the increase of calcium and magnesium at expense of man- 
ganese and zine. Schefferite, close to the last named, contains 
no zine, little iron and a larger proportion of magnesium. 
Schefferite was found only in well-defined crystals in hme- 
stone from Stirling Hill. The analyses here given are of a 
very fresh jeffersonite from Parker shaft, Franklin Furnace, 
and of schefferite which has not been before described from 
this region. 

1. Analysis of jeffersonite, Steiger, U. 8. G.S., 1906. 

2. Analysis of schefferite, Schaller, U. 8. G. 8., 1907. 


SiO, CaO MgO MnO ZnO FeO Al,03 Fe.,0; H,O— H.O+ Na.O CO; 
Hea lg oS ool 791 (14° 3°95 086. 4:22 0°60. 0°70. 2.2... 
P8021 0712-30 9:69 tr 1-61 0°26 -146. 1°55. 1°31» 0°9° 0°43 

[F = 0°31 = 99-93 less 18 = + 
Nasonite: Crystal Form. 


The erystal form of nasonite could not be determined by 
Penfield in the absence of crystals, but he concluded that it 
was tetragonal because of chemical analogy with ganomalite— 
a tetragonal mineral. 

Crystals of nasonite were intrusted to the writer by Mr. 
Canfield, who had recognized their hexagonal character. One 
of them proved measurable and showed the forms a (1120), 
m (1010), » (1011) and & (9092), the hexagonal symmetry 
being well defined. The axial ratio, based on two measure- 
ments or angle ¢ ~ p=56 40°, 1s @ve—1: 1°316T. 

Angle ¢ ~ z, calculated 81° 41’, measured 81° 36’. 

The faces of m are cavernous except at the prism edges, 
where they are well defined and generally truncated by a. 
The prism rounds over into the pyramid p on most of the small 
erystals seen, the form «# representing a plane face ¢ in this 
surface on one crystal. The faces of p were dull on all except 
the measured crystal. This was afterwards tested qualitatively 
and gave the reactions of nasonite. 


Glaucochroite: Crystal Form. 


Terminated crystals were not present in the origipal speci- 
mens of glaucochroite described by Penfield, but he obtained 
an approximate axial ratio by measurement of the inclination 
of individuals in twin position. 

Two terminated crystals were secured from a specimen 
loaned by the Foote Mineral Co. which yielded fair measure- 
ments, determining the following axial ratio and forms. 


182 C. Palache y of Franklin Furnace, NV. J. 


"4409 : 1-: °5808 
440 : 1 : 566 (Penfield). 
Forms: a@ (100), 6 (010), m (110,) s (120), « (103), 2 (021) 
eX) (121). 
Combinations: 1. 0. m. s. x. 


Oe (te SB Os JP 


O20 26 


Calculated Measured 
EES 9 pee Se ae a 
@ p ? p 
TRL 66712) | aon lee) CGS sama ales 2 faces good 
121 © 48 36") GOT Or 22 eG029 1 face poor 
110 6912 29 0V 00) HECRO9 e000 4 faces good 
120 48 36 90 00 49 14 90 00 poor 


Bementite: Composition, System. 


The description of bementite by Koenig was incomplete and 
its relations were not clear. Study of a later find of better 
material from the Parker shaft, Franklin Furnace, establishes 
its close relationship to tephr oite in system and composition. 

System orthorhombic, shown by three pinacoidal cleavages 
at right angles but unequally perfect ; and by a symmetrical 
biaxial interference figure with small axial angle seen on plates 
parallel to the best cleavage. 

The analysis given below agrees closely with that of Koenig, 
but the water is shown to be constitutional, coming off for the 
most part at a red heat. It leads to the formula H,Mn, 
(SiO,), with more or less replacement of manganese by iron, 
zinc and magnesium. ‘This is analogous to “the: formula of 
tephroite, which may be written Mn,Si 1005 in bementite three 
molecules of manganese are replaced by constitutional water. 
That it is not a simple case of partial hydration is shown by the 
optical homogeneity of the bementite crystals. 

1. Analysis of bementite, Geo. Steiger, U. 8. G. S., 1906. 

2. Same recalculated to 100 per cent after omitting AI,O,, 
Fe,O, and H,O— and substituting for FeO, MgO, CaO, and ZnO, 
equivalent amounts of MnO. 

3. Theory for H,Mn, (Si0,),. 

Sid. MnO FeO ZnO MgO CaO H.20+ H.2O— Al.O;3 FesOs 


1 38°36 39°22 494 2°93 3:35 062. 801 0:60 0:96 0-71. 99.70 
2 37°93 53°06 851 100-00 
3 37°18 54°53 8°29 100-00 


Willemite: Axial Ratio, Refractive Indices. 

No accurate measurements of willemite crystals from New 
Jersey have been hitherto recorded. The fundamental angle 
employed by Dana was based on contact measurements of 
troostite. Other authors use the element determined by Lévy 
on crystals from Moresnet, on which the sole form is a rhombo- 
hedron not found on Franklin erystals. A number of measur- 
able crystals, all from the Parker shaft, Franklin Furnace, 


C. Palache—Mineralogy of Franklin Furnace, N. J. 188 


passed through the writer’s hands and the data secured from 
them permit the establishment of a satisfactory axial ratio. 
The five measured crystals were colorless or pale green prisms 
terminated by the base and one or both of the rhombohedrons 
é (0112) and (1011). 


Angle ca e, 19 readings average 20° 47’, limits 20° 35'—21° 04 


mar aaa eae Cl 7 een 90! 37° 40! 
Whence a:c = 1: 0°6612 
Lévy C= = 026690 
Dana coc -— i]: 06775 
Calculated angle,.¢ Ae = 20° 53’ 
ct CPR CUAS aN 


Refractive indices, measured on a prism || c¢. 
Sodium light, Op 169390 hee le ae30e 
Mihi toe 16889 ee = Ae ele 


Friedelite: Occurrence ; Composition. 


Friedelite has not been before described from America. It 
was identified by the writer on a single specimen from Buck- 
wheat mine, Franklin Furnace, in the Kemble Collection, and 
in minute amount on specimens from the Parker shaft. The 
mineral! occurs in scales or tabular crystals with the unit rhom- 
bohedron and base, not measurable. 

The analysis. with others for comparison, follows : 


1. Friedelite, Franklin Furnace, Schaller, U. 8. G. S., 1906. 

2. Same recalculated to 100 per cent after removing H,O— 
and substituting equivalents of MnO for FeO, MgO, 
ZnO and CaO. 

3. Average of four analyses of friedelite (Dana, System and Ist 
Appen.) recalculated as in number 2 above. 

4. Theory for H, (MnCl) Mn, (Si0,), 

a. theory tor HH. (MnCl), Mn,, S1,,0,, 

6. Theory for H,, (MnCl), R,, 81,, O,, (Zambonini). 


1 2 3 4 5 6 
Sid, BAGO 34-95. 34°42 > BAS 7 3800 34°43) 134-80 
MnO AS- 00; 53-20), 54°35) 2 54°80. | 54°33 2753-60 
Cl 3°43 3°45 Sesh) 3°42 3°39 4°12 
H,O+ 9°08 9°15 8°84 7°82 8°60 8°36 
H,O— 1°94 
FeO 1°45 
MgO 98 
ZnO 1°05 
CaO 63 

Loto seo 7 LOO A 10077. 100-75 ) 100-92 

Less O = Cl Nh 7 "5 ais 0°75 ‘92 


—_—____——- ——___— — _—_— ——_—. ——___. <- eee 


100°48 100°00 100°00 100°00 100°00- 100°00 


184 C. Palache—Mineralogy of Franklin Furnace, WV. J. 


The Franklin friedelite agrees closely in composition with 
that of other localities, as shown by comparison of columns 2 
and 3. Groth’s formula for the mineral, used by Dana, does 
not well express the results of these analyses, which uniformly 
give a higher content of manganese or its equivalents and a 
lower content of chlorine than demanded by it. The formula 
adopted here, H,(MnCl)Mn,(Si0,),, is satisfactory as to all 
constituents save water, for which it is too low. The formula 
H,,(MnCl), Mn,,8i,,0,,, obtained by adding one-half mole- 
cule of water to the latter, comes nearest to the exact 
equivalent of the analytical data but was rejected as not being 
reducible to the orthosilicate form. Zambonini* has derived 
for pyrosmalite and friedelite the formula 


RCI,.12R0.10810, + 8H,0 


an expr ession which takes no cognizance of the fact that the 
water in these minerals is apuapanad. The above formulas, 
reduced to this form of expression, are: 


(1) RCI,.15R,O.128i0, +9H,O 
(2) RCl,. 15RO. 12810, “+10H, O 


This formula of Zambonini gives a composition very similar 
to (2) and quite as close to the analytical results except for 
chlorine, which is too high. It is better than (1) as to water 
but is no closer in regard to other constituents. 


Vesuvianite, variety Cyprine: Analysis. 


Bluish green fibrous vesuvianite corresponding in character 
with the Norwegian cyprine was found in 1905 in granite from ~ 
the Parker shaft. The material was carefully freed from 
minute specks of metallic copper and had a specific gravity of 
3451. The analysis by Steiger, U. 8. G. 8., 1907, follows: 


S10, 36°41 PbO trace 
BIO). oe Na,O 0°44 
HeiOe)) 1-86 K,O 0°50 
FeO | H,O— 0-24 
MgO 1°38 H,O+ 3°51 
MnO Nertss F 0°36 
ZnO 1°74 
CuO 1°85 100°23 
CaO BO ll less. O27 Ory 
Sum 100:06 


This analysis agrees closely with that of the cyprine from 
Tellemarken save in the greater amount of water and less 
fluorine. It corresponds to ahs formula: 


* Zeitschr. Kryst., xxxiv, 904. 


C. Palache—Mineralogy of Franklin Furnace, N. J. 185 


EL(AT He) -Cazsi7@7, 
with part of the lime replaced by a number of oxides. 


Datolite: Crystal Form. 


Datolite has been known for some time from the Parker 
shaft, Franklin Furnace, but crystals have not hitherto been 
described from there. Complex crystals were found in a 
specimen in the Harvard Collection on which were observed a 
number of forms including several new to the species. In the 
following list new forms are marked with an asterisk : 

@ (001) ¢ (023) & (101) y (221) « (111) f: (241) & : (245) 
e (100) M (011) #1 (304) A: an a (221) j : (243) 

rile) 0 (021) & (102) 6 (112) @- (121) *a (263) 

m (120) * gq. (701) € (101) Y- (223) p: (211) *& as 

Symbols and lettexs after Goldschmidt, Winkeltabellen. 

The pyramid d (263), new to datolite, is present on all the 
erystals with characteristic form. 


Cuspidine: Occurrence ; Composition. 


The occurrence of this mineral, known hitherto solely from 
Vesuvius, at Franklin Furnace is established by the following 
analysis, for which the writer is indebted to Dr. C. H. Warren. 

The material, which occurred with nasonite, was isolated by 
hand-picking and heavy solution and analyzed by him at the 
time (1899) Penfield and Warren were working on nasonite 
and other peculiar silicates from the Parker shaft. At the 
time no satisfactory interpretation of the analysis was hit upon, 
the identity of the mineral remained hidden, and, all the mate- 
rial having been used in analysis, the matter was put one side. 
The imaterial analyzed consisted of glassy white crystal frag- 
ments of specific eravity between 2°965 and 2-989. 

I. Analysis of cuspidine, C. H. Warren, 1899. 

II. Same recast and recalculated to 100 per cent after substi- 

tuting equivalents of Ca for Mn, K, and Na. 


iE II Molecular Ratio 

SiO, 32°30 Si 15:10 "539 1 
CaO Gita Ca 44°63 Leste 2°05 
MnO eral | Fe 9°05 238 ) ‘ 
ay 04s t Ose 1-051 Ge ek 2 OP 
K,O 0:27 
EF 9°05 

104°24 


Less.0'= F,.. 3°81 


100°43 


Mineralogy of Franklin Furnace, NV. J. 


186 @C. Palache 


The ratio Ca: Si: (O+F,) = 2:1:4 very nearly, leading to 
the formula Ca,Si(O, F,),. This is the formula suggested by 
Dana (System, 529) for cuspidine, in which fluorine is treated 
as replacing oxygen. No other treatment of the analytical 
data gave a satisfactory ratio. It is much to be regretted that 
no further material remains for more complete physical deter- 
mination of this interesting species. 


Humite: Crystal Form. 


Minerals of the humite group have long been known from 
Franklin under the name of chondrodite. They have not been 
analyzed nor till recently have good crystals been found. In 
1906 were found orthorhombic crystals of deep orange-red and 
pale yellow color which yielded contact measurements accurate | 
enough to prove the material to be humite. 


Forms : 6 (010), 0, (210), m (110), €; (102), m,(112), 7, (214). 
Combinations: 


Oy Oy Wig Ce 


nD 


5 0, Og Ons Gon Pos 


ee 


, 


JE On, (ly yy Ven Pe 


Leucopheenicite: Crystal Horm. 


Leucopheenicite was described by Penfield, whose material 
did not permit him to determine the system to which the crys- 
tals belong. From its relation in composition to the humite 
group he believed it to be monoclinic. 

Crystals of measurable quality very kindly placed in the 
writer’s hands by Mr. Canfield, furnished data for the determi- 
nation of system and forms. 


System, monoclinic: — Axial ratio: @: 6: ¢ = 1:1045: 1:: 2°3155. 
B= 162445 


Forms: | 
c (001) s (120) @ (103) y (103) 7% (121) d (123) 
6 (010) e (101) 2901) 0 (OL) Yah et eae on, 
@ (100) fF (102) ea O22 (0121) ree 1) gales 
m (110) 


The crystals are of epidote habit, elongated parallel to the 
b-axis, the orthodome zone deeply striated. Crystals are 
twinned on a face in this zone which was taken as the basal 
pinacoid, the two individuals frequently interpenetrating. The 
form series is peculiar and could not be correlated in any way 


Chemistry and Physics. 3 187 


with that of any member of the humite group to which leuco- 
pheenicite is related chemically. 


The presence at Franklin Furnace or at Stirling Hill of the 
following minerals, not hitherto recorded, has been established : 
Marcasite, millerite, pyrrhotite, aurichalcite, hydrozincite, 
psilomelane, géthite, albite, chlorite, ganophyllite, manganese 
pectolite, descloizite, anglesite and native silver. 

With these additions and the omission of a number of spe- 
cies of the older lists which could not be verified, the number 
of minerals recorded for this locality becomes ninety-three. 


Harvard University, October, 1909. 


Se bE NRL EEC INTEL ELG ENE. 


I. CHEMISTRY AND PHYSICS. 


1. The Formation of Colloidal Solutions by the Action of Ultra- 
violet light upon Metals.—It was observed by Lenard and Wolf 
in 1889 that certain substances, particularly metals, were resolved 
to dust by the action of ultra-violet light. This effect was detected 
both by the roughening of the surfaces and the detection of 
the detached particles in the adjacent layers of air. It was found 
that different metals gave different degrees of this action, that 
the electrical condition of the metallic plate exerted a pronounced 
influence upon the action, as did also the nature of the source of 
light employed. These investigators did not attempt the pre- 
paration of colloidal solutions by this means, but they observed, 
when experimenting with a zine plate, that a layer of water held 
back the zinc dust. SvepBERG has now made use of this 
phenomenon in preparing colloidal solutions of various metals in 
various liquids. He placed the metal, the surface of which must 
be freed from layers of oxide, in a shallow dish, placed the liquid 
upon it, and exposed it to the rays of a Heraeus’ quartz-mercury 
arc lamp at a distance of a few centimeters. After afew minutes 
the liquid when examined by the ultra-microscope showed the 
characteristic appearance of a colloidal solution. Different metals 
and different liquids behaved very differently. Silver, copper, 
tin and lead gave colloidal solutions easily, while platinum, 
alumininm and cadmium showed little or no effect. The action 
with lead was particularly strong. When water was used this 
metal gave a milky liquid in five minutes, probably colloidal 
hydroxide, while with ethyl alcohol the same metal gave a 
colloidal metallic solution. Furtherexperiments with lead and 
silver in water and six different organic liquids indicated that 


18 


06) 


Scientific Intelligence. 


the size of the particles is very different in the various cases, and 
that this depends upon the nature of the liquid employed. It 
was especially interesting to find that it was possible to produce 
solutions with particles of very small, uniform size which dis- 
played the Brownian movements in a very lively manner. Fur- 
ther study of this matter, which the author is undertaking, 
promises to be of great interest, and he suggests that it may be 
of importance in explaining the mechanism of common photo- 
chemical reactions.—erichte, xlil, 4377. H. L. W. 

2. Potassium Percarbonate.—Much uncertainty has arisen in 
regard to the true constitution of the product prepared in 1897 
by Constam and von Hansen by the electrolysis of concentrated 
potassium carbonate solutions to which the percarbonate formula, 
K,C,O,, was ascribed by the discoverers. Up to the present time 
this product has always been obtained in an impure condition, 
containing carbonate, bicarbonate and water, and since it yields 
hydrogen peroxide and potassium carbonate when dissolved in 
water, it has been possible to regard it as potassium carbonate 
with hydrogen peroxide of crystallization, instead of a true per- 
carbonate. Moreover Tantar has obtained a well crystallized 
product by the combination of sodium carbonate and hydrogen 
peroxide, to which he gave the formula Na,CO,+4H,O,+ H,0, 
regarding it as a percarbonate combined with both hydrogen 
peroxide and water. 

RiksENFELD and REINHOLD have now succeeded in preparing 
the electrolytic product in a nearly pure anhydrous condition by 
the use of special precautions. The absence of hydrogen in this 
preparation proved that it was not a hydrogen peroxide addition 
product and analyses confirmed the formula K,C,O,. They have 
also found a means for distinguishing between percarbonate and 
hydrogen peroxide in the fact that the former liberates iodine 
immediately from a neutral potassium iodide solution, while 
hydrogen peroxide acts only slowly upon such a solution. By 
means of this reaction they found that ‘Tantar’s product contains 
no percarbonate, so that its formula should be given as Na,CO, + 
13H,O,.— Berichte, xii, 4377. H. L. W. 

3. A Practical Application of Radium.—In connection with 
a research on a revision of the atomic weights of iodine and 
silver, BaxTeER and TirtEy found it necessary to determine 
small quantities of water in the iodine pentoxide which they 
were analyzing. ‘This water was absorbed and weighed in glass 
U-tubes containing phosphorus pentoxide. The usual difficulty 
in weighing glass apparatus, due to electrical disturbance from 
wiping it, was avoided here by placing in the balance a few 
milligrams of radium bromide of radio-activity 10°000 to dispel 
electrical charges. Under these conditions no difficulty was 
experienced in weighing the tubes within a few hundredths of a 
milligram, since they quickly came to constancy in the balance 
case and retained their weights unchanged for days at a time.— 
Jour. Amer. Chem. Soc., xxxi, 212. H. L. W. 


Chemistry and Physies. 189 


4. Volumetric Determination of Selenious Acid.—L. Marino 
has-devised a method for this purpose which he prefers to those 
previously in use. The solution of the selenious acid is made 
slightly alkaline with sodium hydroxide solution, then a specially 
prepared alkaline permanganate solution is added gradually, 
until after heating to boiling a strong violet color is permanent 
for 4 or 5 minutes. After cooling somewhat the liquid is acidi- 
fied with dilute sulphuric acid, and an oxalic solution is run 
in until all the manganese dioxide has dissolved. Then, finally, 
the excess of oxalic acid is titrated with the permanganate 
solution. ‘The test-analyses given show very satisfactory results. 
A special method is given for the removal of nitrates in order 
that this method may be applied.—Zeitschr. Anorgan. Chem., 
Ixy, 32. H. L. W. 

5. A Contract for Radium.—lIt is stated on the authority of 
the London Times that a contract has recently been entered into 
between the British Metalliferous Mines (Limited) and Lord 
Iveagh and Sir Ernest Cassel for the supply of 74 grams of pure 
radium bromide at the rate of four pounds per milligram (total 
about $150,000). The source is pitchblende from the company’s 
mine in Cornwall. ‘This radium bromide is to be presented by 
Lord Iveagh and Sir Ernest Cassel to the Radium Institute, 
which will be under the direction of Sir Frederick Treves, for 
use in the treatment of cancer.— Chem. News, xci, 303. H. L. Ww’ 

6. Absolute Measurement of High Pressure with the Amagat , 
Manometer._-PETER Paut Kocu and Ernst WaGNeER have de- 
scribed in a previous paper a method of measuring accurately 
high pressures which gave very satisfactory results; but in order 
to reach a higher degree of exactness they concluded to measure 
the pressures directly by a height of mercury. ‘The tower of the 
Laboratory in Munich afforded a height of 25™, and they describe 
the arrangement of steel tubes by means of which they contained 
the mercury. A comparison is given of the results of the Ama- 
gat manometer, with the results obtained by direct measures, 
obtained from the height of the mercury column. <A constant of 
correction is given.—dAnn. der Physik, 1910, No. 1, pp. 31-50. 

iy 

7. A Relation Between Absorption and Phosphorescence.— 
The observations of M. G. Lecoq de Boisfaudran and M. G. 
Urban show that the best known phosphorescent bodies result 
from a phosphorogéne in a solvent or diluent. M. L. Brtnine- 
HAUS points out a very simple relation between absorption and 
phosphorescence. The light emanating from the phosphorogéne 
molecules situated in the depths of the medium suffer absorption 
by the superficial layers, and the radiations observed at the sur- 
face are only those for which the phosphorogéne is relatively 
transparent.— Comptes Rendus, Dec. 13, 1909, pp. 1124-1129. 

Boge ae 

8. Mass of Moving Electrons.—The new theories of electrons 
are concerned with hypotheses of change of mass with velocity. 

Am. JOUR. Sci.—FourTH Series, Vou. X XIX, No. 170.—Frxsruary, 1910. 


15 


190 Seventifie Intelligence. 


Abraham supposes electrons unchanged by velocity, while the 
Lorentz-Hinstein theory is based upon the relativity principle. 
EK. Hvurxa in his investigation endeavors to decide which theory 
is the most probable. ‘The article is interesting principally from 
the view of technic : for the author describes minutely the method 
by means of which he excited electron streams in high vacua. 
Although he did not attain to the velocity of the @ ray, he suc- 
ceeded in producing rays of great homogeneity, suitable for meas- 
urement. The vacua were produced by liquid air and the use of 
charcoal, and he used potentials as high as 90,000 volts. The 
paper contains many tables and plotted charts, giving compar- 
isons of results on the Abraham or solid sphere theory and the 
Lorentz-Einstein relativity principle. The measurements agree 
better with the latter theory than with the sphere theory of 
Abraham.—Ann. der Physik, 1910, No. 1, pp. 169-204. 
See 
9, Hertz’s Photoelectric Hffect.—M. Euctnr Buocs criticizes 
the conclusion that this effect coincides in greatness with the 
Volta series, the metals, more photoelectric, being the more 
electropositive, and believes that the order can be reversed when 
one passes from one wave length to another.— Comptes Kendus, 
Dec. 13, 1909, p. 1110. J, at 
10. Influence of Thunder on Size of Raindrops.—V. J. Laine 
has studied the changes in rainbows which apparently follow 
peals of thunder. He describes as follows a typical case: Between 
six o’clock and five o’clock in the evening he observed in the Hast 
arainbow accompanied by a secondary bow. During thunder the 
colors of both bows trembled to such a degree that the color 
limits and the edges of the bows were entirely weakened, and 
one observed very quick vibrations over the entire rainbow. This 
occurred with each peal of thunder. The change in color Laine © 
attributes to changes in size of raindrops. The size before peals 
of thunder was under 0:1™™, and during the thunder it increased 
to 0°5™™ and to 1™™. ‘The author attributes the change to the 
acoustical vibration of the thunder.— Physikal. Zeitschrift, Dec. 
1, 1909, pp. 965-967. J. T. 
11. Conduction of Hlectricity through Gases and Radio- 
activity ; by R. K. McCrune. Pp xvi + 245. Philadelphia, 
1909. (P. Blakiston’s Son & Co.)—This is a “text-book with 
experiments” designed to introduce college classes to the fasci- 
nating and important subjects indicated by the title. There has 
been so great a development during the past twelve years in our 
knowledge of the ionization of gases and the properties of the newly 
discovered radiations that ample material exists for an interesting 
and instructive course for students. The present book is the 
first to be written with this end in view, and it seems well adapted 
to the purpose. The descriptive portions though very concise 
are fairly satisfactory and many useful directions are given for 
performing experiments in this field. H. A. 2B 


Geology and Natural History. iil 


12. Die Strahlen der positiven Elektrizitdt ; von E. GEHRCKE. 
Pp. xi+ 124. Leipzig, 1909. (S. Hirzel.)—This is an excellent 
and timely account of a class of radiations which have of late years 
come to be of great importance in physics. The rays which con- 
sist of positively charged particles include the canal rays dis- 
covered many years ago by Goldstein, certain other rays which 
are observed in ordinary vacuum tubes, the a-rays from radio- 
active substances and the “anode rays” (recently discovered by 
Gehreke and Reichenheim), which are given out by anodes con- 
sisting of the salts of various metals. ‘The properties of all these 
rays and their accompanying phenomena are described in detail, 
and the book forms a very useful collection of data upon an 
important subject. ECA ES. 


Il. Grotogy ann Natura History. 


1. United States Geological Survey, Thirtieth Annual Report, 
1908-1909, of the Director, Grorce O. Smiru. Pp. 128, with 
two plates.—This report contains a statement of the work done by 
the various divisions of. the Survey during the fiscal year ending 
June 30, 1909. Besides the progress in geologic investigations 
and topographic mapping, for which the Survey was initially 
organized, the special lines of work which Congress has delegated 
to it are worthy of note. The classification of public lands has 
been carried forward with great activity, resulting in a proper 
valuation of land according to the use for which it is most valua- 
able. As a consequence the government is deriving a revenue 
from the sale or lease of said lands many times greater than the 
cost of the surveys. Fraudulent entries are made more difficult 
and monopolistic control is prevented, but immediate utilization 
is fostered ; the present system resulting in the greatest good to 
the nation at large. 

The division of mine accidents has been organized within the 
year, studies have been carried on in Europe and in this country 
and already large results begin to show toward the prevention of 
the destruction of both human life and mineral resources. 

The technologie branch by its investigations of materials used 
in government contracts has, during the year, guarded the 
expenditure of tens of millions of dollars and saved millons to 
the government. 

Because these additions to the work of the Survey are so imme- 
diately important and popularly recognized as of great value, 
conscious effort should be maintained to prevent their encroach- 
ment upon the equally valuable purely scientific work upon 
which such developments ultimately rest. That Congress does 
not fully appreciate this broader view is shown by the fact that 
the Survey was only granted $100,000 for stream measurements, 
whereas $250,000 was appropriated for testing fuels. For topo- 


we 


192 Scientifie Intelligence. 


graphic surveys $300,000 was appropriated, for geologic surveys 
$200,000, as during the previous year. The entire appropiation 
for the year was $1,590,680. TB 

2. Lifth Biennial Report. State Geological Survey of North 
Dakota; A. G. Leonarp, State Geologist. Pp. 278, plates xxx. 
Bismarck, North Dakota.—The purposes of the reports of the 
survey are educational in the teaching of physical geography 
and elementary geology, and developmental of the economic 
resources of the state. In this volume, besides the administrative 
report, there are papers on the geology of southwestern North 
Dakota with special reference to the coal, by A. G. Leonard ; the 
geology of northeastern North Dakota with special reference to 
cement materials, by John G. Barry and V. J. Melsted ; the 
geological history of North Dakota, by A. G. Leonard; the 
Bottineau gas field, by John G. Barry, and a paper on good roads 
and road materials, by W. H. Clark. The papers in general 
meet well the purposes for which they are planned and the sur- 
vey by such a report demonstrates its value to the state. The 
paper on the geological history of North Dakota could, however, 
have been improved in a number of particulars. 

It was prepared for the use of schools and the general reader, 
yet there is no statement in it of the fundamental conception 
that geologic time embraces tens of millions of years. Yet 
without such discussion the general reader is apt to preserve the 
inherited notion that time is antediluvian and postdiluvian and 
the whole embraced in some thousands of years. This, however, 
iS &@ minor point in comparison with definite errors retained from 
an earlier period in geology. For example, it is sweepingly 
stated that “granites are examples of Archean rocks.” Whereas 
they are now known to occur as massive intrusive rocks of any 
age up to middle Tertiary. Further, it is stated “that the oldest 
part of the continent, that which was the first to be raised above 
the sea, was a U-shaped land mass, the two arms of the U enclos- 
ing Hudson Bay. At the beginning of the Paleozoic Era by far 
the greater part of our continent, with the exception of the above 
land, was beneath the sea.” This statement may be compared 
with Walcott’s well-founded conclusions, published in 1891, that 
the area of the pre-Cambrian Algonkian continent was larger 
than at any succeeding period until the Mesozoic, and that the 
Cambrian sea did not begin to invade the great interior con- 
tinental area until late Middle Cambrian time. It is true that 
these and other important conceptions have not been properly 
emphasized in many text-books, but that cannot be regarded as 
good reason for their further perpetuation. Their importance in 
geologic theory is, furthermore, such as to warrant calling atten- 
tion to their occurrence in this report. The idea, however, of , 
publishing in state reports popular expositions of geologic struc- 
ture and history, as is here done, is a most valuable one from the 
educational point of view, and one which state surveys have 
largely neglected. Soe 


Geology and Natural History. 193 


3. The Figure of the Earth and Isostacy from Measurements 
an the United States; by Joun F. Hayrorp, Inspector of 
Geodetic Work, and Chief, Computing Division Coast and Geodetic 
Survey. Pp. 178, plates and figures 17. Washington, 1909.— 
This report is one of great interest to geodesists and geologists, 
for though the principal conclusions have been previously 
published by Hayford, this is the first appearance of the complete 
work. ‘The author points out that earlier computations upon the 
elements of the spheroid have regarded the deflections of the 
vertical as accidental errors, an assumption which is evidently 
untrue. By considering them as due to the known irregularities 
in topography largely counterbalanced by the unknown irregu- 
Jarities in subsurface densities, a solution is reached giving the 
character of the latter, and by thus allowing for constant errors 
attaining more correct and larger values for the dimensions of 
the spheroid. By assuming in the solution the existence of 
certain deficiencies of mass underlying elevated tracts, the weight 
of the new determination of the terrestrial dimensions becomes 
17 times that derived otherwise. This may be taken as a 
mathematical demonstration of isostacy. Hayford furthermore 
finds that isostatic adjustment is so nearly complete that the deflec- 
tions of the vertical average are less than a tenth of what they 
would be if due to topographic irregularities alone and the stress 
differences in the crust are not more then one-twentieth what 
they would be if isostacy did not prevail. Consequently the 
United States is not maintained in its position above sea level by 
terrestrial rigidity but is in the main buoyed up, floated, in each 
of its parts, because it is composed of material of deficient but 
irregular density. The solution further shows that the flotation 
is not due to a lighter crust resting upon a fluid and denser sub- 
stratnm and that the isostatic compensation is approximately 
satisfied within a hundred miles of the surface. This report 
brings forth the results of a monumental labor and its author 
and the organization which he represents are to be congratulated 
upon its ecules. The results will be most interesting if 
gravity determinations are now made in order to throw further 
light upon the variations in subsurface densities extending to the 
depth at which isostatic compensation becomes complete. 

The reviewer would point out that the conclusion, that the 
various physiographic provinces are now so closely compensated 
that the unbalanced stresses in the earth are not more than a 
twentieth as great as they would be if isostatic adjustment did 
not prevail, is seemingly at variance with the geological evidence 
that the crust is able to remain unwarped during long periods ot 
time, permitting the wide development of base- leveled surfaces. 
The reconciliation of these .two well-founded conclusions of 
modern geology is one of the larger problems awaiting solution 
in the future. Although, as Willis has suggested, the present 
epoch may be one of tnusually complete isostatic adjustment, 
how comes it that if so complete at present, at other times 
the crust could for so long have resisted the stresses due to wide- 
spread erosion ? a ee 


194 Scientifie Intelligence. 


4. Geological Survey, Cape of Good Hope; by A. W-~ 
Rocers, Director; 13th Annual Report, Cape Town, 1908.— 
The 1908 Report of the Geological Commission contains the fol- 
lowing papers: (1) Report on the Geology of parts of Prieska,. 
Hay, Britstown, Carnarvon and Victoria West, by A. W. 
Rogers and A. L. du Toit; pp. 9-109, figs. 13; (2) The kimber- 
lite and allied pipes and fissures in Prieska, Britstown, Victoria. 
West and Carnavon, by A. L. du Toit ; pp. 111-127, 3 figs.; (8). 
Notes on a journey to Knysna, by A. W. Rogers ; pp. 129-134, 1 
plan.; (4) The Tygerberg anticline in Prince Albert, by A. W. 
Rogers ; pp. 135-139. Field work in Prieska and adjoining 
regions included a study of areas previously mapped, with the ~ 
result that errors were found to have been made in the determi- 
nation of structural and stratigraphic relations. This present 
report, therefore, replaces in large part the report for 1899. 
(This Journal, xiii, 413.) New occurrences of Dwyka beds are 
described and petrographic studies have been made of a number 
of igneous and metamorphic rocks including an unusually large 
variety of granulites, the origin of which is in doubt. An inter- 
esting economic feature is the fact that the water supply is found 
in decomposed dikes of kimberlite, ete., rather than in the shales 
and other sedimentaries. H. E. G 

5. The Devonian fauna of the Ouray limestone; by EH. M. 
Kinpie. Bull. 391, U.S. Geol. Survey, 1909; pp. 60, plates 10.— 
This Upper Devonic fauna characterized by Plethorhyncha end- 
licht and Spirifer cf. whitneyi is now known to extend from 
southern New Mexico to the north line of Colorado. It is com- 
posed of 40 species, most of which are restricted to this biota. 
The strikingly new element is a brachiopod related to Syringo- 
thyris, for which is here proposed the new generic name Syringo- 
spina. 

The author does well in removing for western faunas the name 
Spirifer disjunctus, but he should have gone a step farther and 
renamed the so-called S. whitneyi, as these Colorado shells are 
not identical with the typical Iowa individuals. The reviewer 
has seen the Ouray species also in the Three Forks of Montana and 
in British Columbia north of the Canadian Pacific Railway. c.s. 

6. Lower Paleozoic Hyolithide from Girvan; by F. R. 
CowrreR Reep. Trans. Royal Soc. Edinburgh, 47, 1909; pp. 
203-222, pls. 3.—From the Ordovician and Silurian beds of the 
Girvan district the author describes 10 new species of Hyolithes, 
4 Orthotheca, 2 Ceratotheca, and 5 Pterotheea. OLS: 

7. Die asiatischen Fusulinen. Die Fusulinen von Darwas ; 
von Gtnrer DyHrenFurtH. Paleontographica, Band 56, 1909, 
pp. 137-176, pls. 13-16.—In this work, which is a continuation of 
Ernst Schellwien’s contemplated Monographie der Fusulinen, 
are described with great care six forms of Fusulina illustrated by 
many microphotographs. ‘The geologic occurrence is also fully 
given. Cis 


Geology and Natural History. 195 


8. Paldozoische Seesterne Deutschlands. £. Die echten Asteri- 
den der rheinischen Grauwacke ; Frrepricu ScuéOnporF, Pale- 
ontographica, 56, 1909, pp. 38-112, pls. 6-11.—Here are described 
in detail 12 species of Lower Devonie starfishes of the family 
Xenasteridz. These are grouped in the genera Xenaster (4 
species), Spaniaster (1), Agalmaster n, gen. (3), Khenaster n. gen. 
(1), Zrimeraster n. gen. (1), Hifelaster n. gen. (1), and Aséerias. 
The drawings are somewhat diagrammatic but illustrate the 
characters far better than would photographs. 

In all the genera the ambulacrals are directly opposite one 
another and do not alternate. The ambulacrals and adambula- 
crals are also opposite each other. The mouth opening is 
bounded by 5 pairs of mouth plates and 5 pairs of slightly modi- 
fied ambulacrals. No ocular plates are preserved, according to 
the author; the reviewer has seen none in these old starfishes 
before the time of the Lower Cariboniferous. 7 C... 8. 

9. La Vallée de Binn (Valuis). Etude géoyraphique, géolo- 
gique, minéralogique et pittoresque ; par Lion Derspuissons, 
Pp. vill, 324; 51 illustrations, etc. Lausanne, 1909 (G. Bridel & 
Co.).—This is a popular work on a mineralogical locality which 
occupies a unique position in the interest of the occurrence and 
the almost inexhaustible variety of new and rare species which 
it has afforded. These facts are briefly summarized here, and 
many illustrations give an admirable idea of the scenery of the 
valley. 

10. Catalogue of the Fossil Bryozoa in the Department of 
Geology, British Museum of Natural History. The Cretaceous 
Bryozoa, Volume II; by J. W. Grecory. Pp. xlviii, 346, 9 
plates, 75 figures.—The first volume of this catalogue was pub- 
lished in 1899 and the appearance of the present volume has 
been delayed in consequence of the retirement of the author 
from the staff of the British Museum. In the years which have 
intervened a large amount of material has been added to the col- 
lections of the Museum, so that the whole work has been expanded 
and when complete will embrace a third concluding volume. It 
is expected that this will be shortly prepared by Mr. W. D. 
Lang, who succeeded Dr. Gregory as Assistant in charge of this 
section of the Museum. 

11. A Hand-List of the Genera and Species of Birds | Nomen- 
clator Avium tum Fossilium tum Viventium|; by R. BowDLer 
SHaree. Volume V. Pp. xx, 694.—This volume of the British 
Museum Handlist of Birds deserves to be especially noted, 
since it completes a large and most important labor begun in 
1898. ‘The author and those who have worked with him deserve 
the congratulations of zoologists for what they have done in this 
way to advance the study of ornithology. 

12. Physiologische Pflanzen-Anatomie ; von Dr. G. Haser- 
LANDT. Pp. xvili, 650. Vierte ‘Auflage. Leipzig, 1909 (Wil- 
helm Engelmann).—This is the fourth and enlarged revision of a 
very important work. A quarter of a century has passed since 
Professor Haberlandt, then as now at Graz, published the first 


196 Scientific Intelligence. 


edition. The treatise was recognized from the outset as opening 
up fresh fields of research on the borders between three allied 
departments of Botany. The relations which exist between 
form, function, and origin are sometimes exceedingly obscure, 
and this obscurity was deepened in many instances by the neglect 
of some gross morphologists to investigate the minute anatomy 
of the organs in question. ‘To Schwendener and Haberlandt is 
due a large part of the credit for stimulating observers to enter 
upon this middle ground in the right way. The present volume 
by Haberlandt is in many respects a great improvement upon the 
previous editions, since it enters more boldly upon the field of 
cecology and brings up some of the very attractive questions in | 
the domain of what we may term applied physiology. It is 
truly surprising to notice the small number of changes in the 
statement of facts which the author has been compelled to make 
in the period of twenty-five years. The extreme caution which 
characterized the early edition has borne good fruit in the later 
ones, since there have been practically no mistakes to recall. 
The treatise in its enlarged form is of great value to morpho- 
logists, anatomists, and cecologists, and, in a general way, to 
systematists, as well. 

The publisher has wisely reprinted as a separate, the pages 
devoted to the irritable organs of plants, since the subject of 
sensitiveness is attracting at the present time a good deal of 
attention. A few physiologists will not agree with some of 
Haberlandt’s conclusions, but even they must admit his fairness 
and clearness. G. L. G. 


JI. Miscetznangovs Screntiric INTELLIGENCE. 


1. Report of the Secretary of the Smithsonian Institution, 
Dr. Cuartes D. Watcort, for the year ending June 30, 1909. 
Pp. 95.—The annual report of the Secretary of the Smithsonian 
Institution for the year ending June, 1909, has recently appeared. 
It gives the usual interesting summary in regard to the activity 
of the Institution in its varied functions. Dr. Walcott draws 
attention to the fact that in the estimates for the present year 
there is an increase of $10,000 for the Bureau of Ethnology, to 
be used in connection with researches among the tribes of the 
Middle West and also in Hawaii and Samoa. A larger appropria- 
tion is also called for to carry on the work of the Astrophysical 
Observatory, for the Zoological Park, and particularly for the new 
building of the National Museum, which is now nearing comple- 
tion. In regard to the latter it is stated that the entire stone 
work of the outer walls is completed, as also the roofs and 
skylights, and much progress has been made in the interior, 

that it was expected that some of the halls and work-rooms 
would be ready for use early in the autumn (1909). The Inter- 
national Tuberculosis Congress, in the autumn of 1908, utilized 


Miscellaneous Intelligence. 197 


for its meetings and exhibitions a large part of the first and 
second floors. A full statement in regard to the National 
Museum as a whole is given by Dr. Rathbun in the volume 
noted below. 

A brief summary is given of the first accessions to the Museum 
from the Roosevelt expedition in Africa. The results have been 
even more important than anticipated, including many excellent 
Specimens, particularly of the skins of the larger mammals. 
Special funds were provided by friends of the Institution to pay 
for the outfit and expenses of the naturalists who accompanied 
Col. Roosevelt, while his own expenses, with those of his son, 
have been met by himself. Mr. W. W. McMillan of Juja farm 
near Nairobi, East Africa, has presented an exceptionally fine 
collection of living African animals, 

Of other scientific work carried out under the auspices of the 
Institution may be mentioned the continued explorations by 
the Secretary, Dr. Walcott, in Montana and the Canadian 
Rockies, having as their object the study of Cambrian geology 
and paleontology. Professor J. P. Iddings is now carrying on 
researches on a Smithsonian grant in Japan, EKastern China, and 
Java. Miss Alice Eastwood, also as the result of a orant, has 
re-collected the botanical species from the region of Santa Bar- 
bara secured by Thomas Nuttall in 1836. Under the Hodgkins 
fund several investigations have been prosecuted. The state- 
ments in regard to the Library, the Gallery of Art, the Zoologi- 
cal Park, etc., are all interesting, but cannot be summarized here. 
As usual, Mr. C. G. Abbott, director of the Astrophysical 
Observatory, gives a summary of the work carried on under his 
direction at Washington, at Mt. Wilson, and on Mt. Whitney. 

2. Annual Report of the Board of Regents of the Smithsonian 
Institution, showing the Operations, Expenditures, and Condi- 
tion of the Institution for the Year ending June 30, 1908. Py. 
x, 801, with 23 plates, 25 figures, and 4 charts. —The Secretary’s 
Report, which forms the opening portion of this volume, was 
noticed a year since (see vol. xxvii, p. 196). The general 
Appendix (pp. 113-801) contains as usual a large series of papers 
on scientific subjects, covering many lines of scientific activity 
and discovery. No more well- “selectéd and useful presentation of 
recent scientific memoirs, in a form to interest the intelligent 
public, can be found in a single volume. The opening paper is 
devoted to aeronautics and is profusely illustrated; aviation in 
France and wireless telephony follows, then phototelegraphy, 
and the gramophone ; while on the Natural History side we find 
reproduced (from this Journal, xxv, 169) the important paper by 
Dr. Lull on the Evolution of the Elephant, with another on Angler 
Fishes by Dr. Gill. The volume closes with several biographical 
papers. 

Recent publications from the Smithsonian Institution are noted 
in the following list: 

Report on the Progress and Condition of the U. 8. National 
Museum for the year ending June 30, 1909. Pp, 141. pid Is a 
full and very interesting account of the Museum, its buildings, 


198 Scientific Intelligence. 


collections, and library, by Dr. Ricwarp Ratusun, Assistant 
Secretary of the Smithsonian Institution. 

The National Gallery of Art: Department of Fine Arts of the 
National Museum; by Ricnarp Ratupun. Pp. 140, 26 plates.— 
Dr. Rathbun has given here a full history of the development of 
the department of Fine Arts in the National Museum, begun in 
1840. The bequest of Mrs. Harriet Lane Johnston in 1908 and 
the gift of Mr. Charles L. Freer of Detroit have given the 
National Gallery a notable position in the country; a suitable 
building for its preservation must be provided later. The con- 
cluding chapter of this volume gives a preliminary catalogue of 
the collection with numerous reproductions of important pictures. 

Bureau of American Ethnology, Bulletin 38. Unwritten Liter- 
ature of Hawaii. The Sacred Songs of the Hula; collected and 
translated, with notes and an account of the Hula ; ; by Naruan- 
ret B, Ewrsoy. Pp. 288, 24 plates, 3 figures. 

Bulletin 39. Tlingit Myths and Texts ; recorded by Joun R. 
Swanton. Pp. viii, 451. 

Bulletin 41. Antiquities of the Mesa Verde National Park : 
Spruce-Tree House; by Jesse Waiter Frwxes. Pp. 57, 21 
plates, 37 figures. Washington, 1909. 

Bulletin 42. Tuberculosis among certain Indian Tribes of the 
United States; by Ates Hrpticka. Pp. vii, 48, 22 plates. 

3. National Antarctic Hxpedition, 1901-1904. Magnetic 
Observations. Prepared under the Superintendence of the Royal 
Society. Pp. vil, 274 ; 13 figures, and 43 plates, map and sketches. 
London, 1909.—The earlier volumes containing the records of the 
Antarctic Expedition of 1901-1904, under Captain R. F. Scott, 
R. N., have already been noticed in this Journal (xxvi, 588 ; xxvii, 
271); that on Physical Observations included a report on a por- 
tion of the magnetic work. The present volume completes this 
subject, giving detailed tables of hourly values of the magnetic 
elements with an exhaustive discussion of the same. Dr. 
Charles Chree of the Kew Observatory has taken an important 
part in the elaboration of the observations. 

Among the special topics discussed may be mentioned a com- 
parison of Antarctic disturbances and the aurora, and also an 
examination of disturbances simultaneous in the Antarctic and 
Arctic, from October, 1902, to March, 19038, by Prof. Kr. Birke- 
land. ‘The sketch map which forms the frontispiece shows a por- 
tion of the coast of South Victoria land with the winter quarters 
of the “ Discovery” on Ross Island. On it are noted the posi- 
tions of the south magnetic pole as given by three successive 
recent expeditions, The close agreement between these, the dis- 
tance varying from a maximum of about 80 miles to a minimum 
of about 40 miles, is particularly noteworthy. The latitude and 
longitude of these three positions are as follows : 


Position found by the ‘‘Southern Cross,” Lat. 72° 40'S Long. 152° 30' E 
oo DISCOVeLyna 72° 51’ 156° 25’ 
42 es Lieut. Shackelton, be eo! 155° 16’ 


Miscellaneous Intelligence. 199 


4. The Evolution of Worlds ; by Percivat Lowe. Pp. 
xili, 262. New York (The Macmillan Co.).—This book is a ° 
revised edition of lectures delivered in February and March, 1909, 
before the Massachusetts Institute of Technology, in which 
institution the author is non-resident professor of astronomy. 
The lectures present the most recent facts and speculations 
regarding the past and future of the Solar system, illumined by 
the play of the author’s active imagination and colored by an 
astonishing vividness of language. We do not remember to 
have met in any of Dr. Lowell’s previous essays any such free- 
dom in the use of English. Some of the theories which he 
explains are startling, but the language in which they are set 
forth is much more so. If we all permitted ourselves such 
liberties with our mother tongue it would speedily descend to a 
chaos and darkness such as Dr. Lowell predicts for the solar 
system itself. 

We quote at random from the first few pages. 

“Unimpressing our senses,” ‘grandiose vicissitudes spectrally 
revealed,” “stars cuticle,” “ambidextrous impartiality of space,” 
“The culmination of Coalition’—‘“the acme of accretion.” 

But such mishandling of language, though it irritates the reader 
and mars his enjoyment, does not vitiate the logic or destroy 
the substance of the book. 

The first two chapters, entitled “ Birth of a Solar System,” and 
“< Evidences of the Initial Catastrophy,” will excite most interest, 
The author considers that the initial stage of our solar system, or 
rather the beginning of the cycle of change through which it is 
now passing, was that of a spiral nebula. From this the present 
order arose and to it in some distant age and region it may again 
return, to repeat the cycle indefinitely. Such an enormous pro- 
gram, which explains everything but the origin of matter and 
provides for its eternal activity, satisfies the mind and makes us 
wishful that it may be true. 

Space forbids a discussion of it further than to say that the 
spiral form in a nebula is held to be due to action from without 
rather than from within, in fact to a tidal disruption caused by 
the passage of a large body close to the previously quiescent 
mass. ‘Thns an old and worn out sun may be torn up within a 
few days into a meteoric nebula, heated by collisions of its frag- 
ments and developing under gravity into a planetary system. 

W. B. 

5. Hyperbolic Functions, prepared by Grorce F. Brecker 
and ©. EK. Van Orstranp. Pp. li, 321. Smithsonian Mathemat- 
ical Tables, No. 1871. Washington, 1909.—In the systematic 
study of mathematics hyperbolic functions do not receive the 
attention which their practical importance as a tool of investiga- 
tion warrants. Invented or first employed by Mercator in the 
development of his system of projection, on which to this day all 
deep sea navigation depends, they have come to play an important 
part in many branches of applied mathematics. Thus in physics 
whenever an active entity is extinguished or absorbed (e. g. light, 
velocity, radio-activity) the decay is represented by some form of 


200 Scientific Intelligence. 


hyperbolic function. Mechanical strains also are most simply 
expressed in this form. Hence the study of geological deforma- 
tions always requires the use of these functions ; and it is for 
this reason that the overseers of the U. 8. Geological Survey, 
Messrs. Becker and Van Orstrand, have prepared this most com- 
plete and scholarly treatise. 

The book has a two-fold value. The tables, eight in number, 
furnish everything that a worker with hyperbolic functions can 
need, and they are preceded by an admirable exposition of the 
theory of hyperbolic function. The subject is developed both 
from an analytic and independently from a geometrical basis and 
the relation to elliptic functions is described and also the con- 
nection with the geometry of the pseudo sphere. An historical 
sketch adds greatly to the breadth of view of the subject and 
fifteen pages are given to formulas which the writers designate 

s “those most likely to be needed by computers.” 

This description should make it evident that the book furnishes 
the most satisfactory treatise on this subject that has hitherto 
been published. W. B. 

6. Robbins’s Plane Trigonometry ; by Epwarp R. Ropsins. 
Svo, pp. xiii, 153. New York (American Book Company).—A 
book well adapted for the secondary school course. It represents 
the experience of a mature and careful teacher whose first object is 
to get the essentials of the subject into the head of the average 
boy as quickly and firmly as possible. The learner is introduced 
to the solution of trigomometric equations sooner than usual, in 
fact in the first chapter, but the treatment of identities is post- 
poned until quite late for the reason that the author aims to give 
his followers strength and courage for the assault of this formid- 
able enemy of the weak trigonometer. The distinction between 
an identity and an equation, however, is not explicitly stated. 

W. B. 

7. Experimental Dairy Bacteriology ; by H. L. RussEru and 
K. G. Hastixes. 147 pages; illustrated. Boston 1909 (Ginn and 
Co.).—The purpose of this book is to present an elementary course 
in general dairy bacteriology. Though brief and somewhat 
limited in its scope, it is complete in itself. The sources of milk 
contamination, the biological changes that take place in milk, 
with methods of identifying milk bacteria, the preservation of 
milk, butter-making, cheese, and milk as a vehicle of disease, are 
some of the important topics discussed. A thorough mastery of 
the book should enable the student to pursue intelligently more 
advanced work in connection with the problems of dairy bacteri- 
ology or dairy manufactures. eRe 

8. Bref och Skirfvelser af och till Carl von Linné; af Tu. 
M. Fries. Pp. iv, 342. Stockholm, 1909.—This third part of 
the first volume of the correspondence of Linnaeus contains let- 
ters Nos. 459 to 573; they are arranged alphabetically, accord- 
ing to the names of the recipient or writer, from A to B. This 
important publication is being carried on under the auspices of 
.the University of Upsala, and the librarian of the University 
asks that any persons possessing letters of Linnaeus communicate 
with him on the subject. 


7 P S AC =) 4 “er - . " CJ ‘ 
Librarian U. S. Nat. Museum. 


mevy OL, XXIX.- . MARCH, 1910. 


si 
ee 


Established by BENJAMIN SILLIMAN in 1818. 


AMERICAN 
JOURNAL OF SCIENCE. 


Environ: EDWARD S. DANA. 


ASSOCIATE EDITORS 


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


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


Proressorn GEORGE F. BARKER, or PHILADELPHIA, 
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Proressor JOSEPH S. AMES, or Battimorz, 
Mr. J. S. DILLER, or Wasurneton. 


FOURTH SERIES 


VOL. XXIX—[ WHOLE NUMBER, CLXXIX.} 


No. 171—MARCH, 1910. 


NEW HAVEN, CONNECTIOUT. 


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la 
: 


NEW ARRIVALS’ 


Braziu, I have just received from this locality an excellent shipment which 
includes the following specimens: An exceptionally large Tourmaline, green 
and pink, showing good color and form with its crystal attached to a quartz 
crystal ; deep green Tourmaline Crystats, gem quality with very steep 
rhombohedral terminations ; a fine lot of EucLAasr CrysTAts showing sharp 
crystal faces and good form ; a number of the new gem PHENACITE CRYSTALS 
and Groups which show better quality for this mineral than has ever before 
been found, and some excellent AmMETHYsSTS, deep in color, in good crystal 
form. ; 

SouTH CALIFoRNIA. From here a new lot of Tourmalines, green and 
brilliant pink in color; some showing both colors together, others in groups; 
a fine lot of beautiful TouRMALINE SrEcTIons ; and fine Topaz CrYsTALs 
from Ramona, clear, sharp and symmetrical. 

Happam, Conn. From an old collection which I secured complete I have 
a fine lot of Tourmalines showing beauty in color and form not to be found 
elsewhere. 

New Mexico. From this place a lot of beautiful BLuz Turquoise in the 
matrix. . 

Besides these additions I have still on hand a number of AWARUITES, as 
announced and described in the February issue. 

I am still receiving small shipments of Franklin Furnace Minerals, con- 
sisting of excellent Rhodonite, Willemite, Franklinite, Zincite specimens, etc. . 

ICELAND. Some very fine specimens of Iceland Zeolites, including Stil- 
bite, Heulandite, Ptilolite, Quartz geodes, etc., are still in my possession. 

AUSTRALIAN MINERALS. I have received a small lot of these which in- 
cluded: Atacamite, Cerussite and precious Opals, both cut and in the rough 
also a few Tasmania Crocoites ; one very fine, with large crystals. 

Prices on application. ~ 


Having an exceptionally large lot of common and rare SEMI-PRECIOUS and 
PREcIOUS Stones, both cut and in the rough, I am in a position to satisfy 
the wants of all my customers. 

I also have a fine collection of Antique CAMEOS, cut in Malachite, Coral, 
Lava, ete. 

Roman and Florentine Mosaics showing excellent artistic workmanship, 
and REconstRUcTED Gems as follows: Rubies; blue, white and pink 
Sapphires; pink Topaz, etc. 

Anything desired for selection I shall be pleased to send to my patrons on 
approval. Special lists with prices cheerfully given on application. 


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


THE 


AMERICAN JOURNAL OF SCIENCE 


moun Ta SmrRIn Ss.) 
EL eee 
Arr. XIV.—TZhe Armor of Stegosaurus ; by Ricwarp S. 
| Lex. 


[ Contributions from the Paleontological Laboratory of Yale University.] 


I, Introductory. 
II. Character of armor. 
Ill. Morphology of the plates. 
IV. Position of the armor, 


I. Inrropucrory. 


Tue American genus Stegosaurus, first made known to 
science by Professor Marsh, includes the most bizarre and 
grotesque of armored dinosaurs; a group apparently quite 
apart from the glyptodon-like Ankylosauridee with heavy mail 
developed over the entire body, for in Stegosaurus the striking 
armament was confined to certain regions and, so far as our 
knowledge goes, but little developed elsewhere. 

Stegosaurus, while belonging to the Morrison, the beginning 
of the Lower Cretaceous (Lull, this Journal, vol. xxix, p. 15), 
was highly specialized and evidently represented a senile race, 
and was, as Beecher has shown with other spinescent forms, on 
the verge of extinction, for it shortly disappears entirely from 
our records. 


II. CHARACTER OF ARMOR. 


The known armor of Stegosaurus includes five: types of 
structures, all dermal in origin, of which the first are the small, 
rounded ossicles (gular plates) found 7m sz¢éw beneath the skull. 
These form a continuous, pavement-like investiture protecting 
the throat (fig. 1) and doubtless extending over a considerable 
portion of the body as well, though not elsewhere preserved, 
for it is unreasonable to suppose that an armored reptile would 
have any portion of the skin bereft of scutes or scales of some 
sort. These throat ossicles increase in size as one goes back- 


Am. Jour. Sc1.—Fourts SEeriss, Vou. XX1IX, No. 171.—Marca, 1910. 
14 


202 R. 8. Lull— Armor of Stegosaurus. 


1/30 natural size. 


After Marsh. 


Weve; Jk, 


Restoration of Stegosaurus ungulatus. 


Bie. 1, 


R. S. Lull—Armor of Stegosaurus. 203 


ward from the apex of the jaw, the largest of them being not 
less than 25"™ in diameter. 

The dorsal armor consists in turn of four distinct shapes, two 
apparently defensive and two offensive, with a marked differ- 
entiation in form as well as in function. Of these the first 
(fig. 2) are more or less oval, with a base divided longitudinally 


Bie. 2: 


Fic. 2. Cervical plate of Stegosaurus ungulatus. After Marsh. 1/12 
naturalsize. a, side view; b, inferior view of base ; c, opposite side; d, thin 
margin; e, rugous bases; f and f!, surface marked by vascular grooves. 


by a deep cleft so as to be distinctly bifid and of very short fore 
and aft extent compared with the expanse of the plate. These 
plates show a very rapid increase in size, though the largest of 
them in Stegosaurus ungulatus is only about half the height 
and one-third the antero-posterior diameter of the largest of the 
next type. These bifid based plates seem to have been borne 
on the neck, the largest oval one here figured (fig. 2) being 
near the point of junction between the neck and the trunk. 
The second type are the large, thin, rectangular or somewhat 
triangular plates with a thick base but without the median 
longitudinal cleft. They doubtless stood in pairs along the 
trunk region and upon the proximal portion of the tail (fig. 3). 


BIG. 3: 


Fic. 5. Dorsal plate of Stegosaurus ungulatus. After Marsh. 1/12 
natural size. a, right side; b, thick basal margin; c, leftside; other letters 
as in fig. 2. 


204 RL. S. Lull—Armor of Stegosaurus. 


Stegosaurus ungulatus as represented by the specimen (Cat. 
No. 1853) now being mounted at Yale was apparently the best 
endowed with offensive weapons of any of its relatives, for there 
are associated with the one skeleton no fewer than four pairs 
of spines and three odd, sharp-edged, spine-like plates, one of 
which is so much larger than the other two that it seems to 
imply that at least one intervening size is missing. 

The spine-like plates are characterized by a very oblique, flat 
base, by sharp edges fore and aft and, like the others, by the 
impression of blood-vessels over the side expanse (fig. 4). In 


Fig. 4. iGo! 


Fie. 4. Caudal spine-plate of Stegosaurus ungulatus. After Marsh. 
1/12 natural size. a, side view; 6b, posterior view; c, section; d, inferior 
view of base. 

Fie. 5. Caudal spine of Stegosaurus ungulatus. After Marsh. 1/12 
natural size. a, side view; 6, dorsal view; c, section; d, inferior view of base. 


common with the dorsal plates they give evidence of having 
been deeply imbedded in the integument and underlying con- 
nective tissue, but, unlike the latter, they show a better surface 
for the attachment of muscles to give rigidity to their position. 

Of the caudal spines (fig. 5) the anterior ones are the larger 
and more deeply embedded, being lodged in a thicker portion 
of the tail, and in common with all of the plates give evidence 
of having been ensheathed with a close-fitting imtegument, 
probably of a horny character as in the modern horned toads 
(Phrynosoma) and in Moloch horridus. 


II]. MorrHoLocy OF THE PLATES. 


Upon comparing a given plate with a scute of a crocodile, or 
that of such a dinosaur as Ankylosaurus or Stegopelta, it at 
once becomes apparent that the great expanse of the first rep- 
resents merely an enormous hypertrophy of the median ridge 


R.S. Lull—Armor of Stegosaurus. 205 


or carina of the latter. This expanse is practically alike on 
both sides, with blood-vessel impressions and no indication that 
either one side or the other was in contact with the creature’s 


Wigs Ge 


Fic. 6. Dermal plate of Ankylosaurus. Figured by Marsh as that of 
Triceratops and showing the median carina. 1/8 natural size. 


flesh. On the other hand, the base, the morphological equiva- 
lent of the body of the scute in crocodile or Ankylosaur, is 
always somewhat asymmetrical even when divided into two 
portions by the longitudinal cleft of those of the cervical 
region. This base in the great dorsal plates particularly is 
extremely rugous, implying either a heavy pad of cartilage or a 
very thick connective tissue between the plate and its under- 
lying skeletal support. There is in no instance any indication 
of a true articulation with the subjacent bones. 


IV. PositIon OF THE ARMOR. 


The position of the armor plates has given rise to an animated 
discussion as to whether they were in one row or two, opposite 
or alternating, erect or procumbent. The evidence seems to 
point to a double row of paired, erect plates, though toward the 
end of the tail the aggressive series evidently stood out at 
a decided angle from the perpendicular. It is quite possible 
that they were provided with an erectile musculature to give 
them greater rigidity especially in time of use, ag is the case 
with the nasal horn of the rhinoceros. This seems to have been 
particularly true of the tail. 

Professor Marsh (this Journal, xxxiv, 1887, p. 415), who first 
described and figured the dermal armor of Stegosaurus, says: 
“The upper portion of the neck, back of the skull, was protected 
by plates arranged in pairs {italics mine] on either side. 
These plates increased in size farther back and thus the trunk 
was shielded from injury. From the pelvic region backward, 
a series of huge plates stood upright along the median line, 
gradually diminishing in size to about the middle of the tail.” 

In his restoration of Stegosaurus (fig. 1), first published in 
1891, however, Marsh places the entire series of plates in a 
single row along the mid-line of neck, back, and tail, although 
the caudal spines are represented as paired. 


206 R. 8. Lull—Armor of Stegosaurus. 


Evidence for pairing of the entire series is shown in two 
specimens preserved in the U. 8. National Museum, in one of 
which the plates alone are represented while in the other they 
are actually in association with the underlying bones. These 
plates if placed consecutively would measure twice the length 
of the neck and back, the proportion being 16 to 8 feet. This 
evidence, together with the fact that each individual plate 
as shown above is in itself not symmetrical, indicates that the 
plates were not median but lateral structures and were arranged 
in at least two rows. , 

The first restoration showing the plates in two rows is given 
in a drawing made by Charles RK. Knight under the direction 
of F. A. Lueas and published by the latter first in his book 
“Animals of the Past,” New York, 1901, fig. 24, and again in 
the Smithsonian Report for 1901, plate rv. Later, under Mr. 
Lueas’s direction, a model was made by Mr. Knight in which 
the number of caudal spines was reduced to two pairs and the 
plates were placed in such a way as to alternate along the back. 
The reasons given for this arrangement were two-fold : first, 
that the plates did actually alternate as they lay embedded in 
the rock, and second, that no two of them were precisely 
similar in exact.shape or dimensions. Against the argument 
that no known reptile has alternating dermal elements was 
urged the apparent fact that this did not render it an impossi- 
bility in Stegosaurus. It seems to me, however, that the posi- 
tion of the plates in the rock is hardly conclusive, for the series 
of one side might easily have shifted forward or backward 
slightly during maceration or in the subsequent movement of 
the rocks, as an oblique crushing of fossil bones is a very 
familiar phenomenon. 


The slight disparity of size and shape in the two plates ofa 


pair is not surprismg when one considers that the entire 
hypertrophy of the plate is in a sense abnormal and is com- 
parable to the growth of the antlers of deer of which those 
borne by an individual are rarely if ever precisely similar in 
size, weight, form, or even in number of points. I should con- 
sider a precise matching of the stegosaur plates remarkable 
rather than the reverse. The fact that in no other reptile the 
lateral dermal elements alternate seems too weighty an argu- 
ment to be lightly dismissed. 

The evidence in favor of an erect rather than a procumbent 
or imbricating position is the morphology of the plate itself, 
as described above, and the fact that in the crocodile and gavial 
one can witness the actual hypertrophy of the median keel in 
the two rows of scutes, which finally merge into one along the 
mid-dorsal line of the distal half of the tail. The elevation of 
the keel becomes more and more pronounced beginning with 


RL. S. Lull—Armor of Stegosaurus. 207 


~ 


ie 


iirey 


Fie. 8 


Fic. 7. Section of neck of Stegosaurus ungulatus. pl, plate; r, rib; 
v, vertebrum. 

Fic. 8. Section of the trunk of Stegosaurus ungulatus. p, transverse 
process ; other letters as in fig. 7. 


208 R.S. Lull—Armor of Stegosaurus. 


the second quarter of the tail, reaching its maximum where the 
two rows merge into one and finally dwindling again toward 
the tip. 

In AS specimen of Stegosaurus stenops, No. 4934 of the 
National Museum, the last three plates, those over the sacral 
region, lie as though they had fallen to the right, the anterior 
ones to the left, a thing manifestly impossible in plates 
naturally procumbent on either side. 


Hie. oF 


Fic. 9. Section of the proximal part of the tail of Stegosaurus ungulatus. 
¢, chevron: n, neural process; other letters as in fig. 7. 


R. S. Lull—Armor of Stegosaurus. 209 


Bie 20} 


Fie. 10. Section of the distal portion of the tail through the spines. 
s, caudal spine ; other letters as in fig. 7 


The four sections of Stegosaurus which I present will show 
the relationship of the plates to the underlying skeletal 
elements. The first section (fig. 7), that through the neck, 
shows the piates with bifid base astride the transverse process 
of the vertebra, and the second, that through the trunk (fig. 8), 
the immense broad-based plates borne over the transverse 
process and ribs. <A beautiful mechanical device is shown in. 
that the transverse process is triangular and the rib T-shaped 
im cross section in the armor-bearing region, giving the 
maximum of strength, a wide bearing surface and a minimum 
expenditure of material. The significance of the great eleva- 
tion of the transverse process is also apparent. 

In the sacral and anterior caudal region the bases of the two 
rows of plates are approximated, and now the summit of the 
neural process broadens out to support their weight, as 
indicated in the third section (fig. 9). This broad-topped type 
of neural process ceases with the proximal third of the tail and 
indicates the beginning of the flexible aggressive weapon of 
offense bearing the sharp-edged spine-plates and caudal spines 
which are inserted obliquely into the muscular mass on either 
side in the angle formed between the neural process and the 
centrum (fig. 10). 

Some of the larger spines, notably that described by Marsh 
as the type of Stegosaurus sulcatus, have the base divided by 
an asymmetrically placed longitudinal ridge (fig. 11) into two 
facets which seem to have borne against the neural process and 
centrum of the vertebra. This character is only present in 
very large spines which have a deep insertion into the under- 
lying tissues. Ordinarily the insertion seems to be too shallow 
to give rise to the facets. 


210 RL. S. Lull—Armor of Stegosaurus. 


Owen has figured what he calls the “carpal spine” in 
Dacentrus (Omosaurus) hastiger from the Kimmeridgian of 
Wiltshire (Mon. Brit. Fos. Repts. pl. 77), which shows precisely 


Fie, 11. Caudal spine of Stegosaurus sulcatus. After Marsh. 1/12 
natural size. Dorsal, anterior and ventral aspects. 6, the base showing 
longitudinal ridge. 


this same structure of the base as in Stegosaurus sulcatus. 
Dacentrus is the probable Old World ancestor of Stegosaurus, 
but while the caudal spines are known, the presence of the 
armor plates has not as yet been demonstrated. 


° 


O. C. Farrington— Times of Fall of Meteorites. 211 


Art. XV.—Times of Hall of Meteorites; by O. C. 


FARRINGTON. 


Tus times of fall of meteorites may be studied with reference 
to the year, month, day and hour. The yearly falls should 
give evidence as to the fr equency of the occurrence and exhibit 
periods if any occur. The falls by months should show the 
relation of meteorites to well-established star showers and the 
portion of the earth’s orbit where meteorites are most fre- 
quently encountered. The falls by days should exhibit perio- 
dicity if any exists and variation in the uniformity of supply. 
Finally, the hours of fall should give the direction of move- 
ment of meteorites. Since new falls occur yearly, data for 
study of these points are obviously constantly on the increase. 
It is desirable, however, to make comparisons at intervals in 
order that any changes may be discerned. At the present 
time the admirable catalogues of Wiilfing* and others afford 
excellent means for the collection of such data. From these 
catalogues, with such additions and corrections as could be 
made from other sources, the writer has obtained record of 
800 well authenticated meteorite falls of which the year and 
month are known, 327 of which the day is known, and 268 
of which the time of day is known. In this number it has 
been sought not to include finds referred by residents of a 
locality to meteors which they had seen a year or more before, 
since the residents of most localities can, on the occasion of a 
meteorite find, recall a large meteor seen in that locality at 
some previous time. To connect this, however, without fur- 
ther reason with the meteorite found seems an unreliable 
method of procedure. 

Considering the falls by years, it is well known that previous 
to the nineteenth century little reliable record of meteorite 
falls is available. Single falls are known for the years 1492, 
1668, 1715, 1728, 1751, MCO NSeliSom ki Sie. UiOOpnI( oe. 
1795 and 1796, and two falls each for the years 1753, 1768 and 
1798. Also for the early part of the nineteenth century the, 
record is not very complete, since during that period the possi- 
bility of meteorite falls was yet much doubted. However, the 
record may as well begin with 1800. From that year to the 
present, 331 falls may ‘be accepted as well authenticated as to 
their month and year. During this period eleven years show 
no falls whatever. These years are—1800, 1801, 1809, 1816, 
1817, 1832, 1839, 1888, 1906, 1908, and 1909. Of these the 
years of the present decade will probably have falls to their 


* Die Meteoriten in Sammlungen, Tubingen, 1897. 


“ 


Ww 


212 OO. C. Farrington— Times of Fall of Meteorites. 


credit after a time, since the record of falls usually lags several 
years behind their occurrence. The largest number of falls | 
shown in any year during the period is 11, in 1868. The years 
1865, 1877 and 1886 show 7 each. All the other years show 
from 1 to 6 falls each. On the whole, therefore, the record 
seems to indicate a comparatively uniform supply of meteorites, 
which is the more remarkable when one considers the various — 
chances affecting the observation of their fall. The record 
seems to afford no evidence of cycles or periodicity which can 
be traced with certainty. Still the record of years is perhaps 
not as satisfactory for establishing conclusions in this regard 
as is that of other periods. As the writer has shown else- 
where,* at least 900 meteorites probably reach the earth yearly. 
Of these only an average number of 3 is recorded, so that it is 
evident that a large allowance must be made for unrecorded 
ones. Yet it is fair to presume that those recorded are typical 
of the whole, because while opportunities for observation of 
meteorite falls have probably continually increased in number 
since 1800, the record by decades shows that the decade from 
1860 to 1870 considerably exceeded in number of falls either 
of the two succeeding ones. 

Passing from the falls by years, the falls by months may be 
examined. Snch an examination should have an especial sig- 
nificance in showing the relations which meteorites may have 
to well-known star showers. Two of the best known of these 
showers occur in August and November. If meteorites are 
related to these, these months should show a larger fall than 
others. If meteorites are not related to these, no special 
increase for these months should be shown. On compiling the 
results the latter proves to be true. The months exhibiting the 
greatest number of falls are May and June. The number for 
November falls below the average and that for August rises only 
slightly above. The evidence from this record is therefore that 
meteorites are not related to the best known star showers. It is 
fair to presume that the record by months will be somewhat 
influenced by the time that observers are most abroad. Most of 
the observations of meteorite falls are made in the northern 
hemisphere and in this hemisphere observers are more likely 
to be out of doors and hence more likely to observe the fall of 
meteorites in the summer than in the winter months. The 
record shows that as a whole the number of falls recorded 7s 
less for the winter than the summer months, yet the number 
of falls cannot be influenced by that alone since the high record 
for May and June drops to nearly half that number in July. 
Further the months of August, September and October are 


* Pop. Sci. Mon. 1904, pp. 301-304. 


O. OC. Farrington—Times of Fall of Meteorites. 218 


- lil > - P) 
= o ia rr > z2 ej oS a. & > >) 
< < 
LJ oO =) ui oO e) Wl 
= Le = < = = = <q. 7) ° z ra) 


Fig. 1. Falls of meteorites by months. 


equally favorable as regards weather for observations of mete- 
orite falls with those of April, May and June, yet the latter 
period much excels the former in number of falls. The excess 
of falls in May and June must, therefore, be due to other causes 
than favorable conditions of observation and seems to indicate 
that in the portion of the earth’s orbit passed through in these 
months there is an unusual number of meteorites. The full 
record for the different months is as follows: 


Jan. Feb. Mar. April May June July Aug. Sept. Oct. Nov. Dec. 
Dam 2A 22) ae 44 45°23. 386 9 30° 24: 24 21 = 350 


This record is shown graphically 1 in the accompanying diagram, 
ne: 1. 

"Comparison of the falls of meteorites by months as here 
given with those of falling stars and fireballs as given by W. H. 
Pickering* shows a marked difference of distribution. Accord- 
ing to Pickering’s list the falling stars and fireballs are much 
more uniformly distributed through the year than are meteorites, 
and the period of greatest number is from July to November. 
In May and June their number is at its minimum. Hence the 
record seems to show a difference in character between mete- 
ors and meteorites and furnishes per se a ground for question- 
ing the gradation that has been supposed to exist between 
meteors and meteorites. 


* Popular Astronomy, No. 165. 


214 O. OC. Farrington—Tumes of Kall of Meteorites. 


Tabulation of meteorite falls by days of the year seems to 
show little of significance. The largest number of falls for any 
one day is five on October 13, and this is a month when the 
total number of falls isnot large. Four days of the year show 
four falls each and 158, or nearly half the total number, no falls 
at all. The days without falls seem to be scattered indiserimi- 
nately through the year, without marked grouping or arrange- 
ment. The days showing falls aside from those mentioned 
have from one to three falls each without any marked grouping 
that is apparent. Such a record seems also to indicate that to 
refer a meteorite falling on the day of a star shower tosucha 
shower is unsafe, especially if the observations are not sufficient 
to assign the two to the same radiant. Meteorite falls are so 
distributed thronghout the year that the two occurrences 
might easily be coincident without being otherwise related. 

Of all times of fall of meteorites the most satisfactory for 
study are probably the hours of fall, since the ratio of number 
of falls to number of hours is larger than to days, months or 
years. Asis well known, the hours of fall show the direction 
of movement of meteorites, since (with a few minor possible 
obvious exceptions) meteorites fallmg from noon to midnight, 
or afternoon falls, must be moving in the same direction as 
the earth; while those falling between midnight and noon are 
moving ina direction opposite to that of the earth or else at a 
speed so slow that they are overtaken by it. While the hour of 
fall is not known of as many meteorites as is the year and 
month, yet of 268 sufficiently satisfactory records are available. 
Of these 268 falls 180 occurred in the time from noon to 
midnight, and 88 from midnight to noon. Meteorites, there- 
fore, in the proportion of at least two to one, have direct motion 
and overtake the earth. Of the others it is probable that the 
majority have retrograde motion, since cbservations indicate 
that but few, comparatively, are traveling at so slow a speed as 
to be overtaken by the earth. As in the case of the months and 
the years, it is quite likely that here also considerable allowance 
should be made for conditions of observation. It is reasonable 
to expect that the number of falls recorded in the early morn- 
ing hours would be less than that for other times, since man- 
kind is generally asleep then. That some such allowance must 
be made is indicated by the records, for the number of falls 
from midnight to 6 a.m. is only 21, while from 6 a.m. to noon 
it is 67; from noon to 6 p.m. 122, and from 6 p.m. to midnight — 
58. Hence it seems probable that some of the diminution in 
the number of falls is due to lack of observers, although New- 
ton* concluded from studies of the orbits of the morning falls 
that the lack of observers had little to do with their seareity. 


*This Journal (3), xxxvi, p. 10, 1888. 


Pirsson—WNote on the Occurrence of Astrophyllite. 215 


During the other periods of the day, however, the figures 
should be little affected by conditions of observation and there 
seems much reason for reaching the conclusion that the major- 
ity of meteorites have direct motion and travel at a velocity 
greater than that of the earth, or 18 miles per second. Here 
again meteorites differ from meteors, since the larger number 
of meteors fallin the morning hours. In times of fall by months, 
days and hours, therefore, the majority of meteorites differ from 
meteors. Their position in space, orbits and direction of move- 
ment must, therefore, differ correspondingly also. 
Field Museum of Natural History, 
December 15, 1909. 


Art. XVI.—Wote on the Occurrence of Astrophyllite im the 
Granite at Quincy, Mass. ; by L. V. Pirsson. 


Tuer interesting note of Professor Warren on the finding of 
a pegmatitic facies of the alkalic granite of Quincy,* and of 
the minerals it contains, recalls to the writer that he has 
recently noticed in a specimen of this rock the mineral astro- 
phyllite. The occurrence is entirely a microscopic one and the 
crystals are too minute to be detected and tested megascopi- 
eally, but as the real home of this rare and peculiar species, as 
shown in the few places in which it has so far been found— 
Langesund fiord, South Norway; southern Greenland, and St. 
Peter’s Dome, Colorado—is in the pegmatites of the alkalic 
rocks, it seems worth while to call attention to the occurrence 
in order that it may be placed on record, and that attention 
may be directed to the Quincy pegmatites in the hope of find- 
ing itin megascopic crystals. This is more especially necessary 
since from its dark or brownish color and excellent mica- 
ceous cleavage it is apt to be mistaken for biotite and over- 
looked. A chemical test for titanium will, however, serve to 
distinguish it readily from ordinary biotite and zinnwaldite, 
while lepidomelane, which might be expected in such associa- 
tions of minerals, rarely contains more than a trace of this ele- 
ment. In this connection it might be stated that the writer 
has not observed any of the dark micas in the study of a con- 
siderable number of sections of the Quincy rock, although 
Whitet+ mentions it as occurring at times in minute flakes. 

* This Journal, vol. xxviii, p. 449, Nov. 1909. 


+T. G. White, Petrography of the Boston Basin, Proc. Bost. Soc. Nat. 
Hist., vol. xxviii, No. 6, p. 131, 1897. 


216 Pirsson—Note on the Occurrence of Astrophyllite. 


The astrophyllite was found in a rock of the usual Quiney 
type consisting of riebeckite, aegirite, microperthite and quartz, 
with zircon as the most common accessory mineral. It is in 
minute, elongated laths grouped into bunches and associated 
with the riebeckite. It was also observed intergrown with 
the riebeckite in such a way that the axis of elongation parallel 
to the cleavage was parallel with the vertical axis of the rie- 
beckite; hence in section it appears as if wedged in between 
the hornblende cleavages. It was noticed that the riebeckite 
in this case had on its margin with the feldspar what the 
writer has drawn and figured as the interdented texture,* indica- 
tive of crystallization from eutectic conditions. 

The astrophyllite was found to have the following proper- 
ties: cleavage, excellent micaceous, and accepting this cleavage 
as the pinacoid 6 (010) the direction of elongation of the erys- 
tals is on the ¢ axis and the directions of elasticity are a =c; 
6=a and ¢c=b; strongly pleochroic, a, red-orange, c, lemon- 
yellow; absorption a >c; refractive index >1°7; extinction 
parallel to the cleavage cracks; birefringence high >0-04. 
In convergent light a single biaxial optic axis was obtained on 
the edge of the field; the limited number of erystals and their 
nearly parallel orientation did not permit of further investiga- 
tion of the optic scheme. 

These are the properties of astrophyllite and definitely 
determine it; from the micas, which it resembles in thin sec- 
tion, it is easily distinguished by the much higher relief, the 
reversal of the absor ption scheme referred to the cleavage and 
the wide optic angle indicated. 

There is yet much to be learned concerning this interesting 
mineral, whose formula is still uncertain, but which Broggert 


ie it I : Ir 
believes to be R,R,Ti(SiO,), in which R = H, Na, K and R= Fe, 
Mn, and a new occurrence well investigated might be expected 
to throw much light upon its composition. 


Sheffield Scientific School of Yale University, 
New Haven, Conn., Nov. 1909. 


* Contributions to the Geology of New Hampshire. No. III, On Red Hill, 
Moultonboro ; this Journal, vol. xxiii, p. 273, 1907. 
+ Zeitschr. fur Kryst., xvi, p. 212, 1890. 


O. NV. Fenner— Crystallization of a Basaltic Magma. 217 


Art. XVIIL—The Crystallization of a Basaltic Magma from 
the Standpoint of Physical Chemistry ; by CiaRENcE N. 
FENNER. 

Introduction. : 
Scope of the article. 
Part I. 
Process of crystallization as demanded by the laws gov- 
erning eutectiferous solutions. 
Petrographic description of the Watchung basalt. 
Part LY. 
The crystallization of a magma as affected by the law 
of mass-action. 
Dispiacements of equilibrium within a solution effected 
by changes of temperature and pressure — van’t 
Hoff’s law. 
Resorption of olivine in the Watchung magma. 


INTRODUCTION. 


Wirxtn the last few years petrographers have recognized 
the important aid which might be rendered to the interpre- 
tation of the structure and history of igneous and metamorphic 


rocks by an application of the pr inciples of physical chemistry. 

The discoveries which have been made regarding the laws gov- 
erning the crystallization of solutions, the application of the 
phase-rule of Gibbs and of the law of mass-action, and the new 
conception of the phenomena of solid solutions, are believed to 
be capable of rendering very great assistance in interpreting 
the meaning of the structures with which petrographers have 
become familiar. 

Although the applicability of these principles is generally 
conceded, very little has yet been done in applying them to 
specific cases. 

In making a study of certain peculiar phases of the basalt 
which forms the Watchung Mountains in New Jersey, it came 
to be recognized that the rather unusual conditions which had 
attended its solidification had produced results which illus- 
trated certain laws of the crystallization of solutions more per- 
fectly than could be hoped for from the most elaborately 
devised laboratory experiments. 

_ Ina previous articie* the author has shown that the Watch- 
ung sheets were surface flows poured out over areas in which 
Triassic shales and sandstones were accumulating under con- 
ditions of continental sedimentation in structural valleys.¢ At 
most points the basalts present the dense, holocrystalline 
texture normal to this type of rock, but in certain areas the 
flows appear to have spread over the sites of shallow lakes, and 

* Features Indicative of Physiographic Conditions Prevailing at the Time 
of the Trap Extrusions in New Jersey. Journ. of Geol., vol. xv, No. 4, 
May-June, 1908. 

{See also J. V. Lewis, Annual Report N. J. State Geol. Survey for 1906. 


Am. Jour. Sci.—FourtH SERIES, VoL. X XIX, No. 171.—MArcg, 1910. 
15 


218 CO. WV. Fenner—Crystallization of a Basaltic Magma 


many modifications of structure resulted. The chief effect, as 
regards the features which will be considered in this paper, 
was that the fused magma was rapidly chilled and rendered 
viscous. In places the stiffening liquid accumulated in masses 
of rounded or bowlder-like forms similar to the “ pahoehoe” of 
Hawaiian flows. The progress of er ystallization was checked 
at various stages and the bowlder-forms were crusted with 
basaltic glass, in which examination with the mier oscope shows 
few phenocrysts, while the more slowly cooling interiors of the 
bowlders assumed the normal texture. Between the two types 
transitions occur, by which one may trace the passage of the 
microlites of the vitrophyrs into the well-developed crystals of 
normal basalt. 

The glass-enerusted bowlders are especially well developed 
in an area lying between Paterson and Montclair Heights. 
Quarries have been opened at several points, as it has been 
found that this variety of trap is easily blasted and crushed 
for road-material. It has therefore been possible to obtain 
material for petrographic study unacted upon by weathering. 


ScoPE OF THE ARTICLE. 


Two principal features of the Watchung basalt will be con- 
sidered, and in accordance with this the article is divided into 
two parts. Part I will deal with the order of crystallization of 
the constituent minerals, and it will be shown that, contrary to 
certain prevalent ideas regarding the order of succession of the 
minerals of a basaltic rock, the three constituents, plagioclase, 
diopside, and magnetite, began to appear almost simultane- 
ously from the magma and onemcd to crystallize side by side 
until complete solidification was attained. In order to show 
that this result is demanded by the laws of crystallizing solu- 
tions, a very brief outline of these laws will be given as a pre- 
liminary to the petrographic study. 

In Part II resorption- -phenomena will be considered in con- 
nection with the resorption of olivine, a minor feature as 
regards the constitution of the rock, but very significant in its 
interpretation. 

The law of mass-action will be considered in this connection, 
and the author will endeavor to show that the usual explanation 
of resorption is inadequate to explain certain phases of the 
phenomenon, but that a very satisfactory explanation may be 
derived from an application of van’t Hoft’s law. 


Parz I, 


Pre ocess of Crystallization as demanded by the Laws governing 
Hutectiferous Solutions. 


In order that the crystallization of a magma may proceed 
strictly along the lines indicated by eutectic laws, it is essential that 


From the Standpoint of Physical Chemistry. Pah 


there shall be little or no reaction going on within the magmatic 
solution from the time that the initial erystals appear until the 
process of solidification is complete. In such cases the pro- 
eress of solidification is very regular. Hach compound present 
in the fusion has its temperature of solidification depressed 
according to the number of mols (gram-molecules) of other sub- 
stances present and begins to appear at the appropriate point in 
the process of coolmg. That mineral will first appear which, 
under the conditions stated regarding fusing-point, still has the 
highest temperature of fusion. 

The first mineral may be regarded as that which is present 
in greatest excess over the eutectic ratio. Within a certain 
range of temperature it alone will be thrown out of solution. 
At a certain point, however, it will be joined by a second min- 
eral, and these two in turn by a third. ‘The composition of the 
solution approaches the eutectic ratio by the elimination of those 
constituents which are in excess. A sudden chill at any stage 
of the process causes a great increase of viscosity, which acts as 
a very effectual check to further crystallization. The result is 
the production of the greatly undercooled liquid of immense vis- 
cosity which is termed a glass. The com position of the glass 
depends upon the stage of progress toward the attainment of 
the eutectic ratio which has been reached. If no such inter- 
ruption occurs, at the eutectic point the group of minerals form- 
ing the eutectic will crystallize out in the proper ratio. No 
further depression of the temperature of solidification can 
oceur, and the loss of heat will be merely that due to the latent 
heat of fusion given up by each mineral in passing from the 
liquid to the crystalline phase. An application of the phase- 
rule of Gibbs confirms this conclusion, for at the eutectic point 
the number of phases exceeds the number of components by 
one, and no change of temperature or composition of the 
system can occur. 

It is doubtful whether the solidification of a magma is ever 
quite such a simple process as is expressed in the form de- 
seribed, but though complications may ensue, the underlying 
principles of eutectics hold and should constitute a guide of 
great value in interpreting rock structures and history. In 
the solidification of the Watchung magma the reactions which 
would tend to obscure the process were of such nature that 
their results do not offer great obstacles. The only one of 
moment is that by which olivine was crystallized out and later 
was resorbed by the magma and did not again appear. This 
phenomenon will require explanation, but it is due to other 
physico-chemical laws, and the reaction was so nearly complete 
before the three final constituents, diopside, plagioclase, and 
magnetite, began to appear, that its effects may be disregarded 
for the present. 


220 OC. V. Fenner—Crystallization of a Basaltic Magma 


Petrographic Description of the Watchung Basalt. 


In those portions of the Watchung flow in which chilling 
was most rapid the surfaces of the pahoehoe. -like bosses were 
erusted with much glassy material. Apparently, however, 
judging from the study of a great number of slides, orystalli- 
zation was under way and phenocrysts had begun to appear in 
the mass of flowing lava before the sudden chill occurred which 
stiffened it into a glass. The resultant glass shows a typical 
vitrophyric texture. The well-developed phenocrysts are sur- 
rounded by isotropic glass or by a groundmass in which glassy 
material is more or less mixed with the feathery forms of micro- 
lites. Under the generally accepted hypothesis, in a typical 
diabase consisting of magnetite, plagioclase, and diopside, the 
magnetite would ‘be first to form, and its elimination from the 
magma would be complete before the plagioclase began to 
appear. These two are held to be followed by the third constit- 
uent, diopside, which oceupies the space left by the other two. 
On the other hand, the manner in which the minerals should 
erystallize out, as demanded by the principles of eutectiferous 
solutions, is quite different, and in every case the sections exam- 
ined conform to the latter requirements. No matter to what 
degree glass may be present in the slide, plagioclase and 
diopside appear side by side. It is evident that almost from 
the beginning of crystallization these two constituents were 
being eliminated simultaneously. At times it appears that the 
diopside is in somewhat preponderant amount, and at other 
times the plagioclase. 

With regard to the magnetite the evidence is more obscure 
The proportion of magnetite in the magma is not large and it 
seems to appear first as a dark dust. The exact point at 
which elimination from the fusion began is not clear, but it is 
certain that growth of magnetite grains continued while 
diopside and plagioclase were still forming. 

Slide No. 105 shows a typical development of glass and . 
phenocrysts. (See ites IE) 

Probably three- ine of the section is isotropic glass, 
uniformly pale green or light olive-green in the thin section. 
Scattered throughout are numerous phenocrysts of plagioclase 
and diopside. The plagioclase is in typical lath-like crystals 
reaching an ordinary maximum of 0°2—0°3"" long by -05™™ 
wide. The diopside is developed in more nearly equidimen- 
sional forms of a characteristically stouter appearance. An 

exceptionally large crystal measured 0°6 by 0-2". The out- 
line is sometimes octagonal, but in general irregular. In 
many cases the plagioclase and diopside are closely associated, 
small clusters of mutually intergrown individuals lying in 
groups surrounded by glass. It is noticeable in such cases 


From the Standpoint of Physical Chemistry. 221 


that while the plagioclase laths are indented by the diopside 
erystals, the characteristic elongated form of the plagioclase is 
maintained. 

These phenocrysts of diopside and plagioclase are bordered 
by dark plumose growths, or hair-like tufts, fading out at the 


Imes Jie 


Fig. 1. Typical structure of the vitrophyric phase resulting from quick 
chill. (Slide No. 105.) Elongated crystals plagioclase, stouter forms diop- 
side, matrix light-green glass, perfectly isotropic. Actual diameter of 
field 1:5™™. 


periphery into the surrounding glass. Under the high-power 
objective they are resolved into innumerable microcrystalline 
growths, straight or curved, sometimes branching in lattice-like 
forms, thrown out from the boundaries of the phenocrysts. 
With the high magnification they exhibit the development 
sketched in fig. 2. 


= A 


Fie. 2. Microlitic growth of plagioclase and diopside, greatly magnified. 


222 CO. N. Fenner—Crystullization of a Basaltic Magma 


The phenocrysts were probably formed during rather slow 
cooling in the flowing mass of lava, and the bordering micro- 
litie erowths represent the continuation of the er ystallization 
during the initial stages of chilling, before increasing viscosity 
put a stop to the process. Their brown color seems best 
explained by the separation of magnetite dust at the same time 
that diopside and plagioclase were crystallized out. If this is 
true, the eutectic ratio had been reached, and if normal crystal- 
lization had been followed the continuation of the process would 
have taken the form of simultaneous growth of crystals of 
diopside, plagioclase, and magnetite. This was prevented by 
the increasing viscosity of the liquid, with which erystalliza- 
tion could not keep pace. 

The almost simultaneous appearance of diopside and plagio- 
clase at the initiation of erystallization, attended or followed 
after only a short interval by magnetite, would appear to 
demonstrate that the composition of the magma as erupted did 
not differ greatly from that required to form a eutectic of the 
three. 

The only other feature of interest in the slide is the presence 
of a number of olivine crystals, which have been strongly 
attacked and resorbed by the magma. This phenomenon will 
be taken up later. 

Slide No. 1 is almost a duplicate of No. 105 and exhibits the 
same set of phenomena, except that there is no evidence of 
olivine grains, and that the glassy groundmass shows with 
high magnification abundant brown dust. Diopside pheno- 
crysts are a@ very minor constituent but plagioclase is abundant. 

In No. 57 the chilling was apparently a little less sudden, for 
the phenocrysts have a tendency to blend with the plumose 
microlitic borders and a smaller proportion of the slide is 
occupied by strictly undifferentiated glass. 

Slides 30, 85, and 90 are other examples showing essentially 
the same relations of phenocrysts, microlites, and undifferen- 
tiated glass. In No. 182 (fig. 3), the microlites are seen to 
be spreading over a greater portion of the field, and in No. 2 
a further stage is shown. 

This latter slide was taken from the same hand specimen as 
No. 1, but whereas the portion of the rock from which No. 1 
was taken presented a decidedly vitreous appearance, that from 
which No. 2 was prepared was a little farther removed from 
the chilled crust and was of a felsitic character. Microscopie 
examination confirms the deduction which would naturally be 
drawn. In No. 1 the phenocrysts are merely bordered by 
plumose microlites and a large part of the section is undifferen- 
tiated glass. In No. 2 the microlites have spread over the 


rap) 
entire field not ocenpied by the phenocrysts and no glass can 


from the Standpoint of Physical Chemistry. 223 


be perceived. Instead there is a beautiful development of 
tufts and sheaves of feathery microlites occupying the entire 
groundmass. The phenoerysts, as before, show groups of 
diopside and plagioclase in mutual intersrow th. ‘Fhe general 
dark brown color of the groundmass appears to be due to dust 


hie=o: 


Fig. 3. Microlitic additions to phenocrysts of diopside and plagioclase. 
(Slide No. 152.) Diameter of field 1°5™™. 

Fic. 4. Intermediate texture between microlitic and holocrystalline. 
(Slide No. 58.) Diameter of field 1:56™™. 


and grains of magnetite developed along the lines of growth 
of the feathery microlites and outlining their form. 

In slides No. 96 and No. 58 (fig. £4) a-step in advance is 
shown toward the holocrystalline texture of a normal basalt 
resulting from moderately slow cooling. The sharply detined 
outline of the phenocrysts has been ‘lost and their borders 
fray out into the finely erystalline groundmass. The ground- 
mass itself is coarser than in the earlier described sections 
and the subhedral crystals are comparable in size to the 
phenocrysts. Some of the magnetite is in distinct grains, but 
much of it is still in the form of a dark dust lying between 
the lighter minerals. 

Nos. 98, 99, and 18 (Photograph, fig. 5) show successively 
coarser phases of crystallization, and Nos. 23, 24, and 25 show 
the normally developed texture of these basalts. Nos. 47 and 
64 represent the maximum of coarseness of crystallization 
attained. 

In the normally crystallized basalt the essential constituents 
are plagioclase, pyroxene (diopside), and magnetite, the first 
two in crys talline forms, the last in dust, gr anules, or trellis- 
like groups. (See fig. 6 

The plagioclase i is In oT shaped crystals, euhedral to subhe- 
dral, generally showing two or three stripes of albite-twinning 
lamelle. Pericline twinning is rarely present. Its average 


294 OC. N. Fenner— Crystallization of a Basaltic Magma 


dimensions are ‘15 by :03"™, but occasionally crystals of larger 
size up to 1™™ in length, and more nearly equidimensional, 
are scattered through the mass. It comprises, roughly speak- 
ing, two-fifths of the whole. 


TENG. 


Fie. 5. Photograph of normally eryetalized basalt. (Slide No. 18.) 
Diameter of field 24™™. 


Fic. 6. Ophitic texture of normally crystallized basalt. (Slide No. 47.) 
Plagioclase laths, diopside granules, and crystals and dust of magnetite in 
mutual intergrowth, The magnetite is mostly included in the ‘diopside, 
but partly also in the plagioclase. Diameter of field 1:o™™, 


Extinction angles measured on symmetrically extinguishing 
albite twins give maxima of 383-34 degrees. This indicates 
a medium labradorite of about the composition Ab 40 An 60. 

The pyroxene is in stouter forms of an irregularly angular 
outline. The grains show a tendency to coalesce in groups of 


From the Standpoint of Physical Chemistry. 225 


individuals of different extinction. Single units show dimen- 
sions of 0°2 by 0°15™" with occasional larger grains up to 0°5™™ 
in size. The crystals are almost colorless , with a faint tinge of 
brown or green. In many slides twinning i is a common char- 
acteristic. Twinning and composition plane the orthopinacoid 
(100). Polysynthetic basal twinning is absent. Optical 
character biaxial and positive. No difference in dispersion 
between red and violet can be perceived. Prismatic cleavage 
often poor in the small grains but well developed in the larger. 
Birefringence 0-020 —0-022. 

Extinction measured from the ortho-pinacoidal twinning 
plane to the axis of minimum elasticity, Z, gave angles of 45 
degrees. The mineral is evidently not pure diopside, but 
whether it varies toward hedenbergite or toward augite would 
be difficult to determine without chemical analysis. It is 
referred to as diopside. The quantity is somewhat in excess 
of the plagioclase. 

The magnetite is seldom in euhedral crystals, more often 
in fine dust or in trellis-like or fir-tree groups. During the 
erystallization of the plagioclase and diopside the magnetite 
appears to have been mechanically pushed aside until the last 
stages of crystallization were reached, and then included within 
the final er ystals of the lighter constituents, to which it gives a 
dark brown color. Even in the final stages the plagioclases 
seem to have had the power to free themselves of the magnetite 
dust fairly effectually, and most of it is included within diop- 
side grains. A small portion is enclosed within irregular 
patches of light-green chloritic material, which may represent 
resorbed olivines “subsequently chloritized. 

Tn addition to these essential constituents there are a number 
of well-defined areas of what was originally olivine, but which 
show strong resorption and later alteration to serpentine and 
chlorite. 

The magnetite in these rocks is probably titaniferous, as it 
gives rise on decomposition to milky-white leucoxene. 

In examining those slides which have the texture normal to 
basalts the plagioclases appear to have the crystals developed 
in more nearly euhedral forms than the diopside, and it might 
be argued that this is confirmatory of the generally accepted 
view that the growth of the plagioclases was finished before that 
of the diopside began, and that the latter minerai molded itself 
around the plagioclase. It is only necessary, however, to 
devote a little study to the question to determine that this is 
emphatically rot the case. In those vitrophyrie rocks first 
described (e. g. No. 105 and No. 57) in which plagioclase and 
diopside undoubtedly developed while swimming freely in a 


296 0. N. Fenner—Crystallization of a Basaliic Magma 


liquid, the plagioclase is bounded by plane faces, while the 
diopside has irregular outlines, and it appears that this differ- 
ence in development is due to the mode of growth, the cause 
of which is not germane to the subject. When, in the more 
glassy types, the plagioclase and diopside form groups of 
intergrown crystals, as they often do, the characteristic form 
is shown in fig. 7, a notable feature of which is the manner 
in which the plagioclase laths wedge out toward the central 
portion of the diopside grains. 


Fig. 7. 


Fie. 7. Intergrowth of diopside and plagioclase. (Slides Nos. 2 and 57.) 


These features are apparent in all phases of development of 
the basalt from glassy to holocrystalline, and alone would be 


Fie. 8. 


Fic. 8. Modification of forms of plagioclase and diopside resulting from 
simultaneous crystallization. A few magnetite grains (black) and some 
chlorite (gray) are also present (Slide No. 64). 


almost conclusive evidence of simultaneous growth of the two 
minerals. 


from the Standpoint of Physical Chemistry. 227 


In the holocrystalline phases the plagioclase gives, at first, 
Fie. 9. 


an impression of being much more euhedral 
than the diopside, but it is almost impossible 
to find a crystal in which the symmetry is not 
destroyed by encroachment of diopside, and 
the extremely irregular growth of plagioclase 
sketched in fig. 6 (Slide No. 47) and fig. 8 


(Slide No. 64) is entirely normal and charac- ACA 
Fie. 9 Inter- 
teristic. : . : > : erowth of magne- 
The magnetite is often in such fine evans tite, diopside, and 
that no conclusions can be drawn regarding plagioclase (eutec- 
its period of growth, but in No. 23 it is found ds Ae oan Hea 
in better developed crystals, which show un- eee 
mistakably a simultaneous deposition with plagioclase and 
y S 


diopside. Fig. 9 shows the general relations. 


Part ILI. 


The Crystallization of a Magma as affected by the 
Law of Mass-Action. 


It was pointed out on a preceding page that in order that the 
crystallization of a magma should follow strictly the laws of 
eutectiferous solutions the compounds present in the fusion- 
solution should have no inter-reaction during crystallization, 
but that simply the freezing-point of each should be depressed 
by the presence of the others and each should begin to crystal- 
lize at the appropriate temperature as thus modified. In the 
Watchung magma it appears that this ideal course was nearly 
realized as regards the final products of crystallization, and in 
many other cases this is probably true, especially where the 
range of temperature from the beginning of erystallization 
until the final consolidation of the eutectic is not large and 
where great variations of pressure do not occur. Reference 
was made, however, to resorbed olivines which appear in 
certain slides, and resorption-phenomena are of common occur- 
rence in the study of igneous rocks. Their chief features are 
explainable by the law of mass-action. 

It is well understood that when substances capable of 
reaction are brought together in a solution the reaction does 
not ordinarily proceed to completion, but that in principle 
every reaction is reversible and the degree to which a reaction 
will proceed under given conditions of temperature and 
pressure is dependent primarily upon the concentrations or 
active masses of the substances participating. 

In solutions of molten silicates it is recognized that we have 
very little knowledge of the extent to which reactions proceed 
to attain equilibrium; but we know that the state of equili- 


228 0. NV. Henner— Crystallization of a Basaltic Magma 


brium, i.e., the proportions in which various mineral compounds 
exist in the solution, depends upon the concentrations of the 
various oxides present. 

If we imagine that in a solution of this nature in which 
equilibrium has been attained, crystallization begins, it is seen 


e ° co) 
that a disturbing factor is introduced; for the removal by 


erystallization of one or more compounds is constantly chang- 
ing the relative proportions of the substances left in the 
mother-liquor. It is evident that certain substances which 
may have been present in small amount in the original magma 
may reach a high degree of concentration in the residual dr COS 
of mother liquor. The conditions of equilibrium are com- 
pletely shifted. New compounds are formed, while those 
compounds which were present in preponderant amount in the 
original magmatic solution may be entirely broken up and 
destroyed. ‘As a result the crystals first deposited become 
unstable in contact with the mother-liquor and are either taken 
up by the solution or react with it to form zones of new min- 
erais. ‘This consequence of the principle of mass-action is well 
understood. Pirsson has thus explained reaction-rims of ensta- 
tite and biotite surrounding olivine erystals and separating 
them from alkali.feldspar in the shonkinite of the Little Belt 
Mountains, Montana.* 

While it is possible to account for certain phases of the phe- 
nomena of resorption in this manner, there are others which 
cannot be brought into hne with this explanation. Magmas 
consolidating at depth frequently exhibit a different association 
of minerals from magmas of the same composition consolidat- 
ing on the surface ; and a magma in which intra-tellurie erys- 
tallization has begun may, when er upted at the surface, attack 
the minerals first deposited and take them more or less com- 
pletely into solution, and in the final consolidation these min- 
erals may not re- appear. In the Watchung magma olivine 
erystals of the intra-telluric period were attacked and in most 
cases almost. completely resorbed before any notable develop- 
ment of the three final products of surface crystallization 
appeared. In this case it is obvious that the phenomenon 
cannot be explained by reference to a concentration of material 
in a residual mother-liquor. To account for such occurrences 
the author would offer another explanation, based upon the 
displacements of equilibrium which take place within a solu- 
tion under conditions of simultaneous diminution of pressure 
and temperature. 

Displacements of equilibrium within a solution effected by 
changes of temperature and pressure —vawt Hof’s law,—The 
extension of the law of mass-action to include changes of tem- 


*L. V. Pirsson: 20th Ann. Rept. U. 8. Geol. Sur., 1898-99, p. 482. 


From the Standpoint of Physical Chemistry. 229 


perature was developed by van’t Hoff. The principle is of 
gyeat importance, but it does not appear to have received the 
attention it merits in the study of petrological problems. 

The basic principle of van’t Hoff’s law is that.change of 
temperature displaces the equilibrium within a-solution. If, 
then, crystallization of a magma can be brought about, in one 
ease at a higher and in another case at a lower temperature, 
the chemical state of the solution as regards compounds exist- 
ing within it will be different in the two cases. Change of 
pressure between the depths of the earth and the surface is an 
effective agent in changing the temperature at which crystalli- 
zation begins. Pressure alone, as has been pointed out by 
several writers,* is not capable of causing great variations in 
the melting-points of minerals; but it is quite conceivable, and 
in fact probable, that within a complex solution the variation 
of the temperature of crystallization caused by relief of pres- 
sure is often attended by displacements of equilibrium, such 
that reactions proceed further in one direction or another and 
the relative proportions of the various compounds present is 
altered. These displacements of equilibrium find correspond- 
ing expression in the point at which crystallization is initiated 
and in the minerals deposited. The change thus begun tends 
to progress continuously in the same direction and may result 
at the final consolidation in an association of crystallized prod- 
ucts quite different from what would be found under conditions 
of greater pressure.t+ 

* A. Harker: The Natural History of Igneous Rocks, New York, 1909, pp. 
163 and 194. 

+ The effects of temperature and pressure upon reactions within a system 


of the nature of a magmatic solution are expressed by two fundamental equa- 
tions. ‘he first is van’t Hoff’s formula 


= Wayep — al =) 
log K og Kay, OT 
in which K’ and K are the constants of mass-action at the (absolute) tem- 
peratures T’ and T, q is the heat of the reaction per unit considered, and R 
is the gas-constant (= 2 cal.) 

From this equation it follows that with decrease of temperature (T greatcr 
than T’) a reaction which evolves heat (q positive) is driven forward or in 
that direction in which heat is given out. (It will be noted that this is in 
accord with Le Chatelier’s theorem.) 

If, forexample, two substances, A and B, unite to form AB with evolution 
of heat, the formation of the compound AB will increase as the temperature 
is lowered, and the greater the value of g the greater will be the amount of 
the compound formed. 

The eifeet of pressure in inducing crystallization at a higher temperature 
is expressed by the formula 

BYE oe w 

APS Dee = v2) 
in which Ap is the pressure required to cause crystallization to begin at the 
temperature increased AT degrees above the normal crystallizing point, zw is 
the latent heat of fusion, T is the absolute temperature, and 7, and v2 are 
the specific volumes of the substance in the liquid and solid forms respectively. 


230 C. VN. Fenner—Crystallization of a Basaltic Magma 


Resorption of Olivine in the Watchung Basalt. 


In hand specimens, both of the vitreous and the aphanitie 
varieties of the Watchung basalt, small, dark-green spherulitie 
bodies can often be seen. They appear in many of the thin 
sections and are found to be built up of concentric shells of 
hghter and darker material of chloritic or serpentinous nature. 
A typical example is shown in slide No. 105 (fig. 10). 

The diameter of the spherulite is about 0:27", but larger 
ones are not uncommon. The central portion is composed of 
comparatively large blades of radial 
chlorite, decidedly birefringent. The 
outer shells are very feebly polarizing 
and appear to be made up of minute 
scales of chlorite mingled with isotropic 
glass. Beyond the border of the spheru- 
lite the normal vitrophyrie structure is 
found, consisting of small crystals and 
grains of feldspar and diopside and 

brown microlitic tufts, set in the paste 

His, 10) Oblorivic nod= of glass, Im this case recorpmomeama 
ule in vitrophyr (Slide No. . 

105). alteration have progressed so far that 

there is almost nothing suggestive of 
the manner in which the spherulite originated, but in other 
cases the evidence is plain. Outlines of some original min- 
eral are left, to whose resorption by the magma the spheru- 
lites are attributable. None of the mineral itself remains, 


“oz. ) 


EG lle Fie. 12. 


Fig. 11. Partially resorbed olivine, subsequently altered. (Slide No. 
100.) 

Fic. 12. Separation of oxide of iron along cracks in olivine crystals 
which have been replaced by secondary products. 


the crystal outlines being filled with chlorite, calcite and 
other alteration products. These retain certain features, how- 
ever, which point strongly to olivine. 


From the Standpoint of Physical Chemistry. 231 


All stages of resorption appear in different parts of this 
slide. An example is sketched in fig. 11. Without the analy- 
zer the corroded forms shown in heavy hnes in the sketch 
(now replaced by calcite) are all that appear, but with crossed 
nicols the erystal form, almost complete, is brought out in 
serpentine. Immediately adjacent are remnants of several 
other crystals which the crossed nicols similarly outline. 

In fig. 12 the typical manner in which oxide of iron has 
separated along cleavage cracks of the original mineral is 
shown, although nothing but alteration products survive. The 
resemblance to olivine is obvious. 

From such examples one may pass by gradual transition to 
the results of almost complete resorption, in which the rounded 
and blurred outlines convey only a vague suggestion of the 
original form of the crystal, and upon whose areas, spreading 
out into the glass, microlites are encroaching. The color in 
such cases is pr actically the same as that of the surrounding 
glass, but crossed nicols show the presence of aggregates of 
minute chlorite scales. 

The stages of the process and the relations which the olivines 
bear to the plagioclase and diopside are sketched in fig. 13. 
Similar phenomena are shown in slide No. 83, in No. 30, 
and in No. 48. In No. 57 the several steps can be followed 
very perfectly. 


IRS 1133. 


Fic. 18. Breaking-up and resorption of olivine. Several stages, found 
in various portions of the slide, are brought together. (Slide No. 105.) 
Diameter of field 1°5™™, 


In No. 54 the outline of an original olivine crystal is pre- 
served, but most of the area within the boundary of the 
original crystal is occupied by a mixture of brown glass and 
irregular grains of a dark brown color. This form of attack 
upon the olivine, by which the crystal has been broken up 
into many fragments, appears to have been common, and the 
brown grains show up in many of the slides, at times associated 


282 OC. WV. Fenner 


Orystallization of a Basaltie Magma 


with chloritic areas retaining a suggestion of a erystal unit, 
and again scattered through the glass. 


Lidice 


Fie. 14. Inclusions in glass, resulting from the breaking-up of olivine 
erystals. (Slide No. 17.) Diameter of field 1:6™™. 


These effects are shown in slide No. 17, sketched in fig. 14. 
The greenish glass is filled in places with brownish inclusions, 
arranged in erescentric or cusp-like figures. The inclusions 
appear to be in part surviving fragments of olivine, and in 
part magnetite dust set free in the reaction. The figures 


Ie! 105). 


