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THE 


AMERICAN 
JOURNAL OF SCLENCE. 


Epitrorn: EDWARD S. DANA. 


ASSOCIATE EDITORS 


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


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


Proresson HENRY S. WILLIAMS, or ItHaca, 
Proressorn JOSEPH S. AMES, or Batrimore, 
Mr. J. S. DILLER, or Wasuineton. 


FOURTH SERIES 


VOL. XLII—[W HOLE NUMBER, CXCII}]. 


WITH PLATE I. 


NEW HAVEN, CONNECTICUT. 
Ls ei oye 


ne ate a tnet 
“<yhsonian Insts, 
YS Sif 
en WtieN 


tonal Musev2 


THE TUTTLE, MOREHOUS 
; on 


& TAYLOR CO 


SI 
"q 


CONTENTS TO VOLUME XLII. 


Number 247. 
Page 


Arr. I.—Discovery of Fossil Human Remains in Florida in 
Association with Extinct Vertebrates; by E.H.Srrnarps 1 


II.—New Cyprinid Fish, Leuciscus rosei, from Miocene of 


British:Columbia; by L. HussaKor 22.2 ..--.---.25--- 18 
III.—Cycadophyte from the North American Coal Measures; 

yl dis ley VEYA SISU on Sh cdb Bees =a be a ee eae eee a ee | 
IV.—The Pleionian Cycle of Climatic Fluctuations; by H. 

PRECIO SIA Ge arte Cee a ney iM cds He i a oat OH 
V.—Geodes of the Keokuk Beds; by F. M. Van Tuyzt ---- 34 
VI.—Berea Formation of Ohio and Pennsylvania; by W. A. 

NYSP EN 030551) Se ee ace Se ae epee hee Uy one ea 43 


VII.—On Hydrozincite; by W. E. Forp and W. A. Brapitey 59 


VIII.—Rotation of Interference Fringes in Case of Non- 
reversed and of Reversed Spectra ; by C. Barus ------_- 63 


SCIENTIFIC INTELLIGENCE. 


Chemistry and Physics—Qualitative Separation of Tin, Arsenic and Anti- 
mony, J. M. WevicH and H.C. P. Wesrer: New Method for Estimating 
Ammonia, G. EK. FoxwEeun: Analytical Chemistry, F. P. TREADWELL, 74.— 
System of Physical Chemistry, W. C. McLrwts, 75.—Practical Physio- 
logical Chemistry, P, B. Hawx: Ionization and Dissociation of Hydrogen, 
A. J. Dempster, 76.—Structure of Broadened Spectrum Lines, T. R. 
Merron, 77.—Single-Line Radiation of Magnesium, McLmunnan, 78.— 
Treatise on Electricity, F. B. Prppuckx: Physical Properties of Colloidal 
Solutions, E. F. Burton, 79. 


Geology and Natural History—Stratigraphy and fauna of Tejon Eocene of 
California, E. Dickrrson, 80.—New fossil Coleoptera from Florissant 
beds, H. F. Wickuam: Eocene of the Lower Cowlitz River valley, Wash- 
ington, etc., C. E. WEaver: Upper Cretaceous Horas of the world, E. W. 
Berry, 81.—Geology and underground water of Luna County, New Mex., 
N. H. Darton: Contributions from Walker Museum, Univ. of Chicago: 
Virginia Geological Survey, University of Virginia, T. L. Watson, 
82.—The Physical Geography of Wisconsin, L. Martin: Publications of 
U. S. Bureau of Mines, V. H. Mannine, 83.—Canada, Department of 
Mines: Oiland Gas Map of Southwestern Pennsylvania, 1915, R. H. Hice: 
Bulletin of Imperial Earthquake Investigation Committee, 84.—Min- 
eralogic Notes, Series 3, W. T. ScHALLER: ‘The Emerald Deposits of Muzo, 
Colombia, J. EK. Pogun: Microscopical Determination of the Opaque Min- 
erals, J. MurpDocK, 85.—Collection of Osteological Material from Machu 
Picchu, G. F. Eaton: Birds of North and Middle America, R. Rip@way : 
R. Comitato Talassografico Italiana, 86.—British Museum Catalogues : 
Museum of the Brooklyn Institute of Arts and Sciences: The Involuntary 
Nervous System, W. H. Gaske~i; Laboratory Manual in General Micro- 
biology, W. GiLTNER, 87. 


Miscellaneous Scientific Intelligence—Carnegie Foundation for the Advance- 
ment of Teachers: Public Education in Maryland, A. Fuexner and F. P. 
Bacuman, 88.—General Education Board : Napier Tercentenary Memorial 
Volume, 89.—Mining World Index of Current Literature, 90. 


Obituary—S. P. Taompson: O. Lianier: E, JunGFLEtscu, 90. 


iv CONTENTS. 


Number 248. 
Page 
Arr, IX.—The Problem of Continental Fracturing and Dias- 
trophism in Oceanica; by C. Scmucumre .-_..--..-..- 91 
X.—On the Qualitative Separation and Detection (I) of 
Tellurium and Arsenic and (II) of Iron, Thallium, Zir- 
conium and Titanium; by P. E. Brownine, G. S. 
Simpson and L. E. Porrer 
XI.—The Separation of Vanadium from Phosphoric and 
Arsenic Acids and from Uranium; by W. A. Turner... 109 
XII.—Some Notes on Japanese Minerals; by 8. Icurkawa-.- 111 
XUI.—The Algonkian-Cambrian Boundary East of the  , 
Green Mountain Axis in Vermont; by T. N. Date .... 120 
XIV.—The Thermochemistry of Silicon; Heat of Combina- 
tion of Silica with Water; by W. G. Mrxrmr ...------ 125 
XV.—Composition of the Selensulphur from Hawaii; by G. 
V. BROWIN 2256) AM ce eee eee ean a rece 132 


XVI.—Insects in Burmese Amber; by T. D. A. CockERELL 135 


XVII.—The Preparation and Properties of Lead-Chlor 
Arsenate, Artificial Mimetite ; by C. C. McDonneLi 
ands GAM, (Sarre Sos) Bee Son ees Sate en eee apa 139 


XVIII.—The Effect of a Magnetic Field on the Initial Re- 
combination of the Ions Produced by X-Rays in Air; 
bytGe dl. MM DA omy, 2 kes 8 Se ae ae ee 146 


XIX.—The Separation of Thorium from Iron with the Aid 
of the Ammonium Salt of Nitrosophenylhydroxylamine 
(“Cupterron’”’); by. WM. TnoRNTON, (Jit 222 sea 151 


XX.—On the Quantitative Estimation of Small Quantities of 
Sulphide Sulphur; by W. A. Drusuer and C. M. Euston 155 

XXI.—Margarosanite, a New Lead-Calcium Silicate from 
Franklin, N. J.; by W. E. Forp and W. M. Brapiey._ 159 

XXII.—On the Paleozoic Aleyonarian, Tumularia; by W. I. 
FROBINSON, (0 4504 See era a ena a oe ic oo a 162 


SCIENTIFIC INTELLIGENCE. 


Ohemistry—Organie Agricultural Chemistry, J. S. CaamMBERLAIN: Outlines 
of Industrial Chemistry, f. H. THorp, 165.—Method for the Identification 
of Pure Organic Compounds, S. P. Muniixen: Annual Reports of the 
Progress of Chemistry for 1915, 166. 

Geology—Origin of the Earth, T. C. Coamprriin, 167.—Jointing as a 
Fundamental Factor in the Degradation of the Lithosphere, by F. 
EXRENFELD, 168.—The Fauna of the Chapman Sandstone of Maine, H. 5. 
Wixiiams, 169. 


Miscellaneous Scientific Intelligence—A Comprehensive Plan of Insurance 
and Annuities for College Teachers, H. S. PrircHErr, 169. 


Obituary—W. Ramsay: EH. MetcuniKorr, 170. 


CONTENTS. Vv 


Number 249. 


Page 
Arr. XXIII.—The Geological History of the Australian 
Flowering Plants; by E. C. AnpREws -.--.---------- 171 


XXIV.—Mineralogical Notes; by B. K. Herson----.---- 233 


XXV.—A New Tortvise and a Supplementary Note on the 
Gavial, Tomistoma americana; by E. H. Sernarps...._- 235 


~XXVI.—A Fossil Nutmeg from the Tertiary of Texas; by 
MING INR Vee a soreeteees Costs Ce ee SN 23 8 241 


XXVII.—Notes on Devonian Faunas of the MacKenzie 
uiver valleys. MIND Me ees 2) Jarek poo ais 246 


XXVIII.—New Points on the Origin of Dolomite; by F. M. 
Van re ib eM Mes ihe in hk) a ire cerned i 249 


XXIX.— Volcanic Domes in the Pacific; by S. Powrrs...- 261 


XX X.—New Zinc Phosphates from Salmo, British Columbia; 
logy pas. el. ed Ban Cerra Sl oeaaival aecpleee leer yet ee Rn Ren aeegee 275 


XXXI.—On the Separation of Cesium and Rubidium by the 
Fractional Crystallization of the Aluminium and Iron 
Alums and its Application to the Extraction of these 
Klements from their Mineral Sources; by P. E. Brown- 

PNG RAMC On LU OHIN CRs epee San MeN 3 eal 279 


SCIENTIFIC INTELLIGENCE. 


Miscellaneous Scientific Intelligence—Collection of Osteological Material 
from Machu Piechu, G. F. Haton, 281.—Geology, Physical and Historical, 
H. F. Cuenanp, 282.—Handbook and descriptive Catalogue of the Meteor- 
ite Collections in the United States National Museum, G. P. MERRILL: 
A Student’s Book on Soils and Manures, E. J. Russauu, 283.—Plant Anat- 
omy, from the Standpoint of the Development and Functions of the Tis- 
sues, and Handbook of Micro-Technic, W. C. Stnvens: Principles of Plant 
Culture; a Text for Beginners in Agriculture and Horticulture, E. S. Gorr: 
Annual Report of the Board of Scientific Advice for India for the year 
1914-15, 284. 


vi CONTENTS. 


Number 250. 


: Page 
Arr. XXXII.—The Geologic Réle of Phosphorus; by E. 
BLACK WELDER ioe! feos ee ee area 285 
XXXIII.—Notes on Radiolarian Cherts in Oregon; by W. 

DO SMES: . .-.¢25eeses soo eee ee ee 299 
XXXIV.—On the Rates of Solution of Metals in Ferric  , 
Salts and in Chromic Acid; by R. G. Van Name and 

DU; itn) asta eu sey ee eee ee eee 301 
XXXV.—Sulphatic Canerinite from Colorado; by E. 8. 
LaRsentand!G STEIGER ee yee. oe ee ee eee 
XXXVI.—An Early Pliocene One-Toed Horse, Pliohippus 
lullianus;sp. m0v.- (by 2. lh iRoxnt @ a a eee eee 335 
XXXVII.—The Igneous Geology of Carrizo Mountain, 
Arizona; by Wel. MERY 2 Sse ee Pee aie ee egg oe 


SCIENTIFIC INTELLIGENCE. 


Chemistry and Physics—Fluorine in the Animal and Vegetable Kingdoms, 
A. Gautier and P. CLausMANN: Qualitative Separation of the Common 
Metals whose Sulphides are Insoluble in Dilute Acids, M. J. CLARENS, 
364.—Estimation of Vanadic Acid after Reduction by Metallic Silver, G. 
Epear: Density of Radio-Lead from Pure Norwegian Cleveite, T. WwW. 
Ricuarps and C. WapsworrtH, 3d, 365.—Theory of the Lead Accumulator, 
C. Féry, 366.—An Active Modification of Nitrogen, 368.—Emission of 
Electricity from Hot Bodies, O. W. Ricaarpson, 369. 


Geology—La Flora Liasica de la Mixteca Alta, G. R. WimLanp, 370.—Isos- 
tasy in the Light of the Planetesimal Theory, T. C. CHAMBERLIN, 371.— 
Relations between the Cambrian and Pre-Cambrian formations in the 
vicinity of Helena, Montana, C. D, WAtcort, 372. 


Obituary—C. S. Prosser: J. Roycr: G. SchwaxLse: K. SCHWARZSCHILD: 
PRINCE Boris GALITZIN, 372. 


CONTENTS. vil 


Number 251. 
Page 


Arr. XXXVIII.—The Aneestry of Insects with particular 
references to Chilopods and ‘Trilobites; by J. D. 
UNGHATROWUS is Siti tPA Ne TINE ag | Ae ar eo een an ES 3 


XXXIX.—Some Characters of the Apical End of Pseudor- 
thoceras knoxense McChesney; by G. H. Girry (With 
LENIN DG 2 I At cee ae ce aR ne a) eae ee 387 


XL.—On the Electrolysis and Purification of Gallium ; by 
H. 8. Unter and Puiir E. Brownine..-------.------ 389 


XLI.—A Pleistocene Locality on Mt. Desert Island, Maine ; 
bye Da DbuANrreand. Hb. LOOMIS) 2,25 66's = oa 399 


XLII.—Methods in Reversed and Non-reversed Spectrum 
interterometry ;; by ©, Barus 22. 22.2.2. 425325- ).2) 402 


XLIIL—A Study of the Separation of Hydrofluoric Acid 
and Fluosilicic Acid ; by J. G. Dinwippik --_--------- 421 


SCIENTIFIC INTELLIGENCE. 


Chemistry and Physics—Occurrence of Germanium in Zinc Materials, G. H. 
Bucwanan, 430.—New Volumetric Method for Cobalt, W. D. Eneiz and 
R. G. Gustavson, 431.—Determination of Aluminium as Oxide, W. Brum: 
Ozone, its Manufacture, Properties, and Uses, A. VosMAER, 432.—A 
Theory of Color Vision, R. A. Houstoun, 433.—On the Auditory Sense, M. 
MaraGe, 435.—Concise Technical Physics, J. L. ARNoxLpD, 4386.—A Text- 
Book of Physics, Fourth Edition, A. W. Durr, 437. 


Geology—Expedition to the Baltic provinces of Russia and Scandinavia, 
1914, P. E. Raymonp and W. H. TwensoreL, 437.—Upper Ordovician 
formations in Ontario and Quebec, A. F. Formrste: Lower Eocene floras of 
Southeastern North America, E. W. Berry, 438.—Some Permian Brachio- 
poda of Armenia, A. Srowanow: Cambrian Geology and Paleontology, 
iii, No. 5, Cambrian Trilobites, C. D. Waucott: Checklist of the Recent 
Bivalve Mollusks (Pelecypoda) of the Northwest Coast of America, W. H. 
Dau: Interrelations of the Fossil Fuels, J. J. Stevenson, 439.—The 
Echinoidea of the Buda limestones, F. L. Wuitnry: Publications of 
the United States Geological Survey, G. O. Smiru, 440. 


Miscellaneous Scientific Intelligence—Diseases of Occupation and Vocational 
Hygiene, G. M. Koper and W. C. Hanson: Problems of Physiological and 
Pathological Chemistry of Metabolism (von Fiirth), A. J. Smiru, 442. 


Vill CONTENTS. 


~ 
i 


Number 252. 


Page 
Arr. XLIV.—The Lava Eruption of Stromboli, Summer— 
Autumn, 19153 by FLA. Parga 22) 22 bie see 443 
XLV.—Determination of Fluorine in Soluble Fluorides; by 
JOG. Din winnie e225. Oe eae ees eee 464 


XLV1I—The Albertella Fauna Located in the Middle 
Cambrian of British Columbia and Alberta; by L. D. 
BURLING 1.18 hee ae es eC eas oe ene eee meee) 


XLVII.—Some New Forms of Natrolite; by A. H. Parmurrs 472 
XLV III.—On Pre-Cambrian Nomenclature; by C. Scuucumrr 475 
XLIX.—Plotting Crystal Zones on Paper; by J. M. Brak. 486 


L.—A Graduated Sphere for the Solution of Problems in 
Crystal Opticss)by (GH. Warrnns- > aa Soa oe 493 


SCIENTIFIC INTELLIGENCE. 


Chemistry and Physics—Separation of Lithium from Potassium and Sodium, 
S. Parkin: Action of Light upon Iodine and Iodide of Starch, M. H. 
BorvierR, 496.—Crystallization of Calcium Tartrate, F. D. Coatraway: 
Basic Copper Sulphates, 8S. W. Youne and A. E. Srrarn, 497.—Determi- 
nation of Chlorides in Presence of Thiocyanates, F. W. BRUCKMILLER: 
New Method of Determining Refractive Indices, R. W. CHEsurre, 498,— 
Fluorescent Vapors and their Magneto-optic Properties, 499.—Problems in 
Physics for Technical Schools, Colleges, and Universities, W. D, HENDER- 
son, 501.—General Physics, Third Edition, H. Crew, 502. 


Geology and Mineralogy—Coal Measures Amphibia of North America, R. L. 
Moopir, 502.—Papers from the Geological Department, Glasgow Univer- 
sity: West Virginia Geological Survey, I. C. Wuitr: Papers on Coal and 
the Coal Industry, 503.—Notes on Radiolarian Cherts in Oregon: a Correc- 
tion: New Mineral names, W. E. Forp, 504. 


Miscellaneous Scientific Intelligence—Centennial Celebration of the United 
States Coast and Geodetic Survey. E. L. Jonrs, 505.—National Academy 
of Sciences, 506.—American Association for the Advancement of Science, 
507.—Publications of the Carnegie Institution of Washington, 508. 


Obituary—C. Appr: P. Lowry: P. Dunem, 509. 


b {37 & 
A vor. xii 


| 


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Established by BENJAMIN SILLIMAN in 1818. 


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THE 
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AMERICAN = 


JOURNAL OF SCIENCE, 


Epitrorn: EDWARD S. DANA. 


ASSOCIATE EDITORS 


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


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


-Proresson HENRY S. WILLIAMS, or Irnaca,. 
Proressor JOSEPH S. AMES, or Batrimore, 
Mr. J. S. DILLER, or Wasuineron. 


FOURTH SERIES 


VOL. XLII-[WHOLE NUMBER, CXCII}. 
Mor 247 IU EY 1916. 


NEW HAVEN, CONNECTICUT. 
1916. 


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


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et March 3, 1879. 


JULY, 1916. 


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JUST PUBLISHED 


Principles of Oil and Gas 
Production 


BY 
ROSWELL H. JOHNSON, Professor of Oil and Gas Production, 
University of Pittsburgh, and 


L. G. HUNTLEY, Lecturer on Foreign Oil and Gas Fields, 
University of Pittsburgh ; 


This book is a timely answer to the widespread questioning 
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TABLE OF CONTENTS 


Varieties of Oil and Gas. Origin of Oil and Gas. Distribution of 
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Reservoirs. Classification of the Attitude of Reservoirs. Application 
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in a Well.” Management of Oil Wells. Completing the Extraction 
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THE ac 


AMERICAN JOURNAL OF SCIENCE 


[FOURTH SERIES.] 


———_~++s—___. 


Art. I.—On the Discovery of Fossil Human Remains in 
Florida in Association with Hatinct Vertebrates; by HE. H. 
SELLARDS. 


A new and very important locality for vertebrate, inverte- 
brate, and plant fossils was found in 1913 at Vero on the 
Atlantic Coast in Central-Eastern Florida, the occurrence of 
fossils at this place having first become known as a result of 
the construction of a drainage canal made by the Indian River 
Farms Company. Throughout the greater part of its course 
this canal, which extends from the coast several miles inland, 
cuts through the surface materials including sand, marl, and 
muck beds, and into marine shell marl. In the marine marl, 
invertebrates are found in abundance and in an excellent state 
of preservation, while in the sands, fresh-water marls, and muck 
beds, vertebrates and fresh-water invertebrates are not infre- 
quently preserved. ‘The chief locality for vertebrate and plant 
fossils, however, is at the public road crossing one-half mile 
north of Vero, where the canal cuts into an old stream bed. 
The canal enters the stream bed about 500 feet west of the 
crossing, and follows it while passing under the bridge and for 
500 or 600 feet beyond, or for a total distance of about 1,000 
feet (Sketch map, fig. 1). 

Although this locality has been known and collected from for 
nearly three years, it has now acquired a new interest by the 
discovery, during the past year, of human remains in associa- 
tion with the vertebrate, fresh-water invertebrate, and plant 
fossils. The results obtained at this locality are of exceptional 
value since in addition to a record of early man in America, 
there are here preserved the fauna and fiora with which man 
was then associated. 


Am. Jour. Sc1.—FourtH Serizs, Vou. XLII, No. 247.—Juny, 1916. 
1 


20 ££. HM. Sellards—Discovery of Fossil Human Remains 


Acknowledgments.—N otice of the occurrence of fossils at 
Vero was brought to the writer’s attention in November, 1913, 
by My. Isaac M. Weills, the presence of fossil bones in the 
canal having been reported to him by Mr. IF. C. Gifford. Mr. 
Weills, with the assistance of Mr. Frank Ayers, has constantly 
watched the canal banks and has thus obtained the fossils as 
they were exposed. Among others,,who have contributed fos- 
sils from this locality, are Messrs. F. C. Gifford, E. J. Wood, 
J. McCullers, N. F. McCall and J. W. Welch. To Messrs. 
Weills and Ayers in particular are due the very important 
results that have been obtained, Mr. Ayers’ close watch of the 
canal bank having been rewarded by the fortunate discovery 
of the human remains while they were still in place im the 
undisturbed walls of the canal. Additional collections at 
this locality have been made by H. Gunter and the writer. 
Acknowledgments are due the officials of the U. S. National 
Museum, and especially to Mr. J. W. Gidley, assistant Curator 
of Mammals, for facilities afforded in consulting the collec- 
tions of the Museum. ‘The turtles of the Pleistocene of Florida 
contained in the Florida State Geological Survey collection, 
including those found at Vero, have been identified, and subse- 
quently will be deseribed, by Dr. O. P. Hay of the Carnegie 
Institution. The photographs included im this paper, except 
that of text-figure 7, were made by E. P. Greene. The chemi- 
cal analyses have been made by L. Heimberger, under the 
direction of R. E. Rose, State Chemist of Florida. 


The Geologic Section at Vero. 


It is desirable, before describing the human remains, to con- 
sider the general geologic section at Vero, as well as the late 
geologic history of this part of the Atlantic Coast. The 
marine shell marl into which the canal cuts, number 1 of the 
section shown in text-figure 2, is a part of the extensive series 
of marine marls which border the Atlantic Coast, beginning on 
the north near St. Augustine, where the marl is known as 
“Coquina” rock, and extending south to the Everglades of 
Florida, beyond which the shell marls give place to the shal- 
low-water limestones of extreme southern Florida. These 
marls and limestones are known by their invertebrate fauna to 
be of Pleistocene age.t 

The sands which as a rule overlie the shell marls are in part 
of marine origin, having accumulated in shoal waters, or as 
‘ *Florida State Geol. Survey, Second Annual Report, 1909. 


in Florida in Association with Hxtinct Vertebrates. 5 


beaches and dunes, at the time the sea withdrew from the land; 
and are thus contemporaneous in age or nearly so with the 
marine shell marls. However, in ponds, streams and lakes, 
fresh-water marls, sand and muck deposits accumulated which 
rest upon and hence are of somewhat later age than the marine 
marls, and it is in deposits of this kind chiefly, as would be 
expected, that the land and fresh-water fossils are preserved. 
A more detailed account of a section through a stream bed at 
Vero will be given in connection with the description of the 
fossil human remains. 


Geologic History of the Florida Hast Coast. 


The geologic history of the Florida East Coast will be con- 
sidered in this paper only in so far as it affects the locality 
under discussion. It is known that the early Pleistocene 
included a period of great submergence during which the exten- 
sive marine marls and limestones of eastern and southern 
Florida were deposited. Following the accumulation of these 
early Pleistocene formations the peninsula was lifted in rela- 
tion to the strand-line to a level somewhat above its present 
elevation. ‘This period of probably slight emergence was fol- 
lowed by a depression, proof of which is derived from many 
sources and is conclusive. Shaler long ago noted the fact that 
the important harbors of Florida are flooded river valleys.” 
Vaughan likewise has called attention to the submerged chan- 
nels of both the Atlantic and the Gulf coasts which, together 
with other evidence, lead him to conclude that both the mainland 
and the Keys of the Florida East Coast stood at the time of 
maximum Pleistocene emergence as much as 30 feet above the 
present strand line? The existence of a Pleistocene cypress 
swamp in Hillsboro Bay, 20 feet below the present sea level, 
and of a peat bed at the same depth near the Florida Keys on 
the Atlantic Coast, has been noted by the writer. Additional 
evidence of changes of level may be adduced from physio- 
graphic features in the interior of the State, particularly from 
the lakes of the “Lake Region” of Florida, the basins of 
which probably originated through sinkhole formation at a 
time when the land area stood higher than at present.* The 


*The Geological History of Harbors, U. S. Geol. Surv., 138th Ann. Rept., 
pt. 2, pp. 190-192, 1893. 

*Sketch of the Geologic History of the Florida Coral Reef Tract and 
Comparisons with Other Coral Reef Areas, Washington Acad. Sciences, 
vol. iv, p. 30, 1914. 

‘Florida State Geol. Surv., Seventh Annual Report, p. 56, 1915; ibid., 
Sixth Annual Report, p. 155, 1914. 


4 EF. H. Sellards—Discovery of Fossil Human Remains 


land fauna found in the stream beds and ponds of the Atlantic 
Coast of Florida, therefore, represents that part of the 
Pleistocene following the deposition of the marine shell marl 
and the subsequent emergence of the land. In some of these 
ponds deposits have probably accumulated continuously from 
the Pleistocene to the present time. 

The excavations as well as the timber growth show that the 
old stream-bed or valley at Vero had a width of from 350 to 
500 feet for a distance of about three-fourths of a mile from 
the Indian River, which is itself an inlet from the ocean. 
The stream valley, however, is very shallow, the material which 
fills it having at the present time a thickness of not more than 
from four to six feet. At the time the canal was cut, a sluggish 
stream, known as Van Valkenburg’s Creek, following an ill- 
defined channel, flowed through the valley which had been 
ageraded to within three or four feet of the surrounding land 
level. The fill in the stream valley includes, as shown in the 
accompanying sketch (fig. 2), two successive fluviatile deposits. 
From the sketch map (fig. 1) it will be seen also that the broad 
valley is formed, near the place where the fossils are found, 
by two tributaries which enter, one from the north and one 
from the south. These streams originate only a few miles 
inland and their course is controlled by the Pleistocene beaches 
and dunes which here parallel the coast. The position of the 
original stream may have been determined by a natural depres- 
sion or inlet from the ocean which possibly accounts for the 
great width as compared to the shallow depth of the valley. 
_ The possibility of the stream having in former times been fed 
by a spring also suggests itself, especially as the number of 
vertebrates found in this locality seems to imply some kind of 
a fresh-water resort. 


Section through the Stream Bed. 


The section through the stream bed, as exposed in the banks 
of the canal at the place where the human fossils are found, 
is represented by text-figure 2: The section as here shown 
does not extend directly across the stream, but as will be seen 
by referring to the sketch map (fig. 1), runs approximately 
parallel to the general course of the valley, from the union of 
the two tributaries to the crossing of the Florida East Coast 
Railroad, a distance of 512 feet. Number 1 of the section 
represents the marine shell marl which is common to this part 
of the state, and is cut into by the canal here as elsewhere. 


in Florida in Association with Fxtinct Vertebrates. 5 


The material next following the marl, number 2 of the sec- 
tion, includes cross-bedded river-wash sand, partially decayed 
wood and muck, sand stained brown by organic matter, and at 
places fresh-water marl rock. The distinctly cross-bedded sands 
of this stratum are found near the base, and it is here chiefly 
that the decayed wood and muck occur lying in stream chan- 
nels in the shell marl. The brown sand contains in places 
many fresh-water shells, and at the top grades into the fresh- 
water marl which in places reaches a thickness of as much as 
two feet. Vertebrates and fresh-water invertebrate fossils 
occur throughout this bed from the cross-bedded sands at the 
base to the marl rock at the top. It is from this bed also that 
the first human fossils found at Vero were taken. 

Resting upon this sand and marl bed and in places eutting 
into it is an alluvial deposit consisting chiefly of vegetable 
material intermixed with sand, grading at the top in places, 
as is true also of the bed beneath, into a fresh-water marl. 
The average aggrading of the stream valley by this alluvial 
material amounts to about two feet, although locally where the 
stream cut deeply into the underlying bed this deposit reaches 
a maximum thickness of five or six feet. This alluvial deposit 
contains vertebrate and plant fossils and in the fresh-water 
marl occasional invertebrates. Human fossils are found in this 
deposit also, their place in the section being indicated in 
text-figures 1 and 2. 


The Human Remains. 


Fossil human bones from two skeletons have been obtained 
at Vero. Of the two individuals represented one is from the 
older deposits of the stream valley, number 2 of the section 
shown in text-figure 2, while the other is from the base of the 
next overlying bed, number 3 of the section. 


Human Remains from the Older Stream Deposits. 


In October, 1915, Mr. Ayers, while examining the stratum 
which contains the vertebrate fossils, found some bones in place 
which seemed probably to belong to a human skeleton. In 
order to verify the place of the bones in the section he then 
ealled Mr. Weills, and together they removed the bones. The 
parts of this skeleton obtained include the right and left femur, 
lacking the extremities; right patella; left tibia and frag- 
ments of the right; right fibula; right caleaneum, right and 
left astragalus; left navieular; external cuneiform of the right 


Fic. 1. Sketch map showing the locality at which human fossils were 
found at Vero. Scale, 1 inch equals 300 feet. The location of the human 
remains in the canal bank is indicated in the sketch by a cross. The 
margins of the broad valley are indicated by the dotted lines, and the 
swamp growth in the valley by the conventional character. The canal 
follows the stream valley while passing under the Florida East Coast 
Railroad and the public road. The modern stream in this valley followed 
an ill-defined, anastomosing and frequently changing channel. 


Fig. 2. 


Fic. 2. Sketch showing the section of the canal banks from the Florida 
East Coast Railroad bridge west to the entrance of the lateral streams. 
Horizontal scale, one inch equals 125 feet; vertical scale, one inch equals 
40 feet. The base line is drawn at water level in the canal which at 
that time stood 18 feet below the top of the railroad track. The break 
in the sketch indicates the entrance of the lateral canal from the south. 
(1) Marine shell marl found generally throughout this part of the state 
and cut into by the canal here as elsewhere. (2) River deposits consisting 
near the base of cross bedded sands with inclusions at places of muck 
and vegetable material; at a higher level the sand is prevailingly of a 
brown color, fairly well indurated, and contains many fresh-water shells; 
at the top the sand at places grades into a fresh-water mar] which reaches 
a maximum thickness of two feet. Vertebrate fossils are found through- 
out this deposit from the marl at the top to the muck inclusions at the 
base. The first human bones obtained are from! this bed, the location in 
the canal bank being indicated in the sketch by a cross. (3) Alluvial 
deposits having an average thickness of about two feet. The second human 
skeleton was obtained from the base of this bed at a place where it 
reaches a maximum thickness of about five feet. The location of human 
bones in this bed is also indicated in the sketch. 


in Florida in Association with Extinct Vertebrates. Wi 


foot; right metatarsals one to four; left metatarsals three to five ; 
a part of the shaft of the left humerus; right os magnum; three 
metacarpals; and three phalanges. All of these bones pertain 
apparently to the same specimen, representing a small indi- 
vidual, probably a female. From the lower margin of the 
lesser tuberosity to the upper margin of the inner condylar 
notch, the femur measures 29 em., the corresponding meas- 
urement on the femur of a large modern adult being as much 
as 832 em. The extremities of the larger limb bones of this 
skeleton are but poorly preserved, a condition common to 
many of the bones in this sand, although the bones found in 
muck in this bed are as a rule more nearly complete. 

The section of the bank at the place where these human bones 
were found is as follows: 


FEET INCHES 


SenaGir Inge! ionewrll OGle soon ccccoccoonanouncdnaacgde 1 3 
Sand stained brown by organic matter .............. 3 9 
Marine shell marl to water level in the canal ........ 5 9 


The marl rock and the brown sand beneath represent stratum 
number 2 of the general section (Text-figure 2), the alluvial 
bed, no. 3 of the section, being absent at this place. The human 
remains were imbedded in the brown sand about three feet 
from the base or two feet from the ground surface as it existed 
previous to the construction of the camel 

That the sands in which the human remains are found repre- 
sent a continuation of the stratum holding the other vertebrate 
fossils there can be no question, as the section is continuous 
along the canal bank and the deposits identical in appearance. 

Hlephas columbi, Equus leidyi and other extinct species are 
found at an equal or higher level in the beds on either side of 
the human remains. From the marl rock which lies at the 
top of the section the writer obtained within six feet of the 
place where the human skeleton lay, a premolar tooth of a fox, 
representing not the common gray fox of that region, but 
either an extinct species, or possibly the red fox, Vulpes penn- 
sylvamicus, which at present is not known in Florida. In 
immediate association with the human bones were the scapula 
and astragalus of a deer which is also found elsewhere in the 
sands, being one of the common fossils of the bone bed. In 
addition a hyoid bone of the sloth, Megalonyx jeffersoni, and 
pieces of the teeth of the mastodon, Mammut americanum, have 
been collected from the canal bank at the place where the 
human bones were found. 


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ze Aq poyeorpur sovjd ayy 4e ‘(g aA1nsy-9x0} Jo g ou) yIsodap weai4s Ieplo oy} ur oovpd UE puMoF URUE Jo Iq 4JoT “EG DIT 


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“G “OTS 


in Florida in Association with Extinct Vertebrates. 9 


Preliminary List of Mammals from the older Stream Deposits 
at Vero, 


In the following list those species that have been found in 
place in the older stream deposits at Vero are indicated by 
the use of the dagger. All others have been taken not in place 
and are here referred provisionally to the older bed as their 
probable source, although some may prove to have been derived 
from the next overlying deposits. In addition to the mammals, 
which include those best known and most characteristic of the 
North American Pleistocene, there have been found in this 
bed, vertebra and teeth of a large and probably extinet croco- 
dilian, some bird, fish and batrachian bones, and a considerable 
variety of turtles, including two very large extinct land 
tortoises, the whole vertebrate fauna obtained including prob- 
ably not less than twenty-five species. This fauna affords con- 
elusive proof of the Pleistocene age of the deposits in which 
it is found, 


Megalonyx jefferson} Bison sp. 

Mylodon sp. Mammut americanumt 
Chlamytherium septentrionalis Elephas columbit 
Equus leidyit Hydrochaerus sp. 
Equus complecatus Smilodon sp. 

Equus litoralis Canis sp. 

Tapirus haysii?t+ Edentate, indt. 

Peceary, indt. _ Procyon sp. 

Cameloid, indt. Vulpes pennsylvanicus ?+ 


Odocoileus sp.f 


Chemical Analysis ——The chemical analysis of fossil bones 
is usually considered as affording important contributory evi- 
dence of age. In the present instance the opportunity for com- 
parative analysis is particularly good, since it is possible on 
the one hand to compare the fossil human bones with recent 
human bones from the Indian mounds, and on the other with 
the bones of animals, known to be of Pleistocene age, found in 
the same bed as the human bones. Accordingly, analyses have 
been made at the writer’s request in the State Laboratory under 
the direction of the State Chemist. The results of the analyses 
are presented in the following table. All of the analyses 
included in this table were made at the same time and by the 
same methods. 


10 £. LL. Sellards—Discovery of Fossil Human Remains 


Awnarysis oF Recent anv Fosstz Bonrs rrom Vero, Frora. 
No. 1 No. 2 No. 3 No. 4 


SPCCING OT ANY? Artin accep eta. 2.0627 2.83857 2.6293 2.7505 
MOISTUTEToR LOO ICs eet see eas 10.72 2.07 4.09 3.89 
Wolatile (matters (iii serine raminnenoree 19.59 8.92 8.22 10.30 
IPhosphoniceacidyme On cern nae 27.24 APA, 30.88 32.00 
Galeinm somderCa@wy ster hoe 39.75 46.80 45.69. 48.31 
Insoluble matter, silica, ete. ....... 0.60 1.11 3.61 1.39 
Tron and aluminum oxides ......... 0.13 3.71 1.85 0.76 


No. 1 is from a recent human tibia taken from an Indian mound near 
Vero. Fla. Surv. coll. No. 5537. No. 2 is from the right tibia of a man 
taken in place in the Pleistocene bed at Vero. Fla. Surv. coll. No. 5200. 
No. 3 is from the femur of Canis sp. from the stream bed at Vero. Fla. 
Surv. coll. No. 5449. No. 4 is from the front part of the jaw of Megalonym 
jeffersonii, from Vero. Fla. Surv. coll. No. 4374. 


The specific gravity was obtained from the finely powdered 
bone by the pyenometer method. The moisture, taken at 
100° C., includes, as will be recognized, any other constituents 
sufficiently unstable to be driven off at that temperature. 
Volatile matter, likewise, represents the constituents driven 
off when the sample is maintained at red heat in a muffle for 
several hours, and necessarily includes carbon dioxide, and 
possibly other constituents in addition to the organic matter. 
The phosphoric acid, calcium oxide, and iron and aluminum 
oxides were determined by standard methods. The analyses 
show, as may be seen from the table, that the fossil human bones 
are quite as well mineralized as are the associated bones of the 
Pleistocene animals. 

Since the stratum holding the bones les near the surface the 
possibility of the human bones having been placed in it by 
burial must be considered, although in case of a burial it seems 
probable that more of the skeleton would have been found. 
Since being dug the canal has gradually widened by the caving 
of the banks, and at the place where the human fossil was 
found the rock at the top of the section had broken from the 
ledge and lay inclined on the canal bank, having moved some- 
what from its original position. When in place, however, this 
rock rested above the human bones. The sand in which the 
bones were imbedded had not been disturbed. Moreover, the 
human bones are thoroughly mineralized, and it is highly im- 
probable that a recent skeleton, if placed in these beds, would 
have become equally as well mineralized as the much older 
Pleistocene bones. Without doubt the mineralization of the 
bones is the result of the slow chemical changes by which bones 
are altered while being fossilized, a process which at this 


in Florida in Association with Extinct Vertebrates. 11 


locality has affected alike, although in a slightly varying degree, 
all of the bones of the deposit. The fossil wood in this bed, on 
the contrary, has apparently undergone but little change, hav- 
ing merely become water soaked and softened. No implements 
have been taken in this part of the section, although a fragment 
of bird bone and the tip of the tusk of a proboseidian taken in 
place at the base of this bed, show markings which apparently 


Fic. 7. 


Fic. 7. Photograph of the bank showing the human remains in place 
in bed no. 3 as shown in text-figure 2. The ulna lies at (1); the humerus 
at (2); and the radius at (3). The human bones, although found at 
slightly different actual levels, lie at the same place in the section, at the 
bottom of the alluvial bed. 


were made by tools. Charcoal is found in this as well as in 
the later bed at this locality. 


Human Remains from Bed No. 3 of the General Section. 


In February, 1916, Mr. Ayers obtained a human right ulna 
which, although not found in place, was recognized as having 
been derived from the bank, since the degree of mineralization 
was similar to that of the associated vertebrate fossils. The 
skeleton from which this bone came, however, was not located 


‘OL “Ol 


in Florida in Association with Extinct Vertebrates. 13 


at that time. Again in April, 1916, Mr. Ayers found the dis- 
tal end of a humerus, which, although not in place, had 
recently fallen from the bank. The discovery of this bone led 
to the location of the second human skeleton to which belongs 
also the ulna found three months earlier. 

At the place where these bones were found, the stream had 
cut into the earlier river deposits, making a narrow channel with 
abrupt slopes at the sides. At the center this channel cuts 
through to the shell marl and the first foot or more of deposits 
in the channel includes coarse sand mixed with broken shell 
from the marl beneath. This is followed by alternating layers 
of muck and sand. A soft fresh-water marl, which in places 
reaches a maximum thickness of two feet, is found at the top 
of the section. 

This second human fossil was taken from the bank by 
Weills, Ayers and Sellards. Im addition to the ulna and 
humerus, there were obtained from cavings from the bank a 
part of a sphenoid bone, scapula, and a left first upper incisor ; 
and in place in the bank the left ulna, a femur, radius, base 
of a jaw, parts of the skull and two metatarsals. Subsequently 
a toe bone was found on the opposite side of the canal in the 
same bed and at the same level. The first bone found in place 
was the left ulna, of which the proximal part only was present, 
although the distal part lacking the extremities was later 
obtained a few inches farther back in the bank. The bone next 


Fic. 8. The right ulna lacking the distal one-fourth; exterior view, 
very slightly reduced. Actual length of specimen as preserved 20 cm. 
Fla. Sury. coll. No. 5895. On the exterior side of the bone at the union 
of the olecranon process with the shaft is a deep pit or excavation through 
which a nutrient canal enters the bone. Just posterior to this pit may be 
seen a pronounced line or ridge which passes from the posterior margin 
obliquely outward and becomes confluent with the outer margin of the 
greater sigmoid cavity at the base of the olecranon process. The angle 
which separates the superior from the posterior side of the olecranon process 
is gently rounded, not being as pronounced as in most modern skeletons. 
Although not taken in place this ulna was subsequently found to belong 
with the skeleton from bed no. 5 of the section, as it agrees in all details 
with the left ulna found at that place. 

Fic. 9. Same bone, anterior view. 

Fic. 10. Right ulna of a large wolf, Canis sp., included to illustrate 
the identity of preservation of the human and other Pleistocene fossils 
from this deposit. Seven-tenths natural size. Fla. Sury. coll. No. 5451. 
The canid found in this deposit, no. 2 of the section, is of the size of Canis 
dirus and the limb bones, when isolated. are scarcely to be distinguished 
from those of that species. The skull, however, is longer and more narrow, 
the snout in particular being narrow. The teeth likewise are not crowded 
in the jaw as are those of ©. dirus. The canid obtained from bed no. 3 
of the section, referred to in the text, represents a smaller and more 
stocky species. 


14 “HW. Sellards—Discovery of Fossit Human Remains 


found, the femur, of which only a part of the shaft is preserved, 
was lying near the ulna and at about the same level. The 
radius, of which the proximal part only was obtained, was 
found five feet north of east of the ulna, and at the same place 
in the section, that is at the bottom of the bed of sand and 
alluvial material. Owing to the slope of the bed at this place, 
however, this bone lay at an actual level fully two feet lower 
than the uma. The jaw and the parts of the skull were found 
chiefly between the ulna and the radius and from a few inches 
to two feet farther back in the bank. One of the foot bones, a 
fifth metatarsal, was taken about eight feet east of the ulna and 
at an actual level, owing to the change in slope, above that of 
the radius and approximately the same as that of the ulna. 
Above the human skeleton four feet of alluvial material are 
found at this place, consisting of alternating layers of sand and 
muck, which in places grade into soft fresh-water marl having 
a thickness of as much as two feet. Fossil plants including 
leaves, stems and seeds are found in the muck bed. ‘The plants, 
apparently, are but little changed from their original condition. 

In this deposit were found also numerous pieces of pottery, 
fragments of charcoal, and a few implements. Of the imple- 
ments three are of bone, one of wood, and one of flint, possibly 
the tip of an arrow point. 


The Associated Vertebrate Fossils. 


The position of this skeleton and the conditions of preserva- 
tion are such as to exclude definitely the possibility of its repre- 
senting a human burial. In discussing the human remains it 
is well, therefore, to pass at once to a consideration of the 
associated fossils. The stream bed at the place where the 
human fossils were found, as already noted, cuts through the 
older stream fill and into the marine shell marl. Under these 
conditions it becomes necessary to carefully exclude any fossils 
that may have washed in from the older bed beneath. It is by 
no means unusual for fossil bones and teeth to wash from an 
older and lodge in a newer formation, although such bones are 
very sure to betray their true origin by their rounded and worn 
condition. It is a significant fact, therefore, that the bones 
found in association with the human fossils, as well as else- 
where in this alluvial bed, are sharp cornered and entirely 
unworn. The associated bones are frequently broken, but no 
more so than are the human bones. The fact that deli- 
cate jaws and teeth are here preserved is conclusive proof that 
the animals represented were actually contemporaneous with 
man at this place. 


in Florida in Association with Extinct Vertebrates. 15 


Of mammals found in association with the human bones 
twelve species may be recognized. Of these five or six are 
extinct, the remainder being identical, so far as can now be 
determined, with existing species. Of the extinct species, one, 
an armadillo, is referable to the extinct genus Chlamytherium, 
while another, a rabbit which is quite unlike any rabbit now 
known in the United States, is probably to be referred to a new 
extinct genus having affinities possibly with the genus Romer- 
olagus of Mexico or Pronolagus of South Africa. In addition 
to mammals there are found in this bed bones of crocodilians, 
fishes, birds, and a variety of turtles, as well as plant and insect 
remains. The human fossils are mineralized and in all respects 
preserved in the same manner as the associated vertebrate 
fossils. 


List or Mammarian Species From Brp No. 3. 


Chlamytherium septentrionalis. This extinct armadillo-like ani- 
mal is represented by dermal plates taken from the muck 
and sand layers about one foot above the human remains. 
The articulating margins of the plates, although very delicate, 
are uneroded. 

Lynx sp. Represented by a tibia and a lower jaw lacking only the 
incisor teeth. This lynx differs from the modern lynx now 
found in Florida by a large canine which crowds upon and 
reduces the space available for the incisors; the diastema 
between the canine and the premolars is reduced, the jaw 
as a whole is thicker, and the teeth more closely crowded than 
in the modern species. 

Rablit Gn., sp. nov. Represented by right and left jaws, taken 
from the muck eighteen inches above the human radius. In 
the structure of the first molariform tooth this rabbit differs 
from any known from the United States and resembles in this 
respect the aberrant Romerolagus known only from the west 
side of Mt. Popocatepetl in Mexico, and the South African 
rabbit, Pronolagus. 

Vulpes pennsylvanicus? Represented by a part of the lower jaw 
with two premolars preserved. 

Neofiber allent. Represented by the front part of the skull and 
two lower jaws. 

Canis sp. Represented by a scapula, humerus, radius and tibia, 
indicating a canid of more stocky build than the coyotes. 

Sigmodon sp. Represented by a right lower jaw. 

Odocoileus sp. Represented by a part of the lower jaw and various 
parts of the skeleton. 

Lutra canadensis. Represented by humerus, femur and tibia. 

Didelphis virginiana. Jaw, humerus and ulna. 


16 FE. LL. Sellards— Discovery of Fossil Human Remains 


Neotoma sp. Lower jaw. 
Procyon lotor? Ulna and radius. 
Ursus indt. Part of crown of molar tooth. 


Elephas columbi and Equus leidyii( ?) have also been obtained 
from this deposit, but as these two species are represented only 


Fre. 11. 


Fic. 11. Photograph showing plant remains from bed no. 3 of the section 
at Vero. The plant remains are found from one to two feet above the 
human bones. In addition to the plants the slab illustrated shows the 
scale of a fish and the tibia of an insect. Natural size. 


by broken -teeth from near the bottom of the bed, they are not 
at present included as a part of this fauna. 


in Florida in Association with Extinct Vertebrates. 17 


Summary. 


That the human bones found in the older stream deposits at 
Vero belong with and are a part of the fauna with which they 
are associated, and were not placed in the bed by human burial 
is supported by the following observations: A part only of the 
skeleton was present; the sand in which the bones were 
imbedded had not been disturbed, nor had the overlying cover- 
ing of hard rock been removed; the human bones are thoroughly 
mineralized, agreeing in this respect with the bones of the asso- 
ciated Pleistocene vertebrates; the scapula and astragalus of 
a deer common to this and the succeeding river deposits were 
found in immediate association with the human bones; bones 
of the sloth, Megalonyx jeffersoniz, and teeth of the mastodon, 


Hie. 12: 


aks 


ey 


Fic. 12. Fragment of a bird bone showing markings which were appar- 
ently made by a tool. Natural size. A tip of a proboscidian tusk obtained 
at the same place shows markings which by their regularity of spacing 
may indicate design. Both specimens were taken in place at the base of 
bed no. 2 of the section as shown in fig. 2. 


Mammut americanum, have been found in the canal bank at 
this place showing, together with evidence based on the texture 
and appearance of the sand, that there is no break in the 
continuity of the stratum holding the Pleistocene fossils. 

That the human bones found in the newer fluviatile deposits 
in this valley do not represent a human burial, but are contem- 
poraneous with the fauna with which they are associated, is 
shown by the entire similarity in the manner of deposition and 
preservation of the bones; that the associated fossils were not 
washed in from some older deposits is shown by the fact that 
the bones are not in the least eroded, rounded or water-worn. 

Aside from the change in the fauna the time interval since 
the human skeletons became lodged in the stream bed is meas- 
ured by the accumulation of the overlying fluviatile deposits. 
The aggrading of the stream valley as a whole since the later 
of the two skeletons became entombed includes an accumulation 
over the whole valley of an average of about two feet of 
vegetable material and sand. Inasmuch as the streams tribu- 


Am. Jour. Sct.—Fourta Smries, Vou. XLII, No. 247.—Jury, 1916. 
9 


a 


18 £&. LH. Sellards—Discovery of Fossil ITuman Remains. 


tary to this valley originate only a few miles inland, and the 
valley in recent times has been occupied merely by a small 
sluggish clear-water stream, the aggrading of the stream valley 
must have progressed very slowly. ‘The fact that the fresh- 
water marl which overlies the alluvial bed amounts in places 
to as much as two feet in thickness is further evidence of the 
considerable length of time that has elapsed since this deposit 
was accumulated. 

The mammalian fauna contained in the older stratum holding 
human remains at Vero, No. 2 of the section, makes it dombata 
that this bed was deposited during the Pleistocene period. That 
the overlying bed, No. 8 of the section, is likewise of great 
antiquity is established by the fact that it contains a number ‘of. 
extinct mammalian species, as well as by the fact that the 
human and other bones which it contains are well mineralized. 
However, further discussion of the place of this bed in the 
geologic time scale will be deferred until a more complete 
determination has been made of the associated fauna and flora. 
This is the more desirable since the collections from this very 
important locality are being rapidly increased, thus affording 
additional data with which to determine the age of the deposits. 


Florida Geological Survey, Tallahassee, Fla. 


Arr. Il.—A New Cyprinid Fish, Leuciscus rosei, from the 
Miocene of British Columbia; by L. HussaKor. 


Some time ago Dr. B. Rose, of the Geological Survey of 
Canada, sent me for examination four fossil fishes which he had 
collected while investigating the geology of the southern part 
of British Columbia in 1912. The specimens are from a 
formation known as the Tranquille beds, probably of Miocene 
age, on Kamloops Lake, B. C.* Each specimen consists of a 
more or less complete fish about 6 inches in length, represented 
by its skeleton in a layer of stratified light brown tuff. The 
fishes apparently represent a new species. 


Leuciscus rosei, n. sp. 


Type.—\mpression of a complete fish lacking only the lower 
lobe of the caudal. Total length, 127™™. In the collection of 


* A brief description of the geology of the region in which the specimens 
were collected was given by Dr. B. Rose in his paper, ‘‘Savona Map-area, 
British Columbia.” Summary Report, Geological Survey Canada, for the 
Calendar year 1912 (1914), 151-155. 


L. Hussakof—New Cyprinid Fish. i) 


the Geological Survey of Canada. Locality: Red Point, on 
Kamloops Lake, B. O. 


Head 23 in length to base of caudal; depth 2%. Dorsal 14; 
anal 18 or 19. Vertebree about 40. 

Fish rather short and deep, with large head and projecting 
lower jaw. Dorsal triangular, its front rays the longest, half 
again as long as the dorsal base. Origin of dorsal behind that of 
ventrals, at about middle of the total length; 4 of dorsal base 


Fic. 1. 


Leuciscus roseit, n. sp. Type, x 2%. Tranquiile beds (probably Mio- 
cene); Kamloops Lake, British Columbia. 


in front of anal. Anal larger than dorsal, its anterior rays 
elongated, its base separated from the caudal by a distance 
slightly less than the depth of the peduncle. Origin of 
ventrals about equidistant between origins of pectorals and of 
anal. Peduncle rather deep, equal to base of dorsal. Caudal 
not completely preserved, but obviously forked as shown by 
the elongation of the upper rays and the shortness of the 
middle ones in the type specimen. 

Remarks.—The Oyprinid fishes are distinguished into genera 
largely by the character of their pharyngeal teeth, and since 
these are not preserved in the present specimens one cannot be 
absolutely certain as to the generic determination. However, 
a comparison with figures of various genera would indicate from 
the proportions of the fish, the position and size of the 


20 L. Hussakof—New Cyprinid Fish. 


fins, and the projection of the lower jaw, that the species most 
probably belongs in the genus Leuciscus. 

It is interesting to note that the fossil has considerable 
resemblance to Leweiscus balteatus (Richardson), a species now 
living in the same region and said to be ‘generally abundant 
ey erywhere in the Columbia Basin, and very variable.”* It 
differs, however, in being deeper, in “having a larger head, and 
a longer dorsal, with 14 rays as against “10. ‘The anal in 
Leuciscus balteatus is given by Jordan and Eyermann as “11 
to 22, usually 16,” so ‘that the anal of the fossil species falls 
within this range of variation. 

Six other fossil species of Lewciscus have been described 
from North America,t but only one is known by a complete 
fish, the other five—trom the Pleistocene of Idalo—being 
based on pharyngeal teeth. The complete fish is Zeweiscus 
turnert Lucas,t from the Miocene of Nevada. From this 
species the present one differs in proportions, position of the 
fins and other details. 

Besides the type, I have in hand three other specimens 
(paratypes) from the same locality, and also collected by Dr. 
Rose. One is a fish as large as the type but with the fins in 
less perfect condition and lacking the upper margin of the 
body. This specimen also belongs to the Geological Survey of 
Canada. Secondly, two imperfect fishes in the American 
Museum collection: one, an impression lacking the snout and 
the lower margin of the body including the pectorals, one 
ventral and the front portion of the anal; tle other, a poorly 
preserved mold of a fish about as large as the type with the 
bone completely weathered away but showing part of the out- 
line of the body and tracings of the opercular region and of 
the dorsal and caudal fins. 

The species is named for Dr. Bruce Rose, of the Geological 
Survey of Canada, who collected the specimens, and kindly 
placed them at my disposal for study. 

* Jordan and Hvermann, Fishes of North America, Pt. I, 288; and Pt. IV, 
pl. xlii, figs. 105, 105a. 

+O. P. Hay, Bibliogr. and Catal. Fossil Vertebr., N. Amer., 1902, 396. 


{ F. A. Lucas, A New Fossil Cyprinoid, Leuciseus turneri, from the 
Miocene of Nevada. Proc. U.S. Nat. Mus., xxiii, 1901, 333-384, pl. viii. 


H. Bassler—Oycadophyte from the Coal Measures. 21 


Arr. IIL.—A Cycadophyte from the North American Coal 
Measures; by Harvny Basser. 


Aurnoucs the remains of fronds of indubitable cycadophytes 
have long been known from the European Paleozoic none have 
heretofore been known from the North American Paleozoic. 

During the summer of 1915 the writer, while collecting from 
the so-called Four-foot Coal Seam opposite Barnum, W. Va., 
discovered a single characteristic specimen of the genus 
Plagiozamites. 

The importance attached to the finding of this genus in the 
Paleozoic of North America and the possible significance of 
the occurrence of such a well-known Permian type as low in 
the coal-measures as the middle of the Conemaugh forma- 
tion warrants the publication of the present announcement in 
advance of the publication of the detailed account of the flora 
which is now approaching completion. 

The genus Plagiozamites was established in 1894 by Prof. 
René Zeiller* to include cycadean fronds with oval-lanceolate 
leaflets resembling in their general form those of Zam7tes, but 
inserted obliquely on the common rachis, the leaflets differing, 
further, from those of Zamites in that they do not display at 
the base the callous thickening that always or nearly always 
characterizes the latter. The Maryland specimen is not, how- 
ever, specifically different from Plagiozamites Planchardi 
(Renault) Zeillert of the Lower Permian of Trienbach in 
Alsace, and this makes the discovery of peculiar interest, for 
the American material comes from a horizon in the Middle 
Conemaugh 410’ below the Pittsburg seam of coal, which 
marks the base of the superjacent Monongahela Formation, 
and nearly 700’ beneath what has been considered to be the 
base of the Permian in this region. This fact, however, is in 
perfect accord with other evidence tending to show an interest- 
ing relationship between the middle Conemaugh of the Ap- 
palachian province and the Permian of other regions. 

The appearance in the Conemaugh for the first time since 
the close of the Mississippian of inherently red sediments has 
for some yearst been considered significant of some important 
geologic change such as might mark the passage from the true 
Coal Measures to the Permo-Carboniferous and this found con- 
firmation in 1908 when in the Annals of the Carnegie Museum, 
vol. iv, pages 234-241, Prof. E. C. Case described a small col- 
lection of vertebrate fossils made by Dr. Percy E. Raymond in 

*Zeiller, 1894, Bull. Soe. Geol. France, 3e Serie, xxii, pp. 174, 177. 

+ Zeiller, 1894, ibid., p. 174, pl. viii, figs. 1-5, pl. 1x, fig. 1. 

t White, I. C., 1903, West Virginia Geol. Survey, vol. ii, pp. 165, 226, 227. 


22. -H. Bassler—Cycadophyte from the Coal Measures. 


the middle Conemaugh at Pitcairn about fifteen miles east of 
Pittsburg, Pa. The determinable specimens of this collection, 
to the number of about twenty, are distributed among the 
reptilian genera Vaosaurs and Desmatodon and the t amphibian 
genus Eyyops, and are declared to be distinctly of the same 
character as those from the Permian beds of northern Texas. 
These bones came from a horizon in the Pittsburg Red Shale 
about 35 feet beneath the Ames or Crinoidal Limestone which 
in turn lies 315 feet beneath the base of the Pittsburg Coal 
Seam and marks the last paleozoic marine invasion of this 
general region. Further, Dr. I. C. White, in Vol. II (A) of 
the West Vi irginia Geological Survey (1908), page 623, men- 
tions the discovery near Salt Lick Bridge, Braxton Co., 
W. Va., a few feet above the horizon of the Ames Limestone; 
of what appears to be a perfect cast of the tibia of a large 
reptile allied to the Permo-Triassie Pareiasauria. In this 
connection it is interesting to recall that Scudder in 1896 (Bull. 
U.8. G.S., No. 124, p. 12), in discussing a collection of in- 
sect wings made near Steubenville, Ohio, from a horizon “a 
little above the Crinoidal” or Ames Limestone, states that 
this insect fauna closely resembles one from the Lower Permian 
of Weissig in Saxony. 

The reference of each of the above faunal horizons to the 
Ames marine horizon raises the question of the relation of the 
“ Four-foot Seam” at Barnum to this marine limestone. This 
coal-seam is the same as that at Barton, Md., 9 miles to the 
northeastward in the Georges Creek Valley which is known 
in the literature of the region as the Bakerstown Coal and 
which at Barton is about 135’ above the uppermost known 
marine fauna—Brush Creek of the literature—but this so- 
called Brush Creek horizon on the evidence of a considerable 
marine fauna is considered by Drs. C. K. Swartz and W. A. 
Price as probably that of the Ames Limestone. 

In addition to the occurrence of Plagiozamites Planchardi at 
Teufelsbrunnen in Alsace it has been found also in France, in the 
Tranchée de Forét, in shales associated with the Grand Couche 
of the Commentry Basin* and in shales associated with the 
upper seam of coal at the mines of Longpendu in the Blanzy 
Basin,t in both cases at practically the same horizon (slightly 
older than the one in the Vosges) which Zeiller{ considers 


* Renault, 1890, Flore Foss. terr. houill. de Commentry, 2e part, p. 615, 
Atlas, pl. Ixvii, fig. 8. 

+ Zeiller, 1906, Flore foss. bass. houill. et Perm. de Blanzy et du Creusot, 
page 193, pl. xlvii, fig. 2. 

tZeiller, 1894, Sur l’age des depots houill. d. Commentry, Bull. Geol. 
Soc. France, 3e ser., t. xxii, p. 275 et seq., also Zeiller, 1906, loc. cit., pp. 
237, 247. 


I. Bassler—Cycadophyte from the Coal Measures. 28 


uppermost Stephanian and which Sterzel* and Potoniét both 
consider referable to the lowermost Autunian or Rothliegenden 
(Permian). This horizon will be referred to as Permo-Car- 
boniferous in the sense that it probably occurs in the narrow 
zone of passage from the Stephanian to the Autunian. 

The material from Maryland falls well within the limits of 
this species as described by Zeiller, for, while the leaflets are 

rather less bluntly terminated than i is the case with the Alsatian 
specimens or with the one from Longpendu, they are distally 
somewhat less attenuate than that from Commentry. The 
rachis of the Maryland specimen, unlike the rather poorly 
preserved rachises of the material figured by Zeiller, instead of 
being terete as these appear to have | been, is flattened above, is 
rather coar sely but somewhat indistinctly lineate and is 
traversed longitudinally by a shallow median channel. The 
manner in which the base of the pinnules obliquely half en- 
circles the rachis and the evidence near the base, of the torsion 
of these leaflets during fossilization, out of the plane they 
occupied during life, is well seen in the accompanying figures. 

The better to show the nervation with its rather infrequent 
dichotomies and the spinulose denticles into which the nerves 
are produced, I have added a somewhat diagrammatic line 
drawing. The nerves occur to the number of 10 to 13 in each 
half centimeter. 

Associated with Plagiozamites Planchardi in Europe are 
two species of Pteridosperms—Linopteris Germari (Geibel) 
Potonié and Odontopteris genwina Grand’Eury—which I 
believe do not anywhere range lower{ and it is a matter of 
considerable interest to know that these three species are like- 
wise found associated in Maryland. 

If we are not yet prepared to correlate the beds of the 
middle Conemaugh of the Appalachian basin with the Permo- 
Carboniferous of. Europe, then the horizon which has yielded 
the plant here considered is lower than any other from which 
zamitoid cycadophytean fronds have yet been collected. The 

* Sterzel, 1899, Flora des Rothl. von Oppenau, Mitth. d. grossherz. Badisch. 
Geol. Landesanst., Bd. 3, p. 340 et seq., also Sterzel, 1893, Flora d. Rothl. 
in Plauenschen Grunde bei Dresden; Abhandl. k. Sichs. Gesell. Wiss., vol. 
xix, pp. 157, 159. 

+ Potonié, 1893, Die Flora des Rothl. von Thiiringen; Abh. kgl. Preuss. 
Geol. Landesanst., neue Folge, Heft 9, Theil ii, p. 224. 

{To the species Odontopteris genuina Grand’Hury I would assign only 
material the pinnules of the more distal pinnae of which are obliquely 
ovate-triangular in shape with the upper margin straight or slightly concave, 
thus excluding the plant figured under this name by Kidston in 1901, in 
Flora Carb. Period, Proe. Yorksh. Geol. and Polytech. Soc., vol. xiv, pt. ii, 
pl. xxviii, fig. 1, from the Middle Coal Measures of England and that by 
Potonié in 1904 in Abbild. u. Beschreib., Lief. ii, No. 22, fig. 1, from the 
Westphalian of the basin of the Saar, forms which appear to have more in 
common with Odontopterisbrittanica Gutbier. 


~ 


4 


LH. Bassler—Cycadophyte from the Coal Measures. 


Fie. 1. 


H. Bassler—Cycadophyte from the Coal Measures. 25 


present known distribution of Paleozoic cycadophytean re- 
mains, the nature of which is reasonably above suspicion, may 
prove of interest in this connection. This material gives 
representation to three genera—the zamitoid genera Plagio- 
zamites, confined to the Paleozoic, and Sphenozamites which 
ranges from the Permian to the top of the Jurassic, and the 
encephalartoid genus Plerophyllwm which ranges from the 
Westphalian (Carboniferous) to the Wealden (Cretaceous), 
but is most extensively developed in the Keuper (Triassic). 


Fie. 2. 


In addition to Plagiozamites Planchardi there are five 
other described and figured species of this genus.* Plagzo- 
zamites carbonarius (Renault) Zeiller occurs in the Permo- 
Carboniferous, at the Tranchée de Foret in the Commentry 
Basin and in the Lower Rothliegenden (Gehrener Schichten) 
at Stockheim in Thuringia,t while P. manierd Renault sp., 
P. acicularis Renault sp., P. regularis Renault sp., and P. 
Saportanus Renault sp. have not yet been reported outside of 
the Commentry Basin, where they also occur in the Permo- 
Carboniferous at Tranchée de Forét.¢ 

The single Paleozoic representative of the genus Spheno- 
zamites is S. Rocher Renault§ from the (Lower Permian) 
Autunian shales at Lally in the coal basin of Autun in France ; 

*In Hrlaut, z. geol. Specialkarte d. k. Sachs. Sect. Zwickau 1901, p. 135, in 
a list of the more important Middle Rothliegenden plants of Saxony, Sterzel 
gives Plagiozamites Liebeanus which in Pal. char. d. ober Steink. u. Rothl. 
im erzgeb. Beck (Ber. d. nat. Ges. z. Chemnitz) 1881, he had described, with- 
out figure, as Cordaites Liebeanus from the lower tuff in Helene-Schachte 
near Olsnitz in Saxony. 

+ Potonie, 1893, loc. cit. p. 210, pl. xxix, fig. 5. 

¢ Renault 1890, loc. cit., p. 614-618, pl. Ixvii, figs. 7-19. 


§ Renault, 1896, Flore foss. bass. houill et perm d’Autun et d’Epinac, 
p. 327, pl. 81, fig. 1. 


26 LH. Bassler—Cycadophyte from the Coal Measures. 


Pterophyllum, on the other hand, is well represented, with 
P. cottwanum Gutbier from the Lebacher Schichten (Middle 
Rothliegenden) at Reinsdorf near Zwickau, Saxony,* from the 
lower Porphyrtuffe (Middle Rothliegenden) at Bernsdorf near 
Chemnitz, Saxonyt and from the Lower Permian (Middle- 
Rothliegenden) at Zbeschau near Rossitz, Moravia,t P. blech- 
noides Sandberger, from the Middle Rothliegenden at Holzplatz 
near Oppenau in the Black Forest of Baden,§ and from the 
Middle Rothliegenden at Weissig near Pilnitz, Saxony ;| P. 
Layolt Renault, from the Permo-Carboniferous at the Tranchée 
de Pochin in the small coal basin of Montvieq a short distance 
northeast of Commentry, France ;§ P. Grand Huryi Saporta 
et Marion, from the ‘upper zone’ (Permo-Carboniferous) at the 
mines of Montchanin and Montmaillot in the Blanzy Basin,’ 
France ;** P. Cambrayi Renault from the Upper Autunian 
shales immediately overlying the Boghead of Thelot in the Basin 
of Autun;{t+ 2. cnflecum EKichwald, from the indurated red 
slate at Socolowa near Afonino in the coal basin of Kouznetzk 
which lies in the central part of the province of Tomsk, on the 
northern slope of the Altai Mts., Siberia,tt and from the red 
slates in the valley of the Inia River in the same region§§—both 
Permian||| of what has been called the northern type—and 
finally the unique occurrence of an unnamed species of Ptero- 
phyllum from the Transition Coal Measures (Westphalian) at 
Barfreston in the Kent Ooal-field of Great Britain reported in 
1912 by Prof. E. A. N. Arber,4{4] which marks the earliest 
occurrence thus far recorded of the plant group here con- 
sidered. 


Geological Laboratory, 
Johns Hopkins University, 
March 31, 1916. 


* Gutbier, 1849, Die Versteinerungen d. Rothlieg. in Sachs., p. 21, pl. vii, 
fig. 7. 

+ Sterzel, 1907, Mitth. d. grossherz. Bad. Geol. Landesanst., Bd. v, p. 380. 

+ Hofmann u. Ryba, 1899, Leitpflanzen, p. 103, pl. xx, fig. 3. 

§Sandberger, 1864, Flor. d. ober Steinkohl. im bad. Schwarzawald, p. 34, 
pl. ii, figs. 1-4. 

|| Geinitz, E., 1873, Brandschiefer von Weissig, p. 701, pl. iii, fig. 9, 
including P. cotteanus EH, Geinitz (non Gutbier), p. 701, (excl. syn.) pl. iii, 
fig. 8. 

*| Renault, 1890, loc. cit., p. 619, pl. Ixviii, fig. 1. 

** Teiller, 1906, loc. cit., p. 194, pl. xlvii, fig. 1. 

+t Renault, 1896, loc. cit., p. 322, text fig. 64. 

tt Hichwald, 1860, Letheea Rossica, vol. i, p. 215, pl. xv, figs. 5, 6. 

S$ Geinitz, 1871, in Cotta’s Der Altai, p. 172, pl. iii, fig. 7. 

||| Zeiller, 1902, Nouv. obsery. sur la flore foss. d. bass. de Kousnetzk ; 
Compt. rend., t. cxxxiy, p. 887. 

“|| Arber, 1912, Geol. Mag., Dec. v, vol. ix, p. 98, pl. v, figs. 2, 4. 


Arctowski—Pleionian Cycle of Climatic Fluctuations. 27 


Art. 1V.—The Pleionian Cycle of Olimatie Fluctuations,* 
by Henryk ARcTowsKI. 


As we observe changes of weather from one day to another, 
so we observe climatic fluctuations from one season to another, 
from one year to the following year. Persistency of given 
weather conditions may frequently be observed. In the case 
of climatic fluctuations, also, there may be a series of years 
abnormally dry or abnormally rainy, or we may have groups 
of years offering some other particularities such as a late spring 
for example, or an unusually warm winter, and such excep- 
tional conditions, recurring for a succession of years, give the 
impression of a radical change of climate. 

In reality, therefore, we may consider the study of these 
changes or fluctuations just as important and as having a far 
more practical value than the study of the so-called normal cli- 
matic conditions. 

Considering ten-yearly means of atmospheric temperature as 
representing quasi-normal values, I inscribed the annual depar- 
tures from these means on maps. For each year so far taken 
into consideration the departures are never positive all over 
the world, or negative; in each case some regions are charac- 
terized by an excess of heat, whereas in other regions tempera- 
ture is in deficiency. ‘The areas of positive departures have 
been called thermo-pleions and those of negative departures 
anti-pleions. The anti-pleions do not necessarily compensate 
the thermo-pleions. The year 1900, for example, was a year of — 
an excess of pleions and the year 1893 was a year of deticiency 
of pleions. The difference of the world’s temperature, for such 
exceptional pleionian and anti-pleionian years, may reach 0°5° 
C. or perhaps even more. 

Taking barometric measurements into consideration, one also 
finds that for each year some centers of abnormally high and 
abnormally low atmospheric pressure are conspicuous.+ These 
baro-pleions and anti-baros displace themselves from year to 
year, and evidently influence atmospheric circulation very 
greatly. 

These changes must have an effect on the distribution of 
storm frequency and on rainfall. Of rainfall data, I have 
studied extensively the ombro-pleions observed in Europe dur- 
ing the years 1851-1905, but the results of these researches 
have not been published. 

* An address before Section ILb of the Second Pan-American Scientific 
Congress, on December 29th, 1915. 


+ Bull. Amer. Geogr. Soc., v. xlii, p. 270, 1910. 
t Month. Weath. Rev., v. xliii, p. 379, 1915. 


28 Arctowshi—Pleionian Cycle of Climatic Fluctuations. 


In order to investigate these phenomena more thoroughly, 
the monthly means of temperature, atmospheric pressure, 
rainfall, sunshine duration and thunderstorm frequency have 
been taken into consideration and the changes from one year 
to another have been studied by the method of overlapping 
means. 

Among other results it was found that at many stations, par- 
ticularly in equatorial regions, temperature rises or falls prac- 
tically simultaneously and that the pleions disappear and 
reappear more or less periodically at intervals of 2 to 3 years.* 
The records of the Harvard Observatory station at Arequipa, 
in Peru, have been taken as a standard of the occurring plei- 
onian fluctuations,t and the results of the comparisons made 
induced me to search for the cause of this cycle of climatic 
variations. 

After it was demonstrated that the cause of the formation 
of pleions could not be attributed to the presence or absence 
of voleanic dust-veils in the higher levels of the atmosphere,t 
it was but natural to search for their origin in the variations of 
the solar atmosphere. 

It seems obvious that, if changes in the vertical circulation 
of the incandescent solar clouds exist, these changes must pro- 
duce oscillations of the quantity of thermal energy radiated 
into space. 

A few words of explanation are necessary. 

Although it is difficult to imagine how the heat of the solar 
atmosphere originates, or where it originates, we must admit 
that the amount of heat is greater below the incandescent pho- 
tospheric clouds than above,—sim ply because these clouds are 
a phenomenon of condensation, due to loss of heat, and because 
condensation could not take place if the temperature below the 
clouds was not higher than the temperature above. In conse- 
quence, we must admit that, just as in the case of terrestrial 
atmospheric conditions, the radiation into space, from below, 
must be a question of cloudiness. This radiation is not neces- 
sarily constant. If the vertical currents producing the ascend- 
ing clouds are intensified, the loss of heat must be greater. 
For the sake of comparison, our terrestrial Cu—Ni clouds, 
with their panaches of false-cirri, may serve as an exainple. 

I imagined that the solar-facule, which always accompany 
the formation of sunspots, might have an origin similar to the 
false-cirri, and this vague aualogy led to the supposition that 
perhaps the facule would give some information concerning 
possible changes of the intensity of the output of solar energy. 

* Annals N. Y. Acad. Sc., v. xxiv, p. 39, 1914. 


+ Bull. Am. Geogr. Soc., v. xliv, p. 598, 1912. 
t Annals N. Y. Acad. Se., v. xxvi, p. 149, 1915. 


Arctowshi—Pleionian Cycle of Climatic Fluctuations. 29 


Facule are indeed merely a product of the solar atmospheric 
circulation. Facule occur often independently of sunspots, 
but more often they accompany the spots. Some connection 
exists also between the frequency of spots and the formation 
of facule. When sunspots are numerous, larger areas of the 
solar surface are occupied by facule. For the average charac- 
teristic outbursts of sunspots, the accompanying faculze reach 
their maximal development about nine days after the spotted- 
ness has reached its maximum.* The facule are evidently 
one of the phases of the phenomenon that produces the 
formation of spots. 

Admitting that a sunspot is the center of violent descending 
currents in the solar atmosphere, we must admit that the 
vapors slide sidewise from the spot when they reach the lower 
levels and reascend, at a certain distance from the spot, more 
quietly and overheated. It is to these ascending currents that 
the formation of facule must be ascribed. Facule must, 
therefore, radiate into space a quantity of heat larger than the 
quantity of heat radiated by the spotted area. If so, the ratio 
of the surfaces occupied by faculee and sunspots must equal or 
be proportional to the ratio of radiation. 

If, therefore, the pleionian cycle of terrestrial temperature is 
to be ascribed to solar fluctuations, we may presume that 
the quotient of the areas of faculz and sunspots is not con- 
stant, and we may suppose that the changes of this quotient 
vary in harmony with the pleionian cycle. And the fact is, 
that not only this ratio of faculee and spots varies extensively, 
but also that these variations present some striking similarities 
with the Arequipa or standard type of thermo-pleionian fluctua- 
tions. 

The figures I have utilized+ are those of the Greenwich 
photo-heliographic measurements. In order to eliminate the 
shorter fluctuations, and to obtain numbers comparable to 
annual means of temperature, I have formed the totals of the 
areas of umbree and faculze for every consecutive solar 10 
rotations. I have used the figures given for the rotations 275 
to 805, or the results of the measurements made during the 
years 1875 to 1913. Then I divided the facule numbers by 
those for umbree. The quotients thus obtained express numeri- 
eally how many times the areas of facule exceeded those of 
umbre. The curve representing these figures graphically, com- 
pared with the curve of sunspots, shows an unmistakable cor- 
relation with the 11-year period. The curve may indeed be 
characterized as follows: 


* Mem. Soc. Spettr. Ital., Ser. II, vol. iv, p. 181, 1915. 
+Tbid., p. 185, 1915. 


380) Arctowshi—Pleionian Cycle of Climatic Fluctuations. 


Well-pronounced minima preceding by approximately 12 
rotations (or more or less 9 months) those of spots ; less pro- 
nounced minima coinciding or preceding by a few rotations 
the maxima of sunspots; then, in each 11 years’ cycle, another 
minimum between the minimum and maximum of the curve 
of sunspots and two minima between the maximum and the 
following minimum. And so, in the period of more or less 
11 years’ duration there are 5 maxima of the ratio of facule 
and umbree; the first coincides with, or closely follows the 
minimum of spots, the second occurs between the minimum 
and the maximum and the three others occur between the 
maximum and the minimum of the sunspot curve. 

It may be useful to mention that the range of these varia- 
tions is well pronounced. The highest observed ratio of 10 
consecutive rotations is 73°74, while the lowest figure is 2°42. 
But these are extreme values. The average ratio of the 15 ob- 
served crests is 26°93 and the mean of the corresponding de- 
pressions is 11-47, or less than one-half. Such are the facts. 

To come back to hypothethical considerations, it may be 
asked how these fluctuations of the ratio of facule and sun- 
spots can be explained ? 

Let us say that the depth to which our terrestrial storms éx- 
tend is limited by the surface of the earth crust or the surface 
of the sea. Evidently the sun does not present similar condi- 
tions and @ priord we may admit the possibility of variations 
in the depth to which the cireulation of the solar atmosphere 
may extend. If so, the proportion of facule to spots must 
vary, and when the faculee are more predominant, we may sup- 
pose that the ascending columns of vapors come from greater 
depths and that, in consequence, the radiation is increased. 
Some sort of tidal movements making the solar atmosphere 
more or less expanded would explain tie possibility of changes 
of depth to which the vertical circulation extends. 

Now, since the maxima of solar facule—umbre ratios reoccur 
—just like the terrestrial thermo-pleions, ombro-, helio- and 
baro-pleions,—at intervals of 2 to 3 years, and since some 
striking time coincidences exist, I shall call these maxima 
of solar fluctuations, horme-pleions,—which simply means 
pleionian impulses. 

I say expressly horme- and not arche-pleions, because this 
last name must be reserved for the solar, or planetary, or 
cosmical relations which cause the changes of the solar atmos- 
pherie vertical circulation, changes for whieh the horme- 
pleions are simply numerical expressions. 

In the foregoing considerations I have spoken of solar clouds. 
This expression may displease some of the students of solar 
phenomena. But what difference does it make if condensation 


Arctowshi—Pleionian Cycle of Climatic Fluctuations. 31 


of calcium for example can or cannot take place at the very 
high temperatures of the photosphere? For my considerations it 
is absolutelyindifferent if the faculee are formed of incandescent 
dust or of metallic vapors condensed into liquid drops or 
whether they are simply gaseous vapors. 

Again, another objection may be raised against the concep- 
tion of the circulation in and around the solar spots that I have 
adopted. But in this case also, theory has no importance since 
the fact is that umbre radiate less heat than the average photo- 
spheric surface and that faculee seem to radiate more heat. 

Speaking of heat, it would also be preferable to avoid that 
expression entirely and use the words radiation, or energy, or 
radiant energy of the sun. 

But all such objections have nothing in common with the 
fact of the existence of a horme-pleionian variation, a fact 
which is a result of the Greenwich measurements and of my 
calculations. And now, in order to establish a theory of the 
terrestrial pleionian fluctuations, more calculations are neces- 
sary. 

The first effort to be made is to find out whether 
atmospheric temperature varies proportionally to the ratio of 
the facule and umbre, or, if such a law cannot be established, 
because of the complexity of meteorological phenomena, it will 
be necessary to show at least some striking correlations between 
the variations of one and the other. Up to the present, a lack 
of time has prevented me from making more than one single 
attempt, which has been successful, and I wish to show 
now how the horme-pleionian maximum of the solar rotations 
772-781 found its repercussion in the temperatures observed 
on our earth-surface during the years 1911 and 1912. 

In order to have figures corresponding exactly to the same 
time-intervals as those of temperature, monthly means of the 
areas of faculee and umbree were calculated, for the years 1909 
to 1913, and then the ratios of the overlapping yearly totals 
were formed. 

These figures expressed graphically on a diagram show a 
well-pronounced crest of the horme-pleion corresponding to the 
mean of June 1911 to May 1912. But before this maximum 
is reached we notice two steps, one at the mean of April 1910 
to March 1911 and the other corresponding to the mean of 
November 1910 to October 1911. In 1912 the ratios decrease 
till a minimum corresponding to the mean of March 1912 to 
February 1913 is reached, and from then on the ratios again 
increase and form the ascending branch of a new horme-pleion. 
To simplify comparisons, we may call 1911:2 the mean of 
February 1911 to January 1912; 1911:3 that of March 1911 
to February 1912, and so forth. The figures for 1910:4,— 
1910 :11,—1911: 6 and 1912: 3 are therefore conspicuous. 


82. Arectowski— Pleionian Cycle of Climatic Fluctuations. 


For the same years 1909-1913 I have prepared more 
than 150 curves of overlapping temperature means of stations 
from all parts of the world. This amount of already computed 
data is very respectable, but of course I am anxious to obtain 
more data, and I do not think that the difficulties one eneoun- 
ters in collecting the results of meteorological observations 
made in some countries or the shocking mistakes that may be 
found in the tabulations of official publications of some other 
countries, will prevent me from trying to make my research as 
thorough as possible, 

If my reasoning is correct, it follows that at the time of the 
occurrence of the horme-pleionian maximum of 1911:6, or 
shortly afterwards, we should observe thermo-pleionian crests 
on the curves of overlapping means of the observed tempera» 
tures. Or, since it has been found that in no ease studied so 
far, temperature was above the average all over the world, that, 
on the contrary, anti-pleions always compensate the pleions, 
more or less, it will be necessary to find at least a predominance 
of thermo-pleions synchronal with the solar maximum. 

And so it seems to be. 

Of the records studied so far I may say that an abnormal 
increase of temperature during the latter part of 1911 and 1912 
is a striking feature of the curves of meteorological stations in 
Alaska, British Columbia, Vancouver Isl., Oregon, and, to a 
certain extent, California, then of Mexico, Panama, the West 
Indies and Bahamas, British and French Guiana, Matto Grosso, 
Parana, Peru,—the Firoé Isls., Holland, Northern Germany, 
Switzerland, Italy, Gibraltar,— Algeria, Morocco, the Canary 
Isls., the Sahara, Egypt, Senegambia, the French Congo, the 
Transyaal,—Aden, Quetta, India, Ceylon, Mauritius and Sey- 
chelles Isls., the Strait Settlements, Cochinchina, China, Japan, 
Eastern Siberia,—Australia, and the Touamotou Isl. in the 
Pacitic. 

The records of a certain number of stations show a retarded 
pleionian effect. I will cite those of Greenland, Iceland, Caro- 
lina, Florida, Cuba,—the Caucasus and Russia,—Southern 
Nigeria, Togo, German South Africa, Madagascar,—Palestine, 
Mesopotamia, some stations of India, Christmas Isl., the 
Philippines, and New Caledonia. Even in the Antarctic 
regions the records of Cape Evans station, under 77° 38’ §. lat., 
show that during the months of May to September, or during 
the South polar winter, the mean temperature in 1912 was 
10° F. higher than in 1911. 

In striking contrast with these results most stations of the 
United States, as well as Wellington and Auckland in New 
Zealand, and some stations in Russia, show a well pronounced 
depression of temperature corresponding in time with the 


Arctowski—Pleionian Cycle of Climatic Fluctuations. 33 


occurrence of the horme-pleion and the greatest development 
of thermo-pleionian conditions in so many countries in different 
parts of the world. 

The American anti-pleion is of particular interest, because 
of the pleions observed in the Northwestern states, Alaska, 
Canada and Greenland, as well as in the Southeastern states, 
the West Indies and Mexico. In North America temperature 
conditions were evidently in conformity with the horme-pleion, 
except in the greatest part of the central portion of the conti- 
nent. Moreover, it was precisely at the time of occurrence of 
the horme-pleionian maximum, or soon afterwards, that the 
greatest lowering of temperature was observed in the Middle 
West from North Dakota down to Texas. 

Evidently the supposition that these abnormally low tem- 
peratures were due to the veil of volcanic dust produced by the 
Katmai eruption of June 6th, 1912, is completely out of the 
question. If that had been the case, temperature would have 
decreased from that date on, whereas it was decreasing for 
more than a year before that date in order to reach the mini- 
mum at the time of the occurrence of the horme-pleionian 
maximum and accidentally at the time of the Katmai eruption. 
The conclusion to be drawn from these facts is that the Ameri- 
ean anti-pleion of 1911-1912, corresponding in time with prac- 
tically universally observed pleionian vonditions, must have 
been mechanically produced by abnormal pressure distribution 
and the resulting abnormal winds. In other words, it seems 
most probable to me that the anti-pleion observed in the United 
States was simply due to changes of atmospheric circulation 
due to the exceptionally well-developed pleionian conditions in 
the North as well as in the South of the States. The same 
must have been the case of the other anti-pleions in New Zea- 
land and in Russia, and perhaps in some other countries. But 
precisely because these anti-pleions are to be considered as an 
effect of dynamical reaction against the predominant pleionian 
conditions, it is evident that they could not compensate the 
action of the horme-pleion. 

The direct effect of fluctuations of solar activity upon atmos- 
pheric temperature can also be observed in some of the details 
of the horme-pleionian crest. The steps of the ascending 
branch, corresponding to the means 1910:4 and 1910: 11, as 
well as the minimum of 1912:3, may easily be distinguished 
on many of the overlapping temperature curves. But even in 
more minute details some of the curves present such similari- 
ties with the solar curve, that a simple chance circumstance 
can hardly be presumed, and that forcibly, we must admit that 
the cause of these temperature fluctuations is really a question 
of ratio between solar faculee and umbre. 


Hastings-on-Hudson, December, 1915. 


Am. Jour. Sct.—Fourts Series, Vou. XLII, No. 247.—Juny, 1916. 
3 


34 EF. M. Van Tuyl—Geodes of the Keokuk Beds. 


Art. V.—TZhe Geodes of the Keokuk Beds; by Francis 
M. Van Tuyt. 


Introduction. 


Prozsasity nowhere else in America do geodes attain such 
an exceptional development as in the Keokuk beds of the Cen- 
tral Mississippi Valley, and representative specimens of geodes 
from this region are now found in the mineral cabinets of 
many of the museums of the world. Apart from Professor 
Brush’s preliminary examination and description of a few 
select specimens submitted to him in 1865 by A. H. Worthen, 
then director of the Geological Survey of Illinois, no study of 
these remarkable geodes has ever been made in spite of the 
fact that they bear a variety of metallic sulphides and promise 
to throw some light upon the origin of more important deposits 
of these minerals in sedimentary rocks showing no signs of 
igneous influence. The following brief report on their sake! 
teristics may therefore seem justified. 


Occurrence. ° 


The typical geode area is located in Southeastern Iowa and 
adjacent parts of Northeastern Missouri and Western Illinois. 
The most famous localities for geodes in this region are Keokuk 
and Lowellin lowa; Wayland and St. Francisville in Missouri ; 
and Warsaw and Niota in Illinois. 

The age and stratigraphic relations of the geode-bearing 
beds are shown in the accompanying table: 


System | Name of Formation | aoaenee 
Pennsylvanian | Des Moines sandstone 0 — 50 
eats nye Se eet =~ diSCODLOTMITGY oe etee eae: eee 
| Pella limestone 0 — 30 
- discontormity = ja 52 be mre yen SOI 3 
| St. Louis limestone |. 130 — 60 
| > Sedisconformity, os: > 242682 PREPS re re a 
| Mississippian Salem limestone | 0 — 36 
+: Wdiseontonnn tty” ~ - i! _ Ave SER a ole 
Warsaw shale and limestone | 40 
Kookie Geode bed . 40 
Keokuk limestone | 50 
Burlington limestone | 75 
Kinderhook beds | 150 


F.M. Van Tuyl—Geodes of the Keokuk Beds. 35 


The geodes attain their maximum development in the 
Geode bed but some layers of the Keokuk limestone are geo- 
diferous locally. 

The Geode bed consists in its typical development of an 
impure, siliceous, dolomitic limestone at the base, usually con- 
taining large and well-developed geodes, followed by an argil- 
laceous shale with more numerous but less perfectly developed 
geodes. ach subdivision is about twenty feet in thickness. 

The composition of the lower subdivision of the Geode bed 
where it contains large and well-formed geodes at Keokuk, 
Towa, is as follows: 


Insoluble matter (largely free silica). ......-- 33°80% 
We Ost Or seems. eee a es ees O80 
CACC te See. 8809 
WAGE NS) Ss pt eS eile 9 a email) 
Moisture and carbonaceous matter..._._.___. 7°70 
Windetenminediss e) summ em atria mete | ae PIS sO 
4 Roy) aed a Ao hate pi eee ee 100°00 


In size the geodes range from about -2° up to 75°™* in 
diameter. But well-developed geodes of either extreme are 
rarely found. In general, the geodes of a given layer do not 
vary greatly in size at a given locality, but there may be con- 
siderable variation in this respect at different levels in the 
same exposure. Moreover, there. may be marked changes in 
their dimensions at. the same level at different localities. Often 
geodes of similar size are arranged roughly in bands parallel 
to the stratification. They usually lie with their longest diam- 
eter parallel to the bedding-planes, and at some localities they 
are closely associated with calcareous concretions of similar 
shape and size. 

The abundance of the geodes in the geodiferous phase of 
the Keokuk formation is quite variable both laterally and 
vertically. At times they are so numerous, in a given layer 
that their freedom of growth has been interfered with, and 
they are thus of very irregular shape. At other times, they 
may be so sparsely distributed through the rock that none may 
appear in an outcrop embracing several square yards. Again 
they may be absolutely wanting at some localities. The pro- 
portion of well-developed geodes in the beds varies greatly at 
different localities ranging from less than ten per cent at some 
places to more than ninety per cent at others. 

As to the mineralogical relationship of the geodes to the 
containing rock, it is found that at any given locality each 
geodiferous layer as a rule bears geodes which are closely 
related among themselves, but which may be mineralogically 


36 FF. M. Van Tuyl—G@eodes of the Keokuk Beds. 


unlike those from other layers. But sometimes closely placed 
specimens in the same layer may bear very different minerals. 

The contact relations of the geodes with the containing 
rock are not such as to indicate appreciable expansion during 
their formation. At no place is the inclosing rock found to 
be under any strain, nor is there any evidence of deformation 
of the layers at the contact. Rather the layers end abruptly 
where they abnt into the geodes or exhibit a thinning where 
they pass immediately over or under them. The calcareous 
concretions which oceur in the beds at some localities exhibit a 
similar relationship. 

The extent of the geodes in the rock back from the outerop 
is worthy of consideration. Bassler,* in his discussion of the 
geodes of the Knobstone shales of Kentucky and Indiana, 
calls attention to the impervious nature of shale and inclines 
to the view that the geodes of that formation are confined to 
the surface or the immediate neighborhood of joint planes or 
rifts in the strata through which water had easy access. Such 
a relationship does not seem to hold for the geodes of the 
Keokuk beds. 


Mineralogy of the Geodes. 


Mineralogically, the geodes are almost invariably siliceous 
but a few calcareous geodes have been found. ‘Lhe siliceous 
types are characterized without exception by a thin outer shell 
of chalcedony and this is usually followed inwardly by erystal- 
line quartz, but calcite may succeed the chalcedony. In some 
instances, however, the interior is lined with botryoidal chal- 
cedony and no crystalline quartz nor calcite appears. At other 
times these minerals may all occur in a single geode, but usually 
only quartz and calcite or chalcedony and calcite are present. 
In addition the interior linings of the geodes are frequently 
studied with dolomite or ankerite, and one or more metallic 
sulphides are often represented. Moreover, some hollow 
siliceous geodes contain water, and in the vicinity of Niota, 
Illinois, many specimens are filled with black viscous bitumen. 
Finally others contain kaolin in the form of flocculent, white 
powder. 

The primary minerals found in the geodes are: quartz, chal- 
cedony, calcite, aragonite, dolomite, ankerite, magnetite, 
hematite, pyrite, millerite, chalcopyrite, sphalerite, kaolin, and 
bitumen. The alteration products represented are: limonite, 
smithsonite, malachite and gypsum. 

With reference to the paragenesis, or order of deposition of 
the primary minerals, no constant order of succession holds for 


*Proc. U. S. Nat. Mus., vol. xxxv, p. 138 ff. 


FF. M. Van Tuyl—Geodes of the Keokuk Beds. 37 


all geodes, and the same order of deposition may not obtain in 
two adjacent specimens. 

For the purpose of illustrating the variations in the succes- 
sion of the primary minerals in the geodes, the order of deposi- 
tion in a number of typical specimens isgiven. The chalcedony 
of the shell is listed first in each case. 


Chalcedony, quartz. 

Chalcedony, quartz, chalcedony. 

Chalcedony, quartz, chalcedony, quartz, ehalcedony, 

pyrite, calcite with included pyrite. 

4, Chalcedony, quartz, chalcedony, pyrite, calcite. 
5. Chaleedony, quartz, chalcedony, pyrite, sphalerite. 
6. Chalcedony, quartz, dolomite, calcite. 
7. Chalcedony, quartz, magnetite, hematite 
8 
9 

10 


oe ies 


Chalcedony, calcite, calcite. 

Chalcedony, calcite, millerite. 

Chalcedony, quartz, ankerite, calcite, aragonite. 
11. Chalcedony, quartz, calcite, bitumen. 
12. Chalcedony, calcite with included chalcopyrite. 
13. Chalcedony, quartz, pyrite, magnetite. 
14. Chalcedony, chalcedony, sphalerite. 


First, then, in the development of the siliceous geodes there 
was formed a thin chalcedonic shell. Upon this is superim- 
posed quartz, either in the crystalline or chalcedonic condition, 
or caleite. It is a remarkable fact that when calcite and quartz 
appear in the same specimen the calcite is normally subsequent 
to the quartz, which rests directly on the siliceous shell. This 
relationship, first pointed out by Professor Brush,* has been 
found to hold in every instance by the writer, but A. H. 
Worthen claims to have found a single specimen at Keokuk 
“in which large crystals of calcite are partly covered with 
smaller crystals of quartz.” + 

The alternation of crystalline quartz and chalcedony in some 
of the geodes is difficult to account for. If the layers were all 
formed during one period of growth as seems probable, changes 
in the condition and amount of silica supplied may have given 
rise to the phenomenon. Changes in temperature or pressure 
eannot be appealed to, because adjacent quartz geodes in the 
strata frequently do not show the same alternations. 

The position of calcite in the geodes is subject to many varia- 
tions. At times it succeeds the chalcedonic shell directly, but 
more often it rests upon an inner lining of quartz or chalce- 
dony. In some of the geodes, calcite of two generations ap- 
pears. The earlier calcite is often discolored brownish, and is 
frequently associated with or directly followed by sphalerite, 


* Geological Survey of Illinois, vol. i, p. 90, 1866. 
+ Idem, p. 90. 


38 I. M. Van Tuyl—Geodes of the Keokuk Beds. 


millerite, chalcopyrite or pyrite. Intervening between this 
ealcite and that of younger age, crystals of dolomite or ankerite 
are also sometimes found. 


Origin of the Geodes. 


The origin of the geodes of the Keokuk beds has long been 
a disputed question, and, although there has been considerable 
speculation npon the subject, no one theory of their develop- 
ment has, as yet, been widely held. 

The existence of perfectly developed geodes in strata often 
very impervious to underground circulation furnishes a problem 
which is exceedingly difficult to solve. The containing rock 
in the Keokuk region is often highly argillaceous and no 
structures which might serve as passage ways for mineralizing 
solutions are to be seen. 

It was formerly believed that the geodes were formed by the 
deposition of mineral matter on the walls of cavities formed 
by the solution of sponges imbedded in the rocks. Thus, Dana 
states :* 


“They have been supposed to occupy the centers of sponges 
that were at some time hollowed out by siliceous solutions, like 
the hollowed corals of Florida, and then lined with crystals by 
deposition from the same or some other mineral solution.” 


This theory has had many followers and 8. J. Wallace has 
even gone so far as to coin a generic name for the sponge 
whose solution is supposed to have afforded the cavities in 
which the geodes were developed.t To this genus, called 
Biopalia, eight species were referred upon the basis of differ- 
ence in size, shape, and surface markings of the geodes. The 
sponge hypothesis, however, is not now widely held. No 
evidence of sponges capable of giving rise to geodes have ever 
been found in the Keokuk beds. Moreover, the geodes vary 
widely in size and shape, a fact which argues strongly against . 
any theory which presupposes such an origin. Many speci- 
mens are nodular and irregularities of the greatest variety char- 
acterize their exterior form. It may safely be said that no 
two of them assume exactly the same proportions. 

Professor Shaler, in a paper entitled ‘“‘Formation of Dikes 
and Veins,”t also devotes some space to the development of 
geodes and, although his studies were based upon geodes known 
to be of fossil origin which occur in the Knobstone shales 
of Kentucky, his conclusions may well be considered at this 
point : 

* Manual of Geology, 4th ed., pp. 97, 98, 1895. 


+ This Journal (3), vol. xv, p. 366 ff., 1878. 
¢ Bull. Geol. Soc. Am., vol, x, p. 208 ff., 1899. 


EF. M. Van Tuyl—Geodes of the Keokuk Beds. 39 


“ Normal geodes are hollow spheroids and are generally found 
in shales. They clearly represent, in most cases, a segregation of 
silica, which has evidently taken place under conditions of no 
very great heat, brought about by deep burial beneath sediments 
or other sources of temperature. It is difficult in all cases to 
observe the eircumstances of their origin, but in certain instruc- 
tive instances this can be traced. It is there as follows : Where 
in a bed in which the conditions have permitted the formation of 
geodes the calyx of a crinoid occurs, the planes of junction of 
the several plates of which it is composed may become the seat 
of vein-building. As the process advances these plates are pushed 
apart and in course of time enwrapped by the silica until the 
original sphere may attain many times its original diameter and 
all trace of its origin lost to view, though it may be more or less 
clearly revealed by breaking the mass. 

In the process of enlargement which the geodes undergo they 
evidently provide the space for their storage by compressing the 
rock in which they are formed. In the rare instances where I 
have been able to clearly observe them in their original position 
they were evidently cramped against the country rock, the layers 
of which they had condensed and more or less deformed. Al- 
though when found upon the talus slopes or the soil these spheres 
usually contain no water in their central cavities, these spaces are 
filled with the fluid while they are forming and so long as they 
are deeply buried. There can be no doubt that this water is 
under a considerable though variable pressure. 

The conditions of formation of spheroidal veins or geodes 
clearly indicate that an apparently solid mass of crystalline 
strueture may be in effect easily permeated by vein-building 
waters, and this when the temperature and pressure could not 
have been great. It is readily seen that the walls of these hol- 
low spheres grow interstitially while at the same time the crystals 
projecting from the inner side of the shell grow toward the 
center. We, therefore, have to recognize the fact that the silex- 
bearing water penetrated through the dense wall. In many of 
these spherical veins we may note that the process of growth in 
the interior of the spheres have been from time to time interrupted 
and again resumed. ‘These changes may be due to the variations 
in pressure to which the water in the cavities is necessarily sub- 
jected as the conditions of its passage through the geode-bearing 
zone are altered.” 


More recently Bassler has written* on the formation of the 
Knobstone geodes. He says: 


“The majority of geodes in the Knobstone group may be 
traced directly or indirectly to a crinoidal origin for the simple 
reason that these strata are often crowded with the fragments of 
this class of organisms. Probably next in order as a geode maker 
is the common brachiopod Athyris lamellosa, but no class of 


* Proc. U. S. Nat. Mus., vol. xxxv, p. 133 ff., 1908. 


40 I. M. Van Tuyl—Geodes of the Keokuk Beds. 


fossil is exempt from replacement by silica when the proper con- 
ditions obtain.” 


Bassler is of the opinion that the Keokuk geodes may have 
the same mode of origin as those of the Knobstone. But he 


disagrees with Shaler as to the details of geode development. 
Thus: 


“Returning to the suggestion in Dana’s Manual of Geology 
that the Keokuk geodes are hollowed out sponges lined with crys- 
tals it seems more reasonable, in view of the absence of such 
sponges in that formation and the presence of numerous speci- 
mens indicating the origin described above, that the latter is 
nearer the truth. Prof. “Shaler? s idea that this class of geodes is 
formed when deeply buried is not in accord with the facts, nor 
does there appear to be any necessity for the water of formation 
to be under a considerable though variable pressure. Ordinary 
surface waters charged with silica seem to be sufficient.” 


This generalization in so far as it relates to the geodes of the 
Keokuk beds in the region studied, would seem to be too broad. 
Out of several thousand geodes examined from the Keokuk 
beds only one, which had plainly been formed by the enlarge- 
ment of a specimen of the crinoid Baryerinus, showed evi- 
dence of this method of geodization. 

The origin of the Keokuk geodes in the region studied is 
believed by the writer to be related to the calcareous concre- 
tions which originally must have been very abundant in the 
beds and which are still preserved at some localities. These 
nodules, being more soluble than the inclosing rocks, have been 
in large part removed, thus affording cavities in which the 
geodes could be formed. Where still preserved, the concre- 
tions have exactly the same relationship to the containing rock 
as the geodes and possess analogous shapes. They were 
obviously formed on the sea-bottom while the strata were being 
deposited, since lines of stratification do not pass through them 
and no evidence of expansion is encountered about their 
borders. The process of solution seems to have started in the 
interior and proceeded outwards. That this was the method 
of removal is indicated by the occurrence, in the beds, of some 
geodic nodules whose interiors were only partially hollowed 
out when deposition began. Carbonic acid and sulphuric acid, 
of which the latter must have been generated by the decompo- 
sitiun of the pyrite so common in the beds, were probably the 
most active solvents. 

The white powder of kaolin found in some of the geodes is 
thought to represent, at least in part, a residual product result- 
ing from the leaching of the original argillaceous content, of 
the nodules. That kaolin can be 60 formed is clearly indicated 


F. M. Van Tuyl—Geodes of the Keokuk Beds. 41 


by the presence of this mineral so related to impurities in some 
of the nodules that its derivation cannot be questioned. The 
more common occurrence of kaolin in the geodes from the 
more argillaceous portion of the beds is significant in this con- 
nection. Moreover, the great majority of the geodes which 
contain kaolin are imperfectly developed and the calcite of 
such specimens invariably includes the white powder of this 
mineral. These facts strongly support the idea that the kao- 
lin must be a residual product. 

Concerning the time of formation of the geodes, little is 
definitely known. The removal of the calcareous nodules 
which, it is assumed, preceded the geodes, implies an interval 
of solvent action during which the Keokuk beds were above 
ground-water level. Such a condition must have obtained dur- 
ing the period of denudation which succeeded the deposition 
of the St. Louis limestone. Some solvent action must also 
have been inaugurated during the pre-Salem and post-Salem 
emergences but these were of limited duration. The growth 
of geodes, on the other hand, undoubtedly took place below 
ground-water level. 

In the development of the geodes at least two periods of 
mineralization are involved. The first period of development 
was by far the most important. During this period of growth 
the quartz, chalcedony dolomite, and a considerable amount of 
the calcite together with almost all of the metallic sulphides 
were deposited. This period of mineralization possibly took 
place during the interval which just preceded the Pennsylvanian 
inundation. The region was certainly near base level at this 
time and the Keokuk beds must have been below ground-water 
level. The occurrence of geodes, supposedly derived from the 
Keokuk beds, in the basal Pennsylvanian conglomerate in 
Indiana, where similar conditions probably prevailed, supports 
this view. 

Of the minerals of the second period of growth, transparent 
erystals of calcite and slender, untarnished flakes of pyrite are © 
by far the most important. The minerals of this class are 
doubtless much younger than those of the former as suggested 
by the fact that in the same geode the pyrite associated with 
the newer calcite is often perfectly fresh while the earlier 
pyrite is badly decomposed. 

The secondary minerals of the geodes such as limonite, gyp- 
sum, smithsonite, and malachite are for the most part of much 
more recent origin. They have resulted from the alteration of 
the primary sulphides as shown by their association with the 
partially decomposed members of this group. 

The bitumen which occurs in some of the geodes must have 
been introduced sometime after their formation, since it has 
not interfered with the normal geode development. 


42 FF. M. Van Tuyl—Geodes of the Keokuk Beds. 


The process of geodization evidently consisted of the inward 
growth of crystals upon the inside walls of cavities left by the 
solution of the imbedded concretions. The growth was neces- 
sarily accomplished by deposition from a solution which filled 
the interior completely. As this solution became depleted in 
its mineral content, more was introduced by some process of 
diffusion and a continuous deposition resulted. In some 
instances a very impervious wall was developed and growth 
must have been extremely slow. But in the majority of 
geodes numerous feeding channels in the walls afforded: ready 
passage to the solutions after they penetrated the siliceous 
shells. 

The mineralogical variation of geodes which may occur in 
close proximity to each other is difficult to account for. It 
must either be assumed that the process of geodization was a 
very local one and that each individual geode possessed only a 
small sphere of attraction, or that a peculiar localization of con- 
ditions favored in some instances the deposition of mineral 
matter more widely diffused through the mineralizing solu- 
tions. 


University of Illinois, Urbana, Ill. 


W. A. Verwiebe— Berea Formation. 43 


Arr. VI.—TZhe Berea Formation of Ohio and \Pennsyl- 
vania; by Wattrr A. VERWIEBE. 


{Paper read before Section H, A. A. A. S.. at its 68th meeting. ] 


One of the most important formations of Ohio geology, not 
only for economic reasons, but also for stratigraphic reasons, 
is undoubtedly the Berea sandstone. It has long been known 
as the source of some of the finest building stone as well as 
most of the abrasive stone in the United States. As a reservoir 
of oil and gas it has brought many millions to the common- 
wealth of Ohio and adjacent states. Its stratigraphic impor- 
tance consists in the fact that it is the first prominent and per- 
sistent sandstone horizon above the Devonian limestones, and 
thus serves as an excellent and reliable datum plane. Further- 
more evidence is accumulating that its irregular base and 
thickness are due to a disconformity with the subjacent 
Bedford ; and this diastrophic break corroborated by strong 
evidence of a faunal break, point to the conclusion that the 
Berea is the basal formation of the Carboniferous system. 

The following table of formations in Ohio and Pennsylvania 
will give the reader a perspective of its stratigraphic position. 
(The Roman numerals are the ones used in fig. 1.) 


Ohio. Pennsylvania. 
Pottsy te 
LAS nape Veh ae lh oh aia eae (unconformity ) 
Logan IV Bienneo shale 
Cm ene ra 2 UE) Burgoon (Butts) 
Black Hand* | III iets sandstone 
TAB HES (Meadville 
Cuyahoga 
II Sharpsville 
Sunbury | 
Orangeville 
Sieiese USEe 5S cael 2 ache ae ea ap maa | 
Healy salsa LOil Lake evoup (White) 
‘Cussewago J 
‘cay dag Po iiceviien 
Bedford ) 
Pees VI Venango \ Conewango (Butts) 
Chemung 


* Hyde considers the Black Hand a local facies of the Cuyahoga. See his 
‘Stratigraphy of the Waverly Formations of Central and Southern Ohio,” 
Jour, of Geol., vol. xxiii, p. 655 ff., 1915. 


44 W. A. Verwiebe— Berea Formation. 


It can readily be understood that students of geology have 
devoted much time and thought to the proper stratigraphie 
relations of such an important member of the Ohio section. 
As early as 1838, O. Briggs, Jr., in the first report of the state 
geologist, described it as part of the ‘Waverly Sandstone 
Series’ and pointed out its value as a building stone. When 
after a lapse of thirty years the work of the State survey was 
again taken up, J. S. Newberry added a good deul of detailed 
information regarding the character and distribution of the 
Berea. To him also is due the credit for the name it bears.* 

Careful and valuable work on this formation was also done 
by Edward Orton. In volume VI of the Ohio geological sur- 
vey publications, he added many details as to the character and 
distribution of the Berea. The most important contribution, 
however, was furnished by Charles 8. Prosser in Bulletin: 15 
of the State survey reports. This work contains detailed sec- 
tions showing the thickness and character of the formation 
from the Rocky River on the west well into Crawford Co., 
Pa., on the east, across the northern part of Ohio. 

Summarizing briefly the results obtained by these investiga- 
tors, the Berea formation of Ohio may be described as follows : 
A sandstone of prevailing buff color, where seen above drain- 
age, having a rather persistent uniform texture which varies 
locally from a very fine grain to a medium-coarse grain. 
Locally also it may be replaced by shales which are generally 
arenaceous and bluish grey to buff in color. Toward the east 
these shales become more prominent, so that the formation 
takes on a tripartite character, the shales occupying the center. 
The upper part continues into Pennsylvania, where it is called 
the Corry sandstone (I. C. White) and the middle shales and 
lower sandstone are called the Cussewago shales and Cussewago 
sandstone. Whereas the Corry phase of the Berea retains its 
typical lithology practically across Ohio and well into Penn- 
sylvania, the Cussewago sandstone phase begins to show a 
strong tendency to increasing coarseness when followed east- 
ward, although nowhere in Ohio does it become a true con- 
glomerate. 

The correlation indicated above has called forth a good deal 
of discussion among geologists. The first to make an attempt 
at correlation was perhaps J. S. Newberry,t who seems to 
have regarded the Shenango sandstone of northwestern Penn- 
sylvania as the equivalent of the Berea. Curiously enough he 
also states that it does not exist along Oil Creek as a prominent 
layer and on this basis deduces the derivation of the sediment 
for the formation from the northwest. Some confusion was 


* Geol. Surv. Ohio, vol. i, p. 186, 1873, 
+ Geol. Survey of Ohio, vol. ii, p. 90, 1874. 


W. A. Verwiebe— Berea Formation. 45 


also created by M. C. Read in his report for Ashtabula and 
Trumbull counties.* On the map accompanying this report 
the Berea is shown as splitting into two parts near the Penn- 
sylvania line. Neither of these, however, represented the true 
Berea; the upper one being the Shenango sandstone and the 
lower the Sharpsville sandstone (Warren sandstone of Cush- 
ing). As a result of this, no doubt, White at first correlated 
the Sharpsville with the Berea.t+ Later White reached the 
conclusion: “ It certainly looks as if . . . the Berea grit of Ohio 
and my Oil Lake group in Crawford and Erie counties 
occupied the same horizon.” + 

About twelve years later, Edward Orton, in a summary of 
the geological formations of Ohio, says that “his (W hite’s) 
Corry sandstone appears to be none other than the Berea 
erit.Ӥ George H. Girty states (1905) that in his opinion 
“The Berea grit of Ohio is White’s Cussewago sandstone, 
together with probably the Cussewago flags and Corry sand- 
stone,”|| though four years earlier he was inclined to limit its 
equivalence to the Cussewago sandstone only.47 Other in- 
vestigators, including notably Stevenson** and Cushing,tt 
regarded only the upper part of White’s Oil Lake group 
(Corry) as the equivalent of the Berea in Pennsylvania. 

Thus it develops that considerable difference of opinion 
existed in regard to the correlation of the Berea in Ohio and 
Pennsylvania; due, no doubt, to the fact that the conclusions 
were largely based on the literature, instead of precise and 
eareful field-work. Consequently, the credit for solving this 
perplexing problem should go to Dr. Prosser, who first pre- 
sented convincing evidence, based on numerous detailed sec- 
tions. His conclusion on this point is stated as follows: “It 
is evident from the description of sections in this bulletin, 
extending from Cuyahoga Co., Ohio, into Crawford Co., Pa., 
that Dr. White was perfectly correct if he intended to cor- 
relate the Oil Lake group of Pennsylvania with the Berea 
formation of Ohio.” ¢¢ 

In Pennsylvania the Berea has been studied in Crawford and 
Erie counties by I. C. White,$§ and along the Allegheny River 
by Chas. Butts. || 

* Geol. Survey of Ohio, vol. i, pp. 483 and 505-508. 

+ Pa. 2d Geol. Survey, @38, p. 124, 1881. See also Prosser, C. S , Devo- 
nian and Mississippian : Geol. Survey of Ohio, Bull. 15, p. 855 ff. for a dis- 
cussion of this. 

{Penn. 2d Geol. Survey, vol. Q4, p. 91, 1881. 

§ Geol. Survey of Ohio, vol. vii, a 33, 1894. 

|| Proc. Wash. Acad. Sci.. vol. vii, p. 6, 1905. 

“| Science, N. S., vol. xiii, p. 664, 1907. 

** Bull. Geol. Soc. Amer., vol. xiv, p. 41, 1908. 

++ Proc. Amer. Ass. Adv. Sci., vol. xxxvi , p. 215, 1888. 

{t Geol. Survey of Ohio, Bull. "15, p. 394, 1912. 


SS Pa. 2d Geol. Survey, 4, 1881. 
il Rept. Topog. and Geol. Survey Comm. for 1906-08, p. 190. 


46 W. A. Verwiebe—Berea Formation. 


The former described it under the heading of Oil Lake 
group, which consists in descending order of the Corry sand- 
stone, Cussewago shales and Cussewago sandstone. Mr. Butts 
published a continuous section along the Allegheny River from 
the New York state line to Emlenton in the southern part of 
Venango Co., Pa. (See fig. 2.) In discussing the section he 
states: ‘The Berea sandstone lying 300 feet above the Sala- 
manea ean be identified by its characteristic fossils in every 
section down to the bend of the river 2 miles south of Tionesta, 
where it passes below the railroad grade. About 160 feet 
above the Berea and separated from it mainly by blue shale, is 
a rather thin-bedded, generally fine-grained, sandstone. This 
was traced with a good degree of certainty from two miles 
south of Tidioute to a point about one mile south of Hunter, 
from which point it is exposed at many places near railroad 
level and was traced continuously to Oleopolis. A similar and 
probably the same sandstone is exposed at Oil City at railroad 
level and dips below the railroad about one and one-half miles 
south of Oil City.”* 

From the above it will be seen that the literature covered 
pretty thoroughly the correlation of the Berea in Ohio and 
Pennsylvania, as well as the extent of the formation in north- 
eastern Ohio, Crawford and Erie counties in Pennsylvania, and 
apparently along the Allegheny River. There remained sim- 
ply to fill in the gap between Crawford Co. and the Allegheny 
River, involving a survey of parts of Venango, Forest and 
Warren counties. (Compare fig. 2.) This part of the work 
was undertaken by the writer during the summer of 1915. 
After a careful study of the Berea in Ohio it was traced con- 
tinuously from the boundary line of Ohio and Pennsylvania 
across Crawford Oo. to the Allegheny River. Many sections 
were made along this line, the most important of which will be 
found in fig. 1, and in greater detail at the end of this discus- 
sion. Asaresult of this work the following conclusions were 
reached : 

1. The Berea formation is represented in Pennsylvania by 
the Corry sandstone, and the Cussewago shale and sandstone 
of I.°Cr White: 

2. The Corry sandstone increases in thickness when followed 
eastward from the state line, attaining a thickness of about 50 
feet along the Allegheny River. (See fig. 1, section E and 
following sections.) 

3. The Corry sandstone becomes gradually coarser toward 
the east, changing from a rather fine-grained, even-textured 
rock along the state line to a coarse-grained, pebbly sandrock 
(at least in its upper part) on the Allegheny River. 


*Tdem, p. 192, 


W. A. Verwiebe—Berea Formation. 47 


4. A limestone layer (Cussewago limestone) is practically 
always to be found immediately underlying the Corry, or sepa- 
rated from it by a few inches of shale. This varies in thick- 
ness from 8 inches to 1 foot 10 inches. (See sections E, F, 
and I.) 

5. The Cussewago sandstone thins out and disappears from 
the section about longitude 80° 5’ W.; though it may be repre- 
sented farther east by a part of the shales and sandstones 
underlying the Corry. 

6. The Corry sandstone is represented along the Allegheny 
River by the sandstone indicated on Mr. Butts’ diagram as 
lying about 160 feet above the sandstone labelled ‘“ Berea 
(Corry).” See the quotation above and compare the sections 
K, L, and M in fig. 1.) 

7. The Berea is absent along the Allegheny River north of 
Tidioute. The sandstone, regarded by Butts as the Berea, north 
of this point, is probably the Venango first oil sand. 

The evidence for the conclusions enumerated above is based 
on paleontology, lithologic character, and on stratigraphic posi- 
tion. It is a well-known fact that clean sandstones are not 
adapted to the preservation of life forms. It occasions no sur- 
prise therefore to find that fossils are very rare in the Berea 
formation. It is true that some have been reported by Orton, 
White, and others; however, for practical stratigraphic pur- 
poses the formation may be considered unfossiliferous. Still 
this very fact proves itself an important factor in the identifica- 
tion of the formation, inasmuch as the sandstones above and 
below, viz., the Shenango sandstone and the Venango first oil 
sands are not unfossiliferous. Hence the paleontologic evi- 
dence, though negative, is considered of importance. 

The lithologie character is rather more valuable. For this 
purpose the Corry phase is most consistent. It is almost always 
a fine to medium-grained sandstone, of very uniform texture, 
and very compact. Also its color is a very persistent charac- 
teristic, being a bluish-grey in the unaltered rock, and almost 
invariably a buff in the weathered rock. The Cussewago 
shales, on the other hand, are very unreliable, inasmuch as they 
may be arenaceous or argillaceous, bluish-grey, drab, olive-grey 
or buff; and are frequently ferruginous and micaceous. In 
addition they may be largely replaced by flagyy sandstones of 
a similarly varying nature. The Cussewago sandstone phase 
when typically developed is unmistakable. It is a coarse, 
loosely-cemented, much discolored sandstone, breaking down 
readily into an incoherent mass. However, its extent is very 
limited, and it seems to be more or less lenticular, which is well 
illustrated by the sections in fig. 1. So far as the writer is 


aware it does not occur west of longitude 81° nor east of longi- 
tude 80° W. 


W. A. Verwiebe—Berea Formation. 


= 
(6 6) 


Stratigraphic position was considered most helpful in’ trac- 
ing the Berea. It is overlain in Ohio and to a certain extent 
in Pennsylvania by a black shale, which is, in addition, rather 
fossiliferous, containing numerous Lingule and Discine. This 
is the Sunbury shale of Ohio, and is equivalent to the lower 
part of the Orangeville shale in Pennsylvania. It gradually 
loses its black color when traced into Pennsylvania, but it 
can always be identified by its characteristic fauna. In addi- 
tion to this the Meadville limestones are excellent horizon 
markers, being very persistent and of a peculiar lithologie 
character. Finally, the Shenango sandstone, if it can be found, 
is of great value in interpreting the section. It is a rather 
coarse, siliceous sandstone, weathering a deep brown .by the 
alteration of iron, scattered abundantly through its mass in the 
form of concretions, secretions and veinlets; it is also quite 
uniform in thickness. 

In this manner the upper part of the Berea or the Corry \as 
traced, it is felt with certainty, as far as the Allegheny River. 
The determination of the base of the formation was not so 
easy. Where the Cussewago sandstone is present in typical 
development the succession and correlation are perfectly clear, 
but where it is missing it is somewhat ditticult to draw the line 
marking the base. The Oussewago shales are very similar to 
the underlying Devonian shales; however, in this region buff 
sandstones occur in the former but are absent in the latter ; 
also the Cussewago shales are quite barren, whereas the Devo- 
nian shales are not, and contain a Spirifer disjunctus fauna 
(Chemung) practically to the top. The section secured at 
Miller Farm is a typical one to illustrate this point. It will be 
seen that the Corry is underlain by 30 feet of buftish sand- 
stone and bluish-grey shale and sandstone, which in turn rests 
upon a 6-inch layer of calcareous sandstone containing fossils. 
This layer is therefore chosen to mark the base of the Berea, 
partly because it is fossiliferous and partly because below it no 
prominent buff layers occur. It-is more than likely that the 
Cussewago sandstone is represented in this section by a part of 
the 30 feet mentioned. In that case it would seem to be but a 
horizontal variation of the lower buff sandstones of the Berea, 
in Pennsylvania, exactly as it has proved to be in Ohio. A 
bit of evidence which may perhaps substantiate this view is 
the fact that the well drillers in this region call the Berea the 
“ Forty-foot.” A typical well drilled (section M in fig. 1) 
less than three miles east of Miller Farm, where section I was 
secured, illustrates in excellent fashion the character of the 
formations underlying the Berea. It appears from this record 
that the drillers would include a good share of the 30-foot 
interval in their “ Forty-foot,” which thus indicates the sandy 


W. A. Verwiebe— Berea Formation. 49 


nature of the material and a difference from the material below 
when encountered by the drill. 

It has been suggested that the sandstone in the section along 
Oil Creek is not the Corry but the Cussewago sandstone.* 
However, the presence of the Cussewago limestone under it in 
typical development and the excellent exposures of the Orange- 
ville shale immediately above it point to the conclusion that it 
is the Corry. 

Farther to the east, as shown in the sections at President and 
Hunter, the Corry becomes still thicker and also rather coarser. 
The superjacent Orangeville also undergoes much the same 
change, becoming more arenaceous and containing more sand- 
stone layers. At the base of the Corry, which may be traced 
for miles along the Allegheny from President northward, the 
Cussewago limestone occurs. It may be seen to good advan- 
tage at Baum (almost on the line between Forest and Venango 
counties) where it is two feet thick and lies about 20 feet 
above the railroad tracks. 

Northward, along the Allegheny River, the Corry sandstone 
has been traced in excellent fashion by Butts; however, from a 
careful study of the stratigraphy of the region the writer is 
unable to accept his correlation with the Venango first oil sand. 
The evidence noted above to indicate that the formation is 
equivalent to Butts’ middle Cuyahoga sandstone is further 
corroborated in a graphic manner in fig. 1. A section was 
taken from Butts’ diagram at a point about midway between 
Tionesta and Hunter (section K in fig. 1). This is inserted 
between sections M (Miller Farm; 9 miles N.W.) and section 
L (Oil City: 12 miles S.W.), first using the nomenclature of 
Butts (section K’—), and again between the same two sections, 
but considering his middle Cuyahoga sandstone as the Berea 
(section K*). The base of the Shenango sandstone is used as 
the datum plane. It will now be seen that the interval between 
the Shenango and the Corry is suddenly increased from 160 
feet (section M) to 360 feet in a distance of less than 10 miles 
if the section K’ is correct. However, if the section be inter- 
preted as at K* the base of the Shenango sandstone will be 
seen to vary but slightly, and the interval between it and the 
Corry will be practically the same as in sections L and M. 

A correct correlation of the Berea sandstone should have a 
far-reaching effect in clarifying the stratigraphy of the whole 
of western Pennsylvania, for it has been used as a key horizon 
not only in the extensive oil and gas fields, but also in the diffi- 
cult northern area underlain mostly by Devonian shales. The 
oil and gas field extends roughly southwest from the district 
studied into West Virginia, Ohio and Kentucky. It has been 


* White, I. C., Pa. 2d Geol. Survey, vol. Q4, p. 98, 1881. 
Am, Jour. Sci.—Fourts Srrizs, Vou. XLII, No. 247.—Juny, 1916. 
4 


W. A. Verwiebe— Berea Formation. 


Fie. 1. 


HO EF 
fit 
OTH 


A 


Dp2i2g dE 
wboyphny 1 


QuUopPspungy obunueyo TI 
27749 obunuey¢ ne 
SIEGAL ab 

hot a AT AY I 


W.A. Verwiebe— Berea Formation. 51 


thoroughly studied and the productive formations described in 
many Federal and State publications. Of course it must be 
granted that many difficulties are encountered by the geolo- 
gist in attempting to unravel the stratigraphy of rocks totally 
concealed. However, the many accurate and detailed well 
records now available enable a person, thoroughly familiar 
with the formations on the outcrop, to make rather satisfactory 
correlations. | 

Of the formations involved in this discussion the following 
in descending order are locally important as oil or gas horizons : 
Shenango sandstone, Berea (Corry), and the Venango Ist and 
2d sands. Of these the first is generally identified with the 
“ Big Injun” of welldrillers. No doubt it frequently includes, 
besides the Shenango sandstone, also the Shenango shale as 
well as some of the overlying Pottsville (where the Mauch 
Chunk is absent) and some of the upper Meadville (as in sec- 
tion M). Beneath this, and with an interval varying from 150 
feet in the northern part of the field to about 350 feet in the 
southwestern part, occurs the Berea sandstone. It carries oil 
and gas in some parts of the Pennsylvania field, but is rather 
unimportant in other parts. For this reason it does not always 
have a prominent place in the well records. However, the 1st 
Venango oil sand, which is widely known as the Hundred-foot 
sand in Armstrong, Butler and Beaver counties, or as the Gantz 
and Fifty-foot sands in Washington and Green counties, is a 
very important source of oil as well as gas; and this furnishes 
a very reliable datum plane when accurately determined. By 
using the latter in addition to the base of the “ Big Injun,” it 
is possible to trace the Berea sandstone with considerable defi- 
niteness, southwest, from its outcrop on the Allegheny into 
southern Pennsylvania, and also into Ohio and West Virginia. 


Explanation of fig. 1.—The sections in fig. 1 (opposite page) were chosen 
to illustrate the character and thickness of the Berea formation along an 
east and west line, from its type locally east to the Allegheny River. Their 
relative location is indicated on the accompanying map (fig. 2). Sections A, 
B, C, and D are taken from Prosser’s report on the Devonian and Mississip- 
pian (Geol. Survey of Ohio, Bull. 15) and may be found in detail on pages 
485, 125, 321, 433 respectively. Sections G and H were taken from White’s 
report on Erie and Crawford counties (Pa, 2d Geol. Survey, vol. Q4, p. 164 
and 182). Sections H, F, 1, L and M were made by the author and the last 
three will be found in greater detail at the end of the paper. Section K is 
taken from Butts’ work as explained in the above pages. 

The top of the Berea (Corry) was used as the base line in platting the sec- 
tions. The symbols used are the conventional ones. The legend in the 
upper left hand corner gives the equivalents of the Roman numerals used. 
For the correlation of these, see page 43. (The scale is 175 feet = 1 inch.) 

A rather interesting feature brought out by this figure is the irregular thick- 
ness of the Berea, which may be construed as evidence of a disconformity at 
the base. Another fact well shown is the lenticular character of the Cusse- 
wago sandstone. 


52 W. A. Verwiebe—Berea Formation. 


If this is done it will soon appear that there is a considerable 
difference in the correlation of the Berea on the one hand and 
the limits of the Pocono (which is nearly universally accepted as 
the basal member of the Mississippian in eastern Pennsylvania) 
as a result of this on the other. Years ago Carll* established 
the equivalence of the Ist Venango oil sand and the Hundred- 
foot or Butler 2d sand. This correlation is still accepted by all 
who have worked on the problem. Therefore, in the stratig- 
raphy of the quadrangles more recently described and pub- 
lished since Butts’ article appeared, his conclusions regarding 


Fie. 2. 


Fic. 2. Map of northeastern Ohio and northwestern Pennsylvania, show- 
ing the location of sections plotted in fig. 1. 


the correlation of the Venango ist oil sand with the Berea 
have largely been accepted. For example, in the Foxburg and 
Clarion quadrangles, which lie immediately south of the region 
discussed in the preceding pages, the Hundred-foot sand is con- 
sidered equivalent to the Berea sandstone,t whereas the sand- 
stone, which in the estimation of the author is the true Berea, 
is called the Sharpsville sandstone.t 

In the Sewickley quadrangle Munn makes the same correla- 
tion, and places the base of the Pocono at the base of the 
Hundred-foot, thus giving it a thickness of approximately 800 


Pa. 2d Geol. Survey, vol. i°, pp. 178 and 272. 
. S. Geol. Survey, Folio No, 178, p. 4, 1911. 


* 
+U 
t U.S. Geol. Survey, Bull. No, 454, p. 18, 1911. 


W. A. Verwiebe—Berea Formation. 53 


feet.* The same is true of the Claysville,t and the Burgetts- 
town and Carnegie quadrangles.t In the Claysville quadran- 
ele the author (M. J. Munn) evidently realizes that there is a 
discrepancy somewhere and tries to explain it in the following 
words: “ The writer does not question the correlation by Butts 
for northern Pennsylvania, but, in tracing the Hundred-foot 
sand southward to Washington county from Clarion, there is 
evidence that the sand is broken by persistent shale beds into a 
group of sandstones embracing the Fifty-foot, the Gantz and 
the Murrysville or Butler Thirty-foot sands, and that the last 
sand is equivalent to the thin oil-bearing sand in southeastern 
Ohio, which is widely known as the Berea sand.Ӥ Thus he 
clearly defines the position of the “ Berea sand” of Ohio, but 
not the Berea sandstone of northern Ohio, for he includes in it 
all the rocks down to the base of the Venango Ist oil sand ; 
and coneludes: “If this is true, the Berea sand of southern 
Ohio is equivalent to only the upper portion of the Berea of 
northern Ohio.” On the basis of the above correlation the 
Pocono is made to include all rocks between the top of the 
Burgoon and the base of the Hundred-foot. 

This tendency to fix the lower limit of the Pocono at the 
base of the Berea or its equivalent is no doubt an excellent one. 
Although the evidence of a disconformity is perhaps not as 
striking or apparent as in the case of the other systems, yet it 
certainly occurs locally. Furthermore, the paleontologic evi- 
dence is sufficiently convincing to indicate a probable break. 
At any rate it is granted by some of our most eminent authori- 
ties| that the base of the Berea certainly forms the most con- 
venient place to draw the line between the Devonian and the 
Mississippian systems. Assuming that this is the case, it will 
immediately be patent to one familiar with the stratigraphy of 
western Pennsylvania that a great deal of obscurity and uncer- 
tainty in correlation will be eliminated. It is admitted by all 
who have worked in the oil fields, that the top of the Devonian 
is difficult to fix. It seems, therefore, that the proper correla- 
tion of the Berea sandstone should serve also to fix the base of 
the Pocono or the Mississippian. This, of course, is not a new 
idea. It simply became apparent that no sharp dividing line 
between the systems could be established by tracing the forma- 
tions from the east, hence they were traced from the west. 

*U.S. Geol. Survey, Folio No. 176, 1911. 

+Ibid., No. 180, 1912. 

tIbid., No. 177: also Bull. No. 456, 1911. 

§ U.S. Geol. Survey, Bull. No. 456, p. 16, 1911. Also Folio No. 180. 

|| Prosser, C. S., The Huron and Cleveland Shales of Northern Ohio, Jour. 
of Geol., vol. xxi, p. 362, 1918. Prosser, C. S., Geol, Survey of Ohio, Bull. 
15, pp. 106 and 512. Girty, G. H., Proc. Wash. Acad. Sci., vol. vii. p. 6, 


1905. Also see ‘‘ Geologic Age of the Bedford Shale of Ohio,” Ann. of N. 
Y. Acad. Sci., vol. xxii, p. 295, ff. 


54 W. A. Verwiebe—Berea Formation. 


Thus L. H. Woolsey* defines the Pocono as extending from 
the top of the Burgoon to the base of the Berea, which is cor- 
rectly identified in this bulletin, and lies about 350 feet below 
the top of the Burgoon. No doubt other investigators had 
this in mind when they included the rocks down to the base of 
the Hundred-foot in the Pocono, since they considered it the 
equivalent of the Berea. 

Summarizing briefly the above, we would then have the fol- 
lowing correlation of oil sands in western Pennsylvania : 


Burgoon = = Big Injun (as explained above) 
Pocono Murrysville or 
Berea = =  { Butler Gas or Ist sand 
Butler Thirty-foot ; 


foot 
Butler 2d. 


: Hundred-foot or Gantz & Fifty- 
Venango lst = 


The literature dealing with the stratigraphy to the north is 
not so voluminous. Perhaps the most important recent work 
published is that of the Warren quadranglet and the section 
along the Allegheny River.t The latter was discussed some- 
what in the preceding pages. It may be added that it appears 
probable that the interval between the 1st Venango oil sand 
(called “ Berea”) and the Shenango sandstone was named 
Cuyahoga simply becanse the Berea was used as the key forma- 
tion and hence with a total disregard of other evidence. This 
interval corresponds to the Riceville in its lower part (from the 
top of the Venango oil sand (Berea) to the base of the Berea 
(middle Cuyahoga sandstone), and would be left without a 
name in Butts’s classification. That part of the section between 
Butts’s middle Cuyahoga sandstone and the base of the She- 
nango sandstone will then become the Cuyahoga formation and 
represent it im toto. The section along the Allegheny River, 
reconstructed in this manner, will then appear as in section K’ 
of fig. 1. 

The Berea can be traced with ease along the Allegheny from 
Venango county north toward Warren; and it will be found 
to disappear from the section about a mile south of Tidioute, 
being absent north of this point because of erosion. This fact 
will necessitate a revision of the geologic section in the Warren 
quadrangle. The succession in the quadrangle is given as 
follows :§ 


*Hcon. Geol. Beaver Quad., U. S. G. S., Bull. No. 286, 1906. 

+ Butts, Chas., U. S. Geol. Survey, Folio No. 172, 1910. 

{ Butts, Chas., Pre-Pennsylvanian Stratigraphy, Rept. Topog. & Geol. 
Surv. Comm. of Pennsylvania, 1906-1908. 

§ U.S. Geol. Survey, Folio No. 172, p. 23, fig. 5, 1910. 


W. A. Verwiebe— Berea Formation. 55 


Pennsylvanian Pottsville 35 ft.-200 ft. 
BP eva iam ear. + ce oi, (UNCONLOTEItY ) 
a hin Ses Cuyahoga 5 ft.-200 ft. 
List Berea sandstone 2 ft. 
i Knapp 80 ft. 
De ean | Conewango 510 ft.-560 ft. 
Devonian Chemung 1120 ft. 


Regarding the Berea the author says: “It has not been seen 
exposed in place in the quadrangle, but loose pieces of sand- 
stone crowded with its fossils have been found at many points 
in such position as to indicate that their parent bed immedi- 
ately overlies the upper member of the Knapp formation, 
whether that be conglomerate or sandstone.”* In tracing the 
Knapp formation to the south, it strikes one immediately as 
not improbable that the Knapp is the northern representative 
of the Venango Ist oil sand. This equivalence is admirably 
substantiated by the fossils contained in them, both being char- 
acterized by a Syringothyris fauna.t It follows from this that 
we should look for the Berea sandstone at a higher strati- 
graphic level. This interval is approximately 150 feet at a 
point a few miles south of Tidioute. North of this point the 
shales underlying the Berea come up from beneath and present 
an eroded surface to the Pottsville. This erosion plane cuts 
across successively older portions of the Riceville shales as it is 
followed northward. The Berea is therefore absent in the 
Warren quadrangle. This conclusion automatically eliminates 
the Cuyahoga formation from the Warren section. The rocks 
which have been included under that heading are stratigraphi- 
eally the equivalent of the Riceville of I. C. White; and, as 
far as we may be guided by our present knowledge, there 
seems no good reason to change this name. 

Doubtless much work still needs to be done, before the exact 
equivalence of the Mississippian and Devonian rocks of the 
Appalachian and Ohio basins can be precisely established ; how- 
ever, it is hoped that the facts set forth in the above discussion 
may prove of some value in attaining this result. 

The sections I, L, and M are considered most important of 
those platted in fig. 1 and are appended in greater detail for 
those readers who desire more precise data. 


* Idem, p. 36. 
+N. Y. S. Mus. Bull. No. 69, p. 995, 1902. 


56 W. A. Verwiebe—Berea Formation. 


Section L, Oil City, Pa 


No. 

4, Shenango shale. Bluish-gray, argillaceous shale, 
interbedded with thin shaly sandstones. ._-- 

3. Shenango sandstone. Massive layers up to 5 feet 
in thickness, fairly coarse grain, whitish 
quartz sand weathering buff. About 9 feet 
from the bottom occur abundant micaceous 
layers. Many layers throughout the mass also 
show bands of white, opaque quartz pebbles, 
Iron is present in considerable proportion. It 
occurs largely as botryoidal filling of hema- 
tite in geodes, some is concretionary and some 
appears in thin bands .--- .--- Aedes nH ka 

2. Meadville, Sharpsville and Orangeville. This in- 
terval is largely covered, except the lower 50 
feet or thereabouts, which consists of rather 
sandy shales, drab in color and micaceous, in- 
terbedded with thin sandstones -__.---.---- 

1. Corry. Sandstone, medium-grained, compact, 
hard, buff in color; the layers are massive, 


some reaching a thickness of 3 feet ; however 


they show great irregularity in this respect, 
the same layer often showing marked differ- 
ence when traced horizontally. Also a more 
or less conchoidal mode of breaking up is 
much in evidence. Some shale occurs toward 
the top eres Nhe ee EE ee eee 


Thick- 
ness 
Feet 


12 


33 


16 


Total 
Feet 


216 


16 


This section was secured at Oil City, Pa. It begins in the 
old quarry of the Oil Well Supply Co. and follows down the 
adjacent ravine to the Pennsylvania Railroad tracks. 
excellent exposures of the Corry occur along the tracks and it 
may be easily traced to the north in the numerous rock cuts of 


the railroad. 
Section I, Miller Farm, Pa. 


No. 

10. Meadville and Sharpsville. Sandstone, flaggy, 
bluish-gray and brownish due to weathering; 
some sandy shale is interbedded _._._.----- 

9. Orangeville. Shale, soft, argillaceous, drab and 
blue; thin sandy layers occur at intervals ; 
the surface of the whole is much stained by 
incrustations of iron compounds. Fossils may 
be found at various horizons and in consider- 
able abundance lo. 222-2 eee eee 


Thick- 
ness 
Feet 


45 


50 


Some 


Total 
Feet 


2054 


160} 


Or 


is a rather high rock cut. 


W. A. Verwiebe—Berea Formation. 


Sandstones, mostly thin and bluish ; some of the 
lower layers are buff in color and rather hard ; 
interbedded are typical Orangeville shales -- 


. Corry. Sandstone, mostly massive buff layers 


up to 24 feet in thickness, though some are 
ne Lethe en pe ee a tel aa 
Cussewago limestone. Very typical, a blue 
siliceous lime-rock which also carries much 
iron. On weathering the carbonate of lime 
is dissolved, leaving behind a crust of deeply 
stained ferruginous sand. This separates in 
more or less conchoidal layers, thus leaving 
the unaltered rock with rounded edges - -_-- 


. Oussewago shale (and Cussewago sandstone ?). 


Sandstone and shale ; thesandstones resemble 
the Corry very much; some layers are quite 
massive (1 foot thick), buff in color and hard ; 
the other sandstones and the shales are bluish- 


ay. lees UD eye 2 PP ese Gls - ie 


. Shale, bluish, some sandy layers......_._...-- 
. Sandstone ; in this interval there are again some 


hard buff layers interbedded with blue sand- 
Stomesrand shales ses. bee ooo oll 


. Liceville. Sandstone, rather limey with fossils 
. Shale and thin sandstones to the level of the 


R.R. tracks ; bluish-gray and mostly arena- 
COIS ib ris es Ste el ealas eet aoe ae 


57 
Thick- 

ness Total 
Feet Feet 
20 110} 
28 904 
18 624 
14 604 
10 464 
6 364 
04 304 
30 30 


Less than a quarter of a mile south of the station called 
Miller Farm on the Oil City branch of the Pennsylvania R.R. 


Here the above section was made. 


It is an excellent one to show the character of the Berea for- 
mation along Oil Creek. The Corry sandstone can be followed 
without much difficulty along the R.R. tracks from here south 
to Oil City, at which point it can be conveniently connected up 


with the Allegheny River section. 
Section M, Shamberg Weil Record. 