Fie. 15. Effects of resorption of olivine accentuated by secondary altera- 
tion. (Slide No. 54.) Diameter of field 1:o™™. 


assumed would appear to be due to the manner in which the 
resorbed material was diffusing in the surrounding magma 
when increasing viscosity terminated the process. Diopside 
and plagioclase are present in minor amount. 

A slight degree of subsequent zeolitic alteration of glasses 
containing partially resorbed olivines serves to accentuate the 
features described. This is seen in slide No. 54 (fig. 15) and 
in many other cases. Even in advanced stages of secondary 
alteration traces of these features persist. 


From the Standpoint of Physical Chemistry. 233 


In all cases the olivine shows unmistakably that corrosion 
had attacked it and that it was in process of resorption by the 
magma, from which plagioclase, diopside, and magnetite were 
beginning to erystallize. At some point in the history of the 
magma the olivine which was first deposited became unstable 
and would undoubtedly have gone completely into solution if 
sufficient time had been allowed. It is noticeable that in the 
later erystallization olivine did not again appear as one of the 
products. It must follow, therefore, that the olivine molecule 
which was absorbed underwent some change within the solu- 
tion by which it entered into new combinations. 

Considered from the standpoint of the principles previously 
developed, the most probable explanation of the resorption of 
the olivine appears to be the following: Before extrusion the 
magma had cooled sufficiently so that erystallization had begun. 
Inasmuch as most rock-forming minerals occupy less volume 
in the solid than in the fused condition, the great pressure to 
which the magma was subjected aided erystallization, so that 
it was Initiated at a somewhat higher temperature than would 
be the case under less load. The effect upon the crystalliza- 
tion of a given mineral would vary inversely as the heat of 
solution and directly as the difference in volume between the 
two states. Pressure may also have had an appreciable effect 
upon the direction of reaction within the fusion-solution. 

Olivine was the chief mineral deposited under these con- 
ditions but there are indications that a little plagioclase had 
also begun to crystallize out. (In slide No. 47 a large plagio- 
clase crystal shows some indication of zonal structure, most 
probably developed during this period.) 

When extrusion of the magma occurred it was attended by 
great changes in all the physical conditions. 

Diminution of load would be a factor of prime importance 
in causing the minerals which had erystallized out to be 
resorbed. The loss by volatilization ‘of aqueous and other 
vapors also affected the combinations existing within the solu- 
tion. It can hardly be supposed that the vapors evolved 
existed in the solution entirely in the combinations in which 
they were given off. Undoubtedly a portion of the vaporized 
material was combined with the nonvolatile portion and its 
removal from the system necessitated more or less readjust- 
ments of equilibrium throughont. 

Under these circumstances it is not surprising that most of 
the olivine which had been deposited was taken up by the 
magma. Still if the olivine molecule continued its existence 
in the re-fused mixture it would be redeposited when the appro- 
priate temperature was reached under the new conditions, but 
it appears that the lower temperature to which the initiation 


Am. JOUR Sci.—FOuRTH SERIES, VoL. X XIX, No. 171.—Marcu, 1910. 
16 


234 OC. WV. Fenner— Crystallization of a Basaltie Magma. 


of crystallization was carried, together with the other disturb- 
ing factors, resulted in an entir ely new chemical arrangement. 
The olivine molecules which were resorbed thereby lost. their 
entity, being distributed among other compounds in a manner 
which cannot be completely followed, and olivine as such did 
not reappear among the products of crystallization. 

The fact that remnants of the olivine persist is due to lack 
of time given for resorption before increasing viscosity put an 
end to the process. Under somewhat different conditions, 
easily conceived, the less complete resorption of a mineral 
would be attended by the formation of reaction rims, or 
replacement by an aggregate of other minerals; or its slow 
solution in a magma in which crystallization was far advanced 
would constantly change the composition of the mother-liquor, 
with consequent displacements of equilibria. Im the case 
studied the resorption or solution was nearly complete before 
the second period of crystallization began, and the effect as 
regards complexity of results was almost a minimum. 

Petrographic Laboratory, 


Columbia University, 
Nov., 1909. 


bo 
or 


Goldschmidt and Parsons—WNotes on Goethite. 3 


Art. XVIII.—Wotes on Goethite* (Abstract); by V. Gotp- 
scuMipt (Heidelberg) and A. L. Parsons (Toronto). 


Iy the summer of 1908 Mr. Parsons collected some speci- 
mens of goethite which occurs in veins in carboniferous shale 
at Walton, N. S. The veins are brecciated and the center 
filled with calcite. When the calcite was dissolved in hydro- 
chloric acid the goethite was left as a druse of bright crystals. 


nek. Fig. 2. 


Three crystals were measured. The observed forms are: 
6=00(010); M=20(210); a=x0(100); y= (110); 
mee ott) 6 — OL (011)5 4 = 10 (101); p=1011); p = 
31(311). The form designated as XX appears in all the erys- 
tals as the face with the greatest development. This face is 
striated lengthwise and is not a single face but a transition 


* Abstract of a paper in Groth’s Zeitschrift fir Krystallographie. 


bo 
os 


3 Goldschmidt and Parsons—LNotes on Coethite. 

face or “ Scheinflaeche,” and it gives a bright band of light in 
the prism zone with the angle @ varying from 3° to 20°. In 
this band are bright points which imperfectly indicate the 
positions of the faces 0 3 (180), « 4(140), 0 5 (150), « 6 (160), 
o (180), 0 12(1:12°0). The harmonic discussion of the char- 
acteristic diel in this series gives 0 3, 04, 06, and «8 as 
the points of best position, but no characteristic letter is assigned 
to them until they have been determined by single distinct 
reflecting faces. The symbol XX is used for the series and in 
figure 2, o 4 represents the series. 

For comparative purposes three crystals from Lostwithiel, 
Cornwall, were measured and the habit and faces are shown in 
figure 1. he observed norms are) = 0ao (O10). il zee 
(CRD Resi eo (a0) v7 == col). ) == co B(120))- u=10 Gon): 
ga Ul (011); p=l (111); w= 41 1 (413), All the forms except 
a were present on every crystal. The new form w = $0 (480) 
was present on two crystals and for the best reflections gave 
angle @ 55° 6" and 55°33’. A poor reflection gave one face as 
57°27’. Angle p was in every case 90°. The caleulated 
angles are @ 55°26’, p=90°. The face is small but well 
defined, and may be regarded as well established. The form 
w= Ft (413) i is also new and is present on all three crystals 
with four faces on each. The faces reflect well and give a dis- 
tinct signal cross, but it is worthy of remark that the reflection 
is sliohtly yellow while the others are white. The, angles 
agree well among themselves, but in every case the angle p is 
2” to 69’ less than the calenlated angle. The calculated 
angles are d = 77° 4’, p 42° 6. Considering the good character 
of the reflection and the sharpness of the faces, this difference 
is not easily understood, but the form may be considered as 
well established. 


Heidelberg, Aug. 14, 1909. 


Van Name and Edgar— Velocities of Certain Reactions. 237 


Arr. XIX.—On the Velocities of Certain Reactions between 
Metals and Dissolved Halogens; by RK. G..Van Name 
and GRAHAM Ene ar. 


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


In a reaction between a liquid and a solid, according to the 
so-called diffusion theory of reaction velocity, a thin layer of 
liquid adhering to the solid remains unaffected by stirring, 
and the reaction is maintained by the transport of dissolved 
substances across this layer by diffusion. When the diffusion 
is sufficiently slow compared with the other stages of the reac- 
tion, the velocity of the whole will be determined by the rate 
of diffusion alone. 

This theory was proposed by A. A. Noyes and W. R. 
Whitney,* in 1897, for the special case of the solution of a 
solid in a liquid, but Nernst and E. Brunnert were the first to 
suggest its general applicability to the various types of hetero- 
geneous reactions. It was tested by Brunner for cases of 
simple solution, neutralization, action of acids on metals, and 
for several electrolytic processes, and has since been accepted 
by various other investigators as giving the best explanation 
of the facts in the case of a number of other types of reac- 
tions,t including even gas and enzyme reactions. 

On the other hand, the validity of the diffusion principle in 
the case of reactions between metals and acids has been dis- 
puted by Ericson-Aurén and Palmaer,§ and R. Marec| has 
shown that the crystallization of supersaturated solutions of 
certain salts seems to follow a different mathematical relation. 
Recently the theory has been vigorously attacked by M. 
Wilderman,{| who holds that the hypothesis of a diffusion layer 
is improbable and unnecessary, and shows that the same velocity 
equation can be derived without it. Furthermore, Wilderman 
has found that the rate of solution of gypsum is not constant 
as the theory would require, but varies widely with its physical 
state, and is different on different surfaces of the same erystal. 

The experiments to be described deal with the rate of reac- 
tion between dissolved iodine and the metals mercury, copper, 
silver, cadmium, and zinc, also with those between bromine 
and mercury, and between cupric bromide and mercury. The 
work was undertaken with a view to testing the applicability 

* Zeitschr. phys. Chem., xxiii, 689. + Tbid., xlvii, 52 and 56, 1904. 

tSenter, ibid., li, 696; Teletew, Dissertation, Heidelberg, 1906; Jabl- 
ezinsky, Zeitschr. phys. Chem., lxiv, 748: Spear, Jour. Am. Chem. Soc., xxx, 
195; Bodensteln and Fink, Zeit. phys. Chem., 1x, 1; Schleuderberg, Jour. 
Phys. Chem., xii, 583. 

§ Zeitschr. phys Chem., lvi, 689. || Ibid., 1xi, 885 ; Ixvii, 470. 

“| Ibid., lxvi, 445. 


238 Van Name and Kdgar— Velocities of Certain Reactions 


of the diffision theory, and the results have proved to be in 
agreement with its requirements in all essential details. A 
similar field was covered by the work of Schiikarew,* in 1891, 
on the reaction velocities between metals and halogens, 
but the failure to provide for effective and constant stirring 
renders Schiikarew’s results uncertain. So far as known to the 
present writers, a few experiments by Brunner,t on the rate of 
solution of pure electrolytic zine in iodine, constitute the only 
real test of the validity of the diffusion principle for a reaction 
between a halogen and a metal, of which an account has been 
published up to the present time. Brunner does not give his 
results in detail but found the theory confirmed, especially in 
the fact the velocity constant agreed with that for the elec: 
trolytic reduction of iodine. 


Apparatus and Method. 


For all of our experiments the apparatus shown in the figure 
was employed. The liquid, an aqueous solution of iodine or 


m, metal disk. 
s, speed indicator. 


bromine with a large excess of the corresponding potassium 
halide, was contained in an ordinary beaker of about 11°5™ 


* Zeitschr. phys. Chem., viii, 76. yp Lowel 5 Jk, SM) 


between Metals and Dissolved Halogens. 239 


diameter and 1} liters capacity supported in a thermostat con- 
taining about 50 liters of water. Most of the experiments 
were conducted at 25° +0:1°; one, however, at 35°. In the 
reaction vessel was a two-bladed ‘elass stirrer of the ae m 
illustrated, the blades standing at an angle of about 45° to th 
vertical stem. The latter was attached to a brass shaft run- 
ning in a bearing rigidly supported above the beaker and 
terminating in a horizontal pulley. A speed indicator provided 
with a bell which sounded every 100 revolutions was attached 
above the pulley and kept permanently in position. 

The different metals were taken for experiment in the form 
of circular disks 40" in diameter and usually 0°6™" in thick- 
ness. or the experiments with mercury the disk was of pure 
gold heavily amalgamated. The holder for the disks was 
made of a thin class rod provided at its lower end with three 
branches bent at right angles to the stem and tipped with an 
easily fusible glass, which “orasped the disk at three points on 
its circumference. By softening one or more of these tips in 
the flame the disk was inserted so as to be firmly held with the 
minimum of contact between glass and metal. The glass stem 
was mounted in a cork which fitted into a brass socket in the 
form of a vertically slotted ring held by a stationary support 
above the beaker, so that the disk with ‘its glass holder could 
be quickly removed from the apparatus or returned to exactly 
the same position. When in place the disk was held as shown 
in the figure, with its plane vertical, opposite the blades of the 
stirrer and 5-7™™ distant from the wall of the beaker, so that 
the liquid circulated freely behind it. Care was taken that 
the relative position of disk, stirrer, and beaker should be the 
same in all the ace The stirrer was driven by an 
electric motor of ¢ horse power, and the different speeds 
obtained partly by interposing pulleys of various sizes and 
partly by adjustment of a rheostat in series with the motor. 
Variations in the speed of the stirrer were small and for the 
most part negligible in comparison with the other errors of 
experiment. 

The rate of fall in concentration of the free halogen was 
determined by removing samples of the liquid with a pipette 
at definite intervals and titrating. ee each two successive 


C 
titrations the value of the expression ; 3 In < > was calenu- 


lated and found, as required by the theory, to ee practically 
constant throughout each series; ¢, and c, being the concentra- 
tions of the halogen at times 7, and t.. and v the volume of 
the solution, which remains constant ‘during the interval in 
question. 


240 Van Name and HLdgar— Velocities of Certain Reactions 


From ‘the point of view of the diffusion theory the mechanism 
of the reaction is as follows: The weight of bromine or iodine 
which reaches and reacts with the surface of the metal in the 
time interval d¢ is the amount which can diffuse through the 
adherent layer of liquid in that time, that is, according to 
Fick’s law, it is proportional to the concentration fall across 
the layer. Owing to the rapidity of the chemical reaction the 
concentration of the halogen at the surface of the metal is 
always practically zero. At the outer surface of the layer it is 
equal to ¢, the concentration of the main solution. Hence the 
concentration fall is ce, and if m is the total weight of available 
halogen in the solution, 3 


dm 2 EN AGED) 
ae dt 


where K is the velocity constant. Integrated for constant 
volume this gives 


== 1Ke) 


i = 


i ca a In @. 
the expression referred to above. 

To assume that K is proportional to the area of the surface 
of contact, and to calculate upon this basis its value per unit 
of surface, is only permissible when the reaction takes place 
uniformly at every point of the surface. In the following 
tables this has not been done, since under the conditions of 
experiment the stirring could not have been equally effective 
on both sides of the disk. 

Finally, it should be mentioned that the above equation, 
though a necessary consequence of the diffusion hypothesis, is 
by no means dependent upon it, since it is nothing but an 
expression of the a@priori very probable assumption that the 
reaction velocity is proportional to the concentration of the 
halogen. 

Heperiments with Iodine. 


The iodine solutions were initially about 0-03—0-045 equiva- 
lent normal, and contained in different cases from 100 to 800 
grams of potassium iodide per liter (0°6 to 4°8 normal with 
respect to KI), the larger concentrations of potassium iodide 
being needed with the metals copper and silver to prevent the 
formation of a coating of insoluble iodide. 

In the experiments with mercury and iodine the procedure 
was as follows: The gold disk was immersed in clean mercury, 
a known volume (500—520°) of the solution was placed in the 
beaker, and the stirrer adjusted to the required speed, after 
which a 20° sample was removed with a pipette and delivered 
into a glass-stoppered flask for subsequent titration. The disk 


between Metals and Dissolved Halogens. 241 


_was then lifted from the mercury, the excess shaken off, and at 
a definitely noted time inserted in the liquid. Exactly at the 
end of the chosen time interval the disk was removed from the 
solution, rinsed with water and again inserted in the mercury, 
and another sample of the solution taken for titration as before. 
This cycle of operations was repeated as often as desired, or 


TABLE I. 


Rate of Solution of Mercury in Iodine at 25°. 


c ENG vo 1K Cc At v Kk 

eee s00m. AE per liter. . r=170 2. 100 g. KI per liter. r=240 

0:0381 500 : 0:0378 500 en 
00356 =? agp «8 0-0315 10 Ago oe 
$e 6 6:30 , 10 8°83 
0°0328 5-3 460 6-36 00260 10 460 8°89 
00304 57 440 6-35 0:°0213 10 440 8-79 

0:0279 : 420 ns 00172 420 
Ses 5 655 my 10 8°87 
0°0236 380 ree 0:0109 380 re 
Average 643 |. Average 8°81 


3. 200 ¢. KI per liter... r=170 4, 200 g. KI per liter. r—210 


0-034 5 510 (6-92 0-0288 10 510 8-49 
0-0319 490 : 0:0238 490 
or 10 718 : 10 8°64 
0°0274 470 0:0198 470 ; 
Ae 10 = 7°23 10 8°65 
0:0233 450 Bhs 0:0163 450 Sc 
£01 Q' 10 . 7:26 10 : & 49 
0°0197 10 430 7-90) 00134 7 430 8°45 
0:0165 410 0-0116 410 
Average 7:21 Average 8:04 


d. 200 g. KI per liter. r=240 On 00Rey Kel per liter) 7—300 
0:0372 0:0346 520 


0.0305 1p A800 DIIGO FR 500 aoe 
0:0248 460 ee ~ 0:0211 480 Ko 
: 10 9°73 MVE 10 A 11°34 
90199 10 440 9-63 0:0165 10 460 11-31 
00158 10 420 9°50 0:0127 10 440 10°82 
0°0125 10 400 9-38 0-00984 10 420 10°82 
0-00978 SCO are 0-00751 ADO ees 
Average 9°00 Average 11°12 

7. 400 g. KI per liter. r—170 8. 400 g. KI per liter. r=240 

0°0332 ‘500 oat 0:0439 500 ; 
re he AR0i iy er), ; 0°0850: | Fails) 2480, tae 
0°0236 10 460 8-09 0:0276 10 460 10:61 
0:0197 10 440 8-95 0:0219 10 440) 10°52 
00162 10 420 8:14 0°0171 10 420 10-48 
0°0132 10 400 8-39 0:0131 10 400 10°30 
001057 SEO) ah e. D.OL00N iia, Se Uneaiy as 
Average 8:14 | 000672 SOU: aa 
Average 10°48 


249 Van Name and Edgar— Velocities of Certain Reactions 


until the volume had been reduced to 380°, which was thought. 
to be a safe limit. Under these conditions the mercury goes 
into solution as the complex ion HgI,”, and no mercurous salt 
appears to be formed. The samples were carefully titrated 
with N/20 sodium thiosulphate, using starch as indicator. 
The burette used had been certified by the Berlin Reichsanstalt. 

In Table I are given the results of the experiments with 
mercury and iodine. The four columns taken in order contain : 
1st, the concentration ¢, of the iodine in gram atoms per liter*: 
2d, the time interval Az (the same as ¢,—7,), in minutes; 3d, 
the volume v, in cubic centimeters ; 4th, the velocity constant, 
K, as calculated by the equation above. The speed of stirring, 
in revolutions per minute, is denoted by 7. In this and the 
following tables abnormal values of the constant, indicated by 
parentheses, have been disregarded in caiculating the averages. 
It may be stated in this connection that the experiments recorded 
in this article include all that were made with the exception of 
preliminary experiments and a few affected by known errors. 

On comparing the experiments carried out with like rates of 
stirring it is evident that the velocity of the reaction is greater 
the higher the concentration of the potassinm iodide. ‘This 
effect of the iodide will be equally conspicuous im the experi- 
ments with other metals, and will be discussed later. An 
increase in the rate of stirring also accelerates the reaction, as 
was to have been expected, the value of the constant being 
here approximately proportional to the 4/5 power of 7. 

To obtain the temperature coefficient of the reaction a 
single experiment was carried out at 35° with the following 
result : 


Lop. 9.—Mercury and Iodine at 35°. 

100 g. KI per liter. n= 240 
eG (Oe eee eae ta) il aie 11°59 
Average tleas 


The ratio of this constant to that of experiment 2 gives 1:3 
as the temperature coefficient for 10°. This is in sharp con- 


| : 
trast with the usual value of Kuno 


t 

neous systems, which is on the average about twice as large. 
In the experiments with metals other than mercury the 
method followed only differed from that just described in that 
the metal disk, after its insertion into the solution, was allowed 
to remain in position until the close of the experiment, and the 
calculations were based upon the time intervals between suc- 


for reactions in homoge- 


* Halogen concentrations are expressed in these units throughout this 
article. 


between Metals and Dissolved Halogens. 243 


cessive fillings of the pipette. As the filling process occupied | 
less than five seconds, the time was easily defined with sufficient 
accuracy. 


TABLE II. TaBLeE IIT. 
Copper and Iodine at 25°. Silver and Iodine at 20°. 
€ At v K | c At v K 
1. 400 g. KI per liter. r—170 {400% = Ket per liter. 7——1S0 
00347 500 wie, || 00405 ipa ees 
eee gy | 90340 29 ag BP 
10 SOR | NIRS 10 8°49 
0-0248 AG0e aaat cerns (es 020283 460 ‘ 
10 i999 | E 10 8:14 
0-0207 440 ow, 0°0235 440) 
10 Sis | 10 5 8:17 
0:0172 10 A20 Re Gin o| 0:0198 10 420 7.98 
0:0141 400 ||  0-0159 10 400 8.95 
Bear enti 1001280 380) 


Average 790 | --— 
Corrected 7:95 |. Average 818 
Corrected 8:23 


2400 & Ki-per liter, r=240 
0:0277 620 


CaS) 


400 g. KI per liter. r=240 


10 8-78) || ss S 
e239 5, os | C0 1 S00 gee 
00202 580 Fs 00358 480 eG 
2 10 a 9-78 NORY 10 10 13 
0:0169 560 : 00287 460 = 
= 10 9°69 “92 10 9°" 
0:01415 540 : | 0°0230 4A me 
10 ; 9°38 : 10 5 9°65 
0-01181 10 520 9-53 0:0183 10 420) 9-69 
0:00976 10 500 Pe eeeOO143 10 400 9-80 
0:00796 480 ees Heres OG OTST SOO Hi ssiue 
Average 9°67 | Average 9°87 
Corrected* 9:98 Corrected 9:93 


3. 800 g. KI per liter. r=240 


0-0378 10 500 (9-91) 
0-0304 49 {99 

OAS 10 10°20 
0°0245 460 ; 

0192 10 10°31 
0°0192 440) ae 
0-0151 ay ee 

: es 10 10°30 
0:00894 380 


Average 10°21 
Corrected 10°27 


* The disk was below standard size both in diameter and in thickness. 


Table II contains the results obtained with copper. The 
disks were cut from a good quality of commercial sheet copper 
of the same diameter (40™") as the gold mercury disk, but 
were slightly thimner at the outset, and during the experiment 
of course became still thinner, though the diminution of sur- 
face area from the latter cause was barely appreciable. From 
measurements made before and after the experiment the aver- 


244 Van Name and Kdgar— Velocities of Cn Lreactions 


age thickness was estimated, and the necessary on corréction 
calculated and applied to the mean value of the velocity con- 
stant. Where “corrected” values of the constant are given 
in this and the following tables the corrections have been made 
necessary by slight deviations of this kind from the normal 
dimensions. In cases where no correction is mentioned the 
disk was of the standard diameter and thickness. 

A relatively high concentration of potassium iodide was 
found to be necessary in the work with copper. An experi- 
ment carried out with a concentration of 200 grams of the 
iodide per liter was a failure owing to the for mation of a layer 
of insoluble cuprous iodide on the disk, which caused a rapid 
fall in the value of the constant. Even in the presence of 400 
grams of potassium iodide per liter traces of such a film were 
noticed at the close of the experiment, although, as the table 
shows, fairly good constants were obtained. With 800 grams 
per liter no visible film was formed. 

With silver the same ditticulty was encountered. A concen- 
tration of 200 grams per liter of potassium iodide was not 
enough, and 400 grams per liter barely sufficient, to prevent a 
decided interference with the reaction by a coating of silver 
iodide on the metal. The disks were cut from a very pure 
sheet silver and were a little below the standard thickness, so 
that a correction had to be applied to the values of the veloc- 
ity constant as in the case of copper. The results are given in 
Table ILL. 

For the experiments with cadmium, recorded in Table IV, 
Kahlbaum’s metallic cadmium was employed. This was cast 
into thick disks which were either rolled out to the proper 
thinness or ground down with emery. Experiment 1 was 
made with a disk of rolled metal, experiments 2 and 3 with 
cast and ground disks. The more crystalline nature of the latter 
was apparent after the action of the iodine; in fact, these two 
disks showed more roughening of the surface during the experi- 
ment than was the case with any of the other metals investi- 
gated. Even here, however, the roughening was comparatively 
slight, and seems to have affected the value of the constant but 
little, although experiment 2 shows a rise in the constant which 
may be due to this cause. 

In order that the constants might be comparable with oe 
obtained with mercury, the concentration of the potassium 
iodide in the work both with cadmium and with zine was fixed 
at either 100 or 200 grams per liter, a much larger amount, in 
view of the ready solubility of the iodides of these two metals, 
than would otherwise have been needed. 

The zine disks used in the experiments of Table V were 
prepared by casting and grinding into shape from a sample of 


between Metals and Dissolved Halogens. 245 


TABLE LV. 


Cadmium and Iodine at 25°. 


c At v K c ‘At v K 
Peres Keb per liter. r=176 | 2. 100 g. KI per liter. r=240. 

0-0364 BOOT cyt | ee 0c0a29 500 
0-0340 2 Ce Abe 0-0301 : FETT ars 
0:0318 5 460 (5-95) 00274 5 4608.49 
0-0276 x 420 B98 _ 0:0214 6 420 9.93 
00255 = 400 6-28 0:0195 6 400g. 
0°0235 2 SSO) | SOLON O) SS) aiee 
Average 6°29 Average 8°69 

Corrected 6°36 


C At v IKE 


d. 200 g. KI per liter. r=240 


0-0387 : BOO. Bees 
00350 3 HO area 
0:0316 2 A603 
00283 AO ess 
0-0253 : OE a 
00224 2 LOO ei 
00197 320 


Average 9°56 


metal of high purity, obtained from Kahlbaum. Experiments 
carried out in the same manner as those with cadmium and the 
other metals gave low and rapidly diminishing values of the 
constant. On examining the disk at the close of such an experi- 
ment a whitish semi-transparent film could be seen on its sur- 
face which proved to consist of zine hydroxide, evidently 
formed by hydrolysis of the zine iodide. 

To obviate this diticulty the iodine solutions were made 
1/100 normal with respect to sulphuric acid, after it had been 
proved by trial that sulphuric acid of this strength had no 
appreciable effect upon the very pure zine of the disks. This 
expedient proved effective and at once gave normal values of 
the constant. 

According to Schiikarew,* the reaction between zinc and 
iodine is retarded by the presence of zinc iodide, but no figures 
are given in support of the statement. As the reaction is non- 
reversible such an effect would hardly be expected. To test 
this point, ten grams of zinc iodide, prepared by direct action 
of the two elements, was added at the outset to the solution in 
experiment 4, which in other respects was carried out exactly 


* Zeitschr. phys. Chem., viii, 81. 


246 Van Name and Kdgar— Velocities of Certain Reactions 


TABLE 


Zine and Jodine at 25°. 


Cc At v K. Cc at v Ke 


ie LOO ee Kis persliier en —se 2. 100 g. KI per liter. r=240 


H.SO,=N/100 H.SO,=N/100 
00339 500 00371 500 

0-0316 2 age 78S 0-0339 : 480 ee 
00292 5 460 4.ng 0:0309 2 460 bg 
00270 440 & 99 0 0280 4 440 oe 
00249 5 420 6.99 0:0253 5 420 6.60 
0-0228 2 400 von 00227 : 400. Ginn 
0-0207 z S807 at ake 0-0202 380 4) eae 
Average 7:03 Average 8:64 

3. 200 g. KI per liter. r=240 4. 200 g. KI per liter. r=240 

H.SO.=N/100 20 g. Zul. per liter. 
00300 BU aes H.SO,=N/100 

0-08538 Pp 480 9.71 00402 : 500 
00318 ? Hae is 0-0364 3 Mey 
0:0225 : 400 a 0:0264 d 420) 9°52 
D 9°60 5 ee 9:55 
0°0198 380 0:0235 2 400 Gro 

eae 
Average 9°64 00207 380.7) soe 
Average 9°40 


like experiment 8, using the same zine disk, repolished. 
Untortunately, through an oversight, the disk was not re- 
measured for experiment 4, so that the correction for dimin- 
ished thickness can only be roughly estimated. Allowing for 
a correction of 0:04-0:08, the constants for experiments 5 and 
4 agree to within the possible error of experiment, so that they 
can not be considered to confirm the observation of Schukarew. 
Owing to lack of time this point was not further investigated. 


Bromine and Mercury. 


Bromine dissolved in potassium bromide solution of sufficient 
strength reacts with mereury in much the same way as lodine. 
Such a solution has, however, a considerable bromine vapor 
pressure, and to measure the rate of reaction with a metal the 
evaporation of bromine must either be prevented or a correc- 
tion must be apphed. We have followed the latter method. 

If the reaction with the metal is conducted and calculated 
as in the case of iodine, disregarding the evaporation of bromine, 
a fairly good constant is nevertheless obtained. ‘The reason 
for this is obvious. The vapor pressure of the bromine is 
approximately proportional to its concentration in the solution, 


between Metals and Dissolved Halogens. 247 


so that the rate of evaporation (for constant volume and 
constant free surface) must be proportional to the concen- 
tration, and will follow a mathematical expression of the same 
form as that which holds for the reaction with a metal. To 
correct the observed velocity constants it is therefore only 
necessary to subtract from them the velocity constants for the 
evaporation of bromine, as determined by separate blank 
experiments under like conditions. 


TaBLE VI. 
Evaporation of Bromine. 
Temperature 20° 400 g. KBr per liter. r= 240 
' At 0 a 
. Se min. GG: ie 
a 
0:02882 0:02767 500 
0-02418 002322 2 500 ee 
0:02027 0-01946 15 500 4-37 
0:01707 0:01639 15 500 led 
0°01484 0:01377 15 500 4-09 
0-01218 500 pais 
Av. 4°38 
2. 
003262 0:03117 ps 450 
0-02669 002550 ie 450 fee 
0:02171 002074 15 450 4-89 
0°01766 0:01688 15 450 (5°47) 
0-01406 0:01344 15 450 4-8] 
0°01145 0:01094 15 450 Ao 
0:009335 : 450 pean 
Av. 4°77 
3. 
003526 0:03350 400 
002764 002626 1B 400 a 
0-02165 002057 15 400 5-97 
001687 001603 is 400 Tey 
0°01333 0-01266 1b 400 4-88 
0-01054 400 eee 
Av. 95:06 


in practice the rate of evaporation of the bromine increases 
as the volume diminishes, owing to the increasing concavity 
of the surface of the solution caused by the rotary stirrer. 
The blank experiments recorded in Table VI were therefore 
carried out at constant volume, which was accomplished by add- 
ing to the liquid, immediately after withdrawing each sample 
for analysis, an exactly equal quantity of fresh potassium 
bromide solution. The resulting bromine concentrations were 
readily calculated, and are given in the column headed ©’, 


248 Van Name and Ldgar— Velocities of Certain Reactions 


while the concentrations directly indicated by the titrations 
are given under ©. It will be observed that each C’ denotes 
the concentration of the bromine at the beginning of a time 
interval Az, the concentration at the end of the same interval 
being that value of C which is found in the table on the 
horizontal line next below, so that the equation by which the 
constant K” is calculated takes here the form 


aon ee Gn! 
KY ee ae 


The analyses, both here and in the later experiments with 
mereury, were made by running each sample from the pipette 
into an excess of potassium iodide solution and titrating the 
iodine in the usual way. 

From the mean values of K” in the three experiments of 
Table VI the following values were obtained by graphic 
interpolation : 


TaBLE VII. 
log oF 
Cy 
v Kk" LOG At —wli 

480 4°55 
460 4°70 0°0044 
440 A°84 0 0048 
420 4°96 0°0051 
400 5°06 0°0055 
380 5°15 0:0059 


In the experiments with mercury and bromine the same 
method was followed as in those with iodine, but with atten- 
tion to certain details which were previously not important. 
The pipette was filled immediately after each removal of the 
disk from the solution, and the time during which the disk 
remained out of the liquid was limited to exactly one minute in 
each case. The concentration changes due to loss of bromine 
during each such interval were calculated with the aid of the 


/ 


above values of loge - Table VIII contains the results of 


: ; 
two parallel experiments on the rate of solution of mereury in 
bromine, with the necessary corrections applied. Under ¢ 
are the bromine concentrations as determined by direct analysis, 
under c’ the (calculated) concentrations at the moment of 
inserting the disk. The concentrations at the beginning and 
end of the same reaction period AZ are therefore given respec- 
tively by ¢’ and that value of ¢ which stands on the next line 
below. K’ is the combined velocity constant for the solution of 
mercury and the evaporation of bromine. K is the velocity 
constant for the solution of mereury alone, obtained by sub- 
tracting from K’ the corresponding value of K”, as given in 


Table Vik 


between Metals and Dissolved Halogens. 249 


TasBLE VIII. 


Mercury and Bromine. 


Temperature 20° 400 g. KBr per liter. r= 240. 
, At 4) ! 
¢ & min. ec. kK K 
if : 

0-03133 0-03133 500 oe 
0:02658 0:02630 2 480 Gone cS ®) 
0-02188 0:02162 y 460 

: prides 5 17°10 12°26 
0-01780 0:01759 440) nal ee 
0-01434 001416 _ 420 17-19 19-11 
001142 001126 9 400 17-08 11°88 
0:00900 3 380 

NN Pes 
2, 
0-02919 0:02919 ‘ 500 ns, 
0-02494 0-02469 GATT, aa ee co) 
0-02047 0-02025 oe inte see ee 
001654. 0 01634 2 440 17-397 san 
0-01330 0-01318 : 420) 1743 19-06 
0-01060 0:01046 400 es fscie 
000832 380 4 spa 
Av. 12°40 


Owing to the method by which they were obtained these 
constants are necessarily somewhat more uncertain than the 
iodine constants. A comparison between the two is rather 
unsatisfactory on account of the presence in both cases of the 
large excess of soluble halide, and of the pronounced effects 
which the potassium iodide, and presumably also the potassium 
bromide, exert upon their respective reaction velocities. In 
Table I, experiment 8 is the one which approximates most 
closely to the conditions of the bromine experiments. If we 
take equal concentrations of the potassium halide as the basis 
of comparison, we must allow for the fact that the halide con- 
centration was not the same in the two cases, but was greater 
in the bromine experiments in the ratio 166/119. Upon the 
assumption, based on the results of Table I, that a doubling of 
the concentration of the potassium iodide increases the constant 
by about ten per cent, the value of the iodine constant, at the 
same halide concentration as the bromine experiments, would 
be about 11:0. So compared, the reaction between mercury 
and bromine would appear to be about twelve per cent more 
rapid than that with iodine. 

As an example of a reaction of a somewhat different type 
the rate of solution of mercury in cupric bromide was also 
determined. The presence of a sufficient quantity of potassium 
bromide was found to effectually prevent the formation of 


Am. Jour. Sci.—FourRtTH SERIES, Vout. X XIX, No. 171.—Marcu, 1910. 
4a 


250 Van Name and Edgar— Velocities of Certain Reactions 


TaBLe IX. 
Mercury and Cupric Bromide. 
Temperature 25° 400 g. KBr per liter. 
c At 1 c At v 
mol/liter min. ec. us mol/liter min. cc. = 
ihe _r=160 2. r=215 
Uae 10 900 485 0-0074 10 510 8-40 
0:0529 480 i 0-0679 490 
TAVIS 10 4°86 10 6°38 
0:0476 460 : 0°0593 470 
11 5°02 ARIA 10 6°24 
0:0420 440 ! 0:0516 450 
oon 10 4-92 : 10 6°29 
0:0378 420 ; 0:0446 430 
i 10 4°96 10 6°27 
0:0330 10 400 4-94 0:03882 10 410 6-19 
0:0290 380 0:0326 390 
Av. 4:93 Av. 6°30 


insoluble bromides, and the reaction was followed by adding 
samples of the liquid to a large excess of potassium iodide and 
titrating the iodine set free. If the solution is exposed to the 
air throughout the experiment some oxidation of the cuprous 
salt occurs, as the steady fall of the constant in the following 
preliminary experiment will show: | 
400 g. KBr per liter. p= YX) 
K = 6°59, \6-54y 6°93, 6:17, 5-62.) ayaa 

This was avoided in the experiments of Table IX by saturat- 
ing the cupric bromide solution with carbon dioxide at the 
outset and conducting, throughout the experiment, a rapid 
current of the gas into the upper part of the reaction vessel, so 
that the liquid was covered at all times by a layer of carbon 
dioxide. Under these conditions, as the results indicate, little 
or no oxidation took place. 


Discussion. 


In Table X the values of the velocity constants are sum- 
marized for convenient comparison. The agreement between 
the constants obtained for different metals under like condi- 
tions is unmistakable, and is especially striking with the metals 
mercury, cadmium and zine, which show a maximum variation 
of less than two per cent. This can hardly be an accident and 
points strongly to the conclusion that the reaction velocity is 
independent of the metal. As compared with mercury the 
constants for copper and silver are uniformly slightly lower, 
the largest difference being about five per cent, which is more 
than can reasonably be ascribed to experimental error alone. 

The difficulty encountered in the work with copper and with 
silver in entirely preventing the formation of coatings of 
insoluble iodide upon the metal at once suggests itself as a 
probable explanation of the lower constants. As stated above, 


between Metals and Dissolved Halogens. 251 
TABLE X. 
Summary of Velocity Constants. 
A. 
Iodine with Various Metals. 
; | Concentration of KI 
: | grams per liter. 
revs. per 
ee | 100 | 200 | 400 800 
E | 648 (Hg) | 721 (Hg) | 8-14 (Hg) 
170 } QR 
6:36 (Cd) 95 (Cu) 
180 703% (Zn) 8°23 (Ag) 
210 8:54 (Hg) 
8-81 (Hg) 9°55 (Hg) | 10-48 (Hg) | 
9:98 (Cu) F) 10227 (Cu) 
240 8°69 (Cd) 9°56 (Cd) . 
8°64 (Zn) 9°64 (Zn) | 
9-93 (Ag) 
300 11°12 (Hg) 
Pea 182 
B. 
Bromine with Mercury. 
r= 240 400 g. KBr per liter. Kes ae 
C. 
Cupric Bromide with Mercury. 
r=160 400 g. KBr per liter K=4:93 
t=219 400 g. KBr per liter K=6:°30 


traces of such coatings were observed in some of the experi- 
ments included in the table, and it is by no means certain that 
their effect was wholly absent even when no sign of a coating 
was detected, and the value of K was fairly constant. Further 
evidence on this point is brought out in the two following tables. 

Table XI shows the increase in K with the rate of stirring 


Ik, Dc ey ei sks 
cleat 


applied to each pair of comparable experiments carried out with 
one and the same metal. It will be observed that nearly all of 
the constants in Table X have been used in these calculations, 
including five of the six which stand alone in Table X and 
hence can not be directly compared with any others. This is 
important because a comparison of the values of 7 affords the 
best available test of the concordance between these isolated 
constants and the others. 


as measured by the value of 7 in the equation 


252 Van Name and Edgar— Velocities of Certain Reactions 


TABLE XI, 


Influence of Rate of Stirring. 


Metal - Table Experiments ——-Kk-—— nN: 
Hg I Ibn oO 6°45, 8°81 0°91 
i a SG) ON POA don NYS) 0°82 
I 4 & 6 S04 die 0-74 
I 0G 3) 8°14, 10°48 0°78 
Cu IL In igo 2) 7°95, 9-98 0°66 
Ag Ill Lee 8°28, 9°93 0°65 
Cd IV We SG 6°36, 8:69 0°90 
Zn V il 9s 3B 7°03, 8°64 0-75 
Hgin CuBr, IX Selene 4°93, 6°30 0°83 


The values of 2 for copper and for silver are the lowest in 
the table. Except for these the agreement is about as.good 
as could be expected ; first because is in all probability not 
a constant but variable with the conditions of concentration, 
ete., and second because n, for mathematical reasons, is rather 
sensitive to variations in K. 

The effect upon the reaction velocity of doubling the con- 
centration of the potassinm iodide is shown in Table XII, 
where the ratios of the constants are given for such pairs of 
experiments as differed only in this respect. Here again 
copper shows a distinct difference in behavior from the other 
metals, silver not being represented in the table. The differ- 
ence is unexpectedly large, but in the absence of other data. 
to confirm it, nothing more than a qualitative significance can 
be attached to this single result. 


TABLE XII. 


Influence of Concentration of Potassium Iodide. 


Metal Table Experiments ——-k-——X Ratio 
Hg I Sou all 721, 6:48 1°12 
I Dou e SSO Mimteloill 1:08 
I (Oe paem O) Slack 1°18 
I 8 & 95 10°48, 9°55 1°10: 
Cu II 3) We 1 OPA SOs 1°03 
Cd IV By Sey a 9:56, 8 69 1:10 
Zn Vv We CG a 9-64, 8°64 tai2 


These comparisons serve to emphasize both the close agree- 
ment in the reaction velocities of mercury, cadmium and zine, 
and the consistent though usually small deviations shown by 
copper and silver. The latter, however, are all explainable 
upon the assumption that the reaction is retarded to a sheht 
extent by the presence of traces of the solid iodide at the 
contact surface. This explanation is a probable one and in 
the opinion of the writers may reasonably be accepted. We 
may conclude, in other words, that not mereury, cadmium, 


between Metals and Dissolved Halogens. 253 


and zine only, but all the five metals investigated react with 
iodine at practically the same rate. 

Unless we accept the diffusion theory there seems to be no 
reason why these reaction velocities should be the same. But 
even if the above result should be found to hold for a large 
number of metals, it would not constitute conclusive proof 
that the diffusion of iodine is, as: it appears to be, the deter- 
mining factor. Evidence of a more direct nature is needed 
upon this point. 

As shown above, a doubling of the concentration of the 
potassium iodide accelerates the reaction by about ten per 
cent. According to the diffusion theory such an acceleration 
might be due to an increase in (a), the rate of diffusion (here 
that of the iodine), or to a decrease in (0), the average thick- 
ness of the unstirred layer, or to both together. While (@) 
is In general directly measurable, little can be predicted about 
(6) except that it would vary with the properties, especially 
the viscosity, of the liquid. It seems, however, permissible 
to assume that in the majority of cases the changes in (@) 
would predominate over those in (4), and especially here, since 
the viscosity of strong solutions of potassium iodide at 25° 
varies but little with the concentration.* According to this 
view the rate of diffusion of iodine, or more accurately, that 
of potassium triiodide,; ought to show a distinct increase with 
the concentration of the potassium iodide. 

As we have been unable to find any published data which 
either confirm or disprove this conclusion, we have carried out 
a qualitative test by comparing in two Nessler tubes of the 
same dimensions, clamped side by side in a large water bath, 
the rate at which the color spread from a lower layer of iodine 
in potassium iodide into an upper layer of pure potassium 
iodide of the same strength. The potassium iodide solutions 
in the two tubes contained respectively 25 and 400 grams of 
iodide per liter, and the iodine concentrations (the same in 
both tubes) were similar to those used in the previous work. 
Several repetitions of the experiment gave the same result. 
After a few hours a difference was visible in the extent to 
which the brown color had progressed beyond the initially 

* According to W. W. Taylor and C. Ranken (Proc. Roy. Soc. Edinburgh, 
xxv, 251) the viscosities of 1 and 3-normal KI at 25° are 0°467 and 0°459 
respectively, that of water at the same temperature being 0°501. 

+ With the aid of the equilibrium constant of the reaction KIz==KI+I,, 
(k = 0:0014 at 25°), determined by Jakowkin (Zeitschr. phys. Chem. xx, 19), it 
may easily be calculated that in no experiment in the above tables did the 
proportion of free iodine exceed a few tenths of one per cent of the total 
iodine, i.e., that indicated by thiosulphate. A similar calculation based on 
Jakowkin’s data for bromine shows that in the experiments of Table VIII 
the tribromide bromine formed in all cases more than 98 per cent of the 


total bromine, so that here too the diffusion velocity would be practically 
that of the tribromide. 


254 Van Name and Ldgar— Velocities of Certain Reactions 
sharp boundary, and in every case it was the stronger solution 
in which the diffusion appeared to be most rapid, thus confirm- 
ing the conclusion drawn above with the aid of the diffusion 
theory. A confirmation based upon quantitative measure- 
ments would of course be much more satisfactory, and an 
attempt will be made by one of us in the near future to obtain 
quantitative evidence on this question. The result obtained 
is interesting in that it seems to be an exception to the rule 
of Abege and Bose® according to which an electrolyte diffus- 
ing in the presence of a large excess of a salt with like cation 
tends to assume the velocity of its own anion. As the electri- 
cally measured velocity of I,’ ion is much less than that of Kt 
lont, a retardation would ‘be expected in the present case 
instead of the observed acceleration. 

We have still to consider the application of the diffusion 
theory to the explanation of the observed reaction velocities. 
of mercury with iodine, bromine, and cupric bromide respec- 
tively. ‘The values of the iodine and bromine constants, for 
a potassium iodide or bromide concentration of 3°4 normal 
and stirring at 240 revolutions per minute, were compared on 
page 249. A correction for difference in the rate of stirring 
permits the cupric bromide constants of Table IX to be 
included in the comparison, which gives, for the approximate 
ratio of the reaction velocities, iodine 11-0, bromine 12°3, cupric 
bromide 6°9. Of the three solutions corresponding to these 
constants the last two would have practically the same vis- 
cosity ; that of the iodine solution, judging: by the viscosities 
given by Taylor and Ranken? for 3normal solutions of potas- 
sium bromide and iodide, would be slightly lower. The differ- 
ence between the iodine and bromine constants is therefore in the 
wrong direction to be explained by difference in the thickness 
of the unstirred layer, so that we must conclude, first, that the 
rate of diffusion of potassium tribromide is somewhat greater 
than that of potassium trilodide, at least in the concentrated 
solutions here used, and second, that cupric bromide diffuses. 
decidedly slower hon either. Both of these conclusions can 
be tested by direct measurement, but at present experimental 
confirmation is lacking. Both however are plausible, especially 
the last, which is in full agreement with the slow rates of dif- 
fusion of copper salts in ceneral as compared with potassium 
salts. 

We are far from regarding the evidence presented above as 
in any way conclusive in favor of the diffusion theor y as 
applied to the reactions in question, but the fact that it 

* Zeitschr. phys. Chem., xxx, 901. 


+ See Burgess and Chapman, Jour. Chem. Soce., lxxxv, 13800. 
{ Proc. Roy. Soc. Edinburgh, xxv, 231. 


between Metals and Dissolved Halogens. 255 


accounts for the results obtained, and so far as yet shown leads 
to no inconsistencies, would seem to justify its retention for 
the present in dealing with reactions of this class. The work 
will be continned along similar lines. 


Summary. 


1. The rates of solution of the metals mercury, cadmium, 
zine, copper, and silver, in aqueous iodine solutions containing 
a lar ge excess of potassium iodide, have been measured at 25° 
and shown to be practically equal, a shght difference observed 
with copper and silver being in all probability due to accumu- 
lation of the solid jodide at the contact surface. 

2. The temperature coethicient for 10° (between 25° and 35°) 
is about 1°3. 

3. An increase in the concentration of the potassium iodide 
produces a marked acceleration of the reaction. 

4. Mercury dissolves in bromine in the presence of potassium 
bromide slightly faster than in iodine, but in cupric bromide ~ 
much more slowly, the ratios of the velocities being about 
irons E10: :6°9. 

5. The reaction velocity was found to be proportional, on 
the average, to the 4/5 power of the rate of stirring. 

6. So far as can be decided from the data at present avail- 
able, the diffusion theory of Noyes, Whitney, and Nernst 
gives a satisfactory explanation of the results obtained. 


256 Berry—New Cretaceous Bauhinia from Alabama. 


Art. XX.—A Wew Cretaceous Bauhinia from Alabama, a) 
by Epwarp W. Berry. 


In a recent note in Torreyat a new Cretaceous Bauhinia 
was described from the Magothy formation of Maryland, and 
the writer at that time took oceasion to call attention to the 
various fossil species, seven in all, ascribed to this genus of 
the Czesalpiniacese with their respective ages. Still more 
recently Cockerell has described{ an additional species from 
the Florissant, Colorado, shales which he calls Bauhinia 
pseudocotyledon. While the genus is known from both the 
Oretaceous and the Tertiary of Europe, no Tertiary species had 
heretofore been described from North America, although the 
Cretaceous forms are exceedingly well marked and characteris- 
tic. The species described by Cockerell is not as characteristic 
_either in outline or venation as might be desired and should 
possibly be compared with other genera of the Ceesalpiniaceze 
or Mimosacee ; at the same time its relations are sufficiently 
obvious to indicate the presence of a warm temperate element 
in the Florissant flora. Lesquereux insisted that these deposits 
which Cockerell calls late Miocene were the same age as the 
Green River shales, a position no longer tenable; and in this 
connection it is interesting to recall that they were originally 
called Pliocene by Dr. A. iC. Peale. 

The occasion for the present note, however, is furnished by 
the discovery of a large and striking species in the Tuscaloosa 
formation of Alabama which may be characterized as follows: 


Bauhinia alabamensis sp. nov. 


Bilobate leaves of medium and large size, 8°" to 15° i 
sreatest lenoth by 11 10 13 im ereatest breadth. Medial 
sinus rather broad and rounded, reaching two-thirds of the dis- 
tance toward the base or even more. Lobes somewhat reni- 
form in outline, sublobate, rounded above and with three 
broadly rounded sublobes on the outer side, the entire margin 
curving upward and inward from the lower and largest lobe 
to the truncate or deeply cordate base, which appears to be 
shghtly peltate in some specimens. Midrib comparatively 
slender, 1°7 to 3°" in length, running to the base onesme 
medial sinus and sending off two branches in its upper part, 
one on each side, which curve upward parallel with the inner 
margin to join inwardly directed branches from the lateral 
primaries. Main lateral primaries stout, sending two or three 

* Published by permission of the Director, U. 8. Geol. Surv. 
+ Berry, Torreya, vol. viii, p. 218, 1908. 
{ Cockerell, ibid., vol. ix, p. 184, 1909. 


oe 


Berry—New Cretaceous Bauhinia from Alabama. 257 
upwardly directed branches inward and three or four longer 
less oblique branches outward, the latter forking and forming 
broad arches in the lateral lobes. One or two additional 
lateral primaries on each side take their origin from the com- 
mon point of divergence of the palmate or bilateral system of 
venation of this species and are confined to the lower lateral 
lobe on each side along the margin of which their branches 
arch. 

This ornate and butterfly-like species of Bauhinia is not 
uncommon in the sandy clays of the Upper Tuscaloosa near 


HiGaule 


Fic. 1. Restoration of Bauhinia alabamensis Berry, 4/7 nat. size. 


Havana in Hale County, Alabama, but owing to the unsatis- 
factory character of the matrix, which is too sandy for good 
collecting, and also to the fact that the plant remains had 
evidently been in the water a long time before entombment, 
only fragmentary specimens were secured. These represent, 
however, ali parts of the leaf and are complete enough to serve 
as an entirely accurate basis for the complete leaf shown in the 
accompanying figure. 

This species is markedly distinct from any of the fossil 
species hitherto known. In size and general appearance it 


258 Berry—New Cretaceous Bauhinia from Alabama. 


suggests Bauhinia cretacea Newberry* of the Raritan forma- 
tion in New Jersey, and it may well be a descendant of that 
species, which as time passed widened out and became sub- 
lobate. It differs from any existing species known to the 
writer in its great width and sublobate character, although 
several recent smaller-leaved Species approach it in ‘the latter 
respect, and it seems probable that if representative collections 
of the foliage of the recent forms showi ing the limits of specific 
variation were available for comparison, it would be found that 
a tendency toward the formation of ‘sublobes was far from 
exceptional. Two recent species were noted as showing this 
marginal character. These are Bauhinia hookeri F. v. M. of 
Australia and Bauhinia tomentosa Linné of the West Indies. 

The display of species of this modern tropical genus in the 
Upper Cretaceous of the Atlantic coastal plain is certainly 
remarkable, for it embraces very small and very large forms 
and shows a variety almost as great as that furnished by the 
existing species. Quite recently still another and very dis- 
tinct species of Bauhinia was collected by the writer from 
typical Ripley strata in Alabama and this will be described 
upon a subsequent occasion. 


Johns Hopkins University, 
Baltimore, Md. 


Art. XXI.—Anhydrite and Associated Minerals from the 
Salt Mines of Central Kansas; by Avcstin F. Rogurs.t 


In this country anhydrite, the anhydrous calcium sulphate, 
seems to be a rather rare mineral. A year or so ago the 
writer found it in some abundance at several of the salt mines 
in central Kansas. So these must go on record as occurrences 
similar to the well-known localities in Germany and Austria 
where it is a common mineral. In characters and paragenesis 
the Kansas anhydrite resembles the foreign anhydrite. 

The anhydrite was collected from the dump-piles of the salt 
mines at Kanopolis, Ellsworth Co., and at Lyons, Rice Co. 
At Kanopolis rock-salt is mined in one shaft at a depth of 795 
feet and in another shaft at a depth of 805 feet. The layer of 
salt is about 11 feet thick. A log of the Lyons shaft and of a 
deep well at Kanopolis are on record{ but the anhydrite evi- 

eee berry, Fl. Amboy Clays, p. 91, pl. xliii, figs. 1-4; pl. xliv, figs. 1-3, 
1 


+ Published by permission of the State Geologist of Kansas. 
¢ Annual Bulletin on Mineral Resources of Kansas for 1898, pp. 93-4. 


A. F. Rogers—Anhydrite and Associated Minerals. 259 


dently was not identified, as no record of it appears. At Lyons 
a 17-foot bed of salt occurs at the bottom of a shaft 1100 feet 
deep. At Kingman, Kingman Co., Prof. J. T. Willard of 
Manhattan also obtained anhydrite from the dump of a salt 
mine. Bailey and Failyer in their list of Kansas minerals* 
mention this occurrence of anhydrite, but it has evidently 


Fic. 1. 


Fic. 2. 


a, anhydrite. 
J, Sypsum. 


been overlooked, for no mention of it is made in any ofthe 
reports of the University Geological Survey of Kansas. 

From an examination of the dump-piles it is evident that the 
anhydrite occurs in thin lenticular layers interbedded with 
shales, and probably has an appreciable vertical distribution. 
This is also true of the salt according to the shaft and well 
records cited above. Some specimens from the dumps show 
an intimate mixture of salt and anhydrite. The writer was 
also informed that at Lyons anhydrite occurs below the main 


* Transactions Kansas Academy of Science, vol. xili, p. 78, 1891-2. 


260 A. F. Rogers—Anhydrite and Associated Minerals. 


salt bed. At the salt mines gypsum occurs in small quantities 
and probably only as a secondary mineral. The explanation of 
the association of anhydrite with the salt is based upon the 
experimental work of Rose and others. When- sea-water is 
evaporated CaSO,.2H,0 is the first substance to crystallize out. 
On further evaporation NaCl forms and with it CaSO,. That 
is, anhydrite instead of gypsum forms from a concentrated solu- 
tion saturated with NaCl. Later magnesium and potassium 
chlorids and sulphates are formed. In the Kansas deposits these 
have been dissolved if ever they were formed. 

The salt and anhydrite occur in the lower Permian. Accord 
ing to Plate V of the report on Kansas salt,* the salt-beds are 
between the Wellington and Marion formations. Nota single 
fossil was found on the saltmine dumps, and this is not strange 
when we consider the conditions under which these deposits were 
formed. rom evidence gathered in various places it seems 
certain that throughout the northern hemisphere an arid climate 
prevailed in the Permian. The poverty of fossils, the oceur- 
rence of Red-beds, and the presence of extensive beds of gypsum 
and salt, all point to the fact that Kansas was like the rest of 
the northern hemisphere during Permian time. Now the occur- 
rence ot anhydrite with the salt is additional evidence that the 
Kansas Permian is like the Permian (Zechstein) of Germany 
during which time the salt-deposits of Stassturt, Leopoldshall, 
Vienenburg, and Bernburg were formed. At all these localities 
anhydrite occurs with salt. 

Anhydrite.—The massive anhydrite is a gray or reddish gran- 
ular rock occurring in thin lenticular layers rarely over four 
inches thick. Itresembles gypsum but is heavier (sp. gr. 2°9) and 
harder (h. 34). A microscopic examination of the rock shows 
an aggregate of imperfect sub-angular squares and rectangles, 
with bright interference colors and parallel extinction. Some 
of the massive anhydrite gives off water in the closed tube. 
This points to the presence of gypsum, which is shown in a 
thin section (figure 1). . The mineral with high relief marked 
ais anhydrite. The spaces between the anhydrite are filled 
with gypsum marked g, which has low relief, aggregate struc- 
ture and low-order interference colors. The gypsum has evi- 
dently formed from the anhydrite by hydration. Dolomite is 
also present, marked d. Cleavable and fibrous anhydrite occurs 
in seams often an inch or more thick. The anhydrite has the 
typical pseudo-cubic cleavage and one of the cleavages is usually 
parallel to the plane of the seam. The seams are often fibrous 
in an oblique direction. The explanation of this is shown in 
figure 2, which represents a cross-section of a seam. The 
fibrous structure is due to polysynthetic twinning parallel to an 


*Annual Bulletin of the Mineral Resources for 1898. 


A. F. Rogers—Anhydrite and Associuted Minerals. 261 


oblique face. The twinning is probably secondary, as it appar- 
ently begins at one side of the seam and gradually causes the 
mineral to take on a fibrous structure. A few minute pseud- 
eubie crystals of anhydrite were found in close association with 
halite. These are doubtless secondary and on account of the 
halite crystallized as anhydrite instead of as gypsum. ~ 

Gypsum.—Gypsum is present as a subordinate mineral and 
apparently is always secondary. It occurs in some of the mas- 
sive anhydrite as an alteration product (figure 1). Also coats 
seams of cleavable anhydrite but as sharply defined layers 
(figure 2). On the surface of some of the anhydrite specimens 
are small gray crystals of gypsum mixed with clay. These 
have evidently been formed since the material was thrown on 
the dump-piles. 

Dolomite.—Dolomite occurs in minute crystals disseminated 
through some of the massive anhydrite (see d, figure 1). . In 
habit the crystals are unusual, the forms being (4041) and (0001) 
as represented in figure 3. Similar crystals occur in gypsum 
at Hall in the Tyrol. 

Celestite.—A heavy reddish mineral, occwrring in masses of 
imperfect tabular crystals and also in small fibrous forms in 
the cleavable anhydrite, proves to be celestite. This intimate 
connection with anhydrite would perhaps indicate that the 
celestite is a direct deposition from sea water. 

Quartz.—Quartz occurs in sinall (2 or 3 mm.) pale reddish 
erystals imbedded in the massive anhydrite. It has the usual 
faces (1011), (0111), and (1010) and the habit is like that of the 
Suttrop, Westphalia crystals. 

Pyrite.—Pyrite is found in minute brown oxidized erystals 
in the anhydrite. Itis coated with a yellow alteration product 
resembling copiapite. | 
_ Halite.—Halite occurs in clear cubic cleavages up to three 
or four inches in size. Negative crystals filled with a liquid 
and moving bubbles are common. A red fibrous halite occurs 
at Kanopolis. Halite is directly associated with anhydrite and 
is sometimes embeddded in it. 

Careful search was made for the other Stassfurt minerals 
but none was found. A reddish fibrous mineral very much 
resembled polyhalite but proved to be celestite. 


Stanford University, California, 
December, 1909. 


262 Screntifie Intelligence. 


SCIENTIFIC INTELLIGENCE. 


I. CwHemistry AND Puysics. 


1. Zhe Purple Dye of the Ancients._-In an address delivered 
at Frankfort a. M., P. FrrepLaENDER has given an interesting 
account of the highly prized purple dye of the ancients, together 
with a solution of the mystery of its chemical nature. It appears 
that Greek and Roman literature supplies abundant information 
concerning the history of this dye, but the technical details of the 
lost art of applying it are almost wholly lacking. It is hardly 
possible that the process was a secret one, since it was employed 
by nearly all Mediterranean peoples in many localities, hence the 
lack of information seems to be due to the low social status of the 
dyers of ancient times. The species of mollusks employed in the 
preparation of this royal purple are well known, both from 
ancient descriptions and the remains of broken shells still existing 
in heaps at places where the dye was prepared, and it appears 
that the sea-snails or periwinkles now known as murex brandaris, 
murex trunculus, and purpura haemostoma were those chiefly 
used. It is known also that only a very small organ of the snail 
was utilized. From ancient statements concerning the value of 
the dyed material the calculation is made that the value of the 
dyestuff must have been something like $5,000 per pound. 

Several previous investigators have attempted the study of this 
coloring matter, but without definite results, except that color 
tests seemed to indicate some analogy to indigo-blue or indigo- 
red. In undertaking a new study of the matter Friedlaender 
obtained a supply of mollusks from various Mediterranean 
zoological stations. After breaking the shells, the glands, which 
show no color in their original condition, were taken out, their 
contents were spread upon filter paper and exposed to sunlight 
for the development of the color. This material was then treated 
with hot dilute sulphuric acid in order to remove more soluble 
matters, and then the coloring matter was extracted with a high- 
boiling solvent, such as quinoline or benzoic ether, from which it 
was easily obtained pure by crystallization. ‘The yield was very 
smal], amounting to only 1°5 g. from 12,000 specimens of murex 
brandaris. 

Upon analysis the remarkable fact was found that it contained 
much bromine, and it was established without doubt that the 
substance was 6,6, diabrom indigo, a compound already known 
which can be synthesized in several ways, and which could be 
manufactured at a price a thousand times less than its cost in 
times of antiquity. But it is hardly to be expected that it will 
be used at the present time, for it has a rather dull, reddish-violet 
color, which makes no marked i impression upon modern eyes, and 
besides the tint can be reproduced by several thio-indigo deriva- 
tions. Friedlaender says that we have thus lost one of our 


Chemistry and Physics. , 268 


illusions ; but still he has observed that murex trunculus gives, 
besides this reddish-violet coloring matter, also a dark blue one, 
which results by oxidation, and not by the action of ligbt, from a 
colorless body. 

In spite of Friedlaender’s verdict in regard to the royal purple, 
it still seems possible that the ancients may have been able to 
produce a really magnificent color by means of some lost method 
of combination or manipulation.—Zeltschr. angew. Chem., xxii, 
2321. lo We Ais 

2. The Purification of Water Supplies by the use of Hypo- 
chlorites.—Dr. W. P. Mason has given an account of the use of 
bleaching powder or of sodium hypochlorite in the purification 
of water supplies. He says that those who have been opposed 
to this method must change their position on account of the 
results that have been obtained in France and England, as well 
as at the Chicago Stock Yards and with the municipal supply of 
Jersey City. In the latter case the dose of available chlorine 
used during the month of December, 1908, averaged approx- 
imately 0°03 grains per gallon, and has since been materially 
reduced. While using the above amount the daily counts of 
bacteria per c.c. were as follows : 


Raw Water ‘Treated Water 


Naam Wims2 oo see oe 1600 fae 3() 
WMirrriritit=-- 2. 2s ee 240 0 
Ay WORE Fae See a eae 559 2°7 


No part of this minute dose of hypochlorite reaches the con- 
sumer, and protection against pathogenic germs appears to be 
assured. It is not expected that the process will take the place 
of filtration, because it does not improve the physical appearance 
of a water, but as an adjunct to a filter plant there can be no 
question of its usefulness in times of emergency, and it can be 
depended on to render a somewhat polluted water safe for 
domestic purposes at a moderate price.—-Proc. Amer. Phil. Soc., 
xlviii, No. 191. Hae Wo 

3. Allen’s Commercial Organic Analyses, edited by Henry 
LerrMann and W. A. Davis. Fourth edition, entirely rewrit- 
ten. Philadelphia, 1909 (P. Blakiston’s Son & Co.).—The first 
volume of a complete revision of Allen’s great work will be wel- 
comed by all commercial analysts. The revision is being under- 
taken by specialists in the various branches of the subject, an 
arrangement which will undoubtedly lead to a presentation of 
the most recent and best methods. The present volume contains 
an introduction dealing with general operations and the deter- 
mination of physical properties of substances, and takes up the 
subjects of alcohols, malt and malt liquors, wines and potable 
spirits, veasts, neutral alcoholic derivatives, sugars, starch and 
isomers, paper and paper-making materials, and acid derivatives 
of alcohols. The contributors to this volume are EK. Frankland 
Armstrong, Julian L. Baker, William A. Davis, G. C. Jones, 
Henry Leffmann, Emil Schlichting and R. W. Sindall. Two of 
these contributors and several others who will assist in the prepa- 


264 Scientific Intelligence. 


ration of subsequent volumes are Americans, so that the work 
will have an international character. The complete work will 
consist of eight volumes, which will be issued rapidly. 4.1. w. 

4. Introduction to Physical Chemistry ; by Harry C. Jonzs. 
12mo, pp. xv+279. New York, 1910 (The Macmillan Co.).— 
This book is practically an abbreviated edition of the author’s 
Introduction to Physical Chemistry and is designed for a shorter 
college course in physical chemistry. Much of the text and many 
figures are taken from the larger book. The six chapters in the 
book are on the atom, gases, liquids and solids, solutions, thermo- 
chemistry and photochemistry, electrochemistry, and chemical 
dynamics and equilibrium. 

It will probably find considerable use in the colleges. 

H.W. F 

5. Change from Positive Reflection to Negative through Pres- 
sure.—O. LumMER and K. Sorex have repeated Lord Rayleigh’s 
observations on this subject, moved, probably, to a consideration 
of the subject by the remark of Rayleigh, that in the study of 
surface conditions by means. of light much can be learned of 
the constitution of matter. The authors of this paper show that 
the ellipticity at a reflecting surface can be appreciably changed 
by a mechanical change of the medium without influencing the 
reflecting surface.—Ann. der Physik, No. 2, 1910, pp. 325-342. 

Je Bs 

6. Study of Gaseous Suspensions.—MauvricE DE BROGLIE 
refers to the Brownian movement in fluids and calls attention to 
analogous movements of suspended particles in air or gases. He 
describes an ultra microscopic arrangement which he uses to 
study smoke particles. He discusses the ‘effect of an electric 
field, influence of weight, and the relations of the movements 
observed to Brownian movements, In smoke, he finds particles 
of which the radius lies between py and a hundredth of py.— 
Physik, Zeitschrift, Jan. 15,1910, pp. 33-39. Sealy 

7. Constitution of the Electric Spark.—The work of Schuster 
and Hemsalech has been continued by T. Royps, under the 
advice and suggestion of Schuster and Rutherford. The method 
of observation consisted in focussing the spark upon a rapidly 
revolving photographic film. The velocities of metallic vapor 
caused by the spark between different terminals are given in a 


oe vee m 
table. In general these velocities are within 10° a The author 


shows that the vaporization of the metallic electrode is simul- 
taneous with the pilot or initial spark. Two simultaneous veloci- 
ties were obtained in the case of calcium vapor.— Phil. Mag., 
Feb., 1910, pp. 285-290. Jos 
8. Cadmium Amalgams and the Weston Normal Cell.—In a 
communication from the National Physical Laboratory, F. E. 
SMITH reviews the work of previous writers on this subject and 
submits his own measurements. There are many suggestions 
,deduced from his work. Among them is the advice that the 123 
per cent amalgam be replaced by a 10 per cent amalgam.— Phil. 
Mag., Feb., 1910, pp. 250-276. seem 


Or 


Geology and Natural Mstory. 26 


If. Grotogy anp Natura History. 


1. Florida State Geological Survey; E. H. Srttarps, Geolo- 
gist. Second Annual Report, 1908-9. Pp. 296, 19 pls., 5 figs., 
geologic and topographic map in_ pocket. —This includes the 
following : 1. A Preliminary Report on the Geology of Florida ; 
by Grorer Cuartton Matson and Frepericx G. CLAPP, pre- 
pared in codperation between the United States Geological Sur- 
vey and the Florida State Geological Survey under the direction 
of Tuomas Wayianr.VauGHAN. 2. Topography and Geology of 
Southern Florida; ‘>y Samuret Sanrorp.—Scattered papers and 
reports dealing segs with the coast line have heretofore been 
the basis of our knowledge of Florida geology. We now have, 
however, a preliminary report on the geology of the whole state, 
together with a topographic and geologic map. In view of pre- 
vious opinions, the reader of this report will be interested to 
learn that the geologic structure of Florida is diversified, not 
simple ; and that corals, instead of being the chief agent in the 
formation of the bed rock of the state, have really played a minor 
role: have always been limited to the extreme southeastern part 
of the peninsula. ‘‘There appears to be no reason to suppose 
that reefs have existed on the west coast or north of the north 
line of Palm Beach County on the east coast ” (p. 40). 

Florida is a region of low plains and deeply dissected uplands. 
The state as a whole has an elevation of less than 100 feet. The 
topographic map shows an area in the southern part of the state 
150 miles long by 100 miles in width, with an altitude of less 
than 50 feet ; and one of the longest rivers in the state, the St. 
Johns, is nowhere more than 30 feet above the tide. On the 
other hand, detached areas along the Georgia-Alabama line reach 
250 feet and “small areas may exceed 300 feet.” The drainage 
is consequent and superimposed, and includes excellent illustra- 
tions of extended streams. The imperfectly drained areas con- 
tain thousands of lakes occupying either solution cavities or 
shallow basins due to unequal deposition of sands. Lakes of the 
former type predominate in the more elevated portion of the 
peninsula, and the rate of solution by ground water in this area 
is found by Sellards to equal the annual removal of 400 tons per 
square mile. The Everglades, 22.4 feet above tide, are found to 
be almost completely surrounded by a rim of rock ; and are 
believed by Mr. Sanford to be similar in origin to the Dismal 
Swamp of Virginia. 

In structure Florida is “the southern extension of the coastal 
plain, and its history, in general, has been the same.” An uplift 
similar to the Cincinnati arch has raised the lower Oligocene 
more than 100 feet above the sea. 

The geological formations include Tertiary and Quaternary ; 
the oldest rocks belong to the Oligocene Period, and include the 


Am. JOUR. ag ea Series, Vou. X XIX, No. 171.—Marcu, 1910. 


266 Scientific Intelligence. 


Vicksburg and Appalachicola groups. ‘Three of the four forma- 
tions of the latter are believed to have been deposited contem- 
poraneously. Two formations have been distinguished in the 
Miocene, five in the Pliocene, including the Lafayette. The 
various formations are discussed in detail, pp. 50-162. The 
Pleistocene geology is unusually interesting here because of 
abundant proof of several elevations and depressions of the penin-: 
sula, including movements going on at the present time. Modi- 
fied drainage, sea cliffs and terraces are topographic features 
abundantly represented. 

The report of Samuel Sanford on the Topography and Geology 
of Southern Florida (pp. 177-231) is the fst attempt at a com- 
plete geological description of this area. The studies include 
the Everglades, the Coastal Plain, and the reefs and keys along 
the line of the Florida East Coast Railway. Owing to the recent 
deposition of the beds and their more recent elevation, the 
topography of this area is in a stage of infancy. “ Drainage is 
defective, sloughs, shallow ponds and lakes abound. Most of the 
interior is 4 swamp, there are no well-defined river systems nor 
stream valleys, and some of the short rivers that flow from the 
Everglades into the Atlantic are, where bed rock comes a few 
feet above tide level, characterized by rapids in their upper 
courses.” The author agrees with Dall that “the present Florida 
mainland is but the top of a vastly greater submarine plateau, 
the southeastern and southern edges of which are near the pres- 
ent shore line, the western edge many miles to the west.” One 
of the striking features of southern Florida is the absence of 
rock outcrops over wide areas where the ledge is but a few feet 
below the surface. Part of the extensive mantle of sand which 
so effectually conceals the bed rock has been carried down the 
Atlantic coast by waves and currents, and part of it comes from 
the disintegration of arenaceous linestones and marls. — 

The State Geologist discusses the origin, distribution and com- 
mercial importance of phosphates, diatomaceous earth, fullers’ 
earth, and other economic products. H. E. G. 

2. Report of Topographic and Geologic Survey Commission 
of Pennsylvania, 1906-1908. Pp. 375, 21 plates and 21 figures, 
Harrisburg, 1908.—The First Geological Survey of Pennsylvania 
under the direction of H. D. Rogers was organized in 1836, and 
issued reports in 1836, 1838, 1840, 1841, and 1842, with two vol- 
umes of final reports in 1858. The Second Geological Survey, 
organized in 1874 under the direction of J. P. Lesley, was con- 
tinuously in operation from 1874 to 1887, issuing 77 volumes, 38 
atlases, in addition to a “grand atlas.” Three volumes of the 
final report of this survey were issued in 1893-1895. in 1899 a 
topographic and geologic survey was organized to work in codper- 
ation with the United States Geological Survey. Under these 
auspices work was carried on under the general direction of M. 
Rh. Campbell until 1894, when the general supervision was placed 
in the hands of George H. Ashley. The results of the work have 
been published from time to time by the United States Geologi- 


Geology and Natural Mstory. 267 


cal Survey. Under present conditions, accuracy and complete- 
ness in topographic and geologic work have reached a much 
higher level than was possible under the conditions controlling 
the earlier state surveys. 

The present volume will doubtless be welcomed by the people 
of Pennsylvania as well as by students of geology in general, 
because it contains within a reasonable compass a discussion of 
the salient features of the geology of the state. By means of 
this General Review it is possible now to get a clear conception of 
Pennsylvania geology, stratigraphic and physiographic, as well 
as economic, and including recent discoveries, without reading 
through a mass of detailed and technical description. The gen- 
eral geologic report has been largely written by R. W. Stone, the 
pre-Pennsylvanian stratigraphy by Charles Butts, the petroleum 
and gas report by M. J. Munn. Es Gy 

3. Virginia Geological Survey ; THomas L. Watson, Direc- 
tor. Bulletin No. I-A; The Cement Resoarces of Virginia, 
West of the Blue Ridge, by Ray S. Bassier, with an Introduc- 
tory chapter on the Materials and Manufacture of Hvdraulic 
Cements, by Epwin C. Ecker. Pp. xii, 309, 30 plates, 30 figures. 
Charlottesville, 1909.—The development of the cement industry 
in Virginia justifies the publication of the present report, which, 
however, is more than an economic paper, and includes a valuable 
report (pp. 136-185), chiefly stratigraphic, on the geology of 
western Virginia, a region which has heretofore been inadequately 
studied. 3 Heprlig Ge 

4. Illinois State Geological Survey ; H. Foster Bain, Direc- 
tor. Bulletin 11; Physical Features of the Des Plaines Valley, 
by James WaLtEeR GoLpTuwait. Pp. x, 103, 9 plates and 21 
figures. Urbana, 1909.—Attention has previously been called to 
the admirable series of Educational Bulletins dealing with the 
geology of the state of Illinois, planned by the Illinois Geological 
Survey. This present bulletin is fully up to the standard «f the 
others, and amply justifies the labor expended. ‘Too little atten- 
tion has been paid by state and national surveys to the needs of 
teachers and general readers ; and it is hoped that this series, 
dealing-in a more or less untechnical way with interesting type 
localities, will encourage other organizations to undertake a similar 
work. H. E. G. 

5. Geology and Water Resources of the Northern Portion of 

the Black Hills and Adjoining Regions in South Dakota and 
Wyoming ; by N. H. Darron. Professional Paper, U. 5. G.S., 
No. 65, 1909. Pp. 105, 24 plates, 15 figures.—Several previous 
papers and reports by Mr. Darton, dealing with the Black Hills 
and the surrounding region, have presented the geology of this 
interesting area in an exceptionally attractive manner. These 
papers of Darton’s taken in connection with the reports by 
Professor Jaggar and Professor Irving, and the earlier report of 
Newton and Jenney, constitute a body of geologic literature 
available for few areas in the United States. 


268 Scientific Intelligence. 


The present report includes part of the material previously 
published, as well as much additional matter ; and, taken in con- 
nection with the author’s report on the southern Black Hills, will 
remain as the authoritative work on this area. This paper, 
including as it does the topography, general geology, strati- 
graphy, structure, geological history, as well as a discussion of 
the water resources, mineral resources, and climate, all parts of 
it well written and well illustrated, may serve as a type publica- 
tion if the United States Survey desires to be directly helpful to 
teachers and students, and to the increasing body of readers who 
are interested in geography, physiography, and general geologi- 
cal description, rather than in details of paleontology, petrog- 
raphy and economic geology. He ER inGe 

6. Biological Survey of Michigan: An Ecological Survey of 
Isle Royale, Lake Superior ; prepared under direction of CHaRLEs 
C. Apams. Pp. xiv and 422, 63 figures.—The following papers are 
included in Part I of this report: 1. Isle Royale as a Biotic 
Environment ; Dr. Charles C. Adams. 2. The Ecological Rela- 
tions of the Invertebrate Fauna of Isle Royale, Michigan; Dr. H. 
A. Gleason. 3. The Ecological Distribution of the Birds of Isle 
Royal, Lake Superior ; Otto McCreary. 4. The Fall Migration 
of Birds at Washington Harbor, Isle Royale, Lake Superior ;. 
Max Minor Peet. 5. The Ecological Succession of Birds; Dr. 
Charles C. Adams. 6. The Coleoptera of Isle Royale, Lake 
Superior, and their Relation to the North American Centers of 
Dispersal ; Dr. Charles C. Adams. 

Part II contains the following annotated lists: 1. Notes onthe 
Vegetation of Isle Royale, Michigan; W.P. Holt. 2. Annotated 
List of Certain Isle Royale Invertebrates ; ; Dr. Charles C. Adams. 
3. Annotated List of the Mollusca of Isle Royale, Michigan ; 
Bryant Walker. 4. Report on the Isle Royale Orthoptera of the 
1905 Expedition to Isle Royale ; A. P. Morse. ‘5, Neuropteroid 
Insects from Isle Royale, Michigan; Dr. James G. Needham. 
6. Diptera of the 1905 University Museum Expedition to Isle 
Royale ; Professor James 8. Hine. 7. Annotated List of Isle 
Royale Hymenoptera; E. 8. Titus. 8. The Ants of Isle Royale, 
Michigan; Dr. Wm. M. Wheeler. 9. The Cold-Blooded Verte- 
brates of Isle Royale ; Dr. A. G. Ruthven. 10. Annotated List 
of the Birds of Isle Royale; M. M. Peet. 11. Notes on Isle 
toyale Mammals and their Ecological Relations ; Dr. Charles C. 
Adams. H. E. G. 

7. The University Geological Survey of Kansas, Erasmus 
HawortH, State Geologist. Vol. ix, Special Report on Oil and 
Gas. Pp. xiv, 586, with a geological map, 1 chart, 107 plates, 
and 8 figures. Topeka, 1908. Sent when applied for upon the 
receipt of 30 cents postage.—This large volume is devoted to a 
special report on the petroleum and natural gas of Kansas, and 
has been prepared by the state geologist and his assistants. The 
great economic development of these industries in the mid-con- 
tinental field of Kansas and Oklahoma within the first few years 
(see also xxvili, 560) gives a peculiar interest to this volume. It 


Geology and Natural History. 269 


opens with a historical chapter in regard to the discovery of oil, 
particularly in Kansas, from 1860 down to the present time, the 
third or most important period beginning with 1890. Chapters 
follow on the history of field work, the stratigraphy, etc., while 
the subjects of the chemical composition of both gas and petro- 
leum are taken up in much detail. J. W. Beede and- A. F. 
Rogers (pp. 318-389) contribute an account: of faunal studies 
from the Coal Measures, and E. H. Sellards chapters on fossil 
plants (pp. 386-480) and on fossil cockroaches (pp. 501-541). 

8. Das Antlitz der Hrde; von Epnuarp Surss. Third vol- 
ume, second half; conclusion of the entire work. Pp. iv+789, 
55 text illustrations, three tables and five colored maps. Accom- 
panied by an index of 153 pp. bound separately.—The publica- 
tion of this final volume of ‘The Face of the Earth” marks the | 
consummation of the life work of the distinguished leader of 
European geology, the completion of a labor so important and so 
vast that at the recent annual meeting of the Geological Society 
of Ameriga a resolution of congratulation and admiration signed 
individually by the entire body of geologists present was trans- 
mitted to its author. 

In this work, the publication of which has extended over a 
generation, the entire geological literature of the past century of 
‘both the old and new worlds has been drawn upon for the mate- 
rials of construction. The more important papers have been 
abstracted and numerous references will enable the future investi- 
gator to use these volumes as a starting point for research on 
any geological province or to acquaint himself with that degree 
of progress in the earth science which marked the nineteenth 
century. It must not be thought of, however, as primarily a 
compilation, for Suess has done this work with a breadth of view 
which has made all subsequent generations of geologists his 
debtors and has used the materials to achieve ends of his own, 
bringing forth conclusions which the individual workers did not 
perceive. ; 

The volume opens with a description of the regions folded at 
the close of the Paleozoic in the old and new worlds and goes on 
in later chapters to consider folded tracts of later date, faulted 
regions, and the island arcs of the Pacific. Later parts treat of 
the theories of origin of these structures and of igneous activity. 
A chapter is devoted to the Moon and a concluding chapter to 
the life of the earth. 

In a brief notice of a voluminous work such as this no. discus- 
sion can be given of the subject matter and conclusions, as space 
would only permit a partial view of a few arbitrarily selected 
topics. It may be noted, however, regarding the mode of treat- 
ment that the work is built upon an exhaustive study of areal, 
structural and paleontological geology. It sums up, therefore, 
and uses with great power the modes of research which were 
especially employed in the nineteenth century. The youngest 
member among the family of geological sciences, physiography, 


270 Scientific Intelligence. 


has been widely applied as a mode of research only since the 
opening of the twentieth century and the light which it is throwing 
_on the continental histories since the close of the Paleozoic has. 
come too late to be incorporated into the body of this work. It 
is to be hoped that an English translation of this, as of the pre- 
vious volumes, will soon appear in order that a wider and more 
intimate acquaintance of it among English readers may be 
acquired. Jj Be 

9. Beitrdge zur Flora der unteren Kreide Quedlinburgs, Teit 
IT; Die Gattung Nathorstiana P. Richter und Cylindrites spon- 
gioides Goeppert ; by P. B. Ricurrer. Pp. 11, with 62 figures 
and 6 plates. Leipzig, 1909 (Wilhelm Engelmann).—In this part. 
are described in detail two new species of the new Lycopod 
genus Nathorstiana and Cylindrites spongioides. The latter is 
thought to be a strand nian either a conifer or Pseudocyceas. . 

Gruss 

10. Cave Vertebrates of America: A Study in Degenerative 
Evolution ; by Cant B. Kicenmann. Pp. ix, 241, with 72 text 
figs., 29 plates and frontispiece. Carnegie Institution of Wash- 
ington, Publication No. 104, July 9, 1909.—Dr. Higenmann has. 
enjoyed unusual privileges for the study of cave life and its de- 
generating influence, and the results of his years of study are 
embodied in this handsome quarto. Some of the more striking of 
the author’s conclusions are as follows : 

“The bleached condition of animals living in the. dark, an indi- 
vidual environmental adaptation, is transmissible and finally 
becomes hereditarily fixed. 

“ Ornamental secondary sexual characters not being found in 
blind fishes are, when present, probably due to visual selection. 

“ Individual degeneration of the eye may begin in even earlier 
stages of development until nearly the entire development be- 
comes affected, that is, functional adaptations are transmissible.” 

The cave environment is divided into three regions: (1) Twi- 
light just within the cave bounded by the distance to which light 
penetrates from without; (2) Region of fluctuating tempera- 
tures ; (3) Inner cave region with absolute darkness, very slight 
temperature changes. The animals constituting the cave fauna 
are not all of one class, nor do those within one class belong to. 
one family. They are very diverse in character and origin, but 
not all families of vertebrates are represented, as a certain predis- 
position in habit and structure is necessary 

Caves are populated by one of the four following processes : 
(1) By accidental carrying into caves; (2) Animals may step by 
step have colonized the caves, becoming adapted to the environ- 
ment as successive generations gradually entered deeper and 
deeper recesses of the caves; (3) Animals which had elsewhere 
become adjusted to do without light may have gathered volunta- 
rily in caves; (4) Animals may have developed along with the 
development of the caves. 

The plant food of cave dwellers is from the nature of things 


Geology and Natural History. 271 


all imported. Eyes and color tend to degenerate ; but cave ani- 
mals are marvelously sensitive to tactile sensations, especially to 
vibrations; and experiments goto prove that blind cave fishes are 
still sensitive to pencils of light over the entire body. In general 
the older caves have a more profoundly modified fauna than the 
newer, and cave animals tend to converge while epigean animals 
tend to diverge. Ri, Sal: 

11. Die Sdugetierontogenese in threr Bedeutung Sur die Phy- 
logenie der Wirbeltiere ; by A. A. W. Husrecnt. Jena, 1909 
(Gustav Fischer). Pp. 247. with 186 figures in the text.—In this 
important memoir Professor Hubrecht discusses the early ontog- 
eny of mammals and its bearing upon the accepted phylogeny of 
the vertebrates. The paper sums up the later work not only of 
the author but of contemporary embryologists and arrives at some 
very interesting conclusions, several of which, however, are yet 
open to corroborative proof from other branches of biology. 

Hubrecht regards the fetal structures as of prime importance 
in the study of mammalian evolution, for the finer details of ontog- 
eny give us a keen insight into the relationship of the various 
groups. The author proposes a new classification based upon 
this source of knowledge, which will not, however, be universally 
accepted. He divides the vertebrates into four super-classes : 
(1) Cephalochordata (Amphioxus); (2) Cyclostomata; (3) 
Chondrophora (Elasmobranchii) ; (4) Osteophora (all higher 
vertebrates). 

He suggests that many of the Dipnoi, Ganoids, and Teleosts 
may have had terrestrial ancestors just as did the Cetacea ; that 
the mammals and Sauropsida may both trace their phylogeny back 
through amphibian-like Carboniferous animals and thence back- 
ward through aquatic ancestors to worm-like forms derived from 
the Celenterate stem. Based upon evidence derived from the 
placentation, Hubrecht concludes that Man, the Anthropoid apes 
and the insectivorous hedgehog are most primitive; the human 
ontogeny showing the most archaic characteristics of all—an 
interesting argument in favor of the high antiquity of Man. 

Re Sa D. 

12. The Occurrence of Strepsicerine Antelopes in the Tertiary 
of Northwestern Nevada ; by Joun C. Merriam. University of 
California Publications, Vol. V, No. 22, pp. 319-330,—The expe- 
dition of 1909 to the Virgin Valley and Thousand Creek region 
of N. W. Nevada procured a wide range of mammalian forms of 
which a considerable per cent are new. Of these some of the 
most interesting are twisted-horned antelopes, known now only 
in Africa and throwing additional light upon past mammalian 
migrations. Two new genera, each with a new species, are de- 
scribed which are most nearly related to the strepsicerine or tra- 
gelaphine division of the antelope group, now confined to Africa, 
but represented by several typical twisted-horned types in Europe 
and Asia in later Tertiary time. Ry Sed 


272 Scientific Intelligence. 


13. Recherches Géologiques et Pétrographiques sur ? Oural du 
Nord. Le Bassin dela Haute Wichéra; par L. Duparc. Mem. 
Soc. phys. et d’hist. nat. de Genéve. 4°, vol. xxxvi, fase I, 1909, 
pp. 207, pls. v.—The author states ‘that in this work he has had 
the codperation, especially in the field, of Prof. F. Pearce and 
Mdlle. Tikanowitch, It is the third volume on this region pub- 
lished by the author, the two preceding volumes being devoted 
to other parts of the northern Urals. The geological map shows 
that the bottom of the basin and the course of the river is 
determined along belts of Devonian rocks consisting of schists 
and dolomites, flanked on the one side by a range of Carbonifer- 
ous limestones and quartzites, and on the other by mountains of 
pre-Devonian metamorphic schists of various types containing 
quartzite belts and injected masses of diabase. The various geo- 
logic features of this region, including studies of its structure, of 
terrace formations, of the petrology of its rocks with a number 
of chemical analyses, are given in considerable detajl. Attention 
is also paid to the iron mines in a study of them and of the 
probable genesis of the ores. ‘The whole forms a useful addition 
to our knowledge of the geological features of a little known 
region. Li, VorBs 

14. Laboratory Botany for the High School ; by WiLuaRp 
N. Crutz. Pp. xiv, 177. Boston, New York, etc., 1909 (Ginn 
& Company).—This little laboratory manual is divided into three 
parts. The first deals with the structure and life processes of 
angiosperms ; the second, with the structure and evolution of 
the plant kingdom ; while the third describes a series of experi- 
ments in plant physiology. The distinctive feature of the book 
is that the student is left largely to his own resources. Under 
each topic a long series of questions is asked, and these are to be 
answered independently through the study of appropriate mate- 
rial. The advantage of such a method is that the knowledge 
thus gained will be first-hand knowledge. The disadvantage is 
that much of it must of necessity be fragmentary and uncor- 
related. Of course a well-trained teacher would be able to 
counteract this disadvantage by a formal and connected presenta- 
tion of the more important topics, and in the hands of such a 
teacher the book should prove of distinct service. A. W. E. 


III. Miscettanseous Screntiric INTELLIGENCE. 


1. The Norwegian Aurora Polaris Hepedition 1902-1903. 
Vol. J. On the Cause of Magnetic Storms and the Origin of Ter- 
restrial Magnetism ; by Kr. Birrketanp. First section. Pp. vi, 
315, with 21 plates. Christiana, 1909.--The author of this work, 
between the vears 1896-1903, carried out three expeditions to the 
polar regions, with the object of procuring material for the 
investigation ‘of terrestrial magnetism and the aurora. The 
investigations are recorded in this work, the first section of 
volume I having the special title given above, while volume II 


Miscellaneous Intelligence. 2738 


will treat of the aurora and some results of the meteorological 
observations made. The amount of material available will be 
obvious from the fact that in 1902 and 1903 magnetic register- 
ings were available from twenty-five observatories, seattered over 
the world, including the four Norwegian stations on Iceland, 
Spitsbergen, Novaja Semlja, and Finmark. Certain well-marked 
magnetic storms in 1882-3 have also been treated from the 
observations in the reports of the International Polar Expedition. 
The author in 1896 advanced the theory that magnetic disturb- 
ances on the earth, as well as the aurora borealis, are due to cor- 
puscular rays emitted by the sun; and the observations recorded 
have been treated with a view to show their relation to this 
theory. He says: “The magnetic storms, for instance, have been 
studied in such a manner, that on the one hand we have formed 
from our observation-material a field of force which gives as 
complete a representation as possible of the perturbing forces 
existing on the earth at the times under consideration. On the 
other hand, by experimental investigations with a little magnetic 
terrella in a large discharge-tube, and by mathematical analysis, 
we have endeavoured to prove that a current of electric corpuscles 
from the sun would give rise to precipitation upon the earth, the 
magnetic effect of which agrees well with the magnetic field of 
force that was found by the observations on the earth.” 

He adds : “The disintegration theory, which has proved of the 
greatest value in the explanation of the radio-active phenomena, 
may possibly also afford sufficient explanation as to the origin of 
the sun’s heat. The energy of the corpuscular precipitation that 
takes place in the polar regions during magnetic storms seems, 
indeed, to indicate a disintegration process in the sun of such 
magnitude, that it may possibly clear up this most important 
question in solar physics.” 

He believes that future results in this line will serve to solve 
the questions as to the origin of terrestrial magnetism and that of 
the sun’s heat. Professor Stormer has carried on the mathe- 
matical investigations in connection with the author’s theory, 
which are intended to make clear the movement of electric cor- 
puscles from sun to earth. These will be published in a special 
part of the present work. 

The author considers it to be beyond doubt that the powerful 
‘magnetic storms in the northern regions are due to the action of 
electric currents above the earth near the auroral zone. The 
attempt has been made in the case of some of the storms to cal- 
culate the strength of horizontal currents that would cause them, 
supposing that they acted magnetically as galvanic currents. In 
the case of the greater storms, current strengths of from 500,000 
to 1,000,000 amperes or even more have been obtained. He has 
calculated also that according as to whether the currents are due to 
cathode or to B-rays, the energy for 1,000,000 amperes would be 
19°6 X 10° or 535 10° horse-power. Further considerations lead 
to an estimate of 10’° horse-power for the energy of the rays 


274 Screntific Intelligence. 


that would come in contact with the earth if the latter was 
non-magnetic. 

2. Carnegie Institution of Washington.—In connection with 
the dedication of the administration building of the Carnegie 
Institution at Washington, Dec. 13, 1909, a pamphlet has been 
issued describing the plan and scope of the Institution, and 
showing in brief form what it has grown to be in the past eight 
years. There are ten departments enumerated, most of which 
have their own permanent homes where active research is being 
carried on ; these are illustrated by numerous views in this report. 

The Highth Year Book of the Institution (pp. vii, 259, with 
16 plates), which has just appeared, gives a detailed account of 
its work during the year 1909. On the financial side it is inter- 
esting to note that about $700,000 of income were available, of 
which the sum of $467,500 was expended for the now well estab- 
lished larger projects, $50,000 for minor grants toe individuals, 
$30,600 for research assistants and $104,600 for publication and. 
administration. The entire amount expended by the Institution 
up to 1910 reaches the imposing total of $4,129,000. 

The work of the Institution has expanded in a remarkable 
manner, particularly along the lines determined by the various 
special departments of research to which the resources are chiefly 
devoted. ‘These include, as enumerated in former notices, the 
Solar Observatory in California ; the Geophysical Laboratory in 
Washington (the important results from which are contained in 
this Journal); the Marine Biological Laboratory at Tortugas, 
Florida, and that of Experimental Evolution at Cold Spring, N.Y.; 
the Desert Botanical Laboratory at Tucson, Arizona, and others. 
The non-magnetic yacht Carnegie started’ on her first trip in 
August last and at this date has just returned from a highly 
successful voyage of 8,000 miles. An interesting digest of the 
results accomplished in these and the other lines of research is 
given in the Year Book ; as a whole it gives a good idea of the 
efficiency of the entire organization under the charge of Dr. 
Woodward, and the vast amount of good work which is being 
accomplished. 

As noted above, the administration of the Institution has now a 
permanent home in a handsome building at the corner of Six- 
teenth and P streets in Washington, dedicated in December last. 
The work of publication has gone on steadily through the year, 
nineteen volumes, aggregating about 5,000 pages, having been 
issued (see vol. xxvii, 347, xxvill, 564). The total number of 
publications is now 141, with some 35,000 printed pages. 

3. Lhe Carnegie Foundation for the Advancement of Teach- 
ing. Fourth Annual Report of the President, HENRY Sm1ITHa 
Pricurtr, and the Treasurer, Tuomas Morrison CARNEGIE. 
. Pp. 201; 576 Fifth Avenue, New York City.—At the end of 
September Jast the total funds of the Carnegie Foundation 
amounted to $11,108,000. The income for the year was $544,355, 
of which $343,870 was paid out for retiring allowances and about 


Miscellaneous Intelligence. 275 


$53,600 for expenses of administration, publication, etc. An 
unexpended balance of $147,000 remained, which is included in 
total amount of the fund as stated above. During the year 115 
pensions aggregating $177,000 were granted, bringing the num- 
ber of pensions now being paid up to 318, involving a cost of 
$466,000; this statement alone shows how widely the benefits of 
this great contribution to the cause of the higher education are 
being distributed. There are now 67 institutions in the accepted 
list, including five state institutions, one of these at Toronto, 
Canada. 

An important change has been made the past year in the work- 
ing of the system, the service pension, which allowed an indi- 
vidual to retire at any age after twenty-five years of professional 
service, having been withdrawn except in the case of teachers 
who from disability are unable to continue active work. On the 
other hand, the age pension, which as previously allows retirement 
at an age of sixty-five years, is extended to all who have served 
twenty-five years, including their work as instructors. The 
reasons which have led to these changes are clearly stated by the 
President. A variety of other problems are also discussed by 
him: these are in part administrative, dealing with college finances 
and financial reports, advertising, the function of the trustee, and 
other related points. Other matters treated of are educational 
and have to do with the standards of entrance examinations, and 
of college and university instruction in general. The Foundation 
aspires to be a powerful force in raising and unifying college 
requirements and standards; in this direction it can accomplish 
great good, but constructive criticism from without, in the case 
of an established institution, involves many delicate questions 
which require careful handling that good results may be assured. 

4. Relief Maps.—The geological department of the University 
of Wisconsin has prepared a geological relief map, or model, of 
the state of Illinois, copies of which may be purchased from the 
Board of Regents at Madison for $100. The map framed is 6 
feet 7 inches < 3 feet 9 inches, and is on a horizontal scale of 
five miles to one inch and a vertical scale of 1320 feet to one 
inch. A model of the Malaspina glacier, Alaska, including the 
adjacent region near Mt. St. Elias and Yakutat Bay, may also be 
obtained for $125. It is about 7 feet x 4% feet, and is on a scale 
(horizontal and vertical) of 1 : 80,000 or one inch to one and one- 
quarter mile. 

5. Report of the Librarian of Congress and Report of the 
Superintendent of the Library Building and Grounds for the 
fiscal year ending June 30,1909. Pp. 220, with 6 illustrations. 
Washington, 1909.—The Library of Congress is so universally 
recognized now as the standard of work of that kind in the coun- 
try that the report of Mr. Putnam has great interest for those 
especially concerned. It may be noted that the appropriation for 
1916 amounts to $855,000 as against an expenditure of $685,560 
in 1909. The Library on June 30th, 1909, contained 1,703,000 


276 Scientific Intelligence. 


books, a gain of nearly 168,000 for the year. The most important 
accession of the year was a gift from the Chinese Government of 
a set of the great Chinese Encyclopedia, comprising over 5,000 
volumes; this was brought to Washington by a special ambas- 
sador. Another important gift is that of one hundred printed 
volumes from the library of George Bancroft presented by Mrs. 
J. C. Bancroft Davis. The Library has also issued the follow- 
ing : 

Want List of Publications, 1909, pp. 30. 

Publications issued since 1897. Pp. 48. January, 1910. 

Select List of References in Sugar, chiefly in its economic 
aspects ; compiled under the direction of Hermann H. B. MEyer. 
Pp. 238. 

4. Harvard College Observatory: Enywarp C. Pick RING, 
Director.—Recent publications are noted in the following list 
(continued from vol. xxviii, p. 565). 

Annats. Vol. LI, Part II. A Discussion of the Eclipses of 
Jupiter’s Satellites, 1903-1893 ; by RatpH ALLEN Sampson. Pp. 
153-343, with 4 plates. 

Vol. LV, Part Il. Maxima and Minima of Variable Stars of 
Long Period; by AnniE J. Cannon, under the direction of 
Epwarp C. Pickrerine. Pp. 99-291. 

Vol. LIX, No. V. Photographic Magnitudes of 76 Stars ; by 
Epwarp 8. Kine. Pp. 128-155. 

Vol. LXIX. Part I. Photometric Observations made with 
the Fifteen-inch East Equatorial during the Years 1892 to 1902; 
by Otiver C. WENDELL. Pp. ii, 97. 

Vol. LXX. Durchmusterung Zones observed with the Twelve- 
inch Meridian Photometer ; by Epwarp C. PickERiING. Pp. vi, 
235. 

Crrcutars. No. 149. Group of Red Stars in the Constellation 
Sagittarius. Pp. 3. 

No. 150. A Standard Scale of Photographic Magnitudes. 


No. 151. 20 New Variable Stars in Harvard Map, No. 49. 


No. 152. New Variable Stars in Harvard Map, Nos. 2, 5, 32, 
44, and 53. Pp. 3. 


OBITUARY. 
M. Serce Nixitin, geologist-in-chief of Comité Géologique of 
Russia, died on the 18th of November, 1909. 
Dr. SHELFORD Bmw Lt, the English physicist, died on Decem- 
ber 18 at the age of seventy-one years. 


Dr. Cyrus Adler, 
‘Librarian U. S. Nat. Museum. 


mreVOL. XXL. APRIL, 1910. 


Established by BENJAMIN SILLIMAN in 1818. 


\ 


THE 


AMERICAN 
JOURNAL OF SCIENCE. 


Environ: EDWARD S. DANA. 


ASSOCIATE EDITORS 


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


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


Proressor GEORGE F. BARKER, or PumapE.pHi, 
Proressork HENRY S. WILLIAMS, or ItwHaoa, 
Proressorn JOSEPH S. AMES, or Battrmore, 
Mr. J. S. DILLER, or Wasurneton. 


FOURTH SERIES 


VOL. XXIX—[WHOLE NUMBER, CLXXIX.] 


No. 172—APRIL, 1910. 


NEW HAVEN, CONNECTICUT. 


Lape tsOy, 


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_ Published monthly, Six dollars per year, in advance. $6.40 to countries in the 
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3 apeetored letters, or bank checks (preferably on New York banks). 

“5 , 


es ) 
—% 
' a 
\ 
*S 
a 


NEW ARRIVALS 


BRazIL. I have just received from this locality an excellent shipment which 
includes the following specimens: An exceptionally large Tourmaline, green 
and pink, showing good color and form with its crystal attached to a quartz 
erystal; deep green Tourmaline CRYSTALS, gem quality with very steep 
rhombohedral terminations ; a fine lot of EucLase Crystats showing sharp - 
crystal faces and good form; a number of the new gem PHENACITE CRYSTALS 
and Groups which show better quality for this mineral than has ever before 
been found, and some excellent AmETHYSTS, deep in color, in good crystal 
form. 

SouTH Catirornia. From here a new lot of Tourmalines, green and 
brilliant pink in color; some showing both colors together, others in groups; 
a fine lot of beautiful ToURMALINE SEcTIONS ; and fine Topaz CRYSTALS 
from Ramona, clear, sharp and symmetrical. 

Happam, Conn. From an old.collection which I secured complete I have 
a fine lot of Tourmalines showing beauty in color and form not to be found 
elsewhere. 

New Mexico. From this placea lot of beautiful BLum TurQuotse in the 
matrix. 

Besides these additions I have still on hand a number of AWARUITES, as 
announced and described in the February issue. 

I am still receiving small shipments of Franklin Furnace Minerals, con- 
' sisting of excellent Rhodonite, Willemite, Franklinite, Zincite specimens, etc. 

IcELAND. Some very fine specimens of Iceland Zeolites, including Stil- 
bite, Heulandite, Ptilolite, Quartz geodes, etc., are still in my possession. 

AUSTRALIAN MINERALS. I have received a small lot of these which in- 
cluded: Atacamite, Cerussite and precious Opals, both cut and in the rough; 
also a few Tasmania Crocoites ; one very fine, with large crystals. 

Prices on application. 


Having an exceptionally large lot of common and rare SEMI-PRECIOUS and 
Precious Stones, both cut and in the rough, I am in a position to -satisly 
the wants of all my customers. 

I also have a fine collection of Antique CamEos, cut in Malachite, Coral, 
Lava, etc. 

Roman and Florentine Mosaics showing excellent artistic work mance 
and RECONSTRUCTED Gems as follows: Rubies; blue, white and pink 
Sapphires; pink Topaz, etc. 

Anything desired for selection I shall be pleased to send to my patrons on 
approval. Special lists with prices cheerfully given on application. 


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


(ata 


AMERICAN JOURNAL OF SCIENCE 


[FOURTH SERIES.] 


——___ 99 ———— 


Arr. XXII1.—Studies on the General Circulation of the 
Earth's Atmosphere; by Frank H. Biartow. 


A Discussion of the Departures and the Residuals of the 
Tenperature and Precipitation in Climatology. 


Merrorotocicat and climatological observatories, at numer- 
ous stations in all parts of the world, are turning out an 
enormous mass of raw material every year, which is of only 
moderate value unless it can be intelligently and thoroughly 
discussed. This material consists of daily observations which, 
when collected together in tables, produce the daily, monthly 
and annual means, respectively, by the usual processes of 
summation for the several time-terms. When these time- 
terms or periods are repeated many times, a normal mean can 
be computed as a reference value. The variations of each 
time-term on the normal may be called its departure ; the 
variation of a time-term on its consecutive mean may be called 
its residual. ‘To illustrate these terms, take the following 
examples derived from Bulletin 8S, U. S. Weather Bureau, as 
given in table 1, 1909. The annual means from 1873 to 1905 
for five stations are called Z,, ¢,, ¢,, ¢,, ¢, and this notation can 
be extended for v stations to t,. When the original observa- 
tions are reduced to a strictly homogeneous series by eliminat- 
ing the errors of observing and computing, the mean of a long 
record, as of thirty-three years, is the normal, t,.. The differ- 
ences ¢,-¢,, ¢,-¢,, . . . 4,-?¢,, for the several years, 7 in number, 
give the departures, v, having 7 values for the first station, 
v, having 7 values for the second station, and v, having 7 
values for the mth station. There are rm departures for n 
stations and 7 time-terms. Since it is evident that in restricted 
areas, as the Lake Region of the United States, the variations 


Am. Jour. Sci.—FourtH Series, Vou. X XIX, No. 172.—Aprin, 1910. 


278 F. H. Bigelow—Studies on the General Circulation 


p 


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Fic. 1. Long period of prominences and temperatures. 
Fic. 2. Short period for prominences and temperatures. 
Fic. 3. Summation of variable periods in a single definite period. 


in the temperature system, month by month, year by year, are 
similar, it is proper to concentrate the departures by taking 
the mean, 7, for several stations, 5 in this case, or m in general. 
The mean departures, 7,, for 7 years, make good material for 
the discussion of problems concerned with the general and 


279 


of the Earth’s Atmosphere. 


TasBLe [.—ILLUSTRATIONS OF TIME-TERMS, DEPARTURES, MEAN DEPARTURE, CONSECUTIVE 
DEPARTURE AND RESIDUALS. 


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potted y.10oyg | Ad 1 1G) HH ID IG ~~ 9] 1GB GD SB CRAREBSARSSIRRES rot 
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Residuals 


280 #. H. Bigelow—Studies on the General Circulation 


cosmical causes, such as the movement of the sun in declina- 
tion, from 23° north latitude to 23° south latitude, due to the 
annual motion of the earth about the sun, the rotation of the 
sun on its axis, the aperiodic fluctuations of the solar radiation 
due to its thermodynamic internal actions, which affect the 
temperatures of the earth in small regions or as a whole. 
These mean departures, 7,, usually consist of long and short 
fluctuations, and it is necessary to separate them in preliminary 
studies, in order to obtain some idea of the kind of action 
underlying the variations, with the purpose of finding out the 
laws representing the physical processes involved. The most 
convenient way is to take consecutive means for a selected 
number, 7,, of the available 7 time-terms. In the example the 
consecutive years are 5 in number, and the 5-year means 7, 
derived! toni gee T, 1n succession are placed in the next 
~eolumn, that for 1873-1877 against 1875, that for 1874-1878 
against 1876, the last being 1900-1905 against 1903. The 
T, consecutive departures represent the long period term, 
which is found in the rapidly changing system of departures 
Vin» The short-period term is found by subtracting each r, 
from 7, in succession, so that the vreseduals, t,-7,, are short 
period variations in the system of departures. Examples of the 
use of this method can be found in the following papers : Bul- 
letin R, The Daily Normal Temperature and Precipitation of 
the United States; Abstract of data, No. 3, The Annual Pre- 
cipitation of the United States; this Journal, vol. xxv, p. 413, 
May 1908, The Relation between the Meteorological Elements 
of the United States and Solar Radiation. In the last paper 
the data of the solar prominence frequency numbers and the 
European horizontal magnetic force are treated in the same 
way, and the data of the solar prominences here used are 
extracted from it. The long-period consecutive means P,, for 
5-year intervals, and the short-period residuals, P—P.,, are 
placed in Table 1; they are plotted together with the corre- 
sponding temperature variations in fig. 1. An inspection of 
these diagrams brings out clearly several features of the 
problems of departures and residuals, which must be care- 
fully considered in discussing the physical causes that produce 
them. It is apparent that the long-period curves have a 
similar synchronism, but that the temperatures seem to lag for 
about two years behind the prominences during the interval 
1877 to 1888, while the lag has apparently disappeared after 
1888. In the short-period the same lag occurs in the first half 
of the run, the crests being displaced in the temperatures 
about two years to the right, while in the second part of the 
curve the crests synchronize or become minor and irregular 


of the Harth’s Atmosphere. 281 


together. Both sets of curves are inverted so that an zncrease 
in the solar prominence frequency is followed by a decrease in 
the annual temperatures of the Lake Regions of the United 
States. 

It is not our purpose to discuss these problems here other 
than as illustrating certain principles in the discussion of 
departures and residuals in solar and meteorological data 
derived from observations. Similar data, as stated, are being 
collected in every branch of physics pertaining to the atmos- 
pheres of the sun and the earth. In stellar and planetary 
astronomy the problems of variations and departures, called 
perturbations, are comparatively easy, because the effects of 
the laws of gravitation are studied in rigid masses that can be 
reduced to ideal points. In astrophysics and meteorology 
these problems become enormously difficult, because the masses 
are gases flowing in complex paths that cannot be traced 
directly, as one follows a comet or a planet in the heavens, but 
only indirectly in the accumulated effects of a general circula- 
tion, and its local disturbances, that is in the barometric 
pressures, the temperatures, the densities, and the velocities of 
the atmosphere, at the numerous meteorological stations, these 
being located only in the lowest stratum of the moving fluid. 
The problem is so exceedingly difficult in itself that we may 
fairly be permitted to employ such means of discussion as are 
obviously suitable in order to avoid an inevitable failure in 
reaching a valuable result. The problems of solar and ter- 
restrial synchronism can be discussed by two general methods, 
(1) a strictly rigid mathematical analysis, and (2) a statistical 
method combined with an interpretation guided by graphic 
traces. The former is preferred by some as applying definite 
principles, and allowing no chance for accommodation by a 
biassed judgment; the latter is preferred by many as the only 
method for a first approximation to a clear understanding of 
relations too complicated to be unravelled by any mathematics 
now in existence. Some criticise the former method as allow- 
ing no room for the practical judgment, and the latter method 
is criticised by others as allowing too much room for the judg- 
ment, especially on the part of those who seek a special result. 
The truth seems to be that the former method is allowable for 
the adjustment of the constants and terms of an equation 
wherein the physical processes are already approximately . 
understood. The latter method is necessary and allowable in 
those preliminary researches which seek to discover what the 
law in question is, rather than in the refinement of it. The 
first method always leads to zero-results in dealing with solar 
and terrestrial phenomena. The latter offers some hope of 


282 FF. H. Bigelow—Studies on the General Circulation 


success in the present state of the development of this branch 
of science. We mean to include under the former method of 
rigid analysis, (1) the usual appleation of the theory of least 
squares for the detection of an unknown period, by the 
criterion of the sum of the squares of the departures being a 
minimum ; (2) Professor Schuster’s Harmonic Analysis and 
Periodogram for the detection of hidden periodicities, Terr. 
Mag. 1898; (8) the Fourier series in various forms of the 
harmonic analysis; (4) Professor Newcomb’s criterion for 
fluctuations without any discernible period, Am. Phil. Soce., 
vol. xxi, part v, 1908. 


Periodic and aperiodic synchronism. 


There is one general principle underlying each of these 
methods of analysis, namely, that they seek a definate period, 
and assume as the premise of argument that synchronism 
between solar and terrestrial variations depends upon the 
existence and proof of such a period. It has, however, not 
been established that the cycle of the solar thermodynamic 
processes is periodic, in anything like the same sense that the 
annual orbital motion of the earth about the sun produces one 
true period in the processes within the earth’s atmosphere, 
while the rotation of the earth on its axis produces another 
true periodic cycle of variations. On the contrary, the 
observed solar processes are so irregular as to be distinctly 
aperiodic. The so-called 11-year period varies between 8 years 
and 14 years in iength in an irregular succession ; the synodic 
rotation of the sun on its axis varies in latitude and altitude 
above the photosphere, from 26°7 days at the equator to 31:0 
days near the poles for the level of the photosphere, but from 
26°0 days at the equator to something like 29 days for the 
upper levels of the chromosphere. There are numerous 
irregularities noted in the irruption of the prominenees in dif- 
ferent longitudes so that they appear earlier in the middle - 
latitudes of the sun than in the equatorial and the polar zones. 
Furthermore, it is found that in the analysis of the sun spot 
numbers, the prominence frequencies, and the magnetic field 
intensities, there is usually superposed upon the long period, 
ranging from 8 to 14 years, four minor crests, though only 
three of them are fully developed in some periods. If, for 
example, we assume a long period of variable length, hav- 
ing three or four minor variations within each of them, and . 
attempt to sum them together on any assumed definite per iod, 
the result will be similar to that displayed in fig. 3. If the 
ll-year period with four crests be summed with an 8-year 


of the Karth’s Atmosphere. 283 


period and a 14-year period, it is evident that the summation 
will destroy all evidences of periodicity and synchronism in 
the minor fluctuations. The long periods may survive with a 
feeble amplitude, while the short periods will certainly vanish. 
It is a misnomer to speak of these irregular oscillations as 
periods, and it is a non sequitur of analysis to assume that 
synchronism depends upon periodicity. If the irregularities 
in the variations of the solar and the terrestrial phenomena 
match each other in the time-sequences, this is a better proof 
of synchronism in physical causes and effects than could be 
obtained by employing a definite period having wide ampli- 
tudes of oscillation. 


Inversion effects. 


Besides the impropriety of forcing the observed departures 
of different phenomena into mean periods which do not exist 
in nature, there is a failure to recognize the fact that the same 
external or general cause, as an increase in the solar radiation 
energy, may produce inverted effects within the earth’s atmos- 
phere when different localities are compared together. Since 
the total weight of the earth’s atmosphere remains fixed, it is 
obvious that the pressures of the atmosphere can be distributed 
in diverse manners only by balancing an excess in one region 
by a defect in another region. It has been found that the 
pressures of the atmosphere of the earth as a whole vary in 
such a manner that the years of annual excess in the eastern 
hemisphere are compensated by simultaneous deficiencies in 
the western hemisphere, the variations following the sequence 
of the solar prominences. Since the sum of the moments of 
inertia for the whole earth’s atmosphere must be equal, in 
order to maintain the period of the earth’s rotation on its axis 
a constant, it follows that the cerculation of the atmosphere 
adjusts itself automatically under the action of the force of 
gravitation to certain velocities appropriate to the latitude away 
from the equator, and the height above the earth’s surface. 
This complex process is only partially understood as yet, but 
it is evident that along with the readjustment of the circula- 
tion there is a redistribution of the terrestrial temperatures in 
latitude and in longitude. Thus, it has been found that the 
year of excess of temperature in the tropical zone is accom- 
panied by a defect of temperature in the temperate zones, this 
being due to the return-cold or polar currents bringing down 
air from the higher levels to the surface in temperate zones, 
to compensate for the increase of the upward circulation in 
the Tropics as caused by the increase in the solar radiation. 
This general principle has many exceptions in the temperate 


284 FF. H. Bigelow—Studies on the General Circulation 


zone, due to the relative action of the continents and the 
oceans upon the general circulation in the surface levels where 
the observations are generally made. Again, it is not possi- 
ble to treat a continent, or even a portion of a continent, as a 
unit. Thus, there is usually a temperature oscillation between 
the Pacific States and the Central and the Eastern States in 
North America, one being high while the other is low. Some- 
times the interior stations of the United States show an excess 
of temperature, while all the states bordering on the Atlantic 
Ocean, the Gulf of Mexico and the Pacific Ocean have a simul- 
taneous defect. The complications of the circulation are 
excessive and difficult to classify in a simple system, but it is 
important to emphasize the fact that stations from all parts of 
the world cannot be massed together for short-period varia- 
tions, and even for long-period oscillations a discriminating 
knowledge and judgment is demanded. The selection of sta- 
tions for any least square or harmonic analysis should have as 
much regard for the fact of inversion-effects, proceeding from 
the same external general cause, as for the other fact that 
periodicity is not necessary for synchronism in physical pro- 
cesses, 


FHlomogeneous direct observations. 


The means, departures, consecutive means, and the residuals, 
depend upon ‘original observations which must be homogene- 
ous to produce valid variations of any sort. In the tempera- 
tures, the observations are made at a few selected hours; in 
the precipitation they are made occasionally, at the end of ‘the 
irregular rain and snow intervals; in the solar prominences 
they are made from a few stations as sights of the sun are per- 
mitted by local cloudiness; and similarly with other phenom- 
ena. In the United States the daily temperatures depend 
upon observations made at 7 A. M., 3 Pp. M., 11 Pp. m., Washing- 
ton meridian time, 1871-88; at 8 a. M., 8 p. m., 75th meridian 
time, or maximum and minimum temperatures since July, 
1888. Previous to the publication of Bulletin 8, 1909, there 
was no series of homogeneous temperatures in the United 
States available for discussion. The hours of observation 
differ widely in other countries, and in general the entire sub- 
ject of temperature variations for the world is very chaotic 
and unsatisfactory. The practical ditticulty of securing 24 
hourly observations every day, except by self-registering instru- 
ments, is so great that different combinations of selected hours 
have been used as substitutes, to the great detriment of scien- 
tific meteorology. Since the selected hours of observation are 
on Washington or 75th meridian mean time, it follows that the 


of the Karth’s Atmosphere. 285 


local hours of observation change by the difference of longi- 
tude between the standard meridian and the local meridian, so 
that 8 A. M., 8 Pp. mM. becomes 7 A. M., 7 P. M. on the 90th 
meridian, 6 A. M., 6 p. M. on the 105th meridian, 5 a. m., 5 Pp. M. 
on the 120th meridian. If the mean of 8 a. Mm. and 8 P. M. on 
the 75th meridian gives the same mean as the mean of 24 
hourly observations, it will not do so on other meridians at 
some distance from it, because the temperatures change with 
the local hours. The mean of the maximum and the mini- 
mum temperatures, taken with the standard thermometers, is 
the best substitute for 24 hourly readings, considering all the 
irreeularities produced by local conditions, though a correction 
is required for accuracy. It is obvious that these selected 
hourly readings having been used to compute the daily, monthly 
and annual means, from which the normals, departures, and 
residuals are derived, introduce systematic errors in the varia- 
tions, which render them unfit for discussion by any graphic 
method or harmonic analysis. If the published reports in 
meteorological libraries are used without any reconstruction 
such as that indicated, it is evident that conclusions derived 
from them cannot carry much weight in any problem of solar 
and terrestrial synchronism. 


Grouping of Stations into districts and size of means. 


A preliminary examination of the pressure and temperature 
departures for the whole earth, 1873-1901, as published in the 
Monthly Weather Review, November 1903, indicates the fol- 
lowing conelusions : (1) inversion of pressure variations between 
the eastern and western hemispheres ; (2) inversion of tempera- 
ture variations between the tropics and the polar temperate 
zones ; (3) very small survival of the long, or 11-year, period, 
for the entire earth ; (4) comparatively large departures for the 
short, or 3-year, period ; (5) the inversion of temperature from 
the tropics to the poles producing a vanishing or irregular 
variation along the high pressure belt near latitude 35°; (6) an 
increase of amplitude in the direct temperature type towards 
the equator, and an increase in the amplitude of the inverse 
type towards the pole from latitude 35°; (7) a tendency to 
invert between the ocean and continent; (8) that the 11-year 
period amplitude does not diminish from the equator to the 
pole by the function of the cosine of the latitude ; (9) that it 
is not proper to combine tropical and temperate zone stations 
in the same summation without regard to inversion; (10) that 
it is not proper to combine several periods of unequal length 
in one summation without’reducing the phases for the short 
period to an assumed standard period, as 11-years. 


286 LF. H. Bigelow—Studies on the General Circulation 


To illustrate a few of these points, take the stations in the 
United States, Washington, Key West, Galveston, St. Louis, 
Salt Lake City, Phoenix, San ee. and sum the departures 
as follows in four groups, in Table 2 


Eastern Districts, Wash., K. W., Gal. S. L. and take mean 7, 


Western Districts, Salt Lake, Ph., 8. D. - & be ae 
Inland or Northern, Wash., 8. L., 5. L. C., Ph. * “6 eo 
Coast or Southern, K. W., Gal., S. D. oh ss as 


If now we combine 7, and 7, in a general sum, taking the sum 
of the positive values ‘of ae and setting against tT, the algebraic 
sum as it comes, in order to see whether there is inversion or 


not within the United States, we find the following results: 
When T, +107, 7, = — 4° 
= i 


t= 101, as 


Oo Ww 


showing that there is a tendency to inversion between eastern 
and western districts. Similarly, 


when Tees aa lO = ea 
(== = 104, 7 = Se OS 


showing that when the inland or northern districts vary the 
tendency is for the coast and southern districts to fluctuate 
accidentally. The smallest variations in the United States are 
on the Southern Rocky’ Mountain plateau, and the largest in 
the Lake Region. Similar studies should be made of residuals 
before attempting to combine them, because the same external 
and general cause produces inverted effects through the action 
of the complex circulation of the atmosphere, as will be 
explained in other papers. 

The size of the annual departures demands a statement as 
regards their value in practical meteorology. On the face of 
it, the annual variations on the normals are small, and they show 
that there is no secular progressive change in the conditions of 
the clmate. An examination of the daily and monthly means 
from which the annual means are divided shows that the years 
divide into two classes, (1) those of wide oscillations and those 
of narrow oscillations. When the years of wide swing occur 
it implies that the cold polar currents and the warm tropical 
currents which meet in the United States are each respectively 
more pronounced, colder and warmer in succession, than in 
the quiet years. This intensification of warm and cold eur- 
rents is due to an increase in external solar radiation, which 
produces a stronger general and a more irregular local cireu- 
lation, Now the mean of these wide oscillations of the several 
months in a year, amounting in the winter in the Lake Region 
to as much as plus 18° F. to minus 18° F., will be about the 


287 


RAM NVNARNNHeHBDHPMOSMrAMHWSHDOSKNMAMAAHNISGHSHADIOSNDSH OD 


Se QSOS oOo BO) HS | OS SS SS HOS SIS) SS HOS SOS oa) >) oo 
pt+etet] t+etee) | +++ 1+) Cte dtl ll | 


}+) [+++] lool Pose RR tee fe a ee 


eer Teg AA 0.) eee ha en a Ole OM erne Tec Tecels Fie mulio? & eh - es sl emomte i. 16) 5 (0) ats) Sayeee Nene leer neh) «esters uence, ie 


SHrHooceontononoocooconnCococonmHToocooHnOoScoSsoS bas I | 
iltilrtl+itl tl tri tettet i | ptt) pte] et 


Se BOL s UCR ROT Meee Een Oo wkam Ver Es eer Ol ea wees ems te orb ern e "Sie, Fee. jem ecolecm ey ie Lelie ey, ney. Te 


[+] +++tttt+ +) 1 +4 +l +l t+t+e¢t¢ 1 ¢til 


| OHRRNGDHGSOSHSOHMOWABAMHRBHAOSOSO AR HAMAEDSOeH |Ot 
Set oocoooconsoooescooSoosertOorneoooneooococo pS 


RAR SAOPDH SM SOS HOM IOA ADE SSOHDIOHHANHAD (ND 


| + 
HHADOM CM OPW OCHLe OM PeCOHMLeWMenOMIMMleIOHOHD ~~ 
SS 


Eastern Districts 
Western Districts 
Inland Districts 
Coast Districts 


Ree OMe Od Ce) ee terre. wi oe en 8. MNS)! Siew eNy ei ie) Key (Oy. ONE P OXas @LU Vote Vell Lae Mag ei seeetehinters leuiiene leo Me 


Speers ny hen EL oe eee ee 


Fi IBIONDS OOH aay 
ie KIKI UOMO 7h ten hot bp 1 tO OSS ISSO eS 
De apa tae Re med alee seat) || Ue 


CB O19 OO CD 4 f= GC Ge SH 


SoSH SH HS OOD DW I$ KONDMr OO MAMA IDIDOS HOODMAN 
COCO nMMDMONOOSCOnnATAOCOnMnHOOCHOMHOHeOS 
Pret paleanarkel Pham cl oa Pal earee aera aad (lhe WP foaeelie Iie lates cess pa eR 


of the Kurth’s Atmosphere. 


DHAHNMAWDAIDHOOMSI DOH SCHDOSOMOSCHAABDNONDS 


eh oj eer 20 cone Ves Qe big Orme ie. ale OVelDs emits 0 pe [Os OL Ee Re Sams eae aie OR er meta isn ecm octet rehmhie e MCeIN “deial Vetcoble. 


V2 eres bl salar a ee 


Rye SNe El en eles a Peel bh 08. eh Heke wigs Wes Liege leueh colt: tana maiee ent pe... Teme. .-res eh: wists Labo © 


SSOSHSSSSHSSSHS SS HSS SSNS SSS ESENSS 
ete cee eeeee ee | ea aes inaere he | 


SI Oar ey Side er ey (OG Oe”. yal up SOME aye wL Mib, Oleg Se el | el) (Ohi uiel “inal ERiw Sef MeNT Taste tbe! venmemetdere. | tw 


SnnroocoeeoNnnnooocoosooonoooooooHnoeoonsS 
ae SOC RAS Ae Ae! 4) ge asearoa| elfeal| ete! Fiber lls INL er Pea te 


4) +1 
1°8} —1 
+1 
6} +171 
4} +0 
6] + 
+ 
+ 
== 
Combinations of Stations 


TABLE II].—GROUPING OF THE DEPARTURES IN DIFFERENT DISTRICTS. 


Wash. 5.0h.,.5. Lb: C.,) Ph. 


Wash? KW, Gal.S. ix 
Ke Wiee Gale Sane 


So mecis Phe SUD! 
same as when the monthly oscillations are only 6° F. or 5° F., 


when the twelve months are summed together. 


If 


mall annual excess it means that many colder waves 


lue. 
sed over the United States, and if there is a small 


In so long an 
, whether they are strong or weak in 


wv 


interval as 365 days, the oscillations due to the passage of 
nearly balanced each other about the normal va 


cyclones and anticyclones 


type, 


annual deficiency, that more warm waves have passed over the 
country. The annual departure is a guide to the interpreta- 
tion of the kind of weather conditions that have prevailed, and 


there isas 
have pas 


288 FE. H. Bigelow—Studies on the General Circulation — 


its practical value is far greater than its apparent numerical 
size, when rightly interpreted. The departures of tempera- 
ture and precipitation, monthly and annual, must be interpreted 
by the true significance of their component parts in a typi- 
eal oscillation. The 11-year variation may be very small, but 
it is made up of numerous wide oscillations of short duration, 
and the mean departure is a key to their inner meaning. 


Professor Newcomb’s Criterion of the Mean Departure. 


Before leaving the discussion of the temperature departures 
and residuals, it will be proper to summarize Professor New- 
comb’s criterion for the computation of a world-departure, that 
is, 2 variation common to the entire earth, and due to an 
external cause as the change in the intensity of solar radiation. 
One may conceive the earth as hung in space and affected as 
a whole by the intensity of the radiant heat energy that falls 
upon it. If this outside energy produces a simultaneous rise 
in the temperature of the atmosphere at the surface of the 
earth, it should be possible to compute the amount by combin- 
ing stations in different parts of the world for the same inter- 
val of time. It this effect were a simple response to the out- 
side cause, it would be an easy problem, but since it is complex 
it becomes an exceedingly difficult question how to discuss the 
observed departures and residuals. Supposing that the obser- 
vations at each station to have been made homogeneous, it is 
evident that they can be combined in one summation only upon 
the following conditions: (1) The series of fluctuations depend- 
ing upon solar action must be reduced to the same period, or 
else by taking the same phase at different intervals of time 
from the epoch, the summation will destroy the residuals by 
mere dislocation. (2) Since the same outside cause produces 
inverted effects in different parts of the atmosphere, an inver- 
sion of departures and residuals must be admitted. (8) The 
magnitude of the departures depends upon the place in the 
general circulation to such an extent that the local effect of | 
oceans and continents must be considered in the method of 
collecting the data. Since the same outside cause produces 
opposite effects, in consequence of the general and local circula- 
tion, unless discrimination is made in the grouping of the data, 
a non sequitur in the argument follows. Ii the existing de- 
partures are summed together indiscriminately, making no 
ablowance for periodic oscillations of irregular lengths, for im- 
version effects between the tropics and the temperate zones, for 
the local influence of land and water masses upon the absorp- 
tion of solar heat, and the radiation of the heat at terrestrial 
temperatures, the surviving sum of the departures and residuals 


of the Larth’s Atmosphere. 289 


will be so nearly zero as to be regarded elusive and unimport- 
ant. 

Jt may be remarked, in passing, that Professor Newcomb’s 
paper does not sufficiently recognize these principles to do 
justice to his criterion. Since this method may properly be 
applied to many problems in meteorology, it should be fully 
understood, and the following statement of it is made, slightly 
changing the original notation. Let, 


m = the number of stations in each time-term. 

7 = the number of time-terms (11-years, 3-years, year, etc.). 
v,, = the departures from a long-record normal. 

T. == the mean departure in each term-time. 

tT, = the world-departure, or regional-departure. 


Uny = Une — T, = the residuals. 
Uy = Um — T = the purely accidental local departures. 


€ =T, — T = the mean accidental local regional departure. 
> yg’? 2 i 
f= st = = the square of the mean v’. 
n I 
,2 
2 2,0 


= ne* = the mean square of v’. 


m 
| 
| 


n 
Hence, v = 7, + v’,andr =7T, + @. 
The original equation is by definition. 
Opes nuda OG eee Us) Sr. (1) 


Square this equation term by term, form the squares and the 
products, and take the sums, calling vv the successive pairs, 


SU 2 Soy = a Sr (2) 
If the variations v,, v,, v, ete. are purely accidental, there 


will be as many positive as negative values of vv,, and the 
sum of the products will be zero, 


DZCCs = 0; (3) 
Hence, if the departures are purely accidental, 
nr — sv = 0 = A = Criterion. (4) 


If A = 0 the value of the regional departure is zero; if A 
is a positive quantity, there is a true regional-departure or a 
true world-departure ; if Ais a negative quantity, one regional- 
departure is hotter or colder at the expense of another regional- 
departure. Substitute 7, + v’ for v, and 7, + ¢ for 7 in (4), in 
order to separate the purely accidental parts of the local and 
regional departures. 


A=n 27, + ¢) — 3,(7 +0)’. |» Expand, (5) 
A= 7n*3(t, + 27,€ +6’) — 3, (7. + 27,0’ + 0’). (6) 


290 #. HH. Bigelow—Studies on the General Circulation 


The terms 227,¢ and 227,v’ are each equal to zero, and since 
née = ,v" by detinition, 
A=nVr, —1t, =n sy — 2,0 — 0;1or accidental os aaa) 


A=n(n—1)r,? = 1? 37° — 3’, for n stations. (8) 
Similarly, 
A, = rn(n —1)r,’ = 73,77 — &,,0°= 0, for r series. (9) 


This is Newcomb’s Criterion for accidental departures for 
a large regional or world departure 7,. (1) Take the mean 
of the departures v, for the 7; square them and take the sum 
multiplied by n*; (2) square all the v in the n-stations and 
r-time-terms and take the sum; (8) divide the difference by 
ri(a—1) to find 7, the mean regional departure. These should 
be completed by consecutive series in succession, as 1872-76 
for T, at 1874, 1873-77 for 7, at 1875, and so on, thus elimina- 
ting all periods shorter than 7 time-terms, 5 years in this case. 

The probable error of the world or regional departure from 
the normal is found as follows: The probable error is, by the 
theory of least squares, 


OF = i (10) 
Substitute » = 7,+ v’ andt—7,+ @, 
wu ov’ — 6? — Q7,(v' + @). (11) 
In the summation the product 227,(v’ + e) = 0 
Sue ==) 0 7 ae: (12) 
SUDstikite 2-0 a — ie. amClecu— ee 
y,wW= n& — P= (n — 1)P= 3,v°— nz’. (13) 
Similarly for a series of 7 time-terms, 
rw — l)e = 30° — 22,7, (14) 


from which the value of ¢ or e, are found. 

These mathematical principles are valuable in some cases of 
pure homogeneous data, simple definite period, no inversion 
effects and no complex absorption and radiation effects of land 
and water masses, but they must be applied with discrimina- 
tion and knowledge of facts in order not to lead to a vanishing 
summation, and a non sequitur conclusion as to the meaning 
of the fluctuating departures and residuals in the observations. 
It is proper that meteorologists should approach these samma- 
tions cautiously. At present they are engaged in making their 
records of observations homogeneous, and in studying the 
general principles of inversion, radiation and absorption, under 
the dominating influences of circulation. 


The Departures and Residuals of the Precipitation. 


Unfortunately it is more difficult to know how to discuss the 
departures and residuals of the precipitation, because of the 
greater irregularity in this element due to transportation of 


Fie. 4. Typical examples of precipitation records from which to obtain 
normals, departures and residuals. 


a at ti 
ee Sa 
\ 


| mil ental 
meee btm mee 
ee es SL 
JERR SSeS Pease. 


Sec. 1.—Annual precipitation in the Lake Region and the central valleys. 
Heavy lines for the means of successive five-year groups. 


1890 1895 1900 1905 


50 Oo ase fame see eas or 
Si 
eae fs a ee | 


ss cas ae |S | a |B A ESL fs fst |e Na |) 
EE SE CF 


Sec. 2.—Annual precipitation in the east Gulf States. Heavy lines for 
the means of the successive five-year groups. 
1870 1875 1880 1885 1890 1895 1900 1906 
7 JJ nee ieee eee See eee 
= JOSS SSR ESP 2 eae eee Rees aes ee 
2 JUD OSes Sat] Pea eas Seesaw eeeeey.e 
ptt TT TT tT} 
_ Se eee a eee eee eee eee Ree aR 
BEER EEE EEE EEC EEE 
tt AY | at | rs 
pues ONS eh NE | STERN 
22) GS ERE Nee ine eA NT ge TM eel medal 
| stan oo Sa 
CERFREOTIE Eu PND aia 
ECCI ACIS CC 
BOISE ONS Ave see eRe eee 
rs) ae ne IN |e eal | Tae Te 
ages as Le eee el 
HERES US See eae ee eae ase 
eee es ee pT ET | 
RR e ee saa Se eee 
RSDEe SOUS oe eae eee see eRe 


Sec. 3.—Annual precipitation in the South Pacific States and southern 
Rocky Mountain Plateau. Heavy lines for the means of successive five-year 
groups. 


292 I. Hf. Bigelow— The Harth’s Atmosphere. 


aqueous vapor in the great currents of the circulation. It has 
been customary to take the mean of a series of years or months 
for the normal, and the difference between this normal and the 
individual values for the departures. Fig. 4 shows the general 
case that is to be considered, the data being taken from Abstract 
3 of the Climatological Division. The normal of precipitation 
for the Lake Region and Central valleys, 1872-1907, is 35°55; 
for the east Gulf States it is 50°04; for the south Pacific 
States and southern Rocky Mountain Plateau it is 14°55 inches 
per year. If the normal line on fig. 4 hes between the two 
close parallel lines, the departures are measured from this nor- 
mal to the crests of the annual line; the reseduals would be 
measured from the consecutive mean line to the crests. When 
the normal and the consecutive mean line are practically coin- 
cident as in the section 3, the departures and the residuals 
agree together, and no question arises. When, as in sections 1 
and 2, the normal line and the consecutive mean line do not 
agree, then the residuals are different from the departures. In 
such a case as the east Gulf States for 1872-1889 the entire 
system is above the normal, and for 1890-1907 it is entirely 
below the normal. It does not seem proper to confuse residuals 
with departures for practical purposes, because a series of de- 
partures all largely positive for a set of years, and all largely 
negative for a following set of years, does not give a good idea 
of the course of the phenomena in the current years that are 
within the memory of man. 

It is not easy to see how the line of consecutive five-year 
means can be extended forward with such accuracy as to make 
it suitable for a computation of the residuals of the current 
month and year in which the Climatological data are to be 
published. It is proper to submit this question to public dis- 
cussion, and an expression of opinion is solicited from engineers 
regarding the desirability of substituting approximate residuals 
for the wide departures at present inuse. The question is not 
concerning the causes of the change in the normal precipitation 
in different series of years, such as change in the general cir- 
culation, change in the exposure of the rain gauges ‘due to the 
growth oe cities, nor of the effect of deforestation and cultiva- 
tion of the soil upon climate. It only concerns the treatment 
of the records of precipitation as they are actually made. It 
is obvious that the departures of precipitation differ materially 
in principle from the departures of temperature as published 
in the Monthly Weather Review, and its readers should at 
least be aware of the problems concerning their discussion. It 
the printed departures stand as raw material without fixed 
principles of interpretation, it is evident that differences of 
opinion will arise regarding practical results which are due 
solely to different ways of interpreting the facts of observation. 


Van Name and Bosworth—Silwer Sulphate, etc. 293 


Arr. XXIII.—On Mixed Crystals of Silver Sulphate and 
Dichromate; by R. G. Van Name and Rowtzanp S&S. 
Boswortu. 


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


In 1891 Retgers* described an attempt to form mixed erys- 
tals of silver chromate and sulphate by allowing an ammonia- 
eal solution of the two salts to evaporate. The two silver salts 
were found to crystallize separately and no mixed crystals 
were obtained. The failure of this experiment makes it seem 
doubtful whether the sulphate and normal chromate of silver 
possess, to any appreciable extent, the property of forming 
mixed crystals together, especially since Retgers was unable 
to obtain mixed crystals of the corresponding sodium salts. 

We have found, however, that if the solution be sufficiently 
acid, and the ratio of chromate to sulphate within certain nar- 
row ‘limits, well developed crystals are formed, of colors rang- 
ing from pale yellow through shades of orange and vermillion 
to a deep scarlet, according to the value of the ratio just 
mentioned. Analysis of these crystals shows that they con- 
sist of silver dichromate and normal silver sulphate in varying 
proportions. As these mixed crystals have not, so far as we 
know, been described heretofore, it has seemed desirable to 
carry out the following brief investigation of their properties. 

A series of erystallizations was made at 25° starting with 
solutions of the same total acidity, about one fourth normal, 
but containing different proportions of the two acids. The 
change in concentration caused by the crystallization was kept 
as low as practicable by using in each experiment a large 
volume of solution, two liters, and so choosing the conditions 
that equilibrium was reached when only a small weight of 
erystals, usually less than three grams, had been formed. As 
will appear later, mixed crystals were only obtained when the 
molecular ratio of SO, to Cr,O, in the solution was above 99 
to 1. An increase in the proportion of Cr,O, gave only pure 
crystals of silver dichromate, so that the investigation of solu- 
tions containing high proportions of dichromate was unneces- 
sary. It was therefore possible to obtain a sufficient range of 
concentration of dichromate for all needed experiments by 
merely dissolving various amounts of silver chromate in the 
same volume of the standard sulphuric acid solution, previously 
warmed. When a higher concentration of silver was required 
silver sulphate was also added. 

The different sulphuric acid solutions were adjusted to 


* Zeitschr. phys. Chem., viii, 52, 1891. 
Am. JouR. ScI.—FourRTH SERIES, VoL. X XIX, No. 172.—Aprit, 1910. 


~ 


294. Van Name and Bosworth—Mined Crystals of Silver 


exactly the same strength by comparison with the same sodinm 
hydroxide solution. Silver sulphate was prepared from the 
purchased salt by dissolving in sulphuric acid, precipitating by 
diluting with water, and washing on the filter until the filtrate 
showed no acidity. Silver chromate was prepared by evaporat- 
ing an ammoniacal solution of the ordinary precipitated pro- 
duct, a method which gives the salt in a finely crystalline state, 
in which it is very easily washed. 

The method in detail was as follows: Two liters of the 
standard sulphuric acid solution were warmed to about 50° 
and the desired amounts of silver sulphate and chromate dis- 
solved as described above. This solution was filtered while 
still warm into a large beaker, cooled to nearly 25°, and placed 
in the thermostat. A rotary stirrer kept the liquid in con- 
stant motion during its crystallization. After 24 hours, sam- 
ples of the liquid were taken for analysis, and the erystals 
collected, washed, and dried at 180°. The crystals were small, 
and when examined under the microscope were found to be well 
developed and apparently free from inclusions of liquid. 

In analyzing the solution Ag, SO,, and Cr,O, were deter- 
mined in separate portions of 25° each, the first two by weigh- 
ing as AgO] and. BaSO, respectively, the last volumetrically 
by titrating the iodine set free from KI. The same methods 
were used in analyzing the crystals. The results are given in 
the accompanying table. 

Owing to the small differences in composition between the 
different solutions analyzed, and to the high ratio of SO, to 
Cr,O,, experimental errors have a very disturbing effect, as is 
evident on comparing the values obtained, given in the first 
four columns of the table.* The next four columns contain 
the molecular ratios of SO, to Cr,O, in the solution and erystals 
respectively. The ninth column gives the total acidity in 
equivalents per liter, calculated by subtracting the equivalent 
concentration of the silver from the sum of those of SO, and 
Cr,O,.. The observed slight variations in the total acidity 
were probably caused in part by difference in the amount of 
evaporation which took place during the experiment, and in 
part by loss of chromic acid through the erystallization of 
dichromate. 

In experiment I no chromate was present. Experiments I 
and III gave mixed crystals containing different proportions 
of dichromate and of different color, vermillion in II and deep 

* Thus in experiment IV the proportion of dichromate in the solution 
must in reality have been larger than in experiment II, although the analy- 
sis, probably owing to a summation of errors, indicated the reverse. The . 
large effect of certain errors is well illustrated by the fact that a difference 


of less than 0°2°° in the amount of thiosulphate used in experiment IV 
would have eliminated this inconsistency. 


Sulphate and Dichromate. 


295 


Formation of Mixed Crystals of Ag,SO, and Ag, Cr,O, at 25°. 


| Analysis of 25° of solution Molecular ratio Acidity 
| Na.S.0.~ equiv. 
| Ag. | So, CaO: Solution Crystals per Solid phase 
| liter 
seem. -|-srm.. | cc. |. grm SO, | Cr.0,} SO, | CreO, 
I | 0°1621 | 0°3690 | 100°0 | 0:0 /100°0; 0:0 | 0°2476 Ag.SO, 
II 0°1645 | 0-3693 | 2-41 0:0074 99-10) 0:90 | 98-8] 1-2] 0-°2496| Mixed crystals 
| = 
We ae : WAY ioe : i : : : Mixed crystals 
lil | 0 1621 | 0°3666 ; 2°41 | 0:0074 | 99°09 ? 91 | 95°91 4:1 | 0:2484 (trace of AgsCr,0;) 
LV 01612 | 0-3666 | 2-23 | 0-068 99:2 | 0-8 | 845 155 | 0-249g, Mixed crystals 
| + AgeCr.0, 
V_ 0°1630 | 0°3617 | 2°46 | 0°0076 | 99°0 a) 0-0; 100-0 | 0°2440 AgeCr20, 
| Me Aas 
VI 01381 | 0:3476 | 3°00 | 0:0093 | 98-8 ee, 0:0} 100 0 | 0°2420 Ag.CraO; & 
Se: 
VII 0 :0583 7°13 | 0:0230 | 96-7* | 3°4* | 0:0; 100-0 AgeCr.0; 


* Calculated from the average acidity. 


scarlet in Il]. With the scarlet crystals produced in experi- 
ment III was mingled a minute quantity of much darker 
erystals. These were again obtained in experiment 1V in 
large amount, together with mixed crystals of the same scarlet 
color as before. The three remaining experiments gave crys- 
tals in which no sulphate could be detected, and which, on 
complete analysis, were found to be pure silver dichromate. 
The color of these crystals, deep wine red by transmitted hght, 
metallic gray by reflected light, was the same as that of the 
darker crystals obtained in experiments III and IV. With 
much labor about 15 milligrams of the latter crystals were 
separated under the microscope from the scarlet crystals with 
which they were mingled, and were carefully tested for sul- 
phate without result, thus showing that they too consisted of 
pure silver dichromate. 

The mixed crystals, as proved by the usual goniometric and 
optical tests, were orthorhombic, having the same pyramidal 
habit and nearly the same crystal angles as those given by 


296 Van Name and Bosworth—Silver Sulphate, ete. 


Mitscherlich* for silver sulphate. The silver dichromate was 
found to be triclinic, as stated by Tschermachert and Schabus.t 

From the above results it is clear that silver sulphate is 
“insoluble” in the ordinary triclinic silver dichromate and 
that the formation of mixed crystals is due to a rather limited 
solubility of silver dichromate in orthorhombie silver sulphate. 
The extent of this solubility at 25°, i.e. the composition of 
the saturated mixed crystals, must be very near the value 
given by the analysis of the crystals in experiment III, since 
the pure silver dichromate mingled with the mixed crystals 
was present in too small a quantity to seriously affect the 
result, and would, moreover, tend to compensate for the error 
introduced by the gradual change in the composition of the 
solution during the erystallization. As a check upon this 
result an analysis was made of another sample of approximately 
saturated mixed crystals prepared in a different experiment. 
The value obtained was 4-4 molecular per cent of dichromate, 
against 4:1 per cent in experiment III. On account of the 
small amount of material available for this last analysis, the 
result is probably less accurate than that obtained in experi- 
ment III. 

To determine the effect of an increase in acidity a series of 
crystallizations was made at 25° from solutions whose total 
acidity was approximately twice equivalent normal, prepared 
by mixing standard solutions of the two acids in a known ratio. 
The crystals were not.analyzed as the two kinds could readily 
be distinguished by their color. An initial ratio of 1:2 equiv- 
alents of Cr,O, to 98°8 of SO, gave both dichromate and mixed 
crystals, a ratio of 1:1 to 98°9, mixed erystals only. The com- 
position of the solution which is in equilibrium with both kinds 
of erystals must evidently lie between these limits. 

The above facts may be briefly summarized as follows: 

The mixed crystals formed at 25° resemble the orthorhombic 
silver sulphate in crystal form and habit, and contain a maxi- 
mum of about 4 molecules of dichromate to 96 of sulphate. 
The solution which is in equilibrium with these saturated 
mixed crystals, and at the same time with pure silver dichro- 
mate, has a composition, expressed in molecular per cent of 
Cr,O, (equivalents of Or,O, per 100 equivalents of the mixture 
of Cr,O, and SO,), lying between the limits 0°90 and 0°95 when 
the total acidity of the solution is one fourth normal, and 
between 1°1 and 1:2 when the acidity is twice normal. 

The authors wish to express their thanks to Professor Edward 
S. Dana for his kind assistance in the crystallographic and 
optical tests. 

* Pogg. Ann., xii, 137, 1828. + Phil. Mag., [2], i, 345, 1827. 

{ ‘Bestimmung der Krystallgestalten in chemischen Laboratorien erzeug- 
ter Producte,’’ Wien, 1855, page 185, | 


F. B. Loomis—The Genus Stenomylus. 297 


Arr. X XIV.— Osteology and Affinities of the Genus Stenomy- 
lus; by FrepERic B. Loomis. 


Durine the summer of 1907 the Amherst College field party 
while prospecting in the sandstones of the Lower Harrison 
levels some five miles to the southeast of the Agate Spring 
postoffice, Sioux Co., Nebraska, found fragments of a Steno- 
mylns smaller than the S. gracilis then known. -During that 
season a few badly shattered remains were collected, after 
which work was continued in other sections of the field. On 
returning the next season, however, the same levels were fur- 
ther excavated, on which it developed that there was a verita- 
ble quarry of these skeletons at this locality; for no less than 
eighteen skulls, together with enough disarticulated bones to 
represent the complete skeletons, were collected from one 
pocket, and in an adjacent portion of the hill three complete 
skeletons were found. Following this the Yale University 
party collected three skeletons, the American Museum party 
five or six skeletons, and the Carnegie Museum party five or 
six. During the season of 1909 the Carnegie Museum again 
collected in this quarry, obtaining a large number of skeletons. 
Thus already not less than forty skeletons, and I should esti- 
mate many more, have been taken out, and as the specimens 
are found along over 150 feet of the face of the hill, I see no 
reason why as many more complete skeletons should not be 
obtained from the same source. With this wonderful and 
well-distributed material there is every reason that a complete 
description should be made both for identification, osteological 
study, and comparison. 

The quarry.—The Stenomylus quarry is located some five 
miles due southeast of Agate Spring postoffice, and about one 
and a half miles up the “draw” south of the upper Harris 
place, and about the same distance a little east of south from 
the famous Agate Springs quarry of the Carnegie Museum. 
The horizon is in the Lower Harrison beds about 75 feet from 
their upper boundary. The matrix is a fine, homogeneous, 
well-bedded, soft sandstone, which differs materially from the 
much coarser and more irregularly bedded sandstone typical of 
these beds. These fine sands are about 100 feet in thickness 
and seem to have a limited extension, being traced only about 
three-fourths of a mile to the south and thinning out very soon 
in the other directions. To the east the Upper Harrison beds 
directly overlie these fine sandstones. The Stenomylus remains 
occur in two levels; the one about four feet above the other, 
and both some 70 feet below the top. In the lower of the two 


298 EF. B. Loomis— Osteology and Affinities 


levels the skeletons are pretty nuch disassociated, while in the 
upper level, when a specimen is found, it is usually a more or 
less complete skeleton. Above these levels there is nothing 
approaching a bone bed, but occasionally Stenomylus remains 
are, however, found throughout the whole thickness of the fine 
sandstones. The even sorting and bedding of these sands indi- 
cate deposition in comparatively quiet water ; and as the Lower 
Harrison beds seem to be flood-plain deposits, it would appear 
that these finer sandstones were laid down in some more shel- 
tered area behind a barrier, which barrier must have been of 
considerable extent and height to account for the deposition of 
about 100 feet of uniform material. The Stenomylus remains 
presumably floated to their final resting place, and each of the 
two bone-bearing levels represents the destruction of scores of 
individuals. The simplest reconstruction of conditions would 
picture a herd of the unfortunate creatures during the distress 
of a great flood taking refuge on the highest available point of 
land; which, however, proved too low, and after surrounding 
them the rising waters drowned and carried off the whole 
herd, males and females, young and old. The carcasses then 
floated down stream and were accumulated in the backwater, 
where they were then buried in the accumulating sands. This 
was apparently a relatively rapid accumulation, for the careasses, 
especially in the upper level, are not pulled to pieces by carni- 
vores. The position of the head in the type (fig. 1) is charac- 
teristic of a good many of the skeletons, and I believe is common 
among drowned animals. Presumably the same point of land 
in two seasons proved to be a fatal trap for herds of these deli- 
cate creatures, and afterward it was only occasionally that an 
individual carcass was washed into the area where these sands 
were accumulating. Remains of other animals are very scarce 
in these sandstones, but a few isolated bones, the Dicerathe- 
rium, and the major part of a skeleton of Daphenodon 
superbus Peterson, and a few bird bones do occur with the 
Stenomylus bones, and confirm the stratigraphic determination 
of Lower Harrison. 

Plan.—In considering the material it seems best to give a 
detailed osteological description of this species, followed by the 
distinctive comparisons of the three known species, and finally 
to consider the affinities and phylogenetic position of the 
genus. 


Stenomylus hitchcocki sp. nov. 


Type.—The type is a complete skeleton, all the bones articu- 
lated and in place, No. 2059 of the Amherst College collection. 
With this are used six skulls and a dozen upper and lower 
jaws, together with some four disarticulated skeletons and 1so- 


of the Genus Stenomylus. 299 


Hie.) 


SZ 


— 


f 
y 


fy 


Fic.1. Stenomylus hitchcocki, type specimen as seen lying in the original 
matrix. x1/6. 


300 F. B. Loomis—Osteology and Affinities 


lated bones, and the four complete skeletons of the American 
Museum. In the series are individuals which are interpreted 
as male and female, and a number of young having but their 
milk dentition. The species is named after Dr. Edward 
Hitcheock, whose work in comparative anatomy and paleon- 
tology was the stimulus for the expedition and the work of the 
writer. The individual used for the type is one which 
has just reached maturity as shown by having all the molars 
worn, but that is all, for the epiphyses of several of the 
limb bones are still free from their shafts. The position of the 
type specimen is that of an animal which has just laid down 
with legs outstretched and head thrown back, or probably 
better, of an animal which has been drowned, but is natural 
enough so that we can readily get measurements of the whole 
animal. 


Height at the shoulders __. 684™™ (27 in.) 


Length of head __--__-.--- uyiayemene (70 Thal) 
eng th! of mecha =) ae ae 380™™ (13% in.) 
Length) of body 225.22 2222 5 438" Cie ins) 
ens bhikof tail eae ee asset (Gee wa, 


This individual is slightly smaller and hghter in build than 
some of the others, and I have interpreted it as a female. In 
comparing the measurements with those of other Tylopoda it 
will be apparent that the body is unusually short; the limbs, 
therefore, appear long, though when compared with the 
length of the humerus, they are but little longer relatively 
than those of Poebrotherium. The neck in conjunction with 
the increase of limb is also a little longer than that of the Oli- 
gocene tylopod. 

Skull.—The relatively small skull has a wide cranium but a 
narrow compressed muzzle. The basicranial axis is only 
slightly bent. In conformity to the lateral compression of the 
muzzle the nasals are slender splints which diverge when they 
reach the wedge-shaped anterior end of the frontals. These 
latter bones are very wide, overhanging the orbits which stand 
out from either side of the skull. The two parietals are fused 
medianly and make a bone of considerable extent, on the pos- 
terior half of which is situated a low sagittal crest, which unites 
with the strong lambdoidal crest. This latter crest is high and 
projects strongly backward, overhanging the occiput. The 
premaxille rise rapidly on the high muzzle, expanding some- 
what at the upper end. It is the maxilla which makes up the 
greater part of the side of the snout and in this bone are two 
deep pits on either side, the first a preorbital pit, a little in 
front of the orbit and high up on the muzzle; the second a 
subnasal pit, considerably in front of the former and much 
lower on the muzzle. The preorbital pit, situated some 20™™ 


of the Genus Stenomylus. 301 


in front of the orbit, is an oval depression some 25™™ long by 
12™™ high, and so deep that between the two sides there is but 
97, which must nearly close the olfactory space within the 
muzzle. In like manner the subnasal pit is well down on the 
side of the snout, and extends from over premolar 1 to over 
premolar 4, being about the same size as is the preorbital pit. 
In the latter case the depth of the pits is, however, such that 


ineaeoe 


Fic. 2. Stenomylus hitchcocki, skull seen from above. x 1/2. 


there is but six millimeters between the two sides of the skull 
opposite the bottom of the pits, so they must practically close 
the internal olfactory passage in that vicinity. Similar, though 
less developed, pits occur in other primitive genera among the 
Tylopoda: and the preorbital pit.is also characteristic of several 
species of horses of the Oligocene genus, Mesohippus. The 
pits were probably occupied by glandular structures, but pits 
of such extent are not known to the writer among recent 
genera. The pit occupied by odor-secreting glands among cer- 
tain artiodactyls may be cited as a counterpart, but it is hard 
to believe that odor glands im any species became as large as 
those pits would indicate. 

As is usual for members of the tylopod phylum, there is an 
orbital vacuity of some extent at the juncture of the maxilla, 
nasal and lacrymal bones. The lacrymal bone itself is rela- 
tively large, extending considerably in front of the orbit. The 
margin of the orbit is sharply outlined and smooth except that 
on the lacrymal there are two deep and characteristic notches. 
The lacrymal foramen is well within the border of the orbit. 
The jugal bone bounds the front and lower part of the orbit, 
meeting in the rear the broad postorbital process of the frontal. 
The squamosum is of moderate dimensions, and carries a 
slender zygomatic process. On the lower surface the glenoid 
articular surface can scarcely be described as a cavity, making 


\ 


302 Lf. B. Loomis—Osteology and Affinities 


as it does rather a wide convex rectangular area which must 
have allowed very free movement to the lower jaw, both later- 
ally and vertically. The postglenoid facet is practically verti- 
cal and closely appressed to the bulla, the two facets (glenoid 
and postglenoid) being separated by a gap, as is the case in 
modern camels. The tympanic bone is fused to the squamo- 
sum, the external auditory meatus being a closed slightly pro- 


Fie. 3. 


Fic. 3. Stenomylus hitchcocki, side view of the skull. x 1/2. 


jecting ring; while the greatly inflated bulla is filled with 
cancellous bone, as is the case in Tylopoda generally. The 
bulla is also fused to the paroccipital process for most of its 
length. The occipital bones are all fused, and the occiput is 
narrow and small. The two condyles are sessile, and do not 
project behind the plane of the occiput. Below, their facets 
do not quite meet, being separated by a narrow groove of about 
a millimeter, the groove being, however, much wider in 
youthful specimens. The pterygoids unite with the pala- 
tines to make deep plates projecting below the base of the 
skull. The posterior nares open between the palatines so far 
forward as to make a very short hard palate. The front of 
the naral opening is opposite the front of the second molar, 
which in general is very far forward for this opening. How- 
ever, in the Tylopoda generally it is characteristic to have the 
posterior nares open well forward: so that this genus simply 
shows a somewhat higher specialization in this feature. I feel 
that the compression of the muzzle by the preorbital and sub- 
nasal pits tends to cause the posterior opening of the respira- 
tory passage to emerge into the mouth as far forward as 
possible. 

The mandible is decidedly deep for so slender a creature, 
but the reason for this is readily seen in the extreme hypso- 
dont condition of the teeth, which in a recently mature indi- 
vidual extend nearly to the bottom of the jaw. Thesymphysis 


of the Genus Stenomylus. 303 


is of moderate length and spout-like in form. The angle of 
the mandible is not produced into the upward hook-hke pro- 
cess so common among the tylopods but shows simply a slight 
projection (see fig. 6) at that point. The coronoid process is 
short and slender, being slightly recurved. The articular con- 
dyle is broad and slightly concave, the postglenoid facet being 


large and resembling that of the lama. 
The following measurements give the proportions of the 


skull: 
| Lengthin-; Length Orbit |Width| Width 
Specimen jcisor to occ. premolar 2-)weight by| across} across Age Sex 
condyle molar 3 width | orbits} molars 2 
S. hitchcocki 166 60.5 7 x 96-5 cawelly 9 
type mature 
S. hitcheockti ~ ~ ¢ ~ ‘ old 
2019 179 58 24 x 28 67 a7 Q 
S. hitcheockt ~ 92L09 mature 
1090 191 64 28 x 29 68 3 
S. hitchcocki ou milk 
2009 eae 
S. crassipes 211 Tis mature 
S. gracilis 80 27 x 26 95 57 mature 


Age.—The series of adult skulls fall into two classes irre- 
spective of the amount of wear of the teeth, namely smaller, 
lighter ones, which I should interpret as female ; and larger, 
heavier ones, which would be males. Aside fr om these char- 
acters of relative proportion I have found no distinctive sex 
characters. As all the associated skeletons must have been 
accumulated at one time, and births presumably took place in 
the spring, such individuals as show differences in age must 
have been a year apart. On this basis, the youngest, which 
have the entire milk dentition and the first molar just showing, 
would be one year old; while the next set, in which the third 
molar is just up, would be two years old, ‘at which time they 
have reached nearly full size, as shown by such a specimen as 
the type. How long they lived would be difficult to estimate, 
but every indication points to very rapid wear of the teeth ; 
so that tive or six years seem to me to represent the probable 
length of life of the older individuals studied. 

Dentition.—The dental formula is i. $c.p.gm.3 = 3F = 44, 
which is the full and primitive set. The upper incisors are 
simple chisel-shaped teeth, entirely unreduced and crowded 
into a full series. The upper canine is laterally compressed, 
making it into a subincisiform tooth, which stands a little 
apart from the incisors, however. Behind the canine there is 


304 I. B. Loomis— Osteology and. Affinities 


a moderate diastema which precedes the reduced two-rooted 
first premolar, while behind this tooth a much greater diastema 
occurs, separating it widely from the second premolar, which, 
like its predecessor, is reduced and two-rooted. The third pre- 
molar follows without any diastema, and is a narrow elongated 
tooth, but with none of the specializations of the teeth which 
follow it. The fourth premolar has acquired the selenodont 
character, though but single-lobed, its inner and outer cusps 
having developed into high crescentric ridges, with a deep pit 
between. The three molars are all extremely hypsodont, 


Gea 


Fie. 4. Stenomylus hitchcocki, upper dentition and palate. x 1/2. 


which is one of the most marked features of the genus. Each 
tooth is very simple, consisting of two lobes, each with a deep 
pit in it. There is no cement in the valleys. Hach tooth is 
nearly flat on the outer side, there being but a slight convexity 
outside the paracone and metacone, and no column except that 
the anterior border of each molar is developed into a parastyle. 
The widest portion of the series is at the second lobe of the 
first molar. The crown of each molar is greatly developed in 
height, as is seen in the section of a second molar (fig. 5), the 
top being slightly narrower than the base, so that as they wear 
the teeth appear relatively wider. A slightly worn second 
| upper molar of S. Aztchcocki has a 

Fie. 5. crown 23™" high which contained a 

pit 19™™ deep, these pits in the upper 
molars being materially deeper than 
in the lower molars. The successive 
molars seem to come up slowly or 
else the wear is very rapid, for when 
molar 3 is but shghtly worn the first 
molar is down to the bottom of the 
Fic. 5. Stenomylus hitch- pit. In addition to the considerable 
cocwi, section of upper second height of the crown the upper part 
ma ee mame reo) ve live pulp cavity fills in with dent- 
ine, so that some time after the bot- 

tom of the pit is reached the tooth still has a solid center, in 
the middle of which is a small discolored “mark.” Inasmuch 
as the wear seems to continue considerably below the base of 


of the Genus Stenomylus. 305 


the pit, the tooth in addition to its great height must increase 
still more by growth at the base during life. 

The lower dentition.—The lower incisors are flattened and 
expanded at the top so that each successive incisor slightly 
overlaps the preceding one, The laterally compressed canine 
is grouped with the incisors and has assumed the incisiform 
character completely. Even the first premolar is sem1-incisi- 
form and stands close behind the canine, being thus in the 
incisor group. Behind this there is a considerable gap in front 
of the second premolar, which, though two-rooted, is con- 
siderably reduced. Behind this in turn occurs a wide dias- 
tema followed by the small but sharp third molar. It is only 


Fie. 6, 


Fie. 6. Stenomylus hitchcocki, mandible with lower dentition. x1 / 2. 


the fourth premolar which is to any degree functional as a 
grinding tooth, and this is a short, narrow, single-cusped tooth 
without any pit, of molariform adaptation. The three molars, 
however, are developed into deep hypsodont and compressed 
teeth, each with its deep pits. The first molar is the smallest 
of the three, consisting of two lobes, which like the others 
have a straight face on the inner side, there being no columns 
except the parastyle on the front margin of each molar. This 
tooth cuts the gum apparently at about the end of the first year 
and wears very rapidly, for when the third molar appears this 
tooth has worn below the base of the pit ; but it is to be remem- 
bered that in the lower teeth the pits are not nearly as deep as 
in the upper molars. While the second lower molar is some- 
what larger, it is otherwise like the first. But the third molar 
has three lobes, the last one being only a little smaller than the 
two preceding it. The extreme depth of this tooth is shown by 
the illustration (fig. 7), which is a typical young specimen of 
S. hitchcocki, and shows that in a crown 34™™ high the pit is 


306 FF. B. Loomis—Osteology and Affinities 


but 9™™ deep. However, the tooth is available for much 
greater wear than the depth of the pit; for as age increases 
the pulp cavity fills with dentine and makes some 18™" more 
available. The great height of these teeth is the cause of the 
ereat depth of the lower jaw noticed in the description of the 
mandible. 

Milk dentition Young jaws are found in surprisingly 
large numbers, practically all of them being of about the same 
age, and showing the full milk dentition, together with the 
unworn first molar. These skulls are entirely disarticulated, 
and I have seen no incisor or canines of the upper jaw, though 
they were doubtless there. The first upper premolar is situ- 
ated near the canine and behind it is a considerable diastema, 
between it and the second small pointed premolar. It is on 


Hie. 7. Fie. 8. 


Fie. 7. Stenomylus hitchcocki, section of third lower molar to show 
depth of pit. x1/1. ; 
Fic. 8. Upper premolars of the milk.dentition. x1/2. 


the third and fourth of this series that the burden of grinding 
is thrown. Like adult molars, they are strongly hypsodont 
with high erescentric crests and deep pits. They differ, how- 
ever, in having the outer face more convex over the paracone 
and metacone, and in having a well-developed mesostyle as 
well as a parastyle; from which it may be concluded that 
these features were also present on the teeth of the ancestral 


Fig. 9. 


Fie. 9. Stenomylus hitchcocki, mandible with the milk dentition. x1/2. 


form. The third and fourth deciduous premolars are each 
two-lobed and: in general resemble the permanent molars. 
Lower jaws are usually the better preserved, the alveoli for 
the three incisors and the canine being present on several 
specimens. The canine is grouped with the incisors as in the 
adult. The first premolar is represented by a tiny alveolus 


of the Genus Stenomylus. 307 


scarcely larger than a pin hole, from which I judge that the 
tooth was vestigial. The second premolar stands isolated with 
a considerable diastema on either side of it, and like the third 
premolar is still a single-cusped tooth. The grinding tooth of 
the lower jaw is the fourth premolar, and this is developed as 
a large three-lobed, molariform tooth, with high crescentic 
cusps, and deep pits in each lobe. In all the specimens this 
tooth is well worn as thongh it had been used for grinding 
grass some time, which is the reason that I have assigned the 
age of one year ‘to the individuals with this and the first molar 
just showing, as is uniformly the case. 

Cervical vertebre.—The neck as a whole is long and slen- 
der, each constituent vertebra being markedly elongated, as is 
usual among Tylopoda. ‘The atlas is relatively long and nar- 
row, the anterior cotyli being deeply excavated to make the 
articulation for the occipital condyles. In the lower side the 
two articular facets are separated by a groove in SN. hitehcocks 
(confluent in S. crassipes), while on the upper side the two 
cotyli are separated by a wide notch. The posterior ends of 
the transverse processes are prolonged backward to make short 
horn-like projections, which extend behind the facets for the 
axis much asin Poebrotherium. The posterior facet for the 
axis is high and inflexed along the upper border, for the under 
side of the odontoid process. The edges of the transverse pro- 
cesses makea nearly straight line, in contrast to the sinuous 
one commonly found. The vertebrarterial canal enters the 


Ries £0: Fie. 11. 


Fie. 10. Stenomylus hitchcocki, atlas seen from the dorsal side. x1/2. 
Fic. 11. Axis seen from the side. x1/2. 


neural pedicle just to one side of the axial facet and passing 
throngh the arch comes out again about the middle of the 
centrum. The first spinal nerve had its exit adjacent to the 
anterior opening of the vertebrarterial canal. 

The axis is also a long and slender bone, with a long, low 
spinous process ending to the rear in two small tubercles, a 
feature very characteristic of the camels. The transverse 
processes begin just in front of the middle of the centrum and 
make moderately expanded wings to either side, their outer 


308 FF. B. Loomis— Osteology and Affinities 


edges being slightly flexed downward. The anterior facet for 
the atlas is a wide concave face extending in a trifle over half 
a circle, and dying out on the neural arches. The odontoid 
process is short and thick with a tubercle on its upper surface. 
In this the genus differs from the early tylopods, which have a 
semicylindrical odontoid, while that of the modern genera is 
spout-like. The vertebrarterial canal is confluent with the 
neural canal through the posterior third of the vertebra, then 
enters the pedicle of the neural arch, passing obliquely through 
and coming out about a third of the way from the front of the 
centrum. Just in front of the vertebrarterial foramen there 
is a wide opening for the exit of the second spinal nerve. 

The third, fourth and fifth cervicals are so similar that they 
may be treated together. They are all long and slender, hav- 
ing only the smallest vestiges of a spinous process, in which 
feature they resemble the modern camels, even having the 
characteristic to a more marked degree than any of the other 
genera in the family. The transverse processes, expanding 
wing-like on either side, extend the whole length of the cen- 
trum, and then are prolonged into slender projections as seen 
in fig. 12. These transverse processes do not have the anterior 
portion of the wing prolonged into a distinct lobe, as is the 
case in the modern Tylopoda; but rather have the lobe barely 
indicated, as is the case in Péebrotherium and Oxydactylus. 
A ventral keel develops on the posterior third of the centrum, 
expanding to the rear until it is very prominent. In none of 
these three vertebree is the vertebrarterial canal visible exter- 
nally. On cervicals 8-7 the anterior of the centrum is moder- 
ately convex, the posterior end concave. 

The sixth cervical is markedly different from the others. 
First its dorsal spine is vestigial, which is well developed in the 
modern camels and in Poéebrotherium: then the transverse 
process is a short thin plate the distal end of which is bent 
backward. The interior lamelle are developed into wide 
plates which extend the whole length 
of the centrum and project downward. 
These are not, however, divided into 
an anterior and posterior lobes as in 
the modern tylopods, but) havewa 
straight lower border as is the case in 
Poebrotherium. The vertebrarterial 
canal enters the base of the neural 

Fic. 12. Stenomylus pedicle at the rear and penetrates the 
hitchcocki, sixth cervical entire length, leaving just under the 
seen from the side. x1/2. prezygaphysis. 

The seventh cervical is much shorter than the others, and 
has a moderate neural spine. The transverse processes are 


Fie. 12. 


of the Genus Stenomylus. 309 


developed as wings to either side and about half the length of 
the centrum, the outer margin being prolonged fore and aft 
and thickened. The wide posterior facet is placed obliquely 
to the length of the centrum, indicating a marked upward 
bend to the neck, so it is fair to conclude that the head was 
carried high. On the rear there are facets for the first ribs. 

From the foregoing it is clear that this genus in such deep- 
seated characters as the position of the vertebrarterial canal, the 
reduction of the neural spines, and the characters of the trans- 
verse processes, relates itself closely to the Tylopoda, having 
especial affinity to the primitive genus Péebrotherium. 

The following measurements give the relative sizes of the 
various vertebree in the three known species and in Po6e- 
brotherium. 


Length of Centrum x Width of Vertebra. 


1sé. Oden Sree eth. thee Ghul i Tbh 
i fone ede) Soe be. 54) edo ss 
eee eo eo ide (129. \.41 | 87. | 37 |. 37 | 40 
oe. 35 Bo Bie BA 48 
Oe Sl BB 85 ae | ae 
75 Wee, 
S. gracilis ar ay 
P. wilsoni 36 66 63 58 56 45 36 


Dorsal vertebre.—The dorsal series consists of twelve 
vertebre, measuring 242°". The neural 
spines are all wide thin plates, so closely 
set in front as to leave almost no inter- 
vals between vertebree, and reaching a maxi- 
mum in height on the fifth dorsal, from 
which point on they are lower with increas- 
ing intervals between successive spines. 
The anticlinal vertebra is the eleventh dor- 
sal. Metapophyses appear first on the 
eighth dorsal and occur on each successive 
centrum, situated each time a little higher 
and further forward, until on the eleventh 
the metapophysis unites with the prezy- wy, 13. stenomylus 
gapophysis and together they make a con- hitchcocki, sixth dor- 
cave facet which incloses the cylindrical Saree Oa the side. 
postzygapophysis. ae 

Lumbar vertebree —The lumbar series consists of seven ver- 
tebree, which total 1907" in length. Each one is characterized 

Am. Jour. Bre ne SERIES, VoL. X XIX, No. 172.—Aprit, 1910. 


Fie. 18. 


310 F’. B. Loomis—Osteology and Affinities 


by having the above described interlocking series of concave 
pr ezygapophy ses and cylindrical postzy gapophyses as 1s typical 
of Tylopoda generally. While the neural spines only rise to 
moderate heights, they are wide, thin plates, considerably 
pees above. The transverse processes extend, attaining 
the (for so small a form as S. hetchcockt) considerable length 
of 34°”. 

Sacrum.—The sacrum consists of four fused vertebre hav- 
ing a total length of 59™™ and a width of 62™. The first of 
the component vertebree sends out a stout and much expanded 
pleurapophysis to receive the ilium. To this is added the 
smaller but still stout pleurapophysis of the second sacral ver- 
tebra. These two sacrals are heavy, but the two posterior 
vertebree having only to support the tail are reduced and have 
become very siender. 

Caudal vertebre.——The tailis supported by 14 vertebre, of 
which the proximal ones are short and wide with well-marked 
transverse processes. Beginning with the seventh, however, 
the vertebree are without transverse processes, and become 
approximately cylindrical rods, the last one being but 5"™ long 
and but 1™” in diameter. The whole series measures 170™™, 
indicating a tail of moderate length. 

ftibs.—The first of the ribs is short and stocky, while the 
succeeding eleven are thin and wide (though not so wide as in 
the living camels), the interval between succeeding ribs being 
about half the width of the rib itself. A typical rib measures 
175°" long by 18 wide. Each rib has two heads rather close 
together, followed by a narrow abruptly curving neck, and 
then expands and stretches in a gentle curve toward the 
sternum. The uncrushed ribs show the body to have been 
decidedly narrow and moderately deep. The first five ribs 
were attached directly to the sternum by short calcified costal 
cartilages; the sixth and seventh by longer calcified cartilages ; 
and the succeeding three are connected by long costal cartilages 
to each other and indirectly to the sternum; while the eleventh 
and twelfth are free ribs. 

Sternwm.—The sternum consists of a slender presternum of 
22" length, followed by five wide sternal segments fused to 
each other. Opposite the point of union of each two segments 
the margin is expanded and offers an attachment for the 
costal cartilages. The sixth joint receives the two longer 
costal car tilages. Finally there is the xiphisternum, a thin 
expanded lamella of bone extending sume 42™™ behind the 
rest of the sternum. 

Fore limb.—The scapula is relatively long and narrow, the 
anterior margin extending upward in a decidedly concave curve, 
while the posterior margin is bounded by a like though less 


of the Genus Stenomylus. 311 


concave curve. The high spinous crest divides the blade into 
a smaller prescapular and a larger postscapular fossa, the latter 
being bounded on the outside by a raised ridge running along 
the posterior margin. Along the upper edge, the spine of the 
scapula is thickened and rugose for muscular attachments. 
Proximally it extends forward, making a slender acromian 


Hien 145 


Fie. 14. Stenomylus hitchcocki, scapula seen from the dorsal side. x 1/2. 


process which does not extend quite to the level of the glenoid 
fossa. The coracoid process is of but moderate dimensions and 
rolled inward, making a hook-like process. The shallow 
elenoid fossa 1 is wider than high in the ratio of 4 to 3. 

The humerus is slender and moderately long, the shaft hav- 
ing a well-marked sigmoid curvature. Corresponding to the 
shallow glenoid, the sessile head is but moderately convex. 
The greater tuberosity spreads along fully half of the width of 
the head, rising high above it, and overhanging the narrow 
bicipital groove; while the low lesser tuberosity of only half 
the width of its neighbor bounds the groove on the inner side. 
The bicipital groove when viewed from the front is seen to lie 


Fie. 15. 


Fie. 15. Stenomylus hitchcocki, humerus, seen from the dorsal side. 
x 1/2. 
just to the inner side of the median line; and while narrow at 
the bottom, it expands up onto the lesser tuber osity, so that its 
width is about equal to that of the tuberosity. There is no 
trace of the bicipital tubercle dividing the groove into two 


312 FF. B. Loomis—Osteology and Affinities 


parts as in modern camels. The deltoid ridge is well-marked, 
rising just under the head and reaching down to about the 
middle of the shaft. The supinator ridge is barely visible. 
The trochlea stands at almost right angle to the length of the 
shaft, is a little higher on its inner than on its outer margin, 
and has the intertrochlear ridge but feebly developed and 
situated near the middle of the ulnar side. The anconeal fossa 
is low and deep, but does not perforate the shaft. 

The radius and ulna are completely fused throughout their 
entire length, thus making a long, slender curved shaft. Using 
the length of the humerus as a unit, the length of the ulnar- 
radius would be 1°38, which is relatively longer than is the 
ease In Poebrotherium (1°15) or the modern camel (1°25), but 
does not compare with the length of Oxydactylus. At both 
the upper and lower ends of the radius occurs a groove indicat- 


IRE, Io, 


Fic. 16. Stenomylus hitchcocii, fused radius and ulna outer aspect. x 1/2. 


ing the original boundaries of the ulna, the lower end of the 
groove penetrating so as to make a complete foramen. The 
compressed olecranon process is moderately high and wide, the 
upper anterior edge having in it a wide groove for the extensor 
tendon.* The humeral facets on the ulna are confined to the 
superior border of the sigmoid notch and are not confluent 
with the facets on the inferior border on either the inner or 
outer side. To this statement I found in ten cases but one 
exception, in which case the upper facet was confluent with 
the lower along the inner side of the sigmoid notch. It isa 
peculiarity of Poebrotherium and the Tylopoda generally that 
the humeral facet on the upper border of the sigmoid notch is 
confluent with the facets on the lower border only along the 
inner side. This typical tylopod condition is characteristic of 
the species S. gracilist and S. crassipes also. On the distal 
end of the radius there are three facets for articulation with 
the carpal bones, that for the scaphoid being the largest and 
rectangular in outline; that for the Innate being narrow and 

* This groove is characteristic of Péebrotherium and Oxydactylus but not 
found in modern Tylopoda. Peterson does not find the groove in S. gracilis. 


Ann. Carnegie Museum, vol. iv, p. 292. 
+ Last cit. p. 450. 


of the Genus Stenomylus. 313 


obliquely placed; while that for the cuneiform is triangular in 
outline and about half of it carried on the lower end of the 
ulna. 

The carpus is compact and relatively high, the upper row of 
bones being the scaphoid, lunate and cuneiform as is typical 
for Tylopoda, their only peculiarity being that the lunate 
is relatively high and narrow. In the 
distal row the unciform is considerably 
deeper than the magnum; magnum and 
trapezoid are distinct, as is characteristic 
of tylopods; and the trapezium is rep- 
resented by a tiny ossicle found also in 
Péebrotherium. The pisiform is light 

Fic. 17. Stenomylus and slender in its outlines. 
eee the The metacarpus consists of the func- 

7 tional digits Ill and IV, together with 
tiny nodules representing the upper ends ot digits vandi ve 
Metacarpus II is a nodule some 10™™ in length, occupies a pit 
on the outer side of the third metacarpal, and carries two 
tiny artificial facets, one for the trapezium, the other for the 
trapezoid. Metacarpals III and IV are relatively long, almost 
equaling the humerus in this dimension, and separate from 
each other throughout their entire length. Along the upper 
two-thirds they are closely appressed and flattened, but through 
the distal third they spread apart and each metacar pal bone 
has a circular cross section. At the proximal end metacarpal 
III rises slightly above me. IV and has on the end a larger facet 
for the magnum and a smaller one for the trapezoid, behind 
which is a tiny facet for the trapezium, while on the lateral 
border there is a smoothed surface tor the vestigial me. II. The 
proximal end of the fourth metacarpal has almost the entire 


Eire. 17. 


Fic. 18. 


Fic. 18. Stenomylus hitchcocki, metacarpus from the anterior side. x 1/2. 


upper surface given up to a large facet for the unciform, only 
a small spur rising behind and presenting facets to the mag- 
num and trapezoid. On the ulna side there is a small excava- 
tion for a tiny nodule some 5-7™ long and representing the 
fifth metacarpal. The distal ends of the third and fourth 
metacarpals carry the enlarged trochlea for the phalanges, 


314 I. B. Loomis—Osteology and Affinities 


each with a high carina, which is, however, confined to the 
plantar side. 

The two first phalanges are long and slender, with the distal 
ends expanded in true tylopod manner. The upper articular 
surface is a shallow concavity, a notch 
in the lower margin being the only 
indication of the carina of the meta- 
podial. The distal phalanges are a trifle 
over half the length of the proximal 
ones, and like them are considerably 
expanded, though not to the extent 
found in modern camels. The upper 
articular face is a shallow groove, while 
that on the lower end extends from on 
the upper clear around on to the plantar 
surface. The ungual phalanges are 
| high, long pointed, rounded on the outer 

Mei. Geemomains Ce amet meal) vertical on the inner 
hitcheocki, phalanges from tace. They are typical for a distinetly 
the upper side. x1/2..  digitigrade artiodacty]. 

The following figures give the measure- 
ments for the various front limb bones in the three known 
species: 


Fie. 19. 


Scapula Humerus Ulnar-radius * Metacarpus |Phalanges 


idth - |diame-| diame- _. | length 
length) width Oe length feGE fenoe length ae length ae 
fossa head |trochlea BE ena Sa) 
Sa Liecncocki| 138 i278, 22. | L6sh26 27°5 225 (191) 10°5 |158°5| 11°25 |35 20/17 
S. crassipes 194| 32 | 28°57/229(194)| 13 |166 |135 |41| | 
8. gracilis 195| 37 | 33 |254(295) 184 44] | 


Fic. 20. Stenomylus hitchcocki, os innominatum seen from the lateral 
aspect. x1/2. 


Hind imb.—While in general the innominate bone is of 
the tylopod type, it is longer and relatively less expanded, 


*Tn parenthesis is given the length of the radius. 


of the Genus Stenomylus. 315 


especially in the iliac region. The upper end of the ilium is 
widely expanded and has a large area for the attachment on 
the sacrum. The neck of peduncle is longer and slenderer 
than usual. In the neighborhood of the acetabulum this bone 
is marked by several transverse ridges for the attachment of 
muscles quite as in the modern camels. The ischium is stout 
and expanded behind, a high slender process with its tuberos- 
ity rising on the superior ridge, and a second, the ischial 
tuberosity, being well developed at the posterior angle. The 
pubis is short and stocky, being expanded along the wide 
symphysis until it meets the ischium. In general conformity 
to the elongation of the pelvis the thyroid foramen 1s oval. 
The acetabulum is deep with a wide notch below. 

The short femur has a marked curvature, being generally 
tylopod in character. Its head is small and rounded, with the 
pit for the round hgament well to the posterior side. The 
bridge between the head and the greater trochanter is both 
short and high, as is common to the camels generally ; and the 
greater trochanter rises high above it, making a wide notch, as 


Hac. 20. 


Fie. 21a. 


Fie. 21. Stenomylus hitchcocki, femur seen from the inner side. x 1/2. 
Fic. 21a. Head of femur from the posterior side. 


is also found in Poebrotherium. The bridge is compressed 
antero-posteriorly, so that the digital fossa makes a deep pit, 
the bottom of which is about on a level with the lesser trochan- 
ter. This latter is situated high on the shaft, and from it 
runs a long ridge for muscular attachments. The rotular 
trochlea is broad and shallow and does not extend far up on 
the shaft. The external condyle is larger than the inner, 
which stands obliquely to the transverse axis of the shaft. 


316 FE. B. Loomis—Osteology and Affinities 


The patella is broadly oval and simple in outline, having 
nothing of the prolonged process common to later Tylopoda. 
The slender tibia is about a fourth longer than the humerus, 
which, when compared with other tylopoda, is not long. The 
facets for the femoral condyles are wide and 
Hig. 22. nearly flat, being separated by a bifid tubercle, 
The cnemidial crest is extremely prominent, and 
extends about a third of the way down the bone. 
In the regions of the crest the cross section is 
triangular, but below the section is transversely 
oval. The distal end of the bone is expanded 
Fie. 22. Patella. and the inner astragular facet much wider and 
x 1/2. j . 
shallower than the outer, the two being sepa- 
rated by a prominent septum. Both these facets and that on 
the septum are interrupted in the middle by a shallow depres- 
sion, which extends from near the inner margin of the inner 
facet all but to the outer margin of the outer facet. This is a 
very marked characteristic of the modern camels, and begins 
as far back as in Poebrotherium at least. The fibular facet is 
divided by the groove for the fibula shaft into anterior and 
posterior portions. 
The proximal end of the fibula is reduced to a tiny spine 
fused to the fibula; the distal end to a nodular bone wedged 


Fic. 23. 


Fic. 23. Stenomylus hitchcocki, tibia and fibula from the anterior 
side. x1/2. 


in between the tibia and the caleaneum. It presents a tiny 
spur above, vestige of the original shaft, which fits into the 
groove on the tibia; and has a long continuous facet for 
articulation on the tibia. On the inner surface is a crescenti¢ 
grooved facet for the astragulus, and on the lower surface a 
concave face for the caleaneum. 

In conformity to the slender build the tarsus is narrow and _ 
high. The astragulus is narrow, with the external condyle 
somewhat higher than the internal. On the distal trochlea 
the facet for the cuboid is relatively narrow, while that for the 
navicular is proportionally wide. The plantar facet is com- 
paratively narrow and small. In general, however, the 
astragulus would be recognized as tylopod. The calcaneum is 
of moderate length, being distinguished only by the consider- 


of the Genus Stenomylus. 317 


able antero-posterior diameter of its shaft, this depth being 
especially great near the facet for articulation on the cuboid. 
The cuboid is compressed- trans- 
versely, developed in the antero- 
posterior diameter, and carries a 
heavy plantar hook in the rear. The 
navicular is moderately developed, 
having a large concave face for the 
astragulus, which facet is notched on 
Fic. 24. Stenomylus hitch- 

fee Garsus. x 1/2. the inner margin. The lower side 

has a large facet for the ecto-meso- 
cuneiform and a smaller one for the ento- cuneiform, beside the 
lateral articulations where it rubs against the cuboid. The 
ecto-meso-cuneiform is free from the navicular, rectangular in 


Fie. 24. . 


Fic. 20. 


Fic. 25. Stenomylus hitchcocki, metatarsus from the anterior side. ~x1/2. 


form, and carries a single facet above for the navicular, 
second below for the third metatarsal, and a third laterally for 
the ento-cuneiform. This last bone is a small nodule, with 
Og facets for the navicular, the ecto-meso- 
IG, 26 : 
cuneiform and for the plantar process 
of the cuboid. 

The metacarpus consists of the func- 
tional digits III and IV, fused for 
little more than the upper half of their 
length, a tiny nodule representing mt. 
IJ, and a still smaller nodule represent- 
ing mt. V. In length the metatarsus is 
a trifle longer than the metacarpus. The 
vestige of ‘the second metatarsal is 8" 
long by 6™™ wide and carries a tiny 
facet for articulation on the ento-cunei- 

Fic. 26. Stenomylus form. The vestige Obimite V Lisppuio = 
hitchcocki,phalanges of the Jong and 5™™ wide and has no facets. 
ae Sie the upper The upper end of the third metatarsal 

is occupied by the facet for the ecto- 
meso-cuneiform, that of mt. IV by the facet for the cuboid ; 
then each eoanepnnce a strong process from the plantar side, a 
the inner side of which is a facet for the ento-cuneiform. The 
distal ends of the two metapodials spread in a characteristic 


318 FF. B. Loomis—Osteology and Affinities 


manner and each carries a broad trochlea for phalangeal articu- 
lation, and on each of these there is a prominent carina, which, 
however, is confined to the lower side and is not as promi- 
nent as the corresponding ones on the front metacarpals. 

The proximal phalanges are a trifle shorter than those of 
the front foot, but otherwise similar in form. The distal and 
ungual phalanges are also very like those of the front foot. 

The following figures give the comparative measurements 
of the three species of Stenomylus. 


Femur Tibia Metatarsus Phalanges 
diame-| diame- diameter 
‘length! ter of ; ter of |length of length |thickness} 1 2 38 
head |trochlea| upperend 
S. hitchcocki, 176; 18 | 31 210 32°95 166 TL y i3i6 2017 
S. gracilis | 205) 19 | 34 248) 38 198 44 


S. crassipes | 212) 20 | 38°6 | 213 | 39 Soi ehoan 


CLASSIFICATION. 


Stenomylus Peterson 


Ann. Carnegie Museum, vol. iv, 1906, p. 41. 
es vol. iv, 1908, p. 286. 

The type species is S. gracilis, found by Peterson m the 
Lower Harrison beds of Sioux Co., Neb. The genus may be 
defined as follows: Stenomylus is a slender member of the 
Tylopoda, no aouet to an upland life, with an extreme hypsodont 
dentition of 1.3¢.¢p.4m.3=$$=44,; the upper canines partly 
and the lower canines wholly incisiform, the first lower 
premolar tending the same way; vertebral formula c.7d.12- 
].%e.143; an elongated neck; limbs didactyl and digitigrade; 
magnum and trapezoid free ; and navicular and ecto-meso- 
cuneiform free. Horizon, Lower Harrison. 

At present three species are distinguished as follows: 


. Stenomylus gracilis Peterson 


Ann. Carnegie Museum, vol. iv, 1906, p. 41. 
ie vol. iv, 1908, p. 286. 
Distinguished “by larger size, narrower upper molars, lower 
canine less incisiform, diastema between lower premolar 1 and 
2 shorter, lower jaw narrower, metacarpals codssified a part of 
their length, and in details the most specialized of the three 
species. 


Stenomylus hitchcocki sp. nov. 


See preceding description of osteology for details. The 
species 1s distinguished by its small size, relatively narrow 


of the Genus Stenomylus. 319 


molars, lower canine completely caniniform, diastema between 
lower premolar 1 and 2 relatively long, premolar 2 greatly 
reduced, lower jaw deep, metacarpals separate their entire 
length. In general the species is the least specialized of the 
three. 


Stenomylus crassipes sp. nov. 


The species is distinguished in that while the size of the 
skull is approximately that of S. gracilis, the neck and limbs 
are markedly shorter and heavier; the premolars are much 
more reduced; and the lower canine is completely incisiform. 

To this the following details may be added as a description 
of the species. The type is number 2150 in the Amherst 
College collection, and was found seven miles northeast of 


IDE, 2%. 


Fie. 27. Stenomylus crassipes, upper dentition and palate. x 1/2. 


Agate, Sioux Co., Neb., in the uppermost sandstones of the 
Lower Harrison beds. The type consists of the skull (lacking 
premaxille) and lower jaws, together with 6 cervical, and 3 
dorsal vertebree, scapula, humerus, ulno-radius, carpals, meta- 
carpals, and phalanges. With this has been used specimen 
14220 of the American Museum of Natural History, consisting 


Fig. 28. 


Fie. 28. Stenomylus crassipes, mandible and lower dentition for the 
outer side. x1/2. 


320 LI. B. Loomis—Osteology and Affinities 


of nearly all parts of the skeleton; but the find is composed 
of the bones of more than one individual, 

As is characteristic of the skeleton, the skull is heavily 
built, the cranial region being short, and the frontals wide. 
The premaxille and premolar regions are shortened over the 
corresponding regions of S. gracilis, but the back of the skull 
is about the same size. In dentition the upper incisors are the 
usual well-developed chisel-shaped teeth crowded together ; 
the canine is reduced and separated from the incisors by a 
diastema of 4™™, being a like distance from the tiny first 


Fie. 29. 


Fic. 29. Stenomylus crassipes, fused radius and ulna from the outer 
aspect. x1/2. 


premolar. The second premolar is also much reduced, as is 
the third and the fourth, this last being 2™™ shorter than its 
counterpart in S. gracilis. The molars, however, are relatively 
enlarged, corresponding in length and width with those of 
S. gracilis. The lower jaw is shortened in the regions in 
front of the molars, the lower canine being wholly incisiform, 
as is also the first premolar which is placed close to the canine, 
all five of these teeth being grouped in the incisor ageregation. 
The second premolar has a considerable diastema, both in 
front and behind it, both being, however, shorter than those of 
S. gracilis. The third and fourth premolars are also reduced, 
and the molars are enlarged corresponding to those in the 
upper jaw. 

The cervical vertebrae resemble those of S. hitchcockt in 
character, but are thicker and shorter than in that of the S. 
gracilis species. From the table of measurements it will appear 
that the humerus is about the same length as that of S. gracilis, 
but the ulno-radius is some 30™™ shorter and at the same time 
much stockier. In the same way the metacarpus is materially 
shorter and heavier, mt. III and mt. IV being fused together 
for about half. their length as in S. gracilis. The femur is 
relatively long, actually longer than that of S. gracilis, but as 
in the fore limb the tibia is “extremely short, 35™™ shorter than 


that of S. gracilis. The metatarsus is also short and stocky, mt. 


321 


of the Genus Stenomylus. 


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322 F. B. Loomis—Osteology and Affinities 


III and mt. [V being fused rather more than half their length. 
From the foregoing it will appear that S. crassipes is a species 
closely resembling S. gracilis, but differentiated by the short- 
ening of the limbs, especially below the elbow and knee, a 
heavier shorter-limbed type being thus evolved. 
Afjinities.—In his descriptions Peterson has placed the 
genus Stenomylus among the Tylopoda, near the long-limbed 


Fig. 30. 


Fic. 30. Stenomylus crassipes, metatarsus and proximal phalanges. x 1/2. 


type Oxydactylus ; while Matthew* has associated the genus 
with Hypisodus among the Hypertragulide. In order to 
show concisely the points of likeness and difference to one or 
the other of these types, the characters of Stenomylus are in 
the above diagram arranged in parallel columns with those 
of Hypisodus on the one side and with Poebrotherinm on the 
other, the latter being used as illustrating a primitive tylopod. 
From the foregoing table it is evident that in the matter of 
dentition (number 1-5) the genus Stenomylus approximates 
Hypisodus; but in the other skeletal features it is distinetly 
allied to the Tylopoda. This is especially marked in such 
deep-seated and fundamental characters as the cancellous bone 
in the bulla, the position of the vertebrarterial canal, the matter 
of the fusion of the magnum and trapezoid, the matter of 
Tusion of the navicular and cuboid, and the manner in which 
the lateral digits have been reduced. These are characters 
less liable to modification ona change of habit, while the den- 
tition is the first to respond to changes in the matter of food. 
I fee] therefore that Stenomylus should be placed among the 
Tylopoda. Then as it is evident that the dentition is aberrant 
in its extreme hypsodont specialization, and presuming that 
this characteristic has been acquired in conjunction with a spe- 
cial feeding habit (which feeding habit would presumably be 
the same as characterizes Hypisodus, but a parallel adaptation), 
I feel that Stenomylus should be set off by itself. The habit, © 
which is general to forms having this hypsodont dentition, is 
feeding on hard grasses, usually on the open prairies, the grass 
haying in its stem considerable quantities of silica which causes 
extremely rapid wear of the teeth. I take it then that while 


* Bull. Amer. Museum Nat. Hist., xxiv, 1908, p. 539. 


of the Genus Stenomylus. 323 


the typical tylopod contemporaries of the Protomeryx type, 
fed on a generalized diet, and retained their brachydont den- 
tition, and while the long-limbed Oxydactylus group were 
feeding on leaves and shrubbery, and likewise retained their 
brachydont dentition, that there arose another group of upland 
tylopods which took up the grazing habit, and these developed 
the hypsodont dentition. These then represent a separate branch 
of the Tylopoda, which must have had its beginning in the 
later part of the Oligocene, being derived from Poebrotherium, 
which genus Stenomylus resembles in most of its characters. 
This group of tylopods seems to have flourished greatly during 
the lower Miocene, especially during the Lower Harrison, out- 
side of which horizon it has not been found. I see no especial 
affinity to Oxydactylus other than that common to all Tylopoda. 
The affinities may be graphically indicated as follows: _ 


Middle Alticamelus Protomeryx 

Miocene 
Lower Oxydactylus. Protomeryx Stenonylus 
Miocene | 


Paratylopus Poebrotherium 
— = 


Poebrotherium 


Upper 
Oligocene 


Middle 
Oligocene 


The Lower Harrison beds then will show three types of 
Tylopoda, each presumably in a different type of habitat, the 
Stenomylus in the upland, the Protomeryx near or in the val- 
leys where a considerable variety of vegetation flourished, and 
the Oxydactylus in the intermediate country and probably 
feeding on leaves and twigs of trees. 

Collectors in the Lower and Upper Harrison beds can not 
but be greatly impressed by the great variety of tylopods which 
occur in these beds, there being beside the already known spe- 
cies certainly as many more indicated by the great variety of 
toe and isolated bones found. The Lower Miocene seems to 
be the period of especial luxuriant development for all types 
of camel-like forms. 


Amherst College. 


Cg 


324 W. T. Schaller—Kefractive Indea of Canada Balsam. 


Arr. XXV.—The Refractive Index of Canada Balsam; by 


‘WALDEMAR TT’. SCHALLER. 


Tue refractive index of Canada balsam, as it occurs in the 
thin sections made for the a S. Geological Survey, was 
determined on the request of Mr. F. C. Calkins, who had 
found* that the index, or », was not absolutely constant but 
varied between two extremes. by the examination of 300 
slides, he found 7 to reach and even slightly exceed » of quartz 
(1:544), though was found greater than 1°544 only in the 
proportion of one slide in a hundred. The excess was very 
small and the balsam was decidedly yellow. The lowest value 
found by him was about 1:535 + :002. 

The value of 2 for sodium light was determined on an Abbe- 
- Zeiss refractometer by total reflection on three kinds of slides, 
which were (1) not cooked as much as usual, (2) cooked as 
ordinarily done, and (8) over-cooked. The differences found 
between (1) and (2) are very slight, and, in fact, the individual 
values show almost as much variation as between the different 
groups. The values obtained are: 


(1) (2) (3) 

1°543 

'1°539 1°536 | 1°540 
= Alene == N°5BS Nas 1°540 
1°539 1°539 | 1542 

| 1541 


The average values are for (1), 1°5387: for (2), 1°5377; for 
(3), 15412, or, as the average of all, 15395, which is almost 
identical with the value (1°5393) given by Beckert in 1898. 
A determination of m in a slide six years old gave the value 
15390. These values show that, in general, 1 lies very close 
to 1539 and that this value may well be used in a study of a 
thin section, while the actual possible variation was found by 
Mr. Calkins to be from 1°535 to 1:545, though the extreme 
values are but seldom reached. The uncooked, liquid balsam 
has a refractive .index of 1°524, which, after cooking, rises to 
1:54. The older a slide, the higher the index of the balsam 
becomes, which after a time, especially if the air has access, 
reaches towards the highest value, or 1°545. 


Chemical Laboratory, U. S. Geological Survey. 


* Science, vol. xxx, p. 978, Dec. 31, 1909. 
+ This Journal [4], v, p. 349. 


Leichardson—Stratigraphy of the upper Carboniferous. 325 


Arr. XXVI.—Stratigraphy of the wpper Carboniferous 
in West Texas and Southeast New Mexico; by G. B. 
RicHARDSON.* 


Introduction. 


In the trans-Pecos portion of Texas and New Mexico, every- 
where that basal strata of upper Carboniferous age have been 
observed they lie uncontormably on older Paleozoic strata or 
on pre-Cambrian rocks. This unconformity marks one of the 
important time breaks in the geological history of the south- 
west. The upper Carboniferous rocks consist of limestone, 
shale, sandstone, and variegated red beds. Limestone, with 
locally a basal conglomerate, usually forms the lower part of 
the section, and the uppermost strata are red beds which are 
unconformably overlain by deposits of Triassic age. The 
sequence, however, is extremely varied. The lowest rocks 
are Pennsylvanian and the uppermost are Permian, but where 
to draw the dividing line between Pennsylvanian and Permian 
in this region is an open paleontological question. These rocks 
comprise a maximum of more than 15,000 feet and thus con- 
stitute one of the thickest upper Carboniferous sections known. 

In connection with work in the Van Horn quadrangle in 
west Texas, it became desirable to examine the northward con- 
tinuation of the rocks there exposed, and last summer (1909) I 
had the oppertunity to make a short trip to the Guadalupe 
and Sacramento mountains and adjacent portions of New 
Mexico. The result enables a comparison of several upper 
Carboniferous sections in the little-known area between the 
Rio Grande and Pecos River. In the following descriptive 
sections I have summarized the results of my own work of the 
past several seasons, and for comparison I have referred to the 
work of J. A. Udden in the Chinati Mountains and of C. H. 
Gordon and Willis T. Lee in Rio Grande Valley. I grate- 
fully acknowledge my obligations to Dr. Girty, who has accom- 
panied me on several trips into the field and has examined all 
of my collections of fossils. 

Section in Chinati Mountains, Texas (No. 1, figs. 1 and 2).— 
J. A. Uddent in 1904 reported the presence of some 6,000 feet 
of upper Carboniferous rocks in the Chinati Mountains, about 
175 miles southeast of El] Paso. These consist of conglomer- 
ate, sandstone, shale, and limestone, which he separated into 

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


+ Udden, J. A., The Geology of the Shafter Silver Mine District: Bull. 
University of Texas Mineral Survey No. 8, 1904, pp. 11-26. 


Am. Jour. Sct.—Fourts Series, Vou. X XIX, No. 172.—Aprit, 1910. 
22 


326 Richardson—Stratigraphy of the upper Carboniferous 


three formations called the Cibola beds, the Alta beds, and 
the Cieneguita beds, and named,the whole the Chinati series. 
These rocks are delimited below by intrusive granite and are 
unconformably overlain by Lower Cretaceous strata. The 
fossils obtained from Udden’s Chinati “series,’ Dr. Gurty 


1Divele: Ie 


informs me, are more suggestive of the Hueco fauna than of 
the typical Guadalupian. Recently Stuart Weller,* in describ- 
ing some crinoids from the Cibola beds, has referred to them 
as Permian. Correlation by stratigraphic tracing is precluded 
by the isolated occurrence of the rocks in the Chinati Moun- 


* Journal of Geology, vol. xvii, pp. 623-635, 1909. 


[ 
RE 


me West Texas and Southeast New Mexico. 


Chises TMs.” West Texas 


Texas 


/ 


Triassic 


Rasfle jaa 


Castile 


= 


Crefaceaus Delawer 


Fennsylvanian 


Intrusive 
Granite 


Mouttam FEEoee4 


Hig 2. 


South Fast 
Tew Mexico 


Guadulubran 


a C p rire 
imi yd 

' ; 
{1 (i 
=|} |H . 
| ere 


HH 


(aan ewig 


ain 


Pail 


= pe oticd | 
Mississibban — Mgqdalena == 
a 


Forly 
Paleorsic 


Rio Grande 
Valley 


East 
Central 


New Mexiee 
3 


joull 
Re Cambrian 


327 


Fic. 2. Generalized columnar sections of upper Carboniferous strata in 


southeast New Mexico and west Texas. 


328 Lichardson—Stratiqraphy of the upper Carboniferous 


tains, they being more than 50 miles distant from the nearest 
known Carboniferous outcrops farther north, in the vicinity 
of the Texas and Pacific Railway, where what are presumably 
equivalent beds are all limestone. The section in the Chinati 
Mountains compared with those described below illustrates 
the variability of the upper Carboniferous deposits in the 
area under consideration. 

Section in Rio Grande Valley, New Mexico (No. 4, figs. 1 
and 2).—Rocks of Carboniferous age have long been known to 
occur in the ranges on both sides of the Rio Grande in New 
Mexico, although the section there exposed is not nearly as com- 
plete as farther east. Gordon, Lee and Girty* have recently 
summarized the knowledge of the upper Carboniferous in 
that region and they divide the rocks into the Magdalena and 
Manzano groups. 

The Magdalena group, the older of the two, consists chiefly 
of limestone but it contains minor beds of shale and sandstone. 
Gordon states that in Socorro, Valencia, and Bernalillo coun- 
ties the Magdalena group comprises 1,000 to 1,300 feet of 
sediments, which he divides into the Sandia formation (con- 
sisting of sandstone, shale, and limestone) and the overlying 
Madera limestone:. In southern New Mexico the Magdalena 
group is chiefly limestone and its outcrop in the San Andreas 
Range, save for minor interruptions caused by intrusive igne- 
ous rocks and by deposits of unconsolidated Quaternary debris, 
can almost be traced into the Hueco limestone on the western 
flanks of the Franklin Range in Texas. Pennsylvanian fos- 
sils from the two limestones confirm this correlation. The 
Magdalena is separated from the overlying Manzano group by 
a local unconformity which is not persistent throughout south- 
east New Mexico and west Texas. 

In the northern part of Rio Grande Valley the Magdalena 
group is overlain by a mass of red beds to which Herrick 
‘applied the name Manzano. Lee has recently revised the 
nomenclature and includes in the Manzano group the follow- 
ing three formations named, in ascending order: the Abo sand- 
stone, consisting of a maximum thickness of 800 feet of coarse 
red to purple sandstone with subordinate shale and earthy 
limestone ; the Yeso formation, consisting of 1,000 to 2,000 
feet of alternating vari-colored strata of shale, friable sand- 
stone, gypsum, and earthy limestone; and the San Andreas, 
a massive limestone of variable thickness which overlies the 
red beds in the southern part of the Rio Grande region. 
Farther north the San Andreas hmestone becomes less promi- 

*Gordon, C. H., Notes on the Pennsylvanian Formations in the Rio 
Grande Valley, New Mex., Jour., of Geology, vol. xv, 1907, pp. 805-816 ; 


Lee, Willis T., and Girty, Geo. H., The Manzano Group of the Rio Grande 
Valley, New Mex., Bull. U. S. Geol. Survey, No. 389, 1909. 


in West Texas and Southeast New Mexico. 329 


nent and finally disappears and the top of the Manzano group 
is marked by an erosional unconformity above which are strata 
of unknown age. Numerous fossils, which are described by 
Dr. Girty in the bulletin above referred to, have been found 
in the Manzano group, those occurring in the several forma- 
tions being not radically different. They are referred to the 
Pennsylvanian and the Manzano group is correlated with part 
of the Hueco formation. 

Section in west Texas north of the Texas and Pacific Rail- 
way (No. 2, figs. 1 and 2).—One of the thickest sections of the 
upper Carboniferous in the area considered in this paper is 
exposed in Texas between the western escarpment of the Staked 
Plains and the Rio Grande. Although this section is not com- 
plete, being interrupted by faults and by a local unconformity, 
it is more than 10,000 feet thick. 

The lower part of the section consists of the Hueco forma- 
tion, which underlies an area of several hundred square miles 
and outcrops in the Hueco, Franklin, Finlay, Cornudas and 
Sacramento mountains and in the Sierra Diablo. | It is in many 
areas mainly limestone but in other areas consists also of shale 
and sandstone, including red beds, and in places a basal con- 
glomerate is well developed. A well recently sunk in the 
Hueco formation in the drift-covered area between the Sierra 
Diablo and the Cornudas mountains, about 40 miles north of 
Sierra Blanca, is reported to have encountered a thin deposit 
of red beds intercalated in the prevailing imestone. This is of 
interest in the correlations discussed below (p. 335). Exact 
measurements are difficult to obtain, but in Texas the Hueco — 
formation is approximately 5,000 feet thick. Wherever 
exposed, the base of the Hueco hes unconformably on rocks 
ranging in age from pre-Cambrian to Silurian. Over wide 
areas the top of the formation has been eroded; locally the 
Hueco is overlain by Lower Cretaceous strata and relations 
to higher rocks in the Carboniferous section are completely con- 
cealed in Texas by the bolson plain known as Salt Flat. 

The Hueco formation bears a rich Pennsylvanian fauna 
which Dr. Girty states is widely distributed over the Western 
States and which he provisionally correlates with the fauna of 
the Aubrey group in Arizona, etc. 

The upper Carboniferous section is continued east of the 
Salt Flat bolson, in the Delaware and Guadalupe Mountains, by 
4,000 feet of strata which contain Girty’s* Guadalupian fauna. 
These rocks have been separated into the Delaware Mountain 
formation, consisting of 2,200 feet of variable beds of sand- 
stone and limestone, and the overlying Capitan limestone, 


*Girty, George H., The Guadalupian Fauna: Prof. Paper U. S. Geol. 
Survey, No. 58, 1908. 


3380 Lechardson—NStratigraphy of the upper Carboniferous 


which is at least 1,800 feet thick. The stratigraphic position 
of these formations is not determinable in Texas, but their 
position in the upper Carboniferous section is shown in the 
northern part of the Guadalupe Mountains in New Mexico 
and will presently be referred to. On the eastern flanks of 
the Delaware Mountains, which constitute virtually a dip slope, 
the Capitan limestone is missing—presumably either because 
of non-deposition or erosion—and the Delaware Mountain 
formation is directly overlain by a mass of bedded gypsum. 
This deposit, named the Castile gypsum, is approximately 300 
feet thick and covers an area of several hundred square miles. 
The gypsum is overlain by magnesian limestone and associated 
lenses of sandstone, in all about 200 feet thick, which have 
been named the Rustler formation. The section is here inter- 
rupted by Quaternary deposits in Pecos Valley, but occasional 
outcrops of red beds, which overlie the Rustler formation, are 
locally exposed and it is evident that both the Castile gypsum 
and the Rustler formation are members of the red bed com- 
plex that underlies the valley of Pecos River. 


Kted Beds of Pecos Valley. 


The red beds of Pecos Valley were examined in 1891 by 
W. F. Cummins,* and they have been studied in the vicinity 
of Roswell by C. A. Fisher,+ but thick deposits of unconsoli- 
dated Quaternary debris conceal complete exposures and com- 
paratively little is known of them. They consist of a group 
of vari-colored sandstone and shale, red predominating, inter- 
stratified with beds of magnesian limestone and gypsum. In 
detailed study it is desirable to divide these rocks into a num- 
ber of formations of comparatively limited extent similar to 
the Castile gypsum and the Rustler formation, which when 
traced for a number of miles beyond the area in which they 
were named, lose their individual character and become diffi- 
cult to recognize as such. The formations of the red bed 
group are lenticular in character but the group as a whole is a 
distinet unit. 

Measurements of thickness are practically impossible to 
obtain short of drilling, and as yet no hole has been sunk 
through the entire group. Minimum figures, however, are 
afforded by two deep wells; one, sunk by Capt. John Pope in 
1855-57, about ten miles east of where Delaware Creek enters 
Pecos River in New Mexico near the Texas boundary, was 
1,050 feet deep and appears to have been in red beds all the 

* Cummins, W. F., Notes on the Geology West of the Plains: Third Ann. 
Rept. Geol. Survey of Texas, 1892, pp. 201-218. 


+ Fisher, C. A., Geology and Underground Waters of the Roswell Artesian 
Area, New Mexico: Water Supply Paper U.S. Geol. Survey, No. 158, 1906. 


in West Texas and Southeast New Mexico. 331 


way;* another was sunk by H. J. Hagerman in 1909 about 20 
miles east of Roswell, New Mexico, in section 5, T. 1158., R. 
28 E., to a depth of 2,850 feet. Apparently this well was 
begun near the top of the local section of red beds and was 
continued in them to a depth of 1,625 feet, beneath which 
limestone, including some thin sandy layers, was encountered 
down to the bottom of the well. A minimum thickness there- 
fore of these red beds is 1,600 feet. 

The red beds of Pecos Valley are delimited above, as Cum- 
mins and Draket determined a number of years ago, by an 
erosional unconformity which separates them from the over- 
lying Dockum formation of Triassic age. 

The lower limit of the red beds of Pecos Valley, defined as 
the lowest occurrence of either red strata or of gypsum, is 
variable and is not a definite horizon, but rather forms a zig- 
zag line extending diagonally across the strike of the rocks. 
In Texas the basal formation of the red bed group, the Castile 
gypsum, rests directly on the Delaware Mountain formation. 
Farther north in New Mexico, southwest of Carlsbad, the red 
beds rest on strata which are a few thousand feet above the 
Capitan limestone but which are conformable with it. On 
the eastern flanks of the Guadalupe Mountains west of Carls- 
bad red beds occur at a somewhat lower horizon interbedded 
with these strata which lie above the Capitan limestone. 
Local exposures clearly show the “fingering out” of red beds 
and their merging into the more sombre-colored deposits, the 
occurrence of the red coloration extending across the strike of 
the rocks. West of Roswell the main red beds lie upon a 
massive limestone which is the northern continuation of the 
rocks that have just been referred to. Deposits of red sand- 
stone and shale are also intercalated in the limestone west 
of Roswell. Farther north, along the line of the Eastern 
Railway of New Mexico, as shown below, almost the entire 
Carboniferous section is composed of red beds. 

Fossils are of rare occurence in these red rocks, although at 
a few localities shells have been obtained from the interbedded 
limestones, and fragments of fossil wood also have been found. 
Dr. Girty does not feel justified in saying anything definite as 
to the age of the fossils collected from the red beds either by 
Mr. Fisher or by myself. These include Schizodus ovatus 

*Annual report of Capt. A. A. Humphreys to the Secretary of War, 
December, 1858. 

+ Drake, N. F., Stratigraphy of the Triassic Formation in Northwest Texas : 
Third Ann. Rept. Geol. Survey of Texas, 1892, pp. 227-285. 

¢{ When detailed work is done in this region these strata which lie above 
the Capitan limestone will be separated into formations and probably 


included in the same group with the Delaware Mountain formation and the 
Capitan limestone, but it is not desirable now to introduce new names. 


332 Rechardson—Stratigraphy of the upper Carboniferous 


and Pleurophorus aff. subcostatus from seven miles north- 
west of Roswell, New Mexico, and a Schizodus having the 
general shape of S. Aarez, and a form suggesting by its shape a 
small Myalina from the Rustler Hills, El Paso County, 
Texas. Nevertheless the stratigraphy indicates that the red 
beds of the Pecos Valley are to be correlated with part of the 
Permian red beds of Oklahoma and northwest Texas, for they 
were connected by tracing around the northern border of the 
Staked Plains by W. F. Cummins in 1891; and on my map of 
trans-Pecos Texas, published in 1904, the Castile gypsum and 
Rustler limestone were referred to the Permian with a query. 
Cummins’ work has been confirmed by C. N. Gould, who has 
mapped the Greer and Quartermaster formations, which are 
part of the Permian red beds of Texas and Oklahoma, across 
several counties in the panhandle of Texas, and along Cana- 
dian River as far as the Texas-New Mexico boundary.* 

This stratigraphic correlation is in agreement with paleon- 
tologic data recently obtained by Dr. J. W. Beede, with 
whom I was associated in the field for a few days in 1909 and who 
found fossils in a limestone in the red beds south of Lake- 
wood, New Mexico, which he correlates with the White- 
horse—Quartermaster fauna. A discussion of this correlation, 
however, is outside the scope of the present paper, and is left 
to Dr. Beede. 

Section across east central New Mexico (No. 5, figs. 1 
and 2).—In 1905 I traversed the line of the Eastern Railway of 
New Mexico, then under construction, and made the following ~ 
observations between the Manzano Range and Pecos River. 

This region, considered as a whole, is an undulating plateau 
125 miles wide. On the west the plateau is separated from 
Rio Grande Valley by the Manzano Range, and on the east 
the escarpment of the Staked Plains rises above Pecos Valley. 
The western portion of the plateau, averaging about 6,000 
feet in elevation, is dissected by the north-south trending 
Estancia and Encino valleys and is surmounted by oceasional 
isolated mesas, while the eastern portion slopes gradually to an 
elevation of 4,000 feet at Pecos River. The topography of 
this belt is in marked contrast to that of the mountainous area 
south of it in New Mexico and Texas, where other sections of 
upper Carboniferous rocks described in this paper are exposed, 
the difference in topography being largely due to the varying 
hardness of the rocks. This contrast further emphasizes the 
variability of the upper Carboniferous stratigraphy. 

* Gould, C. N., Geology and water resources of the eastern portion of the 
Panhandle of Texas: Water Supply Paper U. S. Geol. Survey, No. 154, 


1906; and Geology and water resources of the western portion of the Pan- 
handle of Texas: Water Supply Paper U. S. Geol. Survey, No. 191, 1907. 


an West Texas and Southeast New Mexico. S30 


At the base of the Manzano Range the extreme western part 
of the plateau is underlaid by several feet of limestone 
(Magdalena ?) containing a Pennsylvanian fauna, allied to that 
of the Hueco formation, and above the limestone there is a great 
mass of red beds that outerop as far as the vicinity of Lucy, a 
railroad station about 45 miles east of the Manzano Range. The 
rocks consist of prevailing fine-textured dark red sandstone 
with which are associated layers of red sandy shale and lenses 
of gypsum; and thin beds of limestone, containing numerous 
Pennsylvanian fossils, also occur towards the upper part of the 
section. 

Five miles south of the town of Willard, at the crossing of 
the Santa Fe Central Railway, 25 miles east of the Manzano 
Range, the following section was measured : 


Section Five Miles South of Wiliard, New Mexico. 


Feet. 
Limestone, grey, cherty, fossiliferous- - --- 50 
Pandstone, erey, friable 2252-22... 2.2 Lee. 300 
ang croMewrede. en hyo el ae SL 10 
Gypsum, massive, bluish white _...------ 100 


The fossils in the limestone are of Pennsylvanian age, so that 
the great mass of red beds lying between limestones contain- 
ing Pennsylvanian fossils clearly are of that age. These beds 
belong to the Manzano group, but on account of the varied 
stratigraphy it cannot at present be stated that the limestone 
at the top of this local section is the San Andreas limestone, or 
one of several other lenses in the Manzano group. 

The eastward continuation of the red beds is interrupted at 
the divide between Estancia and Encino valleys by an area of 
low relief, about ten miles wide, that is underlain by a ecrystal- 
line complex consisting of granite and other igneous rocks, 
slate, ete., which apparently represent the southward continua- 
tion of the pre-Cambrian core of the Rocky Mountains. About 
fifteen miles southeast of this area, northeast of Torrance on 
the El Paso and Southwestern Railroad, isolated areas of mica 
schist surrounded by unconsolidated deposits were also found. 
The relations of these ancient rocks to the red beds is obscured 
by Quaternary material and is not known. 

East of this crystalline area the character of the underlying 
rocks is much obscured by surface debris, but the general low 
eastward dip apparently prevails throughout the region. Lion 
Summit, just east of Encino Valley, is formed by about 50 feet 
of white sandstone capped by a bed of limestone in which no 
fossils were found. Thence eastward down the long, gentle 
slope of 60 miles to Pecos River there are few exposures of 


334 Lichardson—Stratigraphy of the upper Carboniferous 


bed rock. The surface is generally covered by Quaternary 
debris, but a number of exposures show the presence of red beds 
and gypsum dipping low to the east, and records of deep wells 
indicate that all of this area is underlain by red beds. For 
instance, a well at Vaughan, a station at the crossing of the El 
Paso and Southwestern Railway near the western end of this 
long slope, is 1,855 feet deep in red beds all the way; and 
a well at Ricordo, 62 miles southeast of Vaughan along the 
railroad and thirteen miles west of Pecos River, shows red 
beds, below a superficial coating of sand, down to a depth of 
595 feet. It appears then that red beds dipping eastward at a 
low angle underlie the entire area between Vaughan and Pecos 
River, and assuming a dip of only one degree a thickness of 
approximately 6,000 feet of strata is thus Indicated. Practi- 
cally the entire plateau, therefore, between the Manzano 
Range and Pecos River, with the exception of a small area 
of ancient erystalline rocks, is underlain by gently east dipping 
red beds which, unless they are duplicated by faulting, of 
which no evidence has been obtained, are more than 9,000 
feet thick. 

No fossils, excepting fragments of wood, have been found in 
the red beds between Willard and Pecos River. A thin section 
of a fragment of wood from the red beds one mile east of Pecos 
River, 65 miles north of Roswell, New Mexico, was reported 
on by David White as follows: This fragment ‘ has lost many 
of its trachial punctations by reason of advanced bacterial 
action which has also obliterated many of the medullary rays. 
On the basis of the remaining ray features and the occasional 
obscure pores, I am disposed to regard this specimen as post- 
Pennsylvanian. These rocks are the northern continuation of 
the red beds of Pecos Valley described above, and here also 
they are unconformably overlain by the Dockum formation 
(Triassic), which in turn is succeeded by the Tertiary deposits 
of the Staked Plains. 

The point to be emphasized about this section between the 
Manzano Range and Pecos Valley is that almost the entire 
history of upper Carboniferous sedimentation is a record of 
red bed deposition, which is in marked contrast with the cor- 
responding record in southern New Mexico and Texas. 

Section across southeast New Mexico between Tularosa 
Desert and the Staked Plains (No. 3, figs. 1 and 2).—The 
section in the Sacramento and Guadalupe Mountains in south- 
east New Mexico exposes a great thickness of rocks and reveals 
the stratigraphic position of the strata which contain Girty’s 
Guadalupian fauna, the correlation of which has caused dis- 

ute. 
, East of Tularosa Desert, the local name of the bolson plain 


in West Texas and Southeast New Mexico. 335 


along which the El Paso and Southwestern Railroad extends 
between El Paso and Alamogordo, a zone of faulting marks 
the western foot of the Sacramento Mountains. Red beds, in 
fault contact with limestones of Mississippian age, form the 
local base of the upper Carboniferous section in this vicinity, 
These red beds constitute the western escarpment of the Sacra- 
mento Mountains, and are at least 2,000 feet thick, the section 
being obscured by faulting. They consist of a variegated 
group of prevailing red sandstone and shale, minor beds of 
buff sandstone and drab shale, and lenses of gray limestone. 
The red beds are overlain by a great’ mass of limestone 
and subordinate gray sandstone having a minimum. thick- 
ness of 3,000 feet.. These upper strata form the eastern 
slope of the Sacramento Mountains, which is thirty miles 
long, the strata dipping low to the east at an angle slightly 
greater than the inclination of the surface. Numerous fossils 
have been collected at various horizons from the lme- 
stone lenses in the red beds and from the overlying strata. 
Dr. Girty states they are all unmistakably Pennsylvanian and 
correlates them with the fauna of the Hueco formation. This 
correlation is strengthened by the partial tracing of the beds 
from the southeastern base of the Sacramento Mountains into 
limestones in the upper part of the Hueco formation exposed 
in Texas east of the Cornudas Mountains; and by the recent 
discovery of red beds in a well north of Sierra Blanca (p. 329). 
This latter occurrence appears to represent the southern wedg- 
ing out of the mass of red beds exposed in the escarpment of the 
Sacramento Mountains. 