No. Driller’s terms Geological equivalent 

15. Bluff rock Connoquenessing 

14. Slate and shale Pottsville & Shenango 
shale 

13. Mountain sand (90 ft.) Shenango sandstone 

12. Meadville upper sand- 
stone 

11 


. Slate ana shale Meadville, Sharpsv. & 
Orangeville 


Thick- 

ness Total 

Feet Feet 
60 992 
140 932 
30 798 
60 

100 402 


58 W. A. Verwiebe—Berea Formation. 


Thick- 
ness Total 
No. Driller’s terms Geological equivalent Feet Feet 
10. Blue Monday (40-foot) Corry sandstone 40 602 
9. Shale blue Riceville 100 562 
8. Shale red 100 462 

7. First sand Top of Venango oil 

group 50 362 
6. Slate and shale . 100 812 
5. Salt sand Venango 2d oilsand 30 212 
4. Slate and shells 90 182 
3. Gray sand Stray 3d 12 92 
2. Slate and shells 40 80 
1. Third sand Base of Venango group 40 40 


This record was furnished by Mr. L. N. Stevenson, a well 
driller residing in Petroleum Center, Pa. It was drilled by 
him in July, 1915, for Mr. Robert Foggans on the Clarke farm 
near Shamberg (about 3 miles east of Miller Farm), Venango 
Co., Pa. The correlations indicated in the second column are 
based on a careful study of the rocks on the outcrop in the sur- 
rounding region. It was on this basis that the “mountain 
sand” was subdivided as indicated in Nos. 12 and 13. 


Section at President, Pa. 


‘Thick- 
ness Total 
No. Feet Feet 
4. Berea sandstone. Coarse sandstone, consisting of 
rather loosely-cemented white quartz grains 
which are, however, much discolored, giving 
the rock a spotty appearance. Pebbles aver- 
aging the size of a pea occur, more or less 
abundantly scattered through the mass ---- - 12 46 
3. Sandstone, more compact, fine-grained, massive, 
| 0 07 es a 2 ce eA Rice rh ad tate) Malet > eed 1 34 
2. Shale, drab in color, arenaceous...-.-.-.------ 1 19 
I.) Sandstone; sameras tn No. 3, 222 22eee 22 2 eee 1S 18 


This section was added because it shows the character of the 
Berea along the Allegheny River and some distance east of 
Oil City. It was found’ just south of the R.R. station of Pres- 
ident on the north side of the river. The striking thing about 
it is the lithologie character of the upper part. Zones No. 1 
and 3 are very typical. Unfortunately, the base is covered, so 
that the presence of the Cussewago limestone could not be 
determined. There is little doubt that it exists here, however, 
since it may be found typically developed a few miles north of 
this locality, where the dip of the rocks brings the base above 
the level of the R.R. tracks. Another section was made at 
Hunter (about 3 miles north). Here the upper coarse part of 
the Berea was found to have a thickness of 22 feet. 


Ohio State University, Columbus, Ohio. 


Ford and Bradley—On Hydvrozincite. 59 


Art. VII.—On Hydrozincite ; by W. E. Forp and W. A. 
BRaAvDtey. 


Hyprozrnxcite is a basic carbonate of zine that has long been 
recognized as a distinct mineral species. It is a secondary 
mineral that commonly occurs as an incrustation on other zine 
minerals. Its structure is usually massive to fibrous or often 
earthly to compact. Frequently it occurs as botryoidal crusts 
with a concentric formation. As far as is known, it has never 
been observed in crystals until its recent discovery at Good 
Springs, Lincoln County, Nevada. Since no determinations of 
the erystal or optical characters of the mineral have ever been 
made and since the varying results of the recorded chemical 
analyses have left its composition in doubt, it was thought 
worth while to undertake an investigation of this crystalline 
material. 

The specimens from Good Springs are composed chiefly ot 
a massive, earthy material of a light brown color which is 
apparently mostly smithsonite. Occasional small crystalline 
masses of calamine and calcite are to be observed. The hydro- 
zineite is found lining the cracks and irregular openings in the 
massive material. It occurs as delicate incrustations of very 
small erystals grouped in radiating masses. Commonly under- 
neath the crystals is found a thin layer of the same mineral in 
a mass of interlacing crystalline needles. 

When the crystals are examined under the microscope it is 
seen that they are exceedingly thin with a tabular, lath-shaped 
form. They are usually sharply pointed at their free ends, 
but the terminations were too irregular to permit of the 
measurement of any angles. They show a pearly luster with 
frequently an iridescent play of color on their surfaces. With 
crossed nicols they always showed an extinction parallel to 
their elongation. This was found to be the direction of the 
slower ray while the direction acruss the crystals was that of 
the faster ray. With convergent light they proved to be 
biaxial in character and to have apparently their tabular 
development parallel to the optical axial plane. Obscure dark 
interference curves were shown which moved rapidly from the 
field when the sections were turned from the position of ex- 
tinction. Their character was such as would be expected with 
sections that were parallel to an axial plane. These curves 
moved out of the field toward the vibration direction a. If the 
orientation of the sections was as suggested, this direction is, 
therefore, that of the acute bisectrix and the mineral is optically 
negative. The two extreme indices of refraction were deter- 


60 Ford and Bradley—On Lydrozincite. 


mined by the immersion of the crystals in high refracting oils. 
The results were, a = 1°650 and y = 1°740; both, +°005. In 
spite of the high birefringence, which equals about ‘09, the 
interference colors shown are usually gray or yellow of the first 
order, although occasionally second order colors were seen. 
This is due of course to the extreme thinness of the crystal 
lates. 

In studying the optical nature of minerals similar to hydro- 
zincite it was found that there is an almost complete agree- 
ment between the characters given above with those of auri- 
chalcite as determined by Buttgenbach.* His observations, 
which have been confirmed by the present authors, were made 
on the fine material found recently at the Kelly mine, Mag- 
dalena, New Mexico. He describes this material as follows : 
“The aurichalcite is in small elongated plates with a pearly 
luster. Between crossed nicols the very thin plates give 
various colors which do not go higher than the yellow of the 
second order. The extinction is parallel to the elongation of 
the erystals with this direction coinciding with the c vibration 
direction. The plates, examined in converging light, are 
parallel to the plane of the optical axes. By the movement, 
however, of the dark curves which leave the center of the 
field when, after having formed the black cross, the table of 
the microscope is turned a little, it is easily determined that 
the direction of the acute bisectrix coincides with the direc- 
tion a. This proves that the sign of the mineral is negative. 
The indices of refraction of aurichalcite are given by Lacroixt 
as approximately between 1°67 and 1°755.” 

From the above it is readily seen that as far as the crystal 
and optical characters are concerned the two minerals are prac- 
tically identical. The refractive indices of aurichalcite are a 
little higher, but some variation here would have been ex- 
pected because of the presence of copper in that mineral. 

It would naturally be expected, therefore, that the formula 
of hydrozincite should be analogous to that of aurichalcite. 
The latter mineral was analyzed by Penfieldt on excellent 
material and with results that left no doubt but that its formula 
should be 2(Zn,Cu)CO,.3(Zn,Cu)(OH),. Hydrozincite, there- 
fore, if the agreement between the physical properties as given 
above is significant, should have the same formula, but without 
the presence, of copper, or 2ZnO0O,.3Zn(OH),. If that is true 
the theroretical composition of hydrozincite would be that 
given below. 

* Ann. Soc. geol. de Belgique, xl, B119, 1913. 


+ Min. de la France, iii, 739. 
+ This Journal (8), xli, 106, 1891. 


Ford and Bradley—On LHydrozineite. 61 


Theory for 2ZnCO3.3Zn(OH)p. 


Zsa) CGI BO eae oe OO am al! 
COO Mere ec et se aint L608 
ED Os, seen es Aer ty Ocak 1G? 83 

100-00 


About thirty analyses of hydrozincite have been published 
which have shown considerable variation, due largely doubtless 
to the unsatisfactory character of the material examined. 
Twenty-seven analyses were collected, more than half of which 
are given in the fifth and sixth editions of Dana’s System of 
Mineralogy. These included the new analyses given below 
together with all published analyses except such as showed 
considerable amounts of unusual constituents. No other at- 
tempt was made to consider them critically. The average of 
these analyses is as follows: 


Average of 27 hydrozincite analyses. 


TiN ONES TS Te hy baie 9 Reena abet teers Heyl f 
EOE WME RR et, 15°19 
EO) Qiasitteuy | i inc: Merton 

99°95 


This result does not agree very closely with our assumed 
composition, but considering all facts is probably close enough 
to lend support to that formula. In the great majority of 
cases the material analyzed was amorphous in its structure. 
Further, one of the constituents was unquestionably commonly 
determined by the method of difference. It will be noted 
that the average percentage of the most important and prob- 
ably most accurately determined oxide, ZnO, is only about 0-70 
per cent too low. 

It was felt that new analyses of the mineral, particularly 
upon the erystallized material, would be of importance. Un- 
fortunately the amount of material available was very limited, 
which necessitated making the analyses on small amounts, 
and the use of analytical methods which were not the most 
desirable. Two different analyses were made on the mineral 
from Good Springs, one on carefully selected material consist- 
ing only of crystal fragments and the other on the crystalline 
material that lay beneath the coating of crystals and which it 
was felt might not be quite as pure. No evidence was found, 
however, to show that there was any impurity present in the 
latter material and as a larger amount of it was available for 
analysis it is thought probable that its analysis is more nearly 
correct than that of the crystals, In order to experiment with 


62 Ford and Bradley—On Hydrozincite. 


the analytical methods used, a third analysis was made on 
massive material in the Brush Mineral Collection from Mal- 
fidano, Sardinia. 

The analytical method adopted was extremely simple. The 
water was determined directly by heating the mineral in a 
closed glass tube, collecting the water in the upper part of the 
tube and weighing it, making the proper corrections for the 
presence of CO, in the tube. The zine oxide was determined 
by igniting the mineral, driving off all the water and carbon 
dioxide and weighing the residue. This method was tested by 
dissolving the residue and redetermining the amount of the 
zine oxide after the precipitation as sulphide from a formic 
acid solution. The two results agreed. Careful tests were 
made for the presence of other possible elements but with 
negative results. The carbon dioxide had to be determined by 
difference. The analyses by Bradley follow : 


Good Springs, Nevada. 


Crystalline Theory for 
Crystals material 2ZnCO;.8Zn(OH). Sardinia 
LO). Sn ee OS 74-67% 74°14 iui, 
co, SS hae [15°78] [16°41] 16°03 [15:47] 
leh Ces aes Sane 8°64 8°92 9°83 10°81 
100°00 100°00 100-00 100°00 


* Average of two closely agreeing determinations. 


These results do not agree as closely with the assumed 
formula as could be desired. It is to be regretted that more 
material was not available in order that the portions used 
could have been larger and direct determinations made of all 
constituents. Still, no other formula could be proposed which 
would agree more closely with the analytical results except one 
that would be very complicated and improbable. Considering, 
therefore, the unfavorable conditions of the analysis and the 
very strong argument provided. by the close physical resem- 
blance between aurichalcite and hydrozincite, it is felt that the 
formula given must be correct. 

The conclusion of the investigation, therefore, is that 
aurichaleite and hydrozincite are practically one species, only 
distinguished from each other by the introduction into the 
former of some copper oxide which replaces an equivalent 
amount of zine oxide. 


Mineralogical Laboratory of the Sheffield 
Scientific School of Yale University, 
New Haven, Conn., March 22, 1916. 


C. Barus— Rotation of Interference Fringes. 63 


Arr. VIIL.—Rotation of Interference Fringes in Case of 
Non-reversed and of Reversed Spectra; by C. Barus.* 


1. Won-reversed spectra—When the slit is oblique, it 
effectively reproduces the wide slit, locally, and therefore 
does not destroy the colored fringes. At every elevation 
in the field the slit is necessarily linear though not verti- 
eal. In figure 1 let the heavy lines, H, denote the colored 
fringes for a fine vertical slit and white light, showing 
nearly the same distance apart, throughout. Let the light 
lines, Z, denote the fringes for a wide vertical slit and 
homogeneous light, A. These fringes are due to the sue- 
cessively increased or decreased obliquity of the rays, in the 
horizontal plane. Now let ach be the image of the oblique slit 
in homogeneous light. It is thus merely an oblique strip, cut 
from the area of light lines or striations, as it were, and con- 
sists of an alternation of black and bright dot-like vertical 
elements, in correspondence with the original striated field. 
We may suppose ad to have rotated around ¢, so that the ver- 
tical through c is its position on the colored field (white light 
and fine vertical slit). 

A color, \’ (near the one 2), corresponding to the field of the 
lines, Z, in case of a wide slit and homogeneous light, 2’, 
will supply nearly the same grid, so far as the distance apart 
of fringes is concerned. But the grid is displaced laterally, 
in consequence of the different angle of diffraction, 6. This 
is shown by the dotted lines D, in figure 1, the effect being as 
if the slit had been displaced laterally. If the wide slit for 
homogeneous light \’ is now narrowed and inclined as before, 
an alternation of bright and dark elements will appear 
in the image of the slit, ed, corresponding to 2X’. If we 
suppose that for white light and the fine vertical slit, the 
position of the fringe (A’) was at ¢c’, we may again regard c’ as 
an axis of rotation. To find the fringes such as 7, it is then 
only necessary to connect corresponding black elements on ad 
and ed. Their inclination is thus opposite to ab and ed, or 
they have rotated in a direction opposite to that of the slit. 
If, for, instance, the slit image ad or ed is gradually moved 
back to the vertical, the points g and / will move with great 
rapidity and in both directions toward infinity and the 
fringes #f and ff become vertical lines through ¢ and ¢’, 
respectively. 

* Work done on a grant from the Carnegie Institution of Washington, 
D.C. See earlier papers in this Journal, xl, pp. 486-498, 1915; xli, pp. 
414-434, 1916. The phenomena of §1 are most easily produced with two 


transmitting gratings, parallel and having their ruled faces towards each 
other, Science, xlii, p. 841, 1915. 


64 C. Barus—Rotation of Interference Fringes. 


It is interesting to inquire into the frequency of fringes, n, 
when the angle of diffraction, @, is changed. From the original 
equation e = nd/(1 — cos @), since dA/d@ = D cos 8, the rate of 
change 


dn e 1 é 


dd Di+cos6 D+ / Dr’ 


where e is the distance apart of the rulings and D the grating 
space. Since cos @ varies but slowly with @ and is additionally 


augmented by 1, dn/d@ is nearly constant and about equal to 
e/2D. 

The fringes and slit images are thus given by the two sides 
of the parallelogram cge’h, tor the two colors A and X’. The 
diagonal ce’ represents d@; the diagonal g/ has no signification. 
On the other hand the normal distance apart D’ and D” of 
# and ff and ab and ed are both important. 

The equations useful elsewhere* have very little immediate 
value here, because the experimental variables, figure 1, are B, 
the distance between two consecutive colored fringes, and 
b” and 0’, the corresponding distance between the fringes in 
ease of homogeneous light in each case d, d’ and the angle y’, 
which indicates the inclination of the slit. Thus Bd’b” are 
given by computation and y’ is specified at pleasure. Ob- 


* This Journal, xli, p. 428, 1916. 


in Case of Non-reversed and of Reversed Spectra. 65 


viously, if parallelograms are to be obtained in figure 1, b’=b’, 
appreciably. This is the case in experiment. Hence if we 
evaluate the height in the triangle cgc’ for each angle, it fol- 
lows that 


Pilg tan 7’ 
sin x = 
—  V(B/b'— 1) + tan’y’ 


If B=0’, x =90° for all values of vy’; 1. e., the fringes remain 
vertical. If B is equal to 2b’, x’ =y’, the fringes and slit are 
symmetrically equiangular with the longitudinal axis of the 
spectrum. ‘This is nearly the case in figure 1 and frequently 
occurs in experiment. If 0’ differs from }”, the fringes would 
not be straight. This also occurs, particularly when the thick- 
ness é of the air film is very small. 

2. Treatment of reversed spectra.—To obtain an insight into 
the cause of the interferometer fringes as obtained with 
reversed spectra and two gratings, it is convenient to represent 
both gratings, figure 2, GG@ and G@’G’ as transmitting, and 
suppose both diffracted beams, 2D’ and JD”, subsequently 
combined in view of the principal plane, PP, of an objective 
oralens. It is clear that this simplified device can apply only 
for homogeneous light. In the case of white light, the opaque 
mirrors, J/ and JV, of the interferometer (1. c.) return a diver- 
gent colored beam or spectrum, so that only for a single color 
can the second incidence be the same as the first. Again, if 
the constants of the two gratings are different, it is the function 
of these mirrors to change the incidence at the second grat- 
ing, correspondingly, so that for homogeneous light the rays 
issue in parallel. Finally, no reference to the lateral displace- 
ments, OG” and OG’, of rays need be made because (as shown 
in the next paragraph) this is eliminated by the theory of dif- 
fraction. 

The motion of the opaque mirrors Jf and JV (above), on a 
micrometer merely shortens the air path GG’ or GG" in its 
own direction and consequently the same fringe reappears for 
a displacement of half a wave length, as in all interferometers. 

The case of a single grating, moreover, is given if the planes 
of the grating GG and G’G” and their lines are rigorously 
parallel, the planes OG’ and G”O being coplanar. To repre- 
sent the interferences of the two independent gratings and with 
homogeneous light for the case of obliyue incidence, it is 
necessary to suppose the grating G’G” cut in two halves at O, 
parallel to the rulings, and to displace the parts OG’ or OG” 
separately, normally to themselves as at O,G@,”. The figure 


Am. Jour, Sct.—FourtH Serizs, Vou, XLII, No. 247.—Juty, 1916, 
5 


66 C. Barus—Rotation of Interference Fringes 


shows that for normal incidence, 7 = 0, the displacement per 
fringe de would be 


or the fringes are similar to the coarse set described elsewhere.* 

If the rays impinge at an angle 7, figure 2, they will be 
parallel after the two diffractions are completed ; for it is 
obvious that the corresponding angles of incidence ‘and diffrac- 
tion are merely exchanged at the two gratings. Hence the 
homogeneous rays J’, impinging at an angle 2, leave the grat- 
ing at » D,’ and DP,” in parallel, at an angle of diffraction OF mand 
the rays unite into a bright image of the slit. If however 
OG’ be displaced a distance, e, to 0G", ”, parallel to itself, as in 
figure 2, the paths intercepted are 


€ é : 
——- and ——— cos(@— 2) 
cost cos? 


and the path difference per fringe therefore 


A cost 


waa — cos (6 — 7)’ 


which reduces to the preceding equation if 7=0. Hence a 
series of interference fringes of the color ) must appear in the 
principal focus of the telescope or lens on either side of 7 = 0. 
The theory of diffraction again annuls the apparent path dif- 
ference between GG and G’G". 

As to the number of fringes, n, between any two angles of 
incidence 2 and 2’, it appears that » vanishes with ¢, or the 
fringes become infinitely large. 

If the grating G’' is rotated over an angle ¢, fig. 2, and 

= bd, where d is half the virtual distance apart at the grating 
G’ of the rays impinging upon it, the rotation per fringe i is 
r COS 7 
te b 1 —cos(6—%)° 


Again, 7 (above) passes through zero as ¢ or b decreases from 
positive to negative values. Variable J implies a wedge effect 
superposed on the interferences. 

It is this passage of m through zero that is accompanied by 
the rotation of the fringes, as observed. 

In case of two independent g gratings GG and G’G” (G’G" to 
be treated as consisting of two “identical halves 0G" and G0), 
nearly in parallel, fringes may be modified by rotating G’G” 
around the three cardinal axes passing through the point of 
symmetry 0. The rotations of G’G” around an axis O normal 


* Phys. Review, vii, pp. 79-86, 1916. 


in Case of Non-reversed and of Reversed Spectra. 67 


to the diagram is equivalent to the fore and aft motion of 
G’@" when mirrors are used.* The rotation around OZ’ in 
the diagram and normal to the face of the grating, requires 
adjustment at the mirrors around a horizontal axis, to bring 
the spectra again into coincidence. ‘This is equivalent to rota- 
tion around @" 0G’. Both produce enlargement and rotation 
of fringes as already explained. 

Let the grating G’G” be rotated over an angle ¢ into the 
position g’g”. Thenit may be shown that only so long as ¢ is 
very small are the rays appreciably parallel on emerging ; but 
this is usually the case, as ¢ = 0 is aimed at, and fringes are 
thus seen in the principal focus. 

The next question at issue is the rotation of fringes with 
fore and aft motion, or rotation around O normal to the dia- 
gram. Whene, the virtual distance apart, is zero, since n a e/X, 
the fringes are infinitely large horizontally. The collimator, 
however, furnishes a pencil of rays which are parallel in a hori- 
zontal plane, only. They are not collimated or parallel in the 
vertical plane (parallel to the length of the slit). Hence when 
the fringes are reduced to a single one of infinite size horizon- 
tally, this is not the case vertically, i. e. from top to bottom of 
the spectrum the path difference still regularly varies. The 
adjustment around an axis through O, G’OG’, normal to the 
rulings, is still outstanding. 

Finally, the rotation around an axis parallel to 77 in figure 
2 is to be considered. This has already been given in terms of 
colored fringes (white light), but it occurs here for homogene- 
ous light, in which case the above explanation is not applica- 
ble. Seen in the principal focal plane with telescope and wide 
slit, the non-reversed spectra require careful adjustment of 
longitudinal and tranverse axes; otherwise they vanish. Noth- 
ing will rotate them. 

Figure 2 shows that if @’G@” is rotated abont Z7, the 
effect is merely to destroy the fringes, since the coincidence of 
the longitudinal axes of the spectra is here destroyed. No 
effect is produced so far as path difference is concerned. To 
restore the fringes therefore, either of the opaque mirrors, JZ 
or VV of the apparatus, must be rotated on a horizontal axis, 
until the two spectra are again longitudinally superposed. It 
is this motion that modifies the path difference of rays in a 
vertical plane. In other words, when the fringes correspond- 
ing to any virtual distance apart, ¢ = d¢ of the two halves of 
the grating G’G", have been installed, the rays as a whole may 

still be rotated at pleasure, around a horizontal axis. In this 
way a change in the number of fringes intersected by a vertical 
line through the spectrum, is produced. The number of inter- 


*This Journal, xli, p. 419, 1916. See fig. 12. 


68 C. Barus—Rotation of Interference Fringes 


sections will depend on the obliquity of the rays (axes of verti- 

cal pencils), and will be a minimum when the center of the 

field of view corresponds to an axis of rays, normal to the grat- 

ing G’G@". Inother words, the vertical maximum occurs under - 
conditions of complete symmetry of rays in the vertical plane. 

If therefore ¢, or the virtual distance apart of the half gratings, 

GO and OG’, is also zero, the field will show the same 

illumination throughout. 

Therefore, to completely represent the behavior of fringes, 
it will be sufficient and necessary to consider that either grat- 
ing, G’G” for instance, is capable of rotation, not only around 
a vertical axis through QO, but also through a horizontal axis 
through O parallel to the grating. The last case has been 
directly tested. Buta rotation around these two axes is equiva- 
lent to a rotation around a single oblique axis and the fringes 
will therefore in general be arranged obliquely and parallel to 
the oblique axis. 

Thus if ¢, and ¢, is the angle of rotation of the grating 
(always to be small) around a vertical and a horizontal axis 
respectively, and if w' is the angle of the interference fringes 
with the horizontal edge or axis of the spectrum, 


py 


tan a =’ = 
h 


Son that al oO, == (0, 7 = Oe I sop ake) 0 eon ien 
words, for a rotation of grating around a vertical axis (parallel 
to slit) the fringes of maximum size will be horizontal, because 
the adjustment around the horizontal axis remains outstanding 
and the residual fringes (large or small) are therefore parallel 
to it. For a rotation of grating around a horizontal axis, the 
fringes of maximum size will be vertical, for the vertical adjust- 
ment is left incomplete. When both adjustments are made 
a single fringe fills the whole infinite field, and this result fol- 
lows automatically if but a single grating is used to produce 
the fringes, as in the original method (1. ¢.). 

3. Case of Reflecting Gratings. Homogeneous Light.—The 
results exhibited in figure 2 for transmitting gratings are shown 
in figures 3 and 4 for the combination of one transmitting 
grating G and one reflecting grating @’, the adjustment used 
in the preceding paper (I. ¢.) and for which the path lengths 
of rays were computed without allowances. (Cf. figures 10, 11, 
§8). The path differences obtained were inadmissible. It is 
now necessary to completely modify the demonstration. 

In figure 3 the rays are shown for the case of symmetry of 
all parts, gratings at G and G’ vertical and parallel, opaque 
mirrors at JZ, and JV,, telescope or lens at Z. The incident 
ray Z at normal incidence is diffracted and reflected into 


in Case of Non-reversed and of Reversed Spectra. 69 


Y, X, 7, and Y’, X’, 7, respectively; the incident ray Pes, 
an angle of incidence di, into Y,, X,, etc. and Y,’, X,’, ete., 
respectively ; both at a mean angle of diffraction @@ (nearly) to 
the right, corresponding to d. 

The angles of diffraction (di = 0) are @,, and @,, the double 
angles of reflection therefore 6 = 6, — @,, on both sides, the 


Fie. 4. 


double angles of the grating G’ with the mirrors J/, and J, 
symmetrically, o = 0, + @, 

The normal from the point of incidence at G, and at G’, V 
and 7, makes angles 6/2 with Y and_X, respectively, on both 
sides. 

The method of treatment will consist in reflecting G’ in J, 
and JV,, producing the planes G,’ and G,’ (virtual images), and 
then rotating JZ, and G,' 180° around /7’ (axis of symmetry) 
into coincidence with JV, and G,’ (interferences). Thus the 
rays prolonged into a and @ coincide with the rays prolonged 
into a’ and 6’ and the (virtual) diffracted rays 7’, 7’, become 
T/ and T,/. The ray on the left prolonged into e, is diffracted 
into 7,. Then the interferences will all be given by discuss- 
ing the left half of this diagram, which is amplified in figure 4. 

Since the distance GG’, figure 3, is very large, the rays are 
nearly parallel, and hence the are oy with its center at G, 


70 C. Barus—Lotation of Interference Fringes 


is practically a plane wavefront, perpendicular to the rays in 
0’, 8’, y, and the diffracted rays 77’, Py. T,’, avealso practically 
parallel. Hence in case of symmetry and coincidence of JZ_V,, 
the points 6’, B’y, 8',a’e, are in the same phase (diffraction). In 
other words, there is no path difference between Y + X and 
Y’ + X’, whether the angle of incidence is zero or not (Y,+X, 
and ¥,’ + X’). The whole field in the telescope must there- 
fore show the same illumination (homogeneous light, wide slit) 
between the maximum brightness and complete darkness. 
Interference fringes can only occur when the opaque mirror 
JM, is displaced parallel to itself, out of the symmetrical posi- 
tion. If JZ, and J, aré symmetrical, as in figure 3, the dis- 
placement of G’, fore and aft, parallel to itself, is withomt 
influence. 

This reduces the whole discussion to the normal displace- 
ments of the system G’, I/,, WV,, given in figure 4. Let the 
mirror JZ, be displaced over a normal distance, ¢,, to the posi- 
tion M,, V, remaining in place. Then the image of G’ will 
be at G,’, at a perpendicular distance ¢ from its original position 
G,’.. The path difference so introduced, since 6’, 8’, y, then 6’, 
a’, e’, finally e’, n, &, are in the same phase, is 


2e,, cos 6/2 


5 being the double angle of reflection, and the displacement per 
fringe will be 

vi r 

~ 2¢0s 8/2 


which is very nearly equal to X/2, as in most interferometers, 
remembering that ¢ and ée refer to the displacement of the 
virtual image of the grating G’ and e@, to JZ, Two interfer- 
ing rays will be coincident. 

If the mirror J/, is further displaced normally to JZ, the 
image of G’ will be at G,’ (the total displacement being ¢’), 
and the rays in e and yp (at a distance c apart on the grating 
G,’) will correspond with the path differences 


2¢,,' cos 6/2 
while per fringe 6¢ = 6ée’. 

In the next place, ¢ and é6¢ may be reduced to the corre- 
sponding displacements ¢, and de,, of the mirror JZ. From 
figure 3 

sin o/2 


6, = @ = 
sino 


m 


= gesec 0/2. 


If G’ is displaced parallel to itself, 6e will not be modified, 
since each virtual image G,’, G,’ moves in parallel in the same 


in Case of Non-reversed and of Reversed Spectra. 71 


direction, by the same amount. If then the grating G,/ is 
rotated around an axis at G’, perpendicular to the diagram, 
fig. 3, over a small angle, ¢, the result (apart from the super- 
posed rotational effect) is equivalent to a displacement of the 
mirrors JZ, and JV, in opposite directions, producing a virtual 
distance apart e and the corresponding interference fri inges. 
In other words, the rotational effects may be cap ained here in 
the same way, as in the preceding paragraph. 

The angle 2d@ within which the interference rays Ee, per 
fringe, is subtended by de and is very small, scarcely ;,55 of 
the DD. D, distance of sodium light. Hence all pencils consist 
of practically parallel rays. 

Another result is the angular size of fringes : i. e., if. ¢,, and A 
are given 

dO, r 
~ dn” esind/2 


Thus they become infinitely large when e passes through zero. 
The pee size is independent of the distance between the 
gratings. It ought, therefore, to be easy to obtain large inter- 
ference fi inges, which is not the case. The reason lies in this, 
that the two opaque mirroys are net quite symmetrical, so that 
in fig. 3, on rotation of JZ, 180° on GG", the trace of I, 
crosses yy, at an angle (wedge effect). It d0@/dn = Stk DCO ee 
the distance apart of the sodium lines, and D,=173 < 10-® em., 
e=1'8cm.,1.e., path lengths on the two ‘sides would differ 
by about 2 centimeters. 

4. Nonsymmetrical positions. Fore and aft motion.—it 
remains to account for the marked effect produced on displac- 
ing the grating G’, in a direction nearly normal to itself. If 
the displacement is symmetrical, or even if the grating and 
mirrors are reciprocally non-symmetrical, the former at an 
angle @ to the transverse line of symmetry gg’, figure 5, no 
effect results from the displacement of G’. The virtual i images 
G,» and G, are parallel and the different rays therefore also 
parallel. 

If, however, this compensation does not oceur, if the grating 
G’, the mirrors VV, and J/, make angles ¢, o/2, 7/2, respec- 
tively, with the transverse line of symmetry gg’, the fore and 
aft motion of G’ is more effective as a—@ (a angle between 
the mirrors) is greater. The diffracted rays are then no longer 
parallel, but make angles of incidence at the second grating, 
0,’ for the NV, side and "6, for the M, side, and of diffraction 
i and 7 , respectively, as shown in fioure at Landay, slic 
following relations between the angles are apparent 


¢=6,+90,—¢ T=60,4+060,+¢ 


72 C. Barus—Rotation of Interference Fringes 


If at the first grating @,= 0’, 
2a = tr—o = 8, — 8G, + 2¢. 
The images are at an angle 8, where 
B=2(a—¢)=6, — 86, 


If G’G’ is displaced to G’G’ over a normal distance e or 
e/cos d along the line of symmetry @7Z, the virtual images 


Fie. 5. 


Gand G, will be displaced to G’,, and G’, over the same 
normal distance ¢. This is obvious, since the quadrilaterals ab 
and ab’ are rhombuses by the law of reflection, and have the 
perpendicular distance e between the (equal) sides all identical. 
If D, is the grating space of G’, 
sin 6, + sing = A/D, (1) 
sin 6,'+ sind’= r/D, 
or if ¢ and 7 are very nearly equal and both small, as in the 
experiment, 


cos 6, d6 = — cos tdi. (2) 
Again in case of a displacement ¢ of G’, the paths are short- 
ened at G,, by 
€ 
cos 6, 


in Case of Non-reversed and of Reversed Spectra. 73 


at @, by (3) 


cos6,’ 


2 


resulting in the path difference AP, the difference between 
these expressions. 

Since 6, and @,’ are nearly the same, AP may be simplified. 
One may notice in passing that in equation (1) and (3) the 
negative sign of dz/d@ and the positive sign in cos(@ + 7) 
belong together. 

Differentiating the functions (8) with respect to @, putting 
dé = 0, — 0,/ = 2(a— $), and reducing the displacement 6¢ 
per fringe, apart from sign, is 


dX cos 76 


oie 2(a — p) sind (4) 


Thus if 
op els ems a id —— (Nae iO == 200 
de = ‘0044 em. 


The effectiveness of the fore and aft motion, according to 
this equation, is evidence of a considerable angle of non- 
symmetry, a—¢. This is not improbable, as my apparatus 
was an improvised construction, lacking mechanical refinement. 
Further the wedge effect due to a would be superimposed on 
the interferences and hence these could not be increased in 
size above a certain maximum, This is also quite in accord 
> with observation. 

Iia=¢, B=0, 0,=@,';1.e., the virtual images G,, and G, 
and the diffracted rays are parallel and 6¢—o. In other 
words, the fore and aft motion has no effect. If a=0, 
B= 2¢; orif ¢6=—0, B= 2a. In eitlier cases de is finite, and 
fore and aft motion is effective. If the mirrors and grating 
were rotated in counter direction so that ¢ is negative, de will 
depend on a + @, and the fore and aft effect be correspondingly 
marked. In general, moreover, the interference will not ap- 
pear in the principal focus, but as a rule sufficiently near it for 
adjustment. 

If de, is the actual displacement of the grating G’ in the line 
of symmetry, 6¢, = de/cos d, so that the angle ¢ enters equa- 
tion (4) again, but only to a small extent. 


Brown University, 
Providence, R. I. 


74 Scientific Intelligence. 


SCIENTIFIC INTELLIGENOE. 


I. Cnemistry anp Puystcs. 


1. The Qualitative Separation of Tin, Arsenic and Antimony. 
—J. M. Wetcu and H. C. P. Weper have observed that the 
method of Noyes and Bray which consists in treating the three 
higher sulphides with concentrated hydrochloric acid on the 
steam bath, thus leaving the sulphide of arsenic undissolved, then 
diluting the liquid with about four volumes of water and pre- 
cipitating sulphide of antimony in hot solutien with hydrogen 
sulphide, and finally precipitating sulphide of tin after further 
dilution, does not give satisfactory results in many cases in the 
hands of inexperienced operators on account of failure to adhere 
to the exact conditions. They observed that when antimonious 
and stannic sulphides happen to precipitate together they 
frequently show a brown color which is not intermediate between 
the usual colors of the two sulphides, but much darker. The 
authors consider this dark precipitate as a characteristic test for 
both tin and antimony, and they prefer to allow the hydrochloric 
acid solution to cool while hydrogen sulphide is being led in, so 
as to obtain this test if possible. To finish the analysis they dis- 
solve the sulphides by evaporating or using an oxidizing agent, 
then add oxalic acid (F. W. Clarke’s method), precipitate anti- 
mony with hydrogen sulphide, boil the filtrate with granulated 
lead and test for tin with mercuric chloride.—Jour. Amer. Chem. 
Soc., Xxxvill, 1011. H. L. W. 

2. A New Method for Estimating Ammonia.—For determin- 
ing ammonia in dilute waste liquors, G. E. Foxwe tt takes 5° of © 
the liquid, makes it up to 300° with water, puts 5° of the diluted 
solution into a test-tube, and then adds 1° of 4 per cent phenol 
solution and 1° of a dilute sodium hypochlorite solution and heats 
by placing the test-tube in boiling water for at least 14 minutes. 
A blue color is developed which is compared with a series of 13 
test-tubes containing from 0-1 to 3° of a solution of ammonium 
chloride containing 0°063 g. of the salt in 1000°, all of which are 
diluted to 5°° and treated in exactly the same way as the other 
liquid. Free acid vitiates the test, while CaO has no influence. 
The method is not recommended for larger amounts of ammonia, 
and it is not as accurate as the distillation method for the smaller 
amounts. It serves well, however, for control purposes, as a test 
can be made in 3 or 4 minutes. Asa qualitative test the method 
gives a distinct coloration with less than 0°0001 mg. of NH,.— 
Gus World, liv, No. 1654. H. L, W. 

3. Analytical Chemistry ; by F. P. TReapweEtt, translated and 
revised by W. T. Hatt. Volume I, Qualitative Analysis. 8vo, 
pp. 538. New York, 1916 (John Wiley & Sons, Inc.).—This is 
the fourth edition in English, which is based upon the eighth 
German edition. The translator has not strictly followed the 


Chemistry and Physics. 15 


German text, but has made many changes and additions, par- 
ticularly in laying greater stress upon the theoretical side of the 
subject in connection with the applications of the principles of 
mass action, the ionization theory, and the theory of oxidation 
and reduction. The first part of the book comprising 76 pages 
is devoted to general principles and presents in an excellent man- 
ner the important theories bearing upon the subject. It is to be 
hoped that the student is not expected to learn this part thor- 
oughly before beginning the study of qualitative analysis, for 
without a basis of many facts much of the theory would be very 
difficult to understand. The second part of over 200 pages deals 
with the metals, while the remaining parts deal with the acid 
constituents, systematic analyses, and the reactions of some 
of the rare elements. The descriptive parts are very com- 
prehensive and equations of reactions are liberally supplied. 
Many equations are given in the ionic form, but this feature is 
not carried far enough to be particularly objectionable. The 
analyses are given in tabular form, but each of the tables is 
accompanied by a full description of the procedure, to which con- 
venient reference is made by numbers in the tables. It is a very 
excellent text-book, containing a vast number of facts, and giving 
very satisfactory methods of qualitative analysis. Its use in this 
country has been very extensive, and the new and improved 
edition will undoubtedly add to its popularity. H. L. W. 

4. A System of Physical Chemistry ; by Wittiam C. McC. 
Lewis. 12mo, 2 vols. Pp. 523 and 552. London, 1916 (Long- 
mans, Green and Co. Price $2.50 per vol. Sold separately). 

This book is of quite different character from most treatises on 
physical chemistry. As the two volumes indicate, the treatment 
is far more elaborate than in many text books, while it is not in 
any sense a reference book like Ostwald’s lehrbuch. It might per- 
haps be classed as a treatise on chemical physics than on physical 
chemistry. The arrangement of the book is interesting. It 
“consists in regarding all physico-chemical phenomena as being 
capable of separation into two classes: first, phenomena exhibited 
by material systems when 77 a state of equilibrium ; and, secondly, 
phenomena exhibited by material systems which have not 
reached equilibrium.” In the first volume, the two classes of 
phenomena are treated from the standpoint of the kinetie theory 
while the second volume is devoted to considerations based on 
thermodynamics. As an illustration, equilibrium from the stand- 
point of the law of mass-action is considered in the first volume, 
while the application of the phase rule to equilibrium is in the 
second. In fact, equilibrium is the main subject in both volumes, 
but treated in each from an entirely different standpoint. 

The newer developments of physical chemistry are given full 
consideration. ‘Thus, some forty pages are devoted to Nernst’s 
heat theorem, which formed the basis of his Silliman lectures at 
Yale a few years ago, 

The book should prove of great interest and value to advanced 
students. He We oF 


76 Scientific Intelligence. 


5. Practical Physiological Chemistry ; by Purmire B. Hawk. 
Fifth Edition. Pp. xiv, 638. Philadelphia 1916 (P. Blakiston’s 
Son & Co.; price, $2 50). —The latest edition of this widely used 
manual has experienced very substantial enlargement by the 
addition of descriptions of new chemical methods applicable to 
biochemical analysis. Chapters on Nucleic Acids, Intestinal 
Digestion, Blood Analysis and Metabolism have been added. 
The directions for conducting metabolism experiments under 
laboratory conditions represent a somewhat novel and useful addi- 
tion to a book of this character. The descriptions of procedures 
continue, as in the earlier editions, to be presented with accuracy 
and sufficient detail to serve as a useful basis for practical work. 
Even cursory examination of the analytical technic or demonstra- 
tion procedures selected shows that the volume is an up-to-date 
product. L, B. M 

6. Lhe Ionization and Dissociation of Hydrogen.—It has 
been shown by J. J. Thomson that in a discharge tube contain- 
ing hydrogen there are present charged atoms, charged molecules, 
and sometimes a constituent having a mass three times that of the 
hydrogen atom. ‘The pressure used was about 0°003™™ of mer- 
cury and the necessary potential difference was of the order of 
20,000 volts. A different experimental method of obtaining posi- 
tive rays has been recently devised and successfully employed by 
A. J. Dempster. The electrons leaving a Wehnelt cathode were 
accelerated by the field between this electrode and the anode. 
The electrons ionized the gas between the electrodes and thus 
produced positive particles which acquired a sufficiently great 
velocity to carry them past the edge of the cathode (2™™ wide) 
and thence through a hole of small diameter which had been 
made in a screen. This screen was roughly normal to the electric 
field and parallel to the axis of a magnetic field which could be 
established at will between the poles of an electromagnet placed 
opposite to the emergence end of the hole. The north and south 
pole pieces also served respectively as the negative and positive 


ends of an electrostatic field. After passing through these two - 


superposed deviating fields the positive particles fell npon another 

screen in which a snitably-disposed parabolic slit had been cut. 
By properly adjusting the deviating fields the parabolas corre- 
sponding to each constituent of the “beam of positive particles 
could be brought successively into coincidence with the slit. 
After passing through the curved slit the particles entered a 
Faraday chamber and recorded their charges in the usual way. 
The advantages afforded by the Wehnelt cathode are that low 
potentials may be used, and that the pressure of the gas may be 
made as small as desired and may also be varied without chang- 
ing the potential. 

Three diagrams are shown in the paper, each having the strength 
of the deflecting magnetic field plotted along the axis of abscissas 
with the charge on the Far aday chamber as sordinates. The first 
curve corresponds to 800-volt rays produced in hydrogen at a 


Chemistry and Physics. VE 


pressure of about 0°01™. It has three pronounced peaks or 
maxima which pertain to H,, H, and H,. The maximum for H, is 
nearest to the axis of ordinates while the peak for H, is reached 
at a more intense magnetic field than is required for either H, or 
H,. The value of the charge at the maximum for H, is slightly 
greater than for H,, whereas the greatest ordinate for H, is 
decidedly higher than for H,. It thus appears that the particles 
of molecular weight 3 were present in relatively large numbers. 
The second curve was obtained with a gas pressure of 0:°0U17™™, 
It too presents three peaks, but now the H, maximum is about 
two and one-half times as high as either one of the remaining 
peaks. The third curve indicates the relative proportions of H,, 
H, and H, when a pressure less than 0:0005"™ was used. Under 
these circumstances the H, and H, peaks have nearly disappeared 
while the H, maximum has retained its former value. That this 
change was caused by decreasing the pressure, and not by the 
removal of some constituent of the gas by the charcoal was shown 
by the fact that when hydrogen was admitted, while the charcoal 
and liquid air were kept in action, H, and H, regained their 
original relative intensities. 

The writer of the paper accounts for the phenomena in the fol- 
lowing way. Since in the high vacuum. the free-path of the 
molecules is very great, the positive ions which are still tormed 
by the dense stream of electrons coming from tae Wehnelt 
cathode make very few collisions with the hydrogen molecules. 
Hence these positively charged diatomic molecules are analyzed 
in the condition in which they were at the instant of their forma- 
tion. We must conclude, then, that electrons ionize only by 
detaching a single electron from a molecule, and are not able to 
dissociate a molecule into atoms. When the pressure is greater, 
some of the positive ions collide with the neutral molecules of the 
gas before the cathode and dissociate them. A positively charged 
atom thus formed may attach itself to a neutral molecule and 
give rise to H,. The author also concludes that H, cannot be 
regarded as a stable gas since it is not present when there is no 
dissociation of the hydrogen molecules.— Phil. Mag., xxxi, p. 
438, May, 1916. Hees Ue 
7. The Structure of Broadened Spectrum Lines.—In the pre- 
ceding number of this Journal the results obtained by Nicholson 
and Merton were given, but details of the experimental method 
were lacking in the original paper. Consequently it may not be 
superfluous to give a brief description of the essential feature of 
this method as explained in another article by T. R. Mxrron. 
A neutral-tinted wedge (of the type used for recording thé sensi- 
bility curves of photographic plates) of density graded from 0:2 
to 4°2 was mounted on the slit of a single-prism spectograph with 
its refracting edge at right-angles to the axis of the slit. Before 
the wedge was placed in position care was taken to have the slit 
uniformly illuminated over its entire effective length. Under 
these conditions each line of the spectrum appears brightest at 


~ 
‘ 


8 Scientific Intelligence. 


the points corresponding to the thin end of the wedge and grad- 
ually fades off toward the thick region of the absor bing sereen.. 
It is evident that the relative intensities of two lines can be cal- 
culated from the lengths of their images, provided the lines are 
so close together that errors due to the variation of the sensibil- 
ity of the plate to different wave-lengths are negligible. A 
broadened line gives a wedge- shaped impression on the plate, the 
apex corresponding to the maximum of intensity in the radia- 
tion, and, from the shape of these wedges, the intensities at 
different distances from the maximum can be deduced. It is thus 
clear that the method consists in picking out points of equal 
density at different wave-lengths and deterr mining the thicknesses 
of the wedge to which they ‘correspond. Points of equal photo- 
graphic density must indicate equal illumination since they are 
exposed for the same time and subjected to the same chemical 
treatment. The neutral-tinted wedge, of course, does not vary 
in absorbing power for neighboring. wave-lengths. Accordingly 
the method is unaffected by the eccentricities of the photographic 
emulsion, and it is only necessary to assume that there is one par- 
ticular density which can be recognized at different points. 
Enlargements of spectrograms of the first three series lines pro- 
duced by the passage of condensed sparks through hydrogen at 
atmospheric pressure are reproduced in the paper. Ha consists 
of a strong maximum falling off rather rapidly and apparently 
regularly. ‘The intensity decreases much less rapidly for Hg and 
there is a distinct minimum at the center of the line, which 
appears to bea close doublet. Hy hasa bright axis with very wide, 
nebulous wings. The distribution of intensity in each of these 
lines is in complete accord with that deduced from Stark’s data 
on the electric resolution and polarization of the lines.— Proce. 
Roy. Soc., vol. xcii (A), p. 322. 1: a eS 
8. The Single-Line Radiation of Magnesium.—The earlier 
work of McLennan and Henderson showed that the vapors of 
each of the elements cadmium, mercury, and zine, can be caused 
to emit a single spectral line by bombarding the particles with 
electrons possessing a certain amount of kinetic energy. For 
cadmium and zine the range of kinetic energy corresponds to 
potential differences lying between 4 volts and 13-6 volts, This 
investigation has been recently extended by McLennan to mag- 
nesium. The vapor of this metal was fond to emit the line of 
wave-length 285222 A, and no other line, when the kinetic 
energy was included within definite limits. The numerical values 
of the limits have not yet been determined, but the range 
agrees, in part at least, with the interval for cadmium and zine. 
Absorption lines homologous to those already observed for cad- 
mium, mercury, and zine were photographed in the case of mag- 
nesium. The wave-lengths of the two absorption lines ara 
recorded as 2852°22 A and 2073°36 A. When sufficiently magni- 
fied the less refrangible band is seen to consist of two very close 


5 
narrow bands similar to the mercury doublet at A2536°72. On the 


Chemistry and Physics. 79 


other hand, the corresponding bands for cadmium and zine have 
not yet been resolved into two components. The absorption lines 
of all four metals are the first members of the combination series 
symbolized (on Paschen’s notation) asv = 2,p, —m, S, and 
v=15,S—wm, P. Finally, the author computes the ionizing 
potentials of cadmium, magnesium, mercury and zinc to be 8°85, 
9°13, 10°27 and 9°24 volts, respectively. Proc. Roy. Soc., vol. 
xeli (A), p. 305. Hi. S.pU 
9, A Treatise on Electricity ; by F. B. Prppuckx. Pp. xiv, 
646, with 369 figures. Cambridge, 1916 (University Press. Also 
G. P. Putnam’s Sons).—This book is not intended for beginners 
but is designed for those readers who require an advanced text 
covering both the theoretical and practical sides of the subject. 
The first eight chapters have been kept fairly simple and contain 
all the mathematical and physical principles necessary for a right 
appreciation of the subject, while the remaining six chapters form 
introductory accounts of special fields, which may be consulted by 
students before starting on treatises devoted to them exclusively. 
Thus the ninth chapter, entitled “Applied Electricity,” deals 
with shunt, series, and compound wound dynamos, with direct 
and alternating current motors, with induction motors, with elec- 
tric lighting, ete. Chapter X, on electrolysis, is followed by a 
longer and very interesting chapter on electric oscillations. 
Among other things this chapter contains accounts of the experi- 
ments of Tesla, Hertz, Bjerknes, and of Sarasin and de la Rive. 
Coupled oscillation circuits, the singing arc, the electromagnetic 
theory of light, and wireless telegraphy also receive due attention. 
Chapter XII is devoted to the conduction of electricity through 
gases. It is fully up to date and includes, for example, the 
theory of the sparking potential, the phenomena of the photoelec- 
tric effect, and the theory of the diffraction of Rontgen rays. 
The next two chapters pertain respectively to radioactivity and 
the theory of electrons. This last chapter involves the electron 
theory of metallic conduction, Lorentz’s equations, the theory of 
the normal Zeeman effect, the Lorentz-Einstein transformation, 
the theory of quanta, etc. ‘The text has been written carefully 
and accurately, the selection of material is excellent, and the num- 
_ ber of typographical errors is very small so that the volume 
should be found very useful by first-year graduate students in 
particular, and by others who need an introduction to the highly 
specialized, advanced treatises. ey Sethe 
10. Zhe Physical Properties of Colloidal Solutions ; by EK. F. 
Burton. Pp. vii, 200. London, 1916 (Longmans, Green and 
Co.).—“ The present attempt to give an outline of the study of 
colloidal solutions has to do particularly with its interest to the 
student of Physics.” The second chapter deals with the prepara- 
tion and classification of colloidal solutions. It contains sys- 
tematic tables of various classes of colloids having something in 
common, and quotations of types of methods of preparation which 
will enable the reader to find out where to look for detailed 


80 Scientific Intelligence. 


information. In the very nature of the case, this chapter is rather 
dry, while the next five chapters, which deal with the pure physies 
of colloidal phenomena, are very interesting both on account of 
the subject matter itself and also because of the clearness of pre- 
sentation. More specifically, these chapters deal with the ultra- 
microscope, the phenomena and theory of Brownian motion, the 
optical properties of colloidal solutions, the determination of the 
size of ultramicroscopic particles, and the motion of colloidal par- 
ticles in the electric field. The titles of the eighth, ninth and 
tenth chapters are respectively : “The Coagulation of Colloids,” 
“Theory of the Stability of Colloids,” and “ Practical Applica- 
tions of the Study of Colloidal Solutions.” This last chapter is 
also very useful since it deals with various manufacturing pro- 
cesses, dyeing, purification of effluent waters, agriculture, and 
physiological ‘applications. 

The value of the monograph is increased by the presence at the 
end of each chapter of a long list of bibliographical references. 
Since the important subject of colloidal solutions is often neg- 
lected this compact and excellent text should be welcomed by 
advanced students and teachers of physics. H. 8. U. 


Il. Grotogy anp Naturan History. 


1. Stratigraphy and fauna of the Tejon Eocene of Califor- 
nia ; by Roy E. Dickerson. Univ. California Pub., Bull. Dept. 
Geology, vol. ix, No. 17, 1916, pp. 363-524, pls. 36-46, text figs. 
1-14.—This valuable work has far-reaching import in that it 
stratigraphically and faunally establishes the Tejon formation in 
its variable development throughout California. The ‘Tejon, 
although a thick formation, is a faunal unit, and unconformably 
overlies the basal Eocene, the Martinez; it in turn is usually 
unconformably overlain by the Oligocene. The fauna consists of 
about 300 species and many range throughout the series. Not 
more than four forms pass into the Oligocene and but 25 are 
derived from the Martinez. The Tejon is divided into four 
faunal zones and their distribution is shown on paleogeographic 
maps ; the youngest zone has widest distribution when the Pacific 
Ocean lapped the base of the Sierra Nevadas, depositing here the 
Ione formation and its equivalent, the auriferous stream and 
bench gravels of the Sierra Nevadas. The Eocene closed with 
extensive deposits of rhyolitic ash and mud flows, followed by 
andesitic tuffs, lavas, and mud flows. 

The Tejon fauna is partly a descendant of the earlier Martinez, 
to which were added many migrants from the Gulf of Mexico by 
way of the Panama or Tehuantepec portals, though less than 20 
species, or about 7 per cent, are common to the two realms. The 
relationship of the Tejon is with the Midway, Wilcox, and Clai- 
borne of the Gulf of Mexico area, but more decidedly with the 
last, while the Martinez appears to be older than anything in 
the Tertiary of the Atlantic area. Cc. 8. 


Geology and Natural History. 81 


2, New fossil Coleoptera from ihe Florissant beds ; by H. F. 
Wicknam. Bull. State Univ. Iowa, vol. vii, No. 3, 1916, pp. 
3-19, pls. 1-4.—The author describes four new genera and 21 new 
species ; the Miocene of Lake Florissant is now known to have 
no less than 515 different forms of beetles, the majority of which 
are inconspicuous. The climate was then mild and moist. “ The 
insects of the Florissant Miocene stand in direct ancestral relation- 
ship to our present fauna.” Cc. 8. 

3. I, Hocene of the Lower Cowlitz River valley, Washing- 
ton ; II. The post-Hocene formations of western Washington ; 
ITT. The Oligocene of Kitsap County, Washington ; by CHaRLEs 
EK. Waaver. Proce. Calif. Acad. Sci., 4th ser., vol. vi, Nos. 1-3, 
1916, pp. 1-52, pl. 1, fig. 1. 

Tertiary faunal horizons of western Washington ; by CuaRLes 
KE. Weaver. Univ. Washington Pub. in Geology, vol. i, No. 1, 
1916, pp. 1-67, pls. 1-5.—The last-named paper is a record of 
305 Tertiary localities in Washington, together with descriptions 
of 41 new species, mainly from the Oligocene, and lists of the 
Eocene (130 species), Oligocene and Lower Miocene (155), and 
Upper Miocene (81) molluscs found in the state. The maximum 
thickness of these deposits is 34,000 feet; the time of most 
marked deformation was in the Middle Miocene, with marked 
volcanic activity toward the close of the Eocene. Cas. 

4. The Upper Cretaceous floras of the world; by E. W. 
Berry. Maryland Geol. Sury., Special publication from Upper 
Cretaceous Report, 1916, pp. 1$3-313.—The author presents here 
lists of the Cretaceous floras of the world and comments more or 
less on their age relations. He accepts as the base of the Creta- 
ceous the Albian of the European standard. Accordingly the 
Raritan is of Cretaceous age but older than the Dakota, and he 
correlates it with the Washita, and both with the European 
Cenomanian. Thisis a striking and far-reaching conclusion. As 
the Washita is a part of the Comanchian and is of Upper Creta- 
ceous age, he further concludes that this term is invalidated as a 
substitute for Lower Cretaceous. This is a great and unadjusted 
question in American stratigraphy and can not be so easily fixed. 
In the first instance it is accepted that the Trinity, Fredericks- 
burg and Washita divisions of the Comanchian represent an 
unbroken series of deposits that together make up the Coman- 
chian. On the principle that diastrophista is periodic avd more 
or less simultaneous throughout the world, we should then have 
to refer not only the Washita but all of the Comanchian to the 
Cretaceous. The reviewer does not intend to go into this correla- 
tion, but wishes to ask, Are the Lower and Upper Cretaceous 
divisions of the European standard representative of but one 
period, or of two (Lower and Upper Cretaceous), or of three 
(Lower, Middle and Upper Cretaceous) periods? Further, be- 
tween what series do the important diastrophic movements of the 
sea occur? Certainly the break between the Comanchian and 
the American Cretaceous is clearly marked and universal in the 


Am. JouR. pole Oe SERIES, Vou. XLII, No. 247.—Juxy, 1916. 


82 Scientific Intelligence. 


United States, and appears to be of the order that distinguishes 
periods. 

The author leans to the hypothesis that the dicotyledon floras 
originated “in high latitudes, from which region they spread 
southward over the continents of the northern hemisphere in sue- 
cessive waves of migration.” The Cretaceous climate was more 
uniform than at present and the floras are of a ‘ warm temperate 
rain-forest type, less tropical than succeeding Eocene and Oligo- 
cene floras.” Hardly any of the Cretaceous species “ survive into 
the Eocene” and “ many of the genera, particularly among the 
conifers, die out before the close of the period.” 0. 8. 

5. Geology and underground water of Luna County, New 
Mexico ; by N. H. Darton. Bull. 618, U. 8. Geol. Surv., 1916, 
188 pp., 13 pls., 15 text figs—This welcome report on an area 
almost unknown geologically presents a discussion of the geology 
and mineral and water resources of southern New Mexico to the 
west of El Paso, Texas. The marine geologic record is of Upper 
Cambrian, Beekmartown, Richmond, Silurian, ?7Devonian, Lower 
Mississippian, Pennsylvanian, Comanchian, and Benton times. 
There is also non-marine Tertiary present. 0. S. 

6. Contributions from Walker Museum, Vol. I, No. 9, (1) 
The Osteology of some American Permian vertebrates ; (2) 
Synopsis of the American Permo- Carboniferous Tetrapoda, Vol. 
I, No. 10, (1) cltactocrinus, a new crinoid genus from the Rich- 
mond of Illinois ; (2) Description of a Ste. Genevieve limestone 
fauna from Monroe County, Illinois. 1916.—A new scientific 
publication has been started by the University of Chicago under 
the title of ‘ Contributions from Walker Museum.” So far ten 
numbers have appeared. In No. 9 of Volume I, Professor Witt1s- 
TON describes the Permian cotylosaurian Pantylus, the oldest 
armored reptile ; Zsodectes ; Theropleura, as represented by a won- 
derfully good specimen which proves that the sternum of verte- 
brates evolved out of the anterior ventral ribs, the parasternum 
of Gegenbaur; and Puwercosuurus,a new reptilian genus from 
New Mexico. The second paper in No. 9 presents a new synop- 
tic review of the genera, families, and orders of the earliest 
Ampbibia and Reptilia, furnishing very valuable material for 
further attempts toward unravelling the true genetic relations of 
these old animals. No. 10, by Professor WeEtuxr, describes a 
new Ordovician genus of crinoids, and an interesting Upper 
Mississippi fauna of fifty-six species which lived im an oolite 
environment. Cc. 8. 

7. Virginia Geoloyical Survey, University of Virginia ; 
Tuomas Lronarp Warson, Director. 

Administrative Report of the State Geologist for the Biennial 
Period 1914-1915. Pp. 45, 2 pls., 1916.—A summary is given 
here of the work done by the Virginia Survey in 1914 and 1915. 
The codperation of the United States Geological Survey, both as 
to topography and geology, has enabled the state organization to 
accomplish much more than would otherwise have been possible. 


Geology and Natural History. 83 


The work done is largely economice in character, and maps of the 
coal fields in the southwestern part of the state show the progress 
which has been made, and what areas still remain to be covered. 

Bulletin No. X. Surface Water Supply of Virginia ; by G. C. 
Stevens. Pp. 245; 5 pls.—This bulletin, prepared in codpera- 
tion with the United States Geological Survey, presents the 
records accumulated in regard to the prominent river basins of 
the state. 

8. The Physical Geography of Wisconsin ; by Lawrence 
Martin. Pp. xxii, 549 ; 41 pls., 206 figs. Wisconsin Geological 
and Natural History Survey. E. A. Bireg, Director. Bulletin 
No. XXXVI. Educational Series No. 4. Madison, 1916.—The 
surface features of Wisconsin are so varied in character that the 
systematic presentation of them in the present volume results in a 
reference book on physical geography, both complete and com- 
prehensive. The text is prepared with a view to being made as 
intelligible as possible to the general public, and the illustrations 
are liberal in number and excellent in character. 

9. Publications of the U. S. Bureau of Mines ; Vax. H. Man- 
niInG, Director.—Recent Bulletins from the Bureau of Mines 
are noted in the following list (see Jan. 1916, p. 149). Numer- 
ous Technical Papers have also been issued. 

No. 74. Gasoline mine locomotives in relation to safety and 
health ; by O. P. Hoop and R. H. Kupiicw. With a chapter on 
methods of analyzing exhaust gases ; by G. A. BuRRELL. Pp. 83; 
3 pls., 27 figs. 

No. 86. Some engineering problems of the Panama Canal in 
their relation to geology and topography ; by D. F. MacDonaxp. 
Pp. 86; 29 pls., 9 figs. 

No. 89. Economic methods of utilizing Western lignites ; by 
E. J. Bascocnx. Pp. 74; 5 pls., 5 figs. 

No, 91. Instruments for recording carbon dioxide in flue gases ; 
by J. F. Barxiery and 8. B. Frace. Pp. 60; 1 pl., 25 figs. 

No. 92. The feldspars of the New England and North Appa- 
lachian States, by A. 8. Warts. Pp. 181; 8 pls., 22 figs. 

No. 93. Miners’ nystagmus; by F. L. Horrman. Pp. 67. 

No. 96. The analysis of permissible explosives; by C. G. 
Storm. Pp. 88; 3 pls., 7 figs. 

No. 97. Sampling and analyzing flue gases; by H. KreisincEr 
and F. K. Ovirz. Pp. 67; 1 pl., 34 figs. 

No. 99. Mine ventilation stoppings, with especial reference to 

py mines in Illinois; by R. Y. Writrams. Pp. 30; 5 pls., 4 
gs. 
No. 100. Manufacture and uses of alloy steels; by H. D. 
Hiipparp. Pp. 77. 
No. 102. The infiammability of Illinois coal dusts ; by J. K. 
Crement and L. A. Scuout, Jr. Pp. 74; 5 pls., 2 figs. 
No. 104. Extraction and recovery of radium, uranium, and 
vanadium from carnotite; by C. L. Parsons, R. B. Moors, 8. C. 


S4 Scientific Intelligence. 


Linp, and O. C. Scnarrer. Pp. 1243; 14 pls., 9 figs. See notice 
on p. 214, vol. xli. 

Nos. 113,118. Abstracts of current decisions on mines and 
mining reported from May to September, 1915 ; by J. W. Tuowr- 
son. Pp. 123. No. 118, October to December, 1915. Pp. 74. 

No. 114. The manufacture of gasoline and benzene-toluene 
from petroleum and other hydrocarbons. Pp. 2683; 9 pls., 45 
figs. 

No. 115. Coal-Mine fatalities in the United States 1870-1914, 
with statistics of coal production, labor, and mining methods, by 
states and calendar years; compiled by Atserr H. Fay. Pp. 
3703; 3 pls., 13 figs. 

10. Canada, Department of Mines.—The following are import- 
ant recent publications (see vol. xli, pp. 467-469): 

(1) Geological Survey Brunch. R. W. Brock, Director. ; 

Summary Report of the Geological Survey for the calendar 
year 1915. Pp. viii, 307 ; 8 maps, 3 figs. Ottawa, 1916. 

Memoirs.—No. 55. Geology of Field Map-area, B.C. and 
Alberta ; by Jonw A. Atran. Pp. vii, 312, vi; 21 pls., 5 figs. 

No. 77. Geology and Ore Deposits of Rossland, British Co- 
lumbia; by Cuartes W. Dryspate. Pp. ix, 317, vii; 25 pls., 26 
figs. 

“No. 79. Ore Deposits of the Beaverdell Map-area ; by Lroroip 
Rervecke, Pp. v, 178, vii ; one map, 13 pls., 9 figs. 

(2) Mines Branch. Evcrne Haanet. Director, 

Annual Report on the Mineral Production of Canada during 
the calendar year 1914 ; Jonn McLetsu, Chief of the Division of 
Mineral Resources and Statistics. Pp. 362. 

ll. Oil and Gas Map of Southwestern Pennsylvania, 1915. 
Pp. 22 with map on scale of 1 : 250,000. Topographic and Geo- 
logic Survey of Pennsylvania ; Ricuarp H. Hicer, State Geolo- 
gist. Harrisburg, 1916.—It is stated in the pamphlet accompany- 
ing the large and detailed map now issued, that the value of the 
petroleum produced in Pennsylvania in 1900 was $18,000,000 and 
nearly $20,000,000 in 1913. Between these two dates the value 
fluctuated, falling as low as $11,000,000 in 1911. On the other 
hand, the value of the natural gas has risen somewhat regularly 
from $10,200,000 in 1900 to $21,700,000 in 1913. 

12. Bulletin of the Imperial Earthquake Investigation Com- 
mittee. Vol. VIII, No. 2. The Sakura-Jima Eruptions and 
Earthquakes. U.;by F. Omori. Pp. 35-179 ; pls. VIII-X XXII, 
Tokyo, April, 1916.—This Bulletin of the Japanese Earthquake: 
Commission is devoted to a discussion of the recent violent vol- 
canic eruption of Sakura-Jima. An introductory chapter gives 
notes in tabular form on the time distribution of Japanese erup- 
tions dating back to the seventh century. The earliest recorded 
eruption of Sakura-Jima was in 1468 and the twenty-six eruptions 
noted, down to 1914, with their individual dates, are given with 
their special characters. The special topics discussed in regard 
to the eruption of January 12, 1914, are as follows : the meteoro- 


Geology and Natural History. 85 


logical conditions ; the propagation of sound waves ; the accumu- 
lation and transportation of ashes ; the abnormal changes in the 
height of water at Kagoshima Bay ; also the changes of level and 
horizontal displacements in the ground. A series of excellent 
charts illustrate the entire subject, and help to make the volume 
a notable addition to vulcanology. 

13. Mineralogic Notes, Series 3, by W.'T. Scuatuer, U. S. 
Geol. Sury., Bull. 610, 1916 ; pp. 164, 5 pls., 99 figs.—In this report 
Dr. Schaller gives the results of the various smaller pieces of 
mineralogical investigations carried on by him in the chemical 
laboratory of the Geological Survey, between July, 1911, and 
January, 1914. It includes some twenty-five different com- 
munications, the majority of which have not been completely 
published elsewhere. Among these are the descriptions of five 
new species, namely, koechlinite, inyoite, meyerhofferite, lucinite 
and velardenite. Important contributions concerning variscite, 
schneebergite, romeite and the melilite group are included. 
Through the courtesy of Dr. Schaller it was possible to publish 
in the Third Appendix to Dana’s System of Mineralogy, issued 
last year, brief summaries of the descriptions of the new species 
together with the other more important results which are given 
in this Bulletin. W. E. F, 

14. The Emerald Deposits of Muzo, Colombia; by J. E. 
Poeur. Reprint from the Trans. Amer. Inst. Min. Eng., 1916.— 
This paper gives a brief and interesting account of the history, 
geology and mineralogy of the famous emerald deposits of 
Colombia. ‘The emeralds are found almost entirely in calcite 
veins that traverse a black, carbonaceous, intensely folded forma- 
tion consisting of thin-bedded shale and limestone. ‘This forma- 
tion lies discordantly upon steeply dipping strata composed of 
heavier beds of carbonaceous limestone intercalated with black 
shale. Between the two formations are thin layers of three other 
rocks consisting of (1) chiefly albite, (2) a granular aggregate of 
calcite, dolomite, quartz and pyrite, (3) aggregates of large cal- 
cite rhombs in a fine-grained matrix. Small amounts of peg- 
matite have been observed. The presence and association of 
emerald, parisite, fluorite, apatite, albite and barite in a sedimen- 
tary formation indicates the action of strong mineralizing 
solutions which introduced them. Structural conditions indicate 
that the emerald formation was overthrust to its present position 
upon the underlying series, and that this movement was followed 
by a period of mineralization which attained its most conspicuous 
results along the fault plane and its economic results above that 
plane. W. E. F. 

15. Microscopical Determination of the Opaque Minerals: 
An Aid to the Study of Ores ; by JoszepH Murpocu. New York, 
1916, pp. vi, 163 (John Wiley and Sons).—Since the publication in 
1906 of a paper by W. Campbell on “The Microscopical examina- 
tion of opaque minerals,” the use of this new and important 
means of identification of these minerals has been steadily grow- 


86 Scientific Intelligence. 


ing. The study of the Secondary Enrichment Investigation con- 
cerning the occurrence and alteration of ore minerals necessitated 
the use and elaboration of these methods. The present book 
must be considered as one of the important results of this investi- 
gation. 

The methods used involve the observation under the micro- 
scope by reflected light of polished sections of the opaque min- 
erals. ‘Che means of identification include, first, the color of the 
polished mineral, which is more accurately jndged by comparison 
with definite mineral standards; secondly, the har rdness; and thirdly, 
microchemical reactions through the use of various reagents. By 
means of these tests and the use of the determinative tables given 
in the book, it is possible to accurately determine the character of 
a given mineral. 

“An important result of this new method of investigation has 
been to show that opaque minerals are very liable to contain 
impurities in greater or less amount which would entirely escape 
detection by any ordinary methods of observation. It will be 
necessary in the future to make such an examination of an opaque 
mineral before analysis in order to be certain of the purity of the 
material analyzed. A considerable number of species that have 
been described as definite compounds have already been shown to 
be mixtures of two or more different materials. 

Itis proposed to call this new branch of mineralogical study by 
the name “ Mineralography.” W. E. F. 

16. Zhe Collection of Osteological Material from Machu 
Picchu ; by Guorce F. Eaton. Quarto, pp. 96 ; 39 pls., 50 figs., 
2 tables, one map. Memoirs of the Connecticut Academy of 
Arts and Sciences, New Haven. Volume V, May, 1916.—This 
valuable report on the osteological collections made in connection 
with the Peruvian Expedition of 1912 has been recently issued. 
A notice will appear in a later number. 

17. The Birds of North and Middle America ; by Rosrrr 
Ripeway, Curator, Division of Birds. Part VII. Pp. xiii, 
543, 24 pls. Bulletin of the U. S. National Museum. No. 50.— 
This extensive work on American birds was begun in 1901. The 
seven volumes thus far published include 564 genera and 2,319 
species and sub-species, with a considerable number of extra- 
limital genera and species, whose characters are given in the 
“Keys.” The present volume contains the cuckoo-like birds, 
parrots, and pigeons. Part VIII, in preparation, will include the 
gulls and auks with their near allies. 

18. &. Comitato Talassografico Ltaliana.—N otwithstanding 
the far from quiet condition of the seas which surround Italy 
during the past two years, the work of the Italian commission, 
begun in 1910, still goes on uninterruptedly. Fifty-two memoirs 
are now included in the list of publications. Recent sendings 
include the bi-monthly bulletin for 1915 and memoirs 44-52. 
The last-named are all on subjects in natural history except No. 
50, which discusses the solubility of gypsum in sea water. 


Geology and Natural History. 87 


19. British Museum Catalogues.—The following have been 
recently received : 

Catalogue of the Ungulate Mammals in the British Museum 
(Natural History). Volume V. Perissodactyla, Hyracoidea, 
Proboscidea ; with addenda to the earlier volumes ; by the late 
Ricuarp LypEKKER. Pp. xlv, 207 ; 31 figs.—This concluding 
volume opens with an excellent portrait of Mr. Lydekker, the 
author of the work, whose death occurred in April, 1915 (see vol. 
xl, p. 668). Fortunately it was found that his preparations for 
the present volume had progressed so far that it has been possible 
to bring it out as he left it. The families here included are the 
horses, tapirs, rhinoceroses, hyraxes and elephants. 

Report on Cetacea stranded on the British Coasts during 1915 
(with one map), by S. F. Harmer. Pp. 12.—War conditions 
have not been favorable for observations such as those included 
in the present paper, hence, only 28 specimens are recorded for 
1915, compared with 76 in 1913 and 57 in 1914. This year, how- 
ever, includes a record of a specimen of Cuvier’s whale, and a 
new record of Sowerby’s whale, both very rare on the British 
coast. 

20. The Musewm of the Brooklyn Institute of Arts and Sciences. 
—Science Bulletin, vol. 3, No 1, on the Long Island Fauna (IV), 
has recently appeared. The subject is ‘The Sharks,” by Joun 
T. Nicnors and Rosrrt C. Murruy. Pp. 34; 3 pls., 19 figs. 

21. The Involuntary Nervous System ; by W. H. GasKeEtt. 
Pp. ix, 178, with several diagrams in colors. London, 1916 
(Longmans, Green and Co.).—This is the first volume of a series 
of monographs on physiology, to be written by English physiol- 
ogists who have authority in their special fields of research. The 
book is essentialiy an epitome of the author’s yearly lectures on 
the subject, and was completed during the last two months of 
his life. It consists of a general account of our present knowl- 
edge of the distribution and functions of the sympathetic and 
allied nervous systems of vertebrates. WwW. R. C. 

22. Laboratory Manual in General Microbiology ; by Warp 
GILTNER and Associates in the Laboratory of Bacteriology, 
Hygiene, and Pathology, Michigan Agricultural College. Pp. 
xvi, 418. New York, 1916 (John Wiley and Sons).—This labora- 
tory guide contains complete directions for the isolation, cultiva- 
tion, and study of bacteria, yeasts, and molds. The book is 
designed to furnish the student with sufficient information to 
enable him to carry on his laboratory experiments with the 
minimum assistance from the instructor. There are explicit direc- 
tions for preparing culture media, stains, and other reagents, 
with typical experiments to illustrate the physiology of micro- 
organisms. There are also special exercises on the microbiology 
of air, water, sewage, soil, dairy, and plants, and on animal dis- 
eases and immunity. Ww. R, C. 


ZX 
DB 


Scientific Intelligence. 


Ill. Muiscerianrovus Sorentiric Inve iigEnce. 


1. The Carnegie Foundation for the Advancement of Teach- 
ing. Tenth Annual Report of the President, HENry S. Prir- 
cuEerr und of the Treasurer, Roperr A. Franks. Pp. vi; 141. 
New York City, October, 1915.—In the regular work of the Carne- 
gie Foundation, the total number of retiring allowances and pen- 
sions for the past year was 445 (in 1914, 433), of which 118 were 
widows’ pensions ; 43 new names were added to the list. The 
Foundation since the beginning has paid out the large sum of 
$4,225,000 to 639 individuals. The expenditure in the past year 
for allowances and pensions was $674,000 ($635,000 in 1914), while 
$55,000 was devoted to the department of educational inquiry 
and $37,000 to administration. 

The annual volume, in addition to the routine matter, discusses 
a number of pr oblems of great importance from the educational 
standpoint. The subject of legal education in this country, pre- 
sented in Bulletin No. 8, by Professor Redlich of the University 
of Vienna (see vol. xxxix, p. 611), has been further investigated 
with striking results. It seems that there are 147 resident schools, 
of which all but ten confer degrees, and 17 correspondence schools, 
a total of 164. It is worthy of note that of the degree-conferring 
schools, Connecticut has 1, Massachusetts 4, Pennsylvania 5, New 
York 9 ; while the District of Columbia has 8, California 10, and 
Illinois 12 with 8 correspondence schools in addition. 

Other subjects now undertaken for study, but not reported 
upon at length, are those of Engineering Education and the 
Training of Teachers in Missouri. The legislative results follow- 
ing the publication of the Foundation’s study of education in 
Vermont (Bulletin No. 7 ; see vol. xxxvii, p. 564) give a gratify- 
ing evidence of what the Foundation is able to accomplish. 
discussion of the charges for tuition in one hundred representa- 
tive institutions for the past ten years is given in another chapter, 
with interesting remarks showing the uniform tendency to ad- 
vance the fees. Finally, to the study which comes closest to the 
definite work of the Foundation, and for which it has done most, 
that of systems of pensions, fifty pages are devoted, with a tabu- 
lar summary of 65 pension systems for teachers and 58 industrial 
and institutional systems. All of these are regarded as unsound. 
The special Bulletin, now in_ press, describing the ten years’ 
experience of the Foundation with its own system, and plans for 
its future development, will be looked forward to with great 
interest. 

2. Public Education in Maryland: A Report to the Mary- 
land Educational Survey Commission; by AzraHam FLEXNER 
and Frank P. Bacuman. Pp. xviii, 176, with illustrations. 
New York, 1916 (The General Education Board).—The Commis- 
sion, charged with the investigation of the education in Mary- 
land, was appointed by the legislature in 1914, and at its request 


Miscellaneous Intelligence. 89 


the General Education Board undertook the survey. The field 
covered embraces the elementary and secondary schools of the 
counties, but not the schools of Baltimore. ‘the general decision 
reached is that the public education of Maryland is on the whole 
soundly organized and that the State deals with it generously, 
although some of the counties do less than their share. Practi- 
cally, however, while a few counties have good schools, many of 
the schools are inferior, the inspection ineffective, the children 
irregular in attendance, and the buildings very unsatisfactory; 
for much of this the influence of politics is unfortunately respon- 
sible. The report discusses in detail the individual schools 
themselves and offers suggestions as to legislation calculated to 
improve the situation. ‘These results are highly important, not 
for Maryland alone but for other States also, particularly those 
like it having a large negro population. 

3. The General Education Board, FKreprrick T. Gartss, 
Chairman. eport of the Secretary, Wattace Burrricn, 1914— 
1915. Pp. xi, 82. New York, 1916 (61 Broadway).—The Rocke- 
feller fund in the hands of the General Education Board amounts 
to some $34,000,000, from the income of which appropriations 
amounting to $1,577,000 were made in the year ending June 30, 
1915. Eight colleges and universities are mentioned in the 
list as having received the greater part of this sum, namely, 
$1,275,000, these appropriations being towards the maximum sum 
of $5,200,000, to be raised by them. Other important measures 
discussed, towards which the funds of the Board are being used, 
include clinical instruction on the “full time plan,” the education 
in the southern states, public education in Maryland (see above), 

ete. 

4. Napier Tercentenary Memorial Volume. Edited by Car- 
aac Gintston Knorr. Pp. xi, 441, with illustrations, including 

5 plates. London, 1915 (Published for the Royal Society of 
ene gh by Longmans, Green and Company).—The three hun- 
dredth anniversary of the invention of logarithms was celebrated 
in Edinburgh, July 24-27, 1914. Delegates were present from 
universities, - observatories and learned societies in all parts of the 
world. Addresses were given and papers were read dealing with 
the life and work of John Napier, with the influence of his great 
discovery upon the progress of science, and with the history of 
the theory and art of calculation as it developed in the years 
which followed the publication of his Mirifici Logarithmorum 
Canonis Descriptio. There was also a most interesting exhihition 
of rare mathematical books and of calculating machines both 
ancient and modern—from abaci and sets of “ Napier’s Bones” 
to the most recent devices for mechanical computation, some of 
them of surprising complexity and ingenuity. In addition to the 
scientific attractions of the Congress, a number of social gather- 
ings added much to the pleasure and interest of the occasion ; 
among these was an evening reception by the Lord Provost and 
Magistrates of Edinburgh, and a garden party at Merchiston 


90 Screntipic Intelligence. 


Castle, the birthplace and home of Napier, now occupied by a 
boys’ school. 

In the present handsome volume, Dr. Knott has collected the 
addresses, lectures and papers given at the Congress together 
with an account of the celebration, copies of the congratulatory 
addresses to the Royal Society of Edinburgh, lists of the institu- 
tions which participated and of their representatives. It is illus- 
trated by portraits of Napier, facsimile pages from his works and 
from other important early books, and by engravings of Merchis- 
ton Castle at different times. 

The papers which deal with the historical development of the 
subject, especially the memorial address by Lord Moulton, can 
scarcely fail to excite the eager interest of anyone who has a 
taste for mathematics. The methods by which Napier reached 
his great discovery and the course of subsequent progress are at 
once fascinating and surprising. -As one comes to realize, how- 
ever, what the state of mathematical knowledge was three hun- 
dred years ago, the wonder is that such a discovery could have 
been made at that time and in a place so remote from the centers 
of intellectual life as Scotland then was. It was an achievement 
of genius and well worthy of being celebrated, as it was, by the 
last International Congress before the beginning of the Great 
War. é HAs Bs 

5. The Mining World Index of Current Literature. Vol. 
VIII. Last Half Year, 1915; by Guo. E. Sisuny. Pp. xi, 228. 
xxv, Chicago, 1915 (Mining World Company).—The Index 
published by the Mining and Engineering World, which covers 
the world’s current literature in this field, has now been completed 


for the last half year of 1915; it forms volume VIII of the 


Series (see earlier notices). 


OprruaRY. 


Proressor Sytvanus P. Tompson, the noted physicist and 
electrical engineer, died in London, June 13, in his sixty-sixth 
year. He was the author of several volumes on electricity and 
optics, etc., and made important contributions particularly in 
electrical machinery. 

Proressor Ocrave Licnimr, the able French paleobotanist of 
the university of Caen, died on March 19 at the age of sixty-one 
years. 

Proressor Emite Junerieiscu, of the College de France, dis- 
tinguished particularly for his work in organi¢ chemistry, died on 
April 24 at the age of seventy-seven years, 


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. VERWIEBE ~.. 20. 1g Se 32 ee eee ees 


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VIII.—Rotation of Interference Fringes in Case of Non- 
reversed and of Reversed Spectra ; by C. Barus 


SCIENTIFIC INTELLIGENCE. 


Chenistry and Physics—Qualitative Separation of Tin, Arsenic and Anti- 
mony, J. M. WeLicew and H.C. P. Weser: New Method for Estimating 
Ammonia, G. E. Foxwetn: Analytical Chemistry, F. P. TREADWELL, 74.— 
System of Physical Chemistry, W. C. McLewts, 75.—Practical Physio- 
logical Chemistry, P. B. Hawk: Ionization and Dissociation of Hydrogen, 
A. J. Dempster, 76.—Structure of Broadened Spectrum Lines, T. R. 
Merton, 77.—Single-Line Radiation of Magnesium, McLennan, 78.— 
Treatise on Electricity, F. B, Prppuck: Physical Properties of Colloidal 
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ae ee ee ee ee Pe eT? ee a eee ee 


Geology and Natural History—Stratigraphy and fawna of Tejon Eocene of 
California, E. Dickerson, 80.—New fossil Coleoptera from Florissant 
beds, H. F, WickHam: Eocene of the Lower Cowlitz River valley, Wash- 
ington, etc., C. E. Weaver: Upper Cretaceous floras of the world, E. W. 
Berry, 81.—Geology and underground water of Luna County, New Mex., 
N. H. Darton: Contributions from Walker Museum, Uniy. of Chicago: 
Virginia Geological Survey, University of Virginia, Tl. L. Warson,) 
82.—The Physical Geography of Wisconsin, L. Martin: Publications of’ 
U. S. Bureau of Mines, V. H. Mannine, 83.—Canada, Department of 
Mines: Oiland Gas Map of South western Pennsylvania, 1915, R. H. Hice: 
Bulletin of Imperial Earthquake Investigation Committee, 84.—Min- 
eralogic Notes, Series 3, W. T. ScuatteR: The Emerald Deposits of Muzo, 
Colombia, J. E. Pogun: Microscopical Determination of the Opaque Min- 
erals, J. Murpocx, 85.—Collection of Osteological Material from Machu 
Picchu, G. F. Earon: Birds of North and Middle America, R. Rip@way : 
R. Comitato Talassografico Italiana, 86.—British Museum Catalogues ; 
Museum of the Brooklyn Institute of Arts and Sciences: The Involuntary 
Nervous System, W. H. GASKELL ; Laboratory Manual in General Micro- 
biology, W W. Gitryer, 87. 


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Bacuman, 88.—General Education Board: Napier Tercentenary Memorial 
Volume, 89.—Mining World Index of Current Literature, 90. 


Obituary—S. P. THompson: O. Lianier: E. JunGFieiscH, 90. - 


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AMERICAN JOURNAL OF SCIENCE 


[FOURTH SERIES.] 


———~~++>__—_- 


Arr. IX.—The Problem of Continental Fracturing and 
Diastrophism in Oceanica;* by Cuartes ScHUCHERT. 


Latitudinal arrangement of ancient lands.—Paleogeographic ~ 


studies during the past thirty years have been developing the 
hypothesis that the ancient continental platforms were arranged 
latitudinally rather than longitudinally as they are now, and 
further, that their areal extent, including their emerged and 
submerged portions, was greater than at present. It appears 
that vast landmasses have been fractured, broken up, and more 
or less permanently taken possession of by the oceans, a history 
which none exhibits better than the Australia-New Zealand 
region. 

Time when oceans became deep.—We have learned from the 
several deep-sea expeditions something of the rare and strange 
life of the oceanic abysses. . An sanlrsis of these organisms 
shows that no Paleozoic forms occur among them and, indeed, 
very little of the life is ancestrally traceable even to the stocks 
of Triassic times. It is with the Jurassic and later life that 
the organisms of the abysses have their affinities. -This seems 
to indicate that the oceans have been progressively deepened 
only since the Triassic. As one of the most marked crustal 
deformations, however, began in the Coal Measures of the 
Paleozoic and continued, though with pauses, well into the 
Triassic, it therefore appears that the oceans have been periodi- 
cally enlarged and deepened ever since Permian time. This is 
in keeping with the theory that the earth’s radius has been 
gradually diminishing, and that the periodic compensation 


* Read before the National Academy at Washington, April.17, 1916. 
Am. Jour. Sc1.—FourtH Series, Vou. XLII, No. 248.—Aveusr, 1916. 
ff 


92 C. Schuchert—Problem of Continental Fracturing 


therefor has been greatest in the oceanic basins, the areas of 
greatest rock densities. 

Increase of water with time.—If the oceans have progres- 
sively enlarged and deepened, it is natural to ask, Has the 
quantity of water increased with time, and if so, what was the 
source of supply? Some geologists, and more especially some 
petrologists, have concluded that every active voleano and most 
of the thermal springs»are adding much new water—the so- 
called “juvenile” water, of magmatic origin—to the old 
accumulations of the hydrosphere. As yet we have but little 
in the way of estimates based on field or laboratory experiments 
to give us any adequate idea how much water an active voleano 
liberates. Some years ago the writer hazarded the guess that 
the increase of water since the beginning of Paleozoic time 
may have been as much as 25 per cent. 

Decrease of water during glacial periods.—That the strand- 
lines of the oceans are decidedly mobile is well known and 
these oscillations are generally ascribed to the rising and sink- 
ing of the continents. This conclusion is undoubtedly in large 
measure true, but that the ocean bottoms also rise locally and 
so displace water, resulting in rising strand-lines, is readily 
deducible from the mere presence of oceanic islands and sub- 
merged ridges, because these masses have risen above the mean 
of the oceanic bottoms. On the other hand, it is known that 
periodically the ocean bottoms subside, but apparently no more 
than a few hundred feet at a time, and as a result of these 
subsidences the strand-lines the world over are markedly lowered 
when the overlapping marine waters are withdrawn and the 
continents are most emergent as they are at present. The 
mobility of the strand-lines is every now and then further 
augmented during the glacial periods when the volume of 
water in the oceans is decreased and the extracted quantity is 
piled up on the land as ice. During the Pleistocene, Daly? 
states that the strand-line was thus repeatedly lowered in the 
tropical areas, and estimates that the maximum was from 200 
to 230 feet, during the times of greatest cold. At the same 
time reef-corals were then almost non-existent, permitting the 
ever active marine waves to cut down the protruding oceanic 
islands within the tropics to a little below sea-level. These 
truncations are now the submerged platforms that lie as a rule 
between 180 and 300 feet beneath the present sea-level, and 
on which the reefs have since grown, keeping pace with the 


1R.. A. Daly, The glacial-control theory of coral reefs, Proc. Amer. Acad. 
Arts Sci., li, 157-251, 1915. | 


and Diastrophism in Oceanica. 93 


rising strand-lines resulting from the melting of the ice. On 
the other hand, the Pleistocene strand-lines remained neutral 
at about 35° north and south latitudes; further poleward they 
were positive, due to the gravitative power of the great masses 
of polar ice. 

Permanency of continents and oceans.—It is now more than 
fifty years since James D. Dana began to teach that the rising 
continents and the sinking oceanic basins have been, in the 
main, permanent features of the earth’s surface. He did not 
mean, however, that the continents have always had essentially 
the same shape, elevation, and areal extent that they have 
to-day. Still, Dana did not fully appreciate the amount of 
continental fragmenting that has taken place in the course of 
geologic time, though he clearly pointed out the foundering 
of Australasia, speaking of it in his famous Manual of Geology 
(page 797) as “a fragment of the Triassic world.” The 
teachings of Dana as to the permanency of continents and 
oceanic basins have been accepted in some form by all geologists, 
and lie at the basis of all zoogeography and evolution as well. 
In Dana’s time and to some extent even to-day geologists are 
swayed by the Wernerian or Neptunian theory of earth history, 
which postulates a gradual emergence of the land out of the 
decreasing hydrosphere through loss of water by crustal absorp- 
tion. Now, however, geologists are holding more and more to 
the hypothesis that the earth periodically shrinks, and each time 
it does so some parts or all of the continents rise more or less; 
but that in the main there is subsidence of the ocean bottoms 
equal in amount to the rising land-masses, that the water of 
the hydrosphere is constantly increasing in amount, and that 
even though the continents are in the main permanent, yet 
they are partially breaking down into the oceanic basins. 

From this we conclude that the enlarging oceanic basins are 
the most permanent features of the earth’s surface. On the 
other hand, along with the progressive subsidence, the bottom 
of the Pacific is also built up into many local volcanic cones 
by outpourings of lava, and further, it rises into more or less 
long mountain ridges. Some of these elevations of the bottom 
appear at the surface of the ocean as groups or lines of dead 
or active voleanoes (see fig. 1). Another general conclusion is 
that most of the “deeps” of the Pacific Ocean situated between 
18,000 and 31,800 feet beneath the surface occur near the con- 
tinents that exist now or existed formerly, or that they are 
located on the outer or oceanic side of mountain chains. These, 


94 ©. Schuchert—Problem of Continental Fracturing 


the ‘‘foredeeps” of Suess, are striking tectonic features of the 
lithosphere. As for the true limits of the Pacifie Ocean, Suess 
states that they are seen in the trends of long mountain folds. 
“So it is from New Zealand and New Caledonia to the borders 
of eastern Asia, to the Aleutians, and all along the western 
coast of both Americas.’”” 

Topography of the Pacific basin—So far we have been 
considering the problem of crustal depressions essentially from 
the standpoint of hypothesis. Now let us see what is actually 
known as to the topography of the Pacific Ocean and the geo- 
logic history of the Australasian region. An excellent summary 
of the present geography of the Pacific Ocean and the topo- 
graphy of its bottom is shown on the splendid map by Max 
Groll, recently published by the Institut fiir Meereskunde of 
the University of Berlin (1912). This map is based on Lam- 
bert’s equal-area azimuthal projection, with a replotting of all 
geographic and bathymetric data ascertained up to January, 
1912, and is therefore more up-to-date and far better than any 
heretofore published. Groll states that he considered at least 
15,000 soundings, made in all the oceans, and that yet there are 
many areas in the Pacific, hundreds of miles across, that are 
without a single one. It is therefore natural for him to add: 
“The greater part of the Pacific Ocean is still unexplored. . . . 
One is actually frightened at the little that is yet known of the 
bottom relief of the oceans and at the few data on which our 
representation of it is based. . . . Even in so relatively well 
known an area as the East Australasian seas, there are rarely 
more than from four to six deep-sea soundings to each five- 
degree field.” Our detailed knowledge of the actual configura- 
tion of the bottom of the Pacific is therefore seen to be very 
slight deed. 


PALEOGEOGRAPHY OF AUSTRALASIA. 


Formation of two geosynclines (see fig. 1).—Let us now 
review the larger features resulting from the ancient cycles of 
aérial erosion and marine deposition through which has been 
determined the paleogeography of Australasia. An analysis of 
this history since the Cambrian seems to show that at least two 
northeasterly trending troughs of sedimentary accumulation 
began to form early in the Paleozoic, The western one, which 
may be known as the Tasman geosyncline, almost wholly of 
Paleozoic development, is now partially elevated into the plains 

* Ed. Suess, Nat. Sci., ii, 180, 1893. 


and Diastrophism in Oceanica. 95 
Fie, 1. 


a 

> 
m 
> 


ee Ds ¢ 


vd 


We 


Fig. 1. Geologic plan of Pacific Ocean and bounding lands drawn on 
Groll’s map. Spaces between dashed lines circumscribe Australasia and the 
Oceanide arcs. Oceanic deepsin solid black. Closely ruled horizontal lines 
indicate the areas of the Tasman and New Zealand geosynclines. 

Lands ruled vertically indicate the Antarctic system of structures; lines 
to left, the Asiatic system ; lines to right, the American system ; horizontal 
lines, the Atlantic system. 


96 C. Schuchert—Problem of Continental Fracturing 


and mountains of eastern Australia, while the rest of it has 
sunk deep into the present Tasman sea. The other, or eastern 
trough, which also appeared early in the Paleozoic, maintained 
itself after this era in diminished extent throughout the Meso- 
zoic and even into Pliocene time. This may be known as the 
New Zealand geosyncline, a far narrower but longer one than 
that of Australia; the shorter southern portion has now risen 
into the mountains of New Zealand, while the much longer 
northern part has apparently subsided to a depth of not more 
than 9,000 feet, forming a submerged plateau upon which stand 
the voleanic islands of the Kermadecs and the Tongas. 
Historical geology of New Zealand (see figs. 2 and 3).—In 
the New Zealand trough there appear to be, according to Park,? 
no less than 45,000 feet of Paleozoic and 11 ,000 feet of Meso- 
zoic sediments, all of which are apparently ‘of marine origin. 
These are coarse in grain and have much interbedded igneous 
material, indicating that the adjacent lands were unstable and 
repeatedly reélevated into high lands. There appear to be no 


Cambrian or Triassic strata here, but the remainder of the . | 


geologic column is as well represented by marine deposition as 
is usually the case in geosynclines. There were at least four | 
times when the New Zealand trough was markedly subject to 
folding and uplift; these were toward the close of the Silurian, 
Devonian, Jurassic, and Cretaceous periods. During the Ceno- 
zoic, the New Zealand trough also appears to have been in con- / 
tinuous subsidence from late Eocene into Pliocené time, when 
about 9,000 feet of marine sediments had been laid down along 
the eastern sinking margin. Late in the Pliocene there was 
marked vertical uplift, probably as much as 4,500 and possibly 
even 6,000 feet. The nearly horizontal Cenozoic strata are now 
found in places at an elevation of 3,000 feet, having been 
depressed 1,500 feet during the time of Pleistocene glaciation. 
The high condition of New Zealand at this time united into a 
greater New Zealand all of the present outlying islands of the 
New Zealand plateau, no part of which is now submerged 
more than 3,000 feet. It should be added that Captain Hutton 
and Professor Dana thought that New Zealand was united with 
Wilkes Land of Antarctica in late Permian time. ~ 

Historical geology of Australia (see figs. 2 and 3).—In 
Australia there is no evidence of the Tasman sea during Cam- 
brian time, for the marine invasions at first were from the 
south and later across the entire medial portion of the con- 

* Jas. Park, Geology of New Zealand, 1910. 


and Diastrophism in Oceaniea. vt 97 


tinent. The trough began to appear as a sea-way in the 
Ordovician (75,000 feet of deposits, according to Siissmilch*), 
with the greatest time of subsidence during the Devonian 


(27,000 feet); it continued with some interruptions through- : 


out the Carboniferous and Permian (36,000 feet). During the 
Paleozoic, about 70,000 feet of essentially coarse sediments and 
interbedded volcanics were laid down in New South Wales, 
though smaller thicknesses seem to prevail elsewhere in eastern 
Australia. Here again we see the geologic results of high 
adjacent and often rejuvenated western lands. The record also 
shows that there were in Paleozoic time at least three periods 
of decided crustal folding (Ordovician, Silurian, and Devon- 
ian), and one of vertical uplift with faulting (during the close 
of Permian time). 

The marked crustal unrest of eastern Australia is also demon- 
strated by the vast quantities of extruded volcanics that in the 
main precede and accompany the deformations, appearing in 
greatest quantity-in the Ordovician, Devonian, and-Lower Car- 
boniferous. According ‘to Siissmilch,® “Nearly. every period 
belonging to. the Paleozoic era had its active voleanoes, from 
which extensive floods of lava were poured out. ~The Mesozoic 


era, on the other hand, appears to have been quite free from’ 


a voleani¢ displays. In the Cenozoic era, renewed activity took. 
place.” Following the Permian deformation’ the continent was, 
- repeatedly lifted above the embrace’ of the Tasman sea. It is 


true, however, that the Cretaceous seas have-recorded themselves: 
widely in this continent, but it was a shallow-water flood from, 


the north across medial Australia, and to the west of the high 
eastern margin, a condition. bringing to mind. the similar Cam- 


brian invasion. In the Eocene and Oligocene, the sea again. 
overlapped from the south across a part of central Australia, | 


and most markedly so in the Pliocene, when all of eastern 


Australia was vertically elevated and block-faulted between: 
1,500 and 7,300 feet above the level of the sea (during the 
“Kosciusko epoch” ). In compensation for this elevation the. 


Tasman sea sank, there being now great depths close to the 
continent which in one place go down to 18,500 feet. 

Time of severance of Australia from Asia: —Australasia 
(Australia, Tasmania, New Guinea) has been the most remark- 
able asylum among the continents for the preservation to this 


day of living examples of the plants and animals of the medieval ' 


world. Among these in great variety of size, habits, and adap- 


*C. A. Siissmilch, Geology of New South Wales, 1911. 
5 Op. cit., p. 161. 


98 CO. Schuchert—Problem of Continental Fracturing 


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Fie. 3. Paleogeography of Australasia in Permian, Triassic, Cretaceous, and late Hocene times. 


100 C. Schuchert—Problem of Continental Fracturing 


tations are the marsupial or pouch mammals, which in many 
ways parallel the placental evolution, and the far less diver- 
sified, more primitive, but more remarkable egg-laying mono- 
tremes. All seemingly had their origin in the continents of 
the northern hemisphere. The marsupials were at their culmin- 
ation in the Pliocene, when forms existed larger than any 
living rhinoceros (Diprotodon australis). From the chrono- 
genesis of these stocks and their diverse evolution in Australia, 
we learn that they must have been on that continent long before, 
and that they had been free from all northern invasions and 
hence escaped destruction by the higher, more intelligent, 
carnivorous placental mammals. We must, therefore, conclude 
that Australia has been an island continent at least since late 
Eocene time, for it is since then that the placental mammals 
have elsewhere dominated all other land life. 

The question next arises, When was Australia severed from — 
Asia? From the paleogeography as now deciphered, we learn | 
that Asia and Australasia were in complete connection during — 
most of the time from the Cambrian to the close of the Devon- 
ian. In the Lower Carboniferous, however, southeastern Asia 
began to be invaded by the Indian and Pacific oceans in the | 
region of what are now the East Indian Islands, and this inva- 
sion continued into the Pennsylvanian, after which there was — 
again connection lasting into Triassic time. A greater areal sub- 
sidence then occurred in southeastern Asia, New Guinea, New 
Caledonia, and elsewhere in Australasia; it began in the 
Jurassic and probably was repeated in Comanchian and Cre- 
taceous times. However, from the fact that carnivorous dino- 
saurs—land reptiles that arose in the northern hemisphere 
either late in the Permian or shortly afterward—are known in 
the Triassic of Australia (none at all occur in New Zealand); 
we must conclude that there was still. at this time an inter- 
mittent land-bridge connecting this continent with Asia. The 
time of more complete severance apparently came in the Juras- 
sic, though intermittent land connections probably persisted 
to the end of Cretaceous time.. The troughs of separation that 
distinguish the Asiatic land-masses from the Australasian ones 
seem to be the present Molucca-Banda-Arafura seas, which have 
depths varying between 4,650 and 21,000 feet (see fig. 1). 

The “Asiatic system” of tectonic structures takes in not 
only the Asiatic continent, but also the outlying series of island 
ares and the greater part of the East Indies, as Sumatra, Java, 
the islands east of and including Timor, Borneo, Celebes, and 


and Diastrophism in Oceanica. 101 


the Philippines. The Moluccas, however, appear to be geo- 
logically and structurally a part of New Guinea, and are there- 
fore remnants of the foundered continent of Australasia (see 


resalu)'s 


THE OCEANIDES AND FOREDEEPS. 


Oceanides.—Long ago Dana pointed out that there are fifteen 
chains of islands in the Pacific Ocean, all trending from 
N.30°W. to N.65°W. These are a part of the Oceanides of 
Suess, and Dana states® that they “are not independent lines, 
but subordinate parts of island chains. There are three great 
island chains in the [ Pacific] Ocean which belong to the north- 
westerly [trending] system—the Hawaiian [1, 500 miles long], 
the Polynesian [parallel chains 5,500 miles long], and the 
Australasian [2,000 miles long].” The first two series are 
chains of oceanic islands built wp largely by volcanoes, while the 
Australasian and the 2,500-miles-long New Zealand chain, with 
its northeasterly trend, are but the rising northern and eastern 
boundaries of the otherwise much broken down and foundered 
continent of Australasia. Here occur andesitic and other rocks 
characteristic of continents, and also much compressed and 
metamorphosed formations not seen on the oceanic islands. 

Foredeeps (see fig. 1).—In front of the New Zealand chain 
lies one of the five greatest deeps of the Pacific, the Tonga- 
Kermadec-New Zealand foredeep (known as the Aldrich deep), 
whose deeper parts are between 26,000 and 31,800 feet. There 
are no known foredeeps along the northern outer boundary of 
Australasia, but just within the outer chains there have been 
found three deeps ranging between 19,500 and 29,700 feet— 
the two Solomon Islands deeps (the nonihemn one is known as 
the Planet deep), and the unnamed deep between the New 
Hebrides and New Caledonia. To the east of the Philippines 
is another, more extensive foredeep attaining to 27,800 feet 
(Swire deep); the Pourtales deep lies 500 miles to the east 
and the Challenger deep 500 miles still farther east along the 
eastern side of the Guam-Ladrone or Marianne Islands, with a 
greatest depth of 31,315 feet. To the east of the Asiatic fore- 
deeps lies the Pacific Ocean proper, whose average depth varies 
between 15,000 and 18,000 feet, and on its floor rise the more 
or less submerged Oceanides. 


*J. D. Dana, Manual of Geology, 4th ed., 1895, p. 37. 


102. C. Schuchert—Problem of Continental Fracturing 


Origin of the Oceanides.—Finally, we must ask, When did 
the thousands of oceanic islands—the Oceanides—arise? They 
occur singly, in groups, and most abundantly in linear arrange- 
ment. The isolated and the grouped islands probably all repre- 
sent great voleanic cones that have built themselves up from 
the ocean bottom through the eruption of rock material. What 
is the origin, however, of those that are arranged in linear 
series? Are they ranges of voleanoes that have likewise grown 
from the depths but are situated on lines of fracture in the 
lithosphere, or do they rest on the crests of great arches or 
foldings of the ocean bottoms? Equally important questions 
are: What is their geological history, and have they simul- 
taneous or successive origins? So far as known, none of the 
smaller oceanic islands reveals fossils older than the later Ter- 
tiary, a condition that appears to be in harmony with the theory 
that the sum of their movements is negative and thus in keep- 
ing with the idea that the oceanic bottoms are in the main sub- 
siding areas. Because of the fact that in the oceans volcanic 
mountains and folded mountains are protected from erosion 
by the covering of water, they, unlike the ridges of the dry land, 
last from one era to another. In fact, the submerged ridges 
lying at depths of less than 10,000 feet will be built up through 
the rapid accumulation of organic calcareous débris, while the 
abysses on either side will receive little solid matter, because of 
the great solvent power of the water of the deeper parts of the 
ocean. In the words of Suess’: “The result is an exaggera- 
tion of the relief.”” Because of the inaccessibility of the sub- 
merged parts of the Oceanides, we have as yet little evidence 
showing when they originated, and yet on the basis of the 
periodically recurring diastrophism it would seem that none is 
older than the Permian, a time of intense and world-wide 
crustal deformation. Others may have originated during the 
late Cretaceous crustal movements, and all may have again been 
reélevated and stirred into volcanic activity with the world-wide 
crustal readjustments that began in the Miocene and continued 
into late Pliocene time. 

Some objections to continental fracturing.—The views just 
presented are those of most paleontologists, but there are geolo- 
gists and zoogeographers who do not accept the idea of conti- 
nental fragmentation taking place on so large a scale as is here 
indicated. They hold firmly to the theory of the permanency 
of continents and ocean basins, believing that these positive and 
negative elements of the earth’s surface have always retained 

7 Ed. Suess, Face of the Earth, vol. iv, p. 326. 


and Diastrophism in Oceanica. 108 


the forms they now have. In their eyes, the physical evidence 
in the areas of fragmentation, and especially in the southern 
hemisphere, is not of a nature to compel the view that large 
lands formerly existed here, and they say, further, that there 
is no process in the mechanics of the earth known to them that 
would account for such down-breaking of the lithosphere. 

Coleman in his presidential address of 1915 holds firmly to 
the theory of the permanency of oceans and continents. He 
does not believe in a Gondwana Land across the Indian Ocean 
uniting Africa to peninsular India. His belief is founded on 
the knowledge that “the earth’s crust over large areas . . . 
approaches a state of isostatic equilibrium,” and that ‘‘on the 
broad seale continents are buoyed up because they are light, 
and ocean bottoms are depressed because the matter beneath 
them is heavy.” In this we agree with Coleman. But he then 
concludes: ‘‘There is no obvious way in which the rock beneath 
a sea-bottom can be expanded enough to lift it 20,000 feet, as 
would be necessary in parts of the Indian Ocean, to form a 
Gondwana Land; so one must assume that light rocks replace 
heavy ones beneath a million square miles of the ocean floor.” 

The fallacy of this conclusion is the assumption that the now 
sunken parts of eastern Gondwana were raised out of the depths 
of the Indian Ocean after it became very deep, i. e., seemingly 
since the later Mesozoic and certainly not before Permian time. 
The paleontologists, on the other hand, postulate the existence 
of Gondwana at least as early as the Carboniferous, because 
of the origin and wide distribution in the southern hemisphere 
of the Glossopteris flora (Africa, India, Australia, Antarctica, 
South America), and the writer has long been holding that the 
origin of Gondwana goes back into Proterozoic time. It is 
therefore not a question of raising Gondwana out of the realms 
of Neptune and of buoying up its rocks and lessening their 
specific gravity through expansion. These postulates are 
unnecessary, for Gondwana has always been in existence since 
there were oceans, or at least since the beginning of Paleozoic 
time; when the oceans began to deepen markedly in the earliest 
Mesozoie and since then, these great sinking fields took into 
themselves the above-mentioned sunken parts of Gondwana and 
Australasia. 

Another. erroneous though less significant argument of Cole- 
man’s is that because “geodesists are demonstrating that the 
earth’s crust over large areas, and perhaps everywhere, 


*A. P. Coleman, Dry land in geology, Bull. Geol. Soe. America, XxXvii, 
175-192, 1916. 


104 C. Schuchert—Problem of Continental Fracturing 


approaches a state of isostatic equilibrium,” therefore this 
balance is demonstrated everywhere over the earth’s surface. 
It is true that he writes “perhaps everywhere” but his argu- 
ment is positive and unqualified when applied to Gondwana. 
We must therefore ask, What do we know about the detailed 
isostasy of the oceanic areas? The answer must be that in a 
broad way we know much, and that the oceanic bottoms are on 
the average of denser rock than the lands. However, it is not 
only a question of average densities but the greater one as to 
what we know of the specific gravity of the entire area of any 
ocean bottom. The answer in this case must be ‘Very little 
indeed,” because it is well known to geodesists that no knowl- 
edge is more desirable than a complete survey of the oceanic 
areas as to their detailed specific gravities and bottom relief. 
The writer therefore concludes that it is not “hard to imagine 
a mechanism that could do the work” because it is the same 
mechanism that in Mesozoic time made the present channel of 
Mozambique which separates Madagascar from Africa—a 
sunken block now a water-way from 240 to 600 miles wide 
and from 5,000 to 10,000 feet deep. 

As for the ancient life found living and fossil in the conti- 
nents of the southern hemisphere, and especially with regard 
to the distribution of the Permian Glossopteris flora, those who 
hold to the complete permanency of continents and oceans say 
that we are still too ignorant of the world’s organisms and their 
histories to conclude from them that their asylums (Australia, 
India, Africa, South America, Antarctica) were formerly con- 
nected one with another; or they hold that the organisms 
reached these places by accidental dispersal through the air 
or by being rafted across the intervening water areas. This 
conflict of views marks one of the greatest outstanding problems 
of geology and paleontology. The writer, however, is over- 
whelmed by the facts revealed in the geographic distribution 
of the ancient land floras and faunas and the marine life, and 
is compelled to dissent from the rigid view of the permanency 
of continents. 

Conclusions.—To sum up, we may say that the bottom of the 
Pacific Ocean in the region of greater Australasia seemingly 
became more and more mobile with the Lower Carboniferous 
and especially during the Jurassic and Cretaceous. During this 
very long time the eastern half of the Australasian continent, 
a land about 1,800 miles east and west and 2,200 miles north 
and south, was folded into a series of parallel ridges trending 


and Diastrophism in Oceanica. 105 


northwest and southeast, nearly all of which went down more 
and more beneath the level of the sea to a maximum depth 
of about four miles and an average depth of between one and 
two and a half miles. Small parts of the ridges still protrude 
above the ocean (at least New Caledonia), but most of what 
we see are the volcanoes that have built themselves up above the 
folded rocks to the level of the sea. Further, the entire oceanic 
area of the Oceanides also subsided during the Mesozoic and 
Cenozoic, and possibly as much as 7,000 feet; while this was 
taking place the bottom was apparently folded and built up by 
voleanie material into many more or less parallel ridges, the 
Oceanides, a series of ares extending over an area of about 
3,500 miles east and west and the same distance north and 
south. Finally, we may add that the entire western half of the 
Pacific bottom, and especially the Australasian region, appears 
to be as mobile as any of the continents of the northern hemi- 
sphere, with the difference that the sum of the continental 
movements is upward, while that of the ocean bottoms is 
downward. 


106 Browning, ete.— Tellurium, Arsenie, ete. 


Arr. X.—On the Qualitative Separation and Detection 
(L) of Tellurium and Arsenic and (LL) of Lron, Thalliun, 
Zirconium and Titanium; by Puiu E. Brownie, G. S. 
Siupson and Lyman E. Porter. 


{Contributions from the Kent Chemical Laboratory of Yale Univ.—celxxviii. | 
ib 


In a previous paper from this laboratory by one of us* it 
was shown that an attempt to separate arsenic and tellurium by 
the addition of magnesium chloride mixture to a solution of 
ammonium arsenate and tellurite according to the method of 
Noyes and Brayt+ often resulted in some confusion due to the 
fact that a magnesium compound of tellurous acid was precipi- 
tated which interfered with the test for arsenic and removed a 
considerable part of the tellurium. 

The fact that the original hydrogen sulphide precipitate is 
decomposed by hydrochloric acid and potassium chlorate, and 
that this oxidation process would probably effect at least the 
partial oxidation of the tellurium to telluric acid, suggested the 
investigation of the formation of the telluric acid under these 
conditions and its effect upon the method. A number of 
experiments along this line seemed to show that after the treat- 
ment of tellurium with hydrochloric acid and potassium chlor- 
ate a mixture of tellurous and tellurie acids resulted and that 
the ammonium tellurate gave a precipitate with magnesium 
chloride mixture as has been shown to be the case with ammo- 
nium tellurite. From these results we conclude that any attempt 
to remove tellurium from arsenic by this method is apt to yield 
doubtful conclusions. We therefore recommend that the tel- 
lurium be removed first by the method of Noyes and Bray, 
viz. precipitation of elementary tellurium by sodium sulphite 
in dilute hydrochloric acid solution in the presence of potas- 
sium iodide. The filtrate from the teliurium should be boiled 
to remove excess of sulphur dioxide, then treated with hydro- 
gen dioxide, boiled to remove the greater part of the iodide 
and then made alkaline with sodium hydroxide and treated 
with more dioxide to oxidize the arsenic to arsenate. This 
solution is then acidified to destroy sodium hydroxide and 
made alkaline with ammonium hydroxide and treated with 
magnesium chloride mixture which precipitates the arsenate. 
The filtrate from the arsenate may be tested for molybdenum 
by potassium sulphocyanide and zinc in hydrochloric acid solu- 
tion according to Noyes and Bray. This modification of the 
original method gave satisfactory results when used by a class 
of about forty. 


* Browning, this Journal, xl, 349, 1915. 
+Jour. Amer. Chem. Soc., xxix, 137. 


a a 


Browning, ete.—Tellurium, Arsenic, ete. 107 


TABLE I, 
Test for Tellurium and Arsenic in Hydrochloric Acid Solution. 
Treatment of solution with Na,SO, + KI. 
| | 
Pi Te F 
Treatment by boiling to remove 
the SO,, by H,O, to break up the 
iodide, by boiling to remove iodine, 
by excess of NaOH and H,O, to 
oxidize the arsenic to arsenate, 
acidifying to remove excess of 
NaOH, by NH,OH and MgCl.. 
NH,Cl mixture, and filtration. 


P. NH,MgAsO, F 
Confirmation by Testing for Mo by 
AgNO,, forming red KSCN and Zn in HC). 
brown Ag, AsO,. Red Mo(SCN),. 
TaBLeE II, 


Test for Iron, Thallium, Zirconium and Titanium Taken in the Form of 
Hydrowides. 

Solution of hydroxides in the least amount of H,SO,. Treat- 
ment with H,O,, a red coloration indicating titanium, Treatment 
with Na,HPO, in the presence of NaOH* and addition of H,SO, 
to acidity. 


P, ZrOHPO, FE. 
Treatment with NaOH. 
P. Fe Nie hydroxides FF. 
Tl { or phosphates Treatment with 
Solution in H,SO,. H,SO,, Na,SO, and 
Treatment with Na,SO, Na,HPO, and fil- 
+ KI and filtration. tration. 
Pe MiOHP@: 
P. Til BF. 


Treatment by boiling (to remove 
SO,), with H,O, to break up iodide, 
by boiling to remove iodine, with 
KSCN. Red coloration indicates 
Fe. 


* This step is to prevent the excess of acid when sodium phosphate is 
added which interferes with the ready precipitation of zirconium phosphate. 
Gentle warming after the addition of the sodium hydroxide gives good 
results, but in no case should the solution be boiled, and if warmed it 
should be cooled and treated with hydrogen dioxide before acidifying with 
sulphuri¢ acid, 


Am. Jour, Sci.—FourtH Smrizes, Vou. XLII, No. 248.—Aveusr, 1916. 
8 


108 Browning, etc.— Tellurium, Arsenic, ete. 


i015 


The separation of iron in the ferrie condition, thallium in the 
thallic condition, titanium, and zirconium is made by Noyes 
and Bray* by dissolving the hydroxides in hydrochlorie acid 
1°12 sp. gr. and shaking the solution with ether; the ferric 
and thallie chlorides dissolving i in the ether and the chlorides 
of titanium and zirconium being left in the water layer. The 
iron and thallium are separ ated by sulphnrous acid and potas- 
sium iodide and the titanium and zirconium by sodium phos- 
phate in the presence of hydrogen dioxide. 

This method gives good results but is slow in manipulation 
and inconvenient and difficult to carry out successfully in the 
hands of a large class of students lacking experience in such 
procedures. 

As a substitute we present the following method which has 
given satisfaction and rapidly obtained results -— 

The hydroxides are dissolved in sulphuric acid and hydro- 
gen dioxide added, a red coloration indicating titanium. The 
solution is then made faintly alkaline with sodium hydroxide 
and sodium phosphate is added. Sulphuric acid containing 
hydrogen dioxide is added to acidity, the latter reagent serving 
to keep the titanium in the higher condition of oxidation. 
The zirconium phosphate remains as a precipitate and is filtered 
off. After the zirconium is removed the filtrate obtained is 
treated with sodium hydroxide which precipitates the iron and 
thallinm. After these are removed the alkaline filtrate con- 
taining the titanium is acidified with sulphuric acid and treated 
with sodiam sulphite and a little more sodium phosphate, when 
the titanium phosphate appears. The precipitated hydroxides 
or phosphates of iron and thallium are dissolved in sulphuric 
acid, the solution treated with sodium sulphite and the thallous 
iodide precipitated by potassium iodide. The filtrate from the 
thallous iodide is boiled to remove sulphur dioxide, treated 
with hydrogen dioxide and again boiled to remove iodine and 
oxidize the iron, and then with potassium sulphocyanide to 
identify the iron. 


* Jour. Amer. Chem. Soc., xxx, 481. 


ee 


a 


W. A. Turner—Separation of Vanadium. 109 


Art. XI.—The Separation of Vanadium from Phosphoric 
and Arsenic Acidsand from Uranium; by W. A. Turner. 


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


Iy a previous paper* the determination of vanadium when 
present in the form of a soluble vanadate has been described. 
It seemed desirable to make use of this determination for 
separation of vanadium from some of the common impurities 
with which it is associated in nature. To this end separations 
from phosphoric and arsenic acids and from uranium have been 
attempted and the following pages are a record of these ex- 
periments. 

In the separations from phosphoric and arsenic acids the pro- 
cedure was exactly the same as in the simple determination of 
vanadium with the exception that the precipitates required a 
more thorough washing. This procedure is briefly as follows : 

Portions of about 25 em* of the metavanadate solution, 
accurately weighed, were diluted to about 150-200 cm*. The 
amount of phosphate or arsenate indicated was added and 
enough sulphuric acid to make about one per cent of the 
volume. COupferron (the ammonium salt of nitrosopheny!l- 
hydroxylamine) was then added in six per cent solution with 
stirring until a slight excess was present as shown by the ap- 
pearance of a white precipitate of nitrosophenylhydroxylamine 
(formed when cupferron comes in contact with an acid solution). 
Two or three cubic centimeters in excess are added and the 
precipitate is filtered without delay and washed with a one 
per cent solution of sulphuric acid containing a little cupferron. 
The precipitate after being allowed to drain for a time on the 
filter is transferred to a platinum crucible, dried, ignite] and 
weighed as vanadium pentoxide. 

The vanadium used was a solution of ammonium metavana- 
date in distilled water which when standardized by the cup- 
ferron method gave the following result : 

25 grms. NH, VO, sol.=>= 0°1003 grm. V,O.. 

As sources of phosphoric and arsenic acids disodium hydro- 
gen phosphate and disodium hydroven arsenate were used. 
The precipitates were washed fifteen times. 

The following table shows how successfully these separations 
can be accomplished : 


Grms. V,0; per 
20 grms.NH,VO; sol. 


Grms. NH,VO; Grms. V2.0, — “x ~ 
sol. taken Impurity added found Found Taken 
25°0940 15 grms. 

Na, HPO,.12H,O 0:1008 0°1004 071003 
25°0973 ee 0°1006 0°1002 0°1003 
95°0244 1°5 grms. 

Na,HAsO,.12H,O 0'1006 0°1005 0°10038 
25°0841 ee 0:1007 0°1004 0°10038 


*This Journal (4), xli, 339, 1916. 


110 W. A. Turner—Separation of Vanadium. 


The separation of vanadium from uranium presents greater 
difficulty and in fact as yet a good separation has not been 
accomplished, or this the same ammonium metavanadate 
solution used in the previons experiments served. As a source 
of uranium a solution of uranyl nitrate in distilled water was 
made. ‘This solution, when standardized by the ammonium 
hydroxide method (in which ammonium uranate is precipitated 
bY, ammonium hydroxide in the presence of ammonium 
chloride, washed with a dilute ammonia solution containing 
ammonium chloride, ignited first in the Bunsen burner and 
then in the blast to U,0,) eave : 

25 grms, uranyl nitrate sol.-c=0°1991 grm. U,O,,. 

When these vanadium and uranium solutions are brought 
together a yellow precipitate of uranyl vanadate is formed. If 
sufficient hydrochloric or sulphuric: acid is added the pre- 
cipitate will dissolve. The precipitate appears to be insoluble 
in ammonia. 

It is necessary therefore in order to effect a separation of 
these elements to make the cupferron pr ecipitation in a fairly 
strongly acid solution. In the experiments recorded about 
10 cm* of sulphuric acid per 100 cm’® of solution were used, 
The wash-liquid also was a sulphuric acid solution of about the 
same strength containing 1:5 grms. cupferron per liter. 

Another expedient adopted to accomplish a more complete 
separation was to place filter and precipitate after thorough 
washing back in the original beaker, treat with ammonia 
(which dissolves the, vanadium precipitate) then make nearly 
acid and cool to 20° before bringing to acidity. After dilution, 
acidification and the addition of a little more cupferron bring 
down the vanadium which after filtration and washing is 
obtained in fairly pure form. 

The uranium in the filtrate was determined by the ammonium 
hydroxide method. 

In this way the foilowing results were obtained : 


Grms. V0; Grms. U30¢ 
Grms. Grms. per 25 germs. per 20 grms. 
NH,VO3 U0.(NOs)z Grms. Grms. NH,VO; sol. U0.(NOs)o sol. 
sol. sol. V20; U308 SS ' ammmmmtatiatnco a 
taken taken found : found Found Taken Found Taken | 
15°3903 25°1603 0'0683 0'2013 0°1109 0°1082 0°2000 0'1991 
90°2137 20°2317 0°0905 0°1610 0°1119 0'1082 0°1990 0°1991 
20°2757 19°0602 0°0904 0°1514 01115 0'1082 0°1985 01991 


June 14, 1916. 


S. Ichikawa—Some Notes on Japanese Minerals. 111 


Art. XII.—Some Notes on Japanese Minerals; by Suim- 
matsu IcHrkaWa. 


I. Natural Etching of Galena Crystals. 


Gatena crystals with rounded edges from Kuratani, Kaga 
Province, have been long known. Their rounded: edges, how- 
ever, have not yet been discussed in detail. In 1908 I also 
observed galena crystals with rounded edges from the Kamioka 
mine in Hida Province. The natural etching of galena crystals 
from the above localities is illustrated in the figures of the 
following plate (1). 

Fig. 1 shows the natural etching of a galena crystal from 
Kuratani. The pits and elevations are given in detail in figs. 
2 to 6. 

Fig. 2 shows varieties of natural pits on an octahedral face, 
the three walls of the pit being parallel to the cubic faces. 
Fig. 3 shows pits on a cubic face, the sides being parallel to 
the octahedral faces. Fig. 4 shows natural elevations on a 
eubie face; the sides of these elevations are formed by the 
faces of an octahedron. Fig. 5 shows the relation between the 
outlines of the natural pits and the edges of the cubic faces. 
Fig. 6 gives the relation between pits and the cubic cleavage ; 
the dotted lines of ad, cd, etc., are innumerable pits in the 
direction of the cleavage. 

Fig. 7 shows the natural etching of a galena crystal, from 
the Kamioka mine; details are given in figs. 8 and 9. 

In fig. 8 the pits and striations on the cubic and octahedron 
are shown much magnified. Fig. 9 shows the relation between 
outlines of the different pits and the edges of the octahedron. 

Fig. 10 is a cubic crystal with rounded edges, also from the 
Kamioka mine. The etchings observed on a rounded solid 
angle are given in fig. 11 (compare fig. 4). 

Fig. 12 shows the etchings on a rounded edge of a cubic 
erystal; and fig. 13 the various forms of natural pits on the 
rounded-edges of a similar erystal. Both of these are also 
from the Kamioka mine. 

The symmetry of the etched figures on the above crystal 
faces corresponds to the symmetry of the group to which the 
given crystal belongs, and the resulting form in the etching is 
supposed to make up an octahedron (see figs. 4 and 11). 

Fig. 1 is magnified 3 times; fig. 7, 1:5 times; fig. 10, 2 
times; the other figures from 80 to 140 times. 

Reference should also be made to Becker’s results on galena 
erystals published in 1885. (Min. petr. Mitt., vi, 237.) 


112 


S. Ichikawa—Some Notes on Japanese Minerals. 


Natural etching of galena crystals. S. Ichikawa, del. 


S. Ichikawa—Some Notes on Japanese Minerals. 118 


Il. Natural Etching of Calcite Crystals. 


The natural etching of Japanese calcite crystals has already 
been described by Prof. K. Jimbo and Mr. F. Otsuki, but the 
etched figures on other faces (except m2, —m2, etc.) and the 
forms resulting from the etching have not yet been described 
in detail. In 1907 I observed calcite crystals in Tertiary tuff 
from Shimoshijo, Shinyokoe-mura, Imatate-gun, Fukui-ken. 
Since then, I have repeatedly visited the same locality and 
collected additional crystals more etched than those before 
described. These specimens are illustrated in the accompany- 
ing figures 1 to 7 (LI). 

Fig. 1, A, shows a short prismatic crystal (42, -rR, wf, 
mn, »P2, ete.) with natural etchings. B shows the rhom- 
bohedral elevations that are observed on the face -47, in hori- 
zontal projection; here the pole-edges of the rhombohedral 
elevations are parallel with striations on the face—$. C shows 
two elevations accompanied by rhombohedral elevations which 
are rarely found. D shows the relation between the outlines 
of the pit, striations, ete., and the edges of the faces of. In 
the striations the angle BAC is nearly 140°. In the pits 
the angles are: AOB= 120°; BOC = 28°; COD =45°; 
DOE =90°. E and F show a group of the pits on the faces 
of of. The outlines of the figures A and B are magnified six 
times, but the pits themselves are magnified 80 to 140 times. 

Fic. 2, A, is a long prismatic crystal with the same faces as 
fig. 1, A. Bisa horizontal projection on the vertical axis of 
the er ystal. The outline of the figure is magnified 7 times, 
but the pits 80 times. 

Fig. 3 shows various forms of natural pits on the faces -m R, 
wf, ete., of the above crystals. On the face -mf, A and C 
are observed abundantly, but B is very rare. On the faces 
of wf, D, E, and F are observed abundantly, but G and J 
are very rare, the angles are: E(A BC) = 90° ; F(A BC)=110°; 
G(ABC) = 80°; : J(ABC) = —100°. On the face A(mfn 2), 
H and I are observed. On the faces 4h, wP2, mPn, ete., 
striations are usually observed. The outline of the figure i is 
magnified 10 times, but the pits are magnified 80 to 140 times. 

Fig. 4 4 shows natural pits formed on the rhombohedral faces 
(m R) of a prismatic crystal. A isa front view. B isa hori- 
zontal projection on the vertical axis. C and D show pits on 
the rhombohedral face in horizontal position ; the angles are : 
ABC == 80°; ADC — 40°. : 

Fig. 5 shows natural pits and striations formed on a face of 
ao P2 (magnified 360 times). 

Fig. 6 shows natural etchings on the solid angles between 
and «0 #. The figure is magnified 9 times, the etched figures 
140 times (angle A = 30). 


S. Ichikawa—Some Notes on Japanese Minerals. 


114 


Il. 


il 


iN 


D 


| 


gs of calcite crystals. §S. Ichikawa, del. 


Natural etchin 


S. Ichikawa—Some Notes on Japanese Minerals. 115 


Fig. 7 shows rhombohedral elevations formed on a face » 
of a short prismatic crystal more etched than fig. 1, A (magni- 
fied 70 times). 

The symmetry of the etched figures on the above crystal 
faces corresponds to the symmetry of the group to which the 
given crystal belongs, and the form resulting from the etching 
is supposed to be a rhombohedron (see fig. 1, B; fig. 7, etc.). 

For Meyer’s results on calcite crystals see Jahrb. Min. I, 74, 
1883; and for those of Lavizzari on a calcite ball etched with 
sulphuric acid see Naumann-Zirkel’s Elemente der Mineralogie, 
p. 200, 1907. 

The results of K. Jimbo on the natural etching of calcite 
erystals from Kitahama, Izumo Province, are described in 
Jour. Geogr. Tokyo, vol. vii, 226, 1899. Also those of F. 
Otsuki on the natural etching of calcite crystals from Sawada- 
mura, Kamo-gun. Izu Province, in the same journal, vol. viii, 
283, 1900. 


Ill. Pinite: A Mica Pseudomorph after Cordierite in Trillings 
, Srom Torihama. 


The trillings of Japanese cordierite crystals and their pseudo- 
morphs have already been described by Prof. A. Kikuchi,* B. 
Koto,t K. Jimbo,t Mr. S. Hirose,$ and others. In these 
papers, however, the structures of the trillings in the crystals 
and their pseudomorphs have not yet been discussed in detail. 
In 1908 I personally visited Torihama, Ya-Mura, Mikata-gun, 
Wakasa Province, which has been long known as a locality of 
pinite, and collected a few weathered specimens of the mineral. 
The results of the study of these specimens are mentioned in 
the accompanying figures (III). 

Fig. 1 is an individual of the pinite (natural size). A, shows 
a part changed into mica. 

Fig. 2 shows the structure of the trilling in a section plate 
eut perpendicularly to the vertical axis of the pinite. The 
black portion shows the original substance of the cordierite ; 
the remainder is the pseudomorphons mica; parallel lines show 
cleavage fissures changed into mica (magnified 2 times). 

Figs. 3-4 show the structure of the trillings in basal sections ; 
the specimens are wholly changed to mica. The white part 
in the figure shows micaceous substance, and the rest is an 
earthy substance produced by the decomposition of the mica 
(nat. size). 

* Cordierite from Watarasegawa, Jour. Sci. Coll., vol. iii, 1890. 

+ Cordierite from Doshi, Jour. Geogr. Toky0, vol. xvi, 224, 1909. 


{Cordierite pseudomorphs from Tsukuba, Torihama, Doshi, etc., Beit. 
Min. Japan, II, 62, 1906. 


§ Cordierite from Sakuratenjin, Jour. Geogr. Tokyo, vol. xxi, 66, 1904. 


116 S. Lehikawa—Some Notes on Japanese Minerals. 


Ill. 


Trillings of cordierite. S. Ichikawa, del. 


S. Ichikawa—Some Notes on Japanese Minerals. 117 


Figs. 5, 6 are similar to fig. 2, but only fig. 6 shows the 
original cordierite-substance (nat. size). 

Fig. 7 shows transverse and longitudinal sections of a pinite 
er ystal, The outer part of each changed into mica, the wedge- 
shaped pieces look as if rounded or hollowed ; par allel lines in 
each piece are cleavage fissure changed into mica (nat. size). 
Figs. 8 to 12 are the same as fig. 7, but the funnel-shaped 
por rtion in fig. 8 is more micaceous than the adjoining portions, 
and those in fig. 11 is opposite to the former (nat. size). 

Fig. 13 is a model figure showing the natural composition of 
the trillings, separated into eight parts by weathering (mag- 
nified 2°5 times). 

Figs. 14 to 16 show parts of the trilling separated by 
weathering, each piece consists of cordierite and the outer 
parts are somewhat changed into mica (nat. size). 

Fig. 17 shows the weathering of a pinite, the radial mesen- 
teries in the center seem to be the secondary sediment of 
silica which filled the fissures of the trilling and cleavage of 
the crystal (magnified 3 times). 

In the above study, it is proved that the trillings in the 
cordierite crystals and the pseudomorphs are separated into 
eight parts by weathering, and also that each portion of the 
trillings is gradually changed into mica from the outside and 
their cleavage-fissures by weathering, till finally a completely 
micaceous pseudomorph results, The funnel- shaped pieces in 
the trillings are more rapidly separated or decomposed than 
the adjoining parts. In the entire micaceous pseudomorph, its 
cleavage is found in the direction of the basal face as mica, and it 
is easily cleaved by the finger-nail. The micaceous pseudo- 
morphs are decomposed into earth at last. 


IV. On the Crystal-Aggregates of Native Arsenie. 


Native arsenic crystals from the Akadani mine, Shimoadimi- 
mura, Ono-gun, Prov. Echizen, have been long known by the 
name of “ konpetoishi”; they occur in association with stib- 
nite, realgar and minute erystals of pyrite; the country rock is 
a liparite. The mineral was first observed by N. Sasamoto,* 
who also sent specimens abroad, where they have been ex- 
amined and in part described. Since 1906 1 have repeatedly 
visited Akadani and collected some interesting specimens show- 
ing the crystal-ageregates. A preliminary note has already 
been published ;+ the following gives fuller details. The varic- 
ties noted are: 

* Jour. Geol. Soc. Toky6, vol. ii, p, 461, 1895 ; see also two notes by T. 
Hiki, ibid., vol. v, pp. 78 and 167, 1898, and vol. vii, p. 368, 1900; Mr. 
Wada’s ‘* Minerals of Japan,” p. 26, 1904 ; Naumann-Zirkel’s ‘‘ Elemente der 
Mineralogie,” p. 414, 1907. 

+ Jour. Geol. Soc,, Toky6, vol. xvi, p. 197, 1909. 


118) S. Lehikawa—Some Notes on Japanese Minerals. 


IV. 


Crystal aggregates of native arsenic. S. Ichikawa, del. 


S. Ichikawa—Some Notes on Japanese Minerals. 119 


a. Concentric radial aggregates about the principal axis of 
the rhombohedron forming a sphere, this form has long been 
known by the name of “konpetoishi,” they measure 10 to 15"" 
in diameter (fig. 1.) 

b. Parallel growth of numerous rhombohedrons forming 
cube-like forms, measuring 5 to 10™™ in diameter (fiy. 2.) 

ce. Complex penetration- -twins of four individuals of the 
type, of many interesting forms, measuring 5 to 10™" in 
diameter (figs. 3 to 10.) 

d. Irregular-ageregates of the individuals of d measuring 20 
to 830™™ in diameter. 

Simple rhombohedral crystals, 8 to 4"™ in diameter, were 
also found attached to the vein-stone. In the above erystal- 
ageregates, a and d are found more frequently than 6, but the 
b type is very rare. 

When fresh, the arsenic is tin-white, but after half a day 
it is gradually tarnished to a dark color, and after six montlis 
becomes dark-gray by oxidation. When decomposed by long 
exposure to the air, the spherical aggregates sometimes natu. 
rally reveal the concentric zonal structure in their fracture 8, 
and the spongy structure in their outer part. 

The crystal-aggregates, especially the irregular forms, some- 
times enclose stibnite and minute crystals of pyrite; this is espe- 
cially common with the irregular forms. Some specimens are 
also colored by orange-yellow realgar. 

The microscopical structure in the fracture of spherical 
ageregates or complex penetration twins shows innumerable 
cleavages in the layers of the concentric zonal structure much 
resembling that of the bulb of a lily (ex. jig. 12.) 

Native arsenic (so-called “ ROABELOIEAR? *) is said to have been 
recently observed also, in Kochi, Kawada-mura, Imatate-gun 
near the Akadani-mine. 


The above papers, with the accompanying illustrations, were 
presented to the Twelfth International Geological Congress i in 
Toronto, Canada, in August, 1913. 


Kitashinjo-mura, Imitate-gun, Fukui-ken, Japan. 


120 T. N. Dale —Algonkian- Cambrian Boundary. 


Arr. XIII.—TZhe Algonkian-Cambrian Boundary East of 


the Green Mountain Awis in Vermont ;* by T. Netson 
DALE. 


Dvurine parts of three summers, 1918-1915, the writer was 
engaged in tracing the boundary between the pre-Cambrian 
rocks of the Green Mountain range in Vermont and the Cam- 
brian beds east of them. The work began on the south near 
Heartwellville, in Readsboro township, "Bennington County 
(lat. 42° 50’; Jong. 73°), and ended on the north at the southern 
line of the town of Stockbridge in Windsor County (lat. 43° 
42’ 30”; long. 72° 49’), the whole latitudinal distance being a 
little more than 60 miles, of which, however, two stretches were 
not studied, reducing the distance to 46-7 miles, In this the 
boundary, measured “along its meanders and sinuosities, is 57 
miles long. 

As many years will probably elapse before the geological 
mapping of this region is completed and the U.S. G. S. folios 
of it reach the public, the more important results of these ex- 
plorations are here briefly outlined. These results concern the 
structure of the rocks and their origin and composition. 

The recent geological literature of the region consists of two 
papers by ©. L. Whittle and an abstract of a note by Arthur 
Keith.t 

The gist of Mr. Whittle’s papers is “‘ that immediately below 
the Lower Cambrian quartzite in Vermont there is a series of 
more or less metamorphosed clastic rocks of no inconsiderable 
thickness; the upper member of this series being a dark 
chloritie mica schist; the lower member a highly metamor- 
phosed conglomerate and between these several pebbly lime- 
stones and pebbly micaceous quartzite strata. . . . These rocks 
are referred to the Algonkian Period.” Below the above series 
‘a still older more metamorphosed and more variable series of 
stratified rocks of Algonkian age occurs, together with gneisses 
and schists whose origin is unknown, and abundant metamorphic 
equivalents of old basie rocks.” 

In his article in this Journal (p. 351) he thus refers to two 
divergent foliations. ‘Structurally we have stronger evidence 
furnished by a conglomerate gneiss at North Sherburne where 
an anti-clinal axis trending about 25° west of north represents 

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

+ Whittle, Ch. L., The occurrence of Algonkian rocks in Vermont and the 
evidence for their subdivision, Journ. of Geol., vol. ii, pp. 396-429, 1894. 

Whittle, Ch. L., The general structure of the main axis of the Green 
Mountains, this Journal, 3d ser., vol, xlvii, pp. 347-855, 1894. 

Keith, Arthur, A pre-Cambrian unconformity in Vermont, (Abstract) 
Geol. Soc. Am. Bull,, vol. xxv, No. 1, pp. 89-40, Mch. 30, 1914. 


T. N. Dale—Algonkian-Cambrian Boundary. 121 


the first period of disturbance ; a later one induced in the rock 
the regional schistosity of the range striking N. 10° to 15° E.” 

The gist of Mr. Keith’s note is that the Cambrian quartzite 
and conglomerate of Vermont unconformably overlie a great 
thickness of schist, dolomite, graywacke, quartzite and con- 
olomerate and that “these older sediments bounded above 
and below by conglomerate and unconformities are properly 
classed as Algonkian.”’ 

Structure.—While at many points along this boundary the 
rocks on both sides of it appear to be conformable, at others 
the divergence between the strike of the foliation of the pre- 
Cambrian gneiss (and the bedding of the rocks associated with 
it) and that of the bedding of the Cambrian beds amounts to 
from 18° to 140°. The pre-Cambrian strike ranges from 
N. 30°-90° W., averaging N. 70° W. The Cambrian from 
N. 12° W. to N. 50° E., averaging N. 30° E. 

These structural relations can be observed at the following 
points: In the town of Jamaica, in the deep E.-W. cut made 
by the West River, two miles north of Jamaica village, the 
granite-eneiss strikes N. 30° W. and the Cambrian micaceous 
quartzite a few hundred feet east strikes N. A mile south on 
the -hill west of Ball Mountain the granite-gneiss strikes 
N. 40° W. and the quartzite near on the northeast strikes 
N. 20° E. 

In the town of Andover, 12-15 miles north of the Jamaica 
eut, the granite-gneiss of the north and south humps of Ter- 
rible Mountain strikes N. 35° to 70° W., but the Cambrian 
schist along the east base of Terrible Mountain strikes 
Naa SO Wig NOS INSANE: 

In the town of Ludlow, 5 miles farther north, on the east 
side of Ludlow Mountain, where the boundary doubles over on 
itself for several miles, exposing a tongue of pre-Cambrian up 
to a mile in width, the granite-gneiss strikes N. 45°-90° W.., 
but the Cambrian schist and quartzite east and west of the 
tongue strike N. 10° to 35° E. 

In the town of Sherburne, 134 miles further north, in the 
Falls Brook, at the falls two miles E.SE. of Killington Peak, a 
pre-Cambrian arkose strikes N. 30°-40° W., but the Cambrian 
schist and dolomite a little east of it strike N.40°-50° E. Six 
miles further north in the same town, 1? miles N.NW. of 
Sherburne village, in a small tributary of the Ottaquechee 
River, pre-Cambrian quartzite and arkose strike N. 35°-40° 
W. but the Cambrian schist at the foot of the falls and also on 
the east side of the river strikes N. Two miles further north 
in the mass east of North Sherburne the pre-Cambrian granite 
gneiss strikes N. 57°-70° W. and various sedimentary rocks 
associated with it strike N. 30°-70 W., but the Cambrian schist 
east of them strikes N. 