The description of this section may here be interrupted to 
revert to the rocks of the Guadalupe Mountains, the northern 
end of which coalesces with the eastern base of the Sacra- 
mento Mountains. It will be recalled that the rocks of the 
Guadalupe Mountains at their southern termination in Texas, 
near the New Mexico boundary, consist of about 4,000 feet of 
sandstone and limestone which have been separated into the 
Delaware Mountain formation and the Capitan limestone, the 
relation of which to the Hueco limestone, in Texas, is con- 
cealed by the Quaternary deposits of the Salt Flat bolson. In 
the New Mexico portion of the Guadalupe Mountains a more 
complete section is exposed than in Texas, and there the Capi- 
tan limestone is overlain by a few thousand feet of limestone 
and sandstone as stated above (p. 331). Throughout this entire 
region, the general dip is eastward at a low angle. The strati- 
graphy is varied, and both the Delaware Mountain formation 
and the Capitan limestone lose their individuality when traced 
far along the strike. The massive Capitan limestone, for 


336 Richardson—Stratigraphy of the upper Carboniferous 


instance, locally gives way to or is replaced by thinner bedded 
limestone and intercalated beds of sandstone, so that it is diffi- 
cult to distinguish the northward continuation of the formation 
from the overlying and underlying beds. Considered as a 
whole the rocks of the Guadalupe Mountains constitute a 
group which in detailed work will be separated into units 
similar to the Delaware Mountain formation and the Capitan 
limestone. A red bed phase is developed in the upper part of 
the Guadalupe Mountain section 25 miles southwest of Carls- 
bad, where, as stated above, deposits of red sandstone and 
shale are present in the prevailing limestone and gray sand- 
stone. To the east the red sediments become more abundant, 
and in Pecos Valley the strata of the Guadalupe Mountains 
are overlain by the red beds of Pecos Valley. 

Followed along the strike to the northern termination of 
the Guadalupe Mountains in the vicinity of Penasco River, a 
distance of fifty miles north of the Texas-New Mexico bound- 
ary, the Guadalupian series are found to overlie the limestones 
and sandstones, which have just been described, on the eastern 
flanks of the Sacramento Mountains. No evidence of any dis- 
turbance which would alter the apparent simple relations of 
the rocks was observed. The zone of faulting developed along 
the western base of the Guadalupe Mountains near the state 
boundary fades away northward, and is represented in Panasco 
Valley, if at all, by a belt of vently undulating dips. The 
strata of the Guadalupe Mountains, therefore, overlie the 
Hueco formation conformably, and in turn are overlain 
by the red beds of Pecos Valley into which they tend to 
merge. 

Comparatively few fossils have been obtained from the 
rocks in the New Mexico portion of the Guadalupe Mountains, 
and these Dr. Girty states show but little relationship to the 
typical Guadalupian fauna from the Texas portion of the 
mountains.* It is not within the province of this paper to 
consider the Guadalupian fauna or its relation to others which 
is discussed by Dr. Girty. It seems probable, however, that 
the difference in the fauna in the same group of rocks in the 
Texas and the New Mexican portions of the Guadalupe 
Mountains is due to changed environment, which is indicated 
by the varied stratigraphy. 


Summary. 


The following is a summary of the chief facts, which I wish 
to emphasize in this review of the upper Carboniferous strati- 
graphy of southeast New Mexico and west Texas: 


* Girty, George H., The Guadalupian Fauna and New Stratigraphic Evi- 
dence: Annals N. Y. Acad. of Sciences, vol. xix, pp. 185-147, 1909. 


ain West Texus and Southeast New Mexico. 337 


The upper Carboniferous strata in the area considered are 
separated from underlying and overlying rocks by major ero- 
sional unconformities. The lower beds are Pennsylvanian and 
the upper beds are Permian, but the separation of the two series 
is not well marked. 

The total thickness is enormous, the stratigraphy is extremely 
varied, and two local unconformities occur in the upper Car- 
boniferous section. In the east central New Mexico section, 
excepting a relatively thin deposit of limestone at the base of 
the section, almost the entire upper Carboniferous record is 
of red bed deposition. In southeast New Mexico a great 
body of sandstone and limestone occurs between and merges 
into red beds. In west Texas, north of the Texas and Pacific 
Railway, red beds are practically confined to the top of the 
upper Carboniferous section, and in the Chinati Mountain 
region no red beds have been ‘reported. : 

The sections which have been described can be approxi- 
mately correlated and together they comprise the local com- 
plete upper Carboniferous column. It appears: (@) that the 
Hueco formation embraces both the Magdalena and Manzano 
groups of the Rio Grande Valley section in New Mexico; (0) that 
the Guadalupian series lies between the Hueco formation and 
the red beds of Pecos Valley; (¢) that the red beds of Pecos 
Valley constitute a variable group, the base of which is not a 
definite horizon, the occurrence of the red color extending 
irregularly across the strike of the rocks; (d) and that the 
upper part of the red beds of Pecos Valley is equivalent to the 
upper part of the Permian red beds of northwest Texas and 
Oklahoma. 

The varied stratigraphy is an expression of changing geo- 
graphie conditions which accompanied the emergence of the 
continent at the close of Paleozoic time. Apparently an open 
sea gave way, with some alterations, to shallower water and 
to local enclosed basins.. The Guadalupian fauna probably 
migrated from the south, and its spread northward and eastward 
seems to have been checked by changing environment. Itis to 
be noted that while from Kansas to Oklahoma shales and lime- 
stones merge into red beds from north to south, in west Texas 
and New Mexico a similar transition occurs from south to 
north, indicating an east-west zone in the upper Carboniferous 
area of deposition in which red beds accumulated. 


338 Perkins— Gravimetric Determination of Free Bromine. 


Art. XX VIL—TZhe Gravimetric Determination of Free Bro- 
mine and Chlorine, Combined Iodine, and Oaidizing 
freagents by means of Metallic Silver; by CraupE C. 
PERKINS. 


[Contributions from the Kent Chemical Laboratory, Yale Univ.—ccix. ] 


In a former paper* a method for the gravimetric determina- 
tion of free iodine by means of metallic silver was described 
in detail. This paper has to do with the application of the 
same process to the determination of free bromine and chlor- 
ine, other members of the halogen group, to the estimation 
of combined iodine, and, indirectly, to the determination of the 
oxidizing power of certain oxidizing reagents. ) 

The silver best adapted for this process is obtained electro- 
lytically in a very finely divided state, being deposited as a 
black mass (probably silver hydridet+) upon a small moving 
cathode. As long as the mass adheres to the electrode it 
remains perfectly mtact but as soon as it is shaken off into the 
solution it immediately turns to a dull gray color, the hydro- 
gen escapes, and the silver settles to the bottom in a fine flour- 
like powder. The mass of silver hydride should not be 
allowed to adhere to the electrode after it begins to change 
color, as the silver then collects in a crystalline form which 
does not absorb iodine readily. 


Determination of Free Bromine and Chlorine. 


In applying the process to the determination of bromine 
and chlorine a definite amount of the aqueous solution of these 
haloids was introduced into a flask containing an excess of 
potassium iodide made acid with hydrochloric acid and the 
whole shaken in an atmosphere of hydrogen with a weighed 
amount of silver. The residue of silver and silver iodide was 
collected in a Gooch crucible, washed, dried, and weighed. 
The increase in weight of the silver should represent the 
weight of iodine liberated from the iodide and from this the - 
amount of halogen may be easily calculated. Table I shows 
the results of three determinations with bromine and five 
determinations with chlorine in which the average error falls 
within 0:0002 grm. 


Determination of Potassium Iodide. 
In applying the process to the determination of combined 
iodine a definite amount of a solution of potassium iodide, 
previously standardized by the distillation method with sul- 


* This Journal, xxviii, 338, 1909. 
+ Bartlet and Rice, Am. Chem. Jour., xix, 49. 


Perkins— Gravimetric Determination of Free Bromine. 339 


Taste I, 
‘ Calculated 
Silver Halogen Iodine amt. of 
taken taken found halogen Krror 
erm. erm. erm. orm, erm. 


(a) Determination of bromine. 


3°0000 0°0213 0°0336 0°0211 —0°0002 
3°C000 0°0426 0:0678 0°0427 +0:0001 
3°0000 0°1065 0°1694 0°1067 +0°0002 
(b) Determination of chlorine. 
3°0000 0°0161 0°0574 . 0°0160 —0:0001 
3°0000 0°0322 0°1146 0°0320 —0°0002 
3°0000 0°0322 0°1145 0°0320 —0°0002 
3°0000 0°0322 0'1141 0°0318 — 0°0004 
3°0000 0°0483 0°1716 0:0479 —0°0004 


phuric acid and potassium hydrogen arseniate,* was intro- 
duced into a flask with an excess of the calculated amount of 
an oxidizing reagent (usually potassium nitrite or hydrogen 
peroxide), the whole made acid with hydrochloric acid, and 
shaken with a weighed amount of silver. The increase in the 
weight of the silver indicates the amount of iodine liberated 
from the potassium iodide and from this the amount of potas- 
sium iodide may be easily calculated. Table II shows the 
results of five determinations with potassium iodide in which 
the average error is —0°0002 grm. between limits of —0-0005 
and +0-0002 grm. 


Taste II. 
Determination of potassium iodide. 

Silver KI Iodine Calculated 

taken taken found amt. of KI Error 

grm. — erm. erm. erm. erm. 
2°7803 0°1144 0°0872 Oe elt —0°0008 
3°0028 0°1346 0°1026 0°1342 —0°0004 
2°7800 0°1279 0°0978 O°1281 + 0°0002 
2°0008 0°1279 0°0974 0°1274 —0°0005 
3°0001 0°1346 0°1029 0°1346 + 0°0000 


Determination of Oxidizing Reagents. 


The process has also been applied to the indirect determina- 
tion of several of the common oxidizing reagents with a view 
to showing that it may be used for the estimation of oxidizers 
that will liberate iodine quantitatively. In these experiments 
definite amounts of the oxidizer, standardized in the usual 
way, were added to an excess of a solution of potassium iodide 
acidified with hydrochloric acid, and the whole shaken with a 


* Gooch and Browning, this Journal, xxxix, 188, 1890. 


340 Perkins—Gravimetric Determination of Free Bromine. 


weighed amount of silver in an atmosphere of hydrogen. The 
value of the oxidizer is then calculated from the increase in 
weight of silver which represents the amount of liberated 
iodine. Table III shows the results obtained in the determina- 
tion of potassium permanganate, hydrogen peroxide, potassium 
dichromate, and ferric chloride, in all of which the error is 
well within experimental variation. 


Taste III. 
Oxygen 
Silver represented Calculated 
taken by oxidizer Ifound amt. of oxygen Error 
erm. erm. erm. erm. erm. 
(a) Determination of potassium permanganate. | 
3°0000 0°0123 0°1956 0°0123 +0:°0000 
3°0000 0°01238 0°1936 0°0122 —0:0001 
3°0100 0°0123 0'1964 0°0124 +0°0001 
3°0100 0°0123 0°1968 0°0124 +0:0001 
4°0101 0°0185 0°2926 0°0184 —0°0001 
4°0101 0°0247 0°3886 0°0245 — 0.0002 
(b) Determination of hydrogen peroxide. 
3°0000 0°0202 0°3200 0°0202 +0°0000 
3°0000 0°0202 0°3214 0°0203 +0:0001 
3°0100 0°0404 0°6427 0°0405 + 0°000] 
3°0000 0°0311 0°4937 0°0311 +0°0000 
3°0000 0°0322 0°5128 0°0323 +0°0001 
3°0000 0°0606 0'9590 0°0604 — 0°0002 
(c) Determination of potassium dichromate. 
3°0000 0:0080 0°1272 0°0080 +0:0000 
3°0000 0°0160 0°2552 0'0161 +0:0001 
3°0000 0°0201 0°3141 0°0198 —0:00038 
3°0000 0°0402 0°6390 0°0408 +0:0001 
3°0000 0°0160 0°2552 0°0161 +0:°0001 
3°0000 0°0160 0°2571 0°0162 +0°0002 
(d) Determination of ferric chloride. 
3°0000 0°0218 0°3470 0:0219 + 0:0001 
3°0000 0°0218 0°3476 0°0219 +0 0008 
3°0000 0°0437 0°6922 0°0436 —0:°0001 
3°0000 0°0218 0°3489 0°0220 + 0°0002 
3°0000 0°0262 0°4183 0°0264 + 0°0002 
3°0000 0°0218 0°3516 0°0222 + 0°0004 


The results obtained fully justify the statement that metal- 
lie silver may be used for the determination of free bromine 
and chlorine, and combined iodine, and for the estimation of 
the oxidizing power of those reagents whose reaction with 
potassium iodide is definitely known to set free iodine quanti- 
tatively. 


Trowbridge—Llectric Discharges through Hydrogen. 341 


Arr. XX VIIL—Discharges of Electricity through Hydro- 
gen; by Joun TROWBRIDGE. 


Reflection of Cathode Rays. 

Striz. 

A method of rectification of alternating discharges. 
The Doppler effect. 


fe oe Dea 


Reflection of Cathode Rays. 


Iy the course of this paper I shall refer to certain hydrody- 
namic analogies which the discharges of electricity through 
gases present; but not with the conviction that in these 
discharges we have to deal solely with questions of flow. 
The complicated phenomena give large scope both to theories 
of flow and molecular theories ; the hydrodynamical analogies 
are more striking in discharges through gases at comparatively 
high pressures; while molecular theories apply best in highly 
rarefied gases. There seems to be a certain continuity here 
similar to that between motions of matter in the liquid state 
and in the gaseous state, when such matter is subjected to 
forces that can produce movement or flow of the particles. 

The condition of electrical discharges in a tube represented 
in fig. 1 remind one of the flow of a fluid, interrupted by a 


Hig 21: 


plane lamina. A is a cathode, K an anode, D a diaphragm, 
P a plane lamina which can be moved about an axis perpen- 
dicular to the plane of the paper: fig. 1 being a plan of the 
discharge tube. PP can also serve as an anode. 

At the striz stage the electrical conditions in the tube are 
very little modified by turning the lamina through small incli- 
nations to the line of discharge. The strize remain practically 
unafiected in shape and position until the angle between the 
normal to the lamina and the axis of flow reaches 50°. This 
phenomenon is analogous to the case of a lamina subjected to 
the flow of a liquid (Lamb’s hydrodynamics, p. 94 and p. 111). 
It is also analogous to the conditions presented by the impact 
of wind on sails fronts. 


Am. Jour. Sci1.—Fourts Series, Vou. X XIX, No. 172.— Apri, 1910. 
23 


342 Trowbridge—Electric Discharges through Hydrogen. 


By means of a side adjunct, a thermopile, T, was introduced 
in order to measure the heat excited by the reflection of the 
cathode rays passing through the diaphragm D and being re- 
flected from the lamima, when the latter was inclined to the 
axis of the cathode rays at varying angles. Here also there 
was an action similar to the reflection of a stream of liquid 
from the lamina, proceeding in the direction of the cathode 
rays. The angle between the normal to the lamina and the 
axis of flow or discharge could vary largely without affecting 
the amount of heat from the reflected cathode beam, shown by 
the thermopile. 


Strice. 


The striee, or stratifications in Geissler tubes, constitute a very 
beautiful and mysterious phenomenon of the discharge of elec- 
tricity through gases, and if one could follow perfectly the 


BiG, 2. 


Fic. 2 represents an apparatus by means of which two pistons driven by 
a motor in opposite directions cause waves in a trough filled with water. 


mechanism involved one could feel sure of having penetrated 
far into questions of the method of propagation of electricity. 
There seems no reason to doubt that the strize are phenom- 
ena of ionization; but the regularity of the striz leads one to 
ask if this regularity could arise from some pulsation or rhyth- 
mical action—the ionization being, so to speak, on top of such 
rhythmical action. When the strie are excited by a storage 
battery they are perfectly steady, and when it is certain that 
there are no breaks in the cireuit a telephone introduced into 


Trowbridge—Electric Discharges through [ydrogen. 348 


the cireuit is silent; moreover, a large self-induction included 
in the circuit does not affect the strie. 

Under certain conditions the current from a storage battery 
oscillates, or pulsates, but such oscillations or pulsations do not 
seem to modify the appearance of the stratifications. If, on 


BiG. a: 


M 


Fic. 3 shows the arrangement in plan by means of which the ripples 
are studied. M is a mercury lamp of the Cooper-Hewitt form. This is 
placed directly behind the trough containing the pistons. The surface of 
the water, totally reflecting the light, forms a dark line which, under the 
‘motion of the pistons, undulates in waves which can be studied by instanta- 
neous photography. P and P’ are the pistons, and D is a diaphragm with a 
rectangular orifice. 


the other hand, there is a flow from the cathode which pulsates 
at a different rate from asupposititious flow from the anode, one 
might expect strie, or accumulation of ionic disturbances at 
regular intervals. An hydrody namical analogy is afforded by 
the motion of two pistons moving against each other at differ- 
ent rates in a channel filled with water. 


res 


Fic. 4 represents a case in which P moves twice as fast as P’.. The waves 
are formed nearer the slower-moving piston. The method seems to be use- 
ful in studying ripples and waves. 


All who have worked in the field of discharge of electricity 
through gases must recognize the suggestiveness of the theory 
of ionization by collision, especiaily with reference to strie ; 
but one who was jonorant of this theory, seeing the action 
of the cathode in driving back striee into the anode, might 
attribute this action to an actual repelling force, arising from 
the cathode. When this supposititious force is diverted by a 
magnet the strize appear and more current flows. One igno- 
rant of the many facts of ionization by collision might further 
suppose that heavier particles of slower motion might be held 
back by swifter particles issuing from the cathode. These 


344 Trowbridge—Electric Discharges through Hydrogen. 


views of a mind not biased by ionization theories would appear 
to be supported by the phenomena presented by the tube rep- 
resented in fig. 5. 

One branch of this tube is at right angles to the other 
branch. There are two anodes, A and A’, and two perforated 
cathodes, K and K’. When a multiple circuit is formed by 
leading in the current to the two anodes and out by one 
cathode, K, strize form in the branch A’K’ after they disappear 
in the branch AK; and they persist m A’K’, when the 
branch AK appears to be nearly at the X-ray stage. One 
looking at the branch A’K’ would suppose that the rarefac- 
tion of the entire tube was low; and gazing at the branch AK 
would think it very high. The bend in the tube acts like a 
magnet in allowing the striz to emerge from the anode A’; 


Fig. 9. 


and it does this by enfeebling by reflection the effect of the 
cathode rays in the branch A’K’. 

The function of the cathode beam seems to be twofold; it 
forces back the striz; and at higher exhaustions it ionizes the 
gas ; for the current ceases to flow at high exhaustions when the 
cathode beam is strongly diverted by a magnet. These fuuc- 
tions are illustrated by the phenomena in a tube represented 
in fig. 6. 

Between the anode, A, and a cathode, D, the glass tube is con- 
stricted. The cathode D is a circular dise with an orifice a 
little larger than the glass orifice. The cathode rests upon the 
walls of this orifice, presenting no metallic surface toward the 
anode A. The cathode beam produees fluorescence toward D’ 
and is marked in the direction toward A by a white beam 
which produces hardly a perceptible fluorescence. The latter 
beam does not come from the metallic surface of the cathode ; 
but seems to come from the gas in the region DD’. At com- 


Trowbridge—llectric Discharges through Hydrogen. 345 


paratively high exhaustions this latter portion of the cathode 
beam ceases to ionize the gas; the current ceases and the 
potential between A and D rises to the full potential of the 
battery, indicating an open circuit. When, however, D’ is 
made the cathode, the current is immediately re-established and 
the cathode beam from D’ ionizes the 
gas between D’ and A. The tube 
acts as a rectifier; for when JD is 
made the anode and A the cathode a 
current passes ; on reversal of the cur- 
rent, as I have said, no current passes 
in the opposite direction. 

It is interesting to observe the effect 
of a transverse magnetic field on the 
discharge in this tube when A is 
made a cathode and D’ an anode and 
striee appear in the portion DD’. 
The magnetic field placed near A 
diverts the cathode beam and striz 
advance in the portion DD’. While 
this field is still on, another trans- 
verse magnetic field placed near D’ 
diverts the striz independently of the 
action of the field at A. This indi- 
cates the well-known fall of potential 
from striz to strie. 

The rectification observed under proper conditions in the 
tube fig. 6 suggests other forms of tubes by which rectification 
ean be produced. Even with a straight cylindrical tube the 


ie: 


~ 


eS, Hs 


current can be stopped at high exhaustions by touching the 
outside of the tube with the finger, thus diverting the cathode 


346 Trowbridge—Electric Discharges through Hydrogen. 


beam by electrostatie action ; it readily passes when the current 
is reversed. The phenomenon of rectification is shown in a prac- 
tical way in the U-shaped tube represented in fig. 7, which 
is provided with two anodes, A and A, and two cathodes, D 
and D’. The cathodes have orifices at their centers. The two 
anodes are connected together, and also the two cathodes—the 
tube forming a multiple circuit. A transverse magnetic field 
can be so placed near one cathode that no current will pass in 
the branch of the tube of which it is a part, while the current 
passes freely in the other branch of the U tube. This form of 
tubes rectifies an alternating current. 

The apparent repelling, or driving back action, of the cathode 
beam on strive is shown ina suggestive manner in a straight 
cylindrical tube when a diaphragm is inserted between the anode 
and the cathode. We will take for illustration one branch of 
the U-shaped tube (fig. 7), and suppose that the current is 
led into the tube at A and out at D. A metallic diaphragm 
with a small hole at its center is inserted in the tube about one- 
third of the distance between A and D, measured from the 
cathode to anode, the latter also having an orifice at its center. 
The strive are slowly driven back by the cathode rays as the 
exhaustion proceeds». At a definite stage of this exhaustion a 
stria takes refuge behind the diaphragm near the anode, where 
it is protected from the driving back action of the cathode 
rays; finally at higher exhaustions this stria is driven through 
the orifice in the anode and shelters itself behind the anode. 

At a higher state of rarefaction a stria issues from the orifice 
in the anode and this also shelters itself behind the diaphragm 
on the side toward the anode. There are, thus, three definite 
stages of stratification in this form of tube. At a pressure of 
four centimeters fine strize appear on the side of the orifice in 
the diaphragm opposite to the anode. These soon disappear 
with increasing rarefaction. At a pressure of approximately 
3™” a large stria shelters itself behind the diaphragm opposite 
the anode. This disappears with diminishing pressure ; and 
at a pressure of approximately 15™™ a large stria wells up out 
of the orifice in the anode and takes a similar place near the 
diaphragm. When the state of canalstrahlen is reached, all 
strize have been driven into the anode. Can we regard these 
strahlen as a stratification which cannot be driven back by the 
cathode rays? In this form of tube we find evidence of suc- 
cessive states of stratification which may depend upon positive 
rays of different velocity. 

When we turn our observation of stratification in the neigh- 
borhood of the cathode instead of in the neighborhood of the 
anode, we find that a stratification always takes place on the 
glass wall close to the entrance of the cathode, or to its sealing 
in place. It can be produced equally well by causing the 


Trowbridge— Electric Discharges through Hydrogen. 847 


eathode to approach the wall of the tube opposite to the sealing 
in place. Fig. 8 represents the phenomenon in a tube with a 
dome-shaped chamber near the electrode. We seem to have 
two dissected striz; one on the wall of the tube nearest to 
the cathode, which provides a beautiful hght blue cathode 
beam thrown into the dome; and another stria on the oppo- 
site wall of the dome. The original cathode beam excites both 
positive and negative rays in these striee. 


Fic. 8. 


In considering these detached striz it seems that the cathode 
rays in striking the glass walls can excite both positive and 
cathode rays. 

When a spark gap is inserted in a circuit containing a dis- 
charge tube which is properly exhausted to the strie stage, 
the latter apparently disappears, the light of the tube becomes 
more brilliant and fluorescence is generally manifested. This 
is also the case when a condenser is discharged through the 
tube. The eye cannot perceive any evidence of stratifications ; 
for the brightness of the pilot spark, together with the fluores- 
cence both of the gas and the glass walls, effectually shield 
any strize of lesser radiance which might be present. It is not 


348 Trowbridge—EHlectrie Discharges through Hydrogen. 


possible to employ the revolving mirror. The only method 
which seemed to promise any results in detection of possible 
stratifications was the employment of a portrait lens of large 
aperture—four inches—in photographing single discharges. 
Accordingly a discharge tube was filled with hydrogen and 
exhausted to the striz stage. A condenser of ‘02 mf. capacity 
was charged to a difference of potential of 10,000 volts and | 
discharged through the rarefied tube by flat copper bands of 
inappreciable self-induction. The photographs showed unmis- 
takable strize, superposed upon the general illumination of the 
tube. It is difficult to reproduce the photographs by half 
tones. 

With an anode consisting of a rim of wire placed in a eylin- 
drical tube °5™" internal diameter a striation is formed at a 
short distance from the anode by condenser discharges and there 
are traces of similar striations at greater distances along the 
tube. If these striations are formed by ionization by collision, 
the time of ionization is that of the duration of the pilot spark, 
a time which at present is beyond our power of measurement. 


Doppler effect. 


When two anodes and two cathodes are employed in the 
form of tube represented in fig. 7, there are two canalstrahlen 
which emanate from orifices in the cathodes in opposite 
directions. One might suppose that the Doppler effect would 
be modified by collision of the particles in these rays and that 
the effect would certainly be less than when only one anode and 
one cathode were employed—the current thus passing through 
but one branch of the U-tube. It is true that the difference of 
potential is less between A and D when the tube is coupled in 
multiple circuit than when only one branch of the tube is 
connected to the battery; but this difference in the case I 
studied was comparatively small. With both branches of the 
tube constituting a multiple circuit there were two strong 
canalstrahlen passing through the orifices in D which were 
undistorted and which gave the same Doppler effect which 
was obtained when only one branch of the tube was excited. 
It seems difficult to reconcile this result with any theory of 
fiow. 

Conclusions. 

1. The strize in Geissler tubes are analogous to waves set up 

in narrow channels by opposite pulsations of different periods. 


2. Strie are greatly influenced by the direction of cathode 
rays. 


Trowbridge—KHlectric Discharges through Hydrogen. 349 


Certain forms of tubes, described in this article, can imitate 
the action of a transverse magnetic field in apparently increas- 
ing the conductibility of the rarefied gas and restoring the 
condition of stratification. 

3. Strize can be formed by condenser discharges; and such 
striz lead one to suppose a time of ionization beyond our 
power of measurement. 

By means of a suitably placed diaphragm, successive stages 
in stratification can be produced. 

4. By modification of the form of discharge tubes rectifica- 
tion of alternating discharges is possible. 

5. The Doppler effect in hydrogen is not modified by caus- 
ing two canalstrahlen to oppose each other. 


Jefferson Physical Laboratory, 
Harvard University. 


3850 O. C. Farrington—New Pennsylvania Meteorite. 


Art. XXIX.—A New Pennsylvania Meteorite; by O. C. 
FARRINGTON. 


To the iron meteorites known from Pennsylvania, Bald 
Eagle, Pittsburg and Mount Joy, a fourth is now added. This 
last cosmic accession was found in 1907 on a farm about seven 
miles north of Shrewsbury, York County, Pennsylvania., It 
was discovered by being struck by a plow while plowing and 
attracted attention on account of its unusual weight. As the 
region is one in which more or less brown limonitic iron ore 
occurs, the meteorite was supposed by its finder to be an 
unusually heavy specimen of such ore and as such was shown 
to Mr. F. Justice Grugan of Philadelphia when in the vicinity 
in June, 1909. Mr. Grugan, in whose possession the meteorite 
now is and to whom the writer is indebted for the history 
here given, at once recognized the meteoric nature of the mass, 
and took steps for its preservation. He also instituted a 
search for any associated specimens that might be in the 
vicinity. In this he was suecessful to the extent of finding 
several fragments that had been distributed as curiosities, but 
no important additional individuals were found. The smaller 
pieces obtained were reported to have been found about 
three-quarters of a mile northwest of the main mass. If this 
distribution was a natural one, a southeasterly course of the 
meteor is indicated. The fragments and mass placed in the 
hands of the writer for examination had evidently all belonged 
to a single individual. The main mass as received weighed 
twenty-four pounds and the fragments three pounds more, 
giving a total weight to the meteorite as now known of 
twenty-seven pounds (12°2 kgs.). The form of the meteorite 
as restored by adding the fragments is roughly rhombohedral, 
with dimensions of about six inches (15°) on a side. At the 
same time there is much rounding of the solid angles and 
there are many depressions and irregularities which make the 
above characterization of the form only an approximate one. 
Owing partly to decomposition from lying in the soil and 
partly probably to rough handling, the appearance of the 
original surface of the meteorite remains over less than half 
the mass. Where seen it shows the usual rounded and smooth 
exterior of iron meteorites with broad, shallow pits, the broad- 
est being about three inches (7) in diameter. There has 
been considerable alteration of this surface through weather- 
ing, so that its substance has become more or less friable and 
limonitic in character. This alteration appears to extend in 
places to a depth of about half an inch (1%). Where the 
original surface is not present the meteorite shows a jagged, 
fractured appearance and exhibits typical octahedral structure. 
It is probable that over such portions the original surface has 
disintegrated and fallen away, though the appearance at one 


O. C. Farrington—New Pennsylvania Meteorite. 351 


point would indicate a rending of the mass in the air like that 
shown by one of the Glorieta Mountain individuals. 

On account of oxidation the mass as a whole presents a 
generally rusty brown color with spots of a green incrustation, 
due doubtless to the formation of some nickel salt. The 
undecomposed nickel-iron is easily cut by a file, but is not 
malleable owing to a well-developed laminated structure. Under 


Gale 


Fig. 1. Shrewsbury meteorite—3/5 nat. size. 


the hammer, therefore, it is inclined to crumble. Plates 
of bronze-yellow, flexible, magnetic taenite can be easily sepa- 
rated both from the decomposed and undecomposed nickel-iron. 
Analysis of the meteorite by Dickman and Mackenzie of 
Chicago gave the following result: 
Fe Ni Co S Je 
90°84 8°80 tr. ‘Ol 297 = PO IEGA 


Sections of the meteorite show a firm, homogeneous interior 
with little or no disintegration. Broad, straight lamellee 
almost entirely prevail. These lamelle average a little over 


3852 O. OC. Larrington—New Pennsylvania Meteorite. 


one millimeter in width, thus placing the meteorite in the 
group of medium octahedrites. For the most part the lamelle 
show simple, broad bands of kamacite, but some of these are 
seen on closer examination to be made up of smaller lamelle 
grouped together. The kamacite shows considerable hatching, 
generally in a single direction. Where fields occur they 
appear to be: mainiy of two kinds: 1, those made up of 
numbers of minute teenite folize with parallel arrangement and 
parallel to the adjoining bands, and 2, those made up of 


Teh, Rag 


Fic. 2. Etched section of Shrewsbury meteorite—1/2 nat. size. 


kamacite grains bordered by teenite and showing a more or 
less divergent arrangement. Accessory constituents are com- 
paratively abundant and scattered irregularly over the section 
though somewhat more numerous toward the periphery. They 
include troilite and schreibersite, the troilite occurring in sphe- 
roidal and the schreibersite in hieroglyphic forms. The troilite 
is characterized by a bronze-yellow color and dull luster, the 
schreibersite by a tin-white color and shining luster. One 
troilite nodule in the section especially studied by the writer is 
nearly circular in form, 2°" in diameter and has an irregular 
border of schreibersite. In other places the troilite has a 
more nearly vein-like distribution and is more or less mixed 
with schreibersite. | Hieroglyphic schreibersite occurs at 
several points, usually in groups of three. The grains are 
from 4 to 8 millimeters in length. Swathing kamacite from 
2 to 4 millimeters in width surrounds the scheibersite 
inclusions, but there is none about the troilite. 


A. H. Clark— Pentamerous Symmetry of Crinoidea. 358 


Arr. XX X.—Remarks en the Pentamerous Symmetry of the 
Crinoidea; by Austin H. Crarx. 


THE pentamerous symmetry of the echinoderms is now 
admitted to be a feature of phylogenetically secondary import- 
ance—a radial symmetry superimposed upon a primarily bilat- 
eral symmetry and so perfectly developed as almost entirely 
to mask the original condition. It has been pertinently sug- 
gested that the sedentary life of the animals has induced a 
radial arrangement of their structures, analogous to what has 
occurred in certain other groups, though in the echinoderms 
this has been carried so far as to result in a complete absence 
of any head region, and, consequently, a complete decentraliza- 
tion of the nervous system, so that, in many cases, the only 
trace of the original bilateral symmetry is found in the diges- 
tive system. In the Astroradiata* (Asteroidea and Ophiu- 
roidea) even this has yielded to the radial tendency, through 
here the water-vascular system, as evidenced by the so-called 
“stone-canal,” shows indications of a former bilateral arrange- 
ment. 

The larva of all echinoderms are bilaterally symmetrical, and 
pronouncedly so, the pentamerous symmetry only appearing 
when the adult formis acquired. The astroradiate echino- 
derms are all, except for the stone canal, radially symmetrical 
in every respect; but in the heteroradiate forms (Pelmatozoa, 
Echinoidea, and Holothuroidea) there is often, one might 
almost say usually, a more or less pronounced leaning toward 
the bilateral type, as seen, for mstance, in the Comasteride 
among the crinoids, in the clypeastroids and spatangoids among 
the urchins, and in the Elasipoda, and in such forms as 
Lophothuria and Psolus, among the holothurians. There are 
two possible explanations of this bilateral condition in the 
heteroradiate echinoderms; (1) the animals may never have 
attained the perfected radial symmetry, or (2) they may have 
passed through a radially symmetrical condition and, reacquir- 
ing the habit of moving in a definite direction, have again taken 
on a bilateral habit, this bilateral condition having been super- 
imposed upon the previous pentamerous condition, which itself 
was superimposed upon the primitive bilateral state. It is 
probable that the so-called “irregular” urchins (the clypeastroids 
and spatangoids) as well as the Elasipoda and other bilateral 
holothurians exemplify the latter condition, while certain of 
the Pelmatozoa furnish an instance of the former. It is among 
the erinoids, then, of the living echinoderms that an explana- 


* American Naturalist, vol. xliii, p. 686, Nov., 1909. 


Wis 


354 A. H. Clark—Pentamerous Symmetry of Crinoidea. 


tion of the origin of pentamerous symmetry must be sought, 
and a review of the data gleaned from a study of certain 
species offers some points of considerable interest. But just 
because certain of the crinoids appear never to have attained 
a true and complete radial symmetry, it does not at all follow 
that the marked bilateral arrangement of all types can be thus 
explained ; for instance,in the recent representatives of the 
family Comasteridee there are several species having the arms 
arising from the two posterior rays much shorter than the 
others, and devoid of ambulacral grooves or tentacles. This 
isa bilateral symmetry derived through a pentamerous sym- 
metry clearly, for in the less specialized species belonging to 
the same genera, and in their own young before adolescent 
autotomy, the two posterior rays and the arms arising there- 
from are just like all the others. 

That classical genus Antedon, the “Comatula’ of most 
text-books, represents a form with the most highly perfected 
pentamerous symmetry, yet exhibiting no advance whatever 
toward the more highly specialized secondary bilateral sym- 
metry seen in the comasterids. Antedon is strictly penta- 
merous in all respects, excepting only the digestive system; 
but that this pentamerism is really quite superficial is strikingly 
shown by a variant described by Professor Bateson* in which 
one of each of the posterior pairs of arms was abnormally 
palmate. It would seem, then, that Antedon was a good 
genus in which to search for an explanation of the origin of 
pentamerism. 

Dr. P. H. Carpenter had the good fortune to be able to 
examine several four-rayed comatulids, most of them. belong- 
ing to the genus Antedon; and it is a fact of the highest inter- 
est that in every case 7¢ was the anterior ray, the one directly 
opposite the anal area, that was missing. The U.S. National 
Museum possesses a four-rayed specimen of that magnificent 
comasterid Comanthus polycnemis, which was brought from 
the Philippine Islands; on examining it I found that here 
again it was the anterior ray that was missing. Such a remark- 
able coincidence of observations can mean but one thing; 
there must be some good reason why the anterior ray should 
be deficient rather than any of the other four. Simece we can 
safely say that there is no physiological reason why the ante- 
rior ray should be suppressed in preference to the others— 
indeed in the case of comasterids one would think that one of 
the normally abortive posterior pairs would be the first to 

*Proc. Zool. Soc. London, 1890, p. 584, fig. 4. The eleven and twelve 
armed specimens of Antedon described by Dendy and Carpenter are not 


bilaterally arranged ; but probably they arose through accident and are not 
congenital, not being, therefore, strictly comparable. 


A. H. Clark—Pentamerous Symmetry of Crinoidea. 355 


disappear, since it is quite useless for the collection of food— 
we are forced to look for some phylogenetic cause. 

Young erinoids are, as has been mentioned, bilaterally sym- 
metrical; all the four-rayed adults of the comatulids so far 
observed are bilaterally symmetrical; the normal five-rayed 
adults are the equivalent of the four-rayed adults, plus the 
interpolation of an additional ray between the = of the 
anterior pair. The more or less frequent reversion of the 
five-rayed crinoids to a four-rayed form (a permanent condition 
in Tetracrinus) would appear to be an index pointing back 
along the phylogenetic path travelled by the race: and this 
index becomes all the more significant when we glance at the 
record of six-rayed variants in which there is no such uni- 
formity of place of interpolation. 

It would appear as though the evidence pointed to an 
original bilateral condition among the adult crinoids in which 
there were two pairs of body processes that had become, 
through similarity of function, the same; in other words, a 
bilateral condition which had become as well, through induced 
radial symmetry due to inactive habit, quadriradial. We may 
readily imagine that, by sporadic variation, an additional ray 
might sometimes be produced between the two of the anterior 
pair, especially in animals of such remarkable regenerative 
powers as the crinoids. This additional ray would be just 
like those on either side of it; and in a sessile animal it would 
cause no inconvenience but "would, on the contrary, be of 
distinct advantage in furnishing a very marked increase in 
food-collecting power. Animals with this additional ray 
would therefore have, in the case of sessile forms lke the 
crinoids—passive feeders which must wait for their food to 
come to them—a great advantage in the struggle for existence, 
and we might well imagine that nature would be quick to 
take advantage of such a variant, and to fix permanently this 
pentamerous condition. 

If we can admit that the four- cara condition which, so far 
as is known, always arises from the loss of the anterior ray, is a 
true phylogenetic index—and there is no good reason why we 
should not—then we would be led to the conclusion that the 
crinoids are primarily animals possessing a bilateral symmetry, 
with two pairs of similar appendages, an anterior and a poste- 
rior, upon which a secondary pentamerous symmetry has been 
superposed, due to interpolation of one half of one of the 
bilaterally symmetrical pairs of appendages between the two 
components of the original anterior pair. 

It might be urged that supernumerary paired appendages 
would be unlikely to put in an appearance except in pairs; but 
we find instances of just that thing in other widely different 


356 A. H. Clark 


Pentamerous Symmetry of Crinoidea. 


animals which possess two similar pairs of appendages like our 
theoretical ancestral crinoid. I may mention in this connec- 
tion three-legged (five-limbed) chickens among the birds, and 
five-winged butterflies and moths (in cases where the additional 
wing does not replace a leg). In one case of the latter, a 
beautiful female of Platysamia cecropia, which has recently 
come under my notice, the similarity to the theoretical phylo- 
genetic condition among the crinoids-is very -striking, for the 
additional wing (which unfortunately failed to spread properly) 


Specimen of Platysamia cecropia with an additional primary inserted 
just anterior to the normal right primary. 


is inserted anterior to one of the primaries, where, were the 
animal sessile and incapable of motion, it might, through fixa- 
tion in subsequent generations, very well give rise to as truly 
a pentamerous condition as is exhibited by the crinoids. 
Although I have treated in detail only the evidence brought 
out by the erimoids, I have no doubt that the pentamerous 
symmetry in all the other groups has arisen in the same way, 
by the interpolation of an extra ray between the two original 
anterior rays; and that this accounts for the excess of plasti- 
city of this ray in certain groups, and its more or less frequent 
suppression in others. In six-rayed specimens almost invari- 
ably the sixth ray is obviously formed by a more or less com- 
plete division of one of those already existing—a sort of 
echinodermal polydactylism—and these six-rayed examples, 
therefore, are very suggestive in indicating that echinoderm 
symmetry isnot by any means radial, but is a composite of 
five equivalent parts, two paired and one, the anterior, odd. 
The echinoderms as known to us are extremely ancient 
animals, zoologically speaking, so ancient that they were 


A. H. Clark—Pentamerous Symmetry of Crinoidea. 357 


brought to their present state of perfection, or were even more 
highly specialized, in the earliest geologic epochs of which we 
have any record. The enormons time through which they 
have passed without any appreciable change toward further 
specialization has resulted, by the operation of the law of accel- 
eration of development, in pushing the various ontogenetic 
steps further and further back until all such stages as the 
biserial arrangement of the crinoid arm, the change from 
bilateral to pentamerous syinmetry, the reduction and transfor- 
mation of the ambulacral plates in the crinoids into division 
series, ete. have been entirely lost. The echinoderms as a 
whole I believe can be compared with the other invertebrate 
groups in their mode of development only in the way that the 
curiously specialized Gecarcinus can be compared with other 
crabs, or ylodes with other frogs; in other words, they form 
a group in which extreme specialization and its effect upon the 
earlier stages of the ontogeny has obscured or obliterated 
much of the phylogenetic data ordinarily available. 

_ Larval echinoderms are as extraordinarily specialized as the 
adults, but along radically different lines; many of them have 
specially developed skeletons, entirely different from those 
of the adults, which are lost in later life. It seems to me that 
the echinoderm larvee, owing to their extraordinary speciali- 
zation, must be treated almost as a different class of animals 
from the adults, specialized along entirely different lines, and 
fitted for an entirely different mode of life; and that we can 
expect to learn little more about the interrelations of the 
echinoderm groups from the study of their larve than we 
could of the relationships of the groups of lepidoptera, diptera 
or coleoptera from a study of their caterpillars or maggots. 


Am. Jour. Sc1.—FourtH Series, Vou. X XIX, No. 172.—Aprin, 1910. 
24 


358 W. M. Thornton, Jr.—Lnargite, Covellite, and Pyrite. 


Art. XXXI.—An Association of Hnargite, Covellite, and 
Pyrite from Ouray Co., Colorado; by Witiiam M. 


THORNTON, JR. 


In October, 1906, Professor William H. Echols received a 
curious sample of copper ore from the Genesse Vanderbilt 
mine in the Red Mountain district, Ouray county, Colorado. 
The specimen was seen to consist of three distinct metallic 
minerals, which were subsequently identified by physical 
properties, behavior before the blowpipe, and quantitative 
analysis as enargite, covellite, and pyrite. 


General Description. 


The enargite is closely interlocked with pyrite—both grow- 
ing out from a quartz gangue. The color of the enargite is 
dark grey; and the luster metallic. The structure is columnar. 
The cleavage is easy in one direction. Specific gravity=4-49. 
A few crystals are present but badly crushed and distorted. 
The covellite joins the other two minerals, and includes here 
and there a little pyrite or gangue. The color is indigo-blue 
and the luster sub-metallic. The structure is foliated, and the 
mineral can be easily cleaved into thin plates. 


Analysis of enargite by Wm. M. Thornton, Jr. 


Coppersictn ws Nis oe 50°82 per cent. 

LANG ae SS Da rea ieee fie Oca onarecs 

VATSOMIC 22% 2 ees ert SIO Re 

Sulphur se ors sey cee BDFD Sue me 

DULVier a2 ae ee Vielen None “ 

TON oe A ae ene @race. 6 
100°96 


Corresponds approximately to the formula: Cu,AsS,2-3Cu,S, 
As 


Dao 


Analysis of covellite by John E. Seabright. 


Copper ie 2 eee) ag oe8 68°38 per cent. 
Sul pl urea eee ey ries BPH 
100°89 


Corresponds to the formula: CuS. 


Methods of Analysis.—The enargite was first treated with 
nitric acid and the resulting mass thoroughly dried. <A fusion 
was then made with sodium carbonate and potassium carbonate 


W. M. Thornton, Jr.—Enargite, Covellite, and Pyrite. 359 


(weight for weight) and potassium nitrate, and the melt 
leached with water. An aliquot part (8/4) of the filtrate was 
concentrated for the precipitation of arsenic as ammonium 
magnesium arsenate. The precipitate was ignited to magnesium 
pyroarsenate. A trace of arsenic was recovered from the fil- 
trate by hydrogen sulphide and weighed as arsenic trisul phide. 
In one-fourth the original solution the sulphur was determined as 
barium sulphate in the usual manner. The residue, consisting 
chiefly of copper oxide, was dissolved in sulphuric acid and a 
little nitric acid; and the copper precipitated with sodium 
thiosulphate, ignited under hydrogen sulphide, and weighed as 
- euprous sulphide. In the filtrate from the cuprous sulphide , 
the zine was precipitated by ammonium sulphide and ignited 
to the oxide. 

The covellite was dissolved in nitric acid; and with the aid 
of potassium chlorate the separated sulphur was converted into 
one clean globule. The sulphur thus separated was weighed 
as free sulphur. One-fifth of the filtrate was employed to 
determine the remaining sulphur as barium sulphate. In two- 
fifths of the origimal solution the copper was estimated as 
above. 

This cuprous sulpharsenate is not among the commonly 
occurring ores of copper. Cupric sulphide, as compared with 
euprous sulphide, or ordinary copper glance, is rare. This 
association, therefore, is in the author’s opinion a very interest- 
ing one and deserving the brief notice here given. It may 
also be mentioned that the minerals of this aggregate contain 
no silver, which is quite the exception for ores of the Red 
Mountain district. 

Virginia Geological Survey, 


University of Virginia, 
January 22, 1910. 


360 Scientific Intelligence. 


SCIENTIFIC INTELLIGENCE. 


I. CwHemistRy AND Puysics. 


1. The Detection of Sodium, Cesium, and Rubidium.—Some 
years ago W.C. Batt described some complex nitrites of bismuth, 
prepared from the yellow liquid obtained by the interaction of 
bismuth nitrate and sodium or potassium nitrite. Among these 
were the triple salt Bi(NO,),.2NH,NO,.NaNO,, and the double 
salt Bi(NO,),.3KNO,.H,O, both very soluble compounds. On 
attempting to prepare similar rubidium and cesium derivatives, 
it was found that dilute solutions of the nitrates of these metals 
produced yellow, ‘crystalline precipitates with the reagent 
obtained from sodium nitrite and bismuth nitrate. These are 
triple nitrites of bismuth, sodium, and rubidium or cesium, and 
their formation serves as a very useful method of detecting these 
metals in the presence of an excess of potassium. The reaction 
for cesium is especially delicate. Furthermore, a reagent may 
be prepared by the addition of a cesium salt to the product of 
the reaction of bismuth nitrate and potassium nitrite, which 
serves aS a remarkably delicate test for sodium in producing a 
precipitate of the same triple bismuth-sodium-cesium nitrite. 

The bismuth-sodium nitrite reagent is best prepared by dis- 
solving 50g. of pure sodium nitrite in 100° of water, neutral- 
izing with nitric acid if necessary, and adding 10 to 20 g. of 
powdered bismuth nitrate. The resulting orange-colored solution 
must then be filtered and kept in a well-stoppered bottle, as it 
absorbs oxygen and becomes turbid when exposed to the air. In 
using this reagent to test for rubidium and cesium, the solution 
to be tested is added to a large excess of the reagent acidified 
with one or two drops of nitric acid to prevent the formation of 
a basic bismuth salt. In all these tests it is better to use nitrates 
or sulphates, rather than chlorides, on account of the tendency of 
bismuth oxychloride to precipitate when concentrated solutions 
of chlorides are used. The reagent gives a precipitate quickly 
with a 0°5 per cent solution of rubidium. Only heavy metals 
and cesium interfere with the test, which affords an easy method 
for distinguishing rubidium from potassium, ammonium, lithium, 
thallium, etc. The precipitate is bright yellow and crystalline, 
and probably corresponds to the formula Bi(NO,),.2RbNO,.- 
NaNO,. The test for cesium with this reagent is still more 
delicate, 1°° of a 0-2 per cent solution of cesium nitrate giving an 
immediate yellow crystalline precipitate with 4 or 5° of the 
reagent. 

The reagent for sodium is prepared by dissolving 50 g. of 
potassium nitrite in double its weight of water, neutralizing with 
nitric acid, adding 10 g. of powdered bismuth nitrate, filtering, 
adding a 10 per cent solution of czsium nitrate until the powdery 


Chemistry and Physics. 361 


yellow precipitate, invariably produced by traces of sodium 
present, ceases to be formed after keeping the liquid for several 
hours. The liquid is then filtered and the addition of cesium 
nitrate continued until about 2°5 g. have been used. The reagent 
is most sensitive when a precipitate of yellow, hexagonal plates, 
a nitrite of cesium and bismuth, is formed on further addition of 
the cesium salt. With 2° of this reagent 0°1°° of a 0°5 per 
cent solution of sodium, as nitrate, gave a considerable precipitate 
within 5 minutes, and by long standing it was found possible to 
detect as little as 0°01 mg. of sodium in the presence of much 
potassium salt. Most of the heavy metals interfere with this 
test, but zinc, cadmium, magnesium, barium, calcium, strontium, 
lithium, thallium and potassium do not interfere with it. The 
formula for the precipitate appears to be 5Bi(NO,),.9CsNO..- 
6NaNO,,. | 

Preliminary experiments indicate that small amounts of sodium 
may be quantitatively determined very accurately by means of 
this method. The precipitate contains only 3°675 per cent of 
sodium.—Jour. Chem. Soc., xcv, 2126. H. L. W. 

2. Volumetric Determination of Sulphates.—MircuEti and 
Smit have worked out the details of a method for this purpose, 
which is based on well-known reactions, and which had been sug- 
gested, in its essential features, by Precht as early as 1879. They 
take a convenient quantity of a sulphate, dissolve it in water or 
pure hydrochloric acid, or, if necessary, dilute nitric acid, and 
then add a slight excess of 1/5 normal barium chloride solution. 
They then boil the mixture, make it neutral with ammonium 
hydroxide, add ammonium acetate, acetic acid, and a slight 
excess of 1/10 normal ammonium dichromate solution, make up 
the mixture to 100°, allow the precipitate to settle, take out 25° 
of the clear liquid and titrate it with 1/20 normal ferrous 
ammonium sulphate, using potassium ferricyanide as an external 
indicator, and taking the first tinge of green as the end point. 
They use ammonium dichromate on account of the fact that 
barium dichromate appears to carry down with it traces of the 
potassium salt. The method was tested with ammonium sulphate, 
sodium sulphate, potassium sulphate, zinc sulphate, magnesium 
sulphate, and copper-ammonium sulphate. With potassium 
sulphate there was evidence of adsorption, to the extent of nearly 
2 per cent, but this was minimized by boiling the precipitate for 
several hours with a little dilute hydrochloric acid, neutralizing 
with ammonia, and proceeding as before. It is to be observed 
in applying this method that ammonium dichromate which is 
1/10 normal in regard to oxidizing power, is only 1/30 normal 
in regard to precipitating power. ‘The test analyses give very 
satisfactory results, and it is stated that, excluding weighings, 
five determinations can be made in an hour.—Jour. Chem. Soc., 
xcv, 2198. ED GSW 

3. The Action of Metals on Fused Caustic Soda.—As there 
are conflicting statements in respect to the stability of sodium 


362 Screntific Intelligence. 


hydroxide at high temperatures, and its action upon metals when 
heated in contact with them, LeEBLanc and Brremann have 
made an investigation of these matters. They find that caustic 
soda can be easily dehydrated,.as far as accidental water is con- 
cerned, by heating it in a gold crucible to 400° C., and that it 
shows no tendency to give off water of composition at 720°. 
Gold is the only metal experimented with which is not at all 
acted upon at the temperature just mentioned. Silver and 
sodium, in the absence of air, cause the evolution of hydrogen 
alone, while under the same conditions platinum, copper, iron, 
nickel, aluminium, zinc and magnesium cause the evolution of 
both hydrogen and water vapor. The ideal reactionis Me+xNa- 
OH = Me(ONa),+xH, so that the reason for the production 
of water in nearly all cases is somewhat obscure. This point the 
authors will study by means of further experiments.— Berichte, 
xlu, 4728. H. L. W. 

4. Transformation of Diamond into Graphite.—VocE.t and 
TaMMANN have investigated the temperature at which this 
change takes place. Splinters of diamond were placed in sealed 
porcelain tubes and heated in an electric furnace. At 1000° C. 
the change is exceedingly slow, and may not occur at all; at 
1200° a considerable transformation takes place within 24 hours, 
and at 1500° the change is comparatively rapid. A piece of © 
diamond, which was heated to 1600° in fused calcium silicate, so 
as to exclude air, was also changed superficially into graphite. 
—ZLettschr. physikal. Chem., 69, 598. H. Le We 

5. The Johns Hopkins University Circular, No. 2. Pp. 92. Bal- 
timore, Md., February, 1910.—The recent circular of the Johns 
Hopkins University hasa double interest. It opens with a series of 
papers, seventeen in number, from the physical laboratory, edited 
by Professor Ames. Five of these are by Professor Wood, includ- 
ing two on his recent photography with infra-red and ultra-violet 
rays; three each by J. B. Whitehead, J. A. Anderson, and W. 
W. Strong, and others by A. H. Pfund, P. H. Edwards, and C. 
M. Sparrow. A list of recent publications (since April, 1906) 
by those who are, or have been, members of the University fills 
pages 55-76. 

This circular also contains the record of the commemorative 
meeting held on December 19, 1909, of Professor Simon New- 
comb, whose active connection with the University extended over 
the sixteen years from 1884 to 1900. ‘The address delivered by 
Professor Milton Updegraff, of the U. 8. Navy, is given in full. 

6. Meteorologische Optik; von J. M. Pernrer. IV Abschnitt; 
von Fruix M. Exner. Pp. xviii, 559-799. Vienna, 1910 (Wil- 
helm Bratimuller).— Earlier parts of this valuable work have been 
noticed in this Journal (see vol. xill, 472, xxii, 81.) As will be 
recalled, the work as planned by Professor Pernter in 1901 was 
intended to embrace all the material dealing with meteorological 
optics, a field which has never been filled before. The author 
unfortunately died in December, i908, before it was possible for 


Geology and M ineralogy. 363 


him to finish his task. The completion of the work, therefore, 
has been placed in the hands of his associate, Dr. Exner, who 
with much thoroughness and industry has prepared a well- 
arranged digest of the special subjects to be covered. As this 
field, however, is one to which he had not devoted particular 
attention, he disclaims any attempt at originality of presentation, 
_ except in regard to Lord Ravyleigh’s theory of the blue color of 
the sky. Some of the topics treated are as follows: The apparent 
form of the firmament ; atmospheric refraction and the connected 
phenomena, as the Fata Morgana, scintillation, etc.; halos and 
rainbows and their explanation; the color and polarization of the 
sky, the weakening of light in the atmosphere and twilight phe- 
nomena. 


Il. Gronogy anp MINERALOGY. 


1. Publications of the U. 8S. Geological Survey, Gro. OTIs 
Smiru, Director.—Recent publications of the U.S. Geological 
Survey are noted in the following list (continued from vol. xxviii, 
p- 557). 

BG cclasioal Atlas of the United States.—No. 167. 
Field edition, in octavo form. Trenton, New Jersey—Pennsyl- 
vania Folio. Description of the Trenton Quadrangle: F. Bas- 
com, N. H. Darron, H. B. Kémuer, W. B. Crarx, B. L. Minter, 
and R. D. Sarispury. Pp. 185; 2 maps. Structure section 
sheet, columnar sections, 3 figures. 

No. 169. Watkins Glen—Catatonk Folio, New York; by 
Hryery 8S. Wittiams, Ratpu 8. Tarr, and Epwarp M. KInpts. 
Pp. 338, 3 colored maps, 37 figures. 

PRoFEssIoNAL Papers.—No. 65. Geology and Water Re- 
sources of the Northern Portion of the Black Hills and Adjoin- 
ing Regions in South Dakota and Wyoming; by N.H. Darron. 
Pp. 105, 24 plates, 15 figures. See p. 267. 

Minerat Resources of the United States. Calendar year 
1908. Part I—Metallic Products. Pp. 816, 2 plates, 3 figures. 
Part II—Non-Metallic Products. Pp. 899, 1 plate, 6 figures. 
These important volumes, each with its own index, bring together 
the numerous separate chapters, prepared by many different 
authors, which have already been issued in advance. ‘The gen- 
eral summary of mineral production in 1908, with which Part I 
opens, has been prefaced by W. T. THom. 

Buiietins.—No. 378. Results of purchasing Coal under Goy- 
ernment Specifications; by JoHn SHoBER Burrows. With a 
paper on Burning the Small Sizes of Anthracite for Heat and 
Power Purposes ; by Dwicut T. Ranpatu. Pp. 44. 

No. 386. Pleistocene Geology of the Leadville Quadrangle, 
Colorado; by StepHen R. Capers, Jr. Pp. 99, 7 plates, 18 
figures. 


364 Screntific Intelligence. 


No. 390. Geology of the Lewistown Coal Field, Montana ; by 
W.R. Catvert. Pp. 83, 5 plates, 1 figure. 

No. 396. Paleontology of the Coalinga District, Fresno and 
Kings Counties, California; by Ratpu ARrnoup. Pp. 173, 30 

lates. 
5 No. 397. Mineral Deposits of the Cerbat Range, Black 
Mountains and Grand Wash Cliffs, Mohave County, Arizona; - 
by F. C. ScorapEr. Pp. 226, 16 plates, 37 figures. 

No. 400. Iron Ores, Fuels, and Fluxes of the Birmingham 
District, Alabama; by Ernest F. Burcuarp and CHAR LEs 
Burts. With Chapters on the Origin of the Ores ; by Epwin C. 
Eoxet. Pp. 204, 17 plates, 19 figures. 

No. 404. The Granites of Vermont; by T. Nretson DALE. 
Pp. 138, 5 plates, 25 figures. | 

No. 405. The Mercury Minerals from Terlingua, Texas; by 
W. F. Hittesranp and W. T. Scuatuer. Pp. 174, 6 plates, 44 
figures. 

No. 408. A Reconnaissance of Some Mining Camps in Elko, 
Lander and Eureka Counties, Nevada; by Wittiam H. Emons. 
Pp. 130, 5 plates, 22 figures. 

No. 409. Bibliography of North American Geology for 1908, 
with subject index; by Joun M. NickiEs. Pp. 148. 

No. 410. The Innoko Gold-Placer District, Alaska, with 
accounts of the Central Kuskokwim Valley and the Ruby Creek 
and Gold Hill Placers; by A. G. Mappren. Pp. 87, 5 plates. 

No. 411. Results of Spirit Leveling in Ohio, 1898 to 1908, 
inclusive ; compiled by 8.8. Gannetr and D. H. Batpwin. Work 
done in codperation with the State of Ohio during 1901 to 1908, 
inclusive. Pp. 147. 

No. 412. Tests of Run-of-Mine and Briquetted Coal in a Loco- 
motive Boiler; by Watrer T. Ray and Henry KReEIsincEr. 
Pp. 31, 9 figures. 

No. 418. A Reconnaisance of the Gypsum Deposits of Cali- 
fornia; by Frank L. Hess, with a Note on Errors in the Chem- 
ical Analysis of Gypsum ; by GEorGESTEIGER. Pp. 36, 4 plates, 
2 figures. 

No. 414. Notes on Some Mining Districts in Humboldt 
County, Nevada; by Freperick Lestiz Ransome. Pp. 75, 1 
plate, 7 figures. 

No. 416. Recent Development of the Producer-Gas Power 
Plant in the United States; by Ropurr Heywoop FERNa.p. 
Pp. 82, 2 plates, 3 figures. 

No. 418. The Fire Tax and Waste of Structural Materials in 
the United States; by Harpert M. Wirson and Joun L, Cock- 
RANE. Pp. 30. 

No. 421. Results of Spirit Leveling in [Illinois 1896 to 1908, 
inclusive ; compiled by 8. 8. Gannerr and D. H. Batpwin, in 
codperation with the Illinois State Geological Survey during 
1905 to 1908, inclusive. Pp. 74. 

No. 423. A Primer on Explosives for Coal Mines. By 


Geology and Mineralogy. 365 


Cuartes E. Munrokr and Crarence Hatr. Pp. 61, 9 plates, 
12 figures. 

No. 424. The Valuation of Public Coal Lands. The Value 
of Coal Land ; by Grorer H. Asutey. Depth and Minimum 
Thickness of Beds as Limiting Factors in Valuation ; by Cassius 
A. Fisuer. Pp. 75. | 

Warter-Suppty Paprrers.—No 233. Water Resources of the 
Blue Glass Region, Kentucky; by Grorar CHaritton Matson. 
With a chapter on the Quality of the Waters; by CuasE Pat- 
MER. Pp. 223, 3 plates, 6 figures. 

No. 236. The Quality of Surface Waters in the United States. 
Part I. Analyses of Waters East of the One Hundredth Merid- 
iam, by K.B, Dove. Pp. 123. 

No. 238. The Public Utility of Water Powers and their Gov- 
ernmental Regulation; by Renf TaveRNIER and MarsHaty O. 
Leieguton. Pp. 161. 

2. Canada Department of Mines. GroLogicaL SURVEY 
Brancu, R. W. Brock, Director.—The following publications of 
the Survey have been recently received : 

No. 973. Catalogue of Canadian Birds ; by Joun Macoun 
and James M. Macoun. Pp. villi, 761, with index. 

_ Nos. 980,1081. Reports on a portion of Algoma and Thunder 
Bay Districts, Ontario; by W. J. Witson. Pp. 49, 6 plates. 
Report on the Region Lying North of Lake Superior, between 
ape Pic and Nipigon Rivers, Ontario; by W. H. Cottins. 

p- 24. 

No. 1035. The Coal Fields of Manitoba, Saskatchewan, 
Alberta, and Eastern British Columbia ; by D. B. Dow1ine. Pp. 
111, 11 plates, 1 map. 

No. 1050. The Whitehorse Copper Belt, Yukon Territory ; 
by R. G. McConnett. Pp. 63, 2 figures, and maps. 

No. 1059. A Geological Reconnaissance of the Region trav- 
ersed by the Transcontinental Railway between Lake Nipigon 
and Clay Lake, Ontario; by W. H. Cottins. Pp. 67, 2 plates, 
1 diagram. 

No. 1073. Catalogue of Publications of the Geological Sur- 
vey, Canada. (Revised to January 1, 1909.) Pp. 181. 

No. 1085. <A Descriptive Sketch of the Geology and Kcon- 
omic Minerals of Canada; by G. A. Youne. Introduction by 
R. W. Brock. Pp. 151, 82 plates, 2 maps. 

Mines Brancu.—Eucenst Haanet, Director.—No. 23. Report 
on the Iron Ore Deposit along the Ottawa (Quebec side) and Gati- 
neau Rivers; by Fritz Cirxet. Pp. vu, 147, 5 plates, 15 figures, 
2 maps. 

No. 62. Preliminary Report on the Mineral Production of 
Canada during the calendar year 1909; prepared by Joun Mc- 
“Lease. Pp: 18. 

Special reports (Nos. 42-46) have also been issued on the pro- 
duction for the calendar years of 1907-08 of the following : 
iron and steel; chromite ; asbestos; coal, coke, and peat ; natu- 
ral gas and petroleum. 


366 Scientific Intelligence. 


Nos. 55 (Mines) and 1107 (Geologic Survey). Joint Report on 
the Bituminous or Oil-Shales of New Brunswick and Nova 
Scotia; also on the Oil-Shale Industry of Scotland. Part I, Eco- 
nomics ; Part II, Geology; by R. W. Exus. Pp. 75, 15 plates, 
6 figures. 

3. Hilauea and Mauna Loa, Hawaiian Volcanoes ; by Wm. 
T. Briguam, Mem. Bernice Pauahi Bishop Mus., vol. i, No. 4. 
Pp. 222, 4°, 67 plates, 143 figs. Honolulu, 1909.—The author 
states in the beginning of his work that it is mainly for the pur- 
pose of presenting his studies, which have continued for nearly 
half a century, on the Hawaiian volcanoes, and thus supplying a col- 
lection of material which may be used by students of vul- 
canology ; he modestly disclaims any attempt to solve by theoriz- 
ing the deeper problems of this science, the source of volcanic 
heat and energy; in short, the cause of volcanic action. The 
work is thus mainly a record of observations of volcanic phe- 
nomena, and the writer has compiled so largely from the writings 
of other observers in this region, that the whole forms practically 
an historical account, in considerable detail, of the activity dis- 
played here during the past fifty years. Particularly valuable in 
this connection are the various maps showing the changes which 
have taken place from time to time in the different craters. 
Much of the work, entirely aside from the standpoint of its being 
a collection of recorded observations, is very interesting reading, 
and the author’s personal knowledge has enabled him to correct 
a number of errors, which at one time or another have crept into 
various publications on the volcanic phenomena of the islands. 

The volume is well printed and bound, and embellished with a 
large number of half-tone cuts and plates from photographs, 
which greatly enhance its value and interest; the only criticism 
which might be offered in this connection is, that had a different 
kind of paper been employed, the half-tone cuts would have given 
much better results. The work as a whole is a very useful addi- 
tion to the literature of vulcanology. Ty, Vai oe 

4. Deviations from the Normal Order of Crystallization in 
Granite.—Macki8, in an article entitled ‘ Micropegmatites in 
Granite,” gives the results of a study of a number of Scotch 
granites in which deviations from the usually assumed order of 
crystallization of the minerals occur. While ostensibly a study 
of various types of micropegmatite, its chief interest consists in 
the discussion of the order of crystallization and the explanations 
devised to account for irregularities. He finds in granite that 
quartz is the most aberrant mineral, its occurrence in abnormal 
position being equal to orthoclase and plagioclase together, and 
there are two maxima of this, one in the hornblende of horn- 
blendic rocks, the other in the orthoclase of the more acid rocks. 
He explains this by supposing that in the molten solution the 
liquid hornblende is able to keep a certain amount of silica (or 
quartz) dissolved, but when the hornblende crystallizes this is 
also forced to crystallize; later the rest of the quartz would 


Geology and Mineralogy. 367 


appear innormal position. By thus considering the various solu- 
bilities of the different minerals in one another, the solvent 
action of contained water, and rises of temperature and resolution 
occasioned by successive crystallization, he is able to devise a 
scheme which will account for abnormalities in the order of 
appearance. In connection with this the reviewer would point 
out that it has scarcely been shown as yet that hornblende, as such, 
can exist in the molten solution ; the trend of investigation, indeed, 
tends to prove that the mineral molecules existent in the magma 
are of much simpler composition, and it seems probable that 
hornblende comes into being only in the act of crystallization.— 
Trans. Edinb. Geol. Soc., ix, pt. iv, 247, 1909. Lis Vi 2. 

5. Wew Occurrence of Lujavrite.-—The very rare and remark- 
able rock lujavrite was first found and named by W. Ramsay, 
from its occurrence at Lujavr Urt in the Kola Peninsula, Rus- 
sian Lapland. It has been subsequently described by Ussing 
from southern Greenland. A new locality is now announced by 
H. A. Brouwer from Pilandsberg in the Transvaal. Like the two 
former occurrences, it consists of very flattened alkalic feldspars 
intermingled with nephelite and eudialyte and is pegged through 
with acicular aegirite. It also contains the associated rare min- 
erals astrophyllite, mosandrite and lavenite. The eudialyte is 
apt to be changed into catapleiite, while considerable quantities of 
secondary pectolite are present. The following analyses of two 
varieties of the rock are by F. Pisani: 


Si0, AMOR ZrO. Al.,O3 Fe.O03 FeO MgO CaO Na.O K,O0 H.O 

IT 52°35 0°59 0°39 14:11 7:98 2:17 066 4°65 9°30 2°78 3:20 
= 100°30 

If 51°35 2°75 0°54 11°45 9:40 2°41 054 3°27 10°80 2°52 3°20 


Sie total includes in- I, Mn@— 0°62 and CO,= 1°50; in II, 
MnO = 1:25. These correspond closely with the analyses of the 
Kola and Greenland rocks. It may be also mentioned that rocks 
resembling lujavrite have been described by Lacroix as a marginal 
facies of nephelite syenite from the Los Islands, French Guinea. 
The association with nephelite syenites occurs also with the 
lujavrites previously mentioned.— Comptes Rendus, Nov. 29, 1909. 
Tis WB: 

6. Zhe Mercury Minerals from Terlingua, Texas.—The 
remarkable minerals from Terlingua, several of them new, were 
described by Moses in 1903 (this Journal, vo]. xvi, 253) ; later a 
preliminary account of their chemical examination was given by 
HILLEBRAND and ScHALLER (vol. xxiv, 259, 1907). The latter 
authors have now published their complete results in Bulletin 
405 of the U. 8. Geographical Survey. Many points of interest 
are brought out, particularly the remarkable complexity of the 
crystallization of the new species: thus montroydite is shown to 
have 56 forms, terlinguaite 134 forms, and even the isometric 
eglestonite 20 forms. 


368 Scientific Intelligence. 


7. The Rochester Collection of Meteorites ; Descriptive List 
of Specimens ; by KenneTH S. Howarp. Pp. 28, with 2 plates. 
Rochester, 1909.—The Rochester collection of meteorites, of 
which a catalogue has been recently published, contains a total of 
234 falls, represented by 267 specimens: these include 89 sider- 
ites, 19 siderolites and 126 aerolites. A large part of the mate- 
rial was accumulated by the late Professor Henry A. Ward as 
duplicates in the course of his labors in bringing together the 
Ward-Coonley meteorite collection. Many fine individual speci- 
mens are noted in the catalogue, the collection being particularly 
rich in the irons, two-thirds of which weigh over 100 grams each. 

8. A new Meteorite from Georgia.—A new meteoric stone has 
been recently described by G. P. Mrrritn from Thomson, 
McDuffie county, Georgia. It was found on October 15, 1888, 
but has been in private hands and its existence has only now 
been made public. Its present weight is 218 grams and could 
not have been greater originally than 250 grams; it is largely 
covered with a black crust. The specific gravity is 3°51 and a 
polished surface shows a light gray ground resolved with a lens 
into a compact mass of gray chondrules, with small particles of 
metallic iron and iron sulphide. It is somwhat similar to the 
Mécs meteorite.—Smithsonian Misc. Conts., lii, pp. 473-476, 2 
plates. 


IJ. Misceruaneous Screntiric INTELLIGENCE. 


1. Carnegie Institution of Washington.—Recent publications 
of the Carnagie Institution are noted in the following list (con- 
tinued from vol. xxviii, p. 564) : 

No. 74. The Vulgate Version of the Arthurian Romances, 
. edited from Manuscripts in the British Museum; by H. Oskar 
Sommer. Vol. I, Lestoire del Saint Graal. Pp. xxxii,296. Vol. 
II, Lestoire de Merlin. Pp. 466. 

No. 85 (Kentucky). Index of Economic Material in Docu- 
ments of the States of the United States. Kentucky, 1792-1904. 
Prepared for the Department of Economics and Sociology of the 
Carnegie Institution of Washington; by ApELaipr R. Hassx. 
Pp. 452. 

No. 100. The Seal Cylinders of Western Asia; by Witiiams 
Hayes Warp. Pp. xxix, 428, 1315 illustrations. 

No. 108. The Atrium Vest ; by Estupr Bors—E Van DEmaN. 
Pp. ix, 47, frontispiece, 10 plates and plans A—-F, showing walls 
of various periods. 

No. 116.—The Differentiation and Specificity of corresponding 
Proteins and other vital Substances in relation to Biological 
Classification and Organic Evolution: The Crystallography of 
Hemoglobins; by Epwarp Tyson Rercuert, and Amos PzASLEE 
Brown. Pp. ix, 338, 100 plates and 56 tables. 

No. 121. Inheritance of Characteristics in Domestic Fowl ; 
by Cuarues B. Davenport. Pp. ili, 100, with 12 colored plates. 

2. Publications of the Allegheny Observatory of the University 
of Pittsburgh.—The following has been recently issued: Vol. I, 
No. 20. : The Algol—Variable 6 Libre. Pp. 123-134. 


r. 


Lib 


yrus er 
rarian U. S. Nat. Museum. 
VV AALA. MAY, 1910. 


Established by BENJAMIN SILLIMAN in 1818. 


THE 


AMERICAN 


JOURNAL OF SCIENCE. | 


Epirorn: EDWARD S. DANA. 


ASSOCIATE EDITORS 


Proressorss GEORGE L. GOODALE, JOHN TROWBRIDGE, 
W. G. FARLOW anp WM. M. DAVIS, or Camsrince, 


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


Proressor GEORGE F. BARKER, or PHmabDe.puia, 
Proressor HENRY S. WILLIAMS, or Irnaca, 
Proressor JOSEPH S. AMES, or Battimore, 
Mr. J. S. DILLER, or Wasuineton. 


FOURTH SERIES 


VOL. XXIX—[WHOLE NUMBER, CLXXIX.] 


No. 173—MAY, 1910. 


NEW HAVEN, CONNECTICUT. 
WAY 2 19) 


ae Nations Muse 


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


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Published monthly. Six dollars per year, in advance. $6.40 to countries in the 
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registered letters, or bank checks (preferably on New York banks). 


IMPORTANT ANNOUNCEMENT. 


I beg to advise my numerous patrons that I have succeeded in procuring 
a collection of minerals which represents the best quality of specimens 
from old finds and exhausted localities. Most of these choice specimens 
are finely crystallized, and represent years of labor in collecting by an old ~ 
time mineralogist. This collection practically covers the whole Dana 
system, and I feel that I can fully satisfy the requests of my patrons for 
choice specimens. I would therefore advise any who desire to fill the gaps 
in their collections to send mea list of their wants and I will send them 
full details of the specimens which I can supply. This is a fine opportunity 
for collectors to secure old finds which are not otherwise procurable. Send 
in all your orders early, therefore, to avoid disappointment, as my rule is to 
serve those who come first. 

I have on hand several lots of Cripple Creek Tellurides such as Sylvanite, 
Calaverite and Krennerite ; Gold Pseudomorph after Calaverite; Tellurium, 
mostly showing good crystals ; also some Amethyst specimens, showing 
parallel growth, and of good color ;. Calciovolborthite crystallized ; and 
Carnotite in fine yellow masses. 

From Old Mexico I recently received a number of specimens of beautiful 
crystallized Silver, Argentite, Polvbasite, Pyrargyrite, etc., and a number 
of Vanadinite specimens with bright crystals of different color on Barite, 
from Kelly, New Mexico ; also Smithsonite from the same locality. 

J can claim, besides, the finest specimens of California minerals: Tour- 
malines, both loose crystals and in groups of all colors and sizes, some with 
several colors; pink Beryl; Benitoite; Neptunite ; Gold Topaz ; Spessart- 
ite from a new find; Orthoclase crystals, and Quartz in fine specimens. 

I must not forget to mention, besides all these, that I have several fine 
Phacolite specimens from Australia, some of these having Phillipsite crys- 
tals on the matrix. 

Besides these additions I have still on hand a number of Awaruites from 
Smith River, California, as announced and described in the February issue 
of this magazine. 


At this opportunity I wish to inform my customers that I have the best 
quality of reconstructed Gems, in all sizes, namely : 

Rubies ; blue, pink, white and yellow Sapphires; pink Topaz; and an 
unusually large stock of common and rare Semi-Precious and Precious 
Stones, both cut and in the rongh, and am able to supply any gem desired, 
in best quality. 


Any of the above which may be desired for selection I shall be glad to 
send on approval to patrons and customers. 

Information and prices of individual specimens cheerfully furnished 
upon request. 


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


TEE 


AMERICAN JOURNAL OF SCIENCE 


Ph O.U ht Hees ret hs. | 


Arr. XXXII.—Contributions to the Geology of the Grand 
Canyon, Arizona.—The Geology of the Shinumo Area; 
by L. F. Noste. 


Part TI. 


PREFACE. 
INTRODUCTION. 

Location. 

Field Work. 

Literature. 

Acknowledgments. 

Geologic Nomenclature. 
TOPOGRAPHY, CLIMATE AND VEGETATION. 
GENERAL GEOLOGY. 

Archean— Vishnu Schist. 

Name. : 

Distribution in the Kaibab Division. 

Occurrence and Distribution in the Shinumo Area. 

Lithology. 

Origin. 

Age and Correlation. 

BIBLIOGRAPHY. 


PREFACE. 


Exrosurss of unaltered pre-Cambrian sediments are of great 
interest to the geologist in any part of the world. Especially 
is this true in the Grand Canyon of Arizona, where the cer- 
tainty of stratigraphic position and completeness of exposure 
are almost without a parallel, and where the spectacular nature 
of the occurrence partakes of the stupendous and fantastic 
scenery of that mighty gorge, from the spell of which the 
observer is never entirely free. During a pleasure trip in the 
Grand Canyon region in January, 1908, in company with 
Professor H. E. Gregory of Yale and others, the writer chanced 
to visit a hitherto undescribed exposure of these rocks on the 


Am. Jour. Sci.—FourtH Series, Vou. X XIX, No. 173.—May, 1910. 
25 


370  Noble—Geology of the Grand Canyon, Arizona. 


Colorado River at the foot of Bass Trail. Although only a 
few hours were spent in the vicinity, the diagrammatic sim- 
plicity with which the structural relations were revealed was 
such that the interest could be immediately realized. In the 
summer of that year the writer returned with the intention 
of making a detailed study of these pre-Cambrian rocks. He 
speedily found that the interest in this part of the Grand 
Canyon did not end with the study of the pre-Cambrian alone: 
it was tound that the line of displacement of the West Kaibab 
fault which runs into the Grand Canyon at this point was itself a 
remarkable structural feature and worthy of considerable atten- 
tion; that the entire Paleozoic section of the canyon wall was 
here, as elsewhere, undescribed in absolute detail; and’ finally 
that there were problems of physiographic interest in the Grand 
Canyon region the ultimate solution of which could be greatly 
helped by a detailed study at this point. It was therefore de- 
cided to extend the work to a complete areal study of the 
region, including for this purpose the greater part of the new 
Shinumo topographic sheet of the United States Geological 
Survey. This report, accompanied by an atlas containing the 
geologic maps, sections, and plates, was presented to the faculty 
of the Graduate Department of Yale University in June, 1909, 
as a thesis in partial fulfillment of the requirements for the 
degree of Ph.D., under the title of “The Geology of the 
Shinumo Area, Grand Canyon, Arizona.” 

It is intended to present the substance of the thesis in two 
or more articles in this Journal. The entire report is to be 
published an extenso at a later date as a Bulletin of the United 
States Geological Survey. or this reason, as well as because 
of the large scale and elaborate nature, the geologic map, sec- 
tions, and plates will not be published here. 

The first article will be presented in two parts. Part I, now 
published, comprises a general introductory description of the 
Shinumo area and deals with the basement rocks of the Archean. 
Part IJ, to follow in a later number, will be devoted to the 
Algonkian rocks of the Grand Canyon series and will include 
a map showing the distribution of the Vishnu and Grand 
Canyon series in the Grand Canyon. 

It is also proposed to devote a later article or articles to the 
Paleozoic section of the canyon wall; to a structural study of 
the area, including both the pre-Cambrian and later structure 
and a study of the displacements on the line of the West 
Kaibab fault; and finally to features of physiographic interest 
in the area,—such as the drainage system of the plateaus and 
the origin of the Esplanade and Tonto platforms. 


The Shinumo Area. 371 


INTRODUCTION. 


Location and geography.—The area studied lies in Coconino 
County in the northern part of Arizona in what is known as 
the Plateau Province of the Territory. It is inclosed between 
meridians 112° 25’ and 112° 15’ and parallels 36° 20’ and 36° 
05’, and includes about 150 square miles. It comprises rather 
more than the eastern half of the area of the Shinumo topo- 
graphic sheet of the United States Geological Survey. 

The greater part of the area lies within the depths of the 
Grand Canyon and includes the Shinumo Amphitheater, which 
is the largest of the great amphitheaters in the Kaibab divi- 
sion. The eastern and northern parts of the area include that 
part of the “ mainland” north of the canyon which forms the 
immediate rim of the Shinumo Amphitheater, reaching from 
the promotory of Point Sublime on the east to the Muav 
Saddle on the west; this northern mainland is a part of the 
Kaibab Plateau. The northwestern part of the area includes 
the surface of Powell Plateau, a great butte, or “island,” lying 
athwart the course of the Grand Canyon. The southwest cor- 
ner includes a part of the southern “mainland” which cul- 
minates in the great promontory known as Havasupai Point ; 
this southern mainland belongs to the Coconino Plateau. 

About a mile west of Havasupai Point is situated Bass Camp, 
the only habitation in the area. The camp was established by 
Mr. W. W. Bass some twenty-five years ago to accommodate 
the tourist traffic. From this point a trail was constructed to 
the river, which was crossed by boat at times of low water. 
A permanent camp was established in the bottom of the can- 
yon on the north side of the river about a mile up Shinumo 
Creek, where an irrigated garden was made upon the site of an 
ancient one cultivated by the prehistoric inhabitants of the 
region. Later a trail was constructed up Muav Canyon to the 
north rim, by means of which access may be had to points on 
the Kaibab Plateau and the settlements in Southern Utah. 
Recently deposits of copper and asbestos have been discovered 
by Mr. Bass in the depths of the canyon, to which he has con- 
structed additional trails. In March, 1908, three wire cables 
were suspended across the granite gorge at the foot of Bass 
Trail. On these cables travels a wire car, so that at the present 
time the Colorado River may be crossed at this point regard- 
less of high water. Bass Camp is most easily reached by 
wagon road from Bass Station on the Grand Canyon branch of 
the Sante Fe Railroad, a distance of 20 miles southeast; or 
from the El Tovar Hotel at the terminus of the railroad 25 
miles east. Another road leads 20 miles southwest to the rim 
of Cataract Canyon, into which a trail leads down to the Supai 


372  Noble—Geology of the Grand Canyon, Arizona. 


Indian village. Roads also lead to the towns of Williams and 
Ash Fork, about 60 miles respectively south and southwest. | 

Tied Work.—The geological field work upon which the 
thesis is based was begun upon the 23d of August, 1908, and 
ended upon the 12th day of December of the same year. The 
greater part of the work was done from a permanent camp on 
the Shinumo, which served as a base of operations for studying 
all the region in the greater depths of the canyon. Two trips 
were made to the northrim. The first was made in September 
and the second in November. Lach trip lasted a week. Oamp 
was established in the Muav Saddle and excursions were made 
from there over the surface of Powell Plateau and over the 
Kaibab mainland as far as the head of the Shinumo Amphi- 
theater. The writer was accompanied on these occasions, as 
well as during his stay in camp on the Shinumo, by Mr. John 
Walthenberg as guide, whose detailed knowledge of the region 
and whose assistance in other ways were invaluable. The work 
in the southern part of the area was done from Bass Camp, 
from which point excursions were made over the Coconino 
Plateau and into the upper part of the canyon. 

Literature.—Two references to the geology of the area are 
to be found in geological literature: 

Captain Dutton in his monograph entitled “The Tertiary 
History of the Grand Canyon District” (Dutton, a) describes 
most fully and charmingly the geology of the north rim in 
this section of the Grand Canyon. In Chapter VII he describes 
the surface features and scenery of the Kaibab Plateau in the 
vicinity of Point Sublime. Chapter VIII is devoted to the 
panorama disclosed from Point Sublime, while Chapter [X 
describes the walls of the amphitheaters of the north side in 
detail. The Muav Saddle and Powell Plateau are described 
on pp. 162-167, and the Shinumo Amphitheater on pp. 167-174. 
His work, however, did not extend into the depths of the 
canyon. 

Mr. J. S. Diller of the United States Geological Survey 
describes in his report on the production of asbestos in ‘¢ Min- 
eral Resources for 1907” (Diller, a) the deposits of asbestos 
occurring in the Algonkian sediments of this area near Bass 
Ferry. This is the only reference in the literature to the 
presence of Algonkian strata in this part of the Grand Canyon. 

Acknowledgments.__In 1901 Mr. Charles D. Walcott and — 
Mr. G. K. Gilbert spent several days at Mr. Bass’s camp on the 
Shinumo and at that time worked out the structure of the 
pre-Cambrian sediments, which Mr. Walcott correlated with 
the section described by him in Unkar Valley (Walcott, a, 0, 
c,d, and e). His notes, however, are unpublished, and it is 
due to his kindness and courtesy that the writer is enabled to 
present the first description of the area. To Mr. Walcott the 


The Shinumo Area. 373 


writer is also indebted for the identification of Cambrian 
fossils, for a list of the Cambrian fossils found in the region, 
and for assistance in interpreting the stratigraphy. 

To Professor Joseph Barrell, to Professor Charles Schu- 
chert, and to Professor Louis V. Pirsson, all of Yale University, 
the most sincere thanks are due for continued-interest and 
advice during all stages of the work. To Mr. W. W. Bass the 
writer is indebted for material assistance and guidance during 
his work in the field. ; 

Geologic Nomenclature.—The geologic names employed in 
this article are revised names recently authorized by the 
United States Geological Survey, with the exception of those of 
the Cambrian, which as yet have not been formally revised. 
The first table below gives the rock formations of the Shinumo 
area in terms of the revised terminology, while the second 
table gives the equivalent of the newer in the older nomen- 
clature. 


I. 
Geologic column of the Shinumo Area. 
System Series Group Formation 
) ( Kaibab limestone 
Pennsylvanian ... Aubrey --< Coconino sandstone 
Carboniferous < . | Supai formation 
Pennsylvanian and 
Mississippian Redwall -.- Redwall limestone 


(Unconformity of erosion without uniformity of dip) 


‘“¢ Marbled limestone” 


; Acadian 
Cambrian ._. = Tento “Tonto shale” 
9 - <= 
(and Saratogan?) “Tonto sandstone ”’ 


(Great angular unconformity) 


Algonkian _.... Grand Canyon ._. Unkar 
(Greatest angular unconformity) 
peremeuma 0 5.62 Vishnu 
I. 
Classic Nomenclature of the reports of 
Revised Nomenclature Dutton, Gilbert, and Walcott. 
Formation Formation Group 
Kaibab limestone-__ -__- Cherty limestone -_-____-. U ee 
Coconino sandstone___- Cross-bedded sandstone -- Dena 
Supai formation. ....-. Lower Aubrey sandstone_. Lower Aubrey 
Redwall limestone_-_-. Redwall limestone....... Redwall 
“ Marbled limestone” ._ Marbled limestone -~-.-_-- U T 
promo sitald’ Sos oh < Wontorshale *./2. 2. Pee ORLO 


“Touto sandstone .-.- Tonto sandstone__... 222. Lower Tonto 


374 Noble—Geology of the Grand Canyon, Arizona. 


Topography, Climate, and Vegetation. 
The surfaces of the plateaus in the Shinumo area through 


which the pathway of the Grand Canyon is trenched are every- - 


where developed at the same horizon on the highest member 
of the Paleozoic series occurring in the Canyon wall and known 
as the Kaibab limestone, the Mesozoic and Tertiary formations 
having been stripped back to the terraces of southern Utah. 

The surface of the southern, or Coconino, plateau slopes to 
the southwest away from the canyon rim at the rate of about. 
200 feet to the mile. The drainage system of the plateau 
surface consists of a series of mature, open-floored valleys with 
gently sloping sides, which contain no living streams. These 
valleys trend southwesterly away from the canyon rim with 
the slope of the plateau surface and drain into the broad, shal- 
low synclinal basin occupied by Cataract Canyon. In tracing 
one of these mature valleys toward its head, it is a common 
thing to find it truncated as a hanging valley by the wall of 
tbe Grand Canyon. So general is this phenomenon, that the 
stranger who loses his way on the southern plateau has only to 
keep in mind that if he follow any valley far enough headward 
he wil] come out upon the rim of the Grand Canyon. _ 

The surface of the northern, or Kaibab, plateau is in every 
respect similar to that of the Coconino. The same system of 
mature valleys covers its surface, which slopes southwesterly to 
the rim of the canyon. The only difference is that the surface 
drainage runs into the Grand Canyon instead of away from it. 
Neither plateau surface contains a living stream. 

Powell Plateau may be regarded as a dismembered part of 
the Kaibab. Its surface is developed at the same horizon on 
the Kaibab limestone, slopes southwesterly at the rate of 900 » 
feet in five miles, and contains the same mature drainage 
system. It is substantially a great island, surrounded on three 
sides by mile-deep canyons, and isolated from the mainland by 
erosion in the line of displacement of the West Kaibab fault. 
The gap that separates Powell Plateau from the mainland is 
called the Muay Saddle, and is notched 800 feet below the 
surface of the plateaus. No more striking topographic con- 
trast can be imagined than that between the mature drainage 
systems of the plateaus and the youthful topography within 
the deep-trenched canyon. 

The strata of the Paleozoic rock system within the area dip 
gently and almost uniformly to the southwest at the rate of 
about 200 feet to the mile, and the surfaces of the plateaus are 
everywhere accordant with the rock structure. A slight local 
interruption occurs where the line of the West Kaibab fault 
crosses the area, along which the strata are flexed into a mono- 


The Shinumo Area. 375 


cline dipping sharply northeastward. A few minor flexures 
cross the area in a northwesterly direction; all dip to the 
southwest and are hardly more than gentle swells upon the 
general warping. 

The Shinumo Area is a critical area for the study of the 
topography within the canyon itself. Itis here that the topog- 
raphy undergoes a transition from the profile which is char- 
acteristic of the Kaibab division to that which is characteristic 
of the Kanab. 

In the eastern, or Kaibab, division of the canyon, the de- 
scent of the wall is unusually abrupt throughout the entire 
Paleozoic rock series. The only bench or terrace of an 
extent or definition is that which is developed near the bottom 
of the canyon upon the summit of the basal sandstone of the 
Tonto group. The bench is known as the Tonto platform ; in 
it is cut an inner gorge, in which the river flows upon the base- 
ment schists of the Archean. The platform averages a mile 
in width on either side of the canyon, and is so well defined 
that one may travel upon it throughout the length of the 
Kaibab division. In the next western, or Kanab, division of 
the canyon the lower terrace has disappeared. Instead, a 
wide bench is opened out upon the summit of the hard red 
sandstones of the Supai formation of the Aubrey group, about 
a thousand feet below the level of the canyon rim. This 
bench forms a broad level platform averaging two miles in 
width on either side of the canyon, and has been named by 
Dutton the “Esplanade.” Through it is cut a deep and narrow 
inner gorge, at the bottom of which flows the river. 

The topography of the Kaibab division is characterized by 
a much greater dissection than that of the Kanab; great 
amphitheaters are eroded back into the north wall, thronged 
with buttes and outliers fashioned out of every formation of the 
Paleozoic rock series and trenched by a multitude of side 
gorges. The topography of the Kanab division is very simple, 
consisting only of a broad outer canyon in which is cut the 
inner gorge; the great dissection which makes the fantastic 
scenery of the Kaibab division is entirely lacking. 

Eastward from Havasupai Point in the Shinumo area the 
topography in the canyon is that which is characteristic of the 
Kaibab division. Westward, however, the upper platform or 
“Esplanade” begins to appear. The Shinumo amphitheater, 
which occupies the greater part of the area to be described, 
presents a combination of both types of topography; the oreat 
dissection and the presence of the Tonto platform are features 
characteristic of the Kaibab division, but the Esplanade charae- 
teristic of the Kanab division is developed to quite an equal 
extent upon the upper surface of the Supaisandstone. In the 


376 Noble—Geology of the Grand Canyon, Arizona. 


western part of the area the Tonto platform fades out,?the 
river closes in a deep inner gorge in the Esplanade, andthe 
profile of the canyon becomes that of the Kanab division,— 
the view of the canyon westward from Bass Camp discloses a 
broad expanse of Esplanade for fifteen miles, through which 
the inner gorge sweeps in two great meanders almost from wall 
to wall. In the center of the Shinumo area the Esplanade is 
rather more dissected than in the Kanab division farther west, 
but its identity as a topographic feature is already well 
established. 

The floors of the Esplanade and Tonto platforms, like the 
surfaces of the plateaus, are structural surfaces developed 
everywhere at the same horizon on the underlying formation. 
In conformity with the dip of the rock system they likewise 
slope to the southwest at the rate of about 200 feet to the 
mile. 

Another topographic contrast is presented in the difference 
in dissection of the two sides of the Grand Canyon, a feature 
which is characteristic of the entire pathway through the 
Kaibab. The north rim lies three times as far back from-the 
river as the south rim; the great amphitheaters with their 
limiting promonotories extending far into the canyon, the 
buttes and temples, and the deep lateral gorges all belong to 
the north side of the canyon. The south wall presents a 
simple aspect: the side gorges rarely extend back into the rim 
of the canyon, there are few buttes and outliers, and the great 
amphitheaters are wholly lacking. Compared with the fan- 
tastic topography of the north side, the scenic effect of the 
south wall is precipitous and somber. 

The Colorado River enters the area in the southeast corner, 
flows northwestwardly to the center of the area, and turns 
sharply west at the point where it is joined by the Shinumo. 
The Shinumo is the only living tributary in the area, and is 
the master stream that drains the Shinumo amphitheater of the 
north wall. It is astream of clear water of the same order of 
magnitude as Bright Angel Creek twenty miles east, and is in 
striking contrast to the muddy Colorado. 

The topography of the Shinumo amphitheater, besides pre- 
senting an equal development of both the Esplanade and Tonto 
platforms, is remarkable in another way. In the other great 
amphitheaters of the Kaibab division the master gorges trend 
to the southwest ; the tributary gorges trend in the same general 
direction and lateral gorges perpendicular to the main axes of 
the amphitheaters are of minor development. In the Shinumo 
amphitheater the lateral gorges have become the dominant 
feature, so that the main axis of the amphitheater trends to the 
northwest at right angles to the course of the master stream 


The Shinumo Area. aire 


and parallel to the course of the Colorado River. The greatest 
lateral gorge extends entirely across the Shinumo amphitheater 
from Point Sublime on the southeast to the Muav Saddle on 
the northwest. Only a mile of this lateral gorge is occupied 
by the master stream of the Shinumo; the remainder is occupied 
by two small intermittent streams. The western part of the 
gorge which extends from the Muav Saddle to Shinumo Creek 
is drained by Muav Creek and is called the “ Muav Canyon” ; 
the eastern part extending from the Shinumo to Point Sublime 
is drained by Flint Creek and has no local name. The entire 
lateral gorge will be referred to as the “ Muay-Flint Creek 
Canyon.” This remarkable linear depression is situated upon 
the line of the West Kaibab fault and has been conditioned by 
erosion in that line of fracture. Two smaller lateral gorges 
eross the heart of the amphitheater parallel to the “ Muav- 
Flint Creek Canyon”; these are situated upon minor lines of 
fracture. 

_ It may be noted here that Tapeats amphitheater to the west- 
ward, in the Kanab division of the canyon, is characterized by 
similar topographic features where it is crossed by the West 
Kaibab fault. 

In general the surface of the Kaibab plateau at the rim of 
the canyon is about 1000 feet higher than that of the Coconino 
plateau directly opposite. But since the surfaces of the plateaus 
and of the platforms within the canyon are structural surfaces, 
elevations diminish progressively southwestward in all parts of 
the area in accordance with the dip of the underlying rock 
structure. For example: the elevation of the Kaibab Plateau 
at the head of the Shinumo amphitheater is 8000 feet; at the 
end of the promontory of Point Sublime, four miles southward, 
it is 7500 feet. The elevation of the Coconino Plateau at the 
end of Havasupai Point is 6750 feet; at Bass Camp, a mile 
southwestward, 6652 feet. The eastern end of Powell Plateau 
at Dutton Point is 7555 feet; the western end is 6600 feet. 
Within the canyon the elevation of the Esplanade platform on 
the north side of the river below Point Sublime is 6250 feet; 
on the south side of the river beiow Bass Camp, 5400 feet. 
In the eastern part of the area the Tonto platform is 3500 feet ; 
in the western part, 2700 feet. 

The elevation of the surface of the Colorado River where it 
enters the area on the east is 2250 feet; where it leaves the 
area on the west, 2150 feet,—a drop of 100 feet in 10 miles. 
The river at Bass Ferry is 300 feet wide and 50 feet deep, with 
a rise of 40 feet at time of high water. 

The greatest drops in the shortest linear distance in the area 
are at Dutton Point, where a drop of 5355 feet to the river is 
accomplished in a distance of three miles; and at Havasupai 


378 Noble—Geology of the Grand Canyon, Arizona. 


Point, where a drop of 4500 feet is accomplished in a distance 
of a mile and a half. The latter drop is not equaled elsewhere 
in the Grand Canyon. 7 

The width of the Grand Canyon in the Shinumo area from 
Bass Camp to Dutton Point is seven miles; from Bass Camp 
to the head of the Shinumo Amphitheater it is twelve miles ; 
from Havasupai Point to Point Sublime it is five and one-half 
miles. The latter is the minimum width of the Grand Canyon 
in the Kaibab division. Even at this, the narrowest point, the 
width is over five times the depth. 

The differences of climate to be found within the Shinumo 
area are remarkable. The range in climate between the Kai- 
bab Plateau 6n the north rim and the bottom of the canyon is 
as great as that between the mountains of Colorado and the 
Mojave Desert. The winters on the Kaibab are extremely 
severe: from November to April the snow lies deep in the 
woods, often accumulating to a depth of ten feet ; even in mid- 
summer the nights are chilly and days delightfully cool. Within 
the canyon, however, the snow rarely falls below the level of 
the Esplanade, while on the Tonto platform a fall of snow is 
practically unknown. The winters in the depths of the can- 
yon are mild, and freezing temperatures are rare. From April 
to October the entire canyon below the Red Wall concentrates 
the solar heat, transforming it into a veritable oven; all day 
the bare rocks absorb the heat of the sun, becoming so hot as 
to burn the hand; by nightfall the wind becomes a furnace 
blast, and until after midnight the rocks radiate their heat, 
feeding the hot wind, which blows without ceasing. The 
effect of the heat, however, is not enervating, for the dryness 
of the warm wind evaporates all moisture from the body and 
keeps it cool. The climate of the southern, or Coconino, Pla- 
teau at Bass Camp is characterized by more open winters than 
the Kaibab, as well as by warmer summers: the snow in winter 
rarely accumulates on the surface to a great depth, and asa 
rule vanishes entirely within three days after a storm ; in sum- 
mer the days are unpleasantly hot. 3 

The climate of the Kaibab Plateau is decidedly moist, the 
precipitation being probably twice as great as that received 
upon the Coconino Plateau across the canyon ; this is chiefly 
due to its greater altitude. In winter the precipitation takes 
the form of snow ; in summer it comes in the form of showers, 
which oceur through the afternoon and evening. Looking 
across the canyon from Bass Camp on the south rim, almost 
any summer evening one may see storm after storm sweeping 
over the Kaibab surface, usually accompanied by violent elec- 
trical display, while the sky overhead and to the westward 
over the Kanab Desert remains as clear as crystal. Another 


The Shinumo Avea. 379 


phenomenon that contributes tc the greater rainfall of the 
north rim seems to be the presence of the Grand Oanyon itself: 
after every general storm that visits both sides of the canyon 
alike, there follows on the south rim a day of clearing; but the 
clouds that rise out of the canyon after the storm sweep back 
over the north wall and re-precipitate on the Kaibab surface ; 
these secondary storms almost never return over the south rim. 
The climate of the Coconino Plateau in the area is semi-arid ; 
often no rain will fall fora month at atime. The precipi- 
tation is greatest in the winter months and in the month of 
July. Within the canyon much of the rainfall evaporates 
before it reaches the greater depths, so that the climate of the 
lower part of the canyon is more arid than that of the south- 
ern plateau. 

Powell Plateau, whose higher eastern portion has an aititude 
equal to that of the Kaibab rim, and whese lower western por- 
tion has an altitude equal to that of the Coconino, has an inter- 
mediate climate. Its situation as an island in the canyon serves 
to moderate the cold in winter, for the warm air, rising out of 
the deep canyons that surround it, acts as a radiator: the snow 
does not accumulate so deeply on the eastern end as on the 
Kaibab; and on the western end does not accumulate at all. 
Its surface is a resort in winter for the game and wild horses 
that are driven out of the Kaibab by the snow. Its exposed 
position subjects it to violent gales of wind at all times of the 

ear. The higher eastern end receives an abundant rainfall, 
while the lower western end is semi-arid. 

The variation of the flora in the Shinumo area is as great as 
that of the climate. The surface of the Kaibab Plateau is 
covered with a magnificent open forest of yellow pine; the 
trees grow large and far apart and the ground is free from 
undergrowth, giving its surface the aspect of a great park; 
Englemann spruces grow on the north slopes of the washes, 
and cottonwoods, aspens, and scrub oaks in their bottoms; a 
minor flora of flowering plants, exceedingly rich in species, 
covers the floor of the forest. The flora of the plateau surface 
of the south rim of the canyon differs completely from that 
of the Kaibab; it is covered with a forest of gnarled and 
stunted trees of juniper and pifion, with here and there a buck- 
brush bush; the trees never form thickets, but grow wide 
apart ; while the open stretches are covered with sage brush 
and mormon tea, with occasional cactus, mescal, and plants of 
the century family. This difference between the floras of the 
north and south rim is due to the differences in precipitation 
and temperature, which vary directly with the altitude. For 
this reason the floras of the plateaus furnish an almost unfail- 
ing index of the elevation. This is beautifully shown on the 


380 Woble—Geology of the Grand Canyon, Arizona. 


southwestward-sloping surface of Powell Plateau, the whole 
eastern half of which lies at an elevation of from 7000 to 7500 
feet and is covered with the open pine forest characteristic of 
the Kaibab. At about 7000 feet the character of the flora 
changes, and passes into the gnarled and stunted forests of juni- 
per and pifion characteristic of the southern plateau across the 
canyon. 

Within the canyon itself the variation in the flora is just as 
great, and is again an index of the elevation. 

The flora of the Esplanade platform, a thousand feet below 
the south rim, consists of stunted bushes of juniper and pifion 
with greasewood as the ground bush in place of the sagebrush 
of the Coconino Plateau. The cactus, mescal, and plants of the 
century family are present in greater abundance than on the 
plateau, but in less abundance and in more stunted develop- 
ment than in the bottom of the canyon. This is due to the fact 
that the Esplanade level is within reach of the winter snows 
and frosts. 

The flora of the Tonto platform, three thousand feet below 
the south rim, and of all the interior of the canyon below the 
Red Wall, is the flora of a hot and arid desert in its most 
characteristic form. The dominant plants are the greasewood 
bush, the mormon tea, and the cactus. The mescal and the 
plants of the century family here attain their greatest develop- 
ment and size. The cacti are particularly rich in species. 
Every plant in the flora is either prickly or aromatic ; leaf sur- 
faces are reduced to a minimum; devices for storing water 
attain the greatest perfection; and the dominant color is a 
somber gray. The somber colors and the reduction of leaf 
surface are apt to deceive the observer, both in regard to the 
richness of the flora in species and the abundance of plant 
life, which is far greater than one would suspect. The only 
tree is the screw- -mesquite, which grows in the beds of those 
washes that contain living or intermittent streams. 

The vegetation in the bottoms of those canyons of the north 
side in the Shinumo Amphitheater which contain living streams 
is beautiful beyond description, and in refreshing contrast to 
the desert flora of the Tonto platform. Tall cottonwoods 
erow in the lower canyons; the walls are hung with maiden- 
hair fern in the shady places; and willow thickets border the 
stream. Grass grows on the banks where there is soil. 
Higher up in the canyons, oaks, maples, and other deciduous 
trees come in, and often beds of tall rushes. The most 
characteristic bush of these upper north-side canyons is the 
manzanita, which does not grow on the south side of the 
Grand Canyon. 


The Shinumo Area. : 381 


GENERAL GEOLOGY. 
ArcHEAN— Vishnu Schist. 


Name.—The name “ Vishnu Terrane” has been given by 
Walcott (Walcott, c) to the fundamental crystalline com- 
plex of the Grand Canyon region that underlies the unaltered 
sedimentary rocks of Algonkian age, and is separated from 
them, as well as from the overlying Cambrian, by a profound 
unconformity. The type locality is situated on the Colorado 
River thirty miles east of the Shinumo area at the base of one 
of the great buttes called “ Vishnu’s Temple,” from which he 
derives the name. | 

Distribution im the Kaibab division.—The rocks of the 
Vishnu series are exposed continuously for a distance of over 
forty miles within the Kaibab division of the Grand Canyon in 
the bed of the Colorado River and in the walls of its gorge 
which is cut beneath the Tonto platform. The Shinumo area 
is at the western end of this long exposure. The eastern limit 
of the exposure is determined by the appearance of great 
thicknesses of overlying strata of the Grand Canyon series 
dipping northeastward into the bed of the river, in the classic 
locality described by Walcott. The western limit of the 
exposure is likewise defined by a structural cause: three miles 
west of the Shinumo area a southward bend of the river 
causes it to flow parallel to the gentle southwestward dip of 
the Paleozoic rock system of the canyon wall, carrying the bed 
of the stream up out of the schists and into the basal Tonto 
sandstone of the Cambrian. 

Occurrence and distribution im the. Shinumo area.—The 
Vishnu schists are exposed for a distance of three miles in 
the gorge of the Muav-F lint Creek Canyon. They are exposed 
in the bed of the Colorado river throughout its course across 
the Shinumo area. Along the south bank of the river for a 
distance of four miles, and along the north bank for a distance 
of seven miles, in the eastern half of the area, sediments of 
the Grand Canyon series intervene between the Vishnu schists 
and the Tonto sandstone of the basal Cambrian. Elsewhere 
the schists are exposed without break in the walls of the river 
gorge beneath the Tonto sandstone. 

No detailed study of these rocks was made in the Shinumo 
area beyond the general location and determination of the vari- 
ous types represented, since the limited extent of the expo- 
sures precludes the possibility of unraveling any general 
Archean structure from the study of this area alone. They 
are here a metamorphic complex of quartz, mica, and horn- 
blende schists, invaded by a batholithic mass of quartz-diorite, 
and injected by veins of pegmatite and aplite. 


382 Noble—Geology of the Grand Canyon, Arizona. 


Five main types of rock are found in this complex within 
the area: 

The first type is a quartz schist, with graduations into mica 
schist. It comprises the greater part of the Vishnu schists 
that are exposed in the gorge of the Colorado River west of 
the cable crossing at Bass Ferry. It is also exposed in the 
bed of Muav Canyon, and in the bed of Flint Creek above the 
junction with the Shinumo. 

The second type is a quartz schist with gradations into 
quartz-hornblende schist. It is exposed in that part of the 
Muavy-F lint Creek Canyon that is occupied by the living stream 
of the Shinumo, grading both eastward and westward into the 
quartz-mieca schist. 7 

The third type is a hornblende schist. It occurs in one 
small outcrop about 200 feet wide, on the east side of “ Fault 
wash,’ a dry wash which joins the Shinumo just below the 
mouth of Muav Canyon, and is sharply bounded on both sides 
by the quartz-mica schist. 

The fourth type of rock is a quartz-diorite. So far as 
observed, it constitutes all of the Vishnu series of the Shinumo 
area that is exposed in the “ granite gorge” of the Colorado 
River east of the cable crossing. Its western contact is well 
defined. The eastern limit of the exposure was not located. 

The fifth type of rock is a granitic pegmatite which occurs © 
in dikes that cut all the rock types of the Vishnu. These 
dikes occur in two generations. ‘The older generation is folded 
with the schists. The younger generation occurs in a great 
network or mesh of dikes cutting both the quartz-diorite and 
the schists. 

The Vishnu schists have a typical schistose structure. The 
planes of schistosity have a dip that seldom departs greatly 
from the vertical, The dominant trend of the schistosity is 
northeasterly, but varies, from place to place. Locally, the 
schists are much twisted and contorted. 

LInthology.—The less micaceous phase of the quarte-mzca 
schist has a dark grey color with a greenish tinge. The cleay- 
age is imperfect and the surfaces have a satin-like luster. 
The texture is fine-grained and the unaided eye can distinguish 
no mineral constituents except quartz.’ The microscope shows 
the rock to be composed almost entirely of fine interlocking 
grains of quartz, with occasional small flakes of white mica, 
arranged in parallel lines. In the extreme quartzose phase 
the amount of mica is almost negligible, just enough being 
present to impart a satin-like luster to the rock. 

The micaceous phase of the schist has a slight grey color : 
with either a pinkish or greenish tinge on the fresh fracture. 
Where the rock is weathered, the color becomes red. The 


The Shinumo Area. 383 


cleavage is rather distinct. The texture ranges from fine to 
coarse. To the unaided eye both the quartz and mica are visi- 
ble. Under the microscope the rock is seen to be composed 
of interlocking grains of quartz, with an almost equal amount 
of mica. The mica flakes are arranged in parallel lines. The 
greater part of the mica is muscovite, with occasional flakes of 
brown biotite. ) 

Loeally the schist is garnetiferous, and in one locality tour- 
maline was observed. All gradations between the quartzose 
and the micaceous phases occur, but in no instance does the 
mica exceed the quartz in quantity. 

The quartz-hornblende schist is dark green in color. The 
cleavage is imperfect, and the texture fine-grained and uni- 
form. The rock is dense and hard. The mineral constituents 
cannot usually be distinguished in the hand specimen without 
the aid of the lens. Under the microscope the rock is seen to 
consist of about equal proportions of quartz and green horn- 
blende. The quartz is present in interlocking grains. The 
hornblende tends to form automorphic crystals whose longer 
axes have a roughly parallel arrangement. No other minerals 
were present in the slides examined. in some phases of the 
rock the quartz exceeds the hornblende in amount. 

The hornblende schist is dark green in color. It is a soft 
rock, considerably disintegrated, and crumbling under the 
hammer. ‘The texture is coarse granular. Megascopically the 
rock appears to consist almost entirely of dark green horn- 
blende. No schistose structure is observable in the mass. 
The microscope shows the rock to consist almost wholly of 
large crystals of green hornblende in all stages of alteration. 
A small amount of interstitial quartz occurs. The quartz 
granules are strung out in a roughly parallel fashion. The 
rock is badly altered and the thin section is unsatisfactory. 

The guartz-diorite found in the river gorge eastward from 
the cable crossing is a coarse-granular rock of typical granitic 
texture. Itis a hard, resistant rock, which tends to weather 
into roughly angular. blocks, a feature that distinguishes it in 
the mass from the exposures of the schists. The minerals visi- 
ble to the unaided eye are white striated feldspar, dark horn- 
blende, and glistening black biotite. The color of the rock is 
dark grey and the appearance is remarkably fresh. The tex- 
ture is uniform throughout the exposures observed, and the 
rock is apparently without contact modifications. No ten- 
dency to gneissoid banding was observed. 

Under the microscope it is seen to be a coarse-granular rock 
of granitic texture. The dominant mineral coustituents are 
plagioclase and common hornblende. The plagioclase ranges 
from oligoclase to labradorite. Microcline, orthoclase, and 


384 WNoble—Geology of the Grand Canyon, Arizona. 


quartz are present in about equal proportions, but their total 
amount does not equal that of the plagioclase. Brown biotite 
is present in somewhat less quantity than the hornblende. 
Titanite and magnetite occur as accessories. Occasionally the 
quartz is poikilitic in the orthoclase. The feldspathic and fer- 
romagnesian minerals are present in about equal proportions. 
If it were not for the preponderance of the plagioclase the 
rock might be classed as a quartz-monzonite or grano-diorite. 
It is probably best classed as a quartz-diorite with a monzo- 
nitic aspect. The microscope reveals no cataclastic structure 
nor other evidence of dynamic action, and the minerals are 
fresh and unaltered. 

The pegmatites are pink in color and usually very coarse in 
texture. They are composed chiefly of quartz and pink ortho- 
clase. Some of the dikes carry large crystals of silvery-white 
mica. No other minerals were noted. The dikes usually 
exhibit the typical comb-structure inward from the walls and 
the graphic arrangement of the quartz and feldspar. Along 
the walls of some of the dikes the texture becomes aplitic. 

Origin.—There is no clear evidence in the Shinumo area by 
which the original character of the schists of the Vishnu 
series can be determined. ‘There is no evidence of a banding 
that can be clearly referred to original sedimentary bedding, 
nor is there evidence of any original clastic texture. The 
mineralogical composition, however, suggests a sedimentary 
origin for the quartz schists of the mica and hornblende type: 
either might have resulted from the regional metamorphism of 
an arkose sandstone or shale. According to the lesser or 
greater abundance of iron in the original sediments the rock 
would assume the mica or hornblende type of quartz schist. 
Certainly the great preponderance of quartz as a constituent 
of these rocks would seem to weigh against an igneous origin 
in the balance of probability. The causes operating to pro- 
duce the schists in their present aspect are conceived to be 
the processes connected with regional metamorphism, namely, 
subsidence and deep burial, subsequent folding and mashing, 
and a slow recrystallization in process of time. 

The original character of the hornblende schist described as 
occurring in a narrow outcrop between the schists is not clear. 
The fact that the rock consists of little else than hornblende 
suggests that it originally constituted an igneous rock of a 
basic type. The fact that the microscope discloses a schistose — 
structure is evidence that the rock is at least earlier in age. 
than the period of regional metamorphism that was responsible 
for the present structural and mineralogical character of the 
enclosing schists. 


The origin of the guartz-diorite is reasonably clear. Since 


The Shinumo Area. — 385 


it is a coarse-granular, igneous rock of plutonic aspect occur- 
ring over a large area, clearly cutting the schists, and showing 
no textural modifications at the contact, it is concluded that 
it represents a deep-seated igneous invasion of considerable 
size, of the type known as a “batholith.” Because of the 
unaltered character of the rock and the absence of any gneis- 
soid or ecataclastic structure, it is argued that the batholithic 
invasion took place at a time later than the period of regional 
metamorphism that produced the recrystallization and schistos- 
ity of the enclosing schists. The question may arise as to 
whether the invasion of the batholith was not of itself a par- 
tially operative cause in producing this recrystallization and 
schistosity. The field evidence is against such a conclusion : 
there is no gradation in the schist away from the contact, 
either in texture or in minera! composition, nor are the planes 
of schistosity parallel to the contact. 

The older pegmatite dikes are folded intimately with the 
schists. Their injection may have either preceded or accom- 
panied the regional metamorphism. 

The younger pegmatite dikes cut both the schists and the 
quartz-diorite. Where they cut the schists they break cleanly 
across the schistosity. The injection of these dikes is the latest 
visible event in the igneous activity of Archean time within 
the area. 

Age and correlation.—The rocks of the Vishnu series are 
rocks which, in the light of present knowledge, van only be 
conceived to have acquired their present character at great 
depths beneath the earth’s surface in what is technically known 
as the “zone of flowage.” It is therefore evident that the 
unconformity which separates them from the overlying Algon- 
kian sediments of the Grand Canyon series represents a vast 
amount of erosion and the consequent lapse of an enormous 
interval of time,—an interval vastly greater even in events 
than that represented by the profound unconformity which 
separates the succeeding Grand Canyon series from the over- 
lying Paleozoic. The Vishnu schists are therefore assigned to 
the Archean in the usage of the United States Geological 
Survey; but whether as a group or a complex is as yet unde- 
cided. It seems likely, as stated by Ransome (a, p. 21), that 
they are to be correlated with the Pinal Schist of the Globe 
and Bisbee regions, and ‘ present somewhat different aspects 
of the fundamental crystalline complex of Arizona.” 

Up to the present time no detailed study of these rocks has 
been made in the Grand Canyon region, and their internal 
structural relations are unknown. It is not unlikely when 
such a study is made of their exposures in the Kaibab division 
of the canyon, in the Shivwits division to the west, and along 


Am. Jour. Sci.—FourtH SrrRies, Vout. X XIX, No. 173.—May, 1910. 
26 


386 WNoble—Geology of the Grand Canyon, Arizona. 


the southwest border of the Plateau Province, that a general 
Archean structure may be unraveled and their relation to the 
fundamental complex of the southern part of the territory 
may be definitely established. 


BIBLIOGRAPHY. 


References to the bibliography are made by name and letter. 
Thus: In referring to an article by Walcott, entitled “ Pre- 
Cambrian Igneous Rocks of the Unkar Terrane, Grand Canyon 
of the Colorado, Arizona,” ( Walcott, ¢) is imserted in paren- 
thesis in the text and the reader will find the reference under 
that name and letter in the Bibliography. 


Bibliography. 


Diller, J.S. a. The Production of Asbestos in 1907. Mineral 
Resources of the U. S. for 1907. } 
Dutton, C. E. a. Tertiary History of the Grand Canyon District, 
with Atlas. Monograph II, U. 8. Geol. Surv. 1882. 
Ransome, F. L. a. The Geology and Ore Deposits of the Bisbee 
Quadrangle, Ariz. Professional Paper, No. 21, U.S. G.S. 
Walcott, C. D. ‘a. Pre-Carboniferous Strata in the Grand Can- 
yon of the Colorado, Arizona. This Journal (38), xxvi, 
1883 (Dec.), pp. 437-442, 484. 
b. Study of a Line of Displacement in the Grand Can- 
yon of the Colorado in Northern Arizona. (Read 
Aug. 29, 1889.) Bull. Geol. Soc. America, I, 1890, 
(Feb.) pp. 49-64. 
c. Pre-Cambrian Igneous Rocks of the Unkar Terrane, 
Grand Canyon of the Colorado, Arizona, by 
Charles D. Walcott; with notes on the Petro- 
graphic Character of the Lavas, by Joseph P. 
Iddings. 14th Ann. Rept. U. 8. Geol. Survey for 
1892-1893, Pt. 2, 1894, pp. 497-519 (Walcott) and 
520-524 (Iddings), pls. 1x—lxv. 7 
d. Algonkian Rocks of the Grand Canyon of the Colo- 
rado. Jour. Geol., III, No. 3, 1895 (Apr.—May), 
pp. 312-330, pl. vi. 
e. Pre-Cambrian Fossiliferous Formations. (Read Dec. 
30, 1898.) Bull. Geol. Soc. America, x, 1899 
(April) pp. 199-244, pls. xxil—xxvill. 


Auburn, N. Y., January, 1910. 


E. W. Berry— Pleistocene Flora of Alabama. — 387 


Arr. XXXIIL— Additions to the Pleistocene Flora of Ala- 


bama; by Epwarp W. Brrry.* 


A srieF contribution to the Pleistocene flora of Alabama 
was made by the writer in 1907+ in which twelve species were 
described from the Pleistocene clays and peat outcropping 
along the Chattahoochee River near Abercrombe Landing in 
Russell County, a few miles below Columbus, Georgia. During 
the past field season the writer, in company with Dr. L. W. 
Stevenson, was engaged in studying the Mesozoic sections 
along the principal rivers of Alabama for the U. S. Geological 
Survey. In the course of this work Pleistocene plants were 
discovered at a number of scattered localities which it seems 
desirable to place on record at the present time. The local- 
ities will first be briefly described, after which the forms iden- _ 
tified will be enumerated. 

The present contribution extends the range of the ten spe- 
cies previously recorded from the Alabama Pleistocene and 
records the occurrence there of sixteen additional forms, bring- 
ing the total flora up to twenty-eight species. Among these 
the following existing species have not heretofore been found 
as fossils: Panus taeda Linné, Arundinaria macrosperma 
Michx., Hicoria villosa (Sarg.) Ashe, Populus deltocdes Marsh, 
Phoradendron flavescens (Pursh) Nutt., Acer saccharinum 
Linné, Acer rubrum Linné, and Osmunda spectabilis Willd. 
In addition the range of several species in the Pleistocene is 
seen to be quite different from their present range: for one 
thing the Fall-lme which marks such an important line of 
demarcation in the distribution of our existing flora seems to 
have largely lost its significance at the time when the glaciers 
crowded our eastern Pleistocene flora southward and a large 
part of the coastal plain was submerged. However, any general 
conclusions may well be postponed until the completion of the 
writer’s studies of the eastern Pleistocene floras. 

Locality No. 1.—This locality is on the right bank of the 
Warrior River, about 356 miles above Mobile and about 200 
yards above the mouth of Big Creek. The following section 
at this point is typical of much of the Pleistocene seen along 
the Alabama rivers, lacking only the gravel bed at the base of 
the section which is probably present at this point beneath 
water level: 


Section. | 
fj row isu, massive, Sangyclay oo 2.223 os Se 30 feet 
2. Brownish, laminated, iron-stained, sandy clay --_---- (3: ie 
3. Dark, bluish eray, thickly- laminated, sandy clay with 
Deahciapeiecies etek ec a SS et ag 


* Published by permission of the Director of the U. S. peclaciesl Survey. 
+ Berry, Amer. Nat., vol. xli, pp. ee pl. 15-2, -180%. 


388 Ek. *‘W«. Berry—Pleistocene Flora of Alabama. 


The following species were identified from this outerop: 
Arundinaria macrosperma, Betula nigra, Quercus nigra, 
Phoradendron flavescens, Liriodendron tulipifera, Platanus 
occidentalis and Acer saccharinum. | 

In the absence of topographic maps it is impossible to iden- 
tify the various systems of Pleistocene terrace deposits which 
cross the state approximately parallel with the coast and which 
extend inland up the present rivers, passing insensibly from 
marine to estuarine, and finally to fluviatile conditions of depo- 
sition. ‘The present outcrop is believed to form a part of the 
Northport terrace, which at Tuscaloosa is about 70 feet above 
low-water mark in the Warrior River and about 140 feet above 
sea level. | | 

Locality No. 2.—This outcrop is on the right bank of the 
Warrior River about 342 miles above Mobile, and shows the 
following section: 

Section. 
1. Yellow, massive, compact sandy clay, bedded and 
ferruginous below .225_.2:.2.. 2.5.0) 0 2022 ee Omen 
. Light drab, yellowish and brownish sandy clay with 
pockets, thin seams and lamine of fine micaceous 
sand and numerous thin iron crusts, becoming 
more sandy toward the base where a few pebbles 
of quartz and coal are found =. ~2 12-24) > aaa 
3. Dark drab clay interbedded with yellowish sand and 
carrying much comminuted vegetable matter and 
leaf impressions toward the base _-_/_=_.22_222 Sie 
4. Concealed 2 i... gree 3 USP et 


The following species were identified from this outcrop: 
Pinus echinata, Taxodium distichum, and Quercus phellos. 

Locality No. 3.—This outcrop is on the right bank of the 
Warrior River near Fosters Landing, about 3283 miles above 
Mobile. The following diagrammatical section (fig. 1) well 
illustrates the character of the materials at this point: 


TGs pdg 


ib) 


Diagrammatical Section of the Pleistocene at Locality No. 3. 


EE. W. Berry—FPleistocene Flora of Alabama. 389 


Section. 
os SEGA SO 2 ee ea ge ee about 5 feet 
2. Similar materials concealed by landslips------- < ees 
3. Sand with much gravel containing some pebbles of 
coal and rather angular bowlders of Paleozoic 
EPson tO tect. IN. Giameterss. a jee ss. 2 ES T1Onss 
4, Massive, dark gray, finely micaceous, plastic clay with 


leaf impressions and overlain by a thin iron crust 0-3 “ 


The following species were identified from this outcrop: 
Betula nigra, Populus deltoides, Liriodendron tulipifera, 
Platanus occidentalis, and Acer rubrum. 

Locality No. 4.—This outcrop is on the right bank of the 
Warrior River at Steeles Bluff, 3114 miles above Mobile, and 
is well illustrated by the following diagrammatical section 
(fig. 2). 


Big. 2: 


Diagrammatical Section of the Cretaceous and Pleistocene at Locality No. 4. 


Section. 
Pleistocene. 


Beatin Clays ee eka we about. 6 féet 
2. Light colored massive clay and sand with lig- 
nitic layers in both the clay and the sand, 
grading laterally, i.e. up the river, into the 
SE DO a) fede a po LE Siac SR ON Pee eee aL be 
. Coarse yellowish sand with gravel and pebbles 
toward the base, lignitic at the base toward 
paC Owe enh Shri Se 8 
4. Yellowish micaceous stratified sand with scat- 


iw) 


beled miliait peubles. = oy 2 a EOm 3 
5. Sandy argillaceous peat with fruits, seeds, and 
Pe eepOnCasiOma aay oe LS le LO—19 


Upper Cretaceous (Tuscaloosa formation). 


6. Blotched purplish, massive, somewhat sandy clay 

With irom GEusis, much eroded... _. 202 Je5.- WI 
7. Light gray, finely arkosic, slightly micaceous 

sand, argillaceous and compact in places.... 4-8 “ 


390 FE. W. Berry—Pleistocene Flora of Alabama. 


The following species were identified from this outcrop: 
Osmunda spectabilis, Pinus taeda, Arundinaria macro- 
sperma, Betula nigra, agus americana, Quercus nigra, 
Quercus primus, Quercus phellos, Curpinus caroliniana, 
Ostrya virginiana, Uimus alata, Hicoria villosa, Juglans 
ine Populus deltoides, Liquidambar styraciflua, Nyssa 
biflora, Vaccinium corymbosu, Aolisma ligustrina. 

Locality No. 5.—This locality is on the left bank of the 
Chattahoochee River and therefore in the state of Georgia. 
It is about one mile above the Abercrombe Landing exposure 
and is represented by three unimportant species found in pieces 
of Pleistocene clay along the river cove and not in place. The 
species are Arundinaria macrosperma, Betula nigra, and 
Carpinus caroliniana, all of which occur in the Alabama 
Pleistocene. 

Locality No. 6.—This outcrop is on the right bank of the 
Chattahoochee River near Abercrombe Landing, about one 
mile below locality No. 5 and was described in the article pre- 
viously mentioned.* The following species new to this local- 
ity were collected: Pinus taeda, Populus deltoides, Phora- 
dendron flavescens, Acer sacchaninum. 

Locality No. 7.—This outcrop shows the Pleistocene in a 
pocket of the Lower Cretaceous on the left bank of the Ala- 
bama River abont one-half mile below Gun Island and about 
12 miles above Montgomery. It is shown in the following 
diagrammatical section (fig. 3): 


IME By 


Diagrammatical Section of the Cretaceous and Pleistocene at Locality No. 7. 


Section. 
Pleistocene. 
1. Light yellowish, somewhat argillaceous sand, with 
gravel base.) oo 528 2 a ON tn ee 
2. Buff sandy clay with leaf impressions....... “ 6 ois 


* Berry, 10c, cit... 1907; 


EF. W. Berry—Pleistocene Flora of Alabama. 391 


Lower Cretaceous (Cape Fear Formation). 


3. Compact, somewhat arkosic and micaceous sand, 
meimenoncdes 2/0 0 Li MEE Ferg Mes Ba 2 oO 0-5 feet 


The following species were identified from this outcrop: 
Fagus americana, Quercus nigra, Platanus occidentalis, and 
Vaccinium arboreum. 

There follows a briefly annotated enumeration of the species 
collected in systematic order, with citations of the fossil records 
of the various forms. 


OsMUNDA SPECTABILIS WILLD. 


The royal fern frequents swamps and openings and borders 
of wet woods. It ranges from Canada to Mexico and probably 
into South America, but is often confused with the old world 
Osmunda regalis Linné. In the existing Alabama flora it is 
common throughout the State. None of the existing species 
of Osmunda, which are six or eight in number, have here- 
tofore been found fossil, although Hollick records* masses of 
rootlets attached to rhizomes in the swamp deposits of the Tal- 
bot formation in Maryland, which are almost certainly refer- 
able to Osmunda. ‘The present record is based upon a single 
specimen showing a part of a pinnule and exhibiting the char- 
acteristic venation and marginal characters of this species found 
at locality No. 4. 


TaxopiuM pisTicHuM (Linné) Rich. 


Holmes. Journ. Elisha Mitchell Soc. for 1884-85, p. 92, 1885. 

Berry, Torreya, vol. vi, p. 89, 1906. Jour. Geol., vol. xv, p. 339, 1907. 

Hollick, Md. Geol. Surv., Pli. and Pleist., pp. 218, 287, pl. 68, 1906. 

The cypress was probably one of the commonest forest trees 
of the Pleistocene from New Jersey southward, at least it is the 
one most frequently met with, having been recorded from New 
Jersey, Delaware, Maryland, Virginia, and North Carolina. 
The more northerly occurrences probably represent inter and 
post glacial warm periods. The recent collections show no 
trace of this species except at locality No. 2, where impressions 
of the detached leaves of this species are common in the clays 


Pints TAEDA Linné. 


In the existing flora the Loblolly pine extends from Dela- 
ware and Maryland to Florida and Texas. In the northern 
part of its range it is confined to the coastal plain but farther 
south it spreads over the Piedmont Plateau and into the 
mountain region. In the Pleistocene it apparently extended 
farther north than at the present time since seeds which are 


* Hollick, Md. Geol. Surv., Pli. and Pleist., p. 214, pl. 67, fig. 8, 1906. 


392 EF. W. Berry— Pleistocene Flora of Alabama. 


believed to belong to this species have been collected by the 
writer from the Pleistocene of New Jersey. 

The present record is based on cones and cone-scales from 
locality No. 4 and seeds from locality No. 6. The cones are 
frequent at the former locality but much water worn; some of 
the scales, however, preserve the characteristic markings of 
the species. 


Pinus rcoHtnaTa Mill. 
Hollick, Md. Geol. Surv., Pli. and Pleist., p. 217, pl. 67, fig. 1, 1906. 


This is a species found on sandy soils from New York to 
northern Florida and west to northeastern Texas, reaching its 
greatest development in the Mississippi Valley. Cones have 
been recorded in the Pleistocene as common in the Talbot 
formation of Maryland and the present record is based upon 
seeds which are common in the clay at locality No. 2. 


ARUNDINARIA MACROSPERMA Michx. 


In the recent flora this species forms those remarkable plant 
associations known as “ canebrakes ” in the bottom lands alone 
the larger streams from southern Virginia to Florida and 
Louisiana and extending up the Mississippi Valley to Missouri 
and Kentucky. It has not previously been recorded in the 
fossil state but was evidently common in Alabama during 
Pleistocene time since characteristic fragments of the leaves 
have been collected from localities No. 1, 4, and 5. 


JUGLANS NiGRA Linné. 
Berry, Torreya, vol. ix, p. 98, fig. 6, 1909. 


In the recent flora this species is found in rich soil from 
Canada to Minnesota and south to Florida and Texas. In’ 
Alabama according to Mohr it is found scattered in rich bottom 
lands from the Tennessee Valley to the Coast Pine belt, spread- 
ing southward along the banks of the larger rivers. As a 
fossil it was recently recorded by the writer from the Talbot 
formation in Maryland, the remains consisting of the character- 
istic nuts. The Alabama occurrence is based upon a single 
nut from locality No. 4. 


Hicorta vinLosa (Sargent) Ashe. 


This species, differentiated from the common Hicoria glabra 
by Sargent, is an inhabitant of the Carolinian zone ranging — 
from Delaware to Georgia and Alabama. In the latter state 
it is said to be one of the commonest hickories in the upland 
and mountainous parts of the state, extending southward to 
the Coast Pine belt. It has not been previously found fossil, 
the present record being based upon several husks and three 


eecigite 
pete 


EL. W. Berry—Pleistocene Flora of Alabama. 398 


nuts from locality No. 4. The latter are identical with the 
more globular nuts of the recent tree resembling somewhat in 
appearance the nuts of Hicorza minima but with much thicker 
shells. 


PoruLUS DELTOIDES Marsh. 


In the existing flora this species ranges from Canada and 
New England westward to Colorado and southward to Florida 
and Texas. In Alabama and throughout the Coastal Plain it 
is most frequent in the bottoms and alluvial river swamps. 

The genus extends back to the late Lower Cretaceous and a 
large number of extinct species have been described. The 
present species has not heretofore been found fossil, but both 
Populus balsamifera Linné and grandidentata Michx. are 
present in the Canadian inter-glacial deposits and Hollick has 
recorded three species from the Pleistocene of Maryland. 
From the European Pleistocene the following still existing 
species are known: Populus alba Linné, canescens Sm., nigra 
Linné, and tremula Linné. 

The present record is based on the characteristic leaves 
which are abundant at locality No. 3 and less common at 
localities No. 4 and No. 6. 


Beruna niGRA Linné. 


Knowlton, Amer. Geol., vol. xviiim, p. 371, 1896. 

Berry, Journ. Geol., vol. xv, p. 841, 1907. Amer. Nat., vol. xli, p. 692, 
pl. 2, figs. 2-4, 1907. Ibid., vol. xliii, p. 485, 1909. 

This species is common along streams and in bottoms with 
an existing range from Canada to Florida and Texas, and is 
common throughout Alabama. It was a common species in 
the Pleistocene, at least it was frequently preserved, and has 
been recorded by the writer from several localities in North 
Carolina and Virginia as well as from near Abercrombe Land- 
ing on the Chattahoochee River in Alabama. Knowlton has 
described it from the Pleistocene river terraces near Morgan- 
town, West Virginia. 

The present record is based on leaves from localities No. 1, 
3, 4, and 5, they being especially abundant in the peat at 
locality No. 4. 


FAGUS AMERICANA Sweet. 


Hollick, Md. Geol. Surv., Pli. and Pleist., p. 226, 1906. 

Berry, Torreya, vol. vi, p. 88, 1906. Journ. Geol., vol. xv, p. 341, 1907. 
aaa Nat., vol. xli, p. 692, pl. 2, fig. 7, 1907. Ibid., vol. xliii, p. 485, 

Fagus ferruginea Michx., Lesq., this Journal, vol. xxvii, p. 363, 1859. 
Geol. Tenn., p. 427, pl. 7 (K), fig. 11, 1869. 

Fagus ferruginea Ait., Knowlton, Amer. Geol., vol. xviii, p. 371, 1896. 
Mercer, Journ. Phila. Acad. (11), vol. ii, pp. 277, 281, fig. 8 (15), 1899. 


394 EL W. Berry—Pleistocene Flora of Alabama. 


This common mesophile forest tree of the Alleghenian, 
Carolinian, and Louisianian zones which is common through- 
out Alabama is of frequent occurrence in the Pleistocene from 
Maryland southward and it has been recorded from a large 
number of localities, the buried swamp deposits usually furnish- 
ing remains of nuts or burrs, while the leaves are generally 
confined to the clays. 

This species was recorded from near Abercrombe Landing 
in 1907 and additional occurrences are locality No. 4 (leaves, 
nuts, and burrs) and locality No. 7 (leaves). 


QUERCUS PHELLOS Linné. 


Berry, Journ. Geol., vol. xv, p. 342, 1907. Amer. Nat., vol. xli, 2 694, 
play fig. el OO 


This common mesophile tree of the Carolinian and Louisi- 
anian zones ranges from New York to Florida and Texas. It 
is common in northern Alabama, but becomes rare south of the 
central part of the state. It is a common fossil in the North 
Carolina Pleistocene and at Abercrombe Landing on the 
Chattahoochee River in Alabama. 

The present cccurrences are at locality No. 2 (leaves) and 
locality No. 4 (leaves, cupules and acorns). 


QueERcuS NiGRA Linné. 

Berry, Journ. Geol., vol. xv, p. 342, 1907. Amer. Nat., vol. xli, p. 693, 
pl. 1, figs. 3, 4, 1907. 

In the existing flora this is a widespread species of the 
Carolinian and Louisianian zones extending northward to 
Delaware, Tennessee, and Missouri and common all over Ala- 
bama in low rich woods and swamps. As a fossil it has been 
recorded from the Pleistocene of North Carolina and eastern 
Alabama. 

The present records are locality No. 1 (leaves), locality No. 
4 (leaves and acorns, common) and locality No. 7 (leaves). | 
One specimen from locality No. 4, while too imperfect for 
carey, suggests its reference to Quercus virginiana Mill., 

a species previously recorded by the writer from Abercrombe 
Landing on the Chattahoochee River in Alabama. 


QUERCUS PRINUS Linné. 


Berry, Journ. Geol., vol. xv, p. 342, 1907. Amer. Nat., vol. xli, p. 693, 
plo, figs 2, 1907: 


This is an upland tree of the Alleghanian and Carolinian 
zones, of rare occurrence in the southern Coastal Plain,* and 


*This species has not been found in the Coastal Plain of Alabama, 
although Hilgard reported it years ago from Tippah County, Mississippi. 
In Georgia, according to R. M. Harper, it does not even approach the Fall- 
line, while in North Carolina it is confined to the Piedmont and mountains, 
according to Pichot and Ashe. Farther northward, however, it is found in 
the Coastal Plain from Long Island to Virginia, occurring in this province 
of New Jersey outside of the pine barrens and common on the upper eastern 
shore of Maryland and in Delaware. 


E. W. Berry— Pleistocene Flora of Alabama. 395 


since it is easy to confuse the leaves of this species with those 
of Quercus michauxii, a common tree of Coastal Plain bot- 
toms, doubt has been expressed regarding the identifications 
cited above. However, it is believed that the fruit of Quercus 
prinus is sufficiently distinct for certainty, and when it is 
remembered that at some time during the Pleistocene practi- 
cally the whole Coastal Plain was submerged by the sea and 
that there was a massing of species in the emerged portion of 
the southern Piedmont area, which served as a center of radia- 
tion for inter- and post-glacial dispersion,* the propriety of 
finding the species in the Pleistocene sediments is unquestion- 
able. 

The present record is based upon an acorn and leaf frag- 
ment from locality No. 4. : 


CARPINUS CAROLINIANA Walt. 


Berry, Journ. Geol., vol. xv, p. 340, 1907. Amer. Nat., vol. xli, p. 692, 
pl. 1, figs. 8, 9, 1907. 

This is a wide ranging species of low rich woods occurring 
from Canada to Florida and Texas. It is common in suitable 
situations over the greater part of Alabama and appears to 
have been frequent in the later Pleistocene of America, 
previous Pleistocene occurrences being along the Neuse River 
in the North Carolina Coastal Plain and from near Aber- 
crombe Landing on the Chattahoochee River in Alabama. 

The new records are localities No. 4 and No. 5, this species 
being especially common at the former of. these. 


OstRYa virGINIANA (Mill.) Willd. 


Hollick, Bull. Torrey Club, vol. xix, p. 332, 1892. 

Penhallow, Amer. Nat., vol. xli, p. 447, 1907. 

In the recent flora this species ranges from Canada to 
Florida and Texas, ordinarily in dry soil and on hillsides. It 
is said by Mohr to occur principally on calcareous soils in 
Alabama, where it ranges from the Tennessee Valley to the 
upper division of the coast pine belt, its southern limit corre- 
sponding roughly to the northern limit of the Cuban pine. In 
the fossil state it is recorded by Hollick from the late Miocene 
or Pliocene of Bridgeton, New Jersey, and by Penhallow 
from the interglacial deposjts of the Don valley in Canada. 
Material indistinguishable from the modern species has been 
described by Nathorst from the post-Miocene of Japan under 
the varietal name fossilis. Finally the material from Wythe- 
ville, Virginia, said to be of Pleistocene age, which was 
identified by Lesquereuxt as Ostrya Walkert Heer, an early 


* See the various papers by C. C. Adams on this subject. 
+ Lesq., Proc. U. S. Natl. Mus., vol. x, p. 38, 1887. 


396 =F. W. Berry—Pleistocene Flora of Alabama. 


Tertiary arctic species, is probably identical or closely allied 
with the present species. 

The present occurrence consists of leaves which are infre- 
quent at locality No. 4. 


Uxmus ALATA Michx. 


Lesq., this Journal, vol. xxvii, 365, 1859. 

Berry, Journ. Geol., vol. xv, D. BAS, 1907. Amer. Nat. , vol. xli, p. 694, 
pla le ties, Gai 1907. 

This species is a common element in the recent flora of 
Alabama in low woods particularly along stream banks. It 
ranges northward to Virginia, Illinois and Kansas and south- 
ward to Florida and Texas. As a fossil it was recorded from 
the Pleistocene near Columbus, Kentucky, by Lesquereux, and 
from the Neuse River in North Carolina and Abercrombe 
Landing on the Chattahoochee River in Alabama by the writer 
(loe. cit.). Two species of Ulmus occur in the Pleistocene of 
Maryland, Ulmus racemosa is recorded from the Pleistocene 
near Morgantown, West Virginia, and both the latter and 
Ulmus americana occur in the interglacial beds of the Don 
valley in Canada. 

The present record is based upon infrequent leaves from 
locality No. 4. 


PHORADENDRON FLAVESCENS (Pursh) Nutt. 


A species, in the modern flora, of the Carolinian and Louisi- 
anian zones ranging northward as far as New Jersey and 
common throughout Alabama. It has not previously been 
recorded as a fossil, although certain European Upper Plocene 
remains have been described as Viscophyllum. However, it is 
not at all certain that these are not related to the genus Pasta 
rather than to Visewm. 

The present record is based on the characteristic leaves of 
the modern species found at localities No. 1 (common) and 
No. 6 (1 specimen). 


LIRIODENDRON TULIPIFERA Linné. 


Rr Amer, Nat., vol. xli, p. 695, 1907. Torreya, vol. ix, p. 71, ney 
1909. 

This common mesophile forest type of the Alleghanian, 
Carolinian, and Louisianian zones finds its present southern 
limit in Alabama at about latitude 31°. Previous fossil 
records are based on fruits from Abercrombe Landing on the 
Chattahoochee River in Alabama and upon abundant leaves 
from the Wicomico formation near Weldon, North Carolina. 

The present record is based upon leaf fragments from 
locality No. 1 and upon a leaf and a carpel from locality 


INGi3: 


E. W. Berry— Pleistocene Flora of Alabama. 397 


PLATANUS OCCIDENTALIS Linné. 


Knowlton, Amer. Geol., vol. xviii, p. 371, 1896. 

Penhallow, Trans. Roy., Soc. Can. (II), vol. ii, sec. 4, pp. 68, 72, 1897. 
Amer. Nat., vol. xli, p. 448, 1907. 

Mercer, Journ. Phila. Acad. (IJ), vol. ii, p. 277, 1899. 

Berry, Journ. Geol., vol. xv, p. 344, 1907. Amer. Nat., vol. xli, p. 695, 


ple, He. 9), 1907. 

Platanus aceroides Gopp., Hollick, Md. Geol. Surv., Pli. and Pleist., p. 
231, pls. 73, 74, 1906. 

This modern inhabitant of low woods and banks from 
Canada to Florida and Texas is frequent in the bottom lands 
of central Alabama but not common elsewhere in the state. 
As a fossil it is of frequent occurrence in Pleistocene deposits 
from those of the Don Valley in Canada to Alabama. 

The present record is based upon characteristic leaves which 
occur in considerable abundance at localities No. 1, No. 3, 
and No. 7. 


LIQUIDAMBAR STYRACIFLUA Linné. 


Hollick, Bull. Torrey Club, vol. xix, p. 381, 1892. 
Knowlton, Amer. Geol., vol. xviii. p. 371, 1896. 
Berry, Journ. Geol., vol. xv, p. 348, 1907. 


This species ranges from New England to Florida and west- 
ward to Texas and Mexico in the recent flora and is found 
throughout Alabama, more especially in the rich bottoms and 
swamp borders of the Coastal Plain. It has previously been 
recorded from the Pleistocene of North Carolina and West 
Virginia. The present record is based upon leaf fragments 


and upon two somewhat macerated and flattened but charac- 
teristic fruits from locality No. 4. 


ACER RUBRUM Linné. 


A species of swamps and low ground ranging from Canada 
to Florida and Texas in the existing flora and common 
throughout Alabama, not previously known as a fossil. The 


present record is based upon leaf fragments from locality 
No. 3. 


ACER SACCHARINUM Linné. 


This species in the existing flora ranges from Canada to 
Florida and westward to the Great Plains. It extends from 
northern Alabama southward along the larger streams. It 
has not been previously recorded from the Pleistocene, the 
form described by Penhallow under this name from the Cana- 
dian Pleistocene being referable to Acer saccharum Marsh. 

The present record is based on characteristic samaras from 
locality No. 1 and No. 6. 


398 FE. W. Berry—Pleistocene Flora of Alabama. 


Nyssa BIFLORA Walt. 


Hollick, Md. Geol. Surv., Pli. and Pieist., p. 285, pl. 69, fig. 5, 1906. 

Berry, Torreya, vol. vi, p. 90, 1906. Journ. Geol., vol. xv, p. 345, 1907. 

This species in the Recent appears to be contined to the 
Coastal Plain, ranging from Virginia to eastern Texas. Asa 
fossil it has been recorded from the Pleistocene of Maryland, 
Virginia, and North Carolina. The present record is based 
upon leaves from locality No. 4. 


VACCINIUM ARBOREUM Marsh. 
Berry, Torreya, vol. ix, p. 73, 1909. 


This species, which ranges from Virginia to Indian Territory 
and southward to Florida and Texas in the Recent, has previ- 
ously been recorded from the Pleistocene of North Carolina. 
The present material comes from locality No. 7. The genus 
is wide ranging and a number of Pleistocene occurrences are 
known both in this country and abroad. Thus in addition to the 
next species, Vaccinium spatulata Berry occurs in the Pleisto- 
cene cf North Carolina and Vaccinium uliginosum Linné at 
Scarboro Heights, Ontario, Vaccontum maderense Link is 
known from the Pleistocene of Madeira and Vaccinium myr- 
tillus Linné and Vaccinium vitis-rcdea Linné occur in the 
interglacial peats of the southern uplands in Scotland. 


VACCINIUM CoRYMBOSUM Linné. 


Hollick, Md. Geol. Surv., Pli. and Pleist., p. 236, pl. 69, figs. 7-9, 1906. 

Berry, Journ. Geol., vol. xv, p. 346, 1907. 

This species ranges in the modern flora from Canada to 
Louisiana and in Alabama is said to be confined to the moun- 
tain region. As a fossil it is recorded from Maryland and. 
North Carolina. The present record is based upon leaves 
from locality No. 4. 


XOoLISMA LIGUSTRINA (Linné) Britton. 


Hollick, Md. Geol. Surv., Pli. and Pleist., p. 236, pl. 69, fig. 6, 1906. 

Berry, Journ. Geol., vol. xv, p. 346, 1907. Amer. Nat., vol. xli, p. 696, 
pl. 2, fig. 6, 1907. 

This species has been previously recorded in the Pleistocene 
of Alabama as well as from Maryland and North Carolina. 
The present record is based on leaves from locality No. 4. 


Johns Hopkins University, 
Baltimore, Md. 


Palmer— Application of Potassium Ferricyanide. 399 


Art. XXXIV.—The Application of Potassium Ferricyanide 
in Alkaline Solution to the Estimation of Arsenic, Anti- 
mony, and Tin; by Howarp E. Patmmr. 


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


In 1892, Quincke* published a method for estimating arsenic 
and antimony gasometrically, consisting essentially in oxidizing 
the arsenic or the antimony by a known excess of potassium 
ferricyanide in the presence of alkali, and determining the 
excess by measuring in a gasometer the oxygen evolved by the 
action of hydrogen peroxide on it according to the following 
equation: ; : 


2K FeC,N,+H,0,+2KOH = 2K FeC,N,+2H,0+0,. 


In previous papers from this laboratory, methods for the esti- 
mation of cerium in the presence of the other rare earths,t+ 
and for the estimation of thallium,t have been described, based 
on oxidation by potassium ferricyanide in alkaline solution and 
titration with permanganate of the ferrocyanide formed. 

The work to be described is the result of an attempt to 
apply this reaction to the estimation of arsenic, antimony, and 
tin, which are oxidized according to the following equations: 


As,O,+4K,FeC,N,+4KOH = As,O,+4K,FeC.N, +290. 
Sb,O, -+4K,FeC,N, +4KOH = Sb,0, +4K,FeC,N, + 2H,0. 
SnO +2K,FeC,N,+2KOH = Sn0, +2K FeC,N,+H,0. 


The ferrocyanide formed is then oxidized by permanganate 
according to the equation 


10K,FeC.N,+2KMnO,+8H,S0, = 
10K,FeO,N,+6K,SO,+2MnSO, +8H,0. 


Estimation of Arsenic. 


The essential procedure was to oxidize the arsenic by 
potassium ferricyanide in alkaline solution, and after making 
ammoniacal by the addition of ammonium sulphate, to precipi- 
tate the arsenic by magnesia mixture, filter off the ammonium 
magnesium arseniate, and titrate the filtrate with permanganate, 
after acidification with sulphuric acid. 

For the work a solution of arsenious acid was prepared in 
the usual way by dissolving pure sublimed arsenious oxide in 
potassium hydroxide, neutralizing with sulphuric acid and 
adding sodium bicarbonate. The magnesia mixture used 


* Zeitschr. f, Anal. Chem., xxxi, 1. 
+ This Journal, xxvi, 83. t This Journal, xxvii, 379. 


400 Palmer—Application of Potassium Ferricyanide 


was made up by dissolving 55 grams of the crystallized magne- 
sium chloride and 29 grams of purified ammonium chloride in 
a liter of water, with the addition of about 5 cubic centimeters 
of concentrated ammonium hydroxide. The potassium ferri- 
cyanide used was puritied by recrystallization, but even then, 
as in the previous work, it was necessary to apply a correction 
to the determinations for the number of cubic centimeters of 
permanganate required to give the pink coloration to the ferri- 
cyanide alone, generally amounting to about one-tenth of one — 
cubic centimeter. A solution of potassium ferricyanide of 
convenient strength for use in the determination of all three 
elements contained 20 grams to 100 cubic centimeters. 

In the preliminary experiments, recorded in Table I, low 
results were obtained, apparently due to the incomplete oxida- 
tion of the arsenic by the amounts of ferricyanide and potas- 
sium hydroxide used. If at least ten times the theoretical 
amount of ferricyanide, with a rather dilute solution of potas- 
sium hydroxide, is used, as in experiments (1) to (12) of Table 
II, the oxidation is complete; or, if a more concentrated solu- 
tion of potassium hydroxide is used, as in experiments (13) 
and (14) of Table II, less ferricyanide is necessary. In an 
case, it is advantageous that the total volume of the solution 
be rather small, preferably less than 100 cubic centimeters, 
since, as shown by experiments (4), (5), and (6) of Table I, if 
the volume is greater than that, low results are obtained. 


TABLE I. 
Vol 

As2O3 of As2O3 

taken K3;FeC;N, KOH sol. found Error 

grm. erm. grm. cm?, erm. grm. 
(1) 0°0997 Z 1°25 100 0:0966 —0.00381 
(2) 0:0997 4 1°25 75 0:0987 —0°0010 
(3) —0°1496 8 1°25 100 0:1486 —0°0010 
(4) 0:0997 8 1°25 150 0°0982 —0°00i5 
(5) 0:0997 4 2°95 175 0:0978 —0-°0019 
(6) 0°'1001 4 4° 150 0°0984 —0°0017 


The procedure to be recommended, therefore, is as follows: 
To the solution containing the arsenic in the arsenious condi- 
tion is added an amount of potassium ferricyanide equal to at 
least five times the amount theoretically required to oxidize 
the arsenic to the higher condition of oxidation, and about 25 | 
cubic centimeters of a 20 per cent solution of potassium 
hydroxide, keeping the volume of the solution less than 100 
cubic centimeters. After standing a few minutes, the solution 
is made ammoniacal by dissolving in it about 10 grams of am- 
monium sulphate, which acts on the potassium hydroxide, set- 


to the Estimation of Arsenic, ete. 401 


TABLE II. 
Vol. 
As2O3 of As2O3 
taken K3;FeC;N, KOH sol. found Error 
erm. erm. erm. cm3. erm, erm, 
(1) 0:0499 8 1225 100 0°0502 +0:°0003 
(2) 0°0499 4 1°25 75d 0°0499 + 0°0000 
(3) 0:0499 3 le25 75 0°0501 +0°0002 
(4) 0:0501 4 1525 75 0°0500 —0°0001 
(5) 0:0997 8 eS) 100 0:0999 +0°0002 
(6) 0°0997 6 25 90 0:0993 -—0°0004 
(7) 0°0997 6 E25 90 0°:0993 —0°0004 
(8) 0°1001 8 1°25 100 0°0998 —0°0003 
(9) 0°1496 9 125 110 0°1492 —0:0004 
(10) 0°1496 LO 1°25 110 0°1495 +0:°0000 
(11) 0°1502 10 1°35 LEO 0°1502 + 0°0000 
(12) 0°1994 2 1°25 125 0°1994 + 0°0000 
(13) 0°1001 4 4° 75 0°0998 —0:0008 
(14) 0°1001 3 4° 75 0:0998 —0°00038 


ting free ammonia, and about 100 cubic centimeters of the 
magnesia mixture are added. After settling, the ammonium 
magnesium arseniate is filtered off on asbestos, and washed 
with faintly ammoniacal water. The filtrate is strongly acidi- 
fied with dilute sulphuric acid, and titrated with permanganate. 

As Griitzner* has shown, during the titration of Jar oe 
amounts of ferrocyanide by. permanganate, a precipitate of 
K,MnFeC,N, often forms by the action of the manganese 
sulphate, which is formed by reduction of the permanganaite, 
on the unchanged ferrocyanide. ‘This precipitate slowly clears 
up as more permanganate is added, clearing up entirely as the end 
point is reached, but it tends to cause high results, on account 
of the difficulty in noting the end point exactly. It was found, 
in connection with the present work, that by titrating in the 
presence of a large amount of sulphuric acid, the formation of 
this precipitate is prevented. The titration may safely be 
made in the cold in the presence of ten per cent of sulphuric 
acid, and this amount will generally be sufficient to prevent the 
formation of the precipitate. 


Determination of Antimony. 


A solution of antimony trichloride was made up by dissolv- 
ing pure antimony trioxide in hydrochloric acid, and diluting 
to a definite volume with the addition of sufficient hydrochlorie 
acid to prevent the formation of the basic salt; the standard 
of this solution was determined by titrating with standard 
iodine. 


* Chem. Centralblatt, 1902, I, 500. 
Am. Jour. Sct.—FourtuH Series, Vou. X XIX, No. 173.—May, 1910. 


27 


402 Palmer—Application of Potassium Ferricyanide 


The procedure was, in general, the same as in the determina- 
tion of arsenic, except that it was found unnecessary to remove 
the antimony before titrating with permanganate. At. least 
five times as much potassium ferricyanide as theoretically 
necessary was added in solution, and about 25 cubic centimeters 
of a 20 per cent solution of potassium hydroxide. After stand- 
ing a few minutes, the solution was strongly acidified with 
dilute sulphuric acid and titrated with permanganate. The 
results are given in Table III. 


TABLE ITI. 
: Vol. 
Sb203 of Sb203 
taken Ks;FeC,;N, KOH sol. found Error 
orm. grm. grm. em?, grm. grm, 
(1) 0°0986 8 4 100 00989 + 0°00038 
(2) 0:0986 4 4 TS 0:0984 — 0:0002 
(3) 00986 2 4 US 0:0984 —0°0002 
(4)  0:0986 + 4 150 0°0984 —0-0002 
(5) 0:0986 4 4 15 0°0984 = 00002 
(6) 0°0493 4 4 75 0:0495 +0:°0002 
(7) 0°04938 4 4 75 0:0497 +0°0004 
(8)  0:0493 4 4 TE 0:0495 +0°0002 
(9) 01479 4 4 75 0°1482 + 0:0003 
CUO) Ould s 4 4 75 071477 —0°0002 
(i) 0°1479 4 - 4 75 0°1476 —0°00038 
Ge). Olginl 8 8 125 01972 +0:0001 


Determination of Tin 


Definite portions of metallic tin were accurately weighed out 
and dissolved in concentrated hydrochloric acid; it was found 
necessary to perform this operation in the cold, and to keep an 
atmosphere of hydrogen over the liquid during solution of the 
tin, as under other conditions results lower than the theoretical 
were obtained, indicating that the stannous salt had been par- 
tially oxidized by the air or by dissolved oxygen. When the tin 
was completely dissolved, asolution containing at least five times 
as much potassium ferricyanide as theoretically necessary was 
added, and enough of a solution of potassium hydroxide to 
completely dissolve the precipitated stannic acid, the two solu- 
tions of ferricyanide and potassium hydroxide having been pre- 
viously mixed. The stannic salt was removed by the addition 
of about ten grams of ammonium sulphate, and warming to 
50° or 60°, under which conditions the tin was completely pre- 
cipitated. After it had settled, the precipitate was filtered off 
on asbestos, under gentle pressure, and washed with a 10 per 
cent solution of ammonium sulphate. The filtrate was strongly 
acidified with sulphurie acid, and titrated with permanganate 


to the Estimation of Arsene, ete. 4.03 


in the usual manner. The results of the determinations are 


recorded in Table LY. 


TABLE Ve 
Vol. 
Sn of Sn 
taken K;FeC;N, KOH - sol. found Error 
erm. erm, erm, em? erm. erm, 
(1) 0°1032 25 6 65 0°1038 +0:°0001 
(2) 0°1022 Dee 6 65 0°'1016 — 0:0006 
(3) 0°1029 3° ef 60 0°1030 +0:°0001 
(4) 0°1009 5° 6 85 O°1011 +0:°0002 
(5) 0°1005 5° 3) 60 0°1010 +0:0005 
(6) 0°1011 Os 3) 85 0°1015 +0°0004 
(7) 0°0995 10° 3) 85 0°1004 +0°0009 
(8) 0°2020 4° 6 80 0°2019 —-0°0001 
(9) 0°20038 oe 6 90 0°1998 —0°0005 
(10) 0°2Z021 10s 3) 85 0:2027 + 0°0006 


404 W. A. Parks—Lepadocystis clintonensis. 


Arr. XXXV.—A New Cystid from the Clinton Formation of 


Ontario—Lepadocystis clintonensis ; by WriittAm ARTHUR 
Parks. | 


In 1873, F. B. Meek described a peculiar Cystid from the 
upper part of the Cincinnati formation at Richmond, Ind., 
under the name of Lepocrinites mooret.* This form, accord- 
ing to Meek, differs from all other examples of Lepocrinites 
by the possession of four instead of three pectinirhombs and 
five instead of four arms. P. H. Carpenter} regards these 
peculiarities as of generic value, and proposes to establish the 
genus Lepadocystis for the reception of Meek’s species. 
Jaekel, in 1899, suggests J/eekocystis as the generic name, but 


Fie. 1. 


Lepadocystis clintonensis, sp. nov. 


Fig 1. Viewed from the right postero-lateral aspect. x3 


Bather gives precedence to Carpenter’s name and recognizes 
the genus as a distinct member of the sub-family Cadlocystine 
of the Glyptocystide.t 
So far as I am aware, no other example of the genus has 
hitherto been described, so that its discovery at a higher hori- 
* Geol. Sur. Ohio, Paleontology, vol. i, pp. 39-41, pl. iii, figs. 4a and 4b. 


+ Jour. Linn. Soc. Zool., vol. xxiv, p. 10. 
{ A Treatise on Zodlogy, E. Ray Laneaster, vol. iii, the Echinoderma, p. 61. 


W. A. Parks—Lepadocystis clintonensis. 405 


zon, the Clinton, is worthy of note. This formation is pos- 
sessed of a very meagre Echinoderm fauna, the exposures in 
Ontario having yielded only a few fragmentary Crinoids. The 
present example lay for a long time in our collection as an uni- 
dentifiable specimen. Recently, however, an attempt to clean 
it was made with unexpectedly satisfactory results. By sawing 
the specimen out and treating it with caustic potash the organ- 
ism was entirely freed from the matrix, so that it now shows 
the chief anatomical peculiarities in an excellent manner. 
Adopting the method of numbering the plates proposed by 
Forbes,* we have, in the lower circlet, four plates, of which 1 
and 2 are regularly pentagonal. Plate 4 is irregularly penta- 
onal, and 3 is hexagonal with its upper edge curved inwards. 
Of the second circlet, plates 5 and 6 are irregularly hexagonal: 


IiGe-o: 


Fie. 2. Dissection of cup. 


7 is also hexagonal, but it has an heptagonal appearance owing 
to the encroachment of the anal orifice on its upper, right- 
hand angle. Plate 8 is smaller than 7 and is likewise deeply 
cut by the anus on its upper left-hand corner ; its lower side 
is curved to fit into plate 3. Plate 9 is irregularly hexagonal. 
-Of the third circlet, plates 10, 11 and 12 are hexagonal, but 12 
is larger and more irregular than the other two. Plate 13 is 
narrower and reaches farther up the cup than any other plate 
of the ring: it is five-sided or six-sided 1f the deep anal exca- 
vation on its lower right-hand angle is included. Plate 14 is 
large and hexagonal, with the anal notch in the lower left-hand 
corner. The five plates of the fourth circlet (16, 17, 18, 19, 
15) are pentagonal with the upper margin deeply notched for 
the ambulacral furrows. The plates of the fifth circlet (21, 22, 
23, 24, 20) are small and almost indistinguishable in the speci- 
men. 

All the plates of the cup are ornamented with polygonal 
ridges, separated by shallow depressions. On the first two 


* Memoirs of the Geol. Survey of Great Britain, vol. ii, pt. ii, p. 488. 


406 W. A. Parks—Lepadocystis clintonensis. 


cirelets of plates these ridges are radially arranged, but on the 
upper plates this regularity is lacking. 

Pectinirhombs appear across the sutures between plates 1 and 
5,12 and 18, 14 and 15, and 10 and 18. Pectinirhomb 1-5 
presents two small, oval discrete halves without apparent ster- 
eom folds. Pectinirhomb 12-18 is larger: the half on plate 
12 shows indistinct stereom folds, but that on 18 is almost 
destroyed. Pectimirhomb 14-15 has a large oval half on 14, 
presenting eight folds of stereom and lip-like margins. The 
half on 15 is triangular in shape, with stereom folds reaching 
to the suture and not confined by a lip. Pectinirhomb 10-15 
has a small, oval, lipped, discrete half on 10. The portion on 
15 is exactly the same as the other half-rhomb belonging to 
that plate. 

The anus is large and is situated at the angle between plates 
7, 8, 18 and 14. These plates are deeply excavated by the 
anal margin, which is raised into an oval or circular ridge. 

Except for distinct evidence of their original presence on 
the median line of each plate of the fourth cirelet, the ambu- 
lacral furrows are not perceptible. 

The column is round and tapers distally. The first ten 
segments show a sharp median crest and occupy a space of 
about 7". They show a gradually increasing thickness dis- 
tally. Beyond the tenth segment, the median crest is less 
defined, the segments gradually becoming barrel-shaped. The 
17th segment is 2"™ long and of about the same width. 

The present example differs from Meek’s species in its 
larger size, being 15™™ high by 10™™ wide, while the genotype 
is 11°57" by 9™™. The column, at its proximal end,as 4 
thick as compared with 3°5™™ in Meek’s species. The seulp- 
turing of the plates is different, as LZ. mooret shows only 
“thread-like, radiating costee, one of which, passing from the 
middle to each side of each plate, is usually slightly larger than 
the others between.” The shape and arrangement of the 
plates of the cup are strikingly alike in the two species. 


Florizon—Clinton. 

Locality—F¥ orks of the Credit River, Ontario, 

Collector—Mr. Joseph Townsend. 

Specimen number—University of Toronto Museum, No. 372 Cl. 


FE. Wright—New Petrographie Microscope. 407 


Art. XXXVI.—A New Petrographic Microscope; by FREv. 


EuGENE WRIGHT. 


EXPERIENCE has shown that the so-called universal instru- 
ments are as a rule unsatisfactory, and often do not accomplish 
in a thoroughly competent manner any one of the several 
purposes for which they are intended. To fulfill a given set 
of conditions adequately, it is usually necessary that a special 
instrument be designed for the purpose. Thus, a small calibre 
rifle may be admirably suited for small game, but for 
larger game it is totally inadequate and might even be of more 
harm than service in an emergency; and vice versa, a large 
calibre rifle is of little value in hunting small game. 

The same principle of adaptability applies equally to micro- 
scopes and scientific apparatus in general. The ordinary 
microscope, which is designed to aid in the examination of thin 
sections of rocks and minerals, is satisfactory and convenient 
for such purposes, but is less so for use in the investigation of 
artificial preparations which are usually very fine-grained, the 
diameter of the individual grains averaging often not more 
than -01"™. ‘To determine satisfactorily and with fair accuracy 
the optical constants of substances in such minute grains, special 
methods of attack are required, and these in turn postulate 
certain new conditions to be fulfilled by the petrographic 
microscope. It was with this end in view, to construct a 
microscope better adapted than the microscopes now available 
for the examination and determination of fine-grained artificial 
silicate preparations, that the present microscope was designed 
and constructed in the workshop of the Geophysical Laboratory. 
Several of its features appear to be of general application, and 
a brief description of its essential parts is therefore justified. 

In the construction of the present instrument (fig. 1), a 
Zeiss microscope No. 1 C for photomicrography served as base, 
and on it extensive changes were introduced so that the result- 
ing microscope resembles the original only slightly. This 
particular model was chosen chiefly because of its wide upper 
barrel, which was well adapted for the introduction of 
diaphragms and the movable Bertrand lens. The changes which 
have been introduced are essentially as follows.* 

(1) The nicols are revolvable simultaneously about the optic 
axis of the microscope. They are connected rigidly by the 
bar T of fig. 1, and their angle of revolution can be read off 
directly by the vernier on the stage. This method obviates 
the errors introduced by the usual system of gear-wheels with 
accompanying lost motion in the moving parts. The details of 

* A still further change, made recently aud not shown in fig. 1, is the intro- 
duction of a block just below the upper tube support. The distance between 


the stage and the upper tube is thereby increased and the use of the univer- 
sal stage facilitated. 


408 FE. Wright—New Petrographic Microscope. 


Gaels 


Fic. 1. New petrographic miscroscope. T, rigid bar connecting two 
nicols and effecting simultaneous revolution of the same; A, arm connect- 
ing upper nicol carriage with T; C, part supporting bar T and revolving 
about stage: B, arm from lower nicol carriage connecting with bar T; by 
means of the screw and cross plate at B, this arm can be instantly released 
from T and the lower nico! either revolved by itself or, after a release by a 
snap spring not shown in the figure, thrown out of the field altogether. The 
total angle of simultaneous revolution of both nicols by this device is 190°. 
O, new mechanical stage, simple in design and construction and fairly 
dust-proof. H,, stage screw with divisions on head reading to ‘01™™ 
motion of stage plate. Q, sensitive-tint plate inserted above lower nicol, W, 
and revolvable about microscope axis by means of containing carriage, F. 
M, combination wedge above objective ; a; de, fine adjustment screws above 
objective ; U, screw of fine adjustment device of upper microscope tube; V, 
iris diaphragm below Bertrand lens, diaphragm opened and closed by turning 
head V, which is connected with iris diaphragm by pin and ratchet move- 
ment; KH, pin for insertion of Bertrand lens which moves in an accurately 
fitting carriage, supporting iris diaphragm V, Bertrand lens E and auxiliary 
lens L, which swings on an arm indicated in fig. la and is of such focal 
length that together with ocular, it forms a small microscope used in 
focusing the image from the objective in the plane of the iris diaphragm, 
V. The supporting carriage of V, KE, and L, can be moved up and down in 
the microscope tube and the amount of movement read off on the adjacent 
scale, thus obtaining different magnifications (6°5 to 15°2 diameters) of the 
interference figure. G, upper iris diaphragm directly beneath ocular. 


FE. Wright—New Petrographic Microscope. 409 


Fies. la, 2, 3. 


Fic. la. Section through microscope of fig. 1, showing working parts. 
The letters T, A, B, C, H, W, Q, F, O, U, V, HE, L, and G, refer to the same 
parts asin fig.1. I= lower iris diaphragm ; N, upper nicol; X, Y, Z, brass 
parts effecting revolution of upper nicol; P, revolving stage supporting 
movable plate, O. 

Fic. 2. Section showing stage P and microscope plate supporting stage 
and other revolving parts and support for revolving nicol device, C ; T, cross 
section of bar connecting two nicols ; this bar slides accurately in the arms 
A and B of fig. la. 

Fic. 5. Cross section through mechanical plate 1 of stage. I,, Iz, brass 
plates screwed to revolving stage P and with wedge-shape sides in which 
rectangular plate K can move in an east-west direction, the movement being 
effected by the screw He. Jy, Je and Js, three plates attached to under side 
of stage plate, O, and forming grooves for plate K, permitting stage plate O to 
move only in north-south direction, the movement being accomplished by 
screw, H,, which in turn fits in a sliding block attached to the upper plate 
O, and traveling in the pin, D. 
construction are shown in fig. la. By means of the screw 
and cross bar at B the connecting rod T can be instantly 


released and the lower nicol withdrawn or revolved by itself 


410 LF. EL Wright—New Petrographic Microscope. 


independently of the upper nicol. The total angle through 
which both nicols can be revolved by this device is 190°.* 

(2) A mechanical stage of new designt (fig. 3). This 
stage is practically dust-proof and mechanically simple in con- 
struction. In fig. 8. the vertical edge or rim of the cap, O, 
of the stage plate is indicated by the shaded broken circle, the 
upper surface of this plate being considered removed and the 
working parts as seen from above thus exposed to view. The 
small plates I, and I, are attached to the lower stage and 
are so constructed that wedge-shaped edges allow the 
rectangular plate K to move only in an east-west direction. 
This movement is effected by means of the screw H,. The 
plates J,, J, and J, of fig. 3, on the other hand, are attached 
to the upper movable plate O, and their wedge-shaped edges 
are so adjusted that they allow the upper plate to move’ only 
in a north-south direction with reference to the rectangular 
piece K. The screw H, which terminates in a block attached 
to the upper plate and running in a sliding pin D, accomplishes 
these north-south movements. The heads of both screws H, 
and H, have divisions reading to -(01™" movement. Springs 
not indicated in the figure have been introduced and oppose 
the forward motion of the screws H, and‘H, and thus obviate 
errors due to lost motion in the screws. The total movement 
of the stage plate in any direction is 24". Mechanically, it is 
of simple construction and consists of few parts. 

(3) The metal part containing iris diaphragm and polarizer 
can be withdrawn from the optic axis of the microscope by 
means of a release spring not shown in fig. 1. This part is 
also revolvable by itself about the axis. This arrangement 
was adopted in preference to the usual method of inserting 
and withdrawing the upper nicol because of the disturbing 
effect which the introduction of the upper nicol causes, both on 
the focus and position of the field. With the present disposi- 
tion, the upper nicol t remains permanently in the upper tube 
and the optical system, objective, nicol, and ocular, is not 
disturbed in passing from ordinary to polarized light. In 
certain microscopes the effect of the upper nicol on change of 
focus is compensated by means of a small lens of weak magni- 
fying power, but even after the introduction of this device 
some shifting of the field may still be experienced on inserting 
the upper nicol. 

*FHuess & Company have recently constructed, at the writer’s suggestion, 
a simplified model of microscope on this principle of a rigid bar connection 
between the two nicols, so that the two can be revolved simultaneously. 
(Price 300 mks.) 

+ This stage was designed by Mr. Chamberlin of this laboratory, and con- 
structed by Mr. Semple. 

t For certain positions of the reflector and on certain days the light from 
the reflector is polarized to such an extent that faint polarization colors are 
observed on minerals in the thin section even after the polarizer has been 
withdrawn. For this reason it would be an improvement if the upper nicol 


also could be withdrawn readily, whenever desirable. This is the case on 
the model constructed by Fuess & Co., noted above. 


FE. Wright—New Petrographic Microscope. 411 


(4) An Abbe condenser is used, and with it a large nicol 
prism, or an Ahrens prism, 15™™ edge, after the manner of the 
Fuess microscope No. la. With this arrangement the entire con- 
denser lens system remains in position and its upper lens need 
not be removed when low-power objectives are used. This does 
away with the devices which have been employed for throw- 
ing the upper part of the condenser combination out of the 
axis of the optic system and which complicate the construction 
considerably. 

(5) The selenite, or quartz, plate of sensitive tint is inserted in 
a metal case at Q (fig. 1), just below the condenser. It is revolv- 
able in the carriage F about the optic axis of the microscope, an 
arrangement which often facilitates the determination of the 
ellipsoidal axis of a particular section because the abrupt rise 
or fall of interference colors on insertion and rapid revolution 
of the plate appears more clearly than if the slower moving 
stage itself were revolved. At M a combination wedge is 
introduced as in ordinary microscopes. 

(6) The Bertrand lens E, fig. 1, is mounted on a sliding 
arrangement which, in connection with the sliding ocular tube, 
permits of different magnifications of the interference figure, 
an arrangement already adopted on several well-known micro- 
scopes. In the present microscope the focal length of the 
Bertrand lens (55™™) has been so calculated that the initial 
magnification of the interference figures can be varied from 
"81 diameters to 1°90 diameters. The ocular itself magnifies 
this image in turn eight-fold, so that the resulting magnifica- 
tions range from about 6°5 to 15-2 diameters. The fact that 
the upper nicol intervenes between the objective and Bertrand 
lens limits very materially the range of magnifications possible 
by the Bertrand lens. Aniris diaphragm is introduced directly 
below the Bertrand lens and slides up and down simultane- 
ously with it. This diaphragm is opened and closed by means 
of the pin, V, fig. la, which is connected with the diaphragm 
itself by means of pin and ratchet movement. 

(7) A second iris diaphragin is introduced at G, fig. 1, directly 
below the oeular, and is used in connection with the observa- 
tion of interference figures by the Lasaulx method without 
the Bertrand lens. To be of service in this connection, the 
iris diaphragm should be located precisely in the image plane 
from the objective, as was emphazised especially by Czapski 
in 1891,* for in that plane alone can light be excluded from 
adjacent minerals in the thin section. To realize satisfactorily 
this condition, the writer has heretofore used the cap stop 
indicated by fig. 4, with two sets of slides, S, and S,, at right 

* Neues Jahrbuch, Beilage Band vii, 506, 1891. 


412 Ff. EL Wright—New Petrographic Microscope. 
angles to each other. ‘This cap fits the microscope tube and is 
inserted in place of the ocular. By means of the lens “a” 
the field is focused in the plane of the slides and any por- 
tion singled out for examination. 
Because of diffraction phenomena 
the aperture should not be made 
less than :5™™ in diameter, but even 
with this restriction, and with the 
ordinary objectives, 3 or 4™™ focal 
length, grains not over:01™™ furnish 
good interference figures which or- 
dinarily would be completely over- 
shadowed and not discernible if 
adjacent light were not exclnded. 
Experience has shown that the 
effects are still clearly recognizable 
if the diaphragm is at a distance of 


Dicey ae 


Fic. 4. Device for cutting 


down the field when interference 
figures from small grains are 
being observed as they form in 
the objective itself (Lasaulx 
method). Two sets, S: and Sa, 
of two plates at right angles 
and sliding in grooves permit 
the observer to cut off the light 
from any part of the field. Be- 
fore observing the interference 
figure, the image from the objec- 
tive is first brought to coinci- 
dence with the plane of the iris 
diaphragm by means of the field 


not over 5 from the eye, and for 
convenience sake, therefore, this 
diaphragm was inserted just below 
the ocular. The usual round disks 
with small aperture supplied with 
microscopes serve the same pur- 
pose but are less convenient. 
Before stopping down the field 
by the diaphragm V just below 
the Bertrand lens, the image plane 
from the objective should on the ° 


lens ‘‘a,.” same principle be brought to coin- 


cide with the plane of this dia- 
phragm and the desired mineral section isolated by shutting off 
light. from the adjacent grains. To accomplish this readily, a 
small lens, L, fig. la (19° focal length) has been introduced in 
the present microscope above the Bertrand lens, and in conjune- 
tion with the ocular serves the purpose of bri inging to sharp 
focus the image picture in the plane of the Bertrand lens iris dia- 
phragm, in accord with the principle noted above. In place of 
this small auxiliary lens, the writer has heretofore used a lens of 
Jong focal length and viewed the Bertrand lens diaphragm 
directly from the top of the tube. The new arrangement is 
more convenient, however, and obviates the necessity of remoy- 
ing the ocular before viewing the interference figure. ‘The 
lens L swings on an axis and can be instantly thrown out of 
the field. A small spring with pointer automatically indicates 
the correct position of the lens when thrown into the field. 
The Bertrand lens diaphragm ordinarily supplied with micro- 
scopes is of little value in the observation of interference 


EF. EL Wright—New Petrographic Microscope. 418 


figures by the Lasaulx method without the use of the Bertrand 
lens, chiefly because of the disturbing effects of diffraction from 
the small apertures required and the distance of the aperture 
from the eye of the observer. 

In designing this instrument, special attention has been paid 
to adjustment facilities and arrangements by which adjustmeuts 
ean be readily accomplished by the observer himself. In scien- 
tific instruments in general, too much reliance is often placed 
on the adjustment by the maker and the assumption ‘“ once in 
adjustment always in adjustment” notwithstanding jars and 
jolts of transportation, and the gradual relief of stress in any 
complicated mechanical system. Fortunately, the principle, 
which some manufacturers have adopted, of making all parts 
rigid and eliminating adjustment facilities, cannot be carried 
out in the construction of the microscope. In this instrament 
the axis of both the upper tube and the condenser holder on the 
microscope must coincide precisely with that of the revolving 
stage, in order that in every position the optical system remain 
centered. Since the ocular and the condenser remain auto- 
matically centered with respect to the revolving stage, while 
the objective changes its position slightly on each insertion, it 
is necessary that centering screws (@,, @,, fig. 1) be introduced 
for the objective itself and the direction of motion of center- 
ing should be parallel with the cross hairs of the ocular, as the 
eye estimates much more readily coordinate directions than 
diagonal directions. The principle sometimes adopted of 
placing the centering screws with directions of movement 
along the diagonals is therefore less favorable than along the 
cross hairs, and places a burden on the microscopist which 
might easily be avoided. The practice of placing the adjustment 
screws on the revolving stage instead of above the objective is 
wrong. The part of the optic system which is not in adjust- 
ment is the objective, not the stage. The axis of revolution of 
the stage should form the starting point for the adjustment of 
the whole instrument and should always remain fixed in its 
position. To this axis the ocular, condenser, and objective 
should be adjusted, and since the ocular and condenser remain 
practically stationary while the objectives are changed con- 
stantly, the only logical point of adjustment, to obtain satis- 
factory results, is above the objective. 

To summarize briefly, the most important changes intro- 
duced on the present microscope are: (1) Both nicols revolve 
simultaneously, the connection between the two being a rigid 
bar, thus eliminating the errors due to lost motion in the gear- 
wheels of the systems ordinarily employed for this purpose. 
Since adopting the above device, the writer has learned that . 
the scheme of revolving the nicols by a rigid connecting bar 


414. FE. Wright—New Petrographic Microscope. 


was used over thirty years ago by Dick in London, but was 
applied only to the revolution of a cap nicol above the ocular 
in conjunction with the polarizer. It was, therefore, slightly 
different from the present disposition. (2) The upper nicol 
always remains in the tube and the substage nicol is inserted 
or withdrawn on passing from ordinary light to crossed nicols. 
This device eliminates the annoying change of focus and shift 
of field ordinarily experienced when the nicol is inserted in 
the upper tube. (8) The sensitive plate is inserted just below 
the condenser and fits in a carrying device which is revolvable 
about the axis of the optical system. This disposition has been 
found convenient in determining the relative ellipsoidal axes 
in a plate, since the plate can be revolved more quickly and 
easily than the microscope stage or the two nicols together. 
(4) It has a new mechanical stage of novel design and simple 
but effective mechanical construction. The stage is practically 
dust-proof, has a free upper plate and a movement of 24” in 
any direction. (5) The Bertrand lens is fitted in a sliding 
device such that the magnification of the interference figure 
can be varied from 6°5 to 15:2 diameters. Immediately below 
the Bertrand lens, the iris diaphragm is introduced, while 
above this lensa second lens of short focal length can be 
thrown into the field which, together with the ocular, serves 
the purpose of focusing the image picture sharply in the 
iris diaphragin. (6) The second iris diaphragm at G, immedi- 
ately below the ocular, is intended for use when observing 
interference figures directly by the Lasaulx method without 
the ocular and Bertrand lens. This iris diaphragm is a substi- 
tute for the device indicated in fig. 4, and the Saal cap 
plates usually furnished with microscopes, and although theo- 
retically less satisfactory, practically it answers the purpose 
sufficiently well. (7) A large Abbe condenser is used, together 
with an Ahrens prism of 15™™ edge, or large nicol in place of 
the usual nicol and condenser with removable upper lens. 
This arrangement, first introduced on the Fuess microscope 1a, 
is a marked improvement over the usual arrangement and does 
away with the more or less complicated devices for removing 
the upper condenser lens from the optic axis of the microscope. 


Wright—New Ocular with Petrographic Microscope. 415 


Arr. XXXVII.—A New Ocular for Use with the Petro- 
graphic Microscope ; by Frep. EvGENE WRIGHT. 


Mrverats in the thin section are determined and recognized 
chiefly by the effects they produce on transmitted light and 
the relation of these effects to observed crystallographic 
features, such as cleavage, crystal form, ete. The usual optical 
properties which are thus made use of in determinative work 
are: crystal habit, cleavage, character of elongation, color, 
pleochroism and absorption, refractive indices, birefringence, 
extinction angles, optic axial angle, optical character, and rarely, 
dispersion of the optic axes. 

These characters can be divided into two classes based on 
the methods of their determination. Those of the first-class 
(crystal habit, color, pleochroism and absorption, optical charac- 
ter of elongation, optical character of the mineral, and dispersion 
of the optic axes) are ascertained by direct observation without 
measurement, while for the second class (cleavage angles, 
extinction angles, optical axial angles, refractive indices and 
birefringence) numerical values obtained by actual measure- 
ment are required. 

The ordinary petrographic microscope is adequate and satis- 
factory for the determination of the features included in the 
first class, but not for the second, if accurate data are desired. 
The result is that in petrographic determinative work and de- 
scription these data are often only very roughly measured and are 
then expressed in general terms, such as “‘optic axial angle large,” 
“birefringence strong,” etc., without giving actual numerical 
data. The importance of quantitative measurements in all 
scientific work is obvious. The chief reason for the absence 
of the quantitative element in the major part of petrographic 
descriptions must, therefore, be sought in the cumbersome 
methods now available for the purpose. Thus a Babinet com- 
pensator, or other special device, is required for the measure- 
ment of the birefringence; a double screw micrometer ocular 
or Becke drawing stage for the measurement of the optic axial 
angle, ete. Believing that these various requirements can be 
met with sufficient accuracy by the use of a single ocular, 
which can be made to fit any ordinary microscope, the writer 
has had the present ocular constructed, which has proved satis- 
factory and convenient in actual use.* The ideas involved in 
this ocular are not new,t but the assembling of the different 

*This ocular was constructed by Fuess & Co. of Steglitz, Germany, 
(cost 200 mks.) and the writer desires to express his appreciation of the care 
taken by that firm in carrying out his suggestions. 

+ Compare F. E, Wright, this Journal (4) xxiv, 317-369, 1907; xxvi, 349- 


099, 1908; Journal of Geology, x, 33-35, 1902; Tscherm. Min. Petr. Mitteil., 
xx, 275, 1901. J. W. Evans, Min. Mag., xiv, 87-92, 1905. 


416 FE. EB. Wright—New Ocular for Use with the 


attachments into one ocular is novel and of sufficient general 
interest to warrant brief description. 

The ocular is represented in fig. 1, and consists essentially 
of a metal holder, which is inserted in the microscope tube in 
place of the ordinary ocular and into which in turn a positive 
Ramsden ocular* is introduced at A and certain plates 
mounted in metal carriages, a, 6, c, are inserted at B. Cross 
hairs are attached to the base of the tube A and are practically 
in the same plane with the upper surfaces of the sliding plates 
a, b, e¢, with the result that on focusing the Ramsden ocular on 
the cross hairs, the divisions marked on the plates a, 0, ¢, are 
also in focus and their relative movements can be read off 
directly. With the above arrangement the optical constants 
required can be measured directly by means of the three plates. 


Fine ale 


Fic. 1. New ocular with accompanying plates a, b,c, to be used in 
measuring the birefringence, the optic axial angle, and extinction angles of 
minerals in the thin section or in powder form. 


Plate @ (fig. 1, fig. 2a, b) is a combination quartz wedget 
35°3™™ long and 10™™ wide, and consists (fig. 2a) of a 
quartz wedge cut parallel with the principal axis (direc- 
tion of elongation—c) °5™™ thick at the thin end and 
‘89"™ at the thick end, its pitch being, therefore, about 
6° 16’; and (2) of a quartz plate with direction of elonga-— 
tion a of same length and width and °56™™ thick. If these 

* An ordinary Huyghens ocular can also be used, provided the plates be 
inserted in the focal plane of the aplanatic eye lens. 


+ Compare F. E. Wright, Tscherm. Min. Petr. Mitteil., xx, 275, 1901; Jour. 
Geol., x, 35-35, 1902. 


Petrographic Microscope. ALT 


dimensions be followed exactly, 1/10 millimeter divisions 
ruled on the upper surface of the wedge (fig. 26) will 
give directly the difference in distance in we between emergent 
light waves at a particular point. Thus, for sodium light the 
distance between successive interference bands will be 5:89™™. 
The zero line of the scale must coincide precisely with the 
black line of exact compensation between wedge and super- 
imposed plate. In the present wedge this is the case; the 
slope of the wedge, however, is not exactly correct, and a 
slight correction must be applied to the readings obtained 


Fic. 2a. 


<<, z 
Fie. 2a. Combination wedge. Upper part of combination quartz wedge 


with direction of elongation=a, while lower part is a quartz plate, direction 
of elongation=c. 


since 22™™ on the wedge is equivalent to 22°62 wu. For inter- 
ference colors of the first and second order this error (nearly 3 
per cent) is very slight and can practically be neglected, but 
- for higher orders it must be taken into 
1G. 2b. : ane 
account and the readings multiplied 
by a factor of proportion. In actual 
work a table of equivalent values can 
HAI} be prepared or an inclined line of 
ee oe proper slope:can| be added ‘to the color 
chart and the correct value equiva- 
Hi 2b. Top view of com- Jent to any observed value read off 
ination wedge showing divi- |. : 

sions and position of dark directly. With proper care, however, 
line of exact compensation of it 1s possible to grind these wedges 
wedge and plate. The 01™ correctly, so that the 1/10 millimeter 
divisions on the scale are not Bei ad direntie iter lait 

ete he Genre, ivisions read directly in terms of di 

ferences in wave length (up). 

In practice, the determination of the birefringence of a 
erystal plate in the thin section requires the determination of 
two distinct factors—the thickness of the crystal plate and the 


Am. Jour. Scl.—Fourts Series, Vou. XXIX, No. 173.—May, 1910. 
28 


XL 


418 -F. EF. Wright—New Ocular for Use with the 


path difference between the emergent light waves. The thick- 
ness of the plate can be measured either by direct contact by 
micrometer screw or spherometer or by means of the fine 
adjustment screw of the microscope, or indirectly by means of 
the interference color or path difference of an adjacent mineral, 
properly cut and of known birefringence. Of these different 
methods the second is most convenient, although possibly less 
aceurate. ‘The usual method consists in bringing to sharp 
focus the upper surface of the plate and then the lower surface 
as seen through the plate itself, or if the plate be free along 
one side, to focus on the object plate on which the section is 
resting. In the first case, the apparent thickness must be 
multiplied by the refractive index of the mineral to obtain the 
true thickness. Since the average thickness of minerals in the 
thin section is about -0380"™, an error of -001™™ in setting 
the micrometer screw will produce an error of 8 per cent in 
the thickness determination. In ordinary microscopes this 
error may frequently amount to 002 or 003, and the resulting 
error in thickness to 10 per cent. 

Suppose the extreme limits of error be -003"™ or :0015™™ on 
either side of the true value, then an error of 5 per cent in the 
actual thickness determination may be considered probable. 
If this probable. error be increased to 8 per cent to allow for 
multiplication by the refractive index and to introduce a safety 
factor, it can safely be assumed that the thickness of favorable 
crystal plates in thin sections, ranging from ‘03 to -05™™" in 
thickness, can be determined readily by this method within 8 
per cent of the true value. For minerals in powder form, the 
thickness of the individual grains may be much greater and 
the thickness determination correspondingly more accurate. 

On the wedge whose scale divisions correspond to 10 py 
path difference of light waves, the error of determination is 
not over one division on the scale (-1™™), which is less than 2 
per cent. 

The total probable error of the determination of the bire- 
fringence of a mineral plate in the thin section in an unfavor- 
able instance may amount, therefore, to 10 per cent. As the 
birefringence of the ordinary rock-making minerals ranges 
from about -005 to -050, an error of 10 per cent is confined to 
the third decimal place.* 

In determining the birefringences (y—a) or (y-) or (6-a) of 
a mineral the position of the mineral plate (under examination) 

* An average of the birefringences of the 118 minerals listed under bire- - 
fringence on page 292-295 of Rosenbusch-Wiilfing, Micros. Phys. I, ie 
gives ‘040 as the mean value, while the value of the members midway 
between the two limits is °020--025. This value represents more nearly 


the mean value of the birefringence of rock-making minerals than the arith- 
metical mean, ‘040. 


Petrographie Microscope. 419 


Fie. 3. 


Fic. 3. In this stereographic projection plat (circles 10° apart) the posi- 
tions of the directions in a biaxial crystal whose birefringence (y'~a’) is 2 per 
cent less than that of the optic normal (y-a) are indicated for the optic 
axial angles 2 V—0°, 45° and 90°. The optic normal coincides with the 
central point of the figure. 


Fic. 4. 


Fie. 4. Stereographic projection plat showing positions of the directions 
for which the birefringence (y'-a’) is 5 per cent less than that of the optic 
normal (y-a@) which coincides with the center of the concentric 10° circles. 
These curves are drawn corresponding to the optic axial angles 2 V=0°, 45°, 
and 90°. 


420 FL Ek. Wright—New Ocular for Use with the 


Fic. 5. 


Fic. 5. Like fig. 4, except that the directions are indicated whose bire- 
fringence is 10 per cent less than that of the optic normal located at the 
center of the projection plat. The positions of the curves corresponding to 
optic axial angles 2 V=0", 15°, 45°, 60°, 75°, 90°, are indicated in the figure. 


Fig. 6. 


Fie. 6. In this figure the directions whose birefringence is 10 per cent 
less or greater than that of the acute bisectrix (optic axial angle 2 V—45°) 
are shown by the dotted curves. In this figure the dotted curve which 
passes through the center point (acute bisectrix) marks the directions whose 
birefringence is equal to that of the acute bisectrix (y-@) or (G-a) as the case 
may be. 


is ascertained by means of convergent polarized light. In — 
actual work it is not always easy to find a plate cut precisely 
normal either to the optic normal or to one of the bisectrices, 
and it is of interest to know the percentage error caused by 


Petrographic Microscope. 421 


ite We 


Fic. 7. Similar to fig. 6, except that the center of the projection plat is 
the obtuse bisectrix (2 V=45°). As in fig. 6, the directions whose birefring- 
ence is 10 per cent greater or less than that of the obtuse bisectrix are 


indicated. 
HGS: 


Fic. 8. Similar to fig. 6, except that the optic axial angle is 2 V=—90°. 
The dotted curves again represent the directions for which the birefringence 
is 10 per cent greater or less than that of the bisectrix at the center of the 
projection plat. In this stereographic plat, as in all preceding, the concen- 
tric circles are 10° apart. 


492 «FL EF. Wright—New Ocular for Use with the 


using sections inclined at low angles with the correct direc- 
tions. Fora given plate the birefringence can be calculated 
approximately from the usual formula, 
2 cin aime 
Y —a 

in which I and I’ are the angles which the normal to the plate 
makes with the two optic axes (or optic binormals) respectively. 

In figs. 8-8 these relations are shown graphically in stereo- 
graphic projection. In each figure the angular distance 
between any two successive concentric circles is 10°. Thus in 
fig. 3 are indicated the positions of the sections whose bire- 
fringence is 2 per cent less than the true birefringence (y—a) 
exhibited by a properly cut plate exactly perpendicular to 
the optic normal. The position of these lines of equal bire- 
fringence is different for different optic axial angles as indi- 
cated by the lines for 2 V=0°, 45° and 90°, but it is evident 
from the figures that an inclination of 10° with the true 
optic normal section will cause an error not over 2 per 
cent less than the true value (y-a) and often much less. In 
fig. 4 lines of equal birefringence 5 per cent less than the 
correct value (y—a) are drawn for different optic axial angles 
and show that inclinations of 15° produce errors of 5 per cent 
and less in the true value (y-a), while inclinations of 20° 
(fig. 5) produce errors of 10 per cent and less of the total bire- 
fringence. Similarly, for sections normal to a bisectrix, fig. 6 
indicates that for an optic axial angle 2 V=45°, a plate cut at 
an angle of 7° with the bisectrix may produce a positive or 
negative error of 10 per cent or less in the birefringence (y—8) 
or (8-a). But in this case the birefringence (y—) or (@-a) is 
only about 14 per cent of the total birefringence, and an error 
of 10 per cent, therefore, usually applies only to the fourth 
decimal place. In fig. 7 the directions for which the bire- 
fringence is 10 per cent greater or less than (S—a) or (y—#), here 
about 8) per cent of (y—a) for 2 V=145° (obtuse bisectrix), 
approach within 18° of the bisectrix. In this figure, the curve 
indicating an increase of 10 per cent birefringence is 50° and 
over from the obtuse bisectrix. Plates making an angle of 
less than 20° with the bisectrix can, therefore, be safely 
assumed to furnish values of (8-a) or (y—@), which are not 
over 10 per cent in error. An inclination of 8° would 
produce an error of about 2 per cent in (@—a) or (y-8). In 
fig. 8, the rate of change of birefringence for sections at differ- 
ent angles with the bisectrix is indicated on the assumption 
that 2 V=90°; there an inclination of 12° and over is required 
to effect a negative error of 10 per cent in the birefringence 
(y-8) or (@-a), and 18° or more to effect an equal, positive 
error.—Assembling these data, it may be assumed in general 


Petrographic Microscope. 423 


that the birefringence of a plate, inclined at an angle of 5-10° 
with the true direction (optic normal or bisectrix), will be in 
error about 2 per cent of the true value (y-a), (y—8) or (6-a) ; 
an inclination of 10-15°, about 5 per cent, while for 15°—20° 
inclination the error may be as much as 10 per cent of the 
true value desired. By means of the optic axial angle grating 
device described below, the angular inclination of the section 
can be ascertained and the probable error due to this cause 
thus eliminated. 

In actual practice, therefore, the method of procedure in the 
determination of the birefringence of a mineral plate in the 
thin section or a mineral grain is to measure first the thickness 
by one of the methods noted above and then to insert the 
wedge “a”? and determine under crossed nicols and in homo- 
geneous (e. g. sodium) light, the path difference between the 
interfering light waves.~ For less accurate work the direct 
determination of the interference color and equivalent path 
difference indicated on standard color charts like that of 
Michel Levy is sufficient.—The actual error of such a deter- 
mination should not exceed 10 per cent of the true value of 
the birefringence of the section. The probability of finding a 
section making an angle within 10° of a particular direction 
(optic normal) is about 1 in 66; and a section within 20° about 
lin 16. Since wedge “a” is merely a refined combination 
wedge, it cau be used for all purposes for which the latter 
serves. 

Fic. 9. 


Fic. 9. Top view showing cross grating ruling on plate 6 used in the 
measurement of optic axial angles of mineral plates in the thin section. In 
this figure, the 0°5™™ divisions are indicated but not the 0:1™™. 


(b) Plate 4 (fig. 1 and fig. 9) and the measurement of the 
optic axial angle.—By the use of this device, which is simply 
athin glass plate 1°5"™ wide, on which fine codrdinate linés 
Q-1"" apart have been ruled, the optic axial angle of a mineral 
can be measured, provided one or both optic axes appear 
within the field of vision. The principles on which the 
method is based are considered in detail in a former paper.* 

* The Measurement of the Optic Axial Angle of Minerals in the Thin Sec- 
tion, this Journal (4) xxiv, 317-369, 1907; also, Das Doppel-Schrauben- 
Mikrometer-Okular und seine Anwendung zur Messung des Winkels der 


optischen Achsen von Kristalldurchschnitten unter dem Mikroskop, 
Tscherm. Min. Petr. Mitteil., xxvii, 293-314, 1908. 


494 Ff. EF. Wright—New Ocular for Use with the 


There the different methods for measuring the optic axial 
angle are treated at length, especially those of Mallard, 
Becke and Fedorow, together with a new method which 
requires for its application a double screw micrometer ocular 
or a cross grating ocular like plate b (fig. 9). The method of 
procedure for both double screw micrometer ocular and cross 
grating ocular is the same,—the observed coordinates being 
first reduced to equivalent angular values, and these in turn, 


Fie. 10a. 


Fic. 10a. View of bi-quartz wedge plate showing relative positions of 
right and left-handed wedges and underlying left and right-handed quartz 
plates, all normal to the optic axis, and in combination forming the most 
sensitive device for the determination of the exact position of total extinc- 
tion of minerals in the thin section. To be used also in adjusting the nicols 
in the petrographic microscope. 


Fic. 10b. 


Fic. 10b. Top view of bi-quartz wedge plate. The position of dark line 
of zero rotation or exact compensation is indicated at C. 


after reduction to values obtaining within the crystal, plotted in 
stereographic projection in order that the axial angle values may 
be found graphically. In the article mentioned the different 
steps requisite for this method are described at length and need 
not be repeated here. By means of this ocular, with ruled cross 
section slip, the optic axial angle of a favorable section on 
which both optic axes are visible can be determined within 


Petrographic Microscope. 425 


1-2°. If only one optic axis appears within the field, an error 
of +38° is possible on even a favorable section. 

(c) Plate ¢ (fig. 1 and fig. 10a and b), bi-quartz wedge plate for 
the accurate determination of extinction angles.—The principles 
and methods for determining extinction angles are presented at 
length in another paper,* where it is shown that for general 
purposes with variable light conditions and varying sensitive- 
ness of the eye, a satisfactory general method should possess an 
element of adjustable sensibility in order to meet best the dif- 
ferent conditions. This was found to be realized most satisfac- 
torily in the bi-quartz wedge plate. The present plate was 
made after the following specifications: (fig. 10a) Wedge of 
right-handed quartz, length 35°3"", width 6™", thickness at 
thin end 35™™, at thick end :85™™; plate of left-handed quartz, 
lene@th 3537", width 6™™, thickness -47™; thin plate to be 
cemented on the wedge to a combination plate wedge which 
gives zero extinction at a distance 3°5™™ from the thin end. 
The same specifications to be followed with a wedge of left- 
handed quartz and a plate of right-handed quartz, likewise 
superimposed and cemented side by side as indicated in the 
figure and in such a way that the line of total extinction in the 
first combination is the extension of the line of zero extinction 
in the second (C in fig. 10b). This wedge in sodium light 
gives at the extreme end symmetrical extinction of about 
+10° (fig. 10b), while at the thin end it is +1°. 

The position of darkness between crossed nicols for any plate 
is tested by simply inserting the bi-quartz wedge plate and 
observing the effect on the adjacent halves of the plate. If 
the position of total extinction coincides precisely with the — 
planes of the nicols, both sides of the wedge will show the 
same intensity of illumination on insertion. If this is not the 
case, the observed plate must be revolved again and the test 
repeated. With this method on favorable sections the position 
of total extinction can be determined on a single trial within 10’. 

The determination of an extinction angle on a mineral plate 
involves two distinct steps—the location of the exact position 
of total extinction and the angular relation (optical system, 
accurately centered) of this direction to some observed crys- 
tallographic direction, as crystal edge or cleavage line. The 
error of the latter determination is not great since the eye is 
sensitive to errors in parallelism of adjacent lines as cross hair 
line and cleavage line. The measurement of the extinction 
angle by simply revolving the stage and thus determining the 
position of total extinction, is sufficiently accurate for ordinary 
purposes, if the average of a number of determinations be 


*On the Measurement of Extinction Angles in the Thin Section, this 
Journal (4), xxvi, 349-390, 1908. 


426 Wright—New Ocular with Petrographie Microscope. 


taken, and for ordinary petrographic work the expensive 
bi-quartz wedge might possibly be omitted altogether. The 
time saved, however, by its use in accurate work isa factor — 
which would soon offset the expense involved. 

For the adjustment of the petrographic microscope the 
bi-quartz wedge plate is also well adapted. * 

With the three plates, a, 6, ¢ (fig. 1), accompanying this 
ocular, it is therefore possible to determine with sufficient 
accuracy the birefringence, the optic axial angle and extine- 
tion angles of mineral plates in the thin section. There remains 
still the determination of the refractive indices, and no satis- 
factory method has yet been devised for the accurate deter- 
mination of these on plates in the covered thin section. On 
the polished thin sections the refractometer attachment of 
of Wallerant has proved satisfactory, while for minerals in 
fine grains or powdered sections the immersion method in 
liquids of known refractive index is best adapted. By this 
method, the refractive indices can readily be obtained on 
favorable sections with a probable error of about +:002.+ 
By such direct refractive index measurement, birefringence 
determinations and optic axial angle measurement can be 
checked and possible errors eliminated. 


Summary. 


With the ocular pictured in fig. 1, three fundamental optic 
properties of minerals in the thin section can be measured. (1) 
With the combination wedge “a” the birefringence; (2) with 
the ruled plate “b” (cross section ruling interval -1™™) the 
optic axial angle, provided one or both optic axes appear 
within the field of vision ; (3) with the bi-quartz wedge plate “ce” 
the extinction angle. These three features, and particularly 
the first two, are usually estimated only roughly and not meas- 
ured accurately in petrographic work, chiefly because of the 
complicated apparatus now required for the purpose. The 
present ocular was constructed to serve as a simple but effective 
substitute for such apparatus, and thus to facilitate the actual 
measurement of these important properties. In the same 
holder other wedges and plates can be introduced which may 
serve for the determination of the above and other optical prop- 
erties of a crystal plate. 

Geophysical Laboratory, 


Carnegie Institution of Washington, 
Washington, D. C., January 31, 1910. 


* PF. E. Wright, this Journal (4), xxvi, 386-388, 1908. 

+ Compare O. Maschke, Pogg. Ann., cxlv, 568, 1872 ; Wiedemann’s Ann., ii, 
722-734, 1880; J. Thoulet, Bull. Soc. Min., Fr., iii, 62-68, 1880; J. L. C. 
Schroeder van der Kolk, Zeitschr. f. Wiss. Mikroskr., viii, 458, 1892; F. EH. 
Wright, this Journal (4), xxvii, 385-387, 1907; Tscherm. Min. Petr. Mitteil., 

x, 239, 1901. 


C. Travis—Behavior of Crystals in Light. 427 


Art. XX XVIIL—On the Behavior of Crystals in Light 
Parallel to an Optic Axis ;* by Cuartes Travis, Ph.D. 


Ir a section of a biaxial crystal be cut normal to an optic 
axis, and this section examined in parallel light between 
erossed nicols, it appears uniformly bright in all positions 
when rotated about the axis. This is commonly ascribed to 
interior conical refraction, the explanation given by various 
authorities} being the equivalent of the following : 

When a ray of light, the wave-front of which is normal to 
the optic axis, enters the section, it is broken up into a cone 
of rays, each element of which is polarized in a different 
plane. Hence the light on emerging is polarized in all azi- 
muths. This is equally true if the entering ray is plane polar- 
ized, for its vibration will have a component parallel to the 
vibration direction of each elementary ray of the cone. No 
matter how the analyzing nicol is placed with respect to the 
polarizer, then, it will fail to extinguish all the light that 
comes from the crystal. Following out this line of reasoning, 
it appears that the intensity of the light passing the upper 
nicol will be one-half of that from the lower. 

Certain important factors are neglected in reaching this con- 
clusion, which is untenable when these are considered. It is, 
therefore, the object of this paper to present a discussion of 
the behavior of crystals in light that is approximately parallel 
to an optic axis, and to explain the observed differences between 
uniaxial and biaxial crystals under these conditions. 

$1. In any pencil of light that it is possible to obtain in 
practice, there are rays having all directions within certain 
limits. ‘The energy of those rays that are strictly parallel to a 
given direction (e. g., the optic axis) is infinitesimal compared 
to the total energy of the pencil. An example will make this 
clear. Suppose our source of light is.a circular area of radius, 
7, at the focus of a collimating lens of focal length, 7. The 
angular radius of the pencil is then equal to the angle whose 


tangent ist. A line drawn through the optical center of the 


lens, parallel to the optic axis, will intersect the source in a 
point, ~, and from this point only do we obtain rays that are 


* This paper was suggested by the work of W. Voigt (referred to below), 
who shows that interior conical refraction has no practical existence. The 
writer’s chief object is to point out the correct explanation of a phenomenon 
that is well known to crystallographers. 

+ For example, cf. Groth, P., Physikalische Krystallographie, Leipzig, 
1905, p. 109. 


428 OC. Travis—Behavior of Crystals in Light 


parallel to the axis. The area of the point p is obviously zero 
compared to the total area of the source, no matter how small 
we may make the latter. | 

It appears from this that interior conical refraction is a 
purely mathematical ideal, never attained in practice. Yet it 
is a well-known fact that a small source of light (a pin hole), 
viewed along the optic axis of a biaxial crystal, appears not 
as a double image, but as a luminous ring. Voigt* has shown 
that what is observed in this case is not interior conical refrac- 
tion, but simply an approximation to it. His reasoning may 
be summarized as follows: 

A hollow cone of rays, of very small angular radius a, and 
surrounding the axis, traverses the crystal in two hollow cones 


of radius, & + a, where ¢, is the angle of the cone of interior 


refraction. <A solid cone of rays, of the same angular radius, 
will traverse the crystal under the same conditions in the 
annular space included between the two cones of radius 
© ea, If, however, we consider not the summation of the 
effects produced upon a cone of rays, but the effect upon any 
individual ray, we see that this ray undergoes simple double 
refraction, and traverses the crystal in two definite rays. In 
other words, there is no essential difference between the 
behavior of rays near the axis and that of those at an appreci- 
able distance from it. 

§2. Plane polarized light is split up, by passage through a 
biaxial crystal, into two sets of rays, vibrating at right angles. 
The components of these vibrations, in any one plane (obtained 
by placing the analyzing nicol above the crystal), produce 
certain definite interference effects. From the foregoing, light 
in the neighborhood of the optic axis forms no exception to 
. this; but as the divergence of the two complementary rays is 
often a maximum near the optic axis, it is well to consider the 
effect produced by having the source of light at a finite dis- 
tance from the section. : 

A ray SA (figure 1), from a source 8, is divided, upon 
entering the crystal, into the rays AB and AC, which vibrate 
at right angles. From the same source, another ray, SD, may 
be found, which will divide into DC and DE; C is then the 
common point of emergence of one ray from each of the points 
A and D. These rays are polarized at right angles. If the 
crystal is between crossed nicols, interference takes place 
between the components of AC and AD, parallel to the plane 
of the upper nicol. The effect produced is dependent upon 


* Voigt, W., Ann. Phys., xviii, 1905, p. 645. 


Parallel to an Optic Aus. 429 


the difference in phase at OC, and this is due to the difference 
in the optical length of the paths SAC and SDC. 

Let us assume that the wave-front of the two rays is essen- 
tially normal to the optic axis, so that the front a (not 


ray velocity) is the same for each, and is equal to a? ; let MN be 


the direction of the wave-front in the crystal and M’N’ that 
outside the crystal; also let SA be very large compared to AD. 
In the crystal, the path difference is 8. AD.sin MNN’, AC 
having the longer path. Outside the crystal, the path differ 


Wire. ol. Hig ce 
M =a Tt) E Be Goce 
N ne 
A D 
S 


ence is AD. sin M’N’N, SD having the larger path. But sin 
M’N’N=8. sin MNN’; therefore SAC is optically equivalent 
to SDC. 

If, then, S is at a great distance, the two rays ai C will be 
in phase; their vibrations will give a resultant which is parallel 
to the plane of the lower nicol, and this resultant will be ex- 
tinguished by the upper nicol. 


In discussing the case in which the source is at a finite dis- 
tance, the condition that the section be taken normal to the 
axis is assumed temporarily. (Figure 2.) The maximum phase 
difference is that between the two rays that lie in the plane of 
the optic axes; in the figure, this plane is taken as the plane of 
the paper. 

Let Ay=the path difference, SD—SA. (AC and DC are 

optically the same.) . 
D=the distance of the source, SA. 
$;=the angle of the cone of interior conical refraction. 


430 C. Travis—Behavior of Crystals in Light 


AD ae tani): 

Then BN exis a0) ake 
_ (¢ tan ¢,)’ 
os Ne 

For other pairs of rays in the plane of the axes, the relative 
lengths of SA and SD are changed, but the phase difference A 
at the point of interference is constant if the rays are so nearly 
parallel to the axis that their front velocity in the crystal may 
be considered constant. ‘The reason for this is evident upon 
reference to fig. 1 and the accompanying discussion. 

When the section is not cut normal to the optic axis (as in 
figure 1), it can be shown that the above results hold if ¢, the 
thickness parallel to the axis, be substituted for 7. 

For equally thick sections, with the source of light at-a con- 
stant distance, the maximum phase difference A, due to the 
cause considered above, depends upon tan ¢; The value of — 
¢; for aragonite is 1°50’, which is exceeded in very few other 
substances; the greatest known value is that for sulphur, for 
which ¢,—=7° approximately. Approximate values of A for 
sections of sulphur and aragonite, with D assumed as one meter, 
and » as 0:0005™", are as follows: 


Sulphur Aragonite 
¢ (mm.) A ¢ (mm.) A 
10 1°0 10 Ovl 
i) 0°25 5) 0°025 
I 0-01 o Abal 0-001 


We may conclude from this, that with the source of hight at 
distances commonly used when working with the polarizing 
microscope, A becomes practically zero in the very great majority 
of cases. (This assumes that the condensing system is removed 
from the polarizer.) Any illumination that is observed between 
crossed nicols is, therefore, due to the fact that the direction 
of the light is so inclined to the optic axis that one ray is appre- 
clably retarded with respect to the other, in traversing the 
crystal. In other words, the behavior of the crystal an light 
that 7s approximately parallel to an optic axis, must be 
referred to interference effects of exactly the same nature as 
those observed in any general section, with the light falling at 
any inclination to the axis. 


§3. The relative amount of light that a erystal section will 
transmit, when examined between crossed nicols, may be 
determined by means of the interference figure given by the 
same section in convergent light. This figure is virtually a 
spherical projection, in which each point represents a ray direc- 
tion: if ais the angle between a given direction and the line 


Parallel to an Optic Axis. 431 


of collimation of the instrument, the point that represents this 
direction will lie at a distance from the center of the figure 
proportionate to sin @ The pencil of light that falls upon the 
section consists of rays having all directions within certain 
limits ; if in any given pencil the maximum divergence between 
rays is 2a, a circle drawn upon the interference figure, with 
radius proportionate to sin @, will represent the limits of the 
pencil. The average intensity of that portion of the figure 
lying within the circle is obviously equal to the relative amount 
of light transmitted by the section, when this is illuminated by 
the pencil under consideration. 

The intensity at any point of the interference figure may be 
found from the following equations :* 


I=sin’ 26. sin’rA (1) 
AA=F p sin ?, sin d, ) 


(a-}) 


ieee y | 

1 eee + (For biaxial crystals.) (2) 
[aos an Bay 
a Wee | 
a Y | 
2 | J 
A\=F p sin’ 4, ) 
Hoey ed 

jpegs Was \ (For uniaxial crystals.) (3) 
eee 
esas 


Equation (1) gives the relative intensity I at any point of 
the figure, in terms of the phase difference A between the two 
sets of interfering rays projected in that point, and the angle 
@ that the vibration planes of these rays make with the planes 
of the nicols. In equations (2) and (8), which give us A, p is 
the thickness of the section measured along the wave-front 
normal of the rays, ¢, and ¢, the angles that this normal 
makes with the two optic axes in a biaxial crystal, and ¢ the 
angle that it makes with the single axis in a unaxial crystal. 
In both cases F is a function of the principal indices of refrac- 
tion; if (y—a) for a biaxial crystal is equal to + (w-e) for a 
uniaxial one, F will not be very different in the two cases. 

Near the optic axis, (2) may be written 


F : 
A= y+ , sin 2V 
* Liebisch, Th., Grundriss der physikalischen Krystallographie, Leipzig, 
1896, p. 273, 356, 375. The above forms for the equations are somewhat 
different from those given by Liebisch. 


432 C. Travis—Behavior of Crystals in Light 


or, dropping the subscript, 


kA 
Bos sin 2V (4) 


2V being the angle between the optic axes, and *& a small con- 
stant. Under the same conditions, (8) may be written 
p= a/ kk (5) 

Hence in the figure given by either kind of crystal, the loci of 
points of equal phase difference A are concentric circles. 
When A is an integer, the factor sin*7rA in (1) vanishes ; when A 
is an odd number of times one-half, sin’7rA attains its maximum 
value, which is unity. The dark circles around the axis are 
the loci of points for which A is equal to ”, and the bright 
ones those of points for which A is equal to n—4, m being an 
integer. 

It is evident that the average intensity of the portion of the 
figure included in a circle whose center is the axis, creases 
with the size of the circle until this coincides with the first 
ring of maximum brightness; after this the average intensity 
fluctuates, but undergoes no great change. If, then, a crystal 
section is illuminated by a pencil of angular radius 7, the 
intensity of the light transmitted is zero when 7 is zero, 
increases with r until 7 is equal to the radius of the first bright 
ring, and is approximately constant as 7 increases beyond this. 

The only important difference between biaxial and unaxial 
erystals, in this regard, lies in the difference between the radii 
of the first bright rings in the two cases. If the birefringence 
and the thickness of section are the same for both, & (equations 
(4) and (5)) has roughly the same value for either kind of erys- 
tal. But the radius of ane first bright ring for the biaxial 
erystal is 


$k 
aN 2 
OS Fa 2V 
whereas for the uniaxial crystal it is 
$. = Vk 


and if & is very small (as it commonly is), d, is much larger 
than ¢). 

This is well shown by comparing sections 1™ thick of 
aragonite and calcite. It is to be noted that while calcite has 
the greater birefringence, the first bright ring for this substance _ 
is six times as large as that for aragonite. In the calculation,* 
sodium light is assumed, for which 7 = -000589™™. 


* The radii of the circles of maximum and minimum intensity are calcu- 
lated as they appear after refraction from the crystal into the air. 


Parallel to an Optic Aus. 433 


Aragonite Calcite 
a = o3s0l O== 16585 
8 == Osi e = 1°48638 
Va 6859 (w—e) = 0°1722 
ON Ves) 47750! log & = 7:46201 
—a) = 0°1558 
log & = 758012 
Radii of Redii of Radii of Radii of 
bright dark bright dark 
rings zings rings rings 
O36. Soe 
de 1" OT 
1 48 OG 
2 24 5 
3 00 8 O07 
3 36 8 54 


$4. The maximum divergence of so-called parallel light is 
often considerable, as a simple calculation will show. The 
lowest power objective (No. 0) that is furnished with the Fuess 
No. 3 microscope has a focal length of about 42™™; its work- 
ing distance was found to be 38-2", its aperture, 6°8"™, and 
its field, 4°8"" in diameter. From this, its angular aperture is 
17° 30’ approximately, and when the low power lens that is fur- 
nished with the polarizer is in place, the objective works at 
this full angle. By removing this condensing lens, the effective 
aperture is considerably diminished, becoming approximately 
7° 30’; this may be reduced to 6° 30’ by the substage diaphragm. 
Only by decreasing the size of the source of light, or by in- 
creasing its distance, can we obtain light that has less divergence 
than this. A source 1™ in diameter, at a distance of 1 meter, 
for example, gives with the above objective a pencil whose 
angle is roughly 1°. | 

By comparing these values with the diameter of the first 
bright ring for aragonite, the reason is apparent for the bright- 
ness of a section of this substance, cut normal to an axis, of 
appreciable thickness. It is evident that a basal section of 
uniaxial calcite, 1™™ thick, should also be bright when exam- 
ined with the above objective, even without the substage con- 
densing lens; experiment verifies this. 

The dark brushes of the interference figure, that mark the 
points for which the factor sin’2@ (in (1)) approaches zero, 
widen out as the distance from the axis increases. At an 
appreciable distance from the axis, a small circle, centrally 
located in a brush, has an average intensity that is practically 
zero. This is the reason why a biaxial crystal, placed so that its 
axial plane coincides with the plane of one of the nicols, and 
rotated in this plane, is dark except in those positions in which 
an axis 18 approximately vertical. 


Am. JouR. Necioites SERIES, VoL. X XIX, No. 173.—May, 1910. 
9 


434 C. Travis—Behavior of Crystals in Light. 


In the above discussion, the light in every case is assumed 
to be monochromatic. When white light is used, we must 
consider two additional factors. 

(1). The size of the rings in the interference figure in- 
creases with the wave length of the light; the average intensity 
for a pencil concentric about the axis is therefore dependent 
upon wave length. If the pencil is small, we may say that 
with light of a greater wave length, less is transmitted. 

(2). In biaxial erystals, the dispersion of the optic axes 
renders it impossible to center a pencil about the axis for light 
of more than one wave length. 

The total result of these two factors is that the intensity of 
the illumination varies with its color, and the crystal in white 
light, which is approximately parallel to an optic axis, shows 
impure interference colors. 


Summary. 


In regard to the observed fact that a section of a biaxial 
crystal, cut normal to an optic axis, is uniformly bright between 
crossed nicols, we may conclude that :— 

(1). Interior conical refraction, in a strict sense, plays no 
part whatever as a cause of the phenomenon. 

(2). The cause is to be found in the fact that so-called 
parallel light has commonly a considerable divergence. 

(3). In any given case, the observed intensity of illumimation 
is equal to the average intensity of that portion of the inter- 
ference figure bounded by the limits of the pencil of light 
used. The general configuration of the interference figure is 
dependent upon the optical constants of the crystal, and upon 
the thickness of section; these, as well as the amount of 
divergence of the light, are the determining factors. 

(4). The reason why the same phenomenon is not commonly 
observed in uniaxial crystals, is that in the uniaxial figure the 
first bright ring about the axis is in general much larger than 
that in the biaxial figure. Under proper conditions, however, 
the phenomenon may be also shown by a uniaxial crystal. 


University of Pennsylvania, January, 1910. 


Johannsen—A Petrographical Microscope. 435 


Arr. XXXIX.—Some Simple Improvements for a Petro- 
graphical Microscope ; by ALBERT JOHANNSEN. 


1. A rotating upper nicol in which the annoying reflection 
of light from the surface is overcome.—In examining, between 
crossed nicols, minerals which are rather dark, a small amount 
of light falling upon the upper surface of the nicol produces 
a hazy appearance of the image. Figure 1 represents a light- 


BG ae 


3 
» 
it) 


ZL 
% 


ZZ 


TIAL 
SSMSSSS SSS 


SSSSS S 
CLLiikda 


SSSSSSSSSS 


UI IIILAII LILI 


SSS 
NZ 


7 
ASS 


NS 
N 
N 


om 
oN 
. 


tight modification of the upper nico] of the Fuess I1]—a@ micro- 
scope. <A vertical section through the carriage is shown at A. 
A rotating collar (a a’) is moved by the lever ¢ and is supported 
by the flanges 6 6’ of the outer tube in which it rotates. A 
part of the scale (d) is attached to the box and is divided into 
degrees, although only the 10° divisions are shown at B. 

B and C are respectively the horizontal and the vertical 
projection. The separation of the scale into two parts, which 
was made necessary by its lowered position, is shown at 
eand f. The slot g, which is also shown in figure 1-O, is for 
the easy removal of the nicol from the carriage. The prism is 
rotated 90° and is lifted out, after the entire carriage is taken 
from the tube of the microscope, by the removal of the 
screw 7. Figure 1—D is an end view showing how the plate m 


436 JSohannsen—Some Simple Improvements for a 


entirely closes the upper part of the opening in the tube and 
prevents all reflection from the surface of the nicol. The 
lever c is shown at c’, rotated through 90°. 

2. A permanently attached combination wedge.—A great 
deal of time is ordinarily lost in picking up the accessories 
to the microscope and in hunting for the slot into which they 
are to be inserted. The simple contrivance shown in figure 2 


nike 2s 


has been found to overcome all this. A carriage, exactly fit- 
ting the slot above the objective, is inserted in the tube of the 
microscope and is kept in place by two end screws like those 
holding the Bertrand lens bar. At one end is a square of 
gypsum (a) giving red of the first order; 4 is an opening; and 
c is a quartz wedge underlain by a mica plate, the two minerals 
having their c directions at right angles to each other, and sim- 
ilar in construction to a Wright quartz gypsum-wedge. The 
thickness of the underlying mica plate is so chosen that it 
exactly compensates the front end of the quartz wedge, con- 
sequently the colors of the combination wedge begin at dark- 
ness and gradually increase to the fourth order as the wedge is 
shoved forward. A spring (S) attached to the side of the 
microscope tube presses against the carriage and produces 
enough friction to hold it wherever it is placed. When 
the opening 6 is centered, the spring drops into a rounded 
notch as shown. Upon the upper side of the carriage a 
scale is engraved and the end of the spring shows the order 
of the color at that time beneath the cross hairs of the 
microscope. 