129 7. N. Dale—Algonkian-Cambrian Boundary. 


Another structural feature of the region is that the pre- 
Cambrian gneiss exceptionally has two foliations with strikes 
corresponding to that of the pre-Cambrian and Cambrian 
respectively. Thus on the east base of Ludlow Mountain 
some granite-gneiss ledges have coarse plications ee 
N. 50°-90° W. but a fine foliation striking Ng 20°-30° E 

A pre-Cambrian conglomerate in North Sherburne consists 
of pebbles arranged in ‘small beds in aschistose cement. The 
pebble beds strike N. 60° W. with the granite-gneiss but the 
slip-cleavage foliation of the cement strikes N. 10° W. with 
the Cambrian schist of the region. 

A bed of quartzite 40-50 ft. thick, in the mass east of North 
Sherburne, has the typical pre-Cambrian strike of N. 70° W. 


but curves around sharply to strike N. 30°-50° E. with the © 


Cambrian beds. The bending has resulted in much minor 
faulting. This occurrence indicates that the conformity of 
strike existing in so many places between the pre-Cambrian 
and Cambrian may be due to changes produced by the post- 
Ordovician movement in the pre-Cambrian structure. 

Origin and composition.—The Cambrian rocks along the 
boundary studied include: metamorphic arkose, quartzite, al- 
bitie muscovite, and museovite-biotite, also albitic-chlorite schist, 
and dolomite, both granular and twinned. The quartzite 
generally includes some beds of sericite schist. Black tourma- 
line is abundant and in places associated with pegmatite. 

The pre-Cambrian rocks include various granite-gneisses, 
aplite gneiss, metamorphic arkoses, quartzite, conglomerate 
with pebbles of quartzite, albitic sericite schist and graphitic 
sericite schist. The age determination of these Algonkian 
sedimentaries is based entirely upon their strike being con- 
formable to that of the underlying granite-gneiss and uncon- 
formable to the adjacent overlying Cambrian beds. Some of 
these Algonkian schists are petrographically identical with 
Cambrian and Ordovician ones of the Green Mountain region. 

The arkose and quartzite conglomerate call for more detailed 
description. One of the marked types of arkose is a medium 
to dark grayish rock, in places with lighter grayish less micace- 
ous bands. It consists of more or less angular grains of quartz, 
of multiple-twinned plagioclase, of microperthite, in places of 
microcline, in a cement of muscovite, chlorite, biotite and epi- 
dote with accessory zircon, apatite, pyrite, limonite. The 
quartzite conglomerate in North Sherburne measures roughly 
not less than 275 ft. in thickness and is separated from an 
underlying 40-50 ft. thick bed of quartzite by a hundred feet 
or more of albitie sericite-chlorite schist. At the contact 1? 
miles N.NW. of Sherburne village the Algonkian schist and 
arkose include two beds of quartzite, 10-15 and 3-L0 ft. thick. 


—~ es 


i 


T. N. Dale—Algonkian-Cambrian Boundary. 123 


The pebbles of the North Sherburne conglomerate are nearly 
all quartzite and measure up to two feet in length and eight 
inches in width. Fig. 1 shows the form of these pebbles. 
Some of them seem to have been elongated in metamor- 
phism. One from a loose block from the same ledge measures 
15x4-6x 24 inches. The quartzite of these pebbles in thin 
section shows the presence of a little muscovite, chlorite, sider- 
ite passing into limonite, and grains of zircon. A section of 


Bie. 1. 


We ZZ ye 


Fic. 1. Diagram-sketch of north side of an E.-W. joint in Algonkian con- 
elomerate showing sections of quartzite pebbles. North Sherburne, Ver- 
mont. 


the quartzite of the thick bed shows quartz grains much strained 
and granulated, and a little muscovite and chlorite, and limon- 
ite stain of uncertain source. There is thus no marked differ- 
ence between the material of the pebbles and that of the bed. 
The cement of the conglomerate is muscovite-quartz-chlorite 
schist. 

Inductions.—The original general strike of the pre-Cambrian 
granite-eneiss and the associated Algonkian sedimentaries in 
the southern 60 miles of the Green Mountain range in Ver- 
mont was probably about W.NW. and was due to the direc. 
tion of the post-Algonkian movement. The general strike in 
the same region of the Cambrian beds east of the pre-Cambrian 
was about N. 30° E., and was due to the direction of the post- 
Ordovician movement, but in many places the pre-Cambriau 
rocks yielded to the later crustal contraction and acquired a 


Am. Jour. Sct.—Fourts Srries, Vou. XLII, No. 248.—Avcusr, 1916. 
9 


124 7. N. Dale—Algonkian-Cambrian Boundary. 


general N.NE. strike. Some pre-Cambrian rocks show the 
effects of both crustal movements. 

Wherever in the Green Mountain region both Cambrian and 
pre-Cambrian have a N. 70°-90° W. “strike it must be due 
either to transverse folding in the course of the post-Ordovi- 
cian movement, or, as surmised by Pumpelly, to compensatory 
movement due to the resistance offered by rigid granite masses.* 

If the prevalent strike at the close of Algonkian time here 
was W.NW. then the original orographic features of the 
Green Mountain region, or at least of the southern half of it, 
must have trended W.NW.-E. SE., and therefore wherever a 
ridge of pre-Cambrian rocks with this strike has this trend it 
may be regarded as a remnant of Algonkian physiography. 
The two mile long ridge in Andover and Weston, known as 
Markham Mountain, appears to be such an Algonkian moun- 
tain-remnant. 

As, along the boundary studied, Cambrian rocks are in some 
places in contact with Algonkian ones but in others with vari- 
ous granite-gneisses, we must suppose in the latter places either : 
(1) Denudation in Algonkian time of the Algonkian land sur- 
face and the removal of the Algonkian sediments that had 
transgressed the pre-Algonkian gneisses, or else (2) the expo- 
sure of part of the land surface of Algonkian time which was 
transgressed by Cambrian sediments but never had been by 
Algonkian ones. 

As the Algonkian conglomerate contains pebbles of quartz- 
ite and conformably overlies schist and quartzite this con- 
glomerate should be regarded as “ intra-formational,” i. e., a8 
- resulting from the slight and temporary elevation of part of an 
Algonkian sandstone above sea-level but not from a general 
ereat unconformity. The metamorphism that altered the 
bedded quartz sandstone into quartzite must also have altered 
the sandstone of the pebbles of the conglomerate into quartz- 
ite ; and this metamorphism must have been that which accom- 
panied the post-Algonkian movement. 

Since the completion of this paper the Bulletin of the Geol. 
Society of America for March, 1916, has appeared containing a 
brief abstract (p. 101) of a paper by C. E. Gordon, entitled 
“Some structural features in the Green Mountain belt of 
rocks.” In this paper he refers to having observed in certain 
places an east-west trend in the foliation of the ancient gneisses. 


Pittsfield, Mass., May 4, 1916. 


* See Pumpelly, Raphael, Geology of the Green Mountains in Mass. Gen- 
eral structure and correlation. U.S. Geol. Survey, Mon. 23, p, 21, 1894. 


W. G. Minter—Thermochemistry of Silicon. 125 


Art. XIV.—TZhe Thermochemistry of Silicon; Heat of 
Combination of Silica with Water; by W. G. Mixrerr. 


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


Tuts article contains experimental work by the writer and a 
review of the thermochemistry of silicon, which has been 
regarded as very uncertain. Some of it is undoubtedly good 
and some of the fundamental values from which others are 
derived are far from accurate. The writer’s results are given 
first as they are used in discussing the work of others. 

There is nothing in the literature bearing on the heat effect 
of SiO, + Aq except the heat of formation of SiO,.Aq, 179°6 
Cal. and of SiO,, 191 Cal. These indicate that it is endothermic. 
The problem of finding the heat of union of silica with water 
is complicated sinee they do not combine directly and because 
molecules of silica are complex at temperatures required to 
dehydrate silicic acid. It is impossible to determine with an 
approximation to accuracy the quantity of heat required to 
separate a small quantity of water firmly held, but it appears 
practicable with silicic acid containing much water. Two 
methods have been tried, one by fusion with sodinm peroxide 
with unsatisfactory results and the other by solution in hydro- 
fluoric acid. 

In order to learn whether or not silicic acid prepared at 
room temperature differs from that made at 100°, two prepara- 
tions were made as follows: A solution of sodium silicate was 
added gradually to hydrochloric acid and the silicic acid which 
separated after a time was washed with water at room tempera- 
ture. It was dried in the air, then by a current of dry air 
under diminished pressure passing through the powder, and in 
vacuo over oil of vitrol until the water content was reduced to 
69 per cent.* Another preparation was made by adding a 
solution of sodium silicate to an excess of hydrochloric acid and 
evaporating on a steain bath. The dry residue was moistened 
with acid and the silicic acid was washed with hot water. It 
was then left some time in a steam drying oven and then over 
oil of vitriol. It contained 8-0 per cent of water. The results 
on p. 126 show that the silica of silicic acid prepared at 100° 
is In the same molecular condition: as that made at room 
temperature. Hence other lots of silicic acid were made by 
the second method, as it is somewhat simpler. The water con- 
tent was found by the common method, heating finally over 
q large blast lamp to constant weight. The determinations of 

* Since gelatinous silicic acid dries to hard tough lumps it should be pul- 
verized from time to time during the drying process in order to obtain a 
uniform product. 


126 W. G. Miater—Thermochemistry of Silicon. 


water were made either before and after the calorimetric tests 
of a preparation or with a portion weighed at the time of a test. 
since silicic acid with small water content gains weight rapidly 
in the air while that having much water may have lost some 
combined water in a closed vessel if the room is hot. For 
example, preparation A (Table II) contained 0:3 per cent of 
combined water and 0:2 per cent absorbed during the neces- 
sary exposure to the air. The term “silicic acid” is applied 
to all preparations having combined water. 

The following are the results obtained with fusions of mix- 
tures of silica or silicic acid, sodium peroxide and lampblack : 


TABLE I. } 


Amorphous silica which was heated to a constant weight over 
a blast lamp: 1218, 1217, 1226: mean 1220 cal. 


Silicie acid having 


69 per cent of H,O 1316, 1307, 1301: mean 1308 cal. 
8:0 “ *¢ 1302, 1341 pln is j.242) 7 
12°5 f «1386, 1390 v2) ailsseie} 2 
215 ~~ “ 1230, 1402, 1310, 1204 “ 1236 « 


The reason for the wide variation in the last results is this 
The silicic acid in the dry air of the mixture gives off water 
which reacts with the sodium peroxide. A thermometer 
placed in the last mixture before closing the bomb showed a 
slight rise in temperature. The silicic acids with 6-9 and 8:0 
per cent of water have vapor pressures too low to affect the 
determinations. Any of the results may be low owing to a 
little silica left unchanged im a fusion which can not be deter- 
mined since it would dissolve in the water solution of the 
fusion. 

From the results with the silicic acids containing 6°9 and 
8-0 per cent of water we have the equations 


0'931a@ + 0:069 y = 1308 
092% + 0'°08y = 1322 


in which # == 1250 and y= 2100 eal., in which x equals the 
heat effect for 1 gm. SiO, and y is the heat effect for 1 gm. of 
water. The value for y is 200 cal. higher than the heat of the 
reaction of solid water, ice, with sodium oxide. These derived 
values are only approximations. They indicate, however, that 
little energy is required to separate water from silica. For the 
heat of polymerization of silica we have 1250-1220 x 60:4 
= 1800 cal. or about 2°0 Cal. This small value accords with 
the fact that silica does not glow when heated. 


—— a a 


W. G. Mixeter— Thermochemistry of Silicon. 127 


The apparatus in which silicic acid was dissolved in hydro- 
fluorie acid is shown in fig. 1. It is an old sterling silver 
bomb with a new silver-plated brass top and fixtures. The 
dise 6 is held in place by the rod d. The cup ¢, shown better 


Fics. 1 anp 2. 


| 


Wy 


‘J 


ZZ, 


iL bh hth 


WILL he hors 


Md bd 


4 


1 
SEMADLEMELILLILD, 


CLLLLLLL. 


L0G 


in‘fig. 2, is made of thin sheet silver. The small hole in the 
bottomfallows air to escape so that ¢ may sink in the acid. The 
hole is covered by a dise of silver. The silicic acid for an ex- 
periment is placed in ¢ which is closed by a cover not shown 
in the figure. The weight is taken and ¢ is at once placed in a. 
The cover is removed and @ is closed by 6 and the joint is made 


128 W. G@. Mixter—Thermochemistry of Silicon. 


tight with beeswax. The hydrofluoric acid is weighed in the 
open bomb and then the top is put on. After the preliminary 
observations of temperature in the calorimeter the dise 6 is 
pushed down, thus allowing the silicic acid and cup ¢ to fall 
into the acid. The mixture is stirred by moving d and } up 
and down. 

Hydrofluorie acid having a density of 1-079 and containing 
approximately 22 per cent of HF was used in the work. The 
specific heat of it was found by cooling about 200 g. in a 
platinum bottle in snow for hours, in one case oyer night, and 
then placing it in the calorimeter used for the work. Two 
determinations gave 0°80 and 0°81. The method is not a good 
one, but the result is sufficiently accurate for the work as shown 
by 0°994 found for the specific heat of water. The heat capac- 
ity of the hydrofluoric acid solution was so small compared 
to the total heat capacity, that an extremely accurate value is 
unnecessary. The calorimetric experiments were made under 
fairly uniform conditions and hence the results are comparable. 
One source of a small error was the undetermined specific heat 
of the solution of hydrofluosilicic acid. 

The line e of Table II shows the heat effect of 1 g. of SiO, 
if the water is combined with the silica without-heat effect. 
These ¢ values indicate that little energy is required to separate 
the water. The heat effect of 1 g. of SiO, derived algebraically 
from the d values of B and C is 594 cal.; from E and F, 588; 
E and G, 587; F and G, 588 cal. Now the heat of combina- 
tion of water in B is calculated thus : 

592 — (594 & 0°99) =4 cal. That is 4 cal. are required to 
separate 0-01 @. of water from 0°99 g. of silicaand for 1 gram 
molecule, 7200 cal. Likewise we find that 7000 cal. are 
required to separate 18 g. of water in preparation OC. These 
results are within the experimental errors, but they indicate 
that energy is required to separate the small quantity of water 
retained by silica at a red heat. ~The values found algebraically 
for the heat of solution of the silica in E, F and G in hydro- 
fluoric acid are the same as the e values. This indicates that 
water is combined without heat effect in silicic acid containing 
75 to 21°4 per cent. It should be understood that the silicic 
acid giving this result was made at 100° and may have con- 
tained capillary water. Such water would not affect the result 
essentially. 

Silicon dioxide in its union with water with small or no heat 
effect resembles the anhydrides of weak metallic acids. The 
oxides given below are more or less polymerized, hence the 
difference between the heat of formation of an acid or hydrox- 
ide and that of a corresponding oxide is not in all cases the 
heat effect of the combination of water. 


W. G. Mixter—Thermochemistry of Silicon. 129 


Sn + 20 + Aq = 133 Cal. 
25b + 80 + Aq = 167 Cal. 
Sn + 20 = SnO (erys.) = 137 
2Sb + 30 = 163 
2Bi + 30 + Aq = 137°7 


9Sb + 50 + 3H,O = 228'8 
2Bi + 30 wa leiio 
2Sb + 50 == 299°6 


The heat of solution of 1 ge. of silica in hydrofluoric acid 
found in experiments E, F and G, Table II, is 588 cal. or 
35°5 Cal. for 1 gram molecule. (Si = 28-4.) Guntz* obtained 
33°6 Cal. (Si = 28.) Thomsent found in the reaction of 
hydrofluorie acid on a solution of silicic acid that the heat 
effect rises regularly until eight molecules of acid are added 
and ceases with the tenth. With 6HF it is 382°3 cal. In the 
writer’s experiments 12 to 17 HE were used to 18i0,. It 
may be stated that anhydrous silica dissolves too slowly in 
hydrofluoric acid for a calorimetric test. 

The heat of formation of silicic acid is most important, as 
other values may be obtained from it. Berthelott derived 
from the heat of the reaction of SiCl, with water 


Si (crys.) + O, + Aq = SiO,Aq + 179°6 Cal. 


The only uncertain value used is that for the heat of formation 
of SiCl,. Troost and Hautefeuille§ burned impure amorphous 
silicon in chlorine and gave as the result 157:°6. B corrected 
for an error in the water equivalent given by T and H for the 
mereury calorimeter used, and for Si (amor.) —~ Si (erys.) and 
states that 


Si (cryst.) + 20], = SiCl, (liq.) + about 128°7 Cal. 


The heat effect of SiCl, (liq.) + Aq is, according to Berthelot, 
69:0 eal.: to Thomsen, 69°3 Cal. 

The heat of oxidation of silicon has been determined by two 
methods with fairly concordant results. The writer| burned 
erystalline silicon, 99°95 per cent pure, carbon and silicon ear- 
bide in sodium peroxide, and the last two in oxygen, and from 
the results derived 


Si(crys.) + O, = SiO (polymerized) + 191°0 Cal. 


von Wartenburg4 burned amorphous silicon, containing 2°5 
per cent of SiO,, in oxygen and from nine experiments obtained 
a mean of 194:9 Cal. + 4:1 Cal. He also found by dissolving 


* Ann. Chim. Phys. (6), iii, 60. 

+ Ber. deutsch. Gesellsch., iii, 575. 

} Thermochemie, II, 123 and 151. 

S$ Ann. Chim. Phys. (5), ix. 77. 

| This Journal, xxiv, 120, 1907. 

‘| Nernst Festschrift, 459; Chem. Zentralblatt, 1912, II, 1095. 


130 W. @. Mixter—Thermochemistry of Silicon. 


the two forms of silicon in a mixture of hydrofluoric and nitrie 
or chromic acids in a calorimeter that Si (amor.) —> Si (eryst.) 
= less than + 2 Cal. The writer* burned a mixture of erys- 
talline silicon and carbon in oxygen in a bomb. As the 
results varied widely they were disregarded at the time. Seven 
experiments in all were made with an average of 187-2 
Cal. But the average of tive, leaving out the two lowest 
results, is 191-8 Cal. for 28°4 @. of crystalline silicon. When 
the products of a combustion were treated with hydrofluoric 
acid to dissolve the silica a little gas came off, presumably 
hydrogen, indicating the presence of SiO or a soluble form of 
silicon. In either case this would make the result a little high | 
for Si + 20. It is impossible to say which is the most aceu- 
rate of the values found, but it seems best to use 191 cal. in 
deriving other values from results obtained by the writer. 

It has been shown that #SiO, (unpolymerized) = (SiO,)« 
(polymerized) + about 2 Cal. Then 191— 2 = 189 Cal. for 
the heat of formation of silicon dioxide as it exists in silicic 
acid. And it has also been shown that silica combines with 
water with very small or no heat effect. Hence the conclusion 
that 189 Cal. is the best value at present for the heat of 
formation of silicic acid from erystalline silicon, oxygen and 
water. 

If we accept the above value for the heat of formation of 
silicie acid, 35°5 for SiO, + 6HF,Aq, Berthelot and Moissan’s 
for H + F + Aq = 50:3, then SiO, Aq + 6HFAgq = 35°5 
= 2H + Si+ 6F + Aq + 22H + O) = (Si + 20 + Aq) 

iv 139 189 


— 6(H + F Aq) 
301°8 

in which w= 387-1 Cal. the heat of formation of hydrofluosilic 
acid in water from crystalline silicon. From the heat effects, 
of a number of reactions, using Berthelot’s value 179-6 for 
silicic acid, Guntzt derived in a different way 374°3 (Si = 28° 
and 380 Cal. (Si = 28-4). Berthelott gives 3744 Cal. and 
gives with the reactions measured and used in the calculation 
Truchot’s for Sif, + 2HF = 34 Cal. But Truchot’s num- 
ber given in the Physikalisch Chemische Tabellen for hydro- 
fluosilicie acid is 375°1 Cal. Guntz’s value given in the 
Tabellen for Si (erys.) + 4F = 239°8 Cal. the same as Per- 
thelot gives. This is obviously 


Sif, =(211+S8i+6F + Aq) 
3744 —2(H+F+Aq)—(Sif + 2HF, Aq)=239°8 
100°6 34 


* Loe, cit. + Loe. cit. 
+ Thermochemie II, 152. 


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132 W. @. Mixter— Thermochemistry of Silicon. 


Evidently the values for hydrofluosilicic acid and silicon tetra- 
chloride are subject to the uncertainty in the value for silicon 
tetrachloride from which the value for silicie acid is derived 
and also to the unestablished heat effect of Si(erys.) —> 
Si(amor.). Nevertheless the writer’s results indicate that the 
saa of silicon, excepting the tetrachloride and 
silicic acid, is fairly well established. 

Table Ul, Tanda “H, Land J, contain experiments with silica 
holding 1:8 per cent of combined water and considerable 
adsorbed water. The results indicate that more energy is 
required to separate adsorbed water and convert it into the 
liquid state than to melt ice. This is what would be expected. 
The molecular condition of adsorbed water has not been found. 
Such water is known to have a lower freezing point than 
ordinary water and Foote & Saxon* have shown that it is 
different from combined water. 


Art. XV.— Composition of the Selensulphur fron Hawaii ; 
by Guiunn V. Brown. 


In the conrse of an investigation of the chemical reactions 
of selenium, the writer had occasion to look’ up the occurrence 
of this element in natare. It is usually found combined in 
selenides of the heavy metals, but also occurs free, especially 
in voleanic regions. One of its most frequent forms is as an 
isomorphous mixture with sulphur, named selensulphur in the 
books on mineralogy. Selensulphur is classed by Danat as a 
mineral species, No. 4, and is described as “an orange-red or 
reddish brownish mineral containing sulphur and seleninm, but 
in unknown proportions.” It seemed incredible that no quan- 
titative analysis had ever been made of a mineral known since 
1825 and reported to occur at a number of localities, yet such 
appears to be the case, for no analysis could be found in any 
available book on mineralogy or chemistry. On talking over 
the matter with Dr. Edgar T. Wherry, Assistant Curator, 
Division of Mineralogy and Petrology, United States National 
Museum, the writer learned that at least one authentic speci- 
men of ’ selensulphur was included in their collection, and 
through the kindness of Richard Rathbun, Assistant Secretary 
in charge of the Museum, a small fragment of this specimen 
was received for investigation. This specimen was collected 


* Jour. Am. Chem. Soc., xxxviii, 588, 1916. 
+ System of Mineralogy, 6th edition, 1892, p. 10. 


Brown— Composition of the Selensulphur from Hawaii. 133 


by James D. Dana while mineralogist to the Wilkes Exploring 
Expedition at Kilauea in 1840. 

The fragment (U.S. N. M. Cat. No. 12901) consisted of a 
slaggy, vesicular lava, almost a pumice in structure, impreg- 
nated with an orange-red tosulphur yellow crystalline mineral, 
and contained minute needle-like crystals in the cavities. It 
yielded the following reactions : 

Before the blowpipe: Bluish flame, odor of burning sulphur 
plus the pungency and odor of burning selenium (suggesting 
scorching cabbage); residue reddish-brown, non-magnetic. 

In closed tube: Sublimate, similar to that of pure sulphur ; 
banded appearance while hot; on cooling, lower portion clear, 
light yellow merging into a darker, grayish upper portion. 
The yellow portion of the sublimate was insoluble in carbon 
disulphide, but readily soluble in bromine. 

Qualitative analysis of the rock and mineral showed the 
presence of silicon, phosphorus, sulphur, selenium, iron, alumi- 
num, titanium, calcium, magnesinm, sodium and potassium. 
Tests on the largest amounts which could be spared failed to 
show even traces of tellurium or of arsenic. 

The specimen was crushed to a coarse powder and the yellow 
to orange-red portions, high in selensulphur, were picked out. 
The selected material was then finely powdered, and amounted 
to 8°2 grains. Determinations were made of the specific grav- 
ity with a pyknometer, loss at 103°, sulphur content and 
selenium content. 

The selensulphur was extracted from the finely powdered 
mixture of rock and mineral with bromine and the selenium 
determined by the method of W. Smith,* as follows: the bro- 
mide of selenium was decomposed by the addition of succes- 
sive small amounts of bromine water, the solutions were filtered 
and the selenium precipitated from the combined filtrates by 
potassium iodide and hydrochloric acid. The solution was 
then boiled to convert all of the selenium to its black modifica- 
tion, filtered through a Gooch crucible, the precipitate washed 
with hot water, and the selenium finally weighed as the ele- 
ment. In another portion of the mineral the sulphur was 
oxidized to sulphuric acid by fusion with sodium peroxide, the 
melt treated with hydrochloric acid and the insoluble residue 
filtered off. Upon boiling the solution, red selenium separated, 
and after standing over night the separation of the selenium 
was complete. The selenium was then filtered off, and the sul- 
phuric acid in the filtrate precipitated and weighed as barium 
sulphate. 

In determining the loss at 103° traces of sulphur and 
selenium were vaporized, asshown by the odor present when 


*J. Ind. Eng. Chem., vii, 849, 1915. 


134 Brown— Composition of the Selensulphur from Hawaii. 


the air bath was opened to remove the samples. The amounts 
lost were, however, too minute to cause appreciable difference 
in the determinations. The lava discarded as showing practi- 
cally no selensulphur must have contained some as an invisible 
impregnation, for an analysis of this material showed selenium, 
0-07 per cent, and sulphur, 3°32 per cent. 

The composition of the handpicked sample is given in col- 
umn 1, the same after deducting the material other than 
selenium and sulphur recalculated to 100 per cent in column 2, 
and the ratio of selenium to sulphur in column 3. 


1 2 3 
Loss at 108° (moisture)... 3°164 
Sulphur sos sss eos eee 12°44 94°82% 2°956 45°5 
Selenium! .).2 es) sees 0°68 5°18 065 1 
Remainder (lava)... ---- (83°72) 


100°00 100-00 
Specific gravity 2°378. 


Alloys of sulphur and selenium containing from 35 to 
66 per cent of the latter have been described,* but the min- 
eral selensulphur is here found to contain such a small amount 
of selenium that it can hardly be considered more than a 
variety of the main substance, sulphur. It is therefore sug- 
gested that ‘‘seleniferous sulphur” would be a more appropri- 
ate term than selensulphur to apply to this mineral. 


Bucknell University, Lewisburg, Pa. 


* Browning, Introduction to the Rarer Elements, 2d ed., p. 145. 


ae 


Cocherell—Insects in Burmese Amber. 135 


Arr. XVI.—Jnsects in Burmese Amber; by T. D. A. 
CockERELL. 


I am greatly indebted to Mr. R. C. J. Swinhoe, of Man- 
dalay, Upper Burma, for the loan of some specimens of burmite, 
or Burmese amber, containing well-preserved insects. Mr. 
Swinhoe writes that “there is no reason to doubt that the 
stratum in which the amber is found is Miocene.” Thus we 
have for the first time a record of Miocene insects from Burma ; 
and it need hardly be said that this amber fauna, as it becomes 
better known, will prove of the greatest interest and importance 
for the understanding of insect evolution and migrations. The 
material now submitted, which will eventually be placed by 
Mr. Swinhoe in the British Museum, includes three species 
suitable for description, an Hemipteran, a Termite and a Psocid. 
In the Records of the Geological Survey of India (vol. xxv, 
Part 3 pais0) 18o2eandi vole xxvi,, Part 1, p. 3, 1893), Dr. 
Fritz Noetling describes the occurrence of amber in Upper 
Burma, and gives particulars of the localities. The amber- 
bearing beds, which he considers probably lower Miocene, 
consist of a soft blue clay, which is superficially discolored 
brown. The amber appears to be limited to the upper 
part of this clay, and was certainly not produced where it 
is found, but must have been washed down the rivers to the 
sea, where the deposition of the clay was going on. In 
the same Records (xxv, p. 180) Dr. Otto Helm discusses the 
Burmese amber, and decides that it differs from all other fos- 
sil resins known to him. In the next volume (xxvi, Part 2, 
p- 61) he returns to the subject, and gives a lengthy account of 
the physical and chemical properties of the amber, for which 
he proposes the name Burmite., Burmite differs from suc- 
cinite (Baltic amber) in lacking succinic acid; and is further 
distinguished by its hardness and toughness, its vivid colors, 
and its fluorescence. It resembles Sicilian amber in its 
frequently red color. 


Enicocephalus fossilis n. sp. (Enicocephalide). 


Dark brown; legs and antennz dull ferruginous; wings 
dusky hyaline. Wings broadly rounded at end, extending 
some distance beyond tip of abdomen; discal cell closed. Form 
and structure of body, legs and antenne essentially as in 
£. culacis Uhler, except in the following points: last antennal 
joint a trifle longer than penultimate; anterior tibiee longer, 
much more slender basally; anterior tarsi with only one claw, 
which is long; hind tarsi longer and more slender. The fol- 
lowing measurements are in microns: total length 3040 ; length 


136 Cockerell—Insects in Burmese Amber. 


of beak 870; second antennal joint 496, third 352, fourth 368 ; 

base of anterior legs to base of antenne about 800 ; length of 
anterior wing about 2080. This agrees with the type of the 
genus (£7. flavicollis Westw.) in the closed discal cell and single 
claw on anterior legs. The venation is more complex than in 
the living species “of which I have any information, and is 
therefore apparently more primitive. Possibly a distinct genus 
is indicated, but existing species differ greatly in venation, 
which also appears to vary a good deal within the species. 
The second vein from the stigma is rather weak, and appears 


Fie. 1. } 


Fic. 1. Enicocephalus fossilis. A, anterior tibia, tarsus and claw; B, 
antenna; C, end of wing. 


to represent a cross-vein proper. The closed quadrate’ cell 
below the discal cell appears to be a primitive character ; it is 
found in Scytinoptera from the Permian, one of the Paleo- 
hemiptera. The species of Hnicocephalus swarm in the air 
like gnats, so it is easy to see how they might be trapped in 
the resin forming amber. Handlirsch records no fossil species, 
but when Westwood originally described the genus in 1837 he 
included four species, of which two were from “ gum animé,” 
which I suppose to be copal, of postertiary age. Ashmead 
remarked in 1892: “The genus is evidently an ancient phylo- 
genetic type, now nearly extinct.” The few living species are 
widely scattered over the world. 


Psyllipsocus (?) banksi un. sp. (Psocide),. 


Black, with dark brown legs; wings ample, broad, extending 
far beyond abdomen, hyaline, spotless, without scales, the veins 
not hairy. Antennz very long, and (except the base) ex- 
cessively slender, thread-like. Anterior tarsi three-jointed, the 
first joint considerably longer than the other two combined, 
and haying a row of short oblique bristles on its lower side. 
Hind tibize and tarsi very long and slender. Head large; 


ll el al 


Cockerell—Insects in Burmese Amber. 137 


abdomen short. Venation of anterior wings: stigma with its 
lower side nearly straight, not bulging; radial sector forked 
below basal half of stigma; media with stem (after leaving 
radial sector) nearly straight, and with two forks as,usual in 
related forms; fork of cubitus with the lower branch well- 
developed though short, directed downward to the margin. 


Hind wings with a cubital fork ; the hind wings on the two sides 


eo 
me nee 


ant. leg. aa 
8 


Fic. 2. Psyllipsocus banksi. A, anterior wing; B, anterior leg. 


Fic. 3. 


anttinne, | 


Fic. 3. Psyllipsocus banksi. ©, hind wings of both sides; D, antenna. 


have very different venation, as shown in the figures, one hay- 
ing a closed cell absent from the other. The following 
measurements are in microns: length, about 1600; length of 
anterior wing about 1840; width of anterior wing 720; length 
of anterior tarsus about 320; hind femur about 370; hind tibia 
670; hind tarsus 465; length of stigma 340. 

This minute insect could not be identified with any genus 
described from European amber or in the modern fauna in the 
scanty literature on Psocide at my command, so I sent a sketch 
to Mr. Nathan Banks, asking his advice. This he very kindly 
gives as follows: ‘“‘The Psocid you figure must be close to 


138 Cockerell—Insects in Burmese Amber. 


Psyllipsocus de Selys ; that is the only one I know of with the 
hind wing showing a forked vein near hind margin. In the 
fore wing the media varies from two to three branched in the 
same species. In Psyllonewra Enderl. the fore wing is just 
about the same, but hind wing has not the forked vein; in 
both, and other Psyllipsocinee, the stigmal vein is fairly 
straight.” Psyllipsocus is a living European genus; Psyllo- 
neura was based in 1908 on a species from New Guinea, and 
no other species have been added since. Psyllipsocus ramburi 
is sometimes injurious in houses, according to Bertkau. The 
straight lower edge of stigma and the cubital fork of hind wing 
appear to be primitive characters. The fossil’ may be generic- 
ally distinct from Psyllipsocus, but it seems best to provision- 
ally refer it to that genus. 


Fic. 4. Termopsis swinhoei. A, Costrapical part of wing; B, side view 
of head; C, joints of apical half of antenna. 


Termopsis swinhoei n. sp. (Termitide). 


Length 3:8"; black; wings about 4:°5™™ long, hyaline, with 
brown costa; head of moderate size, the face flat and vertex 
not conspicuously elevated; antennee with the joints beyond 
the middle mucli broader and larger than those near the base ; 
legs rather small ; cerci small. Radius running close to costa, 
giving off two branches above, one very close to the end, the 
other not far from it. Media running very close to radius, and 
giving off oblique branches. 

So far as can be seen, the structure of the wings resembles 
that of Zermopsis procerus Heer (the type of Termopsis), 
from the Miocene ot Croatia. The radius is however less com- 
plicated than in Heer’s species. 


University of Colorado, 
Boulder, Colo. 


MeDonnell and Smith—Lead-Chlor Arsenate. 139 


Arr. XVIJ.—TZhe Preparation and Properties of Lead- 
Chlor Arsenate, Artificial Mimetite ; by C. C. McDonnetu 
and ©. M. Suir. 


Tur mineral mimetite, the composition of which as first 
shown by Wohler in 1825 is 3Pb,(AsQ,),.PbCl, or Pb,(PbCl) 
(AsO,),, was made artificially, first by Lechartier,* and also by 
Michel,t by fusing together lead arsenate and lead chloride. 
Weinschenkt accomplished the same by heating a mixture of 
water, ammoninm chloride, lead chloride and ammonium arsen- 
ate at a high temperature in a sealed tube. Its preparation in 
the wet way at ordinary temperature has never been recorded, 
although it was observed by H. Rose§ that when a solution 
containing arsenates and chlorides is precipitated with lead 
nitrate or acetate, “lead chloride is also precipitated with the 
lead arsenate and forms a double compound with the latter 
which cannot be decomposed by washing with a large volume 
of water.” The nature of this compound was not further 
studied by him and has apparently been overlooked by later 
investigators. 

During an investigation of the arsenates of lead, while 
endeavoring to produce crystallized dilead arsenate (PbH AsO,), 
various media were tried as solvents. It was found that a 
boiling 40 per cent solution of ammonium chloride dissolved 
dilead arsenate to the extent of about 4 per cent of the ammo- 
nium chloride present. When such a solution was poured into 
a large volume of cold water a gelatinous precipitate was pro- 
duced, which on analysis was found to contain 74°54 per cent 
PbO and 23-00 per cent As,O,, leaving 2°46 per cent unac- 
counted for. Qualitative tests revealed the presence of chlor- 
ine, and another sample of the material prepared in the same 
way, and washed free from soluble chlorides, was analyzed with 
the following results: 


Theory for mimetite 
Found Pb,(PbCl)(AsO.)s 


lead iomdew PbO. 2225. 2. 74°64% 74-97% 
Arsenic pentoxide, As,O, -.---- 22°81 23°18 
Cinlorme cle tees eee ae ae oi 2°38 
100°17 100°53 
©, equivalent to Cl ... ::----- 061 0°53 
99°56 100°00 


*Comptes Rendus, lxv, 172, 1867. 

+ Bull. Soe. Min. de France, x, 133, 1887. 

¢ Zeitschr. Kryst. Min., xvii, 489, 1890. 

$ Ausfiihrliches Handbuch der Analytischen Chemie, IT, 406, 1851. 


Am. Jour. Sci.—Fourta Serigs, Vou. XLII, No. 248.—Aveust, 1916. 


140 MeDonnell and Smith—Lead-Chlor Arsenate. 


It was found that a chlor compound was also formed (slowly 
in the cold, and very rapidly on warming) when a mass of 
dilead arsenate was digested with ammonium, sodium or potas- 
sium chloride. Sodium chloride seemed to be particularly 
effective in forming a product of nearly theoretical composi- 
tion. ‘Two samples resulting from the digestion of dilead 
arsenate for 5 minutes at boiling temperature with (@) 2 per 
Sie and (4) 10 per cent sodium chloride* solutions analyzed as 
follows: 


a b 
Leadtoxide sPbOis_ caer eee 74:°75% 74:56% 
Arsenic pentoxide, As,O,.-..--- 23°25 23°39 
ChiorinesClhesr eit ea 2°39 280i) ee 
100°39 100°34 
O, equivalent to Cl .---.--.-.- 0°54 0°54 
99°85 99°80 


These transformations are accompanied by the solution of 40 
per cent of the total arsenic in the dilead arsenate,+ the super- 


natant liquid showing a distinct acid reaction toward methyl 


orange. The reaction may be expressed by the following equa- 
tion : 


5PbHAsO, + NaCl = Pb,(PbCl)(AsO,), + NaH,AsO, + H,AsO, 


A particularly interesting reaction is that between dilead 
arsenate and a solution of lead chloride. which substances were 
found to react readily on warming, giving a solution contain- 
ing free hydrochloric acid and a residue corresponding closely 
to theory for mimetite. This may be expressed by the follow- 
ing reaction : 

3PbHAsO, + 2PbCl, ==> Pb,(PbCl)(AsO,), + 3HCI. 


In all of these reactions we have the rather strange phenome- 
non of the transformation of one lead arsenate into a more 
basic one with liberation of a strong acid. 


*Dilead arsenate boiled for about 5 hours with solutions of potassium 
bromide, potassium iodide or sodium fluoride (35 grams to 1 1.) gave prod- 
ucts similar in composition. The bromine compound contained 5:79 per 
cent Br (theory 5°22) and 21°92 per cent As.O; (theory 22°51); the iodine 
compound 23°57 per cent As,O,; (theory 21°84); and the fluorine compound 
23°71 per cent As,O; (theory 23°44). The reaction with KI apparently did 
not proceed as rapidly as the others, and did not go to completion during 
the time of the digestion. 

+It was noted by Headden (Colorado Agricultural Experiment Station 
Bulletins, 131, 22, 1908; 157, 30, 1910), and by Haywood and McDonnell 
(Bur. Chem. Bull. No. 131, 46, 1910), that water containing sodium chloride 
extracts a greater amount of arsenic from commercial lead arsenates than 
does pure water. This also explains why greater injury to foliage occurs 
when lead arsenate is applied with water containing chlorides in solution, 
as has been shown by the latter authors (ibid., p. 49). 


McDonnell and Smith—Lead-Chlor Arsenate. 141 


The precipitates resulting from the preceding experiments, 
when examined under the microscope, were seen to consist in 
the main of amorphous material, but many crystals were 
observed, usually small prismatic forms, apparently hexagonal, 
though too small for definite determination. After many 
attempts, we were successful in obtaining crystals sufficiently 
large to permit of the determination of their optical properties. 
Uniformly erystalline material was first obtained by dissolving 
pure dilead arsenate in hydrochlorie¢ acid (36° of concentrated 
acid to 860% of water) adding ammonia until a precipitate 
was just about to form and then pouring the solution into 10 
liters of cold water. A precipitate formed immediately and 
when examined with the microscope was found to consist 
mostly of very small erystals with numerous long sprismatic 
ones, apparently hexagonal prisms doubly terminated by pyra- 
mids of the same order, or a combination of the pyramid and 
basal pinacoid. Two such preparations were made and gave 
when analyzed the following results : 


4 “s ". bi 7 4a ; 3 b 
Weadvoxides PhO, 2.522000. 5: 13,08 % 74°83% 
Arsenic pentoxide, As,O, ..-. -- 5 92°34 22°76 
@hilorine, Clie see Oe 2866 2°96 

100°56 100°55 
Omequivalent to Clz--2- 3. -_.. 60 67 


99°96 99°88 


Considerably larger crystals (see fig. 1*) were obtained by 
treating a solution of PbHAsQ, in dilute hydroehloric acid 
with lead acetate to incipient precipitation and: allowing it to 
cool to room temperature. In one such ‘preparation many 
crystals were obtained -07 by -01"™, while a few measured ‘13 
by 03". The chlorine content of products prepared in this 
way varied from 2°52 to 2°83 per cent. 

When lead-chlor arsenate erystallizes from a solution con- 
taining hydrochloric acid it is sometimes accompanied by 
dilead arsenate or lead chloride. In one case crystals of all 
three compounds were obtained from the same solution. 

Dilead arsenate is slightly soluble in concentrated sodium 
chloride solutions (probably because of the acid liberated) but 
only a few crystals were obtained from a solution of 150 grams 
of salt in 500° of water, which had been boiled in contact with 
dilead arsenate for one hour and the clear filtrate allowed to 


* Photomicrographs made by G. L. Keenan, micro. analyst, Bureau of 
Chemistry. 


142 MeDonnell and Smith—Lead-Chlor Arsenate. 


cool. However, by first adding arsenic acid to the boiling 
salt solution, followed by lead acetate just short of a permanent 
precipitate and allowing the solution to cool, a slightly greater 
precipitate was obtained. The crystals so produced differed 
from those obtained from dilute hydrochloric acid solutions in 
that they were terminated by pyramids of the second order (fig. 


Fie. 1. 


Fic. 1. Lead-chlor arsenate, artificial mimetite (x 234). 


2). Sodinm and potassium chlorides were the only media from 
which crystals with pyramids and prisms of different order 
were obtained. A few attained the dimensions :06-04™", 
The filtrate from the experiment just described was kept at 
about 15° C. for 5 weeks, when a mass of sodium chloride con- 
taining a small amount of lead-chlor arsenate had separated 
out. The salt was removed by washing with water and the 
lead-chlor arsenate remaining was examined with the micro- 
scope. It consisted of small crystals, showing no abrupt transi- 
tion from lateral to end faces, resembling prolate spheroids. 


McDonnell and Smith—Lead-Chlor Arsenate. 143 


Crystals of this form are very frequent when produced by slow 
growth. They resemble more nearly natural mimetite, which 
rarely shows clear cut crystals but almost always characteristic 
*‘ barrel-shaped ” forms. 

In the preceding experiments the resulting products in every 
case (except where dilead arsenate was transposed by boiling 


Fie. 2. 


Fie. 2. Lead-chlor arsenate, artificial mimetite ( x 238). 


with sodium chloride solutions) contained chlorine in excess 
of the theoretical amount for mimetite.* 


*This suggested that there might be other Jead-chlor arsenates containing 
relatively more lead chloride. In fact a natural mineral (Georgeadisite) has 
been reported (Comptes Rendus, cxlv, 783, 1907) the analysis of which corre- 
sponds to the formula Pb,(AsO4)o.8PbCl, or (PbCl)sAsO,. We have 
succeeded in producing another compound of this class, having a chlorine 
content of 3°4 per cent, which is referred to later, and evidence of a third 
containing about 4 per cent. . 

A Jead-chlor arsenate is formed by double decomposition between dilute 
solutions of di- and trisodium arsenates, or even arsenic acid, and lead 
chloride, and also when dilute solutions of sodium and potassium dihydrogen 


144 MeDonnell and Smith—Lead-Chlor Arsenate. 


It was found, however, that a product of practically theoret- 
ical composition was obtained by diluting a boiling saturated 
solution of sodium or potassium ehlor ide, to which had been 
added arsenic acid and lead acetate, with a small amount of 
boiling water: To 2000° saturated sodium chloride solution at 
boiling temperature were added approximately 30 grams of 
arsenic acid, then lead acetate solution until a permanent pre- 
cipitate remained, filtered and added 600% of boiling water to 
the clear filtrate. A precipitate formed almost immediately 
and settled rapidly, leaving a clear solution. This was decanted 
after a few minutes and the precipitate washed by decantation 
with boiling water until no reaction for chlorine was obtained 
in the wash water. The precipitate recovered weighed 48 
grams and consisted of beautiful cr ystals similar in appearance 
to those shown in fig. 2. In-vsize they averaged about 
‘015 x -01™", but some were observed as large a6 “10 SO 

Analysis : 


Lead oxide, PbO.___. .__- A eS 73°90% 
Sodimm-oxide, NasO 225 eae 64 
Arsenic pentoxide, WAS! O> (Soom 23°18 
Chlorine sCiicee2 = fn soe fay 2°46 
100°18 

O;equivalentato Cl ot. 2> eee ao 0°55 
99°63 


arsenates are added-to lead chloride. However when a solution of lead 
chloride is added to sodium or potassium dihydrogen arsenate, the latter 
remaining in excess, dilead arsenate is formed. A chlor arsenate will be 
precipitated by lead acetate or nitrate from a solution of disodium arsenate 
containing sodium chloride. 

* The same compound was formed, but in much smaller crystals, when the 
boiling saturated sodium (or potassium) chloride solution, prepared as 
described, was added quickly to three to six times its volume of boiling 
water. However, when a portion of the same solution was added, at boiling 
temperature, to five times its volume of cold water (28-30° C.), a crystalline 
precipitate was produced which analyzed : 


Lead oxidemeb@Ors Sk: 3k ae eee. 73°80% 
Sodiumioxider Na O2 es eee eee ee 32 
Arsenic pentoxide, As2O; ------.---.---- 22°30 
@hloring) (Cle ern cs are oe er 3°42 
Water (expelled on ignition) Bee a cacha seienee Or 
100°81 
O equivalent torC lars. sss seeee eee 0-77 
10004 


This corresponds closely to the formula: 2Pb;(AsO,)o.PbCly.H.0, or 
Pbs(PbCl)a(As0,4)4.H,0. This experiment was repeated a number of times 
and always resulted in the production of this compound, which differs from 
mimetite in containing a greater proportion of lead chloride and also a small 
amount, apparently one molecule, of water of crystallization. 


McDonnell and Smith— Lead-Chlor Arsenate. 145 


Compounds prepared in this way from saturated sodium 
chloride solutions generally contained a small amount otf 
sodium, replacing, apparently, an equivalent amount of lead, 

The following physical properties of the artificial mimetite, 
prepared as just described, were determined : 

Color.—In bulk this material had a slight yellow tint, but 
the color varied with the different preparations, which suggests 
that it is probably due to traces of impurities. 

Specific Gravity —T15 at 15° C. (determined by the use of 
a 10° specific gravity bottle with 4 grams of material and 
water as the medium). This agrees with the value for the 
natural mineral, which according to Dana* varies from 7:0 to 
125. , 

Optical Properties.t—Parallel extinction, apparently uni- 
axial (if biaxial the axial angle is very small); approximate 
refractive indices, ¢ = 2°18, and = 216, and therefore 
optically negative. These observations and the general form 
of the crystals indicate that they belong to the hexagonal sys- 
tem. 

It will be noted that the artificial mimetite which we have 
prepared is, in so far as we have been able to determine from 
the examination of a number of preparations, uniaxial. Natu- 
ral mimetite, the occurrences of which, as stated by Clarke,t 
indicate formation by hydrochemical reactions, is generally 
biaxial. Specimens from Johanngeorgenstadt, examined by 
Bertrand,§ had an axial angle in air of 64°. Jannettaz| found 
an axial angle of 39° in air on a specimen from the same local- 
ity. A variety of uniaxial mimetite has been reported by 
Jeremejew.4 The optical properties of the artificial mimetite 
prepared by Lechartier, Michel and Weinschenk are not 
recorded. The anomalous optical behaviour of natural mime- 
tite may be due to the presence of other chlor arsenates such as 
we have here briefly referred to. We have not been able, 
however, to prepare any of the higher chlor arsenates in 
sufficiently large crystals to determine their optical properties. 


Insecticide & Fungicide Laboratory, 
Bureau of Chemistry, Washington, D. C. 


* System of Mineralogy, 6th ed., p. 772, 1892. 

+ Determinations made by F. HE. Wright, Geophysical Laboratory, Car- 
negie Institution of Washington. 

{U. S. Geological Survey Bull. No. 616, p. 682, 1916. 

S$ Bull. Soe. Min. de France, iv, 36, 1881; v, 254, 1882. 

|| Tbid., iv, 39, 1881. 

“| Verh. Russ. min. Ges., (2), xxii, 179, 3812, 332, 1886; through Zeitschr. 
Kryst, Min., xiii, 193, 1888. 


146 Jauncey—Liffect of a Magnetic Field. 


Arr. XVUI.—TZhe Lffect of a Magnetic Field on the Initial 
Recombination of the Ions Produced by X-Rays in Air ; 
by G. E. M. J AUNCEY. 


$1. Introduction. 


AssuMING a given number of ions to be distributed uniformly 
throughout a gas and using the known coefficient of recom- 
bination and the known mobilities of the ions, the saturation 
voltage can be calculated for an ionization chamber of known 
dimensions. This caleulated saturation voltage is much less 


than the observed saturation voltage when the gas is ionized . 


by a-rays. It, therefore, appears that i ions, produced by a-rays, 
recombine at an abnormally high rate when first formed. This 
abnormal recombination is known as initial recombination. 

The generally aceepted explanation of this fact is that con- 
ditions are abnormally favorable for recombination along 
the path of an a-particle where the ions are much crowded 
together. 

W. H. Brage* has pointed out that the recombination of 
ions may be complicated or influenced by the fact that when a 
pair of ions is first formed the ejected electron may not have 
sufficient velocity to break away from the parent atom and a 
strong electric field would tend to complete this incipient ion- 
ization. Thus one effect of the electric field would be to 
actually increase the rate of formation of ions and under these 
conditions there may be no such thing as saturation voltage. 
A gas ionized by X-rays shows to a small degree the effects of 
initial recombination. In this case the excessive density of 
the ions in the region of formation cannot be used as an ex- 
planation for initial recombination. ‘The only available ex- 
planation seems to be the above hypothesis of Bragg. 

If a magnetic field is applied to a gas ionized by X-rays 
then the electron which is ejected from an atom by means of 
the ionizing agent will follow a curved path and will therefore 
remain for a longer time near the parent atom and so there 
will be a greater chance of it being drawn back into the atom. 

Furthermore Br age in his “ Studies in Radioactivity ” cites 
many experiments which support the hypothesis that a gas is 
not to any great extent directly ionized by the X-rays but by 
the secondary high-speed cathode rays which are produced by 
the direct action of the X-rays. In contradiction to this, 
KJeemant concluded from one of his experiments that as much 
as half the ionization in an air-filled chamber was due to the 


* Studies in Radioactivity, p. 73. 
+ Cambridge Phil. Soc., Proc. 15, pp. 169-177. 


Jauncey—Liffect of a Magnetic Field. 147 


direct action of y-rays on air. In this experiment Kleeman 
passed the y-rays from radium through an aluminium plate and 
then through a window of thin paper into an ionization 
chamber, the distance between the aluminium plate and the 
paper window being a few centimeters. On applying a mag- 
netic field to the space between the plate and the window 


Fie. 1. 


battery 2 battery 


ground 


electroscope 


Kleeman found that the ionization in the chamber was 
decreased to about 55 per cent of its original value. The 
magnetic field deflected the secondary 8-rays produced in the 
aluminium so that these @-rays no longer entered the ionization 
chamber. 

It seems, therefore, that Kleeman’s conclusion is invalid. 
The secondary 8-rays which are scattered from the atoms of 
the gas in the ionization chamber are not, according to Brage,* 
prevented from producing ionization by a magnetic field. — 


* “Studies,” p. 166. 


148 Jauncey—Efect of a Magnetic Field. 


The present work was undertaken with the object of testing 
the direct effect of a magnetic field on the ionization current 
in air at atmospheric pressure when the applied voltage is 
either above or below the saturation voltage. 


$2. Heperiment I. Voltage above Saturation. 


Homogeneous secondary X-rays from copper were used. 
Fig. 1 shows the connections. Primar y X-rays from the X-ray 
tube D, which was enclosed in the lead box H, fell upon the 
sheet of copper E which was bent into the shape ofaV. This 
copper was caused to emit secondary X-rays, part of which 
entered the chamber A through the paper window F and part 
entered the chamber B through the slit OC and the paper win- 
dow G. The ionization chamber A was placed between the poles 
of an electromagnet and the other chamber B was outside the 
magnetic field. The opening of the slit © could be varied by 
means of a micrometer screw. The ionization chamber A was 
connected to a positive and the chamber B to a negative volt- 
age or vice versa, the voltage being such as to give “the satura- 
tion current for both chambers. The inside electrodes of both 
chambers were connected together and to a Wilson tilted 
electroscope as shown. The chamber A was made of lead, the 
inside being coated with paper in order to cut out the effect of 
secondary ¢ cathode rays from the lead. The dimensions of A 
were 7:5 X 2°30 X 1:0 em’, the X-rays entered through a win- 
dow 1-0 x 1:5 em* and travelled for a distance of about 23 ems, 
in the chamber. The inside electrode was a wire which could 
be extended to various lengths along the middle line of the 
chamber A in order to vary “the saturation voltage. With this 
arrangement the reading of the slit opening when there was no 
deflection of the electroscope was taken as a measure of the 
ionization current in the chamber A. Any variation in the 
primary X-rays produced proportional changes in the total 
1onization in the two chambers and thus any fluctuation in the 
strength of the primary X-rays was compensated. The electro- 
magnet being necessarily near the X-ray tube, the bright spot 
on the anti-cathode was deflected by the magnetic field. This 
was partially overcome by means of a compensating magnet. 
The strength of the magnetic field was found by means of an 
exploring coil and a ballistic galvanometer in the usual way. 

In this experiment the effect of a magnetic field on the total 
ionization produced by X-rays was examined. The results are 
shown in Table I. 

This table shows that the magnetic field, and consequently 
the bending of the secondary cathode rays into eurvilinear 
paths, does not alter the total ionization produced in a gas by 
X-rays. 


Jauncey—Liffect of a Magnetic Field. 149 


“Taste J.) Exrrermenr, I. 


Ionizing agent : Homogeneous X-rays from copper 
Strength of magnetic field ; 4200 gauss 
Gas ionized : Aix at atmospheric pressure 


Voltage peas Ahationtzaimon Tonization Caen (slit readings) 
Chamber A | Without magnetic |. With magnetic 
| field field 
Above saturation voltage * 641 631 
627 629 
634 | 621 
637 637 


Mean _:..635° ° Mean __..629 


$3. Experiment II. Voltage below Shnbation. ° 


The compensation arrangement of Experiment I was sli 
doned because the saturation voltage was less than 7 volts 
which was too low and because a compensation method is not 
desirable when the voltage-current relation is being determined, 
the shape of the curve depending upon the absolute value of the 
lonization-current. 

In this experiment primary ‘X-rays entered the lead 
chamber A directly, the distance between the electromagnet 
and the X-ray tube being such that the bright spot was not 
noticeably deflected by the magnetic field. The reciprocal of 
the time for a given’) deflection of the gold leaf of the electro- 
scope was taken as a measure of the ionization current. 

In this experiment the effect of a magnetic field on the 
relation between the voltage and the ionization current was 
examined. The results are shown in Table II. 


Taste II, Exrxeriment II. 


Tonizing agent 
Strength of magnetic field 
Gas ionized 


Primary X-rays 
4200 gauss 
Air at atmospheric pressure 


ee 88 ee 


Tonization Current 


Voltage across 


chamber Without magnetic | With magnetic With Aine 
re 201 (corrected values) 
15°0 52 ees Bee 
45°0 141 148 142 
67°5 180 199 191 
120°0 250 268 257 


150 Jauncey—Lffect of a Magnetic Field. 


In this table each of the values of the ionization current 
in columns 2 and 3 is a mean of four or five readings, which 
were taken alternately with and without the field. It is seen 
that in the given set of readings the ionization current was 
always slightly greater with the field than without. By chang- 
ing the positions of the bulb this effect could be reversed, thus 
showing that the effect is probably due to the field having a 
small action on the cathode stream in the X- -ray tube. When 
187°5 volts was put across the chamber the reading was 310 
without the field and 324 with the field. Since the results of 
Experiment I have shown that the total ionization is unaltered 
by a magnetic field if the strength of the ionizing agent re- 
mains constant and since the ionization currents of 310 and 324 
are nearly the saturation currents, the readings with the field 
were all reduced in the ratio of 324 to 310 and these corrected 
values are shown in the fourth column. 

From Table II it is seen that the corresponding numbers in 
the second and fourth columns are almost identical, the small 
differences observed not being greater than those due to ex- 
perimentalerrors. Hence it is concluded that a magnetic field 
has no effect on the saturation curve and therefore no effect on 
the initial recombination of the ions. 


§4. Summary. 


1. A magnetic field of the intensity here used has no effect 
on the total ionization produced by X-rays. 

2. A magnetic field of the intensity here used has no effect 
on the initial recombination of the ions produced by X-rays. 

In conclusion, the author wishes to thank Professors Franklin 
and MacNutt for their interest and help in this research. 


Physics Laboratory, Lehigh University, 
South Bethlehem, Pa., April 29, 1916. 


Thornton, Jr.—Separation of Thorium from Iron. 151 


Art, XIX.—The Separation of Thorium from Lron with the 
Aid of the Ammonium Salt of Nitrosophenylhydroxylamine 
(“ Cupferron”); by Wirt1am M. Trornton, Jr. 


Tue ammonium salt of nitrosophenylhydroxylamine, which 
was first introduced into analytical chemistry by O. Baudisch,* 
has been made a subject of study by several chemists.t+ 
Because of its selective action as a precipitant many clean 
cut separations have been effected; thus solving a variety ot 
analytical problems which without the use of the reagent 
would involve much difficulty. Bellucci and Grassi t have 
shown that in solutions decidedly acid with either sulphuric 
or hydrochloric acid, the substance precipitates quantitatively 
titanium and that under like conditions titanium can be 
completely separated from aluminum in one precipitation. 
Following the work of Bellucci and Grassi, the author § 
has demonstrated that, after throwing down the iron as ferrous 
sulphide from a solution containing sufficient ammonium tar- 
trate to hold up titanium, and after acidifying the iron free fil- 
trate, the titanium can be quantitatively precipitated by the ‘“cup- 
ferron” reagent notwithstanding the presence of tartaric acid ; 
and, further, that, if the above-mentioned filtrate be strongly 
acidified with sulphuric acid and contain also a sufficient 
quantity of tartaric acid, titanium can be quantitatively sepa- 
rated from both aluminum and phosphoric acid in one operation. 
Pursuing a similar technique, E. M. Hayden, Jr. and the 
author| succeeded in separating zirconium from both iron and 
aluminum. During the same year,4/ Ferrari, by means of the 
“eupferron” reagent, separated zirconium from aluminum; 
but did not consider the more complicated case of iron being 
present as a third ingredient. Owing to the fact that thorium 
bears a marked resemblance to zirconium in its chemical 
relations, the author has seen fit to study the former element 
with respect to the “ cupferron” reagent. The outcome of 
this investigation has been to establish conditions under 
which thorium is quantitatively precipitated by the reagent 


* Chem. Zeitung, xxxiii, 1298, 1909; xxxv, 913, 1911; Baudisch and King, 
Jour. Ind. Eng. Chem., iii, 629, 1911. 

+ Nissenson, Z. angew. Chem., xxiii, 969, 1910; Chem. Zeitung, xxxivy, 539, 
1910; Biltz and Hodtke, Z. anorg. Chem., lxvi, 426, 1910; Hanus and 
Soukup, ibid., Ixviii, 52, 1910; R. Fresenius, Z. anal. Chem., 1, 35, 1911; 
Bellucci and Grassi, Gazz. chim. Ital., xliii, I, 570, 1918; Rodeja, Anal. Fis. 
Quim., xii, 305, 1914; xii, 379, 1914; Ferrari, Annali Chim. Appl., ii, 
276, 1914 ; iv, 341, 1915; Turner, this Journal, xli, 339, 1916. 

t Loc. cit. 

§ This Journal, xxxvii, 178, 1914; ibid., xxxvii, 407, 1914. 

This Journal, xxxviii, 137, 1914. 

“| Loe. cit. 


152 Thornton, Jr.—Separation of Thorium from Iron. 


and also toaccomplish the indirect separation of thorium from 
iron. 

A standard solution of thorium sulphate was employed for 
these experiments. This was prepared. by dissolving the 
Welsbach Light Company’s thorium nitrate in boiling water 
and precipitating the thorium with a boiling solution of. “sebacic 
acid according to the method of Smith “and James.* The 
thoroughly w ashed precipitate was dried and ignited to thorium 
oxide in a platinum dish. The residue was then subjected 
to a prolonged digestion with hot sulphuric acid. After cool- 
ing, the semi- solid mass was poured into cold water and the 
solution filtered from an insoluble residue of wnattacked 
thorium oxide. The filtrate was made nearly neutral with 
redistilled ammonium hydroxide and the thorium precipitated 
with recrystallized oxalic acid. The thorium oxalate, after 
complete washing, was dried at 110° C. and the sample pre- 
served. Of the ‘oxalate thus obtained 8-5 grams was digested 
with 50 em* of sulphuric acid (made by diluting acid of sp: 
g. = 1°84 with an equal volume of water), adding a little nitric 
acid to oxidize traces of organic matter which discolored the 
liquid, and warming until nitric acid could no longer be detected 
by its odor. On pouring the residue into cold water the 
thorium sulphate dissolved completely and the solution was 
made up to a volume of one liter. Two experiments were 
made in order to set the standard of this solution. Weighed 
portions were treated with redistilled ammonium hydroxide at 
the boiling temperature, the resulting thorium hydroxide was 
ignited to the oxide, and the latter was brought to constant 
weight over the blast lamp. Duplicate determinations gave 
the ‘following result :— 


Thorium sulphate solution Thorium oxide 
(a) 25 cem* 25°740 grm. 0'0922 grm. 0°3582% 
(6) 25 em* 25°757 grm.  - 0:0925 grm. 0°3592% 


The mean of these two values was taken as correct. 
Preliminary experiments soon revealed the fact that even 
with small concentrations of free sulphuric acid the precipi- 
tation of thorium by the “cupferron” reagent is incomplete. 
The author, therefore, resorted to the expedient of throwing 
out the thorium from a medium containing acetic as the 
only tree acid. Accordingly weighed portions of 25 cm* of 
the standard thorium sulphate containing also about 1:25 em* 
of sulphuric acid (1:1) were taken and treated with 15 grm. 
of ammonium acetate in the form of a strong solution and the 
volume made up with water to 500 em*. <A 5 per cent “cup- 


* Jour. Am. Chem. Soc., xxxiv, 281, 1912. 


Thornton, Jr.—Separation of Thorium from Iron. 158 


ferron” solution was then added gradually with constant 
stirring till present in some excess—15 em* being the volume 
actually used. The precipitate, after having been thoroughly 
coagulated by stirring, was thrown onto a paper filter and 
washed with a 1 per cent solution of ammonium acetate. The 
moist paper with its contents was then placed in a tared 
platinum crucible, dried at 100-110° C., and ignited first with 
the Bunsen burner and then with the blast lamp to constant 
weight. In this way the results of Table I were obtained, which 
are within the limit of error for ordinary analytical work. 


“ TABLE I, 
The Estimation of Thorium by Means of the ‘‘ Cupferron” Reagent. 


Tho, ThO, Vol. of 
taken found Error C.H;0.NH, .~ Solution 
No. grm. grm. grm. erm, em? 
1 0°0925 0:0924 —0:°0001 15 500 
2 0'0923 0:0917 —0:0006 15 500 


The thorium salt of nitrosophenylhydroxylamine* differs a 
good deal in properties from the corresponding compound of 
either titanium or zirconium. Im the case of the two last 
elements a high concentration of free sulphuric acid is con- 
sistent with total precipitation; while in the case of thorium 
extremely small concentrations of the same acid exert a marked 
solvent effect on the precipitate. Although very similar in 
appearance to the zirconium precipitate, the thorium pre- 
cipitate is rather different in texture. Whereas the former 
permits filtration by suction, the latter passes through the 
paper in small quantities under the influence of very light 
pressure. This is unfortunate from a manipulative standpoint, 
since the precipitate cannot be drained at the puinp—neces- 
sitating the removal of included water by slow drying. 

In the second series of experiments thorium was separated 
from iron. Known quantities of iron were taken by weighing 
off portions of pure dry ferrous ammonium sulphate. The 
solution (about 150cm*), containing sufficient tartaric acid to 
hold up the bases in ammoniacal solution, was made slightly 
alkaline with ammonium hydroxide, and colorless ammonium 
sulphide was added in moderate excess. After settling, the 
ferrous sulphide was filtered off and washed ten times with 
water containing a little colorless ammonium sulphide. Five 
cubic centimeters of sulphuric acid (1:1) was then added and 
the hydrogen sulphide thus liberated was removed by boiling. 
After cooling to room temperature, 25 grams of ammonium 


*[C.H.(NO).N.O],Th, assuming a formula analogous to the one proposed 
by Bellucci and Grassi for the titanic derivative. 


154 Thornton, Jr.—Separation of Thorium from Iron. 


acetate was added, the volume made up to 400 em®* or 500 em° 
and a 5 per cent “cupferron ” solution added in decided excess. 
From this point on the determination was made just as in the 
ease of thorium alone. Table IJ contains the results of three 
experiments. 


TABLE II, 


The Separation of Thorium from Iron, 


ThO, Fe,O5 ThO, Vol. of 
taken taken found Error C.H;O0.NH, Solution 
No. grm. grm, grm. grm. grm en} 
3 0°0924 0'1018 0°0922 —0°0002 25 400 
4 0°0924 0°1018 0°0916 —0°'0008 25 500 
5 0°1846 0°1018 0°1840 — 00006 25 400 


A separation of thorium from iron with the aid of the “ cup- 
ferron” reagent has been satisfactorily worked out and the 
experimental data show a fair degree of accuracy. Let the 
reader distinctly understand, however, that the above process 
is not offered as an analytical method for practical purposes. 
The well-known oxalate* precipitation is satisfactory and 
separates thorium from nearly all the common elements with 
which it is likely to be associated. But another link has been 
added to the chain of “cupferron” results and some com- 
parative data on titanium, zirconium and thorium with respect 
to this remarkable reagent have been brought to light, which 
it is hoped will prove of interest. 

Finally the author wishes to state that the experimental part 
of the work on thorium was carried out in the laboratory of 
the College of the City of New York and to thank Professor 
Charles Baskerville for fostering the investigation. 


Wilmington, Delaware, 
June 6, 1916. 


* See E. Benz, Zs. angew. Chem., xv, 297, 1902. 


Drushel and Elston—Sulphide Sulphur. 1155 


Arr. XX.—On the Quantitative Estimation of Small Quan 
tities of Sulphide Sulphur ; by W. A. Druswet and ©. M. 
Eston. 


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


Tue methods of estimating sulphide sulphur in common use 
depend (1) upon oxidation of the sulphur to the sulphate con- 
dition and weighing it as barium sulphate, (2) upon oxidation 
by means of standard iodine and titration of the excess of 
iodine with standard sodium thiosulphate, and (3) upon the 
precipitation of the sulphur by an excess of standard sodium 
arsenite as arsenious sulphide and titration of the excess of 
arsenite with standard iodine. These methods all require con- 
siderable time for execution, and the first and second methods 
are not entirely reliable for quantities of sulphide sulphur 

much smaller than 0:04 per cent. The third method is said to 
be accurate for quantities of sulphide sulphur as small as 0:0003 
per cent, but it is necessary to allow the mixture, after treat- 
ment with sodium arsenite, to stand for twelve hours in order 
that the precipitated arsenious sulphide may be removed quan- 
titatively by filtration before the excess of arsenite is titrated 
baek with iodine. 

The object of the present investigation was to develop a 
rapid method of estimating very small amounts of sulphide 
sulphur with a fair degree of accuracy. The method is a 
colorimetric method and consists essentially of the comparison 
of the depth of color of lead sulphide stains obtained from the 
sulphide sulphur of a given weight of a sample to be analyzed 
with a standard series of stains prepared from sulphide solu- 
tions of known sulphur content. <A set of stains varying in 
depth of color from a faint yellowish brown to black represent- 
ing from 0:0002 per cent to 0-004 per cent of sulphide sulphur 
inay be prepared and used indefinitely for comparison. With 
a set of standard stains at hand the method has the advantage 
that within the range given the sulphide sulphur of a sample 
may be determined with a fair degree of accuracy in less than 
ten minutes. 

Preparation of standard set of sulphide stains.—The appa- 
ratus used for preparing standard stains and for making analyses 
is very simple. The inner tube of a Liebig condenser with its 
larger end about 18™™ in internal diameter was cut off 15™ in 
length. The smaller end was drawn down somewhat, rounded 
and fitted to a sound cork stopper which in turn was fitted to 
a 100°" round-bottom flask. The condenser tube then. served 
as a sort of reflux condenser. To the upper and larger end of 


Am. Jour. Scot.—Foortna Series, Vou. XLII, No. 248.—Aveusr, 1916. 
11 


156 Drushel and Elston—Sulphide Sulphur. 


this tube a filter paper moistened with a dilute solution of 
lead acetate was smoothly fitted and tied, so that the steam 
passing up through the tube and carrying hydrogen sulphide 
was required to pass out through the lead acetate paper. A 
similar tube with the internal diameter of its larger end about 
36"™ was also prepared and used for sulphide sulphur samples 
containing 0-001 per cent or more of sulphur. 

A solution of sodium sulphide was made up with pure dis- 
tilled water and carefully standardized. The solution was then 
diluted to contain exactly 0°01 per cent of sulphide sulphur. 
This solution was used for making up standard solutions con- 
taining 0:0002, 0-0004, 0°:0006, 0-0008, 0-001, 0-002, 0-003 and 
0-004 per cent of sulphide sulphur respectively, taking care to 
use distilled water free from traces of nitrites in making the 
dilutions. It was found that the more dilute sulphide solu- 
tions when made up with ordinary distilled water lost their 
sulphide content either wholly or in part on standing for 
several hours in stoppered bottles. This difficulty was obviated 
by using nitrite free distilled water in making up the solutions. 

Carefully measured portions of 1°™* to 5° of the standard 
solutions were pipetted into the 100° flask and 25°™* of hydro- 
chloric acid of about 0°5 per cent strength were added. The 
flask was immediately attached to the condenser tube fitted 
with moistened lead acetate paper as previously described. The 
mixture was then gently boiled for a few minutes at such a 
rate that the steam issued not too rapidly from the upper 
end of the condenser tube. In this way the sulphide sulphur 
was quantitatively liberated as hydrogen sulphide and evenly 
deposited as lead sulphide on the moistened lead acetate paper. 
The undecomposed lead acetate was then washed out, the 
paper dried and labeled with the amount of sulphide sulphur 
present as one of the set of standard stains. In the same 
way complete sets in duplicate were prepared ranging in sul- 
phide sulphur from 0-0002 per cent to 0-004 per cent. 

In order to determine the accuracy with which sulphide sul- 
phur may be estimated in this way one of us made up a series 
of sodium sulphide solutions which the other estimated by the 
method outlined. The results are given in Table I. The 
first column shows the amount of sulphide sulphur in the solu- 
tions as made up. In the second column are the estimated 
amounts of sulphide sulphur. 

In making these estimations the larger condenser tube was 
used where a preliminary trial indicated that the amount of 
sulphide sulphur was equal to or greater than 0:001 per cent. 
In all other cases the smaller tube was used. The maximum 
error, depending upon the amount of sulphur present, with the 
larger tube was 0°001 per cent and with the smaller tube 0-0003 


Drushel and Elston—Sulphide Sulphur. 157 


TaBLe I. 
Sulphide sulphur Sulphide sulphur 
taken ' found 
per cent per cent Error 
Ile 0:0025 00020 0°0005 
2. 0°0015 0°0012 0°0008 
3. 0-0006 0°0006 ee 
4, 00004 00003 00001 
5. 0°0004 0°0064 et 
6. 0004 0°005 0:001 
ils 0000 0000 mess 
8. 0°0002 0°00015 0°00005 
9. 0°008 0:009 0:001 
10. , ~ 0°002 00025 0°0005 
ile 0-001 0°0015 0:0005 
12. 00001 0-0001 ie an 


per cent. These errors may be reduced by repeating the 
determination and taking the mean of several values found. 
In this way in the pra actical applications of the method the 
errors may be kept within reasonable limits. 

Practical applications.—(1) In gas analysis. The method 
was used for the estimation of the hydrogen sulphide in the 
laboratory atmosphere and in illuminating gas. On a day 
when no hydrogen sulphide generator was being used in the 
laboratory the air contained barely a perceptible trace of 
sulphur; on another day when a class two floors below was 
using a hydrogen sulphide generator the amount of hydrogen 
sulphide in the air of the upper laboratory was found to be 
] part in 5,000,000. Twenty-five liters of air were slowly 
drawn through a Geissler bulb of the most modern type con- 
taining dilute potassium hydroxide solution. This solution 
was then washed into a measuring flash and made up to the 
mark with nitrite free distilled water and aliquot portions of 
this solution were used for determining the sulphide sulphur 
as previously described. The same procedure was used for 
estimating the hydrogen sulphide in illuminating gas. The 
colorimetric method gave 1 part of sulphur in 1,000,000 of gas. 
The same result was obtained by oxidizing the larger portion 
of the solution from the Geissler absorption apparatus with 
bromine water and weighing the sulphur as barium sulphate. 
Duplicate determinations on the same illuminating gas gave 
precisely the same result. 

(2) In coke analysis. The simplest method of estimating 
sulphur in coke given by Fresenius is to boil 5 grams to 10 
grams of powdered coke in dilute hydrochloric acid, and to 
absorb the hydrogen sulphide evolved in dilute potassium 
hydroxide solution. The sulphur is then oxidized to the sul- 


158 Drushel and Elston—Sulphide Sulphur. 


phate condition by chlorine water or bromine water and 
weighed as barium sulphate. This method was used as a con- 
trol to check up the results obtained by the colorimetric method. 
In this method the hydrogen sulphide was liberated and 
absorbed as suggested by Fresenius and aliquot portions of the 
sulphide containing potassium hydroxide solution were trans- 
ferred to the distillation flask and the previously described 
procedure was followed. A comparison of the results obtained 
by the two methods on several samples of coke is found in 
Table IT. 


TABLE IT. 


Coke Analysis. 
Sulphide sulphur found 


by Fresenius grav- by colorimetric 
imetrie method method 
0:°049% 0:050% 
0°050 0:050 
0026 0°025 
0°025 0°026 


0°027 0°025 


(3) In paper analysis. Another practical application of this 
method of determining sulphide sulphur is in paper analysis. 
In order that tissue paper may be used for wrapping polished 
metal without producing a tarnish the paper must be relatively 
free from sulphide sulphur. A weighed amount of paper, 
1 gram to 2 grarns, is cut into small pieces and transferred to 
the distilling flask and digested with gently boiling 0-5 per 
cent hydrochloric acid, collecting the hydrogen sulphide as 
lead sulphide on lead acetate paper as previously described. 
A number of samples of tissue paper were examined and in 
those samples which contained sulphide sulphur the amounts 
varied from 0:0002 per cent to 0-001 per cent. Papers which 
contained the larger amounts of sulphide sulphur when used 
for wrapping polished silver pieces usually produced a marked 
tarnish in the course of two or three weeks. 

This colorimetric method of estimating very small quantities 
of sulphide sulphur is very rapid, fairly accurate, and has a 
number of practical applications. 


Ford and Bradley—Margarosanite. 159 


Art. XXI.—Margarosanite, a New Lead-Caleium Silicate 
Jrom Franklin, NV. J.; by W. E. Forp and W. M. Bravtey. 


THe new mineral to be described in the following paper was 
originally observed on specimens from Franklin, N. J., that 
came from about the 1000 ft. level of the Parker shaft on 
North Mine Hill and were collected during the year 1898. It 
was partially investigated by S. L. Penfield and C. H. Warren 
during their study of Franklin minerals which resulted in the 
description of the other new species, hancockite, glaucochroite, 
nasonite and leucopheenicite.* Partial analyses were made by 
both Penfield and Warren, but the investigation was never 
carried to a conclusion and the results obtained were not pub- 
lished. Their material has remained in the Brush Mineral 
Collection since that time and was added to several years ago 
by a few more specimens presented by the Foote Mineral Co. 
of Philadelphia. It is only recently that a complete and satis- 
factory investigation of this mineral has been possible. The 
results have shown that we have here another new species to 
add to the already long list of those peculiar to the Franklin 
locality. 

Margarosanite, as the new wmineral is called, is a silicate 
essentially of lead and calcium. It occurs in lamellar masses 
composed of thin plates packed closely together and which in 
general show a rhombic outline due to cleavages. It is color- 
less and transparent, showing a distinct pearly luster. It has 
a hardness of 2°5-3; specific gravity of 3°991. In the oxidiz- 
ing flame it fuses with some difficulty, the fragment assuming 
an amethyst color, but in the reducing flame, it fuses easily and 
quietly at about 2 to an opaque grayish glass. In the reducing 
flame it gives a pale azure-blue flame with an outer border of 
pale green. With fluxes on charcoal it gives a metallic globule 
of lead accompanied with the lead oxide coating. It gives the 
characteristic color tests for manganese when fused in the 
sodium carbonate or borax beads. It is decomposed by treat- 
ment with nitric acid, yielding separated silica. 

The mineral shows three good cleavages. The principal 
cleavage is parallel to the tabular development of the mineral 
and is so perfect that it almost gives a micaceous character to 
the material. There are two other well-developed cleavages 
which are nearly, but apparently not exactly, perpendicular to 
the first. These are shown by the characteristic rhombic out- 
lines of the broken plates of the mineral and by the numerous 
cleavage cracks existing within the sections. The traces of 
these latter cleavage directions upon the surfaces of the plates 
make angles with each other which are closely approximate to 
102° and 78°. Ona few of the plates an oblique terminal edge 


* This Journal, viii, 339, 1899. 


160 Ford and Bradley—Margarosanite. 


was observed which was due, apparently, to the presence of a 
erystal face, as no interior cleavage cracks parallel to it were 
observed. The trace of this face upon the surfaces of the 
plates made angles of about 120° and 60° with one of the 
cleavage directions and 42° and 138° with the other. This 
crystal form is not perpendicular to the chief cleavage but 
cuts across the edge of the cleavage plate at some oblique angle. 
These various relations are shown diagrammatically in the figure. 


The two extinction directions in the sections make angles of 
about 44° and 46° with one of the cleavage directions and of 
34° and 56° with the other. The faster of the two rays nearly 
bisects the smaller angle (78°) of the rhomb, formed by the 
two cleavages which are nearly perpendicular to the surface of 
the sections. In convergent light the sections show a biaxial 
figure with one optical axis revolving just outside the field of 
the microscope. The axis lies along ‘the vibration direction a, 
so that the cleavage plates are at least nearly perpendicular to 
the optical axial plane. These optical facts are also summa- 
rized in the figure. The indices of refraction ot the two rays 
vibrating in the section were determined by immersion in high 
refracting oils and low fusing solids with the following results : 
1°730 + 002 and 1:795 + -005. Of these the value 1-795 
must be close to that of the intermediate index of refraction, 
8. From a consideration of the above facts, it is probable that 
the mineral belongs in the triclinic crystal system. 

Upon the specimens, on which the margarosanite was found, 
the following species were also observed: light and dark-brow n 
garnet (almandite), hancockite, reblingite, nasonite, franklin- 
ite, willemite, yellow axinite, datolite and a biotite-like mica 


Ford and Bradley—Margarosanite. 161 


which gave the characteristic reactions for manganophyllite. 
In some cases the margarosanite was found lying immediately 
upon barite. The cleavages and general characters of these 
two minerals are so similar, that it became necessary to sepa- 
rate the magarosanite with great care before analyzing it. This 
was done by erushing the ‘material and picking it over grain 
by grain under a lens. In this w ay material of undoubted 
purity was obtained for the analysis. 

The method of the analysis was simple and was briefly as 
follows. The mineral -was decomposed by treatment with 
nitric acid with the consequent separation of silica. The solu- 
tion was evaporated to dryness and after taking the residue up 
in dilute acid the silica was filtered off. The filtrate was again 
evaporated to dryness to remove the nitric acid and the residue 
treated with water to dissolve the nitrates. During this evapo- 

ration asmall amount of basic lead nitrate was formed which was 
CADE in water. This was taken up in a very little nitric 
acid. The lead was precipitated and weighed as the sulphide. 
The manganese was precipitated as a sulphide and, after pre- 
cipitation as the basic carbonate, was weighed as Mn ;O thie 
calcium was determined as usual and the amount of water 
found by a direct determination, according to the Penfield 
method. 

A number of complete and several partial analyses were 
made by Bradley, the majority of which showed close agree- 
ment with each other. Several of the better determinations 
in each ease are given below : 


Average Ratios 


SiO. __. 33:73 38°78 33:98 38°39 33-71 5581 3:00 . 1:00 
PbO_... 40°15 43°30 43:89 43°67 43°50 +1951 1-04 ) 
CaO____ 21°61 21°62 21:97 21°73 8873) yogx oagr 0986 1-07 
MnO... 0°98 1:01 1:29 1:30. 1714 -0162( ge 
H,O.... 0-48 0°68 0-58 

100°66 


These results are in substantial agreement with those of the 
partial analyses made earlier by Pentield and Warren. Since 
the water isin small amount and since it is driven from the 
mineral at alow temperature, it is thought to be hygroscopic in 
character and is not considered in the calculations. The analy- 
sis points clearly to a metasilicate formula for the mineral. 
The various bivalent oxides may be considered as isomorphous 
with each other and the formula given as RSiO,, or in view of 
the ratio existing between the lead oxide and the calcium-man- 
ganese oxide, it may be written as Pb(Ca,Mn),(SiO,).. 

Below are given the theoretical composition of the last 
formula and the results of recalculating the present analysis 


162 ford and Bradley—Margarosanite. 


with the elimination of the water and the substitution of cal- 
cium oxide for the small amount of manganese oxide present: 


Theory for Analysis 
PbCa.(SiOg)s recalculated 
SiO, dea bat. - Bees l obeys’ 35°10 83°77 
PO) setae re eee 43:17 43°57 
CaQ one aai6'), oe nee ma Onley (8 22°66 
100°00 190°00 


The name margarosanite, which is proposed for this new 
species, has been derived from papyapitys, a pearl, and cavis, 
a tablet or board, in reference to its pearly luster and lamellar 
structure. 


Mineralogical Laboratory of the Sheffield Scientific School 
of Yale University. New Haven, Conn., 
April 18th, 1916. 


Arr. XXII.—On the Paleozoic Alcyonarian, Tumularia; by 
W. I. Rozinson. 


Tre new name Zumularia is here proposed for the forms 
which are now placed in the genus Stylarwa Seebach (1866),* 
since that name was preoccupied by Milne-Edwards and Haime 
(1851),+ for a hexacoral from an unknown locality. A single 
species, S. miilleri, was described by these latter authors and 1s 
therefore the genotype. Later Milne-Edwardst found this 
species to be identical with Porites punctata (Linneeus)§ and 
as the only species of the genus was thus removed to Porvtes, 
the name Stylarwa disappeared, because under the rules of 
nomenclature the same name can not be used for two different 
genera of animals. It was, however, inadvertently again 
‘applied by Seebach| to a single species, Stylarw@a rameri, from 
the Silurian of Esthonia. This form is closely related to 
Protarwa, but is distinct in several important characters, and 
since the name given by Seebach is preoccupied, the name 
Tumularia is here proposed. 

* Zeit. deutsch. geol. Ges., vol. xviii, pp. 304-310. 

+ Polyp. foss. d. Terr. Pal.. Arch. Mus., vol. v, p, 1438. 
{ Hist. nat. d. Coral., vol. iii, 1860, pp. 181-182. 

& Syst. Nat., 10th ed., 1758, p. 1277. 

|| Loe. cit. 


W. I. Robinson— Paleozoic Alcyonarian, Tumularia. 168 


Family Heliolitidze 
Genus Tumularia, nom. nov. 


1859 Columnaria (partim) Billings. Can. Nat. Geol., vol. iv, 428. 

1866 Stylareeu Seebach. Zeit. deutsch. geol. Ges., vol. xviii, 306. 

1878 Stylurcea Nicholson and Etheridge. Mon. Sil. Foss. Gir- 
van Dist., 60. 

1879 Stylarcea Zittel. Handb. d. Pal., vol. i, 239. 

1883 Stylavrwa Roemer. Leth. Geog., Pt. I, Leth. Pal., 456. 

1899 Stylavea Lindstrébm. K. Svenska Vetens.-Akad. Hand- 
lingar, vol. xxxii, 110. 

1899 Stylarea Lambe. Cont. Can. Pal., vol. iv, Part IJ, 91. 


A free translation of the original generic description is as 
follows : 

Vermicular, perforate sclerenchywa forming encrusting 
masses surrounded by a thin epitheca. Cells polygonal ; 
moderately deep, with a strongly developed spongy c¢ columella. 
Walls massive. Spines occur at the corners of the cells. Septa 
strongly crenulated ; descending abruptly to the calyx floor. 

A summary of the genera Protarwa and Stylarwa (=Tu- 
mularia) was given by Lambe,* who described and figured as 
Proturea vetusta a form which differs from other figures and 
descriptions of that species. The form described by him dif- 
fers from Protarwa in that it has a parietal or pseudo- 
columella, the calices are far apart, and there are small tubules 
in the intervening areas. It varies from Zumularia in that it 
has twelve septa while Zumularia has but cight, or rarely 
sixteen ; it has tubules between the ealices while 7wnuwlaria 
has not; the columella is parietal, that of Zumularia is 
essential. 

Excluding this form because of the differences mentioned, 
Protarea is clearly distinct from Tumularia. The original 
description of Protarewa is not detinitive, but the genus was 
redeseribed by Nicholsont+ as follows: 

“QOorallum forming thin crusts, about one-third of a line in 
thickness, which grow par asitically upon foreign bodies. Calices 
nearly equally developed, usually hexagonal, about one line in 
diameter or rather less, shallow, the bottom of the cup. being 
tubereulated. Septa twelve in number, sub-equal, extending 
but a short distance inwards towards the center of the visceral 
chamber. Walls of the calices thick.” 

The points of distinction upon which is based the retention 
ot Zumularia as a distinet genus are: 

1. Eight or sixteen septa; Protarwa 1 has twelve. 

2. An essential columella; Protarwa hasa parietal columella 
or none at all. 


* Cont. (Can. Pal., vol. iv, Part I, p. 89. + Pal. Ohio, vol. ii, p. 221. 


164. W. LZ. Robinson— Paleozoic Aleyonarian, Tumularia. 


3. Broad and petalliform septa; those of Protarwa are 
lamellar. \ 

Coccoseris Eichwald 1860 (== Lophoseris Eichwald 1857) is 
evidently a synonym of Protarwa and not of Sfylare@a as was 
suggested by Lindstrém.* The illustrations in Lethwa Possica 
are very clear and show twelve septa in both the genotype, 
Coccoseris ungerni, and the only other species listed, C. 
approximata, 


ES ee 


— 


LIST OF SPECIES. 


Tumularia parva (Billings). 

Columaria parva Billings. Can. Nat. Geol., vol. iv, 428, 
1859. 

Stylarea parva Lambe. Cont. Can. Pal., vol. iv, Pt. I, 91, 
pl. 5, figs. 9-9b, 1899. 

Locality and horizon: Mingan Islands, Quebec, and the 
Champlain—Montreal area, Canada; Virginia and 
Tennessee. Ordovician (Chazy). 

Tunularia remeri (Seebach). Genotype. 

Stylareea remeri Seebach. Zeit. deutsch. geol. Ges., vol. xviii, 
306, 1866. 

Locality and horizon: Wesenberg in Esthonia. Middle 
Ordovician. 


Tumularia occidentalis (Nicholson and Etheridge). 
Stylarcea occidentalis Nicholson and Etheridge. Mon. Sil. 
Foss. Girvan Dist., 62, 1878. 
Locality and horizon: Craighead, near Girvan, Scotland. 
Silurian, 
Be Index to generic names, K. Svenska Vetensk.-Akad. Handl., viii, No. 9, 
1883. 


Chemistry. 165 


SCIENTIFIC INTELLIGENCE. 


I. Curmisrry. 


1. Organic Agricultural Chemistry ; by JosErpH ScuppER 
CHAMBERLAIN. 12mo, pp. 319. New York, 1916 (The Mac- 
millan Company. Price, $1.60).—This is a text book of general 
agricultural chemistry or of elementary biochemistry for use in 
colleges. A companion volume on inorganic agricultural chemis- 
try covering the subject of soils and fertilizers is being prepared 
by an associate of the author in the Massachusetts Agricultural 
College. The volume under consideration is interesting in being 
novel . in its scope and in its manner of treating the subject. Tt 
aims to give to students of practical agriculture a general scien- 
tific knowledge of organic and physiological chemistry, buat it 
docs not attempt to present agricultural analysis. The first sec- 
tion of the book, comprising nearly one-half of it, deals systemati- 
cally with organic chemistry. The treatment is confined to 
fundamental principles and a discussion of the more important 
compounds occurring in plants and animals. In spite of this 
limitation the course appears to be an excellent one, and to be 
very modern in its presentation. ‘lhe second section dealing with 
physiological chemistry gives a very satisfactory discussion of 
enzymes and fermentation, the composition of plants and animals, 
the living cell and its food, animal food and nutrition, digestion 
and absorption, milk, blood and urine, and plant physiology. 
The last section, which is the most practical one from the point 
of view of the student of agriculture, deals with the food con- 
stituents of plants, and animal food and feeding. As a whole the 
book seems to be very well devised for its purpose. Se OA Nis 

2. Outlines of Industrial Chemistry ; by Frank Hart Tuore, 
with Assistance in Revision from Warren K. Lewis. 8vo, pp. 
665. New York, 1916 (The Macmillan Company. Price, $3.25). 
—This is the third edition of a well known and widely used text 
book which made its first appearance in 1898. The rapid progress 
that has been made in chemical industry in recent years has made 
necessary considerable changes in the present issue, so that many 
sections have been re-written. The book is clementary in its 
character, and the processes are usually described quite briefly in 
connection with their fundamental principles and their important 
features. The number of topics taken up, however, is very large, 
so that the book gives an extensive view of the industry, includ- 
ing the inorganic, the organic, and the metallurgical branches, 
The work is not only a useful text book for students in colleges aud 
technical schools, but it should be of interest to many general 
readers, who need have ouly a moderate knowledge of general 
chemistry in order to understand nearly all of it, as it is ‘largely 
descriptive, contains no:extended mathematical and theroretical 
djscussions, and is clear in style. iy Wig We 


166 Scientific Intelligence. 


A Method for the Identification of Pure Organie Com- 
pounds, Vol. IL; by Samuen Parsons Muiiken. Large 8vo, 
pp. 327. New York, 1916 (John Wiley & Sons, Inc. Price, 
$5 net).—Eleven years have elapsed since the appearance of the 
first volume of this monumental work, a volame which classitied 
and described about 2300 of the more important compounds of 
earbon with hydrogen, and earbon with hydrogen and oxygen. 
Meanwhile, however, the third volume, dealing with the identifi- 
cation of commercial dyestuffs, has been published, s» that a 
fourth volume, now in preparation, will complete the set. ‘The 
second volume, now being considered, contains classitied descrip- 
tions of about 4000 of the more important compounds of carbon 
with the elements nitrogen, hydrogen and oxygen. This volume 
will be particularly useful, since it includes a great many com- 
pounds whose identification may be of great practical importance, 
such as all of the alkaloids, a majority of the most important 
drugs of other classes, many of the most interesting components 
of animal and vegetable organisms, the high explosives, and a 
considerable part of the “intermediates” of the dyestuff industry. 
All of the compounds in this volume are classed as “ Order II.” 
In order to identify an individual compound, it is necessary to 
find, in the first place, whether it is colorless or colored. If color- 
less, it is placed in three “ genera,” according to its acidity, basic- 
ity or neutrality. In each of these genera the compounds are 
separated into solid and liquid divisions. In these final “diy1- 
sions” the compounds are arranged according to melting points 
or boiling points, and finally tests and miscellaneous properties 
are given for each individual. The book gives 43 numbered 
“tests,” which have general application, and many special tests 
are given for the individual compounds. This important work 
makes it possible to identify many compounds much more easily, 
and in many cases more satisfactorily than by the usual method 
of analysis, molecular weight, and the resulting empirical formula. 
The book is of much importance to chemists in general, and much 
praise is due to Professor Mulliken for his labors of many years 
and his success in producing this work. H. 1. W. 

4. Annual Reports of the Progress of Chemistry for 1915. 
8vo, pp. 268. London, 1916 (D. Van Nostrand Company, New 
York. Price $2 net).—This is the twelfth volume of these 
reports, which are issued by the London Chemical Society. It 
contains nine e-says by as many authors, who are specialists in 
the different branches of chemistry that are reported. The sub- 
jects dealt with are General and Physical Chemistry, Inorganic 
Chemistry, three divisions of Organic Chemistry, Analytical 
Chemistry, Physiological Chemistry, Agricultural Chemistry 
and Plant Physiology, and Mineralogical Chemistry. As the 
reports are short, varying in length from 16 to 43 pages, it fol- 
lows that the matter is very much. condensed, particularly in the 
extensively investigated branches, and that the authors have been 
compelled to confine themselves to such topics as appeared to be 


Geology. 167 


most important and interesting. The work appears to have been 
very well done, and the volume i is valuable as a meaus of giving 
chemists who are specializing in their own branches of the sci- 
ence, some information in regard to the important achievements 
in the other branches. It is interesting to observe that the 
references to American researches are numerous in several of the 
reports. This indicates that chemical investigation is being well 
conducted in our country. H. L. W. 


II. Groroey. 


1. The Origin of the Eurth; by Tuomas C. CHAMBERLIN, 
Pp. xii, 272. Chicago, 1916 (University of Chicago Press).— 
Geologists have long been looking forward to this book and to a 
restatement of the planetesimal theory by its creator. As the 
book was written “not only for the specialist but for the educated 
Jayman” as well, the subject is presented “in as summary a 
manner and with as little technical detail as is consistent 
with sound method.” The educated layman will find the 
book highly profitable and fairly easy to master if the author’s 
advice is taken that it were well if the reader were deliberate. 
The specialist will also find much that is new and helpful to a 
better understanding of the planetesimal theory. This hypoth- 
exis, the author tells us, had its origin many years ago in an 
endeavor to explain the climatic conditions of the Pleistocene 
deposits of Wisconsin. “Strangely enough, the cold trail of the 
ice invasion had led by this long and devious path into the 
uebulous field of genesis ” (9). 

The book begins with a discussion of the Gaseous and Laplacian 
theories of earth origin. A ring of gas “such as the Laplacian 
hypothesis postulates as the parent of the earth, with a tempera- 
ture high enough to keep the refractory substances that make up 
most of the earth in the form of a gas, could not have held itself 
together by its own grayity.” Further, it ‘“‘could not have held 
in gaseous relations the waters of the oceans or the constituents 
of the air, nor perhaps even the rock substances of the earth” (36). 

The planetary system of the sun “must clearly have had a bi- 
parental origin” as it clearly betrays a birth through the close 
approach of two bodies whose tidal interactions resulted in the sun 
taking on the form of a spiral nebula. The juvenile earth began to 
form through the infall of the planetesimals upon the earth-knot of 
the nebula. The shaping agencies were primarily (1) gravitation, 
(2) the adjustments due to the periodic shrinking of the earth 
mass, (3) the adjustments following the periodic acceleration in 
rotation, aud (4) the pull of the moon upon the earth manifested 
in the twice-daily tides. 

The newest feature of the book relates to the process of earth 
shaping during the juvenile stages, a process that may be called 
the conte hypothesis of earth structure. This theory states that 


168 Scientific Intelligence. 


the earth is divided into six primary, positive, rigid, conic 
segments of crystalline substance but non-crystalline major 
structure, whose apices unite at the center of the earth, and 
between which lie the more or less irregular, laterally crowded, 
weaker, negative and lighter continental wedges. ‘T'wo of the 
master cones occupy the Pacific depression, two the Atlantic, one 
the Indian, and the sixth takes in the more or less positive 
Mediterranean—Black Sea—Caspian Sea region. The segments 
move upon one another along “yield tracts” or fissure tracts that 
radiate from each pole at angles of about 120°. This hypothesis 
appears to be diametrically opposed to the working hypothesis 
of isostasy and the latter’s postulate that the relief of the earth’s 
surface is compensated for by corresponding variations in syb- 
surface density which cease at a depth equal to a fiftieth ora 
hundredth part of the radius of the earth. The book, however, 
does not follow the digressions in discussions which are necessary 
in pursuing the method of multiple working hypotheses. The 
popular nature of the book was doubtless regarded as a bar to 
such thorough discussion and comparison of conflicting hypo- 
theses. 

The inner reorganization of the earth is due to compression, 
generation of heat, and, through atomic dissociation, the birth of 
radioactive elements. ‘ Radioactive heat was thus added to the 
heat of compression... . It is therefore assumed that there was 
only a sparse distribution of radioactive elements in the parent 
nebula, and hence in the original material of the earth, but that 
there was progressive concentration of these at the surface as effu- 
sive igneous action went on” (227-228). In the course of time the 
metals and metallic alloys probably concentrated toward the 
center of the earth and the silicates toward the surface (237). 

Cc. S. 

2, Jointing as a Fundamental Fuctor in the Degradation of 
the Lithosphere; by Freprerick Eurenretp. Proc. Amer. 
Philos. Soc., vol. lv, 1916, pp. 363-399, pls. vi-vill.—A very sug- 
gestive paper the conclusions of which are as follows: ‘ Law of 
joints.—1. The lithosphere is subject by its nature to the develop- 
ment of lines of weakness or fracturing which in turn develop 
into actual movable segments. These segments or joint lines 
develop in such regularity of arrangement that they may be said 
to occur in ‘joint-systems’ which are shown at the surface as 
controlling agents in land erosion and land shaping ; and they act 
beneath the surface inducing tectonic movements which are in- 
dependent of atmospheric or marine contact. 

“2, Degradation of the lithosphere is fundamentally a factor 
in its own structure and will occur wherever an agent capable of 
transporting the movable joint blocks is in contact with the 
lithosphere. ‘This applies to those portions of the land or rock 
mass below sea level. 

“3, Atmospheric erosion and marine planation are two separate 
phases of a general process of lithosphere degradation which are 


ee 


Geology. 169 


frequently connected into consecutive stages by the presence of 
joint lines which extend from beneath sea level up into the mass 
of the lithosphere above sea level ; these lines are also horizontal 
and thus act to produce flat surfaces. 

“4, Degradation of the lithosphere surface may occur also by 
the vertical displacement of these joint segments irrespective of 
atmospheric or marine contact. 

Joint control of lithosphere degradation has been active 
since the period when the lithosphere possessed a solidified 
structure and has been a fundamental factor in the evolution of 
the lithosphere, or geomorphology.” Cc. S. 

3. The Fauna of the Chapman Sandstone of Maine, inelud- 
ing Descriptions of Some Related Species from the Moose River 
Sandstone ; by Henry Suarer Wiriiams, assisted by Carpel 
Leventhal Breger. U.S. Geol. Surv., Prot Paper 89, 1916, 
pp. 347, 27 pls., 2 text figs.—This excellent monograph consists 
of a very detailed description of the genera and species of one of 
the Lower Devonian faunas of Maine, the Chapman sandstone, 
and comparisons are made with the related forms from all parts 
of the world. The fauna consists of 125 species, chiefly bivalves 
and brachiopods, of which 70 are new (10 brachiopods, 42 bivalves, 
1i gastropods, 2 cephalopods, 5 crustacea). Of new genera there 
is one of brachiopods, Antispirifer ; of bivalves, Granunysioideu, 
Nuculoidea, Preavicula, Sphenotomorpha ; and of ostracods, 
Zygobeyrichia. The work was completed in 1910 and un- 
fortunately has remained unpublished until wow. It therefore 
does not consider the later publications by the New York and 
Maryland State Surveys. 

The Chapman fauna, Professor Williams holds, “ is intimately 
related on the one hand to the Tilestone fauna of England and 
on the other hand to the so-called Hereynian fauna of the Con- 
tinent ” (296). Its age “seems to be strictly Lower Devonian” 
and agrees best “with that portion of it below the Upper 
Coblenzian. It is a later fauna than the Tilestone or Downtonian 
of Great Britain or the terminal marine fauna of Arisaig, Nova 
Scotia” (297). On the basis of the brachiopods alone “the 
chapter fauna is to be correlated with the Helderbergian fauna 
of the interior seas” of the United States (298). With this 
latter conclusion the reviewer does not agree because of the 
presence of Hipparionyx unyuiformis, Cyrtina rostrata, Megu- 
lanteris, Beachia, Rensselueria, and Eunella, all of which are 
more or less decisive indicators of Oriskanian time; the fauna 
seems to the reviewer to be not older than the early Oriskanian. 

Cris: 


Ill. Miscerranrous Screnziric IntTELLigENcE. 


1. A Comprehensive Plun of Insurance and Annuities for 
College Teachers; by Henry 8. Prircurrr. Bulletin Nine of 
the Carnegie Foundation for the Advancement of Teaching. 
Pp. xiii, 67. New York City, 1916.—Ten years of experience in 


170 Scientific Intelligence. 


the administration of the accepted plan of the Carnegie Foundation 
for providing pensions for college teachers has revealed certain 
serious defects in the system. Briefly stated, these include the 
fact that no provision is made, either in the case of disability or 
death, until the individual is well advanced in life ; or, in other 
words, teachers under perhaps sixty or sixty-five years can 
receive no benefit from it. Again although the original endow- 
ment was large and has been ddded to, its income is nevertheless 
limited, the demands upon it are increasing and, therefore, at 
best but a part of the country’s institutions and their teachers can 
come under its provisions. 

The realization of these and other shortcomings in the present 
plan has led to the development of a new system of insurance 
and annuities to be available for “all college teachers of sound 
qualification ” in the United States, Canada and Newfoundland. 
The essential feature of this system is that it shall be contribu- 
tory, the individual and his college sharing the pecuniary respon- 
sibility from the beginning of his career as a teacher. Further, 
The Carnegie Foundation, with its large capital, would administer 
the system, guarantee a good rate of interest on the accumulated 
funds, and assume other responsibilities involved. For the 
details of the plan reference must be nade to the present bulletin; 
it is, perhaps, enough to say that, while its basis is. “socially wise, 
economically sound and permanently secure,” the contributions 
called for from the individual would be small compared to the 
benefits to be received. 

The Foundation is now committed to the existing pension 
system as applied to some seventy-three institutions in the United 
States and Canada. Obviously the older teachers must remain 
under it, but for men of some definite age, to be settled upon, it 
will be profitable to pass from the existing system to that now 
proposed. ‘This point, with the details of the whole scheme, will 
come up for consideration by the trustees toward the end of the 
present year. 

OBITUARY. 


Siz Wirtiam Ramsay, the distinguished English chemist, died 
at his home in Hazlemere, Bucks, England, on July 23 in his 
sixty-fifth year. His career was remarkable alike for the extent 
and the brilliancy of his original scientific work. His discovery 
and investigation of the atmospheric gases argon, krypton and 
neon alone would have established his reputation: while his 
identification of helium both in the atmosphere and in many 
minerals, his investigation of radium, and his discovery, as he 
believed, of the transmutation of the elements, rank with the most 
brilliant contributions to chemical science. 

Proressor Eris Mercunikorr of the Pasteur Institute, famous 
the world over for his investigations and discoveries in bacteri- 
ology and for their application to the prevention and cure of 
human diseases, died in Paris on July 15, at the age of seventy- 
one years. 


Warns Natura Science EstasuisHMENt 


A Supply-House for Scientific Material. 
Founded 1862, Incorporated 1890. 


A few of our recent circulars in the various 
departments : 


Geology: J-3. Genetic Collection of Rocks and Rock- 
forming Minerals. J-148. Price List of Rocks. 

Mineralogy: J-109. Blowpipe Collections. J-74. Meteor- 
ites, J-150. Collections. J-160. Fine specimens, 

Paleontology: J-134. Complete Trilobites, J-115. Collec- 
tions.. J-140. Restorations of Extinct Arthropods. 

Entomology: J-380. Supplies. J-125. Life Histories. 
J-128. Live Pupae. 

Zoology: J-116. Material for Dissection. J-26. Compara- 
tive Osteology. J-94. Casts of Reptiles, etc. 

Microscope Slides: J-185. Bacteria Slides. 

Taxidermy: J-188. Bird Skins. J-189. Mammal Skins. 

Human Anatomy; J-16. Skeletons and Models. 

General: J-155,. List of Catalogues and Circulars. 


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_— 


CONTENTS. 


Page 
Arr. IX.—The Problem of Continental Fracturing and Dias- 

trophism in Oceanica; by C. Scuucnenrr ..-...--.-.-- 91 
X.—On the Qualitative Separation and Detection (I) of 

Tellurium and Arsenic and (II) of Iron, Thallium, Zir- 

conium and Titanium; by P. E. Brownine, G. 8. 

Simpson ‘and Ly 2, PoRTee seo eee eee ee 106 
XI.—The Separation of Vanadium from Phosphoric and 

Arsenic Acids and from Uranium; by W. A. Turnmr.. 109 
XJI.—Some Notes on Japanese Minerals; by 8. Icumkawa.- 111 
XIII.—The Algonkian-Cambrian Boundary East of the 

Green Mountain Axis in Vermont; by T. N. Dare --.. 120 
XIV.—The Thermochemistry of Silicon; Heat of Combina- 

tion of Silica with Water; by W. G. Mixrmr ...--.--- 125 
XV.—Composition of the Selensulphur from Hawaii; by G. 

Vi: Brown 202 oe Mister Se ae ee eee 132 
XVI.—Insects in Burmese Amber; by T. D. A. CocknRELL 135_ 
XVII.—The Preparation and Properties of Lead-Chlor 

Arsenate, Artificial Mimetite; by C. C. McDonnety 

amid (O. S Saamca oe Sis ae tee eran 139 
XVIII.—The Effect of a Magnetic Field on the Initial Re- 

combination of the Ions Produced by X-Rays in Air; 

by GiB. M. Jamyeny. 3a: eG Soa eee eres 146 
XIX.—The Separation of Thorium from Iron with the Aid 

of the Ammonium Salt of Nitrosophenylhydroxylamine 

(“ @upterron”’)3“by We MI TeORNTON, Wit jee = eee 151 
XX.—On the Quantitative Estimation of Small Quantities of 

Sulphide Sulphur; by W. A. Drusnen and OC. M. Eisron 155 

_XXI.—Margarosanite, a New Lead-Calcium Silicate from 

Franklin, N. J.; by W. E. Forp and W. M. Brapiey_. 159 

XXII.—On the Paleozoic Aleyonarian, Tumularia; by W. I. 
ROBINSON “Jab SUG eS Oe OS ee ee eee 162 


SCIENTIFIC INTELLIGENCE. 


Chemistry—Organic Agricultural Chemistry, J. S. CHAMBERLAIN: Outlines 
of Industrial Chemistry, F. H. Taorp, 165.—Method for the Identification 
of Pure Organic Compounds, S. P. Muniixen; Annual Reports of the 
Progress of Chemistry for 1915, 166. 

Geology—Origin of the Earth, T. OC. Cuamprriin, 167,—Jointing as a 
Fundamental Factor in the Degradation of the Lithosphere, by F. 
ExsRENFELD, 168.—The Fauna of the Chapman Sandstone of Maine, H. S. 
Witiiams, 169. 

Miscellaneous Scientific Intelligence—A Comprehensive Plan of Insurance 
and Annuities for College Teachers, H. S. Prircnerr, 169. 

Obituary—W. Ramsay: E. Mrercunixorr, 170. 


brary, U.S. INat. iviuliseurn. f ww Y/Y WJe § VW 


} 


"Nou. XLII. SEPTEMBER, 1916. 


we 


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: AMERICAN 
JOURNAL OF SCIENCE. 


Epirorn: EDWARD S. DANA. 


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FOURTH SERIES 


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Art. XXIII.—The Geological History of the Australian 
Flowering Plants; by E, C. Anprews, Sydney, New South 
Wales, Australia. 


TABLE OF CONTENTS. 


Introduction 
I. The Problem stated 
II. The significance of the present relationships existing be- 
tween families and orders of the flowering plants 
Ill. The difficulty attendant on the determination of fossil flower- 
ing plants by leaf remains only 
IV. General geographical conditions ; transport of plants, dis- 
: tribution of mammals 
(a) Cretaceous and Post-Cretaceous geography and climate 
(b) The transport of plants and the distribution of mammals 
(1) The transport of plants 
(2) The distribution of mammals 
V. The development of the Australian Angiosperms 
(a) The Tropical Problem 
(1) Distribution of Acacia, Cassia, Vernonia, Xanthoxylum 
(2) Leguminosze 
(8) Myrtaceze 
(4) Rutaceze 
(5) Euphorbiacee, Labiats, Verbenacez, Sterculiacez, Pit- 
tosporacese, Tremandracez, Liliacez 
(6) Orchidacez 
(b) The South African Problem 
(1) General remarks on supposed land connections of South 
Africa with Australia 
(2) Proteaceze 
(8) Compositee 
(4) Hricaceze and Epacridacez 
(5) Campanulaceze, Lobeliacez, Goodeniacee and Candol- 
leaceze 
(ec) The South American Problem 
(1) General discussion as to supposed land connections of 
South America with South Africa, New Zealand and 
Australia 
(2) On certain unexplained peculiarities of angiospermous 
distribution in South America, Australasia and New 
Zealand 


Am. Jour. Sct.—FourtH Srrizs, VoL. XLII, No, 249.—SrprrempBer, 1916. 
12 


172 E. C. Andrews—The Geological History of the 


(8) The catkin-bearing plants 
(d) The North Hemisphere Problem 
(1) The Umbelliflorz 
(e) The New Zealand Problem 
(f) The West and East Australia Problem 
VI. Summary 


InTRODUCTION. 


The earlier botanists explained the Australian plants as a 
special creation. It is safe to say that were the flowering plants 
of Europe and Australia to be fossilized, and were it possible 
for a botanist unacquainted with the Australian plant types 
to see the two groups for the first time, he would conclude that 
they did not belong to the same geological period. 

It is fitting, in a report such as the present, to direct atten- 
tion to the conclusion of Bentham as to the probable origin 
of the indigenous flora of Australia. It had been the intention 
of the great systematist to discuss the subject in detail, but 
advanced age and declining health followed on the accumula- 
tion of the botanical data necessary for such discussion and he 
simply wrote the accompanying note in the concluding preface 
to the Flora Australiensis (vol. VII, 1878): “The predomi- 
nant portion appears to be strictly indigenous. Notwithstand- 
ing an evident though very remote ordinal, tribual, or generic 
connection with Africa, the great mass of purely Australian 
species, or endemic genera, must have originated or been 
differentiated in Australia, and never have spread far out of it.” 

It is fitting also at this stage, to acknowledge the great 
help received from Mr. R. H. Cambage during the past twelve 
years in the accumulation of data necessary to write the present 
paper. Indeed it is difficult to indicate just where his influ- 
ence and his help ceased in the preparation of the report. The 
original intention had been to prepare a joint report either 
on the genus Eucalyptus or on the flowering plants in general 
of Australia. Increased professional duties, however, have 
prevented Mr. Cambage from codperating in the preparation 
of such a work, hence the present brief statement by myself. 

Special thanks are due also to Mr. J. H. Maiden, Director 
of the National Herbarium, and to Messrs. E. Cheel and A. A. 
Hamilton, of the Herbarium. 

As the study of the angiosperms in Australia is considered 
more and more in detail, it becomes evident how unsafe it 
would be to accept the evidence of any one family, or order, 
alone, as regards the possibility of former land connection 
with Australia. As examples may be quoted the papers on 


Australian Flowering Plants. 173 


the Distribution and Development of the plants in the groups 
Leguminosve' and Myrtacezx.* The distribution of these groups 
alone, considered without reference to the distribution of other 
families of animals and plants, suggested that the great tropical 
lands had been connected directly with each other as from 
Tropical America to Tropical West Africa, thence through 
Madagascar and Asia through the Malay Archipelago to Aus- 
tralia. But the study of the Amentales, the Composite, the 
Ericacez and many other families, and orders, suggested that 
the discussion of the legumes and myrtles alone had shown 
only one aspect, out of several possible, of the story of angio- 
spermous distribution. The distribution of animals suggested 
another line of evidence and it was decided finally to obtain 
the independent testimony of various witnesses as to the pos- 
sibility of land connections since the early Cretaceous and to 
coordinate the evidence so secured. Thus the student either 
of isostasy or of insular floras and faunas is driven to accept 
the doctrine of the permanence of the larger features of the 
ocean basins since the dawn of the angiosperms. For example, 
it is known that the rock structures underlying the ocean basins 
are heavier than those of the continental areas considered with 
respect to unit columns lying above a certain plane about 100 
miles below the sea-level and such a peculiar adjustment of 
structures has not been attained in a hurry. Again Wallace 
has observed* that the sedimentary deposits of the land areas 
are suggestive of shallow-water conditions, while there is an 
absence of continental areas of deposits such as are found 
to-day on the bottom of the deep sea. 

Throughout these pages the idea of a great two-period dif- 
ferentiation of climate has been made prominent, nevertheless 
it must not be forgotten that the distribution and development 
of almost all of the plant types considered in the present report 
could be explained satisfactorily on the assumption of the 
co-existence of waste places, of barren sandy tracts and of 
subarid to arid regions with the widespread mild and moist 
conditions of the Cretaceous and Eocene, such waste, barren, 
and desert areas increasing in size at various periods, notably 
since the Eocene or Miocene. Indeed it is necessary to postu- 
late the uninterrupted existence of such desert conditions or of 
barren soils throughout the later history of the angiosperms, 
say, since the Lower Cretaceous, otherwise it is difficult to 


+E. C. Andrews, Proce. Roy. Soc. N. 8. Wales, vol. xlviii, pp. 333-407, 
1914. 

*Tdem, Proc. Linn. Soc. N. 8. Wales, vol. xxxviii, pp. 529-568, 1913. 

‘Island Life, 1892, pp. 103-105. 


174 EC. Andrews—The Geological History of the 


explain the existence of so many cosmopolitan forms of 
xerophytie tendency which appear to have spread to the various 
continents while yet these were all connected. Examples are 
Acacia, Senecio, Lobelia, Campanula with Wahlenbergia, 
Gnaphalium, Helichrysum, and many others. Indeed the stu- 
dent of geography who has traveled widely feels the necessity 
for postulating waste places, deserts and barren sandy areas, 
even during the Cretaceous which was a period of base-leveling, 
and of great spilling over of the ocean basins on to the conti- 
nents. Sandy seashores must have existed as well as sandy 
tracts of Triassic, Permian, and other rock types, and these 
must have been relatively barren, while areas well-removed 
from the sea in certain latitudes, would surely have been sub- 
arid to arid as high mountain ranges were rare. Siliceous 
sands whether along the seashore or inland must have produced 
xerophytie growths even if subject to moist seasons. 
Nevertheless in the present report it has been thought advis- 
able to emphasize the apparent zoning of climate both before 
and after the isolation of Australia from the world generally. 


I. The Problem Stated. 


In Australia the flowering plants comprise from 10,000 
to 11,000 species, distributed between about 150 families. 
Eight small families are almost confined to Australia, namely 
Goodeniacez, Candolleacez, Brunoniacez, Casuarinacer, Tre- 
mandracez, Stackhousiacez, Philhydraceze and Pittosporacez 
(with the exception of Pittosporwm, which occurs throughout 
the Old World tropics). 

Australia has an area of about 3,000,000 square miles, and 
is composed mainly of a broad, low, western plateau, a low- 
lying central area, a belt of plateau following the eastern and 
southeastern periphery of the continent much like an intra- 
marginal vein sympathises with -the general curvature of the 
leaf margin, and a narrow coastal strip in Eastern Australia. 
The eastern plateau area is relatively narrow and relatively 
high and is separated from the ocean by a well-watered coastal 
area possessing a mild climate. To the coast the eastern 
plateau, with a height varying from 1,700 to 7,000 feet, above 
the sea, presents a rugged front dissected with profound gorges, 
thus forming a decided barrier locally to direct communication 
between the inland and coastal plants. On the other hand 
relatively-low gaps occur in the plateau masses and these per- 
mit a moderate amount of communication between the coastal 


lod 


Australian Flowering Plants. 175 


and inland plant types. The greater portion of Australia, 
west of the Eastern Australian plateaus, possesses really only 
two well-marked seasons, namely summer and winter. The 
highest shade reading recorded is about 127 degrees Fahren- 
heit, and the lowest winter reading from 10 to 15 degrees; 
moreover, the humidity is remarkably low in these great plains 
or low plateaus. Exceptions occur in the southwestern corner 
of Australia and in the Port Darwin area in the Northern 
Territory. The eastern plateaus are well watered but are 
subject to desolating winds both in summer and winter and 
temperatures considerably below zero Fahrenheit have been 
recorded from southern localities. ‘These plateaus, however, 
afford shelter to the coastal region from the desolating winds 
of summer and winter, especially to those portions immediately 
under the escarpments and in the gorges. This narrow coastal 
strip supports an assemblage of plants of the jungle habit 
crowded together, interlaced with vines, and having a great 
similarity to Malayasian types, and to a lesser degree with types 
found distributed over the whole of the fertile tropics. 

In the subarid to arid regions which comprise so great a 
proportion of the Australian area, there exist numerous spe- 
eialized xerophytes of the families Leguminose, Myrtacez, 
Myoporacez, Euphorbiacez, Verbenacez, Labiatee, Compositee, 
Santalacee, Rhamnacee, Graminacez, ‘Chenopodiacee, Mal- 
vaceze, and ’Stereuliacese. 

But the most instructive feature in the distribution of the 
Australian flora is the great number of genera and species, and 
the individuals innumerable of such genera and species on the 
large and excessively sandy areas lying mainly between 28° 
and 42° south latitude, and especially in the southwestern 
corner of West Australia between 29° and 34° south latitude 
where the rainfall is fair im amount but not great, where the 
summers moreover are very hot and the continental winds from 
the center are very dry. Large patches of sandy soil occur in 
the Sydney-Blue Mountain area, and in the northeastern por- 
tion of New South Wales, but there the rainfall is greater, 
the temperature more uniform, and the effect of the desiccating 
continental winds much less pronounced than in the western 
area. Nevertheless the numbers of genera and species are 
greater in the sandy southwestern area of Australia than in 
the well-watered sandy tracts of eastern New South Wales. 

On these sandy wastes are to be seen not only the great 
proportion of the endemic genera of Australia, but also the 
large genera of Australia. Certain important subgenera or sec- 


176 E. C. Andrews—The Geological History of the 


tions of cosmopolitan tropical genera are here also to be found, 
but so modified as to present an appearance very different to 
their tropical or sub-tropical relations. Examples are the 
phyllodineous acacias, Phyllanthus, and a section of Cassia. 
From County Cumberland, which has an area of about 1,500 
square miles surrounding Sydney, there have been recorded 
more species of Vasculares than from New Zealand or the 
whole of the British Isles. And the district of Perth in West 
Australia is perhaps even more remarkable in this respect. 

In the Sydney district, the name being used in the larger 
sense, there are sheltered areas or pockets of volcanic soil or 
shales, on which dense luxuriant plant growths abound form- 
ing canopies of dark and glossy green, which exclude a great 
proportion of the sun’s rays. Surrounding these patches of 
rich soil are the hungry sandstones forming so much of the 
large Sydney and Blue Mountain district, whose vegetation 
is in striking contrast with that of the rich soils. Here is to 
be seen no luxuriant foliage, no twining nor towering canopy 
to the jungle, but instead merely an array of Hucalyptus, 
phyllodineous acacias, banksias of somber hue and casuarinas, 
pine-like in appearance—with all the vivid green dissolved 
out of the leaves—to all appearance a type of vegetation 
ancient, dilapidated, rusty and weather beaten, some of whose 
members indeed are little better than skeletons. Whole areas 
of heath-like growths occur in the open places with leaves 
terete, cylindrical, involute, revolute, linear, acicular, or pun- 
gent. The most skilful paleobotanist would fail here to dis- 
cover the ‘Open Sesame” to the generic classification of the 
types in the absence of flowers and fruits, for in these acicular 
and linear types of leaves there is no yenation to be seen: 
there is little to distinguish them from each other. Many 
“traps for beginners” are to be found in the study of this sand- 
stone flora and yet, despite their appearance of pauperism, 
they are all the “children of a great king,” their noble ancestry 
being apparent directly the keen winter winds have gone, and 
the warmth of returning spring unfolds their beautiful and 
brilliant blooms. Here both upon shrubs and undershrubs 
with acicular, terete, involute, or revolute leaves, various 
brilliant pea blossoms proclaim the glows and glories of the 
legumes (Pultenea, Dillwynia, Aotus,in the tribe Podalyriez). 
Alongside these golden bushes another type with linear leaves 
bears myrtle blooms (Beckea). 

Other shrubs, undershrubs, or small trees with circular, pine- 
like, or linear leaves, and associated with the xerophytic 


—— 


Australian Flowering Plants. |. 177 


legumes and myrtles are Ricinocarpus (Euphorbiacex), West- 
ringia (Labiate), Persoonia (Proteacer), Grevillea (Pro- 
teacee), Hakea (Proteacex), Acacia (Mimosacex), Kunzea 
(Myrtacee), Melaleuca (Myrtacee), Viminaria (Papilio- 
nacee), Casuarina (Casuarinacee), Banksia (Proteacex), 
Leucopogon (Epacridacex), Candollea (Candolleacee), Hrios- 
temon (Rutacez), all easily classified once they have burst into 
flower, but all riddles to the foreign botanist until they have 
flowered. 

Again, the vast genera of the world generally, such as Piper, 

Eugenia, Cassia, Huphorbia, Senecio, Carex, Psychotria, and 
Phyllanthus, rarely possess numerous species in Australia. The 
exceptions are Acacia (450 species), Phyllanthus (50 species), 
Cassia (30 species), and a few others, but these have been so 
modified to suit the Australian soil and climate that they appear 
as distinet genera in the great majority of instances, so far as 
their foliage is concerned. Acacia indeed, of the phyllodineous 
type, and some Cassias, would never be recognized as such by 
extra-Australian students, in the absence of fruits and flowers. 
The few members of the great cosmopolitan genera which 
oceur within Australia on the hungry sandstones mostly retain 
traces of their ancestry in the possession of pinnate leaves, 
dwarfed, battered and bedragegled, it is true, but nevertheless 
standing in striking contrast with their surroundings, like 
broken-down aristocrats ill at ease among hungry and unclothed 
savages, but still clinging to the rags and shreds of respectability 
(Examples, Breynia, Panax and Cupania). 
_ Again, the great genera of Australia, that is, the genera, 
or sub-genera, peculiarly Australian, such as Hucalyptus, the 
phyllodineous Acacias, Grevillea, Hakea, Hibbertia, Goode- 
nia, Candollea, Pimelea, Pultenea, Leucopogon, Malaleuca, 
Beckea, Daviesia, Persoonia, Banksia, Dryandra, Eremophila, 
Bossvea, and many others, do not occur in the sheltered jungle 
areas, but are to be found most abundantly on the hungry 
sandy and extremely siliceous soils, especially in southwestern 
Australia, where not only are the endemic species most 
numerous but many genera are endemic to that region in 
addition to possessing more than their share of species in the 
genera endemic in Australia generally. 

All this being so, with our knowledge concerning these 
specialized xerophytes, which are all endemic in Australia, but 
absent from the areas of mesophytic and jungle growths, which 
are all, moreover, vigorous, large and aggressive genera, almost 
all confined to or, at least, in their true home, on the hungry 


178 E. C. Andrews—The Geological History of the 


siliceous sands and rocks of Australia, whose seedling stages 
also proclaim their recent derivation from forms very differ- 
ent to their present ones—how are the facts named to be recon- 
ciled with the statement by paleobotanists that they formerly 
existed as luxuriant types in the mild and moist climate of the 
Cretaceous and Eocene? It is not that Australian botanists 
’ would deny the existence of Myrtacez, Proteacex, and allied 
families in Europe, during Cretaceous and Tertiary time; 
what they would deny, however, is that the endemic genera 
of Australasia ever did form a part of the Cretaceous and 
Tertiary flora of the Northern Hemisphere. This is the first 
portion of the problem to be approached. 

Other portions of the problem deal with the hypothecated 
land connections between Australia and: South Africa, South 
America, New Zealand, and the Northern Hemisphere, 
respectively. 

Thus the Proteacez, and the Restiacex, are practically con- 
fined to Australia and South Africa, while certain genera 
such as Helichrysum, Helipterum, and Cassima, in Composite. 
Bulbine, Wurmbea, and Cesia in Liliacez, are almost confined 
to these two countries. 

In Southern South America and Australia, there are many 
genera and species confined almost entirely to the two areas. 
New Zealand and Australasia show even greater affinities, 
while striking similarities exist between the floras of Australasia 
and those of the great temperate areas of the Northern Hemi- 
sphere especially in the families Ranunculacer, Geraniacez, 
Stellate (Lindley), Composite, Cruciferee, Lobeliaceze, Umbel- 
liferze, and Boraginacez. 

There is also the interesting problem to be faced of the 
evident closer connection, in former times, between the western 
and eastern Australian floras. 

One of the most interesting of the questions raised also 
by this knowledge of the broader relations of the Australian 
plant types to the generalized types of the tropics and of 
the world at large is that which is connected with the xerophytic 
forms such as Acacia, many Cassias, Senecio, Lobelia, and 
others. These forms apparently were world-wide in their dis- 
tribution before the isolation of Australia from the rest of 
the world, and they are xerophytic types in nearly every 
country. Do they connote deserts existent with the supposed 
mild and moist climate during the cosmopolitan distribution 
in the Cretaceous and the Eocene; do they imply the existence 
of a differentiation of climate at the close of the Cretaceous ; 


Australian Flowering Plants. 179 


or do they imply merely a response by the plants to their 
environment of extremely poor soil? 

Before proceeding to the general discussion of these points, 
however, it will be advisable to mention briefly the significance 
of the general relationships existing between the families and 
orders of the flowering plants, the significance of the Cre- 
taceous and post-Cretaceous geography and climate, of the 
transporting agency of man, animals, and the sea, of vigorous 
and aggressive plant genera, of the distribution of mammals, 
and of the theory of multiple origins. 


II. The Significance of the present Relationships existing 
between Families and Orders of the Flowering Plants. 


The angiosperms are divided into about two hundred and 
fifty families, according to the various classifications proposed 
by systematists. ‘These families are fairly distinct from each 
other but they may be grouped into series yet more distinctive 
known as orders. With a. few exceptions the many orders are 
quite distinct from each other. If now the orders be taken 
individually it will be found that, in most cases, they possess 
some families characterized by tropical arborescent forms, 
generally also. of luxuriant appearance, while other families 
in the same order are mainly herbaceous and confined to the 
cooler, or colder, regions of the earth. This is most pronounced 
in the more highly specialized types such as the Sympetale 
and the more specialized of the Dialypetalee types, while it 
is less pronounced in the more primitive types of the Mono- 
chlamydezx, such as the catkin-bearing groups. Thus the 
Araliaceee and the Umbellifere with the Cornaceze form an 
order, in which the Araliacez, for the most part, are luxuriant 
trees suggestive of the tropics or sub-tropics while the Umbel- 
liferee are herbs, for the main part, in the cooler portions of 
the globe, their extremely compound leaves, however, suggest- 
ing an ancestry flourishing under mild and moist conditions. 
The Rubiaceze, the Stellate (Lindley), and the Caprifoliacee, 
form another distinctive group, in which, however, the Capri- 
foliacese have preserved their woody nature even though 
acclimatized to the cold. For the Leguminosz, which embraces 
the Papilionaceze, Czesalpiniaceze, and Mimosacez, an ancestry 
of large trees is suggested with luxuriant pinnate foliage, with 
a tendency to adapt itself to temperate climates on the part 
of the Papilionacez, especially in the cases of the herbaceous 
tribes Viciex, Trifoliee, and Lotese. The Gruinales, com- 
prising families such as Rutacez, Geraniacese, Oxalidaces, 


180 E. C. Andrews—The Geological History of the 


Malpighiacex, Simarubacex, Zygophyllacex, and Meliacex, is 
another splendid example. The Ranales form another good 
example of this principle, Magnoliaceee, Anonacez, and Ranun- 
culace, being taken as types. The Myrtales is another good 
example with Myrtacex, Combretacex, Melastomacer, Rhizo- 
phoracex, Haloraghacer, Lythracese, Lecythidacer, and Ona- 
graceee, taken as types. The Sapindaces, Aceracer, and 
Hippocastanacex, furnish another example. The catkin-bear- 
ing families are peculiar in that they suggest an ancestry of. 
large and luxuriant trees with compound leaves dwelling in a 
mild and moist climate, which still are large trees in the main 
although confined for the most part to the eool and cold tem- 
perate regions. Many families again may be divided into 
tribes which have relations one to another somewhat similar 
to those which the various families bear to one another in the 
orders. Thus Papilionacee has the tribes Sophoreee and 
Dalbergieze, which are mainly large trees, with luxuriant pin- 
nate leaves in warm moist regions, Galegese and Phaseoles, 
mainly trees and twining plants in warm and temperate regions, 
while the tribes Viciex, Loteze, and Trifolese, are mainly herbs 
in cool temperate regions.. Many other examples might be cited. 

Again, in many of the more highly organized families, there 
is not only a tendency to become herbaceous in the colder 
regions but also in the warmer parts of the earth. Cucur- 
bitaceze, Lobeliaceze, Campanulaceze, Composite, Solanaceze, 
Liliaceze, and Orchidaces, may be cited as examples. 

The significance of this remarkable arrangement into groups 
as they are seen to-day appears to be that a response was made 
to some widespread mild and moist condition of climate in the 
far past by a great development of large luxuriant trees 
fertilized by winds and clothed with dense foliage, the leaves 
being pinnate, compound or toothed. Jungles were rare, but 
great forests were common, to suit the fertilization by winds. 
Later, as a result of another widespread climatic factor came 
a great and rapid deployment of luxuriant trees with sym- 
metrical flowers which began to supplant the older anemophilous 
types. Then by the introduction of an additional factor came 
the development of the zygomorphic corolla and the tendency 
for such types to crowd together and to push the forest growths 
to the less favored spots, inasmuch as the crowding and cling- 
ing habit tended to prevent wind fertilization. Then came a 
zoning of climates with the development of deserts in both. 
tropics and temperate regions with mild moist conditions in 
local areas. This is suggested first, by the long-established 


Lhe 


Australian Flowering Plants. 181 


development of herbs among the old luxuriant tree forms in 
the temperate regions; second, by the great development of 
herbs and undershrubs in the warm arid and subarid regions, 
and third, by the development of vines and herbs and epiphytes 
in the mild and moist regions. 

An alternative explanation may be found by admitting the 
existence of deserts of limited area even in the Cretaceous and 
Eocene and in the presence of large areas of rocky barren soils 
such as those now found in South Africa and Australia. 

A much later period of climatic zoning throughout the world 
is evidenced by the development of deciduous trees in the 
northern lands and the great development of xerophytic tribes, 
subtribes, genera and species in both the northern and southern 
hemispheres. 

In other words the present classification of the flowering 
plants suggests that the great alliances of orders are of long 
standing, that the families are due to an early world-wide dif- 
ferentiation of climate, and that the present xerophytic and 
deciduous development is due to the later and local modification 
of old and well-established families and tribes. 


III. The Difficulty attendant on the Determination of Fossil 
Flowering Plants by Leaf Remains only. 


It is necessary for true progress in paleobotany that the 
proper determinations of the angiosperms should be agreed 
upon both by botanists and paleobotanists. In this connection 
it seems peculiar that the leaders of the botanical world, past 
and present, both were and are accustomed, respectively, to 
demand full and abundant material before referring a plant, 
previously undescribed, to its proper genus and species.* Paleo- 
botanists, on the contrary, seem content with fossil leaves 
alone for generic determinations of flowering plants although 
those fossil remains may date back to the Cretaceous. It is 
not that the plants so named may be referred to new genera 
for stratigraphic purposes, or that they are referred to genera 
whose names suggest a general likeness in leaf characteristics 
to certain types of modern genera, which causes the confusion, 
indeed upon first thought this may seem a procedure unlikely 
to lead to serious error, but the application of this method has 
led paleobotanists on the evidence of leaves alone to refer many 


*See also a paper by A. A. Hamilton on “The Instability of Leaf Mor- 
phology in its relation to Taxonomic Botany,” Proc. Linn. Soc. N. 8S. W., 
vol. xli, pp. 152-179, 1916, and references therein— [This note was received 
after the article was put into type—Eps.] 


182. E. C. Andrews—The Geological History of the 


fossils of the Cretaceous and Tertiary beds to modern genera 
straight out even when those particular genera no longer exist 
either in or near the regions considered. The particular cases 
which come to the mind of the Australian geologists in this 
connection are the well-known references of Cretaceous and 
Eocene leaf remains in North America and Europe to the 
modern genera Hucalyptus, Hakea, Grevillea, Banksia, Dry- 
andra, Callistemon, and other types now found only in 
Australia, and of various Tertiary leaf remains in Australia 
to Quercus, Alnus, Acer, and other genera, not now existent 
in Australia. 
} 

These determinations, moreover, appear to be opposed to the 
general evidence available on the subject because :— 

First.—The vitality, vigor and aggressiveness of the genera, 
such as Hucalyptus, Grevillea, Hakea, Persoonia, Banksia, 
and Dryandra, is very decided. Anyone who has made a close 
study of Hucalyptus must have observed its adaptation to all 


varieties of moisture, climate and soil in Australia, exclusive . 


of jungle areas. All round Australia it extends, flourishing on 
the actual sands immediately behind the sea beaches, swarming 
up the sides of the mountain gorges, defying the desolating 
winds of the cold plateaus and the desiccating influence of the 
arid to subarid climate of the plains and straining at its fet- 
ters, as it were, as though eager to conquer other areas than 
Australia. In other words it acts as though it were a genus 
which has not yet reached its prime. 

On the sandy areas, especially in West Australia, the same 
remarks are true, although in a measure somewhat slighter, 
of the vast genera Grevillea and Hakea, and the large genera, 
Persoonia, Banksia, and Dryandra. Nevertheless, vigorous 
and aggressive as are all these types to-day in Australia, it is 
stated that in extra-Australian regions they became so unfitted, 
one and all, to survive that they were driven out of the last 
trench even in Africa, a country whose soil and climate is 
similar in many ways to that of Australia. 

This difficulty is accentuated especially when the apparent 
saltation of Hucalyptus, in the eastern portion of Australia, is 
considered, many disputes having arisen as to specific deter- 
minations by highly-trained Australian botanists of certain 
forms found in that region. 

Second.—These types, Hucalyptus (300 species), the phyl- 
lodineous acacias (420 species), Grevillea (200 species), Hakea 
(110 species), Persoonia (62 species), Banksia and Dryandra, 
each about 50 species, are all xerophytic. Their ancestors 


Australian Flowering Plants. 183 


were not xerophytes, nevertheless the fact seems incontrovertible 
that they are xerophytice as genera, and that the actual genera 
were developed as xerophytic adaptations, and that in almost 
all instances the genera, during their existence as these par- 
ticular genera, never had an earlier mesophytic existence. 

This is strongly opposed to the idea that such genera were 
part and parcel of the luxuriant growths of the mild and moist 
Cretaceous in Europe and America. 

Third.—These types are almost entirely confined to the 
hungry, sandy soils of Australia, exceptions being some of the 
more recent species of Hucalyptus, and acacias. Soil condi- 
tions such as these could scarcely be matched in Europe. 

Fourth.—The morphology and earlier history of the genera 
considered are against the idea of matching leaf remains of 
the mild and moist Cretaceous and Eocene in the Northern 
Hemisphere, with modern Australian genera. Thus certain 
lanceolate leaves, in the Northern Hemisphere, possessing a 
venation not much akin to any recent Eucalypt have been 
referred to the genus Hucalyptus, whereas all the botanical 
evidence* indicates that this particular form of leaf lanceolate 
more or less faleate and with twisted petiole, is only a recent 
development and that the earlier form of leaf was more like 
many Myrtez, being opposite, penniveined, generally sessile, and 
more or less orbicular in shape. The venation also is peculiar, 
and the earlier types had closely-set secondary veins, arranged 
to the midrib at an angle approaching the right-angle. 

Grevillea, besides being a vigorous and hardy xerophyte, has 
a very irregular perianth, and a follicular fruit. It is mainly 
a shrub or undershrub, a dwarfed individual, a very spe- 
cialized type, far removed from the primary type of the Pro- 
teaceze as generally conceived, which should have had a regular 
perianth and should have had a luxuriant arborescent form. 
Two of the species, however, are large trees, namely G. robusta 
and B. striata. The same remarks apply to the cases of Hakea, 
Banksia, and Dryandra. Persoonia, by some botanists, with 
its regular perianth, and its drupaceous fruit, might be con- 
sidered as a primary type, but its vigor, its xerophytism, and 
its choice of the most hungry coarse sandy soils proclaim its 
recency as a genus within the Australian States. Callistemon 
is a highly specialized genus among the Myrtacee, closely 
allied to Melalewca (120 species approximately) and one which, 
even to Australian botanists, would be difficult to deseribe from 


*E. C. Andrews, Myrtacer, Proc. Linn. Soe. N. S. Wales, vol. xxviii, 
p. 555, 1913. 


184 § £. CO. Andrews—The Geological History of the 


leaves alone, especially if mixed up with certain Melaleuca 
leaves. 

It seems peculiar also, if it be assumed that a great and 
vigorous genus like Quercus (250 species) once flourished in 
Australia, that some trace of it should not exist now, as the 
climate of Tasmania and Southeastern Australia is adapted to 
its growth, or at least that it made no xerophytie response to 
its environment in much the same way as it has done in 
America. 


IV. General Geographical Conditions. Transport of Plants 
and Distribution of Mammals. 


(a) CRETACEOUS AND PosT-CRETACEOUS GEOGRAPHY AND CLIMATE. 


The accompanying notes on the general geographical condi- 
tions of the world are abbreviations from Vol. III of Chamber- 
lin and Salisbury’s Geology. In the-lower Cretaceous there 
was a general sea transgression and very little diversity im 
the world’s climate so far as can be gathered from a study of 
the fossils. Newberry? suggests that in the upper beds, the 
‘angiosperms belong to familiar genera such as Sassafras, 
Laurus and Hucalyptus. 

In the Upper Cretaceous there was a very great sea trans- 
gression in America (both North and South), Europe, Asia, 
and Australia, and doubtless in Africa, the climate appears to 
have been mild and warm, and is supposed by Neumayr® to 
have been comparable with that of Malayasia at the present 
time. Angiosperms were in marked ascendency. : 

Eocene. Mild climate as told by fossils. Large epiconti- 
nental seas. 

Miocene. Great terrestrial aggradation. Great terrestrial 
degradation also. Floras become more suggestive of temperate 
climates. Deciduous trees make their appearance. 

Pliocene. Differentiation of climate and heralding of the 
approaching Glacial Period. 

Pleistocene. Great Glacial Periods and repeated revivals 
of glaciation. Lowering of temperature simultaneously over 
the globe. Interglacial periods. Great increase of land area 
since the Cretaceous, Eocene, Miocene, and even Pliocene 
Periods with development of deserts, high mountains, and 
marked zoning of climate. 


>United States Geol. Survey, Monograph XXVI, p. 28, 1895. 
° Erdegeschichte, vol. ii, p. 383. 


Australian Flowering Plants. 185 


To this epitome may be added a few notes on the topography 
and climate of Australia as bearing directly on the development 
of the local flora. 

In the Lower Cretaceous the sea transgressed a portion of 
central Australia. 

The Upper Cretaceous sea covered nearly the whole of the 
central portion of Australia and it is probable that this epi- 
continental sea extended from the Malayan area in the north 
to the Southern Ocean on the south. 

The Eocene sea was not large and was confined to small 
areas in the north and south of the continent. Indeed the 
continent as a whole appears to have been growing in size 
subsequently to the close of the Cretaceous although a very 
recent submergence, post-dating the Glacial Periods, appears 
to have isolated New Guinea and Tasmania from the mainland. 

The land history of Australia in Cretaceous and post-Cre- 
taceous times is full of interest and throws a considerable 
amount of light on biological problems. It is as if there has 
been a general tendency in Australasia and New Zealand to 
move in a vertical direction in post-Cretaceous time, the move- 
ment being subject to two great laws, namely :— 

Furst.—That elevation, or vertical movement, of the land 
was emphasized in an easterly direction, due allowance being 
made for the lagging behind of the two great and relatively 
heavy portions, namely, Central Australia and the sub-oceanic 
mass between Australia and New Zealand. 

Second.—That the uplifts after the widespread peneplana- 
tion of the Cretaceous Period did not proceed continuously, 
but were saltatory in their action and, moreover, the periods 
of time punctuating these uplifts became less as the present 
time approached, but the amount of individual vertical uplift 
became greater as the periods separating the uplifts became 
less in duration. This has given rise to great “valley-in-valley” 
structures owing to the interrupted work of the streams. 

Thus during the Cretaceous Period great peneplains were’ 
formed and only the hardest rock structures remained to show 
the existence of former plateaus or hills. In the various 
Tertiary divisions of time the streams carved valleys with 
widths so great as to appear as local peneplains, nevertheless 
they are only very broad shallow valleys, in whose bases other 
broad and shallow valleys have been excavated. The great uplifts 
of the later Kosciusko Period allowed the streams to form pro- 
found canyons receding along these older shallow valleys. In 
other words the main Tertiary land history has consisted of 


186 EL C. Andrews—The Geological History of the 


repeated elevations with stream revivals. During one or more 
of the Tertiary divisions of time, especially the Miocene, the 
land appears to have sunk somewhat with the formation of lake- 
like expanses along the stream courses and the burial, later, 
of deep river deposits beneath basalt floods covering thousands 
of square miles in Eastern Australia. This led to great modi- 
fications in stream drainage, but the great and dominating 
lesson of repeated stream revival cannot be overlooked, the 
modifications due to basalt floodings being only an incident in 
the establishment of the great geographical unity of Eastern 
Australia in Tertiary and post-Tertiary time. 

Two glacial visitations at least during the Pleistocene hdve 
been recorded for Australasia.‘ As the various geographical 
changes were contemplated in Australia, such as the increase in 
height of the plateaus, the approach of the Glacial Period, and 
the succession of the milder interglacial periods, it may be 
understood how vast a change such influences would have 
induced in the flora of East Australia and of New Zealand, espe- 
cially in the extinction of weak types and the saltation of 
vigorous and aggressive genera such as Hucalyptus, Acacia, 
Veronca, Pultenea, and Coprisma. 


(b) THE TRANSPORT OF PLANTS AND THE DISTRIBUTION OF MAMMALS. 


(1) The Transport of Plants. 

By sea currents, by birds, by winds. The works of Charles 
Darwin, Guppy, Schimper, Hemsley, and others, are full of 
instances showing the great power of transportation of plants 
by the agencies here enumerated, and not only so but of the 
vitality of many seeds thus transported. The example of 
Krakatoa populated with many species of plants between the 
years 1883° and 1908, is very significant in this connection. 
If Krakatoa, a small island, has received such a large flora 
as it possesses at present from the action of currents, birds, 
and man, what may have been accomplished during the progress 
of ages in the way of plant transport by similar agencies from 
one great land block to another, such as from America to 
Africa, to Australia, or to New Zealand? Here again we 
have also the cumulative action of time and the long-continued 


7David (T. W. Edgeworth), Geological Notes on Kosciusko, with special 
reference to the evidence of Glacial Action, Proc. Linn. Soc. N. S. Wales, 
vol. xxxiii, pp. 657-660, 1908. David (T. W. Edgeworth), Pittman (E. F.), 
and Helms (R.), Geological Notes on Kosciusko, Proc. Linn. Soe. N. S. 
Wales, xxvi, pp. 26-27, 1901. 

®Ernst, “New Flora of Krakatoa,” Cambridge University Press, 1908. 
Quoted from letter by Dr. H. B. Guppy. 


Australian Flowering Plants. 187 


action of isolation from the ancient home, in producing great 
changes in the nature of the evolution of new genera, sub- 
genera, and species. Two examples may be taken, namely, 
Hawaii and St. Helena. From the geological evidence, neither 
of these appears to have been in direct connection with the 
ereat land blocks, such as North America in the case of Hawaii, 
and of West Africa in the case of St. Helena. Nevertheless 
their endemic flora is so rich and varied as to suggest the 
cumulative action of time and of evolution, under isolation, in 
producing numerous endemic species, if not genera, from the 
waifs brought to them by the sea, by birds, or by man since 
their existence as islands. 

In this connection attention may be drawn to the magnificent 
work of Wallace,? Guppy,’® and Hemsley,"? on Insular Floras.. 
The study of these volumes is of the utmost service in clearing 
the way for a proper discussion of the population of islands 
by various agencies. 

Man. The importance of this agent, in the transport of 
plants from land to land across the sea, appears to have been 
almost always underestimated. Anyone who has lived with 
native races of men must have noted their belief in the necessity 
of certain plants to their well-being, either as articles of food 
or as medicines. Man has had a long history on the globe, 
and in his many wanderings, both in the primitive and civi- 
lized state, he must have been the means, consciously or uncon- 
sciously, of carrying many plants from the northern hemisphere 
to the southern or from the east to the west and so on. Certain 
of the Composite, Cruciferz, Labiatee, Umbelliferze, Caryophyl- 
laceze, Rosaceze, and other families, may be conceived as having 
been transported in this way, for example, Taraxacum officinale. 


(2) The Distribution of Mammals. 

Inasmuch as it is necessary to apply the testimony of inde- 
pendent witnesses, whenever possible, as to supposed land con- . 
nections during particular periods of the earth’s history, it 
would, in the case of the angiospermous distribution, be advis- 
able, if possible, to apply the testimony of the animals. 

The distribution of reptiles, birds, worms, and invertebrates 
generally does not concern us, necessarily, in the distribution 
of the flowering plants, inasmuch as they had their origin long 
before that of the angiosperms, and they, therefore, may have 

‘Tsland Life, 1892. 


“A Naturalist in the Pacific, Plant-Dispersal, vol. ii, 1906. 
“The Voyage of the Challenger, Botany, vol. i, Introduction. 


Am. Jour. Sct.—FourtH Srerizs, Vou, XLII, No. 249.—Srrremper, 1916. 
13 


188) £. C. Andrews—The Geological [History of the 


been distributed over the earth during land connections prior 
to the Cretaceous Period. The discussion of their distribu- 
tion in this connection, therefore, would be liable to result 
in confusion. 

The distribution of the mammals, however, specially the 
placentals, may be taken as independent testimony in the 
discussion of the distribution of the flowering plants. 

The accompanying notes are abbreviations from Chamberlin 
and Salisbury’s Geology (vol. III, 1906). 

Marsupials and monotremes appear to have been in existence 
in the Upper Cretaceous. The earliest actual records of the © 
placentals are from the early Tertiary. Among them were 
undifferentiated sloths, rodents, lemurs, edentates, and carni- 
vores. Before the close of the Eocene, the Ungulata, Carni- 
vora, Edentata, Insectivora, Rodentia, Quadrumana, Cetacea, . 
and Sirenia, were distinctly defined. 

Oligocene. No living genera recorded. 

Miocene. Still no living genera, unless some doubtful Canis 
and allied types be allowed. 

Pliocene. Many strange genera, but there were also many 
modern genera in existence. 

Pleistocene. Many extinct genera, but also very many mod- 
ern genera, in existence. 

In the chapters on the Tropical, the African, the South 
American, and the New Zealand problems, it will be seen how 
valuable is the testimony of these independent witnesses, the 
mammals. 


V. The Development of the Australian Angiosperms. 


If, now, the data supplied in the foregoing chapters be cor- 

rect, it is permissible, perhaps, to suggest along which lines the 
population of Australia by angiosperms has moved. In this 
connection it must be remembered that, vast as is the number 
of species existing still in Australasia, the mere existence of 
types such as Casuarina, Fagus, Epacris, Philydrum, Stack- 
housia, Plewrocarpea, Tetratheca, Hucalyptus, Angophora, 
Brunonia, and many others, implies a wholesale extinction of 
genera and species, intermediate between these types and their 
nearest living allies. 
- For the sake of simplicity, the problem may be considered 
under six heads, namely, The Tropical Problem, the South 
African Problem, the South American Problem, the Northern 
Hemisphere Problem, the New Zealand Problem, and the West 
and East Australian Problem. 


Australian Flowering Plants. 189 


In the succeeding sections the information supplied already 
in the earlier pages is assumed. 


(a) THE TropiIcaAL PROBLEM. 


(1) Distribution of Acacia, Cassia, Xanthoxylum, Vernonia. 

In the fertile tropics there are many large families of flower- 
ing plants containing a great wealth of genera and species, 
which are more or less luxuriant in habit, primary or gen- 
eralized in character, and having a cosmopolitan range in the 
fertile tropics. Im the neighboring extratropical areas many 
types occur secondary to the primary forms of the tropics. 
These secondary forms are mainly xerophytes, and occur both 
as modifications of the cosmopolitan genera of luxuriant type 
and as local genera grouped round the local forms which the 
main cosmopolitan genus may have assumed. These secondary 
sections, subgenera, or groups of genera, considered as distinct 
local groups, appear to have relations more intimate with the 
cosmopolitan tropical type than with each other. The secon- 
dary types in the southern hemisphere are mainly undershrubs, 
shrubs, or dwarfed trees, more rarely herbs, the leaf surfaces 
are reduced and the evidence is that the specialization has been 
in the direction of providing against excessive transpiration of 
moisture. The secondary types in the northern hemisphere 
are peculiar in that they generally are herbs, either annual or 
perennial, more rarely trees, while the primary forms in the 
tropics most frequently are trees of beautiful appearance and 
luxuriant habit, with pinnate leaves. 

Examples are to be found. in families such as the Myrtacee, 
Leguminosz, Rutacez, Rubiaceze, Sapindacez, Euphorbiacee, 
Solanacez, Verbenacez, Orchidacex, Labiate, Malvacee and 
Sterculiacez. 

Before discussing any of these families individually it 
would be advisable perhaps to consider the distribution of a 
few of the most important genera in these and allied groups, 
genera, for example, such as Acacia (or better still Mimosa 
in the Linnean sense) Cassia, Vernonia, and Xanthoxylum. 

Of these Acacia is a peculiar type. Its primary form is 
suggested by the section Gummiferz, which is spread over the 
tropics and subtropies of the world, but occurring not so much 
in the fertile tropics, as on the plains and wastes of the warmer 
world. Indeed it is one of those remarkable types which 
suggest strongly that in the days when some great connection 
existed between all the great land blocks of the world within 
the region of warm climate, that xerophytes had already come 


190 £. O. Andrews—The Geological History of the 


into existence. This may be placed tentatively in the later 
Cretaceous. 

In Australia Acacia and its allies are represented by modi- 
fications of the genus, as local subgenera or sections, which 
have a general appearance very different from that of the world- 
wide section Gummifere. One of the Australian sections, 
namely Phyllodinew, with about 420 species, is leafless, but 
possessing a development of phyllodes remarkable for their 
variety of form and structure. 

Vulgares, another great section, or subgenus, is plentiful 
in Asia, Africa, and America, but is absent from Australia. 
Another subgenus is endemic in Tropical America. 

No local genera grouped around Acacia occur in Australia, 
but in America there is the vast genus Mimosa (400 species) 
with a few outliers in the Old World. 

Cassia contains about 400 species and is divided into three 
subgenera by Bentham’? namely, Senna, Fistula, and Lasior- 
hegma. All these subgenera show the same combination of 
general characters in America, Asia, Africa, and Australia. 

Fistula has above 20 species, about 8 in America, about 5 in 
Asia, 5 in Africa, and but 1 in Australia. These species are 
local, forming natural combinations into intermediate groups. 

The great subgenus Senna, with more than 200 species, has a 
similar wide distribution, excepting the section Psilorhegma, 
which is confined to the Old World with its chief center in 
Australia, but, as Bentham remarks, these Australian species 
are truly Australian in type, namely, in their leaves being 
rigid, vertical, terete, or in having phyllodia developed, and 
with the pods straight or variously twisted. 

Lasiorhegma is world-wide in distribution, but the three 
natural sections, Apoucowta, Absus, and Chamecrista, into 
which it is divided, are distributed differently. Apoucouwita 
consists of 38 or 4 American trees. Absus has 70 localized 
American species and 1 type an annual, abundant in Tropical 
Africa, Asia, and Australia, but not in America. 

Chamecrista has many herbs and undershrubs with 50 to 
60 species in America and from 16 to 20 in the Old World. 

Vernonia, a genus of about 500 species, and closely connected 
with many small genera, “has its chief centers in tropical 
America and tropical Africa, forming in both countries more 
or less divergent groups, but in different directions, the species 
more numerous in America, the forms more varied in Africa. 


“ Revision of the genus Cassia, Trans. Linn. Soc. London, vol. xxvii, pp. 
503-513, 1869. 


Australian Flowering Plants. 191 


From tropical America it spreads more sparingly into North 
America and extratropical South America, and from tropical 
into Southern Africa, and eastward into tropical and_ sub- 
tropical Asia, forming in each of these outlying districts more 
or less local groups. More than three-fourths of the genus 
belong to the section Lepidaploa. . . . At least four-fifths 
of its species are tropical American, but it includes also the 
North American ones, a portion of those from Africa, and five 
or six Asiatic species.’’!% 

Vernoma itself is not indigenous in Australia, but Plewro- 
carpea, close to Vernonia, is in Australia, and is a monotypic 
genus. 

Xanthoxylum. (Fagara) Trees mainly of luxuriant type, 
about 150 species in all tropics and in 5 sections. The first 
section, with about 115 species, extends over all tropics, with 
a few outliers in North America, Paraguay, Argentina, the 
Andes, Japan, China, Korea, Manchuria, and other places. 
The second section is mbnotypic from Juan Fernandez, The 
third section with about 12 species is from the West Indies 
with the trees luxuriant in habit, while the fourth named 
Blackburnia, and at one time classed as a distinct genus, is 
confined to Australia and Hawaii. A fifth section, or, probably, 
a genus, consists of about 10 species in North America and 
temperate east Asia. 

Around this great type are gathered many genera both 
tropical and temperate, but mainly tropical trees with large 
luxuriant and pinnate leaves. 

Around the group or tribe of Xanthoxyle, however, are 
gathered three large tribes, namely Boronier (xerophytes con- 
fined to Australia), Diosmen (xerophytes confined to South 
_ Africa and mostly shrubs), and Cuspariez (confined to tropi- 
cal America). 

A study of Psychotria (700 species in the Benthamian sense) 
and its allies, Hibiscus (150 species approximately), Ticus 
(600 species), Piper (600 species), Phyllanthus (500 species 
approximately), Peperomia (500 species), Solanum (900 spe- 
cies), Huphorbia (700 species), Bauhinia (150 species), 
Hedyotis (in the Benthamian sense), and other vast tropical 
genera, show a very similar distribution to that here outlined 
for Cassia, Vernonia, Xanthoxylum, and Acacia, or better still, 
for Mimosa, in the Linnean sense. 

This peculiar distribution suggests a connection of some 


*G. Bentham, Composite, Jour. Linn. Soe. London, Botany, vol. xiii, 
p: 393, 1873. 


192 E. C. Andrews—The Geological History of the 

decided description between the great tropical land blocks, and 
a connection, moreover, which appears upon first inspection 
to have ceased at the present time. Indeed, were one to con- 
sider only the evidence of one great family or order only, such 
as the Myrtacex, Leguminosx, Solanacex, Rutacex, or Pipera- 
cex, it would seem impossible to escape the conclusion that the 
present tropical lands had been directly connected in the not 
very remote past. But the distribution of the mammals does 
not bear this out and, more important still, the facts of 
structural geology are directly opposed to the idea. In the 
Cretaceous, or Eocene, before the strong zoning of climate 
mentioned by Chamberlin, these genera most probably had a 
much wider distribution than they have at present, and at that 
time they may have moved along land bridges which existed 
much farther to the north than-the present tropics, yet without 
leaving the mild and moist climate apparently so necessary to 
their existence. Such conclusion is indeed suggested by the 
existence of outposts of types such as Solanum, Huphorbia, 
Sophora, and Hibiscus, in the temperate regions. 

The case of the oceanic islands should ever also be kept in 
mind in this connection. All the facts of geology go to prove 
the non-existence of direct land connection at any time between 
islands on the one hand such as St. Helena, the Azores, and 
the Hawaiian groups, and the neighboring continents, on the 
other hand. ‘These appear to have derived their flowering 
plants from the great land blocks through the agency of sea- 
currents, birds, animals, and man. 

For example, are we to conclude that the several species 
of Commdendron in St. Helena, the seven species of Tetramo- 
lobium, the 11 species of Lipocheta, the 12 of Campylotheca, 
6 of Dubautia, 12 of Raillardia, 2 of Hesperomanma (all in 
Composite), 20 of Pilea (Rutacee), 16 of Kadua (Rubiacee), 
11 of Clermontia (Lobeliacee), 29 of Cyanea (Lobeliacezx), 
and so on, in Hawaii, all of endemic genera, were one and all 
wafted or carried to these islands, and yet exterminated on the 
main lands. Is it not rather an inescapable conclusion based 
upon the theory of probabilities that, since these lands must 
have been supplied by waifs and colonists from the great lands, 
inasmuch as the geology appears to disprove their former land 
connection with the continents, then they are the descendants 
of types brought to these islands in old times and which have 
since produced either endemic species or genera or both? 

Among the numerous families which can be considered as 
illustrating the connection of the tropical lands and Australia 


Australian Flowering Plants. 193 


it is proposed to discuss the probable distribution of the 
Leguminose, Myrtacee, Rutacee, Huphorbiacew, Verbenacee, 
Labiate, Sterculiacew, Sapindacee, Pittosporacee, Treman- 
dracece, Malvacee, A pocynacee, Asclepiadacew, and other large 
groups. 

It would be beyond the scope of the present paper to deal 
with these great families in detail and the remarks herein will 
be confined, therefore, to the salient features of distribution 
in a few of the larger divisions of the families. 


(2) Leguminose. 

It seems safe to conjecture that'* during the Cretaceous, or 
the Eocene, or both, the tribes of the Mimosacez, Cvsal- 
piniacez, and Papilionacezx, now mainly confined to the tropics, 
were scattered over the greater part of the world, Australia 
being joined to Asia, and all the great land masses being con- 
nected directly within areas of mild and moist climate, although 
not at all necessarily, within the present tropical or subtropical 
regions. | 

The tribes which do not appear to have been in existence 
during the Cretaceous were the Trifolie, Lotez, and Viciez. 

It may be permissible, moreover, to infer that during this 
stage the great tribes such as Sophorex, Cassieze, Acacieze, 
Galegex, Phaseolew, and Genistee, were abundantly repre- 
sented mainly as trees of luxuriant habit, although the acacias 
and to a less extent the cassias suggest even in that remote 
period either the existence of a great climatic differentiation 
or of the existence of subarid, to arid, areas, or of waste open 
spaces. It may be mentioned in passing that similar evidence 
of the existence of xerophytes at this stage in flowering plant 
development is yielded by a study of many other great families, 
such as the Campanulacese, Lobeliacee, Umbelliferse, and 
Composite. These tribes existed probably in all the great land 
blocks, Europe and Australia included. 

The case of the Sophoreze may be considered at this stage. 
During the zoning of climates, the regions of mild and moist 
climate gradually retreated from the higher latitudes toward 
the Equator, but as the change was accomplished very slowly, 
the plants had a long period in which to save themselves from 
extinction by the adoption of various devices against the 
increasing rigor of their environment. This factor of time 
as an ever-flowing quantity must ever be kept in view in the 
consideration of angiospermous development. The changes 


“E. C. Andrews, The Distribution and Development of the Leguminosae, 
Proc. Roy. Soc. N. S. Wales, vol. xlviii, 1914. 


194 E. C. Andrews—The Geological History of the 


induced were not cataclysmic but gradual, the climate tending 
ever towards the dry and cold but with innumerable recur- 
rences of mild and moist conditions temporarily, the ameliorat- 
ing influences becoming less and less distinet as the Pleistocene, 
with its climatic rigors, was approached. In the earlier mild 
and moist period the luxuriant trees of the Sophores would 
have been enabled to cross from the Old to the New World 
and from the New to the Old, in regions beyond the limits of 
the present tropics, and thus new genera might arise in the 
tribe which might be common to the New and Old World, and 
yet be unknown in Austr alia, which had become isolated before 
the great differentiation of climate ensued. 

Thus would arise the idea that Australia was separated 
earlier than America and Africa. Moreover, great land blocks 
such as America and Western Africa might have effected an 
interchange of genera and species and thus present likenesses 
with each other, of a more modern character, than those of 
Australia with these great land blocks. This of course has 
reference only to the great tropical groups. With the increas- 
ing differentiation of climate, the Sophoree retreated more 
and more to the tropics, but certain hardy forms existed such 
as the old genus Sophora itself, or other hardy genera were 
formed, such as Virgilia and Cladrastis. These were the types 
in extratropical areas which could dispense with the old 
arborescent stage and the luxuriant foliage, and hence, as the 
extreme rigors of the Pleistocene arrived, it is noted that the 
majority of the noble trees of Sophorez vanish, and a herba- 
ceous type is developed, namely, the Podalyriee of the northern 
hemisphere. 

The effect of the climate on the ancestors of the Sophorez 
and the Podalyriez in the southern hemisphere is more instruc- 
tive than in the northern hemisphere. In the north the tribe 
was almost exterminated owing to the excessive climatic rigor 
of the Pleistocene coupled with the ensuing competition of other 
and extremely hardy and vigorous types, begotten by the 
climatic revolution. 

The Podalyriee of the south mark a departure from the 
Sophorez during a great climatic differentiation preceding 
the separation of Australian from the tropical lands when the 
flowering plants began to feel the influence of the climatic 
changes. This land was relatively small and was confined to the 
tropical and warm temperate regions. It might, therefore, be 
expected that there would not, on the one hand, be such a great 
response in genera and species, in the numerical sense, as in the 


Australian Flowering Plants. 195 


vast Eurasian and American regions, and on the other hand, 
there would not be a development along the vigorous and aggres- 
sive lines such as might be expected in the great connected land 
blocks of the northern hemisphere. 

In Australia there are vast expanses of coarse sandy soils 
which have been derived, ultimately, from the great sandy 
granites of East and West Australia—but derived, directly, in 
great measure, from the great exposures of Mesozoic sandstones, 
especially in Eastern Australia. 

These soils are extremely loose and porous and contain 
moisture, almost permanent, at depths of a few yards from the 
surface, but they contain very little moisture near the surface 
except on the mountain sides, or in moist seasons. In dry 
seasons this sandy soil neither becomes caked nor hard, and 
the water level simply sinks at a very slow rate. On the dense 
heavy soils of the slates, andesites, basalts, and allied rock 
types, a long succession of moist and mild seasons would pro- 
duce dense growths of luxuriant trees and vines to the exclusion 
of xerophytes generally, but if the region should be subject 
to great droughts and to long continued desiccating winds, 
and to great diurnal and annual changes of temperature, then 
this luxuriant growth would cease. In moist, mild seasons a 
luxuriant crop of herbage would arise, especially if the seeds 
of such herbage should be protected by special devices against 
excessive loss of moisture. In the long spells of dry weather 
this herbage would be burnt off, as it could not keep in touch 
with the underlying water supply, owing to the tough and non- 
porous nature of the dried upper clods of earth, while only 
trees such as were provided with very long and deep roots, and 
with special devices against excessive transpiration, could 
survive, 

In the old moist and mild climate of Australia the heavier 
soils had a dense covering of luxuriant vegetation while the 
much greater areas of coarse, sandy soils (the central sea being 
then very large and the existing great central black and red 
soil plains being non-existent) were clad with mesophytic for- 
est growths, much as may be seen to-day under similar condi- 
tions in New Zealand, northeast Queensland, and other 
countries, while on the open plains or low plateaus of such 
country there would be a tendency to form stunted forest 
growths of the mesophytes. 

With the alteration of the Australian climate from mild and 
moist and uniform to fiercely-hot and dry summers, and to 
desolating dry winds during the winter, all this condition of 


196 E. C. Andrews—The Geological History of the 


growth was changed. The plains of heavy soil were forsaken 
gradually by the luxuriant vegetation, except for hardy outliers 
which possessed deep roots and which were provided with 
special devices against excessive transpiration, and such plants 
as these even were in great danger of extermination. On the 
coarse, hungry, sandy soils, however, the old luxuriant vege- 
tation found means whereby many of their kind might be pre- 
served. If, for example, during the ages involved in the 
general and great alteration in the Australasian climate, it 
should be found that they could utilize, or modify, certain 
inheritances of structure or of chemical composition, so as to 
provide against excessive transpiration, then their ancient abode 
might still know them; if, for instance, they should secrete 
non-volatile oils or resins; or a latex; if the old luxuriant tree 
should be reduced to a shrub, or undershrub, or better still, 
to an annual herb; if the leaves should be provided with stony 
cells, stomata, and other devices, to conserve their contained 
moisture; or better still, if they should dispense entirely with 
their leaves or reduce them to linear, needle-like, spiny, pungent, 
horny, terete types, or if their seeds should be protected so that 
they could resist a drought extending over periods even of 50 
or 100 years, then the safety of the family might be assured. 
The Sophorez, or at least the ancestor of the tribes Sophorex, 
Podalyriez, and Genistez, found special facilities for survival 
on these hungry, sandy soils which were scorched by the suni- 
mer sun and subjected always to the menace of long continued 
drought and desiccating atmosphere. The Leguminose indeed, 
as a whole are singularly liable to leaf alteration, they are also . 
singularly fortunate as regards seed protection, and as regards 
ready fertilization. As the luxuriant arborescent forms of 
the Sophorez perished, one by one, on the open wastes of the 
heavy soil, so the porous soils of the sandstones were occupied 
by special types of the tribe, which could reduce their leaf 
surfaces; which could endure the gradual dwarfing process 
to shrubs and undershrubs; and whose heritage of long tree 
roots could be utilized in tapping the underlying moisture. 
The nutriment supplied to individual trees of the Sophdrez 
was limited to the area which the roots could tap, and this, 
on barren, hungry soil, was sufficient only for small trees. 
The leaves also underwent wonderful transformations, pinnate 
types becoming simple, or being rolled into mere lines and 
points, or being discarded altogether. In this way a great 
number of individuals could live side by side on a given space, 
because the area covered at the surface was dependent on the 


Australian Flowering Plants. 197 


spread of root at the zone of moisture, and on the relative lack 
ot nitrogenous, calcareous, and allied nutriment in the sands. 
The types thus evolved were exceedingly hardy and became 
vigorous and aggressive with the usual result, namely, the 
production of numerous genera and species. Hence during 
the double period of climatic differentiation the first of which 
occurred while all the great lands were in some close connec- 
tion, the second after the isolation of the great tropical lands, 
the 19 or 20 genera and about 400 species of the Australian 
Podalyriez appear to have been. developed. 

In South Africa, on the hungry Mesozoic sandstones, dined in 

a climatic Seecamen somewhat similar to that of Australia, 
the Podalyrie of that region arose. In South America the 
conditions which obtained in South Africa and in Australia 
were not existent, and moreover, a more severe competition 
arose owing to the ingress of aggressive northern types, whereas 
South Africa, on the one hand, was protected by a barrier from 
northern competition, while Australia was’ protected by the 
ocean. 
The story of the Genisteze is perhaps even more interesting. 
It is supposed by Bentham that Podalyriez is related :more 
closely to Genisteze than to Sophorex, and this may, perhaps, 
be so,’® owing to certain peculiarities of habit and foliage 
common to the tribes, nevertheless the bloom is nearer Sophorez 
than Genistez. In the tropics the Genistez have almost van- 
ished, with the exception of the great. genus Crotalaria (300 
species). In its early days, the Genistez, like Acacia, were 
more given to populate open places than the jungle, hence their 
extinction, in part, in the dry tropics. 

In the Northern Hemisphere, the Genistez retained the 
traces of the old arborescent habit more than did the northern 
Podalyriez and by reduction of size, and the rejection of 
foliage, in great part they held their own, and developed new 
and aggressive genera such as Ulex, Genista, Spartiwm, and 
Lupinus. In Australia the hungry, sandy soils gave them a 
chance, and new genera, such as the peculiar and vigorous 
tribe Bossiaex, were developed on the sandy and rocky wastes 
both as shrubs and undershrubs, with small leaves or with 
none. But the tribe never flourished in Australia as did the 
Podalyriez. In South Africa, however, on the hungry, sandy 
soils, the tribe developed enormously with great aggressive 
genera such as Aspalathus (above 150 species). 


Tf this be so then Podalyrieer has had a parallel development with 
Sophoree and with Genistezx. 


198 F.C. Andrews—The Geological History of the 


The genera Castanospernwum and Podopetalum, in Sophoree, 
were developed in the Australian jungles after the isolation of 
Australia, but these genera are monotypic and probably repre- 
sent decadent genera, despite the fact that the individuals are 
luxuriant types. Sophorex, indeed, appears to be a decadent 
tribe which, however, possesses a powerful and vigorous 
offshoot, the Podalyriez. 

Acacia also is a magnificent example of the adaptation'® of 
a tree with bi-pinnate leaves to a hungry sandstone setting 
by the rejection of its leaves and the development of phyllodes. 
The formation, later, of the great soil plains of the central 
areas, and of the plateaus of the eastern areas of Australia, 
gave the new vigorous subgenus a further field for its energies. 


(3) Myrtacee. 

This is a family less elastic than the Leguminose in accom- 
modating itself to a harsh and severe environment, and from 
the point of view of distribution it is to be compared with 
the Mimosaceze or the Czesalpiniacee rather than with the 
Papilionacez. 

In the tropics the more primary types Hugenia (in the 
Benthamian sense) and Myrtus are widely spread and suggest 
former direct land connections between all the great land 
blocks, this older interchange of fertile types in regions of 
mild and moist climate, however, having ceased long since. 

In tropical and subtropical America, after the zoning of the 
climate ensued, the Myrtacee were modified gradually with 
the development of the true Eugenias, Wyrcia, Calyptranthes, 
Marlieria, and other types. According to Berry’? the genus 
Myrcia contains about 450 species, and represents one of the 
older, or primary, Myrtacez. But the type does not »xist 
outside America, and, moreover, it is a vigorous, vast, and 
aggressive genus, which is confined to one compact area, hence 
it seems unlikely that it is as old as Hugenia, or Myrtus, which 
occur abundantly in all the large land blocks with the exception 
of Europe and America north of Mexico. 

All of these American types belong to the tribe Myrtw, no 
other tribe of the family having been developed in that country. 

In Australia, however, the great areas of hungry, sandy soil, 


1%. C. Andrews, The Distribution and Development of the Natural 
Order Leguminose, Proc. Roy. Soc. N. 8. Wales, vol. xlviii, 1914. 

1. W. Berry, The Affinities and Distribution of the Lower Eocene Flora 
of South Eastern North America, Proc. Amer. Phil. Soc., vol. lili, pp. 222- 
227, 1914. 


Eee a 


Australian Flowering Plants. 199 


already mentioned on a previous page, furnished the Myrtacez 
with a chance for the development of xerophytie characters. 
During the earlier zoning of the climate it is possible that 
the important subtribe Metrosiderexe has been developed in 
the areas of good soils. At a period somewhat later the sub- 
tribe Eucalyptez appears to have been developed, probably 
from the Metrosideree. Hucalyptus represents the adaptation 
of a luxuriant type to hungry, sandy soils in a warm climate.'® 

“The obstinate persistence of juvenile, opposite, cordate, 
sessile, and horizontal leaves in the genus, indicates that such 
leaf-types had been thoroughly well-established for a very 
long period in the family, before the evolution of the genus 
Eucalyptus; and that the later typical Eucalyptus leaf with 
twisted stalk is an adaptation to a harsher climate, and one 
which would tend to become extinct, in part, in favor to the 
old persistent type, under certain favorable climatic condi- 
tions.”!® Moreover, the great size of the trees of the genus, and 
their general appearance, proclaim the subtribe Eucalypteze 
as a remove of no very great degree, from Myrtex, although it 
must be borne in mind that the fruit is a capsule and not a 
drupe. 

Like the phyllodineous acacias, Hucalyptus flourished first 
on the moist, hungry, sandy soils. At a later date, when the 
high plateaus were formed in the east, and when the great 
inland plains were formed, Hucalyptus developed numerous 
new species”? to populate the fresh territory. This, however, 
it was enabled to do only after becoming a vigorous and ageres- 
sive type. All around Australasia it may be seen reaching 
out arms, as it were, for new lands to conquer. The eastern 
species offer never-ending puzzles to the systematists, many 
types apparently being in a state of saltation, the species over- 
lapping in the eastern plateaus, no intermediate areas being 
unoccupied by the genus, it being prevented only from spread- 
ing beyond Australia by reason of the wide ocean barrier 
and the inability of the genus to grow in the jungle areas 
of the neighboring islands. 

Meanwhile in Southern Australia, while the zoning of the 
climate became more pronounced, other subtribes and even 
another tribe of Myrtacez sprang into existence in the hungry, 
sandy areas. These fresh types, as time progressed, became 


*R. H. Cambage, The Distribution and Development of the Genus 
Eucalyptus, Presidential Address, Proc. Roy. Soc: N. S. Wales, 1913. 
' EK. C. Andrews, The Distribution and Development of the Myrtacez, 
Proce. Linn. Soc. N. 8S. Wales, vol. xxxviii, p. 555, 1913. 

* E. C. Andrews, ibid., pp. 554-565. 


200 E. 0. Andrews—The Geological History of the 


smaller in size as individuals, the individuals became more 
depauperate, and more specialized, by far morphologically, 
than the earlier Metrosideree and the Hucalyptus of which 
the latter had not succeeded in reducing itself to a shrub or 
undershrub. Nevertheless the myrtle plants never sueceeded 
in adopting the herbaceous habit. They always remained 
either as trees, shrubs, or undershrubs. The later, more 
depauperate and more specialized types were the subtribe 
Beeckeaez and the whole tribe Chamelauciexr containing many 
genera vigorous in character. 

The genera Melaleuca, Callistemon, and Leptospermum, 
occupy a peculiar position, in that they are not so close to 
Myrtez as are Hucalyptus and Angophora, but their foliage 
suggests some relation with the allied family Melastomacee. 
These types may belong to the first great zoning of climate, 
which is conjectured to be late Cretaceous in age. 

The essential oil in the leaves of this great family appears 
to have been of great assistance in enabling them to adopt the 
xerophytic habit and to populate the hungry sandy soils of 
Australia. 

It is remarkable that nowhere else in the world do the mem- 
bers of the Myrtacez appear to have been enabled to adapt 
themselves well to a hot, dry, and sandy environment. In 
South Africa they are singularly lacking, owing to the inability 
of the old luxuriant type of the Cretaceous to produce a local 
secondary and xerophytice type of aggressive nature as it had 
in Australia. Similarly for the case of South America. The 
New Zealand myrtle members, outside of the tribe Myrtez, 
and possibly of the subtribe Metrosiderex, appear to have been 
derived from Australia, or from Australian and Malayasian 
waifs. It is quite conceivable that the Metrosidereee may have 
developed in the north and entered the New Zealand during 
its connection with Australia by way of New Guinea or North 
Queensland. 

The Myrtez, like their allies, the Combretacese, Melasto- 
maceze, and Rhizophoracez, are essentially lovers of shelter, 
moisture, and heat, and were specially unfitted, as were also 
the Myrteze proper, to withstand the great cold of the Glacial 
Period in Eurasia and North America. 


(4) Rutacee. 

The Rutaceze are essentially magnificent and luxuriant 
arborescent forms, which as the genera Xanthoxylum and allied 
forms, are widespread over the fertile tropics as primary types, 


Australian Flowering Plants. . 201 


with local secondary developments in America, South Africa, 
Australia, and the Northern Hemisphere. The endemic secon- 
dary forms in South Africa and Australia are xerophytes. The 
primary type is characteristically a tree with a beautiful 
appearance, possessing pinnate leaves, and a lover of mild 
and moist climatic conditions. 

After the isolation of Australia from the great tropical lands, 
and the zoning of climates, the luxuriant Rutaceee in that 
country found themselves faced with the great problem which 
had confronted the megathermic Leguminose and Myrtacez, 
namely, the possibility of being forced to retreat, defeated, to 
the narrow belt of coastal area possessing mild and moist con- 
ditions, or of accommodating themselves to the new conditions. 

They had the hungry, sandy soils upon which to make 
experiments and they possessed a stock of essential oil glands 
in the leaves, and other parts of the plants, wherewith to 
check excessive transpiration during the slow desiccation of 
Australia. Like the Leguminosee and the Myrtacee, they 
made use of the great areas of hungry, sandy soils, and by a 
gradual process of reduction in size of the individual from 
trees to shrubs, to undershrubs and herbs, they produced the 
large endemic tribe Boronieze with 18 genera and about 180 
species. The leaf surface was also much reduced, and the 
primitive luxuriant pinnate leaf has been changed in Boronieze 
to small, simple, trifoliolate, or rarely pinnate types. 

The sandy wastes and the sandstone areas contain nearly 
the whole of this large endemic tribe. 

In. South Africa, a similar development took place, where 
the old luxuriant Xanthoxylee produced the large endemic 
tribe Diosmeze in 3 subtribes, the number of genera being 11 
with from 185 to 200 species. As in Australia the development 
took place mainly on the hungry, sandy tracts of land lying 
within the temperate region and the resulting endemic tribe 
is markedly xerophytie. Each country presents a remarkable 
example of the local development of secondary types from the 
primitive Xanthoxylee in hungry, sandy soils in dry hot 
summer regions, the areas being isolated, however, during the 
parallel evolution. As in Australia also the secondary types 
were shrubs, undershrubs, and rarely herbs. 

In tropical America, another endemic tribe, namely Cus- 
pariez, was developed, with about 16 genera and with 85 to 
90 species. 

In the fertile and warm areas of Eastern Australia the 
primary Xanthoxyleee developed about 5 endemic genera, but 


202. EC. Andrews—The Geological History of the 


with the exception of the oligotypie Melicope, these genera are 
practically monotypic and quite unlike the aggressive and 
vigorous Boronie. 

-In the northern hemisphere another tribe, the Rutex, was 
developed, but whether these were hardy secondary types of 
Xanthoxylez or a northern modification of another tribe, allied 
to Xanthoxylez, the writer is unable to say, owing to non- 
acquaintance with the tribe Rute. 

The Toddalez and the Aurantiaceze might, perhaps, for the 
purpose of geographical distribution, better be considered as 
separate families, much as Stellate, in Rubiacez, would be 
considered better as a family distines from Raub eee 

The Malpighiaceee, Meliacee, Burseraceer, and Simaru- 
baceze, are all close allies of Teuedees and their distribution is 
similar to that of Rutacex, except that the Rutacee with their 
essential oil content have been more elastic in accommodating 
themselves to harsh extr atropical conditions. 

Similar evidence is supplied by a study of the Euphorbiacez, 
Labiate, Verbenacez, Sterculiacee, Sapindacez, Apocynace, 
Asclepiadaces, Pittosporacex, Mrementdwacers Liliacez, Orchi- 
dace, and other families. The remarkable cases of the 
Proteacezee and the Epacridaceze are considered subsequently 
under other heads. 

In nearly every case it has been the hungry, sandy soils 
which have formed the areas on which the distinctive develop- 
ments have been conducted during the climatic zoning after 
the isolation of Australia. In every case the primary types 
are luxuriant and cosmopolitan in the tropics; in almost every 
ease the endemic tribe, genus, or species, has been dependent 
for its existence, or its development, on the hungry, sandy soils. 
In nearly every case the development has been markedly 
extratropical, and in every case the new groups, whether 
myrtaceous, leguminous, rutaceous, euphorbiaceous, verbena- 
ceous, lamiaceous, or other angiospermous form, is xerophytiec. 
In every case the tropical family from which the xerophytes 
have sprung has possessed some peculiar virtue, or principle, 
by which the family has been enabled to survive during the 
gradual process of desiccation, and during the interval neces- 
sary to reduce the tree size, the form, the leaf area, and so on. 
In the Legumes it was the ability to dispense with leaves, the 
ability to develop gums, and so on; in Myrtacez it was the pres- 
ence of much essential oil, the development of capsular fruits 
and the reduction of leaf and of plant size; in Rutacez, it was 
the presence of abundant essential oil; im Euphorbiacee, it was 


~ 


Australian Flowering Plants. 208 


the presence of a latex and the ability to modify the leaves 
and stems; this is also apparent in the Apocynacez and the 
Asclepiadacez ; in Verbenacez and Labiate, it was the presence 
of essential oils and the special provisions in the leaves against 
excessive transpiration. In Sapindacez and Sterculiaceze it was 
the presence of viscid substances as also special provisions in 
the leaf and the root. In Liliaceze and Orchidacez it was the 
bulb, the peculiar leaves, and the development of the herbaceous 
habit which helped so materially in the growth of the great 
endemic genera. In the Apocynacez and Asclepiadacee, how- 
ever, the plants were not equipped so well to face the cold, and 
as with Myoporinacez, they are not so much to be found on the 
extratropical sandy soils as on the more tropical subarid areas. 

In each ease they are the vigorous, numerous, aggressive, and 
many-specied genera of Australia, which appear to chafe at the 
limits which the Australian island continent has placed upon 
them and which appear to demand new territory in which to 
develop still further; in other words, they act as though they 
were new and aggressive types, born of a common necessity. 

With the rare exceptions mentioned above these great genera 
occur together in any of the large sandy areas of temperate 
Australia and those types, in the genera Hucalyptus and Acacia, 
which are to be found on the rich heavy soils may be seen, by 
their morphology, to be more highly specialized, and to be more 
recent in their origin, than the great mass of the sandstone flora 
types. In no case has any large genus, any subtribe, or any 
tribe, of Australia been produced away from the barren sandy 
wastes ! 


(5) Huphorbiacee, Labiate, Verbenacee, Pittosporacee, Treman- 
draceew, Inliacee. 

EHuphorbiacee. In this great family, the sandstones pro- 
duced the endemic tribe Stenolobez with 11 genera, and about 
80 species, and as with all the other great families in Australia, 
no other endemic tribe, subtribe, or large genus of this family, 
was developed except on the peculiar hungry sandstone areas 
of Australia. 

Labiate. In this great family the hungry sandstone areas 
practically possess the whole of the endemic tribe Prostan- 
thereze with 5 genera and about 100 species. 

Verbenacee. The tribe Chloanthex here included is endemic 
with 10 genera and about 40 species, all being practically 
limited to the sandy soils and as with the Labiates and other 


Am. Jour. Sct.—FouRTH SERIES, VOL, XLII, No. 249.—Srepremper, 1916. 
14 


204 FE. OC. Andrews—The Geological History of the 


families here described almost all are small shrubby xerophytes 
with special devices for conserving moisture. 

Sterculiaceew. Here the tribe Lasiopetalez with 7 genera and 
about 70 species, almost entirely endemic and markedly xero- 
phytic and mostly on the poor lands of Western Australia. A 
monotypic genus and one or two doubtful species in this tribe 
are said to occur in Madagascar. Other large xerophytic and 
endemic genera belonging to this family also occur in Australia. 

Pittosporacee. This family has 9 genera, and about 110 
species. Of these Pitlosporwm is a large luxuriant type with 
about 70 species spread over the old world tropics and the mild 
and moist extratropical areas in Australi. and New Zealand 
(an exception in the xerophyte P. phillyraoides), the other 8 
genera are endemic in Australia and are mainly xerophytes on 
waste or open spaces or on hungrv sandy areas. 

Tremandracee. This is a small family endemic in Australia 
allied to the Pittosporacez, containing 3 genera and about 25 
species. All are xerophytes and of depauperate type, almost 
confined to barren sandy wastes in extratropical Australia. 

Inliacee. This large family possesses many tribes and sub- 
tribes endemic in Australia, all as depauperate and xerophytic 
types and confined almost entirely to the extratropical barren 
sandy wastes. 


(‘Tribe Xerotexw, 3 genera. Between 30 and 40 species. 
The | Xanthorrhew, 2 genera. About 15 species. 
ree “  Calectasiez, 3 genera. About 3 or 4 species. 
Tribes re Flagellariex, 1 genus (monotypic). 
Endemic “  Drymophilex, 1 genus (monotypic). 
“  Hemerocallidee, 1 genus (oligotypic). 


The tribe Johnsoniez is endemic with 5 genera and about 20 
species. 2 subtribes are endemic in the tribe Melanthacez with 
3 genera and 6 species. 1 subtribe is endemic in the tribe 
Anthericeze with 5 genera ane 40 species. 


(6) Orchidacee. 

In this vast family about 48 genera are found in Australia. 
Of these about 20 genera are practically Australian with about 
160 species. In many of the genera, however, outliers occur 
in New Zealand. These remarkable genera, mainly peculiar to 
Australia, are not epiphytes but occur as very small plants with 
bulbs deeply set in the barren sandy soils, especially of extra- 
tropical Australia. It would appear that the older luxuriant 


Australian Flowering Plants.’ 205 


epiphytes had become terrestrial owing to the severe and harsh 
climatic conditions existing in the extratropical sandy wastes of 
eastern Australia. In short the trees no longer afforded them 
the necessary protection, whereupon they descended and were 
preserved in the sandy wastes by the development there of new 
xerophytic genera. 

Of the 48 genera in Australia, 28 genera, comprising one- 
third of the total number of species, including the whole of the 
tribes Malaxidezx, Vande, Bletidex, Arethusez, the first group 
of Neottidez, and the Ophrydez, belong to the tropical Asiatic 
Flora represented in Australia by endemic or, frequently, by 
identical species. These are all tropical or eastern, some 
extending down to Tasmania, but none found in West Aus- 
tralia; five of these genera are also in New Zealand. The 
remaining 20 genera, comprising two-thirds of the species, are 
essentially Australian, belonging to three Australian groups of 
Neottideze; four of these genera are, however, represented by 
single or very few species in the Indian Archipelago and eleven 
have New Zealand congeners, sometimes identical in species.7? 

This closes the case for the Tropical Problem. When the 
South African Problem shall have been discussed in connection 
with the distribution of the families Proteacez, Epacridacesze, 
Composite, Campanulaceze, Lobeliaceze, Goodeniacez, and Can- 
dolleaceze, it will be evident that the general position in the plant 
world of the endemic Australian vegetation will be even more 
apparent than it is already from the present brief statement of 
the Tropical Problem. A careful consideration of the evidence 
here adduced, however, in which the widespread existence in 
the fertile tropics of luxuriant primary types, distributed 
among vast genera, 1s evident, with the great local developments 
of secondary xerophytic and depauperate forms in these families 
within the great sandy and barren wastes of countries, such as 
extratropical. Australia and South Africa, the genera being 
endemic in each country with very few exceptions, the morpho- 
logical relations between the local, secondary types in the 
several countries being less than between each secondary type, 
the cosmopolitan primary types moreover of the tropics and these 
endemic genera constituting the whole? of the great genera of 
Australia, the same genera being also extremely hardy, vigorous, 
and aggressive, leads to the inevitable conclusion that the vast 
genera of the tropics have developed their existing species in 
situ after the isolation from each other of the old mild and moist 


*1G. Bentham, Flora Australiensis, vol. vi, pp. 268-269, 1873. ~ 
* Excepting the Proteace, Hpacridacee, Goodeniacee and Candolleacee, 
about to be described. 


206 £0. Andrews—The Geological History of the 


regions in America, Australia and Africa and Asia, and that 
the great endemic genera of Australia such as Hucalyptus, Hib- 
bertia, Backea, Pultenea, Daviesia, and the Australian phyl- 
lodineous development of Acacia, are local secondary types of 
the great primary cosmopolitan tropical types, which secondary 
types have been developed as xerophytes on the vast areas of 
sandy wastes in Australia, and have never migrated far from 
the old home, by reason of their isolation, and because, despite 
the vigorous and aggressive nature of these local types, they are 
xerophytes and could not find a suitable environment on the 
outlying islands which are possessed of mild and moist climates 
and “clad with jungle growths. 


(b) THe SourH-AFrRICAN PROBLEM. 


(1) General Remarks on Supposed Land Connections of South 
Africa and Australia. 

This problem has been considered already in some measure 

under the previous heading. In the present part the special 
case of the peculiar relations of the South African and Austra- 
lian vegetation is considered. 

It has been thought by some biologists that Sone Africa and 
Southwest Australia must have been directly connected long 
after the development both of the Monocotyledons and of the 
most complex families of the Dicotyledons, to wit, the Com- 
positee, say at the close of the Cretaceous Period, because the 
genera Helichrysum, Helipterum and Cassinia, in Composite, 
the genera Restio, Hypolena and Leptocarpus, in Restiacez, 
the genera Cesia, Wurmbea and Bulbine, in Liliacee, the tribes 
Protez and Persooniez in Proteacex, occur in both countries, 
while the family Ericacez is abundantly represented in South 
Africa, and the allied family Epacridaceze occurs mainly in 
extratropical Australia. 

But before proceeding with the main discussion it would seem 
advisable to confront this slender evidence of possible former 
direct connection of South Africa and Australia with the evi- 
dence of much greater weight on the other side. 

Thus the great family of the Myrtacez is almost absent from 
South Africa although it possesses very many genera and species 
in Australia, and although the Australian Myrtacez are exactly 
the types which might be expected to occur on the poor sandy 
soils of South Africa on the assumption of the existence of 
a land bridge directly connecting the latter country with 
Australia. 


Australian Flowering Plants. 207 


It may not be out of place at this stage to mention that 
there is at least a double expectation of types such as Huca- 
lyptus, Hakea, Persooma, and Banksia, in both South Africa 
and Australia, on the assumptions made by various biologists, 
firstly, that Hucalyptus forests and other growths now peculiarly 
Australian, were common in Cretaceous and Tertiary time in 
the north temperate regions, and that under the pressure of 
more aggressive types they were driven to Australia, and 
secondly on the assumption made by certain biologists that a 
land bridge directly connected South Africa and Western 
Australia. For, firstly, on the assumption that Hucalyptus 
originated in the Holartic region, as so many mammalian 
groups appear to have done,”* it should have retreated towards 
South Africa during the general expulsion from the north, of 
types unfitted to survive such as Hakea, Grevillea, Hrica, and 
Eucalyptus itself, much in the same way as we may imagine 
the Restiaceze, Proteaceze, and Podalyriez (Papilionacez), to 
have done. Hucalyptus belongs to a tribe which contains 28 
genera, with about 700 species, many of the genera being large 
and aggressive (Hucalyptus 300 species, Malaleuca 112, 
Beckea about 70). Another large tribe, namely the Chame- 
laucieze, is found growing side by side with the Hucalyptus 
tribe. Both are practically endemic in Australia, with the 
exception of a few specialized waifs in outlying islands. Were 
the genera of these tribes to be very few in number and were 
these rare genera in turn to be monotypic or oligotypic and 
specialized or archaic, with huge gaps in the continuity of their 
distribution, these assumptions of land bridges directly con- 
necting Southwest Africa and Southwest Australia might pass 
unchallenged, but when both the tribes and the genera are so 
vigorous, so admirably adapted to the soils and climate of the 
South African sand wastes, it is incredible that Myrtacez such 
as these should not have made use of one of the assumed land 
bridges constructed by biologists apparently for the special 
benefit of the Proteacese and Resticeze, whose greatest desire, 
if one may adopt this teleological form of speech, would appear 
to be to dwell side by side with the myrtle group in their strong- 
hold, namely Australia. But neither the genus Hucalyptus, nor 
any members whatever of the great and aggressive tribes Lep- 
tospermez and Chamelauciex, occur in South Africa! When, 
in addition, it is found that the fossil leaf determinations of 
the northern hemisphere cannot bear the searchlight of im- 


2 W. D. Matthew, Climate and Evolution, Annals New York Acad. Sci- 
ence, vol. Xxiv, pp. 171-318, 1915. 


208. C. Andrews—The Geological History of the 


partial botanical criticism, the necessity for the deletion of the 
genus Hucalyptus from the lists of Cretaceous and Tertiary 
flowering plants in the northern hemisphere must at once be 
evident. 

On the assumption also of a great land bridge which carried 
the Proteacez, Restiaceze and the Gnaphaliese (Composite) 
from Southwest Africa it is strange that the Epacridacee, 
which is a large family in Australia, could not use this bridge. 
This is especially strange, seeing that the Epacrids contain 
large and aggressive genera, which are inseparably associated 
with the Proteacez on the hungry sandy wastes of extratropical 
Australia. Moreover, the Epacrids are not decadent types, but 
on the other hand, they are vigorous and full of life. So also 
the very numerous Hricacex, with Hrica alone containing about 
470 endemic species in South Africa, should have got across 
to Australia if the sandy land bridge existed which is assumed 
to have allowed the Proteacez, Restiaceze and Gnaphaliez to 
cross. But Australia possesses not a single member of the 
vast South African tribe Ericeze nor does it possess any mem- 
ber even of the family Ericaceze save a very few types in the 
southeast which, moreover, do not occur in any form in South 
Africa and which are best explained in Australia as waifs from 
South America and a couple of species in North Queensland 
which are specialized outposts of northern hemisphere types. 

The Compositee also in South Africa on the poor soils possess 
two tribes, practically endemic, which might well be expected 
to have used the land bridge assumed for the Proteaceze because 
the sandy soils of Australia are excellently adapted to support 
such forms as Cryptostemma. Yet only one species of the tribe 
Arctotidez occurs in Australia, namely Cymbonotus, and, 
according to a personal communication from Mr. E. Cheel of 
the National Herbarium, Cymbonotus is not strictly a native 
of Australia and cannot in any way be separated from Arctotis. 
The Goodeniacez, the Candolleacez, the Casuarinacee and the 
Tremandracez, are also families with large, vigorous and 
ageressive genera all confined mainly to the sandy wastes of 
Australia, but without representatives in South Africa, except- 
ing a waif of Scevola. Yet these are just the types which 
should have used the sandy land bridge had it really existed. 

The Rubiaceze of the two countries also are not alike. 
Scarcely a family of flowering plants, outside those already 
mentioned, and the ubiquitous Cyperacee and Graminacee, 
show any close resemblance to each other in the two countries 


Australian Flowering Plants. 209 


excepting indirectly through the primary types of the cosmo- 
politan tropics. 

The nature of this assumed land bridge has been emphasized 
purposely here, because it seems that such bridge has been postu- 
lated without sufficient attention being paid as to its nature. 
The Proteacez of South Africa and Australia both flourish on 
the barren sandy wastes of these two countries in extratropical 
areas, and the few luxuriant types of this family which occur 
in the Australian brushes (jungle) belong to the suborder 
Folliculares, and have no counterpart whatever in South Africa. 
If then there did exist a land bridge which was used by the 
types of Proteacese common to South Africa and Australia, 
then it must have been a sandy waste, and one therefore which 
would have allowed a ready passage for the South African 
Composite, the Liliacee, the Ericacee (Ericer), and the 
Australian family Epacridaces, and the tribes Leptospermez 
and Chamelauciez in Myrtacee. And, again, in addition to 
this overwhelming evidence against the assumed existence of 
the land bridge after the development of the most complex 
types of flowering plants, there are the wonderful differences 
existent among the mammals of the two countries which must 
also be taken into account. South Africa possesses no mar- 
supials, whereas Australia has no placentals. The answer to 
this may be made that marsupials did migrate from Australia 
to South Africa along the old sandy bridge used by the Pro- 
teaceze, Restiacezee, Composite, and a few small genera in Lili- 
aceze, while other flowering plants which loved such sandy soils 
could only look, as it were, towards the promised land from 
the bridge without entering. It may be assumed also that the 
waiting carnivora ate the unsuspecting marsupials as they 
arrived in South Africa by way of the land bridge. The 
wonder, in a case such as this, is that the lions, tigers, hyenas 
and other carnivores, which may be supposed to have annihi- 
lated the marsupials in South Africa, did not follow such good 
food along the bridge to Australia and there in turn feast upon 
the defenceless wallaby, kangaroo, wallaroo, paddymelon, beilby, 
kangaroo rat, opossum, and allied types.* 

The evidence on the other hand suggests that the Proteacez, 
like the marsupials, flourished in the northern hemisphere and 
were driven to ‘dead ends” in South Africa and Australia, 
and there, in each country, on the sandy soils and under very 


*4See also in this connection an admirable paper by Mr. J. H. Maiden, 
entitled “Australian Vegetation,” Federal Handbook on Australia, B. A. 
A. §., Australian Meeting, 1914, by authority. 


210 EF. C. Andrews—The Geological History of the 


similar climatic conditions, and protected in each case by 
barriers from severe outside competition, they rapidly deployed 
into fresh tribes, and subtribes, with the production of great 
vigorous and aggressive endemic genera, genera also which have 
always been endemic. The absence of the placentals in Aus- 
tralia affords some measure of the duration of the period of 
isolation of Australia, while New Zealand was isolated much 
earlier. 

The cases of the Proteacee, Composite, Ericacese, Epacrida- 
ce, Campanulacexe (with Lobeliacez), Restiacez, and Liliacez, 
may now be discussed briefly. 


(2) Proteacee. 

This family is divided into 2 suborders and 7 tribes, contain- 
ing 50 genera and about 1,100 species. 

Of these, Australia has about 700 species, in more than 30 
genera in 7 tribes, in 2 suborders. New Zealand has 2 species 
in 2 genera in 2 tribes. New Caledonia has about 30 species 
in about 6 or 7 genera and several tribes. South Africa has 
about 275 species in 10 genera in 2 tribes, in 1 suborder. 
Tropical Asia has about 30 species in 1 genus in 1 tribe, and 
South America, mainly Tropical America and Chili, has about 
65 species in about 7 genera in a couple of tribes, in one sub- 
order. Although the suborders Nucumentacee and Folliculares 
are both abundant in Australia, the African species all belong 
to Nucumentacez and the Asiatic and American types all belong 
to Folliculares. 

Berry, in an important and comprehensive paper,”° supplies 
convincing evidence for the great radiation of the Proteacez in 
the mild and moist climate oe the Cretaceous, with survivals of 
the family to-day mainly in the southern hemisphere. Ben- 
tham?® was inclined to deny the existence of Proteacez as fossils 
upon general botanical principles and Engler?” wrote “Die 
fossilien, gefliigelten Friichte, wer fiir Samen der Proteaceen 
gehalten wurden, kénnen sich zu den Conifer, Meliacez, 
Sapindacex, gehdren.” The fossil fruits and leaves referred to 
by the various writers mentioned in the previous paragraph”® 


» BE. W. Berry, The Affinities and Distribution of the Lower Eocene Flora 
of South Eastern North America. Proc. Amer. Phil. Soce., vol. liii, no. 214, 
pp. 157-164, 1914. 

* G. Bentham, Presidential address, Linn. Soc., London, 1870. 

*7 Engler and Prantl, Pflanzenfamilien, III Teil, 1 Hiilfte. 

* Ettingshausen, Die Proteaceen der Vorwelt, Jahrbuch der K. K. geol- 
ogische Reichsanstalt, vol. i, Vienna, 1881. Ibid., Wiener Zeitung, 21 
March, 1880. Entdeckung des neuhollindischen Charackters der Eocenflora 
Europas, Vienna, 1862. Unger, Neuholland in Europe, Vienna, 1861. Saporta 
(Marquis de), Flore fossile du Portugal, Lisbon, 1894. Newberry, J. S., 
Fossil Flora of the Amboy Clays, United States Geol. Survey, Washington, 
1894. Berry, E. W., op. cit., pp. 157-164. 


i) 


Australian Flowering Plants. 211 


have been considered by some botanists as belonging to Hakea, 
Grevillea, Persoonia, Banksia, Dryandra, and allied types. 

Although agreeing with Berry in his contention that the Pro- 
teaceze were at one time luxuriant types in the northern hemi- 
sphere which were driven south at a later period, it is impossible 
to review the evidence past and present without coming to the 
conclusion that Hakea, Persooma, Grevillea, Banksia, Dry- 
andra, Protea, Leucondendron, and other allied types, never did 
exist in the northern hemisphere, but that they arose in the 
south as xerophytic developments of older widespread Creta- 
ceous types. In Australia and Africa such genera as are enum- 
erated here are all vigorous, hardy, specialized, aggressive, and 
xerophytic. They avoid the Australian and African jungles; 
they avoid all mild, moist, and sheltered positions; and they 
occur as highly specialized forms on the sandy barren waste of 
the two countries under consideration. Xerophytic Myrtaceze, 
Composite, Leguminosee, Ericacez, Epacridaceze, and Lilacez, 
are their special associates, nevertheless like Hucalyptus, Mela- 
leuca, Hrica, Leucopogon, Goodena, Candollea, Hibbertia, and 
Pimelea, they appear to strain at a leash as though eager to 
people new lands if only their large island home should be 
connected by large barren sandy wastes with other countries. 

It seems permissible to infer that the development of the 
Proteaceze appears to have begun in the great northern lands,— 
but it is difficult to decide upon which suborder was the earlier. 
The Nucamentaceze have the more regular perianth, but the 
Folliculares also have many genera with regular perianths. 
The high specialization, however, of certain genera such as 
Hakea, Grevillea, Banksia, and Dryandra, in Folliculares, 
especially with respect to their anthers, which are sessile upon 
the perianth segments above the tube, together with the 
irregular perianths of Grevillea and Hakea suggests the rela- 
tive recency of such highly specialized genera and, moreover, 
it would appear that they are vigorous and aggressive genera 
because of such specialization. 

.The primitive type appears to have been a large tree of 
luxuriant habit, with regular perianth, free stamens unattached 
to the perianth tube, and with large pinnate, compound, or 
lobed leaves. 

With the zoning of the climate, and the development of 
aggressive plant types in the northern hemisphere, these Pro- 
teaceee were gradually driven south, while the tropical types 
became more and more superseded by the more complex Sym- 
petale, Dialypetalee and the Monocotyledons. The sandy wastes 


2120 ELC. Andrews—The Geological History of the 


of extratropical Australia and South Africa offered a home to 
these trees, and, thus, during the long gradual differentiation 
of the climate, the trees became smaller, and they developed 
marked xerophilous characters; and in proportion as the types 
became specialized and reduced in size or dwarfed, so did such 
types become vigorous and aggressive as Grevillea, Hakea, 
Petrophila, Isopogon, and Persoonia. 


(3) Composite. 

The problem of the development of the Composite as also 
of the Ericacer, Epacridaceze, Campanulacee, Lobeliaceee and 
allied types, might be considered equally well under the heading 
“The South African Problem” or the ‘“Northern-Hemisphere 
Problem.” 

In South Africa and Australia the following genera are 
common : 


Australian Species. South African Species. 
Senecio 30 200 
Gnaphalium 7 8 to 10 
Helichrysum 70 | 140 to 150 
Helipterum 53 12 
Cassinia - 13 1 
Athrixia 4 6 
Cotula 8 22 


Of these Senecio and Gnaphaliwm are cosmopolitan, Heli- 
chrysum has 26 species in Tropical Africa, 40 species in Mada- 
gascar, and the genus also extends into North Africa, Europe 
and Central Asia. Helipterum may be considered as a sub- 
genus of Helichrysum for the purpose of distribution. Cas- 
sima may be discarded as doubtful or as a waif, while Cotula 
has also six species in Europe and Asia. As against this 
resemblance with Helichrysum, Helipterum and Athriaia, the 
absence from Australia of the whole of the two South African 
tribes, Calendulacez and Arctotidez, may be cited. 

It would perhaps be advisable to preface the accompanying 
brief notes of the probable origin of the Composite in Australia 
and South Africa, by mentioning the distribution of the asters, 
the daisies, and the groundsels, as set out by Bentham in his 
monograph on the Composite. 

Aster in the broader sense comprises the true asters of the 
northern hemisphere and a few genera almost inseparable from 
it except in habit which occur in the southern hemisphere and 
in Hawaii. 


Australian Flowering Plants. 213 


The true asters number 300 species and are herbaceous, lov- 
ing cold countries, crossing the Equator only as one species on 
the high plateaus of Africa. Closely allied to the asters is 
Olearia (110 species) in Australia and New Zealand, not herbs, 
but generally shrubs or undershrubs with a few trees of moder- 
ate size. The shrubby South African Felicia, with about 50 
species, is exceedingly close also to Olearta and Aster while the 
arborescent Chiliotrichium of 3 or 4 species in Chili and the 
arborescent to shrubby Diplostephiwm of about 20 species in 
the Andes, are also very close to Olearia and Felicia. The 
arborescent genera Comnudendron (3 species) and Melanoden- 
dron (1 species) also in St. Helena are scarcely separable from 
Diplostephium in South America. The aster type is absent 
from the tropics except on the high plateaus. 

Erigeron, Celmisia, Tetramolopium, Vittadima, and Ter- 
ranea, form a group very similar in distribution to the asters. 

The daisies also have a peculiar geographical distribution. 
Bellis with about 5 species, in Europe and North Africa, 
Astranthium 1 or 2 species in America, Seubertia, 1 species in 
the Azores, Steirodiscus with 2 species in South Africa, are 
all practically identical as genera with Brachycome which pos- 
sesses 40-45 species in Australia, the tropics having no member. 

Calotis (17 species in Australia), Belliwm (3 species in 
Europe), Keerlia (2 species in Mexico), Garuleuwm (3 species in 
South Africa), and Minuria in Australia are exceedingly close 
both to each other and they are close also to Bellis. 

The Groundsels. Senecio contains 1,200 species and is “‘cos- 
mopolitan and ubiquitous” (Bentham). It abounds “in local 
species in almost every region of the globe, in the Old and in 
the New World, from the Equator to the arctic regions and the 
extreme south, on Alpine summits, in stony wastes or sandy 
deserts, im swamps, on sea coasts, on the borders of streams... 
yet individually the species have not wide areas. No species 
is common to the New and the Old World, except in the far 
north no one has... . its range interrupted by any considerable 
interval.’’?° 

Although the majority of the northern hemisphere Compositz 
are herbaceous, as are those also of the deserts and subarid 
wastes, nevertheless the southern hemisphere and the oceanic 
islands preserve many arborescent forms representing all 
the larger tribes such as Asteroidez, Senecionidee, and 
Helianthoidee. 


*G. Bentham, The Composite, Journ. Linn. Soe. London, Botany, vol. 
xlil, p. 456, 1873. 


214 E. C. Andrews—The Geological History of the 


The Composite favor the open spaces and rocky wastes of 
the world and avoid the dense jungle and thicket growths. 

It seems permissible to infer that the ancestor of the com- 
posites was a tree which possessed opposite leaves, pinnate or 
compound, a compacted flower head possessing only dise florets 
with free anthers, flowers regular, but the plant possessing a 
tendency early to xerophytism somewhat similar in point of 
time to that exhibited by the primary type of Acacia. These 
plants flourished in the open places of the world, during the 
Cretaceous. As the seas were drained off the lands, and as the 
climate became differentiated the ancestral types forsook the 
low tropical lands, because in the first place they were not 
adapted to compete with the dense growths of the tropics, and 
because the deserts in the tropics were too dry and hot for the 
old lover of the well-watered but open spaces. As the lands 
became isolated one from the other local differentiation ensued, 
the old trees were weeded out in the north as the severe climatic 
conditions of the late and post-Tertiary approached and vigor- 
ous aggressive herbs were produced, which commenced to work 
their way south along the mountains and high plateaus. 

The old tree Aster was among this group. In Australia the 
arborescent form was reduced in size and a shrubby habit was 
developed. From this the genus Olearia with 110 species in 
Australia and New Zealand was derived. In South Africa 
as in Australia, the old Aster had to face a gradual desiccation 
of climate during the isolation of South Africa, and the shrubby 
Felicia of 50 species was developed. In Chili, the old form 
was modified to the arborescent Chiliotrichium, so also in the 
Andes the arborescent genus Diplostephium was formed, while 
in St. Helena, the arborescent Commidendron and Melanoden- 
dron are closely related to the old widely-diffused tree-Aster. 
In the northern hemisphere the arborescent form was destroyed 
and a vigorous aggressive and cold loving herb was produced 
which worked its way south to the Equator in Africa. The 
evolution of Bellis, Brachycome, Astranthium, Seubertia, 
Garuleum, Keerlia, Beliium, Calotis, Minuria, and Vittadinaa, 
was somewhat similar to that of the asters, except that the 
plants were herbs at an early stage during some differentiation 
earlier than the Eocene, and that they are a decadent race, 
except in Australia and the Mediterranean and, moreover, they 
were not adapted to cold conditions so much as to barren, sandy, 
and open conditions in climates not really cold. 

Senecio, like the Aster, appears to have its primary form as 
a tree, but it is a form which, like all other of the Composite, 


Australian Flowering Plants. 215 


has become more and more herbaceous and correspondingly 
ageressive with the progress of time, and it appears to have 
adapted itself to stony and mountainous, as also to cold 
conditions. 

The more the flowering plants are studied the more is the 
conclusion forced upon the student that many types have passed 
through two periods of climatic differentiation, the one prior 
to the great isolation of Australia, the other after the Eocene, 
or after the great isolation. The first differentiation appears 
not to have become so marked as the second. It has been 
pointed out, however, that the xerophytic angiosperms just dis- 
eussed could be explained on the assumption of deserts through- 
out Cretaceous and Tertiary time with a great zoning of climate 
in past Eocene time. 

It seems permissible to regard the earlier Senecios as trees, 
which frequented the open places and which loved moisture. 
These arborescent forms appear to have populated all the great 
land blocks before the isolation of Australia from Southern 
Asia, and the herbaceous habit also appears to have been 
developed among some of the species even before the isolation 
was complete. After the great isolation and the gradual dif- 
ferentiation of climate the Senecios were unable to make much 
headway in Australia owing to their greater preference for 
moist, cool places and their inability to flourish well within hot 
arid regions. In New Zealand they flourished in the moist, 
cool climate and the old arborescent habit is preserved in some 
species. Hawaii, and Juan Fernandez, illustrate in some 
measure the primary tree type. 

It was in the northern hemisphere, however, that Senecio 
made its great and aggressive response to the cold changes both 
towards, and during, the Glacial Period. Over Eurasia and 
North America the new race spread rapidly, nor did it cease 
to travel until it reached the Magellan Straits where its prog- 
ress farther was stayed. In the cold climate of the Chilian 
heights and of the country about Magellan Straits, however, 
it became strongly developed, about 260 species having been 
recorded thence. (Carl Reiche, Flore de Chili.) 

In South Africa on the poor plateau soils Senecio made a 
magnificent response (200 species) to its environment. 

The Everlastings. The case of Helichrysum and its allies 
may now be considered. These all belong to Inuloidezx, a tribe 
with many genera and species but decadent in great measure, 
although possessing a large and vigorous offshoot from the old 


216) =—E. C. Andrews—The Geological History of the 


more or less withered stock of the tribe, namely, the great sub- 
tribe, Gnaphalier. 

Gnaphalium, close to Helichrysum, is a cosmopolitan, and 
favors the tropics. The Helichrysum, or everlasting, group 
favors waste stony and sandy localities outside the cold regions. 
A study of the Australian types such as Helichrysum and Cas- 
sinia suggests that the early forms were trees favoring open 
places. A study also of the distribution of the Helichrysez 
suggests that they are a branch of Gnaphaliew which arose as 
warmth-loving types during the first great differentiation of 
climate and which spread thence to Australia, Africa, and New 
Zealand. As time progressed, and as the severe conditions of 
the middle, later, and post-Tertiary approached, they took 
refuge, in great measure, on the sandy barren wastes of Aus- 
tralia and South Africa, soils which had also been the salva- 
tion of the Proteacez, the Ericacee, Epacridacere, Legumi- 
nose, Myrtaceze, and many other families. In proportion as 
the arborescent form was discarded, and the herbaceous habit 
adopted, so did the types succeed in hfe. In the northern hemi- 
sphere they were not as successful as in the southern because, 
unlike Senecio and Aster, they were not adapted to the cold cli- 
mate so much as to the drier, sandy and stony wastes in warmer 
climates. The great display of Helichrysum and Helipterum 
both in South Africa and temperate Australia does not, there- 
fore, demand the existence of a dvrect land connection between 
the two so much as it demands an old land connection between 
them by way of the tropical regions, the sandy barren wastes in 
each of the southern areas acting as a place of refuge to these 
types. 


(4) The Ericacee and the Epacridacea. 

These related families appear to have had two, if not more, 
distinct periods of revival, the one before the great isolation 
of the larger land blocks, the other during the great differentia- 
tion of climate culminating in the Glacial Period. 

Both belong to the Sympetale. The Ericaceze possess 8 or 
10 stamens, all free, the anthers generally opening in pores 
and possessing appendages in many instances, while the Epacri- 
dacez have 5 stamens generally attached to the corolla tube, 
the anthers are only 1 celled, and they open in longitudinal 
slits, although a more primitive type (Prionotes), has its 
anthers two-celled. The venation is very peculiar, consisting 
of parallel nerves, very suggestive of monocotyledonous forms, 
while the Ericacez possess penniveined leaves. 


Australian Flowering Plants. 217 


The Epacridacee are peculiarly xerophytic, having leaves 
either small terete, acicular, pungent, grooved, thick or hard, 
and they are trees, shrubs, or undershrubs, which are confined 
principally to moist situations on the barren sandstones of extra- 
tropical Australia. They are as much an integral part of the 
indigenous, endemic, xerophilous, flora of Australia as are the 
Proteacex, and the Myrtacez. 

Erice, in Ericacex, has its stronghold on the sandy barren 
wastes of Southwest Africa. Hrica is only one of the many 
allied genera in that country, Hrica itself, however, possessing 
there nearly 500 endemic species. This genus, however, does 
not favor wet situations as much as the Epacrids do. From a 
consideration of the distribution and the morphology of the 
families, it would appear that both families sprung from com- 
mon ancestral types which were luxuriant trees, especially in 
the great northern lands, and in the tropics possessing leaves 
either nerved or penniveined, stamens free, anthers 5 to 10, 
with two cells opening longitudinally in slits and without 
appendages. 

In the first great radiation these types reached Australia 
and South Africa. After the isolation of Australia and South 
Africa they retreated to the sandy wastes of the two countries. 
In Australia they became the Epacrids, in South Africa the 
Erieas. In each country they developed a great crop of vigor- 
ous and aggressive genera. During the second great differentia- 
tion of climate in the northern hemisphere, the other large tribes 
of Ericaceze became strongly developed in the cold countries 
contemporaneously with Senecio, Aster, and other types, in 
Composite. 

The newer cold types of the north, as Gaultheria, travelled 

.south during the Glacial Period to the extreme south of 
America. Waifs thence were carried by the great westerly 
drift or by other means to Australia and New Zealand, develop- 
ing in those countries a very few individuals belonging to two 
or three genera. (Gaultheria, 3 species, Pernettya, 2 species. ) 
The genus Wittstemia, one species only and belonging to the 
tribe Arbuteze, may be a waif, or it may be a relic of the old 
Cretaceous radiation. 


(5) Campanulacee (with Lobeliacee, and allied families). 

The Campanulacez and its allies are good examples of the 
two-period differentiation of climate. From an examination 
of Campanulacez, Lobeliacese, Goodeniacex, and Candolleaceze 
generally, and of the peculiar arborescent Lobeliaceee of Hawaii 


218 EL C. Andrews— The Geological History of the 


(Clermontia 11 species, Rollandia 6 species, Delissea 7 species, 
Cyanea 28 species), the arborescent Scelerotheca of Tahiti and 
Raratonga, A peth ia of Raiatea, the remarkable tree Lobelias of 
Hawaii, Abyssinia, and Central Africa, and the arborescent 
forms in America, it would appear that the early forms were 
trees which loved moist open spaces, the trees possibly without 
milky juice. 

In the Cretaceous Period the primary types found their way 
into Australia, and during the first differentiation of climate, 
probably during the Cretaceous Period, the arborescent types 
became more and more herbaceous and found their way into 
Australia, South Africa, and other countries, as the genus 
Lobelia, and allied forms. The ancestor of Campanula and 
Wahlenbergia also found its way round the world about this 
period. 

The oldest forms have produced the remarkable and special- 
ized Goodeniacee and Candolleaceze which arose in Australia 
on the barren, sandy wastes, after the great isolation of Aus- 
tralia and after great modifications had taken place in the 
stigma and filaments of the primitive type in Australia. In 
the northern hemisphere the ancestral types were driven out 
and all that we know of the middle era of the race after the 
differentiations into Campanulaceze and Lobeliaceze with milky 
juice, are the peculiar arborescent genera above mentioned, 
which are not actually perpetuations of old time genera, so 
much as they are newer genera allied to the older Lobeliaceze 
and which have been evolved locally in response to their later 
environment of sandy waste in the peculiar climate of 
Australia. 

After the isolation of the northern hemisphere and the cli- 
matic differentiation of post-Eocene time, Campanula appears 
to have been developed in the north, and Wahlenbergia in the 
south. The latter became aggressive and penetrated the north 
at a later date much in the same way as Hrica had done among 
the heaths. 

The Goodeniaceze with an indusium to the stigma and the 
Candolleaceze with filaments and and pistil united into a column 
appear to be magnificent examples of ancestral types which, 
after retreating as arborescent forms from more favored sur- 
roundings in the north to a “dead end” in Australia, gradu- 
ally developed the herbaceous habit on sandy and stony wastes 
which were subject to long, dry, hot spells. In the fullness of 
time these became hardy, vigorous, and aggressive types which, 
like Wahlenbergia and Lobelia of older and more northern 


Australian Flowering Plants. 219 


origin, are ready now to overrun the world, but which are 
limited in their range because of the ocean encircling Aus- 
tralia. Waifs, however, have survived the sea voyage in cer- 
tain cases, for example—(roodema with about 115 species, 

Candollea about 115 species, Scevola about 70, and Dampiera 

35-40 species, and the individuals are exceedingly abundant on 
the sandy wastes of Australia. 

The history of the Campanulacez, in the broader sense, is 
somewhat analogous to the history of the human races which 
reached East and South England as conquerors, and which after 
a time became less vigorous and were in turn thrust northward 
and west by the indriving of new wedges of invasion. In the 
barren wastes to which they were driven, and the consequent 
enforcement of laborious days, together with the elimination 
of luxury and pleasure, magnificent revivals were brought 
about and later days of courage and ability among the old 
exiles who, although beaten aw discouraged awhile, now take 
their place again in the front of the world’s progress. 


(c) Tue SoutH AMERICAN PROBLEM. 


(1) General Remarks on Supposed Land Connections. 

The question of the possible land connection, or connections, 
between South America, New Zealand, Australia and Tasmania, 
has formed one of the most difficult but fascinating problems 
ever faced by students of geographical distribution from the 
time of Hooker®?® and Bentham** in England to that of 
Hedley®? of Australia. 

Hedley, one of the foremost of the present advocates for 
the Tertiary, or post-Tertiary, land connection of the areas 
under consideration with Antarctica, has stated his case simply 
and forcibly in the two papers cited above. 

There are about 88 genera and 68 species of flowering plants, 
confined, almost entirely, to South America, the Antarctic 
Islands, Australia, Tasmania, New Zealand, and the neighbor- 
ing islands. The Beeches (Nothofagus), the fuchsias (Fuch- 
sia), the Arauearias (Araucaria), Discaria, the section Psycro- 
phila of Caltha, Oreobolus, Uncima, Colobanthus, Ourisia, 
Azorella, Hpilobium, Acena, Aristotelia, as also the species 
Geramum sessiliflorum, Oxalis magellanca, Tillea moschata, 
Tillea verticillata, Juncus planifolius, Gentiana  saxosa, 


J. D. Hooker, Journal Botany, London, vol. iv, p. 137, 1845. 

*G. Bentham, Flora Australiensis. Concluding Preface, vol. vii, 1878. 

*C. Hedley, Surviving Refugees in Austral Lands. Proc. Roy. Soe. 
N.S. Wales, vol. xxix, pp. 278-286, 1895. The Paleogeographical Relations 
of Antarctica, Proce. Linn. Soc. London, Oct., 1912, pp. 80-90. 


Am. Jour. Sct.—FourtH Srries, Vou. XLII, No. 249.—Szepremper, 1916. 
15 


2200 E. O. Andrews—The Geological History of the 


Sophora tetraptera, and Huphrasia antarctica, are amongst the 
most noted in this connection. The struthious birds, as the 
Rhea (S. America), the Ostrich (Africa and Asia), the Casso- 
wary (North Australia), the Emu (Australia), the Moa (New 
Zealand), and the Epyornis (Madagascar), are also cited as 
evidence of former land connections between these regions. 
Placostylus, among land shells, the earth-worms, the reptiles, 
the marsupials, and other animals, are also cited as proof of 
former land connections. 

It has been found difficult to diseuss this most interesting 
and complex problem with justice from the point of view of 
the distribution of the animals, nevertheless it is just from the 
animal distribution that the strongest case is said to have been 
deduced for a former direct land connection between the vari- 
ous areas under consideration. The construction of the hypo- 
thetical continent Antarctica reaching arms of land to the 
southern land masses of South America, South Africa, Aus- 
tralia and New Zealand, and acting as a developing ground 
for the life forms common to the areas under consideration, 
is undoubtedly a most suggestive conception, and one which 
especially in the form in which Hedley has stated it, appears 
to be quite convincing from so many points of view. On the 
other hand it would be advisable to indicate some of the dif- 
ficulties in the way of accepting this idea which have been 
suggested to the writer by a study of geology and botany. 

As a preparatory step, however, it might be advisable to dis- 
pose of some of the general objections raised against this doc- 
trine, which has been so suggestive and so full of promise to the 
investigator. It is considered by certain biologists that the 
plants and animals said to be common to South America, South- 
eastern Australia, South Africa, and New Zealand, need no 
direct land connections to explain their peculiar distribution 
but that they are to be explained rather as similar biological 
responses to similar environments. That is to say, the mar- 
supials, the struthious birds, the pine trees, the beech trees, 
and the other forms common to these regions arose indepen- 
dently in each country as a response to a similar geographical 
environment. 

Let us, in this connection, consider the case of the families, 
genera, and species, identical in South America, Australia, and 
New Zealand. The number of families of flowering plants is 
about 250, nevertheless the possible number, probably, is legion. 
Let us assume, however, that 250 is the limiting number. The 
possible number of genera in a family is immense, as is at 


Australian Flowering Plants. 221 


once apparent from a consideration of the doctrine of permuta- 
tions and combinations. Let it be assumed, however, that a 
family may have only 1,000 genera, and furthermore let it 
be assumed that each genus may have only 2,000 species. Then 
because the South American and Australian continents have 
few points in common beyond the fact that each is in the 
southern hemisphere, the chance that a particular family of 
flowering plants should arise independently in each country 
is somewhat similar to the chance that a die with 250 faces 
and thrown fairly into the air, should fall down with any par- 
ticular face uppermost. But there are 250 ways in which this 
may be done, therefore the chance is only 1 in 250. Simi- 
larly the chance that a particular genus should arise inde- 
pendently in each country in such a particular family would 
be similar to the chance of two particular faces on two dice 
falling uppermost if the dice were thrown fairly, the one with 
250, the other with 1,000 faces. But the odds are 250 to 1 
against one particular face turning up on the one die if thrown 
by itself and the odds are 1,000 to 1 against a particular face 
turning up on the other die, therefore the odds against both 
of these particular faces falling uppermost when the two dice 
are thrown together is 250,000 to 1. Similarly the chance 
that a particular species should arise in two countries inde- 
pendently, all other things being equal, is somewhat similar to 
the chance that a particular face on each of three dice, one 
of 250 faces, one of 1,000 faces, and one of 2,000 faces, should 
fall uppermost if thrown fairly into the air. But the odds 
against this are 250 x 1,000 x 2,000 or 500,000,000 to 1, and 
the chance that two identical species should be evolved 
independently in each of two isolated countries would be 
only 1 in 250,000 billions. And the chance that 80 genera and 
60 species should be evolved independently would be infinitely 
more remote than the vanishing chance already mentioned. 

On the other hand, it is well known that plants are con- 
tinually being transported by winds, sea currents, by birds, and 
by man, from various lands to other lands, and, moreover, 
geology teaches us that, in the past, various land masses have 
been directly connected to each other. Identity of families, 
genera, or species, therefore, are more simply explained by con- 
sanguinity of origin than by the assumption of multiple origins. 
The present distribution of the plants and. animals in Aus- 
tralasia, New Zealand, South Africa, South America, and the 
Antarctic Islands, is, therefore, concerned rather with the rela- 
tive merit of certain hypotheses of transport or of migration, 


222 EC. Andrews—-The Geological History of the 


consanguinity of origin being admitted as the simplest explana- 
tion of the presence of identical families, genera, and species, 
in land blocks now not in direct communication with each 
other by land. 


(2) On Certain Unexplained Peculiarities of Angiospermous 
Distribution in these Southern Lands. 

The angiosperms, as a whole, which are common to the lands 
under consideration are not very cold types such as exist in 
many parts of the northern hemisphere. There are, indeed, 
identical species in the areas under discussion which love ,the 
cold. These, however, such as Geranium sessiliflorum, Cera- 
mum dissectum, Oxalis magellanica, Tillea moschata, Euphra- 
sia antarctica, Gentiana saxosa, and Juncus planifolius, may be 
explained as being due to the action of winds, sea rafts, sea 
currents, birds, or of man, much in the same way as, in lati- 
tudes slightly warmer, plants such as H'ntada scandens, Sophora 
tetraptera, Mimosa pudica, Convolvulus soldanella, Ipomea pes 
capre, Senecio lautus, and others, are known to be distributed 
by these and similar agencies. 

On the other hand, many cold types in South America have 
not a single representative (excepting one or two species of 
Oxalis) in New Zealand, Tasmania, or Australia. For 
example, Patagonium with 150 species in Chili, especially the 
Andean heights, Astragalus, one of the most vigorous and 
ageressive of cold country plants, has 75 to 80 species in Chili 
and Antarctic South America, Lupinus (2 species), Vicia (30 
species), Lathyrus (20 species), Haplopappus (100 species), 
Oxalis (90 species), Hscallonia (25-380 species), Valeriana 
above 50 species in Chili and Antarctic South America, Alnus, 
Agrimoma, Saxifraga, Ribes, Hieracitum, and other forms 
which frequent cold countries, and are found in Chili and the 
Andean heights, have no representatives in Australia and New 
Zealand. 

Moreover, there appears to be very meager evidence, either 
astronomical or geological, to justify the assumption as to the 
movement of the Poles even as much as 1 to 3 degrees since 
the Jurassic or Cretaceous. The Poles therefore may be con- 
sidered as having been practically stationary both before and 
after the Pleistocene” glaciations, as far back in time indeed, 
in all probability, as the origin of the angiosperms. This being 
so, it is reasonable to expect, on the assumption of an Antarctic 


*® Joseph Barrell, “The Status of the Hypothesis of Polar Wanderings,” 
Science, N..S., vol. xl, pp. 333-340, 1914. «+ 


Australian Flowering Plants. — 223 


origin for the plants common to South America and Austral- 
asia, that such plants must have made some provision for the 
many months of darkness which they must have experienced 
in their migrations across the South Pole region from South 
America to Australia. What provision, it may be asked, did 
these plants make for the long winter’s night? Did they 
simply rest, and shed their leaves, from which the chlorophyll 
had departed, or did they dispense with their leaves entirely ? 
As a matter of fact, instead of having structures or devices 
specially adapted for the polar darkness, they are just those 
types of plants which might be expected to have been developed 
in a temperate climate, with the exception of the cold species 
common to the various areas under consideration and already 
enumerated in part, and which may be found also on the islands 
lying between Cape Horn and New Zealand. Hpilobwum, 
Senecio, Caltha, Ranunculus, Tillea, and other genera, are 
common to the areas considered, but they are cosmopolitan in 
temperate and cold regions. At the least one would expect 
such types to be deciduous, but this is exactly what they are 
not. 


(8) The Catkin-bearing Plants. 

The possible distribution in time and space of the catkin- 
bearing plants may be considered in this connection. This 
deduced distribution is suggestive of the method of dispersal 
and development of ILibrocedrus, Podocarpus, Dacrydium, 
Caltha, Ranunculus, and EHpilobium, in what may be called 
the southern ‘“‘dead-ends” of the world. 

From a comparison of the various types of plants which bear 
catkins, it may be conjectured that the earlier types were forest 
trees of luxuriant habit, many types possessing beautiful pin- 
nate or compound leaves, and moreover trees which seem to 
have been lovers of mild and moist climates. They appear to 
have spread over the world during the Cretaceous, or at any 
rate, before the isolation of Australia and New Zealand from 
the greater land blocks. At a stage relatively early in the 
history of angiosperms these types appear to have been unfitted 
to cope with the severe competition of the entomophilous jungle- 
plants of the more tropical regions, inasmuch as the catkin- 
bearing plants were adapted to wind fertilization and were 
hampered in great measure by the suffocating and strangling 
action of the later plant types of the milder and moister cli- 
mates. Not only so but the hard baked clays and waterless 
tracts of the dry torrid regions were also unfavorable to their 


224 EE. O. Andrews—The Geological listory of the 


development. Owing to these and other causes they were 
forced north and south of the tropical and subtropical lands. 
This had been the history of the Conifers also about the same 
time, or perchance, at an earlier period. 

In the southern lands Fagus appears to have established 
itself firmly, although there was a wholesale extinction of 
amental types there either at this or a later period. Casuarin- 
ace, however, is one of the families which sprang from an 
early form, by adapting itself to the hungry and barren sandy 
soils in the warmer portions of Australia. One of the most 
serious handicaps which had been imposed upon the Coniferse 
and the Amentales was the peculiarity of their constitution, 
whereby only with the greatest difficulty were they enabled to 
reduce their size as individuals. This inability to reduce the 
great size of their woody stems brought about the extinction 
of very many genera, and, perhaps, even families, during the 
great zoning of the climate. The Casuarinacee offset this 
inherent defect in the family constitution by reducing the leaf 
surface and by sending down long roots to tap the under- 
ground sources of moisture, and, moreover, this type succeeded 
also in life by following watercourses, swamps, and other 
supplies of moisture, such as occur on the sides of mountains 
formed of porous or well-jointed sediments or sandy rocks. 

But during the second great differentiation in the northern 
hemisphere the Amentales became very vigorous especially as 
the Glacial Period was approached. During this post-Eocene 
Period, Quercus, Salix, and other types increased in numbers 
and began to advance south. Especially qualified were these 
grand types for the conquest of cold well-watered regions after 
their development of the deciduous habit, whereby they could 
rest in the winter. In the far south Yagus only succeeded in 
facing the cold by reducing the leaf surface, by the crowding 
together of individuals and by keeping in the shelter of moun- 
tains as much as possible. Magus mooret, in the northern por- 
tion of New South Wales, has a large leaf suggestive of the 
earlier more luxuriant amental leaf. The Casuarines on the 
other hand, are striking examples of the extreme reduction of 
leaf surface. The one exhibits in a marked degree an adapta- 
tion to a cold, moist, but sheltered area, the other exhibits in 
an equally marked degree an adaptation to poor hungry soils 
and to a climate showing marked diurnal changes of climate. 

Alnus. In South America Alnus is to be explained, prob- 
ably, as a southern immigrant during the great Glacial Period, 
although it is possible that it migrated to South America and 


Australian Flowering Plants. 225 


to Australia during the earlier differentiation of climate and 
that it was killed off at a later period in Australia. Quercus 
also may have travelled south during the earlier period, but its 
distribution suggests that it belongs to the later period of 
development. So also Salix appears to belong to the second 
period. It seems permissible, however, to infer that Alnus, 
Salix, Quercus, and some allied types, are to be referred to 
the period of development of Astragalus, Ulex, Lathyrus, Vicia, 
Lupinus, and Carduus, namely, one after the isolation of 
Australia and New Zealand from the world proper. 

The absence of these types from South Africa may be 
explained as being due to the lack there of cool, to cold, and 
well-watered country such as occurs in Southern Chili, South- 
east Australia and New Zealand. Before any family adapted 
to the xerophytic conditions within South Africa had oppor- 
tunity to develop, the plants with catkins appear to have 
perished in that region. 

These notes are inserted here merely with the intention of 
drawing attention to the hitherto unexplained botanical diffi- 
culties on the assumption of a Tertiary or post-Tertiary land 
connection between the southern lands and Antarctica. On 
the other hand the “Cretaceous and Kocene radiation” affords 
one explanation of this peculiar angiospermous distribution. 


(d) THe NorTHerRN HEMISPHERE PROBLEM. 


This is bound up in the general problem of South America 
and South Africa, and the possible distribution of one family 
only, namely, Umbelliferz, is discussed, inasmuch as it is 
typical of the distribution of families such as Cruciferz, the 
Amentales, Ranunculaces, Gentianacex, Scrophulariacese, Bor- 
aginacez, and Stellate (Lindley). 


(1) The Umbellifere. 

A study of the distribution and nature of the umbelliferous 
plants suggests that there have been at least two great dif- 
ferentiations of climate in the world since the birth of the 
family. ‘This is especially well seen by a comparison of the 
Australian and northern hemisphere types. 

The Umbelliferee belong to an order of specialized forms 
known as the Umbellifloree containing three families, namely, 
the Araliaceee, Umbellifere, and Cornacee. The Araliacez 
are large trees of luxuriant habit, which are found generally 
in the fertile tropics or subtropics. The Umbellifere are 
mainly herbs, with leaves usually highly compound. In a very 


226 EE. C. Andrews—The Geological History of the 


few Australian types, however, the shrubby habit is. still 
retained and the leaves may be compound or simple. These 
herbs and dwarfed forms characterize the cool and cold tem- 
perate regions, but in Australia certain large and endemic 
genera are xerophytic and occur on the hungry sandy soils of 
warm and cool temperate Australia. The Cornacez are mainly 
trees and shrubs adapted to the cooler temperate regions and 
with leaves simple or compound. 

From this it may be conjectured that the ancestral forms of 
the Umbelliferze were trees of luxuriant habit, with compound 
leaves, and lovers of mild and moist climate, that upon an 
early differentiation of climate, probably in the Cretaceous, 
the Umbelliferze were developed in open and _ well-watered 
regions after the wide dispersal of the ancestral forms and while 
these earlier Umbellifere were still trees or shrubs. These 
types reached Australia apparently during some portion of the 
Cretaceous and at a later date, after the great isolation of 
Australia from the rest of the world, while the Australian 
plants were faced with the gradually approaching but pro- 
nounced climatic differentiations, these early Umbellifers found 
a refuge on the large barren sandy tracts, which sandy wastes 
at the same time were causing new large and aggressive genera 
to spring up among the Myrtacee, Leguminose, Labiate, 
Euphorbiacez, Epacridacez, Goodeniacee, Candolleacexr, Pro- 
teacex, Dilleniaceze, and other families. In this favorable set- 
ting the large endemic genera Xanthosia, Trachymene, Siebera, 
and Didiscus, were developed, as also the strange and beautiful 
Actinotus. All these are strongly xerophytic and belong to the 
same great period of evolution in Australia which produced 
the Eucalyptus, Goodenia, Leucopogon, the phyllodineous 
acacias, and other types, which-all flourished together on the 
waste sandy tracts of the island continent. A very few of 
these xerophytes bear distinct traces of their old shrubby or 
arborescent habit, such as T’rachymene Billardiert, which is a 
low shrub. In the north these early types of the Umbelliferze 
were subjected afterwards to the great late and post-Tertiary 
differentiation, and the forms which had already been expelled 
in great part from the mild and moist region during the first 
ereat differentiation, were reduced to herbs during this second 
stage, and others being converted to hardy, vigorous, and aggres- 
sive types in the northern hemisphere, they commenced their 
way southwards sending off shoots along the American moun- 
tains to Chili and Antarctic South America. Thence some of 
them appear to have been carried by sea currents, by birds, or 


a a a 


Australian Flowering Plants. 227 


by men, to Australia and New Zealand. Azorella appears to 
have reached Australia and New Zealand from South America 
by one of these means. Daucus also appears to have been 
introduced into New Zealand and Australia from the north by 
winds, by sea currents or by ancient man. 

From this it will be seen that the evidence favors the idea 
that Umbelliferz is a family of great age which had its dwarfed 
and open-country habit determined during a period of climatic 
differentiation, antedating the isolation of Australia, and that 
its great herbaceous and cold-country development is only of 
relatively recent age. The origin of the order may be placed 
far back, perhaps before the upper Cretaceous. 

A similar story is revealed by a study of the Ranunculacez, 
the Magnoliacex, the Anonacez, and allied types. Caltha and 
Ranunculus have had histories somewhat similar to that of the 
types Aster-Olearia-Velicia, of Senecio, of Bellis-Brachycome- 
Astranthium, of Fagus-Nothofagus, and of Campanula-Wah- 
lenbergia. In each case, with the exception of Fagus, the old 
luxuriant and arborescent type of the mild moist regions of 
the world has been altered to dwarfed and specialized types 
which have spread north and south. These in turn have been 
modified considerably during the severe climatic changes of 
late and post-Tertiary time with a deciduous habit among the 
trees, or a herbaceous development in the north and a xero- 
philism adapted to subarid, icy, or sandy wastes in the south. 


(e) Tur New ZEALAND PROBLEM. 


Both this and the problem of the relation between Eastern 
and Western Australia are too complicated to be discussed here 
in detail and the briefest mention only is made of the subject 
at this stage. The literature of New Zealand botany, however, 
is voluminous and valuable owing to the labors of Hooker, 
Kirk, Cockayne, Cheeseman, Thomson and others. 

In the remote past, perhaps in some portion of the Oreta- 
eeous Period, there appears to have been a land connection 
between New Zealand and Northern Australia indirectly by way 
either of Malayasia or New Guinea. The ease for this prob- 
able land connection has been stated ably by Hedley.** 

Along this assumed land connection the earlier Araliacez, 
Leguminose, Rubiacee, Composite, Myrtacez, Cupulifere, 
Coniferze, Scrophulariacee, and other families, may have 
passed. The isolation of New Zealand from the world was 


“OC. Hedley, A Zobgeographic Scheme for the Mid-Pacifiec, Proc. Linn. 
Soc. N. 8. Wales, vol. xxv, pp. 391-417, 1899. 


228) EC. Andrews—The Geological History of the 


effected long before that of Australia, and forms such as 
Coprosma and Celnvisia were developed and sent out here and 
there as waifs. Veronica, Epilobium, Senecio, Celmisia, 
Raoulia, Cotula, Coprosma, Carmichelia, and Ranunculus, and 
some other types underwent saltation during the late and post- 
Tertiary revolutions in the topography while the great plateaus 
and gorges of New Zealand were being formed. Types such 
as Persoonia, Leptospermum, and others, may be considered 
as descendants from Australian waifs. Azorella, Geranium, 
Crantza, and many other forms, appear to have reached New 
Zealand by way of cold or South America, through the agency 
of sea currents, rafts, birds, or by other means. 


(f) THE DEVELOPMENT OF PLANTS WITHIN AUSTRALIA SUBSEQUENT TO 
THE ISOLATION OF THE ISLAND CONTINENT. 


This is too large and important a subject to be discussed in 
detail at this stage and may be dismissed in the present report 
with the statement that Australia appears to have been stocked 
with plants, both as luxuriant trees, as xerophytes, and as 
dwarfed forms, during some distant period, which may be 
conjectured as the upper Cretaceous; that after the isolation 
of Australia from the world generally, many of both the old 
luxuriant types and the stunted forms were driven into the 
sandy wastes of extratropical Australia and there, in their new 
surroundings, they developed numerous xerophytic species, 
many very large genera, numerous subtribes, tribes, and even 
certain families, which from weak and modest beginnings, 
gradually became hardy, vigorous, and finally aggressive, and 
whose only real limits, indeed, in later days, were set by the 
peculiar insular position of Australia on the one hand, and the 
inability of the xerophytic growths to invade the jungle-laden 
areas, on the other hand. During the later and post-Tertiary 
Period, when the great plateaus and gorges of Eastern and 
Southeastern Australia appear to have been formed, certain of 
-the endemic genera underwent saltation thus causing serious 
confusion among the systematists, much in the same way as 
Veronica, Epilobium, Carmichelia, Coprosma, and other types 
had caused trouble among workers dealing with the remarkable 
New Zealand flora. 

So complex and difficult did the problem appear that a 
botanist so eminent as Baron Von Mueller proposed to solve 
it by including numerous forms under one genus which 
hitherto had been described under various genera and many 
species under one species which previously had been described 


Australian Flowering Plants. 229 


as belonging to several species. Bentham also, in his Flora 
Australiensis, included many forms under one species in vari- 
ous genera and families. Cheeseman also appears to have 
experienced the same difficulty in the preparation of his 
“Hand Book of the New Zealand Flora.” This solution is 
unsatisfactory, however, inasmuch as it simply suggests to the 
observer that there are many perplexing forms belonging to 
the one species or genus. 

It is probable that the solution is to be found by a knowledge 
of the geographic and edaphic, as well as of the morphological, 
and chemical, factors. Thus, when the botanist, who may be 
studying Acacia, learns that there has been a great revolution 
in the topography of Eastern Australia by the formation there 
of high plateaus in late and post-Tertiary time, with the con- 
sequent production of a threefold climate in the same region, 
namely, mild and moist along the coast, cold and bleak on the 
plateau heights, and relatively dry and hot on the western 
slopes, and he knows, moreover, that a variety of Acacia longi- 
folia is recorded from the mountains, another from the coast 
and still another from the creek banks, then he may be coura- 
geous. and separate all as species, recognizing each as under- 
going transition or saltation during the present time. Or when 
Acacia salicina is seen as a handsome tree on the deep, loamy 
soils of the watercourses, and as a straggling plant on the dry 
barren sandstones of the interior, the two having very different 
appearances, then A. salicina of the loam may be considered 
as an adaptation of the sandy form to a more congenial habitat, 
and as one which either is, or soon will be, a species different 
from the old type of the barren hillsides. Hucalyptus albens 
and H. hemiphloia admit of similar treatment. Or again, if 
species of Eucalyptus, such as H. amygdalina, E. coriacea, and 
others, should show differences on the mainland of Australia 
from similar forms in Tasmania such that confusion should 
be caused among systematists as to their proper relations to 
each other, then it might be advisable to consider the allied 
types in the two regions as having been the one species in recent 
time when Tasmania was connected to the mainland by a narrow 
neck of land and that geographic isolation under different cli- 
matic environment in the two regions is now converting certain 
individual species into two. 

Similarly Veronica, Epilobium, Coprosma, and other genera, 
in New Zealand might be treated advantageously in this man- 
ner. In other words, the geographical station of the plant, the 
peculiarities of that station with respect to other stations con- 


230 F.C. Andrews—The Geological History of the 


taining species which are closely allied, whether, for instance, 
separated by long stretches of ocean, by wide lowlands unfitted 
to support the species now isolated, whether isolated for a 
long or a short period of time, or now growing under different 
climatic conditions or on different soils; all these points should 
be taken as the testimony of independent witnesses in the 
matter of the classification of the plants, much in the same 
way as the habit of the plant, its foliage, wood, corolla, calyx, 
andrecium, gynecium, oil contents, and other important chem- 
ical and morphological characters, are admitted at present. 

After all it does not alter the position materially so long 
as the workers are consistent in their methods of classification 
as was pointed out in 1869 by the master mind of Bentham 
when describing the genus Cassia. 


Summary. 

It seems permissible to infer from the evidence herewith sup- 
plied, partly as a result of the internal evidence of the recog- 
nized modern classification of flowering plants, and partly as 
the result of the independent testimony of the Australian, the 
South African, the tropical, the South American, and north- 
ern hemisphere, types of plants, that the isolation of Australia 
from the world generally in the later Mesozoic Period was 
preceded by a general condition of mild and moist climate 
over the greater portion of the world with the production of 
the various known orders of the flowering plants, and that this 
period was associated, in its later phases, with the develop- 
ment of families, and of genera, which showed either a tend- 
ency to frequent open spaces, as the Composites, or an actual 
tendency to become xerophytic or herbaceous, such as Acacia 
or Campanula. This condition may have arisen either as a 
development in poor soils and open exposed wastes, moving 
parallel with the great development of luxuriant types in the 
Cretaceous, or it may have marked a differentiation, or zoning 
of climate, after the development of the main orders. The 
study of the Australian plants favors the idea that. desert and 
open waste places existed during the so-called cosmopolitan 
mild and moist. climate of the Oretaceans and the Kocene, as 
exemplified by the perpetuation of xerophytes such as Acacia, 
Campanula, and Helichrysum, prior to the isolation of 
Australia. 

Both before and after the isolation, that is, during the earlier 
and later great differentiations, or zonings, of climate, many 


Australian Flowering Plants. 231 


families of plants, which had been lovers of warmth and mois- 
ture to the north of Australia, had been driven, in part, at a later 
stage, to the south, under the stress of severe competition and, 
in part, by reason of their own facilities for migration. These, 
during the various differentiations of climate, accommodated 
themselves to the peculiar sandy soils of Australasia in the 
temperate regions. This accommodation consisted of reducing 
the size of the old luxuriant tree, of reducing the leaf surface, 
or by the rejection of leaves entirely, of the utilization and 
increase of the amount of latex, essential oils, kinos, or of 
wax, already well developed in the families considered; of 
the development of other special devices for checking exces- 
sive transpiration such as the development of stomata, of stony 
cells and of indumentum; of lengthening the root and other- 
wise enabling it to tap the underground supplies of water. 
These soils were particularly adapted for the support of this 
xerophytice vegetation inasmuch as they never became intensely 
hard in time of drought, and although they never contained 
a rich supply of nutriment even under conditions of heavy 
and continued rainfall, nevertheless they ensured a scanty, but 
sure, supply of moisture for trees or shrubby growths which 
could develop roots long enough to tap such supply. Small 
herbs with either thick roots, or with bulbs, such as the orchids, 
the lilies, or certain composites could grow in most seasons by 
storing moisture either in the thickened rootstock, or in bulbs. 
The most remarkable point about this wonderful Australian 
endemic flora is the focussing, segregating, or congregating, of 
all possible types of the flowering plants on to the barren, unin- 
viting, sandy soils during the great climatic differentiations of 
the later and post-Cretaceous. Thus the Myrtacee in great 
measure foresook the rich soils and the sheltered regions to 
commence afresh on these hungry wastes; the Proteacez, the 
Rutacez, the Sterculiacee, and the Euphorbiacex, all in part 
forsook the jungle for the unattractive setting of the sand- 
stones; the orchids descended the trees to develop numerous 
large genera on the sandy expanses, and the epacrids, the ver- 
benas, the labiates, and the umbellifers, became dwarfed so as 
to flourish on the barren soils. From weakness these peculiar 
plant assemblages became strong; they became numerous in 
species and individuals, they became finally aggressive, but only 
after new genera, new subtribes, new tribes, and even new 
families, in some cases, had been developed. For it must be 
remembered ever by the student of Australian botany, that no 
large genus of world-wide distribution has a great develop- 


232 OE. OC. Andrews—Australian Flowering Plants. 


ment in Australia unless that genus has been modified to an 
extent that it is scarcely recognizable as the world-wide type 
until such time as it has flowered. 

EHxamples: The phyllodineous Acacias, Phyllanthus, and a 
section of Cassia. And in such ease the specialization of the 
forms has always taken place on the sandstone. This speciali- 
zation it is which marks the Australian sandstone vegetation. 
The primary types are to be found mainly as luxuriant forms 
within the cosmopolitan tropics, whereas the secondary, special- 
ized, xerophytic, and depauperate, types are to be found on the 
sandy soils of extratropical Australia. This specialized vegeta- 
tion has an origin relatively recent. 

The genera include Hucalyptus (300 sp.), Grevillea (200 
sp.), Hakea (112-115 sp.), the phyllodineous Acacias (420 sp.), 
Melaleuca (115 sp.), Goodenia (115 sp.), Candollea (105 
sp.), Hibbertia (105 sp.), Persoonia (65 sp.), Banksia (50 
sp.), Dryandra (50 sp.), Pultenea (100 sp.), Casuarina (25 
sp.), and Ptilotus (76 sp.), and these originated on the sandy 
soils of Australasia and have never travelled far from their 
birthplace. 

This Australian vegetation belongs to families which origi- 
nated partly in the north temperate regions, and, partly, in the 
tropics. Under stress of circumstances the plants tended to 
migrate south from the tropics. One branch moved south into 
Australia and developed the secondary specialized forms enum- 
_ erated in the preceding paragraph, another branch travelled to 
South Africa, and there under similar climatic influences, and 
upon similar sandstone areas, it developed a flora analogous to 
that of the specialized Australian types. Another moved down 
South America, but did not meet conditions similar to those of 
Africa and Australia. Another branch which had moved down 
all the great land connections between the northern and south- 
ern continents developed in the cool and moist regions of New 
Zealand, Southeast Australia and South America. This type 
perished in Africa during the great climatic differentiation. 


B. K. Emerson—Mineralogical Notes. 233 


Arr. XXIV.—Mineralogical Notes ; by B. K. Emerson. 


1. Limonite pseudomorph after diabantite, after anhydrite. 


Years ago I discovered anhydrite in large bluish-white 
masses in the trap at Larrabee’s Quarry on the north line of 
Holyoke.* It is in tabular aggregates resembling cleaveland- 
ite, slightly radiate, but sometimes radiating so rapidly that 
plates bend 90 degrees in one inch. ‘The plates vary from one- 
eighth inch thick to extreme thinness. It shows three perfect 
cleavages, and striated crystal faces. Pyrite and calcite are in 
the same cavities suggesting its origin. In many cases regular 
prismatic and tabular cavities occur in the zeolite-calcite aggre- 
gates in the cavities of the trap, which I have been accustomed 
to refer with doubt to selenite.t Recently I have received 
specimens from the third Westfield quarry, counting from the 
south, on hillock 380 feet above sea, and 1/2 mile north of the 
railroad, which show such cavities reaching 2 inches in length 
and width and 1/4 inch in thickness, but generally much 
thinner down to 1/32 of an inch. In several cases the enclos- 
ing mineral has penetrated the two perfect cleavages of the 
original mineral which are rectangular; the one parallel to the 
broadest surface, c, and the other at right angles thereto and 
parallel to the greatest length of the crystal, 6. At times the 
exterior of this broadest face is preserved in a perfect cast 
which is striated like the } face of anhydrite and at other times 
it has been etched during enclosure so that the tracing of the 
two rectangular perfect cleavages parallel to } and ¢ are well 
shown on a The crystals were flat rectangular plates some- 
times cut by a brachydome. 

These cavities have been filled by diabantite which appears 
first in small tufts and then fills the space entirely, showing a 
central suture where the two growths have come together. 
These tufts are often altered to bright gold-yellow forms 
which I have described as diabantite-vermiculite,{ and the com- 
plete fillings also show every stage of the change from fine 
fibrous green diabantite to a porous impure limonite, which 
latter is thus a pseudomorph by replacement of anhydrite, and 
by chemical alteration of diabantite. 

The same negative forms have been found at the Cheapside 
quarry south of Greenfield in thinnest plates and in long stout 
prisms coated with datolite, or enclosed in the same. The 
blades are often over three inches long. The blades have also 
been inclosed in quartz and sometimes several quartz crystals 


* Mineral Lex. Old Hampshire Co., Bull. 126, U.S. G. S., p. 26, 1896. 
+ Loe. cit., p. 90. } This Journal, xxiv, 198, 1882. 


234 B. K. Emerson— Mineralogical Notes. 


have grown directly against the flat surface of a plate produe- 
ing basal faces on the quartz which replace the pyramid 
entirely and take a sharp cast of the striated erystal face of the 
anhydrite. 


2. Paragenesis of minerals in diabase. 


A Quarry No. 1, Westfield. 

. Anhydrite in blades 2 inches long and 1 inch wide. 

. Massive transparent calcite. 

. Datolite massive and in one inch erystal. 

. Solution of anhydrite. ; 

. Diabantite replacing anhydrite. 

Coarse wine-yellow dog-tooth spar. R* sometimes 
truncated at apex by a 

White coating of chalcedony. 

. Fine-grained white dog-tooth spar, R*, «R. 

. Change of diabantite to limonite. 


B_ Cheapside Quarry, Greenfield. 


1. Anhydrite in blades. 
2. Quartz. 
3. Solution of anhydrite. 


. Anhydrite. 

. Datolite and calcite. 

. Calcite. 

. Solution of anhydrite. 


em co hor 


Amherst, Mass. 


Sellards—New Tortoise and a Supplementary Note. 235 


Arr. XXV.—A New Tortoise and a Supplementary Note on 
the Gavial, Tomistoma americana; by EK. H. Srriarps. 


Iy connection with a paper on pebble phosphates the writer, 
in 1915, mentioned and illustrated a large land tortoise from 
the Tertiary of Florida.* Additional specimens of this tortoise 
have now been obtained indicating that it is a characteristic 
and not uncommon fossil of the Florida land pebble phosphate 
deposits. The species apparently is new and may be known as 
Testudo hayi in recognition of the studies of Testudinata by 
Dr. O. P. Hay. The type specimen of this species, which 
includes a part of the carapace and plastron of a single in- 
dividual, was contributed by the Phosphate Mining Company, 
Nichols, Florida. A second specimen including a considerable 
part of the carapace has been obtained from the Amalgamated 
Phosphate Company, Brewster, Florida. Both specimens are 
from the Bone Valley formation which is either of late 
Miocene or of early Pliocene age. The origin of this forma- 
tion has been discussed and a number of the vertebrate fossils 
illustrated in the paper to which reference has been made. 

Testudo hayt, sp. nov.—This species includes large tortoises 
which reach a size of approximately four feet in width by five 
feet in length. The height of the carapace is estimated at 
twenty-seven inches. Of the neurals the second is octagonal 
or nearly so. The remaining neurals four to eight are hexag- 
onal. The proximal end of the second costal is slightly 
reduced in width and comes in contact with the second neural 
only, while the third costal touches the second, third and fourth 
neurals. The first or penultimate supra-pygal is large and 
rests upon the eleventh marginals and the pygal. The second 
or ultimate supra-pygal, on the contrary, is much reduced. 
The length of the xiphiplastron from the bottom of the 
xiphiplastral notch to the outer margin at the suture with the 
hypoplastron is 800™™. 

Under the name Testudo crassiscutata, Leidy in 1889 
described a tortoise obtained on Peace Creek, Florida. The 
type of Leidy’s species includes portions of the anterior and 
posterior lobes of the plastron, a femur and a tibia and frag- 
ments of the carapace. By comparing the posterior part of 
the plastron it is seen that the median notch of Z. hayi is 
deeper and more acute than is that of Z. crassiscutata. The 
exterior wall of the hypopiastron of Z. hayi is vertical while 
in TZ. crassiscutata the exterior wall of this bone slopes in- 
ward. Although representing a larger individual the carapace 
of 7. hayz is thinner than that referred to 7. crassiscutata. 


* Fla. Geol. Sury., Seventh Annual Report, pp. 70, 75, figs. 7 and 9, 1915. 


Am. Jour. Sc1.—Fourts Srrizs, Von, XLII, No. 249.—SmeremBer, 1916. 
16 


“pe1ojsed SI Matitoads oY} UL SUTYOV] ST YOLYA ooVaVIVS oT} FO FAVE FUOTT 
eqT, ‘I00G “ON [109 “ANS “VIA “eZIS TRANFVU T4F[OMF-OUO “aorjsB[d Fo eqoy tonteysod puvcovderwy eddy “winy opnjysay “T “Sl 


Fia. 


Sellards—New Tortoise and « Supplementary Note 
il 


> 
, 


23¢ 


FS PR oe 


on the Gavial, Tomistoma americana. 237 


Supplementary Note on the Gavial, Tomistoma americana. 


The gavial, Zomistoma americana, described by the writer 
in 1915, is of special interest from the fact that it is at pres- 
ent the only known member of this group from the American 
Cenozoic. Of this form there has been known heretofore only 
the rostrum which served as the type of the species and a frag- 
ment of a lower jaw which was regarded as a paratype.* 
Recently, however, there has been obtained from the same 
locality and from the same deposit as the type specimens, parts 
of the lower jaws of ten or twelve individuals, with which is 
associated a few pieces of upper jaws, dermal plates and a ver- 
tebra. From the specimens now at hand it is possible to add 
to the deseription of the lower jaw. The rostrum which 
originally served as the type of the species represents, as 
shown by the specimens now at hand, an individual by no 
means fully grown. As in the case of the specimens first 
deseribed, the additional material representing this gavial has 
been obtained by the Amalgamated Phosphate Company at 
Brewster, Florida, and has been contributed to the Florida 
Geological Survey through the general manager of the com- 
pany, Mr. Anton Schneider. 

The front part of the jaw of this gavial is represented by 
specimens Nos. 6158, 5871, 5875, 5876 and 5879 of the Florida 
Survey collection. The two front teeth of the lower jaw, as’ 
shown by this new material, incline upward, forward and out- 
ward, and thus pass between the first and second teeth of the 
premaxilla which is grooved to receive them. The second 
mandibular tooth is strongly developed and is separated by a 
considerable space from the first tooth, and passes between the 
third and fourth teeth of the upper jaw. The groove in the 
premaxilla which receives this tooth is more pronounced as 
shown by specimen No. 6158 in the large individuals of the 
species than on the specimen which served as the type of the 
species. Into the broad groove between the first and second 
lower teeth is received the second and third upper teeth. The 
space between the first and second lower teeth shows a propor- 
tionate increase with age, the teeth of the young specimen 
being about equally spaced. The third lower tooth is small 
and falls between the fourth and fifth teeth of the premaxilla, 
being there received in a pit at the outer side of the bone 
which in old individuals becomes quite pronounced. The 
fourth mandibular tooth is the largest of the lower jaw and 
passes into the notch or constriction of the rostrum and hence 
between the fifth and sixth upper teeth. From the second 
lower and third upper to the tenth lower and eleventh upper 
the teeth alternate and interlock, the side of the jaws being 


* This Journal, vol. xl, pp. 185-138, 1915. 


238 Sellards—New Tortoise and a Supplementary Note 


grooved between each tooth to receive the corresponding tooth 
from the opposite jaw. Back of the tenth lower and eleventh 
upper the teeth do not pass to the outer side of the jaw, but 
are received in pits in the jaw. 

The symphysis of the jaw, as shown by specimens Nos. 
6158 and 5879, begins opposite the eleventh or the twelfth 
mandibular tooth. In specimen No. 5880, the front part of 
which is wanting, may be seen sockets for seven teeth back of 
the symphysis, ‘representing apparently the eleventh to the 
seventeenth or the twelfth to the eighteenth teeth inclusive, 
from which it appears that the full “number of teeth in the 
lower jaw is seventeen or eighteen. The splenials, as noted »in 
the writer’s original description, take part in the symphysis 
and extend for ward, as shown by the specimens now on hand, 
to a point opposite the seventh mandibular tooth. The under 
surface of the back part of the lower jaw is well shown by 
specimen No. 5891 which is illustrated in the accompanying 
text figure. The bones seen from the underside of the jaw 
are the dentaries, splenials and angulars. The termination of 
the dentaries is not definitely shown, but these bones may be 
seen to extend approximately one half the length of the ramus 
of the jaw. The limits of the splenials are very well shown 
and are seen to extend somewhat more than one half the 
length of the ramus. The angular is wedged in between the 
splenials and the dentaries and forms the lower margin of the 
jaw at the angle. 

While no one jaw has been found complete, yet an approxi- 
mate measurement of the lower jaw may be obtained by com- 
bining measurements from the two Jargest specimens of the 
collection. In the larger of these, No. 6158, the front part of 
the jaw as already noted is preserved, while in the other, No. 
5891, which is but slightly smaller, the back part of the jaw is 
practically complete. The symphysis of the jaw of the large 
specimen méasures 610", while on the slightly smaller speci- 
men that part of the jaw back of the symphysis measures in a 
direct line following the axis of the jaw 725"". The full 
length of the lower jaw of a large specimen of this gavial was, 
therefore, somewhat more than 1335", or about four feet and 
three or four inches. By way of comparison it may be noted 
that the splenial bones in this species take part in the forma- 
tion of about four-elevenths of the symphysis; while the sym- 
physis itself includes about four-ninths of the entire length of 
the jaw. The width of the jaw of the largest specimen, meas- 
ured at the forward end of the splenial, is it 7o™™, the jaw being 
proportionately broader than that of the modern species of the 

enus. 

A number of dermal plates of crocodillians are found at 
this locality which with little doubt are referable to this spe- 


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B sey ydeisojoyd oy4 ut ueas INI OYE “ez1s TeInqvu yIYSie-eu9 ‘8ST9 PUB T68G “SON ‘[[00 “Ang “eTyp ‘DUDoLVLIU DULOISLUWO ‘g pue g ‘sorg 


240 Sellards—New Tortoise and a Supplementary Note. 


cies. These plates are heavy deeply pitted pieces of bone, the 
largest of which measure 100 by 130"™ in size and are 16™™ 
thick. A vertebra, the centrum of which is 70™ long by 50™™ 
wide, has been obtained from this locality and presumably 
represents this species. This vertebra is probably the seventh 
of the series. } 

The skull of this extinet gavial is somewhat more massive 
than is that of the modern species. Thus a jaw of 7. schlegeli, 
the symphysis of which measures 610™", has a width at the 
forward end of the splenials of 170™", the width being more 
than one-fourth the length. In the recent species the width 
of the jaw at the same place is contained in the length 64 times, 
thus indicating a more narrow jaw and skull. The symphysis 
of the jaw of we schlegela begins opposite the fourteenth tooth, 
while in Z. americana the symphysis as previously stated 
begins opposite the eleventh or twelfth tooth. In the propor- 
tionate length of the symphysis to the jaw as a whole, how- 
ever, as well as in the extent to which the splenials enter into 
the symphysis, the two species do not differ to any great 
extent. 

The body proportions of this gavial probably do not differ 
greatly from those of the existing species of the genus, and 
hence by comparative measurements it is possible to form a 
reasonably close estimate of the size of this extinct animal. 
Upon comparing the modern species, Zomistoma schlegeli, it 
is found that in an individual, the full length of the body of 
which is 9 feet and 7 inches, the lower jaw measures 2 feet 
and 2 inches.* Assuming that a somewhat similar proportion 
holds between the length of the jaw and of the body of 7. 
americana, and applying these measurements, the conclusion is 
reached that large individuals of the Florida gavial, the jaw of 
which exceeds 4 feet, attain a length of 18 or 19 feet, and 
hence were somewhat larger than the existing gavial of this 
genus which seldom exceeds 15 feet in length. 


* Measurements from the recent skeleton kindly supplied by Geo. M. Ward 
of tne Ward Natural Science Establishment. 


E. W. Berry—A. Fossil Nutmeg. 241 


Arr. XXVI—A Fossil Nutmeg from the Tertiary of Texas ; 
by Epwarp Wieser Berry. 


Tue Nutmegs, with somewhat less than 100 existing and 
widely distributed tropical forms, constitute the family Myristi- 
eaceee of the order RKanales. Satisfactorily determined fossil 
forms are entirely unknown so that the remains which form 
the subject of the present paper are not without interest. 

These are found in the Catahoula formation of Trinity 
County in eastern Texas from which I described the fruits of 
a date palm some years ago,* and were collected by Charles 
Laurence Baker. The matrix of this material was the basis 
for a highly interesting study of the petrography of the Cata- 
houla' sandstone made by M. I. Goldmant and published in 
this Journal in 1915. The evidence of the flora and that fur- 
nished by the study of the sediments supplement one another 
in throwing considerable light on the physical conditions of 
Catahoula time which will be referred to on a subsequent page. 

The fossil species of nutmeg, obviously new, is represented 
by characteristic remains of the pericarp and of the seeds. It 
may be described as follows : 


Myristica catahoulensis, sp. nov. 


Pericarp broadly ovate, slightly longer than wide, approxi- 
mately cireular in cross section, thick, two-valved, about 5°" in 
length and 3°75°™ in diameter, enclosing a single large seed. 
The aril either decayed before fossilization or became separated 
from the seed and was not preserved in the same deposit and 
the perisperm is likewise missing. The seed is large, circular 
in cross section, evenly rounded proximad and shows a distinet 
hilum. It is slightly narrowed and bluntly pointed distad. 
The surface is ornamented by numerous irregular longitudinal 
corrugations marking the ruminating endosperm. These mark- 
ings are in faint relief and much less prominent than the cor- 
responding markings of. the commercial nutmeg, due in a 
measure to the fact that fossils are all casts in a somewhat 
porous sandstone. Similar artificial casts of the strongly marked 
commercial nuts are scarcely to be distinguished from the 
fossil casts. The nuts, of which several have been found, are 
about 3°" in length by 1-7™ in maximum diameter, which is 
midway between the apex and the base. 

This species is based on the single valve of the pericarp 
shown in figs. 4-6 and on the partial remains of several nuts, 


*This Journal (4), xxxvii, pp. 403-406, 1914. 
+ Ibid., xxxix, pp. 261-287, 1915. 


242 E. W. Berry—A Fossil Nutmeg. 


only one of which is perfect (fig. 1). The nuts were appar- 
ently relatively abundant, but since they were only discovered 
in the weathered sandstone there are few that are reasonably 
complete although there are several showing parts of the sides 
or ends, in some eases half complete as in fig. 2. 

As I have mentioned, all the plant remains at, this locality 
are in the form of casts and the nuts must have been buried by 


Imes al 


Fics. 1-6. Myristica catahoulensis sp. nov. from the Tertiary of Texas. 
1. Side view of seed. 
2, 8. End views of same. 
4-6. Side, top and front view of a valve of the pericarp. 


wind-blown sand since they lie in the sand at all angles. The 
eolian character of the sandstone at this outcrop is of the 
greatest importance in explaining the absence of both aril and 
perisperm, and is, therefore, deserving of comment. The eyi- 
dence for this conclusion is derived from several sources. 
Many of the leaf specimens are curled and not flat as they 
would almost invariably be if laid down in water. These and 


E. W. Berry—A Fossil Nutmeg. 243 


other associated nuts are jumbled in a confused mass at all 
angles. Violent currents could form such a jumble, but the 
nuts would not be heavy enough to be deposited under such 
conditions but would be carried away by water action strong 
enough to stand them on end, nor would water-logging in more 
quiet waters explain their varying positions. Associated with 
nutmegs are much more numerous large-ribbed nuts as yet 
unidentified. These lie at all angles in the sandstone but occur 
elsewhere in clays, in which case they invariably le on their 
sides. The conclusions of Dr. Goldman, based on a petro- 
graphic study of the matrix, i. e., the proportion of different 
sizes of grains present, their rounding, the ratio of feldspar to 
quartz, the degree of weathering, absence of clay, proportion 
of heavy minerals, ete., for a detailed discussion of which the 
reader is referred to the paper cited, point to strong eolian 
action in a hot arid climate. 

The nuts are fully matured and evidently were shed natu- 
rally and at no great distance from the sand flats where they 
subsequently became entombed. The sediments do not, accord- 
ing to Dr. Goldman, show characters of dune sands, and I infer 
that the winds which rounded and sorted the sand grains were 
not constant enough in direction to form dunes of any size. 
Under such conditions of blowing about the arils would soon 
be lost, but the perisperm cannot be conceived of as being so 
readily dissipated although I know of no other method to 
account for its absence. It must be remembered that less than 
a dozen nuts are known, that much of the sand from near-by 
outcrops appears to have been blown into pools of standing 
water where the accompanying leaves were fossilized in a 
normal flat condition, and that the small percentage of nutmegs 
preserved in the wind-blown sands may thus be exceptional 
when the possibility is considered of large numbers fossilized 
in a normal way with perisperm intact. 

That the fossils are unmistakably those of a species of Myris- 
tica I think no botanist will dispute. No leaves that I can 
identify as those of Myristica have as yet been determined, but 
the leaf material is scanty, and I have not enough recent 
material of this genus for intelligent comparison of the foliar 
organs. 

The recent species of this family which number about 90 
forms are variously treated. De Oandolle* referred. them all 
to the single genus Myristica which he segregated into 13 
sections, and this is the method followed by Prantlt in Die 
Natiirlichen Pflanzenfamilien. Other authors raise a num- 
ber of these sections to generic rank, quite rightly so it seems 


* Ann. Sci. Nat., 4th ser., Bot. tome iv, pp. 20-31. 
+ Teil III, Abth. 2, 1891. 


244 E. W. Berry—A Fossil Nutmeg. 


to me. I have, however, preferred to refer the fossil to Myri- 
stica since comparative recent material for closer discrimina- 
tion is lacking. The nutmeg of commerce belongs to the sec- 
tion Eumyristica with about 15 existing species of the Asiatic 
tropics. It is asmall tree, endemic in the Moluccas and has 
long been under cultivation judging both from the numerous 
varieties extant and the historical records, since Europe has 
been reeeiving nutmegs from this region, beginning with the 
trade through the Arabs in the 6th century. “The nutmeg has 
been introduced into other East Indian islands as well as on 
Bourbon, Mauritius, Madagascar and in tropical America, 
usually with indifferent success. 

While the Texas fossil is much like the commercial nutmeg 
in size and characters it is also similar to existing American 
species, of which there are about 25. These are mainly South 
American, but the sections or genera Virola Aublet and 
Compsoneur a De Candolle both occur also in Central America. 
The fossil nuts are remarkably like those of Myristica ( Comp- 
soneura) costaricensis Warburg, but the pericarp is much 
larger and more massive. 

Beyond the fact that they are tropical I know little regard- 
ing the habitat of the recent species. Many are certainly 
insular and coastal forms, their range in the Pacific extending 
eastward to the Fiji, Tonga and Samoan islands, the former 
having 4 or 5 species. Schimper records 4 species in his Indo- 
malayan strand flora. Myristica subcordata Blume ot New 
Guinea and Myristica littoralis Miquel of Java are both mem- 
bers of Barringtonia or beach-jungle association. Both Gaudi- 
chand and Guppy record unopened Myristica fruits in the 
Pacific sea-drift although their floating powers are not great 
and they are normaliy dispersed by fruit pigeons (Moseley, 
Hemsley, Guppy). 

Referring to the foliage it may be noted that contrary to the 
opinion of Hooker and Thomson (Flora Indica), DeCandolle 
found that the flowers and fruits were much alike throughout 
the family and that the leaves furnish the most useful char- 
acters for differentiation, especially in their venation, and this 
opinion was also shared by Miquel. It would seem that the 
lack of comparative material has hitherto prevented the recog- 
nition of fossil foliage of Myristica. Certainly no definite evi- 
dence of extinct species has heretofore been published although 
the distribution of the existing species in tropical Asia, Africa 
and America is convincing enough evidence that the group 
had an extensive, even if ~ unknown, Tertiary history. The 
only previously known fossil records are based on a very few 
and indifferently characterized leaf i impressions from the Mio- 
cene of Labuan (Borneo) described by Geyler* as Myristicophyl- 


* Geyler, Vega Exped., vol. iv, p. 498, pl. 38, figs. 3-6, 1887. 


EF. W. Berry—A Fossil Nutmeg. 245 


lum majus and minus, and by equally unconvincing leaf frag- 
ments described by Engelhardt as Myristica fossilis* and 
coming from beds in Equador and Chile considered to be either 
Kocene or Oligocene in age. 

On the other hand, the family Anonaceze, which is closely 
related to the Myristicaceze, is represented in the fossil record 
by over a score of species of Anona, Asimina, Guatteria, etc., 
ranging in age from the early Upper Cretaceous through the 
Tertiary. Both Anona and Asimina are represented in the 
Lower Eocene flora of the Mississippi embayment area. 

Myristica catahoulensis comes trom a cut on the Inter- 
national and Great Northern Railroad in southern Trinity 
County, where a spur to the Government lock leaves the main 
line, and the Catahoula formation in this area is either late 
Eocene or early Oligocene in age. The flora is a coastal one 
and strictly tropical in character. 


Johns Hopkins University, 
Baltimore, Md. 


* Abh. Senck. Naturf. Gesell., xvi, Heft 4, 1891, p. 668, pl. 6, f. 9, pl. 7, 
fig. 12, 1891. Ibid., xix, p. 13, pl. 1, f. 21, 1895. 


246 Ee. M. Kindle— Notes on Devonian Fuunas. 


Arr. XX VII.—Wotes on Devonian Kaunas of the MacKenzie 
Ltiver Valley ; by E. M. Kinpix. 


Tue Devonian rocks east of the MacKenzie valley are 
bordered for nearly a thousand miles by the Pre-Cambrian 
rocks of the Canadian shield.* The geological map of North 
America, published through the codperation of the geological 
surveys of the United States, Canada, and Mexico,t+ indicate 
the termination of the broad belt of the MacKenzie valley 
Devonian on the north by a western lobe of the Pre-Cambrian 
rocks which, in the region east of the delta of the MacKenzie, 
are bordered by the Cretaceous formations according to this 
map. 

A coral collected by H. W. Jones and transmitted to me by © 
Mr. Chas. Camsell furnishes evidence of the presence of 
Devonian Rocks, in this very northerly region east of the 
delta of the MacKenzie within 70 miles of the Arctic coast, 
where published data show only Cretaceous and Pre-Cambrian 
terraines. The specimen collected by Mr. Jones was obtained 
on the east side of Gull Lake from the limestone shown in 
fig. 1. The photograph shows a limestone section with a thick- 
ness of more than 100 feet in which the beds lie nearly hori- 
zontal. The Gull Lake district is one which does not appear 
to have been traversed by geologists. The geography of the 
district was described by A. H. Harrison in 1908.{ Gull Lake 
is probably Long Lake of Harrison’s map or one of the small 
lakes near Long Lake. Long Lake is the most westerly of a 
chain of lakes lying east of the delta and trending a little east 
of north through a region lying, according to Harrison’s map, 
between 100 and 500 feet above the sea. 

The corallites of the specimen on which the determination of 
this new occurrence of Devonian rocks is based are partially 
silicified and imbedded in an impure grey limestone. The 
coral belongs to the species Acervularia davidsoni EK. & H. 
It represents the variety of this species described by Hall from 
the lowa Devonian as A. profunda. The variable character 
of the size of the corallites ascribed to A. profunda is well 
illustrated by this specimen, the smaller ones having no more 
than half the diameter of the larger ones. Most of the cells 
have 40 or more radial denticulated lamelle. In this identifi- 
cation I have followed Rominger in treating Hall’s A. pro- 
Sunda asa synonym of A. davidsoni. 

* McConneil, R. G., Ann. Rept. Geol. Surv. Can., n. ser., vol. 4, 1890, p. 
Mo. S. Geol. Surv., Prof. Paper 71, 1911. 

¢ A. H. Harrison, In Search of a Polar Continent, pp. 1-292, map (E. 


Arnold), London, 1908. Idem, In Search of an Arctic Continent, London 
Geog. Jour. vol. xxxi, pp. 277-287, map, 1909. 


FE. M. Kindle— Notes on Devonian Faunas. QAT 


Although no other fossil was secured by the collector, the 
occurrence here of this species affords conclusive evidence of 
the presence at Gull Lake ofa Devonian fauna. A. davidson 
is a characteristic species of the Middle and Upper Devonian: 
of Iowa, Michigan and Wisconsin. 

This coral has not been previously reported in western 
Canada. It will therefore be of interest to note here the pres- 


Fie. 1. 


Fie. 1. Devonian limestone at Gull Lake, east of MacKenzie River delta. 
Photograph by H. W. Jones. 


ence of A. davidsoni in another collection from the MacKen- 
zie valley obtained at a locality 30 miles Northwest of Hope, 
which is just inside the Arctic Circle. This collection, which 
was made by Mr. T. O. Bosworth and presented to the Cana- 
dian Geological Survey together with other collections from 
the MacKenzie valley, includes the following species: 


Acervularia davidsoni 
Camarotaechia sp. 
Atrypa reticularis 
Newberrya laevis Meek 
Cyrtina panda Meek 
Martinia meristoides. 


This faunule from Northwest of Hope shows an assemblage 
including several species listed by both Meek* and Whiteavest 
from the MacKenzie valley collections of Kennicott and 
McConnell. Each of these authors considered the MacKenzie 

* Trans, Chicago Academy of Sciences, vol. i, pt. 1, pp. 61-114, pls. 11-15. 


{ Can. Geol. Sury., Contr. to Can. Pal., vol. i, pt. III, pp. 197-258, pls. 
27-32, 


248 k. M, Kindle— Notes on Devonian Kaunas. 


valley fauna to represent a Middle Devonian horizon. It rep- 
resents in the writer’s opinion both Middle and Upper Devonian 
horizons. In the faunnJe now under discussion from North- 
west of Hope such distinctly Upper Devonian species as 
Spirifer dis) wnotus, which is conspicnous in the faunules listed 
by Whiteaves,* are ‘wanting and the species present appear to 
represent the Middle Devonian fauna of the MacKenzie 
valley. 

The single species of coral which represents the Gull Lake 
Devonian fauna affords rather meagre evidence for its close 
correlation with other faunas, but the presence of the same 
species of Acervulariain the fauna just listed from Northwest 
of Hope suggests that they are both representatives of the 
same Middle Devonian horizon. 

Another collection from the MacKenzie River Valley which 
has recently been studied by the writer shows in addition to 
the faunas with which we are familiar through the work of 
Meek, McConnell, and Whiteaves, a Devonian facies not pre- 
viously recognized in that region. This collection was made 
by Mr. Charles Caimsell at Pine Point, on the south shore of 
Great Slave Lake. The fossils from this station are from beds 
described in Mr. Camsell’s notes as “ very bituminous and full 
of fossils. They lie flat and are associated with beds of lime- 
stone in low cliffs 3 or 4 feet high at the water’s edge.” 

The fauna occurs as flattened or crushed shells in a black 
calcareous and highly bituminous shale. Some specimens 
might be properly called limestone,—coal black in color. 
When fr eshly broken this rock gives a strong petroleum odor. 

The species recognized in this black shale fauna are the fol- 
lowing : 

Lingula sp. 

Leiorhynchus cf. laura 
Prerochaenia fragilis 
Styliolina fissurella 
Tentaculites gracilistriatus. 