3. A rotating lower nicol for observing very slight pleo- 
chroism.—In the ordinary petrographical microscope, such as 
the Fuess [[I-a, which is the one generally used, the arrange- 
ment for rotating the lower nicol is extremely crude, and the 
force necessary to overcome the friction by which it is retained 
in place makes smooth rotation impossible. In order to 
observe very slight pleochroism, it is often desirable to turn the 
nicol instead of the stage; the movement of the mineral in the 
latter case causes confusion and makes it impossible to observe 
very slight changes of color. Nor is it possible to obtain the 
same results by removing the lower nicol and rotating the 
upper nicol in its place, for a distortion of the image results 
and consequently, also, a movement of the lines. For this 


Petrographical Microscope. 437 


reason the arrangement described below has been found very 
effective. 

A brass collar was turned to fit the lower part of the nicol tube 
and was soldered on as shown in figure 3. A section through 
the collar is shown at A, figure 3; the nicol tube being here 


WIG. oF 


indicated by dotted lines. B is a view from below; O, a view of 
the inside of the collar as it would appear if straightened out ; 
and D, the outside of the collar similarly unrolled. A groove 
is cut on the inside to receive the head of a screw projecting 
from the side of the nicol tube (6 0’, fig. 8, B and C). On the 
opposite side of the tube, a lever (c) moves in the slot a a” 
(fig. 3, B), which is of such length that the distance between 
centers of the lever, in the positions a’ a’’, is just 90°. The 
screw head and the lever bar thus form the bearings to carry 
the nicol tube. As the lever is moved from @ to a”, 
the screw head 6 slides in the groove from 6 to 6’. (Asa 
matter of fact this groove was turned the entire circum- 
ference of the collar, for convenience of construction, though 
it is not so shown in the diagrams.) The nicol tube may be 
removed or inserted easily by slightly raising and rotating the 
tube until the lever bar passes over the projection at @ 


(fig. 3, D). 


438 Johannsen—A. Petrographical Microscope. 


In the microscope as purchased, the nicol is held in place by 
the pressure of a part of the tube between two saw cuts. 
Before attaching the collar, this pressure arm is cut off just 
above where the upper edge of the collar is to come, and the 
upper part is bent outward until only enough friction remains 
to hold the nicol in any position to which it may be turned. 
It is necessary to saw off the lower part of this section in order 
that the upper part may later, if necessary, be bent more or 
less to produce the proper amount of friction. On a new 
instrument the cut would be made only above. The collar is 
soldered on the tube so that the nicols are approximately 
crossed when the lever is set at 0°. Accurate adjustment 
may later be made by rotating the prism within the tube. 

In the Fuess microscope with rotating upper nicol, the 
vibration plane is at right angles to the direction of the lever, 
and the indicator points to 90° on the scale. Consequently, 
the upper and lower scales have readings differing by 90° 
when the nicols are crossed, and have the same readings when 
they are parallel. 

In using certain accessories it is sometimes necessary to place 
the ocular so that the cross hairs form angles of 45° with the 
vibration directions of the nicols. With a microscope fitted 
as above, both nicols may be rotated to 45° and the ocular left 
in its normal position. 

4. Additions to the Hirschwald stage.—Figure 4 shows two 
scales engraved upon the two parts of the Hirschwald stage. 
A mark on the sliding portion indicates the distance through 
which the plate has been moved. Horizontal movement is 
registered by a small scratch made 
with a diamond point on the lower 
margin of the thin section. Any 
mineral, whose position is once reg- 
istered, may again be located by 
resetting the stage to the former read- 
ing. By reading first the vertical and 
then the horizontal scale, the stage 
setting shown in the diagram is in- 
dicated by the figures “1°5-2:0” (Gf 
the scratch on the slide is at the 
letter @): 

The stage, as made at present, does 
not permit a high power objective to be brought close to a 
slide of normal thickness when the mineral is near either of 
the clamping bars (6, 6’). The bars should be beveled slightly 
at a@ and a’. In a corresponding position on the under side, 
enough of the sliding stage should be cut away to permit the 
condensing lens to be carried against the slide at its edges as 
well as at the center. 


Fie. 4. 


The University of Chicago, February, 1910. 


Richardson and Mackenzie—Natural Naphtha. 439 


Art. XL.—A WNatural Naphtha from the Province 
of Santa Clara, Cuba; by Cuiirrorp Ricuarpson and 
Kenneth GERARD MACKENZIE. 


Tue occurrence of colorless naphtha as a natural product in 
Santa Clara is not new. It was first encountered August 18, 
1881, in the western part of the Province near the town of 
San Jose de los Ramos, at a depth of 300 feet. Its special 
characteristics were, according to Salterain*: “It is colorless, 
transparent as the clearest water, easily inflammable, and leaves 
no sensible residue after its complete combustion; its density 
is 0-754; it boils at a temperature of 85°, dissolves asphaltum 
and resinous matter, and possesses the characteristics of 
naphtha.” Sr. Manuel Cueto, the discoverer, reports that it was 
used with good success in the engine of a steam launch and as 
motive power for automobiles. About 20,000 gallons were 
obtained, but disasters, breaking of drills, etc., caused the 
enterprise to be abandoned, and the buildings were destroyed 
during the war. The wells were visited in 1902 by a Canadian 
driller. He reported that they were not producing, but that 
considerable gas was being evolved. Oil was found 300 feet 
down, which had a gravity of 61°6°B. The rock, through 
which the wells were drilled, was a limestone mixed with a 
black quartz. About 180 feet below the surface, a rock 
resembling serpentine was encountered. 

The oil described in this paper comes from the same general 
locality, at a depth of 1560 feet. The overlying strata as 
shown by the drilling records were as follows: 


Depth Kind of Rock 
18 feet Red soil. 
ce 


44 Yellow clay. 
50 ‘< Hard black rock. 
52 “Flint, gravel and pyrite. 
58 ‘** Loose bowlders. 
- 80 “‘ Bowlders and gravel. 
85 iio a varie. 
88 ‘« Pyrite and sand. 
94 « White quartz. 
96 “ Coral rock. 
101 «¢ 6Sand. 
108 ‘* Hard dark sand. 
118 “ Pyrite. 
124-128 “ Sand. 
128-134 “ White limestone. 


*U.S. Consular Report, vol. x, p. 75, 1883, cited by Wood, Civil Report 
of Military Gov. Cuba, Jan. 1, May 20, 1902, vol. v, pt. iii, p. 82. 


440 Ltichardson and Mackenzie—Natural Naphtha from the 


Depth Kind of Rock 
134-154 feet Black slate and white limestone. 


166-176 “ Green serpentine. 

176-194 ‘* Limestone and slate. 

208-242 ‘“ Black slate. 

302 ‘¢ Soapstone. 

347 ““ Green serpentine. 

425 *‘ Green serpentine and soapstone. 
550 «Dark slate. 

565 “* Hard black “shells” and soapstone. 
590 “‘ Soapstone and green serpentine. 
670 “‘ Slate and soapstone. 

680 ‘¢ Green serpentine, soapstone. 
835 ‘¢ Slate and serpentine. 


Hard black slate and serpentine. 
Black “shells.” 


The rock is strikingly similar to that described by the 
Canadian driller. He found serpentine at 180 feet, in this well it 
first occurs at 166 feet. Furthermore in another well (No. 2) ° 
45 feet N.E., serpentine was found at 183 feet. Likewise the 
black “shells” so often mentioned must be the black quartz 
referred to. Well No. 2 was carried only to 700 feet. Two 
gallons of naphtha were obtained at 580 feet but no more. The 
well described above gave a little gas at 467 feet, half a pint 
of naphtha at 700 feet, but no more till 1560 feet was reached. 

Much water is obtained with the naphtha, the relative propor- 
tions being (average of 17 drawings). 
72°5% by volume. 
27°54 

The oil figure includes a substance which the driller spoke 
of as “paraffin,” and which will be referred to later as 
“emulsion.” 

The naphtha was of a very pale yellow color, and deposited 


on long standing, a slight, light brown sediment. It had: 
Specific gravity, Westphal. ---- 15°6° 0°732 
NHB a Ch ts eae 14092 : 


It gave a fire test below 0°. 
An Engler distillation gave: 


TABLE I. 
Engler Distillation, Cuban Oil. 

Temperature % Wt. Sp. gr.15°6° Sp. gr. 20°/20° Np2d° 
—75° 3°5 eee iS tas Poi 1°3900 
75°-100° 18°9 0°72 ae es 1°4002 
100°-125° 51°3 0°739 Onion 1°4094 
125°—150° 18°4 0°75 0°7497 1°4166 
150°-160° 1°2 Se ts eee 1°4242 
Residue Deal Hades See 1:4492 


Province of Santa Clara, Cuba. 44] 


By way of comparison, two naphtha distillates from Cali- 
fornia petroleum, and samples of 62° and 88° naphtha obtained 
in open market, were distilled. 

TABLE IT. 
Engler Distillation of California Naphiha Distillate. 
Marked “64°7°” 


Spe ere estphal 662.2540. 222 15°6° 0°722 
ENP Dibe eels ea 1°4062 
Temperature % Wt. Sp. gr. 15°6° Np2o° 
= 0m 1°d perc aacn lesioo 
50°-75° 19°4 0°660 1°3814 
75°-100° 23°2 0°716 1°3987 
100°=125° 24°9 0°756 1°4139 
125 -=15 0° 9°8 0:774 1°4261 
Residue 6°0 0°808 1°4480 
TABLE III. 


Engler Distillation of California Naphtha Distillate. 
Marked “ 64°5°” 


Speer. —VWestphaly:--. 2 4 15°6° 0°732 
NOD eee 14141 
Temperature % Wt. Sp. gr. 15°6° Np25° 
-50° 0°5 ay) it 1°3752 
50°-75° 13°5 0°678 1:3818 
75°-100° 32°8 0°716 1°3987 
100°—125° 24°6 0-740 1°4141 
125°-150° 12°3 0°768 1:4270 
Residue 5°9 0°810 14500 
TABLE IV. 

Hingler Distillation of Commercial 88° Naphtha. 
Sper. W estphale sts.) 22. Loe 0°651 
Niobe wins 1°3695 

Temperature % Wt. Sp. gr. 15°6° Np2o° 

—50° A7*7 0°609 1°3605 
50°-75° 29-2 0°65 1°3756 
75°—100° 6°8 0°70 1°3930 
Residue 1°4 ie 14061 
TABLE V. 
Lingler Distillation of Commercial 62° Naphtha. 
Ppt Wiestpialo sae... 1586s 0°732 


INGO er en En: | 1°4106 


442 Lichardson and Mackenzie—Natural Naphtha from the 


Temperature % Wt. Sp. gr. 20°/20° Np2o5° 
—50° Sek ape nae 
50°-75° 1° “9 Bis Be 1°3830 
75°-100° 20°0 0°7029 1°3956 
100°-125° 91°9 0°7286 1°4061 
125°-150° 24°6 0°7462 1°4168 
Residue 9:2 ave 1°4282 


Practically all of the Cuban oil comes over between 75°— 
150°, half between 100°-125°. The California naphthas boil 
somewhat lower, a much larger part coming over 50°-100°. 
The 88° naphtha boils, of course, very much lower, but the 62° 
naphtha shows almost an identical composition by distillation, 
the fraction 125°-150° alone being larger. 

Of the original oils, California 64 5°, 62°, and the Cuban oil 
have the same ovavities, though the California index of retrac- 
tion is higher than the other two. 

A comparison of the different fractions is interesting. The 
first found in all is 50°-75°. The Cuban oil has the highest 
refractive index. The two California naphthas and the 66° are 
close together, while the 88° naphtha is lowest. In the portion 
75°-100°, the Californias are nearly equal to the Cuban, while 
62° and 88° are respectively lower. The gravities do not differ 
materially, but are in the same order from Cuban to 88°. 
Fraction 100°-125° shows a slight variation. 62° and 88° 
indices are equal and lowest, Cuban is next, with California 
highest. The gravities do not reveal an ything, running Cal.— 
Cuba—Cal.—62°. The highest fraction, 125°-150°, gives similar 
constants for the Cuban and 62° naphthas, higher for the Cali- 
fornia. 

It is hard to make a general summary of these comparisons. 
The Cuban oil boils identically with 62° naphtha, but higher 
than the California naphtha. The indices of refraction and 
specific gravities of its fractions are nearest those of 62° 
naphtha, but not as high as California naphtha. 

The action of reagents on the original oils was as follows : 


Removed by Cone. Fuming 

10% NaOH 33% H.SO, H.SO, H.SO, 

Cubaneol ees wees ae! aes 0°76% 1°8% 
“fraction 145°-__-- aids. is 02 % 2°5% 

Cal. naphtha “64:5°” ___ 2°0% 2°9% 36 % 2°9% 
62s naphtha: == ree 1°3% 2a 1133) % 25% 


The refractive indices in each case were not materially 
changed. 

The Cuban oil has practically no unsaturated compounds, 
even the 62° naphtha showing more action with acid, while the 


Province of Santa Clara, Cuba. 443 


California naphtha, besides 3 per cent nitrogen bases, has 6°5 
per cent unsaturated hydrocarbons. 

The California petroleums do not contain hydrocarbons of 
the series O, H,,,,.* The source of the 62° naphtha cannot be 
determined, but it in all probability contains both paraffins 
and naphthenes. The Cuban oil evidently is not composed 
entirely of naphthenes, which are characterized by higher 
gravity and index of refractions, nor yet of paraftins. 

To further investigate its composition, a fractional distilla- 
tion was made, with an 18-column Young dephlegmator con- 
densing with an ice-salt mixture. 


TABLE VI. 
Fraction Distillation Cuban Oil. 

Temperature % Specific gravity Np0° Np2o-° 

= 0° 1°6 0°589 0°/4 oi 1°3706 me as 

30°-35° 0°5 eae 1°3703 Eng te 

35°-50° 0°3 aa ties ese ee 

50°-65° 1°0 Pig ue 1°3905 ee 
65°=75° 3°6 0°685 1°3975 1°3860 
3-80 B35) 0°7266 20°/20- 1°4140 1°4020 
85°-95° 6'8 0°7270 1°4155 1°4032 
95°-105° 19°2 0°7308 Ale 2 1°4061 
105°=115° F2 0°7387 bree AIA? 
115°-125° 2 0°7392 ATE Ae 


Using a 4-bulb Hempel fractionator. 


125°-135° 6°8 O-7477 che 1°4162 
135°-145° ok On 77 ee anes 1°4181 
Residue Sal 0:'7768 Peach 1°4302 


Peraction—30°. Sp: er. 0°89) (0° /4")., IN, 0°) 1-3706. n- 
Butane boils at 1°, tetramethylmethane at 10°; dimethyle- 
thylmethane at 30°, with sp. gr. 0°6385 (14°). This fraction 
must be composed of paraffin hydrocarbons as must also 


Fraction 30°—35° N,0° ie 108 
- Fraction 35°—50° INZOe Dei 72} CAle.IN, 25° 1°365 
n-Pentane boils at 38° and has a refractive index of 1°3649 ; 
trimethylethylmethane boils at 49°6° and Np25°5°—1°3602. 
This fraction also, by its index, is composed only of paraffin 
hydrocarbons. 

Fraction 50°—65°. N,0° 1:3905; cale. N,25° 1°379. Di- 
iso-propyl boiling at 58° has Np25°=1°3648. The index here 
is slightly high for pure paraftins. 

Pracnon 65 —is- ep. or, 0°68 (0° /4 0 ND 25° 13860. 

* Richardson, VI International Congress of Applied Chemistry, iv—a, 248. 


444 Fichardson and Mt ackenzte—Natural Naphtha from the 


n-Hexane boils at 71°,* sp. gr. 0°6630 (17°) Np20° 1°3734; 

methylpentamethylene+ boils at 71°, sp. gr. 0°7474 (21°/4°), 
Np»20° 14101. This fraction consists almost entirely of 
n-hexane with a small amount of My pia 

Fraction 75°—85°. Sp. gr. 0°7266 (20°), Np25° 1:4020. 
Here, also, we probably find n-hexane and Rs, 
thylene and also hexamethylene boiling at 81°,{ sp. gr. 0-771 
(15°)§ Np18° 1:42897.| 

Fraction 85°—95°. Sp. er. 0°7270, N525° 1:4032. Ethy- 
lisoamyl4] boils. at 90°5°, sp. ox. 0;6819. (i->)q eee 
dimethyleyclopentane** boils at 91° , sp. gr. 0°7410 (24°/4°), 
Np18° 1:4253. Evidently contains both paraffins and naph- 
thenes. 

Fraction 95° — Wau Sp. ers) 0-(o0s O20 aw Np2o° 14061. 
n-Heptane boils 98:4°,+] sp. gr. 06886 (1o2) ieee 
1°3854;8§ methyleyclohexanell|| boils 103°, sp. gr. 0°7662 
(18°5°/4°), Np19° 1:-4243.99 Paraffins and naphthenes both 
are present. 

Fraction 105°—115°. Sp. gr. 0°7387 (20°), Np255 12am 

Fraction 115°—125°. Sp. gr. 0°73892 (20°), Np25° 1°4121. 
n-Octane boils 125:°5°,*** sp. sr, 0:7020 (0a 
1:3943 ;ttt two unknown octanes described by Mabery and 
Hudsong$§ boil at 119°5° and 124°—125°, and have gravities 
(20°) of 0°7243 and 0°71384; octonaphthene|||| boils at 119°, 
sp. gr. 0°7508 (18°) Np20° 1:42384;94 4 isooctonaphthene **** 
boils at 124°, and has sp. gr. 0°7637 (175°). The percentage 
of naphthenes in each fraction seems to increase with the tem- 
perature. In this fraction, nearly equal amounts of parafiins 
and naphthenes are present. 

Fraction 125°—135°. Sp. gr. 0-7477 (20°), Np25° 1:4162. 
8—Nonanetttt boils 129°5°, sp. gr. 0°725 (247°); nonanaph- 
thenet{tt boils 135°—1386°, sp. gr. 0-7667 (20°/0°). Here also 
is a mixture of the two classes of hydrocarbons. 

Fraction 1385°—145°. Sp. gr. 07517 G0"), Nj25. ieee 
a—Nonane§$§$ boils 185°—187° and has sp. er. 0°742 (124°). 

From these constants we can see that the lower boiling 
hydrocarbons are of the paraffin series while those coming over 


* Engler and Routala, Ber. xlii, 4615. + Engler and Routala, loc. cit. 
¢{ Fortey, J. Chem. Soc., lxxiii, 982. § Fortey, loc. cit. 

| Engler and Routala, loc. cit. €| Schorlemer, Ann., cxxxvi, 209. 
** Engler and Routala, loc. cit. 

++ Francis, Young, J. Chem. Soc., lxxiii, 921. 

tt Thorpe, Ann., cxeviii, 364. gy Engler and Routala, loc. cit. 
||| Knoevenagel, "Ann. , cexevii, 159. aia] Zelinsky, Ber., xxviii, 1022. 
*** Thorpe, J. Chem. Soc., xxxvii, 217. +++Engler and Routala, loc. cit. 
ttt Engler and Routala, loc. cit. SS§ Am. Chem. J., xix, 255 

||||| Engier and Routala, loc. cit. 9/4/*| Knoevenagel, loc. cit. 

**** Wngler and Routala, loc. cit. 

tt++ Lemoine, Bull. Soc. ‘Chem., Paris, xli, 164. 

tttt Konowalow, J. Russ. Chem. Ges., Xix, 205. 

S§S§ Lemoine. 


Province of Santa Clara, Cuba. 445 


at higher temperatures contain increasing percentages of naph- 
thenes, approximately equal amounts being finally found. 

It has already been mentioned that with the naphtha, a sub- 
stance was obtained which was described by the driller as 
paraffin. It was a grey substance, somewhat gelatinous, and 
similar in appearance to an oil emulsion. Its composition was 
found to be: 


Calill <2) Stee Ae op Ua a ea ag eal aN 0 81% 
A NGGLE | da aL RI eV ce pr 14% 
Oey piy er ee ee ee SG 


in the form of an emulsion. 
The oil had a 


Spor Westphal lo:6" 2 2° - 0°738 
INGOG Ore eer A 1:4100 
Distillation Engler. 

- Temperature % 15° Sp. gr. 20°/20° Np25° 
—75° 0°4 ahs ee Linea 1°4045 
75°-100° 18°0 O-72 O72 17 1°4006 
LOO 125" 56°4 0:74 0'7372 1:4090 
a Sans 18:4 0°75 0°7500 1°4161 
Residue 3°4 Digs Layt) 1:4499 


This oil is practically identical with the clear naphtha, except 
for a slightly higher gravity. It was more deeply colored and 
had a larger amount of brown sediment. 

Action with reagents. Oil from emulsion. Removed by 


OM aw ee mL OW Lie oes "6% 
Concentrated acid. vi.L1.4522 2: 15% 
Bim ey acid ia. Ss (i152 65 Sie 0:0% 


The water had 2°31 per cent total solids. 

The ciay, which was gray, lost 15-7 per cent on ignition, 
the iron being oxidized. It was submitted to the Office of 
Public Roads, Washington, D. C., and an examination by Dr. 
Lord showed that the indurated material consisted essentially 
of highly decomposed fragments of a ferruginous rhyolitic 
glass and rounded grains of bitumen cemented together by 
chalcedonie silica and an indefinite hydrated silicate. The clay 
is composed of the secondary products resulting from the 
decomposition of the rhyolite, with some bitumen grains and 
fragments of undecomposed glass. 

The emulsion is of the greatest interest. 

Gilpin and Cram have shown* that when petroleum is allowed 
to rise in a tube packed with fuller’s earth, a fractionation 


* Am. Chem. J., xl, 495. This property was first pointed out by Day, 
Proc. Am. Philos. Soc., xxxvi, 154. 


446 Lichardson and Mackenzie—Natural Naphtha. 


results, the fraction at the top of the tube has a lighter gravity 
than that at the bottom, and that the saturated hydrocarbons 
come to the top while the unsaturated are lower. Also when 
water is added to the fuller’s earth containing the petroleum, 
the oil is displaced, but about one-third of the oil remains in 
the earth. 3 

Day and Gilpin* have carried this work further and have 
obtained similar results with clay. They have pointed out its 
application to the accumulation of petroleum in different 
places. 

We have in this Cuban oil an exact confirmation of these 
experiments by nature. It will be remembered that from 
the oil well there was obtained naphtha, water and emulsion. 
The history of this naphtha may be very briefly told. At some 
depth, considerably below 1500 feet, a crude petroleum filtered 
up through this rhyolitic clay,t the upper part of the clay 
stratum by fractionation containing the lightest naphtha. 
Saline waters then came in contact with this upper clay layer, 
displacing two-thirds of the oil contained in it and forming 
with it the emulsion. In Trinidad asphalt, as shown by one of 
us,{ we have an exactly similar case of a permanent emulsion 
of bitumen, water and mineral matter. 

To summarize briefly, we have examined a naturally oceur- 
ring white naphtha from the province of Santa Clara, Cuba. It 
occurs at a depth of 1560 feet in black quartz and green ser- 
pentine with water and an emulsion of oil, water and rhyolitic 
clay. It contains practically no unsaturated hydrocarbons, but 
a mixture of paraffins and naphthenes. Over 50 per cent dis- 
tills between 100°-125°, and very little above 150°. It was 
undoubtedly formed by the upward filtration of a heavy pe- 
troleum through the clay stratum, similar to the fuller’s earth 
filtrations of Gilpin and Cram, and the light naphtha in the 
upper part of the stratum was afterwards partly liberated by 
saline waters, the oil remaining in the clay forming with water 
the emulsion. 

Our thanks are due to Mr. L. W. Page of the Office of 
Public Roads for the examination of the clay, and to the 
Cuban American Sugar Company, the owners, for permission 
to publish these resulis. 


New York Testing Laboratory, 
January 31, 1910. | 


*Ind. Eng, Chem., i, 449. 

+ It may be stated that the drillers are confident of finding a heavy 
petroleum at greater depths. 

+ Richardson, Proc. Am. Soc. Test. Mat., vi, 509. 


Loughlin— Granites and Metamorphic Sediments. 447 


Art. XLI.—Jntrusive Granites and Associated Metamorphic 
Sediments in Southwestern Rhode Island; by G. F. 
LovGHuin. 


CONTENTS. 


Introduction. 

Bibliography. 
Résumé of evidence in 8S. E. Connecticut. 
Evidence at Westerly and Niantic, R. I. 
Reconnaissance eastward to the Kingstown area. 
The Kingstown area. 

Granite. 

Time of intrusion. 

The Kingstown sediments. 

Granite pebbles. 

Derivation and correlation of the Kingstown sediments. 
Summary. 


INTRODUCTION. 


Studies in southeastern Connecticut and southwestern Rhode 
Island have convinced the writer that all the granites in this 
area are parts of one composite batholith, and that this batholith 
is not of pre-Cambrian age, but is intrusive into rocks that have 
been mapped as Carboniferous. A detailed report on the 
southeastern Connecticut portion was completed about two 
years ago, and is awaiting publication by the United States 
Geological Survey. * 

The present paper expresses the results of reconnaissance 
work from the Connecticut-Rhode Island boundary eastward 
to the vicinity of Narragansett Basin and of more detailed 
study along the western border of the Basin—here designated 
the Kingstown area. 

Bibliography.—The granites of the area studied have been 
mentioned in a few publications, but their ages and structural 
relations have seldom received close attention, especially at 
critical points. C. T. Jackson, in 1840, mapped the granite 

as “Primary” + and the sediments of the Narragansett Basin 
as “transition graywackes” derived from the Primary. In 
1899, Shaler, Woodworth, and Foerste published “The Geology 
of the Nar ragansett Basin, R. 1.” + Shaler and Foerste, who 
worked in the area under discussion, gave little attention to 
the granites bordering the Basin. They regarded them as 
Algonkian and distinct from the pegmatite dikes that cut the 
Carboniferous strata of the Basin. The latest geological map 
of North America§ represents the granite as pre-Cambrian. 

* Contributions to Geology of Eastern Connecticut. 
+ Geol. and Agricult. Surv. of the State of R. I., 1840. 


t U.S. Geol. Surv., Mon. XX XIII, 1899. 
§ Bailey Willis, Geol. Map of No. America, 1906. 


448  Loughlin—Intruswe Granites and Associated 


B. K. Emerson and J. H. Perry* in 1907 deseribed and 
mapped the formations along the western border of the Narra- 
gansett Basin. The southern end of their area overlaps the 
northeast corner of the area here discussed, but no contacts are 
there exposed. They also mapped the oranite as pre-Oambrian 
(fig. 1 of this paper). 


Résumé of Evidence in S. E. Connecticut. 


As the writer’s work here described has been essentially a 
continuation of his studies in southeastern Connecticut, a sum- 
marized statement of the character and relations of the granite 
and adjacent metamorphic sediments in that area is here given 
to serve as a basis for correlation.+ A portion, also, of the 
map is copied (fig. 1, west of long. 71° 45’ and north of lat. 
41° 25°). 

The metamorphic sedimentaries shown in ibe map are a 
quartzite (Plainfield quartz-schist) and a more extensive 
quartz-biotite-schist, more or less feldspathic ( part of the Put- 
nam eneiss series). These, and closely related metamorphics 
not shown in the map are characterized by the general predomi- 
nance of plagioclase wherever feldspar is present. The com- 
position of the plagioclase ranges from Ab,An, to Ab,An.,. 
They are possibly of Carboniferous age. 

The granite—Sterling granite series—mostly of pine color 
and gneissoid structure, includes three varieties : normal biotite- 
granite, porphyritie biotite-eranite, and alaskite. . The alaskite 
is known to cut the other two varieties, but all gradations in 
composition and texture appear. All the varieties are intrusive 
into the sedimentary series. Pegmatite and aplite, in sheets 
and dikes, cut the granite series, and are abundant in the meta- 
morphic sediments. The granite series is characterized by a 
well-developed microline, in some cases microperthitie, white 
oligoclase, or albite, and some quartz. 

The relation of the micro-textures of the granites to regional 
metamorphism has been treated at some length in the original 
paper, with the conclusion that the normal and porphyritic 
types were intruded and crystallized while the disturbing forces _ 
were most active, and that the alaskite became solid during the 
waning stage of regional movement. This relation, if the sedi- 
mentary series includes Carboniferous rocks, correlates the time 
of metamorphism and intrusion with that of the Appalachian — 
Revolution. The question of age will be furthur considered 
towards the end of this paper. 

* The Green Schists and Associated Granites and Porphyries of Rhode 


Island, U. S. G.S, Bull. 311, 1907. 
+ By permission of the Director of the U. S. Geol. Survey. 


Metamorphic Sediments in Southwestern Ehode Island. 449 


Evidence at Westerly and Niantic, R. I. 


The writer during the past six years has made several visits 
to the Westerly, R. L, granite quarry district along the south- 
ern part of the Connecticut boundary, and one visit to the 
neighboring and similar district of Niantic, R. I. (fig. 1) 
He finds at these places the above summarized evidence dupli- 
cated and supplemented by a later intrusion—that of the Wes- 
terly granite. Metamorphic sediments here appear only as 
isolated inclusions in granite. Both the sediments and the 
Sterling granite series are cut by dikes of the fine-grained 
Westerly granite ( quartz-monzonite according to Dale ).* 
The latter rock has the same mineralogic characters as the 
Sterling granite, differing only in containing a higher percent- 
age of plagioclase. Its contact phase and apophyses are 
medium-grained to pegmatitic, and cannot be distinguished 
in the specimen from the Sterling granite series. The contacts 
of the Westerly with the Sterling granite are sharp, but the 
close petrographic resemblance between the two rocks and the 
absence of any evidence indicative of widely different age 
favor the interpretation that the Westerly granite is not a type 
independent of the Sterling granite series, but the latest 
exposed phase of the same batholith. 


Reconnaissance Eastward to the Kingstown Area. 


Two reconnaissance traverses have been made across south- 
western Rhode Island, one extending from the southeastern 
Connecticut area eastward to Wickford Junction, the other from 
Hope Valley southward to Niantic and thence eastward, in a 
zigzag course, to Wakefield (fig. 1). The outcrops visited 
are plotted on the map. Those along the first, or northern, 
traverse are identical in character with the normal gneissoid 
Sterling granite, save one outcrop of the porphyritic type a 
mile west of Millville. The normal type is disintegrated to 
a considerable extent, a characteristic feature in parts of south- 
eastern Connecticut, and some outcrops are completely reduced 
to a coarsely granular soil to a depth of six feet or more. 

Short veins of pegmatite and pegmatitic quartz, from less 
than an inch to one foot in width, are commonly present, most 
of them cutting across the schistosity of the granite. One small 
dike of fine-grained granite, similar to the Westerly type, was 
noted on the southward sloping ridge 1$ miles east of Pine 
Hill. No inclusions of the metamorphic sediments were found. 

A glance at the map will show that no outcrops were tound 
along the eastern three miles of the traverse; but over 99 per 

* Dale, T. N., The Chief Commercial Granites of Mass., N. H. and 


R. I. Bull., U. S. G.S., No. 354, 1908, pp. 190 et seq. The reader is referred 
to this Bulletin for structural and petrographic details. 


Am. Jour. Sci.—FourtTH Series, Vou. X XIX, No. 1738.—May, 1910. 
30 


450 Loughlin—Intrusive Granites and Associated 


cent of the abundant bowlders in these three miles, and in fact 
along the whole traverse, are of the normal gneissoid Sterling 
granite, and it is the writer’s experience that the majority of 
bowlders in southern New England are of strictly local origin. 
The granite therefore is believed to be continuous from the 
Connecticut boundary to the edge of the Narragansett Basin, 
14 miles west of Wickford Junction, but the relations there 
between the granite and the rocks of the Basin are concealed 
by drift. 

The eastern part of this traverse overlaps a small part. of the 
area mapped by Emerson and Perry as a southward continua- 
tion of the pre-Cambrian Northbridge gneiss of Massachusetts. 
The thorough concealment of all contact relations renders it 
impossible at this point to choose between the conclusion of the 
authors cited and that of the writer. Evidence supporting 
the writer’s views will be presented in the description of the 
Kingstown area. 

Evidence along the southern traverse is not quite so incon- 
clusive as that just presented. The granite outcrops are all of 
the Sterling types, chiefly the normal and to some extent the 
porphyritic. Two small dikes of the Westerly type were 
noted; one a mile south of Plainfield, the other on the summit 
of Shumunkanug Hill. No outcrops were found along the 
eastern six miles of the traverse, but here again practically all 
the bowlders are of the Sterling granite. 

Exposed inclusions of the metamorphic sediments are very 
scarce and only one deserves mention. ‘This one lies in the road 
on the hill a mile west of Worden’s Pond (see map, fig. 1). 
Its texture is pseudo-porphyritic with flattened, lens-shaped 
pebbles of quartz-schist, but the matrix is identical in color 
and texture with the quartz-biotite schist exposed in southeast- 
ern Connecticut and at Westerly. It is also similar to the 
most severely metamorphosed conglomerate in the Kingstown 
area. It is cut by a narrow pegmatite dike of the Sterling 
(or Westerly) type. This evidence though limited proves that 
the age relations found in Connecticut and at Westerly exist as 
far east as Worden’s Pond. 


The Kingstown Area. 


The limits of the Kingstown area are shown in fig. 2. It 
includes the west boundary of the Narragansett Basin sedi- 
ments from Hamilton southward, and has yielded decisive evi- 
dence for determining the relative ages of the rocks in question. 
The area was studied and mapped in detail by Messrs. Y. 5S. 
Bonillas and V. M. Frey under the writer’s direction.* The 


* MS. thesis No. 340, 1908, Min. Dept. Mass. Inst. Tech., Boston, Mass. 


Metamorphic Sediments in Southwestern Lhode Island. 451 


ce 


3 o> DS H 

= x +9 q Sas 5 = 

3 3 ae NN 6 f os QUKx*Xxx] gg & 

> Tor Fas +2 > ROG Ae: ae 

SC 25> Us aN oo Q Oy ioe 5 © 

& Sys 79 +> ie SL ee ol Ma aea: 
738 SBA NN 0 Oo Say es de eS 

eae BREN » 4 e = Bey KXxxx| OX 

gg % Se bo > 3 

= z emo] oz oa 

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= 

3 According to earlier 


maps 

Fic. 1. Geologic map of S. W. Rhode Island and S. E. Connecticut. 

Detailed mapping is expressed only in the eastern and western portions of 

the area. Only outcrops seen by the writer are shown in the central por- 
tion, which is believed to consist essentially of the Sterling granite. 


452 Loughlin—ILIntrusiwe Granites and Associated 


writer has not visited every outcrop in the area, but has studied 
the continuous exposures along the shore of the Bay, and all 
the exposed granite contacts, and has examined thin sections of 
the several rock types represented. 

Granite.—The various granite exposures include types iden- 
tical in texture, mineral composition, and structural relations 
with the several members of the Sterling series (including the 
Westerly granite). These types and their relations to one 
another are perfectly shown in the continuous granite ledge 
which extends along the shore of the Bay from Narragansett 
Pier for two miles southward. There is, in addition to the 
types previously mentioned, a pegmatitic muscovite granite 
which, as will be shown presently, is a contact phase of the 
Sterling batholith, and is transitional into those pegmatites 
which were previously interpreted as post-Carboniferous.* 
Muscovite variations are present in the areas previously 
described, but only in the Kingstown area are they conspicuous 
and important. The feldspars of the muscovite granite are the 
same in character and composition as those of the other types. 
Schist inclusions are found in all the granite types. 

Normal and. porphyritic Sterling granite, moderately to 
highly gneissoid, are the prevailing types in the Kingstown 
area. ‘They comprise the body of the two-mile exposure along 
the shore, and are exposed to the north on Rose, McSparren, 
and Hammond Hills. Exposures are few at intervening points, 
but are of the same types of granite. Small pegmatite dikes, 
more or less muscovitic, are of common occurrence. The 
northern part of this area also overlaps the southern limits of 
the area previously mapped as pre-Cambrian (see p. 448) ; but 
here again, owing to the general lack of local evidence, it is 
impossible to choose between the differing interpretations. 
Weathered schist inclusions are found on MeSparren Hill, but 
the presence of these alone is not convincing evidence. 

Definite evidence, however, is afforded east of Wakefield, at 
the bend of Indian Run, in an exposed contact with quartz- 
biotite schist, the metamorphic sediments of the Narragansett 
Basin. The granite a short distance from the contact 1s red, 
distinctly gneissoid, and irregularly porphyritic. Both its 
megascopic and microscopic characters are identical with those 
of the Sterling granite types of Connecticut. As the contact 
is approached, the gneissoid character is obscure or absent, 
and pegmatitic segregations are numerous. Distinct dikes of 
pegmatite are also. present, cutting the granite. The adjacent 
schist is penetrated by many pegmatitic apophyses, most of 
which follow the foliation plains. 

A mile eastward, along the southeast slope of Tower Hill, 


*U. S. G. S. Mon. XXXII, p. 377. 


Metamorphie Sediments in Southwestern Rhode Island. 458 


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Lois Allen LOL ie 


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S’'Greénes Pt. 


SN 


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7 
[pS Ss PA Bwawaasss, 

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Frele Work 
b 


Dy 
¥ S.Bontllas and 
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---under direction of--—- 


—. GF Loughlin 


Fie. 2. Detailed geologic map and sections of parts of North and South 
Kingstown, R. I., along the western border of the Narragansett Basin. 
Boundaries actually exposed or definitely located are represented by solid 
lines ; indefinite boundaries by dotted lines. The dotted lines in the sections 
indicate the unexposed surfaces of bed rock. 


454.  Loughlin—Intrusive Granites and Associated 


are excellent exposures of granite apophyses following and 
cutting across the foliation of the schist. The apophyses are 
medium-grained to pegmatitic, slightly to highly muscovitic, 
and of red to white color. The white color is more pr onounced 
in the more highly muscovitic rock. The pegmatitic and 
muscovitic characters are best developed in the large dikes 
(fig. 2), which cut approximately at right angles to the 
foliation of the schists. These dikes, or large apophyses, are 
exposed at intervals along Tower Hill towards Bridgetown. 
' Excavations in a oraphitic bed of the schist, between one 
and two miles south of Bridgetown, have exposed pegmatite 
dikes and associated quartz veins. The graphitic rock is also 
cut by small, branching, fibrous veins composed chiefly of 
sillimanite, quartz, and muscovite. ‘These veins are believed 
to be genetically associated with the pegmatite, but no careful 
study has yet been given them in connection with the problem 
under discussion. 

Similar, and even more convincing, evidence is found along 
the shore of the Bay from Little Neck northward to Hazzard’s 
quarry. The muscovitic granite with schist inclusions is the 
prevailing rock on Little and Boston Necks. It is increasingly 
muscovitic and pegmatitic as the contact with the schists is 
approached. At Watson’s Pier schist, cut by many large 
dikes of the granite and pegmatite, is the prevailing rock. 
Large pegmatite dikes are numerous along the coast as far 
as the north end of the Bonnet, and outcrop at intervals as far 
north as Saunderstown. From this point northward, pegma- 
tite dikes are scarce, and the northernmost exposure seen is at 
Hazard’s quarry. Here is a small dike consisting chiefly of 
quartz with a little feldspar and practically no mica. A few 
quartz veins with rare feldspar crystals, exposed near the 
summit of Barber’s Heights, are the northernmost pegmatitic 
exposures found. The evidence in the Kingstown area, there- 
fore, appears conclusive that the granites bordering the meta- 
morphosed Narragansett Basin sediments are members of the 
Sterling batholith and are intrusive into the schists. Petro- 
graphic study proves that the pegmatite dikes on Tower Hill 
and along the shore of the Bay are not independent intrusions, 
but apophyses from Sterling batholith, tending to grade into 
quartz veins as the distance from the batholith increases. 
Evidence in the whole area studied has proved that the gran- 
ites of southwest Rhode Island, south of the Washington Co.— — 
Kent Co. boundary (fig. 1) are not of pre-Cambrian age as 
previously supposed, but belong to the Sterling batholith, the 
youngest formation (including the Westerly granite dikes) of 
the area. 

Time of Intrusion.—The details of metamorphism in the 


Metamorphic Sediments in Southwestern Fhode Island. 455 


Kingstown area have not been exhaustively studied, but it is 
very evident, from the field work done, that vertical dips and 
the most complete recrystallization of the sediments are found 
where granitic intrusions are most abundant. There seems, 
then, no reason for doubting that in. the Kingstown area, as 
well as in southeastern Connecticut, the granite intrusion 
accompanied metamorphism and folding. As the Kingstown 
sediments have been determined to be of Carboniferous age,* 
the time of granite intrusion and folding may be correlated 
with the Appalachian Revolution. 

The Kingstown Sediments—As the Kingstown sediments 
have heretofore been regarded as resting uncomformably upon 
the granite, a study of their composition is necessary for a 
complete solution of the problem here considered, and as a 
check on the conclusions already reached. Detailed descrip- 
tions of outcrops have been made by Foerste,+ and only petro- 
graphic evidence is considered here. 

The sediments comprise chiefly an alternating series of light 
to dark gray arkose, conglomerate and phyllite beds, with at 
least one highly graphitic bed. Metamorphism effects are 
everywhere distinct, varying from moderate around Hamilton, 
the northernmost point studied, to extreme in close proximity 
to granite contacts. In the latter case traces of clastic struc- 
ture are nearly, or quite, obliterated, and the rocks are typical 
gray gneisses and schists, penetrated by the reddish granite. 

The pebbles of the less metamorphosed conglomerate com- 
prise quartzite, quartz-sericite schist, black very fine-grained 
slaty schist, vein-quartz, felsite-porphyry, a fine even-grained 
granite. The granite pebbles, which do not resemble the 
Sterling or Westerly granite, will be separately described below, 
In the highly metamorphosed conglomerate, the pebbles appear 
as flattened lenses and even linear streaks. Only the less 
severely mashed are clearly recognizable. The arkose and the 
matrix of conglomerate consist of quartz, feldspar, biotite, and 
muscovite in varying amounts. The most metamorphosed expo- 
sures present the same general megascopic characters and_varia- 
tions as the quartz-biotite schist of southeastern Connecticut. 
Thin sections prove the feldspars to be mostly plagioclase with 
a few of poorly defined microperthite and, possibly, of ortho- 
clase. Nota feldspar grain was noted with the well-developed 
microcline twinning so characteristic of the feldspar in the 
Sterling and Westerly granite, save in the one instance, 14 
miles south of Narragansett Pier, of a schist inclusion which 
is thoroughly injected with dikelets and stringers from the 
granite. 


* Mon, X<XXLIL U.S. G. S., plate xxxt. 
+ Op. cit., pp. 215 et seq. 


456 Loughlin—Granites and Metamorphic Sediments. 


Granite Pebbles.—The granite pebbles in the conglomerate 
are light gray to pink, fine even-grained to sub-porphyritie, 
and consist of finely intergrown quartz and feldspar with a lit- 
tle biotite and muscovite. Three thin sections were studied; 
one of a pebble from an outcrop 1$ miles west of Wickford 
Junction (fig. 1), one from an outcrop + mile southeast of 
Hamilton, and one from a bowlder south of McSparren Hill. 
The three thin sections present the same characters. The tex- 
ture is conspicuously micrographic. ‘The primary minerals are 
plagioclase and microperthite in about equal amounts, quartz, 
biotite, and the usual minor accessories; the chief secondary 
minerals are muscovite, replacing feldspars, and chlorite replac- 
ing biotite. The microperthite is the same type as that noted 
in the arkose and conglomerate matrix. The plagioclase mostly 
corresponds to oligoclase-andesine, though some grains appear 
more basic. These characters suffice to point out the decided 
lack of resemblance to the Sterling granite. 

Derwation and Correlation of the Kingstown Sediments.— 
The composition of the Kingstown sediments thus verifies the 
conclusions already stated, and no evidence whatever remains 
to indicate that the Sterling granite is not the younger rock. 
The Kingstown sediments were derived from a series of quartz- 
ites and black slaty schists, felsite-porphyry, and igneous rocks 
containing considerable plagioclase. The plagioclase may come 
wholly or in part from the fine-grained granite and possibly in 
part from more basic igneous rocks, no pebbles of which have 
yet been found. None of these rocks are found within the area 
studied, but they may be represented in the Cambrian forma- 
tions and the granite-porphyries to the north.* 

The general similarity in mineral composition between the 
Kingstown sediments and the quartz-biotite schists of the south- 
eastern Connecticut and the Westerly—Niantic, Rh. 1., districts 
favors the correlation of these rocks as parts of one extensive 
formation. Fossil evidence in the areas studied is wholly lack- 
ing, but structural and petrographic evidence favors this provi- 
sional conclusion. 


Summary. 


The principal conclusions reached in this paper are as follows: 

1. The Westerly granite is closely related to the Sterling 
granite in general character and mineral composition, and is 
considered the latest exposed phase of the Sterling batholith. 

2. The Sterling granite batholith is continuous from east- 
ern Connecticut to Narragansett Bay, R. I., and ineludes 
granite formerly thought to be pre-Cambrian. There are no 


* Emerson and Perry, op. cit., pl. 1. 


Chemistry. 457 


pre-Cambrian rocks in Rhode Island south of the Washington 
Co.-Kent Co. boundary. 

3. The Sterling granite batholith is intrusive into all the 
sediments with which it is in contact, including the Kingstown 
sediments of the Narragansett Basin, and its intrusion accom- 
panied metamorphism and folding. 

4. Since the Kingstown sediments are said to be of Car- 
boniferous age, the time of the granite intrusion, metamorph- 
ism and folding may be correlated with that of the Appala- 
chian Revolution. 

5. The Kingstown series were derived principally from 
metamorphic rocks of possible Cambrian age, from felsite- 
porphyry, fine-grained micrographic granite, and possibly more 
basic igneous rocks. 

6. In the absence of fossil evidence, structural and petro- 
graphic data favor provisional correlation of the Kingstown 
sediments with the quartz-biotite schists found in southeastern 
Connecticut and at Westerly and Niantic, R. I. 


Massachusetts Institute of Technology. 


SCIENTIFIC INTELLIGENCE. 


I. CHEMISTRY 


1. Metallic Zirconium.—W x1ss and NEUMANN have succeeded 
in preparing fused zirconium in a pure condition. The metal 
has been previously known only as an impure powder, or con- 
taining much carbon when fused. This difficult operation was 
performed, after many failures, by compressing the powder into 
pencils and passing an electric arc from the end of one pencil to 
another, either in a vacuum furnace containing hydrogen under 
very low pressure, or in the same apparatus containing an atmos- 
phere of nitrogen or ammonia. The upper pencil, forming the 
positive pole, was fused and the metal dropped upon the lower 
electrode, forming a stalagmite-like mass which was sometimes 3 
or 4" in diameter and 2 or 3° high. The light produced at the 
melting point was so intense that the eyes had to be protected by 
very dark glasses when the operation was watched through the 
window of the apparatus. The fused zirconium was somewhat 
tarnished, but the fracture was white and metallic like cast iron. 

t was slightly harder than quartz, and decidedly less hard than 
Moissan’s product containing carbon. It was very brittle, with 
a specific gravity of 6-400. The specific heat was found to be 
0°0804, a value considerably higher than any previous determi- 


458 Scientific Intelligence. 


nation and giving an abnormal atomic heat, 7°316. It burns in 
air, and the average heat of combustion was found to be 1958°7 
cal.—Zeitschr. anorgan. Chem., \xv, 248. H. L. W. 

2. The Gas-volumetrie Determination of Hydrogen.—Hereto- 
fore no liquid reagent has been known for the absorption of 
hydrogen in gas analysis, but Paar and Harrmann have found 
such a reagent which can be used with accuracy in technical gas 
analysis, and which can be employed also for removing hydrogen 
from certain gases in preparative work. The reagent is a solu- 
tion of colloidal palladium and sodium picrate. The metallic 
palladium first absorbs the hydrogen, then immediately acts as a 
- catalytic agent by transferring the hydrogen to the sodium 
picrate and reducing the latter to triamidophenol : 


C,H,(NO,),0H + 18H=C,H,(NH,),OH + 6H,0. 


The absorption requires a little time, depending upon the amount 
of palladium present in the liquid. Experiments with various 
mixtures showed that accurate results could be obtained by the 
method. Since the reagent effects the combination of hydrogen 
with oxygen if both are present, and as it also causes the combi- 
nation of hydrogen with unsaturated hydrocarbons, the procedure ~ 
required in ordinary gas analysis is the application of the reagent 
after the carbon dioxide, unsaturated hydrocarbons, oxygen and 
carbon monoxide have been removed by the usual methods.— 
Berichte, xliv, 243. H. Ic We 

3. Theoretical Principles of the Methods of Analytical Chem- 
istry ; by M. G. CHESNEAU, translated by A. T. Lincoln and D. H. 
Carnahan. 8vo, pp. 184. New York, 1910 (The Macmillan 
Company).—In its general object this book is similar to Ost- 
wald’s well-known work on the subject, but instead of advocating 
the theory of ions, the present author employs what he calls a cal- 
orimetric method for explaining certain reactions. He admits 
that Ostwald’s plan is certainly more attractive @ priorz than the 
calorimetric method, but he objects to the electrolytic theory, and 
gives an extensive discussion of the objections, based chiefly on 
the work of Kahlenberg. ‘Teachers of analytical chemistry, as 
well as advanced students, will doubtless find much that is sug- 
gestive and interesting in the book, particularly if they prefer 
the mathematical form of discussion. H. Li, W: 

4, Analyse Volumétrique ; par Louis Duparc et Mario Basa- 
DONNA. 8vo, pp. 170. Geneva and Paris, 1910 (Kiindig, Geneva; 
Felix Alcan, Paris).—This theoretical and practical manual of 
volumetric analysis has been prepared particularly for the pur- 
poses of laboratory instruction, but it is intended to be useful 
also to the practical analyst. It contains concise and clear 
descriptions of many of the best known and most frequently em- 
ployed methods, including a number of special technical processes. 
Although it is not an exhaustive treatise on volumetric analysis, 
it will be found useful and suggestive in regard to some of the 
methods described. It has the fault of many French books in 


Geology. 459 


lacking an alphabetical index, and since the subject matter is 
arranged according to general methods, and not according to the 
elements to be determined, it is not a convenient book for refer- 
ence. H. L. W. 

5. Solid Bitumens, by 8. F. Peckuam. 8vo, pp. 317. New 
York and Chicago, 1909 (The Myron C. Clark Publishing Co.). 
—This book is a treatise on the natural history, chemistry, phys- 
ical properties, and technology of natural bitumens or asphalts. ° 
The author’s extensive personal experience has been of much 
service in the preparation of the work, and much material from 
other sources is included. The uses of the solid forms of bitumen 
in the construction of pavements are very thoroughly discussed, 
and there is an interesting chapter on the oiled roads and streets 
of the Pacific Coast. He oi) We 


Il. Gronoey. 


1. Lowa Geological Survey ; SamuEt Carvin, State Geolo- 
gist; James H. Less, Assistant State Geologist. Vol. XIX, 
Annual Report for 1908, with accompanying papers. Pp. xii 
and 779, ills. 117.—The original coal supply of Iowa is estimated 
at 29,160,000,000 tons ; 141,608,792 tons have been mined up to 
and including 1908, which indicates that at the present rate of 
production the Iowa supply will last for 2550 years. The 
importance of the coal industry in Lowa justifies the publication 
of a number of papers dealing especially with this subject. 

The first report by Henry Hinds on “The Coal Deposits of 
Iowa” (pp. 25-391) gives detailed descriptions of the geological 
relations, mode of occurrence of the lowa coals and the present 
state of development of the coal industry for each township and 
district in the state. The Fuel Value of Iowa coal is discussed 
by Frank A. Wilder (pp. 401-497) and includes analyses by 
James H. Lees and A. W. Hixson, in which are given the results 
of the fuel tests at the plant established at St. Louis by the 
United States Geological Survey. The History of Coal Mining 
in lowa by James H. Lees (pp. 521-597) is an interesting 
account of the successes and failures in coal mining from 1840 to 
1908. 

The chapter on the Carboniferous Section of Southwestern 
Iowa by George L. Smith (pp. 605-657) deals largely with the 
stratigraphy of the Missouri stage, and in this same report S. W. 
Beyer discusses the origin, distribution and commercial value of 
peat deposits in Iowa (pp. 693-725), and L. H. Pammell describes 
the flora of the northern Iowa peat bogs (pp. 729-776). 

He Ke G. 

2. West Virginia Geological Survey ;. I. C. Wurre, State 
Geologist. County Reports and Maps, 1909. Marshal, Wetzel 
and Tyler Counties, by Ray V. Hennen, Assistant Geologist. 
Pp. xvi and 654, maps 3, plates xii, figures 3.—This second vol- 


460 Scientifie Intelligence. 


ume of the series dealing with individual counties has been pre- 
pared in accordance with the plan announced some years ago of 
furnishing reports dealing with various parts of the state, the 
plan being to include in one volume all the important geological 
matter pertaining to a given section. 

From an economic standpoint, little criticism can be made of 
these reports since they discuss not only coal, gas, oil, building 

estone and clay, but also soils ; but as general reading books deal- 
ing with the geology of the section, they are not so satisfactory. 
It is a legitimate part of the work of a State Survey to publish 
the results of geologic research in a form which may be of use to 
schools and to the average intelligent man. The publications of 
the Wisconsin, the Illinois and the Connecticut Surveys indicate 
how this may be done. 

The maps published with this volume are especially good, and 
the idea of combining the county maps into one map for the 
whole district is to be commended. Hy HG: 

3. New Zealand Geological Survey ; J. M. Betz, Director. 
Bulletin No. 8 (New Series). The Geology of the Whangaroa 
Subdivision, Hokianga Division, by J. M. Betz and E. DEC. 
CLARKE. Pp. v and 107, illustrations xvii, maps 8, geological 
sections 4.—Little geological work has previously been done in 
the area covered. by this report, the northern edge of Auckland 
Island, although this part of New Zealand contained one of the 
earliest settlements and is widely known as a producer of kauri 
gum, which next to gold has contributed most to New Zealand 
revenues. 

The rocks of this area include pre-Cretaceous, argillites, quartz- 
ites, and igneous rock; late Mesozoic and early Tertiary, the 
Kaeo series of sedimentaries ; Miocene, the Wairakau breccias, 
dikes and flows; Miocene or post-Miocene, Kerikeri flows and 
underlying sediments ; post-Miocene lake beds, acid and basic 
volcanics. Since the deposition of the Wairakau series tectonic 
movements include little folding but extensive faulting. The 
surface as a whole is a faulted tableland deeply dissected and 
with volcanic cones rising above the level. The shore line is that 
of a typical depressed land surface. There are evidences of base- 
leveling on the surface of the Kaeo rock and renewed peneplana- 
tion occurred between Wairakau times and the extrusion of the 
Kerikeri volcanics. Rock benches are developed along the shore 
line, but they are believed not to represent planes of marine ero- 
sion, but rather to be due to the cooperation of subaérial weathering 
and marine transport. The freshwater lakes occupy basins due 
to damming by lava flows or explosion craters. 

Chapters 4 and 5 of this report (pp. 41-79) are devoted to 
detailed descriptions of the stratified rocks with their fossils and 
the igneous rocks, including a number of analyses. In the chap- 
ter on economic geology (pp. 80-98), an interesting account is 
given of the occurrence of mercury, which seems to be directly 
associated with hot springs, as in the case of certain Nevada and 
California deposits, discussed by G. F. Becker. H. E.G 


Geology. 461 


4. Certain Jurassic (Lias-Oolite) Strata of South Dorset ; 
and their Correlation; Certain Jurassic (“ Inferior Oolite’’) 
Species of Ammonites and Brachiopoda; by 8. 8. Buckman. 
Quart. Jour. Geol. Soc., London, Ixvi, No. 261, February 1910, 
pp. 52-108, pls. ix-x1i—The author describes here in detail 
certain strata of the Jurassic of the Dorset coast and compares 
them with similar strata inland. 

American geologists often doubt the ability of paleontologists 
to make correlations of zones having thicknesses from 10 to 50 
feet, but Buckman here makes correlations of zones but a few 
inches in thickness! He states : 

“The Inferior Oolite rocks are so remarkably prolific in species 
of Mollusca and Molluscoids—there is so great a number of 
species yet awaiting description—that there seems to be an idea 
among those who have not studied the rocks in the field, that 
they receive a kind of preferential treatment in this respect. 
Another explanation may be suggested—that our judgment as to 
the time occupied in the forming of the so-called ‘Inferior 
Oolite’ strata is warped owing to their tenuity—that they repre- 
sent a time during which destruction of strata was particularly 
active, therefore the remaining deposits are only the fragmentary 
representatives of a whole. 

“This is particularly the case in Dorset. A schoolboy once 
defined a net as a series of holes strung together, and the Dorset 
Inferior Oolite might be defined as a series of gaps united by 
thin bands of deposit. And one reason for the prolificness of 
the deposits is that the amount of deposit can be no indication of 
the amount of time, as shown by the changes in successive 
faunas ; and also that the deposits are so local—the deposits of 
one place correspond to the gaps of another. Therefore many 
localities have to be placed together to produce the full tale of 
the Inferior Oolite. The very local distribution of Inferior 
Oolite species often means that strata of particular dates have 
only been preserved in a few favoured localities. 

“The beds of the ‘ Inferior Oolite,’ in a restricted sense, have 
now been divided as deposits of about twenty-two successive 
dates or hemere. ‘The total for the whole of the Jurassic would 
not be more than about eighty-five, or perhaps, on an extended 
scale, a hundred hemere. ‘Therefore, according to this reckon- 
ing, the few feet of Inferior Oolite represent from about a 
quarter to a fifth of the total time occupied in the deposition of 
the entire Jurassic System. | 

“One can hardly view the few feet of Inferior Oolite lime- 
stone at Burton Bradstock, about 15 to 20 feet say, and imagine 
that it represents an interval of time equal to a quarter or a fifth 
of the whole Jurassic Period—a time during which thousands of 
feet of strata were laid down. But this is because we do not 
allow sufficiently for the gaps. 

“Tf anything like this supposition be correct, then the Inferior 
Oolite prolificness is understandable; it should represent in 


462 Screntific Intelligence. 


species as many as would form from a quarter to a fifth of the 
total for the Jurassic System. At that rate, its tale is nothing 
like complete yet ; which all workers in its rocks know to be the 
case.” (90-91.) | 

“The strata described are classified according to what may be 
called the multizonal or polyhemeral system—in the main, accord- 
ing to the scheme introduced for these strata in 1893 (Quart. 
Jour. Geol. Soc., vol. xlix, p. 481) ; but further divisions due to 
other investigators and to myself are dealt with. 

“The strata described are arranged among thirty-six zonal 
(hemeral) divisions—a greater number of divisions than Oppel 
used in 1856 for all the Jurassic rocks, of which these beds form 
but a small part. 

“The Upper Lias’part of the Junction Bed of Down Cliffs, 
Chideock (Lower or pre-strzatulus Toarcian), is a very condensed, 
imperfect epitome in 20 inches of about 180 feet of strata on the 
Yorkshire coast, and of very much more when allowing for gaps. 

“Between the bzfrons layer and the striatulus layer of the 
Junction Bed there is occasionally a 2-inch layer which is all that 
represents some 250 feet of deposit in the Cotteswolds—so that 
about two feet of Junction Bed was formed while a thickness of 
some 550 feet was being deposited elsewhere.” (89.) 

“The President (Prof. Sollas) congratulated the author on the 
very interesting manner in which he had presented a highly 
technical subject. The correlation of thin seams with thick 
deposits was a matter of great importance, and called to mind 
Suess’s remarks on the partings in the Trias. It might afford 
some hints as to the order of magnitude of the scale of time. If 
we assumed that one foot of sediment might accumulate in a 
century, in an area of maximum deposition, then in the case of the 
seam two inches thick which was represented by 250 feet in the 
Cotteswolds, the rate of formation would be less probably than 
one foot in 150,000 years. 

“The Author, in reply, remarked that Jurassic zones were 
by no means the result of local observation only ; they had been 
followed widely, even the new ones ; the thinness of zones was 
no test of their importance or otherwise, being often only a local 
accident of alternating deposition and denudation. The net 
increase of deposit must have been much less than one foot in 
a century, as this seemed too rapid for the faunal changes in- 
volved.” (109, 110.) C. 8. 

5. Palwontologia Universalis, ser. II, fasc. IV, 1910.—This 
fasciculus contains 71 sheets redescribing 35 species of fossil 
echinoderma and mollusca, and completes the second series hav- 
ing 169 sheets. The entire set may be had for $8.00 of G. EK. 
Stechert, 9 East 16th St., New York City. ens: 

6. Geologic Atlus of the United States. Folio 169, Watkins 
Glen—Catatonk, New York, 1909; by H. S. Witiiams, R. S. 
Tarr, and EK. M. Kinprz.—The topography and the Quaternary 
deposits are described in detail by Tarr, the Upper Devonian 


Miscellaneous Intelligence. : 463 


stratigraphy by Williams and the igneous rocks and historical 
geology by Kindle. The interfingering of the western Portage 
faunas into the eastern Hamilton-Chemung biotas is clearly de- 
scribed and is of much interest to stratigraphers. C18. 

7. Geology of the Auburn—Genoa Quadrangles ; by D. D. 
LuTHer. Bulletin 137 N. Y. State Museum, 1910, 36 pages and 
geologic map.—An excellent description of the areal geology of 
the region of Cayuga and Owasco lakes. The formations range 
from the upper part of the Silurian to the close of the Devonian. 

CLs. 


Til. Muscentantous Screntiric INTELLIGENCE. 


1. National Academy of Sciences.—The annual Spring meet- 
ing of the National Academy was held at Washington on April 
19 to 21 ; some forty members were in attendance. 

The following new members were elected : Douglas H. Camp- 
bell, Professor of Botany in Stanford University ; John Dewey, 
Professor of Philosophy in Columbia University ; Jacques Loeb, 
Professor of Physiology in the University of California; Forest 
R. Moulton, Professor of Mathematics in the University of 
Chicago ; William A. Noyes, Professor of Chemistry in the Uni- 
versity of Illinois ; Thomas B. Osborne, Chemist of the Connecti- 
cut Agricultural Experiment Station ; Charles Schuchert, Professor 
of Paleontology in Yale University. Professor Giovanni Schia- 
parelli, the astronomer, of Milan, Italy, was elected foreign 
associate. 

The list of papers presented at the meeting is as follows: 


EK. C. Pickrerine : The 16-inch Metcalf doublet. 

GrEorGE E. Hate: Solar magnetism. Some visual and photographic 
observations of Mars. 

WILLIAM TRELEASE: The distribution of Agave in the West Indies. 

JoumM M. CovuLter: The vascular plate and cotyledons of Gymnosperms. 

F. E. NrpHER: Some crucial experiments demonstrating the necessity of 
accepting the one-fluid theory in electricity. 

W. J. Humpureys: A probable indirect relation between solar disturb- 
ance and terrestrial temperatures. 

EK. A. HARRINGTON: Quantitative studies of tuning forks. 

S. W. Stratron: The Bureau of Standards. 

ARTHUR L. Day: The determination of temperature constants in mineral 
formations. 

J. M. Crarts: A new form of gas thermometer and the boiling points of 
water and naphthalene. 

H. N. Morse: The temperature coefficient of osmotic pressure. 

H. L. Aspotr: Hydraulics of the Chagres river. 

C. D. Watcotr: The development of Olenellus. 

E. W. Hinearp: A new development of mudlump activity at the mouth 
of the Mississippi river. 

H. F. Ossorn: The correlation of the Pleistocene of Europe and North 
America. The epidermal covering of the trachodont Dinosaurs. Biograph- 
ical memoir of Joseph Leidy. 

W. B. Scorr: Report of progress in the study of the Miocene Ungulates of 
Patagonia. 

J. M. CuarKkeE: The austral Devonian. 


/ 
| 


464 Scientific Intelligence. 


W. M. Davis: Quandaries following from the theory of isostacy. 

R. B. DoLE: Composition of American river waters. 

F. W. Cuarke: A preliminary study of chemical denudation. 

GrEoRGE F. Becker: Denudation evidence in relation to the age of the 
Earth. 

Franz Boas: The influence of environment on human types. 

A. G. WexssTeR: A new method for the study of elastic hysteresis. 

A. A. Noyres: The ionization relations of poly-ionie salts. 

THEODORE GILL: The structural characteristics and relations of the Apo- 
dals. Recent discoveries of the early history of the common eel. 

Ira REMSEN : Some studies in molecular rearrangement. 

R. G. Airken: The number of double stars as a function of the separation 
of the component. 

W. W. Camppe cn and Sepastian ALBRECHT: On the spectrum of Mars as 
photographed with high dispersion. 

W. W. CAMPBELL : ‘Second catalogue of spectroscopic binary stars. 


2. Ostwald’s Klassiker der Hxakten Wissenschaften. Leipzig, 
1909 (Wilhelm Engelmann).—The following are the latest addi- 
tions to the valuable series of scientific classics : 

Nr. 171. Uber unendliche Reihen (1689-1704) ; von JaKos 
Bernovutii. Aus dem Lateinischen tibersetzt und herausgegeben 
von Dr. G. KowaLEewski. Pp. 141, with 12 figures. 

Nr. 172. Abhandlungen Jean Rey’s, Doktors der Medizin. 
Uber die Ursache der Gewichtszunahme von Zinn und Blei beim 
Verkalken. Deutsch herausgegeben und mit Ammerkungen 
versehen von Ernst IcHENHAUSER und Max Sprter. Pp. 56, 
with 2 figures. 

Nr. 173. Untersuchungen tiber die Affinititen tiber Bildung 
und Zersetzung der Ather; von BrrtHEeLtot und L. Pav DE 
Satnt-Gittes. Annales de Chimie et de Physique (3), Ixy, p. 
385 ; Ixvi, p. 5; Ixviil, p. 225. Ubersetzt und herausgegeben 
yon Marearers und Apert LapENBURG. Pp. 242, with 2 
tables. 

Ektropismus oder die Physikalische Theorie des Lebens ; von FELIX AUER- 
BACH. Pp. iv, 99. Leipzig (Wilhelm Engelmann), 1910. 


OBITUARY. 


Proressor ALEXANDER Acassiz of Harvard University, Cam- 
bridge, Mass., died on March 27, in the seventy-fifth year of his 
age; a notice is deferred until a later number. 

Proressor Rosert Parr WHITFIELD, curator in the American 
Museum of Natural History, New York, died on April 6, in his 
eighty-second year ; a notice will be published later. 

Dr. Cranes Ret Barnes, Professor of Plant Physiology in 
the University of Chicago, died on February 24, at the age of 
fifty-one years. 

ProFresson SAMUEL Warp Lopsr, curator of the museum of 
Wesleyan University, died in March, in his seventy-fifth year. 
While he published little in geology, he did much to further pale- 
ontology in making extensive collections of fishes and plants from 
the Connecticut Triassic and in the older Paleozoic formations of 
Texas, Wyoming, and Nova Scotia. 


Dr. Cyrus Adler, 


Librarian U. S. Nat. Museum. 


el JUNE, 1910. 


* 


THE 


AMERICAN 
JOURNAL OF SCIENCE. | 


Epirorn: EDWARD S. DANA. 


Established // ‘Established by BENJAMIN SILLIMAN in 1818, BENJAMIN SILLIMAN in 1818. 
| 


ASSOUIATE EDITORS 


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


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


Proressor HENRY S. WILLIAMS, or Iruaoa, 
Proressor JOSEPH S. AMES, or Batrrore, 
Mr. J. S. DILLER, or Wasuineron. 


FOURTH SERIES 
' VOL. XXIX—[WHOLE NUMBER, CLXXIX.] 


No. 174—JUNE, 1910. 


WITH PLATES II-V. 


NEW HAVEN, CONNECTICUT. 


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sonian Mn tit, tug, 


Published monthly, Six dollars per year, in advance. 86.40 to ae es th 
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registered letters, or bank checks (preferabl y on New York banks). 


fl ala is. 7 
“onal Muse0™~ 


—— 


NEW ARRIVALS. 


I have just received a small consignment of very fine Cerussites in beauti- 
ful combination with bright crystals of yellow Wulfenite on Fluorite, from 
a new locality in Arizona. The prices range from $1.00 to $3.50. 

A remarkable consignment has also just arrived from Europe. Its 
quality both as to locality and varieties is unlimited. In fact, it really 
covers the whole of the Old World. On account of lack of space no further 
description can be given. Write for particulars. 


OLD COLLECTION. 


This was announced in the May number, and I now have almost half of 
this great collection unpacked and arranged on shelves ready for inspection 
and sale. 

Most of these choice specimens are finely crystallized, and represent years 
of labor in collecting by an old-time mineralogist. 

This collection practically covers the whcle Dana System, and I feel that 
I can fully satisfy the requests of my patrons for choice specimens. I 
would therefore advise any who desire to fill the gaps in their collections 
to send me a list of their wants and I will send them full details of the 
specimens which I can supply. This is a fine opportunity for collecters to 
secure old finds which are not otherwise procurable. Send in all your orders 
early, therefore, to avoid disappointment, as my rule is to serve those who 
come first. | : 


I have on hand several lots of Cripple Creek Tellurides such as Sylvanite, 
Calaverite and Krennerite; Gold Pseudomorph after Calaverite; Tellurium, 
mostly showing good erystals ; also some Amethyst specimens, showing 
parallel growth, and of good color; Calciovolborthite crystallized ; and 
Carnotite in fine yellow masses. 


ARE YOU INTERESTED IN GEMS ? 


If so, you will find my stock now richer than ever before in beautiful 
examples suitable both for jewelry and specimens. Among the recon-— 
structed gems in my stock, all of which are of the finest quality, I will 
mention the following : 

Rubies ; blue, pink, white and oe ca es; and an unusually large 
stock of common and rare Semi-Precious and Precious Stones, both cut 
and in the rough ; and I am able to supply any gem desired, in best quality 
and all sizes. 


Any of the above which may be desired for selection I shall be glad to 
send on approval to patrons and customers. Information and prices of 
individual specimens cheerfully furnished upon request. 


81—83 Fulton Street, New York City. 


fasta 


AMERICAN JOURNAL OF SCIENCE 


[FOURTH SERIES. |] 


Cd 


Art, XLIL—An Laxperimental Doves en into the Flow 
of Rocks, by Frank D. Adams, assisted by Ernest G. 
Coker. First Paper— The Flow of Marble. (With Plates 
II-IV.) 


CONTENTS. 


Introduction. 


Factors in Rock Flow. 
Results obtained in former investigation. 
Aims of present study. 
Methods Employed. 
The Flow of Marble. 
1. Deformation of the dry rock at ordinary temperatures. 
(a) At comparatively low pressures. Structure of the 
deformed marble. 
(6) At very high pressures. Structure of the deformed 
marble. 
(c) Strength of the marble after deformation. 
(d) Influence of rest and of heat on the strength of the 
deformed marble. 
2. Deformation of the dry rock when at temperatures of 300° C. 
and 400° C. 
(a) Strength of the marble after deformation. 
3. Deformation of the rock at temperature of 300° C. in the 
presence of water. 
(a) Strength of the marble after deformation. 
4. Specific Bravatyo! of the rock after deformation. 


Conclusions. 
Introduction. 


Tuat the rocks of the earth’s crust, under the stresses to 
which they are subjected, have been bent and twisted in the 
most complicated manner is a fact which was realized by the 
earlier geologists, and it needs but a glance at an accurate geo- 
logical section through any highly contorted district of the 
earth’s crust to see that during the folding of the rocks there 

Am. Jour. Sc1:—FourtH Series, Vout. XXIX, No. 174.—Jonz, 1910. 


3 


466 Adams & Coker—Investigation into the Flow of Rocks. 


has often been a marked transfer or “ flow” of material from 
one place to another within the fold. 

While, however, these facts are undisputed, the precise 
nature of this folding and flowing has been a subject concern- 
ing which there has been much discussion and a wide diver- 
gence of opinion. 

Some authorities—among whom Heim,* whose work in the 
Alps must command the admiration of all, may be mentioned 
—have held that while in the upper portions of the earth's 
crust, rocks when submitted to pressure will break, giving rise 
to faults and overthrusts—the same rocks in the deeper por- 
tions of the earth’s crust are unable to break up in this way, 
owing to the great weight of the superincumbent strata. The 
lines of fracture they hold in this case become smaller and 
greatly increase in number, the various minerals constituting 
the rock thus breaking down into grains, which, however, 
move around and past one another, the adjacent. grains always 
remaining within the sphere of mutual cohesion. The struc- 
ture of the rock thus becomes cataclastic ; but the rock mass, 
while acting as a plastic body and flowing in the direction of 
least resistance, maintains its coherence while altering its shape. 

Now according to Spring,t the property known as regela- 
tion is really due to a power which fragments of bodies have 
of uniting if brought within the range of the molecular forces, 
a property which, although possessed in a marked manner by 
ice, is also, as he has experimentally demonstrated, exhibited 
by many other bodies and would probably be displayed by all 
if the required conditions could be attained. The “ flow of 
rocks ” would, therefore, according to Heim’s view, be a mani- 
festation of regelation on an enormous scale. 

Other writers on this subject have maintained that rocks are 
absolutely destitute of plasticity in any proper sense of the 
term. Pfafft has even held that in the depths of the earth 
great pressure will tend rather to prevent molecular move- 
ment and thus keep the rocks rigid. Those holding such 
views attribute the deformation of rocks either to crushing 
with subsequent recementation of the fragments by mineral 
matter deposited from percolating waters as the movements 
proceed or after they are completed,$ or to a continuous 
process of solution and redeposition of the minerals which 

* Der Mechanismus der Gebirgsbildung, p. 31, 1878; see also Van Hise, C. 


R., Metamorphism of Rocks and Rock Flowage, Bull. Geol. Soc. of America, - 
vol: ix; 1898: 

+ Recherches sur la propriété que possédent les corps de se souder sous 
Vaction de la pression ; Revue Universelle des Mines, 1880. 

t Der Mechanismus der Gebirgsbildung, pp. 19-21. 

S Stapff, Zur Mechanik der Schichtenfaltungen, Neues Jahrbuch fir 
Mineralogie, 1879, p. 792; Reyer, Theoretische Geologie, p. 448. 


Adams & Coker—The Flow of Marble. 467 


make up the rock. The percolating waters, it is held, tend to 


dissolve material at those points where the pressure is greatest, 
and to redeposit it where the pressure is wholly or partially 
relieved ; the movements thus being accompanied by a more 
or less complete recrystallization of the whole rock. Moisture 
would thus bea necessary factor in all rock folding or contor- 
tion, and recrystallization the essential feature of the phe- 
nomenon. The deformation of a body of dry rock would be 
impossible. 

An experimental study* of the subject was undertaken 
some years since, the rock selected being Carrara marble. The 
investigation showed that in the case of this rock plastic 
deformation could be brought about by the action of pressure 
alone, that heat made the rock more plastic, and that under 
the conditions of the experiments, the presence of water 
exerted little or no influence in this respect. 

By this it is not meant to imply that when rocks are folded 
in the earth’s crust solution and redisposition do not play a 
very important role. These processes undoubtedly are at 
work and are widespread in their action. It is quite possible 
that they are the most important agencies in the folding and 
flow of rocks. , 

The experimental study showed, however, that the presence 
of water was not an essential factor in the development of 
flow, in the case of marble at least, and that under the experi- 
mental conditions, that is to say with the deformation carried out 
in days, weeks, or at most in a few months, instead of being 
extended over long periods measured by years or centuries, the 
deformation of the marble took place quite independent of 
solution. 

It showed furthermoretthat the structures displayed by highly 
contorted marbles in many parts of the earth’s crust are identi- 
eal with those produced under the experimental conditions and 
that they have been developed by the same agencies. 

As the subject seemed to be one worthy of further study, 
the work was continued under a grant from the Carnegie 
Institution of Washington, and as the investigation went 
forward it was found to be necessary to follow out several 
separate lines of research. 

The amount of cubic compression which rocks undergo 
when submitted to pressure from every side was first investi- 
gated, all rocks of course being subjected to such compression 
before deformation.t 

* Adams, F, D., and Nicolson, J. T.—An Experimental Investigation into 
the Flow of Marble; Phil. Trans. Royal Soc., London, Series A, vol. cxev, 
pp. 363-401. ’ 

+ Adams, Frank D., and Coker, Ernest G.—An Investigation into the Elas- 
tic Constants of Rocks, more especially with reference to Cubic Compresgsi- 


bility ; Publication of the Carnegie Institution of Washington, No. 46 
(Résumé in this Journal, Aug. 1906.) 


468 Adams & Coker—Investigation into the Flow of Rocks. 


A further study was then made of the “flow of marble” 
under widely varied conditions of pressure, temperature and 
time; after which the investigation was extended to a number 
of fine-gr ained and more or less impure limestones ; to er ystal- 
line dolomites ; and then to a series of typical plutonic intru- 
sives—diabase, essexite and granite. 

A series of comparative experiments were then made a the 
purpose of accurately measuring the loads required for the 
deformation of standard columns of these and other rocks 
under precisely identical conditions of differential pressure and 
extremely slow movement. 

In the present paper it is proposed to outline the methods 
employed in these investigations and to present the results 
obtained by the further study of the “Flow of Marble”; and 
in subsequent papers to set forth the results obtained i a the 
case of some of thé other and more resistant rocks. The 
results of the investigation as a whole when completed will 
appear, in extended form and fully illustrated, as a Publication 
of the Carnegie Institution of Washington. 


Methods Employed. 


in secking to ascertain experimentally the action of cee 
ential pressure on rocks with a view to reproducing more or 
less accurately the conditions of pressure which obtain in the 
deeper parts of the earth’s crust, it is manifestly quite useless 
to attempt to reproduce these conditions by simply submitting 
the rocks to compression in a testing machine, as is done in 
testing the strength of materials. There is cer tainly differen- 
tial pressure in this case, but it is merely the ordinary atmos- 
pheric pressure on the sides of the test-piece, while the 
tremendous pressure of the testing machine acts in the vertical 
direction. It is necessary to increase the lateral pressure and 
make it in some degree at least approach the measure of that 
exerted in a vertical direction if the pressure conditions of the 
deeper parts of the earth’s crust are to be reproduced. The 
material must be held in and supported laterally, so that it will 
not readily break or fracture as the vertical pressure is brought 
to bear upon it until at least the required conditions of differ- 
ential pressure have been secured. 

In the deformation of rocks within the earth’s crust the 
pressure element which corresponds to this lateral resistance is 
furnished by the great weight of overlying strata forming the 
upper portion of the earth’s crust, while the direct pressure 
exerted by the testing machine Tephesents the tangential thrust 
which folds them. 

To secure this lateral resistance, two methods have been: 
proposed. The first is that suggested many years ago by, 


Adams & Coker 


The Flow of Marble. 469 


Kick, in which a stout copper case is prepared within which 
the specimen is placed, the intervening space being filled by 
alum, sulphur or some other more or less plastic material, 
poured in when in a fused condition and which solidifies on 
cooling. (Fig. 1.). The whole is then submitted to the action of 
a powerful press and squeezed down. Upon the-completion of 
the experiment the embedding material is removed by heat or 
solution and the deformed specimen obtained. This method 
is easily carried out, but it has a number of defects. Thus, 
the experiments can be carried out only at the ordinary tem- 


Fie. 1. 


1 TEST PIECE 
EMBEDDING 
MATER/AL 


4-COPFPER TUGE 


BRASS PLATE 


CENTIMETERS 


perature of the laboratory ; the lateral resistance offered is not 
as great as is required in the case of the harder rocks, and it is 
furthermore impossible to determine the pressure to which the 
specimen has been subjected, seeing that the load has been 
divided between the box, the embedding material and the 
specimen itself. | : 

A series of experiments on the deformation of various 
minerals and rocks were, however, carried out by this method, 
the results of which are detailed in another paper.* 

The second method is that employed by Adams and Nicol- 
son in their investigations on the Flow of Marble. In this a 
column of the rock is very accurately turned or ground in a 
lathe and fitted into a heavy tube of steel which has been 
bored out with equal accuracy to receive it. Pistons of hard- 
ened chromium-tungsten steel are then inserted into the ends 
of the tube, the pressure being transmitted through them to 
the column enclosed in the steel. By this method a much 
greater lateral resistance can be secured, which makes it 
possible to carry out the deformation under much higher 

* Adams, F. D.—An Experimental Investigation into the action of Differ- 


ential Pressure on certain minerals and rocks employing the process sug- 
gested by Professor Kick ; Journal of Geol., 1910. 


470 Adams & Coker—Investigation into the Flow of Rocks. 


pressures. This resistance also may be varied as desired by 
altering the thickness of the walls of the enclosing tube, and 
the pressure under which the rock is being deformed can be 
accurately measured, seeing that the whole vertical pressure is 
brought to bear directly upon the specimen. The deforma- 
tion may, furthermore, be carried on at temperatures 
approaching even to incipient redness and, if required, in the 
presence of water or steam. 

The material employed in the construction of the enclosing 
tubes in our earler experiments was wrought iron or a mild 
carbon steel, but in all later work a steel containing 4°10 to 5:18 
per cent of nickel was employed. This steel has a considerably 
higher elastic limit than ordinary carbon steel, and our thanks 
are due to the Bethlehem Steel Company for several consign- 
ments of this steel which have been used in the investigation. 
For the construction of the pistons the chromium tungsten 
““Novo” steel was employed. This steel when heated to 
whiteness and plunged into fish oil develops extraordinary 
strength, a specimen having the dimensions of one of the pis- 
tons—namely °815 inch in diameter and 1°56 inch long—when 
tested in compression having sustained a load of 215,000 lbs., 
equivalent to 411,880 pounds per square inch, with practically 
no alteration of shape. The pistons of this steel may, further- 
more, be used under the great pressures employed at tempera- 
tures as high as 600° C. 

In order that the conditions of differential pressure may be 
satisfactorily developed, it is necessary to make that portion of 
the enclosing nickel-steel tube immediately surrounding the 
central portion of the rock column thinner than it is elsewhere, 
while leaving the portions of the tube about the ends of the 
column thicker. This concentrates the flow or deformation of 
the rock, giving a symmetrical bulge developed within the 
column and between its extreme ends, and prevents the enclos- 
ing tube from opening up under the pressure and permitting 
the rock to force itself up between the pistons and the ends of 
the steel tube. As the result of a long series of experiments, 
too numerous to detail here, it was found that a tube of the 
dimensions shown in the accompanying drawing (fig. 2) was the 
most suitable, the thickness of the wall immediately around the 
central part of the specimen being increased from 25 milli- 
meters to a centimeter according to the amount of lateral — 
pressure or resistance which it is desired to develop, all the 
other dimensions of the tube remaining thesame. The pistons 
at either end were inserted into heavy steel castings by which 
the load was transmitted from the press. 

The rock columns upon which the experiments were carried 
out were in most cases about 2° (°814 inch) in diameter and 


Adams & Coker—The Flow of Marble. 471 


about 4° (1°56 inch) long. In the earlier experiments the 
rock was first ground into rough columns 6™ long and 2-5" 
in diameter on a rubbing bed. Subsequently a small diamond 
drill was installed having a hollow bit, which proved an excel- 
lent device for readily securing a rough column of any rock 
which it was desired to use for experimental work. This was 
then cut into lengths and 
turned into columns of the 
required size in alathe. The 
final very accurate shaping 
of the columns was given to 
them by grinding with an 
emery or corundum wheel 
while in the lathe. In this 
way the little columns were 
turned to the desired shape 
with extreme accuracy. 
They were not as a general 
rule made exactly ecylindri- 
eal in shape, but in order to 
secure a very accurate fit 
were usually made slightly 
conical with a taper of 
1/1000 of an inch in their 
length. 

In the same way the steel 
tube was first turned in a 
lathe in the usual mauner, 
the inner surface was then 
ground to secure greater 
accuracy of shape, and the 
tube was finally finished by 
the employment of a reamer. 
In this way a taper identi- 
cal with that given to the 
column was secured, the 
column, however, being 
slightly larger than that por- 
tion of the tube which was 
to enclose it. The tube was 
then heated by placing a red 
hot iron ring about it and when thus expanded the rock was 
gently shoved into it to the required position, and the tube 
being allowed to cool, a mechanically perfect fit of the tube to 
the column was secured. 

When it is desired to carry out the deformation at tempera- 
tures above that of the laboratory and up to 600° C. or more, 


RiGee: 


SCALE IN CENTIMETERS. 


~ 
Y= 


472 Adams & Coker—Investigation into the Flow of Rocks. 


the rock with its tube is énclosed in a small stove of special 
construction heated by a gas blast, the air being supplied by a 
Reichhelm blower driven by a 2 h.p. electric motor. 

In experimental work formerly carried out on the Flow of 
Marble at temperatures up to 400° C., asmall castaron stove was 
used. As in these later experiments much higher temperatures 
—up to 1000° C.—have been employed, it was found that in 
many cases it was extremely difficult to remove the steel tube 


Fie. 3. 


URE IPNESS) PILATE. 


vltey i OT 


seubnn. ae an eel 
7 ae YS 
las 


BSSSy 


CENTIMETERS 


enclosing the rock from the stove at the conclusion of the 
experiment, the two having become partially welded together. 
A stove of cast steel has, therefore, been substituted, made in ~ 
two parts which are fir mly held tosether by heavy steel collars 
during the experiment, which collars can be removed at the 
conclusion of the experiment, allowing the stove to fall apart 
and access to the enclosed tube to be thus easily obtained. ‘This 
form of stove has proved very satisfactory. A section of it is 
shown in fig. 3. 


Adams & Coker—The Flow of Marble. 473 


The casting is so arranged that hot gases circulate in an 
annular channel (D). within it, and outside of the wrought 
iron cylinder (A), the rock (B) being thus kept at a high 
temperature while the pressure is applied. The casting is as 
massive as possible and a very uniform temperature is thus 
maintained during the whole time of the experiment. The 
temperature of the enclosed rock is ascertained by means of a 
platinum—platinum rhodium couple (C), provided with prop- 
erly calibrated resistance boxes, etc. This lies in the air space 
(E) by the side of the tube which incloses the specimen. The 
hot gases are excluded from this space by the wall (F). The 
whole is well lagged with asbestos, asbestos millboards (H) 
being also inserted between the bases of the pistons and the 
plates of the press. 

When it is desired to deform the rock at high pressures and 
temperatures in the presence of water, a modified form of the 
stove was adopted. The apparatus employed for the purpuse 
has been described in the former paper, to which reference 
has been made. 

Upon the conclusion of the experiment the deformed tube 
with its enciosed rock was placed in a lathe and the steel tube 
was carefully turned off until a mere film of metal remained. 
This was carefully filed through along one line and the enclosed 
rock was thus obtained intact. 

In experiments where very accurate measurement of the pres- 
sures employed was required, the large 100-ton Wickstead test- 
ing machine set up in the testing laboratory in the Engineering 
Building of McGill University was employed. In other exper- 
iments a series of three hydraulic presses, provided with suit- 
able intensifiers and necessary accessory appliances, were 
employed. These were calibrated from time to time by direct 
comparison with the Emery testing machine in the testing lab- 
oratory, and the accuracy of their reading thus maintained. 
The most powerful of these presses, which was the one usnally 
employed, has a capacity of 120 tons. 


The Flow of Marble. 


In a former paper, as has been mentioned, it has been shown 
that under conditions of differential pressure marble flows as a 
plastic body. In the present contribution the results of fur- 
ther experimental work, carried out with the view of obtaining 
a more complete and thorough knowledge of the behavior of 
marble under varying conditions of differential pressure, are 
PE 


474 Adams & Coker—Investigation into the Flow of Rocks. 


1, Deformation of the dry rock at ordinary temperatures. 


(a) Deformation at comparatively low pressures. Structure 
of the deformed marble. 


The pressures employed ranged from 120,000 to 130,000 
lbs. to the square inch. A series of experiments was first made 
in which the marble was enclosed in wrought iron tubes. The 
walls of these tubes immediately surrounding the marble had 
a thickness varying from 1/8 to 1/4 of an inch, and the load 
was slowly applied until deformation, indicated by the bulging 
of the tube, had commenced. So soon as movement ceased 
the load was increased slightly and the movement was thus 
resumed, and in this manner the deformation was carried on at 
a rate which was kept as nearly as possible constant. 

The experiments were arranged so that in some cases the 
deformation went forward rapidly and in other cases very 
slowly, the time occupied being from ten minutes to sixty-four 
days. 

In later experiments, as has been mentioned, the wrought- 
iron tubes were replaced by tubes of steel. These latter had 
the advantage of offering a higher resistance and also of being 
more easily prepared and more uniform in strength than those 
of wrought iron. This latter quality was of especial impor- 
tance In cases where experiments were carried on in series 
under identical conditions for purposes of comparison. Plate 
IV shows such a tube with the enclosed marble column, cut 
open after deformation. 

The deformed marble was uniform and compact and seemed 
to break with equal ease in all directions. It differed some- 
what in appearance from the original rock in possessing a dead 
white color, the glistening cleavage surfaces ot the calcite being 
no longer visible, and the contrast being well brought out 
when the deformed column is split or cut through vertically, 
owing to the fact that a portion of the original marble often 
remained unaltered and unaffected by the pressure. This, 
when present, had the form of two cones of obtuse angle whose 
bases are the original ends of the column resting against the 
faces of the steel pistons, while the apices extend into the 
deformed marble and point toward one another. These cones, 
or rather parabolas of rotation, are also developed, as is well 
known, where cubes of rock, cement or cast-iron are crushed 
in a testing machine in the ordinary manner. In the present 
experiments they sometimes constitute a considerable propor- 
tion of the whole mass; in other cases they are absent or but 
faintly indicated ; but there is always in immediate contact with 
the ends of the steel pistons at least a thin cake of marble pos- 
sessing the character of the ordinary rock. 


Adams & Coker—The Flow of Marble. 475 


Thin sections of the deformed column passing vertically 
through the unaltered cone and deformed portion of the rock 
were readily made and when examined under the microscope 
clearly showed the nature of the movement which had taken 
place. Under the microscope the deformed portion of the 
rock can be distinguished at once by a turbid appearance dif- 
fering in a marked manner from the clear, transparent mosaic 
of the unaltered cone. In that portion of the rock which has 
suffered deformation the calcite individuals have been squeezed 
against one another in such a manner that a distinct flattening 
of the grains has resulted. The individuals are not only flat- 
tened, but in some cases distinctly twisted, these movements 
being effected by the development in the calcite, first of 
marked strain shadows, and then, where the movement is more 
intense, by the appearance in each calcite grain of a series of 
fine parallel lines or very narrow bands giving to it a fibrous 
appearance, which bands become more numerous as the distor- 
tion of the grain becomes more pronounced, the calcite as these 
bands increase in number displaying a progressive decrease in 
transparency. When highly magnified, these lines are seen to 
be due to an extremely minute polysynthetic twinning. The 
chalky aspect of the deformed rock on the surface of fracture 
is chiefly due to the destruction by this repeated twinning of the 
continuity of the even cleavage surfaces of the calcite indi- 
viduals, thus making the reflecting surfaces much smaller. 

By this twinning the calcite individuals are enabled under 
pressure to alter their shape somewhat, while the flattening of 
the grains is evidently due to movements along the gliding 
planes of the crystals. 

In the paper by Adams and Nicolson describing the results 
formerly obtained in the deformation of marble at ordinary 
temperatures, it was stated that a microscopic examination of 
the deformed rock revealed the presence of an “ anastomozing 
meshwork of curved and branching lines” of minutely granu- 
lated calcite running through the rock, these being lines of 
cataclastic structure similar to those obtained when marble is 
deformed by Kick’s process. In our more recent experiments, 
however, this cataclastic structure is seldom found and in 
many cases is entirely absent. This is probably due to the 
fact that in this latter work the grinding and fitting of the 
columns to the tubes has been carried out with the utmost 
accuracy, while in the former experiments mechanical work 
was less perfect and the column probably did not in all cases 
fit its tube perfectly. It is probable that the little lines along 
which cataclastic structure is developed may have been largely 
due to a slight shearing of the column before perfect adjust- 
ment of the tube had been effected by the pressure to which it 
was subjected. 


476 Adams & Coker—Investigation into the Flow of focks. 


A faint but distinct cataclastic structure is, however, found 
in some cases even when the support offered to the marble by 
its steel tube is perfect, and along planes of greatest move- 
ment the calcite individuals can in some eases be seen to have 
been apparently slightly torn. 


_ (6) Deformation at very high pressures—Structure of the 
deformed marble. | 


In order to ascertain whether under a greater load the cata- 
clastic structure would entirely disappear, another series of 
experiments were carried out employing much higher pressures 
and at the same time carrying the deformation as far as pos- 
sible. This was secured by increasing the thickness of the 
wall of the tube which enclosed the marble. A tube of 
wrought iron built up in the same manner as a gun barrel and 
having a wall thickness of °5 inch (12°7™") for a length of °625 
of an inch (15°875™™") along the central portion of the tube 
about the enclosed marble column was employed. Steel pis- 
tons were then inserted and the pressure applied in the usual 
way. The tube commenced to bulge when the pressure 
reached 35,000 lbs. (15,870 kilos.), and the maximum load 
applied to the marble was 154,000 lbs. (169,750 kilos.), that is 
to say, a pressure of 296,725 lbs. per square inch (20,875 kilos. 
per square cent.), the deformation being carried on slowly and 
occupying forty-one hours. This is equivalent to a depth of 
46 miles below the surface of the earth. A photograph 
of the tube upon the completion of the experiment is shown 
in Plate II (a). .Under this tremendous pressure the upper 
steel piston failed, four radial cracks developing on its face in 
contact. with the marble, thus dividing the piston face into 
four nearly equal quadrants. ‘These cracks extended up into 
the piston for approximately half an inch (12°7™™), the largest 
of them being one one-hundredth of an inch (-254™™) in width 
at its widest part, and the marble was forced up into these 
very narrow cracks. Notwithstanding the great thickness of 
the ends of the tube, moreover, a small amount of the marble 
under this enormous pressure passed up between the piston 
and the inner surface of the tube, in.a form which while cohe- 
rent was sufficiently soft to yield to the finger nail with ease. 
Lhe marble was removed from the bulged tube by turning off 
the latter in a lathe. That portion of the rock which had not 
been forced up around the pistons, constituting of course 
almost the entire mass, was obtained in the form of a slaty 
cake °682 inch (17:°3™™) in height and 1:185 inch (28°81™™) 
wide at its widest part, and in form somewhat barrel-shaped. 
This is shown in- Plate I1 6 with a column of its original dimen- 
sions placed beside it for purposes of comparison. On the 


Am. Jour. Sci., Vol. XXIX, 1910. Plate lI. 


a 


Wrought iron tube enclosing marble column after compression (see below). 


b 


Li lil sp Sree sei eit Bit | 
ea a 


Column of marble before and after compression under a load of 296,725 pounds per 


square inch (20,875 kilos. per square cent.) The finer lines of the scale are one millimeter 
apart. 


eg 


Am. Jour. Sci, Vol. XXIX, 1910, Plate Ill. 


Carrara marble— 
inch. (x40 diam.) 


caused to flow under pressure of 296,725 Ibs. per Square 


Am. Jour. Sci., Vol. XX1IX, 1910 Plate IV. 


es 
ae 
ERD 


i 
a 


fae 


= 
= 
a 
i 
ce 


i 


Tube with its enclosed column of Carrara marble—cut open after defor- 
mation. The finer lines in the scale are one millimeter apart. 


ee 
as 


-. 
eo 
+2 


Adams & Coker—The Flow of Marble. ATT 


surface of this cake no reticulating (Luder’s) lines such as 
those observed when marble is deformed in Kick’s experiment 
are seen. : : : 

A series of thin sections of the deformed marble was then 
prepared. When examined under the microscope these sec- 
tions show that the marble has had developed in it a most 
striking and beautiful foliated structure due to the arrange- 
ment of individuals of calcite, each of which has been flattened 
out so that in a section passing vertically through the deformed 
column it presents the appearance of a ribbon drawn to a 
point at either end and from eight to ten times as long as it 
is wide. These elongated calcite individuals are perfectly 
moulded upon one another, coming together along sharp and 
gently sinuous lines. A microphotograph of this deformed 
rock, together with one of the original marble, is shown in 
Plate III. While many of them possess a very fine polysyn- 
thetic twinning, causing them to maintain a generally uniform 
illamination as they are revolved between crossed nicols, the 
movement has evidently been chiefly of the nature of a trans- 
lation or shpping on ghding planes without the development 
of pronounced twinning, so that the elasticity axes of the vari 
ous individuals lie nearly parallel to one another, and the whole 
rock section thus becomes light and dark four times during a 
revolution between crossed nicols, the periods of extinction 
being reached when the longer axes of the crystals (1. e., the 
foliation of the rock) coincide with the vibration planes of the 
nicols. In sections parallel to the foliation, the flattened indi- 
viduals are seen to have a rudely polygonal form, often pre- 
senting somewhat rhombic outlines, some showing strain 
shadows which in many eases can be seen to result from a poly- 
synthetic twinning of almost ultra-microscopic minuteness. 
This is of especial interest, as it is precisely this movement of 
individual lamellee of measurable width over one another that 
gives rise to the phenomenon of the “ flow ” of metals. Calcite, 
however, is apparently much more prone to twin during: this 
deformation than metals are, although the greater difficulty of 
recognizing twinning in metals—the latter being opaque—may 
have led to the frequency of this phenomenon in their case 
being underestimated. : | 

The marble shows no trace of granulation and the movement 
set up in it is an example of perfect plastic flow. 

The rock has a distinct foliated structure and the plane of 
foliation is transverse to the vertical axis of the deformed col- 
umn, that is to say, at right angles to the direction of pressure 
in that part of the column between the piston faces, but imme- 
diately about the sides of the highly deformed and flattened 
column the foliation bends up until it runs approximately par- 


478 Adams & Coker—Investigation into the Flow of Rocks. 


‘allel to the walls, thus following the direction of inovement 
which would be developed in any plastic mass when flowing 
away from between the advancing pistons in a confined space 
such as that afforded by the deformation of the enclosing 
tube. A microphotograph of this deformed marble is shown 
in Plate III 6. 

Another experiment similar to that just described was ear- 
ried out with a column of marble of the same size enclosed in 
a nickel-steel tube with a wall thickness at the thinnest part of 
19 inch (5). This required a pressure of 221,160 lbs. per 
square inch, which increased the diameter of the column to 
36°7 per cent. In this the same structure was developed in 
the marble as in the case of the experiment just described, but 
the deformation being smaller, the foliation developed in the 
rock was not quite so marked. 


(c) Strength of the marbie after deformation at ordinary 
temperatures. 


A series of columns of Carrara marble of the size regularly 
employed, namely 1°575 inch (4™) long and about ‘814 inch 
(2°) in diameter, with a slight taper, were prepared and were 
put into a series of tubes made of a mild carbon steel. The 
walls of the tube were °592 inch (1:5°™) thick, except in 
the central portion of the marble, where for a length of -688 
inch (1°75°™) the wall was thinned away to ‘13 inch (-33™) so 
as to localize the bulging here. The pistons were then put 
into the tubes in the usual way and the marble deformed so as 
to give the column a barrel-shaped form having a diametral 
enlargement of as nearly as possible :2 inch (508), or 24°5 
per cent. This deformation was produced in one minute, a 
100 ton Buckton testing machine being employed. The max- 
imum load required to complete the deformation at this rate 
of speed averaged about 56,000 lbs. (25,390 kilos.). This very 
rapid deformation severely tested the steel tubes, a number of 
them splitting before the required deformation was secured 
and being therefore rejected. Highteen such experiments 
were made, eleven of which were successful, the tube remain- 
ing unruptured. The steel tubes were turned off as soon as 
possible after the conclusion of the experiment and the bulged 
columns of marble thus set free. Of these the first two having 
been carefully measured were at once tested in compression to 
ascertain their strength. In each case the load at which the 
first splitting of the marble took place was noted and then the 
load under which the column finally broke down. 

The next three columns were allowed to stand for 100 days 
(or 2400 hours) and were then tested in the same manner. 
Four others, after having been freed from the enclosing steel 


479 


Adams & Coker—The Flow of Marble. 


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480. Adams & Coker—Investigation into the Flow of Rocks. 


tube, were heated in a water bath for 24 hours and then tested. 
The last two, after being freed from the steel tube, were main- 
tained at a temperature of 350° C. for 20 hours and hes tested 
_ as before. 

Eight columns of the original marble, cut to the same barrel- 
shaped form and having the same average dimensions as those 
resulting from the one minute squeezes just described, were 
then prepared, and these also were tested in compression to 
ascertain. their strength. It was found that these, instead of 
first splitting and then breaking down as in the case of the 
columns of deformed rock, showed no signs of preliminary 
rupture, but gave way suddenly and completely. 

The results obtained, together with certain others to be 
referred to later, are given in the table on page 479. ; 
It will be seen that when the marble is deformed in the 
manner described, the deformation being accomplished in one 
minute and tested so soon as the enclosing tube can be removed, 

it retains 60°6 per cent of its original strength. 

In order to ascertain whether the deformed marble would 
be stronger if the deformation were carried out at a higher 
pressure, a column of the Carrara marble having the same 
dimensions as those above described was deformed in a heavy 
tube of nickel steel having a wall thickness of -197 inch (° bom) 
at the thinnest part. The deformation was carried out a little 
more slowly than in the case of the experiments above described, 
occupying 100 minutes, and the load required to effect the 
deformation was 115 000 Ibs. Upon the completion of the 
experiment the deformed column, having been freed from its. 
enclosing tube, was tested in compression and was compared 
with a column of the original marble cut to the same dimen- 
sions. The deformed column measured 1:07 inch (2-720) mi 
diameter, which represents a diametral enlargement of 31-4 per 
cent. The loads required to crush the two specimens respect- 
ively were as follows: 


Original’ mar bleweaeas .. 6525 lbs. (2954 kilos.) 
Detormed marble sss. == 5470: (247 oe 


The deformed marble thus retains 83°8 per cent of its original 
strength. The experiment was then repeated with three other 
columns and almost identical results obtained. 

It will thus be seen that the increased pressure (accompanied 
by a somewhat slower rate of deformation) led to a greatly 
increased strength in the case of the deformed marble, the 
strength increasing from 60°6 per cent to 83°8 per cent. 

In three other experiments an attempt was made to ascer- 
tain whether, if the marble were deformed under a still higher 
pressure, a still further increase in strength might be secured. 


Adams & Coker—The Flow of Marble. 481 


The thickness of the tube walls was accordingly increased to 
1, that is to say, the thickness was doubled. It was found, 
however, that with a wall of this thickness it was impossible 
to contine the bulging of the marble to the thinner portion of 
the tube and thus secure a symmetrical barrel-shaped mass of 
deformed rock. The pressure required for this deformation 
was 387,000 lbs. to the square inch (273,000 kilos. per square 
em.), and was so great that when subjected to it the marble 
forced its way up between the pistons and the walls of the tube, 
and the thin, wedge-shaped ridges so produced broke away and 
crumbled to powder as the steel tube was being turned off in 
a lathe. 

Attempts were then made, by increasing the length of the 
marble column and altering the dimensions of the enclosing tube, 
to prevent the rock forcing its way up between the pistons and 
the thicker ends of the tube. These attempts, however, were 
unsuccessful, and it was evident from them that the result 
could c .ly be accomplished by greatly increasing the thickness 
of that portion of the walls which enclosed the pistons, which 
would in its turn necessitate the employment of a much higher 
pressure to deform the rock, and this would result in the de- 
struction of the pistons themselves. In the case of these exper- 
iments under very high pressure, furthermore, it was found 
that the deformed marble could not be obtained as a solid 
mass, for so soon as the last thin remnant of the steel tube 
which was left by the lathe was filed through, the marble 
developed cracks running across the column at right angles to 
its vertical axis. In some cases the deformed limestone at once 
broke in two along one of these cracks. In other cases it was 
obtained in what was apparently a solid mass, but upon stand- 
ing a few minutes little transverse cracks, running partially or 
completely across the specimen, made their appearance. ‘This 
phenomenon is apparently due to the expansion of the mass 
upon its relief from the tremendous pressure consequent upon 
the removal of the enclosing tube and is not confined to marble 
deformed under very high pressures, but is met with, as will 
be mentioned, in the case of the various impure limestones and 
dolomites whose deformation will be described later. 

It was, therefore, found to be impossible to test the strength 
of the marble when deformed at these highest pressures owing 
to the fact that these transverse cracks invariably developed, 
thus destroying the continuity of the rock. 


(d) Influence of rest and of heat on the strength of the deformed 
marble. 


It has long been known that iron which has been over- 
strained, that is to say strained beyond its elastic limit, pos- 


Am. Jour. Sct.—FourtH Series, Vout. XXIX, No. 174.—June, 1910. 


D2 


482 Adams & Coker—Investigation into the low of Rocks. 


sesses very different elastic properties from the same iron in 
its original condition. The iron so treated assumes a more 
plastic character and a bar thus stretched will on the applica- 
tion of small additional loads undergo a further elongation or 
creeping, producing a permanent set. It is a well-known fact 
moreover that iron when thus over-strained will, if allowed to 
rest for a sufficiently long time, revert to its former state ot 
normal elasticity, and Muir* has shown that this recovery is 
greatly hastened by raising the temperature of the bar even a 
few degrees, and if the temperature be raised to 100° C., the 
reversion to the state of normal elasticity is very rapid, being 
accomplished in a few minutes instead of requiring several 
days. 

Ne has been shown, the movement set up in marble under 
the conditions of deformation secured in these experiments is 
essentially of the same character as that which takes place in 
iron or other metals when they are deformed, for while there 
is in marble, when deformed at ordinary temperatures and at 
comparatively low pressures, a certain amount of granulation, 
this is very subordinate to the movement of the calcite on its 
gliding places or by twinning, as before described. It was 
therefore conjectured that if the marble was rapidly deformed, 
thus giving rise to a comparatively weak product, this deformed 
rock might, following the analogy of the metals, become 
stronger if allowed to rest for a certain time. If the analogy 
to metals holds, it might still further be expected that the 
application of heat would bring about a more rapid recovery 
of strength on the part of the deformed rock than mere rest 
alone. 

The results of three experiments in which the strength of 
the deformed column was tested after a rest of 100 days, as 
well as the results of four other experiments in which the 
marble after deformation was heated to 100° C. for 20 hours, 
and two experiments in which the marble after deformation 
was heated to 350° C. for 20 hours, are given in the table on 
page 479. As will be seen from an examination of the figures, 
the marble became distinctly stronger as the result of a rest of 
100 days, but the application of heat, whether it be 100° C. 
or 350° C., does not noticeably accelerate the recovery of 
strength as it does in the case of the iron. In fact, the figures 
seem to show that the heating of rock to 100° C. for 20 hours 
rather weakens it and that it recovers this loss at a higher 
temperature. 

Another series of three experiments was then made in which 
columns of marble and steel tubes of the same dimensions were 


*On the Recovery of Iron from Over-strain, Phil. Trans. Royal Soc., 
series A, vol. xciii, pp. 1-46. ; 


Adams & Coker—The Flow of Marble. 483 


employed, but in which the deformation was carried on very 
slowly, being extended over a period of 30 days, and in which 
the marble after deformation was allowed to remain in its 
enclosing steel tube for two years, after which time the steel 
tube was turned off in the usual way and the marble tested in 
compression to determine its strength. As will be seen by 
consulting the table on page 479, under these conditions of 
slow deformation and long, subsequent rest, the deformed 
marble is but little weaker than the original rock, its strength 
being on an average 84:7 per cent of that which it originally 
possessed, while one of the deformed columns in this series 
showed a strength greater than the average strength possessed 
by the columns of the original rock. 

Another series of three experiments, the results of which 
were published in a former paper, show that slow deformation 
alone conduces to increase of strength. In these experiments 
~ the deformation was carried on in wrought iron tubes, and at 
the conclusion of the experiments the tubes, instead of being 
placed in a lathe and turned off from the enclosing marble, 
were sawn in two vertically and the half columns of marble 
thus obtained. These when tested in compression gave the 


following results : 
Crushing load 


Greatest for deformed 
diameter Time of marble, 
Original Original afterde- deforma- Ibs. per 
height diameter formation tion square inch 
Experiment A 15594 1:000 1:407 64 days 5350 
ee Or 594 =) 1-000 1-203 ~=14 hours 4000 
os Peles 05 1-000 1°388 10 minutes 2776 


These values cannot be used for comparison with those of the 
former table owing to the fact that the shapes of the test pieces 
in the two series of experiments were quite different, but 
compared with one another we see clearly that slow deforma- 
tion conduces greatly to the preservation of strength. 


2. Deformation of the dry marble when heated to temperatures 
of 300° C. and 400° C. 

In a former paper an account has been given of the defor- 
mation of the marble at these temperatures. Debray* has shown 
that calcite when heated in closed vessels to a temperature of 
350° C. suffers no decomposition, that at 440° C. the decomposi- 
tion is ‘‘insensible,” while at 860° C. the disassociation of the 
molecule of carbonate of lime is marked. In the experiments 
carried out at 400° C., therefore, it would seem that the marble 
was deformed at the highest temperature which could be 
employed without danger of decomposition under atmospheric 
conditions of pressure. 


*Comptes Rendus, 1867, p. 603. 


484 Adams & Coker—Liwestigation into the Flow of Rocks. 


In these experiments, as in the case of those on page 479, 
the deformation was carried out at comparatively low pressures. 
The marble after deformation was hard and solid. Tested in 
compression it was found to be nearly as strong as the original 
marble. When sliced and examined under the microscope, the 
rock showed no trace of cataclastic structure, but the grains 
were seen to be distinctly flattened, giving to the rock a folia- 
tion which in some places was very pronounced. The ealcite 
individuals showed the very narrow polysynthetic twinning 
producing the fibrous appearance before described. The twin 
lamellee were in some cases twisted, the twisting being accom- 
panied by strain shadows, which phenomenon, however, in 
this rock was neither very common nor very striking. The 
individual grains had to all appearance acted as plastic bodies. 
A very pronounced movement along gliding planes, coincid- 
ing in direction with the course of twin lamelle, is undoubted. 
This movement, induced by comparatively low pressures at this — 
elevated temperature, is identical in character with that pro- 
duced by very high pressures at the ordinary temperatures. 
In both the movement is due to translation and twinning; 
breaking or cataclastic structure is absent. 