The fauna of this black shale has not been previously recog: 
nized in the MaeKenzie River Valley. This fauna contains 
nothing which will enable one to decide positively with which 
one of three or four Middle and early Upper Devonian black 
shale horizons it is most closely allied. The last three species 
might occur as early as the ‘Marcellus shale or as late as the 
Ithaca shale of the New York Portage. The absence of species 
characteristic of the black shale horizons of the Portage, how- 
ever, together with the closer resemblance of the Leorhynchus 
to a form not common above the Mar cellus, lead me to place 

the fauna, provisionally, in the Middle Devonian. 


Geological Survey, Ottawa, Canada. 
* LL, ¢., pp. 248-253. 


VanTuyl— New Points on the Origin of Dolomite. 249 


Art. XX VIII.— New Points on the Origin of Dolomite :* by 
Franots M. VanToyt. 


Historical Review. 


Tur problem of the origin of dolomite has long oceupied the 
attention of geologists and many theories have been advanced 
for its formation, ‘but no one of these theories has been widely 
accepted. Von Buch (1)+ was the first to seriously attempt to 
explain the formation of the rock. As early as 1822 in his 
writings on the dolomite of the Tyrol, he ascribed its origin to 
the action of volcanic vapors, rich in magnesia, on limestone, 
and there was some basis for this belief, for the rocks are there 
penetrated by augite-porphyry. Fr apolli ( 2) and Durocher (3) 
later expressed similar views upon the origin of the rock, and 
Fayre (4), basing his supposition upon the conditions of the 
experimental production of dolomite by Paes concluded 
that the dolomite of the Tyrol was formed by the alteration of 
limestone beneath the sea at a temperature of 200° C. and at a 
pressure of 15 atmospheres, corresponding to a depth of 150 to 
200 meters, by magnesium compounds furnished by the action 
of sulphurous and hydrochloric acids of volcanic origin on the 
lava of submarine melaphyr eruptions. 

In 1834 Collegno (5) pointed out the frequent association of 
gypsum and dolomite in the St. Gothard region and regarded 
them both as transformation products resulting from the action 
of magnesium sulphate in surface waters or limestone. Mor- 
lot (6) also favored such a theory of origin. 

As early as 1836 Beaumont (7) ascribed the origin of dolo- 
mite to the alteration of limestone by circulating solutions of 
magnesium bicarbonate and, assuming that the replacement was 
molecular, he calculated that the change should be accompanied 
by a deer ease in volume of the original rock to the extent of 
about 12-1 per cent. Actual porosity determinations by Mor- 
lot (8) on a dolomite sample from the Alps later seemed to con- 
firm this prediction. 

In 1848, A. W. Jackson (9) suggested that ascending spring- 
water bearing magnesium bicar bonate might effect the change. 
Nauck, Haussmann, Bischof, Zirkel and others, however, 
subscribed to the view that ordinary circulating gr ound water 
bearing magnesium bicarbonate had attacked the limestone. 

* The present article is based on a more extended paper which constitutes 


a portion of volume xxv of the lowa Geological Survey. The reader is 
referred to this report for details. 


+ For numbered references to the literature, see the list at the end of this 
article. 


250 VanTuyl—New Points on the Origin of Dolomite. 


Van Hise (10) also attaches much importance to dolomitization 
after the limestones emerge from the sea. 

In 1846 Green (11) offered the suggestion that some dolo- 
mitic limestones might be formed by the decomposition of 
olivine sand incorporated in the original limestone and the 
recombination of the magnesia with the lime. He calls atten- 
tion to the fact that olivine sand, derived from the action of the 
waves on lava, constitutes an important constituent of the 
eoral-reef rock about the borders of the Hawaiian Islands and 
regards this as significant. 

Dana (12) in 1843, attempting to account for the dolomite of 
the coral island of Metia, supposed that it had been formed, by 
the action of magnesium salts of heated sea water on limestone. 
Twenty-nine years(13) later he expressed the view that the 
same dolomite had been formed in sea water at ordinary tem- 
peratures but perhaps in a contracting lagoon where magnesium 
and other salts were in a concentrated state. Sorby (14) like- 
wise favored the theory of marine alteration and the same 
origin has been urged, either for dolomites in general or in 
special instances, by Von Richthofen, Doelter and Hoernes, 
Hoppe-Seyler, Mojsisovics, Murray, Skeats, and F. W. Pfaff. 
In support of this theory are also the observations of 
Weller(15) who, from a faunal study of the Galena and 
Niagara dolomites of the Upper Mississippi Valley, concludes 
that they were deposited originally as limestones and later 
metamorphosed. More recently, Blackwelder (16) has also 
advocated the replacement theory for the origin of the Big- 
horn dolomite of Wyoming, but owing to the very slight por- 
osity of this rock he is led to suggest that the alteration - 
proceeded contemporaneously with its deposition rather than 
subsequent to its consolidation. 

F. W. Pfaff (17) believes that the alteration takes place at 
considerable depth and in concentrated seas, but Phillipi (18) 
vigorously controverts this view since he has good evidence 
that dolomitization may proceed in the open sea and at shallow 
depths. Skeats’ (19) studies of the coral reefs of the Southern 
Pacific also seem to show that concentration and pressure are 
not important factors. On the other hand, both Nadson and 
Walther (20) have suggested that bacteria may play an impor- 
tant part in the alteration. 

Still other geologists have supported the theory that dolo- 
mite represents a direct chemical precipitate from the ocean. 
Boué (21) as early as 1831 advocated this method of origin. 
Bertrand-Geslin (22) and Coquand (23) were also early sup- 
porters of this view. That dolomite can be formed as a chem- 
ical precipitate is pointed out by Zirkel(24) who shows that 
the occurrence of crystals of dolomite in veins and druses indi- 


VanTuyl—New Points on the Origin of Dolomite. 251 


cates its possible chemical deposition on a larger scale in 
nature. Fournet (25) regarded the dolomite beds interstratitied 
with limestone in the Tyrol as original precipitates. His 
studies showed that the voleanic theory of Von Buch was no 
longer tenable. Others who have advocated the primary pre- 
cipitation theory in one form or another are Loretz, Kurch- 
hammer, Hunt, Vogt, Daly, Linck, and Suess. 

As to the nature and cause of the reactions which have been 
supposed to give rise to the chemical precipitation of dolomite, 
there have been differences of opinion. forchhammer (26) 
attributed the reaction to the action of calcium carbonate of 
spring water on the magnesium salts of the sea, while Hunt, 
(27) basing his views on experimental evidence, regarded dolo- 
mite as the product of the action of sodium bicarbonate on 
the magnesium chloride and magnesium sulphate of tlre sea. 
Linck (28) and Daly (29), on the other hand, emphasize the 
importance of ammonium carbonate furnished by decaying 
organisms on the sea bottom as the precipitating agent. 

Still another primary theory is that introduced by Lesler (30) 
to account for certain dolomitie layers in the ‘* Calciferous ” 
limestone near Harrisburg, Pa. These he believed to repre- 
sent ordinary mechanical sediments which were deposited at 
the time the limestone was laid down. The clastic theory has 
been adopted more recently by Phillipi (31), who regards cer- 
tain impure dolomites of the Muschelkalk of Germany as 
mechanical deposits possibly derived from the residuum of 
limestones low in magnesia. Grabau (82) has concluded that 
certain impure dolomitic limestones and waterlimes of the 
Salinan and Monroan series have had a similar origin. 

An entirely different theory of origin is that which was in- 
troduced by Grandjean (33) in 1844, to explain the production 
of the dolomites of the Lahn district. He assumed that by the 
atmospheric leaching of the lime from an original limestone of 
low magnesia content, a true dolomite might in time result. 
Both Bischof and Hardman later demonstrated the plausibil- 
ity of this theory experimentally, and Hardman (384) immedi- 
ately accepted it to explain the origin of the Carboniferous 
dolomites of Ireland. In 1895 Hall and Sardeson (35) applied 
the same theory in interpreting the history of the Lower Mag- 
nesian series of the Upper Mississippi Valley. 

Hoégbom (36) on the other hand, regards surface leaching as 
of minor importance and emphasizes the effect of marine 
leaching. He has proven the reality of this process, on a small 
seale at ; least, in the modern seas and concludes that some dolo- 
mites of former periods may have been formed in this manner. 
Judd (37) is of the opinion that the weakly dolomitic portions 
of the atoll of Funafuti may be explained upon the basis of 


Am. Jour. Sol.—Fourts Srrizs, Vou. XLII, No. 249.—Suptremsrr, 1916. 


Uri 


252. VanTuyl—New Points on the Origin of Dolomite. 


this theory but regards the magnesia content of the more 
highly dolomitie portions as having been enriched by reaction 
with the magnesia of sea water. 


Experimental Evidence. 


On the experimental production of dolomite there is a vol- 
uminous literature. This has been well summarized by F. W. 
Pfaff (38), and later by Steidtmann (39). Dolomite has been 
frequently prepared artificially under conditions of high tem- 
perature or high pressure, or both, but it has been produced 
in the laboratory at ordinary temperatures and pressures only 
in rare instances, and then in minute amounts and under con- 
ditions which doubtfully operate in nature, at least on a large 
scale. It must be conceded then that these experiments fur- 
nish little evidence as to the actual conditions obtaining when 
extensive beds of dolomite are formed naturally. For the pur- 
pose of obtaining more accurate data on this point, a series of 
experiments was begun at ordinary temperatures and pressures 
early in 1912. In this series it was attempted to simulate 
natural conditions as near as they could be estimated, and to 
obtain some quantitative measurement of the effect of time 
and of concentration in the production of dolomite. In one 
set of experiments it was attempted to reproduce the condi- 
tions which exist in nature when limestone is altered to dolo- 
mite beneath the sea by solutions bearing magnesia. In these 
the effect of solutions of known concentration of MgCl, and 
MgSO,, and of mixtures of the salts, both with and without 
the presence of NaCl, on powdered aragonite was tried. The 
concentration of the magnesium solutions used ranged from 
two to ten times the concentration of the magnesia in sea 
water. After a period of six months, residues from the experi- 
ments were thoroughly tested for dolomite. The results were 
entirely negative. No trace of dolomite could be found. 
Careful re-examination of the residues after a period of nearly 
three years still gave the same result. The analyses showed 
that the CaCO, had reacted slightly with the solutions, but no 
MegCoO, had been deposited. Apparently the soluble trihy- 
drate of MgCO, had been formed. It then appears that dolo- 
mite cannot be prepared artificially under these conditions. 

In a second set of experiments it was attempted to obtain 
dolomite as a direct chemical precipitate at ordinary tempera- 
tures and pressures. First solutions of the bicarbonates of cal- 
cium and magnesium, after being standardized, were mixed in 
molecular equivalent proportions so as to give the same ratio 
of CaCO, to MgCO, as exists in normal dolomite. The solu- 
tion was then allowed to evaporate spontaneously during a 


VanTuyl—New Points on the Origin of Dolomite. 258 


period of one month. It was noted that the carbonates came 
down separately with the CaCO, much in advance of the 
MegCoO,. The precipitate then contained only the mixed ear- 
bonates—no dolomite was formed. Scheerer (40) previously 
obtained the same results in a similar experiment. Negative 
results were still obtained when a solution prepared as above 
was inoculated with a crystal of dolomite and allowed to evapo- 
rate. Nor could the double carbonate be prepared upon evapo- 
rating spontaneously a solution of the two carbonates obtained 
by the action of carbonated waters on normal dolomite even 
when a dolomite crystal was introduced and a concentrated 
solution of sodium chloride and magnesium salts was added. 

The experimental evidence so far obtained, therefore, does 
not suggest the circumstances under which large masses of 
dolomite can be formed in nature under ordinary conditions 
either by the alteration of limestone or by chemical precipita- 
tion. It is to be regretted that a careful study of the process 
of dolomitization where it is going on in the seas to-day has 
never been made. Such a study would doubtless throw much 
valuable light on the problem. It may well be that bacteria 
play an important role in the production of dolomite as sug- 
gested by Nadson. 


Field Evidence. 


Realizing the importance of careful field studies of dolomitic 
formations in interpreting the conditions of their origin, the 
writer undertook a study of the dolomites of the Upper Missis- 
sippi Valley under the auspices of the lowa Geological Survey 
during the field season of 1912. More recently a grant from 
the Esther Herrman Research Fund of the New York Academy 
of Sciences has made possible much more extensive field studies 
in the eastern and central states. Dolomites ranging in age 
from the Cambrian to the Mississippian have now been exam- 
ined and many samples collected for detailed chemical and 
petrographic study. It is possible to outline in this paper 
only some of the more important results obtained. 

It should be pointed out that the term dolomite is used here 
in the broad sense to include both normal dolomite and dolo- 
mitic limestone. It is not necessary to differentiate between 
these in a discussion of their origin. 

The field studies undertaken during the course of this inves- 
tigation have alone furnished irrefutable evidence that most of 
the dolomites examined, regardless of their age, are replace- 
ment products. The following facts support this contention : 
(1) the lateral gradation of beds of dolomite into limestone, 
sometimes very abruptly; (2) the mottling of limestones by 


254  VanTuyl—New Points on the Origin of Dolomite. 


irregular patches of dolomite on the borders of dolomite 
masses ; (3) the existence of remnants of unaltered limestone in 
dolomite, and of nests of dolomite in limestone; (4) the irregu- 
lar boundaries between certain beds of limestone and dolo- 
mite; (5) the presence of altered oolites or fossils in many 
dolomites ; (6) the protective effect of shale beds; and (7) the 
obliteration of structures and textures. 

In some instances the relationship of dolomite to limestone 
is such as to indicate that the alteration was accomplished by 
solutions which migrated from above downwards after the lime- 
stone was formed, or at least in the closing stages of its forma- 
tion. ’ 

It is an interesting fact that certain layers have sometimes 
been passed over during the dolomitization of adjacent ones, 
and show little or no sign of alteration. The so-called inter- 
stratification of limestone and dolomite cited hy some as evi- 
dence in favor of some primary theory of origin is then, in 
some cases at least, rather a pseudo-inter-stratification produced 
by the selective dolomitization of an or iginal limestone. Some 
layers which have been passed over have been noted to be 
coarser grained than the adjacent layers which have been 
altered and this would seem to explain their greater resisting 
power. At times, however, the unaltered layers do not appear 
to differ markedly from the altered ones. The phenomenon is 
then difficult to account for. Normally the contact lines 
between such interbedded layers of limestone and dolomite are 
fairly regular and definite, but in some instances they are 
known to be very irregular and may even simulate irregular 
contacts produced by disconformity. A remarkable example 
of a psendo-disconformity produced by uneyen selective dolo- 
initization has been observed in the St. Louis limestone near 
Farmington, lowa. Here a bed of altered limestone is found 
resting very irregularly on a bed of dolomite. The two beds 
are very different physically and might readily be taken at first 
sight for two distinct formations, ‘put when ‘the contact is 
traced laterally for a short distance the lower bed loses its dolo- 
mitic character and passes into a limestone very similar to and 
continuous with the bed above. 

Another striking relationship of limestone to dolomite is 
exhibited in a certain layer of an interbedded series of lime- 
stones and dolomites of the Beekmantown in the old Walton 
Quarry near Harrisburg, Pa. The beds dip south here at an 
angle of 30°. The layer in question is represented by dolo- 
mite six feet in thickness in the upper part of the quarry face 
and on each side of it appear good limestone layers. Now in 
the lower part of the quarry the lower half of this layer passes 
abruptly into limestone and continues to the quarry floor as 


VanTuyl—New Points on the Origin of Dolomite. 255 


two distinet layers each 3 feet thick. Samples of the dolo- 
mite at the point where it passes into limestone yielded 18°1 
per cent of MgOO, while the limestone itself yielded only 0°83. 

It will be noted that in the above instances the gradation 
of limestone into dolomite is abrupt, but in many cases the 
gradation takes place through transition zones of limestone 
mottled with dolomite. There can be no doubt but that these 
mottled limestones represent an incipient stage in the process 
of dolomitization and it is believed that many dolomites have 
passed through such a stage in the progress of their formation. 
In most cases the phenomenon of mottling appears to be of 
purely inorganic origin, having resulted from a process of dolo- 
mitization which began at certain favorable centers and spread 
outwards. In some cases, however, it has been produced by 
the selectine alteration of areas suggesting algze and fucoids in 
the limestone first, and the spreading out of the dolomite from 
these as nuclei. The Tribes Hill limestone, as developed at 
Canajoharie, New York, furnishes an excellent illustration of 
the mottlmg produced by the latter method. All stages of 
mottling from altered fucoid-like markings to a rock uniformly 
dolomitie may be traced in this. 

It has been observed that the spreading of dolomitization 
from certain centers in a limestone may give rise to mottling 
on a large scale if these centers be few and far apart. For 
example there is a conspicuous bed of dolomite pseudo-bowlders 
in the St. Louis limestone at Alton, Il., which appears to have 
been formed entirely in this manner. These bowlder-like 
masses range from a few inches up to six feet in diameter and 
contain 32°39 per cent of MgeCO, while the limestone matrix 
bears only 8°39. That they were formed in place is clearly 
indicated by the fact that the contact of the bowlders with the 
limestone matrix is occasionally gradational and that the strat- 
ification lines of the limestone may at times be traced directly 
through the bowlders. In a layer of limestone a few feet 
above the bowlder bed here a similar process of local dolomiti- 
zation has given rise to the development of irregular leuses of 
dolomite. 

If has often been noted during the course of the field studies 
that many dolomites known to be of secondary origin show 
little or no evidence of shrinkage and porosity determinations 
have since shown that the transformation of a limestone to 
dolomite, even subsequent to its deposition, need not neces- 
sarily be accompanied by a decrease in volume as pointed out 
by Beaumont and consistently adhered to by later writers on 
the subject. It seems probable, therefore, that the replace- 
ment may proceed at times according to the law of equal 
volumes as enunciated by Lindgren(41) and that the inter- 


256 VanTuyl—New Points on the Origin of Dolomite. 


change need not be molecular, In view of this fact compact 
dolomites showing no shrinkage effects can no longer be 
regarded as primary. 

Further studies will doubtless show that considerable shrink: 
age effects produced by dolomitization are not common. It is 
believed that many vesicular dolomites have resulted from 
atmospheric leaching long after their formation. 


Petrographic Evidence. 


The microscopic study of many thin sections of dolomitic 
limestone has not only further amplified and strengthened the 
field evidence but has also thrown new light upon the details 
of the process of alteration. By employing microchemical 
tests it has been possible to distinguish between calcite and 
dolomite in the sections and make clear the most intimate rela- 
tionships of the two minerals. It should be stated, however, 
that these tests furnish no reliable guide to the exact amount 
of magnesia in the rock, for crystals containing less than 25 per 
cent of MgCO, may behave essentially like normal dolomite. 
But this is to be regarded in truth as a distinct advantage, for 
alterations of only a slight degree are indicated as well as the 
more marked ones. 

It must be admitted that if dolomite has a diverse mode of 
origin the microscope fails to reveal it. Careful examination 
of every variety of dolomite fails to show any positive evidence 
in favor of either the primary chemical or the clastic theory of 
origin. On the other hand, there is abundant evidence in 
favor of the alteration theory. It is true that certain dolo- 
mites, whose origin is not certainly known from their field 
relations, possess an extremely fine and uniform texture, and 
this feature has in fact led Daly (42) to believe that these repre- 
sent original chemical precipitates. In order to test the 
validity of this argument the finest grained dolomite of 
unknown origin encountered by the writer in these studies was 
compared with the finest grained dolomite of known secondary 
origin. For example the Jefferson City dolomite of the Ozark 
region, whose mode of formation is not definitely known, pos- 
sesses ‘unusually dense and compact layers which are seen 
under the microscope to be made up of minute granules the 
majority of which are below -003"™ in diameter, some meas- 
uring only 001™". The granules are vat of an original 
chemical precipitate. The strength of this interpretation is 
weakened, however, by the fact that a dolomite of known 
secondary origin has been found in the Middle Devonian of 
Iowa which is equally as fine-grained. The latter dolomite has 
resulted from the alteration of a dense, lithographic-like lime- 
stone with the approximate retention of the original texture. 


VanTuyl—New Points on the Origin of Dolomite. 257 


As regards the possibility that some dolomites may be of 
clastic origin, none has been found which exhibits any signs of 
clastic structure. But that the original structure might have 
been obliterated during recrystallization is easily conceivable 
in rocks of this type. 

Turning now to the dolomites which from their field rela- 
tions are known to be secondary after limestone we have much 
more definite data. Indeed in these, by virtue of the fact that 
the alteration has frequently been halted before it proceeded 
to completion, we are often able to trace all stages of dolomiti- 
zation from a limestone showing only incipient alteration to a 
good dolomite. Thus, it is possible to describe the steps 
normally passed through during the transformation of a lime- 
stone to dolomite. 

So far as the testimony of the microscope goes the fine- 
grained limestones are more susceptible to alteration than the 
coarser-grained ones, a fact which is in keeping with the laws 
of chemistry. The evidence also indicates that the alteration 
may not proceed in exactly the same manner in the two types 
of limestone. 

The alteration of fine-grained compact limestones seems to 
be accompanied normally by a notable increase in size of grain. 
Usually the diameter of the dolomite crystals formed is many 
times as great as that of the original calcite grains. But in 
rare cases, such as that of the dense Middle Devonian dolomite 
referred to above, the original structure and texture seems to 
be approximately retained. In the dolomitization of such fine- 
grained limestones the replacement frequently begins at many 
centers throughout the rock and spreads outwards from these, 
or if the rock possesses fine stratification the replacement may 
follow closely these original lines of weakness in the early 
stages. In those cases where the alteration begins at certain 
centers and spreads out from these, fucoid-like markings occa- 
sionally serve as the nuclei as in the ease of the Tribes Hill 
limestone. But as a general rule no organic influence is noted. 
Normally the limestone is altered uniformly in the process of 
spreading from the dolomite centers, but it cannot be said that 
it is altered completely, fur the dolomite patches often possess 
less than twenty per cent of MeCO,. Small remnants of lime- 
stone, however, may occasionally escape alteration and become 
incorporated in the dolomite patches. The boundary between 
the limestone and the spreading dolomite area may or may not 
be abrupt. When abrupt, the rock may assume the appearance 
of a breccia and the term ‘“ pseudo-breccia” may aptly be 
applied. When the boundary is gradational, on the other 
hand, rhombohedrons of dolomite, variable in size but usually 
nearly perfect in their development, are disseminated through 


258 VunTuyl—New Points on the Origin of Dolomite. 


the limestone a short distance in advance of the main dolomite 
area. As the replacement proceeds the dolomite areas grow 
larger and larger and eventually meet and become confluent 
thereby giving rise to a rock which is uniformly dolomitie. 
Further addition of magnesia nay then take place by altering 
the rock more completely. 

In the coarse-grained limestones, especially those which were 
originally coarse- -grained, such as the crinoidal limestones, on 
the other hand, mottling does not seem to be the rule in "the 
early stages of alteration. In these the replacement appears to 
affect the matrix first and to spread rapidly through the rock. 
The coarser grains are next affected, being broken down into 
ageregates of small dolomite erains. Tn the end a coarse- 
grained limestone may be changed over into a uniformly fine- 
grained one. 

In the dolomitization of limestones of both types the calear- 
eous skeletons of organisms appear in most cases to successfully 
withstand alteration and these, owing to their greater solubility 
than dolomite, are then removed to leave molds by a process 
of atmospheric leaching when the formation passes into the 
belt of weathering. 


Conclusions. 


Considering all the evidence, it seems probable that the 
great majority of our dolomites had their inception in the 
alteration of limestones. It will not be denied, however, that 
some dolomitic formations of minor impor tance may have had 
a different origin. For instance, some impure dolomitic linie- 
stones associated with shales very probably represent original 
clastic deposits which have not suffered any alteration what- 
ever, and there is some reason for believing that certain dolo- 
mitice limestones high in siliceous material, such as the Silurian 
waterlimes of New York State, may have had a similar origin. 

The importance of marine and surface leaching in increasing 
the magnesia content of limestones originally low in magnesia 
should likewise not be overlooked. There can be no doubt 
that this process has greatly enriched the more vesicular dolo- 
mitic limestones in magnesia. But the leaching theory does 
not explain the ultimate source of the magnesia. It merely 
shows how the magnesia content of a limestone originally low 
in this constituent can be enriched. 

To return now to the dolomites which have resulted from 
the alteration of limestone, there are many rea&$ons for believ- 
ing that the more extensive of these have all been formed 
beneath the sea, and that dolomitization affected by ground 
water is only local and very imperfect. Some of the features 


VanTuyl—New Points on the Origin of Dolomite. 259 


which lend weight to this view are as follows: (1) The dolo- 
mite areas of mottled limestones are believed to have undergone 
recrystallization at the same time as the associated limestone 
areas as suggested by the occasional development of zonal 
growths of calcite and dolomite. (2) In imperfectly altered 
limestones the dolomite is seen to follow original lines of weak- 
ness rather than secondary structures such as ; joints or fractures. 
(8) In most cases of mottling the dolomitization appears to 
have progressed uniformly as we should expect it to in an 
unerystallized rock, rather than to have progressed by forming 
veinlets and stringers in the early stages. (4) The existence of 
perfect rhombs of dolomite in many imperfectly altered lime- 
stones suggests that the latter had not yet solidified when the 
dolomite rhombs were formed. (5) The widespread extent 
and nearly uniform composition of many dolomites indicates 
that they must have been formed by an agent capable of oper- 
ating uniformly over wide areas. (6) An adequate source of 
magnesia for transforming extensive limestone formations into 
dolomite is found only in “the sea which contains many times as 
much of this constituent as ordinary ground water. (7) Many 
dolomites are directly and regularly overlain by pure limestone 
formations or by thick shale beds, proving that they must have 
been formed before these overlying beds were deposited. 

Some dolomites of minor importance, such as those associ- 
ated with ore deposits and probably most, if not all of those 
related to fractures (vein dolomites), must have been formed 
through the agency of ground water. But in general, ground 
water is incapable of carrying dolomitization “far. Study of 
analyses of ground water, and of river water, shows these to 
be uniformly low in magnesia, this constituent normally being 
greatly exceeded in amount by lime. How, then, could such 
waters dolomitize limestone when they already contain lime 
far in excess of magnesia? The law of mass action speaks 
strongly against ordinary ground water being able to accom- 
plish extensive dolomitization. In the case of mineral springs 
and the mineralizing solutions which are related to ore 
deposition, however, it is conceivable that magnesia might be 
present in sufticient proportions to accomplish local dolomitiza- 
tion and doubtless most vein dolomites have been so formed. 

University of Illinois, 

Urbana, Ill. 


REFERENCES TO THE LITERATURE. 


1. Von Buch, quoted by Zirkel, Lehrbuch der Petrographie, 2d ed., vol. 
ili, p. 505. 

Frapolli, Bull. Soe. géol. France (2), vol. iv, p. 832, 1847. 

Durocher, Compt. Rend., vol. xxxiii, p. 64, 1851. 

Favre, ibid., vol. xxviii, p. 364, 1849. 


goto 


Van Tuyl—New Points on the Origin of Dolomite. 


Collegno, Bull. Soe. géol. France, vol. vi, p. 110, 1884. 

Morlot, Haidinger’s Naturw. Abhandl., vol. i, p. 305, 1847. 

Beaumont, Bull. Soc. géol. France, vol. viii, p. 174, 1886. 

Morlot, Compt. Rend., vol. xxvi, p. 311, 1848. 

Jackson, this Journal, vol. xlv, p. 140, 1848. 

Van Hise, U.S. Geol. Surv., Mon, xlvii, p. 804 ff. 

Green, Jour. Roy. Geol. Soe. Ireland, 2d ser., vol. iv (iii), pp. 140-143, 
1846, 

Dana, this Journal, vol. xlv, p. 120, 1843. 

Dana, Corals and Coral Islands, p. 356. 

Sorby, Rept. Brit. Assoc. Ady. Sci., p. 77, 1856. 

Weller, Bull. Geol. Soc. America, vol. xxii, pp. 227-231, 1911. 

Blackwelder, ibid., vol. xxiv, pp. 607-624, 1913. 

F. W. Pfaff, Neues Jahrb., Beil, Bd.. xxiii, p. 529 ff., 1907. 

Phillipi, Neues Jahrb., Festband 1907, i, p. 397 ff. 

Skeats, Bull. Mus. Comp. Zool. Harvard College, vol. xlii, p. 52 it 
1903. 

Walther, Gesichte der Erde und des Lebens, p. 90. 

Boué, Bull. Soe. géol. France, vol. i, p. 115, 1831. 

Bertrand-Geslin, ibid., vol. vi, p. 8, 1834. 

Coquand, ibid., vol. xii, p. 314, 1841. 

Zirkel, Lehrbuch der Petrographie, 2d ed., vol. iii, p. 503. 

Fournet, Bull. Soc. géol. France (2), vol. vi, p. 502, 1849. 

Forchhammer, Journal prakt. Chemie, vol. xlix, p. 52, 1850. 

Hunt, this Journal (2), vol. xxviii, p. 382, 1859. 

Linck, Monatsh. deutsch. geol. Gesellsch., 1909, p. 230. 

Daly, this Journal (4), vol. xxiii, p. 98, 1907; also Bull. Geol. Soc. 
America, vol. xx, p. 153, 1909. ‘ 

Lesler, Penn. Second Geol. Surv., Rept. M. M., p. 311 ff., 1879. 

Phillipi, Frech’s Lethea Geognostica, vol. ii, p. 31, 1908. 

Grabau, Bull. Geol. Soc., America, vol. xxiv, pp. 524-6526, 1913 ; also 
Principles of Stratigraphy, p. 760. 

Grandjean, Neues Jahrb., 1844, p. 543. 

Hardman, Proc. Roy. Irish Acad. (2), vol. ii, Science, p. 705 ff., 
1875-77. F 

Hall and Sardeson, Bull. Geol. Soc. America, vol. vi, p. 167, 1895. 

Hégbom, Neues Jahrb., 1894, vol. i, p. 262 ff. 

Judd, The Atoll of Funafuti, p. 362 ff., 1904. 

F. W. Pfaff, Neues Jahrb., Beil. Bd., xxiii, p. 529, 1907. 

Steidtmann, Jour. Geol., vol. xix, p. 323, 1911. 

Scheerer, Neues Jahrb., 1866, p. 1. 

Lindgren, Econ. Geol., vol. vii, p. 521, 1912. 

Daly, Bull. Geol. Soc. America, vol. xx, p. 158, 1909. 


S. Powers— Volcanic Domes in the Pacific. 261 


Arr. XXITX.—Volcanic Domes in the Pacific; by 
Srpney Powers. 


InrRopuction. 

Srnce the famous dome and spine rose on the summit of 
Mont Pelée on Martinique in 1902-3, five domes of a some- 
what similar nature have appeared on yoleanoes in the Pacific 
Ocean. Three spine-like domes have risen on the summit of 
Bogoslof voleano in Bering Sea, and two of them have been 
destroyed by explosions. The other two domes have appeared 
in Japan, one on the summit of Tarumai, in Hokkaido (Yezo), 
during the spring of 1909, the other on the side of Usu, also 
in Hokkaido, during 1910. It is the purpose of this paper to 
deseribe the latter two domes, which were seen by the writer 
in 1915, together with the other domes in Japan, those at 
Bogoslof, and those which formerly existed at Kilauea, Hawaii. 
A list of the known voleanic domes is appended with a brief 
discussion of the theory of origin of spines and domes in gen- 
eral. A portion of this material has not previously been 
published and a full list of known domes has never appeared. 

Voleanie domes and spines are either masses of new, viscous, 
lava pushed out from the top or sides of volcanoes, or masses 
of material already on the voleanoes which are elevated by the 
push of newly injected magma from below. Im every case 
described below, new lava has appeared at the surface either 
comprising the greater part of the elevated mass or in the form 
of voleanic bombs. Spines differ from domes in the form of 
the extruded mass: Spines (aiguilles, Beloniten,! Felszahne) 
are monolithic needles of new lava, such as the one on Mont 
Pelée, which may form the centers of domes as was seen in 
Perry Peak, Bogoslof Island, after the explosion of 1906-7; 
domes (Staukuppen, Quellkuppen, Tholoiden,! cumulo-vol- 
canoes) are more rounded masses of new lava such as the 
trachyte ‘“Puys” of the Auvergne region or portions of older 
lava or ejectamenta elevated by new lava beneath, as in the 
Usu uplift of 1910 and in the Kilauean domes. 


EXAMPLES. 
Tarumadake.2_ The voleano Tarumai is situated on Hok- 
kaido (Yezo), the northern island of Japan, 30 miles north 
*The terms Beloniten and Tholoiden were introduced by K. Schneider, 
Die vulkanischen Erscheinung der Erde, Berlin, 1911; but F. v. Wolff 
(Der Vulkanismus, vol. i, Stuttgart, 1914, p. 492) points out that the 


former term has been previously used with another meaning. 
* Dake signifies hill or mountain in Japanese. 


262 S. Powers— Volcanic Domes in the Pacific. 


of Voleano Bay and 8 miles from the sea. During the last 
period of activity, in 1909, a volcanic dome rose in the summit 
crater to a height of about 400 feet. The dome (fig. 1) is 
now a steep-sided mass of blocks with a flat top from which 
steam issues. 

Smoke was first seen on the summit of the mountain Jan- 
uary 11, 1909, and ash fell on the 22nd and 27th of that 
month.* During February smoke and ash were reported on 


Fie. 1. 


Fie. 1. The volcanic spine which rose in the summit crater of Tarumai in 
1909 (after Oinouye). 


four occasions; on March 3 a noise was heard and on March 
14 there was an earthquake, caused apparently by a gas explo- 
sion. During this period the new lava was rising in the vent, 
for on March 30 an explosion was accompanied by a heavy 
fall of ash to the southeast and bombs of new material were 
ejected. The mountain was ascended on April 4, but no fresh 
lava had yet appeared in the crater. On April 12 an explosion 
threw out ash, lapilli, and anorthite crystals from the new lava 
which was evidently just beneath the floor of the crater. 

Fire was first seen on April 17, indicating that the new 
lava had reached the surface. A dome commenced to grow and 
it was seen over the rim of the crater on the 20th. Three days 
later an ascent of the mountain was made and a glowing, 
rounded dome was seen. A maximum height of 440 feet was 
reached about May 1, but a considerable settling of the center 
of the mass followed the rapid rise, forming a flat top and 


*The outbreak is described by: H. Simotomai, Der Tarumaiausbruch in 
Japan 1909, Zeitschrift Ges. Erdkunde, Berlin, 1912, pp. 433-444; I. 
Friedlaender, Ueber einige japanische Vulkane, Mitt. Ges. Natur- und 
Volkerkunde Ostasiens, vol. xii, Tokyo, 1909. 


4 
a 


S. Powers— Volcanie Domes in the Pacific. 263 


destroying the domical form. A final explosion on May 12 
opened a large fissure in the floor of the crater near the dome 
and spread a covering of ash over the region on the northeast. 
From this fissure, a crack about 300 feet long with a maximum 
width of 15 feet and a depth of over 60 feet, steam was rushing 
in August, 1915. , 

Huge blocks of porous pyroxene-hornblende andesite of a 
light to reddish grey color compose the outside of the dome. 
The andesite is filled with anorthite crystals 14 to 4% inch in 
length and it shows banding due to variations in porosity. The 
dome may be composed of a uniformly solid mass of andesite 
as figured by Simotomai* or it may be formed around a central 
core as was Perry Peak, Bogoslof, described below. 

Small domes of glassy spleens. are reported on Eniwadake, 
an extinct voleano a few miles west of Tarumai.? The domes 
are located on the northwest side of the summit crater and on 
a small peninsula in Lake Shikotsu. 

Usudake. The voleano Usu, in Hokkaido, five miles north 
of Voleano Bay, is situated on the south side of Lake Toya, 
one of the peculiar depressions like Lake Shikotsu in Hokkaido 
and Lake Ikeda in Kyushu whose bottom is below sea level. 
Usu (see fig. 2) consists of a large “somma” rim about 214 
miles in diameter within which are two rounded domes, O-Usu 
(fig. 3) on the east, 975 feet high, and Ko-Usu (fig. 4) on the 
west, 555 feet high. In 1910 an eruption took place north 
of the somma rim, opening about 45 small eraterlets and uptilt- 
ing a rectangular block of the mountain in a manner somewhat 
similar to uplifts which take place at Kilauea on the edge of 
the crater Halemaumau. O-Usu and Ko-Usu are volcanic 
domes like those of the Puy de Dome region of France. The 
1910 uplift was evidently caused by the intrusion of new magna 
which did not reach the surface. 

The eruption of 1910 commenced with a seismic prelude 
characteristic of Japanese voleanoes, the first shocks being felt 
at the time the barometric pressure was low and the outbreak 
occurring when it was at a maximum (29.99 in.). The first 
earthquakes were felt July 21; 25 were recorded the following 


‘BE. Reyer (Theoretische Geologie, Stuttgart, 1888, pp. 98-9, 152) sug- 
gested this structure for certain rounded masses in Bohemia—notably 
Schlossberg von Teplitz—first described as Quellkuppen but later shown 
to be erosion remnants of Miocene intrusives (v. Wolff, Der Vulkanismus, 
I, p. 484, 1914). 

oul: Friedlaender, Ueber den’ Usu in Hokkaido und iiber einige andere 
Vulkane mit Quellkuppenbildung, Petermann’s Mitt., vol. lviii (1), pp. 
309-12, 1912. 


264 S. Powers— Volcanic Domes in the Pacific. 


day; 110 on July 23; 351 on the 24th; and 162 on the 25th, 
the day on which the eruption began, with the accompanying 
release of gas by explosions.° ‘The first explosions took place 
on the north flank of Usu, about 1,300 feet south of Lake Toya 
and opened craterlets from which ash and rock fragments 
already at the surface of the ground were thrown out. New 


Fic. 2. Map of Usudake showing the volcanic domes O-Usu and Ko-Usu and New 
Mountain, which was tilted up in 1910. The old somma rim of the volcano is shown 
by heavy dashes. Contour interval 20 meters. 


°F. Omori, The Usu-San eruption and the earthquake and elevation 
craters continued to form until the end of the year, but on the 
third day of the eruption smoking bombs of new hypersthene- 


phenomena, Bull. Imp. Earthq. Inves. Comm., Tokyo, vol. v, No. 1, 1911; 
D. Sato, Eruption of Mount Usu, Bull. Imp. Geol. Surv., Japan, vol. 
xxili, 1910. 


; 


S. Powers— Volcanic Domes in the Pacific. 265 


augite andesite were thrown out, indicating that the newly 
injected magma had arisen to within a short distance of the 
surface. Some of the craterlets were active for only a few 
hours, so that the trees on their sides were partly buried but 


Fie. 3. 


Lig 
Ce Oe 


Fic. 3. The dome O-Usu as seen from the west. The south side of the 
dome has been uplifted and the west side steepened by an explosion (after 
Kato). 


Fie. 4. 


Rag hy. ARRAN 
Qu. a 
; Worn dy oo 


es 


Fic. 4. The dome Ko-Usu looking northwest. The east side is supposed 
to have slightly subsided (after Kato). 


not overturned, while others were intermittently explosive for 
several days, forming symmetrical cones and craters with 
diameters as great as 600 feet. In August, 1915, steam was 
still issuing from a few of the larger craters. 

The elevation of the strip of land between the new craters 
and Lake Toya did not become noticeable until August 6, 


266 S. Powers— Voleanie Domes in the Pacifie. 


1910, when it was found that the lake shore for a length of a 
mile had risen 3 feet. A maximum elevation at the shore of 
10 feet at the east end of the uplifted area was reached August 
21, followed by a gradual settling back of 514% feet by 
November 10. 

It was not until four days after the change of level of the 
shore-line was noticed, that attention was called to the forma- 
tion of New Mountain north of a fault-searp which developed 
between East and West Maruyama (fig. 2). New Mountain 
rose gradually, as a more or less rectangular block a mile long 
and 1,000 feet wide, to a maximum height of 310 feet. The 
fault-searp disclosed beds of rock fragments and ash but no © 
massive lava, and these beds were still steaming in August, 
1915. The maximum height of 690 feet above Lake Toya 
(or 956 feet above sea-level) attained by New Mountain was 
not reached until November 9 and by April, 1911, the height 
had decreased 120 feet. A continuation of the uplift under 
Lake Toya was indicated by an increase in the amount of water 
in the lake. 

As indicated above, the force causing the uplift of New 
Mountain appears to have been the intrusion of a mass of 
viscous magma which did not reach the surface, although 
bombs ot the new lava were thrown out. The size of the area 
uplifted may be taken to indicate a large intrusion such as a 
laccolith, as Bailey? has sug ggested, but the arching characteristic 
of the beds above a laccolith was lacking. The partial subsi- 
dence of New Mountain may be compared to the change of 
form of the top of the Tarumai spine from a rounded dome 
to a plateau, and may have been caused by a partial withdrawal 
of the magma, or in part to contraction on cooling and loss of 
gas. 

The voleanie domes O-Usu and Ko-Usu rise to heights of 
975 and 555 feet, respectively, above the floor of the crater. 
O-Usu is the more perfect dome and its symmetry is broken 
only by an uplifted portion on the south side of the summit 
(fig. 3). There is no depression on the summit.’ Ko-Usu is 
an older and less perfect dome, similarly composed of hyper- 
sthene andesite. The east side has apparently been lowered 
by an explosion and a young crater with a diameter of 200 

7B. B. Bailey, Geol. Mag., vol. ix, pp. 248-252, 1912. 

®]7. Friedlaender (Petermann’s Mitt., vol. lviili (1), pp. 309-12, 1912) 
cites certain stream-worn pebbles on the summit as evidence that they 
were elevated to that position with the formation of the dome. It is 


apparent, however, that the dome was formed by new viscous magma and 
that the pebbles were carried up by the Ainus. 


S. Powers— Volcanic Domes in the Pacific. 267 


feet and 100 feet deep exists on the summit. As a Japanese 
painter who lived from 1765 to 1842 showed only Ko-Usu in 
a sketch of the mountain, there is a slight possibility that O-Usu 
rose during historic time. 

Kaimondake. At the southern extremity of Japan in the line 
of voleanoes including Aso, Kirishima, and Sakurajima is the 
quiescent or extinct voleano Kaimondake, 3,030 feet in height. 
Friedlaender® has described the volcano as consisting of an ash 
cone rising to a height of about 2,200 feet where there is a 
crater wall, but the former crater is filled with an andesitic 
dome surmounted by a flat depression but not a crater. The 
dome is composed of very rough lava and it evidently repre- 
sents such a dome as that on Tarumai. The last outbreak of 
the mountain was in 1615, and the last important eruption 
was in 885 A. D. At both these times ash was thrown out, 
but at the former eruption a summit glow was seen, suggesting 
that the dome appeared at that time. 

Sambondake. About 100 miles south of the voleano Oshima 
(Vries Island) and 23 miles southwest of the island Miyake 
is a small group of rocks called Sambondake. The two larger 
masses are described as being composed of andesite, with the 
structure of dikes,1® but the photograph of one of the masses 
(see fig. 5) shows that it strongly resembles in appearance the 
Mont Pelée spine. 

Choka-San. The voleano Chokai-San, in Ugo province, 
northern Japan, has been active seven times since 810 B. C., 
and ten days after the last eruption (1800-1), according to 
B. Koto,14 a cone was raised on the east side of the summit 
erater, very much like the Tarumai dome. 

Kilauea. Several times during the recorded history of 
Kilauea there have been uplifts of portions of the floor of the 
Kilauean sink surrounding the crater Halemauman or of 
debris within the crater and once a dome formed of the con- 
solidated surface of the lava lake was raised over Halemaumau. 

In 1848 the first dome was formed. During the previous 
two years there had been an active lava lake in Halemaumau 
2000 feet in diameter, the surface of which became crusted 


®Peterm. Mitth., vol. lviii (1), pp. 309-12, 1912. 

7. Friedlaender, Mitt. Ges. Natur- und Vélkerkunde Ostasiens, vol. xii, 
Tokyo, 1909. 

“On the volcanoes of Japan, Jour. Geol. Soc. of Tokyo, vol. xxiii, p. 9, 
1916. Professor Koto also mentions that Ma-yama, west of Kampu-San, 
northern Japan, is, according to tradition, a “puffed-up dome” (p. 9). 
Under the head of “Tholoide,”’ Professor Koto classes those voleanoes 
which merely have a rounded form as well as those which are “volcanic 
domes”: in the sense used in this paper. 


Am. Jour. Sct.—FourtH Series, Vou. XLII, No. 249.—Srpremper, 1916. 
18 


268 S. Powers— Volcanic Domes in the Pacific. 


over in 1848. The crust was elevated by a liquid lava beneath 
until it assumed the form of a dome 200 to 300 feet high 
and 2000 feet in diameter. By August the dome had increased 
in height until it was higher than the lower portions of the 
walls of the Kilauean sink, The sluggish basalt was seen 


Fie, 5. 


Fic. 5. Sambondake, an island in the Fujiyama-Bonin Island volcanic 
chain 30 miles south of Oshima, which may be a volcanic spine, 


through cracks in the dome and occasionally it flowed out 
through these cracks and down the sides, increasing the size 
of the dome.*” 

The lava beneath the dome disappeared in the fall of 1848 
and did not rise again until April, 1849, when, for a short 
time, very fluid basalt was thrown from openings in the top 
of the dome to heights of from 50 to 60 feet. With the next 
rise of the lava in 1852 the opening in the top of the dome 
had enlarged to a diameter of 200 feet. The sides of the dome 
were partly flooded by the rise of 1855 and they soon after 
fell into the lake. 


2 W. TT. Brigham, The voleanoes of Kilauea and Mauna Loa, Mem. B, P. 
Bishop Museum, Honolulu, vol. ii, no. 4, p. 61ff., 1909. 


S. Powers— Volcanic Domes in the Pacific. 269 


An open dome was next formed over Halemaumau and it 
remained in place from 1872 until 1886. After the catastrophe 
of 1868 which drained the lava lake, Halemaumau became 
active in 1871 and 1872. In October of the latter year the 
crater had become an immense dome on whose summit were 
two lava lakes. The descriptions of this dome are imperfect, 
but it seems probable that the shores of the single lake of March, 
1872, were elevated by the force of liquid lava below them. 
Four lakes developed on the dome and the tilted beds surround- 
ing the lakes changed in height and form with the variations 
in level of the lakes. In 1880 the dome was regular in form 
with a number of crags elevated above the top of the dome. 
With the emptying of the crater in 1886 the remaining portions 
of the dome, 200 feet in height, collapsed. 

A deep pit with the form of an inverted cone remained after 
the collapse of March, 1886, but four months later lava 
returned and the center of the pit had become a steep cone 
of talus blocks rising 140 feet and partly surrounded by a lava 
lake. The cone rose with the lava beneath until, by October, 
1866, it became a rim of lava blocks 1000 feet in diameter 
and 250 to 450 feet in height with a central depression. The 
basin immediately surrounding the cone rose with it by bodily 
uplift and by flooding"* so that the cone appeared conspicuously 
above the walls of the basin. By July, 1888, the walls of the 
basin had been eliminated and the summit of the cone was 
158 feet higher than two years previously. The cone persisted 
until the collapse of 1891. 

The ability.of molten basalt to raise a dome over Halemau- 
mau in 1848, to elevate the floor of the crater adjacent to the 
open lava lake in 1872, and to elevate a mass of talus into 
the form of a cone in 1886, is confirmed by an uplift in 1894. 
On March 21, the entire surface of the brimming lake appeared 
to be intensely active and agitated. ‘‘Suddenly on the north 
side stones, lava, and ‘dust’ were thrown high into the air 
with spouting columns of fire and in the space of less than four 
minutes the north bank of the lake was tilted to a height of 
100 feet or more, leaving an abrupt wall over the lake with a 
steep and broken slope toward the north.”!* The uplifted area 
was 800 feet long by 400 feet wide. 

One month after the uplift on the edge of Halemaumau the 
hill began to sink and by July 11 it had reached the level of 


18 Measurements by F. S. Dodge, cited by J. D. Dana, Characteristics of 
voleanoes, New York, pp. 109-10, 1891. 

* An observation by Mr. W. R. Castle, cited by W. T. Brigham, op. cit., 
pp. 185-6. 


270 S. Powers— Volcanie Domes in the Pacific. 


the other banks. With the sudden subsidence of the lake on 
that date the hill sank still farther, and the resulting depression 
may now be seen on the northeast side of the Halemaumau pit. 

In December, 1914, a portion of the floor of the Halemau- 
mau pit rose in a manner similar to the 1894 uplift, but more 
slowly. The origin may have been the differential loading of 
other portions of the floor of the pit by fresh flows or it may 
have been the intrusion of lava beneath. On December 4 with 
a lake 400 feet long and 150 feet wide, a portion of the floor 
beneath the main lake and a northeast arm commenced to rise 
as a crag 300 feet long and 100 feet wide. ‘The relative 
movements of the crag and of the lake were irregular: in 14 
days the crag remained 58 feet above the surface of the lake 
while that body rose 41 feet; in 9 days more (January 2, 
1915) the lake rose 12 feet but the crag subsided 23 feet; 
and by March 15 when the lake had subsided 112 feet the crag 
had sunk only 45 feet. 

A similar crag was formed in September, 1915, between 
the main lake and a northwest arm. A rectangular block 
100 feet wide rose about 15 feet, as measured by the writer, 
between September 9 and 10 while the lake remained stationary 
except for the daily rises in the late morning and evening. 
A few days later the lake began to rise and the crag remained 
above the surface of the lake throughout the rising phase. 

Bogoslof. Six peaks have risen from the sea on top of the 
submarine Bogoslof voleano since the early navigators explored 
Bering Sea, about 1768. These peaks have each been composed 
of solid rock and have probably been formed by, the upthrust 
of viscous magma after the manner of the Mont Pelée spine. 
Three of the peaks remain and are connected to form one island 
by the debris from explosions which have destroyed two of 
the other spines. 

The rise of the first peak, Ship Rock, was reported by the 
early mariners, and the rock was not washed away until 1888. 
Old Bogoslof, better known as Castle Rock, was pushed up in 
1796. Various estimates of the size of this island were made 
before erosion began to wear it away, and it appears to have 
been 4,000 feet in diameter and 350 feet in height. There 
was no summit crater, the top being formed of pinnacles. 
New Bogosolf, also called Grewingk and Fire Island, appeared 
in 1883 as a craterless mass of andesite rising precipitously 
from the sea to a height of 800 feet. The name Fire Island 
was applied to the mass for it apparently increased in size by 
newly upthrust masses for several years with accompanying 
smoke, steam, and an occasional glow. 


q 
a 
4 
, 


S. Powers— Volcanic Domes in the Pacific. 271 


Perry Peak (Metealf Peak) appeared in March, 1906, as 
an island 2,000 feet in diameter and 400 feet long, near the 
site of Ship Rock, midway between Castle Rock and Fire 
Island. The sides of the peak were quite smooth and the 
top was described as a “broken horn” as if the mass had 
been foreed through an aperture in the submarine volcano. 
Gas must have accumulated in large quantities within the 
cold exterior of the spine, for after an existence of 10 months, 
an explosion blew away half of it. 

Soon after the destruction of half of Perry Peak, a similar 
spine, McCulloch Peak, rose close by, partly over the place 
which the destroyed half of Perry Peak had occupied. The 
size of McCulloch Peak, when visited in August, 1907, was 
about that of the original Perry Peak. The shattered cross- 
section of the latter showed a central spine, like that of Mont 
Pelée, surrounded by debris which had fallen from and which 
had been blown from the sides and top of the spine during 
its upthrust.’? 

The life of McCulloch Peak, like that of Perry Peak, was 
10 months, for an explosion destroyed the entire mass in Sep- 
tember, 1907, pilmg high with debris the sand bars which 
had formed between Castle Rock, Fire Island, and the remnant 
of Perry Peak. 

During the next few years the changes at Bogoslof are 
uncertain, but in July, 1908, it was reported that no trace 
of Perry Peak was visible, suggesting another explosion. On 
September 10, 1909, the bay which occupied the site of 
McCulloch Peak and of Perry Peak was reported to have 
become a lagoon in which two small islands had appeared, 
These islands continued to rise, so that in June, 1910, the 
larger was 178 feet in height, and the smaller 100 feet. 

The lower peak was named Tahoma Peak in honor of the 
U. 8. S. Tahoma, but the higher one is referred to as Perry 
Peak. On September 18 an explosion opened a crater 
in the higher peak, and ashes together with clouds of smoke 
and steam were ejected. The formation of a crater—so rare 
a phenomenon at Bogoslof—may have been caused by a more 
gradual escape of the confined gases than in the eases of Perry 
and McCulloch peaks. 


»7T. A. Jaggar, Jr., Bull. Amer. Geogr. Soc., vol. xl, pp. 385-400, 1908. 
The earlier history of the voleano is described by C. H. Merriam, Harriman 
ae Expedition of 1899, vol. ii, and Smithsonian Rept. for 1901, pp. 

67-375. 


272 S. Powers— Volcinie Domes in the Pacific. 


SuMMARY. 


The following table shows the size, composition, and impor- 
tant features connected with the various voleanic domes of the 
world. Through lack of sufficient data, the following domes 
are omitted: those of the Auvergne region of France, including 
Puy Chopine, Puy de Déme, “and Puy Sarcouy,2® those in 
Italy, including Monte Tolfa, Monte Cerveteri,!’ Monte Santa 
Croce, Monte Tattani2® and Monte Venere’®; that on Saba??; 
the dome of Chokai-san and the questionable spine of Sam- 
bondake discussed above; and those which may exist on the 
Lipari Islands,*! Pantelleria,?? or on Sardinia.** The lateral 
cone of the Vesuvius formed in 1895-9 grew exotically accord- 
ing to Dr. H. 8. Washington, and does not represent a dome.** 
Certain voleanoes of Eeuador which have been described by 
A. Stiibel,?° as having no summit crater, appear to have suf- 
fered from glacial and other forms of erosion, and in two 
instances the rock at the summit is described as an agelomerate. 

In attempting to draw any general conclusions about vol- 
canic domes it is seen that very little is known concerning 
many of the examples cited. All of the voleanoes on which 
domes have appeared must be classed as old and 13 of the 25 
are extinct. In at least 7 of the 13 extinct volcanoes, activity 
appears to have been closed by the formation of the dome or 
spine over the vent. Not all voleanoes, however, become extinct 
with the formation of domes, for Usu has been occasionally 
active during the Christian era, and a few minor eruptions 
have been recorded in the now quiescent or extinct Kaimondake. 

Tarumai and Mont Pelée have furnished information con- 
cerning the mechanism of dome-formation. The eruption 
commences with earthquakes and explosions as the gas from the 


1° Michel Lévy, Highth Int. Geol. Cong., Paris, 1900, Guide Book 14, 
pp. 7-12; P. Glangeaud, Les voleans d’Auvergne, Paris, 1910; A. Lacroix, 
La montagne Pelée apres ses eruptions, Paris, 1908; M. Boule, La 
Géographie, vol. xi, pp. 7-26, 1905. 

vA. S. Washington, Italian petrological sketches, Jour. Geol., vol. v, 
p. 350, 1897. 

*%Tdem, pp. 241-4. 

*»Tdem, vol. iv, pp. 828-30, 1896. 

77H. O. Hovey, Volcanoes of Martinique, Guadeloupe, and Saba, Highth 
Int. Geogr. Congr., Washington, pp. 447-51, 1904; K. Sapper, In den 
Vulcangebieten Mittelamerikas und Westindiens, Stuttgart, p. 219, 1905. 

OUNE Bergeat, Staukuppen, Festband Neues Jahrb, 1907. 

= Tdem; “also H. S. Washington, Voleanoes and rocks of Pantelleria, 
Jour. Geol., vol. xxi, pp. 662, 1913. 

ag lbleise Washington, Some lavas of Monte Arci, Sardinia, this Journal, 
vol. xxxvi, pp. 577-90, 1913. 

74 Personal communication from Dr. H. S. Washington. 

25 Die Vulkanberge von Ecuador, Berlin, 1897, especially pp. 28, 405, 418. 


273 


C. 


S. Powers— Volcanic Domes in the Paci 


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274 S. Powers— Volcanic Domes in the Pacific. 


rising magma reaches the surface. After the throat of the 
voleano is partly cleared by these explosions, the lava appears 
at the surface as bombs and usually as a mass of incandescent 
blocks which is elevated by the injection of magma from 
beneath. A monolithic mass of rock may be thrust through 
the dome, and, if so, by expansion and explosions of gas it 
becomes surrounded by a pile of debris. Once the dome 
appears at the surface, gas appears to play only a minor réle 
in furthering the uplift, but a major réle in causing the destruc- 
tion of any projecting portions of the dome or even of the 
entire mass. As in the cases of Perry Peak and McCulloch 
Peak at Bogoslof, the gas rising from the deeper seated portions 
of the magma may apparently become confined under a 
hardened crust in such a quantity that the whole top is 
blown off. 

Vicosity is the principal factor which determines whether 
the magma shall appear as a flow or a dome. At Santorin in 
1866 a dome was formed, but the lava finally burst out the 
side as a flow, whereas at Colima in 1869 and at the crater near 
Pauline Lake, Oregon, the flow came first, and an increas- 
ing degree of viscosity finally led to the formation of a dome. 
Contrasted to these domes built by magmas of low fluidity, 
and frequently great porosity, stand the Kilauean uplifts 
caused by basalt, which, when liquid, is one of the least viscous 
of magmas. The frozen crust of a lava lake was elevated about 
600 feet at one time, the floor of older lava surrounding an 
open lava lake was raised at another time, and still later a pile 
of talus in the form of an inverted cone was raised into a debris 
cone in the center of which the lava lake finally appeared. 
The uplifted masses at Kilauea and at New Mountain formed 
at Usu in 1910 differ from the other domes because consoli- 
dated lava or talus instead of newly intruded magma formed 
the uplifted mass. The principle of uplift, however, appears 
to be the same, because in each case new lava appeared later at 
the surface. 


A. Il. Phillips—New Zine Phosphates. 275 


Arr. XXX.— New Zine Phosphates from Salmo, British 
Columbia ; by AtexanpER H. Paicuirs. 


During January, 1916, a small collection of ores and min- 
erals, representing the occurrences and associations at the 
Hudson Bay Mine at Salmo, British Columbia, was received 
by the Geological Department of Princeton, from Mr. Dave 
McBurney. Included in this collection was a small specimen 
which, after analysis, was recognized as a new basic zine phos- 
phate. Mr. McBurney describes the occurrence of this min- 
eral in a letter as follows: ‘“ We ran into this ore last Octuber 
and most all of it was taken out and shipped. This ore was in 
a sort of a cave 16’ by 24’ and 8’ high. When we broke into 
it, there were pillars of the ore reaching from the roof to the 
floor of the cave, also masses hanging down from the roof. 

. The main ledge of zine carbonate ore passes directly over 
this cave. It is cut by two dykes at the cave, one dyke form- 
ing the wall and the other the roof of the cave...... On 
the floor there was a mass of very phosphatic clay, which 
carried 20 per cent zinc, and buried in the clay were great 
chunks of this ore” Mr. McBurney also adds, that the cave 
is on the 200-foot level. About one hundred tons of ore were 
taken from the cave, and the mine is absolutely dry, except 
where the two dikes cut the formation. A description of this 
new zine phosphate has been sent to the Mineralogical Maga- 
zine by Dr. T. L. Walker of Toronto,* and has been named 
spencerite by him and its formula fixed as Zn,(PO,),.Zn(OH),. 
3H,O 

The specimen of spencerite in the collection from Mr. 
McBurney was apparently formed on the floor of the cave, as 
it was coated with clay. It was a mass of radiated and reticu- 
late erystals, some of which are nearly an inch and a half in 
length. The erystals are white, slightly greenish in the mass 
with a strong pearly luster on the good cleavage. There are 
no terminal faces, as the specimen has been much affected by 
solution, and there are solution cavities separating the spencer- 
ite from a thin botryvoidal crust of calamine. Calamine is also 
included in isolated solution cavities of the spencerite and has 
been formed as a later product. 

The spencerite is practically a chemically pure compound and 
as my analysis had been completed before hearing from Dr. 
Walker, I am adding the results here simply to corroborate his 
work. The specimen was air-dried and yielded: ZnO = 60°39, 
P,O, = 26:18, H,O = 13-44. The specific gravity as deter- 
mined by methylene iodide is 3°123. Hardness about 2°75. 
Decrepitates strongly in the closed tube, yielding much water 


* From personal letter from Dr. Walker. 


276 A. Hl. Phillips—New Zine Phosphates. 


and becoming yellow while hot. A sample was tested for loss 
of water at various temperatures with the following results ; 
expressed in percentages. 


110° 190° 140° 167° 2048 944°" 978° = (Redthent 
"19 “41 1°39" 3°89) 9°37. "9°65, 9-41 13°22 - 


All the above results would indicate that the formula assigned 
to the mineral is undoubtedly correct. 

LHibbenite—Mr. McBurney very kindly responded to a 
request for more material with a specimen weighing a little 
over 500 gms. This specimen was, apparently, a portion of a 
rounded nodule of radiated spencerite crystals, enclosed also in 
a botryoidal crust of nearly pure white calamine (silicate). 
Some of the crystals showed cleavage surfaces nearly three 
inches in length. The specimen was much affected by solu- 
tion, and was very friable in portions, some lamine being 
more soluble than others, breaking down into thin seales. 
Under the binocular a crystal angle quite different from the 
spencerite in appearance and slightly yellow in contrast to it 
was noted. Farther search throngh the specimen yielded 
eight or ten of these crystals, varying from eight to twelve 
millimeters in length. These crystals I believe to represent 
another new basic zine phosphate and I suggest the name hib- 
benite for it, in honor of Dr. John Grier Hibben, President of 
Princeton University. 

Habit.—The habit is orthorhombic, tabular parallel to the 
macropinacoid, @ (100), nearly as broad as long and approxi- 
mately one quarter as thick along the brachyaxis, as broad 
along the macroaxis. They are all combinations of the pin- 
acoids a@(100) and 6(010), the prism s(120), the pyramid 
p (ill) and the macrodome d(101). The brachypinacoid is 
the dominant face, yielding the tabular appearance of the crys- 
tals. Implanted separately upon and evenly distributed over 
all the crystal faces are small, rounded lens-shaped crystals. 
They average about one millimeter across, have no definite 
orientation to the crystalline directions of the hibbenite or to 
each other and are so rounded by parallel growths that crystal 
forms or faces cannot be-identified. These small erystals I 
believe to be also another new basic zine phosphate. The hib- 
benite crystals are all simple in habit and separately imbedded 
in the spencerite. In several instances parallel growths were 
attached to the terminations and extending out in the matrix, 
ending in rounded granular stringers. These parallel growths 
were easily detached, leaving the terminal faces intact, but 
much pitted and scarred. The brachypinacoid, 6 (010), is 
inconspicuous, very narrow and striated parallel to the vertical 
axis. It occurs on about half of the crystals. The prism, 


A. Hf. Phillips—New Zine Phosphates. 277 


$(120), is always well developed, but strongly striated verti- 
cally. The alternations of growth between the prism and the 
brachypinacoid are so mar ked, as to round this portion of the 
prism zone almost circular. The pyramid, p (111), is present 
on all the crystals and is the second best developed form. The 
faces are rounded and striated parallel to their intersections 
with the macropinacoid. The form is equally developed at both 
terminations. The macrodome, d (101), is small and variable, 
and while the angle fixes the face, as the unit dome, in several 
cases it appeared triangular, as if not in the same zone as 
p, p’. This is caused by the rounded nature of the pyramid 
faces and in the illustration the dome is shown as the unit 
dome in contact with macropinacoid and its intersections with 
the unit prism parallel. The com- 
parative development of all the forms 
is as represented in the illustration. 

Angles.—While to the eye the 
various faces seemed perfect and 
bright enough to yield reflections, 
in the woniometer they give only 
a confused blur, with no indication 
of a signal whatever. The measure- 
ments are, therefore, very imperfect, 
measured mostly with a small Wol- 
laston goniometer. The axial ratio 
and erystal angles are only approxi- 
mate. 


Average Limits No. 
0} 807 '37' 79° 58" to 80° 50 
Drs 0 7 eros Or. Sd OB! + 4 
bys a79> SAr ee 20! § 800 5 
1G) Rau teal RSH A (Say Wea fs ans Uae 
= 0°589 : 1 : 0-488. 


Boarspere (l2O)a (I 
and (100) :(1 
Gd SOL ie CL 
YORE Gs Pale ea a 
Axial ratioa:b:e 


The combination of forms, the erystal angles and axial ratios 

are very near that of hopeite as given by J. L. Spencer.* 
Chemical composition.—Several crystals were ground, com- 

bined in one sample and analyzed with the following results: 


No. 1 No. 2 Theoretical 
IEIK Die peta saa 57°51 57°60 57°625 
PO. nied ta ee 98°77 28°88 28°721 
H,O Sp 5 MD ona 13°74 13°68 13°653 

100°02 100°16 99-999 


* Mineralogical Magazine, vol. xy, p. 1. 


278 A. H. Phillips—New Zine Phosphates. 


The above represents the results arrived at from the analysis of 
the air-dried sample. The sample dissolved readily in dilute 
acids to a perfectly clear solution leaving no residue and quali- 
tative tests revealed no other elements present, except in traces. 
The analysis yields the ratios of 7ZnO.2P,0,.74H,O, or 
2(Zn,(PO,),).Zn(OH),.64H,0, a formula which is very satis- 
factory, with the possible exception of the water. The water 
is somewhat variable with the condition of the sample. The 
erystals are filled with small cavities which contain water as 
shown under the microscope. Water was determined in 
another sample which had not been exposed to the air as long as 
the first sample, with the result that it yielded 13°90 per cent. 
Then a crystal was picked out of the matrix, ground, and the 
water determined at once with 14°8 per cent as the result. A 
portion of this crystal weighing °348 gms. was then tested for 
loss of water at different temperatures, for comparison with 
that of spencerite. 

It lost at 110° 130° 210° 250° 275° Red heat 

B74% 7:24% 793% 1005% 11°354 14°71 

The erystals are basic, as is shown both by the high tempera- 
ture at which a considerable part of the water is given off and 
by the yellow color of the hot sample, due to the presence of 
zine oxide. 

Physical properties.—There are three cleavages parallel to 
the three pinacoids. Of the three, the brachypinacoidal cleav- 
age is perfect, that parallel to the macropinacoid less so, and 
the basal cleavage is imperfect. The specific gravity, as deter- 
mined on small fragments with methylene iodide, varied but 
little from 3°213. It fuses easily and becomes yellow while 
hot ; decrepitates strongly in the closed tube, yielding much 
water. Hardness is about 3°75, scratching calcite easily. 

Optical properties.—Hibbenite is a pale yellow, almost 
white, translucent, with a vitreous, though somewhat pearly 
luster. The double refraction is very weak. Extinction is 
parallel on all three pinacoidal sections, with the plane of the 
optic axes parallel to the base. The macroaxis 6 is the acute 
bisectrix. Optically negative. 

The small lens-shaped erystals mentioned, as being implanted 
on the hibbenite crystals, are also found in the solution cavi- 
ties of the spencerite and represents a secondary mineral, 
formed from solutions derived from the spencerite. While 
these crystals have been separated from the other material by 
means of methylene iodide, the sample was contaminated with 
considerable calamine. The analysis, however, indicates that 
they, also, are a new basie zine phosphate. It is hoped that 
a pure sample may be separated and the chemical formula 
reported in the near future. 


Princeton, June 16, 1916. 


Browning and Spencer—Separation of Cesium, ete. 279 


Arr. XX XI.—On the Separation of Cesiwm and Rubidium 
by the Fractional Crystallization of the Aluminium and 
Iron Alums and its Application to the Extraction of these 
Elements from their Mineral Sources; by Purr E. 
Brownine and 8. R. Spencer. 


[Contribution from the Kent Chemical Laboratory of Yale Univ.—celxxxi. | 


Rosinson and Hutchins* have recommended the erystalliza- 
tion of the aluminium alums for the separation of cesium and 
rubidium from potassium and lithium in lepidolite after the 
decomposition of that mineral by fluorspar and sulphuric acid. 
They have also called attention to the difference in solubility 
between the cesium and the rubidium alumst and have sug- 
gested fractional crystallization for the separation of these ele- 
ments. The marked difference in solubility between the potas- 
sium alum and the alums of cesium and rubidium makes the 
method quite satisfactory for the separation of potassium from 
these rare alkalies, but the difference in solubility between the 
alums of czesium and rubidium is not sufficiently great to bring 
about a rapid separation of these elements. 

The work to be described was undertaken to obtain some 
definite information as to the value of the process of fractional 
erystallization when applied to the problem of separating the 
alkalies. 

The process may be briefly described as follows: 

A solution obtained from the decomposition of lepidolite by 
heating with fluorspar and sulphuric acid after the removal of 
the calcinm sulphate was evaporated until on standing the 
mixed alums crystallized out. The mother liquor was poured 
off into a second flask and this liquid was evaporated until 
another crop of crystals was obtained and the new mother 
liquor poured into a third flask, and so on. The crystals in 
the first flask were dissolved in a small amount of water, by 
warming, and again allowed to crystallize, the supernatant 
liquid being poured into the second flask upon the crystals 
which had formed there; these crystals, in turn, were dissolved 
in this liquid and allowed to recrystallize ; and the process was 
continued through all the series of flasks. The crystals separat- 
ing in flask number one were repeatedly dissolved in fresh 
water and allowed to recrystallize in this way, and the mother 
liquor was kept moving along the series of flasks in succession. 

By this method the more insoluble alum was coucentrated 
at the upper end of the series while the more soluble alum 
moved toward the lower end. 

* Amer. Chem. Jour., vi, 74. 


+ Note: 100 parts of water at 15-17° C. will dissolve 0°62 parts of cxsium 
alum, 2°83 parts of rubidium and 13°5 parts of potassium alum. 


280 Browning and Spencer—Separation of Owsium, ete. 


After six such erystallizations wpplied to a solution of the 
alkalies from lepidolite, the crystals in the first flask showed 
only cesium and rubidium when examined before the spectro- 
scope on a platinum wire, and the erystals in the sixth flask 
gave a decided test for potassium and a very strong test for 
lithium, and showed only traces of caesium and rubidium. 

A mixture of cesium and rubidium alums obtained by the 
above process was subjected to this same crystallization method. 
After about seven crystallizations, the crystals in the first flask 
were found to be pure cesium alum but the erystals in the 
sixth flask, while strong in rubidium, still gave evidence of the 
presence of cesium. The process of crystallization was con- 
tinued until twenty-two fractions had been obtained before the 
exesium had been completely removed. The crystals in the 
twenty-second flask proved to be pure rubidium alum, no evi- 
dence of the presence of czesium being found. 

Locke,* in studying the properties of the alums, has ealled 
attention to the differing solubilities of these interesting com- 
pounds, and notes in par rticular the great difference of solubil- 
ity of the caesium and rubidium iron alumst as compared to 
that of the corresponding aluminium alums; and it has been 
suggested that this difference might be of analytical value. 

In order to investigate this point a mixture of ceesium and 
rubidium iron alums was prepared and subjected to the same 
process described above. After four crystallizations, the erys- 
tals in flask number one gave no test for rubidium but showed 
abundance of cesium; and after the process had been con- 
tinued until eight fractions were obtained, the eighth fraction 
was found to be free from caesium and contained pure rubidium 
alum. 

A further experiment was made as follows: Ten grams of 
tae mixed cesium avd rubidiuin alums from lepidolite were 
dissolved in water and the aluminium hydroxide was pre- 
cipitated by ammonium hydroxide and filtered off. The fil- 
trate, evaporated to about 130cm*, was poured upon some 
erystals of ammonium ferric alum ‘in quantity somewhat in 
excess of the amount necessary to allow the replacement of the 
ammonium by the ceesiuin and rubidium. The solution was 
then warmed until the crystals were dissolved. On cooling, 
crystals separated which, when examined, gave abundant evi- 
dence of cesium but no test for rubidium. 

This experiment suggested a convenient method for the 
formation of cesium alum and also seemed to show that the 
more insoluble alums were readily thrown out of solution by 
treatment with strong solutions of the more soluble alums. 

* Amer. Chem. Jour., xxvi, 166. 


+100 parts of water at 25° C. dissolve 2°7 parts of ceesium alum and about 
17 parts of rubidium alum, 4 


s 


Browning and Spencer—Separation of Caesium, etc. 281 


This method was applied quite successfully to the extraction 
of exsium from pollucite as follows : 

The mineral was decomposed by hydrochloric acid, and after 
evaporation and the removal of silica the acid extract was poured 
upon crystals of ammonium aluminium alum and warmed until 
the erystals had dissolved. On cooling, cesium alum separated 
in abundance; and the mother liquor, although not free from 
cesium, after one treatment consisted mainly of ammonium 
chloride. After about two recrystallizations the erystals 
obtained in the first treatment were found to give no test for 
either ammonium or chlorine and to be pure cesium alum. 
The remainder of the czsium was easily obtained by a few 
erystallizations of the mother liquor. 

This method has advantages over the other methods for the 
extraction of ecxsium from pollucite which involve the pre- 
cipitation of the czesium as the double lead or antimony chlo- 
ride and the decomposition of these compositions by hydrogen 
sulphide or ammonium hydroxide. 

A few experiments were made to determine the insolubility 
of the cesium and rubidium in a saturated solution of ammo- 
nium aluminium alum. It was found that 1 em* of a solution 
of RbCl containing 0:0002 grams Rb would give a perceptible 
precipitate when treated with 5cm* of a saturated solution of 
ammonium alum, and that 1cem* of a solution of CsCl contain- 
ing 0:00005 grams Cs would give a precipitate of ceesium alum. 

By the careful study of conditions and the use of the other 
alums it is hoped that these observations may lead to some 
advanees in the analytical study of these elements, and we hope 
to give further attention to this problem. 


SCIENTIFIC INTELLIGENCE. 


I. Muiscertannous Screntiric INTELLIGENCE. 


1. Zhe Collection of Osteological Material from Machu 
Picchu ; by Grorcr F. Eaton. Memoirs of the Connecticut 
Academy of Arts and Sciences, vol. V, pp. 1-96, figs. 50, plates 39, 
charts 3. New Haven, Conn., 1916.—The monograph in hand is 
a creditable and well-illustrated report on the collection of 
osteological material gathered from Indian graves at Machu 
Picchu by the Peruvian Expedition of 1912, under the leadership 
of Professor Hiram Bingham, and the auspices of Yale University 
and the National Geographic Society. 

The remains described were obtained from graves “found at 
various places on the steep sides of the Machu Picchu mountain, 


282 Scientific Intelligence. 


from its very foot close to the Urubamba River up to an altitude 
of 1200 feet above the ruins.” The burials were mostly in holes 
and dugouts, or caves, beneath bowlders, very much as in other, 
and in some instances widely distant, parts of the mountains of 
Peru. In the majority of cases the bodies were simply placed in 
these shelters without being interred. In numerous instances the 
skeletal remains were incomplete suggesting secondary burials, 
such as also were common in different parts of the Andean 
region. The total represents 164 individuals. Very curiously, 
of the 124 adults among these no less than 102 were female. The 
author is inclined to explain this by the presence at Machu Picchu 
of an Inca convent, in which case the female skeletons would be 
largely the remains of the inmates ; another possible explanation 
being that a large percentage of the males were withdrawn from 
the community for military operations and would be buried in 
other parts of the country. 

Anthbropologically the crania represent partly the coastal or 
brachycephalic and partly the highland or relatively narrow type, 
showing on the whole a decidedly mixed population. Ten of the 
female and five male skulls show, besides, the Aymara deforma- 
tion, while four of the females present a “‘flat-head” compres- 
sion, such as was common in some regions along the coast. The 
period to which the Machu Picchu skeletal remains are referable 
is in the main probably the late pre-Columbian; but two of the 
burial sites yielded also objects which show contact with the 
Spanish. 

The individual “caves” in which skeletal material was dis- 
covered are described in detail, thus giving the reader a faithful 
picture of the conditions and difficulties of the work of the 
anthropological collector in these regions ; and added to this are 
descriptions of the archeological and animal remains found with 
the human bones, The former include some interesting articles 
of bronze and pottery, while among the latter occur several new 
species of smaller mammals. 

The charts of measurements might have been supplemented to 

advantage by smaller, analytical tables ; and one misses an index, 
But on the whole the memoir bears testimony of careful, pains- 
taking work and is a welcome contribution to the anthropology 
of a region that so far was unknown to science. One can not but 
express in this connection the great pity that such highly promis- 
ing explorations as those of Professor Bingham’s expedition had 
to be abandoned, through the unfavorable attitude of certain 
citizens of the very country which would benefit most by their 
continuance. Aves HrpuicKa. 

2. Geology, Physical and [Historical ; by Herpman Firz- 
GERALD CLELAND, Ph.D., Professor of Geology in Williams Col- 
lege. Pp. 718, figs. 588, pl. I. New York, 1916 (American Book 
Company). ag is an excellently arranged and handsomely 
printed text for college classes. Part I on Physical Geology 
embraces 355 pages | with an appendix of 6 pages on the common 


Miscellaneous Intelligence. 283 


minerals. Part II on Historical Geology contains 307 pages. 
The book gives consequently about equal space and importance 
to the two great divisions of geology. The paper is of such a 
grade that the half-tone reproductions of photographs and wash 
drawings which constitute the bulk of the illustrations are of 
excellent quality. Certain of the full-page photographs of impres- 
sive features, such as that of the Yosemite, reach a height of artis- 
tic excellence. Numerous block diagrams bring out clearly the 
various features of erosion and structure. The number and 
instructional value of the illustrations show that the author, as a 
skilled teacher, has paid much attention to this side of the subject. 
The fragmentary fossils of the older texts have disappeared from 
this and in their places are restorations, wash drawings being 
given of invertebrates. 

The text is equally clear and attractive. It presents the basic 
principles amply, but in a manner which the student can master 
and permits the teacher in lecturing to go directly into the more 
advanced phases or give special illustrations of such subjects as 
may suggest themselves. An excellent list of references is 
appended to each chapter which will be of value to the interested 
student for developing an acquaintance with the important 
literature. TB 

3. Handbook and descriptive Cutalogue of the Meteorite Col- 
lections in the United States National Museum ; by GxEorGE P. 
Merritt. Bull. 94, U. S. Nat. Mus. Pp. 207, pls. 41. Wash- 
ington, 1916.—This is a very interesting catalogue of the mete- 
orites in the U. S. National Museum. These include 329 falls and 
finds in the Museum collection proper and 83 more in the Shep- 
ard collection. The latter, brought together by Professor C. U. 
Shepard and bequeathed to the Museum by his son, includes 234 
falls and finds. ‘The total number is therefore 412 out of the 650 
known in all the world. The descriptions are made more inter- 
esting by the liberal number of excellent plates exhibiting promi- 
nent specimens and sections from them. The Introduction of 27 
pages gives a concise but valuable summary of the subject of 
meteorites ; their classification, mineral and chemical composi- 
tion, structure and phenomena of fall. 

4. A Studen’’s Book on Soils and Manures,; by HE. J. 
Russetu. Pp. ix, 201; with 34 text-figures. Cambridge, 1915 
(Cambridge University Press).—The present work, by the Director 
of the Rothamstead Experimental Station at Harpenden, England, 
isa further evidence of the increased interest in the study of soils. 
It is issued in the Cambridge Farm Institute Series and, although 
intended primarily for the use of the practical farmer, contains 
information of much value to the botanist and chemist. The first 
part includes an account of the soil, discussing its composition, 
its organic constituents, and the changes produced by climatic 
factors. The second part takes up the control of the soil by cul- 
tivation, drainage and other processes. The third and last part is 
devoted to fertilizers, both inorganic and organic. The book 
shows clearly that the art of treating and improving soils from 


Am. Jour, Sc1.—Fourtu Srries, Vou. XLII, No. 249.—SrmrrempBer, 1916. 


284 Serentifie Intelligence. 


théBtandpoint of the farmer is still in an experimental stage, 
and th = much remains to be done before it can be placed on a 
thoro: ly scientific basis. A. W. E. 

5 mt Anatomy, from the Standpoint of the Development 
and 2 ..ctions of the Tissues, and Handbook of Micro- Technic ; 
by Wiu@am Cuast Srevens. Third edition. Pp. xvii, 399 ; 
with 155 text-figures. Philadelphia, 1916 (P. Blakiston’s Son & 
Co.).—The third edition of this very helpful text-book has been 
improved by the addition of a section dealing with the phylogeny 
of the vascular bundle. In other respects it is essentially the 
same as the second edition, although a few minor changes have 
been made. The work consists of two entirely distinct parts. 
The first, comprising thirteen chapters, deals with plant anatomy’; 
the second, comprising five chapters, with micro-technic. Krom 
the standpoint of the teacher these two parts might well be 
issued separately.‘ The part on plant anatomy, following the 
example of Haberlandt’s Physiologische Pflanzenanatomie, em- 
phasizes the relationship between the structure and the functions 
of plant tissues and organs and traces the development of the 
various tissues from a uniform embryonic condition. The second 
part includes an account of the reagents and processes used in the 
study of plants and a description of the micro-chemistry of plant 
products. beule ousieni 

6. The Principles of Plant QCulture ; a Text for Beginners in 
Agriculture and Horticulture ; by E. 8. Gorr. Eighth edition, 
revised by J. G. Moorz and L. R. Jonus. Pp. xxiii, 295; with 
177 text-figures. New York, 1916 (The Macmillan Company).— 
In the preface to the present edition of this useful text-book, Pro- 
fessor L. H. Bailey of Cornell University gives an account of the 
late Professor Goff’s life and work and of his many services to 
agricultural and horticultural science. The book is intended espe- 
cially for students who have had no previous training in botany 
and presents the essential features of plant anatomy, morphology 
and physiology, in clear and non-tegbnical language. ‘The vari- 
ous topics are treated from the standpoint of the practical culti- 
vator, and the concluding chapte:s gliscuss the propagation of 
plants, grafting, transplanting, pruuing,,aud the improvement of 
varieties by breeding. A. W. E. 

7. Annual Report of the Board of Scientific Advice jor 
Indiu for the year 1914-15, Pp. 191. Caleutta, 1916 (Super- 
intendent Government Printing, India).—The Indian Board 
of Scientitic Advice includes ten gentlemen having charge of the 
various scientific activities of the government, with F. Noyce, 
Esq., as ex-officio president. Meetings of the Board were held in 
May at Simla and in November at Delhi. The present volume 
includes contributions from many departments of natural and 
physical science, furnished by some ten different authors. 
These summaries are necessarily very brief, but they call atten- 
tion to the main lines on which progress has been’ made during 
the year. 


Waro’s Natorat Science Estasiisam xt 


A Supply-House for Scientific Materi: . 
Founded 1862. Incorporated 0. 


A few of our recent circulars in the vari us 
departments: 


Geology: J-8. Genetic Collection of Rocks and Rock- 
forming Minerals. J-148. Price List of Rocks. 
‘Mineralogy: J-109. Blowpipe Collections. J-74. Meteor- 
ites, J-150. Collections. J-160. Fine specimens. 
Paleontology: J-134. Complete Trilobites. J-115. Collec- 
tions.. J-140. Restorations of Extinct Arthropods. 
Entomology: J-30. Supplies. J-125. Life Histories. 
J-128. Live Pupae. 
mot) Zoology: J-116. Material for Dissection. J-2°. Compara- 
tive Ostedlogy. J-94. Casts of Reptiles, ate. 
Microscope Slides: J-135. Bacteria Slides. 
Taxidermy: J-1388. Bird Skins. J-189. Mammal Skins. 
s Human Anatomy: J-16. Skeletons and Models. 
General: J-155. List of Catalogues and Circulars. 


Ward’s Natural Science Establishment 
84-102 College Ave., Rochester, N. Y., U.S. A. , 


The American Journal of Science 


ESTABLISHED BY BENJAMIN SILLIMAN IN 1818. 


ConTRIBUTORS should send their articles two months before the time of issuing 
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CONTENTS. 


Art. XXIIL—The Geological History of the Australian 
Flowering Plants; by E. C. AnprEws -.-.-..-.-.------ 


XXIV.—Mineralogical Notes; by B. K. Emerson -.---.---- 233 


XXV.—A New Tortoise and a Supplementary Note on the 
Gavial, Tomistoma americana; by E, H. Seruarps--.. - 235 


XXVI.—A Fossil Nutmeg from the Tertiary of Texas; by 
Ky W.. DERRY 28 22 23 hoe eee ee gee 241 


XXVIL—Notes on Devonian Faunas of the MacKenzie 


River Valleys by Hy MM. KinpEm.2 ot S22 246 
XXVIII.—New Points on the Origin of Dolomite; by F.M. 5 
BP eM bio 0 Sensi ieee ar nega PU i RET Vek come BN G8 249 


XXIX.— Volecanie Domes iahthe Pacific; by S. Powzrs.... 261 


XXX.—New Zinc Phosphates from Salmo, British Columbia; 
hye, EOP arias. 28S oss Loe eee emer 275 


XX XI.—On the Separation of Cesium and Rubidium by the 
Fractional Crystallization of the Aluminium and Iron 
Alums and its Application to the Extraction of these 
Elements from their Mineral Sources; by P. E. Brown- 

-1nG and §.-R. SPENCER ------------ WOE colar eee 279 


SCIENTIFIC INTELLIGENCE. 
ie 


Miscellaneous Scientific Intelligence—Collection of Osteological Material 
from Machu Picchu, G. F. Eaton, 281.—Geology, Physical and Historical, 

« H.F. Crevanp, 282.—Handbook and descriptive Catalogue of the Meteor- 
ite Collections in the United States National Museum, G. P. MERRILL: 

A Student’s Book on Soils and Manures, E. J. Russmiu, 283.—Plant Anat- 
omy, from the Standpoint of the Development and Functions of the Tis- 
sues, and Handbook of Micro-Technic, W. C. Strvens: Principles of Plant 
Culture; a Text for Beginners in Agriculture and Horticulture, E. S. Gorr: 
Annual "Report of the Board of Scientific Advice for India for the year 
1914-15, 284, 


Lea U. ». INat. iviuseum. by ted _— 


, See y 


VOL. XLII. -- OCTOBER, 1916. 


Established by BENJAMIN SILLIMAN in 1818. 


| | JOURNAL OF SCIENCE. 


Epirorn: EDWARD S. DANA. 


ASSOCIATE EDITORS 


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


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


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Prorressorn JOSEPH S. AMES, or Battimore, 
Mr. J. 8S. DILLER, or Wasuinerton. 


“FOURTH SERIES 


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No. 250—OCTOBER, 1916. 


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Important to Collectors 


During the past six months, I have been fortunate in securing 
anumber of very old collections, small and large, containing — 
rare, showy and common minerals, and minerals from old finds. 

Have also received consignments from all over the globe con- 


taining new finds and new discoveries. des 
@ 


Have You Anything to Sell ? i 


If you want to sell your collection or some of your specimens, 
write me. I have made a specialty of selling collections for the 
past ten years ; all those sold have given perfect satisfaction. 
I have the best facilities and am in contact with the largest col- 
lectors who are willing to pay a good price for choice minerals 
and gems. 

I am always in the market to buy rare and showy minerals, 
new finds and new discoveries. 

My approval plan has met with excellent favor in the past. 
Have you been fortunate enough to receive one of my consign- 
ments ? If not, there is a treat in store for you. Just let me 
know in what you are interested and I shall be pleased to send 
you a selection for your inspection. ‘The material not wanted 
may be returned at my expense. If desired, I will send youa 
list of my present stock. . 


Are You Interested in Gems ? 


I carry a full line of precious and semi-precious gems of the 
best quality, in all sizes. 

Also Synthetic gems, including rubies ; pink, yellow, bigs 
and white sapphires. Scientific emeralds of beautiful rich color. 


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f. conan NST; 
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Arr. XXXII.— The Geologic Réle of Ne as ** by Exior 


BLACKWELDER. 


Progress in scientific research is attained largely by the 
most intensive study of minute problems; but it is also neces- 
sary that there should be frequent attempts to view these 
problems in their larger relations. Such undertakings are 
always the more hazardous for the student because they oblige 
him to reach out of his special field into domains with which 
he may have only a general acquaintance. In preparing this 
paper on the part played by phosphorus in geologic processes, 
the writer has tried not only to correlate his work with that of 
many other students in this and other countries, but also to 
understand the bearing of sister sciences upon the subject. 
He has done so with keen realization of the pitfalls that beset 
the path especially outside his own limited field.t 

Phosphorus occurs naturally in many different forms and 
situations. Nevertheless, its varied transformations follow an 
orderly sequence, which is in harmony with the general scheme 
of rock metamorphism and biologic evolution. In a broad 
way, these changes form a cycle within which there are sub- 
ordinate cycles, all having a common beginning, and probably 
capable of being brought to a common end. Any particular 
atom of phosphorus may follow one or more of the subordinate 
eycles while another atom may pursue a different route. 

The primary occurrence of phosphorus in the earth, like the 
beginnings of most things in geology, lies wholly in the realm 

* Presented in summary before the Geological Society of America at 
Washington, December 29, 1915. 

+ For valuable information and advice the writer is indebted to his col- 
leagues, Professors E. V. McCollum and EH. B. Hart, of the University of 


‘Wisconsin, Mr. Chauncey Juday of the Wisconsin Geological and Natural 
History Survey, and Prof. W. A. Noyes of the University of Illinois, 


Am. Jour. Sct.—FourtH SErRigs, Vou. XLII, No. 250.—Octosmr, 1916. 
20 


286 Blackwelder—The Geologic Role of Phosphorus. 


of speculation. If the planetesimal theory of the earth’s 
origin,—elaborated by Chamberlin and Moulton,—is true as 
regards its major points, the original material of the earth may 


/ be comparable to the meteorites which are still falling upon its 


surface from time to time. Nearly all modern meteorites con- 
tain minute quantities of phosphorus,—chiefly in the form of 
the iron-and-nickel phosphide (schreibersite). | Individual 
meteorites vary in the amount of phosphorus which they con- 


- tain. On the whole, the iron meteorites are generally richer 


= 


in the phosphide than are the stony varieties, the range being 
from a trace in the latter to 1:25 per cent, expressed as P,O,, 
in the former. ; 
On the basis of the planetesimal theory, Chamberlin has 
suggested that more or less of the original cosmic matter of the 
globe has been melted and worked its way outward to the sur- 
face. Meanwhile it should have differentiated until the upper- 
most part became a familiar volcanic magma. While there 
are weighty considerations in favor of this concept, it is ad- 
mittedly speculative. Whether or not it be true, it is a fact 
that the nearest approach to a primary occurrence of phos- 
phorus actually known to geologists, is its appearance in the 
igneous rocks, which have crystallized from a hot mineral 
solution (the “magma” of geologists) rising from the unknown 
depths of the earth’s interior. All igneous rocks contain 
small quantities of phosphorus. According to Olarke’s cal- 


_ culation, the average igneous rock of the world contains ‘29 


per cent P,O,. The ratio is usually somewhat higher (*50-1:15 
per cent) in the more basic igneous rocks such as gabbro and 
the peridotites. In all these rocks the phosphorus exists 
chiefly as the mineral apatite,—an anhydrous tricalcium phos- 
phate chemically combined with calcium fluoride or chloride. 
When magma crystallizes it emits large quantities of steam 
and other vapors. At the surface these are discharged into the 
atmosphere; but around deep-seated intrusions of magma the 


- liquid and volatile constituents permeate the adjacent rocks. 


The mineral matter with which these solutions are highly 
charged crystallizes out selectively upon the walls of fissures 
and other openings through which the hot solutions pass, thus 
producing among other things the type of veins known as 
pegmatites. Most pegmatites contain such minerals as quartz, 
feldspar and mica; but in rare instances, apatite is the chief 
constituent. Like the other minerals, it usually occurs as large 
crystals, sometimes a foot or more in length. The so-called 
nelsonites* of Virginia, which contain 5-16 per cent of P,O,, 
as well as certain vein deposits in Quebec and Norway, are 


* Watson, T. L., and Taber, S., The Virginia Rutile Deposits, Bull. U. 8. 
Geol. Survey, No. 430, 1910, pp. 202-213. 


Se 


Blackwelder—The Geologic Réle of Phosphorus. 287 


evidently pegmatites. In similar veins some other phosphatic 
minerals, such as the valuable rare-earth phosphates monazite 
and xenotime, have been found, but they are decidedly rare. 
Certain veins of much less frequent occurrence than the 
apatites consist largely or even entirely of the related minerals 
dahllite or staffelite—considered by the French mineralogist 
Lacroix* to be hy drous caleium earbo- phosphates, containing 


about 39 per cent P,O,. The mineral occurs in lamellar and 


Hie. 1. 


APATITE IN 


IGNEOUS ROCK 


A 
' 


‘ 
i] 
1 
' 
\ 
\ 
\ 


Plants % Animals 
Ss a 
FIBROUS VEINS Ns 

2 . 


NIC SOz 
ocEA 4 Tifa, 


Biochemical” Decay 


PHOSPHATIC SEDIMENT. 


Fic. 1. Diagram illustrating the cycle of changes through which the 
element phosphorus is believed to pass. Solid phosphatic deposits are shown 
in bold-faced capitals and by cross-hatching. Arrows indicate the directions 


‘In which the more important processes move, but many changes of less 


importance have been eliminated for the sake of simplicity. 


radiating aggregates of very minute fibrous erystals, rather 
than in coarse stout prisms like those of apatite. Although a 
vein of this type near Crown Point, New York, has been 
described by Emmons,+ the only large and well-known exam- 
ples are those of the province of Estremadurat in Spain, where 
they have been recognized for nearly 150 years. Several dif- 
ferent hypotheses have been advanced to account for these 
Spanish veins, but most of them are clearly inadmissible. The 
facts that the veins are persistent with depth, contain quartz, 
and traverse such slightly altered rocks as quartzite, slate and 
limestone associated with granitic intrusions, suggests that 
they have erystallized from ascending magmatic solutions but 
at a moderate temperature. It is not certain, however, that 
they have not been produced by waters descending from the 
surface. 

Under ordinary climatic conditions, rocks near the surface 
of the earth are subject to chemical decomposition. Percolat- 

* Lacroix, A , Minéralogie de la France, vol. iv, p. 555 et seq. 


+ Emmons, E. , New York State Geological Survey, Report, 1838, p..252. 
{Fuchs and de Launay, Traité de Min. et Met., 1893, p. 393. 


288 DLlackwelder—The Geologie Rédle of Phosphorus. 


ing underground water containing more or less carbonic acid 
and other solvent materials is one of the chief agents in this 
decay. In such solutions both apatite and dahllite dissolve 
more readily than most other common minerals, although much 
less rapidly than the lime-carbonate minerals such as calcite. 
The phosphate-bearing solution then cireulates through the 
rock and soils, to be disposed of eventually in several different 
ways. 

Much of the dissolved phosphoric acid is taken up by plants, 
whose roots penetrate the soil, and by them is incorporated in 
the nuclear material of their cells, and particularly in their 
seeds. Animals taking the phosphorus indirectly from the 
plants npon which they feed use it not only in various cells 
and tissues, but also in bones and teeth. In the vast majority 
of cases, part of it is soon returned to the soil as a constituent 
of urine, feeces and dead organie matter, but bacteria then 
decompose its compounds and the phosphoric acid returns to 
the state of solution in ground water. Only rarely, when soon 
buried in mud, does it become fixed in land deposits in the 
form of bones and even mineralized feeces (coprolites). On 
the other hand, thin beds with very limited area, consisting 
largely of bones and teeth, have been found in a few places, 
such as Big Bone Lick in Kentucky. 

By far the greater part of the phosphorus in ground water 
solution must either immediately or eventually go into the 
streams and find its way to the ocean. Of the vast quantity of 
dissolved mineral matter annually delivered to the sea by the 
run-off, it is estimated that about -45 per cent consists of phos- 
phorus pentoxide. Using the best available figures for the 
amount of water thus brought to the ocean annually, it is cal- 
culated that if the phosphatic material in the form of solid tri- 
calcium phosphate were loaded into standard railroad cars it 
would fill a train stretching continuously from Boston to Seat- 
tle and would be 7 to 12 times as great as the world’s total 
production of phosphate rock in 1911. Nevertheless, so great 
is the volume of the oceans, and so vast the area of their floors, 
that if all this material were deposited in solid form uniformly 
over the bottom of the sea, it would build annually a layer less 
than one-fifth of a millimeter thick. Of the phosphorus poured 
into the sea, so large a proportion is utilized by living beings 
that the net working balance dissolved in oceanic water con- 
stantly averages less than ‘005 per cent, expressed as P,O,, or, 
in other words, about *18 per cent of the dissolved salts. In 
this solution, phosphorus seems to have reached the most dilute 
state in which it exists during the course of its complex migra- 
tions. Its subsequent transformations, now to be described, 


Blackweldcr—The Geologic Réle of Phosphorus. 289 


generally tend to ever greater concentration, almost until the 
eycle is closed upon itself. 

Soluble phosphates are absorbed by the various oceanic 
plants as well as by those on land. In some measure the phos- 
phoric acid becomes chemically linked in organic compounds, 
but for the most part it probably remains in the ionized state. 
Living diatoms and other alge contain, in both of these forms, 
from ‘1 to -2 per cent of P,O,, chiefly as a minor constituent 
of the cell nucleus. Although the marine animals have the 
power of absorbing phosphoric acid directly from the sea 
water, it so happens that they generally get a surplus of it as a 
constituent of the plants or other animals on which they feed, 
and hence do not exercise that power. 

The round of transformations to which phosphorus is sub- 
jected in the ocean is extraordinarily complex. The plants 
which absorb the element are devoured by myriads of aquatic 
animals, each of which, in its turn, is liable to a similar fate. 
This endless process of devouring is recognized even in the 
ancient Chinese proverb to the effect that “the big fish eats 
the little fish, the little fish eats the shrimp, and the shrimp 
eats the mud.” In the individual animal, the phosphorus 
forms a constituent of its cell nuclei, tissues and liquids. With 
the exception of casein and that of egg-yolk, the proteins do 
not contain phosphorus, but it forms a constituent of certain 
other organic compounds, such as lecithins. As solid calcium 
phosphate it resides in bones, teeth and more rarely in shells. 

As phosphorus ascends in the evolutionary scale of animals, 
its concentration tends to increase, although irregularly. The 
protozoan, air dried, contains less than -6 per cent P,O,. 
According to Juday* quantities of minute crustaceans from 
Lake Mendota contain in the air-dried condition 1°8 to 2:4 per 
cent of P,O,, or several times that of the protozoans. A Rus- 
sian biochemist, Sempelovski, found in entire fresh specimens 
of a cartilaginous fish (the common skate) -91 per cent P,O,, 
whereas the average for eight Teleostean fishes with well- 
developed bones was about 1°5 per cent. Certain brachiopods, 
such as those of the family Zingulide—form shells of fibro- 
erystalline tricalcium phosphate—probably either the mineral 
dahllite or staffelite. 

From its almost endless series of reincarnations in the ocean, 
phosphorus is allowed to escape from time to time by either 
one of two routes. The organisms in the sea may be eaten by 
land animals, chiefly birds, or the phosphates may become 
fixed in mineral form in the solid matter on the sea bottom, 
and eventually buried beneath the accumulating sediments. 
We may consider the second of these processes first. 


*C. Juday, personal communication. 


290 Blackwelder—The Geologie Réle of Phosphorus. 


As the writer has already remarked, the animals of the sea 
are almost never permitted to die of old age, but are devoured 
sooner or later by other animals. Any that happen to die in 
other ways are almost invariably eaten at once by scavengers. 
Even the bones of fishes are rapidly devoured by echini and 
certain other animals. It is conceivable, however, that in 
rare instances the quantities might be too great fur the capaci- 
ties of the scavenger population; and in that event a local 
accumulation of animal matter might result. The late Sir 
John Murray* based upon this idea a hypothesis to explain the 
origin of the phosphatic nodules now dredged up from the sea 
bottom in several parts of the world. In another workt, ‘he 
cited the remarkable case of the tile-fish, which in 1883 were 
killed by hundreds of millions along the Atlantic coast of the 
United States, presumably by a sudden fall of water-tempera- 
ture brought about by the shifting of the position of the cold 
northern current between the Gulf Stream and the coast. 


Using Murray’s figures for the area and number of the fish, the . 


writer estimates that enough were killed at this time to make a 
layer of fish substance about four millimeters deep over the 
affected area, if all had fallen to the bottom and had been uni- 
formly distributed. Other instances of this kind have been 
reported and fish are known to have been killed in great num- 
bers by submarine earthquake shocks, submarine voleanic erup- 
tions, and other catastrophes. It might be supposed that in 
such cases a layer of bones and teeth would be left upon the 
bottom of the sea, and if the process were repeated at inter- 
vals, the layer might gradually attain noteworthy thickness. 
It should be remembered, however, that the carcasses of dead 
vertebrates generally float, because distended by the gases of 
putrefaction ; and both while floating and after lodgment upon 
the shore they are subject to the attack of scavengers as well 
as to the final decomposing action of micro-organisms. As a 
final result, but little of the original fish remains except the 
points of the teeth, which being almost wholly mineral matter 
apparently contain too little nutritive substance either to attract 
the spoilers or to serve the purposes of bacteria. Under these 
circumstances, it is difficult to imagine how a layer of carcasses 
could be deposited in the open sea. On the assumption, how- 
ever, that it is possible, Murray outlined a process of fermen- 
tive decay and chemical interchange which is essentially that to 
be detailed below. It is chiefly this source of supply that is 
here laid open to question. 

As an incident in the normal life of vast numbers of organ- 
isms, both on the sea floor and in the upper waters, shells and 

* Murray, Sir John, Challenger Expedition Report, Deep Sea Deposits, pp. 


396-399, 
+ Murray, Sir John, Geogr. Journ., vol. xii, p. 113, 1898. 


i i a i i 


Blackwelder—The Geologie Role of Phosphorus. 291 


little pellets of excrement are incessantly falling to the sea 
bottom. Some of the dredgings of the Valdivia expedition* 
showed that over large areas ‘of the sea bottom, the latter 
material forms an appreciable part of the soft ooze, and, in 
several places the sediments consist almost entirely of such pel- 
lets. They have been attributed in large measure to holothu- 
rians, echinoids, and marine worms. No chemical analysis of 
this material is available, but it is well known that animal 
excreta in general contain a noteworthy proportion of phos- 
phorie acid. Although the phosphorus in the excreta of 
nearly all animals below the Mammalia seems to exist chiefly 
in the form of insoluble organic phosphates, bacteria are able 
to decompose these compounds, usually with the formation of 
ammonium phosphate which is immediately returned to the 
oceanic solution and there doubtless exists in the ionized con- 
dition. Under ordinary circumstances, as pointed out by Sir 
John Murray in the Challenger Reports,t even bones, teeth 
and shells lying upon the sea bottom gradually lose their phos- 
phorie acid. ‘Hence this fzcal material probably does not 
accumulate to any considerable depth. In fact, over most of 
the ocean bottom it is destroyed about as fast as it is produced. 
In so far as this action prevails, phosphorus cannot well become 
a solid part of the sediments deposited on the sea floors. 

Nevertheless, we find among the rocks derived from oceanic 
sediments in many parts of the world, beds several feet thick 
which are rich in lime-phosphate and extend rather uniformly 
over thousands of square miles. They contain marine fossils 
which indicate that they have accumulated upon the sea bot- 
tom. It is therefore evident that locally there must be condi- 
tions which cause the fixation of the phosphoric acid among 
the bottom sediments. Some students of these deposits have 
ascribed them to the direct deposition of phosphatic shells, 
bones and teeth, and others have made appeal to the agency of - 
mineral springs. Generally they have sought an explanation 
for the abundance of the phosphorus. As the writer has already 
shown, however, the quantity of phosphorus dissolved in sea- 
water is always sufficient to produce in a few thousand years 
even the thickest known phosphate beds ; and hence we need 
only to account for the special conditions which cause it to be 
precipitated on the sea floor. There is excellent reason to think 
that the immediately controlling conditions are chemical or 
biochemical, but these chemical conditions in turn depend 
upon physiogr aphic and climatie factors difficult to analyze and 
estimate. The study of the latter is a task.for the geologist. 

* Murray, Sir John, and Philippi, E., Wissensch. Ergebn. der deutschen 


Tiefsee Exped., Bd, x, Lf. 4, 1905, p. 108, (Carl Chun, editor.) 
+ Loe. cit. 


292 Blackwelder—The Geologic Idle of Phosphorus. 


In its simpler aspects, the chemistry of the marine deposition 
of phosphates has been plausibly interpreted by a number of 
European students of the question, even as far back as 1870. 
The following is a modification of their views, based on modern 
information. The process and results of bacterial decomposi- 
tion of organic matter vary according to the conditions as well 
as the particular class of bacteria that are at work. In air and 
aerated water, decay is generally complete, resulting in the 
production of carbon dioxide, water, soluble nitrates, sulphates, 


Fie. 2 


Lime. Salts y 


Bottom depozits LIME PHOSPHATES HYDROCARBONS METAL SULPHIDES 


Fic, 2. Diagram to illustrate the process and results of the decay of 
organic matter on the sea bottom. In reality the process is much too com- 
plex to be repfesented in this way. (The materials which become fixed in 
the bottom layers are shown in capitals on the lower line. Other marine 
sediments, such as particles of sand, mud, shells and bones, have been 
omitted from consideration. ) 


phosphates, etc. In the absence of oxygen, however, the 
anerobic bacteria somewhat more slowly break down the 
organic compounds and produce a different series of end pro- 
ducts, of which the most important are various hydrocarbons, 
nitrogen, ammonia, and hydrogen sulphide, with only so much 
of the carbonic oxides as the available oxygen in combination 
permits. In so far as free oxygen is present in only small 
quantities, there should be a compromise between the two 
processes. 

Some of the most obvious characteristics of our marine 
phosphatic rocks show that they have been associated in origin 
with the anerobic phase of bacterial action. Almost invariably 
they are black in color and, owing to the fact that they con- 
tain noteworthy quantities of hydrocarbon oils, tars and gases, 


—o- 


a 


Blackwelder—The Geologic Role of Phosphorus. 298 


they are famous for their bad odor. In central Wyoming,* 
phosphate rocks of this kind contain so much oily matter that 
they are being successfully exploited for petroleum. Although 
such phosphates contain a few fossils such as fish teeth, 
brachiopods and larval gastropods, they are invariably devoid 
of sessile bottom-inhabiting organisms, a fact which suggests 
that the bottom layer of sea water lacked the oxygen necessary 
to support life. 

4, The deficiency of oxygen is, therefore, the controlling 

— chemical condition, for it not only determines that the bacterial 
decay shall be of the anerobie type, but also prevents animal 
scavengers from devouring such organic matter as may fall to 
the bottom, for no animal can be active in an oxygen-free 
medium. Through the work of Birge and Juday+ on the 
Wisconsin Jakes, and that of other students of lake phenomena, 
it is now well understood that mechanical circulation of the 
water is the only factor that serves to prevent this deficiency 
of oxygen from becoming general in all waterbodies. At the 
‘present time most parts of the ocean bottom are thus sup- 
plied with enough oxygen to support their benthic faunas. It 
is carried in by the slow convective circulation downward from 
the polar regions and upward near the eyuator. In order to\> 
account for the oceanic phosphate deposits, therefore, we must 
apparently discover those rare areas of the sea bottom where 
this circulation is not effective. Deep inclosed gulfs or seas, 

such as the Black Sea, to-day afford some of the conditions, 
but not all of them. The bottom sediment of the Black Seat 
is now a lifeless mud. blackened by hydrocarbons and charged 
with hydrogen sulphide. There is, however, some condition 
lacking, for the deposition of phosphates in the Black Sea is 
not indicated by the dredgings thus far reported. 

Passing by this question as a room for which the key is yet 
to be found, we may consider the manner in which phosphorus 
comes to be fixed in the oceanic sediments under anerobie con- 
ditions wherever they may be developed. 

As was long ago pointed out by Bonney,$—under ordinary 
circumstances all of the products of decay are likely to either 
remain in solution or escape as gases rather than to be precip- 
itated. Under special conditions, however, most of them 
remain in solid form and others react with the sediments of 
the bottom or with materials in solution, in such a way as to 
form insoluble products. For example, hydrogen sulphide, in- 

* Woodruff, E. G., The Lander Oil Field, Fremont County, Wyoming, 
Bull. U. 8. Geol. Survey. No. 452, 1911. 

+ Birge, E. A., and Juday, C., The Inland Lakes of Wisconsin, Bull. No. 
22, Wis. Geol. & Nat. Hist. Survey, 1911. 

{ Andrussov, N., La Mer Noire, Guide des Excursions der 7™° Congrés 


Géologigue International, No. 29. 
§ Bonney. T. G., Cambridgeshire Geology. 


Lae 


bere 


294 Blackwelder—The Geologic Role of Phosphorus. 


teracting with the iron compounds, forms the mineral pyrite, 
which is common in certain types of black shales. In a similar 
way, phosphorie acid in the presence of ammonia reacts with 
various substances, and especially lime carbonates, in such a 
way as to produce phosphatic minerals, of which the com- 
monest is collophanite,—said to be hydrous caleium cearbo- 
phosphate. These changes have been carried out experimen- 
tally in the laboratory by several investigators, and the neces- 
sary conditions are such as may readily occur on the sea bottom 
where organic decomposition is in progress. The calcareous 
shells and fragments lying on the ocean floor thus become 
phosphatized, and even such organic materials as excretory 
pellets and pieces of wood are known to have been altered in 
the same way. Bones, which initially contained about 58 per 
cent tricalcium phosphate, have their organic matter completely 
replaced by phosphatic minerals, thus raising the ratio to 85 
per cent or more. In addition, collophanite is precipitated in 
concentric layers around particles of sand or any solids, form- 
ing round or elliptical granules which resemble the odlitic 
grains in certain limestones. By the enlargement of these 
coatings, the granules, shells, teeth and other objects are 
cemented into hard nodules or even into continuous beds of 
phosphatic rock. Such nodules have been dredged up from 
the bottom of all the oceans in moderate depths, and are not 
uncommon in certain kinds of marine limestones and shales 
now on land. 

The marine phosphatic sediments now constitute our greatest 
bodies of commercial rock phosphates, exemplified in the 
phosphate beds of Tunis, Algeria, England, and—most extensive 
of them all,—those of the Rocky Mountains of Idaho, Utah 
and Wyoming. In many other places, such as the Carolinas, 
Florida, Belgium, and northern France, marine sediments 
containing only 1 to 5 per cent P;O, have, through secondary 
concentration in later ages, pr oduced rich phosphatic deposits. 

Reference has already been made to the fact that, through 
the agency of land-animals such as birds, the phosphorus may 
escape from the charmed circle of its metamorphoses in the 
ocean. Upon islands where they are out of reach of predaceous 
animals, seabirds congregate in extraordinary numbers, and the 
amount of excrement annually deposited by them upon the 
surface of these islands is large. Ridgeway* cites evidence 
that it accumulates locally at the rate of about 14 inches per 
year. The material is comparatively rich in phosphorus, owing 
in part to the fact that the birds feed largely upon the bony 
fishes ; but it seems to exist chiefly in the form of insoluble 
organie phosphates which are not affected by unaided rain 


* Quoted by G. P. Merrill, Non-metallic Minerals, p. 267. 


Blackwelder—The Geologic Role of Phosphorus. 295 


water. In humid regions, however, bacterial fermentation 
decomposes these compounds, and the soluble resultants, in- 
eluding phosphoric acid, are removed by rain water so rapidly 
that no appreciable residue is left. 

On those arid islands, however, which are situated under the 
trade winds and “horse latitudes,” neither fermentation vor 
solution is favored, and hence the guano accumulates from 
year to year. The well-known deposits on the islets off the 
coast of Peru, in the Leeward Islands of the Caribbean Sea, 
and on many of the East Indian islands, serve asexamples. As 
compared with its ratio in the fishes and other marine animals, 
the concentration of the phosphorus in the freshly deposited 
excrement of the fish-eating birds is about the same,—averag- 
ing but little more than one per cent P,O,. In the thoroughly 
dry guano of the desert islands off the Peruvian coast, where 
almost no chemical change has taken place, it contains 10-16 
per cent P,O,, as well as a noteworthy quantity of nitrogenous 
and other organic compounds. 

On the other hand, where underground water has access to 
the older portion of the deposit, the guano is more or less fer- 
mented, probably by such micro-organisms as the bacteria, with 
the result that the nitrogeneous matter is largely converted 
into nitrates and ammonia, while the phosphorus forms calcium, 
magnesium and ammonium phosphates. The occasional rains 
dissolve out the more soluble ammonium phosphates and nearly 
all the nitrates, leaving the relatively insoluble alkaline-earth 
phosphates to form a residue of solid “stone guano.” The 
latter contains from 28 to as much as 39 per cent P,O.,, 
largely in the form of hydrous acidic and basie calcium phos- 
phates, closely, and probably chemically, associated with more 
or less lime-carbonate, The commercially exploited guanos on 
Baker island in the tropical Pacific, and many others, appear 
to have passed through this type of alteration. 

The strongly phosphatic solutions thus derived from the 
guano sink downward through the underlying rocks and pro- 
duce characteristic alterations in them. Where the rock is 
limestone, it is somewhat rapidly converted into a mass of 
calcium phosphates, in which the mineral species are various, 
although collophanite seems to predominate. On Christmas 
Island in the western part of the Pacific Ocean, Willis* found 
that coral limestone had been changed to calcium phosphate to 
a depth of from 2 to 3 feet within 20 years. In the Jaboratory, 
Collet} immersed a coral skeleton in a weak solution of 
ammonium phosphate, with the result that the coral was 60 
per cent phosphatized in only two months. Still more remark- 


* Willis, J. L., Ottawa Naturalist, vol. vi, p. 18, 1892. 
+ Collet, L. W., Proc. Royal Soc. Edinburgh, vol. xxv, p. 882. 


296 Blackwelder—The Geologic [dle of Phosphorus. 


able cases have been reported in which refractory voleanic 
rocks such as andesite and trachyte have been phosphatized by 
solutions descending from guano beds. 

For many years it was generally supposed that the rich and 
important phosphate deposits of Florida and the Carolina coast 
had been produced by solutions from guano beds percolating 
down into limestones, and thus changing them into calcium 
phosphate; but now it is fairly well established that the phos- 
phatic solutions were derived not from guano, but from 
marine clays, containing 1-5 per cent P,O,. It has been 
demonstrated that these clay beds originally overlie the lime- 
stone but have been rather generally stripped off by erosion im 
more recent time. Although poor in phosphates the clays are 
hundreds of feet thick and have, therefore, yielded a vast 
amount of phosphoric acid. In other countries, there are many 
illustrations of the phosphatized limestone type, and in most 
cases, as in Florida, the source of the phosphorus was not 
guano, but a lean phosphatic clay or chalk. The plateau of 
southern France, the Lasne valley in Germany, and south- 
western Belgium furnish well-known examples. 

Where the slightly phosphatic original rock was chalk or 
limestone, a variation of the process has been brought about 
because the lime carbonate is relatively more soluble than the 
lime phosphate. Therefore, during the slow process of solution 
by rainwater descending from the surface. the calcium phos- 
phate, although actually decreased in total quantity, has been 
relatively concentrated by differential solution. Cases of this 
kind have been reported from southern England, northern 
France, and Belgium. 

Phosphate beds of both of these secondary types are irregular 
in thickness, and rest upon a most uneven and cavernous sur- 
face of the corroded limestone beneath. The deposits often 
contain phosphatized bones and shells of animals really belong- 
ing to a geologic age much more recent than the limestone of 
which they appear to form a part. These have slumped in 
from the surface and been thus mixed with what is in reality 
only a special type of residual soil. 

Although the concentration of phosphorus thus brought 
about by the phosphatization and differential solution of lime- 
stones is never quite equal to that in the leached guanos, it may 
rise to over 36 per cent P,O,, a ratio which indicates almost 
pure collophanite. Sellards* finds reason to think that the 
amorphous and probably colloidal mineral collophanite is 
gradually converted into a fibrous crystalline mineral (staf- 
felite?) which has about the same composition. If this opinion 


* Sellards, E. H., 5th Ann. Rep. Florida State Geol. Survey, 1913, pp. 
37-66. 


Blackwelder—The Geologic Réle of Phosphorus. 297 


is correct, it affords another illustration of the well-known 
tendency of colloidal or amorphous minerals to assume the 
erystalline state with the lapse of time. 

With certain minor exceptions the transformations of phos- 
phorus that take place on the surface of the earth have now 
been reviewed. It remains to trace the element downward 
into the interior of the crust and at the same time more deeply 
into the realm of inference. Phosphatic deposits of any of 
the types already described may have sediments deposited 
upon them until, in the course of geologic ages, they may be 
buried thousands ot feet below the surface. In that region 
pressures are great, temperatures are much increased, and the 
activity of solutions is greater than, or at least different from, 
that above. In the past, some of the older phosphate beds 
have in addition been subjected to overwhelming compressive 
forces, the origin of which is still a debatable subject with 
geologists, although we see plenty of evidence of their opera- 
tion in the folded rocks of our mountain systems. It is now 
well known that under these conditions of the interior of the 
earth, minerals of various kinds undergo radical changes. 
Some, like calcite, merely reerystallize in more compact form. 
Others recombine to form new minerals, while still others are 
metamorphosed by either losing or gaining constituents. 
Although no case of this kind for phosphates has yet been 
proven, it is entirely in harmony with the established prin- 
ciples of rock metamorphism for us to suppose that the phos- 
phatic sediments would, under these conditions, be reorganized. 
The hydrous minerals and the carbonates characteristic of the 
surface should become dehydrated and decarbonated. As a 
result, collophanite and staffelite as well as many other minerals 
of less importance, should pass over into the anhydrous calcium 
fluophosphate, apatite, in which the proportion of P,O, may 
rise to 42-43 per cent,—which is apparently the maximum 
concentration attainable in rocks. It was suggested many years 
ago by Sir William Dawson* and others that some of the rich 
apatitic beds that are intimately associated with the ancient 
- Grenville marbles and gneisses near Ottawa, Canada, are really 
the highly metamorphosed representatives of phosphatic sedi- 
ments which were once deposited on the bottom of the sea. 
No weighty arguments against their hypothesis have been 
advanced. 

There is still another fate that may befall the phosphatic 
deposits either before or after recrystallization. Rocks of any 
kind in the erust are liable sooner or later to be invaded by 

*Sir J. W. Dawson, Note on the Phosphates of the Laurentian and Cam- 


brian Rocks of Canada, Quart. Journ. Geol. Soc. of London, vol. xxxii, 
pp. 285-291, 1876. 


298 Blackwelder—The Geologie Réle of Phosphorus. 


large bodies of fluid magma, issuing from the interior of the 
earth, at initial temperatures well above a thousand degrees 
centigrade. It now seems proven beyond dispute that such 
igneous bodies flux their way through the overlying rocks, 
absorbing them or dissolving them as they rise. Phosphatie 
minerals thus dissolved would later recrystallize out along with 
the other constituents of the magma when it became a solid 
igneous rock. It would then also appear as the mineral 
apatite, which is apparently one of the few phosphates adapted 
to these conditions of high temperature. As the constituents 
of the magma obey the laws of solutions and are diffused 
uniformly through the liquid, the apatite, like the feldspars, 
quartz, and mica, would be evenly distributed throughout the 
resulting igneous rock in the form of minute crystals. Inso far 
as this occurrence takes place, it closes the cycle, for it will be 
remembered that almost at the outset of this review, phos- 
phorus appeared in the form of microscopic apatite prisms as a 
constituent of the typical igneous rock. Meanwhile, however, 
the pbosphorus may have passed through the complex series 
of migrations and transformations over and over again, on and 
near the surface of the earth. Even if the cycle should thus 
become closed, it would be closed only temporarily, for a new 
cycle would be initiated just as soon as the apatite of the 
second generation became subject to the process of weathering. 


Madison, Wisconsin, 
July 11, 1916. 


W. D. Smith—Notes on Radiolarian Cherts in Oregon. 299 


Arr. XXXIJII.—Wotes on Radiolarian COherts in Oregon ; 
by Warren D. Smiru. 


Tuer age of certain cherts found in our West Coast strati- 
graphy has long been a matter of conjecture. Diller described 
occurrences of these in both the Port Orford Folio (U. 8. G.S8.) 
and that for Roseburg and assigned provisionally the rocks to 
the Cretaceous. No genera or species were given, as far as I 
know, nor were any very definite field relations mentioned, on 
account of the unsatisfactory nature of the exposures. 

During the summer of 1915, the writer was in the field for 
the Oregon Bureau of Geology and Mines investigating some 
problems connected with the stratigraphy of the Cascades, dur- 
ing the course of which he obtained some data relative to 
these cherts which may be of interest now and are here given 
with the permission of the Director of that Bureau. 

In the cow pasture back of Mr. Engles’ house at Peel P. O., 
about 25 miles east of Roseburg on the Little River, a branch 
of the Umpqua, there is an almost hopeless mixture of rocks, 
hornblende schists with small patches of these cherts inclosed 
by them. : 

At the time of the writer’s visit to Peel, he was fortunate in 
being able to see these outcrops after some excavating had 
been done for road metal. The value of this for road surfac- 
ing is due doubtless to the combination of the chert and the 
iron, for they are ferruginous at this place. An examination 
of the outcrops as opened up by them showed the stratification 
lines very plainly. The strike was found to be N. 8° E. and 
the dip 70°-90°. The direction of the dip varies, in places 
being to the N.W., and a few feet away, about the same amount 
in the opposite direction. About a quarter of a mile farther 
up the Little River, Eocene sandstone and shales were found 
dipping about 20° to the east (as already noted by Diller), so 
that if these beds do not reverse their direction of dip in the 
intervening distance (no outcrops visible to determine this) 
they would come far above these chert beds and there would 
be a marked angular unconformity between them. 

Thin sections of these cherts were made which showed species 
of the following genera of radiolaria: Cenosphera, Dictyomi- 
tra and Spongodiscus. In most cases, however, only small 
round areas filled with eryptocrystalline silica showed where 
the tests had been. 

Identical forms have been found by the writer* in material 
lithologically similar and in about the same stratigraphic posi- 


* Smith, W. D., Philippine Jour. Science, vol. v, No. 5, p. 327. 


300 W. D. Smith—WNotes on Radiolarian Cherts in Oregon . 


tions in the Philippine Islands. Not only do we find the 
same sort of formation in those islands, but in Borneo,* Java, 
Molluecas, Ceram,t ete. 

Both Martin and Hinde have assigned these cherts to the 
Jurassic or Triassic and, following them, the writer has done 
the same in the Philippines. The radiolarian-bearing rocks 
of Roti and Savu (D. E. I.) are associated with beds of lime- 
stone containing Halobias and Daonellas. The cherts, as 
described, are strikingly similar lithologically to our West 
Coast rocks of this character.t We are nevertheless well 
aware that fossil radiolaria are far from being satisfactory index 
fossils. ‘ 

These notes are here given in the hope that they will throw 
some light on this part of West Coast stratigraphy. To one 
who has dealt with geological problems on both sides of the 
Pacific, there is a remarkable similarity in the stratigraphic 
columns of the two. 


University of Oregon, Eugene, Ore. 


* Hinde, App. I, 9, Molengraaf’s Borneo, 1902. 

+ Marten, K., Reisen in den Molukken, Leiden, p. 164, 1902. 

{ Hinde, Radiolarian rocks, etc. Jaerboek van het Mijnwesen in Nederl. 
Oost-Indie, xxxvii, 1, 2, 1908. 


EE x 


Van Name and Hitl—Solution of Metals. B01 


Arr. XXXIV.—On the Rates of Solution of Metals in 
Ferric Salts and in Chromic Acid; by R. G. Van Name 
and Ds Ws Eins. 


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


Former papers from this laboratory have dealt with the 
rates of solution of metals in iodine.* The present investiga- 
tion is an application of the same method to further measure- 
ments of the rates of solution of metals in oxidizing solutions, 
and was undertaken on account of the probable bearing of the 
results upon the so-called Diffusion Theory of heterogeneous 
reactions. — 

Tt will be recalled that this theory is based on the hypothesis 
that in a reaction between two phases, let us say a solid and a 
liquid, the stirring of the liquid is not effective up to the 
actual boundary surface, but that there remains a narrow zone 
or layer of liquid, adjacent to the solid, which is so far 
unaffected by the stirring that the transport of dissolved sub- 
stances through this layer, to or from the solid, must be 
brought about essentially by diffusion. From this point of 
view the observed velocity of a reaction between a solid and a 
dissolved substance should be the resultant of two consecutive 
reactions, (a) the diffusion process, and (b) the chemical reac- 
tiont proper, which occurs at the surface of the solid. The 
slower of these two reactions will obviously determine the 
reaction velocity actually observed. 

Many instances have come to light in recent years in which 
this hypothesis seems to give the best explanation of the facts. 
As an example the above mentioned work on rates of solution 
of metals in iodine may be cited, in which it was shown that 
eight different metals, Ag, Hg, Cu, Ni, Co, Fe, Cd and Zn, all 
dissolved at the same (equivalent) rate in a solution of iodine 
in potassium iodide. This fact seems to show that the rate of 
diffusion of the iodine is here actually the determining factor. 

Such results are, of course, conditioned upon the absence of 
any interfering secondary effects, which are often encountered 
in practice and may obscure or wholly conceal the intluence of 
diffusion. The formation of an insoluble coating on the solid 
is a common type of interference. Other types will be referred 
to later. As a rule, however, such cases show characteristic 

* Van Name and Edgar, this Journal (4), xxix, 287, 1910; Van Name and 
Bosworth, this Journal (4), xxxii, 207, 1911; Van Name and Hill, this 
Journal (4), xxxvi, 548, 1913. 

+The term ‘* chemical reaction” in this connection is used in the broader 
sense, and may in certain cases include processes not always classed as 


chemical, such as solution in water, or crystallization from solution. No 
such cases, however, are included in the present investigation. 


Am. Jour, Sct.—FourtH SERIES, Vou. XLII, No. 250.—Octosmr, 1916. 
21 


302 Van Name and Hill—Solution of Metals 


peculiarities which make it easy to determine the cause of the 
abnormal results. These anomalous cases can only be inter- 
preted individually, and must, for the present, be excluded 
from our general discussion. 

The hypothesis of a diffusion layer, together with its 
immediate consequences, is usually enough to account for the 
observed results. Nernst, however, whose opinion carries 
special weight since he is to a large extent the originator of 
the diffusion theory,* has introduced a second hypothesis. 
Nernst argues that at the boundary surface between two phases 
considerable differences in chemical potential must exist 
between points infinitely near together, which should make 
the velocity of the chemical reaction infinite, or at least in 
practice extremely high.t Consequently the diffusion process 
will always be slow in comparison, and will therefore deter- 
mine the observed reaction velocity in all cases except, of 
course, the anomalous ones already mentioned. 

If this hypothesis of Nernst’s is to be understood literally it 
means that the ovserved velocity of a reaction between a solid 
and a dissolved substance will never represent, even approxi- 
mately, the trie rate of the chemical reaction. No place is 
left for cases other than those in which the velocity is governed 
solely by diffusion, and those rendered abnormal by disturbing 
influences. From this it follows that when the same dissolved 
substance reacts with different metals the velocity of the reac- 
tion, in all cases free from secondary disturbances, should be 
the same irrespective of the specific nature of the metal. This 
test of Nernst’s hypothesis is applied in the experiments to be 
described. 


EXPERIMENTAL PART. 


The method and apparatus used have been described in a 
previous article.t Such minor modifications in the procedure 
as were found desirable in dealing with the different reactions 
will be mentioned in their proper connection. The different 
metals, in the form of circular disks 0°5™™ in thickness and 
38°3™" in diameter, were exposed to the action of the solution, 
under carefully regulated conditions as to temperature, rate of 


stirring, and position of the disk. Samples of the solution, 


* Noyes and Whitney (Zeitschr. phys. Chem., xxiii, 689, 1897) were the 
first to suggest the conception of a diffusion layer, but they applied it only 
in a special case. Nernst, in 1904, gave the idea a more exact formulaticn, 
showed its wide applicability, and made it the basis for a ‘‘ general theory 
of heterogeneous reactions.” (See following footnote.) 

+ Zeitschr. phys. Chem., xlvii, 52, 1904, also ‘‘ Theoretical Chemistry,” 
3d Eng. ed., p. 586. 

¢ This Journal (4), xxxii, 207, and in part, ibid., xxix, 237. 


in Ferric Salts and in Chromic Acid. 303 


which was initially 600 cm* in volume, were taken at convenient 
intervals. with a 20 cm®* pipette, and the velocity constants % 
calculated in the ordinary way from the observed concentra- 
tions at the beginning and end of the five to ten-minute time 
intervals. The rate of stirring was kept at 200 revolutions per 
minute in all experiments, and although the variations were 
usually very small they were systematically determined and 
corrected for by the method described in the article just cited. 
The temperature was 24°6° C. in all experiments with ferric 
salts, and 25° C. in all those with chromic acid. 


Rates of Solution in Ferric Sulphate. 


Previous experiments on the rate of the reaction between 
ferric sulphate and metals have been made by T. E. Thorpe* 
(1882), and by C. G. Schleuderbergt (1908). Thorpe com- 
pared the action of the ferric salt on zinc, magnesium, and 
iron, but under poorly defined experimental conditions, further 
complicated by the evolution of hydrogen. Schleuderberg 
studied only the reaction between ferric sulphate and copper, 
so that his work affords no comparison between the rates for 
different metals. Though primarily interested in testing for a 
possible effect of light on the reaction velocity, he was led to 
the conclusion that diffusion was the determining factor. 

In the experiments of the writers, the ferric alum solutions 
used were approximately 0:05 molar with respect to RFe(SO,),, 
and contained, besides, various known amounts of free sulphuric 
acid together with a little ferrous sulphate to take up dissolved 
oxygen. Several liters of solution were prepared at one time, 
and the total iron concentration determined once for all by 
reducing duplicate samples in a Jones Reductor and titrating 
with 0:02 normal permanganate. The ferrous iron concentra- 
tion at various stages of the reaction was found by direct 
titration with the same permanganate solution in the presence 
of phosphoric acid, and the ferric iron obtained by difference. 
In the tables C is the total iron, and ¢ the (variable) amount of 
ferrous iron contained in 20 em* of solution, all expressed in 
cubic centimeters of the 0:02 normal permanganate. The 
values of C-e were used in calculating /. 

To prevent oxidation of the ferrous salt in the solution by 
the stirring in contact with air, an atmosphere of carbon 
dioxide was maintained above the liquid by passing a brisk 
current of the gas into the reaction vessel throughout the ex- 
periment. 

In most of the experiments the ferric alum used was the 
potassium salt. Those, however, in which the sulphuric acid 


* Jour. Chem. Soc. Lond., xli, 287. + Jour, Phys. Chem., xii, 574. 


304 Van Name and Hill—Solution of Metals 


was 5 molar were made with ammonium ferric alum, after 
special tests had shown that the two alums gave practically 
identical results. 

Cadmium.—Experiments with metallic cadmium (Kahl- 
baum’s) are recorded in Table I. Here, and in all the follow- 
ing tables, #, is the observed velocity constant, uncorrected, 
k: is the same corrected for variations in the rate of stirring, 
and K the averaged value of & for the single experiment. By 
way of illustration, data for Experiment 1 are given in full. 
For the rest only the corrected velocity constants are recorded. 


TABLE I. ' 
Metal: Capmrum. R'Fe(SO4)2, 0°05 molar. 


k, = velocity constant as observed, uncorrected. /: = constant corrected 
for variations in the rate of stirring. KK = average constant for the single 


experiment. 
ae H80,, 0°01 molar. 
ils C =50°00 : K 
ws 580 560 540 520 500 480 460 
A= 7 6 6 6 6 6 6 
C= 04i 2°78 4:73 6°72 8-72 10:69 12°69 14°61 
(ne 3°96 3°93 4°04 4°11 4°06 4:18 4°04 


(= 3°94 3°93 401 4°11 4°09 4:14 4°02 4:03 


Dit ea 4:01 3°99 4°01 Oro 3°92 410 4°04 4:00 
— 401 4°01 4:05 4:22 4:29 4°12 4:29 4°14 
4. Goes 3°98 3°98 4:08 4°12 4:09 4:02 4:06 4°05 
pele = 4:13 4:00 4:23 4°34 4:48 4:20 4°39 4°25 
6 k= 4:00 3°98 4°20 4°33 4°50 4°34 4:22 4°22 
H2SO;, 0°25 molar. 
Te) 4:14 4°10 4°25 4°20 419 4°25 4°09 4:17 
(sy = 4°18 4°04 3°97 4°19 4°21 4°20 4°12 4:13 
H.S0,, 1°25 molar. : 
Oe aft se 3°48 3°46 3°53 3°56 3°61 3°58 5°61 3°55 
10) Wee 3°46 3-47 3°51 3°60 3°62 3°53 3°61 3°53 
H.SO,, 5 molar. 
ee — 1°78 1°76 1°75 1°84 1°68 1:78 1°68 1°75 
WAS ie 175 1°76 1°74 1°75 179 1°80 1°81 NWT 


Although it might be expected that an increase in acidity 
would raise the reaction velocity, it is seen in the table that 
precisely the reverse is true, at least for concentrations of sul- 
phurice acid above 0:25 molar. This effect will be observed in 
all cases where free sulphuric acid is present, whether the oxi- 
dizing agent be ferric salt or chromic acid. 


TABLE II. 
Metal: Iron. R'Fe(SO:)2, 0°05 molar. 
Bee. HESOM 0-0 molar. 
1. C=50:00 Co = 0°44 Kk 
—U= 580 560 540 520 500 480 460 
At= 8 8 8 8 8 8 8 
C= 4°36 8°20 11°93 15°68 19°15 22°68 25°67 
1 3°90 3°93 3°90 3°99 3°78 3°59 3°73 
i c= 3°87 3°91 3°89 3°99 syorh9) 3°58 33°18) 3°82 
H.SO:, 0°05 molar. 
i 3°97 3:97 3°64 = (lost) 3°76 3°96 3°80 3°85 
H2S0,, 0°25 molar. j 
By Ieee 4:00 3°92 3°95 3:98 3°91 3°94 3°99 3°96 
Ce 3°91 3°90 3°82 3°80 3°85 3°92 3°92 3°87 
H2S801, 1°25 molar. 

Oey y= 3°42 3°38 3°31 3°42 3°35 3°35 3°34 3°37 
(Oy ses 3°45 3°38 3°29 344 = 3°33 3°45 3°31 3°38 
H2SO,, 5 molar. 

Lge tl Ui 1°79 1°74 1°79 1°75 1°78 1°69 1°76 
Lis 175 171 1°69 1°67 1°63 1°64 1°62 1°67 
Os 1°79 174 174 1:72 173 1:72 1:74 1°74 
10. k= 1°80 1-79 1°76 1°76 1°76 1:76 1°78 177 


an Berrie Salts and in Chromic Acid. .- 305 


Jron.—Results obtained with metallic iron are shown in 
Table II, the first experiment, as before, being recorded in 
detail as an example. . The calculation of the constants from 
the titrations is here somewhat different, since for every two 
molecules of ferrous iron formed by reduction of the ferric 
sulphate one more is formed by solution of the metal. The 
concentration of ferric salt at any instant is therefore measured 
by the value of the expression C — ¢, — #(¢ — @), in which C is 
the total iron, c, the initial ferrous iron, and ¢ the ferrous iron 
at time ¢@, all expressed in the same units. In the table these 
units, as before, are cubic centimeters of 0°02 normal perman- 
ganate, and the values refer to 20cem* of solution. The metal 
used was ‘‘ American Ingot Iron,” a special grade of commer- 
cial iron which has a purity of about 99-9 per cent. 


For the lower acidities, 0°01 and 0-05 molar, the results are 
less trustworthy than the rest and probably slightly too low, 
for the disk became covered during the experiment with a 
blackish coating which seemed to consist chiefly of hydroxide, 
since it turned to a rust-red color on drying. In the presence 
of 0°25 molar sulphuric acid the coating was very slight, and 
at higher acidities entirely absent. 


306 Van Name and Hili—Solution of Metals 


Nickel.—Table III contains the results of the experiments 
with metallic nickel. Two samples of ‘pure nickel” were 
used, one furnished by Kahlbaum, the other of unknown ori- 
gin, both of which seemed to give practically the same results. 
The former was used in Experiments 1 and 2, the latter in 
Nos. 3, 4, and 5, and also in the experiments with chromic 
acid, to be described later. 

In no case was the action of the solution on the metal per- 


TABLE III. 


Metal: Nickrt. R'Fe(SO.)2, 0°05 molar. ’ 
ape H.S8O;, 0°01 molar. K 
1. k=. 3°75 3°75 3°53 3°29 3°27 3°33 2°98 3°41 
H.2SO,, 0°25 molar. 

2 k= 3°82 (lost) 3°53 3°36 3°15 3:18 3°15 3°36 
Be | Bea 3°86 3°54 3°49 Be 3°31 3°22 3:11 3°42 
H.SO,, 1°25 molar. 
wep 3°24 3:19 3:07 2°93 2°89 2°82 2°78 2'99 

H.2SO,, 5 molar. 
oh [pe lal 1°69 1°56 1°52 1°49 1°45 1:45 1'55 


Initial velocities by extrapolation: Exp. 1, 3°80; Exp. 2, 3°75; Exp. 3, 3°75; 
Exp. 4, 3:27; Exp. 5, 1°71. 


fectly normal and uniform. In the presence of 0:01 and 0°25 
molar sulphuric acid distinct black coatings formed on the 
disk, while even at the highest acidity, 5 molar, the disk 
acquired a brownish discoloration and, ultimately, a minutely 
spotted appearance. Examined under low magnification these 
spots were seen to consist of irregular rounded hollows, each 
containing traces of a brown deposit. 

As the probable result of these irregularities in the action, 
we find in all cases that the velocity constants decrease as the 
experiment progresses, though less rapidly in the more strongly 
acid solutions. However, the constants for each single experi- 
ment, when plotted with time as the other codrdinate, lie fairly 
close to a straight line, so that by extrapolating this line back 
to time zero we obtain a corrected value for the reaction veloc- 
ity which represents, at least approximately, the rate at which 
the reaction would proceed under the given conditions if the 
sources of disturbance were absent. The initial reaction veloc- 
ity for each experiment, as obtained by such extrapolation, is 
recorded at the foot of the table. Although, owing to irregu- 
larity in the constants, this procedure sometimes fails to give 
sharp results, these extrapolated values are certainly more accu- 
rately and fairly representative of the single experiments, in 


in Ferric Salts and in Chromie Acid. 307 
the present case, than are the average values of their constants, 
and will therefore be given the preference in comparing nickel 
with the other metals. 

It should be noted that this process of extrapolation affords 
a general method for correcting the observed reaction veloci- 
ties for the effect of all disturbances which are initially absent 
but are produced by the progress of the reaction. It will be 
used in a number of the cases to follow. 

Tin.— Metallic tin was found to dissolve readily, retaining a 
clean bright surface, in the ferric sulphate solutions used. The 
results as recorded in Table IV were calculated by using for the 
concentration of ferric salt the expression OC — ¢, — $e — ¢,) 
in which © and ¢, are the initial concentrations of ferric and 
ferrous salt respectively, and c is the titer of the solution at 


TABLE LY. 


Metal: Try. _R'Fe(SO.)2, 0°05 molar. 