The increased temperature evidently gives the calcite a freer 
movement on its planes of translation and twinning,—the rise 
in temperature increases its plasticity. In the case of ice 
crystals, as is well known, a rise in temperature develops simi- 
larly a greater ease of movement along the gliding planes. 


3. Deformation of the marble when heated to 300 C. in the 
presence of water. 


In the series of experiments formerly made, in addition to 
heat and pressure a third factor, viz., the presence of moisture, 
was introduced. A column of Carrara marble enclosed in its 
iron tube was slowly deformed while at a temperature of 
300° C., but in the presence of water vapor under a pressure 
of 460 Ibs. to the square inch (82°33 kilos. per square em.). 
The apparatus used for the purpose of this deformation is 
described in the paper to which reference has already been 
made. This deformation was carried on very slowly, and at 
as uniform a rate as possible, the experiment extending over a 
period of 54 days or nearly two months. Tested in compres- 
sion, the rock after deformation was slightly stronger than the 
original rock. Its structure was found to be identical in char- 
acter with that seen in the case of the marble which had been 
deformed at 300° C. or 400° C. while dry. <A distinct folia- 
tion was induced, some of the calcite individuals being three 
or even four times as long as they were wide. Some few of 
these flattened grains displayed strain shadows, but no twin- 
ning, while the grains in their immediate vicinity showed well- 


Adams & Coker—The Flow of Marble. 485 


defined twinning, giving rise to the fibrous appearance before 
described. Jn some cases a grain showed strain shadows at 
one end which passed over into a very narrow polysynthetic 
twinning at the other. The twin lamelle in many cases are so 
narrow that even when magnified 1050 diameters they are not 
very clearly resolved. The individual lamelle in several sets 
which were measured were found to have an average width of 
between ‘0005 and :0006 of a millimeter (‘00001968 inch and 
"00002361 inch), and some were even narrower. 

While the rock was deformed without loss of strength, the 
presence of water, so far as could be ascertained, did not influ- 
ence the character of the deformation. It is just possible, 
however, that there may have been a deposition of infinitesi- 
mal amounts of calcium carbonate along very minute cracks or 
fissures, thus contributing to maintain the strength of the rock. 
No signs of such deposition, however, were visible. 


4, Specific gravity of the marble after deformation. 


In order to determine whether as a result of deformation 
under high differential pressures, the specific gravity of the 
marble was in any way altered, the specific gravity of two 
specimens of deformed marble was taken as well as the specific 
gravity of two specimens of the original rock. 

‘The first specimen of deformed marble, “A,” had been 
deformed at ordinary temperatures in a tube of nickel steel 
1 thick, the experiment being carried out in 100 minutes, 
the pressure required to effect its deformation being 340,000 
Ibs. to the square inch. The second specimen of deformed 
marble, “ b,”’ had been deformed in a steel tube at a tempera- 
ture of 400° C. in eight and a half hours at a pressure of 
63,000 lbs. to the square inch. Both specimens of the 
deformed marble when placed in water showed at once that 
they were traversed by minute fissures, as a considerable amount 
of air was discharged in the form of minute bubbles. Speci- 
men “A” was allowed to soak in the water until no further 
bubbles appeared. The rock when so treated was found to 
have a specific gravity of 2°65. The rock was then placed 
under water in an air pump. When the pump was worked 
additional air bubbles appeared, and the rock was allowed to 
remain under the vacuum until no further air was given off. 
After this treatment the rock was found to have the specific 
gravity stated in the accompanying table. In the case of 
specimen ‘ B,” the deformed rock was evidently more solid 
and compact, as less air was given off. This gives a partial 
explanation at least for its greater strength, it being evidently 
freer from minute cracks and fissures. 

The following table shows the specific gravity obtained in 
the case of the various specimens: 


aaa 


486 Adams & Coker—Investigation into the Flow of Rocks. 


Original marble— 1st specimen. Specific 
gravity 
Specific gravity after the rock had been placed in 
water under a vacuum of 283 inches of mereury . 


for 24 hours : - L052 (2026 See eee 

Original marble—2d specimen. 
After treatment in a similar manner __---.-..._--_-- 2°722 
Averaces. 402) Sean 2°722 


Deformed marble—specimen “A,” Ist fragment. 
After having been placed in water under a vacuum 
of 28 inches of mercury until no further air was 
given: off slo. a0 eee a ee ea 
Deformed marble— specimen A ” 2d fragment. 
Treated in vacuo in the same manner for 24 hours, 
no further air bubbles being given off __..._._._. Daher 
Deformed marble—Specimen “ B.” 
After having been placed under water in vacuo for 


24 hours, until no further air was given off._.-.._ 2°713 
Average 2.2.2) ae 2°714 

The comparison thus stands : 
Orioinal mathle 2220 so se. 2 ee 2°722 
Marble atter detormation): 252 225) =2) == enna 2-714 
Difference =... ae 008 


This may be taken to mean that the marble remains unchanged 
in specific gravity by deformation, but that in the deformed 
marble some of the little cracks or crevices developed in the 
rock on relief of pressure still remain, into which the water 
can not penetrate, and which give rise to the slightly lower 
specific gravity of the deformed rock. In this connection it is to 
be noted that specimen ‘‘ A ” could not be tested for strength on 
account of the minute fissures by which it was traversed and 
which were developed upon the relief of pressure incident to 
the removal of the steel tube in which it was enclosed during 
deformation, while specimen “ B,” which gave off compara- 
tively few air bubbles, had the appearance of being much more 
solid. 

In connection with these results it is interesting to note the 
results of the investigations carried out by Spring* on the 
specific gravity of the sharply folded limestones in the Alps. 
In these he found that the specific gravity of the limestone on 
the concave side of a sharp fold, where the pressure of course 
is greatest, was slightly higher (003 to 023) than on the con- 
vex side of the same fold. This he at first inter preted as 

* Note sur la véritable origine de la différence des densités d’une couche 


de calcaire dans les parties concaves et les parties convexes d’un meme pli ; 
Ann. Soc. Géoi. de Belgique, xl, p. 4, 1883-4. 


Adams & Coker—The Flow of Marble. 487 


meaning that there had actually been a permanent condensa- 
tion of the calcite by the greater pressure to which it had been 
subjected in folding. Further investigation, however, showed 
that the slightly lower specific gravity of the rock on the outer 
side of the fold was due to the presence in it of minute rifts 
or pores which were wanting in the rock on the more highly 
compressed inner side, the limestone itself really bemg of the 
same specific gravity throughout. 


Conclusions. 


1. Marble when deformed at ordinary temperatures will flow 
readily by distortion of the original calcite grains, accompanied, 
if the differential resistance be low, with the development of a 
certain amount of cataclastic structure. 

2. The marble when deformed at ordinary temperatures will 
increase in strength if allowed to rest. 

3. The marble, if deformed at ordinary temperatures, will be 
much stronger if the deformation be carried on slowly than if 
the deformation be rapid. There is every reason to believe 
that with the extreme slowness of deformation to which the 
rock is subjected in nature, and the long rest which it subse- 
quently undergoes, the change in shape would be accomplished 
without any loss of strength. 

4. If the deformation be carried on at a higher temperature, 
the calcite develops freer movement on its gliding planes, and 
the deformed rock will be relatively stronger than if deformed 
at the ordinary temperature. 

5. Under the conditions to which the rock is subjected in 
these experiments,—although not under all conditions,—the 
presence of water has no recognizable influence on the char- 
acter of the deformation. 

6. The specific gravity of the rock is not increased by the 
pressure to which it is subjected during deformation. 


McGill University, Montreal, Canada. 


EXPLANATION OF PLATES. 


Puate II. 


a. Wrought iron tube enclosing marble column after compression. 

b. Column of marble, before and after compression, under a load of 
296,725 pounds per square inch (20,875 kilos. per square centimeter), The 
finer lines of the scale are 1 millimeter apart. 


PuatTe III, 
a. Carrara marble, original. x60. 
6. Carrara marble, caused to flow under pressure of 296,725 pounds per 
square inch. x40. 
PuaTeE IV. 


Tube with its enclosed column of Carrara marble, cut open after deforma- 
tion. The finer lines of the scale are 1 millimeter apart. 


488 Mixter—Formation of the Oxides of Molybdenum, ete. 


Arr. XLUI.—TZhe Heat of Formation of the Oxides of Molyb- 
denum, Selenium and Tellurium ; and fifth paper on the 
Heat of Combination of Acidic Oxides with Sodium Oxide; 
by W. G. Mixrer. 


[Contributions from the Sheffield Chemical Laboratory of Yale University. | 
Molybdenum. 


THERMAL chemistry of molydenum is lacking, owing, per- . 
haps, to the difficulty of burning the metal completely in 
oxygen. It is remarkable, however, that neither Thomsen nor 
Berthelot recorded any experiments with it. The writer tried 
burning molybdenum mixed with carbon for ignition and to 
supply heat to volatilize the trioxide formed, and the result 
was imperfect oxidation of the metal. Hence the indirect 
method with peroxide was used. ? 

Metallic molybdenum for the work was prepared as follows : 
Compact pellets of pure trioxide were heated in an electric 
furnace in a porcelain tube through which pure dry hydrogen 
was passed. ‘The metal obtained was in the form of a gray 
coherent mass and portions adhering to the tube were rejected.” 
It was rubbed up in a mortar and passed through a fine sieve. 
The purity of the metal was determined as follows: It was 
oxidized by nitric acid, the acid removed by evaporation and 
the residue cautiously heated until it ceased to lose weight. 
The following are the analytical data : 


I IT 
Metal alken 05 st oye 0 eC ee ae ee ree 1°0505,— Sasa 
Molybdenum trioxide obtained ._-.------- 15750 1°7653 
Oxygen taken) Up.o css ees eee eee 0°5245 0°5882 
Molybdenum equivalent to oxygen taken up 1°049 11764 
Per cent of molybdenum as metal. _.._--- 99°86 99°84 


While the results indicate that the reduction by hydrogen was 
not quite complete, very likely there was some loss in oxidizing 
the metal or in heating the trioxide. Hence the metal was con- 
sidered pure and no correction was made for 0-15 per cent of 
oxygen which the above results indicate. The trioxide obtained 
dissolved completely in ammonia, showing the absence of silica 
and alumina. 


* Debray (C. R. Ixvi, 7382) found that molybdenum trioxide affects por- 
celain at high temperatures. To avoid this the reduction was first tried 
in a thin platinum tube contained in a porcelain tube. The platinum 
was made quite brittle and the molybdenum obtained was very slowly acted 
on by nitric acid. The reason of the action on the platinum was not inves- 
tigated. In the reduction, where pellets of the trioxide were in contact with 
the porcelain tube, the porcelain was slightly attacked and the molybdenum 
adhering to it was found to have taken up a little iron. 


Mixter—Formation of the Oxides of Molybdenum, etc. 489 


The results of burning the metal with sodium peroxide are 
as follows: 


1 2 
Molybdenum) 222... .-i*- 7°000 grams 7°000 grams 
Pedram peroxide «..._...--- 25° ‘ 25° i 
Water equivalent of system-- 3,960: es 4,047: ss 
Temperature interval _.-.-.--- 3°803° 3°720° 
Wlleatrenieete le 22.020 o 15,060° 15,055° 
ok oxidation of Irons: .- --48° —A48° 
«< oxygen absorbed - - -- —31° —52° 
14,981° 14,955° 
For 1 gram of molybdenum. - 2,140° Pe MBO 


The mean is 2,138 and for 96 grams of molybdenum it is 205,248°. 


- From this result and the heat of union of sodium oxide with 
molybdenum trioxide found in experiments 8, 4, and 5, the 
heat of oxidation of molybdenum to the trioxide is derived as 
follows : 


3Na,O, - Mo = Na,MoO, + 2Na,0 + .._._..-.-- 205°2° 
em Ouee Oem INaLO 8 oe) en oe os 58°2° 
ne Or Mio -— 30> Na, MoO, +... 2: 12 «=e. 26374" 
Reo MoO = Na MoO... 0 2c 3. See 
Memes Op — WoO neue ie ee oe eh SIS 


Molybdenum trioxide used in the following experiments 
was heated in a porcelain crucible to expel moisture, allowed 
to cool in a desiccator and weighed. Sulphur or acetylene 
carbon was added to the mixture of the trioxide and sodium 
dioxide to reduce the latter to oxide and also to furnish heat 
necessary for fusion. It will be observed that where carbon 
was used the amount of oxygen evolved was large although 
sodium oxide was formed in excess of the amount equivalent 
to the molybdenum trioxide. The following are the experi- 
mental] results: 


3 + 5 
Molybdenum trioxide- .--- EoOleoy. > ol torr, S14 0.04 
ESO ae ee Or618: °° 0°546 “ 
TINT) St) ig Be at ae a ee nee ee 2-000 <“* 
Sodium peroxide. .__...-- Uae eae fo 02 ot neat i 
Water equivalent of system 4,164: “* 4,018" “ 4.196" & 


Temperature interval. _._- aS ie 2°145° 3°616° 


490. Mixter—Formation of the Oxides of Molybdenum, ete. 


Heat effeetis 42 4a ue bp al OA 28 8,619° 15, 173° 
“‘ of oxygen set free..._.. + 796° + 362° +39° 

“¢ “ oxidation of carbon... —6,876° —6,075° 
peta So a so SUITES ieee eae —10,542° 
66 “ce 6c 3 iron Nit ie —4ige —4g¢ LA RE 
4,344° 2,858° 4,622° 
Hor iecram of Mo@is a3 579° 559° 568° 


The mean is 569° and for 144 grams it is 81,936°. 


It was shown* that the heat effect of 3Na,O,R,O,, in which 
Ris phosphorus, arsenic or antimony, is closely related to the 


HIGee de 


180 | 


140 


100: 


60 


Cr are WwW 


atomic weights of these elements. The same relation appears 
in the sub-group of chromium, molybdenum, and tungsten. In 
the figure the atomic weights are plotted as abscissas and the 
heats of combination as ordinates. The line I indicates the 
heat of the reaction Na,O,RO,, and II of R,O,. 


Molybdenum Dioxide. 


Molybdenum dioxide was made by reducing the trioxide as 
follows: a 100° pipette was weighed, filled with molybdenum 


* This Journal, vol. xxviii, 103, 1909. 


Mizxter—Formation of the Oxides of Molybdenum, etc. 491 


trioxide, heated in an electric furnace to expel moisture, 
then the tube was closed with stoppers, allowed to cool 
and weighed. The reduction was made with pure dry hydro- 
gen at temperatures between 410° and 440° approximately. 
It required 76 hours and in the last four hours the loss 
was 20 milligrams. The original weight of the trioxide 
was 49-795 grams and the total loss in weight 6175 grams. 
The composition calculated from these data is MoO, 99-11 per 
cent and MoO, 0°89 per cent. It was not deemed best to try 
to complete the reduction at a higher temperature than used 
on account of danger of reducing some of the substance to the 
metallic state. The following are the experimental data: 


6 7 8 
Molybdenum dioxide------ 10-123 er. 12°028 gr. ‘127000 gr. 
Sodium peroxide __-.----- 13- . 15° ype os 
Water equivalent of system 3,918: $693. 989- cee Osi Ss 
Temperature interval. ---- 1°802° 2°085° 2°08° 
2.2 SG ee ee a 7,060° Gok r 8,397° 
fur Oxyoen set free. ._. =. P36 6 Tt Te. 128° 
ee OXIdAtiON Of Iron —-. . —48° —48° —48° 
8,148° 9,386° 9,477° 
Meet eram‘'ot MoO, =... -- 805° 780° 789° 


The fusions were good and dissolved in water with evolution 
of oxygen and no black residue remained. The oxygen set free 
in the bomb was collected in a flask over water and the volume 
of it found by weighing the flask containing it, then filling 
with water and weighing again. The number of cubic centi- 
meters of oxygen at 0° and 760™" multiplied by 1°73 gave the 
number of calories lost by the change of sodium peroxide to 
oxide. If the experimental data above are reduced, allowing 
for the presence of 0-9 of 1 per cent of trioxide in the dioxide 
used, the result is not essentially different from that given. 
The mean for 1 gram of molybdenum dioxide is 791° and for 
128 grams it is 101,200°. 

The following are the results of the experiments with 
molybdenum : 


meee MOO —*Na. Moles ser ee 10 200° 
we Eagle SEAS eee 9 am a 19,400° 
Ma O-- MoO... 'O°=> Na MoOw- 2.50252 222 120,600° 
mae) 2+ MoO) Na, MoOri-p aa. Oe 81,900° 
GO AO) MOO a te see es bes 2 Le eG Se 38,700° 
Es ea a WO es oe i ek oo Peay.) 181,500° 


vA TOE 5 Pa ot SE eee ee 142,800° 


492 Mixter—FHormation of the Oxides of Molybdenum, ete. 


Selenium. 


Determinations were made of the heat effect when gray 
metallic selenium is burned with sodium peroxide, using 5 to 
10 grams of the former for a test. The mixture fused imper- 
fectly. The water solution of the fusions after acidifying 
with hydrochloric acid gave no precipitate of selenium when 
sulphurous acid was added, showing that only selenic acid 
was present. This was confirmed by the fact that a nitrie acid 
solution of the fusions did not decolorize permanganate. The 
results for 1 gram of selenium were 1216°, 1208°, and 1208°; 
average 1211°. For 79-2 grams it is 95,900°. 

Two combustions were made of a mixture of crystalline 
selenium dioxide, sodium peroxide, and sulphur. 13°940 and 
7-652 grams of selenium dioxide were taken respectively. The 
results for 1 gram of SeO, were 644° and 588°. Two other 
determinations were made, taking 6°118 and 7:109 grams of 
selenium dioxide and an excess of sodium peroxide. These 
two fusions were good and oxygen was not liberated, proving 
conclusively that all of the SeO, was oxidized to SeO,, and 
that the reaction was Na,O,+SeO,—Na,SeO, and not Na,- 
SeO,+0O. The heat effect for 1 gram of SeO, was 617° and 
637°. The fusion giving 588° contained some sodium selenite 
and the result should be discarded. The average of the 
remaining three is 632° and of the two highest results it is 
640°. This last number multiplied by 111-2 gives 71:200° for 
the heat effect of Na,O,, SeO,,. 

The results of the combustions of sodium peroxide are as 
follows: 


3Na,0O, + Se = NaiseO, + 2Na,0 4 S232 s ee 959° 
8Na,0) +.30: =:3Na,0) eos 582° 
Na,O + Se 80) = Na, SeOjit 3 Sanne eee 154-1° 
Na, O74 iSeO n= | NasseO) pip ee eee it 7 oe Tee 
Na,O. + Ore Na Oo cent ueke ee be eee 19°4° 

90°6° 


The heat of formation of crystalline selenium dioxide derived 
from these results is 154°1—90°6=—63°5°. Thomsen’s figures are 
57°1° derived from the heat effect when the dioxide is reduced 
in hydrochloric acid solution by sodium hydrosulphide and also 
from the heat of formation of SeCl, and its hydrolysis. His 
results by the two methods are practically identical. Thomsen 
used amorphous selenium and the writer the grey metallic 
modification, and as the change of the amorphous form into the 
crystalline evolves heat the writer’s results would have been a 
little higher had he used amorphous selenium. The reason 


Mixter—Formation of the Oxides of Molybdenum, etc. 493 


for the difference of 6°4° between Thomsen’s result and the 
writer’s is notapparent. He stated that the hydrolysis of SeCl, 
is complete and is probably right in this view since selenium 
dioxide dissolves in dilute hydrochloric acid without appre- 
ciable heat effect. 

R. Metzner* found the heat of H,SeO,,Aq to be the 
same as that H,SO,Aq. On the assumption that the heat 
effect of SeO,,H,O is the same as SO,,H,O, he calculated that 
Se +30 = 42°1°, using Se,80,Aq = 76°660° (T). That is, SeO,- 
+O—-—144° This explains, according to Metzner, why 
SeO, can not be isolated. The view that SeO,+ O is an 
endothermic reaction accords with the results of the experi- 
ments with sodium peroxide. The observed heat effect of 
Na,O,,SeO, is 90°6°; adding 14°7°, the heat absorbed by the 
oxidation of SeO, gives 105°3° for the heat effect of Na,O,- 
SeO,. If we consider Se,2O—63°5 and subtract 14°7° we have 
for Se,80—48'8° and 


MeO oe gO th 2) lets e ek. 1b ae 
eee Obras Se ere see A abe 48°8° 
RO SCO) = ee ee her ed 165°3° 


This result is identical with that found from the reaction 
between Na,O, and SeO,, but substituting another number for 
14°7 in the calculation will give equal numbers. The heat of 
formation of Na,SeO, in solution calculated from Thomsen’s 
data is 262°3°; subtracting 99°8 for the heat effect of 2Na,O 
gives 162°5° for Na,O,Se,30. The heat of solution of 
Na,SeO, has not been determined but it is negligible, as a 
rough test with 15 grams of Na,SeO, in 200° of water gave 
a rise of approximately 0-1%. The writer is unable to explain 
why 154-1° obtained by burning selenium with sodium peroxide 
is so much lower than the number derived from Thomsen’s 
experiments. 

It should be stated that attempts were made to determine 
the heat of formation of selenium dioxide by burning in a 
bomb a mixture of selenium and charcoal. In one instance 
the bomb was filled with a crystalline mass of selenium 
dioxide, but the combustion was incomplete. In other experi- 
ments the mixture burned only on the surface. 


Tellurium. 


The tellurium used in the work was purified by dissolving 
the crude metal in acid and making a fractional precipitation 
with sulphur dioxide or by recrystallizing the nitrate. The 
precipitated tellurium was fused in hydrogen. Tellurium and 


* Ann. Ch. Phys. (7), xv, 228. 


494. Miaxter—FHormation of the Oxides of Molybdenum, ete. 


its dioxide do not burn well with sodium peroxide and sulphur 
was added to supply the heat requisite for combustion. Tel- 
lurium dioxide was obtained by heating the nitrate and fusing 
the residue. Telluric acid was prepared by Staudemaier’s* 
method by oxidizing the dioxide with chromium trioxide. 
The telluric acid was slowly heated in an electric furnace to 
375-400° and until a sample did not yield water on melting. 
The per cent of trioxide was calculated from the loss of 
oxygen on heating a weighed portion until the weight was 
constant. It was considered better to correct for tellurium 
dioxide present than to attempt to remove it by hydrochloric 
acid. ‘Two different preparations of tellurium trioxide were 
used. That for Experiment 5 contained 80°8 per cent of 
trioxide, and for 6, 91:3 per cent. The following are the 
experiments : | 


1 2 
Mel wary Were aes Oe eee 5:000 grams 6:000 grams 
Sulphur wie en en Pee 1000. « 1000 « 
Sodium’ peroxides 2.03. =: 20° ee 30° a 
Water equivalent of system... 3,866: er 4,032° Bf 
Temperature interval __.--.- 2°883° 3°096° 
Heatveficetie Shiite ae 11,146° 12,483° 
= ‘to tof osu phir. certs eae —5,271° —5,271° 
66 Ts Co ATOM Ries ee ees eee 549 ARC 
‘ «oxygen absorbed —34° — 34° 
5, 793° 7,130° 
For 1 gram of tellurium --.--- 1 Las 1,188° 


The result for 127°5 grams of tellurium is 149,700. 


3 + 
Tellurmamiidioxades 22s sees 10000 grams 10°000 grams 
SUL pos bienae es er ee 15000 9 10007 
podiumperoxide: 2 a ei fo 21° es pele < 
Water equivalent of system__ 3°906° ‘ 3°896. (ee 
Temperature interval_._.-..- 2°968° 207s 
Fleat) eltects.2=:44 UU are 11,593° 11,602° 
<< * of oxygen evolved +51° | +110° 
Rene ESTO ODPL A's ae —5,271° —5,271° 
6 Ge 66 iron an ached gan eats, A == Pat 
6,325° 6,393° 
For 1 gram of tellurium dioxide 633° 639° 


* Zeitschr. anorgan. Chem., x, 189. 


Mixter—Formation of the Oxides of Molybdenum, etc. 495 


The result for a gram molecule of tellurium dioxide is 
159°5 x 636 = 101°400°. 


5 6 

Substance taken.....------- 10:060 grams 6°000 grams 
Composition of { TeO, .----- 82000 ic Beal ee Fo 

substance He Ong Aue BFS SA Mee Be Op Din) 06 
TN eee ee ats Sia: O00 OSC Oa 
BeGiMM peroxide. 4.2. =... 16° f 14° 5 
Water equivalent of system_. 3,963: re 3,152 sc 
Temperature interval .-_-_-- 2;802- 2°537- 
Bieauesiect, 2 oS 8s 11,104° 7,996° 

e «of oxygen evolved -+1,072° + 636° 

A preteens eG) s Se). 2 2 0G —1,241° at ee 

sé *«  jron for ignition —48° — 48° 

% o5n sulphuric: ys —5,271° — 4,216° 

3 EAE BEN 0) el hd a 5,616° 4,036° 
Memlocram of TeO, -. 2... - 684° : TET 


The mean of the results is 708, which gives for the reaction 
Na,O + TeO, = Na,TeO,+175°5 & 708 = 124,300°. 


Summary of results. 


ana O - be = Na VeO, + 2Na,O + 22.2 .2..2_.. 149°7° 
eee Or SINa Oe Orel. Seas ee Se 58°2° 
meme het 3O Na TeOe 4 Los. fe 8s een eee 207°9° 
Bem ehe@) vs Na PeOn teas ose ote ol 12493° 
t=. 30 = TeO, eee eee eee eee Ok tata Ug ar ne aa er ep ok 83°6° 
epee cO). =) Na PeO. ei oe 0 ae A ee 101°4° 
a ON Ose ae ee epee ye ee Sh 19°4° 
epee em. Or Na TeO) ee ee 2058: 


The heat of formation of erystalline tellurium dioxide is 
207°9—120°8=87-1. Thomsen’s result of 77-2° for TeO,Aq is 
too low since TeCl, does not hydrolyze completely. The 
result of experiments 5 and 6 giving 124°3° for the heat of 
combination of Na,O and TeO, is to be considered as approxi- 
mate only on account of the large correction for oxygen set 
free, and hence the heat of formation of TeO, derived is to be 
regarded as an approximation. Since the trioxide and dioxide 
of tellurium give nearly the same heat when fused with 
sodium peroxide, it is evident that the oxidation of crystalline 


496 Mixter—FHormation of the Oxides of Molybdenum, ete. 


TeO, is accompanied by little or no heat effect. The results 
indicate that the reaction is slightly endothermic. 

The heat effect of Na,O,SO, derived from Thomsen’s data is 
125°6° and from the writer’s* 123-7°. That of Na,O,TeO, is 
124°3 approximately. If we take 162°5° based on Thomsen’s 
results and subtract Se,80 = 42°4°, we have 120:1° for Na,O,- 
SeO,. The heat of the reaction Na,O,RO, where R is sulphur, 
selenium or tellurium, is probably nearly the same in all cases. 
This much is however, evident, that it does not increase or 
diminish notably with increasing atomic weights as it does in 
the reaction Na,O,R,O, where R is phosphorus, arsenic, anti- 
mony, and bismuth,t or in Na,O,RO,, where R is chromium, 
molybdenum and tungsten. Moreover the heat effect of Na,O- 
RO, is in all cases higher where R is sulphur, selenium 
or tellurium, than where K is chromium, molybdenum or 
tungsten. 


* This Journal, vol. xxvi, 125. + Loe. cit. 


Noble— Geology of the Grand Canyon, Arizona. 497 


Art. XLIV.—Contributions to the Geology of the Grand 
Canyon, Arizona.—The Geology of the Shinumo Area 
(continued); by L. F. Noztz. (With Plate V.) 


Pore EL. 


GENERAL GEOLOGY (continued). 


Algonkian—Grand Canyon Series. 
Name. 
Distribution in the Grand Canyon. 
Stratigraphic Position, Structure, and Distribution in the 
Shinumo Area. 
Sediments of the Unkar Group. 
Preliminary Ouiline. 
Detailed Section. 
Comparison with the Type Section in Unkar Valley. 
Diabase Intrusive in the Unkar. 
Occurrence. 
Petrography. 
Variations in character. 
Contact Metamorphism. 
Conclusions. 
Age and Correlation. 
GEOLOGIC HISTORY. 
BIBLIOGRAPHY. 


ALGONKIAN. 


Grand Canyon Series. 


Name.—The unaltered pre-Cambrian sedimentary rocks of 
the Grand Canyon region were first studied by Walcott 
(Walcott, 0) at the eastern end of the Kaibab division of the 
Canyon. They are described as a series of sedimentary rocks, 
12,000 feet in thickness; comprising limestones, shales, sand- 
stones, and interbedded flows of lava ; separated both from 
the underlying Vishnu schists and from the overlying Cam- 
brian sediments by profound unconformities ; and exposed over 
a considerable area in the greater depths of the Grand Canyon 
and in the inter-canyon valleys of the north side. To this 
series of sedimentary rocks the name “ Grand Canyon 
series” was given by Walcott. A slight unconformity of 
erosion was found to occur in the middle of the series. The 
strata lyimg below this minor unconformity were designated 
as the ‘“Unkar terrane,” while those lying above it were desig- 
nated as the “ Chuar terrane.” The Unkar terrane derives its 
name from Unkar valley, in which these strata are typically 
exposed. The Chuar terrane is named from its typical 
exposures in Chuar valley. These two valleys are parallel 
inter-canyon valleys of the north side of the Colorado river 
in the area described by Walcott. 

Lnistribution in the Grand Canyon.—There are six locali- 
ties within the Grand Canyon between the mouth of the Little 

Am. Jour. Scl.—Fourts Serizs, Vou. X XIX, No. 174.—June, 1910. 


33 


498 Noble—Geology of the Grand Canyon, Arizona. 


Colorado in the eastern end of the Kaibab division and the 
mouth of Tapeats Creek some 80 miles below in the eastern 
end of the Kanab division, where the strata of the Grand 
Canyon Series are exposed between the crystalline schists of 
the Archean and the basal Tonto sandstone of the Cambrian. 
The location of these exposures is shown on the map accom- 
panying this article. Five of the localities are within the 
Kaibab division; the sixth is within the Kanab. 

The first of these localities is the classic area below the 
mouth of the Little Colorado described by Walcott. This is 
the largest areal exposure of these rocks in the Grand Canyon, 
and includes both the Unkar and Chuar groups. 

The second locality les five miles west of the first at the 
head of the inner gorge of Clear Creek on the north side of 
the Colorado river within the depths of the Ottoman Amphi- 
theater. The exposure is limited to less than a square mile. 
It comprises a small portion of the basal Unkar and is strue- 
turally a unit with the first locality. 

The third locality lies along the north side of the Colorado 
river at the mouth of Bright Angel Creek opposite the railroad 
terminus and hotels of the Sante Fe Railroad. About 1000 
feet of the basal portion of the Unkar group are there repre- 
sented and the areal extent of the exposure is about three 
square miles. This locality has been briefly described by 
Ransome (Ransome, a). It hes about 10 miles west of the 
type locality. 

The fourth locality comprises a limited exposure of basal 
Unkar strata which lies in the depths of the Hindu Amphi- 
theater on the north side of the Colorado river about three 
miles up Crystal Creek from its mouth. It is situated some 
20 miles west of the type locality. The areal extent of the 
exposure is about one square mile. It is as yet undescribed. 

The fifth locality lies about the mouth of Shinumo Creek 
about 30 miles west of the exposures of the type area. It com- 
prises about 12 square miles in areal exposure and represents 
nearly the entire thickness of the Unkar group. It is hitherto 
undescribed in geological literature and is the subject of the 
succeeding pages of this article. 

The sixth locality is situated on the Colorado river just 
above the mouth of Tapeats Creek in the eastern end of the 
Kanab division of the Canyon, about 12 miles northwest of 
the mouth of the Shinumo im a direct line and about 25 miles 
down the river in its actual course. The length of the expo- 
sure is about three miles in the bed of the river and in its 
narrow gorge beneath the Tonto sandstone. About 4,000 feet 
of the basal portion of the Unkar group are exposed, striking 
N.W.-S.E. and dipping about 15° N.E. This locality is 


The Shinumo Area. 499 


structurally a unit with the exposures of the Shinumo area. 
Jt is unmentioned in geological literature. 

In the western end of the Kanab division in a section across 
the Grand Canyon at the foot of Toroweap valley, 50 miles 
west of the Shinumo area, Dution figures “ rocks of Silurian 
and Archean unconformable” in the bed of the river beneath 
the basal Tonto sandstone of the Cambrian (Dutton, a, p. 88). 
It is probable that these *‘ Silurian” rocks there represent the 
Grand Canyon series. 

Whether these rocks appear at places in the Shivwits 
division between the Vishnu schist and the Tonto sandstone 
is not at present known. 

Stratigraphic position, structure, and distribution in the 
Shinumo Area.—TIwo unconformities determine the strati- 
graphic position of the sediments of the Grand Canyon series 
in the Shinumo Area: they are separated from the underlying 
Vishnu schists of the Archean by a profound unconformity 
which represents a base-leveled surface of erosion, and from 
the overlying Tonto sandstone of the Cambrian by an uncon- 
formity which represents a similar base-leveled surface above. 

The strata of the Grand Canyon series here constitute a 
wedge-shaped mass whose apex lies along the south side of 
the Colorado river parallel to its northward course in this 
part of the area. The mass as a whole constitutes one great 
tilted block, which in turn consists of a great number of minor 
tilted and rotated blocks pitching at successively greater angles 
northeast away from the apex of the wedge, until at a distance 
of three miles from the Colorado river the whole mass is 
dropped by a profound fault which. brmgs up the under- 
lying Vishnu schist from a great depth,—a structure which 
strikingly resembles that of the area of similarly faulted 
Triassic blocks of the Connecticut valley. The strike of the 
strata is N. 40° W. The dips are variable: in general the 
strata of the fault blocks near the apex of the wedge dip 
10°-15° N.E.; near the center of the wedge the dips average 
25° N.E.; while in proximity to the line of the great limiting 
fault on the northeast they are completely reversed by the 
“drag” along the fault plane. The truncation of this _pre- 
Cambrian structure by the unconformity at the base of the 
Tonto sandstone is absolute. 

The great pre-Cambrian fault that limits the wedge upon 
the northeast represents the exposure in the basement rocks of 
the line of displacement of the West Kaibab fault and displays 
in the most spectacular manner a phenomenon analogous to that 
described by Walcott upon the line of the East Kaibab mono- 
cline (Walcott, z). Upon the line of the ancient fault in the 
Shinumo area two later displacements have taken place after 


500 Noble—Geology of the Grand Canyon, Arizona. 


the deposition of the entire Paleozoic series of the Canyon 
wall and probably later strata. The first of these is a mono- 
clinal flexure which reverses the throw of the pre-Cambrian 
fault, while the second is a still more recent fault super- 
imposed upon the line of the monoclinal flexure. 

The strata of the Grand Canyon series are exposed beneath 
the Tonto sandstone in all that part of the inner gorge of the 
Muay-F lint Creek canyon which is on the south side of the great 
pre-Cambrian fault,-—a distance of about three miles. They 
are exposed for three miles in the gorge of the Shinumo 
Canyon; for seven miles along the north side of the Colorado 
river; and in all the inter-canyon valleys within that distance 
which are eroded below the base of the Tonto sandstone. The 
two largest of these inter-canyon valleys are the “ Kast Wash,” 
a mile east of the Shinumo, and the “ Asbestos Canyon,” three 
miles to the west. 

The gorge of the Colorado river has everywhere been 
trenched to a depth sufficient to expose the Vishnu schists 
along the river beneath the overlying strata of the Grand 
Canyon series. This is due to the fact that the course of the 
river lies close along the southern apex of the wedge. 

The exposures on the south side of the river are more lim- 
ited, due to the thinning out of the wedge in that direction 
and the lack of inter-canyon valleys trenched beneath the Tonto 
sandstone. The strata are exposed for two miles above and 
one mile below a point opposite the mouth of the Shinumo. 

A southwestward bend in the river in the western part of 
the area carries it beyond the apex of the wedge, below which 
point the Tonto sandstone caps the Vishnu schists which lie in 
the river gorge. Southeastward up the river, in the eastern 
part of the area, a similar relation obtains. 

The hard middle members of the Unkar resisted the erosion 
which preceded the deposition of the Cambrian sandstone and 
stood as an island in the Tonto sea. 

This long monadnock of quartzite runs across the area in a 
N.W.-S.E. direction parallel to the general strike of the strata 
of the wedge, and a narrow outcrop of these quartzites is ex- 
posed along the Tonto platform on the north side of the river 
just at the base of the Redwall cliff, running for a distance of 
about five miles beyond the main areal exposures about the © 
mouth of the Shinumo and uniting with the limestones of the 
upper Tonto group to form the lower part of the great cliff of 
Redwall limestone. In the eastern part of this exposure the 
quartzite monadnock projects 700 feet above the base of the 
Tonto sandstone. Westward from the exposures about the 
Shinumo the prolongation of the monadnock along the strike 
of the quartzites exposes them in a narrow outcrop upon the 
Tonto platform one mile west of the Shinumo. 


LL 


The Shinumo Area. 501 


The total areal exposure of the Grand Canyon series in the 
Shinumo area is about 12 square miles. 

In following up the Shinumo from its mouth to the point 
where it leaves the lateral gorge of the Muav-F lint Creek can- 
yon, a traverse is made of the total exposed thickness of the 
Unkar group from the unconformity at the base to the highest 
member that is limited by the profound fault on the northeast. 
There can hardly be a more magnificent illustration of details 
of geological structure than is here revealed. Along the entire 
western side of the Shinumo canyon, in cliff faces a thousand 
feet above the bed of the stream, is displayed every detail of 
the structure beneath the basal Tonto sandstone. Westward 
down the Colorado river the intersection of the two great 
unconformities forming the apex of the wedge is seen in the 
cliff face above the river bank, below which point the river 
narrows in its somber gorge in the Vishnu schists. From here 
northeastward, in the cliff faces along the western wall of the 
Shinumo canyon, bed after bed of the Unkar strata appears, 
wedging out southwestward beneath the plane of the uncon- 
formity beneath the Tonto sandstone. Every detail of the 
successive fault blocks of the great wedge is clearly shown,— 
their increasing tilt northeastward, the dips of the fault planes 
that bound them, and the occasional down-dropped wedges. 
Above runs the plane of the pre-Tonto unconformity, revealing 
in cross section the monadnock in this peneplain which existed 
as a rocky island during the inroads of the Tonto sea, the debris 
from its wave-cut cliffs being incorporated and preserved to the 
minutest detail in the Tonto sandstone. In the background, 
bed above bed in conformabie succession, lies the horizontal 
Paleozoic section in the wall of the mile-deep Canyon. After 
traversing a thickness of 5800 feet of Unkar strata in a distance 
of three miles dipping northeastward into the bed of the stream, 
the traveler crosses the line of the great pre-Cambrian fault of 
more than 5800 feet and comes once more into the Vishnu 
schists on the farther side of the Muav-Flint Creek canyon. 

Here again is an instance of the simplicity with which the 
geological structure is revealed in this wonderful country. 
Along the whole northern wall of the lateral gorge he the 
Vishnu schists below the Tonto sandstone cliff. On the south- 
ern side, at the same level, lie the upper sandstones of the 
Unkar, their beds dragged up sharply against the fault line, 
which lies in the bed of the stream. The whole Paleozoic 
system on the northern side of the gorge has been dropped 
500 feet by the torn monocline of the West-Kaibab fault, 
reversing the throw of the pre-Cambrian fault on the same 
line in the basement rocks. Looking westward up the Muav 
Canyon, the beds of the Paleozoic are seen bending down 


502 WNoble—Geology of the Grand Canyon, Arizona. 


against the fault line in a graceful arc. Far up the canyon 
at its head under the Muav Saddle, the more recent fault has 
reversed its throw and restored the throw of the monoclinal 
flexure. There is not a detail of this structure that may not 
be seen at a glance. 


SEDIMENTS OF THE UNKAR GRovUP.—LITHOLOGY.. 


Preliminary Outline.—The pre-Cambrian sedimentary rocks 
of the Shinumo area represent the greater part of the Unkar 
group of the Grand Canyon series of Algonkian age. The upper, 
or Chuar, group is not represented in the area. Although 
these sediments present no more evidence of alteration or meta- 
morphism, aside from local igneous contact phenomena, than 
the overlying beds of the Paleozoic, they are destitute of fos- 
sils or decisive evidence of life. In the absence of fossils the 
natural basis for dividing the group into component mem- 
bers is the lithology. On this basis the Unkar group in the 
Shinumo area is divisible into five members, succeeding each 
other in conformable stratigraphic succession. It is not in- 
tended that the importance of this division should be greatly 
emphasized. Its chief value lies in the fact that it furnishes a 
basis for comparing the lithological succession of the Unkar 
group in this area with that in the type locality described by 
Walcott 30 miles to the east, as well as a basis for distinguish- 
ing in a broad way the main changes in the physical conditions 
under which these sediments were laid down. 

At the base, resting upon the profoundly eroded and base- 
leveled surface of the metamorphic rocks of the Vishnu series, 


Synopsis. 
Tonto Group 
Unconformity. 
5. Micaceous shaly sandstone (exclusive 
of 36 feet of intrusive rock)------ 2297 
4, Sandstone and quartzite.__.------- 1564 
| 3. Argillaceous and arenaceous shale 
r f f intrusive 
ia eeaoun (exclusive of 950 feet o 
ce P TOCKs) ih. J Be eee ee 580 
| 2. Calcareous shale and limestone..--. 335 
13, Basaliconslomerates2 228559 2eee 6 
[ Total 2 seduces Se ee 
Unconformity 


Vishnu series. 


The Shinumo Area. 503 


is a thin conglomerate. This constitutes the basal member of 
the Unkar. Overlying the conglomerate is a series of lime- 
stones and ealeareous shales. These grade upward into argil- 
laceous and arenaceous shales which are intruded by a thick 
sill of diabase, and are succeeded in turn by great thicknesses 
of sandstone and quartzite. The uppermost exposed member 
of the group in the area is a thick series of micaceous shaly 
sandstones. 

It has been shown that these strata lie in a wedge-shaped 
mass inset in the Vishnu schists, and that this wedge is com- 
posed of a great number of smaller titled fault blocks. It is 
apparent from this relation that nowhere in the Shinumo area 
ean the thickness be measured in one unbroken section. Sinee, 
however, the lithological characters of the strata are constant 
and easily recognized, and since the throw of the faults that 
bound the titled blocks seldom exceeds 100 feet, the restoration 
of a section showing the unbroken sequence is not a matter of 
great difficulty. 

Detailed sections were made upward from the base of the 
Unkar through each fault block until its limiting fault was 
reached. The highest bed measured was then located in the 
next block to the northeast, and the measurement resumed at 
that point. Except in the fifth, or highest member of the 
group, all sections were measured with a tape along the nearly 
vertical wall faces of the box canyons of the Shinumo and 
other washes that cut across the strike of the strata. In the 
fifth, or highest member of the group, the strong drag of the 
great fault on the northeast has flexed and contorted these 
shaly sandstones in such a manner that accurate measurement 
with the tape alone was impossible. Their thickness was 
computed by the aid of trigonometric formule, using the com- 
bined data afforded by the use of the tape, the topographic 
map, and observations of the varying strike and dip. 

The section incorporated in this article was made in two 
places. The greater part of the total thickness was measured 
in a traverse up the Shinumo. This section includes all the 
strata above the diabase sill which is intruded midway in the 
“arenaceous and argillaceous shales” which comprise the third 
member of the Unkar. It would have been perfectly possible 
to make a complete section of the group in a traverse of the 
entire course of the Shinumo from the basal unconformity at 
the mouth of the creek to the great fault three miles above, 
although four faults cross the creek between its mouth and the 
place where the diabase sill dips beneath the bed of the stream. 
But a place was found in the canyon of the East Wash where 
all the strata between the basal unconformity and the diabase 
sill lie in a continuous unfaulted section, in a fault block that 


504 Noble—Geology of the Grand Canyon, Arizona. 


is tilted about 10° N.E. The section of the basal members of 
the group was measured in this locality, where the sequence is 
unbroken by faulting. 


Detailed Section. 


Lirst Member.—Basal Conglomerate. The surface rep- 
resented by the upper unconformity that separates the Unkar 
group from the basal Cambrian is a striking enough example 
of a base-leveled surface, although monadnocks rise in places to 
a height of 700 feet above the base of the Tonto sandstone. 
But the surface represented by the lower unconformity that 
separates the Unkar group from the Vishnu is an almost per- 
feet plane: nowhere in the seven linear miles exposed in the 
Shinumo area can a difference in relief be observed that 
exceeds 20 feet. The depth of weathering below this surface 
appears to be slight, in spite of the enormous amount of rock 
that has been removed, and the weathering appears to be the 
result of physical disintegration rather than of chemical 
decomposition. 

The basal conglomerate is an arkose conglomerate varying 
in thickness from 1 to 6 feet in the Shinumo area. It is com- 
posed of angular or subangular fragments of the rocks of the 
underlying Vishnu series, cemented by a roatrix of red arkose 
mud which usually contains small fragments of pink feldspar. 
Occasionally the matrix contains small rounded grains of 
quartz. 

The degree of induration of this conglomerate presents all 
variations from a hard, dense, siliceous rock, which fractures 
across matrix and enclosed rock fragments alike, to an easily 
disintegrated rock in which the matrix crumbles away from 
the enclosed fragments. This phenomenon, however, does not 
depend upon original cementation, but upon metamorphic 
effects produced by the diabase sill that is intruded in the over- 
lying rocks, the degree of induration depending upon how far 
the conglomer ate lies below the contact of the sill. 

The matrix is usually of the same composition everywhere 
in the area. The character of the enclosed fragments, how- 
ever, is sharply localized by the character of the underlying 
rock. The rock which underlies the conglomerate in the East 
Wash is the quartz-diorite of the batholith previously 
described. For three feet below the conglomerate the diorite 
is weathered along the joints into roughly angular blocks. 
These joints are filled with the red arkose material of the 
matrix. Above follows a layer of the conglomerate one foot 
in thickness, composed of weathered fragments of the diorite 
cemented with the red arkose material. Then follows a layer 
six inches thick composed of small rounded quartz pebbles and 


The Shinumo Area. 505 


fragments of chert of the same character as that contained in 
the overlying limestones. The whole is cemented with the red 
mud. The conglomerate is very little indurated in this local- 
ity. Although the contact of the diorite with the mica-schists 
in the underlying Vishnu is not two hundred yards distant, 
there is not a fragment of the mica-schist to be observed in the 
conglomerate. 

In the Asbestos Canyon, four miles to the west of the East 
Wash, the underlying rocks are mica schists and veins of 
quartz and pegmatite. Here the Vishnu schist is scarcely 
weathered at all below the unconformity. The overlying 
conglomerate is 6 feet thick and consists of angular fragments 
of the underlying mica-schists, fragments of pegmatitic feldspar 
and vein quartz, and the arkose cement described above. The 
degree of induration is here very great, and the rock fractures 
across the grains like a hard, dense quartzite. This is due to 
the fact that the lower contact of the diabase sill lies only 150 
feet above this basal conglomerate in the Asbestos Canyon, 
while in the locality in the East Wash it lies 550 feet above. 

Two important features characterize the basal conglomerate 
of the Unkar in the Shinumo area; the arkose nature, and the 
lack of sorting and transportation of the component frag- 
ments. 

Second Member.—Calcareous Shales and Limestone. The 
section was measured on the west side of the canyon of 
the East Wash. This and all the following sections read from 
the base upward, a. 1 being the bottom bed, overlain by a. 2, 
ete. 


CHARACTER THICKNESS 
a. Basal white limestone. 


1. White, nodular, cherty limestone. The chert 

occurs in nodules with a roughly concentric 

structure somewhat suggestive of the structure 

GIAO ENO LO ZO OMe Meo edesne att neni nero erate 3 1k6s 
2. White, cherty limestone carrying the chert in 

thin parallel bands which are etched out by the 

weather on the cross sections. ‘The surface of 

each chert layer shows polygonal cracks sugges- 

tive of sun-cracks in shale. This structure 

belongs to each separate chert layer and is not 

a columnar structure. The weathered surfaces 

of these chert layers are dotted with small cubic 

depressions which were apparently formed by 

the leaching out of some mineral of a cubic 

TE en a IG eas Sf otc 4’ 6" 


506 Noble—Geology of the Grand Canyon, Arizona. 


CHARACTER 


b. Argillaceous and calcareous red shale and limestone. 


1. ottenurple: shales: eos a8 oe oe eye eee 
2. sleurple, chert ylumestones 2. == seems. oa iaeee 
3. Purple shale with occasional bands of purple 
Galleite 528/08 ER eee ets cr eee ee 

4, Purple, crystalline limestone ___---.----.-_.-_- 
5, Alternating layers of buff and chocolate-red 
shale with a splintery habit of weathering and 

a roughly concretionary structure. Like all the 
succeeding shales and sandstones of the Unkar 
they are mottled with light-colored spots which 

are usually circular or elliptical in form and of 
aULSIZeS Baa aera a pew ae i se 

6. Blue limestone, white for 1” at the base and 
showing dendritic markings 22225) 32 sees 

Ta redishale ee 2 coe eee ey ee ee oe na 
8. Blue limestone 22-2 e205 a ese 
9. Red shale uy. eos eal wee) gee eee 
10:\Purpledimestone.) 20s 5 2) soe aoe ee 
11. Calcareous, red shale with three thin bands of 
purple limestone [2.0 ese oa ae see ee eee 

12.) Red) crystalline limestone {a5 02252 oe see 
18.) Red shalevsocS 2 ae ee eee 
14. eds crystallinedimestome ===> 222 se eee 
15 Red whale 2G Tee eee Oe ee 
16) Blue limestone hae se 2 ee ee ea 
17, dvedushalesa: se este ee ee ee eee 
18. Bluedimestone en. | ese) oes ees 2 eee 
19.) Pink limestone 3218 oe ee ee 
200 Red: shale ta 425 2e week ues see eee ae 
21, Ohertys aiite limestones aise eee 
22. Compact, red shale forming a cliff.__.-...---- 
23. Alternating layers of buff and red shale-__---__. 


Dense, purple, calcareous shale carrying bands 
of pink calcite and forming a cliff. Contains 
occasional thin bands of chert .--..---------- 


. Blue, calcareous shale with an onion-like concre- 


tionary structure on a large scale_._-..--...-- 


c. White limestone. 


Li, 


2. 


Thin-bedded, white, cherty limestone carrying 
the chert in parallel bands, and containing three 
paper-thin layers of purple shale. Weathers 
to a white powder. Dendritic markings are 
present 2212 ee a ee eee ees Coe 
Nodular, white, cherty limestone. The chert is 
present in irregular nodules of no definite shape. 


THICKNESS 


6” 


85. 7tom 


— 


The Shinumo Area. 507 


CHARACTER THICKNESS 


hie 


23. 


24, 


SO 0-1 


The upper part of the stratum has a paper-thin 
bedding giving it the aspect of a calcareous shale. 
The limestone weathers to a white powder. 
Dendritic markings are present __--..----.--- 


. Dense, homogeneous, white, crystalline lime- 


stone, forming a cliff. The upper part is thin- 
ieee sn oe ees Ses ee 


. Homogeneous, thin-bedded, white, crystalline 


limestone containing occasional thin bands of 
chert and nodules whose character suggest the 
srBueLEre OF Cry ptoz00nt os 2. oats on ee Sc 
White limestone carrying a large amount of 
chert in undulatory and gnarled bands -.----. 
Lumpy and gnarly, white limestone carrying 
chert in large irregular nodules. Crumbles to 
Ba WHECAPOWOEE: 222 ys mat en ees PN Shs 


MreEp le Sale poses fee AH Ses 


Layers of undulatory-banded, bluish chert- ---- 


MSerC WMUEp oO shiale fe oa see! Satya le 


Layer of gnarled and twisted chert nodules in a 
matrix of white talc. The surface of the talc 
is covered with dendritic markings ..-.-_---- 
Thin-bedded, white limestone crumbling to white 
powder or weathering into thin plates like a 
SN See oN Nr ce oe ae Cpe: ok ee Derma 


Be OO Hi saDUPple SMaAlO uss SS hee ooh ts es rege ia 
_ Thin- bedded, crystalline, white finest oe 
. Soft, purple ic eee Ne 
Dense, blue, crystalline limestone hee ae a 


small EE. ard ae ee ee ONE Ao! cole OE AN eS 


. Homogeneous, thin-bedded, white limestone, 


crumbling to a white powder and weathering 
Mino plavesstike a Shalere. S12. 228 Syne 


. Dense, crystalline, blue limestone _-__-.--..--- 
2 APATITE G12 GARR aes Sha secre Saar eC 
. Layers of undulatory-banded, nodular chert in a 


matrix of earthy white limestone __-_-..---.--- 
Thick-bedded layers of pure, homogeneous, 
white marble, forming the strongest cliff in the 
secon member of the Wnkare. 2. 2.22. 


eoamic ut taminer beds: 322225. a's) ee oe oe 
2. Undulatory-banded, cherty limestone becoming 


Gly sia Ne ANON C5 ane pce ee 
Red shale below and purple shale above, sepa- 
rated by a thin layer of chert _._......--...- 
Thick-bedded, crystalline, white limestone of 
ee same character as 20, forming a strong 
CLUTTER = Silence SNES ie 0c oe oD, ae ae 


508 Woble—Geology of the Grand Canyon, Arizona. 


C 


2K 
26. 
Wie 


d. 


oR ONE by 


SoC OGD 


HARACTER 


Thin-bedded, crystalline, white limestone -_-___- 
Gnarled and nodular, white, cherty limestone _- 
Very hard, dense layer of flint forming small 
GUT ooo wn bo ev EB eked ee ee ee 


lue slate and white limestone. 


Soft; purpleishale; Ne 22 eee eae cee 
Hard, blue slate forming small cliff_..__.._-_- 
Fissile, blue slates with fine partings ___.__--- 
Thin-bedded, purple, crystalline limestone ~__- 
Dense, purple, crystalline limestone forming a 
smiall-cliff 2. oe Be eed 
Same aise ha VN es Ue een 
SaMelasiay LOu MMe. sill ee liit mes ee 
Thin-lamellar, spotted, blue slate-_-...__-.-.-- 
Gnarly layers of fine-lamellar, blue calcareous 
slate with a very coarse concretionary struc- 
ture. Irregular nodules of chert occur in the 
middie portion 220 Uae ene ene ee 


. Dense, blue, crystalline limestone forming small 


C)UEE! coor i A En Se en ee ee 


. Thin-bedded, platy, white limestone_.-----.-- 
. Very thin-lamellar, fissile, blue slate________-- 
. Calcareous, blue slate forming a cliff ___.._._- 
. Thin-bedded, platy white limestone.-_-.--.---- 
>. Missile tblaeslate sis 2) os eee ee ee nee 
. Dense, lumpy, white crystalline limestone ---. 


Pinkish-green, fissile, siliceous slate of a jaspery 
appearance Lorine aye lith =e ee eee eee 


. Layers of dense, white, crystalline limestone 


separated by thin bands of pale-green, talcose 
MMAerials Tey Le Bs oe SNe ee re ae ee ee ee 


. Dense, red and black-banded jasper, weathering 


green between the layers and forming a cliff. 
The layers contain shrinkage cracks and ripple 
WALKS" hc se ee ee ee 


. Layers of dense, white, crystalline limestone 


separated by bands of pale green, talcose 
material 2.027. Jo) ee Ss ee eee 


Synopsis of second member of the Unkar. 


a. Basal white limestone eee]. oe ee ees 
b. Argillaceous and calcareous red shale and limestone 
ce. WW thhite limestone {tie ee el oo aie eels a 
d. Blue slate and white lnmestone. 92225225). 223 


Total thieknessaei:. 20 eee Re 


THICKNESS 
5! 6” 
we 


5 y 


9! Bul 
9! 6” 


ay 6” 


aha Au 


The Shinumo Area. 509 


When the specimens of these rocks were examined in the 
laboratory it was found that all the limestones were more or 
less dolomitic. The limestones of division ‘“*¢” were found to 
be entirely dolomites. 

Thin sections were cut from specimens from twenty separate 
beds in the second member. Eighteen of these slides were cut 
from the limestone strata and two from the red shales. The 
sections of the limestones were cut both from the chert 
bands and the nodules and from the limestone itself, for 
the purpose of ascertaining the exact mineralogical char- 
acter of these rocks, and in the forlorn hope that they 
might reveal traces of a structure that could be referred 
to something organic. No ininerals other than calcite and 
quartz were revealed by the microscope in any of the shdes. 
The silica of the chert bands and nodules was found to exist 
in the form of interlocking grains of quartz. None of the 
grains were rounded and there was no suggestion that the 
quartz grains of the chert bands represented an inwashed sand. 
Nor was there any trace of an organic structure revealed, 
either in the chert or in the limestone. The purer limestones 
were found to consist of calcite (or dolomite) alone, the crys- 
talline forms having the typical structure of marble. The 
impure varieties were found to consist of mixtures of quartz 
and calcite in all proportions. The greater part of the lime- 
stone was of this impure character. The shales were found to 
consist of a fine impalpable ferruginous or calcareous mud, 
containing occasionally a minute grain of quartz. 

Several features of interest are shown in the lithologic sec- 
tion of the second member of the Unkar as a whole. 

Ripple marks and sun cracks appear for the first time in the 
shales in stratum No. 18 of division “d,” just below the highest 
limestone stratum at the summit of the member. 

The increasing intensity of metamorphic phenomena in the 
section from the base upward may also be noted. This is due 
to the approaching proximity to the lower contact of the dia- 
base sill which is intruded in the member above. The 
metamorphic action is manifested in the shales by their change 
upward both in color and in degree of induration: the shales 
of division “>” are almost entirely red; from the summit of 
this division upward the color changes to purple and blue. 
Below division “d@” the shales are soft and crumbly; within 
this division, however, they become dark blue slates, while in 
the upper part they become extremely hard, siliceous jaspers. 

The vertical succession of the strata is seen to be broadly 
characterized by continual and rapid alterations of limestone 
and shale. According to the dominance of either type of rock 
the four divisions a, b, c, and d are separated : division “@” is 


510 WNoble—Geology of the Grand Canyon, Arizona. 


entirely limestone, “6” is alternating limestone, and “d” 
predominantly shale. Thus there are four major cycles of 
oscillation upon which the minor cycles are superimposed. 

A comparison of the above section in the East Wash with a 
section measured in the Asbestos Canyon, four miles to the 
west, is of interest. In the Asbestos Canyon the “ basal white 
limestone” (a) has a thickness of 30 feet contrasted with a 
thickness of 6 feet in the East Wash. The lower stratum of 
“nodular, cherty limestone” is there 7’ 9”, contrasted with 
1’ 6” in the East Wash. The upper stratum of “parallel- 
banded, cherty limestone” is 22’ 3” in the Asbestos Canyon, 
containing in the middle an intercalated layer of purple shale, 
and near the top a thin layer of rather fine arkose conglomerate. 
The “ argillaceous and calcareous red shales and limestones ” of 
division “6” have a thickness of 88 feet in the Asbestos 
Canyon contrasted with 85’ 5” in the East Wash. They do 
not have the red color that characterizes them in the East Wash, 
but are purple and blue, and much indurated. This change of 
color and difference in degree of induration is due to their 
closer proximity to the diabase sill in the Asbestos Canyon. 

The correspondence in lithographical character and vertical 
succession of these two sections four miles apart is so close that 
the individual strata of the sections can be matched bed for 
bed. The only marked contrast in thickness occurs in the 
basal white limestone (q). 


Third Member.— Argillaceous and Arenaceous Shale. 


Section measured at East Wash in continuation’ of the pre- 
ceding section. 


a. Clif-forming jasper. 

1. Dense, hard layer of blue-black jasper mottled 
with red spots and showing no banding in the 
mass, forming with the three following layers a 
strong perpendicular cliff. This is the most 
resistant rock in the Unkar. Where the under 
surface shows beneath the overhang of the cliff 
it is sun-cracked on a large scale and in several 
generations! (oc pee! eee Reape) ys, ah 28' 
Same general character as 1, but showing a 
banded structure. The lower 2 ft. are slaty and 


bo 


weather out, giving the cliff an overhang.. ---- 19° 
3. Same as 2 with a soft slaty layer at the base. - - 14’ 
4. Same as 2 and 3 witha soft layer at the base. 12! 


Total 73° 


The Shinumo Area. 511 


6. Caleareous blue slate. 


1. Slaty, black jasper, sun-cracked throughout. -- 12’ 

Ae Eankperystalline limestone: 22222-2205 42 lL. eG 

3. Slaty, blue jasper with small red spots... .- 4’ 6" 
Total ie 


ce. Clif-forming jasper. 
1. Dense, hard layer of blue-black jasper mottled 
with red spots, forming with the following 


prerawesurOme lilt. see as 2¢ ee ou eae 14’ 
2. Same as 1 with a soft slaty layer at the base 
which weathers out, giving the cliff an overhang. 3a 6” 


Total A Pea 
d. Sandy quartzitic jasper. 


ie olaty. blue, spotted jasper.0.-.20 2 22.22.2222 4’ 
2. Fine-grained, pink quartzite, ripple-marked ~ -- 5! 
aa olay, Dive, Spotted Jasper. — 0. - 2.2 2252022- 1? 
fFeob ine-orained, pink gQuartzite. 2-2 22_. 22222222 4! 
5. Slaty, blue, spotted jasper with sun-cracks. .. ._ 6 
6. FHine-grained, pink quartzite, ripple-marked. _- 1 
Bpeieliis UAECZItIC. Jasper... 2. 822 fsa 2 52. Li 5! 
es) Pine-erained, pmk quartzite...2.2.- 22.2.2 4! 
9. Fine-grained, pink, sandy jasper, sun-cracked _. ee 

Total 52! 


é. Red and blue jasper. 
1. Banded, blue jasper with curious spots. Sun- 


ELACKCO CMEOUGNOUW een 4 2 oe ee ee 22" 
2. Red and black banded jasper ..-._----..--.-- 9’ 
Total 31’ 


Jf. At this horizon is intruded a sill of diabase, whose 
thickness varies from 650 feet on the Shinumo 
to 950 feet or more in the Asbestos Canyon. 


The remainder of the section was measured in a traverse up 
the Shinumo, starting with the upper contact of the diabase 
sill. 


g. Blue slate and quartzite forming a cliff.--.-.....-- ee 20, 
Pade state: forming a slope se220 22 222 5 tee feb Le 100’ 
7. Red, argillaceous shale —sun-cracked throughout. 
The rock is very soft and forms a slope together 
with the underlying blue slate... -....2._.2....- ile, 
j. Alternating, vermilion, argillaceous shale and sand- 
stone. 


The alternations in this series occur with remarkable reg- 
ularity. The sandstone is white in color and is compact and 


512 Noble—Geology of the Grand Canyon, Arizona. 


fine-grained. It is cross-bedded and ripple-marked throu; | 

out. The shales of the alternating beds are very soft <.” 

weather out, leaving etched-out bands between the sandsto: » 

which are very conspicuous in the cliff-faces. On the unc 

surface of each sandstone layer are beautifully preserved s 

cracks. The shales are fine-grained, fissile, and argillaceous 
The succession in this alternating series is as follows: 


No. Bed Thickness S. S.—Sh. cycle 

1. Sandstone- __-- Ae pt 

OAD ale tee! tee BO! sa ve eatin 8” 

SMOG et eee nee 

As eSNG ee eae atte Bi ia 5 

BRAS IS: GP aan ie 

i sigro) cgmee en a i Bac OF 25) eee Bes ee 3 

Te Se cen ee Me) Gy 

Sh ee eas LOKI 2078 5 eo ge ae pce Ge 

OLS, Si eames 5 

LOSS bose a eo sapeee Be ge Phe ya ae ee 8! 

Lease nee omen hie, 6! 

Toy eae Beek Rea AGE rete ba ee a ales 8’ 6” 

13 05s Re ee a eee 

eT Asse Shia he i ge pep eens Spc ight. ya dee eae 9’ 6” 

Lye fs tat Fan oe gah itd 6! 

1 GP pS ay SRO erty a ae OG 

C72 CNS ae eee Tain 

16 LON: Maks be Beas Aa ee Vs le ae ee tiesGe 

1 Telia: Bie yg eet et Bou 

TA Othe 1 pee aed IM a AI Gr, Se ee aa 4! 

DAS Sas ae a eee 

DOSED ih oe ees hea Le pe on 

De GND TONe 21ers BO” 

DARA SIs areas cee DECI: Lee T ee a eae Gas 

DSS Sr See are 2 

Vor Siiseeee wr eee OG H Ce ae ees 8) eam 

7a Fidel > ke a 3! 

O80: Sink ee eens Oia te | eine ee a ie 
Otaleuer: 109/47 Ave., 7 Oe 


k, Alternating, vermilion, arenaceous shale and sandstone. 


The sandstone is white, compact, and fine-grained. It 
cross-bedded and ripple-marked throughout. The unde: 
surface of each sandstone layer is sun-cracked where it resi: 
upon the arenaceous shale. The shale is vermilion in coor, 
soft, and very sandy. Sun-cracks occur throughout. 

The succession is as follows : 


The Shinumo Area. 513 


ieesandscones! ai) suse Zoe gi 4 
Jae arenaceous shales 1 aueyegs Fe 21 1" 
Sweandstone se. (kneels eee ieee Se 9! 
£ sArenaceous shale i... 222 bank v2--2 = lh) 87 
Rem Sam@d stoners.) 4 2)... Syne wn eigess = 9-2! 
GapArenaceous shale. . 24.524 <2 22 Se-22: 24! 
MS UNUCTONC 2 xc). eyes oe al! 
Total OS AM 
Synopsis of third member of the Unkar. 
Gae@Mit-formine jasper. o.42 4-55-2229 73° 
b. Blue slate with caleareous band..-.- 18’ 
GC litt forming: jasper essa 1 ae. 2 17 6 
Ge sandy quartzite: jaspeleee = oe a5 2 - 52! 
Go teed and jolie? Jaspelas a2 ase. 31’ 
J. (Intrusive diabase) 
g- blue slate and quartzite. 22222 .< - 20° 
Jimmintucrslater. 20s 0 te eo tee LOO 
a xed areillaceous’ shale. 25225222 81’ 
j. Alternating vermilion argillaceous 
Shera an Seeie sae EeN Sra) 2 NOG 4? 
k. Alternating vermilion arenaceous 
Siialle andusy Si See eee SOURS wee Tope 


Total thickness RO 


Thin sections were cut from several specimens of the 
jaspers. The slides were unsatisfactory, however, because of 
the exceedingly fine grain of the rock. The highest power of 
the microscope revealed nothing more than an impalpable 
silicified mud. -A slide of the ‘“ quartzitic jasper” showed it 
to have been a somewhat arkose sandstone indurated to a 
siliceous quartzite. It was seen to be composed chiefly of 
small rounded quartz grains about which secondary silica had 
been deposited, lying in a fine arkose matrix made up of small 
fragments of pink feldspar. A thin section was also made 
from a specimen of one of the sandstone layers in the “ alter- 
nating argillaceous shale and sandstone” of division “7.” 
The rock proved to consist of small, well-rounded grains of 
quartz, cemented by silica in the form of secondary quartz. It 
is a pure, fine-grained sandstone. 

The metamorphic effects produced by the diabase sill 
intruded at the horizon “7” are seen in the lithologic section of 
the third member given above. This metamorphic action is 
manifested in three ways: 


1. Induration by silicification,—jaspers. 
2. Induration by baking,—slates. 
3. Decoloration,—red to blue and black. 


Am. Jour. Scl.—FourtH SERIES, Vou. XXIX, No. 174.—June, 1910. 
34 


514 WNoble—Geology of the Grand Canyon, Arizona. 


It was noted in the summary of the features of the second 
member that the shales became successively slates and jaspers 
above, while their color changed from red to blue. In the 
third member the shales are represented entirely by jaspers 
and quartzites. Just below the contact the induration is very 
great, and the jaspers are tough and vitreous; the prevailing 
color is blue or black. Above the contact the overlying rocks 
are hard blue slates for 20 feet, succeeded by 100 feet of less 
indurated slate, grading upward into the original red shale. 

The metamorphic effects above and below the contact differ 
in degree of intensity as well as in kind: above the contact 
the induration and decoloration characterize only about 100 
feet of strata; below the contact this action extends through 
300 feet. Above the contact the strata are characterized by 
baking and decoloration only, changing the red shale into a 
blue slate; below the contact there has been a considerable 
addition of silica, transforming the red shales into blue and 
black jaspers; added to this are the effects of baking and 
decoloration. 

It may be said in summary that the third member is charac- 
terized by argillaceous shales in the lower portion, which grade 
upward into arenaceous shales and sandstones through the 
interesting series of alternations described in division “7.” 
There is hardly a stratum in the entire member that does not 
bear marks of shallow water origin, manifested by either sun- 
cracks, ripple-marks, or cross-bedding. 


Fourth Member.—Sandstone and Quartzite. 
Section on the Shinumo. 


a, Purple-brown sandstone of fine grain containing locally 
an occasional lense of fine conglomerate and sometimes 
a thin local bed of red or purple shale. The sand- 
stone is cross-bedded throughout -_..-..------------ 406’ 
b. Compact, white quartzite of fine and uniform grain, 
displaying a faint cross-bedded structure. ‘This quartz- 
ite is the most resistant rock in the fourth member, It 
is exposed everywhere in one massive perpendicular 
cliff face, which does not display the slightest break 
except where it is cut by faults. Wherever its base 
rests upon a shaly lense the under surface displays 
well preserved mud-cracks. The face of the cliff is 
stained magenta by the ferruginous cement of the 
shale lenses in the overlying sandstones, which washes 
down from above 2222... 22 2 eee eee 1197 
c. Purple-brown sandstone of the same character as a.-.- 353’ 
d. Banded, white quartzite, stained magenta on the expo- 
Sures, and forminepanelith).. (eos) se eemeee Cece eee 120’ 


The Shinumo Area. 515 


é. Fine-grained, purple sandstone with a white band in the 
middle. The white band is constant and presents a 
conspicuous feature by which this purple sandstone 
can be distinguished at a distance of several miles. 
The rock is cross-bedded and sometimes displays a 


mimaisted and onarled ” structure: 252500 s5e22 4 2b i.) 150’ 

Jf. Compact, cliff-forming, white quartzite of the same 
character as 6, though not so massive in structure --. 250’ 
Peisandeduwinte quartzite 02.2). 251.2 s be. uot ke 20’ 


4 ter ede bedded sandstone ..-.. --- mprive 
1. “Curiously twisted and gnarled layers,” of. fine- 
grained white sandstone containing large red spots of 
a circular and elliptical form. The upper part of the 
bed is more massive. The twisted and gnarled struc- 
ture seems to have been a phenomenon of the original 
deposition. It gives the rock an appearance which 
suggests that the original sand was moist and plastic 
and once flowed by rolling over and over in the form 
of a quicksand. 105’ 
(It may be noted that a bed of this character is 
described by Walcott in his section in Unkar Val- 
ley. (Walcott 6, page 511.) It occurs at the same 
horizon as the bed described above, and contains the 
same red spots.) 


mesamaed. purple sandstones: 2.21 l.262.5.L-22L205-2- 20! 
3. Green, cross-bedded sandstone .--....-....------_--- DIL 
146’ 


The total thickness of the fourth member of the Unkar is 
1564 feet. 

Slides were cut from several specimens of the sandstones 
and quartzites. All were found to consist of small rounded 
quartz grains, the size of which seldom exceeds 0°7™™. This 
extreme fineness and roundness of the grains, as well as the 
cleanness of the sorting, is remarkable. The cement is usually 


siliceous, sometimes slightly ferruginous. <A slide was made 


from a specimen taken from one of the small conglomerate 
lenses in division a. The conglomerate was found to consist 
of small rounded quartz pebbles, lying in a fine arkose matrix. 
Occasional large angular fragments of orthoclase and micro- 
cline were revealed. 

In summary it may be said that the fourth member is char- 
acterized by great thicknesses of pure, fine-grained sandstone 
of a uniform character. All divisions of the member are 
resistant to the weather and form cliffs. Ripple marks and 
cross-bedding occur throughout. 


Fifth Member.—Micaceous Shaly Sandstone. 


Section measured in Fault Wash, west side of Shinumo 
Canyon. 


516 Woble—Geology of the Grand Canyon, Arizona. 


a. Gray-green, pinkish-green, and brown micaceous shaly 
sandstones, cross-bedded and ripple-marked, varying 
in character only through gradations in color. ‘Fre. 
quent arenaceous and argillaceous shaly partings occur, 
causing the rock to weather like a soft sandy shale. 
The shale partings are usually green. Some of the 
sandy layers near the base show the “gnarled and 
twisted structure.” .__- ..- ite boos. 1 

bs ihe oreen, oray: and brown beds of a pass upward 
through change of color into red and vermilion beds 
of the same general character. These are likewise 
micaceous shaly sandstones, cross-bedded and ripple- 
marked, with arenaceous and argillaceous shaly part- 
ings, which display well preserved mud-cracks. The 
shaly partings are either green or red _-____¥2_ 25528 1197 


Totaliot inci aout fo es ee eee 2297’ 


The summit of the Unkar section is obliterated in the beds 
of division 6 by the plane of the pre-Tonto unconformity. 
The highest beds of this division lie at the upper end of the 
Fault Wash, dragged against the Vishnu schist on the north 
by the great pre-Cambrian fault previously described, and the 
whole overlain by the Tonto sandstone. 

In the uppermost part of division 6 are four thin sills of 
rotten basaltic rock, weathering green and crumbling to small 
fragments. They occur between the beds of vermilion sand- 
stone and shale. Their intrusive character is shown by the 
fact that they have baked and decolorized the vermilion 
beds for a few inches both above and below the contacts, 
changing the color to purple. The rock is too badly weathered 
to allow a petrographic determination in thin section. 

In summary the fifth member of the Unkar may be charac- 
terized as a series of micaceous shaly sandstones of uniform 
character, varying only in color, and bearing marks of shallow 
water origin throughout. 

Comparison with the type section im Unkar Valley.— 
A comparison of the above section of the Unkar group with 
that described by Walcott (d) in the type locality 30 miles to 
the east reveals the fact that the correspondence between the 
two sections is very close, both in thickness and in lithological 
succession ; only in the lower portions do they differ materi- 
ally. The type section in Unkar valley is characterized by a 
eveater thickness of the basal conglomerate, and by only a third 
as much limestone in the members which correspond to the sec- 
ond member on the Shinumo; the deficiency in limestone is made 
up by greater thickness of arenaceous and argillaceous shale. 
Proceeding upward in the section there is a somewhat greater 


The Shinumo Area. EST 


proportion of sand in that division of Walcott’s section which 
corresponds to the third member on the Shinumo. The succeed- 
ing members correspond closely in character and thickness 
even to the minor divisions; an example of this is the 
‘“‘onarled and twisted layers” previously cited. | 

The writer had the privilege of examining Mr. Walcott’s 
field specimens in the National Museum in Washington and 
was particularly impressed by their absolute lithological iden- 
tity with the series collected by himself from corresponding 
horizons on the Shinumo. The two series of specimens, with 
the exception of those rocks altered by local metamorphic phe- 
nomena, might have come from the same locality. 


DIABASE INTRUSIVE IN THE UNKAR. 


Occurrence.—The diabase occurs in the form of an intrusive 
sheet or sill which occupies three separate stratigraphic hori- 
zons in the Unkar sediments in different parts of the Shinumo 
area. On the west side of the Asbestos Canyon three miles 
west of the Shinumo it is intrusive in the limestones of division 
¢ of the second member of the Unkar at a horizon 15 feet above 
their base. On the east side of the Asbestos Canyon it ascends 
out of this horizon and breaks across the overlying limestones 
and shales in an eruptive contact. Most of the lower, and part 
of the upper, sections of the eruptive contact are beautifully 
displayed in the walls of this canyon, but the complete expo- 
sure is obliterated above by the truncating unconformity 
at the base of the Tonto sandstone. Between the exposures in 
the Asbestos Canyon and the main areal exposures about the 
mouth of the Shinumo, the pre-Cambrian structure is hidden 
beneath the sandstone of the Tonto platform. Where the dia- 
base reappears in the exposures about the Shinumo it is found 
to lie intruded midway within the shales of the third mem- 
ber of the Unkar at a horizon 400 feet above that which 
it occupies in the Asbestos Canyon. This is the stratigrapbic 
position which it holds in all the exposures of the central part 
of the Shinumo area. Eastward up the river from the Kast 
Wash the diabase again disappears beneath the pre-Tonto un- 
conformity. But directly under Havasupai Point, about three 
miles farther east, limited outcrops of the basal portion are 
exposed in small inter-canyon valleys on both sides of the river. 
Here the lower contact of the diabase lies just at the top of 
the “ white limestones” of division ¢ of the second member 
of the Unkar. 

The thickness of the sill is approximately 650 feet on the Shi- 
numo and 950 feet on the west side of the Asbestos Canyon. 
Eastward from the Shinumo the outcrop is considerably 


518  Noble—Geology of the Grand Canyon, Arizona. 


thinned by a strike fault, precluding the possibility of measur- 
ing the thickness in that direction. 


PETROGRAPHY. 


Megascopic.—The fresh specimens characteristic of the 
greater part of the mass show it to be a tough, heavy, holo- 
crystalline rock of medium to coarse grain and of a grey color. 
The minerals visible to the unaided eye are plagioclase, olivine, 
augite, and an occasional grain of magnetite. Although the 
olivine exceeds the augite in amount, it is less conspicuous to 
the eye. Aside from a somewhat waxy luster of the feldspars, 
the rock is remarkably fresh. The weathered surface has a 
characteristic warty appearance, imparted by the presence of 
lumps or balls which are of a coarser grain and different tex- 
ture than that of the mass of the rock and are more resistant 
to the processes of disintegration. These lumps and balls can 
be seen to consist of coarse ophitic intergrowths of augite and 
plagioclase. ‘The diabase weathers by mechanical disintegra- 
tion to a greenish-olive sand in which are innumerable lumpy 
kernels of all sizes derived from the ophitic masses described 
above. The rock has no typical columnar structure, but usu- 
ally displays a rough vertical jointing such as is characteristic 
of granite. 

Microscopic.—The slides examined show the typical rock to 
consist primarily of plagioclase feldspar (near labradorite) and 
olivine in about equal amounts, with a subordinate quantity of 
augite and brown biotite. A very little magnetite is present. 
The feldspar is somewhat altered, but all the other minerals 
are fresh. The olivine occurs characteristically in rather large, 
rounded crystals of automorphic habit. The augite is chiefly 
confined to the globular masses which weather out as lumps 
and kernels and does not characterize the rock as a whole. 
Slides cut from these kernels show them to be composed 
entirely of augite and feldspar. The augite is enclosed within 
the feldspar, displaying beautiful examples of ophitic texture. 
Several of the magnetite crystals were observed to have rims 
of brown biotite. The small amount of magnetite is rather 
remarkable, and it seems likely on this account that the olivine 
is rich in magnesia. Because of the predominance of olivine 
and plagioclase in the greater part of the rock, the diabase is 
classified as an olivine-diabase with a troctolitic aspect. 

Variations in character.—All parts of the mass are subject 
to variations in texture and composition toward a coarser grain. 
These are of two kinds. The first type occurs in the ophitic 
intergrowths of augite and plagioclase in the lumps and balls 
described above, and is a segregation phenomenon character- 


The Shinumo Area. 519 


izing the mass as a whole; sometimes this texture becomes 
very coarse, the separate crystals of augite or plagioclase attain- 
ing an inch in length. The second type occurs in typical peg- 
matite dikes cutting the diabase in many places and varying in 
width from a few inches to several feet. The minerals are 
plagioclase and augite and the texture is usually ophitic, 
although not always so. In some of these dikes crystals of 
plagioclase exceeding three inches in length were observed. 

The contact facies of the diabase are frequently fine-grained 
or glassy, but never for more than a few inches from the con- 
tact. The slides typical of this zone reveal a hyalopilitic 
arrangement of glass with skeleton crystals of magnetite 
between badly altered crystals of feldspar. 

For about a half-mile east and west of the Shinumo there 
occurs in the upper part of the diabase sill along the upper 
contact a pink holocrystalline rock of medium grain. The con- 
tact of this rock with the overlying blue slates is sharp and 
well-defined. Downward it appears to grade into the normal 
diabase, and no definite line of contact can anywhere be 
observed. Unfortunately the writer did not collect transition 
specimens, but took only one specimen from the middle of the 
pink mass. The slide from this specimen when examined 
under the microscope showed it to be a granular rock of 
medium texture, consisting of rather fresh crystals of ortho- 
clase, with subordinate quartz and a somewhat altered ferro- 
magnesian mineral which was made out to have been originally 
a hornblende. Some of the quartz displayed a micrographic 
arrangement within the feldspar. The rock is a typical horn- 
blende- -syenite, and is apparently an interesting example of 
differentiation in place within the diabase sill. But a more 
complete set of specimens across the apparent transition zone 
must be collected before such a conclusion can definitely be 
established. 

In the Asbestos Canyon both the lower and upper eruptive 
contacts of the diabase are ragged and considerably injected. 
Many small dikes penetrate the country rock from the main 
mass. They are glassy in texture and badly altered. 

Ransome, in his report upon the “Geology of the Globe 
Copper District, Arizona” (Ransome 0, p. 80 ff.) describes a 
‘diabase of post-Carboniferous age occurring in thick sills in 
the pre-Carboniferous sedimentary rocks of that region. This 
diabase closely resembles the Algonkian diabase described 
above, both in mineralogical character and in the presence of 
the ophitic balls of plagioclase and augite. The analogy is 
made the more striking by the fact that several small masses 
of pink hornblende-syenite are described occurring within 
the diabase sills of the Globe district as a possible segregation 
phenomenon within the diabasic magma. 


520 WNoble—Geology of the Grand Canyon, Arizona. 


Contact metamorphism.—Since the diabase sill occupies 
relatively different horizons in the Unkar strata upon the 
Shinumo and in the Asbestos Canyon, and since in the former 
locality the strata between which the sill is intruded lie in 
undisturbed sedimentary contact in the latter locality, and 
vice versa, the study of the respective contact effects upon the 
invaded strata could be made with great facility. 

The contact effect upon the shales which lie above and 
below the diabase along the Shinumo has already been 
described in the detailed section of the Unkar: there the 
shales were shown to be altered to jaspers by baking and silici- 
fication. It was shown that the intensity of metamorphic 
action was much greater below the sill than above, extending 
through 300 feet of strata below the lower contact and through 
only 100 feet above the upper contact. In the Asbestos 
Canyon these rocks lhe in undisturbed sedimentary contact 
and are there unaltered red shales. 

The contact effect upon the limestones can be studied in the 
Asbestos Canyon, where the diabase sill les intruded within 
them. Immediately below the lower contact of the diabase, 
which is sharp and well defined, is a thin layer of green ser- 
pentine. Below he layers of pure crystalline limestone (dolo- 
mite) alternating with layers of the same character containing 
bands and nodules of serpentine. Within one of the layers 
containing the bands and nodules of serpentine are cross- 
fiber veins of golden-yellow chrysotile asbestos which are 
parallel in general trend to the bedding of the limestone. 
These limestones are the layers at the base of division ¢ of the 
second member of the Unkar. ‘They overlie the red shales of 
division $6, which are here baked to blue slates. 


Section below diabase contact (reading upward from the base) 
Dense, purple, calcareous slate (b, 24 of second member 


of Unkar), 2 2220522 2 ao Se ee ea ey 
Soft, blue :slaten(6,.25) \e,2 oce BE Se 3! 
Nodular, chery, limestones (cy ee?) (ae oe 4! 
Banded, crystalline limestone with bands and nodules of 

serpentine (0S ia te ear os SLL ee ee 
Serpentinous, nodular and banded layer carrying veins 

of ‘asbestos. 2S) U2oL Boao lee ee ee ie 
White, crystalline limestone with bands and nodules of 

serpemtine 22u.l 2 Ss. bc ee eee 2 
Pare, white, crystalline lumestone 922 23252322 Sane Ge 
Layer:of green! serpentines = 2. ..-|45 (es > eee eee 
Diabase. 


Above the upper contact of the diabase the limestones con- 
tain several alternating layers of green serpentine and narrow 


The Shinumo Area. 521 


veins of asbestos occur at several horizons in proximity to the 
contact. 

The geological occurrence of the asbestos is fully described 
by Diller in “ Mineral Resources of the U.S. for 1907” (Diller, 
a), and again by the same writer in “ Mineral Resources for 
1908” (Diller, 6). The contribution of the writer of the 
present article consists of the further data afforded by a micro- 
scopic study of the rocks associated with the asbestos in this 
locality. A microscopic study was made of 25 thin sections 
cut from the limestones, the bands and nodules of serpentine, 
and across the veins of asbestos. Aside from the serpentine 
and asbestos no other minerals were revealed in the limestones 
beyond the dolomitie calcite and interlocking grains of quartz 
already described in the slides cut from the limestones of the 
same horizon in the section on the East Wash, where the same 
strata lie in undisturbed sedimentary contact. The texture of 
the limestones is entirely that of marble. The serpentine of 
the bands and nodules shows no trace of an alteration structure 
which might indicate a derivation from pyroxene, hornblende, 
or olivine. The slides cut across the veins of asbestos showed 
them to be later than the serpentine in which they are usually 
enclosed. A great number of veins of asbestos of microscopic 
size was revealed in some of the slides where their presence 
was unsuspected. Some of these veins were observed cutting 
across both the serpentine and the limestone in the same slide. 

The asbestos which occurs in the larger veins is commer cially 
of high grade and the fiber is of great tensile strength. It is 
pronounced by Diller to be the best in quality yet found any- 
where in the United States. (Diller, 6, p. 11.) Locally the 
crossfiber is 4 inches in length. The horizon of the larger 
veins is confined, so far as is known, to the limestones which 
lie beneath the lower contact of the diabase sill. The veins 
above the contact, although more widely distributed through 
the limestones, are usually of smaller size. The horizon below 
the contact is not absolutely constant in stratigraphic position 
and may he anywhere from 3 to 15 feet below the contact. 
The width of the veins within this horizon varies greatly from 
place to place, so that a vein of three inches in width in one 
locality may be represented by a zone of innumerable small 
veins in another, but the actual continuity of the zone that 
carries the asbestos is rarely broken. 

Co serpentine and asbestos occur in the 
limestones only where these strata are invaded by the dia- 
base sill; where the diabase lies between shales there is no 
development of these minerals within the invaded strata. In 
no place in the area are they developed within the diabase 
itself. It is therefore clear that they are a contact metamorphic 


522 WNoble—Ceology of the Grand Canyon, Arizona. 


phenomenon conditioned by the invasion of the limestones by 
the diabase. It seens probable, as suggested by Diller (a, p. 
72), that the serpentine which encloses the veins of asbestos is 
derived from some mineral in the limestones and not from the 
diabase. ‘The limestones themselves are magnesian, and locally 
siliceous in the form of chert bands and nodules. In another 
part of the area the conversion of the shales to jaspers where 
they are in contact with the diabase is evidence that the fuma- 
rolic action accompanying the injection of diabasic magma 
was manifested by aqueous and probably siliceous emanations 
and was fairly intense. It seems possible that the operation 
of the fumarolic action upon the elements already present in 
the magnesian limestones might have been sufficient to convert 
the more siliceous portions into serpentine. The occurrence 
of the asbestos in veins that cut both the nodules of serpentine 
and the limestones is evidence that the formation of the cross- 
fiber asbestos was itself a somewhat later phenomenon. 


Age and Correlation. 


The Grand Canyon series is referred to the Algonkian in 
the usage of the United States Geological Survey and is ten- 
tatively correlated with the Keweenawan series of the Lake 
Superior region and with the Llano series of Texas, following 
the conclusions established by Walcott (6, p. 518). In the 
Shinumo area the profound nature of the unconformity which 
separates these strata from the basal Tonto sandstone is even 
more striking than in the area described by Walcott, while 
the certainty of their stratigraphic position is in its clearness 
and spectacular character probably unparalleled in the world. 


GroLoeic History. 
Outline. 
The following sequence of events may be distinguished : 


1. Deposition of the Vishnu sediments, source unknown. 
2. Regional metamorphism. 

a. Subsidence and profound burial. 

6. Orographic movement of folding and compression 
resulting in recrystallization and schistosity, accom- 
panied or preceded by injections of pegmatite. 

c. Elevation, accompanying or succeeding the orographic 
movement. 

3. Batholithic invasion of quartz diorite. 

4, Later pegmatitic injections. 

5. Long cycle of erosion carried through to a featureless pene- 
plain of no relief, which truncates the very roots of the 

Vishnu structure. — 


The Shinumo Area. 528 


6. Sudden incoming of the shallow Unkar sea. 
7. Deposition of the Unkar sediments and succeeding strata of 
the Grand Canyon series in shallow water (or upon land ?) 
8. Intrusion of diabase sills. 
9. Orographic movement of block faulting and tilting accom- 
panied or succeeded by elevation. 
10. Long cycle of erosion carried through to a peneplained sur- 
face of small relief. ; 
11. Incoming of the Tonto sea, succeeded by the deposition of 
the Paleozoic strata of the wall of the Grand Canyon. 


The earliest event which is decipherable in the geologic 
history of the Shinumo area is found in the blurred and 
mangled record of the Vishnu schists. Far back in the dark 
ages of geologic time a thick series of more or less arkose 
sands and muds was accumulating upon a subsiding floor. 
So much may be reasonably inferred from the mineralogical 
character of the quartz schists of the mica and hornblende 
type. So dim and vague is the record that the base of this 
series, the floor upon which it was laid down, the thickness, 
and the location of the land mass from which it was derived 
must, perhaps, remain forever unknown. Following the long 
accumulation and burial of these sediments came an orographic 
movement, which wrote across the older manuscript in a newer 
and bolder hand, blurring the ancient writing with the stamp 
of deep-seated regional metamorphism, and imparting to the 
manuscript the aspect of a palimpsest. The regional meta- 
morphism is conceived to have been brought about by deep 
burial of the sediments, followed by folding and compression, 
which engraved upon them the characters of recrystallization 
and schistosity in slow process of time, and accompanied by 
their elevation into lofty mountains. Somewhat later the cores 
of these mountains were intruded by great masses of igneous 
rock, here in the form of quartz diorite, followed by peg- 
matitic injections. Perhaps while this orographic movement 
was still in progress the forces of erosion were already at work. 
Then followed a tremendous cycle of erosion carried through 
to the very end, planing away the ancient mountains to the 
basal roots, and reducing hard and soft rocks alike to an utterly 
flat and monotonous level. Such was the completion of the 
eycle of this vast unknown and unnamed eon of time. 

The next event is the beginning of another great cycle of 
sedimentation resulting in the deposition of the Grand Canyon 
series of Unkar and Chuar strata, ushered in by the sudden 
invasion of a shallow sea which swept over the featureless 
desert surface of the Vishnu plain, depositing the basal conglom- 
erate of the Unkar. The clue to the inferences as to the 
character of this incoming sea, of the rock mantle which it 


524 WNoble— Geology of the Grand Canyon, Arizona. 


found covering the plain, and of the climate of the time is 
preserved for us in the basal conglomerate described in a 
previous part of this article. It was there noted that the 
weathering below the surface of the peneplain was slight, and 
the product of physical disintegration rather than of chemical 
weathering ; that the matrix of the conglomerate is red in color 
and arkose in nature; that the pebbles are angular and show 
no evidence of transportation and sorting. We may therefore 
conclude that the conglomerate represents the soil in place 
which covered the Vishnu plain. All the evidence points 
to an arid climate,—the lack of chemical weathering, the 
freshness of the arkose feldspar, and the red color of the matrix, 
all indicating a lack of vegetation and abundant moisture which 
could decompose the soil and reduce the iron which imparts 
the red color. It is therefore not unlikely that the Vishnu 
plain was a vast desert at the incoming of the sea. The abso- 
lute lack of transportation, sorting, and rounding of pebbles 
indicates that the incoming sea had little chance to rework 
the soil mantle by its waves. It seems impossible to account 
for this phenomenon except by a sudden invasion of the sea 
across the Vishnu desert. If we interpret the past in the light 
of the present our only guide is to seek to picture some present 
condition on the earth which parallels that preserved in the 
geological record. A possible clue may lie in the conditions 
about the Caspian Sea to-day. There is in that region a desert 
about the shores of the Caspian which lies below the present 
level of the Black Sea; a sudden rise in the level of the ocean 
might cause the latter to overflow the low barrier which sepa- 
rates it from the Caspian, and in this way a sudden inundation 
of the desert would be accomplished. It is now thought that 
wind erosion may carry the surface of an old desert to a level 
below that of the sea if the cycle is continued to extreme 
maturity. Such forces might have been active in the last 
stages of the Vishnu peneplain. 

The deposition of the alternating limestones and shales of 
the second member of the Unkar seems to have taken place in 
a permanent water body into which mud was frequently 
washed. It may be noticed from the section of this member 
that the alternations are almost innumerable. The exact cause 
of this is speculative. Possibly the alternations are due to 
climatic oscillation: a movement from an arid to a semi-arid 
climate would load the rivers with sediment, while arid 
intervals would retard their flow, if not dry them up entirely, 
resulting in a temporary clarifying of the sea and a deposition 
of limestone. Whether the limestones are the result of organic 
agencies or of purely chemical precipitation is also a matter of 
speculation, since in regard to decisive evidences of life the 


The Shinumo Area. 525 


geological record is silent. It is believed that the water 
body was for the most part shallow, smce sun-cracks appear in 
the shales in the upper part of the member below the highest 
limestone strata. What the polygonal cracks and the small 
cubie depressions in the banded cherty layers of the basal lime- 
stones mean the writer does not know. The cracks are 
suggestive of sun-cracks and the depressions strongly resemble 
salt hoppers. 

The most striking feature of the third member is the great 
abundance of sun-cracks throughout the shaly strata and_of 
ripple-marks and of cross-bedding in the sandstones. The 
researches of Professor Barrell have made it clear that exten- 
sive sun-cracking is a feature which has a maximum chance of 
preserval on broad flood plains or deltas in an arid climate. 
(Barrell, a, pp. 524-568.) In the opinion of the writer of the 
present paper, the extreme abundance of these cracks in this 
member of the Unkar is hard to account for except by postu- 
lating wide delta flats or flood plains. Furthermore, the bright 
red color of the shaly strata in connection with the mud cracks 
seems to bespeak an arid climate with little or no vegetation 
to reduce the iron. It is at least certain that all this “part of 
the Unkar was deposited in very shallow water which often 
evaporated entirely, leaving broad mud flats exposed to a 
hot sun. In the upper part of the member is the series of 
alternating shales and sandstones already described in detail: 
as may be seen from the sections, the alternations are fre- 
quently as regular as clockwork. The sandstone layers are 
composed of fine, cleanly sorted and rounded quartz grains, 
ripple-marked and er oss-bedded, while the shales are a fine red 
mud. It is thought that the clean character of the sandstone 
layers of this alternating series is a mark of climatic oscilla- 
tion: a climatic movement towards a wetter climate, if increas- 
ing the ratio of run-off to erosion, causes the rivers to flow on 
a lower grade and sweep seaward the piedmont deposits of 
sand and gravel; as the clay was largely sorted from those 
deposits when they were first laid down, their redistribution 
accompanied by a secondary sorting on a delta surface or sea- 
bottom would be marked by extreme cleanness. 

Great thickness, clear sorting, and extreme fineness and 
roundness of ovain are the characters which distinguish the 
fourth member, which is composed entirely of sandstones and 
quartzites. All strata are characterized by cross-bedding and 
ripple-marks, bespeaking shallow water. The origin of these 
great thicknesses of sandstone is a puzzle. The clean sorting 
seems to indicate long transportation: it is not impossible that 
the rivers carrying this material might have flowed through a 
great desert of dune sands, picking up and carrying material 


526 Noble—Geology of the Grand Canyon, Arizona. 


such as is deposited in the Indus delta to-day from a similar 
source. Occasional lenses of fine conglomerate within some 
of the strata suggest scoured and filled stream channels. 

The upper member of the Unkar again bears all the marks 
of shallow water origin: mud-cracks, ripple-marks, and cross- 
bedding characterize the entire thickness. The addition of 
micaceous material and of some feldspar gives aslightly arkose 
character to the rock; possibly a crustal movement rejuve- 
nating the land mass supplying the sediments was responsible 
for the change in character. Here again are marks of aridity, 
seen in the vermilion color and the vast development of 
mud-eracks. 

All subsequent Unkar and Chuar deposits have been removed 
by the truncation of the pre-Cambrian structure by the plane 
of the base-leveled surface of erosion beneath the Tonto 
Sandstone. 

In summary it may be said that the evidence obtainable 
from the lithologic record of the Unkar sediments in the 
Shinumo Area points probably to an arid climate, and almost 
surely to deposition in shallow waters; first in a permanent 
body of water and later in deltas or on flood plains. Which 
of the latter conditions prevailed the writer is not competent to 
say. 

The predominance of clastic sediments instead of limestones 
in the basal portion of Walcott’s section, 30 miles east, sug- 
gests that that area was nearer to the shore line of the early 
_ shallow sea. The close correspondence of the stratigraphic 
succession and lithology in all higher members in the two 
areas suggests uniform conditions over at least that distance. 

The next event which can be read from the geologic record 
is the invasion of the Unkar strata by a thick sill of diabase 
in the lower members, and by four thin sills of basaltic rock im 
the upper part of the section. 

Following this came an orographic movement of block 
faulting and tilting, accompanied or succeeded by elevation, 
breaking the strata of the Grand Canyon series into great 
crustal blocks, and throwing them into high ranges of moun- 
tains which in character and aspect were probably not unlike 
the faulted ranges of the Great Basin or the desert ranges of 
Arizona. 

Then began a second vast interval of erosion, gnawing 
slowly but surely into these faulted mountains, reducing them 
in slow process of time through stages of youth, maturity, and 
old age, and finally planing away all except the very hardest 
strata of their cores to form the broad monotonous expanse of 
a base-leveled surface. The monotony of this surface was 
broken only by an occasional monadnock of hard Unkar quartz- 


The Shinumo Area. 527 


ite, resisting the forces of erosion in that ancient plain by 
virtue of the terrific hardness which causes the same strata 
to-day to wall in the deep box-canyon of the Shinumo. These 
monadnocks of the Cambrian plain may be compared with the 
Baraboo ridges of Huronian quartzite which by virtue of their 
homogeneity and hardness still stand as prominences which 
have weathered repeated cycles of erosion. It is probable 
that this eyele of erosion was not finally completed until well 
along in lower Cambrian time. 

The next event is the incoming of the Tonto sea. Although 
this chapter belongs to the Paleozoic history recorded in the 
horizontal strata of the walls of the Grand Canyon, that part 
which is involved with the distribution of the Unkar strata 
upon the pre-Tonto surface may properly be anticipated here. 

It is not unlikely that this invading sea transgressed a sur- 
face which strongly resembled the present surface of the 
great Laurentian peneplain of Canada with its broad areas of 
crystalline rocks in which are inset occasional blocks of Paleo- 
zoic strata, and above which stand occasional monadnocks of 
quartzite. The story of the invading sea is written in the 
Tonto Sandstone, locked up in which is a record of marine 
transgression which on account of the vertical sections and 
absence of soil is clear beyond belief. When the Tonto sea 
came in over the surface of the ancient peneplain the monad- 
nocks stood out as islands which were gradually overwhelmed 
and buried in the sands of the deepening sea. The long ridge 
of the quartzites of the middle Unkar in the Shinumo area has 
already been described. It stood out as a long narrow rocky 
island whose longer axis extended for an unknown distance 
northwestward along the strike of the strata. The long south- 
west face of this island was undercut by the marine planation 
to form a steep cliff. Every detail of the face of this old sea 
cliff is preserved in the Tonto sandstone in the cross-sections 
cut by the present canyons across its face: at its base, huge 
angular blocks of Unkar quartzite as large as houses are pre- 
served in the Tonto sandstone in the exact position where they 
fell and lodged; farther out from the base are masses of large 
bowlders, worn and rounded by the pounding of the waves ; 
these become smaller and smaller and finally run out into 
lenses of fine pebbly conglomerate, representing the shingle of 
the ancient beach, dragged out by the undertow. No more 
striking example of a fossil sea cliff can be imagined. 


By far the most impressive feature of this wonderful coun- 
try is to traveller and geologist alike the mile-deep pathway 
of the Colorado River of the West across the great plateaus. 
The stupendous and glaring record of erosion revealed to us 


528 Noble—Geology of the Grand Canyon, Arizona. 


in the cutting of this mighty gorge has almost blinded us to 
the realization of the immensity of the vastly greater record 
revealed in its walls. But the story told by the two intersect- 
ing uncontformities in the bottom of the gorge,—two ancient 
cycles of sedimentation, uplift, and erosion carried to a finish, 
separated by hopelessly lost intervals of time, resulting twice 
in the planing down of lofty mountain ranges to the very core, 
written vaguely at first on a blurred and time-worn record, and 
later in an increasingly clearer and bolder hand,—the slow 
accumulation of the strata of the Canyon wall on the floor of 
the Paleozoic sea, the subsequently erased record of the accu- 
mulation of vast thicknesses of Mesozoic and Eocene strata, 
separated in turn by great intervals of erosion, and even the 
“ sreat denudation” which has stripped these Jater strata back 
fifty miles to the terraces of Utah—represents a lapse of time 
compared with which the cutting of the Grand Canyon is but 
the passing of an afternoon ; for in the light of present knowl- 
edge it is safe to say that the Grand Canyon was entirely cut 
since the time when, according to the fossil record, the remains 
of man first appear on earth. : 


Bibliography. 


Barrell, J. a. Journal of Geology, vol. xiv, 1906. 

Diller, J. S. a. The Production of Asbestos in 1907. Mineral 
Resources of the U. 8. for 1907. U.S. Geol. Surv. 

b. The Production of Asbestos in 1908. Mineral 
Resources of the U.S. for 1908. U.S. Geol. Surv. 

Dutton, C. E. a. Tertiary History of the Grand Canyon Dis- 
trict, with Atlas. Monogr. II, U.S. Geol. Surv. 1882. 

Ransome, F. L. a. Pre-Cambrian Sediments and Faults in the 
Grand Canyon of the Colorado. Science, vol. xxvii, No. 
695. April 24th, 1908. 

b. Geology of the Globe Copper District, Ariz. Prof. 
Paper, No. 12, U.S. Geol. Surv. 

Walcott, C.D. a. Study of a Line of Displacement in_the 
Grand Canyon of the Colorado in Northern Arizona. (Read 
Aug. 29, 1889.) Bull. Geol. Soc. America, I, 1890 (Feb.), 
pp. 49-64. 

b. Pre-Cambrian Igneous Rocks of the Unkar Terrane, 
Grand Canyon of the Colorado, Arizona, by Charles 
D. Walcott; with notes on the Petrographic Char- 
acter of the Lavas, by Joseph P. Iddings. 14th 
Ann. Rept. U. 8. Geol. Surv. for 1892-1898, Pt. 2, 
1894, pp. 497-519 (Walcott) and 520-524 (Iddings), 
pls: Ix—lxv. 


Auburn, N. Y., January, 1910. 


Am. Jour. Sci., XXIX, 1910. 


Plate v. 
36° 30’ 
36° 15/ 
: ‘ y gp WARE y 
- | d \ At a) \ \ IAN EL Di Nee oi bs 
‘ We = Ny SS & ny ¢ GA mh 
< 2 y S\“AE p \ 
yar b Z =) fe 7 ))) 
‘ : WC Y é CD | a 36° 
1 AE Male Ae 111° 45/ 
112° 
7 ae 112° 15/ 
112° 30’ 


, 
i 
4 
i 

ru 

- ae 

(ia 

wu, 

, 


EL. W. Brown— Magnetic and other Forces. 529 


Art. XLV.—On the Liffects of Certain Magnetic and Gravi- 
tational Forces on the Motion of the Moon; by Ernest 
W. Brown. 


1. THERE exists a difference between the observed and com- 
puted places of the moon which has hitherto defied explanation. 
Its magnitude is so great in comparison with the accuracy 
obtainable both in theory and observation that it seems highly 
improbable that it should be due to error of any kind. From 
the observational side it has been known for over thirty years 
and during that time many efforts have been made, without 
success, to find its cause in the ordinary gravitational theory. 
It therefore seems pertinent to inquire whether some force 
or forces whose existence is only suspected may not be the 
cause of the discrepancy. 

In setting forth the hypotheses mentioned below, my object 
is not at the outset to present a solution of the difficulty, and 
indeed no solution which can be accepted at the present time 
is offered. The reasons for the publication of the results of the 
investigation are of a different nature. The first is the consid- 
eration of certain forces whose constants are unknown but 
whose magnitudes can certainly be limited. It becomes possi- 
ble in this way to exclude hypotheses which before actual 
computation do not appear to be highly improbable. The 
second object is to point out forces which are able to produce 
the inequality but which require to be confirmed by observa- 
tions ot a kind different from those obtained by the old 
nethods of positional astronomy. And a third is for the pur- 
pose of indicating certain directions in which observations 
may be useful for the purpose of testing these hypotheses. 

A possible magnetic attraction between the earth and the 
moon has occasionally been suggested, though its detailed 
consequences do not appear to have been worked out. The 
results below show that, although the magnitude of this attrac- 
tion need not be very great, if it be a constant force its direction 
is unusual ; or, if the magnitude of the force itself varies, the 
difficulty is only removed a step further back in that we know 
of no cause for such variation. The result arising from the 
figure of the sun demands conditions which may possibly be 
fulfilled but for which we must await further evidence. The 
supposed long-period term in the libration of the moon may in 
time be tested. For this purpose a long series of accurate 
observations would be necessary. In any case, such a series is 
needed in order to furnish more exact information than we at 
present possess of the motion of the moon about its center of 
mass, and this quite independently of any theory, gravitational 
or otherwise. 


Am. Jour. Scl.—FourtH SERIES, Vout. X XIX, No. 174.—Junz, 1910. 
35 


580 = Brown—Lffects of Magnetic and Gravitational 


The mathematical developments by which the statements 
made below have been obtained are somewhat long and 
tedious. Since the results are either of a negative character 
or are obtained from hypotheses for which there is little or no 
collateral evidence, it seems unnecessary to develop at length 
the methods employed. When a disturbing function has once 
been obtained, it has now become a simple matter to compute 
rapidly the effect on the motion of the moon with the formulee 
employed for the planetary terms, so that the details can be 
given at any time when the need for them may arise. 

2. The outstanding inequalities in the moon’s motion.—On 
several occasions during the past thirty years, Newcomb has 
examined the observations of the moon to try and find ont 
what outstanding secular or long-period mequalities there may 
be in its motion which have not been explained by theory. Of 
these, the best known is the slow decrease in its period which 
increases its apparent longitude by 2” multiplied by the square 
of the number of centuries from the epoch of reckoning. 
This is generally ascribed with good reason to tidal friction 
and it is not necessary to consider other causes of change except 
for the purpose of finding the amount of the frictional effect. 

But Newcomb has also discovered a large change which 
appears to be periodic and which he deduced from observa- 
tions of occultations of stars by the moon. His last paper* 
includes observations of this kind from the beginning of the 
seventeenth century, a range of nearly 300 years. The change 
appears to be periodic, with a coefficient of about 12”, a period 
of about 270 years and a phase which puts its maximum effect 
near the year 1795. Mr. P. H. Cowell makes the period about 
350 years and the coefficient 18’’ on the assumption that there 
is no secular change to be ascribed to tidal friction.t It is 
this long-period term for which no cause has as yet been 
assigned. There are also indications of a term with a period 
of about 60 years and a coefticient between 2” and 3”; also a 
term with a period of some 20 years and a coefficient rather less 
than 1”. The last may possibly disappear when a comparison 
with the new tables of the moon’s motion has been made and 
the arbitrary constants properly adjusted. | | 

3. Errors due to observation or theory.—lIt is quite a simple 
matter to show that the peculiarities of observations on the 
moon cannot produce such a term. The majority of them 
are made at night and not very near new moon, and the moon. 
itself has librations which alter its apparent diameter, but 
none of these can give rise to so large a term. There is the 
possibility of errors in Hansen’s tables; but with the correc- 


* Monthly Notices R. A. 8., vol. lxix, p. 164. 
+ Monthly Notices R. A.S., vol. Ixv, p. 84. 


Forces on the Motion of the Moon. 531 


tions now applied, it is extremely unlikely that further errors 
showing a periodicity of this kind are present. 

The ordinary gravitational theory must at the outset be 
excluded. It has been so thoroughly investigated that there 
seems to be no likelihood of a term with so lar ee a coefiicient 
as 12” having escaped detection. The term has fr equently 
been ascribed to planetary action, but this action has now been 
treated in detail by several writers, and, in my own work on 
the subject, several thousands of terms were examined. Not 
the slightest possibility of the existence of a coefficient of any- 
where near this magnitude has arisen. It may be noted that 
we are searching for a term nearly as great as the largest known 
term produced by planetary action, and further, that the next 
largest term has a coefticient only one-tenth of the required 
size. To ascribe the term to this cause would mean a defect 
in the theory so great that a total reconstruction would prob- 
ably be necessary if an omission had been made. 

4, Method of investigation.—The chief point is the period 
of the term, which is known from observation to be about 270 
years. N ow from the lunar theory we know that this period 
can be produced in three ways. It may be the effect of a 
nearly constant force on a term having this period, already 
present in the expressions for the moon’s longitude.» If the 
force be periodic, the period of the force must be either the 
period of the effect, or else the combination of the period of 
the force with one of the known periods in the moon’s motion 
must produce the period of the effect. Now the period of the 
effect being 270 years, we must either look for a force having 
a period of 270 years, or else we must look for a force whose 
period differs from one of the lunar periods by a small quan- 
tity which runs through its changes in 270 years. The hypoth- 
esis of a nearly constant force is extremely improbable. 

There is another point in the investigation that makes it 
easy to reject some of the hypotheses which may be brought 
forward. The mean annual motion of the perigee, as derived 
from theory and observation, shows no outstanding difference 
greater than 3/10 of a second; and a similar statement may be 
made with respect to the node. If, therefore, we assume the 
existence of some force which gives a motion to the perigee, 
or to the node, much greater than this amount, the hypothesis 
must be rejected. 