Initial velocities by extrapolation: Exp. 4, 3°97; Exp. 5, 3°95. 


time ¢. This method of calculation is based on the reaction 
2 Fet+t+ + Sn = 2Fett -++ Sntt, that is, it takes no account 
of the possibility of oxidation beyond the stannous stage. 

The assumption here involved, that stannous sulphate is not 
oxidized by the ferric sulphate, may seem at first sight to be 
unwarranted, even as an approximation, for the reaction 
between stannous chloride and ferric chloride, as shown by the 
work of Kahlenberg* and of A. A. Noyes,t is fairly rapid and 
practically complete, and is, moreover, accelerated by hydro- 
chloric acid. We have found, however, that under the condi- 
tions of our experiments the oxidation of stannous sulphate by 
ferric sulphate is extremely slow. The following observations 


* Jour. Amer. Chem. Soc., xvi, 314, 1894. 
+ Zeitschr. phys. Chem., xvi, 550, 1895. 


No. of 
ce H.SO,, 5 molar. 
1. C= 62:00 Co == 2°46 K 
() 580 560 540 520 500 480 460 
At= 10 10 10 10 10 10 10 
= 5°91 9°48 13°00 16°53 20°13 23°80 27°40 
i= Hert 175 1-71 171 1°75 1°78 1°72 
= 171 1°74 171 171 1°75 1:78 1°72 173 
2 = 1°7 1°76 1°75 1°75 1°71 1°74 171 1°74 
hee ce 1°75 1°70 1°73 1°69 1°67 171 1°66 1°70 
H2SO:, 0°25 molar. 
4 he = 4°07 4°03 4:09 4°10 418 4°22 4°35 4:15 
5. k= 4:07 4°04 411 4°14 4°28 4:27 4°36 4:18 


308 Van Name and Hill—Solution of Metals 


will serve to illustrate this fact: After an experiment on the 
rate of solution of tin, the solution remaining in the apparatus, 
and containing a large excess of ferric sulphate, was always 
found to give a brown precipitate with hydrogen sulphide, 
even after standing over night. Again, a mixture of stannous 
sulphate with a small amount of ferric sulphate, strongly acidi- 
fied with sulphuric acid and colored red by thiocyanate, re- 
tained its color for many hours, but bleached rapidly as soon 
as a little potassium chloride was added, thus showing con- 
spicuously the much greater velocity in the presence of chlo- 
ride ion, 

It is certain, therefore, that comparatively little stannic sul- 
phate can have been formed during the short time occupied by 
the experiment (about 70 minutes). Nevertheless it is desira- 
ble to consider what effect the oxidation of the stannous sul- 
phate by the ferric sulphate would tend to have upon the 
observed reaction velocity. The important point here is the 
fact that this reaction produces no change in the titer of 
the solution toward permanganate. Consequently, the analyses 
yield us no information concerning the extent to which ferric 
sulphate has been replaced by stannic sulphate, but give only 
the sum of the two. Both react with metallic tin, and with 
the same ultimate result so far as the yield of products which 
reduce permanganate is concerned, but the specific rates at 
which ferric sulphate and stannic sulphate, respectively, react 
with the metal, may be, and probably are, quite different. We 
may therefore conclude that the only direct effect on the 
observed reaction velocity to be expected in a case of this kind, 
due to the second stage of the reaction, is a downward or an 
upward trend of the velocity constants, according as the original 
oxidizer, or the one replacing it, reacts most rapidly with the 
metal.* 

Experiments 1, 2, and 8, of Table IV show no such trend in 
the constants, and the averaged values of may accordingly 
be assumed to be practically free from error due to the second 
stage of the oxidation. In Experiments 4 and 5 the constants 
show a slight rise, so that here the initial reaction velocities, 
obtained by linear extrapolation in the way described above, 
furnish the safest basis for comparison with the other metals, 
and will be so used. Whether the observed rise in the con- 
stants is due to the second stage of the reaction or to some 
other cause, no serious doubt attaches to the initial velocities, 
which are entirely consistent with the values given by the 
other metals. 


*Tt is evident that this will in many cases be determined more by rapidity 
of diffusion than by oxidizing activity. 


in Ferrie Salts and in Chromic Acid. 


309 


Copper and Silver.—The results obtained with copper and 
with silver are much alike and can conveniently be considered 
together. They are recorded in Table V, together with two 


experiments on the rate of solution of zine. 


The silver used 


was from a sample of high purity which gave no test for cop- 
per. For the copper disks the best obtainable grade of com- 
mercial sheet copper was employed, but the sample was not 


TABLE V. 


RiFe(SO.i)2, 0°05 molar. 


Copper. 

No. of = 
Exp. H.SO:, 0°25 molar. Kk 
ee 3°83 3°58 3°78 3°68 . 3°54 3°61 3°64 3°67 
eae 3°76 3°64 3°69 3°60 3°50 3°62 3°ol 3°62 

H.SO., 1°25 molar. 
5 3°31 3°21 3°26 3°22 3°24 3°41 3°02 3'24 
Al ¢ 6s 3°36 3 25 3°22 318 3:16 3°13 3°02 319 
H2SO., 5 molar. 

Oe Sie JO 7(S} 1°67 1-64 1°66 1°69 1°46 1°60 1°63 

6: eS — 1°64 1°68 1°59 1°63 1°63 1°53 1°62 

The i 1°68 1°66 1°65 1°60 161 1°59 1°62 1°63 

Initial velocities by extrapolation: Exp. 1, 3°75; Exp. 2, 3°73; Exp. 
3, 3°27; Exp. 4, 3°33: Exp. 5, 1:74; Exp. 6, 1°70; Exp. 7, 1°69. 
Silver. 
H2SO:, 0°25 molar. 
8. = 1°60 1°60 1-44 1°34 1°29 1:19 1:08 1°36 
H2SO:, 1°25 molar. 

9; k= 161 1°49 1°35 1°36 1:23 1°14 1:18 1°34 
OSes er 16 I 1°53 1°48 1°41 1:29 1:27 115 1°39 
il, 4 germ. Ag2SO, added at the outset. 

t= 0°73 0°63 0°62 0°59 0°56 0°52 0-41 0'58 
H2SO;:, 5 molar. 
12. k= 1°28 116 111 1:08 1°06 1:06 1°05 111 
1B. k= 1°25 116 1:17 1:10 1:04 1°05 1°02 lil 
Initial velocities by extrapolation: Exp. 8, 1°67; Exp. 9, 1°61; 
Exp. 10, 1°65; Exp. 12, 1°23; Exp. 13, 1:24. 
Zine. 
H2S0:, 0°01 molar. 
14 he 4°41 4°32 4°35 4°56 4°56 4°57 9°00 4°46 
Woy) 7} 4:27 4°38 4°13 4:07 4°48 4°34 4°39 4°29 


310 Van Name and Hill—Solution of Metals 


subjected to any special tests for purity. Both silver and cop- 
per retained a bright clean surface in dissolving in the ferric 
sulphate, but both gave in all cases velocity constants which 
decreased as the experiment progressed, though this effect was 
much more marked with silver than with copper. 

For silver, at least, the explanation is clear, since the reac- 
tion between silver and ferric ion has been shown to be far 
from complete. Noyes and Brann* found that only about one- 
fourth of the ferric ion was reduced at 25°, The rate of the 
chemical reaction proper must therefore decrease with increase 
in the silver content of the solution, which accounts for the fall- 
ing constants in our silver experiments. The correctness of 
this explanation is placed beyond question by Experiment 11, 
in which silver sulphate, added at the outset, produced a large 
decrease in the reaction velocity.t 

By analogy, the decrease in the copper constants should be 
explainable in the same way. Electrochemical evidence tend- 
ing to confirm this is found in Table VI, where it is shown 
that a copper electrode becomes more positive toward a solution 
of ferric sulphate when copper sulphate is added, thus proving 
that the reaction is to some extent reversible. Silver and cad- 
mium electrodes show a like behavior. All potentials in the 
table are referred to the normal calomel electrode as + 0°560 
volts, but no corrections have been applied for diffusion poten- 
tials. The values lay no claim to accuracy, as the concentra- 


Taste VI. 
Metal. — Solution. Single Foteniaa 
Sinver | 7/20 m: KFe(SO.)., 74m. HaSO., ek eece ere +0937 
3 Pome 6 ra I Pea a SPU NERS Oreo a nhc +0°919 
- erp Ye a pen ME ear Rear Se +0°883 
ce 6c oe wEG Wy oe “e 1/200 m. AgsSO:, +0'948 
CoPprEerR ee es C7 Wena debts A URES an Nien +0'540 
4 eye a 1 Me chai «SE hit SS AA +0°525 
i Mata: Bs OME em LOS SopOMt oo 6 +0508 
a pst ke Be Aye Deshi 1/100 m. CuSO.i, +0°549 
Capmium ‘“ “‘ ca {aan eae soe ACSA Soesdee —0°205 
“ eye « eee 6c TS ee —0'224 
a are oe 5 PORES MES PSTN: ERS MMe: frotane —0'236 
be heen Ge 66 Yy 66 be 1/100 m. Cds0,, —0'200 
Sinver®, “1O70llbtmSOrOi,cn. ek © Rahetgteumtenerrars. rcs +0'968 
a pete ne [1 i ie MR rey cic lee OG +0°894 
a Seatac: «4 1/200 m. AgeSOx, -+0°905 


* Jour. Am. Chem. Soc., xxxiv, 1016, 1912. 

+A part of the silver sulphate added was still undissolved at the start, but 
dissolved during the course of the experiment. This was no doubt the cause 
of the falling constants. 


in Ferrie Salts and in Chromic Acid. 811 


tions of the solutions were only approximate, and the potential 
readings changed somewhat with the time, but the effect of 
the added salts is unmistakable. It is also clear that the elec- 
trode in all eases becomes less positive or more negative to the 
solution as the acidity increases, a fact to which we shall have 
occasion to refer later. 

The reaction between ferric ion and a metal would, in 
general, be expected to be more complete the less noble the 
metal, and this probably explains why the tendency of the 
reaction velocity to decrease during the course of the experi- 
ment, though large enough to affect the results in the case of 
silver, and (to a smaller extent) also in the case of copper, was 
not appreciable with tin, nickel, iron, and cadmium. 

On account of this decrease in the constants it is clear that 
the extrapolated initial velocities, in all the silver and copper 
experiments, are the values which properly represent the 
individual experiments. 

Zinc.—For the experiments with zinc the metal used was 
the very pure commercial grade from the “ Bertha” mine in 
Pulaski, Virginia. This was cast into thin plates and then 
ground and filed to the desired shape and thickness. Un- 
fortunately it proved impossible to obtain the rate of solution 
of zine, free from the disturbing influence of an evolution of 
hydrogen, which was given off in appreciable quantity even in 
ferric sulphate solutions to which no acid had been added. It 
has been shown in a previous paper® that the evolution of a gas 
tends to raise the observed reaction velocity, and by an uncer- 
tain amount, so that the velocity constants obtained in Experi- 
ments 14 and 15, in the presence of 0-01 molar sulphurie acid, 
are probably slightly too high. 

These two experiments are the only ones recorded in this 
paper which are affected by this source of error. None of the 
other metals gave an appreciable evolution of hydrogen under 
the conditions of experiment. 


Rates of Solution in Ferric Chloride. 


No change in the conditions or general procedure 
described above for ferric sulphate was made in the experi- 
ments with ferric chloride, except that in making the titrations 
definite amounts of manganous sulphate, sulphuric acid, and 
phosphoric acid were added to the sample, instead of phosphoric 
acid alone. This modification, made necessary by the presence 
of chloride, involved a slight sacrifice in the accuracy of the 
analyses. Table VII contains the results. 

The experiments with cadmium eall for no special comment. 
In the experiments with metallic iron the disks remained 


* This Journal, xxxii, 217. See also, ibid., xxxvi, 544. 


312 Van Name and LHitl—Solution of Metals 


wholly free from the black coating formed in some eases in 
the sulphate solution. As before, the expression C—c, — }(e-¢,) 
was used in calculating the velocity constants for iron. 

Copper dissolving in an acidified ferric chloride solution is 
oxidized in two stages, the case being therefore unlike that of 
copper in ferric sulphate, but closely analogous to that of tin 
in ferricsulphate. As in the latter case, the titer of the solution 
toward permanganate is not changed by the second stage of the 
oxidation, so that the analyses do not distinguish between ferric 


TaBLe VII. 
FeCls, 0°05 molar. : 
No. of Cadmium. 
Exp. HCl, 0°5 molar. k 
ie 4°17 4°08 4°16 4°16 4:13 4°18 4°20 4°15 
ge) ee 4:09 4°28 415 4:27 4°21 4°18 4°12 4:19 
HCl, 0:1 molar. 
oe 4°32 4°16 4°37 4°12 4-14 4°25 4°29 4°24 
4. Jez 4°12 4°15 4:17 4:18 4°12 414 4°12 4'14 
Tron. 
HCl, 0°5 molar. 
BaAk= 4°26 4°30 4:29 415 4°39 4.50 4°41 4'33 
68S 4°24 4°34 4°39 4:37 4°40 4:40 4:44 4°37 
HCl, 0°1 molar. 

Te alae 418 4°10 4°18 4°35 418 3°83 4°22 415 
8. 4°08 411 4°06 4°12 4:17 4°16 415 4'12 
Copper. 

HCl, 0°5 molar. 

Oh) iiss 4°26 4°22 4°32 4°42 4°33 4:49 4°41 4°35 
NO, = 414 4:25 4:29 4:37 4:28 4:22. 4:20 4°25 
HCl, 0°1 molar. : ; 

Te Tie 3°43 3°28 3°26 3°17, 3°16 3°09 2:99 3°20 
1 k= 3°56 3°30 3°23 3°15 3°02 3°11 3°24 


Initial velocities by extrapolation: Exp. 9, 4°20; Exp. 10, 4°20; Exp. 11, 3°40; 


Exp. 12, 3°48. 


chloride and cupric chloride, but give theirsum. The velocity 
constants have been calculated in exactly the same way as in 
the tin experiments. In fact, the sole difference between the two 
cases is that here the second stage of the reaction is compara- 
tively rapid. A good deal of cupric chloride must therefore 
have accumulated in the solutions, reaching, at the close of 
Experiments 9 and 10, in which this effect was largest, a con- 
centration considerably larger than that of the ferric chloride 
itself. 


an Ferric Salts and in Chromic Acid. 313 


It is evident that this substitution of eupric for ferric 
chloride would tend to cause a progressive change in the reac- 
tion velocity during the experiment. A careful consideration 
of the probable effect of the various factors influencing the 
result seems to show that such changes as those obser ved in 
Experiments 9 to 12, in which the ‘direction of the change 
depends upon the acidity, are not incompatible with the point 
of view which we have adopted. We shall, however, make use 
of only the extrapolated initial velocities, so that the cause 
of the changes in velocity is for our purpose of minor 
importance. 


Discussion of Results Obtained with Ferric Salts. 


Table VIII contains a summary of the results given in the 
previous tables, each velocity constant being the averaged 
result of the various experiments performed under the con- 
ditions specified. These values have been obtained by one or 
the other of the two following methods: (a) For groups of 
comparable experiments in which the results were normal they 
are the averages, for all members of the group, of the average 
reaction velocity in each single experiment. (b) For groups 
of experiments in which the constants showed an unmistakable 
trend upward or downward they are the averages of the initial 
velocities as found by linear extrapolation. Although where 
method (b) is used the constants so calculated must be given the 
preference as more truly representative, the values calculated 
by method (a) are placed beside them, enclosed in parentheses, 
for comparison. 

Considering first the upper section of the table, containing 
the ferric sulphate constants, we observe that in the presence 
of 5 molar sulphuric acid five metals give practically the same 
velocity, which, from the point of view of the diffusion theory, 
would be inter preted to mean that here the rate of diffusion of 
the ferric sulphate is determining the velocity. With decreas- 
ing acidity, however, the agreement becomes poorer, the metals 
tending to draw apart and to show individual velocities whose 
order is that of the electromotive series, the more positive 
metal dissolving more rapidly. It is evident here that the 
specific nature of the metal hasa distinct influence on the reac- 
tion velocity. 

Such results as these are seemingly in direct contradiction to 
Nernst’s hypothesis of infinitely high reaction velocity at the 
boundary surface between two phases. Nernst’s hypothesis, 
as we have already seen, demands that in all normal cases, that 

, in all eases not affected by secondary disturbing influences, 
ire observed reaction velocity shall be determined by the rate 


314 Van Name and Hill—Solution of Metals 


of diffusion of the active substance, and shall be practically 
independent of the nature of the solid. Now it cannot be 
denied that disturbing influences may have slightly affected 
some of the results in the table ; in particular, the nickel con- 
stants are rather uncertain. On the otber hand, there was no 
evidence whatever of interfering effects in the cadmium exper- 
iments. Moreover, the distinctly systematic nature of the 
results in the table argues against the possibility that any con- 
siderable number of them represent ‘ anomalous” cases. 
Finally, the decreasing constants obtained with silver were 
clearly traced to the retardation of the chemical reaction by 
the accumulation of silver sulphate, which would have only, a 
trifling effect on the rate of diffusion. In short, these results 
furnish grounds for seriously doubting the general validity of 
Nernst’s hypothesis. 

A study of the table seems to show that at one extreme we 
have velocities determined largely or wholly by diffusion, at 
the other, velocities determined chiefly by the rate of the 
chemical reaction, and between them velocities in which we 
ean readily detect the simultaneous effect of both influences. 
Although these results do not cover the full range from a 
purely chemical reaction velocity to a pure diffusion velocity it 
is evident that the transition from one to the other is gradual, 
not abrupt. 

This point becomes clearer on further analysis of the results. 
An increase in the concentration of free sulphuric acid above 
0°25 molar produces in all cases a marked decrease in the 
observed reaction velocity. In general, the activity of an oxi 
dizing agent is increased by a rise in the concentration of 
hydrogen ion. It will hardly be doubted that this rule applies 
in the cases with which we are dealing, and we should, there- 
fore, expect that the free energy of the reaction with the metal 
would increase with increasing acidity. This is supported by 
the potentials in Table VI so far as inferences can safely be 
drawn from the behavior of electrodes which are imperfectly 
reversible. This table contains the single potentials of silver, 
copper, and cadmium against solutions of the same composi- 
tion as those used in the reaction velocity measurements. As 
we have already noted, the values show that with increasing 
concentration of sulphuric acid the metal in all cases becomes 
less positive or more negative toward the solution, that is, the 
change is in the direction of increasing free energy. 

For our purpose, however, the important question is the 
effect of an increase in acidity upon the velocity of the chem- 
ical part of the reaction with the metal. Although, in general, 
there is no necessary correspondence, even in sign, between 
variations in reaction velocity and variations in the magnitude 


in Ferric Salts and in Chromic Acid. 315 


of the change in free energy, there would seem to be here a 
rather strong probability that the chemical reaction in most or 
all of the cases with which we shall have to deal is accelerated 
rather than retarded by an increase in acidity. At all events 
we shall make this assumption as a working hypothesis, and 
shall adhere to it consistently throughout. 


TasLE VIII. 
Summary of Velocity Constants. 


Ferric Alum. 


Cone. of H28O.1 0°01 0°25 1°25 5 molar. 

VAISS Bia ORO 4°38 

Cadmium.:.... 4°12 4:15 3°54 1°76 

MTOM sesrecn races: 3°95 (3°82) 3°92 3°37 1°74 

Nickel ........ 3°80 (3°41) 3°75 (3°39) 3°27 (2°99) 1°71 (1°55) 

Lhd ol neice Se Ree ele Wan 3°96 (4°16) mane UG, 

Copper........ sige 3°74 (3°64) 3°30 (8°22) 1°71 (1°63) 

Silwenoies Shee see 1°67 (1°36) 1°63 (1°36) 1°24 (1°11) 
Ferric Chloride. 

Cone. of HCl O1 0°5 molar. 

(Chichiabivieilas Bomoloomace ap Goo os pitee Cio ma bie rain 4°19 4°17 

TTRONO Raat Br cee sa GAS 5 DIRCrOCUChO Conte RSI CRS EAA 4:14 4°35 

(Chyyae sng boomconoosprs oo. qaameuEns obooRvE 3°44 (8°22) 4°20 (4°30) 


We must assume then that sulphuric acid tends to accelerate 
the chemical reaction with the metal, but we find in Table VIII 
that if the acid is present in more than 0°25 molar concentra- 
tion it exerts a strong retarding influence on the rate of solu- 
tion. From the standpoint of the diffusion theory the 
explanation of this effect is clear. The important factor here 
is the viscosity of the solution, which is increased in the ratio 
of about 2°5:1 when the sulphuric acid concentration rises 
from 0°25 molar to 5 molar. An increase in the viscosity 
retards the diffusion process by lowering the rate of diffusion, 
and perhaps, toa slight extent, by increasing the thickness of 
the diffusion layer,* and in this way depresses the rate of solu- 
tion of the metal, this effect here outweighing any acceleration | 
of the chemical part of the reaction resulting from the higher 
acidity. 

A predominance of the diffusion effect, however, does not 
necessarily exclude the influence of the chemical reaction, for 
we find that velocity constants in the same vertical column 
(that for 0°25 molar sulphuric acid, for instance), though they 
differ among themselves in a comparatively systematic manner 
according to the specific nature of the metal, thus showing the 


* See Van Name and Hill, this Journal, xxxvi, 552-4, 


316 Van Name and Hill—Solution of Metals 


influence of the chemical reaction velocity, are all lowered 
by an increase in the viscosity. In other words, these results 
illustrate the case, alluded to above, of a reaction velocity 
determined by the ‘simultaneous influence and mutual relation 
of both factors, diffusion process and chemical reaction. 

Nor is there any reason for believing that such cases are 
unusual. On the contrary, it seems proper to regard the 
observed velocity as being normally the resultant of the simul- 
taneous action of the two factors just mentioned. Cases in 
which one factor predominates to the virtual exclusion of the 
other are, therefore, merely limiting cases, though no doubt 
they oceur very often t in practice. 

This point of view appears to us to be the most reasonable 
and helpful one in dealing with heterogeneous reactions of the 
general type under consideration, and will be the one employed 
throughout the present paper, in interpreting experimental 
results. 

The results obtained with ferric chloride, summarized in the 
lower section of Table VIII, tend to confirm, so far as their 
evidence goes, the conclusions drawn above from the experi- 
ments with ferric sulphate. These values are probably less 
accurate than those for sulphate solutions, and less stress can 
be laid upon small differences, They prove that cadmium and 
iron dissolve in ferric chloride at the same rate in the presence 
of 0-1 molar hydrochloric acid, and probably also when the 
acid is 0-5 molar. This indicates that in’ these eases the 
observed reaction velocities are essentially rates of diffusion. 
It is not clear whetber the effect of this increase in acidity is 
to raise or to lower the observed velocity, but the change is at 
all events small, as would be expected in a case in which the 
viscosity change is almost negligible (about 3 per cent).* 

The same increase in acidity produces a marked rise in the 
rate of solution of copper. We would avoid laying any 
emphasis on the absolute values of these copper constants, on 
account of the complications already mentioned. Neverthe- 
less, it may be pointed out that the relations of these two 
velocities to one another, and to the corresponding values for 
cadmium and iron, involves nothing unexpected or inconsistent 
with the point of view stated above. The lower value for 
copper in 0-1 molar hydrochloric acid, as compared with cad- 
mium and iron, seems to be due to the influence of the rela- 
tively slower rate, in the case of copper, of the chemical part 
of the reaction, this rate being accelerated by the increase in 
acidity to 0°5 molar, up to the point where the rate of diffusion 

*TIn a like manner, the fact that the ferric sulphate constants change so 


little between 0:01 and 0°25 molar sulphuric acid, may be ascribed largely 
to the smallness of the accompanying viscosity change. 


in Ferric Salts and in Chromic Acid. 317 


predominates, thus tending to bring copper into agreement 
with the other two metals. 


Rates of Solution in Chromic Acid. 


In the experiments with chromic acid as oxidizing agent the 
solutions were initially about 0-015 molar with respect to 
CrO,, and contained also definite known amounts of free 
sulphuric acid. The precaution, employed with ferric salts, of 
keeping an atmosphere of carbon dioxide above the liquid 
during the reaction, was, of course, unnecessary in working 
with chromic acid, but in other respects the procedure remained 
as before. As compared with the case of ferric salts, a higher 
concentration of hydrogen ion is essential for the reaction to 
proceed smoothly, and a further difference exists in the fact 
that the acidity decreases during the reaction. But unless the 
initial acidity is low this decrease is relatively small. In the 
experiments accepted as trustworthy, the initial acidity was 
always 0°5 normal (0°25 molar H,SO,) or above, and the 
decrease in acidity, even in the extreme cases, was only about 
6 per cent, an amount too small to have any marked effect 
upon the observed reaction velocity. 

The analyses of the solution samples for chromic acid were 
carried out by one or the other of the two following methods : 
(a) Treatment with an excess of potassium iodide and titration 
of the liberated iodine with thiosulphate, (0) Treatment with 
a known volume of standard ferrous sulphate, and titration of 
the unoxidized ferrous sulphate with permanganate. 

Method (a), which was conducted according to the directions 
of Seubert and Henke,* was applicable only in certain cases, 
and seemed to have no advantage in accuracy over method (0). 
The experiments in which method (a) was used are designated 
in the tables by asterisks. Full experimental data are given 
for Experiment 1, the values of ¢ being volumes of 0°02 normal 
thiosulphate used, which are evidently proportional to the con- 
centrations of chromic acid at the corresponding times, and 
can therefore be directly substituted in the velocity equation 
in calculating #. 

Method (4) was applicable in all cases, and was on the whole 
preferred, after experience had proved that the presence of 
the green chromic salt in the solution did not seriously 
diminish the sharpness of the permanganate end point. Data 
for a typical experiment (No. 4 of Table IX) are given in 
detail, the values of ¢ being here cubic centimeters of 0-02 
normal permanganate used in titrating 20: em* of the given 
ferrous sulphate solution after the addition of the 20 em* sample 


* Zeitschr. angew. Chemie, 1900, 1147. 


Am. Jour. Sct.—Fourts Series, Vou, XLII, No. 200.—Octosrr, 1916. 


2 


ey ae ee oe a 
. a 


318 Van Name and Hill—Solution of Metals 


of solution to be analyzed, together with a little phosphoric 
acid. The concentration of chromic acid is measured, in terms 
of the ferrous sulphate solution, by the expression 20 — we, in 
which a is the volume of the ferrous sulphate equivalent to 
1 em* of the permanganate. This expression was used in cal- 
culating the velocity constants. 

Cadmium and Copper.—Table IX gives the results obtained 
with cadmium and with copper in solutions 0°25, 1:25, and 5 


TaBLE IX. 
CrO;, 0°015 molar. 
Cadmium. ; 
oe H.SO,, 0°25 molar. Kk 
Ponies 580 560 540 520 500 480 460 
At= 10 10 10 10 10 10 10 
C=48'11" (42°68 9 37-74) 3845-92896) Boas V2I 72 sip 
iy 6°94 6°88 7:02 7°00 7°08 6:99 7:13 
i 6:96 6°88 7:02 7:00 7°08 6°99 Tei} 701 
eh” fee 7:04 Gals 7:00 7:08 6°99 7°00 7:05 7°04 
H.SO,, 1°25 molar. 
3) eS 516 541 531 5°29 5°47 B28} 5°37 5°32 
H.S8O;,, 5 molar. 
4. 1 em’ KMn0,=0°388 em? FeSO:. 
— 580 560 540 520 500 480 460 
Af= 10 10 10 11 tS) 10 10 
(ia (YS SoZ) 10289) 12:30) a0) 1622 sre 20.03 
i eit 2°60 2-71 2°73 2°63 2°68 2°68 
ins Dail 2°59 eT Zio 2°63 2°69 2°68 2°68 
a 2°64 2°61 2°70 2°57 2 2:70 2°58 2°65 
H.2SO,, 0°05 molar. 
(Spe 859 . 8°54 8°33 7°94 8°23 7°54 7°81 8'14 
(pee 8°48 8°65 816 7°82 7°82 7'89 7:39 8°03 
* Chromic acid determined by iodometric method. 
Copper. 
H.2SO., 0°25 molar. 
8. k= 118 679) 706 2705 | 678) | AeenC ony OO 
Oi 6°75 6:96 6°91 7:07 6°88 6°84 6°87 690 
i A= 6:96 6°86 6°95 6°99 7°00 7°09 6°85 6'96 
H.SO., 1°25 molar. 
ile a 5°47 5°29 5°39 531 5'34 5°23 5°36 5°34 
H.SO,., 5 molar. 
Bee Pie 2°67 OP 2°73 2°78 2°72 2°76 2°73 
13. oe 27a 2°64 2°76 2°75 2°76 2°69 2°67 271 


H.2SO,, 0°05 molar. 
We ee 2°44 4°02 5°50 6°20 6°76 7°02 Tull! 5°58 


in Ferric Salts and in Chromic Acid. 319 


molar with respect to sulphuric acid. Both metals under these 
conditions behaved normally, giving satisfactorily constant 
reaction velocities, and the values obtained for the two metals 
are, moreover, in excellent agreement with one another 
throughout. 

On the other hand a few experiments conducted in solutions 
only 0:05 molar with respect to sulphuric acid gave distinctly 
abnormal results, the reaction velocities showing progressive 
variation and no ‘appr oach to agreement between cadmium and 
copper. Since these experiments were plainly affected by 
specific disturbances arising from insufficient acidity, the results, 
though included in the table, are of little significance. 

Zron.—The experiments on the rate of “solution of iron in 
chromic acid are complicated by the fact that the oxidation 
takes place in two stages. ‘T’'wo examples of such two-stage 
reactions have already been considered, tin in ferric sulphate 
and copper in ferric chloride, but in both cases the method of 
analysis was such that the second stage of the oxidation had no 
direct effect upon the titer of the solution. Consequently, the 
concentration of the oxidizing agent, as calculated from the 
titrations and used in calculating the velocity constant, was in 
reality the combined concentrations of two oxidizing agents 
present in unknown proportions in the solution, namely, the 
ferric salt, and the higher oxidation product of the dissolving 
metal. (See p. 308.) In the present case it is the concentra- 
tion of the chromic acid alone which is given by the titrations, 
and therefore both stages of the oxidation change the titer of 
the solution. This difference must be borne in mind in com- 
paring the results. 

Now in general, in a two-stage reaction of this type between 
a metal and a dissolved oxidizer, if the second stage is suf- 
ficiently rapid the lower oxidation product will be oxidized 
where it is formed, that is, at the surface of the metal. Thus 
it may happen that a metal in passing through two stages of 
oxidation gives the same velocity constant as a metal undergo- 
ing only one stage, the observed velocity being that of the dif- 
fusion process. Such an instance is apparently offered by the 
ease of tin in chromic acid, to be discussed later. On the other 
hand if the second stage of the oxidation is not quite rapid 
enough to produce the result just mentioned, some of the 
molecules of the lower oxidation stage will not be oxidized 
until they have diffused part way through the diffusion layer, 
or perhaps have passed through it into the solution. The 
effect in either case is to shorten the average length of the dif- 
fusion path for the molecules of the oxidizing agent and there- 
fore to raise the observed reaction velocity. The reaction 
between tin and iodine dissolved in potassium iodide solution 


320 Van Name and Hill—Solution of Metals 
TABLE X. 
CrOs, 0:015 molar. 
: , Iron. 
ee H.SO,, 0°25 molar. K 
ifs 1 em’ KMn0O,=0'385 em? FeSO,. 
y= 580 560 540 520 500 480 460 
At 10 10 10 10 10 10 10 
C= 6195 13°87 20°02 25°60 30°60 35°10 39°17 42°70 
k= 9°67 9°85 10°36 10°93 11°82 13°25 14°86 
hi 9°66 9°85 10°37 10'94 11°83 13°25 14°86 11°54 
a im 9°61 10°39 10°34 11:02 12°10 14:09 15:22 , 11'82 
H.SO,, 5 molar. 
Oe et ep ePafs} 4:16 4°14 4:14 4°08 4:27 4:49 4'15 
Ae 3°96 4:10 4-12 4:19 4°39 4°52 4:49 4°25 
Oi. le 3:95 3°99 4-11 4°32 4°31 4°24 4°48 4'20 
Nickel. 


H2SO;, 0°25 molar. 
6.* Disk immersed in dil. HCl in contact with zinc. 


i 5°75 5°95 5°80 5°40 5'80 5°54 6°12 5°77 
7.* Disk treated as in Exp. 1. 

k= 4°71 600 6°92 6°76 7°05 6°80 6°80 6°43 
8.* Disk treated as in Exp. 1. 

i 5°92 4°56 3°48 2°71 3°27 3°40 3°51 3°84 
9.* Disk cleaned with 2:1 HNOs after each reaction period. 

[fe 0°49 1°54 1°35 0°03 iW7Al 0:09 1:04 0°89 

10.* Disk cleaned with warm 1:2 HNOs after each reaction period. 
k= 037 5°96 G'OL "5:67 9 48 ese ons 82 4°43 
H.S0O,, 5 molar. 

i, |) = 2°55 2°64 2°70 2°66 2°58 2°78 2°56 2°64 
A me 2°61 PETAL 2°72 2°71 2°69 2°75 2°71 2°70 
Tin 

H.SO., 5 molar. 

IBS We 2°76 PAP 2°80 2°72 2°68 2°68 2°78 273 
A i 2°84 2°74 2°78 22 2°66 Pio 2°74 274 
Silver. 

H.2S0O,, 0°25 molar. 
i, [b= 4°51 4°30 4:28 4:24 4°52 4°54 4:40 4°40 
WS) ieee 4°31 4°43 4:02 4:25 4:03 4°22 4°15 4°20 
Wi, hs 4°35 417 4°35 4:10 4:21 4:24 4:17 4'23. 
H.280,, 5 molar. : 
18. eS) (88) h 126" 20 Tae eee pi e132) ats ee 
ONS i (1-52)f 1:28 1°29 1°21 121 1°18 itails) 1°23 


Initial velocities by extrapolation: Exp. 15, 4°40; Exp. 16, 4°27; Exp. 17, 4°28; 
Exp. 18, 1°22; Exp. 19, 1°31. 
* Chromic acid determined by iodometric method. + Not included in average. 


in Ferrie Salts and in Chromic Acid. 821 


probably belongs in this category, as has been shown else- 
where.* There is, moreover, reason to expect similar behavior 
from iron in chromic acid, for Bensont+ has shown that the 
reaction between chromic acid and ferrous sulphate progresses 
in dilute solutions at a rate sufficiently slow to be easily 
measurable. 

The results obtained, shown in Table X, Experiments 1-5, 
are in accordance with this view. Not only are the constants 
higher throughout than with the other metals under like con- 
ditions, but they also show the continuous rise which would be 
predicted from the accumulation of ferric salt, which itself 
reacts with the metal, producing ferrous salt in constantly 
increasing proportion compared with the chromic acid, and 
thus causing a progressive shortening in the average length of 
the diffusion path. 

In Experiments 1 to 4 the titrations were carried out during 
the progress of the experiment, and with very little delay. 
Now Benson has shown, in the article just cited, that ferric 
salts have a retarding effect upon the oxidation of ferrous salts 
by chromic acid. If in our analyses the time allowed for the 
completion of this reaction had been too short this would have 
produced high and rising velocity constants. That the high 
and rising constants actually observed were not due to this is 
proved by Experiment 5, in which the solution samples, after 
mixing as usual with a known amount of ferrous sulphate, were 
allowed to stand for 23 hours before titrating back with per- 
manganate. It is evident that this modification made no 
appreciable difference in the results. 

Nickel.—The experiments with nickel in chromic acid were 
carried out in solutions either 0-25 or 5 molar with respect to 
sulphuric acid. In the former solution the velocity constants 
were in all cases irregular and abnormally low; in the latter 
the results were apparently normal and agreed well with the 
values obtained with cadmium and with copper under like con- 
ditions. 

The nickel disks after use always showed traces of a blackish 
deposit or, in the stronger acid, of a brownish discoloration, 
these surface coatings resembling closely in appearance and 
amount those observed with nickel in ferric sulphate solutions 
of like sulphuric acid concentration (see page 306). The 
effect of these coatings upon the reaction velocity was appar- 
ently negligible in 5 molar sulphuric acid, and even in the 
weaker acid they were probably responsible for only a small 
part of the abnormality observed. 

The chief cause of the low and variable results obtained in 
the presence of 0°25 molar sulphuric acid was the tendency of 


* This Journal (4), xxxii, 216, 1911. + Jour. Phys. Chem., vii, 1, 1903. 


322 Van Name and Hill—Solution of Metals 


the nickel disks to become passive. In Experiments 6, 7, and 
8, to insure activity of the disk at the start, after cleaning in 
the usual manner it was immersed in dilute hydrochloric acid 
and thoroughly rubbed under the acid with a zine rod. This 
treatment did not make the constants regular. Since low con- 
stants are found following much higher ones (notably in Experi- 
ment 8) passivity must have been produced in the chromie acid 
solution. That the reaction velocity also increases at times 
during the course of the experiment is perhaps explained by 
the fact that a partly passive disk in sulphurie acid would con- 
stitute a short-circuited element of which the active areas 
would be the anodes, and the adjacent passive areas would con- 
sequently be subject to cathodic reducing effects which would 
tend to destroy their passivity in so far as it was not re-estab- 
lished by the chromic acid. No explanation is offered for the 
fact that these two opposing tendencies produce fluctuations in 
the degree of passivity. It may only be suggested that the 
variations are in some way connected with the gradual uncover- 
ing of impurities in the metal. 

In Experiments 9 and 10 the attempt was made to restrict so 
far as possible the formation, on the disk, of the blackish 
deposits above mentioned, by removing the disk from the solu- 
tion at the end of each reaction period and cleaning with nitric 
acid. The treatment with a zine rod was omitted. Neither 
hot concentrated hydrochloric acid nor iodine in potassium 
iodide solution would remove the deposit completely. Con- 
centrated nitric acid removed it easily and gave the metal a 
perfectly clean surface, but a disk so cleaned was invariably 
wholly passive and was no longer attacked by the chromic¢ acid 
solution. Nitric acid of two-thirds strength was accordingly 
selected for trial in Experiment 9 but proved too strong, the 
results showing practically complete passivity during two of 
the reaction periods, and a very low activity during the rest. 
The more dilute nitric acid used in Experiment 10 produced 
high passivity during the first reaction period, but the later 
constants showed no more passivity than might be expected, 
according to the results of Experiments 6, 7, and 8, from the 
action of the chromic acid alone. 

For Experiments 11 and 12 the sulphuric acid concentration 
was increased to 5 molar with very beneficial results. The 
absence of any indication of passivity in these experiments 
seems to prove that this concentration of sulphuric acid was 
sufticient to entirely overcome the tendency of chromic acid 
to produce passivity in the nickel disks. The rate of the 
reaction shows a satisfactory constancy, and the mean value of 
the velocity constant agrees with the values obtained with 
several other metals under like conditions. 


in Ferric Salts and in Chromic Acid. 323 


Tin.—The study of tin in chromic acid solution was confined 
to the two experiments numbered 13 and 14 in the table, both 
condueted in the presence of 5 molar sulphuric acid. The 
results are in both cases apparently normal, and the reaction 
velocity has the expected value. This behavior on the part of 
a metal-forming soluble and stable salts of two different valen- 
cies indicates one of two possibilities; either (@) the second 
stage of the oxidation does not occur to a measurable extent 
(the case observed with tin in ferric sulphate), or, (6) the second 
stage is so rapid that no appreciable diffusion of stannous salt. 
away from the metal can occur. As the reaction between 
stannous sulphate and chromie acid is practically instantaneous 
there can be little doubt that explanation (0) is the correct one 
here. 

Silver.—Experiments with silver in chromic acid gave the 
values recorded in Nos. 15-19 of Table X. In general, the 
results resemble those given by silver in ferric sulphate, both 
in the relatively low reaction velocities observed, and in the 
fact that the velocity tends to decrease as the silver salt accu- 
mulates in the solution. On account of this decrease the 
reaction velocity characteristic of a given experiment is best 
represented, as in a number of cases already considered, by the 
““jnitial velocity,” found by extrapolating back to time zero. 


GENERAL DISCUSSION OF RESULTS. 
A summary of the reaction velocities in chromic acid is given 
in Table XI. Comparison with the results obtained in ferric 
TaslLe XI. 


Summary of Velocity Constants. 
Chromic Acid. 


Cone. of H.SO, 0°25 1°25 5° molar 
(Chichambbon been oooc gant on ess 702 9°32 2°67 
INTO] Wickes: aehuceg th cnt eaten, Grregular) (irregular) 2°67 
MINT TNME mucwara Ata tusk yaisicca Mes cre sicae, c Wet Stale 2°74 
(OLD) 3) ofS Te ERR Aiea ee ae OCS 5°34 eT) 
SullWermrnte Nea cseta Maroc. Ras tora asd 4:28 : 1°22 


sulphate, as summarized in Table VIII, shows a marked simi- 
larity between the two series, although chromic acid always 
gives higher velocities than ferric sulphate under like condi- 
tions. The chief points of similarity are the following : 

(a) In each series there is an approximate agreement, in the 
presence of 5 molar snlphuric acid, between the values for cad- 


324 Van Name and Hill—Solution of Metals 


mium, nickel, tin, and copper, the differences being either 
within the experimental error or, at most, exceeding it but 
slightly. 

(2) The values for silver are in all cases decidedly lower 
than for the other metals under like conditions. 

(c) The agreement between different metals tends to become 
closer the higher the acidity. 

Slight deviations from (ce) appear in several cases, but are 
generally smaller than the experimental error, the only clear 
exception being the one which occurs with silver in chromic 
acid, due to the unexpectedly low value 1°22. This exception 
will be discussed on a later page. 

Following the point of view explained on page 316, the 
observed reaction velocity is to be regarded as the resultant of 
the rates of two different simultaneous processes, the diffusion 
and the chemical reaction. The agreement between different 
metals in the strongly acid solutions. indicates a nearly or 
wholly complete dependence, under these conditions, of the 
observed rate upon that of the diffusion process. On the other 
hand, the systematic differences which appear between the rates 
for different metals in the less strongly acid solutions, show 
clearly that in these cases the diffusion process is not the sole 
controlling factor, and point to the conclusion that the chemi- 
cal reaction is here slow enough to have a specific influence 
upon the observed result. Especially significant in support of 
this inference is the fact that the sequence of the metals, when 
arranged in the order of their observed reaction velocities, is 
very nearly the same as that of the electromotive series, the 
agreement being as close as could be expected when due allow- 
ance is made both for the normal error of experiment and for 


the additional uncertainty which attaches to several of the 


values on account of specific complications already described. 

So far, our explanation is well supported by the results. 
One important point, however, remains to be considered. It 
has been shown that the reaction velocity in all normal cases 
obeys the equation for a reaction of the first order, thus prov- 
ing that the rate is pruportional at every instant to the con- 
centration of the oxidizing agent. According to the view of 
Nernst this is due to the high velocity of the chemical reaction, 
which keeps the concentration of the oxidizer at the surface of 
the metal at practically zero. The observed reaction velocity 
is then the rate at which the oxidizer is supplied by diffusion, 
and this in turn is proportional to the difference in concentra- 
tion between the two sides of the diffusion layer, which by 
hypothesis is equal to the concentration in the main body of 
the solution. It is evident that this explanation holds only 
when the velocity of the chemical reaction is very great com- 


in Ferric Salts and in Chromic Acid. 325 


ared with that of the diffusion process, a condition which 
iene! assumes to be always fulfilled except when secondary 
effects interfere. 

Such a case, as Brunner* has shown, may conveniently be 
represented by a diagram, fig. 1, in which the abscissas repre- 
sent distances from the surface of the metal, and the ordinates 
concentrations. The shaded portion is the metal, OY its sur- 


Fig. 1. Hie. 2. Fig. 3. 


face, the dotted line is the outer limit of the diffusion layer, 
and the broken line OAB the concentration of the oxidizer at 
different points. 

In the ease of our results this explanation is applicable only 
to those experiments in the strongly acid solutions, in which, 
within certain limits, the reaction velocity is independent of 
the nature of the metal.’ Under conditions where different 
metals show different specific velocities (exemplified by the 
experiments at the lower acidities), the above explanation can 
not apply, yet we find that in general the reaction velocity in 
such expervments obeys the expression for a reaction of the 
Jirst order quite as well as when the velocity is independent of 
the metal. 

The point of view which we have adopted (pp. 816 and 324) 
assumes that the influence of the metal manifests itself in such 
eases because the chemical reaction is not sufficiently rapid in 
comparison with the diffusion process. In other words, the 
concentration of the oxidizing agent at the surface of the metal 
is not zero but has at every instant a finite value determined 
by the relative velocities of the two consecutive reactions in- 
volved. How this state of affairs can be reconciled with the 
observed obedience to the laws of a monomolecular reaction, is 
a point which calls for explanation. 

The case with which we are dealing, represented on a diagram 
of the same type as fig. 1, gives fig. 2, in which the ordinate OC 
represents the concentration at the surface of the metal. 
Similarly fig. 8 shows the possible case of a reaction whose 
chemical stage is extremely slow in comparison with the dif- 


* Zeitschr. phys. Chem., xlvii, 68, 1904. 


326 Van Name and Hill—Solution of Metals 


fusion stage, thus giving a concentration at the surface of the 
metal which is not sensibly different from that in the solution. 
The possibilities represented by these three figures will be 
hereafter referred to as cases I, II, and III, respectively. 

For Case I, Nernst’s explanation, given "above, is sufficient 
to account for the fact that the reaction velocity obeys the 
equation for a monomolecular reaction. In Cases II and III, 
however, there is a finite concentration of the reagent at the 
surface of the metal. This can only occur when a part (in 
Case IIT, nearly all) of the molecules of the reagent which 
strike the surface of the solid phase fail to react with it, and 
hence remain in the solution. Now the frequency of the 
impacts will be proportional to the concentration of the reagent 
in the layer of liquid immediately adjacent to the solid, and 
the percentage of such impacts which result in reaction will, 
ina given case, be practically constant, independent of that 
concentration. It follows, therefore, that the rate of the 
chemical stage of the reaction will always be proportional to 
the concentration of the oxidizing agent in the layer of liquid 
which is in contact with the solid, that is, the ConeennnanOw at 
the inner surface of the diffusion ‘layer. 

Our results seem to furnish no example of chs Iii, but it 
is clear that here, just as in Case I, the rate would be propor- 
tional to the concentration of the solution, for this is the same 
as the concentration at the surface of the solid, which, in turn, 
determines the rate. 

It only remains to be explained why Case I1* shows the 
saine behavior. As we have already shown that the rate must 
be proportional to the concentration at the surface of the 
metal, the problem resolves itself into proving that the con- 
centration at the surface of the metal is proportional at every 
instant to the concentration in the solution. It is a simple. 
matter to show that this is necessarily true except during a 
preliminary period of extremely short duration. 

Let C,, represent the concentration of the oxidizer at the 
surface of the metal, and QO, its concentration in the solution. 
Further, let dm, be the weight of the oxidizer diffusing to the 
metal during the time interval dt, and di, the weight used up 
during time dz. 

The rate of the diffusion process is proportional to the dif- 
ference in concentration on opposite sides of the diffusion 
layer. Hence 


dm, / dt = K,(C, — C,), 


*Case II is evidentiy the general one, I and III being merely limiting 
cases. 


in Ferric Salts and in Chromic Acid. 827 


and since the rate of the chemical reaction proper is propor- 
tional to C,, 


am, / di = K,C,: 


Since a preponderance of either process tends to retard it and 
to accelerate the other, it follows that condition must sooner 
or later establish itself in which the rate at which the oxidizer 
is supplied is practically equal to that at which it is used up. 
Moreover, owing to the exceedingly small volume of the dif- 
fusion layer compared with that of the whole solution, this 
balance will be established almost instantly. Thereafter we 
can set, without any appreciable error, 
K,(C, — C,,) = K,C,, 

whence 

Cc, K,+K 

Or a Ma ct 
That is, the concentration at the surface of the metal is pro- 
portional to that in the solution, which was to be proved. 

The same reasoning must evidently hold for any reaction 
between a solid phase and a dissolved reagent, provided, of 
course, that the case is not complicated by secondary interfer- 
ing effects, such as the formation of an insoluble product, or 
the oceurrence of further chemical reactions in the solution. 
(See p. 329.) We may, therefore, conclude that obedience to 
the equation for a reaction of the first order ts to be expected 
in all normal cases of this type, quite irrespective of the relu- 
tive rates of the diffusion process and the chemical reaction 
proper. This feature of our experimental results is thus fully 
explained. 

In the discussion of our results we have employed a hy- 
pothesis which is neither a part of the diffusion theory nor a 
necessary consequence of it, namely, the assumption that an 
increase in acidity tends to accelerate the chemical stage of 
the reaction. (See p. 815.) This may or may not be true in 
general, but seems to apply here, for the mutual relation of the 
velocities recorded in Tables VIII and XI (barring minor dif- 
ferences explainable by experimental error) is in qualitative 
agreement with what would be expected if increasing acidity 
accelerated the chemical reaction, the effect of increasing vis- 
eosity being to retard the diffusion process, as we have already 
seen. 

Only one value, the one referred to above as exceptional, 
fails to conform to this explanation. This is the velocity for 
silver in chromic acid in the presence of 5 molar sulphuric 
acid, which is unexpectedly low, as the following comparison 


=, @ constant. 
1 


328 Van Name and Hill—Solution of Metals 


shows: In ferric sulphate the ratio Cd: Ag, as would be 
expected, is lower in 5 molar than in 0°25 molar acid (1°42 and 
2-48 respectively). In chromic acid, on the contrary, the cor- 
responding ratios are 2°19 and 1°64, thus showing that the 
higher acidity has here failed to bring silver into closer agree- 
ment with the other metals. 

We must not overlook the fact that from the standpoint of 
the diffusion theory alone there is no reason for regarding this 
particular value as anomalous. It becomes so only when con- 
sidered in the light of that theory combined with our assump- 
tion concerning the effect of acidity upon the velocity of the 
chemical stage of the reaction. Whether this result is to he 
regarded as an exception to the rule assumed, or is, rather, to 
be ascribed to the effect of some unknown disturbing factor, is 
a question which can hardly be settled without more experi- 
mental evidence. 


The Influence of Adsorption. 


In discussing our experimental results we have thus far 
taken no account of the possible influence of adsorption effects. 
A supplementary hypothesis based on adsorption will now be 
briefly considered. It does not alter or supersede any of our 
previous conclusions, but is offered in order to show that a con- — 
ception of the mechanism of heterogeneous reactions based on 
adsorption is not incompatible with the diffusion theory, but 
rather supplements it. 

Our solutions contained in all cases free acid, usually in 
relatively large proportion, amounting in some instances to 
several hundred times the concentration of the oxidizing agent 
itself. Let us assume that the metal is covered by an adsorbed 
layer of molecules of sulphuric acid. Similar relations are to 
be understood for the hydrochloric acid used in the experi- 
ments with ferric chloride. Following the point of view sug- 
gested by Langmuir,* we may imagine these acid molecules 
to form a layer, one molecule deep, in chemical combination 
with the outer layer of atoms of the metal, which by virtue of 
their position possess residual combining power. Since the 
hydrogen of the acid molecules will be virtually competing 
with the metal for the negative radical of the acid, this hydro- 
gen will be rather loosely combined, and will undergo oxida- 
tion very readily. 

The fraction of the whole number of what Langmuir calls 
“elementary spaces” so covered by adsorbed molecules will 
depend upon their concentration in the solution and upon the 


* Jour. Am. Chem, Soc., xxxviii, 1147, 1916. 


in Ferric Salts and in Chromic Acid. 329 


nature of the metal, and is probably greater the more easily 
oxidizable, i. e. the more electropositive the metal. When 
this fraction is near unity the surface of the solid will prac- 
tically consist of readily oxidizable hydrogen atoms which 
undergo immediate oxidation on suitable contact with a mole- 
cule of the oxidizer, so that the latter will be used up at the 
surface of the solid as fast as supplied by diffusion. This 
explains Case I. When the fraction is below unity the surface 
is only partly covered and some accumulation of the oxidizer 
at the surface results, the molecules which do not encounter 
active hydrogen on contact with the solid reacting slower, or 
not at all. This gives Case II, or, in the limit, Case III. The 
oxidation of the hydrogen of an adsorbed acid molecule is fol- 
lowed by the prompt escape into the liquid of the molecule of 
metallic sulphate or chloride so formed, since owing to the 
low concentration of that kind of molecules in the liquid they 
would be less strongly adsorbed than the acid molecules. 

The fact that in Case II the observed reaction velocities for 
different metals follow the same order as the electromotive 
series can be ascribed either to the dependence of the amount 
of adsorption upon the electromotive behavior of the metal 
(see above), or to the influence of the secondary reaction, that 
is, the one which results when a molecule of the oxidizer finds 
its way into direct contact with the metal. This reaction may 
reasonably be assumed to be more rapid the more electroposi- 
tive the metal. 

The-view that the velocity of the chemical reaction increases 
with the acidity, which we found it expedient to adopt in the 
general discussion of our results, would evidently be a necessary 
consequence of this adsorption hypothesis. Finally, since this 
hypothesis involves nothing to limit or alter the rdle of diffu- 
sion, the explanation, from the present point of view, of those 
phenomena which we have ascribed to the influence of diffusion 
calls for no change. 

In short, it makes little difference here, in employing the 
diffusion theory, whether we consider the case from the stand- 
point of adsorption or not. In general, however, the combina- 
tion of the two points of view: should lead us farther than 
either one alone. 


Status of the Diffusion Theory. Normal and Abnormal Cases. 


An important result of this investigation is the proof of the 
existence of cases in which we are almost inevitably led to the 
conclusion that the reaction at the boundary surface is one of 
limited velocity. Opinions may differ as to whether these 


330 Van Name and Hill—Solution of Metals 


eases represent real or only apparent exceptions to Nernst’s 
hypothesis that the attainment of equilibrium at the boundary 
surface between two phases is practically instantaneous. It is 
after all largely a matter of definitions. The practical bearing 
of these cases, however, is obvious. They show that we can 
not assume, as an over-strict interpretation of Nernst’s view- 
point might lead us to do, that every case in which different 
solids react at different rates with the same dissolved substance 
can be ascribed to some tangible and experimentally demon- 
strable interfering effect.* If the cases in point are due to sec- 
ondary interference it must be interference of a sort which 
only Maxwell’s demon could recognize as not being a normal 
part of the mechanism of a reaction of the given type. In 
order to avoid such fine and elusive distinctions it is much 
better to admit the existence of phenomena which may or may 
not be theoretically equivalent, but are certainly practically 
equivalent, to a limited reaction velocity at the actual boundary 
surface. 

What, then, is the status of the diffusion theory? It is evi- 
dent that by this modification the diffusion theory loses a good 
deal of its simplicity and beauty, but its usefulness is not 
seriously impaired. We must now admit, as strictly normal, 
eases in which the influence of diffusion upon the observed rate 
of the reaction has any value between 100 per cent and zero. - 
It may be that values close to 100 per cent will prove far more 
common in practice than lower ones, or, in other words, that 
Nernst’s hypothesis is sustained much more often than it is 
contradicted, but its validity in a given case cannot always be 
assumed @ prior. 

Finally, in employing the diffusion theory we must be on 
our guard against cases in which the normal relation between 
diffusion and reaction velocity is disturbed by secondary inter- 
fering effects. Since it is desirable to be able to predict these 
exceptions in advance, a knowledge of the different known 
types, and of their specific effects upon the results, is important. 
The present investigation os furnished exainples of four. 
These are 


(a) Insolubility of one of the products of the reaction, with 
consequent formation of a coating on the solid phase. 

(b) Occurrence of the reaction in two stages of which the 
second is of limited velocity and is not confined to the actual 
contact surface. 

*TIf, however, the solid is somewhat soluble in the pure solvent we are 
really dealing with a two-stage reaction, and agreement between the rates for 
different solids would not necessarily be expected, even when the second 


stage is instantaneous. (Example: Solution of different slightly soluble 
acids in the same dissolved base.) 


in Ferric Salts and in Chromic Acid. 381 


(ce) Passivity. 
(d) Evolution of a gas. 


These four types seem to include all that have thus far been 
reported.* Of these, passivity is indicated by a marked depend- 
ence of the initial reaction velocity upon the preliminary treat- 
ment of the metal, and a two-stage reaction can be detected 
either by analysis’ of the solution or by the abnormally small 
effect of variation in the rate of stirring upon the observed 
reaction velocity.t Insoluble or gaseous ‘products will usually 
show their presence by visible effects. All of these types of 
interference are of such a nature that they could generally be 
predicted in advance. 


Summary. 


Measurements have been made of the rates at which different 
metals react with the same oxidizing solution in the presence 
of varying concentrations of free acid. The solutions used 
were (a) ferric sulphate and sulphurie acid, (>) ferric chloride 
and hydrochloric acid, and (¢) chromic acid and sulphuric acid. 
The chief experimental results are the following: 


1. When the acidity is sufficiently high, a number of metals 
give the same reaction velocity under like conditions, showing 
that diffusion is here the determining factor. 

2. With decreasing acidity such agreement tends to disap- 
pear, and the observed velocities then depend upon the nature 
of the metal, the order being approximately the same as the 
electromotive series and the velocity greater the more electro- 
positive the metal. 

3. The rate of the reaction in normal cases is proportional 
to the concentration of the oxidizing agent, not only under 
conditions where different metals give the same rate, but also 
where the rate depends upon the specific nature of the metal. 


From these and related facts the following conclusions are 
drawn. They apply only to normal cases, that is, to those in 
which the progress of the reaction is not interfered with by 
mechanical effects, such as insoluble coatings and the like. 


* Nernst, in his ‘‘ Theoretical Chemistry,” 3d English Ed., p. 587, specifi- 
cally mentions only the first two. 

+ An interesting case of a two-stage reaction is that of arsenic trioxide 
when dissolving in water. After dissolving as As.O; it undergoes hydration 
either in the solution or, possibly, as E. Brunner has suggested, wholly in 
the diffusion layer. This second stage is of course not detectable by chem- 
icalanalysis. See Drucker, Zeitschr. phys. Chem., xxxvi, 201 and 693, 1901; 
L. Bruner and Tolloczko, Zeitschr. anorg. Chem., xxxvii, 455, 1903; E. 
Brunner, Zeitschr. phys. Chem., li, 494, 1905. 


332 Van Name and Hill—Solution of Metals. 


4. The velocity of a reaction at the actual boundary surface 
between a solid and a liquid is not necessarily extremely rapid, 
even when there is no mechanical interference with its progress. 

5. When a solid reacts with a dissolved reagent and the 
reaction velocity at the boundary surface is limited, a balance 
is quickly established between the consumption and the supply 
(by diffusion) of the reagent, such that its concentration at the 
boundary, under otherwise constant conditions, is always pro- 
portional to its concentration in the solution. 

6. The rate of the reaction at the boundary surface may in 
some cases be low enough, compared with the rate of the diffu- 
sion process, to be an important, or even the predominant fac- 
tor in determining the observed reaction velocity. A sound 
interpretation of the diffusion theory must take account of this 
possibility, which has heretofore been neglected. 


Art. XXXV.—Sulphatic Cancrinite from Colorado; by 
Esper 8. Larsen and Gxorce Szrieur,* U.S. Geological 
Survey. 


A number of specimens of the uncompahgrite,t+ collected 
by the author (E. 8. L.) from Beaver Creek, a tributary of 
Cebolla Creek, on the Uncompahgre quadrangle, Gunnison 
County, Colorado,t showed a small amount of a secondary 
mineral which could not be determined optically. A single 
specimen from the northeast slope, about 50 feet below the 
erest, of the hill that is surrounded by contour 8,500, and is 
about half a mile southeast of the mouth of Beaver Creek, was 
made up largely of a coarse-grained aggregate of this mineral. 
From this specimen material suitable for chemical and optical 
study was obtained and the mineral proved to be a cancrinite 
in which nearly half the CO, was replaced by SO,,. 

In the field this specimen was thought to be an altered un- 
compahgrite and the microscopic study confirms this. The 
specimen is made up in large part of the sulphatic cancrinite 
apparently derived from the original melilite, and contains also 
considerable apatite, perofskite, and perhaps melilite. 

* Published with the permission of the Director of the United States 
Geological Survey. 

+ Larsen and Hunter, Journal Washington Academy of Sciences, vol. iv, 
p. 473, 1914. 

tThis work was carried on as a part of the areal mapping of the Uncom- 
pahgre quadrangle, under the direction of Dr. Whitman Cross. 


Larsen and Steiger—Sulphatic Canerinite. 333 


Physical properties—The sulphatie cancrinite is nearly 
colorless; has a hardness of about 5; and fuses readily with 
intumescence. It is readily soluble in acid with effervescence 
and yields gelatinous silica on heating. The specific gravity 
is 2°443. 

Optically it differs considerably from cancrinite; both 
minerals are uniaxial negative, but the mean index of refrac- 
tion of sulphatic cancrinite is considerably lower than that of 
cancrinite, and the birefringence is much lower. The follow- 
ing data for sulphatic cancrinite are from the analyzed 
material. The different grains differ slightly—perhaps -:002 
—in index of refraction. The optical properties of cancrinite 
and natrodavyne are given for comparison. 


Sulphatic cancrinite 


Colorado Cancrinite Natrodavyne 
wo = 1°509 1°524 1°522 
e = 1°500 1°495 1°527 
w—e= ‘009 “029 "007 
Optical character + + — 


Sulphatic canecrinite shows a poorly developed cleavage 
parallel to the prism faces; rod-like inclusions and negative 
erystals are commonly arranged parallel to the prismatic axis. 

Chemical Properties.—The results of a chemical analysis 
made by George Steiger on carefully selected material which 
contained very little impurities are given in column 1 of the 
following table. Column 2 gives the combining ratios corre- 


Analyses and ratios of sulphatic cancrinite and of cancrinite. 


Sulphatic Average of three Cancrinite 
cancrinite cancrinites* Litchfield, Maine + 
Combin- Combin- Combin- 
Analysis ing Analysis ing Analysis ing 
ratios ratios ratios 
SiO, 33°70 34°9 37°31 37°3 36°19 36°3 
Al,O, 29°40 | 180 | 28:22 16°6 29°24 | 17-4 
CaO 4°18 4°6 5°18 23'0 4°72 51 
Na,O 18°52 18°7 16°88 AF 19°20 18°7 
K,O 1°45 1:0 174 yee 14 = 
H,0- 7 aa fie a ra See 
He 4°24 14:7 4°53 15:1 4°15 14:0 
TiO, (et eae thea ae i Sous tes 
Co, 3°18 4°5 5°89 8:0 6°11 8°4 
So, 4°65 3°6 wee Dae ore ae 
SrO 08 eke yen : vat =a) 
100°19 | 100°0 99°75 100°0 99°75 | 100:0 


* One from Ditro, two from Brevik. + Steiger, analyst. 
Am, Jour. oor gua Series, Von, XLII, No. 250.—Ocrosmr, 1916. 


334 Larsen and Steiger—Sulphatic Canecrinite. 


sponding to this analysis and the succeeding columns give the 
analyses and ratios of typical cancrinites for comparison. 

Little can be said regarding the chemical constitution of 
sulphatie cancrinite further than comparing it with canerinite, 
The close agreement of its combining ratios with those of can- 
crinite, about half of the CO, being replaced by SO,, has sug- 
gested the name sulphatic cancrinite. No simple ratios appear 
in the combining equivalents of analyses of cancrinite. 
Clarke* has applied the formula A],(SiO,),.Na,H(AICO,) 
to eancrinite, while Dana considers it to be represented by 
H,Na,Ca(NaOO,),Al,(SiO,),. Clarke considers part of the 
groups — Al=COO, to be partly substituted by — Al = SiO, 
and some of the soda replaced by lime. The formula of can- 
crinite is evidently complicated, our present knowledge throw- 
ing but little light on its constitution, and were it not for the 
well-defined crystallographic properties of the mineral suspicion 
might point to its lack of homogeneity. 

Conclusion.—The data as yet available are not sufficient to 
show clearly the relation between cancrinite and sulphatic can- 
erinite. That the two are closely related, both the chemical 
and optical properties show rather conclusively and they may 
form a complete isomorphous series from normal cancrinite to 
a mineral in which all the carbonate is replaced by sulphate. 
The sulphatic cancrinite described in this paper contains nearly 
equal parts, molecularly, of SO, and CO, and may represent 
an intermediate compound having the same relation to the end 
members as diopside has in the pyroxene group. 

Sulphatie cancrinite has a much lower birefringence than 
eancrinite and it is not unlikely that a member of the group 
somewhat richer in sulphate has zero birefringence and that 
the pure sulphate member is optically negative. 


* Clarke, F. W., The constitution of the silicates, U. 8. Geol. Survey Bull. 
125, p. 28, 1895. : 


LE. L. Troxetl—Early Pliocene One-Toed Horse. 335 


Arr. XXXVI.—An Karly Pliocene One-Toed Horse, Plio- 
hippus lullianus, sp. nov. ; by Epwarp L. TroxEtt. 


CONTENTS. 
I Introduction. 


II Pliohippus lullianus sp. nov. 
The teeth. 
Skull. 
Preorbital pit. 
Ramus, atlas and axis. 
Fore limb. 
Radius and ulna. 
Metacarpals. 
Third phalanx, hoof, 
Measurements. 


III Geology of the Oak Creek formation. 
Character of the deposits. 
Associated fauna. 
Age of the beds. 


IV General Conclusions. 


I Inrropvuction. 


Nrvety years ago the first fossil horse was discovered in 
America, but not until 1856, when Dr. J. W. Leidy described 
the type of Protohippus perditus, did the presence of a race 
of extinct horses especially attract the attention of anyone. 
For the last half century the interest in these animals has been 
steadily growing and in very recent years expeditions have 
been sent out for the single purpose of securing their skeletons. 

The discovery last summer of a skeleton in the Early Plio- 
cene, with but one toe on each foot, yet allied to the protohip- 
pine horses which are known to be mostly tridactyl, furnishes 
a new type of more than ordinary importance. The species is 
described at this time as a matter of expediency, under the 
genus Pliohippus Marsh, in order not to encroach upon 
Professor Osborn’s revision of the horses which is about to be 
published. 

It gives me pleasure to name the new species in honor of 
Professor Richard 8. Lull of Yale. Pliohippus lullianus, 
then, sp. nov. is the chief subject of this paper. 

The list of those who contributed to the success of the sum- 
mer’s expedition or who have aided in the preparation of this 
article is even longer than can be recorded here. The Rey. A. 
B. Clark of Rosebud took an interest in my work and directed 
me to the region where the specimen was found. Professors 
E. C. Case, H. H. Bartlett and Dr. F. E. Robbins, of Michigan 
University, have examined my manuscript and their kindly 
criticisms have been invaluable. Dr. W. D. Matthew and 


336 ELL. Trovell—Early Pliocene One-Toed Horse. 


Professor Lull have generously helped me in many ways, espe- 
cially in the beginning of the work, Professors Schuchert and 
Osborn very kindly allowed me to study the material in their 
respective museuins, 


Il Pliohippus lullianus sp. nov. 


The specimen here described was the skeleton of a young 
colt about ten months old. The milk teeth are all visible and 
some are slightly worn; the first permanent true molar is well 
formed and about ready to be cut—it has, however, no apparent 
cement. The loose epiphyses and the incompletely ossified 
bones also attest the immaturity of the individual. 

Vestigial teeth—The canine teeth of both the upper and 
lower series are scarcely so large as the lead of a pencil, diam- 
eter 1:3", but are about 7°" in length. In life it is quite 
probable that they did not appear above the gum, but lay 
along the alveolar border and, of course, were not functional. 
The first deciduous molar, commonly called the wolf tooth, in 
the upper jaw is large, 17™™ antero-posteriorly, and in a later 
stage of wear might have been functional. The corresponding 
tooth in the lower jaw, like the canines, is vestigial; it meas- 
ures 1°5™™ in diameter and standing erect in front of the larger 
tooth, protrudes 2™™ from the bone. The length, root and all, 
is about 7™™. This tooth is not quite so large as one from a 
small skull of Mesohippus,; the latter has a distinct crown, 
while in the former the diameter is uniform throughout. 

Permanent molars.—Two uncut, permanent molars were 
secured, one upper and one lower. Although the upper molar 
is broken, it shows well certain characters which will be diag- 
nostic of the species. The crown in its present development 
is less than 40™" long; it is slightly curved antero-posteriorly, 
but the pronounced transverse curve of the horses’ teeth of 
that period is not conspicuous ; however, since the tooth is not 
fully formed this observation may be of less importance. 

The diameter of the tooth at the crown, measured over the 
styles, is 30™"; 1°" lower it is 27™™ and here the width across 
mesostyle and protocone is 25™™. With still further wear the 
longitudinal diameter would become less than the transverse. 
The lakes are broad and very simple in pattern; the horns are 
quite long and smoothly curved, while the enamel in places is 
very thick. The protocone, which does not extend anterior to 
its junction with the protoconule, is very long (10™"), but 
rather narrow transversely (5). The sides are parallel for 
quite a distance, making it unlike the round or oval cone of 
Protohippus. There is a sharp, thin fold, the plicaballum, 
between the protocone and the metaconule, which is commonly 


FE. L. Troxeli—LEarly Pliocene One-Toed Horse. 337 


seen in Aguwus but not in Asinus. The parastyle is broad, 
nearly 4"", and has two sharp corners ; the mesostyle is sharp 
but not prominent, while the metastyle is merely the rounded 
corner of the tooth. 

The first true molar of the lower jaw was preserved in good 
condition, but it had not attained its full development. It is 
thin, the width being but one-third the antero-posterior diam- 
eter (80™™) at the crown ; in this respect and also in the great 
inner extension of the parastylid, it resembles the three-toed 
horses. In the new species there is no well defined keel or 
loop antero-exterior to the protoconid. An inconspicuous 
groove separates the metaconid from the metastylid; it is 
sharp but not deep and fades out after running slightly more 
than half the length of the crown. This is like Protohippus 
and results from the narrowness of the metaconid-metastylid 
column (10™™) and its nearness to the protoconid and hypo- 
conid ; the latter are about equal in size. Near the root the 
entostylid blends into the entoconid and here the longitudinal 
diameter of the tooth is reduced to 25"™. There is no cement 
on the tooth. 

Skull.—The antero-orbital fossa shows distinctly the lachry- 
mal and malar parts which are commonly seen in Pliocene 
horses. Although they form a continuous cavity, the two pits 
are separated by a faint ridge running from the infra-orbital 
foramen and the posterior border consists of two distinct, over- 
hanging shelves. 

The presence of a large depression in this region precludes 
the possibility of long crowned teeth like those of the modern 
horse, for both would have to occupy the same space. The 
exact purpose of this pit is not known, but it is generally 
thought to have been the seat of a scent gland, which, like the 
larmier of the deer, was peculiar to animals living in a wooded 
or hilly country. Presumably, as the horses came to live on 
the open plains they had less need for such a device to assist 
in recognizing members of the race, but they had greater need 
for the long grazing teeth ; so that in later generations the pit 
gave place to the longer crowns, while the increased range of 
vision in the open country made it no longer necessary to 
depend on the sense of smell. Even in the life of the indi- 
vidual it is possible that the pit became somewhat obliterated 
as the lengthening of the skull made room for the incoming 
molars: we find the lachrymal and malar pits seemingly best 
developed in young animals. According to Owen (Anat. of 
Verts. III, pp. 633) the presence of the “ maxillary” pit in the 
antelope is associated with those animals which go in pairs. 

It has been suggested that the antero-orbital pit may have 
marked the insertion of a muscle in an animal with a rather 


E. L. Trowell—Early Pliocene One-Toed Horse. 


338 


ees 
= 
gam 
=) 
Aes 
an 2 
a= 2 
rene 
z fo 
oe cs 
S| 
3 
La 


but this seems very doubtful. 
one is thin and its surface is smooth 


a place of muscle attachment is rugose, thicl 


long proboscis, 
specimen the b 


Fria. 2. 


Fie. 1. 


N wl eu 


mill 


‘OZIS [VINJVU PIIG}-2UQ “MOTA [e1}UE A 


W/L 
Hd SSE 


SS 


ae 
N 


“TIOAS 


‘OZIS [BANjeU pIiyy-2uQ 71d [e}Iq4o-erd eSie, Surmoys ‘MolA opIs “ITANG ‘¢ ‘HI 


‘TOIT 


I 


h. 


men the region in front of the orbit would have been much 
longer, in order to furnish room for the six permanent molars 


instead of the three deciduous ones. 


SS 
s 
o 
Qu. 
Qa 
s 
q 
= 
ro 
~ 
> 
m 
fed) 
> 
as] 
=! 
IS) 
es 
mM 
o 
a 
= 
(ed) 
Be 
on 
& 
N 
N 
= 
| 
E 
2° 
ah 
Gs) 
a 
<s 
=| 
ro] 
DM 
~ 
deal 
joe 
— 
a] 
o 
sS 
Sq 


ance above and in front of the molar teet 


n a mature speci- 


E. L. Trowell— Early Pliocene One-Toed Horse, 389 


The antero-orbital pit is of little value as a means of identify- 
ing the species, the genus, or even the sub-family, for it seems 
to be a variable feature depending on age or sex. We find 
both portions well developed in Protohippus and Merychippus 


Fie. 3. 


Fic. 8. Ramus. Side view. One-third natural size. 


Fie. 4. 


Fie. 4. PERMANENT Monars. Two-thirds natural size. 


A, a section 1*™ from the crown of first true, upper molar. B and C, inner 


and outer side views of first true, lower molar. D, a section on line, X-Y, 
of B. 


and the lachrymal pit is even conspicuous in some of the 
Anchitherinae, especially in that aberrant form, Hypohippus. 

On its lower border the ramus has a single large curve in 
front of the angle; it is like that of Asinus and Hippanion 


340 EF. L. Trowvell—Early Pliocene One-Toed Horse. 


rather than Agwus, but in the present specimen it may be a 
character of youth. In the atlas the anterior notch is not 
closed to form a foramen, in which respect it resembles the 
more primitive forms. Likewise the intra-vertebral foramen in 
the axis is not inclosed, showing that it is either primitive or 
immature. 

Lore limb.—The bones of the limb are very slender. In 
length the cannon bone nearly equals that of Zywus scotti, but 


Fie. 5. ATLAS anp Axis. Lateral, dorsal and anterior views. One-third 
natural size. : 


the width is scarcely more than half as great. The distance 
from the hoof to the elbow, which constitutes about half the 
height of a horse, in the new species is 23 inches; therefore 
the whole height is approximately 3 feet and 10 inches. Since 
the scapula and humerus are not so long relatively, this dimen- 
sion may be less. 

It is important to note that the distal segments, especially 
the cannon bones, are long, suiting the animal to greater speed, 
and here may be seen evideace that the race had changed its 


1 


E. L. Trowell—Early Pliocene One-Toed Horse. 341 


habitat. Slenderness and lightness in general are cursorial 
adaptations to the needs of the individual; for instance, where 
food and water are scarce the animal has to go farther to 
satisfy its wants. Moreover, life in the open country was 
imperilled by preying animals and the little horses had less 
opportunity to hide and dodge about among bushes or over 
hilly country ; to offset this disadvantage they had to be able 
to outdistance any pursuers. 

Aside from the actual rate of speed, the long-limbed animals 
seem to be better suited to long continued effort. The slender- 
ness of the cannon bone sometimes goes beyond the point of 
fitness for speed; the Arab, which is probably our swiftest 
horse, has only a moderate speed index: 7:26; on the other 
hand the ass, with a higher index: 8°68, is noted for its endur- 
ance but not for its actual speed. It is equally true that where 
food is scarce nature has to economise, hence the slender, small- 
boned type is better suited to the environment where less 
material is available for building up the frame. 

As a matter of fact the limbs of Pliohippus lullianus are 
not out of harmony with the general build; it stands three 
feet and ten inches, while an ordinary horse may be five feet 
high. The linear dimension of the former is $= that of the 
latter ; if all the proportions are the same the relative weights 
would be as the cubes of 8 and 4, that is as 27 and 64; the 
larger horse would weigh over twice as much and would there- 
fore need greater strength of limb. However, the present 
specimen, being a colt, does not show the development of the 
adult, so it is quite probable that later the bones would have 
increased considerably in diameter, while changing only 
slightly in length. 

Leadius and ulna.—A unique feature in this one-toed horse 
is the complete ulna, separate throughout from the radius. 
As in the modern horse, the proximal and distal portions serve 
as part of the articulations; unlike it, the middle portion is 
not fused to the radius but lies along its posterior surface, a 
mere remnant of.a former functional member. 

The shaft of the ulna in its smallest part is 2™™ wide and a 
little more than half as thick. The distal epiphysis is a long 
segment (8°4™™) which joins the shaft well above the epiphysis 
of the radius and conforms to the contour of the latter. The 
radius is quite slender through its middle portion, but the ends 
are large; the junction planes of the epiphyses mark the largest 
parts. The form would change somewhat with age as the 
shaft fills out to correspond to the heavier joints. 

Metacarpals.—The especial character which distinguishes 
this specimen is its monodactyly. It has commonly been pre- 
dicted that one-toed specimens of the Protohippinae would be 


342. FE. L. Trowvell—Early Pliocene One-Toed Horse. 


Measurements of the Radius. 


Shaft ‘ant‘postyos et Mee eee 172 
Proximal and ant-post.......-.. 38 
Distal end ant-post............. 40 
Shaft transverse... 225.2225. 24 
Proximal end transverse ._.. ._-- 58 
Distal end transverse...._....-. 56 
TheR GHA aon ieee ee eee eee Je 
Fia. 6. 


Fic. 6. Rapius anD ULNA. Rear, side and front views. One-third natu- 
ral size. 


found, but no positive evidence of this feature has, heretofore, 
been presented. 

The splints, Metacarpals II and IV, unlike those of Hywwus 
extend the lengths of the cannon bone, but like those of the 
modern horse they bear no digits on the ends. These slender 


E. L. Troveli—Early Pliocene One-Toed Horse. 343 


bones are large proximally, but at once decreasing in size they 
run at a uniform diameter to the middle; in the next fourth 
of the distance they decrease to a width of about 3" and a 
thickness of less than 15", The distal ends are enlarged to 


Fig. 7. Ricat Manus. Front, side and back views. One-third natural 
size. 


receive the pointed epiphyses, the larger one of which measures 
6™™ in length. They show no evidence of articular facets; in 
fact their very sharp ends eliminate the possibility of their 
ever having borne phalanges. 


344 EF. L. Froxell—Early Pliocene One-Toed Horse. 


Metacarpal LV has a diameter greater by 1°5"™ than that of 
lI. This difference in size is the character apon which Marsh 
sought to found Pliohippus gracilis, but the species has been 
ruled out (Lull, Gidley) and the feature upon which it had 
been established is considered of little importance except as it 
signifies the unsymmetrical reduction of the foot. The dis- 
symmetry of the foot is also shown by the presence of a small 
nodule of bone representing the fifth metacarpal; while on 
the other side the remnant of metacarpal I is not even posi- 
tively known in the earliest forms of Hohippus, showing that 
the first digit was much more progressive in its reduction. 
The vestigial metacarpal V_ has two articular facets joining it 
with the unciform and metacarpal IV. It harps back to the 
period of Hohippus, when for the last time the front foot bore 
the phalanges of a fourth toe. 

Third phalanz.—The hoot of Pliohippus lullianus is very 
flat, especially in comparison with that of Agwus scotti or #. 
caballus. The angle of the front slope in the new type is 
about 273° and in this respect approaches that of Mesohippus : 
about 224°. In Howus this angle measures over 45°. The 
feet have a different structure as a result: in P. duddéanus and 
the earlier genera the second phalanx hangs on the back of the 
hoof with no part of the articular surface horizontal, while in 
the modern genus a part of the weight transmitted falls 
directly upon the hoof bone, a device better suited to the 
greater weight. The cleft in the anterior border of the ungue 
of the new type is a very primitive feature, one not found in 
Equus but common in the earlier forms. 

Measurements in millimeters :— 


Cannon bone Asinus P. lullianus E. scotti 
ratio % ratio % 
Wadth-distalea- =) ee w3558 84 30 BE ie 
Diameter of keel, ant-post. - --- 27°8 94 26 61 42°7 
Shaft tramsverse_.....-.----- 22°0 S619 46 ~=41°0 
Proximal wid theses = aos 38°5 88 34 99) 573 
Proximal ant-post. 23--- 22) 22% 25°3 99 25 60 = 41°5 
Length: 2s 22 aes eae 1910 115 219 90 244-0 
Speed index 282.022 e .. 2) oSeee 8°68 11°53 5°95 
First phalanx P. lullianus Second phalanx  P. lullianus 
iProximea)liwid thee eens Proximal width -_------- 31 
Distal width. 2.25.22 22 29 Proximal, ant-post. ---- - 20 
Shaft width .__..-...-- 19 lhengithi nen cies cee 26 
Proximal, ant-post. .- -- - 25 
Shaft, ant-post.....---- 12 Third phalanx, hoof 
Length to eee = 56 AUTEN GG sae oe eee 20 
WE tha oo ae 40 
Memeth* 222 >. Sota ee 36 


E. L. Trowell—FKarly Pliocene One-Toed Horse. 345 


Comparative measurements of types: P. lullianus nov. P. pernix Marsh 


ratio % 
Ant-post. diameter of wolf tooth..-.... 16 &1 13 
Ant-post. diam. of first upper true molar 27 &1 22 
Ant-post. diam. of second deciduous molar 36 
36 
“ «e “cc 13 premolar Basie 31 
Extent of four upper deciduous molars - 107 
8&2 
ce 6c 6c cc premolars ph Naph covey 88 
Extent of three lower deciduous molars. 89 
SS 
ce ee “ce i premolars ps Bolet <a "4 
A D(GTuyS ia ayy OW Ep 8 XO TVA) sc il i 263 96 253 
Witdtih-or proximal end 20°52 S523! 59 &3 49 
Width of articulation, distal.....--..- 44 &1 4) 
Length of cannon bone.-------------- 219 86 189 
Length: of arst) phalanx». 2522). 2202. 56 98 55 
Length of second phalanx ......------ 26 9G 025 
Teneth of hoof bone 22262428 seleaiics Sees 106 38 
ISA ED Of oof! stu estele: Halse Bese AO 125 50 
Renothiotisicuil: 24h ec es 44 Bote ask 880 108 410 


Ill. Geology of the Oak Creek Formation. 


The skeleton of the new type was found in the eastern part 
of the Rosebud Indian Reservation, near the town of Mission, 
South Dakota. This Reservation, at least the western part in 
the Miocene formation of the valley of the Little White River, 
has long been a favorite hunting ground for specimens of 
extinct animals. 

The region east of Mission is slightly rolling but a very fer- 
tile farming country. Because it is so productive of vegetation, 
it was generally considered an unprofitable place to hunt for 
fossils, for only at infrequent intervals along the crests of the 
hills is the bed rock of the later formations well exposed. 
Most of this land has been allotted to the Indians, whose pres- 
ent peaceful life is in great contrast to that of the time of 
Marsh and the other early explorers. 

A table land, whose northern escarpment extends in a direct 
line for quite a distance and rises about 200 feet above the 
valley floor, forms a divide between the Keyapaha and the 
valley of Oak Oreek. In nearly every direction the flat topped 
hills can be seen, all apparently conforming in height. 

Few geologists have visited this area, but ¢ one, A. B. Reagan,* 
while carrying on his missionary work among the Indians, paid 
much attention to the earth formations and collected many 


* Albert B. Reagan, American Geologist, vol. xxxvi, pp. 229, 1905. 


346 FL. Trowell—Early Pliocene One-Toed Horse. 


fossils. He identified and described the Miocene formation, 
but in the region east of his district he erroneously assumed 
that the rocks were of Cretaceous age ; the fact is that a later 
formation exists there and the fauna indicates the Early Plio- 
cene. 

The rock is entirely of sandstone and most of it is very fine- 
grained. The variety of the grains, their rounded form and 
the absence of larger components, suggest the probable eolian 
origin of the formation, although the sand was shifted and 
finally deposited by running water. The lower strata are 
much harder because the grains are much more firmly cemented 
together; the rock of the main quarry, on the other hand, is 
not so compact, but is soft enough to be cut with a knife. 
Under the microscope the cementing substance, which in this 
case is calcium carbonate, has a filmy appearance and incom- 
pletely fills the open spaces between the grains of sand. 
Where the sandstone is very indurated it stands out in bold 
cliffs, and bowlders of considerable erosional resistance cover 
the slopes. The alternate harder and softer areas give rise to 
differential weathering and in some places result in deep natural 
eaves. That this formation was built up by a stream is quite 
certain, for the sand, the irregularity of the bedding planes, 
the discontinuous layers, the water-worn bones and the posture 
of the complete skeleton, all show this. 

In one of the canyons there appeared to be an irregular line 
marking the boundary of an unconformity and at the bottom 
of the P. lullianus quarry itself, there was a floor of hard 
sandstone only a few inches beneath the complete skeleton. 
There was also other vertebrate material, consisting mostly of 
teeth and small bones, resting on this floor or only an inch or 
two above it. The peculiar association of this fragmentary 
material, most of which was water worn, with the complete 
skeleton, suggests the secondary deposition of these broken 
parts along with the original deposit of the whole skeleton. 
The same torrent which washed out and broke up the other 
bones, once buried, may have engulfed the colt which is now 
the type of the new species. There is a strong probability 
that this less consolidated formation is a channel deposit, rest- 
ing upon and within the Upper Miocene or Earliest Pliocene, 
but itself of later age, for we frequently find patches of a later 
formation occupying the old valley of some prehistoric river. 
Since the Pliocene is commonly considered a period of uplift 
and also of semi-arid conditions, there would be few streams 
and no great amount of stream action ; we, therefore, consider 
this one of the rare deposits representing the period. 

Associated fauna.—Rhinoceroses are represented by frag- 
ments in the quarry and by more complete bones in the neigh- 


E. L. Troxell— Early Pliocene One-Toed Horse. 347 


boring outerops. They are abundant in the Lower Pliocene 
but in all probability soon became extinct. At this time they 
seem to have reached their maximum size and are probably 
best known by the specimens, from Long Island, Kansas; Zvdeo- 
ceras fossiger (Cope) seems very close to the variety with short 
stout limbs represented in the Oak Creek locality. 

Ivory from the main quarry, together with parts of tusks 
and skeletal material from near-by places, shows the presence of 
a very large proboscidian in the fauna. It may represent any 
one of several types of Mastodon, which in the Karly Pliocene 
reached a very great size. 

An incomplete skeleton of J/erycodus sp. was found an eighth 
of a mile away and about seventy-five feet lower than the 
stratum bearing the horse skeleton. This genus is well known 
in the Miocene and Lower Pliocene and is rather common. 
There is a general resemblance in all these forms except that 
some are almost twice the size of others. The present speci- 
men is one of the largest known to the writer and _ is, 
therefore, assumed to be a very late form. It is more than a 
third larger than the type of JZ. necatus sabulonis of Matthew 
and Cook* and is twice the size of their smallest specimen : 
Merycodus sp. indese. ; it is also 1/7 larger than the type of 
M. osborni (Matthew). Merriam reportst JZerycodus from 
the California Pliocene or Late Miocene, and in size the speci- 
men from the Tejon Hills is quite equal to that from South 
Dakota. 

The absence of Merycodus in the Blanco of Texas is taken 
as an evidence that the formation is distinctly more advanced 
than most Pliocene deposits. Scott says “these peculiar 
hypsodont deer persisted even in the Older Pleistocene,” but 
most authors do not credit them with such a long existence. 
Osborn reports this animal mostly in the Lower Pliocene and 
it seems quite probable that this was near the close of their 
career. 

The single molar tooth of a grazing camel gives no trust- 
worthy evidence as to the definite age of the formation, for 
these camels are very abundant in the Upper Miocene and con- 
tinue on until the Pleistocene. 

In this single locality three-toed horses of the Protohippus 
and Hipparion type were found, in addition to the new 
species. Of the true Protohippus both large and small species 
were represented. Three miles from the main quarry, an 
almost complete specimen was found which resembles Proto- 
hippus placidus, especially in its size. The association of feet 

* Matthew, W. D., Cook, H. J., Bull. Am. Mus, Nat. Hist., vol. xxvi, pp. 
412, 1909. 


+ Merriam, J. C., Univ. Cal. Publ., Bull. Dept. Geol., vol. viii, No. 13, 
pp. 287, 1915. 


348 EL. Troxell—Early Pliocene One-Toed Forse. 


and teeth render it of unusual value for comparative study. 
P. placidus is usually found in the Miocene, and this small 
horse, without the malar pit and with semi-functional lateral 
toes, shows characters seemingly too primitive for the Pliocene 
period. 

The fauna of this Oak Creek formation corresponds closely 
with that of the Snake Creek Beds of Western Nebraska; the 
latter, though resembling the Republican River Beds of West- 
ern Kansas, show a more modernized type of animal life and 
are considered by Matthew and Cook to be intermediate 
between the Blanco of Texas and the Upper Miocene. The 
Oak Creek formation, while in some respects like the Etche- 
goin of California, Middle Pliocene, is not so far adyanced 
and in all probability belongs to the Early Pliocene. 


IV. Generul Conclusions. 


Pliohippus lullianus, the earliest one-toed horse now known, 
is here made the type of a new species. It is tentatively 
assigned to Pliohippus Marsh, awaiting the final settlement 
of the status of that genus, which, founded upon an imperfect 
specimen, has been alternately accepted and rejected. 

Observations by Merriam, Osborn, Lull and others, point to 
the protohippine horses as the group from which the modern 
race was derived, and it is probable that Pliohippus lullianus 
sp. nov. was near if not directly in the ancestral line. Through 
its unique characters it seems to offer the connecting link 
between its three-toed ancestors and the monodactylous Lywus. 

The fauna indicates that the age of the beds, from which 
the new type came, is Early Pliocene, a period of grass-covered 
plains. Because the climate was semi-arid and there was little 
stream action, the deposits of that period are rare and at the 
present time are nearly always hidden beneath the luxuriant 
vegetation of the region. 


WB. via y—Lqneous Geology of Carrizo Mountain. 349 


Arr. XXX VII.— The Igneous Geology of Carrizo Mountain, 
Arizona ;* by Wriison B. Emery. 


Dorine the Summer and Fall of 1913, while employed as 
a field assistant by the United States Geological Survey, the 
writer had the opportunity of carrying on, under the direction 
of Professor Herbert E. Gregory, the first detailed geologic 
investigation ever made of Carrizo Mountain, Arizona. Recon- 
naissance studies had been previously made by W. H. Holmes 
in 1875+ and in 1909 by Professor Gregory in connection with 
his work on the Navajo Reservation. + During his brief 
sojourn in the area Professor Gregory noted the main features 
of the geology and it was because he thought them of sufficient 
importance to repay detailed examination that the work during 
the season of 1913 was undertaken by the writer. The results 
of these studies, in so far as they concern the igneous geology, 
are here briefly presented.§ 


Location. 


Carrizo Mountain is located on the Navajo Indian Reserva- 
tion in the extreme northeastern corner of Arizona. The area 
of which it is the central feature, and which is discussed in this 
paper, lies for the most part within Arizona (see map, fig. 1), 
but embraces also a strip of country about three miles wide 
across the border in New Mexico. Rising as it does 2000 to 
3000 feet above the surrounding plain (tie. 2), “an igneous 
island in a sedimentary sea,” Carrizo Mountain forms a prom- 
inent landmark visible for miles in every direction, except to 
the south where the view is interrupted by the Boundary 
Mountains. 


General Features of the Igneous Geology. 


The evidences of igneous activity are now preserved in the 
Carrizo district in the form of various intrusive bodies, sheets, 
sills, dikes, and the main large intrusion, a laccolith. It is 
inferred, however, from the presence of a series of six volcanic 
plugs just southeast of the mountain that igneous activity was 
not confined to intrusion but manifested itself as well in extru- 


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

+ Holmes, W. H., U. S. Geol. and Geog. Survey Terr., embracing Colo- 
rado and parts of Adjacent Territory, 1877, pp. 274-276. 

{ Prof. Paper, U. S. Geol. Survey, in preparation. 

§ The results of the entire investigation, embodied in a report, constitute 
the thesis submitted as partial fulfilment of the requirements for the degree 
of Doctor of Philosophy at Yale University. 


Am. Jour. Sc1.—Fourts Smrtes, Vou. XLII, No. 250.—Octoxsmr, 1916. 


aI 


350 W. B. Emery—ILgneous Geology of Carrizo Mountain. 


Selinesidess 
\Canyon 
v NY 


. 


\ 
\ 
\ 
\ 
\ 
\ 


Ke) 
19 
Zix< 
o| i p 
NIS 
eye / 
< 


\Soeeeas 
\ 


they) 


Be 


Ge 
& ; 
7 \> 1 Red Boers he 


LEGEND 


eae 


Sedimentary rocks Diorite porphyry Melanocratic rocks 


SCALE OF MILES 
Sa Re a ey 4 yl sn (0) 


5 


Contour interval 1000 feet. 
Topography from Canyon De Chelly Quadrangle 


Fic. 1. Geologie map of the Carrizo area. 


W. B. Emery—TLgneous Geology of Carrizo Mountain. 


sion, though all evidence of 
possible outflows has been com- 
pletely removed by erosion. 
The relation of the igneous 
rock and the surrounding sedi- 
mentary beds which range from 
Triassic to Upper Cretaceous in 
age is shown on the accom- 
panying map (fig. 1). 

Major intrusion.—The major 
intrusion which has produced 
the marked upturning of the 
surrounding sedimentary beds 
is only poorly exposed. There 
are a number of large outcrops 
but they are isolated and not 
traceable, the one into the 
other, because of the covering 
of sediments. | Consequently 
the nature of the intrusion is 
with difficulty ascertained. In- 
deed, from the appearance of 
the outcrops, which are in 
many places very steep-walled, 
it would seem that there was 
not one large intrusion but sev- 
eral smaller ones which had 
united to produce a single re- 
sult,—domal uplift. There is 
no reason to doubt that whether 
of one large intrusion or sev- 
eral smaller ones, the outcrops 
represent a single period of 
igneous activity, and that the 
inagma came from one common 
reservoir. 

Sills and  sheets.—On the 
north of the mountain and dip- 
ping from it at an angle of 
about 15° isan intrusion of sill- 
like form entirely confined 
within the base of the Upper 
Jurassic (?) sediments. ‘This 
sill, which has been called the 
Tisnasbas sill, from the canyon 
of that name where it is best 
exposed, is somewhat thicker 
at its innermost margin, where 
it is seen in connection with 


B51 


View of east side of Carrizo Mountain. 


Fig. 2. 


852. W. B. Emery—Iqneous Geology of Carrizo Mountain. 


its source of supply, than at its outer edge, so that it might be 
considered a flat laccolith. However, as it is only 300. feet 
ae at its deepest point, it has been deemed best to eall it a 
sil 

West of North Mesa and between it and Chezhindeza Mesa, 
there is exposed a mass of igneous material having exactly the 
same relations to the enclosing beds as the Tisnasbas sill. \ It is 


Fie. 3. 


Fic. 8. Holmes Dike. 


possible that this is an entirely separate intrusion, but because 
of the very similar character it is thought to be a portion of 
the Tisnasbas sill, though the connection is not visible due to 
the overlying mass of North Mesa. 

Intrusive sheets cap both North and Chezhindeza mesas and 
overlie unconformably sediments of Upper Jurassic (?) age. 
The sheets evidently are offshoots from the main intrusion and 
between them and the Tisnasbas sill and its extension the sedi- 
ments are pinched out. This was noted by Holmes, who says: 


W. B. Emery—ILqneous Geoloyy of Carrizo Mountain. 353 


“Tt does not appear to me that the beds of sandstone that 
occur between the inner mass and the flexed sheets are of uniform 
thickness. Between the capping of the North Mesa and the 
inner mass the sandstones are nearly pinched out. They are so 
obscured by debris that I could not determine their exact rela- 
tion.”* 


Dikes.—The few dikes seen in the Carrizo area, with the 
exception of that forming Zilbetod peak, are arranged about 


Fie. 4. 


Fie. 4. Walker Peak, a voleanic neck. 


the periphery of the intrusions. Of these, Holmes dike, near 
the mouth of Tisnasbas Canyon, is among the most prominent. 
It rises about 200 feet above the creek bed and when seen end 
on, as in fig. 3, where its continuation northward is not evi- 
dent, has the appearance of a volcanic plug. Another large 
dike trends outward from the mountain in the direction of 
Biltabito store. Other smaller dikes are present both east and 
west of the mountain and each volcanic plug has an encircling 


* Holmes, W. H., op. cit., p. 275. 


354 W. B. Emery—Igqneous Geology of Carrizo Mountain. 


group of radiating dikes. In these dikes the rock is soft yet 
more resistant to erosion than the enclosing sedimentary beds, 
so that in every ease the dike stands up as a wall of greater or 
less height. 

Volcanic plugs.—A series of six voleanie plugs is exposed 
southeast of Carrizo Mountain. When these are joined 
together they are seen to be arranged on a very flat reversed 
curve about 20 miles long. Such linear arrangement suggests 
the presence of a fault as a line of weakness favorable for 
intrusion, but no movement of that character was recognized. 
These plugs are rather prominent features of the landscape, 
standing out dark against the red or light-colored sandstones at 
their base. They are all of the same “character, Walker Peak 
(fig. 4), the southernmost one, being typical, rising conical at 
the base but terminated above by cliffs 100 or more feet high. 


The Petrography of the Intrusions. 
Diorite Porphyry. 


Occurrence.—The central mass of Carrizo Mountain is of 
diorite porphyry, as are also the sheet-like intrusions associated 
with it. The porphyry, which is exposed in all the canyons 
and in many other places on the mountain summits, covers an 
area of over 100 square miles. Holmes, in speaking of the 
intrusions and the mountain resulting from them, says 

“Tt is a typical example of the eruptive groups of this part of 
the Colorado plateau. .... It has a nucleus of its own, and so 
far as the surface is concerned is independent of all other erup- 
tive SMAsSeS jeer ue The trachytes [diorite porphyry of this 
report] are now found chiefly in contact with the Lower Cre- 
taceous [now referred to the Jurassic] and Jura-Trias rocks, for 
the reason that the Middle Cretaceous shales, in which a large 
part of the trachyte was originally deposited, have been com- 
pletely carried away, leaving only small fragments imbedded in 
the faces and upper surfaces of the trachyte.”* 


Macroscopic description.—In the hand specimen the dio- 
rite porphyry shows an abundance of plagioclase phenocrysts 
and less numerous prisms of hornblende set in a white to 
grayish, aphanitie groundmass. Quartz phenocrysts are not 
uncommon. With regard to the megascopie character of the 
rock Holmes says: 

“ A specimen of trachyte from West Mesa is found to resemble 
closely in appearance and composition the trachyte of the other 
groups of the southwest. It has a bluish white paste, which con- 


*Holmes, W. H., U. S. Geol. and Geog. Survey Terr., embracing parts of 
Colorado and adjacent territory, 1875, p. 274. 


WB: Emery—Igneous Geology of Carrizo Mountain. 355 


tains the following minerals porphyritically embedded: fine 
crystals of translucent oligoclase, minute crystals of sanidite, fre- 
quently associated with the oligoclase, small crystals of biotite 
(rare), and a few small enclosures of quartz.”* 


Cross later studied the very specimens collected by Holmes, of 
which he says : 


“Three specimens from the Carrizo Mountains, collected by 
Holmes, have been examined by the writer. ‘They are all horn- 
blende-porphyrites, almost identical in character with those of 
the El Late group. There are abundant phenocrysts of black 
hornblende and plagioclase, 1 to 5 millimeters in length, in an 
even-grained groundmass, chiefly made up of quartz and ortho- 
clase. Biotite is rare or wanting. Quartz phenocrysts were not 
seen.” + 


Both Holmes and Cross have brought out the similarity of 
the rocks constituting the numerous laccolithic intrusions of 


‘Fie. 5. 


Canyon 
Ghezhindeza 
Canyon 
Walker Peak 


o 
2 2 
3 

o 
= a 
= a 
= & 
6 o 
= - 


LEGEND 
- = SCALE OF MILES 
= Bis 2 I 0 2 4 


Sedimentary rocks Diorite porphyry Melanocratic rocks (ere 1 t 


Fic. 5. Structure section across geologic map on line AA. 


the Southwest. The writer wishes to further emphasize this 
similarity. So closely does the description of the rock of the 
Henry Mountains, given by Cross, correspond to the diorite 
porphyry of Carrizo Mountain, that his description might be 
employed here with only minor changes. 

Microscopic description.—Iin thin section the rock is seen to 
consist of phenocrysts of plagioclase and hornblende set in a 
groundmass of quartz and orthoclase. Phenocrysts of quartz 
were observed in a number of slides, biotite in one. Iron ore 
is present im two generations in some places; in all slides it is 
seen in the groundmass. Apatite is a constant accessory and 
titanite is not uncommonly present. A few small erystals of 
zircon were noticed. 

Hornblende is of the common, green, strongly pleochroic 
type. In some places, however, it is rather light in color. 

* Holmes, op. cit., p. 275. 

{ Cross, Whitman, The Laccolithic Mountain Groups of Colorado, Utah, 


aud Arizona, 14th Ann. Rept., U. S. Geol. Survey, Part II, 1895, pp. 210- 


or 


356 W. B. Emery—ILgneous Geology of Carrizo Mountain. 


The extinction angles are slight, 8° from the cleavage lines, on 
the face O10. Twinning parallel to 100 iscommon. Zonal 
development is shown in a number of crystals and in some, 
resorption. Euhedral outlines are well displayed. In some 
places, the outline is completely preserved by the alteration 
products; in other places the outline is merely indicated by 
the few remaining shreds of the unaltered mineral. Altera- 
tion to ehlorite and calcite, less commonly to epidote, takes 
place. 

The plagioclase shows both Carlsbad and albite twinning and 
was determined to be an andesine with a composition of about 
Ab,,An,,. Some erystals have a broad tabular outline, others 
a lathlike development. The feldspar alters most abundantly 
to kaolin, in less degree to calcite. Quartz when present as a 
phenocryst is smaller than either the hornblende or the plagio- 
clase. It is of the ordinary type. 

Tron ore, as mentioned, is present in places in two genera- 
tions. As phenocrysts it is observed in places to have a square 
outline indicating that it is magnetite ; elsewhere it is without 
definite outline and is doubtless, in part, ilmenite. In nota 
few places it was seen entirely enclosed by the hornblende, 
indicating its earlier crystallization. It is abundantly concen- 
trated about the borders of the hornblende both within and 
just without the crystal. As a second generation mineral it is 
scattered in small grains through the groundmass. 

Apatite is present in all sections studied, in some in such 
large crystals and so abundantly as to almost merit being called 
a phenocryst. It is of the ordinary type, in long prisms. 
Titanite is of much less importance as an accessory than apa- 
tite, and zircon is of less importance than titanite. Both 
titanite and zircon are of the usual type. 

In the groundmass orthoclase is somewhat more abundant 
than quartz. Both are developed in very small erystals. In 
some places, however, the feldspar has a tendency to lathlike 
development and there it is probably in part plagioclase. 

The texture of the rock as a whole is porphyritic. The 
texture of the groundmass varies from microgranular, where 
quartz and feldspar are present in about equal amounts, to 
nearly trachytic, where feldspar is in excess of quartz. In 
some slides there was observed a tendency toward a micro- 
poikilitic development, and in one section a microspherulitic 
texture was noted. 

Hornblendic inclusions in the porphyry.—There are inelu- 
sions of a hornblendic character present in the diorite porphyry. 
These are ordinarily one or two inches in diameter, but were 
observed to six inches in length. They are of hornblendic 
nature so strongly, in places, as to suggest derivation from a 
hornblende schist, and are in general of very angular outline. 


W. B. Emery—IRgneous Geology of Carrizo Mountain. 357 


One inclusion, however, in the hand specimen, was seen to 
fade gradually into the enclosing porphyry. Study of a thin 
section, containing a portion of both the including and the 
included rock, revealed the fact that in each there were phen- 
oerysts of similar common green hornblende set in a similar 
eroundmass. The inclusion possessed the characters of the 
main mass, developed on a smaller scale. This has led the 
writer to conclude that the inclusions represent portions of the 
magma, previously solidified, which by later movement came 
into place in Carrizo Mountain. An occurrence, very similar 
to this, of hornblende inclusions in diorite porphyry, has been 
described by Iddings from Electric Peak in Yellowstone 
National Park.* 

Classification—Holmes was the first to study the rock of 
the intrusions of Carrizo Mountain. [ike his coworkers in the 
Southwest at that time, he speaks of this rock in the text of 
his report as a “trachyte.”+ However in the legend of the 
geologic map accompanying the reports of the work done by 
the Hayden Survey in Colorado this same rock is listed as 
“porphyritic trachyte (hornblendic).”{ Cross has later had 
oceasion to study the very specimens collected by Holmes from 
Carrizo Mountain, together with the rocks of other laecolithic 
intrusions of the Southwest, brought in by the Hayden geol- 
ogists. He has found that new names must be applied to 
these rocks, and in speaking of this he says 

“‘In describing these rocks, . . . it will be necessary to use a 
nomenclature almost entirely different from that adopted by 
Gilbert, Dutton, Holmes and Peale. That this is true is not a 
reflection upon these able geologists, for the modern science of 
petrography was unknown in this country at the time their work 
in these regions was done. Few of the specimens collected by 
them had been examined microscopically or chemically when the 
published reports were written and it is usually stated in those 
reports that the names used are adopted provisionally.”$ 

Accordingly, in place of Holmes’ name, “trachyte,” Cross 
applied the term hornblende porphyrite to the rock of Carrizo 
Mountain. Since his writing, however, the name porphyrite 
has itself been abandoned by American petrographers, and this 
type of rock is now known as diorite porphyry. It should be 
noted, however, that while the rock is classed as a diorite por- 
phyry, there is in places considerable quartz present. 

Place in the Quantitative Classification.—A chemical anal- 
ysis of a rock which, from his description, is thought to be the 

*Tddings, J. P., The Eruptive Rocks of Electric Peak, 12th Ann. Rept., 
U.S. Geol. Survey, Part I, 1890-91, p. 597. 

+ Holmes, W. H., op. cit. 

{Geol. and Geog. Atlas of Colorado and portions of adjacent territory, 
Hayden, 1877, Sheet XV. 


$ Cross, Whitman, The Laccolithic Mountain Groups of Colorado, Utah, 
and Arizona. 14th Ann. Rept., U. S. Geol. Survey, Part II, 1895, p. 175. 


358) W. B. Emery—lgneous Geology of Carrizo Mountain. 


typical diorite porphyry of Carrizo Mountain is given by Cross* 
and is quoted in the accompanying table. From this analysis 
the norm and mode have been reckoned, and the rock deter- 
mined to be a yellowstonose (symbol I, 4, 3, 4) lying almost on 
the borderline between yellowstonose and tonalose. 


Hornblende-porphyrite. Sierra Carrizo.t 
(Analysis, W. I’. Hillebrand.) 


SQ a ees oe Se ee OG SUE 
QS. a8 ra Se ei a ache mR OG 
Al © 5 eee oo eee on eee 16°47 
Re Ov esac * int) ae ye eee 2°36 ; 
eO lS oe See Ss ee 2°28 
Witty Q:) Pe Soke 12 Ce ea 5s a ene eae ID) 
CaO: PES! Seen eee 4-7 
Ome Le ees 2 ere. see oe "09 
BaOvs- 5 eee Sassen See "15 
MaQ. 5 MISS Eee a ee els 
TOs Si aes Se eerie AEN eee 2°93 
INapOis anh tes) Se pee ee ee eee) 
Til Owed oS Fc eee eee trace 
EE. OT 0OS (ets, 2: Sector ent nene ee NTE 
RISO ah00 eee eg ee 0) 
PLO, os ain cea eee 
Tota Saye Reece ne cree SOLS.) 
Calculation of the Norm of Yellowstonose. 
Molecular 
Analysis Ratio Or Ab An Di Hg Mt Il Ap Q 
SiO, --- 63°18 1:°053 186 426 120 44 21 256 
WO cce | eG WON) 9 
Al,O, 2 16:47 "162 31 iia 60 
He-O) 52 2-36) Els : 15 
HeOl =) a 2.28mi cose" yp  § 16 © 
MnO... ‘15 002 
CaO meal ‘086 60 22 6 
SrOeees ‘09 ‘001 
IBAO) S45. “15 ‘001 
MeOPe= 1-33). lee WANG 
Kies, 2-08 Os lon eel 
Na,O ._ 4:40 ‘0% Ail 
Li,O Se tl 
H,O + - 27 
1,0 — 60 
PLOMSo eS OO? 
Total 99°86 ---- 31 71 (30) We, Bl ile) BP 2 


* Cross, Whitman, The Laccolithic Mountain Groups of Colorado, Utah, 
and Arizona, U. S. Geol. Survey, 14th Annual Report, Part II, 1892-1893, 


p. 227. 


+ Cross, Whitman, op. cit., p. 227, analysis III, by W. F. Hillebrand. 


W. B. Emery—Igneous Geology of Carrizo Mountain, 359 


(Que sae 15°36 Of. aes 15°36 
AK (0) DS aoa treet 17°24 Sal. 86°48 
Ndi be ae er) Fas.4 4 sa riele 
| An Pei nye 16°68 
1D tie Se ee 4°91 
(Reise. 2:26 Ps Seen 717) 
Sr eae es were em 3°48 Ce ne 
(elie ae ee raiahee eM) 0g ee 4-95 (Fem. 12°64 
(Ape se ees 62 ACEI ae "62 J 
WRES6 otros ee 87 
Motaltess-< ce =e 99°99 
Class I Order 4 
Sal 86°48 7 FE 71:12 5 7 
Fem 12°64 Py Orr 15-36 S 3 val 
Persalane Britannare 
Rang 3 Subrang 4 
K,O + Na,O” 102 3 5 EO: 31 8 i 
Cad EO S5CA RAO TSG 
Coloradase Yellowstonose 


Symbols I, 4, 3, 4. 


Melanocratic types. 


Two types of melanocratic rocks are present in the dikes and 
plugs associated with the main intrusions of Carrizo Mountain. 
In the absence of a chemical analysis it is not thought best to 
discuss their petrographic character at this time. It may be 
said, however, that they have been provisionally classified as 
shonkinite and Carrizo minette, since their mineral character is 
such as to indicate their relationship to the types shonkinite 
and minette. Though readily distinguishable under the micro- 
scope, these rocks cannot be separated megascopically and so 
for field purposes may be simply classified as “* mica trap.” 


Leucocratic type. 
Dacite. 


Occurrence.—Dacite was noted in only two places in this 
region. A dike of it is exposed in Seklagaideza Canyon 
where the trail to the head of that canyon ascends the east 
wall, and again on the lower trail from this canyon to Red 
Rock store. Another and smaller dike, thought to be of the 
same character, is imperfectly exposed on the east of Carrizo 
Mountain at the mouth of Chezhindeza Canyon. 


360 W. B. Emery—Tqgneous Geology of Carrizo Mountain. 


Macroscopic description.—In the hand specimen numerous 
phenocrysts of a rather pinkish feldspar, quartz, and horn- 
blende are seen set in a light grayish aphanitie groundmass. 
An occasional phenoeryst of iron ore is present. 

Microscopic description.—Under the microscope the pheno- 
erysts megascopically observed are seen set in a minutely 
granular groundmass of quartz and feldspar. 

Hornblende is idiomorphically developed in long, slender 
prisms. It is of a somewhat lighter green color than common 
green hornblende and in places has a distinctly brownish tinge. 
In it the iron ore is abundantly concentrated. The horn- 
blende is largely altered to chlorite. 

Feldspar occurs in two generations. As phenocryst it is 
present in a few large crystals which show both Carlsbad and 
albite twinning and have been determined to be andesine with 
a chemical composition of about Ab,,An,,. The feldspar of the 
groundmass shows albite twinning in places and for many 
crystals the index of refraction is higher than that of Canada 
balsam, indicating its plagioclase character. As the feldspar is 
developed in long, tabular crystals, many of the pieces seen in 
thin section have a square outline, and as extinction takes 
place parallel or very nearly parallel to the side this feldspar 
is thought to be an acid andesine. 

Quartz is present in two, and very probably in three genera- 
tions. It occurs as phenocrysts, in the groundmass, and very 
likely combined with feldspar in the interstitial glass. As 
phenocryst the quartz is seen in large rounded forms which 
exhibit a nearly square cross-fracturing. About these masses 
the groundmass is much finer grained than elsewhere in the 
slide and it is supposed that the quartz, partially crystallized 
before, has been resorbed, thus giving rise to the rounded and 
embayed outline and a zone of more siliceous character sur- 
rounding it. 

In the groundmass the quartz is seen to have square outlines 
and to extinguish diagonally with respect to the side of the 
square. (Quartz of this character, in minute dihexahedrons, 
has been described by Kiich as being very characteristic of 
certain dacites of the Andes,* and it is interesting to record: 
that in Carrizo Mountain there is found another example of 
this somewhat rare mode of occurrence of this mineral. 

The texture of this dacite is porphyritic. The groundmass 
is of microgranular character with a small amount of glass, 
which very probably consists of unerystallized quartz and 
feldspar, filling up the minute interspaces. 


* Kiich, Richard, Geologische Studien in der Republic Colombia, I, Petro- 
graphie, 1, Die vuleanischen Gesteine, 1892-95, pp. 68-69. 


W. B. Emery —Igneous Geology of Carrizo Mountain. 361 


Name.—The mineral character of this rock is so clearly that 
of a dacite, that, even without chemical analysis, it has been 
classed as such. 


Manner of Intrusion. 


Daly has recently classified all intrusive igneous masses 
under two main heads, (1) injected and (2) subjacent bodies, 
according as they come into place either by the injection and 
consequent uplift of the enclosing strata or by the replace- 
ment of these beds. Under the first division are placed sills 
and laccoliths; under the second, stocks and batholiths. 

The uniform character of the diorite porphyry of Carrizo 
Mountain demonstrates that if, as is possible, the various out- 
crops of that rock are not portions of one large intrusion, they 
at least represent upwellings of magma from a single common 
reservoir. Nowhere were there observed stoped blocks nor 
was any evidence of assimilation noted, facts which, taken 
together with the upturning of the beds at the base of the 
mountain, suggest that intrusion was by injection rather than 
by a replacement of surrounding beds,—that the intrusion is of 
the injected rather than of the subjacent type. 

It is evident from a study of the writings of Holmes and 
Peale that they both considered the Carrizo intrusion as belong- 
ing to the class of intrusion to which the name laccolith was 
later applied by Gilbert. Indeed on the geologic sections 
accompanying the maps of the Hayden Survey, Carrizo Moun- 
tain is portrayed in laccolithic form.* No sedimentary floor 
is as yet exposed by erosion and that this intrusion is sym- 
metrical and of typically laccolithic shape cannot be assumed. 
Aside from the irregularity produced by Tisnasbas sill and the 
sheets capping North and Chezhindeza mesas, it seems clear 
that the intrusion is asymmetrical and has in places broken up 
through the overlying beds. The porphyry may be seen cut- 
ting across the Triassic rocks and the Wingate sandstone 
(Jurassic) in Tisnasbas canyon to supply the material for the 
Tisnasbas sill. It also appears that the igneous mass east of 
Biltabito Canyon has cut across the Triassic rocks and the 
Wingate sandstone, and there are probably other transgressions 
not yet exposed by erosion. Indeed it seems possible that the 
intrusion consists of several sills with their connecting pipes 
which have united in producing the effects of laccolithic uplift. 
Until such facts can be definitely proven, however, it is at least 
convenient to speak of the intrusion as a iaccolith, which 
form of intrusion to all outward appearances it most closely 
resembles. (See fig. 5.) 


*Hayden, F. V., U.S. Geol. and Geog. Survey Terr., Atlas of Colorado 
and portions of adjacent territory, 1877, Sheet XVII, Section 11. 


362 W. B. Emery—Llgneous Geology of Carrizo Mountain. 


Depth of Cover. 


The lowest formation observed in contact with the porphyry 
of Carrizo Mountain is of Triassic age; the highest is the 
McElmo formation (Jurassic ?) within which the Tisnasbas sill 
is intruded. It is evident from a study of the surrounding 
region that the Cretaceous sediments were once continuous 
over the area, but that they were present at the time of intru- 
sion remains to be demonstrated. Indeed the determination 
of the depth of cover depends upon the age of the sandstone 
and conglomerate which cap the mountain summit and outcrop 
for a short distance on the mountain flank south of Chezhin- 
deza Canyon. This sandstone, which is similar both to the 
Dakota and to certain Tertiary sandstones and whose age cannot 
be determined because of absence of fossil evidence, rests in 
angular conformity and apparently without erosional uncon- 
formity upon the Triassic rocks. Whether Cretaceous or Ter- 
tiary, an erosion cycle is necessary to bring the Triassic into 
juxtaposition with formations so much higher than it. It is 
known that in northern Arizona there were such erosion cycles 
in both pre-Dakota and pre-Tertiary time, so that erosion is of 
no avail in the age determination of this intrusion. At present 
it can only be said that if the beds are Tertiary, intrusion took 
place below a cover of 2000 feet; if the beds are Dakota, 
beneath a cover of about 5000 feet, 


Age of Intrusion. 


The age of the various laccolithic intrusions of the Sonthwest 
has been considered by all students of that region as Tertiary, 
but so far as the writer has been able to ascertain, little definite 
evidence of this has been adduced. Were it pos ssible to deter- 
mine the age of the sandstone capping Carrizo Mountain, the 
date of intrusion there might be very definitely ascertained. 
Even in the absence of such proof it is still possible to place 
the age of the intrusion with much assurance as Tertiary, 
though not more definitely than that. It is known that there 
are certain structures of pre-Tertiary age in the area, and that 
these structures have been magnified by intrusion. Since, then, 
intrusion is younger than these features, which were probably 
developed at the end of the Cretaceous, it must have occurred 
in Tertiary time. 

The relative ages of the different intrusions, the main mass, 
the sills, sheets, voleanie plugs, and dikes cannot be determined 
as they were not observed cutting each other. 


Contact Metamorphism. 


Tisnasbas sill.—There are only a few contacts of the diorite 
porphyry and the enclosing sedimentary rocks visible in the 
Carrizo area. The lower contact of the Tisnasbas sill with the 


W. B. Emery—Igneous Geology of Carrizo Mountain. 363 


underlying Jurassic (?) sediments is, however, excellently ex- 
posed and may be considered typical. Study of a series of thin 
sections from specimens collected at various distances from 
this contact revealed a slight increase in the amount of iron 
oxide in the cement of the sandstone directly at the contact. 
If, however, one did not know that such an amount of iron 
oxide was unusual in this sandstone he would not recognize the 
sandstone as metamorphosed in the least, and, indeed, the 
amount of metamorphism has been so small that at a distance 
of three feet from the contact the bed is absolutely normal. 

On the mountain summit metamorphism was somewhat more 
potent inasmuch as the original sandstone has been changed to 
a resistant quartzite, and this to an unknown though probably 
not great distance from the contact. 

Sandstone columns at Holmes Dike contact.—Where mel- 
anoeratic types of rock have penetrated the sedimentary beds, 
metamorphism, though not of great importance, is more pro- 
nounced than that produced by the porphyry. In the major- 
ity of cases a baking of the enclosing sediments has accompanied 
the intrusion of basic types of rock in this region, but Holmes 
Dike (fig. 3) has produced certain quartzite columns similar in 
appearance to those commonly observed in igneous outflows. 
Study of a thin section of one of these quartzite columns 
demonstrated the absence of any admixture of igneous material, 
that the columns consist only of Jurassic sediments altered to 
quartzite. The columns are of various diameters to one and 
one-half inches and in length range to three feet, the maxi- 
mum distance of metamorphic action. Similar, though less 
perfect, columns were observed by the writer 35 miles west of 
Carrizo Mountain along the contact of a dike associated with 
Boundary Butte, Utah; more perfect columns have been noted 
by Professor Gregory at the northern end of Lukachuka 
Mountain, Arizona.* 


Cause of the absence of intense contact metamorphism. 


It is evident from the above discussion that there has been 
no great amount of contact metamorphism in the Carrizo area, 
since such effects are commonly not noticeable at a distance of 
more than three feet from the contact. This phenomenon has 
previously been recognized by Oross as characteristic of lacco- 
lithic intrusions in the southwest and has been attributed by 
him to the lack of the so-called mineralizing agents, fluorine, 
chlorine, and superheated steam in the magma.t The absence 
of intense metamorphism in Carrizo Mountain is believed to 
be due to this cause. 

* Prof. Paper U. S. Geol. Survey, in preparation. 


+Cross, Whitman, Spencer, A. C., Purington, C. W., La Plate folio (No. 
60), Geol, Atlas, U. S., U. S. Geol. Survey, 1899, p. 11. 


364 Scientific Intelligence. 


SCIENTIFIC INTELLIGENCE. 


I. Curmisrry anp Puysics. 


1. Fluorine in the Animal and Veyetable Kingdoms.—ARMAND 
Gautier and P. CLausMANN, in previous researches, have estab- 
lished the fact that fluorine occurs in all animal tissues, but in 
two very different proportions and conditions. In tissues of 
slight vitality, such as epidermis, enamel of teeth, hoofs, hair, 
etc., fluorine is abundant and may reach 180 milligrams in 100 
grams of dry substance, while in the actively vital tissues, such 
as muscles, glands, etc., there is found scarcely more than from 
1 to 4 milligrams of fluorine in the same amount of dry sub- 
stance. Phosphorus always accompanies it, and, without being 
proportional to it, increases and diminishes with it. While in 
the actively vital tissues there are found only about 1 to 4 parts of 
fluorine with 350 parts of phosphorus, the proportion in the less 
vital, protective, or ornamental tissues is one part of fluorine to 
from 3°5 to 5 parts of phosphorus. The latter are practically 
the proportions under which the two elements exist in the min- 
eral phosphates, hence it appears that they occur in a like com- 
bination in these tissues, such as the epidermis, hair, hoofs, 
feathers, etc. As nothing was previously known about the sub- 
ject, the authors have made an extensive study of the occurrence 
of fluorine in plants. It is shown by their results that fluorine 
exists in all vegetable tissues and that it is always accompanied 
by phosphorus. Leaves contain the largest amount, from 3 to 
14 milligrams of fluorine in 100 grams of dry substance, while 
grains and other seeds usually contain from 1 to 2 milligrams, 
and wood contains a somewhat smaller quantity, in the same 
amount of dry substance. In general, the phosphorus is higher 
in the vegetable tissues containing the larger amounts of fluorine, 
but there appears to be no definite relation in any case between 
the two. The conclusion is reached that the occurrence of 
fluorine in all parts of animals and vegetables shows that this 
element, which had been previously supposed to be localized in 
certain exceptional tissues, is indispensable to the living cell. — 
Bulletin, xix, 140. H. L. W. 

2. The Qualitative Separation of the Common Metals whose 
Sulphides are Insoluble in Dilute Acids.—In order to avoid cer- 
tain inconveniences connected with the use of the ammonium 
sulphide separation in the examination of this group of sulphides, 
M. J. Crarzens has proposed a method by which the metals are 
precipitated in three successive groups by varying the amount of 
hydrochloric acid present. ‘The liquid after treatment with 
hydrochloric acid, and filtration if necessary, is neutralized with 
ammonia, then one-half its volume of concentrated hydrochloric 
acid is added and hydrogen sulphide gas is passed into the cold 
liguid. Copper, mercury, arsenic and antimony are thus precipi- 


Chemistry and Physics. 365 


tated as sulphides, and these are filtered, starting with a dry 
filter, and washed with a solution of hydrochloric acid of the same 
strength as was present during the precipitation. In order to 
precipitate arsenic in the higher state of oxidation the filtrate is 
heated and hydrogen sulphide is passed again. Then, after filtra- 
tion if necessary, the liquid is diluted with an equal volume of 
water, and hydrogen sulphide is passed again. ‘This precipitates 
the sulphides of tin and bismuth, which are filtered and washed 
with hydrochloric acid of the proper strength. At last the acid 
is nearly neutralized and the sulphides of cadmium ana lead are 
precipitated by means of a third treatment with hydrogen sul- 
phide. Directions are given for the examination of each precipi- 
tate for the detection of the metals init. It appears that the 
method is one which may be conveniently applied in certain prac- 
tical cases, but for use in laboratories of instruction the necessity 
of three precipitations by hydrogen sulphide under accurately 
regulated conditions would seem to make its utility very doubt- 
ful.— Bulletin, xix, 154. Je 105 Vie 
3. The Estimation of Vanadic Acid after Reduction by 
Metallic Silver.—Grauam Epear has found that finely divided 
metallic silver, prepared by precipitation or by igniting the oxide, 
reduces vanadic acid in hot, dilute sulphuric acid solution to the 
quadrivalent condition, and that three methods for determining 
the amount of vanadium present may be based upon the reaction. 
In the first place, a weighed excess of metallic silver may be used 
and the loss in weight of the silver shows the amount of vana- 
dium. ‘he second method consists in the titration of the reduced 
vanadium, which may be accomplished, conveniently and accu- 
rately, by means of potassium permanganate solution. The third 
method consists in determining the amount of silver in solution 
after the completion of the reaction, for example by titration 
with a thiocyanate solution. It is interesting to observe that the 
three methods can be applied, in the order given, to a single por- 
tion of a vanadate. The results obtained by the author in his 
test analyses show an astonishingly close agreement in the three 
methods not only among themselves but with the known amounts 
present. It will not be attempted to give full details of the 
-process here, but it may be mentioned that solutions of sodium 
vanadate containing not far from 0-1* of V,O, were acidified with 
about 2° of concentrated sulphuric acid, diluted to about TEES 
from 1 to 2° of finely divided metallic silver was added and in 
each case the liquid was boiled for about one-half hour in a small 
flask. The reduction takes place quantitatively in the presence of 
hydrochloric acid, but in this case the oxidized silver forms silver 
chloride, so that the amount of vanadium can be calculated from 
the gain in weight. It appears to be more accurate, however, to 
use sulphuric acid solutions free from chlorides.—Jowr. Aim. Chem. 
Soc., XXxviii, 1297. H. L. W. 
4. The Density of Radio-Lead from Pure Norwegian Cleveite. 
—T. W. Ricuarps and C. Wapswortn, 3p, have obtained from 


Am, Jour. Scr.—Fourrs Srries, Vou. XLII, No. 250.—Ocrozmr, 1916. 


2 


366 Scientific Intelligence. 


Professor Ellen Gleditsch of the University of Kristiania a sample 
of lead sulphide from carefully selected Norwegian cleveite. The 
lead of the sample was carefully purified, and four specific gravity 
determinations made upon a sample of over four grams of the 
metal gave closely agreeing results averaging 11°273. This spe- 
cific gravity is lower than 11°289, the density of the Australian 
radio-lead recently examined by the authors, while the density of 
ordinary lead is 11°337. It is probable that the Norwegian 
sample is a nearly pure isotope. The atomic weight of this 
sample has been determined by the authors, although the details 
have not yet been published, and it is pointed out as an important 
fact that the atomic weight, 206°08, divided by the specific 
gravity gives the atomic volume 18'281, which is practically 
identical with the atomic volumes of the Australian sample, 
18°279 and that of ordinary lead, 18°277, as previously found by 
the authors.—Jour. Amer. Chem. Soc., xxxviil, 1658. uu. L, w. 

5. Theory of the Lead Accumulator.—The important practi- 
cal problem of devising a portable dry-cell of the secondary type 
has been recently attacked by Cu. Frry. The paper under con- 
sideration is preliminary in so far as it deals only with the first 
logical step in the systematic investigation, that is, a thorough 
study of the chemical reactions which take place during the acts 
of charging and discharging lead storage cells. The author first 
reviews the previous work and thereby shows that the various 
hypotheses concerning the behavior of the positive plate are so 
divergent as to leave the whole subject in a state of confusion 
and uncertainty. In particular he concludes that the theory 
advanced (about 1882) by Gladstone and Tribe is incorrect. 
According to this theory, which has received wide acceptation, 
the process of charging peroxidizes the red-lead at the anode and 
reduces this compound at the cathode, first to the lower oxide 
and then to spongy, metallic lead. The discharge may be briefly 
expressed by the equation PbO, +2H)80, + Pb=2PbSO, + 
2H, O, so that both plates would be sulphated. (This reaction is 
called “double sulphating.”) On the other hand, there is com- 
plete accord with regard to the sulphating of the negative plate, 
the increase in the mass being accurately proportional to the 
number of ampere-hours furnished. 

The evidence adduced by Féry will now be given in a fairly 
condensed form. ‘The color of the fully charged positive plate is 
pure black whereas after discharge this electrode assumes the 
characteristic brown color exhibited by lead dioxide when chem- 
ically prepared. Since, however, the color of a given substance 
often depends upon its physical condition (fineness of division, 
etc.), and is therefore not a reliable criterion, the following 
experimental facts are presented to throw doubt on the sulphat- 
ing of the positive plate. The active material was removed 
from the surface of a positive electrode and packed in a porous 
cup surrounding a sheet of platinum. A plate of zine consti- 
tuted the negative electrode, and the cell thus assembled had an 
E.M.F. of 2°5 volts. Under like conditions lead dioxide chemi- 
cally derived invariably gave 0°7 volt. A volumetric test was 


Chemistry and Physics. 367 


next applied. A known mass of the positive material (which had 
been washed and dried) was treated with an excess of a solution 
of oxalic acid of known volume. The oxalic acid reduced the 
higher lead oxide and the nitric acid, which was subsequently 
added, transformed the lead into the nitrate. After all the mate- 
rial had dissolved the excess of oxalic acid was estimated by the 
aid of a titrated solution of potassium permanganate. Knowing 
the volume of permanganate required to reduce the same volume 
of the original solution of oxalic acid, it was a simple matter to 
calculate the quantity of oxalic acid oxidized by the higher lead 
oxide. Let Pb0O,=formula of oxide in question, p = mass of 
oxide used, p'= mass of oxalic acid necessary for oxidation, then 


(« — 1)H,0,0, + PbO, + 2HNO, = 
2(a—1) CO, + «2,0 + Pb(NO,), 
207 + 16a 90(a — 1) 
whence SS SS Sy 
~P 1g 
Experiment gave « = 2°3 so that the required formula for the 
oxide becomes Pd, 0.. 

This result is in complete accord with the mutually independent 
observations of Tennen and Hollard on the electrolytic analysis 
of solutions of nitrate of lead. In the formation of lead peroxide 
the ratio Pb/ PbO, has the observed value 0°853 instead of 
0°866, when electrodes of unpolished platinum are used. The 
smaller number corresponds to the same formula, Pb, O.. 

This higher oxide obtained electrolytically was also analyzed 
by reducing it in a current of hydrogen. This gave # = 2°37. 
At the beginning, the reduction is very rapid and the color of the 
powder changes from black to brown, near completion, it is 
necessary to heat the glass vessel containing the substance. 
When chemical lead dioxide was subjected to the same treatment 
it was found that *=1:96. This method should have given 
# = 2, but a high degree of accuracy was not attempted in the 
last experiment. 

The black substance which would accordingly have the formula 
Pb, O, is very unstable, and the author suggests that the higher 
oxide which is present in the cells of the positive plate, when 
completely charged, may be even more rich in oxygen. When 
placed in a capsule, which was protected from the influence of 
stray reducing dust, the black powder gradually turned brown in 
the course of a few days, the change of color commencing at the 
surface. Féry interprets this phenomenon as being due to the 
spontaneous loss of oxygen and not to an alteration in the 
physical state of the material. 

All the preceding evidence is strengthened by an experiment 
of another kind. When a positive plate made by Planté’s method 
is discharged by means of a plate of zine two distinct stages are 
observed—the one, from 2°5 to 2°3 volts, corresponds to the pas- 
sage from PbO, to PbO,; the other, between 0°7 and 0°3 volts, to 
the reduction of PbO, to the metallic condition. The capacity 
of the second discharge is about four times greater than that of 


368 Scientific Intelligence. 


the first, and this leads to Pb,O, as the formula for the higher 
electrolytic oxide estimated 7 situ. 

For lack of space we shall pass over the remaining lines of 
evidence and quote the author’s conclusions, which are: 

1. The behavior of the lead accumulator while discharging is 
identical with that of a primary cell with a solid depolarizer, the 
manganese cell for example; with this difference that the nega- 
tive electrode gives rise to an insoluble salt. 

2. The theory of “double sulphating” is manifestly inexact 
ard the reaction during normal discharge is given by: 

(a) Pb+ H,8SO, + Pb,0O,= PbSO, + H,0+4+ 3Pb0,, 
or possibly 
(0) Pb + H,SO, + Pb,O, = PbSO, + H,0+2Pb0,. 

Formulas (@) and (>) lead to masses of 15 and i074 grams of 
the higher oxide per ampere-hour respectively, the best commer- 
cial tests giving values of the same order, namely 12 to 14 for 
thin plates slowly discharged, 

3. The quantity of acid combined during discharge is exactly 
one-half of that indicated by the theory of “double sulphating.” 

4. The variations in mass of the positive plate must be very 
small and in the opposite sense to those predicted: by the theory 
of “double sulphating.” 

5. The mass of lead to use for the positive electrode must be 
exactly double that taking part in the reaction at the negative 
grid if the formula Pb, O, be accepted. 

6. When discharged the active material of the positive plate 
becomes lead dioxide.—Jour. de Phys., Jan._Feb., 1916, p. 21. 

H. 8. U. 

6. An Active Modification of Nitrogen.—In his six earlier 
papers on this gas R. J. Srrurr has dealt primarily with the 
properties of active nitrogen when once produced. The seventh 
contribution, now under consideration, pertains chiefly to the 
circumstances of its production by the electric discharge. 

With this object in view it was necessary to abandon the very 
efficient but complicated jar discharge and make use of the direct 
current furnished by three motor-driven magneto generators 
joined in series. At full speed the output was 15 milliamperes at 
5000 volts. The gas used in the experiments was commercial 
bomb-nitrogen which was kept for a time over phosphorus and 
_ then dried by the pentoxide of this element. At least seven dif- 
ferent forms of discharge tube were employed in the investigation 
so that it will not be possible to describe the apparatus in this 
place. The results obtained may be summarized as follows : 

1. The production of active nitrogen in the steady discharge 
is a maximum near the cathode, it falls to a minimum in the 
Faraday dark space, and increases again in the positive column 
until a value is attained which stays constant throughout the 
remaining length of this column but which is less than that at 
the cathode. 

_ 2. When the amperage is kept unchanged, a much larger 
quantity of active nitrogen is obtained from the positive column 


Chemistry and Physics. 369 


in a narrow tube than in a wide one. This difference in yield 
must be connected with the current density rather than with the 
potential gradients, since the difference between the latter in nar- 
row and wide tubes is insufficient to plausibly account for it. 

3. As the length of the positive column traversed by the gas 
is increased the yield of active nitrogen reaches a limit. ‘This is 
due to the destructive action of the discharge which, above a 
certain concentration, nullifies the active modification as fast as 
it is generated. 

4. It has been shown in previous papers that a trace of oxygen 
(or almost any other admixture) greatly increases the yield of 
active nitrogen. The amount of oxygen required to bring about 
this result considerably increases the fall of potential at the 
cathode, but it does not measurably influence the gradient in the 
positive column. 

5. Active nitrogen can be produced by the spark at atmos- 
pherie pressure, but the phenomena are much less brilliant than 
at low pressures. The destructive influence of the surrounding 
gas on the active modification is responsible for this difference. 

6. The particles scattered from a copper cathode when the 
uncondensed discharge passes can be made to emit the line 
spectrum of the metal in a stream of active nitrogen.—Proc. 
Roy. Soc., vol. xeii (A), p. 438, July, 1916. UW. S. U. 

7. The Emission of Electricity from Hot Bodies ; by O. W. 
Ricwarpson. Pp. vii, 304, with 35 figures. London, 1916 
(Longmans, Green and Co.).—This book is the seventh of the 
series of ‘‘ Monographs on Physics” edited by J. J. Thomson 
and Frank Iforton, A fair idea of the field covered in the text 
may be derived from the titles of the chapters, which are : 
“JT. Mainly Considerations of a General Character. II. Theory 
of the Emission of Electrons from Hot Bodies. ILI. Tempera- 
ture Variation of Electron Emission, IV. The Effect of Gases 
on the Emission of Electrons. V. Energetics of Electron Emis- 
sion. WI. The Emission of Positive Ions by Hot Metals. VII. 
The Effect of Gases on the Tiberation of Positive Ions by Hot 
Metals. VIII. The Emission of Ions by Heated Salts, and IX. 
Ionization and Chemical Action.” 

Due to the non-existence of a satisfactory and comprehensive 
theory of conduction for conductors of the metallic type, Richard- 
son has treated the subject of the second chapter in as general a 
manner as possible, thereby reducing the part played by special 
theories to a minimum. ‘The last chapter includes a brief account 
of the results of some experiments recently made by the author 
with regard to electrons liberated by chemical action. The purely 
technical side of the general subject has been wisely omitted 
from the text, but the titles of the most important books and 
papers relating to this phase are given inthe preface. Numerous 
bibliographical foot-notes facilitate supplementary reading, and 
the volume closes with both name and subject indices. The high 
standard set by the preceding numbers of the “ Monographs” is 
fully maintained in the present volume, so that this publication 
will be found very valuable by students of advanced physics. 

1: OO 


370 Scientific Intelligence. 


II. Gronoey. 


l. La Flora Liasica de la Mixteca Alta; by G. R. Wirtann. 
Boletin del Instituto Geologico de Mexico, No. 31. Text of 
VI + 165 pp. quarto (Mexico, 1914); Atlas of 24 pp. and 50 
plates (dated 1916).—This is the first typical North American 
Liassic flora. It was collected in entirety by the writer in the 
winter of 1909. Its age was discussed in this Journal for Septem- 
ber 1913 (vol. xxxvi, pp. 251-281). Evidently the ‘ Mixteca 
Alta” of Oaxaca, Guerrero, and Puebla is one of the richest 
Cycadeoid regions in the world. Neither the Yorkshire coast nor 
the Gondwanas of India surpass the new Mexican realm in any 
respect. 

The main collections described are from the Barranea Consuelo 
in the western part of the state of Oaxaca. The section here 
measured includes 600 meters of plant-beds resting on an eruptive 
floor, and followed by a marine Jurassic series. The measure- 
ments were continued upward through the marine superposition 
about 375 meters to the base of the Cretaceous. The study of 
these superposed beds has not been completed by any one and 
was excluded from the field investigated. Taken as a whole the 
Consuelo section must always rank as one of the most important 
type sections of the North American continent. 

The plant-beds consist in a much varied succession of shales 
and sandstones grading into finer conglomerates. Occasionally 
the finer shales carry coal. In the lower beds seams of a sem1- 
anthracite with a high ash recall the coal of Sutherlandshire, 
Scotland. An equivalent of the Sonoran Trias was not positively 
determined, but may occur in the valley of the Rio Nochixtlan. 
If true Rheetic is present at the base of the Consuelo section the 
fact was not determined. The section readily divides itself into 
a lower series 250 meters thick and an upper series 300 meters 
thick ; but no unconformity was observed. In the collections 
secured the cycads and ferns are relatively modern. The suc- 
cession of plant types precludes any notable time gap. The 
Rheetic and the Odlite must afford the extreme boundaries. 

The discovery of Cordaiteans (Maggerathiopsis) closely asso- 
ciated with Liassic Cycadeoids (Otvzamites) was unexpected. 
The handsome plates of the Atlas show various new William- 
sonian fronds and a fine series of fruits. Yet these must be but a 
mere fraction of the recoverable forms. Of the 70 or more plant 
types illustrated or described, a considerable number so closely 
resemble plants of the European Liassic that new varietal names 
only are attached. It is, however, likely that Professor Nathorst, 
who takes exception to this method in a recent letter, is justified. 
He thinks far separated plants nearly always likely to be of dif- 
ferent species, while varieties even if present can rarely be deter- 
mined. 


Geology. 371 


Owing to difficult conditions precluding proof reading, various 
typographical errors appear in this Bulletin. These should 
occasion no great inconvenience in its use. They are seldom 
serious and may readily be excused in this period of nearly 
universal war. It must be held very creditable to the Mexican 
Survey to bring out the work at all. May it not be recalled that 
our own civil war delayed Newberry’s record of the San Juan 
expcaiion nearly seventeen years ? G. R. W. 

2. Isostasy in the Light of the Planetesimal Theory, by T. 
C. Cuampertin. [Note to the Editors of this Journal.|—In the 
August number of this Journal, “C, 8.” does me the honor to 
give an excellent notice of my recent little book on “The Origin 
of the Earth.” There is one sentence in the notice which, though 
not maccurate when critically read, will, I fear, give to many 
readers an erroneous impression, and as the subject to which it 
relates is one of much importance I beg to add a word to fore- 
stall misapprehension. After referring ‘to the view advanced in 
the book that the earth is segmented into heavy stiff sub-oceanic 
cones between which lie more irregular, weaker and lighter con- 
tinental wedges, and that at times of diastrophism these move 
upon one another along “yield tracts,” the review says: “This 
hypothesis seems to be diametrically opposed to the working 
hypothesis of isostasy and the latter’s postulate that the relief of 
the earth’s surface is compensated for by corresponding varia- 
tions in surface density which cease at a depth equal to a fiftieth 
or a hundredth part of the radius of the earth.” 

It is true that the hypothesis that I have offered departs radi- 
cally from the énterpretation of the mode by which isostasy is 
secured and is at variance with certain limitations that have been 
assigned the distribution of density in the outer part of the earth 
which are not thought to have a secure basis, but the view 
advanced in my book, far from being diametrically opposed to 
demonstrated or theoretically essential elements of isostasy, ex- 
presses its good will toward the doctrine by offering, on its own 
part, a new view of the mode by which such approximate isostasy 
as exists is secured. This new view is consistent with the grow- 
ing evidence of a high state of rigidity in the earth. It also 
postulates an adequate cause for the initiation and maintenance 
of isostasy through all the geologic ages with an effective residue 
operative at the present time. In short, the new view endeavors 
to meet on broad, adequate and lasting grounds what are regarded 
as the weak points in the doctrine of isostasy as it has heretofore 
been advocated. The limitations of differences of density in 
depth are not regarded as having any trustworthy basis, and this 
view is supported by competent mathematical investigation, the 
results of which will appear in time. The purpose of this note 
will be accomplished, if it makes clear that the book in question 
offers a new line of support for the general doctrine of isostasy 
and is at variance with current views only on points in respect to 
which these views are held by some careful students to be weak. 


University of Chicago. 


372 Scientific Intelligence. 


3. Relations between the Cambrian and Pre- Cambrian forma- 
tions in the vicinity of Helena, Montana ; by Cuartes D, W at- 
corr. Smithson. Mise. Coll., 64, No. 4, 1916, pp. 259-801, 
pls. 39-44, text figs. 10-13.—When Professor Rothpletz of the 
University of Munich attended the International Geological Con- 
gress in Canada in 1914, he made it a point to visit’ Helena, Mon- 
tana, and since then has published his conclusion that the Belt 
series held by all American geologists to be of pre-Cambrian age 
is actually of Lower Cambrian time. Such a conclusion from one 
of EKurope’s foremost geologists could of course not be neglected, 
and as Walcott has done more than any other in the interpreta. 
tion of Proterozoic strata it is but natural that he should reply to 
Professor Rothpletz publication. He says: ‘The Rothpletz 
failure to find any evidence of an unconformity at the base of the 
Cambrian is most natural as he unknowingly identified the Cam- 
brian limestones as the pre-Cambrian Helena limestone and hence 
did not recognize and probably did not see at all the Helena 
limestone which is beneath the unconformity. . . The Rothpletz 
view of considering all of the pre-Cambrian sedimentary forma- 
tions of North America corresponding to the Belt series as of 
probable Cambrian age is without evidence to support it” (297— 
298). 

Plates 40-43 are splendid illustrations of the very significant 
unconformities in the Grand Canyon of the Colorado River 
between the Archeozoic, Proterozoic, and Paleozoic, and nothing 
of equal grandeur has ever been published before. Cc. 8. 


OxBIruARY. 


Proressor Cuarvrs 8. Prosser, head of the department of 
geology in Ohio State University and author of many papers and 
books on geological subjects, died suddenly on September 12 at 
the age of ‘fifty: six years. 

Proressor Jostai Royce, from 1892 until his recent retire- 
ment, professor of philosophy in Harvard University, died on 
September 14 in his sixty-first year. 

Proressor Gusray Scuwarsy, the distinguished German 
anatomist of the University of Strassburg, died in July. His 
work was concerned particularly with the study of the Lower 
Paleolithic human remains; it led to the establishment of Homo 
neanderthalensis as a distinct species. 

Prorrssor Karn Scuwarzscuivp, the eminent German astron- 
omer, has died recently. 

Prince Boris Garirzin, the seismologist and professor of 
physics in th? Imperial Academy of Sciences in Petrograd, died 
in May last. 


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Page 
ArT. XXXII —The Geologic Rdle of Phosphorus; by E. 
BLAcKWELDER 


XXXIII.—Notes on Pedioivcian Cherts in Oregon; by W. 
D. Smira 


XXXIV.—On the Rates of Solution of Metals in Ferric 


Salts and in Chromic Acid; by R. G. Van Name and 
Dy UW. Bie eee os ie Sa cae eee ae 


XXXV.—Sulphatic Cancrinite from Colorado; by E. S. 
Larsen and G.:Srnicun: Gia gene pean eee 


XXXVI.—An Early Pliocene One-Toed Horse, Pliohippus 
lullianus, sp. nov.; by E. L. Troxriy 


XXXVII.—The ae Geology of Carrizo Mountain, 
Arizona; by W. B. Emery 


SCIENTIFIC INTELLIGENCE. 


Chemistry and Physics—Fluorine in the Animal and Vegetable Kingdoms, 
A. Gavtimr and P. CLausMANN: Qualitative Separation of the Common 
Metals whose Sulphides are Insoluble in Dilute Acids, M. J. CLareEns, 
364,—Hstimation of Vanadic Acid after Reduction by Metallic Silver, G. 
Epe@ar: Density of Radio-Lead from Pure Norwegian Cleveite, T. W. 
Ricwarps and C. WapswortsH, 3d, 365.—Theory of the Lead Accumulator, 
C. Féry, 366.—An Active Modification of Nitrogen, 368.—Emission of 
Electricity from Hot Bodies, O. W. RicHarpson, 369. 


Geology—La Flora Liasica de la Mixteca Alta, G. R. WimLanp, 370.—Isos- 
tasy in the Light of the Planetesimal Theory, T. C. CHAMBERLIN, 371.— 
Relations between the Cambrian and Pre-Cambrian formations in the 
vicinity of Helena, Montana, C. D. Waucort, 372. 


Obituary—C. S. PROSSER: J. Royce: G, ee K. ScHWARZSCHILD: 
Prince Boris Gairzin, 372 


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AMERICAN JOURNAL OF SCIENCE 


[FOURTH SERIES. ] 


iJ 


Art. XXXVIII.— The Ancestry of Insects with particu- 
lar references to Chilopods and Trilobites; by Joun D. 


Torainu.* 
Introduction. 


Datine practically from the publication of Darwin’s “ Ori- 
gin of Species,” a fund of energy has been directed toward 
elucidating the probable descent of the various groups of liv- 
ing organisms. In these various groups different hypotheses 
of derivation have sometimes followed one another in rapid 
succession. Each in its turn has been of value asa working 
hypothesis and has often served to elicit new facts that have 
formed the basis of a supplanting hypothesis. 

In the case of the Hexapoda the usual gamut of systems of 
classification and of genealogy—the one a necessary hand- 
maiden of the other—has been proposed. We owe to the 
Greek civilization in general and to Aristotle in particular the 
first attempt to arrange insects in a system of related groups. 
In the interim between this first attempt (about 300 B. C.) 
and the more recent one of Handlirsch (1908) there have been 
many derivations proposed. Of these it is necessary simply to 
mention one or two of the more interesting. In 1866 Haeckel 
proposed a genealogical tree deriving the Insecta through the 
“Tocoptera” which included the “Thysanura,’ from ‘ Tra- 
cheata” which also gave rise to the Arachnids and Myriopods. 
Three years later Brauer suggested a derivation through the 
Apterygogenea or wingless insects including Campodea and 
Thysanura; Brauer’s system of classification was based on 
morphology, metamorphosis, and later on embryology ; it was 
thorough-going and forms the basis of all subsequent systems ; 


* Contribution from the Bussey Institution No. 119. 
Am, JouR. Scl.—FourtTH SERIES, Vou. XLII, No. 251.—Novemper, 1916. 
26 


374 J. D. Tothill—The Ancestry of Insects. 


in 1885 it was revised and amplified into a form that has been 
in general use ever since. Packard in 1863 and 1870 suggested 
a derivation through the Apterygogenea (Lepisma) from the 
Myriopods. 

Kingsley in 1894 emphasized the close relationship between 
insects and Chilopods and also the unnaturalness of the old 
group “'Tracheata.” In 1903 Carpenter reviewed the whole 
situation and came to the conclusion that Insects, Chilopods 
and Diplopods were probably derived independently from 
Symphyloid stock—a position that in the light of recent data 
is open to several serious objections. 

Each of the various systems proposed has resulted from dis- 
coveries in morphology, development, or in paleontology. In 
recent years discoveries have been made in two directions, each 
throwing light on the problem of insect genesis. Through the 
efforts of Barrande, Walcott, Lindstrém, Beecher, and Ray- 
mond, our knowledge of detailed structures and of develop- 
ment in the interesting extinct group Trilobita has been 
greatly extended. On the other hand, Handlirsch following | 
the trail blazed by Brongniart and Scudder has greatly enriched 
our knowledge of insect paleontology. In his remarkable 
book “‘ Die Fossilen Insekten” there is proposed a new system 
of classification based, as was Brauer’s, on development, mor- 
phology, and particularly on paleontology. There is also pro- 
posed a heterodox ancestry in which the Hexapods are derived 
not in the usual way through the Apterygogenea from terres- 
trial tracheate myriopod-like animals but directly from trilo- 
bites. This derivation is accepted without reserve by Schuchert 
(1915) in his exceedingly illuminating Text Book of Geology, 
and it has also been accepted by Ruedemann (1916). While it 
is suggestive and very helpful it is open to certain objections 
and the time seems, therefore, opportune to once more review 
the whole question of insect genesis. The object of the paper 
will be largely achieved if it succeeds only in stimulating the 
search for further facts. 


An examination of the available data. 


In tracing the lineage of any complex of related organisms 
the first point is of course to discover the most generalized 
members of the group. In the insects these have been sought 
in both the wingless Apterygogenea and in the winged Ptery- 
gogenea. In the case of the former it will serve the present 
purpose to recall some of the salient. features in a few charac- 
teristic examples. In Lepisma saccharina (fig. 1, A and B), 
the mouthparts are greatly specialized by reduction, the eyes 
are also reduced; on the other hand the primitive number of 


J. D. Tothit—The Ancestry of Insects. 375 


abdominal segments, nameiy, 11, is retained, the tritocerebral 
appendage shows as a rudiment in the young embryo (Hey- 
mons, *97), and there are 11 pairs of spiracles whereas in the 
winged insects these are reduced to ten. In Anwrida mari- 
tima (fig. 1, C and D) studied especially by Claypole (’98) the 
mouthparts show considerable reduction as also do the eyes; of 
particular interest is the reduction of abdominal segments ; 
also according to the same author this singular animal shows 


Fig. 1. 


C 3 


LU Ye 
z 


Ee 
ue 
Vt 
v 
y: 
l 


D 


E 


Fic. 1. 

A. Lepisma saccharina, young embryo. (After Heymons.) 

B. us es mature embryo. (After Heymons.) 

CO. Anurida maritima. Very young embryo showing the tritocerebral 
appendage tc. (After Wheeler.) 

D. Anurida maritima, adult showing collophore, reduced mouth parts, 
and reduction of abdominal segments. (After Claypole.) 

E. Sminthurus. Young embryo showing reduction of abdominal seg- 
ments. (After Lemoine.) 

F. Anurophorus. Embryo showing reduction of abdominal segments. 
(After Lemoine.) 


no traces whatever of a tracheal system ; on the other hand the 
first pair of abdominal appendages is preserved as the collo- 
phore (Claypole, Wheeler) and the same authors agree that 
the tritocerebral appendage is preserved (fig. 1, C). In Smén- 
thurus (fig. 1, E) and Anurophorus (fig. 1, F) there is specializa- 
tion by reduction of mouthparts, eyes and abdominal segments ; 
on the other hand several pairs of abdominal appendages are 
preserved even in the adult condition. 


376 J.D. Tothill—The Ancestry of Insects. 


Examples could be multiplied but sufficient has been said to 
indicate that the Apterygogenea occasionally preserve even 
in the adult condition primitive ‘ancestral’ characters, such 
as the tritocerebral and abdominal appendages, structures 
that have almost or completely disappeared in the Ptery- 
gogenea. In this sense they are more generalized than any 
other living insects. Enough has also been said to indicate on 
the other hand that the Apterygogenea are highly specialized 
animals as indicated by the frequent reduction of mouthparts, 
visual organs, tracheze, etc. ; and by the development of pecu- 
liar structures such as the caudal “spring” and the collophore. 
Handlirsch points out that the absence of wings does not nec- 
essarily represent a primitive condition, but that these insects 
may have once possessed wings and lost them as a result of 
taking up their abode in the peculiar environment in which 
they now live. In cave insects, such as ants, and in parasitic 
insects (especially of fur- or hair-bearing vertebrates), such as 
the fleas and lice, reduction or loss of wings is extremely com- 
mon. Be this as it may, the various specializations found in 
the group seem to make it certain that it is not in the direct 
line of descent of the great Pterygogenea complex. 

Turning to the Pterygogenea, the remarkable findings of 
Handlirsch from the Pennsylvanian rocks engendered a new 
point of view concerning the most generalized insect. Steno- 
dictya (fig. 2) is typical of these ancient insects and I will con- 
fine my remarks to it. It is a large insect with well-differ- 
entiated head, thorax and abdomen; with all abdominal 
segments and with well-developed cerci. The wings are of 
peculiar interest in that the venation is practically that of the 
“hypothetical wing” long since suggested by Comstock and 
Needham. The organs of flight are also of interest in that 
a small pair is developed on the prothorax and because all 
the abdominal segments show lateral wing-like outpushings. 
This seems to indicate the method of origin of wings and does 
away with the necessity of deriving the winged insects from 
the Apterygogenea. 

Ina word the Palzodictyoptera as illustrated by Stenodictya 
appear to represent the ancient stock from which the present 
Pterygogenea complex has been derived. 

If this inference is correct then the problem resolves itself 
into discovering an ancestor for the Palzodictyoptera. Before 
developing the problem, however, it may be pointed out that 
the abdominal appendages on the Stenodictya larva (fig. 2, B) 
figured seductively by Handlirsch opposite a figure of a trilo- 
bite with the same sort of appendages are of doubtful phylo- 
genetic significance. The insect was aquatic in its early stages 
and yet most of the Pennsylvanian insects were terrestrial. . In 


J.D. Tothill—The Ancestry of Insects. 377 


recent aquatic insects such as Sialis and Sisyra there are serially 
arranged jointed appendages functioning as gills, but all such 
struvtures in recent insects are shown by embryology to be 
secondarily acquired. It seems fairly certain that the similar 
structures in Stenodictya are secondarily derived and that 
insects were originally terrestrial; in this case the structures 
would have no phylogenetic significance. 

Returning to our problem, it may be of interest to construct 
from the available data a hypothetical ancestor for the Ptery- 


Fic. 2. 


ie 


See 


awl 


au 


Fic. 2. A. Stenodictya (Paleodictyoptera), one of the most generalized 
of all Pterygogenea. (After Handlirsch.) 

B. Larva of Stenodictya. The abdominal appendages are probably 
secondary. (After Handlirsch.) 


gogenea. As wings seem to have arisen in the Paleeodictyoptera 
the ancestor would have no wings and consequently the thoracic 
segments would be no larger than the abdominal. The result 
would be an animal with head and trunk, the latter with 14 
seoments (fig. 3). The habit must have been predaceous 
which would imply a short straight alimentary tract. 

Turning to the structure of the nervous system, one of the 
most conservative of morphological structures and consequently 
one of the most useful for phylogenetic purposes, embryology 
of recent forms (Viallanes, Wheeler) shows that there are six 
neuromers in the head, a brain triad and a gnathal triad, and 
that a pair of ganglia connected by commisstres follow in each 
segment. Cephalization would be less marked than in recent 
insects. The nervous system is indicated in the diagram 


(fig. 3, B). 


378 J. D. Tothitl—The Ancestry of Insects. 


In insect embryos one of the most universal and striking 
features is the early development and final disappearance of 
ee appendages on the abdominal segments. Graber, 
Vheeler, Heymons and others have figured these structures in 
numerous insects; I find they oceur also in Paratenodera 
(fig. 4), Chauliodes, Ranatra and Polistes. The only possible 
interpretation seems to be that these rudiments represent a 
condition of serial polypody in ancestral forms. This condi- 
tion is therefore represented in the diagram. 


Fie. 3. 


Fic. 3. Generalized hypothetical ancestor of Pterygogenea. (Original.) 


In figure 4 it can be seen that the trachez have already 
invaginated—i. e. the spiracles are plainly visible. These 
invaginations occur generally in insects at an extremely early 
stage, in fact immediately after the appearance of the append- 
ages. This seems to indicate that they are ancient structures 
and that the immediate wingless forbears of insects were 
tracheate and therefore terrestrial. The hypothetical ancestor 
may, therefore, be supplied with tracheal invaginations—at 
least ten pairs as in insects, and probably fourteen. 

There remains the head. I cannot discuss the question of 
head segmentation at this time, interesting though it is. Vial- 
lanes, Wheeler and Heymons are agreed that the insect head is 
composed of six segments and these investigators have paid 
particular attention to the development of the brain. Folsom 


J.D. Tothill—The Ancestry of Insects. 379 


(1900), working with the tiny embryo of Anwrida, supposes 
there are seven segments; the presence of the extra pair of 
appendages described has not been verified, and seems to be 
extremely doubtful. Janet (1899), arguing from adult anatomy, 
supposes there are seven segments; the evidence is not at all 
convincing. In the diagram I have, therefore, indicated six 
head segments. 

The rudiments of the maxilla in insects are characteristically 
paired on each side and possibly indicate a biramous condition 


Fie. 4, 


Fie. 4. Germ band of Paratenodera sinensis, a Chinese mantid, showing 
the rudiments of abdominal appendages, and the spiracles. (Original.) 


of all the ancestral appendages. The evidence, however, only 
points directly to the biramous condition of the first and second 
maxillee. 

The hypothetical ancestor being now visualized (fig. 3), the 
next problem is to search for such an animal in the various 
kindred groups of which we have knowledge. 

The Arachnoidea are by general consent considered to be 
specialized in their own particular direction and may be passed 
by in silence. 

One of the most interesting of all groups is that of the 
Trilobites. In early Cambrian times they were already greatly 
differentiated and dominated the life of the oceans, thus 
occupying the ecological position that the fish do to-day. Some 
were very small, some more than a foot long; some lived in 
deep waters, some in shallow; some were bottom feeders and 
others pelagic. In Ordovician times the group reached its 
climax both in the number of species and in diversity of form. 


380 J.D. Tothil—The Ancestry of Insects. 


With the differentiation and multiplication of fish in the 
Silurian epoch there was initiated the beginning of the end of 
trilobites and the number of species fell away rapidly. There 
was a slight expansion in the Devonian and as in the preceding 
age there was a marked tendency toward the development. of 
(to us) curiously bizarre and ornamented forms. There fol- 
lowed a rapid decline and the group became extinet with the 


Fie. 5. 


SS <a> 
ZEA a 


Tf PLL hanyy 


i “ 
Div y PY 
MY 
yO 
By ) 


: 
d 
Mil 
yy) 
Yat 


IPG 


Cf, 
Zon F 


as 


| 
ih 


om 


S 
y 
M) 


Fie. 5. The trilobite Triarthrus beckii. (From Handlirsch after Beecher.) 


passing of Paleozoic time. More than 2000 species have been 
described and this can represent but a fraction of the total. 

It is a source of surprise that a group showing such collective 
vitality should have given rise to no terrestrial forms as have 
the Annelida, Malacostraca, Arachnoidea, Gastropoda, and 
Vertebrata. Handlirsch indeed takes exception to this view 
and derives a number of groups directly or indirectly from 
these ancient crustaceans. As insects are numbered among 
these the similarities may be examined somewhat closely. 

In Triarthrus beckia (fig. 5), studied with snch signal success 
by Beecher, there are two regions, head and trunk. On the 
twenty or so trunk segments are serially homologous biramous 
jointed appendages. The head carries five pairs of append- 
ages, thus indicating at least five segments. 

The trilobite head problem here suggests itself. Beecher 


i li at 


J.D. Tothitl—The Ancestry of Insects. 381 


(96) supposes that the head of Z7riarthrus is made up of at 
least six segments and possibly of seven; Jaeckel (01) finds 
at least six head segments in a series of trilobites and supposes 
a total of eight. These findings cannot be taken too seriously 
for the reason that the developing trilobite brain has not been 
examined—and it is in the ontogeny of the head that the key 
to the same problem in other groups (Arachnida, Hexapoda, 
Vertebrata) has been found. They are, however, highly sug- 
gestive and it is probable that trilobites had at least as many 
head segments as insects, perhaps the same number. 

Returning to Zriarthrus, the long antennz are instructive 
as are also the compound eyes. 


Fic. 6. 


Fie. 6. a,b, Olenellus thompsoni ; c-e, O. gilberti; f, Mesonacis vermon- 
tana, Showing specialization of first three post-cephalic segments. (From 
Grabau and Shimer, after Walcott.) 


Lindstrém (1901) among others has paid special attention to 
the eyes of trilobites and finds at least three kinds—isolated 
eyes or ocelli, aggregate eyes of biconvex lenses, and compound 
eyes. The three kinds of insect eyes are roughly comparable 
and it is conceivable that they may have been derived from 
those of trilobites. 

In Olenellus (fig. 6) there is a regional specialization of the 
first three post-cephalic segments. In many trilobites, such as 
Albertella, Ceraurus, there is a tendency toward specialization 
of the caudal extremity by the formation of caudal spines ; in 
Neolenus serratus, whose appendages have been recently dis- 
covered by Walcott on specimens from the Burgess shale 
(Middle Cambrian), there are jointed caudal rami strongly 
suggestive of insect cerci. 


382 J. D. Tothill—The Ancestry of Insects. 


In some respects, therefore, the trilobites, especially such 
generalized forms as Mesonacis (fig. 6) and Paradowides, fulfill 
the requirements of our hypothetical insect ancestor. The 
absence of spiracles and the general lack of strong convincing 
evidence of close relationship indicates, however, that if a 
relationship exists, as seems quite likely, it is scarcely as close 
as supposed by Handlirsch. I will return to the group later. 


Fie. 7. 


Fic. 7. A. Lithobiws adult. A representative chilopod. (After Koch.) 

B, Lithobius ; a, Antenne ; 6, Maxillipedes ; c, Brain ; d, Salivary glands ; 
e, Legs ; f, Ventral nervous system; g and h, Malpighian tubes ; 7, Vesicula 
seminalis ; 7 and k, Accessory glands. (After Vogt and Yung.) 


The Progoneata, characterized by the Diplopoda, are by 
general agreement of myriapod students less closely related to 
the Opisthogoneata (Chilopoda) than they are to insects. They 
throw little or no light upon the present discussion, 

Turning to the Chilopoda, there are no fossil forms yet 
known that throw much light upon their lineage, even Palwo- 
campa is distinctly disappointing. Recent forms are, how- 
ever, plentiful and illuminating. A dissection of Scolopendra 
shows that the nervous system is almost identical with that in 
generalized insects. - In Lithobius (fig. 7, A and B) the num- 
ber of trunk segments is reduced to 16 (compare fig. 3); a 
tracheal system histologically identical with that of insects is 
well developed ; also the last pair of legs is larger than the 


J. D. Tothill—The Ancestry of Insects. 383 


others and suggest the insect cerci. The problem of head 
seomentation has been studied by Heymons for Scolopendra 
and the head is composed of six segments as in insects. I find 
the same condition in Scolopendra, Linotenia and Cryptops. 
In all these forms the mandibles and two pairs of maxille cor- 
respond to those in the Pterygogenea and the maxillee are bira- 
mous. The whole group exhibits the condition of serial 
polypody so characteristic in insect embryos. Several kinds of 
eyes are also found in the group (although reduced by reason 
of cave habits) and from these it would seem an easy transition 
to the eyes of insects. Embryological development is also 
remarkably similar in the two groups but that of Chilopods is 
in several important respects less specialized. 

In short the Chilopods are unquestionably very intimately 
related to the Pterygogenea, as Kingsley, Korscheldt and 
Heider, Heymons and others have pointed out. An ancient 
Chilopod showing no specialization of the maxilliped would 
have looked suspiciously like fig. 3 and would have fulfilled 
the specifications better and more closely than any trilobite 
known at the present time. 


The Ancestry of the Opisthogoneata. 


If, as seems probable, the Pterygogenea arose from an 
ancient Chilopod stock it may be interesting to speculate con- 
cerning the ancestry of Chilopods. The primitively biramous 
condition of appendages is suggested by the embryonic con- 
dition of the two pairs of maxillee and of the maxillipedes, also 
by the slight thickenings at the base of all the embryonic 
trunk appendages in Scolopendra, Cryptops and Linotenia. 
The spiracles develop early but perhaps not quite as early as in 
insects—the point needs reinvestigation. In embryos of the 
same forms also, as pointed out by Heymons for Scolopendra, 
there are rudiments of two pairs of antenne. 

The extremely interesting and anomalous Onychophora 
invite at least inspection in this connection. Many investiga- 
tors have supposed that this group, represented by the single 
genus Peripatus, is related to the tracheate arthropods because 
of the paired appendages and trachee. As Handlirsch points 
out, however, the trachez are in position and histological 
structure utterly unlike those of Chilopods and Hexapods. It 
may be recalled that tracheze also occur in many terrestrial 
Arachnoidea and in some half dozen or so genera of Isopod 
crustaceans. In these latter cases the trachez have clearly 
arisen independently and there seems good reason for suppos- 
ing an independent derivation in the case of Peripatus. The 
peculiar fleshy legs and the nervous system are also very 


384 J.D. Tothill—The Ancestry of Insects. 


unlike the corresponding structures in Chilopods or inseets. 
It seems therefore less of a mental effort to regard these 
animals as an independent offshoot from Polychste annelids 
than to regard them as a direct bridge between Annelids and 
Chilopods. 

Returning to the Trilobites, practically all that was said 
concerning the similarities between generalized trilobites and 
Pterygogenea would apply with even greater force to Chilo- 
pods. Regional divisions of head and trunk, polypody, head 
segmentation, antennee, eyes and cerci all suggest athnities. 

If in Cambrian times an adventurous species of the Meson- 
acidze had left its marine surroundings to discover the terres- 
trial world, it seems a fair guess that gills would have been 
exchanged for lungs or tracheze. With no further change than 
the loss of gills and acquisition of trachex (a change actually 
accomplished in the Isopoda and certain Arachnoidea) our bold 
adventurer would now resemble in many fundamental respects 
a generalized Chilopod. 

The lack of knowledge concerning the trilobite head and 
the all-important nervous system preclude the possibility of 
attaching more than suggestive value to a trilobite derivation 
of the Chilopods. With the present lack of data, however, 
this derivation seems at least as logical as any of the various 
ones suggested. 


Conclusion. 


In conclusion a survey of the available data shows that the 
Pterygogenea are closely related to Chilopods and were quite 
possibly derived from an ancient stock in which the maxilli- 
pedes were not developed as jaws. Also that the Chilopods 
were in turn very likely, though by no means certainly, derived 
as Handlirsch suggests, from ancient generalized trilobites. 

The probability of this derivation is increased by comparing 
the manner of development in each group. In the trilobites 
Barrande, Beecher, and others have shown that practically all 
the segments were added after the egg stage; in the Chilopods, 
Zograv, Voerhoff, and Heymons have shown that most of the 
specialization by addition of segments takes place during the 
egg stage; in the Hexapods numerous investigations have 
shown the segments arise only during the egg stage. , This 
brief series exemplifies one of the most fundamental changes 
that has been undergone in the entire history of animals. 

From the ethological point of view also this series represents 
a transition from predaceous marine animals, to predaceous 
terrestrial wingless forms, to predaceous terrestrial winged 
animals. 


J.D. Tothill—The Ancestry of Insects. 385 


From the point of view of vertical distribution a glance at 
figure 8 shows the possibility of the derivations suggested. 
Trilobites were well differentiated at the base of the Cambrian 
series and reached their maximum deployment in Ordovician 
waters; they disappeared toward the end of Paleozoic time. 
The Ohilopoda are known from Pennsylvanian rocks through 


Fie. 8. 


( HILOPODA 


TRILOBITA 


eons 
g PLEISTOCENE ea 
m ¢z [PLIOCENE Pile 
2 =} MIOCENE Lol 
fe 
~ |2 OLIGOCENE bat 
2 peat 
; al 
al 
: nf io 
See he eee | Ce 
(ai 
» [Pennsyuvanan ff | He | | 
S i 
Pe 
z 
a 


PRECAMBRIAN 
Fic. 8. Vertical distribution of trilobites, centipedes and insects. (Original. ) 


the discovery of Palwocampa. As this is clearly a highly 
specialized form (in virtue of the elaborate system of 
macrocheete and the small number of segments) it seems prob- 
able that the group was highly differentiated in Pennsylvanian 
times and that it arose in much earlier Paleozoic times. Many 
insects are known from the Pennsylvanian rocks; it seems 


386 J.D. Tothill—The Ancestry of Insects. 


clear that they reached their stage of maximum deployment 
in the Mesozoic era and that they are now in a condition of 
decline. 

I wish finally to express my appreciation of the kindly help 
and criticism given during the preparation of this paper by 
Dr. Perey E. Raymond in the field of paleontology ; by Dr. 
Rt. V. Chamberlain in connection with Chilopod structures and 
embryology; and by Dr. Wm. M. Wheeler in the field of 
insect embryology. 


LITERATURE CITED. 


Beecher, Charles Emerson } 
1895. The larval stages of trilobites, Am. Geol., xvi, 166-197, pls. 
VIII-xX. 


1896. The morphology of Triarthrus, plate IX, this Journal (4), 1, 
251-256, pl. VIII 
Carpenter, George H. 
1903. On the relationships between the classes of the Arthropoda. 
Proc. Roy. Irish Acad., pp. 320-360, 
Claypole, Agnes Mary 
1898. The embryology and oégenesis of Anurida maritima. Journ. 
Morph., vol. xiv, No. 2, pp. 219-290. 
Folsom, Justus Watson 5 
1899. The segmentation of the insect head. Psyche, August, ’99, 
Cambridge, Mass. 


1900. The development cf the mouthparts of Anuwrida Guer, Bull. 
Mus. Comp. Zool., xxvi, No. 5, pp. 87-157. 
Handlirsch, Anton 
, 1908. Die fossilen Insekten und die Phylogenie der recenten Formen, 
Leipzig. 
Heymons, Richard 
1901. Uberdie Biologie und Fortpflanzung der Scolopender, p. 1-234, 
plates I-VIII. Zoologica Heft 33, Dreizehnter Band, Zweite 
und dritte Lieferungen. 
Jaekel, Otto 
1901. Beitriige zur Beurtheilung der Trilobiten, Theil 1, tafel. ITV- 
VI. Zeitschr. d. deutsch. geol. Gesellsch., liii, Heft 1. 
Janet, Charles 
1899. Essai sur la constitution morphologique de la téte de l’insecte 
DAL einen Paris, Carre et C. Naud. 
Kingsley, J. S. 
1894. The classification of the Arthropoda, Am. Nat., pp. 118-135. 


Lindstrom, G. 


1901. Researches on the visual organs of Trilobites . . . 6 plates. 
Kongl. svenska Vetenskaps-akademiens Handlingar, xxxiv, 
No. 8. 


Raymond, Percy EK. and Barton, Donald C. 
1913. A revision of the American species of Ceraurus, 2 pls., Bull, 
_ Mus, Comp. Zool. Harvard, vol. liv, No. 20. 
Raymond, Percy E. 
1914. Notes on the ontogeny of Isotelus gigas Dekay, Bull. Mus. 
Comp. Zool., vol. lviii, No. 5, Cambridge, Mass. 
Ruedemann, Rudolph 
19i6. On the presence of a median eye in trilobites, Proc. Nat. Acad. 
Sci., vol. ii, p. 234. 


J.D. Tothitl—The Ancestry of Insects. | 387 


Schuchert, Charles . 
1915. Pirsson-Schuchert, Text-Book of Geology : Historical geology, 
New York (Wiley and Sons). 
Viallanes, H. 
1890. Sur quelques points de l’histoire du développement embryon- 
. naire de la Mante religieuse (Mantis religiosa), Rev. Biol. Nord. 
France, ii, pp. 1-12. 
Walcott, Charles D. 
1911. Middle Cambrian Annelids, Smiths. Misc. Col., vol. lvii, No. 5. 


1912. Middle Cambrian Branchiopoda, Malacostraca, Trilobita, and 
Merestomata, ibid., No. 6. 
Wheeler, William Morton. 
1889. The embryology of Blatta germanica and Doryphora decem- 
lineata, Journal of Morphology, iii, September, No. 2. 


1892. On the appendages of the first abdominal segment of embryo 
insects, Trans. Wisconsin Acad. Sci., Arts and Letters, vol. viii, 
pp. 87-140, 3 pls. 


Art. XXXIX.—Some Characters of the Apical End of 
Pseudorthoceras knoxense McChesney; by Grorcr H. 
Grirry.* With Plate I. 


Specimens showing the apical end of uncoiled cephalopods 
are as a rule very rare. It is then somewhat in the nature of 
an exception that the apical end of Pseudorthoceras knowense 
is not uncommonly preserved. The specimens that I have 
heretofore examined, however, show very little save that instead 
of tapering regularly, orif not regularly at least symmetrically, 
to a point, they are obliquely truncated so that the apex is not 
central but lies almost in the periphery. 

There have recently come into my hands two specimens 
which show characters that have not previously been observed. 
Though the characters are not new to the group as a whole, 
but on the contrary are in accord with those of the few types 
on which Hyatt and others have made observations, they 
nevertheless seem deserving of record. These specimens were 
found weathered out of shale and they have had the original 
shell replaced by pyrite, a form of preservation particularly 
favorable to the retention of the finer surface structures of 
fossils. They were collected from the Des Moines group of 
the Pennsylvanian series near Des Moines, Iowa, and were sent 
to me by Mr. G. A. Larson, of whose generosity I avail myself 
of this occasion to make recognition. 

The better of the two specimens shows the usual oblique 
truncation, the end being compressed so that a section across it 


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


388 G@. H. Girty—Pseudorthoceras knoxense McChesney. 


would be elliptical. It is ornamented near the apex by very 
fine, transverse and longitudinal striae which become tiner and 
fainter above, so that all except the embryonic portion appears 
almost absolutely smooth. One side of the shell (that on which 
the apex lies) is marked toward the end by what may be a sort 
of cicatrice. This structure is a minute ridge defined on each 
side by a depression or suleus, both ridge and sulei dying out 
distally and losing themselves within a short distance in the 
general curvature of theshell. Proximally the ridge is strongly 
prominent, its end forming the apex of the specimen. It thus 
resembles a minute rod projecting through the shell and end- 
ing abruptly. Under strong magnification it seems to show a 
very fine, longitudinal groove or slit. From what has been 
said it will be apparent that these structures are developed on 
the non-truncated side of the apex. The rest of the apical por- 
tion shows little besides the sculpture, which is, however, more 
or less modified in harmony with the configuration ; the annu- 
lar markings are not parallel but converge toward the straight 
side, thus apparently rounding over the end, and the longi- 
tudinal lines also are somewhat curved. A stria distinctly 
larger than the rest passes down the center of the straight side, 
in line with the ridge of the cicatrice. 

The second specimen is less regular and less clear than the 
other. The end has a crumpled look and is bent over so that 
the apex projects beyond the plane of that side. A cicatrice 
(a short raised line) is apparently present but it is oblique. 
The concentric striz, rather more irregular and remote than in 
the other specimen, can be distinctly seen, but the fine, longi- 
tudinal markings are so extremely faint as to be doubtful. I 
believe that they are really indicated. Their faintness, how- 
ever, can hardly be ascribed to abrasion, for the other super- 
ficial characters appear to be obscured little, if at all. 


DESCRIPTION OF PLATE I. 


Pseudorthoceras knoxense McChesney. 

Fics. 1 and 2. Two views of a specimen that has the end distorted. This 
specimen does not show the longitudinal lines of the other, and the trans- 
verse lines are farther apart. x 10. 

Fies. 8,4,and 5. Three views of asymmetrical specimen. The very fine 
cancellating sculpture is confined to the apical portion. Figure 3 shows the 
straight side and figure 5 the curved side of the specimen as ‘Pigeaaiad by 
figure 4. x 10. 

Both specimens were obtained in the Des Moines group near Des Moines, 
Towa. 


Amer. Jour. Sci., Vol. XLII, November, 1916. 


Pseudorthoceras knoxense McChesney. 


Plate |. 


Ohler and Browning — Electrolysis, ete. 389 


Arr. XL—On the Electrolysis and Purification of Gal- 
liwm; by Horace 8. Unrer and Puri E. Browntine. 


[Contribution from the Sloane Physical and the Kent Chemical Labora- 
tories of Yale University. ] 

Durtne the process of separating metallic gallium from an 
alkaline solution by electrolysis it was noticed that black coral- 
like deposits sometimes formed around the cathode instead of 
the bright liquid globules which were expected. Since we 
have not found any mention of “trees” in the literature of 
gallium and since one of us has determined a sutiicient condi- 
tion for their production, it seems desirable to present a brief 
account of these interesting structures.* 

The electrolyte used was obtained in the following manner. 
The leady residue} was shaved into small pieces with an ordi- 
nary iron ice-plane and dissolved in a solution made from equal 
volumes of water and strong nitric acid. On. cooling, most of 
the lead erystallized ont as the nitrate. Concentrated sul- 
phuric acid was then added to the filtrate and the resulting 
liquid was evaporated nearly to dryness. The insoluble lead 
sulphate was removed by filtration after the addition of water. 
Silver was next precipitated as the chloride by treating the 
filtrate with hydrochloric acid. By adding an excess of 
ammonia to the filtrate the hydroxides of eallium and indium 
were thrown down while most of the copper and zinc com- 
pounds were kept in solution. When working with large 
masses of material it was found necessary to repeat the last 
operation in order to effect a satisfactory purification of the 
hydroxides of gallium and indium. Finally, these hydroxides 
were separated from each other by taking advantage of the 
facts that indium hydroxide is insoluble in a solution of sodium 
hydroxide whereas gallium hydroxide is readily soluble in an 
excess of caustic soda. ‘The filtrate thus obtained constituted 
the electrolyte used in the cells. With reyard to the chemical 
processes just outlined, it may be remarked that each step was 
checked spectroscopically and found to produce satisfactory 
and efficient separations. 

The electrolytic cells consisted of the following assemblage 
of very simple parts. The vessel containing the liquid was an 
ordinary glass erystallizing dish 10°™* in diameter and 6°3°™5 
deep. The anode was a thin rectangular sheet of platinum 
foil, the edges of the submerged portion being 5:5°™* horizon- 
tally and 8°5°™S vertically. The cathode consisted of a plati- 
num wire sealed into a glass tube with abont 2™"* projecting 
at the lower end. ‘his design usually enabled the gallium to 

*The configuration of the gallium trees closely resembles that of certain 
arborescent forms of native copper, the similarity being very striking in the 


case of a specimen from Bisbee, Arizona. 
+ This Journal, vol. xli, p. 351, April, 1916. 


Am. Jour. Scir.—Fourts Srrizs, Vou. XLII, No. 251.—NovremsBsr, 1916. 
27 


390 Uhler and Browning—Electrolysis and 


deposit as liquid globules which eventually fell automatically 
into a small glass spoon kept vertically below the cathode. A 
sectional view of a cell is shown to scale in figure 1. This 
diagram also indicates the additional convenient accessories 
employed in the production of trees. It was found that trees 
were invariably formed at about 0° C., henee the statement 
that the figure is intended to suggest ice ina porcelain develop- 
ing tray with the crystallizing dish supported on the four feet 
of an inverted brass stool, affords an adequate explanation. 


Fre. 1. 


The current used was about 0°28 ampere giving a mean eur- 
rent density of 0-007 and 6 amperes per square centimeter at 
the anode and cathode respectively. These means are, of 
course, extremely rongh since the distribution of electricity 
was far from uniform, especially at the cathode tip. 

Since the melting point of gallium is about 30° CO. it may 
occur to the reader to look upon the scheme of cooling the 
electrolyte as a perfectly obvious procedure for the production 
of trees. The necessary condition for the formation of these 
solid structures is, however, not as simple as might be expected 
at first thought. With three cells in series and at room tem- 
perature (23° C.) it sometimes happened that one or two of the 
cathodes would continue to present liquid globules while the 
remaining cells or cell respectively would give the solid phase. 
Stroking a globule with a fragment of solid gallium often 
started the growth of a tree, but not invariably. The deposi- 
tion of a tree at room temperature seems to depend upon a 
number of factors, such as the alkalinity of the electrolyte, the 
curvature of the surface of the liquid globule, ete. These 
idiosynerasies are on a par with the predisposition to pro- 


Purification of Gallium. _ 3801 


longed undereooling which metallic gallium ordinarily shows. 
Although we do not know the necessary conditions for the 
generation of trees we have never failed to produce them at 
will by cooling the electrolyte in an ice bath. If the solution 
is at room temperature and a liquid globule is growing, the 
change to the solid phase may be brought about gradually by 
placing ice in the tray and slowly cooling the liquid, whereas 
if the solution and electrodes are at U° C. before and after the 


Fie. 2. 


current is started the deposit will be solid from the very begin- 
ning. 

A fairly complete idea of the appearance of the trees may 
be derived from the associated figures which were obtained by 
first photographing the objects natural size with a long focus 
Dallmeyer “ Rapid Rectilinear” portrait lens stopped down to 
“U. 8. 100” and then enlarging the negatives nearly two-fold. 
Figures 2a, 3a, and 3) show certain trees when the line of 
sight was horizontal, while 20, 3c, and 3d give the respective 
aspects of the same trees when viewed from below, that is, 
when looking vertically upward along the axes of the cathodes. 
The three photographs first mentioned illustrate the fact that 
the branches of the trees are concave on the upper side. 
Figures 2a and 2b pertain to a tree which was formed with 
only one cathode in the solution. The two longest branches 
in 2b were directed approximately toward the outer edges of 
the anode, as was often found to be the case for a single 
cathode. Figure 3 represents two trees which were deposited 
simultaneously on two cathodes joined in parallel. In 3a and 
3b the trees appear as seen from the center of the submerged 
portion of the anode, the plane containing the vertical axes of 
the cathodes being normal to the line of sight. For 8¢ and 3d 


392 Chler and Browning—ELlectrolysis and 


the relative position of the anode was such that if it were 
drawn on the page it would be represented by a straight line 
parallel to the upper edge of the sheet and cutting across the 
tops of figures 3a and 3b. Figure 3e shows the upper sur- 


Fic. 3. 


faces of three of the large branches broken from the pair of 
trees. These surfaces always have a medial groove apparently 
caused by the convection eurrents of hydrogen bubbles which 
stream upward in sheets from the outer edges of each branch. 


Purification of Gallium. - 893 


The fully-developed branches are invariably thinnest at the 
point of attachment to the “trunk” and grow more massive 
at the outer or free ends. (In figure 3¢ the tips of the wires— 
on which the branches were mounted for convenience in pho- 
tographing—can be seen at the free ends of the branches and 
should not be confused with the details of the gallium 
structure.) 

The growth of a tree takes place in the following stages. It 
begins as a spherical ball which appears to be perfectly smooth 
at first but which becomes visibly rough as the diameter 
increases. These rugosities develop into sharp points which 
eventually build up a configuration similar to the outside of a 
chestnut burr. After this the characteristics of a figure of 
revolution are gradually lost as certain branches grow more 
rapidly than others. In general, the branches of young trees 
are thin and pointed while those of more mature trees are 
bludgeon-shaped as shown in figure 3. Under the given 
experimental conditions about 20 hours were required to 
deposit the structures reproduced in the photographs. When 
the cathode consists of a bare platinum wire which projects 6 or 
8 millimeters below the free surface of tne electrolyte, the trees 
develop relatively broad leaves instead of roughly cylindrical 
branches. These leaves are approximately horizontal and are 
piled up one above another over the entire length of the sub- 
merged portion of the wire. 

Passing from geometrical to physical and chemical proper- 
ties, the following facts may merit recording. The material 
of the trees is hard and strong like the solid phase derived in 
any other manner. Hence the trees are stable, permanent 
structures so long as they are kept at a temperature ten 
degrees, more or less, below the melting point. For this 
reason, aS well as on account of their general appearance and 
ease of control during development, the gallium trees would 
afford a more interesting and instructive lecture experiment 
than the classic lead ones. Throughout the period of electro- 
lytic deposition the trees are intensely black. This color is 
largely superficial, for when the branches and trunk are cut to 
pieces, the freshly exposed surfaces have either the dull appear- 
ance of slightly tarnished lead or the characteristic silver luster 
of clean gallium. After removal from the electrolyte and 
drying, the branches become partially covered with gray and 
white patches, as may be seen in the photographs. Three 
trees which had been kept under water for over a month and 
then allowed to dry were chiefly grayish black. The ends of 
their branches, however, had turned brown and a pure white 
powder completely filled the spaces on the undersides of the 
trees where the branches joined the trunk. The color changes 


304 Uhler and Browning—Electrolysis and 


are probably closely related to the following phenomena. As 
soon as the current is interrupted the trees react on the elec- 
trolyte and give off gas bubbles copiously. When kept in ice 
water they evolve a little gas for a day or two, the rate of reac- 
tion decreasing as the time of immersion increases, The evo- 
lution is more rapid in water at 28° C. When a tree (of any 
previous history) is plunged into boiling water a relatively 
large amount of gas is suddenly liberated with a hissing sound 
as the parts of the structure coalesce into a mixture of bright 
liquid globules and the colored compounds. 

The metal deposited in the liquid state has properties similar 
to those of the trees. When a globule is allowed to remain in 
the electrolyte (in the spoon) for ten or more hours the surface 
loses its high reflecting power and becomes coated with 
a blackish skin. The brilliant gallium shot (conveniently 
obtained by dropping a fresh globule into cold water and then 
hastening solidification by kneading the molten metal with a 
thin glass rod which has previously become contaminated with 
the solid phase) gradually acquire a dark coating when kept in 
air, water, ethyl aleohol, and kerosene. It was also observed 
that some gas was evolved in each of the liquids, especially in 
distilled water. In fact, on one occasion the cork stopper of a 
vial, which had contained a pile of shot under water for several 
days, was blown several feet upward by the pressure of the 
gradually accumulated gas. The predisposition of the metal 
to acquire a dark surface may be greatly diminished by first 
removing the black substance with dilute nitri¢ acid (or other- 
wise) and then agitating the liquid gallium in four or more 
changes of boiling water. The metal thus cleansed partially 
crystallizes (sometimes with edges more than 1™ long) when 
converted into the solid phase and only shows a slight gray 
hue after a month’s exposure to ordinary air. Since it was not 
the object of this investigation to identify the black, brown, 
and white compounds mentioned above we are not prepared at 
present to give a complete explanation of the reactions 
involved; nevertheless, it seems probable that the colored 
compounds correspond to different degrees of oxidation and 
that sodium and water play important parts in the observed 
phenomena. 

During the process of electrolyzing (at room temperature) 
the alkaline solution of gallium a white, flocculent substance 
often appears in the liquid, especially in the immediate vicinity 
of the surface of the anode facing the cathode. When the 
electrolyte used is the liquid first decanted the white material 
sometimes forms in relatively large quantities on the anode 
from which it eventually peels off and forms a talus at the 
bottom of the dish. A sample of this substance was collected, 


Purification of Gallium. - 895 


washed with distilled water, and tested both chemically and 
spectroscopically. All the evidence thus obtained favored the 
belief that the compound is gallium hydroxide. In this con- 
nection, it may be remarked that an apparently identical mate- 
rial is produced by bubbling carbon dioxide throngh a solution 
of gallium in sodium hydroxide. The formation of the white 
substance at the anode is doubtless due to the decrease in con- 
centration of the sodium solvent in this region, This decrease 
may be brought about both by the absorption of carbon dioxide 
from the air and by the ionie redistribution involved in the 
passage of the electric current. Obviously the electrolyte may 
be cleared up by adding caustic soda. 

Attention may now be directed to figure 4 which not only 
illustrates the last paragraphs both of the present article and 
of our preceding paper (oc. czt.) but it also constitutes the only 
reproduction of the complete are spectrum of gallium which 
we have seen. Figure 4a shows the spectrum of the mother 
liquor of the caesium-gallium alum mentioned below. The 
purification produced by ten erystallizations of the alum is 
made evident by figure 4b. The spectrum of a specimen of 
electrolytic gallium (not heated in hydrogen) is given in figure 
4c. Spectrogram 4d pertains to the gallium-indium alloy 
obtained by a sweating process. The following table of wave- 
lengths (International System) will assist in the identification 
of the most prominent lines. The bands and faint lines due to 
the carbon arc and to slight impurities are not tabulated. The 
numbers indicating lines belonging to the first order of the con- 
cave grating have no accents. Lines of the second and third 
order are designated respectively by single and double accents. 
H=“head” of gallium band. 2 = new (see previous paper). 
J? = widely reversed throughout entire length of are. r= 
reversed chiefly near positive electrode. Laek of space pre- 
cluded numbering the strong zine lines shown in figure 4d 
between 19’ and 21’. Their wave-leneths are 46807138, 
4729164, and 4810534. In figure 4@ the principal caesium 
lines (AA4555°34 and 4593:21) may be readily seen on the less 
refrangible side of the very intense indium line, 44511°37. 

As already stated in our previous paper,* a fairly satisfac- 
tory separation of gallium and indium may be obtained by the 
action of sodium hydroxide upon the hydroxides of the 
elements, as recommended by Lecog de Boisbaudran. Another 
methodt described by the same inyestigator, the crystallization 
of the ammoniam alums in 70 per cent ethyl alcohol, proves 
also good, a very few crystallizations giving a gallium product 
eens only spectroscopic traces of indium, zine, copper, and 

ead. 


*This Journal, vol. xli, p, 851, April, 1916. 
+ Compt. rend. (Paris), xcy, 410, 


is and 


yst 


Electrol 


Browning— 


Uhler and £ 


396 


€ 
ec 


000L 


Purification of Gallium. - 389% 
Gallium. Lead, 

18’, 18” 9994 n, R. 23! 9802:01 
19’, 19” 2338 One ip 3639'°57 
20’, 20” 9371 N, 1. 10 3683°47 
Q1', 21" 2418 7,1 3740'00 
il el 245010 R. 
DO id 2500718 A. : Zine. 
Soar 2659°84 7. D8} 2800°9 
4, 4! 2719°66 7. ( 3282-28 
5, a 2874:24 R. | 3302°56 ' 
6, 6’ 2943°66 KR. 9, 9’ < 3302°91 
11 3778 nN, LH, | 3344°99 
12 3889 n, H. | 3345°51 
13 4033'08 A. 24 6362°346 
15 4172°05 AR. 

535381 Caleiwm. 
i 1 5359°8 16 4296°72 

6396°84 
26 | 6413-74 

Indiun. 

Day 2560°22 
Ue te 3039°36 7. 
8, 8! 3256°03 r. 
14. —««w 4101°82 
UG 4511°37 


The reasonably complete separation obtained by the frac- 
tional crystallization of the ammonium alums of gallium and 
indium from water solution, as previously described,* suggested 
the substitution of cesium for ammonium. Accordingly, a 
portion of a gallium-indium alloy weighing 2°3 grms., and con- 
taining 10 per cent of indium, small amounts of zine and lead, 
and traces of copper, was converted into the sulphates, and 
a calculated amount of cesium sulphate was added. The 
ceesium-gallium alum crystallized readily,t and after ten 
erystallizations a spectroscopic examination of the product 
showed practically pure gallium; the indium, zine, copper, 
and lead having been almost entirely removed (fig. 44). The 
mother liquor gave evidence of a considerable amount of 
indium and also indubitable evidence of the presence of zine 
and lead, showing that indium, zine, and lead may be removed 
from gallium by this method (fig. 4@). 

The examination of some gallium deposited electrolytically 
from an alkaline solution showed the presence of traces of zine 
(fig. 4c), and the following process was tried to separate the 
zine: a weighed porcelain boat containing 0°15 grms. of the 
element was placed in a combustion tube so connected with a 


* This Journal, vol. xli, p. 351, April, 1916. 
+ These crystals lend themselves well to a microchemical test for gallium. 


398 Uhler and Browning—Electrolysis, etc. 


hydrogen generator that the hydrogen was dried by passing 
through strong sulphurie acid. While the current of hydro- 
gen was passing through the tube the full heat of the Bunsen 
burner was applied directly under the boat, and the heating 
was continued until no further sublimate appeared. This was 
determined by moving the boat from time to time and examin- 
ing the tube above it. The boat and its contents were then 
allowed to cool in the current of hydrogen, and when cool 
were removed and weighed. <A loss of 0:0008 germ. was 
observed, and the contents of the boat, tested spectroscopically, 
did not give the slightest trace of the strongest zine lines. 
The amount of sublimate in this experiment was too small to 
be removed for examination, but a much larger sample of the 
metal, similarly treated, gave a sublimate which proved when 
examined spectroscopically to be chiefly zine. 


Yale University, New Haven, Conn., August, 1916. 


bo 


CO ~T O> OT 


Blaney and Loomis—Mt. Desert Island. _ 899 


Arr. XLI.—A Pleistocene Locality on Mt. Desert Island, 
Maine ; by Dwicur Bianey and F. B. Loomis. 


On the southern end of Mt, Desert Island, Maine, at the 
head of Goose Uove, there occurs a deposit of Pleistocene 
clays which has never been described. The bed is so pecu- 
liarly rich in well-preserved fossils that it should be a fre- 
quented locality for the study of postglacial marine remains. 
It has a further interest because on the other side of the island 
in Frenchman’s Bay, only about ten miles away, a careful 
study of the marine fauna has been made for a period of many 
years, so that an opportunity is presented for an unusually 
interesting comparison of these two faunas, both the Pleisto- 
cene and the recent faunas having lived under approximately 
the same bottom conditions, except as to the matter of tem- 
perature. 

The clays form a bed from below the low-tide level to about 
twenty feet above high tide, making a bank which blocks the 
head of the cove, and especially along its lower portions is well 
exposed, In the shallow water of the cove many of the shells 
may be found washed out, but most of the fossils will not stand 
such rough treatment as the weathering by the sea imposes. 
The elay is fairly soft and as the fossils nearly fill it, collecting 
is rapid work. We found it convenient to collect the larger 
shells on the spot and carry home blocks of clay, from which 
after drying the delicate and smaller shells could be easily 
washed out. The abundance of the material may be judged 
from the fact that in two to three hours we collected over three 
hundred shells. 

The following is a list of the shells taken from this locality, 
with comments as to the abundance of the fossils in the clay, 
and in Frenchman’s Bay, some ten miles away: 


Goose Oove Frenchman’s Bay 
. Pecten islandicus, Miiller The most abundant Very rare, only dead 
and well preserved shells ever found. 
form. 
. Mytilus edulis, Linne Very abundant but Very abundant. 


poorly preserved, 

crumbling easily. 

. Modiolus modiolus, Linne Rather rare and of Very abundant. 
small size, 


- Nucula tenuis, Montagu _— Rare. Common. 
Leda minuta, Miiller Fairly common. Not found. 

. Leda pernula, Miiller Not common. Not found. 

. Astarte elliptica, Brown Very abundant. Not found. 


. Astarte laurentiana, Lyell Common. Not found. 


400 Blaney and Loomis—Mt. Desert Island. 


Goose Cove Frenchman’s Bay 
. Cardium pinnulatum, 
Conrad Not common. Very common. 
. Serripes groenlandicus, 
Gmelin Fairly common. Rare. 
. Macoma calcarea, Gmelin Very abundant. Common. 
. Mya arenaria, Linne Rare, Very abundant. 
. Mya truncata, 
var, uddevallensis Very abundant. Never dredged alive. 
. Saxicava arctica, Linne One double valved = Very common. 
specimen. 
5. Bela turricula, Montagu _— Rare. Very common. , 
. Buccinum undulatum, 
Linne Common. Common. 
. Fusus (Chrysodomus) 
decemeostatus, Say Rare. Very common. 
. Fusus (Sipho) pygmaeus, 
Gould A fragment. Very common. 
. Trichotropis. borealis, 
Sowerby Rather rare. Common. 
. Aporrhais occidentalis, 
Beck Rare. Not common. 
. Lunatia groenlandica, 
Beck Common. Not common. 
. Lepeta caeca, Miller Fairly common. Very common. 
. Margarita cinerea, 
Couthouy Fairly common. Common. 
. Rhynconella psittacea, 
Gmelin Two valves. Not found. 
. Terebratella spitzberg- 
ensis (?), Davidson One fragment. Not found. 


Beside the above these clays contain a series of barnacles, 
and Bryozoa, but we did not collect these in quantities sufh- 
cient to be significant. 

The species most abundant in these Pleistocene clays, like 
P. islandicus, the Ledas, Astartes, Mya truncata, Rhyncho- 
nella and Macoma calcarea, are now either wanting or ex- 
tremely rare in Frenchman’s Bay, but are the common forms 
of the Labrador coast. This whole Pleistocene fauna with 
much the same relative abundance in the different species is 
the typical fauna of the Labrador waters. The conditions 
under which the Pleistocene fauna lived and those of the Lab- 
rador waters of to-day would seem to be much the same, and 
the sole cause of the transfer of this fauna from Maine to Lab- 
rador has been temperature. As the Pleistocene fauna moved 
north, a more southern fauna has taken its place. 

If the Pleistocene fauna of Maine and the recent fauna of 


Blaney and Loomis—Mt. Desert Island.  - 401 


Labrador to-day were both preserved as fossil faunas, the temp- 
tation would be very strong to identify them as of the same 
age, which indicates some of the difficulties in the way of syn- 
chronizing two extinet faunas, when the time element separat- 
ing them is not very great. In this case the constant element 
has been temperature. 

The clays at Goose Cove, Mt. Desert Island, would usually 
be designated as Leda Clays, but it should also be noted that 
they contain Saxicava, which in Canada belong to a later phase. 
The mingling of Leda faunas and Saxicava faunas is character- 
istic of the deposits in Maine. 

In general the Goose Cove fauna resembles most closely the 
fauna found in New Brunswick and described by Matthew. 
It is also very similar to the fauna found at Portland, Me., but 
differs from both of these in many fundamental respects, 
From the collections made at Saco, Me., and at Gardiner, Me., 
the Goose Cove fauna differs even more widely, though it 
would be expected to resemble them more closely. The pres- 
ence of Modiolus modiolus in abundance, of Zrichotropis, of 
the Ledas, and Astartes, of Rhynchonella psitticea and Tere- 
bratella make a surprising close affinity to the fauna found at 
Montreal where these forms are distinctive, and occur in about 
the same relative abundance as at Goose Cove. 

For the most important literature see the following, which 
contain all the minor references : 

Dawson, J. W., Canadian Ice Age, 1894. 

Packard, A. S., Glacial Phenomena of Labrador and Maine, 
Memoirs Boston Soc. Nat. Hist., vol. 1, pp. 210-303, 1865. 

Stone, G. H., The Glacial Gravels of Maine, U. 8. Geol. Sur- 
vey, Monograph 34, 1899. 


Amherst, Mass. 


4.02 OC. Barus—Methods in Reversed and 


Arr. XLII.—dethods in Reversed and Non-reversed Spee- 
trum Interferometry ; by Cart Barus.* 


1. Lntroductory.—Thus far it had been impossible to use the 
fringes individually, because of the tremor of tlie apparatus. 
It is therefore desirable to endeavor to obviate this annoyance, 
if possible, and the end would appear to be most easily obtain- 
able if the distances are made smaller. At the same time the 
results for small distances will be interesting for this very 
reason, in contrast to the long distance methods (meters). 

Furthermore, the development of different methods, with a 
consideration of the peculiarities of each, will constitute an 
essential contribution to the theory of the phenomena. For 
from this, the degree of importance which is to be attached to 
the original diffraction at the slit of the collimator (i. e., the 
limiting angle at the slit, within which diffracted rays must lie 
to be subsequently capable of interference, whether reversed 
or inverted) will appear in its relations to the total dispersion 
of the system. The slit, however fine, is still a wavefront of 
finite breadth. 

2. Apparatus.—In the first experiments, the device with 
two identical reflecting gratings, @G’, fig. 1, was firmly 
mounted on a massive spectrometer, the four mirrors m, n, 
M, NV, being specially attached. White light received from 
the collimator, Z, after two dispersions, was viewed at the 
telescope Z. Both gratings were on a slide ss, enlarged in 
fig. 2, set in the direction ZZ of the previous figure. The 
carriage, ¢, fig. 2, was provided with universal joints (@ with a 
vertical axis, 6 and e with horizontal axes normal to each other), 
while the swivelling of the grating G was controlled by set 
screws at d, relative to the axle at e. 

Unfortunately the displacement of the mirror JZ (on a 
micrometer) passes the corresponding pencil across the face of 
the grating @’ and thus virtually includes a fore and aft 
motion of the latter. Thus the fringes pass, with rotation, 
from very fine hairlike striations, through a horizontal maximum 
of coarseness, back to vertical lines again, when homogeneous 
light and a wide slit are employed. The annoyances due to 
tremor, however, were not overcome. Moreover there is dif- 
ficulty in obtaining Fraunhofer lines normal to the longitudinal 
axis of the spectrum. This method was, therefore, abandoned. 

The design shown in fig. 3, with a transmitting grating 
at G (grating space D = 352 & 10~° em.) and a stronger reflect- 
ing grating at G’ (D= 200 X 10-° em.), was next tested, 
> Gono from a Report to the Carnegie Institution of Washington, 


Non-reversed Spectrum Interferometry. - 408 


being the micrometer mirror. The mean distance of J/ from V 
was about 15™, from JV to G’ about 10™ and to G 40. 
Later these distances were enlarged. First order spectra were 
used and the fringes obtained easily and brilliantly, particularly 
with mereury light, in both green and yellow. They rotated 
as above, admitted a displacement J/ of about 1°". But they 
were still too mobile to be used individually. 

The same design, fig. 8, was now mounted on a round heavy 
block of cast iron, B, 80 in diameter, and 4™ thick, the dis- 
tance G to JLN being about 20°. A number of screw sockets 
b, b, ---, were drilled into & on the right and left, for mounting 
subsidiary apparatus. 4G’ as before was on the universal slide 


(fig. 2), movable in the direction ZZ. The tablets, ¢, /, etc., 
of G, WZ, NV, and G’ were mounted tentatively on standards of 
gas pipe 1:6" in external diameter and 6™ long. Slight 
pressure by the finger tips showed a passage of several fringes 
across the field, but the fringes were stationary in the absence 
of manual interferences and in spite of all laboratory tremors. 
A parallel arm of the same pipe was therefore firmly attached 
to the stem of WV and J/, each arm terminating in a fine hori- 
zontal set screw, s, s, below, adapted to push against the rim of 
the iron block. In this way adequately stationary conditions 
and an elastic fine adjustment for superposed longitudinal 
spectrum axes were both secured with advantage. It was now 
possible to manipulate the micrometer at J/ by hand; but a 
glass plate compensator, C, rotated by a tangent screw over a 
graduated are was also convenient. Later other types were 
attached, including an air compensator, in which path differ- 
ence was secured by exhausting the air within a closed pipe 
provided with glass plate ends. These contrivances were 
eventually superiluous, however, as it was found that on reduc- 


404 C. Barus—Methods in Reversed and 


ing the rotation of the micrometer screw, the latter could be 
used at once, 

In case of homogeneous light and a wide slit, fringes were 
visible in an ordinary telescope for a play of over 2™ of the 
micrometer screw, passing however between extremes of fine- 
ness. The slit images are not of equal breadth, if first and 
second order spectra are superposed, but if the longitudinal 
axes are coincident any position of the narrow image within 
the broader produces a wide vertical strip of fringes, usually 
more or less horizontal. They are very easily found. The 
sodium flame is too feeble for use. The mercury are is unfor- 
tunately too flickering, so that the fringes jump about and are 
useless for measurement. LExcellently sharp quiet fringes are 
obtained with sunlight (white), in which the cross hatched inter- 
ference pattern is nearly linear at the line of symmetry of the 
reversed spectra. The fringes climb very decisively up and down 
this line with the motion of the micrometer, reduced as sug- 
gested. The electric arc or a Nernst filament are equally avail- 
able as a source of light. Finally by suitably rotating the 
grating @’ on the axis e, by aid of the set of screws d, fringes 
whose distance apart is over $ of the width of the telescope field 
may be obtained, quite sharply. As this distance represents but 
30 x 107° em., there is no difficulty of realizing 10-° em., in 
case of these long fringes. 

3. Measurements. First and second order spectra.—The 
steadiness of the fringes even in an agitated location induced 
me to make a few measurements for orientation. Accordingly 
the Fraunhofer micrometer, reading to 10-* cm., was provided 
at its screw head with a light wooden wheel, w, fig. 4, about 
10™ in diameter and 3 millimeters thick. A groove was ent 
in the circumference of the wheel, so that a silk thread, ¢, could 
be wrapped around it. The other end of the thread was 
wound around a brass screw, s, about 6 millimeters in diameter, 
turning in a nut, preferably of fiber, which was fastened to the 
edge of the table by a small brass clamp. In this way it was 
possible to control the motion of individual fringes crossing a 
fiducial line in the field of the telescope. This simple device 
worked surprisingly well, a smoothly running micrometer 
being presupposed. In fact, it was possible to set a fringe to 
a few millionths of a centimeter. Later the micrometer head 
was grooved and a finer turning screw suitably attached to the 
base, L, of the apparatus. 

The fringes should be widened as far as convenient, by 
rotating the grating on the axle e, fig. 2, by aid of the set 
screws, @. In this case they climb up or down the transverse 
strip, as s in fig. 4 is slowly rotated. Fringes moving horizon- 
tally are not serviceable, because they are too near together. 


ee 


Non-reversed Spectrum Interferometry. — 405 


Tt is not difficult to obtain the single vertical line (which shifts 
laterally), black or bright, on suitable rotation about e. On 
either side of this transitional adjustment the fringes move 
vertically (climb or fall) in opposite directions, for the same 
micrometer displacement. The arrow-shaped forms are also 
often satisfactory, and may be obtained by adjusting the two 
bright patches on the reflecting grating into coincidence, by 
the eye, in the absence of the telescope. The grating G’ is 


Fras. 4, 5. 


moved fore and aft for this purpose on the slide, s, fig. 2, 
until the two bright strips become one. 

In making the first adjustment, I incidentally combined the 
first order spectrum from JV, with the second order spectrum 
from JZ, as shown in fig. 5, under the impression that the 
wider D groups from the latter were due to slight curvatures 
of mirrors. The fringes were nevertheless easily found and 
showed no anomalies, except that observation had to be made 
near Jf or JV. 


It appears from fig. 5 that the equations for this case imply 


sind + sin 6,’ = 2A/ D, 
sing —sin 6,’ = dr/D, 


where the angles 7 and @ are equal (0,/—0,”). Thus 
sin? = 3X. /2D, and sind =2/2D,, D, being the grating con- 
stant (D,= 200 X 10~° em). 
Hence sin 7 = -4420, sin 8, = 1423 
nb 14’ Oe Be 11’, 


while from the first grating, D, = 350 x 10-° em., 


6, = 9°38’ ; whence o = 72 + 6, = 85° 52’ 
= 21—@ = 16" 86" 
Am. JOUR. eiege ee SERIES, Vou. XLII, No. 251.—Novemser, 1916. 
9 


~ 


4.06 C. Barus—Methods in Reversed and 


Trial readings of the micrometer for a passage of 20 fringes 
each were made without special precautions and showed 
(omitting the data) an average of 10-' x 30:1™ per fringe. As 
the line of symmetry lay very near the two D,D, doublets, this 
is obviously an approach to half a wave length. For accurate 
work DD, and D’,D’, should be superposed, in which case the 
fringes would lie between and actually correspond to their 
mean wave length. 

A number of measurements, like the above, were now made 
with different types of fringes, and the ayerage values succes- 
sively taken from 3 or 4 batches of 30 fringes each. 

The results were less decided when long fringes were use(l. 
The final mean value of the 10 sets was de x 10° = 30:19™ per 
fringe. Actual or approximate coincidence of the JD lines 
made no appreciable difference. 

In the following results the reflection from the mirror J/, 
fig. 5, was used in the first order and from J in the second 
order after leaving G’. Observations were made near J, 
fig. 5. The displacement corresponding to 80 fringes was 
successively taken. 

The mean value 


10° de = 30:0 


agrees with the above. 

Similar trial observations (combined first order from V and 
second order from J/) were made with red light near the (C line 
in series of six with a mean value de x 10°= 34:0™., 

Again near the 6 line (green) giving de X 10° = 27°5™ per 
fringe. These should therefore be distributed in terms of 
wave length and they are as nearly as may be expected in the 
ratio in question, seeing that the total displacement for 60 
fringes does not exceed (004. For accurate data it would be 
necessary to count many hundreds of fringes, and to correct 
the de values by multiplying by sec (6, — @,)/2. I have not 
done this as the red and green fringes are not so distinctly 
seen as the yellow. 

4. Continued. First order spectra——The apparatus was 
now readjusted in such a way that first order spectra were 
available from both mirrors. This puts the grating G’, fig. 3, 
at a greater distance from the line JZ and J than before, for 
the angle @, is smaller. A series of trial results were in- 
vestigated in the same manner as above, the mean values from 
four successive pairs of eighty fringes, each pes taken in 
three repetitions. They gave an average value of de x 10° = 
29°25, somewhat smaller than half a wave length of the D 
light used. Unfortunately the screw at s (fig. 4) here worked 
jerkily, to which the low value is probably due. 


! 
Non-reversed Spectrum Interferometry. _ 407 


In this case sin?, = »/D,, where D, = 352 x 107° em. or 
0’, = 9° 38’; and sin @’, = A/D, where D, = 200 « 10-° cm, or 
6’=17° 9’, whence 


o = 26° 47’ and 8= 7° 31’. 


In a later series of experiments, the play of the screw, s, 
was improved, so that it ran more smoothly. The following 
values were found in two repetitions, from four pairs of 80 
fringes each : 


(1A $< NO 2 = GORI shoo 


and in five pairs of 100 fringes each, d¢ x 10° = 29°5°™. 
Tf the mean value of these data is compounded with the 
above mean, the average is 


Og elO re 2975000. 


5. Continued. Second order spectran—The same pheno- 
menon was not sought in the two second order spectra from 
G’. Magnificent arrows were obtained, useful throughout 
about 5 millimeters of the micrometer screw, after which they 
lost clearness. This limited range could no doubt be immensely 
increased if optical plate glass were employed in place of the 
ordinary plateused. The data for pairs of observations, includ- 
ing 60 or 80 fringes, gave (5 repetitions) a mean value of 
de X 10° = 30:5. In the last two measurements the sodium 
doublets coincided. 

In this case sin 0,” = 2 / D,, where D, = 200 X 10-° em. 
and D, = 352 X 10~° em. (first grating). Thus 


Gia ao 28 


If the above mean data are summarized the results appear 
as follows (A = 58°93 x 10-° em.): 


G 1st order, G' 1st order, mean de x 10° = 29:56™ 
G ist order, G’ 1st and 2d order, mean d¢ x 10° = 30:2 
G ist order, G’ 2nd order, mean de X 10° = 30°5. 


If computed as 6¢ = 2/2 cos 6/2, these become 


2 Se OY aap DOHC, ID a ee ee 
29°78 + °42 
30°27 + °23 


The maximum error of 4 X 10-7 em. is equivalent to but a 
little over 1 per cent of the distance between fringes, and it 
would be idle to suppose that the apparatus, fig. 4, could be 
set more accurately. In fact, the largest error occurs in the 
second set which were first made and in which the play of the 
apparatus, fig. 4, was inadequately smooth. 


408 O. Barus—Methods in Reversed and 


6. Theory.—Hence the theory* of the apparatus (fig. 6) may 
be regarded as justified. Here the rays Y, and Y’ come from 
the first grating (@ transmitting) and after reflection from the 
opaque mirrors JZ and JV (the former on a micrometer) impinge 
on the second reflecting grating G’, with a smaller grating 
space, and thereafter interfere along the line 7) entering the 
telescope. To treat the case the mirrors J/, ete., may be 
rotated on the axis Z’ normal to G’ in the position 7. @’, and 
G’,, show the reflections of @’ in the mirrors V, and /,. We 
thus have a case resembling the interferences of thin plates 


Fre. 6. ! 


and if ¢, is the normal distance. apart of the mirrors J/, and 
JV,, the displacement Ag,, per fringe is given by 
= 2Ae,, cos 6 / 2 


where 6 is the angle between the rays incident and reflected at 
the mirrors. This is the equation used above. If the mirrors 
and the reflections of the gratings G’ make angles o/2 and o 
with G’, the actual lengths of the rays (prolonged) before 
meeting to interfere, terminate in e and f respectively. Let 
the image of @’ be at a normal distance ¢ apart. Then 
é = 2e,, cos o/2, for the figure fdbe is a parallelogram. If the 
distance eg is called C we may also write 


A= ecos 8, + Csin#, 
since (= 2¢,, sino /2 and the angle of diffraction 0,=(o¢ + 6)/2. 
* This Journal, xlii, pp. 63-78, 1916; cf. §3. 


Non-veversed Spectrum Interferometry. _ 409 


7. Compensator Measurements —A. With the object of 
testing the interferometer under a variety of conditions, 
measurements were made with a number of different compen- 
sators and the experience obtained may be briefly given here. 
The first of these was a very sharp wedge, such as may be 
obtained from ordinary plate glass. The piece selected, cut 
from an old mirror, on being calipered showed the following 
dimensions : 


Length, 5°" ; thickness at ends, °375 and ‘367°™. 


Hence the angle of the wedge is a = ‘0016 radians or about ‘1°. 
No difficulty is experienced from the deviation of the rays for 
so small an angle, though sometimes the fringes are unequal 
and the lines presumably curved. This wedge was attached to 
a Fraunhofer micrometer, moving horizontally parallel to the 
wedge, and the normality of the rays passing through the glass 
was found by rotating it around an axis perpendicular to the 
rays, until the direction of motion of the fringes was reversed. 
In view of the small angle a and the micrometric displace- 
ment, it was easy to count single fringes, or fractions as far as 
about 1/30 of a fringe, even though the beam traversed 
the glass twice. In the first experiments the data of the hori- 
zontal displacement, 7, of the wedge, were found for successions 
of seven fringes. From the mean value of 8 such sets, 
7 = 2008" and the displacement per fringe would be 
O70 2000 

In another series made with care as to the normal adjust- 
ment, the horizontal displacement, 7, of the wedge for succes- 
sions of 11 parallel fringes was taken. Again omitting the 
individual data, the mean displacement was found to be 
r = 3014, whence per fringe, 

Ome 0 2/40m" 
This difference from the preceding result shows that extreme 
care must be taken in placement. . 

If x be the distance from apex of the wedge, its thickness is 
é= za, or per fringe 6¢ = adz = adr. The index of refraction 
was found to be w = 1°526 by total reflection. Thus without 
correcting for dispersion, ; 

2(u— 1) de=A 


and with the above values 


10-° 5°893 ui 
a= 2 = ‘0020 radians. 
2x 526 X *028 


This is larger than the calipered value, because the rays go 


410 OC. Barus—Nethods in Reversed and 


through the wedge twice obliquely. The reduction, however, 
would here be too complicated, but will be treated later. 
The method is interesting as allowing of the complete control 
of a single fringe; i. e. the equivalent of 30 xX 10-"cm. As 
this corresponds to -028°" on the micrometer, the displacement 
dv = ‘001 is equivalent to 10-° em. Furthermore the method 
presents an expeditious means of finding a ==)r/2(m — 1)dx 
when a is very small. 

B. In the next place the revolving compensator, (, fig. 3, 
was employed. This also proved to be an admirable device 
for controlling the fringes, and it was 
much more rapid than the preceding. 
Unfortunately the computation is ineon- 
venient as the normal position cannot be 
ascertained with sufficient accuracy. To 
find it, the plate was revolved until the 
fringes changed their direction of motion. 
This is an indication of the insertion of 
the minimum thickness of glass, but is 
not sharp enough for precision. Hence 
on repetition the data are not liable to 
be coincident. Mean values are given, 
2 denoting the angle of incidence. 

Same plate as in the preceding work, ¢ =-370. 


No. of fringes passing: 0 10 20 30 40 50 
Mean 7: Oo. Mork? TBS 9s b es On ap 


Another somewhat better and thicker plate was now inserted 
with the following mean results. Thickness e = -489°™, 


No. of fringes passing: 0 10 20 30 40 
Mean 7: Ores are NGS. a Beare ose 


The reason for the large discrepancies found is not clear to me, 
even in consideration of the wedge-shaped plates. The mean 
of the results may, however, be used for computation. 

The path increment introduced by the glass of thickness 
e = °489™ and index of refraction » =1'526, at an angle of 
incidence 2 and refraction 7 for fringes, beginning at 7 = 0 
may be written (see fig. 7, where J is the incident ray) 


1 cos (¢ — r) 
yest th (EN |) ge 5 
cos r cos’ 


This is a cumbersome equation. If the angles z are small, the 
cosines may be expanded and then approximately since 7 = pr 
nearly, 

md = e(w— 1) 77/2. 


Non-reversed Spectrum Interferometry. _ 411 


Thus for the second set (mean) 


7 = 8'6° 4°8° 5°9° 6°8° 
TODA = 67 6°4 6°9 Groce 


The wave-length thus comes out very much too large, but in 
consideration of the inadequacy of the fiducial position, 7 = 0°, 
this is not unexpected. Thus the probable values of 2 (com- 
puted from X correct) agree with some of the individual series. 
In addition to this the effect of slightly wedge-shaped plates, 
etc., can not be ignored. For the first set (mean values), the 
results are similar. 

C. An air compensator was now installed consisting of a 
tube e = 15™ long and about 2™ in diameter, closed with glass 
plates’ The fringes were easily found, and sharp. Unfortu- 
nately the pump was not quite tight, so that on breaking the 
count of fringes at low pressures, it was difficult to state when 
the conditions had become isothermal. Hence the following 
results are rough: 


Temp. 19°7. 
No. of fringes, 0 30.) 67 .. 0 30 70 ) 40 68 
Exhausted to(p),75°1 41°83 0. 75:1 43°0 0 75°1 82:1 oem 
dp | dn, Pe oa olen One OG pe LO Lo 
XX 10°, See poogGO Or 4. Seb: “ST 1 i=) Sg-8 -60:0°% 


the mean value thus appears as X= 10-° x 5:88 for sodium 
light. The equations used are (1) nX = e(~ — 1) where n is 
the number of fringes counted, e the tube length and yu the 
index of refraction of air. Again 


p =C(u—1)8 (2) 
where p is the pressure, @ the absolute temperature and the con- 


stant C computed from normal conditions (76°™ and 0° (@) is 
(Maseart’s values) C = 952°6. Hence 


Cay cH n Kei ODI ie Cy-52 0D 
Gans) Co dasyo CS dn 


when & is constant. It is this assumption which is not quite 
guaranteed above. To obviate this in the following experi- 
ments, the total number of fringes were counted from exhaus- 
tion to plennm. Their number was definite to the fraction of 


(3) ——— 


a fringe. 
Temp. 19°3° C.;e =15°™ 
No. of fringes, 0 COO PEG Osa O), 6 u69"5 
Exhausted to (p), 75°8 On 7a:8 Oo VR OPS 
dp /dn, BEAT 000) eet SOOO. a | 51-090 


NSU, os SCR ak AMP Seren bess 


419 O. Barus—Methods in Reversed and 


These results are correct to $ per cent and are as close as the 
estimation of p, ce, &, and fractions of a fringe will warrant. 
If results of precision were aimed at, a long tube should of 
course be used. What was particularly marked in these ex- 
periments was the motion of fringes in the passage from any 
approximately adiabatic to isothermal conditions and on ap- 
proaching a plenum of air. 

Since the refraction depends on density there should not, 
apparently, be any motion at all; but the thin tube is always 
more nearly isothermal than the much larger barrel of the air 
pump. As a consequence there is residual expansion from the 
former to the latter. | ’ 

D. The behavior of an old Babinet compensator, placed 
nearly normal to one of the beams (see fig. 3), was peculiar, 
though the fringes were clear and easily 
controlled. The dimensions of the right- 
handed quartz wedge were roughly eali- 
pered and found to be: Length 4:2, thick- 
ness at ends, 1:°017 and 0°934°". Thus 
there is a grade of :083/4:°2 = -0193, or 
something over 1° of are. Anup and down 
displacement of 2:5" of this wedge was 
available behind the stationary counteract- 
ing left-handed wedge. 

The fringes were not uniform and they 
required an inclination to the vertical of 
the rulings of the grating G’. The fringes 
were evidently curved lines, intersected by 
the vertical strip within which they are 
visible. Consequently they appeared as in 
fig. 8, with linear elements in the middle, 
shortening into dots at either end of the strip. On motion of 
the compensator wedge, they moved toward or from the center 
of symmetry, as is also indicated in the figure. Tiled fringes 
were frequent. The most interesting feature however, was 
their alternate appearance and evanescence, in cycles. While 
the wedge was moved over 2°5°" of its length, 7 of these cycles 
appeared and vanished, each consisting of about 36 to 40 
fringes. The disappearance was not always quite complete, 
but the fringes could not be restored by any adjustment for 
coincidence of spectra. 

An attempt was nade to find the angle of the quartz wedge 
by the first method. Data, -0023, -0024, -:0024°", were found 
for the displacement of the micrometer per fringe. Hence 
(apart from dispersion) 

107° X 5°893 
~ 2X 5442 x 0024 
which as in the glass plate is again above the calipered value. 


Pome mn Hf) 
SSN NE 
~———— % 


ie 8) 
ea 


ee 
MELLEL 


= ‘022 radians 


a 


Non-reversed Spectrum Interferometry. _ 413 


In another somewhat thinner Babinet compensator, the con- 
stants were: Length, 3°35°™, thickness, small end 494°", large 
end -496™; the prism angle is a = °062/3'35 = ‘0185 radians, 
also about 1°. 

In this case there was no periodic phenomenon, but in its 
place the degree of longitudinal coincidence of the axes of the 
two spectra continually changed. ‘The fringes at once sharp- 
ened, however, on readjustment of either mirror, indicating a 
continuous small change of deviation, due to curvature, prob- 
ably, in the quartz wedge. In the preceding periodic case, no 
readjustment of deviation sufficed to restore the fringes. The 
wedge was now detached and used alone. In spite of the 
relatively large angle (1°), no difficulty was experienced in 
adjusting or controlling the fringes; but the face curvature 
just suggested appeared as before, so that readjustment for 
varying wedge angle was required from time to time. 

8. Micrometer displacement of the second grating.—In the 
preceding paper* it was shown that if the angle between the 
gratings G and G’ is ¢ and the angle between the mirrors 
M and NV (which in a symmetrical adjustment would be 
180° — (0, + 9,), @, and @, being the angle of diffraction at 
G and G’ for normal incidence at G) is decreased by a, so that 
the adjustment is non-symmetrical, then the displacement de of 
the grating G’, per fringe, will be very nearly 


ee d cos’ 6, 
~ 2(a — ¢) sin 6, 


ifaand ¢@ aresmall. Here a is effectively the angle between 
the mirrors J/ and iV; since, if J/ is rotated 180° on the line 
of symmetry (normal to the grating G), the two mirrors would 
intersect at an angle a. The result of fore and aft motion thus 
depends on the angle a—g@, and ifa=@¢, de—o, per 
fringe; i. e. fore and aft motion would produce no result. This 
is necessarily the case when but a single grating is used, as in 
the earlier methods. In the case of two gratings, however, it 
is not only difficult to make a perfectly symmetrical adjust- 
ment of mirrors and grating, but it would not be of any special 
advantage. Hence the fore and aft displacement e of the 
grating G’ will probably be accompanied by a slow motion of 
the fringes, from which the angle a — ¢ may be computed. 
The following experiments were made with the grating G’ 
on a micrometer slide, moving normally to the face of the 
grating. With the mirrors, ete., placed so that optical paths 
were nearly equal, the adjustment screws on J/ and JV sufticed 
to bring the fringes strongly into view. Successions of 3 and 


* This Journal, xlii, p. 71, 1916, $4. 


414 C. Barus—Methods in Reversed and 


of 4 fringes were tested, as these required an adequately large 
displacement of the micrometer, which was moved both for- 
ward and backward. The results (omitting details) were : 


Mean de 
displacement 
No. of fringes per fringe 
(mereasing) 20. . 228 ‘0088°™ 
(increasing). .2.4/22.8 4 “008so0™ 
(decreasing) ....-.--- 4 0073" 


The mean of the three results is de = -008™ per fringe. The 
individual data were not smooth, because the micrometer plaged 
between the mirrors Jf and J, is in an inconvenient position 
for manipulation. The different sets of values, moreover, cor- 
respond to different adjustments and therefore to slightly 
different values of a—@¢. As an order of valnes only is 
wanted, it was not considered worth while to remedy the 
deficiencies. 

In accordance with the equation given, if d¢—-008™, 
r% = 589 x 10-° em., 0, = 20° be inserted, 


d cos’ 6, 
o> P= ay Bin, 


The adjustment is thus about half a degree out of symmetry, a — 
result which in ease of improvised apparatus is inevitable and 
moreover without significance in the precision of the method. 

9. Prism Method. Reflection.—The grating G was now 
removed and replaced by a silvered prism (as shown in fig. 9). 
A small prism angle, ¢, is essential (6 = 18°, about), as a large 
divergence of rays would not be accommodated on the inter- 
ferometer, fig. 3. The fringes were found without dithculty, 
in the second order, the arc lamp being used. They are also 
easily distorted, if the edge of the prism is not parallel to the 
rulings of the grating. In such a case the symmetrical arrow- 
shaped forms become one-sided and, as it were, curved or 
faintly fringed beyond the limits of the strip. To get the best 
adjustment, the lamp should shed about the same amount of 
undeviated light from both faces of the prism, on a screen 
temporarily placed behind it. The illuminated strips on the 
grating must coincide to the eye, while making the fore and 
aft adjustment. Finally the grating is to be slowly rotated on 
the axis normal to itself, until fringes of satisfactory shape and 
size appear. Naturally this is done throngh the telescope and 
a readjustment of the longitudinal axes of the spectra is neces- 
sary after each step of rotation. Fringes so obtained are as 
good as those obtained by any other method. 

The range within which the fringes are sharp is small, not 


=-0095 radians = 54°. 


Non-reversed Spectrum Interferometry. 415 


exceeding 2 millimeters of displacement of the micrometer 
mirror, JZ. <A partial reason for this will appear from fig. 9 
and results from the fact that the illumination on the grating 
due to M, moves laterally across the stationary strip due to JV. 
Clearly if the latter is also on a micrometer, it might, in turn, 
be displaced in the opposite direction to Jf and restore the 
fringes to full brilliancy. The range in this case may be in- 


Fie. 9. 


creased, till either illuminated strip gets beyond the edges of 
the grating. 

If the prism angle is ¢ and the angle of diffraction for normal 
incidence is 0, the angle, 6, between the incident and reflected 
ray at JZ is 


8=60—¢ 


Thus ¢ tan 6/2 is the displacement of the strip of light on the 
mirror J, if ¢ is the normal displacement of the latter. Hence 
the corresponding displacement, x, on the grating is 7 = 2e 
sin (6/2)/cos 0. 

If d be the distance from the prism to the light spot reflected 
on J, and ¢ the distance from there to the bright spot on the 
grating, @ may be computed as 

‘ 2Xre 
sind = 2 
for the spectra are in the second order. 

The data are: 


TO poe Ose aro—se0°™ + ¢ 90 4em | JP 2900) x 10° ems 


416 OC. Barus—Methods in Reversed and 


Whence 
= 18° 13', 6= 36° 6’, 8= 17° 54’, 
and 
*50 X °1556 
og) atta ae! ——— = -996°m 
: -808 e 


if e=-25", as found. Thus the rays of the same origin, or 
rays capable of interfering, are found in a vertical strip on the 
grating not more than 1 millimeter wide. It is interesting to 
note that the fringes vanish by becoming coarser and wider 
corresponding to the narrowing of effective edges in contact. 

The attempt to produce these fringes with homogeneous 
(sodium) light and a wide slit again failed, although much 
time was spent in the endeavor. Even with a narrow slit and 
accentuated sodium lines (impregnated arc), the phenomenon 
may be produced between the doublets, however close together, 
but it fails to appear with the same adjustment when two cor- 
responding lines coincide. I was only able to produce it in a 
continuous spectrum between the two doublets, and with a fine 
slit. It is important to ascertain the reason. 

Both mirrors, J/ and JV, are now placed on micrometers 
moving nearly normal to their faces. Beginning with a coin- 
cidence of the illuminated strips on the grating, the JZ mi- 
crometer was moved until the fringes disappeared. The V 
micrometer was then moved in the same direction, until the 
reappearing fringes passed through an optimum and _ finally 
vanished, in turn. Thereafter the J/ micrometer was displaced 
again, always in the given direction and the same cycle re- 
peated; etc. It was possible to pass through about 8 cycles 
with each micrometer, before the illumination reached the 
edge of the grating, each cycle corresponding to a displace- 
ment of about 2 millimeters for a single mirror; but a total 
displacement of 275°" was registered which would obviously 
have been increased much further if the grating had been 
wider. The following data gives a concrete example : 


Position Advance Position Advance 

of N of N Remarks of N of N Remarks 
DINOS Se ee Broad eee ee ue : 
9:90 me i | I 15d ne Vertical lines 
ee -99°m Madvanced | .--- 21°" M advanced 
aie ae IA iy Te6 pipe t Vertical lines 
1°98 thls arrows 1°37 avai, oN 
De 24 M advanced | __-- ile7 M advanced 
1-98 Rng Upright lines etc. 
1°75 a inclination 

i changed 


i 23 M advanced 


Non-reversed Spectrum Interferometry. ALT 


As both mirrors move in the same direction, the two illu- 
minated strips on the grating gradually separate, until they are 
quite distinct. Meanwhile the fringes pass from the original 
sagittate forms to very fine hairlike striations, with rotation. 
Whereas the part of the spectrum within which the former 
occur is less than the distance apart of the sodium lines 
(doublets), the hairlines are visible within a strip of spectrum 
many times as broad as the sodium doublet. Ten such lines 


Fras. 10, 11, 12, 13. 


44 


may be visible. In good adjustments the sagittate forms are 
seen to be a nest of very eccentric, identical hyperbolas, as in 
fig. 10, arranged or strung on the same major axis. The ver- 
tices, a, are therefore thick and pronounced, but taper rapidly 
down into hairlines, 0, 6’, on both sides. Frequently but half 
of the coarse vertices, a, abundantly fringed on one side, d or 
b’, appear. Nevertheless this does not seem to be an exhaus- 
tive description of the phenomena, for it is not uncommon, 
when partial hyperbolas appear, to find the striations (which 
are always faint) in the same direction on both sides, as in 
fig. 11; i.e. the striations are apt to be nonsymmetrical on 
the two sides, as if they constituted a second diffraction 


418 OC. Barus—Methods in Reversed and 


phenomenon superimposed on the first phenomenon. Roof- 
shaped forms, fig. 12, strongly dotted, are also common, often 
irregularly awned. 

Figure 13 may be consulted to further elucidate the subjects 
under consideration. G is the grating, PP’ the principal 
plane of the objective of the telescope, a and 6 are two rays 
interfering at the focus f, and leaving the grating parallel and 
symmetrically placed to the axial ray of. The passage of the 
coarse sagittate phenomena into the hairlike striations, as @ 
and 6 move farther apart, may then be accounted for in accord- 
ance with the general theory of diffraction ; i. e. if the distance 
apart of @ and 6 is d and the principal focal distance of is 2, 

Cah. 

fase & 
where 2 is the distance between the two fringes of wave- 
length A. Hence z will increase as d decreases, agreeing with 
the effect of fore and aft motion, or with the effect of simul- 
taneous, large (2°5°") displacement of both mirrors, neither of 
which destroys the symmetry of the interfering rays. 

The motion of a single mirror, J/ or J, for instance, does 
destroy the symmetry, and it was shown in §8 that the limit- 
ing range of displacement of 25°" moves either a or 6, :096™ 
out of symmetry. The interferences thus vanish without 
much changing in form or size, and vanish in all focal planes. 

The breadth of the blades of light wa’ and 0d’, figure 13, 
capable of interfering is thus x on the grating and 


2 COS 0 = :096 <-808 = 078° 


normally. Since the rays are parallel after leaving the colli- 
mator, this would be about half the breadth of the effective 
. beam on the objective of this appurtenance. Thus 2 x ‘0776 
= ‘155°, increased by the width of the refracting edge of the 
prism is the width of the strip of white light, which after 
separation by the knife edge of the prism, furnishes the two 
component beams which potentially interfere on recombination. 
It is reasonable to suppose that the elements of these beams 
come from a common source and that the width in question is 
produced by the diffraction of the slit. 

This datum is more appropriately reduced to the angle at 
the slit, a, within which the rays, capable of interfering with 
each other after the interferometer cleavage, lie. As the colli- 
mator used was J = 22° from slit to lens, 


a = 22 cos O/] = 155) 22,— “0070, 
Hence the angular width of the wedge of white light, with its 
apex at the slit of the collimator and containing all the rays 


which can mutually interfere, is about ‘007 radians, or less than 
half a degree of arc. One would infer that a long (7) collimator 


Non-reversed Spectrum Interferometry. 419 


(i. e., one with weak objective) is advantageous, as the blade of 
parallel rays issuing is proportionately wide and the range of 
displacement at J/ or JV, larger. Similarly divergence subse- 
quently imparted by dispersion (prism, grating), before the 
rays reach the mirrors, W/, JV, should have the same effect. 
The results obtained for dispersion bear this out, but not those 
for a long collimator. Moreover the width of the slit, so long 
as the Fraunhofer lines do not vanish, is of no consequence. 
It thus seems tenable (to be carefully investigated below), that 
the positive effect of dispersion has a deeper significance, bear- 
ing directly on the structure of the interfering wave trains: 
i. e., the length of the codrdinated, uniform wave train is 
greater, as the dispersion to which the wave train has been sub- 
jected is greater. Two parts of it will therefore fit over a cor- 
respondingly longer range of path difference. 

A number of other results point in the same direction. Thus 
I may instance the impossibility of obtaining fringes with 
homogeneous light and a wide slit, whereas two identical 
sodium lines (2, and D,’), superposed, show the interferences 
strongly. The lines actually become helical in shape and 
much broader. The range of displacement of JV may be 
decreased from -25°™ to -10°", by narrowing the beam emerg- 
ing from the collimator with a slotted screen, while the fringes 
themselves are coarsened by this process. With the screen 
removed the fringes are not only sharper and finer, but appar- 
ently they may be seen to slowly move laterally across the fidu- 
cial sodium lines. This is in accord with the increased range 
of displacement of the mirror. The observation, however, is 
complicated by the fact that the sodium doublets are not quite 
in the same focal plane. The fringes must, in a reduced case, 
lie midway between them, in the line of symmetry of the 
spectra. 

10. Prismatic Refraction, with grating.—The method 
indicated in tig. 14 was next tested for small distances and the 
experiments begun in the third order of spectra of the grating 
G. The refracting prism, /, was a small right-angled sample, 
with faces only about 1° square; but it sufficed very well. Its 
distance from the grating being about 13, and the illuminated 
spots on the mirrors 18°8™ apart, the mirrors were nearly 
normal to each other. In fact, as @ in the third order is about 
62° and 2’ about 28°, 6 = 34° and o = 90°. 

Hence on displacing the micrometer mirrors, JZ or JV, the 
illuminating strips move relatively rapidly across the face of 
the grating, G. Nevertheless the fringes are easily found and 
controlled. Their range of visibility is larger than in the cases 
of the preceding paragraph. They remain in view for normal 
displacement of Mot 3 to 4 millimeters, passing from hairlike 


420 Non-reversed Spectrum Interferometry. 


striations, through sharp arrows, back to the hairlike forms. 
The range has thus been increased by the dispersion. The 
arrows are of the slender type, with re-entrant sides and part 
of the outline accentuated. 

In the second order of spectra from G, the phenomena were 
much the same, but far more brilliant. The arrows were now 
evenly wedge-shaped and very slender. The fringes entered 
as nearly vertical hairlike striations and after passing the 
optimum vanished as inflated arrows. The range of visibility 


Hig, 14; 


was as before about 3°5 millimeters so that the change of order 
has not had any further marked effect, such as might be 
anticipated. As in the preceding paragraph, if the impinging 
collimated beam is narrowed, the range of visibility decreases ; 
in fact the arrows themselves are reduced to slightly oblique 
lines. Within the limits given the fringes are well adapted 
for interferometry. 

First order spectra are not available because of the large 
value of 2’ in the case of the right-angled prism. 

Taking the results of the last two paragraphs together, the 
increase of the range of displacement is due to the dispersion 
of the prism. The breadth of the pencil, diffracted at the slit, 
after leaving the collimator and prism, increases. It was 
shown in the earlier report that inversion of spectra on a 
longitudinal axis does not preclude the possibility of interfer- 
ence. Taken as a whole therefore, the present results have a 
direct bearing on Huyghen’s principle. 

[To BE CONTINUED. | 


Brown University, 
Providence, R. I. 


J. G. Dinwiddie—Hydrofluoric and Fluosilicie Acids. _ 421 


Arr. XLIII.—A Study of the Separation of Hydrofluoric 
Acid and Fluosilicie Acid ; by J. G. Dinwivpre. 


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


Tue work to be described in this article was done with a 
view towards finding some satisfactory method for the analysis 
of a solution containing both hydrofluoric and fluosilicie acid. 

The importance of an accurate method for this determination 
lies in the fact that commercial hydrofluoric acid very often 
contains as an impurity fluosilicic acid, which is of no use in 
etching, and which is a nuisance in analytical work. The value 
of a solution of hydrofluoric acid is obtained often by direct 
titration with alkali using phenolphthalein as indicator. Under 
these conditions each molecule of fluosilicie acid, H,SiF,, 
requires six molecules of alkali for neutralization and, there- 
fore, will be counted as six molecules of hydrofluoric acid. 

Almost the only attempt to discriminate between these two 
acids when present together has been made by Katz,* who 
titrates first in water solution and then in alcoholic solution 
together with potassium chloride in order to get a differential 
equation. The reaction in water solution is 

(a) H,SiF, + 6NaOH = 6NaF + Si(OH), + 2H,O 
and in 50 per cent alcoholic-potassium-chloride solution, 

(6) H,SiF, + 2KCl + 2NaOH = KSiF, + 2NaCl + 2H,0. 


The hydrofluoric acid requires the same quantity of alkali for- 
neutralization whether titrated in water or in alcohol solution, 
while the fluosilicic acid requires one-third of the alkali in 
aleoholic-potassium-chloride solution that it does in water solu- 
tion. 

Were there no complications in the above reactions, the cal- 
culation of the results would be as follows :— 

Let « be the volume of alkali required for neutralizing the 
hydrofluoric acid, and let y be that required by the fluosilicic 
acid in the alcoholic solution. Then 3y will be required by 
the fluosilicie acid in water solution. 

Then, a + 3y == ce. req. in water titration =a 

x+ y=ce. req. in alcohol titration = b 


oy 2a =) (@ — 6)” 
Thus the difference between the amount of alkali required for 
the water and for the alcohol titration is equivalent to two- 
thirds the amount which would be required for the fluosilicic 
acid alone in water solution. 

* Katz, Chemiker Zeitung, xxviii, 356 and 387, 1904. 


Am. Jour. Sct.—Fourts Series, Vou. XLII, No. 251.—Novemper, 1916, 
29 : 


422 J. G. Dinwiddie—Hydrofluoric and Fluosilicie Acids. 


In testing this method on a mixture of known concentra- 
tion, Katz finds that the aleoholic-potassium-chloride titration 
requires considerably less than the theoretical amount of alkali. 
He explains this result by assuming that some of the free 
hydrofluorie acid is absorbed by the precipitated potassium 
fluosilicate and is thus kept from being neutralized. Using 
normal and twice-normal alkali for titrations, he gets results 
which tend to indicate that, for very small amounts of fluo- 
silicic acid, each molecule carries down with it one molecule of 
hydrofluoric acid, while for larger amounts three molecules 
carry down two of hydrofluoric acid. 

On this basis he makes out a sliding factor to be used accord- 
ing to the relative proportions of the two acids present. For 
the fluosilicic acid content, if the difference between the water 
and the alcoholic titration is 


5% or less of the water titration, multiply it by (0576), 


5-10% of the water titration, multiply it by (058-0595), 
1O= 12% (74 its 66 Co 66 ( 06— 061), 
over 12%, 73 (74 (79 13 74 co 6 ti: 0617). 


These factors are calculated on the basis of 2 N alkali. 

Since Katz uses twice-normal alkali, and uses only from 
three to eight cubic centimeters in a number of the titrations, 
there is ample room for very large percentage errors. 

Before attempting to go farther, it was thought advisable to 
repeat some of Katz’s work as well as to compare the titration 
of pure fluosilicie acid in water and in alcoholic-potassium- 
chloride solution. 

For a comparison of the two titrations of the pure acid, 
three samples were used: No. 1 was made by suitable dilution 
of Baker and Adamson’s commercial fluosilicic acid ; Nos. 2 
and 3 were made by treating silica and calcium fluoride with 
concentrated sulphuric acid, passing the evolved silicon tetra- 
fluoride through a double coil of glass tube (water-cooled) and 
then into water where the fluoride of silicon was decomposed 
into fluosilicic acid and silica. 

The following table shows the results of these titrations : 


TABLE I. 


Alkali used was approx, 0°33 normal NaOH. 


H,SiF, NaOH req. NaOH req. NaOH req. 
grm. of solution (in alcohol) (in water) (cc. per gram) 
ce. ce. 
a 76774 42°] 5'48 
1 6°6227 36°3 5°481 
pl 8°5302 15°9 1864 


| 84770 Lot7 1-852 


J. G. Dinwiddie—Hydrofluorie and Fluosilicie Acids. 423 


ec. of solution. 


[ 10 35°78 
| 10 35°79 
10 35°80 
Nene it 35°80 
| 10 12°27 
( 10 12°30 
HaSiF's NaOH req. NaOH req. NaOH req. 
ec. of solution (in alcohol) (in water) (cc. per gram) 
ce. ce: 
( 10 38°28 
10 38°30 
1) ee 58'15 
ato 1318 
| 10 13°20 
{ 30 39°85 


With each of the three samples, the alcoholic titration requires 
from one to three per cent more than one-third of that required 
in the water titration. 

This result might be explained in either of two ways: that 
the fluosilicie acid, as sold commercially and as made in the 
Pentield-Offermann method for determining fluorine, may 
always contain small amounts of free hydrofluoric acid, or the 
solubility of potassium fluosilicate may be sufficient to allow it 
to be appreciably acted upon by the alkaliused. The latter of 
these two explanations seems more plausible; for when the 
end-point has been reached, as shown by the pink of the 
phenolphthalein, the color fades out upon short standing, and 
continues to disappear after successive additions of alkali suf- 
ficient to bring back the pink. Upon heating the mixture, the 
hydrolysis goes much farther and practically all of the potas- 
sium fluosilicate is converted to fluoride and silica. 

To test Katz’s theory of the absorption of hydrofluoric acid 
by potassium fluosilicate, 10°° portions of fluosilicie acid were 
mixed with varying amounts of hydrofluoric acid and these 
mixtures were titrated, after addition of alcohol and potassium 
chloride, with approximately 0°3 normal sodium hydroxide. 
Since the amount of alkali required for each acid separately 
was known, it was easy to calculate what the mixture should 
require, were there no complications. These results are shown 
in Table II. 

The fluosilicic acid used required for 10° in alcohol, 10-77% 
of standard alkali. Upon addition of increasing amounts of 
hydrofiuoric acid, that unaccounted for seems to reach a 
maximum which is equivalent to approximately 1°3° of the 


494 SJ. G. Dinwiddie—Hydrofluorie and Fluosilicie Acids. 


TABLE II. 
H.SiF', HE 
used used KCl NaOH "NaOH 
ce. of grm. of added req. theory Diff. 
solution solution grm. ee. ce. ce. 
10 4°8818 3 19°91 PINOT 1'16 
10 5°6151 VW 21°49 22°62 1°13 
10 10°2629 1 aoe 2 32°42 1°30 
10 12°2639 i Sasa 36°65 1°28 
10 16°3859 1 4401 45°34 1°33 


alkali used. This would give a ratio of absorption of one 
* molecule of HF for about 4 of H,SiF, instead of a ratio of 1:1 
as Katz* found under these conditions. 

If the precipitate of potassium fluosilicate formed in the 
presence of free hydrofluoric acid consisted entirely of potas- 
sium fluosilicate and of free hydrofluoric acid which it absorbed, 
then by determining the potassium in it, a measure of the 
fluosilicic acid originally present would be obtained. Or if a 
known amount of potassium chloride were added for precipita- 
tion and that remaining in the filtrate determined, the difference 
would be that which was used up in forming potassium fluo- 
silicate. For this purpose a standard solution was made of 
which 10° contained 0°5090 grams of potassium chloride. 
Table III gives the results of precipitating potassium fluo- 
silicate from a solution of fluosilicie acid with and without 
hydrofluoric acid being present. 


; TaBe III. 

KCl H.SiF, KClin HE K.SiF', KCl H.Sifs KCl by Total 

used used filtrate used prec. equiv. of equiv. filtering KCl. 

grim. grm. grm. grm. of° grm. K.SiF’, an 

solution grm. decomp. | 

a. 0°5090 0°2634 0-2381 calc. 22 0°4006 0:27085 OR6227 Bene ; 
b. 075090 0°2684 0°2422 38 0°3979 0°2687 O:2601)) See 
ec, 0:5090 0°2684 0°2414 ne 0°3991 0°2695 072609 Rees 
d. 0°5090 0°2634 0°2258 calc. 10 0°4196 cale. 0°2832 calc, 0°2748 —___. 
e, 0°5090 0°2634 0°2288 10 04169 cale. 0°2824 0°2725 +2785 


It will be seen that a, b, and ¢, each give a precipitate 
equivalent to a little less than the theoretical value for fluo- 
silicic acid. This would be expected on account of the 
appreciable solubility of potassium fluosilicate. 

In d and ¢, where about 10 grams of hydrofluoric acid were 
added, in each case the filtrate contained considerably less of 
potassium chloride than would have been the case if no 
potassium had been used up except by fluosilicie acid in form- 


*P. 422. 


J. G. Dinwiddie—Hydrofluoric and Fluosilicie Acids.. 425 


ing potassium fluosilicate. In ¢ the precipitate weighed four 
or five per cent too much. It was decomposed by ammonia 
and the solution was filtered to get rid of asbestos and then 
aciditied with hydrochloric acid and evaporated. The residue 
was heated with hydrochloric acid to drive off all silica and 
fluorine and to convert the entire residue to potassium chloride. 
The residue of potassium chloride so obtained was found to 
weigh several per cent more than if the potassium had been 
present in the precipitate only as potassium flnosilicate. 

The precipitate of potassium fluosilicate formed in the pres- 
ence of free hydrofluoric acid contains an excess of potassium 
salt as well as free hydrofluoric acid, and it is evident that the 
fluosilicic acid in a mixture of the two acids cannot be esti- 
mated by determining the potassium in the precipitate or in 
the filtrate. 

Since the fluosilicie acid carries down with it free hydro- 
fluoric acid and fluorides when it is precipitated in the presence 
of these, it was determined, if possible, to precipitate the hydro- 
fluoric acid as some insoluble fluoride, and, having thus removed 
it from the solution, to determine the fluosilicic acid remaining, 

Accordingly, to a mixture of fluosilicic and hydrofluoric 
acids was added a neutral solution of calcium chloride sufficient 
to precipitate as calcium fluoride all of the fluorine present as 
hydrofluoric acid. Next was added potassium chloride suffici- 
ent to form with the fluosilicic acid, potassium fluosilicate, and 
to the mixture was added alcohol to make the final solution 
consist of 50 per cent alcohol. The precipitate obtained under 
these conditions was found very difficult to filter, so the mix- 
ture was made up toa definite volume and after allowing to 
settle the clear supernatant liquid was decanted through a dry 
filter. Aliquot parts of the total volume were then titrated 
with standard alkali. 

If all of the hydrofluoric acid were actually precipitated as 
calcium fluoride and all of the fluosilicic acid as potassium 
fluosilicate, then for each molecule of HF originally present 
there should be in the filtrate one molecule of hydrochloric 
acid, and for each molecule of fluosilicic acid two molecules of 
HCl, according to the reactions, 


2HF +CaCl,—>CaF, + 2HCl 
H,SiF, + 2KCi —> K,SiF, + 2H. 


Upon titration of this filtrate, therefore, the alkali required 
should be equal to that which would be required in water solu- 
tion for the hydrofluoric acid originally present, plus one-third 
of that for the fluosilicie acid originally present. Thus the 
difference between the original water titration and the titration 


426 J. G. Dinwiddie— Hydroftuoric and Fluosilicie Acids. 


of this filtrate should be just two-thirds of the alkali required 
in the reaction, 


H,SiF, + 6NaOH = 6NaF + Si(OH), + 2H,0, 


and so the amount of fluosilicie acid could be calculated. 

Titrations made in this manner all tended to run low to 
about the same extent as those made after simply adding potas- 
sium chloride and alcohol to the mixture of the two acids. 
The explanation of this is probably that an insoluble compound 
of potassium fluosilicate and hydrofluoric acid is formed even 
in the presence of soluble calcium chloride. 

In a second series of experiments, to a solution of the mixed 
acids calcium chloride was first added, and to an aliquot part of 
the clear liquid was added potassium sulphate and alcohol. 
The potassium ion should form potassium fluosilicate, and the 
sulphate ion calcium sulphate which with 50 per cent alcohol 
is sufficiently insoluble not to decompose the potassium fluosili- 
cate when the solution is made neutral with alkali. The results 
here were low to about the same extent as in the former series 
of experiments. 

This method of making a mixture containing a precipitate 
up to a definite volume and using an aliquot part of the clear 
liquid is not to be recommended unless the precipitate is very 
small and it is impossible to filter and wash it ; therefore, other 
insoluble fluorides such as lead fluoride were tried, but the 
precipitates were just as hard to filter and no better results 
were obtained. 

Since other methods failed, and since calcium fluoride seemed 
to be more suitable for the removal of fluorine than other 
fluorides because of its greater insolubility, it was determined 
to find some method of precipitating this compound in a form 
capable of being filtered. 

The expedient of Rose, which is to precipitate calcium car- 
bonate together with calcium fluoride, was obviously of no 
value since the carbonate would decompose the fluosilicate 
and form calcium fluoride. Calcium sulphate, while being 
rather insoluble in water, is more soluble than calcium fluoride. 
Therefore it was thought that if an excess of pure powdered 
calcium sulphate were added to a solution of sodium fluoride 
the more insoluble calcium fluoride would continue to form at 
the expense of the sulphate until all of the fluoride was pre- 
cipitated as calcium fluoride. There should then remain a pre- 
cipitate of calcium fluoride mixed with the excess of calcium 
sulphate. 

Upon trial, the precipitate formed in the above manner by 
the use of calcium sulphate was found to be quite easy to filter 
and wash, obtaining clear filtrates. A solution containing 


J. G. Dinwiddie—Hydrofluoric and Fluosilicic Acids. 427 


hydrofluorie acid and fluosilicic acid was now treated with cal- 
cium sulphate, and, after stirring well and allowing to stand, 
the precipitate was filtered and washed. To the filtrate was 
added aleohol and potassium chloride, and then the free acid 
was neutralized with standard sodium hydroxide. The results 
here were low, just asin the previous attempts, and the explana- 
tion is very probably that calcium fluoride is sufficiently solu- 
ble in the free acid present to dissolve partially and to form in 
the filtrate free hydrofluoric acid upon addition of the alcohol 
and this would then be absorbed by the potassium fluosilicate. 
If sodium acetate is added in order to decrease the acidity of the 
solution before addition of calcium sulphate, then the filtrate 
continues to require alkali very much beyond the amount 
required by theory. It is probable that in very weakly acid 
solutions the calcium sulphate acts on the fluosilicic acid to 
form calcium fluoride, and this would account for the excess 
of alkali required as follows : 


H,SiF, + 3CaSO, + 4H,0 —>Si(OH), + 3H,SO, + 3CaF,. 


Finally the method of Stolba* for determining the water of 
crystallization in crystallized fluosilicates was tried. This 
method was to heat a weighed amount of the material, e. g. 
CuSiF’,.XH,O with a weighed amount of magnesium oxide. 
The reaction is as follows: 


CuSiF, + XH,O + 3MgO = CuO + 3MgF, + SiO? + XH,0, 


and the loss in weight, therefore, represents the water of crys- 
tallization. 

To a known weight of magnesium oxide in a platinum 
crucible was added a solution containing a known amount of 
fluosilicie acid and the mixture was well-stirred. The reaction 
should be 


(a) H,SiF, + 3MgO = 3MeF, + SiO? + H,0, 


and upon evaporating to dryness and heating to redness, there 
should remain (according to Stolba) only 3MeF, + SiO*. 
With the same weight of fluorine in the form of hydrofluoric 
acid only 3MgF’, would remain according to the equation 


(6)  6HEF +3MgO0 = 3MeF, = 3H,0, 


knowing the total amount of fluorine that in the form of 
hydrofluoric acid and of fluosilicic acid in a mixture could be 
calculated by the increase in weight of the magnesium oxide 
used. However, upon heating the mixture formed as in equa- 
tion (a) to a temperature somewhat below redness, the increase 
in weight was considerably more than required by theory, 


* Stolba, Jour. prakt. Chem., cii, 2. 


428 J. G. Dinwiddie—Hydrofluoric and Fluosilicie Acids. 


showing that all of the water had not been driven off. Upon 
increasing the heat until a low red was reached, there was a 
continued decrease until the loss in weight was much greater 
than that required to account for the loss of water. Therefore, 
it was found that this method is of no use for distinguishing 
between hydrofluoric and fluosilicie acids, and its value in 
determining the water of crystallization as given by Stolba is, 
at least, very doubtful. 

For the determination of fluorine in soluble fluorides, Greef* 
takes advantage of the fact that ferric chloride forms with 
sodium fluoride an insoluble complex fluoride, Fef’,.3NaF, 
which does not give a red color with potassium sulphocyanide. 
By addition of a large amount of sodium chloride, the complex 
fluoride is made sufiiciently insoluble, and the end-point of the 
reaction is obtained by adding 5 em* of a 5 per cent solution of 
potassium sulphocyanide and 20° of a mixture of equal parts 
of alcohol and ether. When ferric chloride has been added in 
quantity sufficient to form the sodinm-iron-fluoride, the next 
drop after vigorous shaking gives a pink color to the alcohol 
ether layer. Knowing the concentration of the ferric chloride, 
the amount of fluoride taking part in the reaction is readily 
calculated according to the equation 


6NaF + FeCl, = FeF,.3NaF + 3NaCl. 


The results of this method are quite accurate provided that 
care is used in detecting the first permanent pink, that con- 
ditions of concentration of the different titrations are uniform, 
and that the solution of the fluoride as well as the ferric 
chloride standard be strictly neutral. 

Since the presence of free acid causes a marked shifting of 
the end-point of this reaction, it was thought worth while to 
make a series of titrations, varying the amount of free hydro- 
chloric acid in order to ascertain the effect on the quantity of 
ferric chloride necessary to give a permanent pink. Table IV 
gives the results of these titrations. 

From the results as shown in this table, it can be seen that 
very small amounts of free acid cause a relatively large decrease 
in the quantity of ferric chloride solution required. Thus in 
a volume of approximately fifteen cubic centimeters only 0-1° 
of normal hydrochloric acid causes a decrease of nearly four 
per cent in the result, while as much as 2” causes a difference 
of almost 50 per cent. In numbers 12 and 13 a small 
amount of acid was added and then the solution was neutral- 
ized before titration just to ascertain how accurate the deter- 
mination could be made when the solution was acid to begin 


*Greef, Berichte, xlvi, 251, 1913; see also Guyot, Comptes Rendus, 
xxi, 274, 1870. 


J. G. Dinwiddie—Hydrofluoric and Fluosilicie Acids. 429 


TaBie IY. 
NaF NaCl KSCu N.HCl FeCl, sol. 

No ee. grm. cc. 0% ce. Ces 

1 10 10 5 0:0 11°50 

2 10 10 5 0:0 11°55 

3 10 10 5 0:0 11°53 

4+ 10 10 5 Ol 1111 

5 10 10 5 0-2 10°63 

6 10 10 5 Or4 10°10 

7 10 10 5 0°6 9°66 

8 10 10 5 0'8 8°88 

9 10 10 5 a) 8°39 
10 10 10 5 2:0 5°90 
11 10 10 5 4:0 3°45 (?) 
12 10 10 5 1° (then 11°65 

neutralize) 

13. 10 10 5 tary Meanie arpa la L15X0) 
14, 20 20 10 0:0 23°12 
15. 20 20 10 0:0 23°14 


with. The results show that with proper care a solution of 
alkali fluoride can be obtained nearly enough neutral to give 
quite an accurate determination. 

Greef claims that by the use of the ferric chloride method 
he can estimate the amount of sodium hydrogen fluoride which 
is present in a mixture containing sodium fluosilicate. Greef’s 
directions for this determination are as follows: ‘‘Titrate a 
weighed portion of the mixture in hot water solution with 
standard sodium hydroxide using phenolphthalein as indicator. 
In this now neutral solution, determine the total fluorine by 
titration with standard ferric chloride solution as described 
above. Dissolve another portion of the mixture in a small 
volume of water and, after addition of alcohol until the con- 
centration is approximately 50 per cent in alcohol, add about 
one gram of potassium chloride and titrate with the standard 
sodium hydroxide until neutral to phenolphthalein.” In cal- 
culating the results from data obtained by following the above 
directions, Greef assumes that the alkali used in the alcoholic 
titration is a measure of the total free hydrofluoric acid in the 
mixture and that in the water titration for each equivalent of 
sodium hydrogen fluoride, one equivalent of alkali is required, 
while for each equivalent of sodium fluosilicate four equivalents 
of the alkali are used. From the total fluorine as found by the 
ferric chloride titration and from the results obtained in the 
water and in the alcohol titration, Greef calculates the content 
of the original material in sodium fluosilicate, sodium fluoride 
and sodium hydrogen fluoride according to the following 
equations : 


430) SJ. G. Dinwiddie— Hydrofluorie and Fluosilicie Acids. 


In the water titration : 
(a) NaHF, + Na,Sif, + 5NaOH = 8NaF + Si(OH), + H,O 
and in the aleoholic titrations : 


(0) NaHF, + Na,SiF, + 2KCl + NaOH = 2NaF + K,SiF, 
+ NaCl 


and the ferric chloride titration for total fluorine : 
(c) 3(8NaF) + 4FeCl, = 4(3NaF-FeF,) + 12NaCl. 


If there were no complications, it is easily seen that the alkali 
used in equation (2) would be equivalent to the sodiudm 
hydrogen fluoride present, while that used in (a) less that used 
in (6) would be a measure of the sodium fluosilicate present. 

However, as has been shown by Katz* and also in the 
present paper, when a mixture of free hydrofluoric acid and of 
fluosilicie acid or sodium fluosilicate is titrated in alcoholic 
potassium chloride solution, a marked absorption of free acid 
takes place. On this account the titration as in (0) can not be 
a measure of all the sodium hydrogen fluoride present in such 
a mixture as that described by Greef. 


* Katz, Chemiker Zeitung, xxviii, 356, 387, 1904. 


SCIENTIFIC INTELLIGENCE. 


J. Cxrrmisrry AND Puystcs. 


1. Zhe Occurrence of Germanium in Zine Materials.—The 
presence of small quantities of the very rare metal germanium in 
zine ores has been observed spectroscopically in several instances, 
but in most cases the amounts present were too small to serve as 
practical sources of the element. G. H. Bucnanay, of the New 
Jersey Zinc Company, has announced that in some material at his 
disposal germanium was found in sufficient quantity to be readily 
detected by the ordinary chemical reagents. The material is a 
by-product from a Wisconsin blende, but its exact nature is not 
disclosed at present. The presence of an unusual element had 
been indicated in the course of analysis, and it was found to give 
in acid solutions a sulphide soluble in ammonium sulphide. hen 
several portions of one hundred grams each of the material were 
treated with concentrated hydrochloric acid and the resulting 
solutions were distilled to about one-half volume in the presence 
of a current of chlorine to keep the arsenic in the pentavalent 
state. The distillate contained the unusual element. Upon 


Chemistry and Physics. _ 431 


dilution with a small amount of water this liquid gave with 
hydrogen sulphide a white flocculent precipitate. If, however, 
the distillate was greatly diluted the precipitation was slow and 
incomplete, but in this case the addition of strong hydrochloric 
acid caused an immediate precipitation. The white sulphide was 
soluble in ammonia and in alkaline sulphide solution. Upon 
ignition the sulphide gave a white oxide. It was found further 
that the element guve a sparingly soluble double potassium 
fluoride. These reactions agree with the properties ascribed by 
Winkler to germanium. Two portions of the sulphide were col- 
lected on a Gooch filter, dried at 110° and weighed, then after 
conversion to oxide by ignition it was found that the ratio 
GeO, : GeS, was 0°749 and 0°744, whereas the theoretical ratio 
for the atomic weight 72°5 is 0-766. An approximate determina- 
tion of the GeO, in the material used gave 0:25 percent. Several 
zine ores were tested for germanium by the chemical method 
that has been mentioned. Joplin ore and some Mexican ores 
gave positive tests, but the amounts were very much smaller than 
that in the Wisconsin material. The Franklin ores gave negative 
results. A spectroscopic examination of the product by Dr. K. 
Burns of the U. 8. Bureau of Standards indicated that germanium 
was the principal constituent while zinc was absent, lead weak, 
silicon present, tin fairly strong, copper present (?), cadmium 
trace, gallium present and indium trace. This occurrence of 
germanium is very interesting and it leads to the hope that a 
practical source of this exceedingly rare element has now been 
found.—Jour. Indus. and Eng. Chem., viii, 585. H. L. W. 
2. A New Volumetric Method for Cobalt.—W. D. EnNGiE and 
R. G. Gusravson have devised a method for the determination 
of cobalt, which can be applied in the presence of nickel and 
gives excellent results according to the test analyses of the 
authors. ‘To apply the method the metals of the copper and iron 
groups and also manganese are first removed by suitable methods. 
The solution may contain, besides cabalt, nickel, zinc and the 
metals of the alkalies and alkaline earths, but must be free from 
any substance that will liberate iodine from potassium iodide in 
acid solution. This solution having a volume of about 100° is 
made acid with dilute sulphuric acid, using about 5° in excess, 
and 1 or 2 g. of dry sodium perborate are added. After agitation 
and solution of the perborate, sodium hydroxide is added to 
strong alkaline reaction and the mixture is boiled for 10 minutes 
to decompose the excess of perborate. This operation precipitates 
cobaltic hydroxide, Co(OH),, while nickel does not form a higher 
oxide. The solution is now cooled to room temperature and, 
after 1 g. of potassium iodide has been added, the solution is 
acidified with dilute sulphuric acid and, after the precipitate has 
dissolved, the liberated iodine is titrated with standard sodium 
thiosulphate solution. The theoretical value of this solution, 
based upon standardization with potassium dichromate, was found 
to agree very closely with the value obtained by standardizing 


432 Scientific Intelligence. 


with a known amount of a cobalt compound by following the 
described analytical process.—Jowr. Indus. and Eng. Chem., 
vili, 901. H. L. W. 

3. The Determination of Aluminium as Oxide.—W1114AM 
Brum of the U.S. Bureau of Standards has made an extensive 
study of this commonly used method. The novel feature of the 
procedure recommended consists in adding a few: drops of an 
alcoholic solution of methyl red (0:2 per cent), heating just to 
boiling, and adding ammonia drop by drop until the color changes 
to a distinct yellow, then boiling for one or two minutes and filter- 
ing immediately. It is claimed that calcium and barium, if pres- 
ent, do not form carbonates with the carbon dioxide of the air 
under these conditions. Attention is called to the well known 
advantage of the presence of ammonium chloride when the 
precipitation is made, and washing with a 2 per cent solution of 
ammonium chloride is recommended. Ignition of the oxide in a 
platinum crucible over the blast lamp for about five minutes is 
advised. Attention is called to the importance of keeping the 
crucible closely covered while cooling and weighing, and the 
importance of weighing very rapidly, but the suspicion arises that 
at the Bureau of Standards they have been following the bad 
practice of trying to weigh warm crucibles ; for the following 
suggestive statement is made: ‘Tests at this Bureau have shown 
that in common with most substances capable of absorbing mois- 
ture (even those not intrinsically hygroscopic) recently ignited 
Al,O, absorbs within the first ten minutes’ exposure to the atmos- 
phere a large proportion of the water which it will absorb in 
twenty-four lours.” It is well known to experienced chemists 
that a slightly warm erucible, when placed upon the balance pan, 
shows a deficiency in weight on account of the ascending current 
of air produced, and that it then requires something like ten min- 
utes for the crucible to cool sufficiently to show its true weight. 
It is advisable either to supply the desiccator with a thermometer, 
or to touch the face with the crucible before weighing, to make 
sure that it is cold.—Jour. Amer. Chem. Soc., xxxvili, 1282. 

H. L. W. 

4. Ozone, Its Manufacture, Properties, and Uses; by A. Vos- 
MAER, 8vo, pp. 197. New York, 1916 (D. Van Nostrand Com- 
pany).—Part I of this book, comprising only 18 pages, deals with 
the early history, constitution, nature, occurrence, and properties 
of ozone, and the testsforit. The second part presents an exten- 
sive discussion of the manufacture of the substance, while the 
third part is devoted to its uses, and the last part gives a list of 
the United States patents, and an extensive bibliography. There 
are 75 illustrations and diagrams. ‘The author has had a long 
period of experience with ozone in Holland, and is thus able to 
give much interesting information. Some of the apparatus and 
methods described are of his own invention, but it appears that 
he gives proper credit to other methods than his own, and that 
he has endeavored to treat the subject from a scientific stand- 


Chemistry and Physics. 483 


point. There is much praise of the application of ozone to the 
purification of water supplies as practiced in Europe, and this 
application is strongly urged for this country, where at present it 
appears to be comparatively neglected. The view that minute 
quantities of ozone in the air make it agreeable and healthful for 
inhalation is advocated, and the use of the substance for the 
purification of air is recommended. H. L. W. 

5. A Theory of Color Vision.—At the present time there is 
no generally accepted theory of color vision, and there is consid- 
erable divergence of opinion as to the tests which should be 
applied for color-blindness. Consequently the new point of view 
proposed by R. A. Housroun may be appropriately outlined in 
this place. The author first shows that the Young-Helmholtz 
theory, which accounts very well for the phenomena of color 
mixing, involves a certain amount of arbitrariness and does not 
demonstrate the existence of three primary color sensations. The 
paper is divided into two parts: the first, which deals with the 
retinal process, applies principles already more or less familiar ; 
but the second part, which relates to the cerebral process, uses an 
idea quite original in its application to color vision. 

(a) The first step in the argument consists in assuming that 
there exist in the eye a very great number of vibrators, with a 
free period in the green, and that these execute forced vibrations 
under the influence of light waves. The amplitude of the forced 
vibrations is a maximum when the free period of the vibrators 
coincides with the period of the incident light. When formu- 
lated mathematically this hypothesis leads to a visibility curve 
which is similar to the one obtained experimentally by H. EH. 
Ives. These graphs suggest probability curves, for each has a 
single maximum ordinate (in the green) and bends down toward 
the axis of wave-lengths on both sides (red and violet). To con- 
form to Fechner’s law the additional assumption is made that, 
when £” acquires a small increment, the increase in the energy 
absorbed is proportional to d(’)/Z’, where £' coswé represents 
the force per unit mass exerted on a typical vibrator by the light 
wave. This assumption implies that some of the vibrators cease 
to act when #” is increased. ‘ When the energy of a vibrator 
reaches a critical value, the force attaching the vibrator to its 
center snaps, the latter then ceases to absorb light energy, and a 
chemical change takes place. This critical value is not the same 
for all the vibrators, but varies from vibrator to vibrator. We 
may identify the chemical change with the bleaching of the 
visual purple, but this identification is not necessary to the expla- 
nation.” When / is kept constant the same identical vibrators 
do not remain in action all the time for there are two processes 
going on in opposite directions which balance one another, visual 
purple being bleached and constantly restored... When Z increases, 
the point of equilibrium is shifted. Owing tothe bleaching and 
restoration of the visual purple the vibrators must be assumed to 
be in a perpetual state of agitation. Their free vibrations are 
continually being renewed. 


434 Scientific Intelligence. 


The Purkinje effect may also be accounted for along the same 
general lines. This effect consists in the horizontal contraction 
of the visibility curve.and in the shifting of its maximum toward 
the limiting wave-length 0°50, as the intensity of the light 
decreases to a very small value. Instead of supposing that the 
rods in the retina are chiefly responsible for vision at low inten- 
sities and the cones for vision at high intensities, itis only neces- 
sary to assume that the vibrators have different free periods and 
that the number 0°55 (which was substituted for a symbol a in 
calculating the first approximation to Ives’ curve) is a mean value. 
In other words, the visibility curve is the resultant of a very 
large number of elementary curves of the same type and not of 
three curves which would correspond to the hypothesis of three 
independent primary sensations. 

(2) Since it is not possible to give briefly an adequate account 
of the general theory of the cerebral process, a few sentences 
from the original paper, which contain the kernel of the matter, 
will now be quoted. “ We suppose the vibrators to set up waves 
in the nerves and that the nerves carry these waves to the brain. 
The analogue of the telephone may be useful in this respect ; the 
vibrators may be likened to the diaphragm and the nerve to the 
telephone wire. There is, however, one important difference. 
When a musical note is sung into the telephone it is transmitted 
correctly along the wire and reproduced at the other end, because 
the diaphragm reproduces accurately the sound wave. It is funda- 
mental to the theory given here that the vibrator does not repro- 
duce the light wave accurately, owing to its being subject to too 
many disturbing influences. No matter how monochromatic the 
incident wave is, the wave transmitted along the nerve is not 
monochromatic. It is ax if the diaphragm in the transmitter 
were subject to disturbing influences of such a nature that the 
person at the other end hears a medley of musical notes over a 
range of half an octave on each side of the notes originally sung 
into the transmitter.” 

Houstoun takes a slightly asymmetric curve of the same gen- 
eral shape as a probability curve as typical of the distribution of 
energy over the range of wave-lengths set up in the nerve by 
monochromatic stimulation. The area under the curve gives the 
luminosity of the impression, the position of the maximum, the 
hue, and the narrowness of the curve the degree of saturation. 
The phenomena of color mixing are readily reproduced theoret- 
ically by drawing energy curves corresponding to the objective 
constituents of the incident light and then constructing the 
resultant curve. For example, we may plot one sensation curve 
for lithium red and another for thallium green and then add the 
ordinates, the abscissas being proportional to the wave-lengths. 
Finally, following Dr. Edridge-Green, the author explains the 
apparent trichromatism of our ordinary visual sensations on the 
ground that the color-perceiving center in the brain is not suf- 
ficiently developed to discriminate between the character of 


Chemistry and Physics. — 485 


adjacent curves. ‘* Two curves must be widely different in shape 
and position, before the colour-perceiving center can detect the 
difference. A curve has an infinite number of points on it. 
The colour-perceiving center is so badly developed that, as far as 
it is concerned, the curve is sufficiently specified by three points 
on it, provided that these points are distributed over the spec- 
trum. We can therefore represent our energy curve by three 
points.”— Proc. Roy. Soc., vol. xcii (A), p. 424, July 1916. 
H, 8. U. 

6. On the Auditory Sense.—An interesting and doubtless 
important contribution to our knowledge of the sense of hearing 
has recently been made by M. Marace. The paper in question 
is the result of a careful scientific study of the various phases of 
deafness arising from certain kinds of injuries suffered by the 
French soldiers in the present war. The author divides the 
causes of the special sorts of deafness, with which he is pri- 
marily concerned, into two classes : (a) a fragment of an ordinary 
shell or a rifle ball strikes the skull at a point more or less remote 
from the ear in such a manner as not to produce any direct lesion 
of the brain. The shock always gives rise to general headaches, 
buzzing, partial loss of memory, lowering of audition, and slight 
trembling of the members. (0) A shell of the largest caliber 
explodes in the immediate vicinity (from 1 to 4 meters) of a 
soldier. No apparent wound exists, but the symptoms just speci- 
fied are met with in an exaggerated degree. Loss of conscious- 
ness lasts from a few hours to six days ; very violent pains in the 
frontal region persist for several months ; very pronounced buzz- 
ing which gradually disappears ; complete loss of memory ; abso- 
lute or nearly complete deafness (sometimes the patient hears but 
does not understand) ; violent trembling, especially of the upper 
portions of the body ; and sometimes total deaf-muteness. 

The apparatus used is a motor-driven siren designed to produce 
the sounds ow, 0, a, é, and 7. The intensity of the vowel sounds 
emitted can be estimated from the indications of a pressure gauge. 
From a statistical study of numerous cases Marage has established 
the fact that there are four and only four curves corresponding 
to the various types of partial deafness. Two curves are asso- 
ciated with injuries to the middle ear, and two pertain to lesions 
of the internal ear and to the auditory centers. These graphs 
are plotted with the vowels equally spaced as abscissas and with 
the corresponding least intensities audible as ordinates. The 
manner of examining a patient seems quite simple since it con- 
sists In sounding one vowel at a time while increasing the inten- 
sity until the subject indicates that he just begins to hear the note. 
The manometer is, of course, hidden from the view of the person 
under examination. The next day, or even a few minutes later, 
the process is repeated. An honest patient-always reproduces 
the first set of data, whereas a simulator of partial deafness can 
never remember the intensities of all the five notes specified by 
him in the first test as inferior limits of hearing. <A case of 


436 Scientific Intelligence. 


feigned total deafness can be readily detected by increasing the 
air pressure to such an extent that the subject can no longer 
endure the intense sounds emitted by the siren. 

From the point of view of the physicist the most important 
conclusion drawn by the author is that “ The theory of Helmholtz 
is insufficient for the explanation of the different kinds of deaf- 
ness: it seems that the auditory centers, situated in the interior 
of the brain, have a preponderating importance for the differentia- 
tion and interpretation of the various vibrations which can influ- 
ence the ear.” 

An interesting corollary is deduced from the fact that the 
curves corresponding to injuries to the inner ear and to the nerve 
centers have absolute minima. In one curve, for example, deaf- 
ness is absolute for @ and 7, but not for ow, o and é. These curves 
pertain to cases of deaf-muteness, and the author explains, in the 
following manner, the fact that normal parents may produce deaf 
and dumb children. ‘ During the period of gestation the mother 
has a fall or receives a mechanical shock which seems unimpor- 
tant. The shock is transmitted integrally by the intermediary of 
the amniotic liquid to the entire surface of the brain of the fetus 
which is not protected by an ossified cranium ; a cerebral agita- 
tion is set up which is much feebler than that caused by a pro- 
jectile, but which, acting upon a far more delicate nervous sys- 
tem, produces analogous lesions and effects.” That deaf-mute 
parents may have normal offspring is consistent with this view 
which does not involve the hypothesis of hereditary influence.— 

Jour. de Phys., vol. vi, Jan.-Feb., 1916, p. 29. H. S. U. 
7. Coneise Technical Physics ; by J. Lortye Arnon. . Pp. 
vill, 275, with 294 figures. New York, 1916 (McGraw Hill Book 
Co.).—This book is intended primarily for use in the first course 
of theoretical physics in schools of engineering, and its differen- 
tiating characteristic is extreme brevity. The author says: “This 
book is intentionally laconic.” ‘It contains nothing but what 
can be required of every student.” “It lays particular stress 
upon fundamental conceptions, to the exclusion of too much 
detail.” <The book aims to give a thorough and comprehensive 
basis on which to build further knowledge in each department of 
the subject.” 

The chief branches of physics are taken up in the following 
order, which differs somewhat from the usual sequence: kine- 
matics and mechanics of solids (67 pages), mechanics of fluids 
(20), sound (23), heat (28), light (44), magnetism and static elec- 
tricity (18), and current electricity (67). With few exceptions, 
the text is as accurate as is consistent with its condensation, the 
line diagrams are numerous and clear cut, and about eighty prob- 
lems are suggested for solution. In the subject of light both the 
ray and wave-front methods are used in the derivation of the 
formulas. The only feature of the book which may be annoying 
to a student who is acquainted with other texts on physics is 
that the typographical errors are concentrated in the names of 


Geology. 437 


eminent scientists. For example, we find: Bjercknes, Clere Max- 
well, Helmholz, Melda, Michaelson, Rhumkorff, ete. Be Sas 
8. A Text-Book of Physics, Fourth Edition ; edited by A. 
W. Durr. Pp. xiv, 692; 609 figures and 279 problems. Phila- 
delphia, 1916 (P. Blakiston’s Son & Co.).—A careful comparison 
of the latest edition of this work with the third (see vol. xxxiv, 
page 483) shows that the text has been thoroughly revised. The 
method of presentation has been simplified and clarified in many 
places, especially in the paragraphs relating to the dynamics of 
rotation. The symbolization has also been improved ; for exam- 
ple, « is replaced by v, in the case of initial velocity. A new 
part on Sound has been written, especial attention being paid to 
the recent investigations of Miller, Sabine, and others. Typo- 
graphical errors have been eliminated as far as possible. It is 
thus evident that the fourth edition shows appreciable improve- 
ment over the third and that it is a thoroughly reliable and well- 
balanced text-book. ul. S U. 


Il. Gnroroey. 