5. In the examination of long-period terms in the moon’s 
motion there is one point of great importance in the consider- 
ation of the magnitude of the disturbing force. If the force 
has a period near that of the month, this period not depending 
on the mean motion of the moon, the factor which is chiefly 
responsible for the large coefficient depends on the square of 


532 = Brown—HLH fects of Magnetic and Gravitational 


the number of months contained in the period; but if the 
force has the same period as the effect, then the factor is only 
the first power of this number. With a period of 270 years, 
the factor is 8600, so it makes an essential difference whether 
the force is of long period or approximates to a month. If it 
approximates to the period of the perigee, or to that of the 
node, we still get the square of the factor, but there are small 
factors which enter and which may diminish the square of the 
large factor to some number between 10° and 10°. 

6. Certain forces may be rejected with but little caleulation. 
Those which arise from a supposed resisting medium will give 
secular and periodic changes, the latter with periods the same 
as those of known terms in the moon’s motion. Again, Jupiter 
has an ellipticity of about 1/17, and therefore might affect the 
motion of the moon. I have examined this and find that. its 
effect on the moon is at most about 1/1300 of the principal 
effect produced by the planet. A small factor in the disturb- 
ing function reduces this very considerably. It is certain that 
t heeffect of Jupiter’s ellipticity must be insensible. Further, 
there is a group of small planets lymg between Jupiter and 
Mars which will undoubtedly have some influence on the 
moon’s motion ; but this influence, when calculated, is seen to 
affect chiefly the motions of the perigee and node. The result- 
ing addition to these motions cannot be more than a few hun- 
dredths of a second per annum; otherwise the group would 
more seriously alter the motions of the inner planets than is 
possible, owing to the close agreement between theory and 
observation. ? 

It may therefore be assumed that no gravitational action of 
the sun, earth, and planets, considered as particles, has been 
left out of account. Further, the figures of the earth and 
Jupiter, considered as spheroids, have been treated ; the other 
planets are too small or too far away for their figures to have 
sensible influence. A possible non-spherical form of the sun 
will be treated in §7. The constant term due to the figure of 
the moon has been taken into account, but an effect which 
would be caused by a certain kind of minute libration of the 
moon, if it existed, will be considered in $9. Light pressure 
is also ineffective in producing a long-period term, and, indeed, 
any effect from it is too small to be detected within historic 
times. 

7. Hypothesis of an equatorial ellipticity of the sun’s figure. 
—Owing to its rotation, the figure of the sun is not a perfect 
sphere. There will be a slight difference between the equa- 
torial and polar axes. This difference cannot, however, do 
more than alter the mean motions of the perigee and node by 
a minute amount. 


Forces on the Motion of the Moon. 533 


The hypothesis under examination demands that the sun be 
not symmetrical with respect to every plane which passes 
through its axis of rotation, and further, that the period of 
rotation approximates closely to one of the lunar months. To 
justify the former we must suppose that the nucleus of the 
sun’s mass is a solid body or behaves like one; otherwise it is 
improbable that an equatorial ellipticity could permanently 
subsist. A coincidence of the period of rotation with one of 
the lunar months is less difficult. Although the photosphere 
shows periods of rotation differing with different latitudes, it 
is probable that the nucleus of the sun’s mass has a period of 
rotation like that of a solid body, and that the period is some- 
where between the greatest and the least of those observed by 
watching the motions of sun-spots. Now this period, between 
25 and 30 days, may possibly coincide very nearly with one of 
the lunar months. If it does so with a difference which is 
small enough, the effect on the moon’s motion will be an 
Inequality of very long period, provided the sun has some 
equatorial ellipticity of figure. We have, therefore, to make 
two assumptions; one, that the period of rotation of the sun 
very nearly coincides with one of the lunar months, and 
second, that its moments of inertia about two axes lying in the 
equatorial plane of the sun are not equal. The computation 
of such an effect is somewhat troublesome, but it gives a per- 
fectly definite result. If the period of the sun’s rotation with 
respect to a line joining the earth and sun differs from the 
period of the synodic month by a small quantity, so that the 
two phases only coincide once in 270 years, it is only necessary 
to assume that the effective ellipticity* of the sun in its 
equatorial plane is about 1/46,000. If we assume that the near 
coincidence is with an anomalistic month, then the ellipticity 
must be about 1,220 to produce the required term. If the 
near coincidence is with a nodal month an ellipticity of 1/2200 
is sufficient. 

These minute values are mainly due to the presence of the 
factor 3600°, explained in $5. The introduction of two new 
hypotheses in order to explain a single phenomenon is objec- 
tionable and therefore requires some examination into their 
probability. Although observation has not yet reached the 
degree of accuracy required to compare the periods, it will be 
advisable to examine the material in order to see how closely 
we can compare them. 

The periods of the three months relative to a line joining 
the mean positions of the earth and sun are: 

* The effective ellipticity is here defined to be the ratio of the difference 


of the moments of inertia to the product of the mass of the sun and the 
square of the radius of its visible surface. 


584 Brown—lHffects of Magnetic and Gravitational 


Synodic month, 277-3317, 
Anomalistic month, 254-6217, 
Nodal month,» 2oes254, 


and one of these is to differ from the sidereal period of rota- 
tion of the sun by about 07-0088, since the angles present in 
the disturbing function are double the differences, and the 
period of the empirical term is about 3600 months. 

The nodal month is nearest to the values found for the mean 
solar rotation period by Carrington (25738) and Spoerer 
(25723) from observations of the motion of sun-spots. W. 
S. Adams,* observing the displacements of certain lines of 
the spectrum, obtains periods ranging from 24°57 at the equa- 
tor to 35°-26 in latitude 79°. He inclines to the view that the 
equatorial velocities give a period approximating more closely 
to the actual period than those of higher latitudes. The evi- 
dence so far obtained indicates a possibility that the true rota- 
tion period may be close to that of the nodal month relative to 
the earth’s mean radius vector. 

A coincidence with the nodal month involves an effective 
ellipticity of about 1/2200. This might be detected over a 
long series of observations if the visible surface of the sun 
were solid. It is extremely unlikely that such an ellipticity 
would persist as far as the photosphere, which ought on the 
average to be a level surface. An indirect method may, how- 
ever, furnish evidence one way or the other. If the ellipti- 
city exists, it is probable that the solar activity would be more 
marked in two sectors on opposite sides of the solar axis than 
in the other two sectors. The average period derived from 
observations of sun-spots or other evidence of abnormal 
activity would therefore furnish the material to be examined. 
It is significant that the nodal period lies between the results 
for the solar period obtained by Carrington and Spoerer. 
The hypothesis opens up a wide field of speculation and 
investigation as to its physical consequences, especially on the © 
motion of the outer liquid or gaseous layers of the sun’s mass. 
The belief that the eleven-year period is due to forces within 
the sun is perhaps less dificult with the hypothesis of such an 
inequality in the distribution of the mass of the nucleus. 

8. Hypothesis of a magnetic attraction between the earth 
and the moon.—For the purposes of this section it will be 
snfticient to consider the magnetic fields of the earth and moon 
as equivalent to fields produced by straight solenoids sym- 
metrical with respect to their respective centers of figure. 
The directions of these solenoids will, in the first instance, be 
taken arbitrarily, but the main results of the discussion depend 
on the directions which may be assigned to them. 


* Astrophysical Journal, March, 1909. 


Forces on the Motion of the Moon. 535 


The chief reason that the effect of magnetic attraction may 
be capable of observation arises from the fact that the result- 
ant force varies as the inverse fourth power of the distance, 
while gravitation varies as the inverse square. It is in this 
respect similar to the attraction produced by the ellipticity of 
the earth’s figure, that is, by the difference between the 
moments of inertia about the polar and ecuatorial diameters 
of the earth. For this reason it will be useful to compare the 
magnitudes of the forces which must be invoked with that 
produced by the earth’s figure. It is, however, to be remem- 
bered that the resolved part of the magneti¢ attraction in any 
direction differs from that of the earth’s figure, mainly 
because the earth’s magnetic axis is not the axis of figure. 

The potential of the magnetic attraction may with sufficient 
approximation be expressed in the form (u,+w,)/7r* where wu, 
is a constant and w, consists of terms whose mean value for 
all time is zero, and 7 is the distance between the moon and 
earth. It is a simple matter to prove that a force due to a 
potential 2,/r* must have an accelerative effect on the moon 
less than 5°10~* of that produced by the earth’s attraction on 
the whole mass of the moon. This fact is deduced from the 
well-known result that the motion of the perigee, as determined 
by observation and theory, is not in error by so much as one 
part in 5-10°. Now the principal effect of the earth’s ellipticity 
is 10-* of that produced by the main attraction of the earth. 
Hence the effect of a term w,/r*, here supposed to be due to 
magnetic attraction, must be less than 1/20 of that of the 
earth’s ellipticity. Further, if the inequality which we seek 
to explain is produced by a force of the same period as that 
of the inequality, this force, contained in w,/r*, will not be 
greater than 1/120 of that of the earth’s ellipticity. 

These facts give the first negative result, namely, that the 
inequality we seek to explain cannot be produced solely by the 
secular motion of the magnetic axis of the earth. This secu- 
lar motion is known with an accuracy for the last 300 years 
which is sufficient to prove that if it produced the inequality, 
it would cause an addition to the mean motion of the lunar 
perigee much greater than the agreement between gravitational 
theory and observation permits. Such a hypothesis appeared 
not unreasonable at one time, since there was some reason to 
think that the period of the secular variation was about 600 
years and this would produce an inequality in the motion of 
the mvon of half the period of the change. The period of 
the secular change, if a real period exists, is now thought to 
be considerably longer than 600 years. 

Next, suppose that the inequality is produced by a variation 
in position only of an assumed magnetic axis in the moon. 


536 Brown—lHffects of Magnetic and Gravitational 


In an exactly similar manner, it is proved that this axis can- 
not oscillate about a mean position coinciding with or near 
the moon's axis of rotation. The only way in which the varia- 
tion of position is effective is an oscillation about a mean 
position in the lunar equator. Further, if the oscillations are 
perpendicular to the equator they must be large (of the order 
of 20°). If the oscillations are within the equator, the product 
of the magnetic moment and the amplitude of the oscillation 
becomes a factor which can be determined from the observed 
coefficient of the inequality, but there is no information at 
hand to separate the two terms of the product, since a motion 
of the perigee is not produced to this order of magnitude. 

Let us next suppose that the directions of the magnetic axes 
are fixed with respect to the axes of figure of the two bodies, 
and that the inequality is produced by a variation of the 
product of the magnetic moments. Then, owing to the facts 
previously mentioned concerning the possible magnitudes of 
the additional motion of the perigee and the variable force, 
the extreme range of values of the magnetic moment is never 
nearer to unity than is the ratio 5/7. That is, the maximum 
variation from the mean is at least 15 per cent, and its period 
must be in the neighborhood of 270 years. 

A magnetic attraction between the earth and moon has, how- - 
ever, a relatively greater effect on the precession and nutation 
of the earth than on the motion of the center of the moon, 
since the principal part is a couple, and the force we have been 
considering is small compared with this couple. An idea of 
the maximum magnitude of the assumed forces can be thus 
obtained. The ellipticity of the earth’s surface, as measured 
by Clarke, is 1/293. The formule of precession and nutation, 
combined with an assumed equipotential surface for the earth, 
give an ellipticity to the latter of 1/297. The observed coefii- 
cient of the nodal term in the motion of the moon gives an 
ellipticity of a similar order of magnitude. The difference 
between the two values quoted amounts to about 1/70 of the 
whole. This limits the resolved part of the magnetic moment 
along the lunar axis of rotation to 1/70 of the earth’s ellip- 
ticity. Hence u,/r* must be less than one-half of u,/7*. 

The formule of precession compared with observation do 
not exclude such a variable part. The amount of the preces- 
sion in 70 years is 3600”, and the maximum change in this 
time due to a variable force of the magnitude considered is 
about 2”. The degree of accuracy attained by observation 
does not exclude such a coefficient. It might even be possible 
to detect it, but the investigation would have to extend over 
the whole range of known observations, and a very large num- 
ber would be required. 


Forces on the Motion of the Moon. 537 


The effect on the constant of nutation is relatively larger,— 
about 0”-1 to 0”°2 in a constant of 9-2. This, again, is not 
excluded by the observations. To detect it with any certainty 
we should need from five to ten periods of 18 years each. 

We must conclude, then, that a variable force with a period © 
of 270 years and a maximum value about 1/120 of that pro- 
duced by the earth’s ellipticity is not excluded by the observa- 
tions. If such a force exists with a potential (w,+z,)/7*, so 
that it may be treated as an addition to the earth’s ellipticity, 
we must conclude that the constant part of the addition is less 
than 1/70 and the variable part less than 1/120 of that caused 
by the earth’s ellipticity. 

Either of the two forms of the hypothesis which are admis- 
sible, an oscillation of a lunar magnetic axis about a mean 
position in the lunar equator, or a variable moment with an 
axis near the lunar axis of rotation, are difficult. There is, 
however, still another effect not yet considered, and one which, 
though secondary, is somewhat remarkable. It will be seen 
in the next section that a minute libration of the moon can, 
under certain circumstances, have a large effect on its motion. 
Now any supposed magnetic attraction between the earth and 
the moon will have its greatest effect in altering the direction 
of the axes of figure of the moon. The force is the same as 
that which would affect the precession and nutation of the 
earth, but its effect is 80 times as great, in general, owing to 
the earth’s mass being 80 times that of the moon. The pos- 
sibilities in this direction will be considered in § 10. 

9. The effect of the physical libration of the moon's axes.— 
It can be shown that if we adopt the ellipticities of the moon’s 
figure as being of the order of magnitude determined by 
observation, an oscillation within the plane of the lunar equa- 
tor of the axes lying in that plane with a period of 270 years 
and a coefficient of 50” will produce the observed inequality 
in the moon’s motion. 

The physical librations of the moon are of two kinds, free 
and forced. The forced librations, produced by the motion of 
the moon round the earth, are for that reason powerless to 
cause any sensible effect on its motion round the earth,—a 
result which can be deduced from the equations of motion. 
There are theoretically three principal free librations each 
with its own period, dependent on the three ellipticities of the 
principal sections of the moon’s surface. The amplitudes of 
these librations have not yet been observed and it is generally 
assumed that they are zero or at least beyond detection by the 
observations hitherto made. The ellipticities, nevertheless, can 
be obtained from the forced librations and thence the periods 
of the free librations. 


588 Brown—LHfects of Magnetic and Gravitational 


The libration along the lunar equator of that principal axis 
of the moon which is directed towards the earth would have, 
according to theory, a period of between two and three years: 
the value is doubtful. The period of the second libration is 
very nearly equal to a month. On examination it is seen that 
neither of these can cause any sensible effect unless it had an 
amplitude which would have been detected by observation. 

The third libration has a period of between 200 and 300 
years. The time is suggestive but its direction of motion is 
perpendicular to the moon’s equator. In order to affect the 
motion of the moon’s center sufficiently it would have to give 
rise to a libration within the moon’s equator. The theory of 
the motion of the moon about its center of mass must be 
worked out to a higher degree of accuracy than yet obtained 
in order to find out whether there may be a long-period term 
of the kind and size required. On the observational side 
sufficient material has not yet been accumulated to test the 
existence of terms of very long period. 

An angular change of 100” in the position of any axis of — 
the moon is the smallest amount which can be detected by a 
single observation, with the methods hitherto used. The 
recent work of Mr. F. T. M. Stratton* shows clearly how 
doubtful the constants of the moon’s physical constitution are. - 
This is to be expected, since the librational coefficients from 
which these constants are determined are of the orderof 100’. 
Hence a long-period vibration of 50” is not at present excluded 
either by theory or observation. 

10. A well known difficulty in the theory of the rotation of 
the moon is the fact that the ellipticities, as determined from 
observation, are some sixteen times as great as the ellipticities 
obtained on the assumption that the outer form of the moon is 
a level surface. It has already been mentioned that a magnetic 
attraction between the earth and the moon would produce the 
largest relative effect on the rotation of the moon. It may be 
suggested that the forced vibrations which are observed have 
their origin mainly in a magnetic attraction rather than in the 
eravitational attraction hitherto considered. ‘The general effect 
is quite similar. 

Nevertheless the free librations in any case depend on the — 
ellipticities alone. If we calculate the free libration in the 
equatorial plane with the theoretical ellipticities first men- 
tioned, the period, instead of two or three years, becomes 14 
years, and this may be still further increased by non-rigidity. 

A free period of 17 to 20 years is effective in producing 
inequalities with long periods and large coefficients in the 


* Memoirs Roy. Astron. Soc., vol. lix, pt. iv. 


Forces on the Motion of the Moon. 539 


motion of the moon’s center of mass. This is due to the near 
coincidence with the period of revolution of the moon’s node. 
But since the amplitude of the inequality in the moon’s motion 
is directly proportional to the ellipticity, the amplitude of the 
free libration must be proportionally increased so that it would 
have to be of the order of 800”. It seems doubtful that such 
a large term should have escaped detection. 

The results of these various computations are therefore not, 
on the whole, favorable to the hypothesis that a librational 
term causes the long-period inequality in the moon’s motion. 
But the magnitudes of the forces which have been considered 
are so small that a more careful examination into the question 
of the whole effect of a magnetic attraction on the motion of 
the moon about its center of mass seems to be a desideratum, 
in view of the discordance between the theoretical and the 
observed ellipticities. This is not the object in view here, but 
the effects are not confined to any one class of observations and 
it may be possible to obtain evidence from various sources by 
which the question can be settled. 


Yale University, April 7, 1910. 


540 Perkins— Use of Silver in the Determination of 


Art. XLVI.—The Use of Silver in the Determination of 
Molybdenum, Vanadium, Selenium and Tellurium; by 
CraupE C. PERKIns. 


[Contributions from the Kent Chemical Laboratory of Yale Univ.—cexi. | 


In former papers from this laboratory a process for the 
gravimetric determination of free iodine by means of specially 
prepared electrolytic silver* and the application of the same 
process to the determination of combined iodine and other 
halogens and the estimation of those oxidizerst whose reaction 
with potassium iodide is definitely known to set free iodine 
quantitatively have been described. The object of the work 
described in the present paper was the application of the same 
process to the determination of some of the rarer elements and 
the study of the reaction of their oxides upon hydriodie acid in 
the presence of silver. 

To test the reaction of a soluble molybdate upon combined 
iodine in the presence of silver, a standard solution was made 
from a weighed amount of ammonium molybdate in which the 
percentage of molybdenum trioxide had been determined by 
fusing with a weighed amount of sodium tungstate which con- 
tained just enough tungstic acid to insure the absence of ear- 
bon dioxide. The ammonia was thus driven off and the 
amount of molybdenum trioxide was found from the increase 
in weight of the sodium tungstate.t Definite amounts of this 
solution were added to an excess of potassium iodide, made 
acid with hydrochloric acid and shaken with the electrolyti- 
cally prepared silver under an atmosphere of hydrogen. From 
the increase in weight of the silver the amount of molybdenum 
trioxide was calculated on the assumption that one molecule of 
molybdenum trioxide liberates one atom of iodine with the 
results shown in Table I. These results would tend to show 
that the reaction takes place according to the following equa- 
tion : 


2Mo0, +4KI+4HCl = 2Mo00,1+4KC1+2H,0+I,. 


TaBLeE I. 
Calculated 
Agtaken MoO; taken I, found MoO; Error 
erm. erm, erm. grm. erm. 
2°0002 O°2127 0°1869 0°2120 — (0007 
2 0006 OFZ ei 0:1874 0°2126 —0:°0001 
2°0012 0°2127 0°1870 0°2121 ~~ —0°0006 


2°0048 0:2127 0°1876 0°2128 +0°0001 
2°0000 0°2540 0°2242 0°25438 +0:°00038 
2°0004 02909 0°2571 0°2916 + 0°0007 


* This Journal, vol. xxviii, 33, 1909. + This Journal, vol. xxix, 338, 1910. 
¢t Gooch and Norton, this Journal, vol. vi, 168, 1896. 


Molybdenum, Vanadium, Selenium and Tellurium. 541 


In testing the reaction of a soluble vanadate with potassium 
iodide an exactly analogous process to that used in the case of 
molybdenum was carried out. The ammonium vanadate was 
fused with sodium tungstate to determine the amount of vana- 
dium pentoxide contained in it. A known amount of the 
- yanadate was shaken with potassium iodide, hydrochloric 
acid, and the silver, and the results calenlated on the assump- 
tion that one molecule of vanadium pentoxide liberates two 
atoms of iodine. The results shown in Table II would indi- 
cate that the reaction takes place according to the equation: 


V,0, +2HCl+2KI = V,0,+H,0+2KC1+I,. 


TaBLeE II. 
Calculated 
Agtaken V.O;taken T found V2.0; Error 
germ. erm, erm. erm. erm. 
2°0012 0°1946 0)°2699 0°1939 —0°0007 


2°0012 0°2051 0°2856 0°2051 +0°0000 
2°0024 071964 '‘' 0°2746 0°1972 +0°0008 
2°0024 0°2362 0°3295 0°2367 +0°0005 


2°0062 0°2958 0°4106 0°2949 —0°'0004 
2°0062 0°2681 0°3729 0°2679 —0°0002 
2°0527 0°5770 0°8038 0°5774 + 0°0004 
2°0006 0°2035 0°2829 0°2032 —0°0003 


With selenium and tellurium it was found that the reduc- 
tion proceeded to the end, giving the free elements, so that in 
weighing the residue of silver and silver iodide the amount of 
selenium or tellurium taken wasineluded.. The results obtained 
indicate that the reactions between selenium dioxide and potas- 
sium iodide and between tellurium dioxide and potassium 
iodide proceed according to the following equations: 


SeO, + 4KI+4HCl = 4KC1+2H,O0O+Se 4 2], 
TeO, +4KI+4HCl = 4KC1+2H,0+4+ Te+2I,. 


The selenium used was carefully purified by twice crystaliz- 
ing from nitric acid solution as selenium dioxide and resublim- 
ing in the presence of manganese dioxide. Definite amounts 
of a standard solution of selenium dioxide were added to an 
excess of potassium iodide in acid solution, and shaken with a 
weighed amount of the silver under the atmosphere of hydro- 
gen. The increase in weight should represent the iodine 
liberated plus the selenium taken. The results in Table III 
were calculated upon the assumption that one molecule of 
selenium dioxide liberates four atoms of iodine, which gives 
13°49 per cent of the increase in weight as the amount of 
selenium taken. 


542 Perkins— Determination of Molybdenum, ete. 
TasuE III. 
Agtaken Se taken Increase Calculated Se Error 
erm. erm. erm. erm. grm. 

2°0133 0°0050 0°0365 0°0049 —0:0001 
2°0133 0:0075 0°0529 0:0071 —0°0004 
2°5639 0°0126 0°0894 0°0121 —0°'0005 
2°5639 0°0428 0°3178 0°0429 +0:0001 
3°0018 0°0504 0°3799 0°0501 —0°0008 


In determining tellurium the dioxide was prepared from the 
basic nitrate by heating to drive off the nitric acid and the 
residual tellurium dioxide was heated to constant weight. 
Definite amounts of astandard solution, made from this product 
of tellurium dioxide, were added to an excess of a solution of 
potassium iodide, made acid with hydrochloric acid, and the 
whole shaken with a weighed amount of the silver under an 
atmosphere of hydrogen. The increase in weight represents 
the iodine set free plus the amount of tellurium taken. The 
results in Table IV were calculated upon the assumption that 
one molecule of tellurium dioxide liberates four atoms of iodide 
which gives 20°07 per cent of the increase as tellurium. 


Taste IV. 
Ne Nis 
Ag taken Te taken Increase Calculated Te Error 

grm. erm. erm. erm. grm. 
2°0152 0°0380 0°1654 0°0332 +0°0002 
2°0152 0°0990 0°4931 0°0989 —0°0001 
2°0815 0°0528 0°2635 0°0529 +0°0001 
2°0815 0°0660 0°3294 0°0661 +0:°0001 
2°0815 0:0990 0°4948 0°0993 + 0°00038 
2°1693 0°1650 0°8240 0°1654 + 0°0004 
3°0126 0°1650 0°8258 0'165% + 0°0007 
3°0126 0'0660 0°3302 0°0663 + 0°0003 


The results show that molybdenum, vanadium, selenium, 
and tellurium, may be determined gravimetrically by making 
use of the reaction of their oxides in liberating iodine from 
potassium iodide in an acid solution and combining the free 
iodine with the specially prepared silver. 


W. T. Schaller —Composition of Hulsite and Pairgeite. 548 


Arr. XLVIIl.—Chemical Composition of Hulsite and 
Paigevie;* by WatpEMAR T. SCHALLER. 


Introduction. 


In the April number of this Journal for 1908+ in conjune- 
tion with Mr. Adolph Knopf, who discovered these minerals 
in Alaska, I published a description of two new borates, hul- 
site and paigeite. These borates contained both ferrous and 
ferric iron, magnesia, and a small amount of water. The 
boric acid was determined by distillation with methyl alcohol 
and subsequent weighing as lime borate. Only a single deter- 
mination of the B,O, was given for each mineral. As, how- 
ever, both analyses footed up well and the ratios, moreover, 
were fairly close to simple numbers, no doubt was entertained 
as to the correctness of the results given. 

Shortly after, Prof. Clarke informed us that the method 
of determining boric acid in minerals was being investigated 
by two students of Prof. Edgar F. Smith, of the University of 
Pennsylvania. On entering into communication with Prof. 
Smith, we were enabled to have the boric acid content of both 
new minerais redetermined by methods devised by EK. T. 
Wherry and W. H. Chapin.t It was found that the values 
first obtained were erroneous, being much too high.§ On 
again examining the minerals, therefore, to account for the 
deficiency, tin was found to be present in appreciable quantity 
in both minerals. It therefore became necessary to revise and 
extend the original analyses in order to definitely fix the com- 
position of these minerals. 

Notes on Chemical Examination.—These borates, having 
very similar composition, contain ferrous and ferric iron, mag- 
nesia, tin, water, boric acid, and there are in addition present 
in the HCl solution of the sample, silica, alumina and lime, 
derived from the gangue. 

After considerable work performed on these two minerals, 
the results herein presented were obtained, but the unsatisfac- 
tory character of the determinations is fully recognized. A 
complete revision of all the chemical data is highly desirable, 
but for this pure material, free from any interfering gangue, is 

* A brief abstract of a much fuller paper which is to appear in a forth- 
coming Bulletin of the U. S. Geological Survey. 

+ Knopf, A. and Schaller, W. T., Two New Boron Minerals of Contact 
Metamorphie Origin, this Journal (4), vol. xxv, p. 525, 1908. 

t Determination of Boric Acid in Insoluble Silicates, Jour. American 


Chem. Soc., vol. xxx, p. 1687, 1908. 
$ This Journal (4), vol. xxv, p. 323, 1908. 


544. W. TZ. Schaller—Composition of Hulsite and Paigeite. 


necessary, and for the complete elucidation of the problem 
considerable material must be available. : 

The present investigation was carried out under two great 
disadvantages, namely, (1) paucity of material, and (2) the 
unavoidable presence of considerable gangue in the samples. 
For the hulsite samples, free from magnetite, less than a gram 
was available, while several grams of paigeite, as pure as possible, . 
had to suffice. Various questions developed only after some of 
the analyses had been completed, so that additional material was 
often needed but could not be had. It was found, too, that 
the different samples of each mineral varied somewhat in com- 
position due to the different quality and quantity of the 
gangue and also to isomorphous replacements in the minerals 
themselves. All these points, developed as the analyses pro- 
gressed, served to render the results obtained unsatisfactory to 
the analyst. 

Analyses of hulsite. 


Three different samples of hulsite were obtained and anal- 
yzed, the first two being the ones given in the original paper. 
Sample No. 1 consisted of about half a gram of magnetite-free 
hulsite, which was partially analyzed, only ferrous and ferric 
iron, magnesia, and the insoluble matter being determined. 
Sample No. 2 was about a gram of material, consisting of 
a mixture of hulsite and magnetite with but a few per cent of 
insoluble gangue. Tin was not determined in either of these 
samples and the value for boric acid given below for sample 
No. 2 was furnished by Wherry and Chapin.* Sample No. 3 
was obtained by reéxamining all the available material and 
picking out a small amount of non-magnetic hulsite mixed 
with considerable gangue. ‘The relatively large amount of the 
gangue that was soluble in acid complicated the discussion of 
the results. : 

Only the average of the analyses of samples Nos. 1 and 2 
are repeated below, the fuller data being given in the original 

aper. 
ee Average analyses of samples Nos. 1 and 2, hulsite. 


Nord. No. 2. 
MeO 5 ori Sh eae eae ws Bare 7 34°44 
MeO - it Geer e 10°17 8:48 
Be, O70 (sae op eee 17°83 27°64 
a co 
Tinsoliccyes 2 ee ae ee 2-24 
SO): Rete eae a ae not det. not det. 


From the analysis of sample No. 3, the ratio of B,O, to Fe,O, 
is found to be 3:2. From this ratio the amount of magnetite 


* Loc. cit. 


W. T. Schaller— Composition of Hulsite and Paigeite. 545 


present in the above sample No. 2 can be calculated. The 
amount of ferric iron belonging to the borate being thus deter- 
mined, the amount belonging to the magnetite is found, and 
deducting the proper amount of FeO to form FeO.Fe,O,, the 
ratios reduce to the figures given beyond, which represent the 
composition of the magnetite-free hulsite. 

The results obtained for the analyses of sample No. 3 are 
given below. Though considerable insoluble gangue was 
present, magnetite was entirely absent. The results shown 
under la were made on a small sample of still impurer material 
aud is chiefly of value for the determination of the tin, as the 
value confirms the other figures given for tin. The ammonia 
precipitate for sample la was not determined, as it was used 
for various qualitative tests:and the calcium precipitate was 
accidentally lost. The figures given under laare not taken into 
the average. The higher value for the boric acid under col- 
umns 1 and 2 is taken in the average instead of the mean of 
the two values, as the second determination given is believed 
to be low. 

Analyses of sample No. 3, hulsite. 


la 1 2 3 Average 

22) eee eles ete ee lone Duar Oe el 
LO Sueo ee eee aie aeang | 4-00 
ee ey 08 ee oe Ont Oh 
ee ala ae aevet! Boy a Aloe on 
Hemi iron as We.O..-  ._-- mt Sew AG 80. A opoe Ve 2: 
iO 5s oo Gls Gy We ye eile 
= eo ame bile 9-0 Quen nint 11) .9290 
Basolwoles: 222-222 2A? e992 (Pico 20) 18°44) 18°63 
EEO CO. SiO. Al O. 532 ee Chilis? fae 23 8°78 
100°00 


From the figures given above for the average analysis the 
ratios were calculated with the following values: 


Ratios of analysis of sample No. 3, hulsite. 


1 GL VSS Sethe geen pie ee "385 10°47 
in 73  ] eae er are ee em ec Oe 107 

1222 (0 Moaked aaa apenas Ms “095 2°02 
SHOe ee ie eee 047 1:00 
5G a Me ER Be 131 2°79 


The analyses of samples No. 2 of paigeite, as given beyond, 
give an indication of the amount of calcium oxide which may 
be derived from the gangue. For 15 per cent insoluble matter 
the calcium oxide content is about 4 per cent. If this ratio 
remains fairly constant, there should be, in the above analysis 
of hulsite sample No. 3, about 5 per cent of lime obtained 
from the gangue. This would leave approximately somewhat 


Am. Jour. Sct.—Fourtu Series, VoL. XXIX, No. 174.—Junz, 1910. 
36 


546 W. 7. Schaller—Composition of HHulsite and Paigeite. 


less than 4 per cent CaO which may belong to the borate min- 
eral. Assuming this to be so, the ratio of (FeO, MgO, CaO) 
to Fe,O, would become 11°9:1 or nearly 12:1. From the 
analysis of sample No. 3, given above, we obtain for the for- 
mula of hulsite, then, either 10£RO.2Fe,O,.SnO,.3B,0,+7H,0O, 
or regarding the 4 per cent of CaO as belonging to the mineral, 
the formula 12RO.2Fe,O,.SnO,.3B,0,+?H,O. 


Discussion of Formule of Hulsite. 


From the results of the analyses of the three samples of hul- 
site, as just given, there are derived the following partial 
formule for the mineral. 


Partial Formule for Hulsite. 
RO Fe,03 SnO, BO; H.O 


From Sample No. 1-.--- 13°2 2-0 i we te 

re Pe cals 12°4 2°0 ae 3°0 19 
a Bona IGS 2°0 1 28 «OF 

rs 3 Sa 5 SheeO) 2°0 1°0 2°8 ae 


From this compilation, incomplete as it is, the most probable 
formula derivable from the results obtained is 12RO.2Fe,O,,. 
1Sn0,.3B,0,.2H,0 or (Fe,Mg),,Fe,SnB,H,0,,. In consider 
ing the relations of the various elements, it becomes almost 
impossible to consider hulsite as a borate of iron (ferrous 
and ferric), tin and magnesia, as the bases are present in 
overwhelming amount. Therefore, the ferric iron may be con- 
sidered as present as an acid, playing the same role as the 
borates. On this assumption the above formula may be writ- 
ten: R”,(BO,),.[R”,[Sn(OH)]’” H,4eO,),]. The tin in hulsite 
is in a condition which is so easily soiuble in dilute acid that 
it seems more probable to regard it as present as some form of 
stannic acid. The presence, however, of stannic acid, in com- 
bination with boric and possibly some iron acid, leads to a 
complicated subject on which it is best to, at present, pass by. 


Analyses of Paigeite. 


For paigeite, three different samples were prepared and 
analyzed. The amount of gangue varied slightly, but no such 
large variations in the amount were encountered as with hul- 
site. Sample No. 1 was the sample on which the first analyses 
were made. Tin was not determined in it, and the value given 
for B,O, is the one determined by Wherry and Chapin. The 
average of the analyses is: 


ReQe See <2 eee ee 44°48 
Mig. Oi cee een! 1°44 
FeO oes i) ee 16°72 

5) ADRS TONED Ole 
BiOs S heees ee DIP Che ee 9°83 


W. T. Schaller—Composition of Hulsite and Paigeite. 547 


The other two samples were prepared from the specimens at 
hand, sample No. 2, consisting of finely-ground material, for 
which reason the value for FeO may be somewhat low. Sam- 
ple No. 3 consisted of coarser material, otherwise very similar 
in character to that of No. 2. 

Analyses of the second sample yielded the following results : 


Analysis of sample No. 2, paigeite. 


CO) eer 40°82 epee ate 40°82 
RECOV 3 202 2- Oil 2°10 2°04 
CO Lena ee 4°28 4°31 3°81 4°13 
6 Cas i SE 18°19 19°34 18°48 18°67 
Total iron as Fe,O,._ 63°54 64°69 63°83 BREE 
52.0) ie iiel ae et OSH 3°14 3:26 3°18 
2. eae 9°10 fb mee 9°10 
iasolubles. = S24. 16°18 15°74 16°38 16°10 
pie A OE O*) 2: by difference 5°96 

100°00 


Considering all the lime as resulting from the solution of the 
gangue, the ratios deduced from the above analyses are: 


Ratios of analyses of sample No. 2, paigeite. 


LEGG) cob 5. eh og i 2 a a el 567 

ese 5 olf. 204 
ene ee eee bs Ie aie 117 5°6 
SO ee eee be Se Se 021 1:0 
EO. = Meee aN ee a wee cmon tegs Et 6-2 
15.) 5 Eee ad Nie x lies ae eae te Nee mee 


From these ratios the formula, incomplete in regard to the 
water content, is 29°-4RO.5-6Fe,O,.1Sn0,.6°2.B,0,. + ? H,O. 

‘Analyses of the third sample yielded the following results. 
The evidence having indicated that the gangue was consider- 
ably dissolved by the HCl, direct determinations of the silica 
and alumina were made. 


Analysis of sample No. 3, paigeite. 


1 2 3 Average 

Ore ae a 34°68 34°86 30°D2 35°02 
MgO cape Page bgt ge 2°25 1°89 2°22 2°12 
DENS Aad elias as Sige 8°97 8°56 8°84 8°79 
Gi) ise 14°69 << 14-84 YD 1518 | 14-90 
Total iron as Fe,O,- 53°22 53°57 54°62 sided 
0) Se eno 2°77 2°86 276% 280 
Oper ears 3 0 tke 6°71 716 6°94 
ihisoluble 2.12. 522- - 18°62 18°81 18°29 18°57 
Si0, NES Saye ot Dp ee a 3°28 2°78 3°25 3°10 
IANO 2300). ¢ 2225. 2°51 2°41 2°09 2°34 
PEO ere. Se by difference 5°42 
100‘00 


* A fourth determination of SnO2 gave 2°97 per cent. 


548 W. TZ. Schaller—Composition of Hulsite and Paigeite. 


In the ratios of the above analysis, the CaO, SiO, and Al,O, 
are excluded as belonging with the insoluble matter to the 
gangue. As obtained from the average analysis, they are :— 


Ratios of analysis of sample No. 3, paigeite. 


HeO 22 Se eee ee eee es "486 

MOO fe oe Te OR ie oe nh ee eae 056 

Be), co i oe ee eee 093 4:9 
SnQ. Wel we cee eee 019 1:0 
By Oech Sine CI Ay ea aha geen 099 572 
HUQ oS eke Uepertie ee: Spugeanes ee 


Like one of the hulsite analyses, the calcium oxide is con- 
siderably higher in sample No. 3 than in sample No. 2 and it 
seems as if somé of the lime belonged to the borate. It would 
need only 1°57 per cent. of CaO to raise the ratio of 
(Fe0+Me0O+CaQ) to SnO, from 28°5 : 1, as given above, to 
30:1. This small amount of lime may, therefore, be con- 
sidered as belonging to the borate. The ratios then obtained 
are 28°5 or 30:0 RO.4:9Fe,O,.18n0,.5°2B,0,+ ? H,O. 


Discussion of Formule of Paigeite. 


From the above three series of analyses, the following are 
the formule deduced for paigeite : 


Formule for Paigeite. 


RO Fe,03 SnO. B.O3 H,O 


Mromsample INO es ole 5:0 he 6°7 5°4 
se ie RE Na al 29°4 5°6 1°0 6°2 pegs 

i 3 Le se 98°5 49° 1:0! 5:0) 
Sale 30°0 4°9 1:0 5°2 rate 


The average of the above shows that the most probable 
formula for paigeite and the one proposed for the mineral is: 
30FeO.5Fe,O,.18n0,.6B,0,.5H,O. While the above formula 
is complex and yields a rather high ratio of FeO to SnO,, there 
does not seem to be any other interpretation to the analyses. 
While not impossible that paigeite is a mixture of two or more 
closely related minerals, nothing but the unusual composition 
indicates such a mixture. The constant small percentage of 
tin oxide shows that the mineral is essentially different in 
ratios from the corresponding hulsite. The occurrence in 
wavy lamellar masses of fine radiating fibers, the intense shiny 
black color, the marked tendency as seen in thin sections for 
the individual fibers and masses to fray out at the ends into a 


Chemistry and Physics. 549 


bunch of very thin fibers, all differentiate this mineral from 
hulsite, which never shows any indication of fibrosity. 

An alternative interpretation of the composition of paigeite 
is that it is a mixture of hulsite and a fibrous borate. Sub- 
tracting from the formula of paigeite the necessary amounts to 
include all the tin with the hulsite, the following results are 
obtained : 

Paigeite = 30 FeO.5 Fe,O,.18n0,.6B,0,.5 H,O 
mee mStte! (2 Sy Qh ody Sorin 1g. 86 
eaeremsilett (be) Se0. aOrse geouey ® OL 
6FeO.Fe 0, eb Ove ©: 


Should future investigation prove this to be the case, then 
the material now called paigeite would consist of a mixture of 
1 part hulsite and 3 parts of the borate 6FeO.Fe,O,.B,O,.H,O, 
to which the name of paigeite could then be referred. How- 
ever, on the evidence at hand, it is most reasonable to regard 
paigeite as homogeneous and with the composition ascribed 
to it. 

To repeat, the formule now proposed are, for hulsite, 
12(Fe,Me)O.2F e,O,.18n0,.3B,0,.2H,0, and for  paigeite, 
30FeO.5F e,O, 1Sn0, [6 by 0,.5 5H,O. 


Chemical Laboratory, 
U.S. Geological Survey. 


se BN YEE ERC OLN EE EET.G HN CE: 


I. CHrmistry AND PHysics. 


1. A Gas containing Helium from the German Potash Deposit.— 
Ernst ERDMANN gives an account of an inflammable gas which 
was set free by a blast in the carnallite deposit of a shaft at a 
depth of 450 meters below the surface. When first liberated, 44 
years ago, it burned with a flame a yard long, and the pressure 
has since diminished only very gradually, and many thousands of 
cubic meters of the gas have escaped and burned. As an average 
of eight analyses the following results were obtained: 


Ebydrogen. 252) 202022 J 83-6 per cent by volume. 
Wekecleagies tri}. 8 2 iv detal 4-4 “ce ct ee 
brecrd nett yh Lov [290 «c &< cc 


The methane was found to be free from other hydrocarbons of 
the series, and the absence of oxygen, carbon dioxide, ethylene, 
and acetylene was established. The residue was found to contain 


550 Scientific Intelligence. 


a considerable amount of helium and also a little neon. These 
gases amounted to 0°17 per cent by volume of the original gas, or | 
nearly one per cent of the residue, so that it was estimated that 
at least 12 cubic meters of helium and neon had escaped from the 
crack in the carnallite during the 4% years of the flow of gas. 
It appears that Strutt had already detected a small quantity of 
helium in carnallite by dissolving the mineral in water. 

In speculating in regard to the origin of the hydrogen the 
author is inclined to discard an ingenious theory advanced by 
Precht, that this gas arises from the reaction of ferrous chloride 
upon the water of crystallization of the mineral with the forma- 
tion of hematite, a well-known constituent of the deposits. In 
fact, by heating appropriate mixtures in evacuated sealed tubes 
at 100-110° C. for 160 hours, no evidence of the formation of 
hydrogen or ferric oxide could be obtained. This experimental 
result, and the fact of the presence of helium, have led the author 
to advance the view that radio-activity has been the cause of the 
formation of hydrogen as well as of helium. Radio-active sub- 
stances are supposed to have decomposed water into its elements, 
then the oxygen has reacted with ferrous chloride to form hematite, 
leaving the hydrogen. The radio-active bodies are supposed to 
have disappeared from the deposit, on account of being of shorter 
duration than uranium, which seems to be absent, and which has 
so long a life that it could not be expected to disappear in the 
time that has elapsed since the deposits were formed. 

The author doubts that the feeble radio-activity of potassium 
is the source of the helium, although Strutt is inclined to take this 
view of the matter, for he argues that the helium is by no means 
uniformly distributed among the potassium salts, and, besides, 
there is no ground at present for assuming the production of 
helium from potassium.— Berichte, xlii, 777. H. L. W. 

9. Detection of Methyl Alcohol.—A rapid and accurate method 
for the detection of this substance, particularly in the presence of 
ethyl alcohol, has been devised by G. Denic#s. It is based upon 
the conversion of the alcohols into their corresponding aldehydes 
by the action of potassium permanganate under definite condi- 
tions, and the testing for formaldehyde by means of bisulphite- 
fuchsine under conditions that the author has worked out. He 
takes 0:1° of the alcohol to be tested in a test-tube, adds 5° of 
1 per cent KMn0O, solution, then 0:2° (not more) of pure H,SO,, 
and mixes. After 2 or 3 minutes 1° of 8 per cent oxalic acid is 
added, and the mixture is agitated. It rapidly becomes decol- 
orized, and when a yellowish wine color is reached, 1°° of pure 
H,SO, is added and it is agitated again, when it becomes com- 
pletely decolorized. Then 5° of bisulphited fuchsine solution are 
added, the liquid is mixed and allowed to stand, when a violet 
color, more or less intense according to the amount of methyl 
alcohol originally present, appears. The color usually reaches a 
maximum in about 15 minutes, it is very strong with 1 per cent 
of methyl alcohol, and is appreciable at a dilution of one-thou- 


Chenustry and Physics. 551 


sandth. The Schiff’s reagent may be prepared by adding to 1 
liter of ;5q fuchsine solution 20° of sodium bisulphite of 36—40° 
Baume, and after5 or 10 minutes adding 20° of hydrochloric acid 
of 1:18 density. In an hour or two the reagent is sufficiently 
decolorized for use.— Comptes Rendus, el, 832. H. L. W. 

3. A Substitute for Platinum Wire for Use in Blowpipe 
Work.—O. F. Krrsy takes a few asbestos threads as straight 
and even as possible, dips them into phosphoric acid diluted with 
one or two parts of water, and heats them gently in the Bunsen 
flame until most of the water has been driven off. The threads, 
which are now attached to each other by the acid, but still flexi- 
ble, are now carefully rolled between the fingers or on paper until 
a thin, even filament is produced, 2 or 8™™ in cross section. They 
are again carefully heated for a few minutes and finally finished in 
the blowpipe flame, when they are converted into a brittle rod or 
wire somewhat resembling porcelain. ‘These rods give perfectly 
colorless borax beads which have little tendency to fall from the 
end. They are practically non-conductors of heat, and give no 
coloration to the non-luminous flame. They can be moistened 
with water or dilute acids without losing their rigidity, though 
when left in contact with these liquids for any length of time 
they become disintegrated and require re-heating before use. 
Though very brittle, pieces of about 8°™ in length will stand a 
good deal of usage, and pieces half as long may be used without 
risk of burning the fingers. They have been found to give 
excellent results in blowpipe work with large classes of students 
as a substitute for the more expensive platinum wire.— Chem. 
News, ci, 170. Ele Da Wis 

4. The Use of Sodium Hypobromite in the Separation of 
Certain Metals.—Pozzi-Escorr has found sodium hypobromite, 
in the presence of a large excess of caustic soda, a convenient 
reagent for separating iron and nickel from chromium, aluminum, 
and zinc. ‘The operation consists in heating the acid solution to 
boiling, adding a large excess of the alkaline reagent, filtering 
upon nitrated cotton, dissolving in hydrochloric acid and repeat- 
ing the precipitation. He recommends the method also for the 
determination of chromium, vanadium, and molybdenum in steels 
as more convenient than the method by use of an oxidizing fusion. 
These acid-forming elements pass into solution while nickel and 
manganese remain with the iron.— Bulletin, IV, vii, 160. 

Ho L. W. 

5. The Doppler Effect in Hydrogen.—B. STRASsSER shows that 
the admixture of other gases with hydrogen influences the rela- 
tive brightness of the stationary lines and the displaced ones. 
The purer the hydrogen the less bright is the stationary line— 
with a very pure gas only the displaced line is visible. Gases 
with larger atomic weights exercise a greater influence on the 
comparative intensity of the stationary and displaced lines than 
gases with lower atomic weights. The cathode dust also influences 
the relative intensities of these lines. A comparison is also made 


552 Scientific Intelligence. 


between the displaced lines in the region near the cathode and at 
: . € : 
a distance. ‘The value of —=10* has obtained from the canal 


m 
rays.—Ann. der Physik, No. 5, 1910, pp. 890-918. ‘me 


6. Effect of Dust and Smoke on the Ionization of Air.—From 
the investigation of A. 8. Evz, of McGill University, it appears 
that “‘the presence of dust, smoke, mist or other centres charged 
or neutral in the air causes a transformation from small to 
large ions. In this way, the total number of ions present may 
be increased, while the conductivity is diminished. In any 
region of air where a charge of one kind is predominant, the 
effect of the presence of centres, neutral or charged, is to increase 
and accentuate the excess. This tendency must have an important 
influence in the variation of the potential gradient and on the 
production of thunder storms.”—VPhil. Mag., May, 1910, pp. 
657-678. Soe 

7. Measurements in the Extreme Infra-Red Spectrum.—H. 
Rusens and H. Hottnacer show that the interferometer method 
is preferable to the diffraction grating method in the study of the 
infra-red region. They have employed a quartz-plate inter- 
ferometer with “ Reststrahlen ” and have determined the wave 
lengths and energy distributions of the Reststrahlen of rock salt, 
sylvine, potassium bromide and potassium iodide and have obtained 
a relation between the molecular weight and the mean wave 
length. The index of refraction of water for A=82°3 yp is of the 
same order as in the visible spectrum. By the investigation of 
Reststrahlen the optical spectrum has been extended 2/3 of an 
octave. Its complete extent is now 10 octaves—two of which 
are in the ultra-violet, one in the visible and seven in the ultra- 
red.— Phil Mag., May, 1910, pp. 761-782. Jira 


II]. GErEouoey. 


1. Paleogeography of North America ; by CHarixs Scuu- 
CHERT. ‘‘ Dedicated to those two great leaders in Geology and 
Stratigraphy, James Dwight Dana and Eduard Suess.” Bull. 
Geol. Soc. Amer., vol. xx, pp. 427-606, pls. 46-101, 1910. Pre- 
sented before the Society December 30, 1908.— With due regard for 
the other important contributions to paleogeography which have 
appeared during the course of the past generation and especially 
within the past few years, this may still be held the most import- 
ant single contribution to the subject which has yet been pub- 
lished. Working for many years in the front rank of invertebrate 
paleontologists, the author’s interests have broadened beyond the 
organisms to the inferences which their relationships imply as to 
the extent, connections, and durations of the continental seas. 
Although the concurrence of conclusions from several branches 
of geologic knowledge is required to attain reasonably safe 


Geology. 553 


results in interpreting ancient distributions of lands and seas, the 
most important of these is clearly a masterly knowledge of 
paleontology. The thirty-eight years spent by the author in 
studying this subject have therefore formed the necessary per- 
sonal preparation, while the growth of the several fields of geology 
through the labors of others has supplied a wealth of literature 
and made possible results which could not have been achieved in 
any previous decade. 

The first 83 pages of the paper give a history of paleogeography 
from the first maps of J. D. Dana to the present time, and a 
statement of its methods. This is followed by a discussion of 
the influences which enter into the shifting of the strand line. 
A geologic history of the North American seas is also included. 
The final 77 pages give a description of the maps which follow 
and the new classification of geologic time suggested by them. 

The first distinctive point to be noted in regard to this work 
consists in the large number of maps, fifty-seven having been 
prepared and fifty-three published, each representing a separate 
time interval, and the whole covering geologic time from the 
Lower Cambrian to the present. The diagram of fluctuating sea 
levels (pl. 101) indicates that at least this number of maps was 
necessary in order to reveal graphically the successive important 
movements that have occurred. All previous maps are therefore 
too synthetic in that each covers so long a time interval that 
significant changes of land and sea are concealed. 

The second distinctive feature lies in the importance given to 
disconformities and the cartographic restriction of the original 
limits of the seas in the direction of the ancient land masses to a 
short distance beyond the farthermost determined outcrops of 
their sediments. As is noted by the author, this method may err 
on the side of too much restriction of the continental seas (p. 
446). Most previous maps, both by representing a longer period 
of time and freely extending the seas beyond the limits of the 
sediments, have, on the other hand, tended to make the seas too 
extensive in time as well as in space. By consistently following 
his method the author is enabled to construct a diastrophic curve 
(plate 101) which shows the percentages of the present area of 
North America and of the United States which were exposed as 
land at each succeeding stage. This is one of the most important 
features of the paper. It brings out the diastrophic basis for 
grouping the geologic periods into eras delimited by revolutions, 
during which practically the whole continent stood for a longer 
or shorter time above the sea level. On the major rhythm are 
superimposed the secondary diastrophic waves, each of which 
marks a transgression and recession of the sea and comprises a 
geologic period. Defined on this basis, the Cambrian and Ordo- 
vician are broken up into three periods each and the Mississippian 
into two, called by Schuchert the Mississippic and Tennesseeic. 
The first of these is not, in North America at least, diastrophically 
distinct from the Devonic, the change being marked faunally 


554 Scientific Intelligence. 


rather than by shiftings of the seas. The fifty-seven maps were 
planned to bring out this diastrophic basis for the geologic 
periods, but beyond these earth movements of the second order, 
which separate the periods, are progressively smaller ones of the 
third and higher orders which the maps and the curves con- 
structed from them cannot show. For these the maps are still 
too synthetic. 

A study of the work gives a very different impression as to the 
character of North American paleogeography from that conveyed 
by the older maps which figure in many text-books. The latter 
show North America almost submerged at the beginning of the 
Paleozoic and gradually emerging during the progress of that 
long eon. The recent maps of Chamberlin and Salisbury, and 
also those.of Willis and others, show quite a wide departure from 
this older conception, but Schuchert’s bring out one totally dif- 
ferent. In the latter the amount of North America covered by 
sea during eleven transgressions and ten emergences up to the 
end of the Carboniferous averages 22 per cent, but the transgres- 
sions being regarded as the longer phases, their average of 29 
per cent represents the more permanent amount of water area. 
Furthermore the maps do not show a gradual emergence and 
growth of the continent such as have been formerly postulated, 
but on the contrary far-reaching oscillations of the sea. This is 
the dominating fact, but it is still true that after the greatest ~ 
transgression of the middle Ordovician each later inundation 
covers somewhat less area. ‘There is thus expressed graphically 
and powerfully what has in recent years come to be believed by 
many geologists, that wide oscillations of continental seas, pro- 
ducing alternate intermingling and isolation of their faunas, 
rather than a gradual retreat of the seas, was the controlling 
principle of Paleozoic tirae. The maps in connection with the 
discussions of the text give also a conception of the topographic 
relief of the continent during this greater part of the fossil-bear- 
ing earth record. The thin and patchy sediments representing 

many epochs and the wide prevalence of limestone, the numerous 
disconformities, only recognizable by finding hiatuses in the fos- 
sil record, indicate the reign of extremely shallow seas lying on 
lands which barely rose above their level. Except for the systems 
of axes on the two sides of the continent which were elevated 
from time to time and shed great quantities of waste into the 
neighboring troughs, the continent was awash. Across now one 
and now another part of this continental interior the ocean rolled 
on and off in waves whose periods were measured by more than 
a million of years. 

A review of so important a paper as this should not, however, 
contain a mere summation of contents but also te some extent an 
examination of the principles upon which it is constructed. Pro- 
fessor Schuchert argues that unlike but synchronous faunas of 
otherwise similar environment could not in the Paleozoic be 
explained by differences in temperature of ocean waters or by sea 


Geology. 555 


currents, but the existence of land barriers must be postulated to 
separate them. Furthermore he holds that wide and shallow 
seas could not be broadly subject to bottom scour in the way now 
observed in limited localities, but would record their presence by 
means of sediments. These two principles as rules of very 
general though of course not universal or rigid application seem 
well taken and give definiteness to the problem. In regard, how- 
ever, to the valuation of the disconformities some departure of 
view may be held from that which the author entertains. He 
States : 


“Neither can it be admitted that... extensive sheets of 
limestone have suffered erosion. If the latter were true, outliers 
of these missing horizons would be found, for the land was so 
low that the wearing away could not have removed them com- 
pletely over hundreds of miles of extent ” (p. 442). 


That is, the disconformity is valued as entirely a land interval 
rather than as partly a sea interval, A, followed by a land inter- 
val, B, during which the sediments of time, A, are removed. ‘The 
reviewer would consider that A instead of being of negligible 
value may comprise almost any part of the entire value A+B of 
the disconformity. Blackwelder has well discussed this idea in 
the “ Valuation of Unconformities”* and Gilbert has clearly 
called attention to the fact that we are ignorant of the maximum 
extent of the great transgressions and still more ignorant of the 
former maximum areas of lands, since the landward sediments 
are immediately subjected to erosion upon the least retreat of the 
sea and continue to be eroded through all later time. The sea- 
_ ward limits of the greater unconformities are, on the other hand, 
forever concealed.t This paper of Gilbert’s, so far as the reviewer 
is aware, is the first in American literature to call in question the 
general conception prevailing until recent years of the continu- 
ous reign of the Paleozoic continental seas. The questions raised 
by Gilbert are strikingly answered in the affirmative through the 
investigations of the past decade. The exceptional preservation 
of outliers of the great transgressions hundreds of miles from the 
nearest regular outcrops, in some places by downfaulting, in 
others by fossiliferous fragments having fallen down fissures and 
so escaping erosion, indicates how accidental is our knowledge of 
the supposed limits of the great transgressions. Limestones 
furthermore being subject to attack by solution are the most 
reducible of formations in a humid climate, as indicated by the 
broad limestone valleys rapidly developed at baselevel. Conse- 
quently under a suitable climate it is to be expected that out- 
lying sheets left above baselevel might be completely dissolved 
away without leaving a trace of their former existence. The 
theory of probabilities would indicate that the plane surface of 
disconformities should more often be due to unlimited though 
slight emergence of the land with following subaérial planation, 


* Blackwelder, Jour. Geol., vol. xvii, pp. 289-299, 1909. 
+ Continental Problems, Bull. Geol. Soc. Amer., vol. iv, pp. 178-189, 1892. 


556 Sceventifie Intelligence. 


aided to some extent by marine planation, rather than that uplift 
of the land should take place until it was exactly flush with the 
surface of the sea. Schuchert’s diastrophic curves are therefore 
presumably too limited in width of oscillations and too smooth. 
The latter point is illustrated by the Pleistocene, which is shown 
on his curve as a straight line representing gradual emergence of 
the continent to its present state, whereas it is known from the 
drowned river valleys that geologically rapid and profound oscil- 
lations have occurred and the continent now stands notably lower 
than in that portion of the Pliocene when the mature valleys now 
submerged were excavated. 

On the other hand, the study of faunas indicates that no great 
oscillations have been missed and by adopting the most conser- 
vative method of mapping Schuchert finds the marked oscilla- 
tions which give him the basis for the new time scale. The 
result proves the wisdom of caution in extending the limits of 
the seas. But while the permanency of these maps and their 
great value as a basis for future work is fully recognized, exten- 
sions of the seas will probably be made in many cases by using 
symbols such as Chamberlin and Salisbury and Willis have 
employed to indicate probable but unprovable extensions beyond 
the limits set by Schuchert. 

Passing next to that part of the paper which deals with the 
causes rather than the results of paleogeographic change, the 
great debt owing to Suess is made apparent. The chief cause of 
the world-wide inundations is ascribed to the erosion of the lands 
and the filling in of the seas, so that an erosion cycle is also an 
inundation cycle. The emergences are ascribed to crustal move- 
ments which increase the relief of the earth, chiefly by increasing 
the volume of the ocean basins. The broad movements of the 
strand line are therefore largely due, both negative and positive 
movements, to changes of sea level, more than to movements of 
the land, but it is especially in positive movements of the strand- 
line that this is so. The problem, however, is by no means a 
simple one and the author classifies continental seas according to 
the dominant feature of their existence. The classification terms 
are not mutually exclusive, since he regards nearly all as aggrad- 
ing seas. During the period of advance they will be transgress- 
ing seas and some of them will be synclinal seas. 

To this valuable part of the paper exception may be taken, 
however, on two points. First, the author frequently ascribes 
vertical warps, even in the continental interiors, to “‘ thrusts from 
the oceans,” by which is meant of course ‘‘the oceanic crustal 
segments.” But it will be seen that for the collapse of geosyn- 
clines situated within continental platforms and often far removed 
from the ocean basins, the immediate cause is a thrust between 
two continental elements while the wltimate cause is held to be 
the contraction of the earth’s interior. Furthermore, horizontal 
thrust in the crust has at most only a remote connection with 
many vertical movements. ‘Thrusts from the oceanic segments ” 
is therefore an expression to be cautiously used, but as the 


J 


Geology. 557 


causes of earth movements constitute a subject not immediately 
connected with paleogeography the doubtful use of this term 
does not affect the conclusions of the paper. 

The other point on which difference of opinion may be held is 
regarding a looseness in the use of the terms syncline and anti- 
cline, a looseness which may be noted not infrequently in paleon- 
tologic literature. 

In this paper syncline is used indiscriminately for syncline 
geosyncline and downwarp, and anticline for the contrary terms. 
At the present time it is well recognized that synclinal and anti- 
clinal folds are adjustments to horizontal pressure dependent 
upon stratified structures and die out in the deeper and unstrati- 
fied crust. Their size is determined by the competency of the 
stronger beds to resist stress. For those broader axial folds 
which involve the deeper crust and are generated by isostatic as 
well as compressive forces, Dana has provided the terms geosyn- 
cline and geanticline. For the combination of smaller folds 
superimposed on greater, Van Hise has used the terms syneli- 
norium and anticlinorium, though as Rice has pointed out, his use 
of the term synclinorium is an unjustifiable departure from 
Dana’s original definition.* For broad vertical regional move- 
ments not clearly defined but in which horizontal thrust appears 
to play no direct part, the physiographers have coined the terms 
downwarp and upwarp, or arch. While the examples grade 
toward each other, the types are markedly distinct and in paleo- 
geography there would seem to be a gain by their clear recogni- 
tion. ‘To illustrate the use of these terms in their defined senses 
it may be said that it is the subsidence of geosynclines and the 
irregular downwarps of the negative continental elements which 
have determined the limits of the epi-continental seas. Down- 
warp may also be a preferable term to basin for such gentle 
depressions without raised rims as constituted the Zndiana and 
Ohio basins of upper Paleozoic time. Usage, however, sanctions 
in this connection the word basin, though the same word is 
employed for intermontane depressions and the oceanic abysses. 

Ue 8 


2. Virginia Geological Survey, Toomas Lronarp Watson, 
Ph.D., Director. Bulletin No. I-A. Annual Report on the 
Mineral Production of Virginia, 1908; by T. L. Warson. Pp. 
139, 25 figures and map. University of Virginia, Charlottesville, 
1909.—The Report on the Mineral Production of Virginia con- 
tains not only statistical material well illustrated by maps, but 
also historical and general geologic information regarding the 
occurrences of rocks and minerals of value. A further interest- 
ing feature is the brief account of the general geology of the 
state. ‘The mineral products discussed are as follows: Iron ores 
and pig iron, manganese ores, gold and silver, copper, lead and 
zine, coal, coke, clay and clay products, lime and cement, sand 


* On the Use of the Words Synclinorium and Anticlinorium, Science, vol. 
xxiii, 1906, pp. 286, 287. 


558 Scientific Intelligence. 


and gravel, sand-lime brick, stone, abrasive materials, silica, mica, 
feldspar, asbestos, tale and soapstone, barytes, gypsum, salt, 
mineral paints, marl, pyrite and pyrrhotite, arsenic, phosphate, 
graphite, rutile (titanium), monazite, mineral waters, precious 
stones. H. E. G. 

3. Geological and Archeological Notes on Orangia; by J. 
P. Jounson. Pp. 102, 45 figures and bibliography. New York 
and London (Longmans, Green & Co.).—This volume might be 
called an expanded notebook on the geography of Orangia 
(Orange River Colony). It is the sort of description which is of 
interest to one who desires a knowledge of the country and its 
people. Interesting notes on climate, topography, on the dia- 
mond, coal and salt prospects are mingled with data regarding 
the plant and animal life of the region, population, history of 
settlement, and present social and industrial conditions. 

The horizontally bedded rocks of the Karroo system extend 
over nearly the entire territory with the exception of rocks of 
earlier age exposed near Vredefort by planing down of an anti- 
cline by marine denudation. Chapters 3 and 4 are devoted to a 
discussion of the kimberlite dikes and pipes and the diamond 
mines. The superficial deposits give evidence of a change in 
climate during recent geologic time. Ancient spring deposits 
and buried sand dunes are in evidence. An interesting series of 
‘“‘nans” apparently corresponding to the “buffalo wallows” of 
North America are found in several localities. The larger pans 
are bounded on one side by large dikes which intercept the 
movement of ground water and determine the location of wells. 

The prehistoric inhabitants of this district are discussed in 
chapters 6 to 8. Two distinct groups of stone implements, the 
Acheulic and the Solutric, have been found, the former supposed 
to be much older than the latter. The richness of the collections 
may be indicated by the fact that on one Solutric site there were 
gathered 1300 flakes and unfinished implements, as well as 700 
finished flake tools. The petroglyphs and rock paintings of ani- 
mals, men and mythological beings, which are figured in chapter 
8, are especially interesting as indicating the stage of develop- 
ment of those prehistoric people. H. E. G. 

4. Handbuch der Regionalen Geologie ; herausgegaben von G. 
STreErnMANN und O. WitckEns. Heidelberg, 1910 (C. Winter).— 
The aim of the projectors of this work is expressed in the title. 
it is to produce a series of volumes which shall give in condensed 
form, and yet with sufficient detail, an account of the regional 
geology of the entire world, so far as now known. It is pro- 
posed to carry out the work in 8 volumes of about 600 pages 
each. ‘The price per sheet, or signature, to subscribers is to be 
50 pfennigs, or about 5 dollars a volume. In executing the work 
the authors will have the help of a great number of geologists, 
all the principal civilized countries being represented. One 
thought that the proposal immediately suggests is that the dif- 
ferent volumes for practical use will have very different values. 


Geology. ay) 


Thus, for example, Germany, Bohemia, Denmark, Netherlands, 
and Belgium, with an area of say 260,000 square miles, are to be 
treated in one volume and one is also projected for the two 
Americas and Antarctica, or say 17,000,000 square miles. It is 
of course true that the geology of central Kurope has been studied 
in relatively great detail as compared with the larger part of the 
Americas and that over wide areas the geology of the latter is 
on a simpler and broader scale, yet to compress only a part of 
what is known of this vast area into one volume will require so 
sketchy a treatment that, as a source of information for regional 
geology, its value can only be small, compared with the first 
volume mentioned. It is to be hoped that as the work proceeds 
this part may be enlarged and more contributors added, if it is to 
have an international scope and use. 

The first sample of the work to appear now lies before us. It 
is vol. Il, part 2, and covers Denmark. It is from the pen of 
Prof. N. V. Ussine of Copenhagen. It is a masterly presenta- 
tion of the subject and, in the 38 pages allotted, a remarkable 
amount of detailed information is conveyed, relating to physiog- 
raphy, stratigraphy, fossils, geological history, tectonics, resources 
of economic value, etc. and a full bibliography. It is an excel- 
lent model for the entire work. ae Ves 


IU. Miscertuaneous Screntiric INTELLIGENCE. 


1. United States Coast and Geodetic Survey. Report of the 
Superintendent, O. H. Tirrmann, showing the Progress of the 
Work from July 1, 1908, to June 30, 1909. Pp. 184, with 4 
appendices and 10 pocket maps. Washington, 1909.—This 
report contains the usual statement of the work accomplished by 
the Survey during the year ending June 30th, 1909. It is accom- 
panied by four Appendixes giving Details of Field and Office 
Operations (Nos. 1 and 2), also Results of Magnetic Observations 
for the time named (No. 3), and further (No. 4), the Distribution 
of Magnetic Declination in Alaska and adjacent regions for 1910. 
This last Appendix, as also No. 3, is by R. L. Faris and is accom- 
panied by a chart giving the lines of equal magnetic declination 
and of equal annual change in Alaska for 1910. 

The Survey has also issued another volume of the results of the 
observations at the permanent magnetic observatories ; this is for 
the observatory at Sitka and covers the years 1905 and 1906. 
This report has been prepared by Daniel L. Hazard, and is accom- 
panied by thirty-six figures reproducing the magnetograms for 
the principal magnetic storms. 


2. Connecticut Geological and Natural History Survey. 
Bulletin No. 14. Catalogue of the Flowering Plants and Ferns 
of Connecticut ; by a Committee of the Connecticut Botanical 
Society, consisting of C. B. Graves, CE. H. Eames, C. H. Bissett, 
L. AnpREws, E. B. Harcur, and C. A. WEATHERBY. Ep d09: 


560 Scientific Intelligence. 


Hartford, 1910.—This important work has been carried through 
by the above-named committee of the Connecticut Botanical 
Society without personal compensation, the State contributing 
$300 for incidental expenses. It gives a complete list, according 
to present knowledge, of the flowering plants and ferns growing 
without cultivation within the limits of the state; the names are, 
in general, those of the seventh edition of Gray’s Manual. This 
list includes 1948 flowering plants and ferns; of these 1487 are 
believed to be native to the state and 461 to have been intro- 
duced by man either designedly or by accident. In addition there 
are numerous forms distinct enough to receive names although . 
not given specific rank, bringing the total number of plants named 
in the book to 2228. The introduction gives an interesting his- 
tory of botanical investigation in the state, beginning with that 
of Dr. Levi Ives (1819), and continued by many active workers ; 
an appendix includes a statistical summary of the plants of Con- 
necticut. Teachers of botany and all interested in our native | 
plants will welcome this thorough and carefully prepared volume. 
Copies may be obtained from the State Librarian for seventy-five 
cents, or gratuitously, where needed by scientific men or teachers 
for professional use. 

3. Kraft das ist animalische, mechanische, soziale Energien 
und deren Bedeutung fir die Machtenfaliung der Staaten; von 
Pror. Dr. E. Reyer. Zweite Auflage. Pp. vii, 471, Leipzig 
(Wilhelm Engelmann), 1909. 

Soziale Michte als Ergdnzung der Arbeit tber “ Kraft” ; von 
E. Reyer. Pp. 111, 34 figures—Readers of the earlier edition 
(see v. xxvii, 272) of Dr. Reyer’s thoughtful discussion of this 
broad and important subject will be glad of this new edition, which 
takes into account the many recent factors in modern industrial 
progress. 

4. Publications of the Alleghany Observatory of the Univer- 
sity of Pittsburgh.—The following memoir of vol. I has recently 
been distributed. 

No. 21. A Comparative Study of Spectroscopic Binaries ; by 
FRANK SCHLESINGER and Ropert H. Baker. Pp. 135-161. 

5. Bulletin of the University of Kansas.—The following has 
been recently issued: Engineering Bulletin No. 1 (vol. xi, No. 1), 
A Ballistic Electro-Dynamometer Method of Measuring Hyste- 
resis Loss in Iron; by Martin E. Rice and Burton McCorium. 
Pp. 23, with 5 figs. Lawrence. 

The Philosophy of Happiness: A Consideration of Normalism; by R. 
Waite Jostyn. Pp. 200. Elgin, Ill. (Normalist Publishing Co.) 

La Vita Della Ricchezza; by EMANUELE SELLA. Pp. 252. Turin, 1910. 
(Fratelli Bocca, Editori.) 


Obituary. 561 


ALEXANDER AGASSIZ, 


Tue sudden death of Mr. Agassiz was announced in the last 
number of this Journal. He was returning on the steamer 
« Adriatic” from a trip to Egypt and southern Europe, in company 
with his son Maximilian, and was apparently in about as good 
health as usual, of late years. He was found dead in his berth, 
on March 27th. 

In his death the world has lost one of its most eminent scien- 
tific men, and probably the most liberal patron of natural science 
that this country has known. 

He not only conducted, at great cost, numerous extensive explo- 
rations of the deep sea and coral islands and reefs in all the 
great oceans, but he personally wrote many of the volumes of 
reports on the results of his expeditions. Moreover, he induced 
many of his colleagues, both in this country and Europe, to write 
reports on his various collections, paying personally all the 
expenses of their publication, including the most liberal illustra- 
tions, and provided in his will for their completion, by a bequest 
of $100,000, besides an equal amount for the general uses of the 
Museum. His zoological and embryological works, both before 
and after his deep-sea explorations, were voluminous and of 
great importance, and his contributions to our knowledge of the 
physical geography and geology of all the great coral-reef 
regions are of inestimable value. 

But aside from these investigations, the building up of the 
Museum of Comparative Zoology, from the comparatively small 
institution, with small funds, as it was left at the death of his 
father, into a magnificent museum, liberally endowed, and filled 
with a wonderfully rich collection, has been one of the great 
achievements of his life. He was not only its curator and 
director for many years, but also by far the most liberal of its 
patrons, for his gifts to the Museum amount to upwards of a 
million dollars. 

However, to the world at large he is, no doubt, more widely 
known as the eminent mining engineer and financier, who devel- 
oped and managed during many years the great Calumet and 
Hecla Copper mine, which made him and some of his friends 
wealthy. It is stated, in the Mining and Scientific Press, and 
in the Engineering News, that this is the greatest single copper 
mine in the world, and that it has paid in dividends over 
$110,000,000. Its wonderful success was due to his skill and 
energy. When Mr. Agassiz commenced to develop it in 1865-6, 
it was considered as almost worthless. 

He was also interested in various other important lines of 
business. But his fame, apart from his scientific work, will, in 


Am. Jour. Scl.—Fourts Series, Vou. X XIX, No. 174.—Junz, 1910. 
37 


562 Obituary. 


the long run, depend rather upon the wise uses to which he 
devoted a considerable. part-of his fortune, than upon its ac- 
quisition. 

Mr. Agassiz came to America in 1849, at the age of 14 years. 
He graduated at Harvard in 1855; in 1857 he took. the post- 
graduate degree of B.S. in Civil Engineering ; ; and in Zoology in | 
1862 ; POET 1885. In 1859-60 he was employed .in the Coast 
Survey, on the Pacific Coast, and on the Northwest Boundary 
Survey. While there he made some collections of the marine 
fauna for his father, and also sent him some very beautiful draw- . 
ings of acalephs, actiniz, ete., which the writer saw at that time, 
and with which his father, Prof. Louis Agassiz, was very much 
pleased. He returned to Cambridge, owing to the urgent desire 
of his father, to continue his zoological studies and especially: to 
assist his father in the installation of the collections in the new 
Museum building, which had then just been built and was not 
finished. During the next few years he was an assistant in the 
Museum, associated with Lyman, Hyatt, Shaler, Putnam, Packard, 
Scudder, Morse, the writer, and others, many of whom have also 
passed away. 

In 1866-7 he was induced to undertake the development of the 
Calumet and Hecla mine, on Lake Superior, where he remained 
as Superintendent most of the time till 1869, and with which he 
was connected as president or director till his death. While there, 
in the early years,,he experienced great hardships and exposure, 
and contracted an illness from which he never fully recovered. 

He was appointed Curator and Director of the Museum, after 
the death of his father, in 1874 and retained that position till 
1898, when he resigned it. He was also fellow of Harvard 
University, 1878 to 1884, and 1886-1890 ; overseer 1873-78 and 
in 1885, and became Director of the Univer sity Museum of Har- 

vard in "1902. 

He had been a member of the National Academy of Sclenees 
since 1866, and for a number of years was its president. More 
recently he has been its Foreign Secretary, up to his death. 

He was a member of a large number of other scientific soci- 
eties, both in this country and Europe, and received numerous 
other honors. 

Among his earlier scientific expeditions was one to the Andes 
and Lake Titicaca, in 1875, where he obtained many archeolog- 
ical and zoological specimens. From 1877 to 1880 he spent most 
of his winters in deep-sea dredging on the “ Blake Expeditions,” 
mostly in the West Indies and Gulf of Mexico. The collections 
thus obtained were very large and valuable and have given origin 
to many valuable reports. Mr. Agassiz himself wrote the gen- 
eral account of the work and its results in two volumes, “ Three 
Cruises of the Blake.” He also made trips to the West Indies 
and Bermuda, to study the geology of the coral reefs. He also 
made an extended exploration of the great Barrier Reef of Aus- 
tralia, in a steamer chartered for the purpose in Australia, in 1896. 


Obituary. 563 


About that time the writer remembers a remark that he made, 
in conversation, to the effect that he proposed to devote the rest 
of his life to the exploration and study of the coral-reefs and 
islauds of the Pacific and Indian Oceans. In pursuance of this 
idea he obtained from the U.S. Government the use of the 
steamer “ Albatross,” of the U.S. Fish Commission, for several 
long trips, both for deep-sea dredging and coral-reef work. How- 
ever, he personally paid the “running expenses,” such as for the 
coal, oil, etc., and his scientific outfit and assistants. He told me 
personally that these trips and those of the “Blake” were often 
no pleasure trips for him, for they involved a great amount of 
hard work and much sea-sickness at times. 

In 1891 he made his first cruise in the Albatross for deep-sea 
explorations of the Pacific Ocean off 8S. America, Central America, 
the Galapagos Islands, and Mexico; in 1897 he explored the 
coral reefs of the Fiji Islands; in 1899 and 1900 he made a very 
extended exploration of the Pacific coral islands, including the 
Marquesas, Paumotu, Society, Fiji, Ellice, Gilbert, Marshall, 
Caroline, Ladrone and other groups, and to Japan. In 1904 and 
1905 he again explored the ocean depths off the west coasts of 
North and South America, extending his cruise to Easter Island 
and the Paumotus. . 

In December, 1901, and January, 1902, he explored the great 
Maldive Archipelago of coral islands in the chartered steamer 
‘“‘ Amra,” steaming 1600 miles among the islands. The fully 
illustrated report of this expedition by Mr. Agassiz is of great 
interest and value. ; 

One of the most important results of his explorations of the 
coral islands was the complete confirmation of the view, already 
held by many geologists, that most coral reefs and islands, both 
Atlantic and Pacific, are built upon eroded banks and shoals of 
ancient rocks, and are not of such great thickness as had been 
supposed, nor ordinarily due to gradual but extensive sinking of 
the land, as Darwin and Dana believed. 

Mr. Agassiz was less known and appreciated popularly than 
his illustrious father, but this was due partly to the fact that he 
wrote few popular works and delivered very few public lectures. 
Nor did he teach classes in the University. But his scientific 
publications exceed those of his father. 

His specialties in Zoology were Hydrozoa and Echinoderms— 
especially the Echini, in which he was the leading authority. In 
Geology the structure and origin of coral islands and reefs were 
his specialties. Among his earlier papers, however, there is one 
on the embryology of annelids, one on the young stages of fishes, 
and another on the larval development of Balanoglossus. 

The following list, which includes most of his more important 
publications, is by no means complete, but it will serve to give a 
good idea of the variety and great extent of his published works. 
He told the writer, a day or two before he started on his last 
trip, that he had other reports in preparation, and that he 


564 Obituary. 


expected to do some work on them while away. He, also, at 
that time, authorized him to have 140 quarto plates printed for 
the report on the Alcyonaria of the Blake Expeditions. Most of 
his own publications, relating to his various explorations, if in 
quarto were published in the Memoirs of the Museum of Com- 
parative Zoology, and the octavo ones in the Bulletin of the 
Museum. 


Embryology of the Starfish. 4to, 8 plates. 1864. 

North American Acalephe. 248 pp., 4to, 360 text figures. 
1865. 

Preliminary Report on the Echini and Starfishes dredged in 
deep water between Cuba and the Florida Reef by L. F. de 
Pourtales. 54 pp. 8vo. 1869. . ) 

Revision of the Echini, 4to, 774 pp., with Atlas of 94 plates. 
1872-1874. 

Zoological Results of Hassler Expedition. I, The Echini. 4to, 
23 pp., 4 plates. 1874. Ss 

Embryology of the Ctenophore. 41 pp. 4to, 5 plates. 1874. 

North American Startishes. Part I, Embryology of the Star- 
fish. Part II, On the Solid Parts of Some North American 
Starfishes. 143 pp. 4to, 20 plates. 1877. 

Paleontological and Embryological Development. 1880. 

Report on the Echinoidea dredged by the Challenger. 321 pp. 
4to, 64 plates. 1881. 

Report on the Echini. Results of dredging by the Blake. 94 
pp., 32 plates, 4to. 1883. 

Three Cruises of the Steamer Blake, in the Gulf of Mexico, in 
the Caribbean Sea, and along the Atlantic Coast of the United 
States. 1877 to 1880. Two volumes, 8vo, 545 text cuts and 
maps. 1888. 

Calamocrinus Diomede, a new Stalked Crinoid. 95 pp. 4to, 
32 plates. 1892. 

A Reconnaissance of the Bahamas and of the elevated reefs of 
Cuba in the steam yacht “ Wild Duck,” January to April, 1893. 
203 pp., 4 plates. 1894. 

A Visit to the Bermudas in March, 1894. 72 pp. 8vo, 30 
plates and a map. 1895. 

Acalephs from the Fiji Islands, 47 pp. 8vo, 17 plates. 1899 
(with A. G. Mayer). 

Preliminary Report, and List of Stations of the Albatross 
Expedition of 1899 and 1900, 114 pp. 4to, 21 charts. 1902. 

The Coral Reefs of the Tropical Pacific. 443 pp. 4to, 238 
plates. 1903. 

The Medusez of the Albatross Expedition of 1899-90. 40 pp. 
4to, 14 plates. 1902 (with A. G. Mayer). 

The Coral Reefs of the Maldives. 4to, 193 pp. and an atlas of 
82 plates, 1903. 

The Panamic Deep-Sea Echini, 254 pp. 4to, 112 plates. 1904. 

Reports on the Scientific Results of the Expedition to the 
Eastern Tropical Pacific, by the Albatross, 1904 to 1905. 75 pp. 
4to, 96 plates and maps, 1906. 


Obituary. : 565 


Many of the plates illustrate the huge prehistoric statues on 
Easter Island and the scenery of the Galapagos. 

Hawaiian and other Pacific Echini. The Cidaride. 50 pp. 
4to, 44 plates. 1907 (with H. L. Clark). 

A visit to the Great Barrier-Reef of Australia in the steamer 
“Croydon,” during April and May, 1896. 55 pp., 42 plates, 1898. 

The Islands and Coral Reefs of Fiji. 167 pp., 120 plates. 1899. 

Hawaiian and Other Pacific Echini. 88 pp. 4to, 17 plates. 
1908 (with H. L. Clark). 

Kchini: The Genus Colobocentrotus. 42 pp. 4to, 49 plates. 
1908. 

Hawaiian and Other Pacific Echini. The Echinothuride. 63 
pp. 4to, 30 plates. 1909 (with H. L. Clark). 

The Tortugas and Florida Reefs. 27. pp. 4to, 12 plates and 
maps, 1883. 

The Porpitidee and Velellitz. 16 pp. 4to, 12 plates. 1883. 

A. E. VERRILL. 


Professor RoBERT Parr WHITFIELD was born at Willowvale, 
Oneida Co., N. Y., on May 27, 1828, and died at Troy, N. Y., on 
April 6, 1910. 

Professor Whitfield’s parents were English, and when young 
Whitfield was about seven years of age, in the fall of 1835, 
the family went to England. From England the Whitfields 
returned to America in 1841, finally locating at Whitestone, adjoin- 
ing Utica, N. Y. Here Prof. Whitfield’s scientific life began, 
and for a time, consonant with the promiscuous impulses which 
first start the naturalist in his course of observation, he turned 
his attention to many fields of natural history. In his twentieth 
year Prof. Whitfield married. For nine years he continued his 
vocation as a maker of philosophical instruments at Utica, but, | 
through his membership in the Utica Society of Naturalists, was 
constantly associated with students of nature. 

During these years he became acquainted with Colonel Jewett, 
and thus came in contact with a representative collection of 
fossils and shells, and the beginnings of his interest in paleon- 
tology, which finally excluded all other phases of scientific activ- 
ity, were laid. 

Through Colonel Jewett he became employed in the service of 
the New York State Survey under Prof. James Hall, and in 
Albany his scientific influences were strengthened, educational 
facilities increased, and a continuous intercourse with workers 
and leaders in science began. Meek, Hunt, Logan, Billings, 
Leslie, Safford, Agassiz, Conrad, Hayden, were a few names 
among the crowd of visitors to Prof. Hall’s home, and in this 
multitudinous circle Whitfield’s acquaintance with men of science 
was greatly extended. 

His work was felt and illustrated in the publications of the 
Survey. He became lecturer in the chair of Applied Geology, 
at the Troy Polytechnic Institute, and in March 1876 resigned 
his position in Albany, and came to the American Museum of 
Natural History, where he installed the great Hall Collection of 
Fossils. 


566 Obituary. 


Besides his work on the New York Survey, Prof. Whitfield 
was engaged in work for the Ohio, Wisconsin, New Jersey and 
Black Hill Surveys, while papers furnished to journals of science, 
and the series of special studies published in the Bulletin of the 
American Museum of Natural History, complete his life of scien- 
tific activity. 

Among contributions to science which merit the distinction of 
being classed as discoveries were his detection of the muscular 
impressions in “true Lingula” in the Trenton limestone, his 
observations on the internal appendages of Atrypa, his reference 
of the fossil forms Dictyophyton and Uphantenia to sponges, 
his description of a fossil scorpion from the Silurian rocks of 
America, his notice of new forms of marine Algz in the Tren- 
ton limestone, the demonstration of Balanus in the Marcellus 
Shale, his papers on fossil teredo-like forms (Xylophomya), and 
the proof of three genera in a single individual of Heteroceras. 
The long series of papers on systematic paleontology, in which 
many new genera and species occur, with numerous observations 
in morphology and correlation, identify his name with American 
Paleontology. L, PG 

Str Wirtitiam HucGerns, the veteran English astronomer, died 
in London on May 12, at the age of eighty-six years. He was 
one of the first to use the spectroscope in the study of the heav- 
enly bodies, and the importance of his researches into the consti- 
tution of the comets, the stars and nebulz can hardly be over- 
estimated. 

Professor Knur Jonan Awnesrrém, the eminent Swedish 
physicist, died on March 4, in the fifty-fourth year of his age. 
He was the son of Anders Johan Angstrém, the pioneer worker 
in exact quantitative work on the solar spectrum, and his labors 
were devoted to the same field of solar physics ; his most impor- 
tant investigations had to do with absorption phenomena, partic- 
ularly in the infra-red, and with the measurement of solar radi- 
ation. 

Professor JULIEN FRaipont of the University of Liége, 
Belgium, died March 22, 1910, at the age of 53 years. At the 
time of his decease he was rector of the University and professor 
af animal geography and paleontology. Author of many papers 
on zodlogy, paleontology and anthropology and a member of 
many learned societies, including the Royal Academy of Belgium, 
Dr. Fraipont was perhaps best known for his work (issued in: 
1887 jointly -with Professor Max Lohest) on the fossil race of 
Spy, entitled: La race humaine de Néanderthal ou de Canstadt 
en Belgique. Recherches ethnographiques sur des ossements © 
humains découverts dans des dépéts quaternaires d’une grotte a 
Spy et détermination de leur age géologique. 

Dr. H. Lanpott, Professor of Chemistry at the University of 
Berlin, died on March 14, at the age of seventy-eight years. 

Dr. E. Puirieri, Professor of Geology at Jena, and geologist to 
the German Antarctic Expedition of 1901-03, died in March. 

Dr. Ricuarp ABeEce, Professor of Chemistry at Breslau, died 
on April 3, in his forty-second year. 


INDEX TO VOLUME XXIx.* 


A 


Absorption and phosphorescence, 
Briininghaus, 189. 

Academy, National, meeting at Wash- 
ington, 463. 

Adams, F. D.., flow of marble, 465. 

Africa, Blood- ‘sucking flies, Austin, 
92 


Agassiz, A., obituary notice, Ver- 
mi 561. 


Alabama, Pleistocene flora, Berry, 

— 887. 

Allegheny Observatory, see Observ- 
atory. 


Allen, E. T., analysis of metals used 
in thermometry, 151. 

Allen’s Commercial Organic Analy- | 
ses, Leffmann and Davis, 263. 

Antarctic Expedition, National, 198. 

Antlitz der Erde, Suess, 269. 

Arizona, Grand Canyon geology. | 
Noble, 369, 497. 


B 


Bacteriology, Dairy, Russell and 
Hastings, 200. | 

Bedell, F., Direct and Alternating 
Current Testing, 83. 

Berry, E. W., Cretaceous Bauhinia 
from Alabama, 206; Pleistocene 
flora of Alabama, 387. 

Bigelow, F. H., general circulation | 
of the earth’s atmosphere, 277. 

Binn, La Vallée de, Desbuissons, 195. | 

Birkeland, K., Norwegian Aurora, 
Polaris Expedition, 272. 

Bitumens, solid, Peckham, 409. 

Black Hills, Dakota, etc., geology | 
and water resources, Darton, 267. 

Bosworth, R. S., crystals of silver 
sulphate and pe, 293. 

Botany, Clute, 272. 

Brigham, W. T., Hawaiian Volca- 
noes, 363. 


British Museum catalogue, Bryozoa, 
195. 


Brown, E. W., effect of magnetic 
and other forces on the motion of 
the moon, 529. 

Browning, P. E., 
cerium, 45. 


separation of 


C 


Cambridge Natural History, Harmer 
and Shipley, 92. 


Camel, fossil, Nebraska, Loomis, 
297. 
Canada balsam, refractive index, 


Schaller, 324. 

— geol. reports, 365. 

Cape of Good Hope geol. survey, 
194. 

Carnegie Foundation, 4th Annual 
Report, 274. 

|— Institution, at Washington, 8th 
Year Book, 274; publications, 368. 

Chemical analysis, Quantitative, 
Clowes and Coleman, 80. 


CHEMISTRY. 


Analyse Volumétrique, Dupare and 
Basadonna, 408. 

Arsenic, etc., estimation of, Palmer, 
399. 

Bromides of barium and radium, 


relative volatility, Stock and 
Heynemann, 79. 

Bromine, free, determination, Per- 
kins, 338, 


Cadmium amalgams, Smith, 264. 

Cerium, separation, Browning and 
Roberts, 45. 

Colloidal solutions, formation from 
metals, Svedberg, 187. 

Dye, purple, of the ancients, Fried- 
lander, 262. 

Helium, gas containing, Erdmann, 
549. 

Hydrogen, determination of, Paal 
and Hartmann, 458. 

— chloride, action of light upon, 
Coehn and Wassiljewa, 79. 


*This Index contains the general heads, BOTANY, CHEMISTRY (incl. chem. physics), 
GEOLOGY, MINERALS, OBITUARY. ROCKS, ZOOLOGY, and under each the titles of Articles 


referring thereto are mentioned. 


568 


CHEMISTRY—cont. 


Metals, action on fused caustic 
soda, LeBlanc and Bergmann, 
o61. 

— and dissolved halogens, velocities 
of reactions, Van Name and 
Edgar, 237. 

Methyl alcohol, detection, Denigés, 
550. 

Molybdenum, etc., formation of 
the oxides, Mixter, 488. 

Platinum wire, substitute for Kirby, 
dol, 

Potassium ferricyanide in estima- 


tion of arsenic, etc., Palmer, 
399. 
—perearbonate, Riesenfeld and 


Reinhold, 188. 

Selenious acid, volumetric deter- 
mination, Marino, 189. 

Silver in the determination of 
molybdenum, etc., Perkins, 540. 

— sulphate and dichromate, crys- 


tals, Van Name and Bosworth, 
298. 


Sodium, cesium, etc., detection, 
Ball, 360. 
—hypobromite, use of, Pozzi- 


Hscott, 551. 
Sulphates, determination, Mitchell 
and Smith, 361. 
Uranium and radium in minerals, 
ratio between, Gleditsch, 79. 
Water supply, purification 
hypochlorites, 263. 
Zirconium, metallic, 
Neumann, 407. 

Chemistry, Analytical, Chesneau, 
translated by Lincoln and Carna- 
han, 458. 

— Physical, Jones, 264. 

Chesneau, M. G., Analytical Chem- 
istry, 458. 

Clark, A. H., origin of crinoidal 
muscular articulations, 40; pen- 
tamerous symmetry of crinoidea, 

Clowes, Chemical Analysis, 80. 

Clute, W.N., Botany, 272. 

Coast and Geodetic Survey, 559. 

Cockerell, T. D. A., descriptions of 
Tertiary plants, No. III, 76. 

Coker, E. G., the flow of marble, 
465. 

Coleman, Chemical Analysis, 80. 

Connecticut, Catalogue of Plants 
and Ferns, 599. 

Crew, H., Elements of Physics, 83. 

Crystals in light parallel to an optic 
axis, Travis, 427. 


by 


Weiss and 


INDEX. 


Cuba, naptha from, Richardson and 
Mackenzie, 459. 
Current Testing, Bedell, 83. 


D 


Davis, W. A., Allen’s Commercial 
Organic Analyses, 263. 

Day, A. L., nitrogen thermometer 
from zinc to palladium, 93. 

Dinosaurs, distribution, Lull, 1. 

Doppler effect in positive rays in 
hydrogen, Royds, 81 ; Strasser, 551. 


E 


Earth, figure of, and isostacy, Hay- 
ford, 193. 

Earth’s atmosphere, circulation of, 
Bigelow, 277. 

Edgar G., velocities of reactions be- 
tween metals and dissolved halo- 
gens, 287. 

Electric discharges through hydro- 
gen, Trowbridge, 341. 

— spark, constitution, Royds, 264. 
Electricity, conduction throughGases 
and Radio-activity, McClung, 190. 

— positive, Thomson, 81. 

Electrons, moving, Hupka, 189. 

Elektrizitat, die Strahlen der posi- 
tiven, Gehreke, 191. 

Erythrea, Hast Africa, petrography, 
Manasse, 87. 

Evolution of Mammals, Hubrecht, 
ale 


F 


Farrington, O. C., times of fall of 
Meteorites, 211. 

— new Pennsylvania meteorite, 350. 

Fenner, C. N., crystallization of a 
basaltic magma, 217. 

Flies, African, Blood-sucking, Aus- 
tin, 92. 

Florida geol. survey, 265. 

Franklin, W. S., Light and Sound, 82 


G 


Gaseous suspensions, de Broglie, 264. 


GEOLOGICAL REPORTS 


Canada, 265. 

Cape of Good Hope, 194. 
Connecticut, Bulletin 14, 560. 
Florida, 265. 

Illinois, 267. 

Towa, vol. xix, 459. 


INDEX. | 


GEOLOGICAL REPORTS-cont. 


Kansas, 268. 

New Zealand, 460. 

North Dakota, 192. 

Pennsylvania, 266. 

United States, 30th Annual Report, 
ile 


— List of publications, 363 ; pocket 


folios, 86. 
Virginia, 267, 557. 
West Australia, 87. 
West Virginia, 459. 
Geologie, Handbuch der Regionalen, 
Steinmann and Wilckens, 558. 


GEOLOGY. 


Antelopes, Tertiary of Nevada, 
Merriam, 271. 

Auburn-Genoa quadrangles, Luther, 
463. 

Bauhinia, Cretaceous, 
Alabama, Berry, 296. 

Brachiopods from the Mississip- 
pian, Greger, 71. 

Bryozoa, fossil, British Museum 
Catalogue, Gregory, 195. 

Carboniferous, upper, Texas and 
New Mexico, Richardson, 325. 

Cenozoic Mammal horizons of No. 
America, Osborn, 88. 

Coleoptera, new fossil from Floris- 
sant, Wickham, 47. 

Crinoids, origin of muscular artic- 
ulation, Clark, 40. 

— pentamerous symmetry, Clark, 
300. 

Devonian fauna of the Ouray lime- 
stone, Kindle, 194. 

Dinosaurian distribution, Lull, 1. 

Erde, das Antlitz der, Suess, 269. 

Flora of Quedlinburg, Richter, 270. 

Fusulina, Asiatic, Dyhrenfurth, 
194. 
Goldfield district, Nevada, geology 
and ore deposits, Ransome, 85. 
Grand Canyon, Arizona, geolog Ws 
Noble, 369, 497. 

Hyolithide, lower Paleozoic, from 
Girvan, Reed, 194. 

Isostacy and figure of the Earth, 
Hayford, 193. 

Jurassic strata of South Dorset, 
Buckman, 461. 

Kilauea and Mauna Loa, Brigham, 
363. 

Lepadocystis clintonensis, Ontario, 
Parks, 404. 

Mammals, new fossil, from Egypt, 
Osborn, 88; Tertiary horizons in 
N, America, Osborn, 88. 


new, from 


569 


Mississippian Brachiopods, Greger, 
Zale 

Ouray limestone, 
Kindle, 194. 

Paleogeography, of North America, 
Schuchert, 552. 

Paleolithic man, 
eae 

Pleistocene flora, Alabama, Berry, 
387. 

Siugetierontogenese, die, Hubrecht, 


Devonian fauna, 


restoration, Lull 


Starfishes, Lower Devonic, of Ger- 
many, Schondorf, 195. 

Stegosaurus, armor, Lull, 201. 

Stenomylus, genus, Loomis, 297. 

Tertiary plants, descriptions, No. 
III, Cockerell, 76. 

Titanotheres from the Eocene and 
Oligocene, Osborn, 90. 

Vertebrates, Carboniferous, of the 
U.S. National Museum, Moodie, 
88. 


Goldschmidt, V., goethite, 235. 

Grand Canyon Geology, Noble, 369, 
497. 

Greger, D. K., rare brachiopods from 
the Mississippian, 71. 


H 


Harvard College Observatory, 276. 

Hawaiian volcanoes, Brigham, 363. 

Hayford, J. F., figure of the earth 
and isostacy, 195. 

Hertz’s photoelectric effect, Bloch, 
189. 

Human Body and Health, Davison, 
92. 

Hyperbolic Functions, Becker and 

Van Orstrand, 199. 


I 


Illinois geol. survey, Bulletin 11, 267. 

Ionization of air, effect of dust and 
smoke on, Eve, 502. 

Iowa geol. survey, 409. 


J 


Johannsen, A., petrographic micro- 
scope improvements, 435. 

Johns Hopkins circular, No. 2, 362. 

Joly J., Radio-activity and Geology, 


ee H. C., Physical Chemistry, 
264. 


~~ 


570 INDEX. 

K | MINERALS. 
Kansas, University, bulletin, 560. Anhydrite, Kansas, 260. Anor- 
— geol. survey, 268. thite, soda, 64. Arsenopyrite, 


Khartoum, Wellcome Research Labo- 
ratories, 91. 
Kraft, Reyer, 560. 


L 


Lahee, F. H., dodecahedral jcint- 


ing, 169 


Leffmann, H., Allen’s Commercial | 


Organic Analyses, 263. 
Library of Congress, report, 275. 


Light and Sound, Franklin and) 


Macnutt, 82. 
Linnaeus, Conmespomlenee of, Fries, 
200. 


Loomis, F. B., genus Stenomylus, 


297. 

Loughlin, G. F., granites and meta- 
morphic sediments in Rhode 
Island, 447. 


Lowell, P., Evolution of Worlds, 199. | 


Lull, 
tion, 1: 
maamyesledals 


201. 


R. S., Dinosaurian distribu- 


M 


MacKenzie, K. G., natural naptha | 


from Cuba, 439. 
Macnutt, B., Light and Sound, 82. 
Magnetic rotation, Meyer, 82. 


— and other forces, effect on motion | 


of the moon, Brown, 529. 
Magnetism, terrestial; Birkeland, 


my) 
Wie 


Man, restoration of Paleolithic, Lull, 
IAD 


Manometer, Amagat, Koch and 
Wagner, 189. 

Marble, flow of, Adams, 465. 

McClung, R. K., conduction of 
electricity through glass, ete., 190. 


Meterorite, iron, Shrewsbury, Pa., 
Farrington, 390. 

— Stone, Georgia, Merrill, 368. 

Meteorites, Rochester collection, 
Howard, 368. 

— times of fall, Farrington, 211. 

Meteorological investigations, Bige- 
low, 277. 

Michigan, biological survey, 268. 

Microscope, petrographic, improve- 
ments, Johannsen, 435. 

— — new, Wright, 407; new ocular 
for use with, Wright, 415. 


restoration of Paleolithic | 
armor of Stegosaurus, | 


New Jersey, 177. Astrophyllite, 
Massachusetts, 215. 

Bementite, New Jersey, 182. Bis- 
mite, 173. 

Carnegieite, 52. Celestite, Kansas, 
261. Covellite, Colorado, 358. 
Cuspidine, New Jersey, 185. 

Datolite, New Jersey, 185. Dia- 
mond, transformation into graph- 


ite, 362. Dolomite, Kansas, 261. 
Enargite, Colorado, 358. 
Feidspar from Linosa, 52. Fluor- 


ite, New Jersey, 177. Franklin- 
ite, New Jersey, 180. Friedelite, 
New Jersey, 188. 


Gahnite, New Jersey, 179. Glau- 
cochroite, New Jersey, 181. 
Goethite, Nova Scotia, 230. 
Goldfieldite, Nevada, 83. Gyp- 
sum, Kansas, 261. 

Halite, Kansas, 261. Heterolite, 


New Jersey, 190. Hulsite, New 
Jersey, 543. Humite, New Jer- 
sey. 185. 
Leucopheenicite, New Jersey, 185. 
Manganosite, New Jersey, 178. 
Nasonite, New Jersey, 180. 
Paigeite, 543. Pyrite, Kansas, 261. 
Pyroxenes, New Jersey, 180. 
Quartz, Kansas, 261. 
Vesuvianite, New Jersey, 184. 
Willemite, New Jersey, 182. 
Zincite, New Jersey, 178. 
Minerals, mercury, from Texas, 
Hillebrand and Schaller, 567. 
Mixter, W. G., heat of formation 
of molybdenum oxides, etc., 488. 
Moon effect of magnetic and other 
forces on motion of, Brown, 829. 


N 


Naphtha, natural, from Cuba, Rich- 
ardson and Mackenzie, 439. 

Nevada, geology and ore deposits, 
Ransome, 89. 


New Zealand geol. survey, 460. 


Nitrogen thermometer from zinc to 
palladium, Day and Sosman, 98 ; 
analysis of metals, Allen, 95. 

Noble, L. F., geology of the Grand 
Canyon, Arizona, 369, 497. 

North America, Paleogeography of, 
Schuchert, 552. 

North Dakota geol. survey, 192. 

Norwegian Aurora Polaris Expedi- 
tion, Birkeland, 272. 


INDEX. 


6 
OBITUARY. 


Abegg, R., 566. 
Agassiz, A., 464, 561. 
Angstrom, K. J., 566. | 
Barnes, C. R., 464. 
Bidwell, S., 276. 
Fraipont, J., 566. 
Huggins, Sir Wm., 566. 
Landolt, H., 566. 
Loper, S. ct 464. 
Nikitin, Se 276. 
Philippi, te 566. 
Whitfield, R. P., 464, 565. 
Observatory, Allegheny, 
tions, 368, 560. 
— Harvard College, 276. 
Optik, meteorologische, Pernter, 362. 
Orangia, Geological notes, Johnson, 
508. 
Ostwald’s Klassiker der 
Wissenschaften, 464. 


publica- 


Exacten 


Pres 


Palache, C., mineralogy of Franklin 
Furnace, N. J., 

Palezontolgia Universalis, 462. 

Paleogeography of North America, 
Schuchert, 552. 

Palmer, H. E., potassium ferricya- 
nide in the estimation of arsenic, 
etc., 399. 

Parks, W. A., Lepadocystis clin- 
tonensis, Ontario, 404. 

Parsons, A. L., sclerometer, 162. 
goethite, 235. 

Peckham, S. F., Solid Bitumens, 
459. 

Pennsylvania geol. survey, 266. 

Perkins, C. C., determination of 
free bromine, etc., 338; silver in 
the determination of molybdenum, 
etc., 540. 

Pflanzen-anatomie, Physiologische, 
Haberlandt, 195. 

Physics, Elements, Crew, 83. 

Pirsson, L. V., astrophyllite in the 
granite at Quincy, Mass., 215. 

Plants of Connecticut, 559. 


R 
Radio-activity and Geology, Joly, 
Radiology and electricity, Congress, 
iii emanation, action upon the 


elements of the carbon group, Ram- 
say and Usher, 80. 


571 


Radium, practical application, Bax- 
ter and Tilley, 188. 

— production of, 189. 

—and uranium in minerals, ratio, 
Gleditsch, 79. 

Raindrops, influence of thunder on 
size of, Laine, 190. 

Ransome, F. L., bismite, 173. 

Reflection, positive changed to nega- 
tive through pressure, Lummer and 
Sorge, 264. 


Rhode Island, granites, etc., Lough- 
lin, 447. 
Richardson, C., natural naphtha 


from Cuba, 439. 

Richardson, G. B., stratigraphy of 
the upper Carboniferous in Texas 
and New Mexico, 325. 

Roberts, E. J., separation of cerium, 
49. 


ROCKS. 


Basaltic magma, 
Fenner, 217. 
Dodecahedral jointing, Lahee, 169. 
Granite, crystallization in, Mackie, 

366. 
-—at Quiney, Mass., astrophyllite 
in, Pirsson, 215. 

Granites and metamorphic sedi- 
ments in Rhode Island, Loughlin, 
447, 

Lujavrite, new, Lapland, 367. 

Petrography of LErythrea, 
Africa, Manasse, 87. 

Petrography of the Urals, Duparc, 
272. 

Rocks, 

465. 


crystallization, 


Kast 


fiow of, Adams and Coker, 


Rogers, A. F., 
Kansas, 258. 


anhydrite, etc., from 


S) 


Schaller, W. T., bismite, 173; re- 
fractive index of Canada balsam, 
324; composition of hulsite and 
paigeite, 543. 

Schuchert, C., Paleogeography of 
North America, 552. 

Sclerometer, new, Parsons, 162. 

Shaler, N. S., Autobiography, 90. 

Smithsonian Institution, report of 
Secretary, 196; Board of Regents, 
197 


Sosman, R. B., nitrogen thermome- 
ter from zinc to palladium, 93. 

Spectrum, extreme infra-red, Rubens 
and Hollnagel, 552. 

Suess, E., das Antlitz der Erde, 269. 


572 


ot 


Temperature, measurements of high, 
Day and Sosman, 93. 

Thermometer, nitrogen, Day and 
Sosman, 93. 

Thornton, W. M., Jr., enargite, 
covellite and pyrite, 358. 

Travis, C., crystals in light parallel 
to an optic axis, 427, 

Trigonometry, Plane, Robbins, 200. 

Trowbridge, J., electric discharges 
through hydrogen, 341. 


U 


United States Coast Survey, report, 


559. 

United States geol. survey, 
GEOLOGICAL Reports. 
Urals, northern, geology and petro- 

graphy, Duparc, 272. 


see 


V 


Van Name, R. G., velocities of reac- 
tions between metals and dissolved 
halogens, 237; crystals of silver 
sulphate and dichromate, 293. 

Verrill, A. E., obituary notice of 
Alexander Agassiz, 561. 

Virginia geol. survey, 267, 507. 

Volcanoes, Hawaiian, Brigham, 363. 


INDEX. 


W 


Washington, H. S., feldspar from 
Linosa, 92. ; 

Wellcome Research Laboratories, 
Khartoum, 3rd report, 91. 

West Australia geol. survey, 87. 

West Virginia geol. survey, 459. 

Wickham, H. F., new fossil coleop- 
tera from Florissant, 47. 

Worlds, Evolution of, Loweil, 199. 

Wright, F. E., feldspar from Linosa, 
02; new petrographic microscope, 
407; new ocular for use with, 415. 


x 


X-ray photography, instantaneous, 
Dessauer, 82. 


Z 
ZOOLOGY. 


African blood-sucking flies, Austin, 
92. 

Cambridge Natural History, 92. 

Birds, Handlist, Sharpe, 195. 

Vertebrates, Cave, of America, 
Kigenmann, 270. 


New Circulars. 


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


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


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


from 1% cents up. 


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


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


Ward’s Natural Science Establishment 
76-104 CotnecEe AvE., Rocuxster, N. Y. 


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A Supply-House for Scientific Material. 


Founded 1862. Incorporated 1890. 


DEPARTMENTS: 


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Mineralogy, including also Rocks, Meteorites, etc. 
Palaeontology. Archaeology and Ethnology. 
Invertebrates, including Biology, Conchology, ete. 
Zoology, including Osteology and Taxidermy. 
Human Anatomy, including Craniology, Odontology, ete. 
Models, Plaster Casts and Wall-Charts in all departments. 


Circulars in any department free on request; address 


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


CONTENTS. 


Page 
Art. XLII.—Experimental Investigation into the Flow of 
Rocks, by Frank D. Apams, assisted by Ernest G. 
Coxur. First Paper—The Flow of Marble. (With ~ 
Plates TP 1 Vigo ex 2 465 
XLIII.—Heat of Formation of the Oxides of Molybdenum, 
Selenium and Tellurium ; and fifth paper on the Heat of 
Combination of Acidic Oxides with Sodium Oxide; by 
WoeG. Mizar so 2020 Se oo 488 
XLIV.—Contributions to the Geology of the Grand Canyon, 
Arizona.—The Geology of the Shinumo Area (continued) 


p) 


by L. F. Nose. (With Plate V.)--.. 2222) eee 497 
XLV.—Effect of Certain Magnetic and Gravitational Forces - 
on the Motion of the Moon ; by Ernest W. Brown.--- 529 


XLVI.—Use of Silver in the Determination of Molybdenum, 
Vanadium, Selenium and Tellurium; by CraupE C., 


PERKING Vs 4. 5.2) SUG i 
XLVII.—Chemical Composition of Hulsite and Paigeite, by 
WALDEMAR “IT. (SCHALLER 222 _ 00.0) = 2) 543 


SCIENTIFIC INTELLIGENCE. 


Chemistry—Gas containing Helium from the German Potash Deposit, E. 
ERDMANN, 549.—Detection of Methyl Alcohol, G. Deniais, 550.—A Sub- 
stitute for Platinum Wire for Use in Blowpipe Work, O. F. Kirpy : The 
Use of Sodium Hypobromite in the Separation of Certain Metals, Pozzi- 
Escort: Doppler Effectin Hydrogen, B. Strassmr, 001.—Effect of Dust 
and Smoke on the Ionization of Air, A. S. Eve: Measurements in the 
Extreme Infra-Red Spectrum, H. Rupens and H. HoLunaGet, 552. 

Geology—Paleogeography of North America, C. ScHUCHERT, 552.— Virginia 
Geological Survey, T. L. Watson, 557.—Geological and Archeological 
Notes on Orangia, J. P. Jounson : Handbuch der Regionalen Geologie, 
G. STEINMANN and G. WILCKENS, 958. 

Miscellaneous Scientific Intelligence—United States Coast and Geodetic 
Survey, O. H. Tirrmann: Connecticut Geological and Natural History 
Survey, 559.—Kraft das ist animalische, mechanische, soziale Energien 
und deren Bedeutung fir die Machtenfaltung der Staaten, E. REYER: 
Soziale Machte als Ereanzung der Arbeit uber ‘“‘Kraft,” E. Reaver: Pub- 
lications of the Allegheny Observatory of the University of Pittsburgh, F. 
ScHLESINGER and R. H. Baxer: Bulletin of the University of Kansas, 
M. E. Rice and B. McCouium, 560. 


Obituary.—ALEXANDER AGASSIZ, 561: RoperT PaRR WHITFIELD, 060: Sm - 


WiLLIAM Huceins, Knut JoHANn ANGSTROM, JULIEN FRaIPont, H. 
Lanvo.t, EK. Purnippi, RicHARD ABEGG, 566. 


InDEX TO VoL. XXIX, 567. 


“313% 


~ 
= 


Se eR CSc ee Te 


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