1. Hxpedition to the Baltic provinces of Russia and Scandi- 
navia, 1914. Part 1—The correlation of the Ordovician strata 
of the Baltic busin with those of eastern North America ; by 
Percy E. Raymonp. Bull. Museum Comp. Zodlogy, vol. lv1, 
No. 3, Shaler Memorial Series No. 2, 1916, pp. 179-286, pls. 1-8. 
Part 2.—The Silurian and high Ordovician strata of Esthonia, 
Russia and their faunas; and Part 3.— An interpretation of the 
Silurian section of Gotlund; by W. UH. Twenuorer. Ibid., 
vol. lvi, No. 4; Shaler Memorial Series No. 3, 1916, pp. 289-354, 
pls. 1-5, text fig. 1.—These important and far-reaching correlation 
papers comparing the Ordovician and Silurian of Esthonia, 
Sweden, and Norway with those of North America, give much 
more detail than any others in the English language. ‘The 
Ordovician begins with the Dictyonema beds, for earlier there 
had been elevation (warping) and erosion throughout the area 
studied. The formations which immediately succeed the basal 
ones are correlated by Raymond with the American Beekman- 
town, and in this he is in harmony with the European strati- 
graphers, but differs from the conclusions of some American 
geologists. In correlation, Raymond places main reliance on the 
graptolites, though he remarks, “If there were no other evidence 
than that afforded by the time of the first appearance of certain 
genera in Russia and America, it might well happen that the 
Walchow and Kunda formations [the basal Ordovician of Estho- 
nia| might be correlated with the Chazy, but I do not see that 
they could be correlated with any younger strata” (268). Since 
the reviewer’s visit to Esthonia in 1903, it has always seemed to 
him that the faunal development of these formations, especially as 
shown in the brachiopods, was rather that of the Chazy than the 


Am. JOUR. Scrt.—Fourta Serres, Vou. XLII, No. 251.—Novemper, 1916. 
30 


438 Scientific Intelligence. 


Beekmantown, for the latter series has but few of these shells, 
whereas there is an abundance in the former and its equivalent, 
the Stones River series. On the other hand, the Ceratopyge 
formations of Sweden, which are absent in Esthonia, are unmis- 
takably of Beekmantown age. The Normanskill Raymond 
regards as probably of upper Chazy time. 

Twenhofel reports on the higher Ordovician and the Silurian, 
and as these deposits have many fossils in common with those of 
America, and more especially those of Anticosti, he has far less 
difficulty than his colleague in determining the equivalent forma- 
tions. ‘The lower Lyckholm Bassler regarded as intimately con- 
nected faunally with the middle Ordovician, a correlation accepted 
by none, and now Twenhofel shows that the Lyckholm is ‘not 
divisible, but that the whole of it is upper Ordovician in age and 
about equivalent to the middle Richmondian. ‘he following 
Borkholm is still higher Richmondian and correlates with the 
Ellis Bay horizon of Anticosti; both are referred to the Ordovi- 
cian period. hen followed emergence of the region and Estho- 
nia was not again invaded by the sea until long after the Silurian 
had begun, in about Clinton time. 

The Silurian of Esthonia and that of Gotland are very different 
in their faunal make-up and in the nature of the sediments as 
well. The difference is apparently wholly due to the fact that 
the Gotland sea abounded in coral reefs, and as these grew far 
more quickly than the surrounding sediments accumulated, and 
show, consequently, a greater variation in strata, this led to 
the development of many different faunules, of slightly different 
geologic ages, which are now found in the same stratigraphic 
horizon. This condition has long perplexed stratigraphers, but 
Twenhofel now shows from a study of recent coral reefs how the 
Gotland stratigraphy may be harmonized with that of other 
Silurian areas. It is interesting reading, and his conclusions are 
all the more acceptable because he has unravelled a similar con- 
dition in the Silurian of Anticosti. 

The authors are to be congratulated upon the great amount of 
first-hand information here presented, and their work clarifies and 
greatly advances our knowledge of the faunal interrelations of 
the European and American Ordovician and Silurian systems. 

Cc. 8. 

2. Upper Ordovician forinations in Ontario and Quebec ; 
by A. F. Forrstz. Geol. Survey Canada, Mem. 83, 1916, pp. 
iil, 279, 8 figs.—This memoir describes in detail the stratigraphic 
and faunal succession of the Cincinnatian series east of Montreal 
and Ottawa, Canada, west of the Adirondacks of New York, 
and in the Lake Huron region. All of the species identified by 
the author have been arranged in tabular form, so as to show 
their stratigraphic range, by Miss A. E. Wilson. Cc. §. 

3. The Lower Eocene floras of Southeastern North America ; 
by Epwarp Wiper Burry. U.S. Geol. Survey, Prof. Paper 
91, 1916, 481 pp., 117 pls., 16 text figs.—In this great monograph 


Geology. 439 


are described 10 plants from the Midway formation and over 
300 species in 134 genera from the Wilcox formation. The 
work, however, is far more than a description of species and 
genera, as 145 pages are devoted to the sections yielding the fos- 
sils, the distribution of the floras, their character and ecology, 
and the correlation of the Wilcox formation. The plants from 
the Wilcox, which Berry correlates in part with the Fort Union 
and the Wasatch, are almost wholly angiosperms (94 per cent) 
and represent a coastal or strand flora under a climate about. like 
that of the Florida Keys. Gus, 
4. On some Permian Brachiopoda. of Armenia; by A. 
Srorvanow. Mém. Comité Géologique, n. s., Liv. 111, 1915, 95 
pp., 6 pls—The author here describes fully, in Russian and in 
English, his genus Tschernyschewia proposed in 1910. At first 
sight the form looks like a sinused Productus, but as it is attached 
by the ventral beak, has a long and narrow cardinal area that is 
bisected by a delthyrium and covered by a very delicate del- 
tidium, with a very high median ventral septum, it is seen to be a 
genus quite different from all known productids. He also dis- 
cusses Richthofenia, Seacchinella, Tegulifera, and Productus. 
Ch 
5. Oambrian Geology and Paleontology, tii, No. 5, Cambrian 
Trilobites ; by Cuartes D. Waucorr. Smiths. Mise. Coll., vol. 
64, pp. 303-456, pls. 45-67, 1916.—The author here describes 17 
genera or subgenera (9 new) and 85 species (54 new) of Cambrian 
trilobites, DProbably the most interesting genus is Pagetia, a 
form not unlike Agnostus, with free cheeks and eyes on the 
dorsal surface of the animals. C. 8 
6. Checklist of the Recent Bivalve Mollusks (Pelecypoda) of 
the Northwest Coast of America from the Polar Sea to San 
Diego, California ; by Wir11AmM Hearty Dat. Published by 
The Southwest Museum, Los Angeles, 44 pp., 1916.—In this 
interesting checklist Dall lists 474 species and varieties of bivalves 
living off the northwest coast of North America down’ to San 
Diego. Of these, 45 are deep-water forms restricted to waters 
below 60 fathoms in depth. ‘There are therefore 429 shallow- 
water forms and of this number 205 are restricted to one of the 
three provinces (77 to the Arctic, 17 to the Temperate, and 111 
to the Tropical), so that about one-half of the shells (219) have a 
geographic range over two of the provinces. This is the second 
publication by the new Southwest Museum of Natural History in 
Los Angeles. Colne 
7. Interrelations of the Fossil Fuels. Purt I; by Joun J. 
StrvEenson. Proc. Amer. Philos. Soc., lv, pp. 21-203, 1916.— 
In this valuable and comprehensive work the author brings 
together all that is known regarding the Pleistocene and Recent 
peats and the coals of the Tertiary. His wide. knowledge of the 
Paleozoic coals and his great industry enable him to summarize 
the voluminous literature bearing upon the problems in hand in 
a clear manner. The area of the peats “is apparently greater 


440 Scientific Intelligence. 


than that on which carbon deposits were laid down during any 
preceding period of similar duration”; nearly a hundred pages 
of the memoir are devoted to them, Ces. 

8. The Echinoidea of the Buda limestones ; by F. L. Wurr- 
ney. Bull. Amer. Paleontology, No. 26, 1916, 87 pp., 9 pls.— 
Here are described ten species of echinids from the Comanchian 
of Texas, four of which are new. i C3! 

9. Publications of the United States Geological Survey, 
GrorGE Oris Suir, Director.—Recent publications of the U.S. 
Geological Survey are noted in the following list (continued from 
pp. 371-373, April, 1916): 

Torocraruic Arias.— Fifty-two sheets. 

Forros.—No, 199. Silver City Folio, New Mexico ; by Sipyby 
Paice. Pp. 19; 3 maps, 13 pls., 17 figs. 

No. 201. Minneapolis-St. Paul Folio, Minnesota ; by Freperick 
W. Sarpeson. Pp. 14; 8 maps, 22 pls., 14 figs, 

Prorerssionan Parers.—No. 89. The Fauna of the Chapman 
Sandstone of Maine, including descriptions of some related 
species from the Moose River Sandstone; by Henry Suarer 
Wictiams, assisted by Carper Levenruat Brecer. Pp, 347 ; 
27 pls., 2 figs. See p. 169, August, 1916. 

No. 91. The Lower Eocene Floras of Southeastern North 
America; by Epwarp W. Berry. Pp. 355; 117 pls., 16 figs. 

No. 98. Shorter Contributions to General Geology, 1916. Parts 
Ato N. Pp. 1-261. Seep. 438. 

Minerat Resources for 1915.—Numerous advance chapters. 

Butrerins.—No. 610. Mineralogie Notes. Series 3; by Wat- 
DEMAR T. ScuaLttER. Pp. 164; 5 pls., 99 figs. See p. 85, July, 
1916. 

No. 618. Geology and Underground Water of Luna County, 
New Mexico; by N. H. Darton. Pp. 188 ; 13 pls., 15 figs. 

No. 619. The Caddo Oil and Gas Field, Louisiana and Texas; 
by Grorcr C. Matson. Pp. 62; 8 pls., 5 figs. 

Nos.’ 620, 621. Contributions to Economic Geology, 1915. 
No. 620, Part) I) M; 0: No, 621,-Part I) Ly Mo aN, 0: 

No. 623. Petroleum Withdrawals and Restorations affecting 
the public Domain ; by Max W. Batx. Compilation by Lucrrra 
W. Srocksrmer. Pp. 427; 9 pls. (in pocket). 

No. 626. The Atlantic Gold District and the North Laramie 
Mountains; Fremont, Converse, and Albany Counties, Wyoming. 
Papers by Arruur C. Spencer. Pp. 85; 5 pls., 6 figs. 

No. 627. The Lignite Field of Northwestern South Dakota ; 
by Dean E. Wincuester, C. J. Hares, KE. Russert Liuoyp, and 
EK. M. Parks. Pp. 169; 11 pls., 3 figs. 

No, 628. Geology and Coal Resources of Castle Valley in 
Carbon, Emery, and Sevier Counties, Utah; by Cuaries T. 
Lurron. Pp. 86; 12 pls., 1 fig. 

No. 629. Natural Gas Resources of Parts of North Texas. 
Gas in the area north and west of Fort North; by Eucenn W. 
Suaw. Gas Prospects south and southeast of Dallas; by Grorcr 
C. Matson; with Notes on the Gas Fields of Central and Southern 
Oklahoma; by Carroti H. Wucemann. Pp. 129; 7 pls., 13 figs. 


Geology. 441 


No. 630. The Chisana-White River District, Alaska; by 
Sreruen R. Carrs; 19 pls., 9 figs. 

Nos. 632. Spirit Leveling, Kk. B. Marsnaur, Chief Geogra- 
pher. No. 632, West Virginia, 1896-1915, pp. 168.—No. 633, 
Maine, 1899-1915, pp. 64.—No. 634, Louisiana, 1903-1915, pp. 
101.—No. 635, Georgia, 1896-1914, pp. 60.—No. 636, Arkansas, 
1896-1915, pp. 56.—No. 638, New Mexico, 1902-1915, pp. 112. 

Nos. 640, 641. Contributions to Economic Geology, 1916.— 
No. 640, Part I,,B, C, D, E.—No. 641, Part IJ, A, B, C, D, E. 

No. 645. Bibliography of North American Geology for 1915 
with subject index ; by Joun M. Nicxues. Pp. 144. 

No. 649. Antimony Deposits of Alaska; by Atrrep H. 
Brooks. Pp. 67 ; 3 pls., 3 figs. 

Water Suprprty Parrrs.—No. 369. Water Powers of the 
Cascade Range. Part III]. Yakima River Basin; by GuEnn L. 
Parker and Franx B. Storny. Pp. 169; 20 pls., 12 figs. 

No. 372. A Water-Power Reconnaissance in South-Central 
Alaska; by C. E. Eritsworrn and R. W. Davenport, with a 
section on Southeastern Alaska; by J. C. Hoyt. Pp. 173; 22 
pls., 6 figs. 

No. 395. Colorado River and its Utilization; by E. C. La 
Rue. Pp. 231; 25 pls., 5 figs. 

No. 399. Geology and Ground Waters of Northeastern 
Arkansas ; by Liroyp W. Srepuenson and Arsert F. Criver, 
with a discussion of the chemical character of the waters by 
Ricwarp B. Doie. Pp. 315; 9 pls., 4 figs. 

Nos. 332, 359, 360, 383, 384,385, 387. Surface Water Supply or 
the United States, 1912-14. Narsan C. Grover, Chief Hydrau- 
lic Engineer.—No. 332, 1912. Part XII. North Pacific Drain- 
age Basins. Pp. 748; 2 pls—No. 359, 1913. Part IX. Colo- 
rado River Basin. Pp. 260; 2 pls.—No. 360, 1913. Part X. 
The Great Basin. Pp. 293; 1 pl.,1 fig.—No. 383, 1914. Part III. 
Ohio River Basin. Pp. 125, xxxii ; 2 pls—No. 384, 1914. Part . 
IV. St. Lawrence River Basin. Pp. 128, xxix; 2 pls.—No. 
385, 1914. Part V. Hudson Bay and Upper Mississippi River 
Basins. Pp. 247, xxix; 2 pls—No. 387, 1914. Part VII. 
Lower Mississippi River Basins. Pp. 60, xxxiv; 2 pls. 

Nos. 374, 397, 398. Ground Water.—No. 374. In the Hart- 
ford, Stamford, Salisbury, Willimantic and Saybrook Areas, 
Connecticut ; by Herserr E. Grecory and Arruur J. Exxis. 
Pp. 150; 13 pls., 10 figs—No. 397. In the Waterbury Area, 
Connecticut ; by Arruur J. Extis, under the direction of Her- 
BERT EK. Gregory. Pp. 733; 4 pls., 10 figs—No. 398. In San 
Joaquin Valley, California ; by W. C. Menpenuatr, R. B. Doue 
and Herman StasterR. Pp. 310; 5 pls, 4 figs., 17 tables. 


442 Scientific Intelligence. 


III. Muiscriuanrous Soipntiric INTELLIGENCE. 


1. Diseases of Occupation and Vocational Hygiene ; edited 
by Grorce M, Koper, M.D., LL.D., and Wittiam C. Hanson, 
M.D. Pp. xxi+918. Philadelphia, 1916 (P. Blakiston’s Son & 
Co.).—In this large handbook the subdivision of hygiene which 
deals with relations of occupation to health and longevity is pre- 
sented in the form of a series of essays prepared by thirty or 
more writers well known as experts in some field of medicine, 
public health work, occupational hygiene, physiology, sociology, 
insurance, etc. The names of these contributors including, in 
addition to the editors, Prof. Clarence J. Blake of Boston, Prof. 
L. Devoto of Milan, Dr. Alice Hamilton of Chicago, Prof. Chas. 
R. Henderson of Chicago, Prof. Frederic S. Lee of New York, 
Sir Thomas Oliver of England, Professors Southard, Tyzzer and 
Whipple of Harvard University among others, gives some assur- 
ance of the worth of the volume. No detailed reference can be 
made in this space to their contributions, They include the spe- 
cific and systemic diseases of occupation, fatigue and the neuroses 
of occupation, the causation and prevention of occupational dis- 
eases and accidents, etc. Somewhat of a novelty is presented in 
the chapters dealing with the relation of clinics, statistics, govern- 
mental study and legislation to occupational diseases. The essays 
on vocational hygiene, with their descriptions of the dangers 
existing in special groups of industries which take a prominent 
place in the commerce of to-day, are full of interesting details 
evidently compiled from many sources and with much effort. 
The book is, in fact, a compilation of manifold useful facts and 
suggestions rather than a “system” of medicine in the usual 
sense, L. B. M. 

2. The Problems of Physiological and Pathological Chem- 
istry of Metabolism ; by Orro von Firtu. Translated by ALLEN 
J. Swrra. Pp. xv +667. Philadelphia, 1916 (J. B. Lippincott 
Company. Price $6 00).—Von Fiirth’s “ Probleme der physiolo- 
gischen und pathologischen Chemie,” which first appeared four 
years ago, immediately gained a deserved popularity because it 
presented in an enjoyable style an admirable survey of the 
literature, both historical and modern, covering a large range of 
timely topics in biochemistry. Evidence was presented, opinions 
were weighed, conclusions were logically drawn, and the outlook 
was clearly disclosed with relation to a considerable number of 
questions which are daily discussed in this field of science. The 
reader could feel the influence of the authoritative statement of 
an experienced investigator, yet still preserve an independence of 
judgment. The young investigator found the new volumes full 
of stimulating viewpoints. Rarely has the subject been so well 
presented. It is gratifying to find an excellent translation of the 
part of von Fiirth’s volumes dealing with metabolism. Professor 
Smith has preserved the spirit of the author’s diction well, and 
has done physiological science a service in making von Fiirth’s 
essays more readily available to those who prefer to read the 
English language. L. B. M. 


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ites, J-150. Collections. J-160. Fine specimens. 

Paleontology: J-184. Complete Trilobites. J-115. Collec- 
tions.. J-140. Restorations of Extinct Arthropods. 

Entomology: J-30. Supplies. J-125, Life Histories. 
J-128. Live Pupae. 

Zoology: J-116. Material for Dissection. J-26. Compara- 
tive Osteology. J-94. Casts of Reptiles, etc. 

Microscope Slides: J-185. Bacteria Slides. 

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Art. XXXVUI—The Ancestry of Insects with particular 
references to Chilopods and Trilobites; by J. D. 
Torstnt, 2) oak Ee eee 


XXXIX.—Some Characters of the Apical End of Pseudor- 
thoceras knoxense McChesney; by G. 1. Girry (With 
Plate I) 

XL.—On the Electrolysis and Purification of Gallium; by 
H. 8. Unter and Pair E. Browning 


XLI.—A Pleistocene Locality on Mt. Desert Island, Maine ; 
by D. Branry and F. B. Loomis . 


XLII.—Methods in Reversed and Non-reversed Spectrum 
Interferometry; by C. Barus 


XLIIL—A Study of the Separation of Hydrofluoric Acid 
and Fluosilicic Acid ; by J. G. Dinwippiz 


SCIENTIFIC. INTELLIGENCE. 


Chemistry and Physics—Occurrence of Germanium in Zine Materials, G. H. 
BucHanan, 430.—New Volumetric Method for Cobalt, W. D. Evers and 
R. G. Gustavson, 431.—Determination of Aluminium as Oxide, W. Bium: 
Ozone, its Manufacture, Properties, and Uses, A. VosMArR, 432,—A 
Theory of Color Vision, R. A. Houstoun, 433.—On the Auditory Sense, M. 
MaraceE, 435.—Concise Technical Physics, J. L. ARnoxD, 486,—A Text- 
Book of Physics, Fourth Edition, A. W. Durr, 437. 


Geology—Expedition to the Baltic provinces of Russia and Scandinavia, 
1914, P. E. Raymonp and W. H. Twennoret, 437.—Upper Ordovician 
formations in Ontario and Quebec, A. F. Forrste: Lower Kocene floras of 
Southeastern North America, E. W. Berry, 488.—Some Permian Brachio- 
poda of Armenia, A. Srowanow: Cambrian Geology and Paleontology, 
iii, No. 5, Cambrian Trilobites, C. D. Wancorr: Checklist of the Recent 
Biyalve Mollusks (Pelecypoda) of the Northwest Coast of America, W. H. 
Dau: Interrelations of the Fossil Fuels, J. J. Stmvenson, 439.—The 
Echinoidea of the Buda limestones, F. L. Wuitney: Publications of. 
the United States Geological Survey, G. O. Smiru, 440. 


Miscellaneous Scientific Intelligence—Diseases of Occupation and Vocational 
Hygiene, G. M. Koper and W. C. Hanson: Problems of Physiological and 
Pathological Chemistry of Metabolism (von Firth), A. J. Smirx, 442. 


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New Discoveries hee New Arrivals, 


Bisbeeite, Bisbee, Arizona. $1.50 to $4.00. 

Shattuckite, Bisbee, Arizona. $1.50 to $4.00. 

Patronite with quisqueite and minasragrite, Minasragra, Peru. 
$2.50 to $7.50. 

Babingtonite, Paterson, N. J. $1.50 to $5.00. 

Willemite, Franklin Furnace, N. J., small bright green 
transparent crystals with new forms. $2. ’00 to $5.00. . 

Euxenite, nr. Tritriva, Antsirabe, Madagascar. Sharply 
developed crystals. 75c. to $4.00. 

Betafite, Betafe and Antsirabe, Madagascar. $1.50 to $5.00. 

Ampangabeite, nr. Tritriva, Antsirabe, Madagascar. $2.00 © 
to $5.00. 

Manganosite, Franklin Furnace, N. J. $1.00 to $3.00. 

Hodgkinsonite, Franklin Furnace, N. J. $1.00 to $3.00. 

Gageite, Franklin Furnace, N. J. $2.00 to $5.00. 

Zincite, crystallized, Franklin Furnace, N. J. $3.00 to 
$10.00. 

Pyrochroite, Franklin Furnace, N. J. 50c. to $2.50. 

Leucophoenicite, Franklin Furnace, N. J. $1.50 to $3.00. 

Spinels, franklinite, rhodonite, apatite, troostite and amazon- 
ite from Franklin Furnace, N. J., from $1.50 to $5.00. 

Spinels, Orange Co., N. oe 50e. to $3.00. : 

Pyrite, Ibex Mine, "Leadville, Colorado, xls. from " to 3”. 
$2.00 to $10.00. 

Tourmalines, Mesa Grande, California ; ; all colors. $2.00 to 
$15.00. 

Tourmalines, Haddam Neck, Conneeticut; green. 50c. to 
$3.00." . 

Pink apatites, Mesa Grande, California. $1.00 to $3.00. 

Chrysoprase, polished, Porterville, Tulare Co., Cal. $1.50 
to $7.50. 

Apophyllite, chabazite, pectolite, natrolite, heulandite, prehn- 
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Polished specimens of aoe malachite, jasper, sorpounate moss 
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Arr. XLIV.—The Lava Eruption of Stromboli, Summer— 
Autumn, 1915; by Frank A. Perret. 


Tuer recent phase of exceptional activity at Stromboli—a 
true eruption in the full sense of being both effusive and 
explosive—may be considered, in a way, as being a Tepetition 
of that of 1891, so ably described by Ricco and Mercalli.* It 
differs from it, however, in some important respects, notably 
in the relative proportions of the different phenomena, the 
earlier eruption having been characterized by a far greater 
degree of seismic and explosive activity, while the recent phase 
was remarkable for its long continued outpouring of lava. 

It will scarcely be necessary to point out the peculiar import- 
ance of such an event, for it will be recalled that effusive phe- 
nomena at this voleano are rare, while the lavas of Vesuvius 
and Etna do not, in our day, reach the sea. This eruption 
furnished, therefore, a precious opportunity for the study of 
the important question of the behavior of incandescent lava in 
contact with water. 

Through a combination of circumstances, however, which 
can never be sufficiently regretted, the true condition of Strom- 
boli during the months of July, August, September and Octo- 
ber was not realized by those voleanologists who are generally 
most active in field research, and it was not until the first of 
November that the Bier writer learned of the magnitude 
and importance of the eruptive phase. Upon receiving con- 
firmation of the reports through the kindness of Profs. 
Platania and Ricco, of Catania, he sailed on November 7 for 
Stromboli via Messina on the ill fated “ Firenze.” 


a A. Ricco and G. Mercalli, Ann. Uff. Cent. Met. Ital., xi, Part III, p. 187, 
1892. 


Am. Jour. Sc1.—Fourts Serizs, Von. XLIT, No. 252.—DxrcremsBer, 1916. 


<< 


eae 


444 FA. Perret—Lava Eruption of Stromboli. 


Leaving Naples at 5 p.m. the light of the eruption was 
plainly visible an hour after midnight. It was so strangely 
white as to make one doubt, for a time, the possibility of its 
being caused by the volcano, although no other source of 
illumination was to be looked for in that locality. In another 
place* the writer has referred to this phenomenon, which often 
has given erroneous impressions concerning the temperature 
of a lava, and which seems due to the selective absorption and 
reflection of certain rays by the vapors emanating from the 
lava. No opportunity has yet been found of experimentally 
studying the matter to a conclusion. 

On approaching and passing the island, it was seen that a 
stream of lava was flowing from the crater, or just below it, 
down the western side of the Sciara to the sea. The nearer 
view gave the normal golden yellow tint of an active lava 
which flows freely and maintains an incandescent surface, but 
this condition prevailed for only a third of the descent. In 
the second section—evidently a deviation from the direct 
descent and a region of accumulation—this glow was only 
visible in the interstices of a blackened crust. Emerging 
anew from this, the lava flowed directly toward, and almost to, 
the sea in a broad stream of which the brightness was little if 
at all, inferior to that of the first portion. 

From a part of the crater nearest the Sciara a bright glow 
emanated continuously, while at intervals of from ten to fif- 
teen minutes a fairly strong explosion would project to a 
height of a hundred meters or more those sheaves of incan- 
descent fragments which are characteristic of this form of 
activity. 

The next evening was spent in the harbor of Lipari, on the 
local steamer, and Stromboli was reached at daybreak of the 
9th. The writer remained until the 30th, when the subsidence 
of the lava column, the extension of the fumarolic area and 
the absence of explosion all. indicated the approaching end of 
this exceptional eruption. From the 12th to the 19th the writer 
had the pleasure of the company of Professor Gaetano 
Platania. 

During this stay three trips were made to the summit, five 
to the Sciara by boat, one in a circuit of the island, and several 
to the Punta Labronzo on those days when bad weather pre- 
vented the more important excursions. It is proposed to set 
forth here those observations and studies of phenomena per- 
sonally made during this time, and to follow this preliminary 
report—when the analyses of the various products shall have 
been made—by a more complete paper, which shall include an 

*<*Voleanic Research at Kilauea in the Summer of 1911.” Frank A. 
Perret, this Journal (4), xxxvi, p. 480, 1913. 


F.. A, Perret—Lava Eruption of Stromboli. 445 


account of the great explosive paroxysms of 1907 and 1912. 
These, together with the recent eruption, constitute a group of 
events markedly analogous to the eruptions of other volcanoes, 
the first two in the formation of a vast crateral abyss and the 
last inthe amplitude and duration of the lava flow. 

It will be well first to take a comprehensive view of the 
initiation and progress of the eruption in the preceding months, 
as shown in the records of the Stromboli Semaphore Service, 
kindly furnished by the Chief, Signor D’Aloisio, to whose 
courtesy and hospitality the writer is deeply indebted. 

It should be remarked that these records also contain notes 
to the effect that in April and in June of 1914* there were 
“eruptions of lava”—probably not true continuous flows but 
ejections from the crater on to the Sciara, which certainly indi- 
eate a high lava column with a tendency to overflow. 

On the 18th of June, 1915 (and possibly also on the 11th), 
there was an eruption of Java which ceased the same day. 
Small shock. 

From July 1 to 24, lava in quantity, and from the 25th to 
31st, in lesser amount. Increased explosive effects at erater. 

During the month of August, continuous emission, always 
in moderate amount. 

September 1 to 14, in considerable quantity ; 15 to 23, less ; 
from 25 to 380, abundant. 

In great quantity during the entire month of October, and 
during the first week of November. Also emissions of ash 
and lapilli. 

The rest of the month may now be summarized briefly from 
the writer’s observations : 

November 7—Explosions from Bocca A of the crater at 
intervals of ten to fifteen minutes, with projection of luminous 
fragments to a considerable height. Ample outflow of lava, 
forming the most westerly of the streams on the Sciara, and 
flowing to within a few meters of the sea. 

November 9—Same conditions at crater. Lava flow dimin- 
ished. Great accumulation of lava at about the middle of the 
descent. Lower extremity immobile. 

November 10—Weaker explosions from Bocca A often fol- 
lowed by landslips within the crater, indicating a sinking lava 
column. Outflow of lava entirely or almost ceased. 

November il—Gradual diminution of all activity. 

November 12—The explosions in Bocca A proceed from a 
constantly lowering lava column, and scarcely reach the crater’s 
edge, but the glow continues. The lava has ceased flowing, 
but the lava bocea is incandescent. 


***T fenomeni eruttivi avvenuti allo Stromboli dal 1909 al 1914, ed il loro 
meccanismo,” O. De Fiore, Zeitschr. f. Vulkanologie, i, p. 236, 1915. 


446 FA, Perret-—Lava Eruption of Stromboli. 


November 13— Paroxysmal explosion at 9.15 A. ., followed 
by weaker repetitions. No lava outflow, but the lava boeea 
emits bluish vapor in strong puffs. At 1.30 Pp. Mm. an imposing 
avalanche of the hardened lava insecurely held on the steep 
slope of the Sciara (36°). 

November 14—Copious outflow of lava, descending the 
easterly side of the Sciara but not reaching the sea in continu 
ous tlow. 

November 15—Diminished flow. 

November 16.—Outtlow continues. One moderate explo- 
sion. 

November 17—Conditions not sensibly different. 
November 18—Copious flow of lava. Fine, full stream 
descending directly into the sea. 

November 19—Lava in large amount—great evolution of 
steam on entering the sea. 

November 20—Same conditions. Quantity of sulphur 
dioxide carried down by the wind over 8. Vincenzo. 
November 21—Large amount of lava—bright glow. 
November 22—Outflow notably diminished. 

November 23—Outflow nearly ceased from 4 to 10 P. m., 
then continued in great quantity. 

November 24—Great quantity of lava. 

November 25——Diminished outflow. Copious white vapors 
at the crater. 

November 26—Little or no lava during the night until 5 
A.M. At 7.12 strong air concussion followed in less than a 
minute by a paroxysmal explosion. At 8 a.m. cessation of 
flow, then a second explosion, small, followed by an abundant 
outflow of lava, which ceased completely at about 8.30 Pp. m. 

November 27—No lava—the bocca gives blue vapor only. 
At the crater white vapors. 

November 28—No lava. 

November 29—At noon a re-fusion at the lava boceas and 
outflow of lava for a distance of a hundred meters. White 
vapors without explosion at the crater. Great extension of 
fumarolic area. 

November 30—A sluggish lava flow, tending to cease 
altogether. 

Throughout all this period, when not otherwise stated, and 
excepting the two great explosions on the 13th and 26th, the 
gaseous outbursts at the crater continually decreased in inten- 
sity and frequency. 

We have, thus, an eruption of lava lasting five months, and 
manifesting powerful explosive phenomena only in the latest 
phase, in contradistinction to that of 1891 when the emission 
of lava was spasmodic and was invariably preceded by strong 
seismic and explosive manifestations. 


F. A, Perret—Lava Eruption of Stromboli. 447 


The Eruptive Apparatus. 


The formation, and the configuration of the crater of Strom- 
boli conform to the same general type exhibited by other vol- 
canoes, i. e. enlargement and abasement as effects of great 
explosive paroxysms, interchanging with upgrowth and restric- 
tion as results of long-continued and moderate activity. It does 
not exhibit, however, those colossal fault-block depressions of 
cealderal magnitude which are caused by rapid emptying of the 
conduit through copious outpourings of lava at low levels. 
But, inasmuch as the conduit of this voleano divides itself, at 
the upper extremity, into various ramifications, and as the 
normal activity is muderate and prolonged, the tendency is to 
form a number of small crateral mouths—as many as seven, or 
even more—crowning, as a rnle, as many distinct conelets more 
or less united into groups. 

And not even the most powerful and continued explosive 
paroxysms of which we have knowledge—such as those in 1907 
and 1912*—have been able to excavate any single crater 
sufficiently profound to unite these several ramifications into 
one single vent. In fact, although on both these occasions an 
immense crateral cavity was formed, it was always possible to 
distinguish four different and distinct centers of explosion, 
easily recordable by photography, and these have persisted as 
principal vents during all recent phases of violent activity at 
this voleano. I have designated them by the letters A, B, C, D. 

The actual crater consists of these four main divisions, 
united in one great group with wails of separation which are com- 
mon to the vents which are contiguous—four perfect craters, 
that is to say, which occupy and fill the space of the great cra- 
ter cavity of 1912. It is probable that these contain further 
subdivisions, but in the conditions which prevailed during this 
visit to the island this could not be determined with certainty. 

This conformation gives, as usual, a satisfactory measure of 
the degree of explosive activity which occurred during this 
phase, and one which here confirms the other observations, 
viz., that the explosive activity was considerable but not by any 
means catastrophic, the only truly paroxysmal explosivity hav- 
ing been extremely limited in time. 

Boeca A, situated near the center of the upper edge of the 
Sciara, is generally the most active, especially in those forms of 
eruption which spring directly from liquid lava. It was the 
source of the recent flows, and of nearly all the incandescent 
ejections during the month of November. 

Adjacent to it, on the east, lies Boeea B, now much enlarged. 

*G. Platania: Ann. Uff. Centr. Met. Ital., xxx, p. 16 (1908), 1910. F. A. 


Perret, Sei. Bull. Brooklyn Inst., i, p. 318, 1907. F. A. Perret, Smithson. 
Inst. Rep. (1912), p. 285, 1913. 


Fie. 1. 


Fic. 1. View of the crater mouths from the south, on the snmmit crest. 
At the right, the mouth ‘‘ D” is obstructed and inactive. Mouths *‘C” and 
** A” are seen at the center, and vapor from mouth ‘‘B” on the right in the 
distance. 


Fic. 2. 


Fic. 2. View of the sukdivided crater from the west, and showing the 
point of lava emission below the crater. 


— oe 


F. A, Perret—Lava Eruption of Stromboli. 449 


Before this eruption, this had been a very small but active vent 
situated on the eastern parapet, with a notable tendency to 
collapse of its walls, giving thus, in its frequent explosions, 
dense clouds of detritus. At present it is one of the great 
mouths of the eruptive apparatus, as it has always been one of 
the most active. 

Boeca C—by far the largest of the four—is situated next to 
the westerly Faraglione, while Bocca D, which is generally the 
least active and recently was obstructed for the greater part of 
the time, lies east of C and more or less directly south of the 
enlarged B. 

At the beginning of this eruption the lava overflowed the 
lower lip of the crater, forming and leaving a consolidated, 
convex ridge, probably a tunnel; later it issued from lateral 
vents on the slope of the Sciara. Owing to lack of observa- 
tions made at the time, we shall probably never be able to 
reconstruct this phase of the eruption. Near the central line 
of the Sciara and starting from Bocca A there is a fracture 
open at the surface for at least two hundred meters, of which 
the two edges are at different levels, but if the lava ever issued 
from this the locality has become hidden beneath later flows 
from the mouth which formed during the month of November. 
This is situated to the west of the fracture and about 160 meters 
from the crater and therefore at a level perhaps a little more 
than a hundred meters below the edge of Bocca A. 

This aperture has the usual form of an ‘“ oven mouth,” and 
is nothing more than the extremity of a tunnel which conducts 
the lava from the interior. 

From this disposition of the eruptive apparatus there results 
an effusion of lava which is in the nature of an overflow, not- 
withstanding the fact that it issues from a lateral opening, inas- 
much as it is an outflow of material from the upper portion of 
the magmatic column—a “sub-aerial” effusive eruption. And 
this disposition further permits, and produces in its perfection, 
that separation and segregation of gas and liquid—the first 
rising and escaping through the central crater, and the second 
flowing out laterally—which so greatly affects the character of 
an eruption, as was demonstrated at Teneriffe* and at Saku- 
rashimat and, as we shall presently see, also here at Stromboli- 


The Fluent Lava. 


_ As a result of the disposition just referred to, the lava issues 
from its tunnel already freed of those large bubbles of gas at 


* The Volcanic Eruption at Teneriffe in the Autumn of 1909, Frank A. 
Perret, Zeitschr. f. Vulkanologie, i, p. 24, 1914. 

{Sakurashima, Rapporto preliminare per Vistituto vulcanologico sulla 
grande eruzione del vuleano Sakurashima, Gennaio, Febbraio, Marzo, Aprile, 
1914, Zeitschr. £. Vulkanologie, i. p. 137, 1914. 


450 I. A, Perret—Lava Eruption of Stromboli. 


high tension which are the cause of the explosions at the era- 
ter, and there results a quiet flow. Although the gas content 
is still high, it is either still in solution or in the form of innu-, 
merable tiny vesicles in which the tension is too small to exert 
further influence upon the form of the viscous mass, and the 
lava possesses, in great part, the qualities of the “ pahoehoe” 
type. But the chemical constitution of this material, together 
with the steepness of the slope upon which it flowed “(36°), 

caused the formation upon its surface of a layer of scoriz 
which, rolling and sliding over the convex surface of the 
stream, accumulated in lateral moraines and gave to the flow 
the appearance of the “aa” type. We may say, therefore, 
that although both types of lava appear, the pahoehoe quality 
predominates, which is but natural considering that we have 
here a lava overflowing from an open conduit. 

That the mass of the flow was compact, coherent and con- 
tinuous was demonstrated by the two “re-fusions,” one of 
which was witnessed by the writer on the 29th. From the 
well-known point of observation west of the crater it could be 
seen that the stream of lava, which had ceased flowing several 
days before, lay black and motionless on the Sciara slope. At 
noon a movement was observed among the scoriz on the sur- 
face of the stream nearest to the vent, and soon this movement 
was propagated some distance forward. The first portion then 
became incandescent and began to flow downward very slowly, 
and this same succession of phenomena—movement of scorie, 
incandescence of the mass, and flowing movement— extended 
progressively along the line of the stream until the whole 
was in full flow for a hundred meters or more. There was 
not the least attempt to break through or over in order to 
seek a new channel, but a revivifying of the original mass 
under the renewed supply of heat and material from the 
source. There was no possibility of determining if the center 
of the flow had retained its original incandescence up to the 
time of the re-fusion. It is, of course, quite possible that a 
tunnel had been left, but the writer has on several occasions 
witnessed true re-fusion of perfectly consolidated lava under 
the onset of fresh material and does not believe these other 
conditions to have been essential to the renewing of the flow 
in the present case. 

The temperature of the lava was, in all probability, at its 
highest during the first period of the eruption when, according 
to the inhabitants, it was possible to walk about at midnight 
through the country lanes brightly illuminated by the reflected 
glare. It would then have been easy to obtain temperature 
ineasurements by means of an optical pyrometer if such an 
instrument had been available. During the month of Novem- 


FA. Perret—Lava Eruption of Stromboli. 451 


ber the direct employment of a thermoelectric pyrometer was 
prevented only by the heavy seas which made impossible a 
sufficiently near approach to the stream flowing into the sea at 
the Sciara’s base. Any approach to the source itself was pre- 
cluded by its position immediately under the crater. 

On the basis of the degree of incandescence. I estimated the 
temperature at 1100(+)°C.—this being mentally compared 
with the ineandescence of lava whose temperature was meas- 
ured, at Etna and Kilauea. 

The solidified lava is a very dense, black basalt, which shows, 
in an evidently vitreous groundmass, many small phenocrysts 
of augite, few of olivine and none of feldspar. Its petro- 
graphical characters and relations will be described later by 
Washington in connection with other rocks of the Aeolian 
islands, but it will be as well to put on record here its chemi- 
eal composition as contrasted with those of other recent Strom- 
boli basalts. 


A B C D 

SiON a2= 50-00 50°55 50°83 51°05 
ANO), SER CE M on 13°99 16°58 16°66 15°09 
Wetman es. 5°13 8-18 1:52 2°07 
JOCK ORE. Gave Far 9°10 a 6°64 6°88 
MeO....._... 4-06 6°10 6-08 6°52 
CaO eS 26. esas 10°81 11°45 10°99 11°34 
INOUE eS ioe. 2 Sx 3°15 2°66 2°53 
K,O ae lens Sah 2°87 3°16 2°05 2°02 
Ose tet eos. 0°24 0:06 0°36 0°15 
WOME Se ers 2 ond: n.d. 0°81 0°83 
LOWS ero ae n.d. n.d. n.d. none 
IO) aera 0°67 161 1-44 
TS) )) eared Ze aah ee trace n.d. n.d. 0:06 
Qi Oa eee) Sa n.d. n.d. n.d. 0°05 
Mn@ierae 2) 22 0:42 n.d. 0-12 0°13 

100°35 99:90 100°33 100°12 


A. Basalt of 1891. L. Ricciardi analyst. Ricco and Mer- 
calli, Ann. Uff. Cent. Met. Ital., xi, Pt. III, p. 202, 1892. 

B. Basalt of 1894. FE. Glaser analyst. A. Bergeat, Die 
Aeolischen Inseln, p. 44, 1899. 

C. Basalt of August, 1914. II. 8S. Washington, analyst. 

D. Basalt of November, 1915. H.S. Washington, analyst. 


Although the two earlier analyses, especially that of Ricci- 
ardi, are not very satisfactory, it is evident that at Stromboli, 
as at Vesuvius, Etna and many other voleanoes, the composi- 
tion of the lavas of the basaltic phase has remained very uni- 
form. As Bergeat points out,* the chemical composition of 


* A. Bergeat, Die Aeolischen Inseln, p. 45, 1899. 


452 EF. A. Perret—Lava Eruption of Stromboli. 


Fig, 3. 


Fic. 3. Showing the mass of new lava on the Sciara. This was built up 
of comparatively narrow streams alternating from side to side and forming 
the great, convex inverted wedge shown in the center of the view. 


Fie. 4. 


Fre. 4. The new Java on the Sciara seen in profile ; the shore line was 
formerly concave. 


FE. A. Perret—Lava Eruption of Stromboli. 453 


these recent Stromboli lavas differs markedly, notably in lower 
silica, from that of the older basalts of San Bartolo (Si0,= 
5Q: 25) and still more from that of the andesite flows at the 
earliest Vancori cone (SiO,=61°78). In this respect, a.so, 
Stromboli resembles many other volcanoes. 

The writer took pains to coat specimens of the basalt, taken 
incandescent from the flow, with paraffine as soon as they were 
sufficiently cool, in order to prevent diffusion of gases from the 
interior, and it is hoped that this lava, when heated in vacuo, 
will yield its original gas content for analysis. Direct collec- 
tion of gas by any other means was not feasible. 

The lava streams have formed upon the surface of the Sciara 
a very considerable mass, in the form of a fan, with a base 
line of perhaps six hundred meters. The shape is due to the 
continual shifting of the course of the flow by the upgrowth of 
its bed through cooling, with consequent lateral overtlow, and 
to the convexity of the solidified mass which diverted the later 
material, flowing from above, to one side or the other—in 
point of fact, the two latest flows are respectively the most 
easterly and the most westerly of all. 

The total quantity of lava emitted during the eruption cannot 
be computed by the usual method of cubic measurement, as 
the larger part is beneath the sea surface, and it is impossible 
to estimate the yuantity on the basis of the rate of flow because 
it was not under observation during four fifths of its period of 
eruptive activity. 

One of the most interesting observations in connection with 
this eruption undoubtedly is the behavior of the lava stream 
on coming in contact with the water of the sea and during its 
continued flow as a sub- -aqueous stream, and this not only 
because of the light which may be shed upon the manner of 
growth of the many volcanoes which have begun their 

existence at the bottom of the sea, but also on account of the 
paramount question of the absorption of water by hot lava— 
whether, that is to say, with the two in contact and under a 
certain amount of pressure, there will or will not be any actual 
acquisition of water by the lava which may result in chemical 
or physical changes therein. 

It goes without say ing that rapidly flowing lava—especially 
if containing large gas bubbles under high ‘tension—will, on 
entering water, cause considerable commotion and wenerate 
ereat quantities of steam with some appearance of violence. 
But when massive, highly incandescent Java, free from large 
gas bubbles, comes slowly into contact with water, also in mass, 
there is an absence of explosive phenomena or of serious 
commotion which at first is very surprising. At Sakurashima * 


*F. A. Perret, Zeitsch. Vulk., i, p. 143, 1914. 


454 I. A, Perret—Lava Eruption of Stromboli. 


there was a submarine lava flow extending from beneath the 
eastern lava field for a distance of two kilometers along the 
sea bottom. The lava had a depth of some seventy-five meters, 
with forty meters of water above it. The pressure at the sides 
of this mass of lava near the bottom was, therefore, equivalent 
to the weight of about 115 cubie meters of sea-water (=tons 
approximately) per square meter of area. The only disturbance 
visible at the surface was a succession of convection currents 
in the water, withont eruption of gas, and without raising the 
water temperature above 64° Fahr. at the surface and 72° 
just over the lava. In this case, however, the entrance of the 
lava into contact with water was mostly sub-surface and there- 
fore removed from direct observation, so the Stromboli event 
was welcomed as a rare opportunity for the study of this pheno- 
menon. 

The best observations were made on Nov. 18 and 25, when 
the sea and weather permitted—although with difficulty—an 
approach to the base of the Sciara by boat, while the lava was 
flowing into the sea in a massive, compact stream. This was 
about twenty meters broad at sea-level, witl moraines of another 
twenty meters on either side, formed of the scorize which slid 
and rolled in avalanches down the side slopes of the convex 
stream, amid clouds of brown attrition dust. 

The full length of the flow was visible, from the mouth of 
emission to the place of disappearance below the sea, and 
presented a striking spectacle, by day as well as by night. 
The narrow upper portion, flowing rapidly down the slope in 
a sinuous curve and slowly broadening, was divided on its 
surface by a “ medial moraine” of scorie forming a black 
streak between two ribbons of light—a phenomenon not un- 
common in flows of this kind, as for example, Etna in 1910. 
From the upper portion of the stream arose the familiar trans- 
parent bluish vapor, which was replaced in the middle section 
by the brown dust due to the attrition of scoriz, while from 
the lower extremity arose the dazzingly white clouds of the 
vaporized water at the point of entrance into the sea. 

The hot lava, with a front of twenty meters, entered the 
water at an average rate of about three centimeters per 
ininute, but the area of contact between water and incandescent 
lava, at any given moment, was rendered very variable by 
reason of the strong sea swell which alternately invaded the 
hot surface of the flow above mean water-level and then left 
exposed to view the cooled surface below. The result was a 
succession of strong steam puffs synchronous with the period 
of the swell. 

It is interesting to note that, even with a perfectly calm sea 
there is rarely a continuous and uniform evolution of vapor. 


FA. Perret-—Lava Eruption of Stromboli. 455 


At Sakurashima, on March 12, 1914, the lava, at one place, 
was entering a sea as Seats ‘as class, yet the evolution of 
steam was spasmodic and resulted in a series of puffs, of which 
one of the photographs taken by the writer might be mistaken 
for a copy of another made at Stromboli in 1915. In the case 


Fie. 5. 


Fic. 5. The descent of a lava stream on the Sciara into the sea. On the 
first third of the descent the vapors are of a transparent blue, very actinic 
and photographing as if white. The middle portion is a cloud of brown 
dust from attrition of scoriz and below is pure white steam from water 


vaporization. 

of the smooth sea some disturbance, such as the flaking off of 
superficial layers of scorize, exposes fresh, hot surfaces to the 
water which is momentar ily repelled by the sudden evolution 


456 I’. A. Perret—Lava Eruption of Stromboli. 


of vapor and returns in a wave, thus instituting a recurrent 
action which continues for a certain time. 

The sudden contact of water and incandescent material, over 
a considerable area, results in a violent evolution of steam with 
a rushing, blowing roar, and the projection outward of fine 
scorize and dust which wives a dark color to the lower portion 
of the cloud of steam. The vapor is often evolved in the 
form of high pressure spiracles proceeding from the interstices 
of the scorize, of which the temperature is such that the vapor 
is invisible for some centimeters above the source, thus render- 
ing difficult the precise photographing of the jets. 

‘But all this commotion—spectacular and impressive thouvh 
it may be—is confined to the water swrface at the point of 
entrance of the lava, and there remains the outstanding, all- 
important fact that the stream of compact liquid lava continues 
on its course beneath the waters of the sea. There is no sur- 
face indication of its existence as it disappears into the depths 
with a smooth, unagitated surface, and we are confronted by 
the fact of a massof highly heated liquid moving through water 
without conflict—a sub-aqueous lava comporting ‘itself as 
quietly as when. sub-aerial. 

That this is possible is due to the formation—by rapid cool- 
ing through contact with a cold, condneting liquid of great 
heat capacity —of a porous lava: sheath of low heat conductivity 
which intervenes to hinder the free passage of heat into the 
water. This may be assumed to be quasi-flexible throughout 
most of its thickness (that portion which includes the temper: ature 
gradient between 500° and 900°), and is probably very tough. 
The “icicles” which fringe the entrance to the spatter-g erottoes 
at the Kilauea lava lake are often several meters in length, but 
so tough and flexible as to remain suspended though buffeted 
in and out by belches of gas from the caves. 

A sheath of water vapor (spheroidal state) will also suggest 
itself as a heat insulator interposed between the hot lava and 
the water, but this well-known phenomenon, under the condi- 
tions here prevailing, is of such short duration that its influence 
to protect the flowing lava stream must be accounted secondary. 

The protective lava sheath will have a total temperature 
gradient from the temperature of the outside water (say 30°) to a 
thousand or more within, Rapid cooling is essential to the forma- 
tion of such a skin, for only in this way is a surface of such 
tough viscous quality and little crystallization obtainable in 
most lavas. Through the interposition of such a non-conduct- 
ing sheath an incandescent flowing lava will protect itself from 
reaction with water, while a hot crystalline rock has no protec- 
tion beyond the momentary check afforded by the spheroidal 
state of the water. At Etna the writer has seen a lava which 


eo 
Or 
~~ 


FA, Perret—Lava Eruption of Stromboli. 


Fic. 6. 


Fic. 6. Lava entering the sea. Photographed during a receding swell, to 
show the formation of the protective sheath, in contact with which no 
water is vaporized. 


Fie. 7. 


Fic. 7. Lava entering the sea. Showing development of high pressure 
steam spiracles, 


458 FE. A. Perret-—Lava Eruption of Stromboli. 


flowed for hours over snow without melting its way through 
it, and the masses of liquid lava thrown from the craters upon 
the snow fields remained virtually upon the surface and later 
formed “alpine mushrooms” by remaining poised on snow 
pedestals as the rest of the field disappeared under the sun’s 
rays—a merely hot rock will rapidly melt its way to the bottom 
of the snow. At Sakurashima, the water was most heated by 
the Java where this entered the sea in a tumble of hot bloecks— 
in the case of a liquid stream there was little heating, as has 
already been shown. 

We may say, therefore, that a flowing lava may exist in con- 
tact with water without the disintegration of either, thanks ,to 
the formation of a protective sheath, and this fact helps us to 
understand the quiet growth of submarine voleanoes. In such 
eases the only surface commotion need be that due to true gas 
emission at the central vent. 

In point of fact, a sub-aqueous lava stream comports itself 
more decorously than a similar sub-aerial one. This is due to 
an important fact which should here be mentioned. It is not 
to be supposed, of course, that the protective sheath absolutely 
and always prevents the entrance of water into contact with 
hot material. Cracks must form at its outer surface and a 
little water enter and be vaporized in the act of sheathing the 
raw places. But that which is thus evolved is simply the 
vapor of water and this, in the presence of water in mass, con- 
denses to water again—there is nothing to reach the surface 
and cause ebuilition. At Stromboli, when incandescent masses, 
detaching from the lava stream, rolled off the beach into the 
sea, those of which a portion remained projecting above the 
surface would steam copiously for a considerable time, while 
others, precisely similar but completely submerged, gave no 
surface indication of their existence. 


The Explosive Phenomena. 


In contradistinetion to that of 1891 the recent eruption was 
not characterized by important precursory explosive phenom- 
ena. There was, apparently, an emission of ash preceding the 
outflow of lava, but no sample of this could be obtained, and 
the emission was unimportant in point of quantity. But, 
toward the end of the eruption, on the 18th and 26th of 
November, two very violent explosions opened the conduits of 
the crater which had evidently become obstructed by collapse 
of the walls as a result of the falling lava column. The first 
of these explosions, oceurring a few hours after the first com- 
plete cessation of the lava flow, seemed a direct result of this 
new condition—“ post hoe, ergo propter hoe.” The second 


FA. Perret—Lava Eruption of Stromboli. 459 


explosion took place under diametrically opposite conditions, 
some hours after a copious outflow, following a temporary ces- 
sation, but it is probable nevertheless that obstruction by col- 
lapse was, in both cases, the determing cause. 

The explosion of Nov. 13 at 9.15 4. m. was sudden, power- 
ful, but remarkably superficial in its nature, and without seis- 


Fic. 8. 


Fie. 8. First phase of the great explosion on Noy. 13, seen from 
S. Vincenzo. 


mic effects, sending rapidly upward a dense, ball-headed cauli- 
flower cloud of detritus of which a shower of large but light- 
weight scoriz fell at S. Vincenzo in from five to six minutes 
after the explosion. In ascending the mountain directly after- 
ward, the detritus was found in masses of constantly increasing 


Am. JouR Scit.—FourtsH Seriss, Vou. XLII, No. 252.—Drcemser, 1916. 
32 


460 LE A. Perret—Lava Eruption of Stromboli. 


density as the crater was approached. On the slopes of the 
cone were splashes of fresh lava which had fallen in an incan- 
descent state and set fire to dry grass and straw, a woman 
working in the vineyards being ‘sliehtly burned in this way. 


Fie. 9. 


Fic. 9. Final phase of great explosion on Noy. 138, showing effect of 
following puffs in enlarging base of the *‘ pino.” 


There was also ejected a large quantity of gray, vesicular lava 
in small fragments with edges rounded as by attrition, and 
large blocks ‘half buried by their fall, still too hot to be touched. 
Many of these were coated with fresh lava which had been 
drawn by the movement into a filiform condition. Finally, 


j 
1 
‘ 


FA, Perret—Lava Lruption of Stromboli. 461 


there were large conglomerate bowlders, consisting mainly of 
old altered lava masses cemented together by fresh lava. Both 
of these explosions, but especially the second, threw out a large 
quantity of free augite crystals, many in the form of the well 
known cruciform twins. 

This first explosion, which was heard at Lipari, was followed, 
at 9.30, by a weaker one. The main explosion was also fol- 
lowed, as is generally the case, by a succession of puffs which 


Fig. 10. 


Fic. 10. Large conglomerate bowlder (about one cubic meter) ejected by 
the explosion of Nov. 26th. 


are comparatively so unimportant as to be noticed only as con- 
tributing to the maintenance of the great ash “ pino” and the 
enlargement of its base. 

The second great explosion, on Nov. 26, was much more pro- 
found, and was preceded by a strong concussion which violently 
shook the windows of the town from half a minute to a minute 
before the sound of the explosion itself reached it. We have 
here a phenomenon, also observed at other voleanoes, which 
requires further study before a satisfactory explanation can be 
reached, the difficulty here being the greater because of the 
uncertainty as to the elapsed time between concussion and 
explosion. No windows were broken, but the flat roofs were 
made to leak. 


462 LA, Perret—Lava Eruption of Stromboli. 


The products of this second explosion were more compact 
than those of the first—fresh lava masses of a beautiful steel- 
gray luster, and conglomerate bowlders of great general density 
and up to a cubic meter in size. 

In connection with the crater emanations a series of phenom- 
ena of great importance to volcanology were so well revealed 
by this eruption that the writer feels that he should not close 
this paper without reference to them. 

From a crater in moderate activity, the usual gaseous emana- 
tion in fair weather takes the form of a light cream-colored 

vapor, which rarely fills the whole area of ‘the crater cavity, 
but rises as a column of smaller diameter. At other times, 
however, a dense mass of pure white vapor fills the entire 
orifice, apparently pouring out of the crater in enormous 
volume and giving the impression of great activity. But it is 
often noticed that these two widely differing appearances may 
oceur during the same state of actual er uptive intensity, and 
even that one condition may be replaced by the other in a few 
minutes and without any increase or decrease of volcanic 
activity. 

Further observation reveals the fact that the condition de- 
pends upon the weather, the first condition prevailing on a 
fair day and dry state of the air, while a humid wind produces 
the second. The usual explanation—simple, and applicable to 
mere fumarolie emanation—is that the water vapor in the 
voleanic exhalations is absorbed in a dry atmosphere but con- 
denses in contact with moist and already saturated air. But, 
to apply this explanation in the case of an active volcano 
would be to assume that these great volumes of water vapor 
are being continuously exhaled from the volcano even when the 
visible ‘* panache ” is a slender column rising in the center of a 
oreat basin, as is so often the case. 

At Stromboli, on Nov. 27, the weather in the morning was 
clear, but threatening change. From Punta Labronzo the crater 
could be seen emitting ght columns of creamy vapor from the 
open mouths while tke most easterly mouth was obstructed, 
and emitted nothing. At noon a chill, moisture-laden wind 
suddenly supervened, and immediately there poured from the 
craters—including the obstructed mouth—a dense column of 
pure white vapor, without the least increase in explosive 
activity having occurred. 

The present writer has long suspected the atmosphere of 
being the source of this water vapor, but while it is easy to 
conceive of a condensation from humid air by a cold mountain 
peak—as in the case of Alpine “cloud banners ”—it was 
more difticult to account for it over a hot crater. It is here, 
nevertheless, that we have to seek the explanation of the 
phenomenon, which is merely due to the nucleation by the 


FA, Perret—Lava Eruption of Stromboli. 463 


voleano of saturated air from without. The great cloud of 
water vapor is notan emanation of the voleano, but a conden- 
sation from the atmosphere upon nuclei furnished by the 
stream of dust particles emanating from the volcano, aided, 
particularly in its initial stages, by direct ionization (electrons) 
in case the volcanic gases are escaping from liquid lava or 
through incandescent conduits. The well-known experiment, 
at solfataras, of holding a lighted torch near a fumarole to 
produce a condensation of the emanating water vapor, may be 
cited as an illustration of the phenomenon with, howev er, the 
conditions exactly reversed—at the more active vent the water 
is supplied by the atmosphere and the volcano is the torch. 

This atmospheric condensation will not always take place. 
Too high a temperature—as over a crater full of incandescent 
lava—will often prevent it, and even at a solfarata if the walls 
of a small fumarole are sufficiently heated artificially it will be 
found impossible to condense the issuing vapor by nucleation 
with a torch; bunt these cases are due solely to excessive heat- 
ing of the saturated air which then returns to an unsaturated 
condition. The importance of an understanding of this phe- 
nomenon lies mainly in avoiding erroneous impressions of a 
voleano’s state of activity based on the apparent emission of 
vreat volumes of steam from a crater which may really be 
almost quiescent at the time. Reports of this kind are con- 
stantly being made, and the dynamic record is often corre- 
spondinely faulty. 

Precipitation of salts from gas emanations was not marked, 
during this eruption, excepting in the fumarolic area, towards 
the end. Thisis perhaps but natural, considering that gaseous 
emanation was not the salient feature of this almost “wholly 
effusive activity. There was evidence during the eruption of 
response to the influence of favorable luni-solar combinations. 

In conclusion it may be pointed out that this last eruption 
offers further proof of the view already expressed elsewhere * 
that this voleano has, since 1907, entered upon a new period 
of inereased activity which has been characterized by powerful 
explosive and effusive eruptions having a greater resemblance 
to the processes of other voleanoes than to what has been 
generally considered to be the normal Strombolian form of 
action. There can be no doubt that Stromboli, to-day, is a 
mine of wealth for the direct observation of volcanic pheno- 
mena, and every effort should be made to provide for a more 
continuous study of it. 


Geophysical Laboratory, 
Carnegie Institution of Washington, 
Washington, D. C., Sept. 29, 1916. 


* Perret, F. A., Bull. Brooklyn Inst., i (1), p. 813, 1907; Ann. Uff. Cent. 
Met. Ital., xxx (1), p. 27, 1910; Smithson. Reports (1912), p. 285, 1913. 


464 J. G. Dinwiddie—Fluorine in Soluble Fluorides. 


Arr. XLV.— Determination of Fluorine in Soluble Fluo- 
rides ; by J. G. Dinwippie. 


[Contributions from tae Kent Chemical Laboratory of Yale Univ.—cclxxxiv. | 


In determining fluorine gravimetrically there are several 
methods. in use. The method of Rose* consists in precipitat- 
ing calcium carbonate together with calcium fluoride so that 
the precipitate of calcium fluoride may, with some degree of 
satisfaction, be filtered and washed. After being ignited, the 
calcium carbonate is dissolved out by means of 1°5 N acetic 
acid and the residue of calcium fluoride is washed, ignited andl 
weighed. This procedure is open to two objections: that the 
ealcium fluoride is very appreciably soluble in the dilute acetic 
acid, and that two filtrations are required. Starck and Thorint 
precipitate calcium fluoride along with a known weight of cal- 
cium oxalate and determine the fluorine by difference. These 
authors claim that the precipitate so formed is granular and 
easy to wash but Adolpht found it very hard to handle. 
Starck§ makes use of the mixed chloride and fluoride of lead. 
This method is said to give good results provided that care is 
taken to use very little wash water. 

In the attempt to precipitate fluorine so that it could be 
separated from fluosilicie acid by filtration, an excess of pow- 
dered calcium sulphate (CaSO,.2H,O) was used. This gave a 
precipitate of calcium fluoride and sulphate which was easier 
to filter and wash and had almost no tendency to run through 
the pores of the filter. It was thought that it might be possible 
to adapt this to the determination of fluorine in soluble fluo- 
rides. Calcium fluoride when treated with sulphuric acid is 
converted to sulphate, the fluorine being expelled as hydro- 
fluoric acid. Now if a mixture of fluoride and sulphate of cal- 
cium be similarly treated with sulphuric acid, the only change 
will be the conversion of the fluoride to sulphate. A gram 
molecule of calcium fluoride, 78, when changed to sulphate 
will weigh 136, so that an increase of 58 parts by weight will 
inean that the precipitate contained 78 parts of calcium 
fluoride. 

In perfecting this method there were several difficulties 
which arose in connection with the filtering, ignition, etc., of 
the precipitates. These will be enumerated, and then will be 
described the expedients which were used to avoid these diffi- 
culties. 

* Rose, Liebig’s Annalen, Ixxii, 343, 1849. 

+ Starck and Thorin, Zeit, Anal. Chem.., li, 1912. 
t Adolph, J. Am. Ch. Soc., xxxvii, 2500, 1915. 
§ Starck, Zeitschr. anorg. Chem., Ixx, 173, 1911. 


J. G. Dinwiddie—F luorine in Soluble Fluorides. 465 


1. Since the fluoride has to be treated with acid, it cannot 
be filtered on asbestos because the hydrofluoric acid set free 
will attack the mineral of the filter. 

2. If an ordinary filter is used, particles of the precipitate 
adhere to it and, when burnt along with the paper, the cal- 
cium sulphate is partly turned to sulphide and leads to incor- 
rect results. 

3. If the mixed precipitate is heated to redness in order to 
obtain a constant weight, the mass fuses together and it is 
almost impossible to completely decompose the solid mass with 
sulphuric acid so as to convert all of the fluoride to sulphate. 

4, When the excess of sulphuric acid is being driven off so 
that the residue of calcium sulphate may be weighed, great care 
has to be exercised to prevent spattering if the heat is supplied 
by placing a bunsen burner beneath the crucible. 

The detailed directions for the determination of fluorine by 
use of powdered calcium sulphate as mentioned above will now 
be given, and it will be made clear how each of the above diffi- 
culties was surmounted. 

The solution of the fluoride, which should occupy as small a 
volume as practicable, say about thirty or forty cubic centi- 
meters, and should be neutral, is heated to boiling and pow- 
dered calcium sulphate is added. After standing from thirty 
minutes to one hour, with frequent stirring, the precipitate of 
fluoride and sulphate of caleinm is washed | by decantation sey- 
eral times and then is put onto the filter for final washing. 
The filter consists of a perforated platinum crucible in the 
bottom of which is a small dise of ashless filter paper, cut so as 
to fit exactly in the bottom without being bent up around 
the sides. By keeping gentle suction upon the crucible, the 
dise is held in place and the filtrate comes through without 
the least turbidity. As soon as the precipitate has been 
sufficiently washed, it is transferred with the aid of a fine 
jet of water from a wash bottle to an ordinary platinum eruci- 
ble; the dise of paper is washed free of the precipitate and is 
ionited on the lid of the crucible, while the precipitate in the 
erucible is evaporated on the steam bath to dryness. If now 
this residue is heated to redness to obtain a constant weight, it 
melts and becomes very difficult to decompose with sulphuric 
acid. By experimenting it was found that at a temperature 
around 300°C. the calcium sulphate loses all of its erystal 
water and a constant weight is obtained. The proper temper- 
ature is obtained by heating the platinum crucible within an 
ordinary iron erucible of diameter about three inches at the 
top, used as a radiator. In order to equalize the heat a thin 
piece of asbestos was placed in the bottom and upon this was 
placed a small triangle for the platinum crucible to rest upon, 


466 J. G. Dinwiddie—Fluorine in Soluble Fluorides. 


By heating the bottom of the iron erueible with a bunsen 
burner to a low red, the contents of the platinum erucible 
reach a constant weight within one hour or less. 

When a constant weight has thus been obtained, the residue 
is mixed with a little water and several cubic centimeters of 
pure sulphuric acid. This mixture is now evaporated on the 
steam bath as far as it will go at this temperature and then, by 
heating further, the sulphuric acid is driven off, the last traces 
requiring the application of a red heat for a few moments. 
As was stated above, there is great danger of spattering when 
the excess of acid is being driven off. In order to avert this 
danger and to permit the acid to be driven off very quickby 
the following method was adopted: The lid is placed on the 
erucible, which is resting on a triangle. A Meker burner is 
fastened above and slightly to one side of the crucible by 
means of an adjustable clamp. The flame of the burner is 
allowed to impinge from above at an angle of about forty-five 
degrees, on the farther side of the lid of the crucible. In this 
way, the heat can easily be regulated so that the sulphuric acid 
volatilizes rapidly and, since the heat radiates from above, 
there is almost no tendency to spatter. The residue obtained 
by igniting at 300° consists of a mixtnre of calcium fluoride 
and sulphate while the residue remaining after volatilization 
of the sulphuric acid consists entirely of calcium sulphate. 
The increase in weight of the contents of the crucible is due to 
the replacement of two atoms of fluorine by the sulphuric 
acid radical. The changes which have taken place may be 
represented by 


2Nak + CaF, > CasO,,. 


Thus 84 of sodium fluoride gives 78:0 of calcium fluoride and 
136-07 of calcium sulphate. Therefore 58-07 of increase cor- 
responds to 84 of sodiuin fluoride and 78 of calcium fluoride, 
and to estimate the calcium fluoride present in the precipitate, 
inultiply the increase in weight by 78/58°07 = 1:3481 and for 
the sodium fluoride multiply by 84/58-07 = 1°4465. 

In order to test out the method which has been deseribed in 
detail, a solution of pure sodium fluoride was used. Com- 
mercial sodium fluoride, even that marked C. P., contains silica 
and so, for a standard solution, pure hydrofluoric acid was 
neutralized to phenolphthalein with pure sodium hydroxide 
obtained by allowing moist air to act on metallic sodium in 
absence of carbon dioxide. This solution was diluted so that 
it contained about three grams of sodium fluoride per 100 cubic 
centimeters. To ascertain the exact concentration of this 
solution, first the method of Rose, of precipitating the fluoride 
along with the carbonate of calcium, was tried. This precipi- 


J. G. Dinwiddie—Fluorine in Soluble Fluorides. 467 


tate was so hard to handle, in that it ran through into the fil- 
trate and clogged up the pores of the paper as well, that the 
attempt was abandoned. Since the solution of which the 
standard was desired contained no other compound besides 
sodium fluoride, its concentration was finally determined by 
evaporating measured portions to dryness in a platinum ecruci- 
ble, igniting to about 800° C. and weighing. The following 
results were obtained on several portions. 10° portions of the 
sodium fluoride solution gave 0°2724, 0°2721, 0°2723, 0°2725, 
02721 grams of sodium fluoride. One determination with 20° 
gave 0°5450 grams. The average of all gave for the standard 
of the solution that 10° contamed 0°2724 grams of sodium 
fluoride. 

The table following shows the results obtained by carrying 
out the determinations as outlined above : 


TABLE VI. 
Sol. Nak Increase Nak 
used Nak F, > 80, equiv. Diff. % error 


Caos’ 0°2724 01894 "2740 + 0016 + 0°62 
6b 10° 0:°2724 0-1888 oye + 0007 +0°25 
E i@* 0°2724 0°1885 2727 +°0003 +011 
Gf see 02724 0°1882 27223 —'00017 —0°062 
é 10°° 0°2724 0°1883 277237 —'00003 —0°015 
jf NOX 0°2724 01876 2714 —‘0010 —0°37 
Ge Pye 0°5448 03752 5427 —°0021 — 0°385 
lo Wee 0:°2724 0-1881 2721 —°0003 —0°082 
@ 


10°° C2724 0°1886 2728 + 0004 +011 


On account of the selubility of calcium fluoride, there will 
be a tendency for the results to run low and, unless the filtrate 
and washings are kept to a low volume, large negative errors 
are liable to occur. In several determinations the filtrate was 
about 200° and the results here were about 1-4 per cent low. 
On account of this danger, a solution saturated with pure cal- 
cium fluoride and ealcium sulphate was used for wash water 
in order to eliminate the solubility error and results very close 
to the calculated value were obtained even when the filtrate 
was allowed to get quite large. These results are shown in / 
and @ of Table VI. 

The weighed precipitate of calcium fluoride and sulphate 
might be converted, according to Loczke,* into chloride and 
sulphate, by evaporating with hydrochloric acid, and the cal- 
cium sulphate be weighed, the fluoride being determined by 
difference. However this would require another filtration and 
would be less accurate. 


* Loczke, Zeitschr. anal. Chem., xlix, 329, 1910. 


468 J. G. Dinwiddie—Fluorine in Soluble Fluorides. 


Since, during the precipitation of the fluoride of calcium by 
the sulphate, an equivalent amount of sulphate ion is set free, 
it is obvious that this method is adapted without any moditica- 
tions to the separation and determination of fluorides in the 
presence of sulphates. It may also be used for the separation 
of fluorine from other radicals which do not form insoluble 
compounds with calcium. 

The method of Bunsen for determining fluoride in the 
presence of phosphoric acid would be applicable here provided 
that it were accurate. This consists in weighing a mixed pre- 
cipitate of orthophosphate and fluoride of calcium and then 
converting it to phosphate and sulphate by ignition with sul- 
phurie acid. He claims that the final residue after ignition 
consists entirely of calcium orthophosphate and calcium sul- 
phate, but Treadwell and Koch,* in experimenting to decide 
upon the best method for this separation in wines and beers, 
heated a weighed amount of calcium orthophosphate with sul- 
phurie acid, as directed by Bunsen, until a constant weight was 
obtained. Instead of obtaining the original weight they 
obtained a much greater weight. Upon testing the residue, 
they found that the precipitate contained a large amount of 
calcium sulphate and that metaphosphorie acid had been formed 
and condensed partly on the lid of the crucible. 


* Treadwell and Koch, Zeitschr. anal. Chem., xliii, 469. 


L. D. Burling—The Albertella Fauna. 469 


Arr. XLVI.—TZhe Albertella Fauna Located in the Middle 
Cambrian of British Columbia and Alberta ;* by Lancas- 
ter D. Burne. 


As announced at the Washington meeting of the Geological 
Society of Americat the reference of the Albertella fauna to 
the Middle Cambrian+ has been confirmed by the discovery on 


Fic. 1. 


_Fic. 1. Outerop of the Albertella shale member of the Cathedral forma- 
tion on Mt. Bosworth, B. C. The thickness of the bed is 7 feet, the figure 
Being so far back of the beds shown in foreground as to make them appear 

icker. 


Mount Bosworth of the parent ledge of the drift block which 
has been so often described. The inability of either Mr. Wal- 
cott or myself, jointly or severally, to find this bed during the 


* Published by permission of Deputy Minister of Mines. 
+See 1 and 2 of the literature references at the end of the article. 


470 L. D. Burling—The Albertella Kauna. 


years in which search has been prosecuted is due to the fact 
that its reference to the Lower Cambrian led us largely to con- 
fine our efforts to the series of thin beds underlying the Oathe- 
dral formation. 

The fauna actually occurs in a 7-foot band of shale which 
interrupts the sedimentation of the massive limestones of this 
Middle Cambrian formation 375 feet above its base. The out- 
crop of this shale, to which the name of Albertella shale mem- 


Fic. 2. Described species of American Albertellas. 


Albertella bosworthi Walcott (British Columbia). 
Albertella helena Walcott (Montana). (After Walcott.) 
Albertella helena Walcott (British Columbia). 


Onp 


ber of the Cathedral formation is hereby applied, has a hori- 
zontal extent of several hundred feet on the east and northeast 
face of Mount Bosworth at an elevation of about 8000 feet 
(see fig. 1). Mount Bosworth lies on the continental divide 
just north of the main line of the Canadian Pacific Railway 
between Alberta and British Columbia. The relations of the 
Aibertella shale to the over- and underlying beds is given in 
the following section of the lower portion of the Mount Bos- 
worth and Castle Mountain sections: 


Prete Mount Castle Mountain, 
(slouiangintoray Bosworth 20 miles southeast 
le | we gee 
& _ Eldon. feet feet 
ee Stephen) ma seee ieee 400 315 
2 | Cathedral (upper) -- 175 565 
© | Albertella shale ___. 7 10 
= Cathedral (lower) -- 375 200 
= Mount Whyte. -.-.. 250 200 
qa 
Lower Cambrian (St. Piran) 


a 


L. D. Burling—The Albertella Fauna. 471 


Attention should be called to the apparent agreement in the 
thinning of the formations to the eastward ; but changes in 
sedimentation in the Canadian Pacitic Railw: ay section are so 
frequent and important that measures of thickness are usually 
local only in their application. 

In 1914° I did not presume to question Walcott’s reference 
of the Albertella fauna to the Mount Whyte formation, indeed 
the writer’s assignment of that fauna to the Middle Cambrian 
necessitated a change in the systemic reference of the Mt. 
Whyte formation. JI am now as thoroughly convinced that all 
but the lowest beds of the Mt. Whyte formation are Middle 
Cambrian in age, but the discovery that the Albertella fauna 
occurs in a shale member embedded 375 feet up in the over- 
lying massive arenaceous limestones of the Cathedral formation 
robs me of one of the main arguments which I used in 1914 
for the Middle Cambrian age of the Mt. Whyte. 

The reported discoveries ‘of the Albertella fauna to date are 
as follows, recording them in the order of their discovery : 


1. Gordon Creek, 6 miles from the south fork of Flathead 
River, Ovando quadrangle (U. 8. G. 8.), Powell County, Mon- 
tana, in a shale 75 feet above a quartzitic sandstone (1905).* 

2. Mount Bosworth, British Columbia, in drift near railroad 
right of way between Hector and Stephen (1907).° 

3. Mount Stephen, British Columbia, 200 feet above the 
quartzitic sandstones of the St. Piran formation (1907).° 

4, Lake Agnes section, near Lake Louise, Alberta, in a shale 
correlated with the horizon on Mount Stephen, No, 3 (1907).’ 

5. Liau-tung, Manchuria, on the shore of Tschang-hsing-tau 
Island (1909).* The correlation of this species with Albertella is 
somewhat doubtful, but it occurs above well marked Middle Cam- 
brian horizons. 

6. Mt. Robson region, British Columbia, 550 feet above the 
base of the Chetang limestones (1912)." 

7. Elko, British Columbia, in the Burton formation (1913)."° 

8. North Kootenay Pass, British Columbia, in shale (1915).” 

9. Mount Bosworth, British Columbia, the horizon of the 
drift blocks mentioned in “ 2” found interbedded in the massive 
limestones of the Cathedral formation 375 feet above its base 
(1915). 

10. Castle Mountain, Alberta, at the same horizon as the one 
on Mount Bosworth (1915). 

11. Mount Robson region, British Columbia, in a limestone 
whose exact stratigraphic relations have not yet been worked out. 
The horizon is comparable, however, with that on Mount Bos- 
worth (1915). 


The genus Albertella has been figured by Walcott in the 
following publications: Smithsonian Mise. Coll., vol. liti, 1908, 
plates 1 and 2; ; and Research in China, vol. iii, 1913, plate 12, 


472 L. D. Burling—The Albertella Fauna. 


figs. 1 and 2. Figures of the three species so far described are 
inserted here because A/berted/w deserves prominence as one of 
the best horizon markers of the early Middle Cambrian. 


Geological Survey of Canada, Ottawa. 


REFERENCES TO THE LITERATURE. 


1. Bull. Geol. Soe. America, vol. xxvii, pp. 63 and 158, 1916. 
2. Geol. Survey Canada, Museum Bull. No. 2, pp. 120 and 128, 1914. 
3. Ibid., pp. 116-120. 
4, Walcott, Mon. U.S. Geol. Surv., vol. li, pt. 1, p. 168, 1912; local- 
ity 4v. 
5. as Smithsonian Mise. Coll., vol. liii, p. 214, 1908. 
6. se Canadian Alpine Journal, vol. i, p. 241, 1908. (p. 10 of 
reprint. ) 
7. Idem, p. 214. 
8. Walcott, Research in China, vol. iii, pp. 27 and 106, 1913. 
$), s Smithsonian Mise. Coll., vol. lvii, p. 338, 1918. 
10. Schofield and Burling, Geol. Survey Canada, Mus. Bull. No. 2, pp. 
82, 98, and 125, 1914. 
11. Adams, Bull. Geol. Soc. America, vol. xxvii, 1916, pp. 62 and 638; 
and Commission of Conservation, Discovery of Phosphate 
of Lime in the Rocky Mountains, by Adams and Dick, 1915, 
p. 1s. 
12. Burling, Summary Rept. Geol. Survey Canada for 1915, pp. 99 and 
100, 1916. 
13. Idem. 
14. Idem. 


Arr. XLVII.—Some New Forms of Natrolite ; by 


ALEXANDER H. Pururirs. 


Some interesting specimens of natrolite were collected by 
Mr. Edward Sampson in the Ice Valley region of British 
Columbia. They were found along the contact of a nephelite 
syenite and limestone. The crystals were very large and indi- 
vidually developed, but forming reticular masses with angular 
cavities. Individual crystals were 6°" in length and 4° in 
diameter. 

A second generation of small, water-clear crystals occurs 
implanted upon the large individuals and terminating freely 
in the angular cavities. The large crystals are milky and 
translucent from inclusions. This second generation of small 
erystals are very rich in crystal forms and with very bright 
and perfect faces. On one crystal, although only a millimeter 
in diameter and terminated at one end, 38 faces were measured, 
representing 13 crystal forms. The large crystals are simple 
in habit; in the prism zone they are combinations of the unit 


A. H. Philtips—Some New Forms of Natrolite. 473 


prism and the two pinacoids with the unit prism as the domi- 
nant form. Terminations are rare and very simple, as they are 
formed by the unit pyramid almost exclusively. 

The chemical composition of the large crystals, as given in 
the analysis below, is that of a normal natrolite with a small 
amount of Na,O replaced with CaO. 


SiO» Aln,O; FeO; CaO MgO Na;O K,.0 H.0 Total 
AT?17 26°84 07 12 ‘05 15°89 02 9°58 99°74 


Crystal forms. 


Eighteen of the small crystals were measured and the fol- 
lowing forms identified : 6(010), a (100), 8(310), 2 (740), ¢(210), 
m(110), 2 (120), 7 (130), g (011), D (101), » (111), 2 (831), s (551), 
y (181), 8 (811), 0(151), o (511), ¢(531). Of the above forms 
the prisms ¢(210), 7(180) and the two pyramids 0 (151) and 
¢(531) are new forms for natrolite. The orthographic drawing 
represents approximately the development and general relations 
of these new forms. 

In the prism zone, the unit prism m (110) predominates, with 
the two pinacoids equally developed, next in importance; while 
the prism 2(120) is a small face, though constant, as it was 
found on 16 of the 18 crystals measured. The prism 7 (740) 
was a very narrow face, represented on 5 erystals and 6(310) 
was represented by equally narrow faces on 4 of the crystals 
measured. 

The new prism ¢(210) was found on 12 of the 18 crystals, 
usually represented by narrow faces but equal in development 
to either 7 or 6. The signals were from good to dull and indis- 
tinct. In one instance the face was large and the reflections 


474 A. HL. Phillips—Some New Forms of Natrolite. 
were all that could be desired. The measurements for this 
face were ¢ = 63° 58’ and p=90°. The average value of 
these angles, yielded by the ten brightest signals, is : 
ti Pp Maximum Minimum 
Measured ._.. 63° 56’ 90° (oye tal! 63° 46! 
Calculated... 68° 52’ 90° 


The prism 7(120) was represented by two narrow faces on 
one crystal which yielded fair reflections: 


v) p 
18° 00’ 90° 
Measured... -- 18° 36! 90° j 
Calculated - __-- 18° 46’ 90° 


The pyramid 0(151) was measured 16 times and was repre- 
sented on 4 crystals. The signals varied with the size of the 
face; taking the average of eight measurements where the sig- 
nals were satisfactory, the angles are 


» p 0 p 


Measured_- 11° 33’ 60° 54’ Maximum-- 11° 42’ 61°05! 
Calculated. 11° 31’ 60° 49’ Minimum -. 11° 27’ 60° 46’ 


The pyramid ¢(531) was represented by three faces on one 
erystal, two of which were well developed, yielding satisfac- 
tory reflections, while the third was very small with an indis- 
tinct signal. 


$ p 
59° 95! 64° 31’ 
Measured ___--- | 59° 93! 64° 31! 
Caleulated...-._ 59° 29’ 64° 22" 


There were several other forms represented, by very small 
faces, yielding signals too dull or indistinct to. give satisfactory 
measurements. The best of these, which occurred several 
times, indicated a pyramid in the zone of the new prism 
e(210), with indices (211). 


Princeton, N. J., Oct. 9, 1916. 


O. Schuchert—Pre-Cambrian Nomenclature. 475 


Arr. XLVIIL.—On Pre-Cambrian Nomenclature ; by 
CHARLES SCHUCHERT. 


Dourtine the past ten years there have appeared a number of 
most excellent studies on the structure and correlation of the 
pre-Cambrian rocks of the Canadian Shield and the Lake 
Superior region. To get these results in such form that under- 
graduate students in geology could easily understand the 
broader sequence of events, the writer asked his colleague, 
Professor Barrell, to set them forth in the shape of a geologic 
time-table.* We held that this classification “ must be regarded 
as provisional only, another step toward a larger and more 
accurate knowledge of the long eons which preceded the fos- 
siliferous record” (p. 17). Since then other classifications 
have appeared, and the one by Professor Lawsont+ stimulates 
the writer to the following remarks. 

The writer admits that he has no knowledge at first hand 
regarding the pre-Cambrian rocks but he is nevertheless 
deeply interested in the wisdom unearthed by those capable of 
working in this exceedingly difficult field. Some of this 
knowledge he is called upon each year to present to students 
in his course in Historical Geology. In this paper the writer 
will limit himself entirely to the terminology, and more espe- 
cially to the primary terms, the eras. As for the nomenclature 
of these ancient times, the paleontologist is as well trained to. 
look into it as is the geologist, and it is therefore beside the 
mark for Lawson to state that “the paleontologists should! 
refrain from insisting on their nomenclature in a field in which 
they do no work” (19). The rules relating to nomenclature: 
- apply to all geologists, and if any one has constructive ideas 
that will help to build up a better geologic time-table, it is his. 
duty to present them to his colleagues. As for “ insisting on 
their nomenclature,” we are all bound to observe the rules of 
nomenclature and to accept that which is well done. 

In regard to rules of nomenclature, Weeks in his Worth 
American. Geologic Formation Namest states: “In determin- 
ing the names to be applied to formations the laws of priority 
and prescription (general usage) should be observed. The 
name first given to a definite formation or series of strata 
should hold, unless this name is superseded in literature by 

* Schuchert and Barrell, A revised geologic time-table for North America. 
This Journal, (4) xxxviii, 1-27, 1914. 

+ A. C. Lawson, The correlation of the pre-Cambrian rocks of the region 
of the Great Lakes. Univ. Calif. Pub., Bull. Dept. Geology, x, No. 1, 1-19,. 


1916. 
+ F. B. Weeks, Bull. 191, U. S, Geol. Surv., 1902, 11. 


Am. Jour. Sct.—Fourts Srerins, Vou. XLII, No, 252.—Drcrmper, 1916. 


476 OC. Schuchert—Pre-Cambrian Nomenclature. 


another which has come into general use. In the latter case 
the first name should be dropped for this formation; and, 
where there can be no question as to the general usage of the 
subsequent name, the first name might be used again for a dif- 
ferent formation without causing serious trouble.” ‘The 
duplication of formation names has become a serious matter, 
as will be seen from an examination of this list... . New 
names should replace those which can not hold their present 
varied definitions.” 

Weeks has a separate list of the geographic names that have 
been applied to masses of igneous rocks occurring in North 
America. Two identical names, one for a stratigraphic unit 
and another for an igneous mass, may therefore remain in use. 

The rule of priority as to formation, series, and period terms 
is now generally adhered to, but in regard to era names the 
rule is not so rigidly followed, because they are more expres- 
sive of ideal conditions than are the smaller divisions of time. 
It is the same in biology in relation to family, order, and class 
terms, and it is from this source that paleontologists and geolo- 
gists get their ideas of fixity in nomenclature. 

The principles of correlation adopted by Lawson (and to 
which the writer also adheres) are, for pre-Cambrian forma- 
tions : 

“(1) The principle of lithologic similarity and the com- 
munity of conditions of deposition inferred from this similarity. 
(2) The principle of the similarity of sequence. (3) The prin- 
ciple of coincidence of unconformities in the sequence. (4) The 
principle of irruptive contacts” (4). On the basis of these 
principles the hypothesis of two periods of granitic invasion 
“states that in post-Keewatin time there were two and only 
two periods in which great granitic batholiths were developed 
in the earth’s crust in the region of the present Great Lakes” (5). 
Furthermore, “in every one of the fifteen districts, considered 
individually, geological time is blocked out into three grand 
divisions by the two granite invasions: the pre-granitic, the 
inter-granitic and the post-granitic ” (12). 

In regard to the major unconformities Lawson correctly 
holds that ‘‘ Wherever the earth’s crust is known to have been 
extensively invaded by granite, an important concomitant con- 
dition has been the uplift of the region affected and the inau- 
guration of a prolonged period of degradation, culminating in 
the removal of the cover from extensive areas of the gran- 
ite. ... The time necessary for the invasion of a region by 
granite is unknown, but it may well have been a long drawn- 
out process. The stripping of the cover of the granite, how- 
ever, and particularly the reduction of a high region to low 
relief, requires a long time in the geological sense; and the 


O. Schuchert—Pre-Cambrian Nomenclature. 


477 


Lawson Classification 1916 


Schuchert Classification 1915* 


Waucobian (Cambrian) 


Paleozvic 


(Primitive life) 


Late Proterozoic Era 
Algonkian 


Great Epi-Proterozoic Interval 


Keweenawan 
(Period) 


Animikian 
(Period) 


(Major division) 


Huronian 
(Period) 


Ep-Algomian Interval 


Early Proterozoic Kra 
(Primitive life) 


Neo-Laurentian 


Algomian Revolution 


(Major division) 


Sudburian 
(Period) 


a 7) Keweenawan 
812 (Epoch, Series) 
So ES 
g\ a8 
ala & | Animikian 
AY | (Epoch, Series) 
Eparchean Interval. Major Unconformity 
Algoman Revolution 
Temiskamian 
(Epoch, Series) 
Fe) 
2 
te] 
ae Unconformity 
ie) 
5 5 
BS 5@ | Bruce 
a q (Epoch, Series) 
3 
q 
= 
<| Epilaurentian Interval. Major Unconformity 


Ep-Archeozoic Interval 


Laurentian Revolution 


—| Grenville 
& | (Epoch, Series) 
~ 
DQ 
Sm | Keewatin 
8 i) (Epoch, Series) 
AE AG 
oe Coutchiching 
~| (Epoch, Series) 


Archeozoic Hra 
(Primal lite) 


Laurentian Revolution 


Paleo-Laurentian 


(Major division) 


Coutchiching | 


Keewatin ) 
; \ 
(Period) \ Grenville 


(Period) 


* Hssentially the same as Schuchert and Barrell 1914. 


478 O. Schuchert—Pre-Cambrian Nomenclature. 


interval of no deposition, between the sediments resting on the 
worn surface of the granite and the sediments into which the 
granite is intrusive, constitutes an unconformity of a major 
order. We may for practical purposes take the appearance of 
a worn surface of granite upon which as a basement sedimen- 
tary strata rest as prema facie evidence of a major uncon- 
formity ” (12). 

On the basis of these principles and their application by 
Lawson and many other geologists in fifteen districts in the 
Great Lakes, Ontario, and Adirondack regions, Lawson pre- 
sents a “ Correlation of the pre-Cambrian on the basis of two 
and only two granitic invasions.” The first column of this 
table is reprinted here and is set side by side with the one in 
the Pirsson-Schuchert Zewt-book of Geology. It will be seen 
that there are several nomenclatorial differences, and one 
marked discord regarding the time of the second granitie 
invasion, the Algomian Revolution. The correct determina- 
tion of the latter point is not within the writer’s scope, and is 
left to those knowing the field relations. 

The above two tables show that we agree that there were 
two times of granitic invasions—Laurentian and Algomian— 
and that there are two major unconformities. The writer 
believes (not knows) that the Keweenawan and more especially 
the Animikian are pre-Cambrian in age, that is, are older than 
the Waucobian or Olenellus tauna, the accepted base of the 
Paleozoic era. Holding to this belief, it follows that there 
should be another major unconformity above the Keweenawan 
and below the Waucobian of the Cambrian. Therefore the 
writer divides pre-Cambrian time into three eras, while Lawson 
holds that there is but one—Archean—and refers the Ani- 
mikian and Keweenawan doubtfully to the Paleozoic era. 
What the writer calls eras and periods, Lawson terms periods 
and epochs. This seemingly trivial matter is, however, not 
one of nomenclature but is of fundamental importance in the 
classification of geologic time. In other words, are we to hold 
with Lawson (1) that all pre-Cambrian time is structurally rep- 
resentative of but one era; (2) that eras may bave within 
themselves “revolutions,” ‘major unconformities,’ and very 
long intervals of erosion ; and (3) since pre-Cambrian time ‘is 
blocked out into three grand divisions by the two granitic 
invasions,” that these two “revolutions,” as Lawson also terms 
them, are but of the value of the breaks that separate the 
accepted periods of post-Keweenawan time? Long before the 
writer presented a text-book on Historical Geology most geol- 
ogists were holding that revolutions and major unconformities 
were indicative of era delimitation. Further, that pre-Cam- 
brian time was as long as and even much longer than all Pale- 


C. Schuchert—Pre-Cambrian Nomenclature. 479 


ozoic, Mesozoic, and Cenozoic time. In this connection it may 
be well to call attention to some conclusions by Van Hise,* 
who states that pre-Cambrian time may represent, according 
to some biologists, nine-tenths of geologic history since life 
began on earth. ‘In some eases the volume of rock and great 
intervening erosions represent a lapse of time which may be 
not inaptly compared with all subsequent time. If geological 
history were to be divided into three approximately equal 
divisions, these divisions would not improbably be the time of 
the Archean, the time of the elastic series between the Archean 
and the Cambrian, and post-Cambrian.” 

As it is generally admitted that pre-Cambrian time is very 
long, the conclusion must naturally follow that the revolutions 
and the major unconformities noted by geologists are of the 
value that distinguish the eras one from another. ‘The Lan- 
rentian and Algomian granitic invasions have the value of 
revolutions—the elevation of mountains and their removal 
through erosion—and the major unconformities in the geologic 
succession must be the places that distinguish eras. These 
unconformities are altogether too pronounced to be representa- 
tive of the breaks that distinguish periods. 

The next point of importance is, what shall be indicated in 
the term or terms to be used for the era or eras back of the 
Paleozoic? The strata of post-Cambrian time are usually 
replete with fossils, and their primary value in geologic chro- 
nology is accepted by all geologists. For this reason the 
Greek ending -zove, meaning life, has long been acceptable 
for the Paleozoic, Mesozoic, and Cenozoic eras. Again, it is 
admitted by nearly everyone that life existed long before the 
Cambrian and there are leaders, as for instance Chamberlin, 
who hold that it was present even before the Coutchiching at 
the base of the Archeozoic. Therefore why should not all era 
terms have the ending -zotc, as Archeozoic and Proterozoic ? 
The writer regrets to learn from so good a teacher as Lawson 
that he questions “ the advisability of teaching visions to begin- 
ners in geology.” It is true that pre-Cambrian life is not yet 
well enough known to be the basis of chronology, nor will it 
seemingly ever be, but what harm can there be in the visions 
of primitive life that are brought to mind by the terms Arche- 
ozoic and Proterozoic? Is it not far better to bring up these 
visions founded on such knowledge as we have, than to suggest 
eras barren of life by the use of the non-committal terms 
Archean and Eparchean? Until more reasonable evidence is 
forthcoming, the writer prefers to adopt terms for all eras that 
end in -zove. 

Let us now examine the various terms that have been pro- 

*C. R. Van Hise, Bull. 86, U. S. Geol. Surv., 1892, 491. 


480 C. Schuchert—Pre-Cambrian Nomenclature. 


ae for the rocks of pre-Cambrian time. It appears that 
rofessor Phillips was the first to use a term for all pre-Cam- 
brian rocks in his Manual of Geology (London 1832), group- 
ing them under Hypozoic. The writer does not have access to 
this book, but in the second edition of it, published in 1855, on 
page 655 the term is defined as follows: “ Hypozoic. A term 
proposed .... for the lowest primary strata, such as gneiss, 
mica, schist, etc., found below all those which contain organic 
remains,” i. e., below the Cambrian and Silurian. The word 
is taken from the Greek words for below and life. In this 
book Phillips further says it equals Murchison’s term Azove. 
The latter, however, dates from 1845* and therefore should not 
dispossess Hypozoic ; it is defined as follows: ‘To the erystal- 
line masses [of Norway and Sweden] which preceded that — 
paleeozoic suecession to which our researches were mostly 
directed, we apply the term ‘ Azoic,’ not meaning thereby dog- 
matically to affirm, that nothing organic could have been in 
existence during those earliest deposits of sedimentary matter, 
but simply as expressing the fact, that in as far as human 
researches have reached, no vestiges of living things have been 
found in them. ... Professor Phillips has applied the word 
Hypozoie to the same rocks which we term Azoic.” 

“One of the Scandinavian features which first strikes the 
ordinary observer with surprise, is the enormous amount of 
erystalline rock that occupies the surface of the country. In 
the term Azoic rocks, we include all the crystalline masses 
belonging to the ancient group of gneiss, together with ancient 
granitic and plutonic rocks by which they have been invaded.” 

The older term Hypozoic was not widely used and finally 
was altogether displaced by Azoic. The first geologists to use 
this term in America, and for all pre-Cambrian rocks, were 
Foster and Whitney.t Sir William Dawson used it also for 
all the pre-Cambrian rocks, the ‘oldest metamorphic rocks of 
Canada,” in the first edition of his Acadian Geology;t in the 
second edition of this book we read:§ The rocks below the 
Paleozoic *‘ until lately, were regarded as azoic, or destitute of 
remains of life; but the discovery of Hozoon canadense | this 
is certainly not a protozoan as held by Dawson, but appears to 
be an algal calcareous secretion] now entitles them to the name 
Eozoic [= dawn life], or those that indicate the morning of 
that great creative day in which the lower forms of animal 
life were introduced upon our planet.” Dana also used Azoic 
in the first edition of his Manwal,| as follows: ‘“ The Azoic 

*R. I. Murchison, Geology of Russia in Europe, 10*. 

+ Foster and Whitney, Geology of the Lake Superior Land District, Pt. IT, 
Washington, 1851, 3 and Chapter IT. 

Eee n Geology, Edinburgh, 1855, 22 and Chapter 15. 


§ 1868 
| incon of Geology, 1863, 134. 


0. Schuchert—Pre-Cambrian Nomenclature. 481 


age is the age in the earth’s history preceding the appearance 
of animal life,’ which he then held ceased with the Potsdam 
or the Cambrian. Earlier H. D. Rogers* had used both 
Azoie and Hypozoic in a modified sense, thus : 

* Azoic (Gr. a, without, zoe, life)—Applied to a group of 
rocks underlying the Palseozoic, and destitute of all traces of 
once vital organisms.” 

“ Hypozoic (Gr. hypo, under, and zoe, life)— A term for the 
egneissi¢ and other rocks which lie beneath the fossiliferous 
strata. The term is conveniently restricted to the more ancient 
metamorphic rocks which underlie the Azoic or semi-meta- 
morphic strata, which are also destitute of fossils, but which 
in many countries immediately support the Palzeozoic, or those 
containing organic remains.” On page 742 it is used in the 
sense of the oldest rocks, beneath the Azoic. 

Sir William Logant refers the Huronian series and the Lau- 
rentian series to the Azoic and remarks as follows: “To the 
Azoic rocks no local names have yet been applied in any part 
of America except in Canada, and as these rocks are here 
more extensively exposed than anywhere else on the continent, 

. . the names of the Laurentian and the Huronian systems 
or series . . . are allowed to remain unchanged.” 

According to the history above recited we should retain the 
term Hypozoie if there is but one geologic era back of the 
Cambrian, and the significance of the word is in harmony 
with the other accepted era terms in that it implies that there 
is life—of course as yet almost wholly unknown—in the rocks 
below the Paleozoic. In this event Azoic becomes a synonym, 
and further, the word is a misnomer in that it labels the pre- 
Cambrian rocks as being withort life. However, as we now 
know that there are at least two eras back of the Cambrian, 
the question arises, can we redefine Hypozoic and Azoic so as 
to be expressive of modern views? To all holding that life 
existed during Ontarian and Huronian time as defined by 
Lawson, it is at once apparent that Azoic should be rejected, 
and as Hypozoie was based upon a theoretic conception and 
not upon a detined rock area, it also seems to have no present 
value. As the writer holds that Hozoon canadense is evidence 
ot algal life, and as Walcott has demonstrated the presence of 
much life in the younger pre-Cambrian strata, it seems best to 
reject the names Azoic and Hypozoic. This becomes all the 
more advisable if there are three eras back of the Cambrian. 

The term <Areheozoic was proposed by Chamberlin and 
Salisbury in 1906. 

The evidence now being unearthed by geologists in the 

* Geology of Pennsylvania, ii, Pt. 11, 1859, 1025, 1026. 


+t Geology of Canada, 1863, 20-21. 
t Geology, ii, 1906, 187-139. 


482 C. Schuchert— Pre-Cambrian Nomenclature. 


pre-Cambrian rocks tends to show, in the writer’s opinion, that 
there are at least three eras back of the Paleozoic. Therefore 
we have to consider what they are to be called. The oldest 
one so far revealed is the Archean, which the writer prefers 
to know as the Archeozoic. This takes in the oldest known 
rocks of the Canadian Shield, which are invaded by the Lauren- 
tian granites as these are now delimited.. Lawson names this 
time the Ontarian period, or the Ontarian system of rocks. 
He well knows that his term is preoccupied by the Ontario 
division of the New York State Geologists, but concludes that 
the term was “still born”. The term, however, has been alive 
ever since 1842, has always had the value of a period, and js 
occasionally used even now, as Lawson may see if he will look 
up the references cited below.* 

According to the rules of nomenclature, Lawson’s Ontarian 
must be abandoned; from the writer’s standpoint there is no 
need for it in any event, because the rocks included within it 
by Lawson represent an era of time and therefore the selection 
is to be made from Archean or Archeozoic. If, however, a 
term is needed as a division of Archeozoic time, then Miller 
and Knight’s substitute, Loganian, should be accepted. This 
term need not be abandoned because of the Logan sill men- 
tioned by Lawson, nor on account of the Logan sandstone pro- 
posed in 1869 for a Mississippian formation in Ohio; the latter 
is a formation name, while Loganian is a different word, has a 
much larger time value and is, furthermore, based on alto- 
gether different rocks. 

Until recently the writer thought that Proterozoic was in 
good standing because of its use in Chamberlin and Salis- 
bury’s Geology. It appears, however, that Agnotozoic has 
priority, as the following clear definition will show. KR. D. 
Irving in 1887 wrote:+ ‘Some term is necessary to cover all — 
of that great gap which lies between the base of the Cambrian 
and the summit of the Archean gneissic and schistose base- 
ment. This name cannot be one of the group rank, since it 

* Ontario division. Vanuxem, Geol. N. Y., Rep. Third Dist., 1842, 13, 

15. Includes Shawangunk, Medina, Oneida, Clinton, Niagara, but not 
the highest Silurian. 
— Mather, Ibid., Rep. First Dist., 1843, 2, 353-365. 
— Hall, Ibid., Rep. Fourth Dist., 1843, 18. 
— Emmons, Agriculture N. Y., I, 1846, 141. Includes all Silurian 
formations. 
Ontarian or Ontaric. Clarke and Schuchert, Science, Dec. 15, 1899, 
875, 876. 
— Weeks, Bull. 191, U. S. Geol. Surv., 1902, 306. 
— Grabau, Science, Feb. 26, 1909, 356. 
— Schuchert, Bull. Geol. Soc. America, xx, 532, 1910. 
— Hartnagel, Handbook 19, N. Y. State Mus., 1912, 44, tables 1, 2. 


— Clarke and Ruedemann, Mem. 14, N. Y. State Mus., 1912, 87. 
+ This Journal, (3) xxxiv, 372-373, 205, 1887. 


CO. Schuchert—Pre-Cambrian Nomenclature. 483 


must cover two or more groups itself; it must be of the same 
rank with Paleozoic, Mesozoic and Cenozoic.” 

“The new term should have some reference to the life- 
conditions of these early times.” It “should then express the 
existence of this early life, and our present ignorance with 
regard to its nature.” Many new terms and one old one were 
considered by Irving. Among these was Proterozoic, a term 
suggested by Mr. Emmons; while the name is “simple and 
made from a Greek word of not too uncommon use, [it] seemed 
to fail in covering the ground sufficiently. I have therefore 
been disposed to return to a term early proposed by Professor 
T. ©. Chamberlin. .. . I would advocate therefore the use 
of the term Agnotozoic (unknown life), to cover all of the 
geological interval lying between the ‘base of the Cambrian 
and the summit of the Archean erystallines.” 

“Tt is suggested therefore that the term Archean be used to 
cover only the pre-Huronian basement crystallines ; that the 
Cambrian group remain as the basal member of the Paleozoic 
System, and that the new system name Agnotozoic ... be 
used to cover, at least provisionally, such clastic groups as inter- 
vene between the Cambrian base and the Archean schists.” 

In another place* Irving writes: ‘It seems, therefore, 
desirable that a new term should be introduced of equal classi- 
ficatory rank with Paleozoic, indicating that these great Pre- 
Cambrian and Post-Archean series are zoic in character, and 
that they cannot, as vet at least, be admitted to the Paleozoic 
series proper. . . . I advocated the adoption of the term 
Agnotozoic, indicating at once the presence of life and its 
unknown character.” 

As stated beyond, Irving credits the first use of the term 
Agnotozoie to Chamberlin, but the latter writes,t ‘ Although 
I have used the term in correspondence, conversation, discus- 
sion, and other informal ways for the past two years, more or 
less, a have nowhere formally proposed it in a scientific publi- 
cation.’ Through first publication therefore the name belongs 
to Irving. 

In this connection it is best also to give the conclusion of 
Van Hise t, who says: “It is imperative that some term shall 
be available to cover the great mass of rocks between the 
Cambrian and Archean. Irving was the first to realize and 
urge the necessity for such a term and proposed for it Agnoto- 
zoic. ‘This term implies the existence of life in this system, 
and the evidence upon this point is conclusive.” 

“The clastic rock masses below the Olenellus fauna are so 
enormous that the proposal to introduce a general term like 

*Seventh Ann. Rep. U. §. Geol. Surv., 1888, 453-454. 


+ This Journal, (8) xxxv, 254, 1888. 
} Bull. 86, U.S. Geol. Surv., 1892, 491, 493. 


484 O. Schuchert—Pre-Cambrian Nomenclature. 


Agnotozoic as the equivalent of Paleozoic, Mesozoic, Cenozoic, 
to cover this great group is a conservative one. Irving fore- 
saw that the term would be objected to because sooner or later 
the life will become to a greater or less degree known, and he 
suggested as an alternative for Agnotozoic, Eparchean in 
contradistinetion to Archean, which was reserved by him to 
cover the fundamental complex. As the character of the life 
of this group is already beginning to be known, it seems to me 
that the term Proterozoic, considered for the place by Ir ving, 
but rejected, is preferable to either Agnotozoic or Eparchean.” 

We, therefore, see that the name Proterozoic has not been 
defined and furthermore that it is synonymous with Agnotozoiec, 
a term in good standing. If the pre-Cambrian rocks are 
separable into three eras, and it so appears to the writer, then 
it would seem that Agnotozoic should be applied to that inter- 
val between the Laurentian and Algomian granites. If, how- 
ever, there are only two eras, it should refer to the second one; 
that following the Archeozoic. In any event, it should be 
applied to the greatest series of pre-Cambrian clastic rocks 
younger than the Archeozoic. 

In regard to the term Algonkian, it appears to have no 
standing at all, since it is a substitute for and a synonym of 
Agnotozoic, as ‘stated by Dana, and Chamberlin and Salisbury.* 
The term Algonkian is ‘usually ascribed to Walcott,t+ and while 
he did use it first in print, in 1889, he did not define it. It 
appears that Director Powell was the first to define Algonkian, 
as follows :t “ This series of rocks [in the Lake Superior 
region | lies beneath the Cambrian and above the Archean, and 
represents a period of the earth’s history during which lowly 
forms of life doubtless existed, but left few definite traces of 
their existence in the form of fossils... . The name ‘ Agnoto- 
zoic’ was... designed as one of the greater terms of geologic 
classification, codrdinate with Paleozoic, Mesozoic, and Ceno- 
zoic. In the geologic atlas of the United States ‘such larger 
classification will not be employed, but the largest time unit 
recognized will be the period. At a recent conference of 
geologists ... it was decided to make but one period of the 
Agnotozoic, and the name ‘ Algonkian’ was chosen to designate 
that period. It is not proposed to cancel the name Agnotozoic, 
but to leave its use to students having occasion to employ 
terms of higher classification.” 

It there are three eras in pre-Cambrian time, and if the 
lowest is to be known as either Archean or Archeozoic, the 

*J. D. Dana, Manual of Geology, 4th ed., 1896, 445; T. C. Chamberlin 
and R. D. Salisbury, Geology, ii, 1906, 162. 

+C. D. Walcott, this Journal (3), xxxvii, 383-384, 1889. 


tJ. W. Powell, Tenth Ann. Rep., U. S. Geol. Surv., 1890, 20, 66; also 
see Van Hise, Bull. 86, U. S. Geol. Surv., 1892, 493. 


CO. Schuchert— Pre-Cambrian Nomenclature. 485 


middle one as Agnotozoic, the youngest remains without a 
name. The writer will not embarrass the workers in this field 
of geologic endeavor by proposing a new name for it, but will 
remark that Proterozoic could be made use of for the youngest 
era. It will be remembered that Agnotozoic and Proterozoic 
are equal terms, but that the former has priority through 
definition, and that both were applied to all the rocks between 
the Archean and the Cambrian. Since it appears that this 
long time is divided by a revolution and at least one major 
unconformity, Lawson’s “intergranitic” division could well be 
agreed upon as the Agnotozoic era and the “ post-granitic ” 
division as the Proterozoic era; or the terms could be reversed 
if they should be found to agree better with the definition of 
Irving and with the actual field relations. 

From the quotations given it was seen that Eparchean was 
applied by Irving to the same time as Agnotozoic and that we 
may therefore write of Archean and Eparchean time. The 
latter term conflicts somewhat with Lawson’s Eparchean In- 
terval, but the latter has a wholly different meaning. Law- 
son is correct in insisting that we should, in our geological 
time-tables, take account of the “intervals,” the erosion inter- 
vals when the geologic record is being removed, and emphasize 
at least the major ones by giving them distinct names. His 
method is to add as a prefix the Greek word ep (=upon or 
after) to the name of the time previous to the erosion interval, 
as Eparcheozoic, Epalgomian, and Epiproterozoic. So long as we 
keep clearly in mind the fact that Irving’s term is monomial 
—Eparchean—and that Lawson’s is binomial—Eparchean Jn- 
terval—there need be no misunderstandings. In any event, 
we must begin to name the breaks in the geologic succession. 

In conclusion the writer offers the following amended ter- 
minology for pre-Cambrian time : 


Paleozoic Era. Basal series : Waucobian of Cambrian Period. 
Kpi-Proterozoic Interval. 
Proterozoic Era. 
Ep-Agnotozoic Interval and Algomian Revolution. 
Agnotozoic Era. 
Ep-Archeozoic Interval and Laurentian Revolution. 
Archeozoic Era. 
The unrecoverable beginning of earth history. 
Cosmic history. 


486 J. M. Blake—Plotting Crystal Zones on Paper. 


Arr. XLIX.—Plotting Crystal Zones on Paper; 
by Joun M. Braxe. (Article 3.) 


Many years ago the writer became interested in the study of 
erystals, and took up the subject of the relative lengths of the 
crystal axes as one step that might lead toward a better under- 
standing of crystal laws. Leading up to the present paper he 
wrote two others, one on zone measurement, which will be 
found in this Journal in 1866, and a second in May, 1915, this 
second paper relating to the growing of suspended crystals for 
the purpose of showing the proportional development of 'the 
planes on different members of an isomorphous group. To 
supplement this was mentioned the brief growing of polished 
erystal spheres of a salt with the object of bringing out the 
maximum number of planes belonging to the species, some of 
which planes may have been undeveloped by the first treatment. 

The mystery connected with the irrational axial lengths 
appears not to have been solved up to this day, and that this 
mystery still exists must be laid in great part to the difficulty 
in making exact measurements. These measurements as a rule 
may vary ten minutes or more in angle, and under these con- 
ditions, it seemed useless to depend upon the ordinary methods 
of utilizing such measurements for the purpose of solving our 
problem. 

The evident need of greater accuracy led the writer to adopt 
several methods for improving and facilitating work on erys- 
tals. In part, these methods were original. It was hoped that 
by attacking the problem in different ways, some progress 
might be made in the solution of the axial question. One of 
these methods is here described. The experimental trials with 
these methods have thus far been limited mostly to the ortho- 
rhombic and the oblique systems of erystals. 

It appears to be generally accepted that the length of the 
axes of acrystal belonging to these systems cannot be expressed 
in whole numbers, or by a vulgar fraction. These axial lengths 
may be square roots multiplied by some rational quantity. The 
parameters or the lengths cut off on the axes by the planes of 
the crystal are generally considered to have the relation of 
simple rational numbers when compared with one another. 

Variations in angle are mostly due to what are called vicinal 
planes. These planes and the related curved surfaces have 
been regarded as secondary and as superposed on the ideally 
perfect crystal. This, however, may be regarded as a tenta- 
tive supposition. These vicinal planes and the related curved 
surfaces are doubtless subject to certain laws by themselves, 


J. M. Blake—Plotting Crystal Zones on Paper. 487 


but their presence prevents exact measurement of the perfect 
erystal, while the want of exactness in determining the perfect 
crystal likewise interferes with the study of her laws of the 
vicinal planes. 

A common practice has been to measure two or three of the 
angles between prominent crystal faces, and to calculate the 
angles between the remaining faces from these measurements. 
These angles have sometimes been measured from certain 
planes which, in a given species, are found to be habitually 
subject to variation, and in such a case all the calculated angles 
would be subject to error. 

In carrying out this present method, the zones are plotted 
from the goniometer measurements, and by this means the sys- 
tem of equal spacing can be at once developed. We will thus 
have our work mapped out and the position of the axes indi- 
cated. The goniometer measurements should furnish a record 
of the character of the planes in regard to their reflections, and 
this record will guide us in our selection of the most suitable 
of the developed spaces from which to estimate the axial ratios. 
This plan will be found very simple and will require no resort 
to equations or formulas, while the results in very many 
instances may be made to exceed in accuracy those obtained by 
the present commonly used methods. 

Epidote has been selected for the purpose of illustrating the 
present paper. Decloiseaux has collected data from many 
sources, and he gives elaborate tables of angles in his Mineral- 
ogy (1862). He mentions various groups of associated planes 
on specimens from widely scattered localities. It would seem 
that the search had been thorough for all possible planes. 
There remains the possibility that some planes of uncertain 
standing may have been included, and other errors are possible. 
The process of clarification and elimination usually adopted in 
making up crystal descriptions may at times destroy details 
which would be valuable in making future revisions. 

Plotting an Indwidual Zone.—This can be done with ease 
from the complete serial goniometer readings, but more difli- 
culty is encountered when we have to work from a published 
description, as in the case of epidote. In this published descrip- 
tion, scattering measurements are given, and also the solid 
angles and not the angles between the normals; and besides, 
some of the planes are “difficult to locate for the reason that we 
miss the sequence which complete zone measurements should 
furnish. Under the conditions as we proceed, we are con- 
stantly reminded that our method is leading us outside the 
regular traveled paths. 

The work of Decloiseaux is valuable for its thoroughness. 
It does not, however, have all the elements we could desire for 


488 J. M. Blake—Plotting Crystal Zones on Paper. 


our present purpose. Such omissions oceur in many similar 
descriptions. These wanted elements can only be supplied by 
a further study of the original crystals. 

We begin our zone plot by first drawing a circle, and we dot 
the position of the normals of the planes on this cirele by 
means of a protractor. We now draw radii through these 
normal points. Then we take a scale of equal parts and rotate 
it in the plane of the paper, and at the same time move it out 
and in from the center until we have the equal spaces on the 
seale coinciding with the extended radii. The straight edge of 
the seale will now represent a tangent line, and the distance of 
this line from the center wil! be the radius, and one of, the 
equal spaces so developed divided by the radius, will give a 
tangent ratio commonly known as the axial ratio. This ratio 
will be that between the two axes that are included in the 
selected zone. 

Guided by our zone plot, we may reach further accuracy up 
to the limit we have-secured by our goniometer measurements, 
by taking the values from a table of natural tangents. Planes 
which do not fall into the system of equal spacing as shown 
on the plot, will be open to the suspicion of being false entries, 
and so, also, complex fractional indices should be subject to 
inquiry. The latter may be due to the position of the selected 
axes, or to the adopted axial lengths. At the same time, frac- 
tional indices are not impossible. The half spaces that are 
shown on fig. 2 appear to belong to the general make up of the 
erystal. The positions of some of the fractional planes have 
been dotted, but the letters designating them have been omitted 
in fig. 2. 

Fie. 1 gives the zone of epidote that contains the inclined 
axis. The horizontal line within the circle represents the 
plotted tangent line on which the equal spacing is developed 
by the intersection of the radii with the equally spaced scale. 
The inner circle gives the symbols from Decloiseaux, and the 
outer circle, the symbols from Dana’s Mineralogy. The radii 
are drawn on fig. 1 to show the equal spacing characteristic. 
These radii are also marked on the marginal ring in fig. 2. 

These two diagrams differ in this way. Fig. 1 shows the 
plane of the plotting paper with the radii drawn upon it. 
The plane in fig. 2 is parallel to this plane and is the plane 6 of 
Dana, and the plane g’ of Decloiseaux. On this plane 3, is a 
projection of all the planes of the crystal whose normals pierce 
this plane at the points lettered on the diagram. The normals 
of the zone which is being plotted are parallel to this plane d 
and do not pierce it, and their position is marked on the mar- 
gin near the circle in fig. 2. 

Decloiseaux’s stereographic projection is much confused by 


J. M. Blake—Plotting Crystal Zones on Paper. 489 


many cireles. This is also a fault with certain more recent 
stereographie drawings. The gnomonic projection is given in 
fig. 2, and the general relation of the zone being plotted to the 
other planes on the erystal can be better traced out upon this 
projection. The direction of the two tangent lines shown in 
tig. 1 is indicated on fig. 2. 

In the zone represented in fig. 1, the clarifying process has, 


Fie. 1. 


of course, been already applied, and we can only follow, and 
have to accept that which remains of the preliminary work, as 
we find it. If we could refer to an original measurement of 
this zone, we would have our choice in selecting the developed 
tangent spaces we regarded most suitable for estimating the 
axial ratio. In this selection we would discriminate against 
imperfect reflecting surfaces, and also spaces too far removed 
from the zero point, because far out from this point the tan- 
gent changes rapidly with small change of angle. We would 
take the average of the most suitable available spaces. In this 


490 J. M. Blake—Plotting Crystal Zones on Paper. 


way we could have a control by using the tangent projection 
system which we would lose when relying on a few single 
measured angles. 

Since the crystals of epidote came from different sources, 
and had different isomorphous compositions, as is indicated by 
the analyses, it would not seem impossible that there might 


Fic. 2. 


\/ 
\e7 DAA (AAA 
S AS 


ONE 


be different proportional soceuapuiede of the prismatie planes 
in this zone in the different specimens, and that disconnected 
measurements of angles might not always be successful in 
bringing the prism in the correct position to make a correct 
reading” of the planes to accord with the originally adopted 
position. This is suggested as a possible result of there being 
two well developed tangent equal-space positions, though the 
spacings slightly differ, and one set does not include all that 
are in the other set. In fact, this last mentioned point led to 
the suspicion that there was some duplication. 


J. M. Blake—Plotting Crystal Zones on Paper. 491 


The diagram in which the tangent line is drawn horizontally 
(fig. 1) is the one which has been made the basis of the gener- 
ally adopted system ofsymbols. The other tangent equal-space 
position as. shown by the oblique tangent line in fig. 1 might, 
it would seem, with equal propriety have been selected as a 
basis of the symbols. 

This condition of things being unusual, if it could be shown 
that it has been the cause of such a mistake leading to duplica- 
tion, it would furnish an argument for making complete zone 
measurements as a preventive measure. 

In attempting to account for these various features we will 
quote Miers’ Mineralogy (1902). He says: “The law of 
rational indices is true if any three edges are taken as axes.” 
We would expect, as a rule, that this would result in very com- 
plicated rational indices. 

The two selected tangent positions in epidote carry out 
Miers’ theory to an unexpected degree. If we take the two 
tangent sets and compare the developed spaces in each set by 
using a table of natural tangents, we find that the Decloiseaux 
ealeulated angles carry out the equal spacing for each set with 
great exactness. That is, the same zone series of angles when 
started from different points, with certain exceptions as shown 
in fig. 1, develop the equal spacing shown on our scale of equal 

arts. 

f It should be understood that by construction as given in 
fig. 1, the two sets of spaces are there drawn as of equal length, 
being controlled by the scale spaces, but if we make the radius 
unity in each case as it should be for comparison, we find the 
axial ratios differ somewhat in the two sets because the spac- 
ings as revised become different. 

‘When we have measured and plotted all the planes on the 
crystal in the way represented for epidote in fig. 2, our chances 
of selecting and averaging suitable spaces from the whole 
erystal system would become much more extended than would 
be the case when we deal with individual zones. We would 
then have command of the crystal planes as a whole, and a 
system of averaging the results of all the measurements could 
then be carried out. 

Since the best selection, and the averaging of the results on 
the erystal as a whole will depend on individual judgment, the 
preservation of the data on which the completed work is based 
would appear to be a wise precaution for use in any future 
revision. 

_There is a method of obtaining the gnomonic or tangent 
plane projection which should be a subject for another article. 
This plotting of separate zones leads up to this tangent plane 
projection from the several zone plots. 


Am. Jour. Sct.—Fourtu Series, Vou, XLIT, No. 252.—Drcremperr, 1916, 
34 


492 J. M. Blake—Plotting Crystal Zones on Paper. 


When the exact laws on which erystal architecture is based 
are definitely determined, we may see a way to condense 
erystal descriptions and still retain the essentials, Some 
erystal descriptions retain the skeleton but lack the substance. 

‘We have shown how, by means of a single circle goniometer 
and a few simple tools, we can get interesting results in study- 
ing erystals. There are means of facilitating this erystal work 
still further, and by their use we may follow this partly ex- 
plored field with good prospects of securing valuable results. 
The act of partially measuring a large number of species, and 
storing away sometimes very bare details, does not advance 
the science in a way we could wish. 

Only a comparatively few out of a very large number of 
subjects have been tested by these methods up to this time, 
but every species appears to present some interesting features 
of its own. 


New Haven, Conn., Aug. 1916. 


OC. HI. Warren—A Graduated Sphere. 493 


Arr. L—A Graduated Sphere for the Solution of Problems 
in Crystal Optics; by Cuartes H. WARREN. 


Amone the many useful adjuncts to work in crystal optics 
is the graduated, porcelain hemisphere devised by Nikitin.* 
Inasmuch as it has been impossible, since the outbreak of the 
European war, to procure this piece of apparatus, it occurred 
to the writer to attempt the construction of a piece of apparatus 
to take its place. The result was so successful that it has 
seemed worth while to publish a brief description of this new 
sphere, with the idea, that others engaged in work in crystal 
optics, and desiring such a piece of apparatus, might find the 
description useful in constructing a similar one. 

While the general design of the sphere was the writer’s, the 
greatest credit is due to Mr. Carl Selig, mechanician for the 
Department of Physics at the Massachusetts Institute of 
Technology, for his skill and ingenuity in working out the 
details of the construction. 

The material first used for the sphere was an eight- iol 
bowling-alley ball. This was found, however, to. depart 
slightly from a true sphere, so that a hollow brass sphere was 
substituted. This was cast with a shell of about #” thickness, 
and the surface was then machined down on a lathe to a per- 
fectly spherical shape. 

The sphere was next given three coats of white enamel 
paint, and then polished with pumice and water. Vertical and 
horizontal meridians, ten degrees apart, were then ruled on the 
enamel surface, this being done on a lathe, using black drawing 
ink, 

The graduated sphere was then mounted in a hollow metal 
cup about five inches in diameter, which was carefully lined 
with felt (see a, fig. 1). The cup was accurately centered 
with reference to the holding frame with its attached scales, 
and so mounted on a post as to allow the cup and sphere to be 
rotated rigidly in the horizontal plane. Three short, brass 
pins (see fig.) serve as handles to make the rotation easier. 

The standard carrying the sphere is surmounted by three 
polished steel scales mounted on a brass backing #” thick. 
_ One is a horizontal scale (0, fig.) and two are vertical scales, 
ninety degrees apart. The three scales are graduated in 
degrees, every five-degree mark being accentuated, and every 
ten-degree graduation being numbered. One of the vertical 
scales (c, fic.) is mounted so that. it can be rotated about a 
horizontal diameter through a range of 125°. To make such 


* Zeitschr. f. Kryst., xlvii, 381, 1910. 


494 OC. H. Warren—A Gaaduaay Sphere. 


a movement possible, the back of the brass plate to which 
the scale is fastened, was bevelled down to a very thin edge, 
the bevel beginning about an inch and one-half back from the 
ends of the scale. The bevelled ends are fastened to a small 
brass block (see d, fig.) to which is attached a pin that rotates 
in another metal block which in turn is firmly attached to the 
horizontal seale (see e¢, fig.). The end of the vertical scale is 
set at 0-180° on the horizontal scale. A clip, fitting into a 


Fre. 1. 


Fic. 1. Photograph of an eight-inch graduated sphere for use in work 
on crystal optics. It is so mounted that it can be rotated rigidly about its 
vertical axis, or moved in any desired direction upon the cup in which it 
rests (a). It is provided with three graduated, metal scales, two vertical 
and one horizontal. One of the vertical scales, (c), can be rotated about the 
horizontal diameter through an angle of 125° by means of a mounting device 
shown by the letters d and e. é 


shallow notch in the second vertical scale (not shown in the 
tivure) can be used to hold the first scale at the vertical center- 
point of the sphere, if desired. In practice, however, the 
writer has not found it necessary to use this clip. 

As the sphere can be rotated rigidly about the vertical axis, 
or turned in any desired direction, and as one of the vertical 
scales can be moved through a large angle (125°), it will be 
evident that there is an entirely adequate freedom of move- 
ment to make possible the solution, with this sphere, of any of 
the usual problems met with in crystal optics where spherical 
projections are used. Great circles, polar to any point, can be 
located and drawn in with a pencil, and angular values may be 
determined with great rapidity and ease. For drawing small 


C. H. Warren—A Graduated Sphere. 495 


cireles, a pencil may be held firmly against one of the vertical 
seales while the sphere is rotated about its axis by means of 
the cup in which it rests, or asmall metal clip could be easily 
made which would serve to hold the pencil instead of using 
the fingers. 

The accuracy which can be attained with this sphere de- 
pends, of course, on the accuracy of its construction. A. skill- 
ful mechanician should, however, be able, with a little pains, 
to construct it’so accurately that the results obtained with it 
will be of the same order of accuracy as those which can be 
obtained by the use of stereographic plats, provided, of 
course, that the same amount of care is taken in drawing, and 
in reading the angles. It has seemed to the writer that this 
form of a graduated sphere has an advantage over that of © 
Nikitin in being somewhat more flexible and easier to use. It 
has been found to be invaluable for purposes e. rapid demon- 
stration in the laborator 

The cost of the sphere built for the writer was about forty 
dollars (labor and materials). The standard, however, was 
taken from another piece of apparatus, so that the probable 
cost of the sphere and mountings would be in the neighbor- 
hood of fifty dollars. 

Department of Geology, Massachusetts 


Institute of Technology, 
Cambridge, Mass., Aug. 1916. 


496 Scientific Intelligence. 


SCIENTIFIC INTELLIGENCE. 


I. Curmistry AND Puystes. 


1. The Separation of Lithium from Potassium and Sodium.— 
SamurEL Parkin has modified the old method of Rammelsberg, 
which consisted in treating the dry chlorides with a mixture of 
anhydrous alcohol and ether in order to dissolve the lithium 
chloride. This method is known to be unsatisfactory, both on 
account of the tendency of lithium chloride to be partially con- 
verted into the insoluble carbonate when dried in the air, and 
also on account of the occlusion of some of the lithium chloride 
by the insoluble chlorides of sodium and potassium. ‘The present 
method avoids these difficulties by precipitating the greater part 
of the sodium and potassium chlorides in the first place by add- 
ing alcohol slowly and then ether to a slightly acid, very concen- 
trated aqueous solution of the chlorides, then after filtration on a 
Gooch crucible, evaporating the filtrate to dryness, taking up the 
residue with absolute alcohol containing a drop of hydrochloric 
acid, adding ether until the small amounts of sodium and potas- 
sium chlorides are completely precipitated, and collecting the 
precipitate with the original one. One volume of alcohol to 
about 5 volumes of ether is the mixture recommended for the 
precipitations and for washing. From the results of test analyses 
it appears that the method gives excellent results. However, it 
does not seem probable that the method will supersede in general 
analytical practice the more convenient and very satisfactory 
method of Gooch, unless, perhaps, there may be some who pre- 
fer the fumes of ether to those of amyl alcohol.—Jowr. Amer. 
Chem. Soc., Xxxvili, 2326. H. L. W. 

2. The Action of Light upon Iodine and Iodide of Starch.— 
It is stated by M. H. Borprer that not only does the well-known 
blue iodide of starch form colloidal solutions, but that the solu- 
tion of iodine itself in water is-also colloidal, showing ultra- 
microscopic particles. He has found that sunlight has an action 
upon very dilute solutions of these two substances. or instance, 
when 10 drops of 10 per cent tincture of iodine are added to 
1000°% of water with agitation after the fall of each drop, a pale 
yellow solution containing about 18™ of iodine is obtained. If 
a little starch paste is then added a blue color is obtained and 
this disappears after several hours of exposure to sunlight. More- 
over if the iodine solution is exposed to sunlight first and the 
starch paste is added afterwards, no blue color is produced. The 
author’s explanation is that the iodine simply goes into the ionic 
condition under the influence of the light, but this does not 
appear to be a very satisfactory explanation. The reaction was 
applied to a test of the colored glasses used for bottles to protect 
substances from the action of light, and it was found that the 
yellow glass most extensively employed for this purpose gives no 


Chemistry and Physics. 497 


protection at all from the action of sunlight upon the iodide of 
starch. Further experiments showed that the action of X-rays 
upon this substance gave the same effect as sunlight.— Cumpies 
Rendus, elxiii, 205, 293. H. L. W. 

3. The Crystallization of Calcium Tartrate.—Few salts have 
been more frequently prepared than calcium tartrate, on account 
of its employment for the recognition of the acid, and it is sur- 
prising to find that little is known of its behavior when crystal- 
lizing from aqueous solution. It has been observed by F. D. 
Cuartraway, of Oxford University, that when equal volumes of 
0-2 NV solutions of calcium chloride and potassium sodium tartrate 
are mixed at ordinary temperature the liquid remains clear for a 
short time, then small tufts of needle-shaped crystals make their 
appearance and rapidly grow until in a few minutes the whole is 
filled with such tufts, which finally interlace, producing a felted 
mass of crystals to such an extent that the vessel may be inverted 
without loss of mother-liquor. This salt is the hexahydrate, 
CaC,H,O,.6H,O. This form is unstable, and after ashort time at 
ordinary temperature small orthorhombic crystals of the tetra- 
hydrate, CaC,H,O,4H,O, make their appearance and grow 
rapidly, settling to the bottom of the liquid, while the needle- 
shaped crystals dissolve and disappear. The change takes place 
more rapidly when the mass is stirred or shaken vigorously, and 
it is still more rapid upon heating. This phenomenon should 
furnish a striking lecture experiment.—Jour. Amer. Chem. Soc., 
XXXVIil, 2519. H. L.. W. 

4. The Basic Copper Sulphates—S. W. Youne and A. E. 
SrEaRN, observing that the results of the analyses of the mineral 
brochantite, a basic copper sulphate, vary widely, and that a very 
large number of artificial products have been described which 
vary between the limits 10CuO.SO, and 2Cu0O.SO,, with vary- 
ing amounts of water, have made an investigation upon the sub- 
ject. By treating finely divided copper oxide in closed bottles 
in a thermostat they obtained some products which appeared to 
be crystalline,-but could not be shown to be homogeneous by 
microscopic examination. No definite chemical formula was 
indicated except perhaps in the cases where two molecules of 
copper oxide were used with one of copper sulphate, and where 
practically all of the copper sulphate was removed from the 
solution, a composition corresponding nearly to the formula 
3Cu0.SO,.2H,O was found. The authors believe that no more 
basic salt than this can be formed under the conditions of their 
experiments, which were made at 25°, 37°5° and 50° with the 
same results at all the temperatures. In the cases where less 
than 2 molecules of copper oxide were used for one of copper 
sulphate there was only a moderate but gradual change in com- 
position, reaching about 2°3 CuO, SO,.2°4 H,O where + molecule 
of copper oxide was used. Although the authors do not suggest 
it, it appears probable that these are mixtures of two basic 
sulphates and it is to be hoped that they will continue their 


498 Scientific Intelligence. 


investigation using still greater proportions and more concen- 
trated solutions of copper sulphate at similar temperatures. It is 
to be regretted that the authors did not fully analyze the basic 
sulphates that they prepared by simply heating aqueous solutions 
of copper sulphate of widely varying concentration. Their 
results, 66°34, 67°00 amd 68°21 per cent of CuO, although they 
regard the composition as “highly influenced by the concentra- 
tion of the solutions,” show fairly good agreement for a com- 
pound that cannot be recrystallized, and the average corresponds 
closely to the formula 3CuO.SO,.2H,O, which they have suggested 
for another product.—Jour. Amer. Chem. Soc., Xxxviil, 1947. 
H. L. W. 

5. The Determination of Chlorides in Presence of Thiocy- 
anates.—It was shown several years ago by Rosanoff and Hill 
that thiocyanates can be destroyed by suitable treatment with 
nitric acid, leaving chlorides unattacked in a condition suitable 
for determination by Volhard’s volumetric method. F. W. 
BruckMiIt_Er has now shown that this treatment will permit the 
determination of chlorine by the use of silver nitrate and chro- 
mate indicator, particularly in water analysis. His process is as 
follows: The solution containing chlorides and thiocyanates is 
heated to boiling and concentrated nitric acid added drop by 
drop, the amount depending upon the thiocyanate present. If 
present in large quantities the nitric acid is added until the solu- 
tion turns light brown. For small quantities 2 to 3° are sufti- 
cient. The solution is boiled for 15 minutes and filtered if 
sulphur has separated, and after cooling is neutralized with 
normal HNaCO, solution using methyl orange as indicator. A 
little more than enough for neutralization is added, then after 
adding the chromate indicator silver nitrate solution is added to 
the usual end point. It was shown by experiment that there was 
no loss: of chlorine by boiling solutions containing -V15® of 
sodium chloride after adding from 1 to 5° of nitric acid in 
volumes varying from 100 down to 25°. It was shown further 
that hydrocyanic acid was so far removed in the operation as not 
to interfere with the process, and that the titration in the presence 
of the methyl orange was accurate.—Jour. Amer. Chem. Soc., 
XXXVill, 1953. H. L. W. 

6. A New Method of Determining Refractive Indices.— 
Since the usual methods for making accurate determinations of 
refractive indices require special preparation (prismatic form) of 
the specimen to be tested and since it sometimes becomes neces- 
sary to investigate figured objects (lenses) or fragments of 
irregular shape which may not be cut, the new method of general 
applicability recently worked out and tested by R. W. CuxsutrE 
merits attention. It is based on the “Schlierenmethode” of 
Topler. 

The following objects are arranged along a straight line. First 
a source of monochromatic light. Then an opaque screen with a 
vertical straight edge. An achromatic lens (focal length 125°", 


‘ 


Chemistry and Physics. 499 


aperture 8") forms a real image of this screen in front of the 
observing telescope in such a manner as to cover one-half of the 
full aperture (35°) of the objective. The distance between the 
lens and telescope is about 5 meters, and the magnifying power 
of the latter is x 24. Not far from the emergence surface of the 
first lens a specially designed cell is mounted on the prism of a 
Pulfrich refractometer. The cell contains the specimen of glass 
to be studied and a certain solution (vide infra). A second 
opaque screen with a vertical straight edge is mounted in front 
of the observing telescope so that “its plane coincides with the 
plane of the image of the first screen. The planes of both 
screens are at right angles to the common optic axis of the cen- 
tered system of lenses. The second screen is provided with a 
rack and pinion combination which enables the observer to impart 
a slow horizontal motion to the edge and so cause it to gradually 
eclipse the telescope objective. 

The immersion fluid finally selected was an aqueous solution of 
mercury potassium iodide, commonly called Thoulet’s solution. 
The index of refraction for D light of this liquid can be decreased 
continuously from 1°72 to 1°33 by increasing the proportion of 
water. The solution possesses two advantageous properties : 
(a) the excess of water can be driven off by heating, consequently 
the double salt can be used repeatedly, and (b) it does not attack 
the Canada balsam employed in cementing together the walls of 
the cell. On the other hand, the mercury compound exercises 
marked absorption at the more refrangible end of the visible 
spectrum. ‘The curve given in the paper shows that the percent- 
age transmissions for the four lines, C, D, F, and G’, are approxi- 
mately 70, 63, 16, and 2, respectively. Although the temperature 
coefficient of refraction of Thoulet’s solution is very high 
(— 0°0006 per degree C.) the author states that no difficulty is 
experienced on this account. 

The experimental procedure consists essentially in moving the 
screen next the observing telescope slowly across the beam of 
light and noting whether the field of view darkens uniformly. 
When the solid s specimen in the cell has a refractive index differ- 
ent from that of the surrounding liquid the portion of the field of 
view corresponding to the image of the object under investiga- 
tion will not darken simultaneously with the rest of the field. By 
varying the concentration of the liquid a match or balance may 
be quickly obtained and then the index of the liquid (and hence 
of the specimen) is determined at once with the refractometer. 
The accuracy of which this method seems to be susceptible is 
about two units in the fifth decimal place. For example, the 
index for D light for a certain glass prism, having a refracting 
angle of 10°, was found to be 1°51492 by the new method and 
151490 by direct use of the refractometer.— Phil. Mag., xxxii, 
p. 409, Oct., 1916. H. S. U. 

7. Fluorescent Vapors and their Magneto-optie Properties.— 
The theoretical aspect of the beautiful experiments by R. W. 


500 Scientific Intelligence. 


Wood on resonance spectra has been successfully attacked by 
L. SILBERSTEIN. Since the paper requires a fairly large amount 
of elementary mathematics for the adequate exposition of the 
subject, the following non-analytic outline is, in the very nature 
of the case, only suggestive and highly fragmentary. 

A resonator obeying the equation & + ku + N*x = 0 is called 
a Hookean resonator by the author for the obvious reason that 
the restitutive force is assumed to conform to Hooke’s law (force 
= N*x/m). When such an oscillator is acted upon by an external 
force of frequency » it will execute vibrations of the same fre- 
quency 2 but will not perform oscillations of any other frequency. 
Consequently this simple type of resonator cannot be responsible 
for all the lines of oné series in Wood’s resonance spectrum. If, 
on the other hand, the term V*x be replaced by a non-linear 
function of a, an impressed force of frequency V will stimulate 
oscillations of frequency YV together with an infinite number of 
other frequencies. It follows at once that the excitation and 
emission of fluorescent line spectra may be described mathemat- 
ically by writing either x + ka + N’x=ce™ + ce™ + ce + 

.,0rx2+khe + Ne + f(x) =e. The first equation is tan- 
tamount to postulating that the atoms of the radiating vapor 
behave as if each contained a Hookean resonator under the simul- 
taneous action of forces of all the frequencies m, = NV, 7,, 7,, 1.) 
etc. The second equation is an expression of the hypethesis that 
each atom contains an appropriate non-Hookean resonator acted 
upon by ¢,e'/m only. f(x) is some non-linear function of the 
displacement. The equivalence of the two methods of treatment 
is manifest, for the non-Hookean resonator will be the “appro- 
priate” one when, and only when, the supplementary term —/(«) 
ultimately reduces to ¢,e" + ¢,e" +... The first equation is 
best adapted to the study of the properties of each line of the 
spectrum separately, whereas the second form is required only 
when we desire to make a guess concerning the law of succession 
of the lines of the spectrum. So much for the underlying prin- 
ciples of the mathematical investigation. 

By making use of the second equation and assuming the form 
ax? for f(x) Silberstein deduces the solution n,; = WV — j(1 — p)X, 
j = 0, 1,2,3,. . ., whence 62 = (1 —yp)N. This means that the 
lines of the resonance spectrum succeed one another at constant 
Srequency-intervals. When Wood’s wave-lengths for iodine fluo- 
rescence are transformed into numbers proportional to their fre- 
quencies, it is found that the intervals are constant within the 
given limits of experimental error. Hence the theory accords 
with the facts. The values of p for three different series are 
0°9889, 0°9882, and 09881 corresponding respectively to- 
6n = 202°53, 203°61,7and 20538. 

Throughout the rest of the paper the first equation is alone 
employed. The author deduces the following results which are 
especially important for the reasons that none is in contradiction 
with known facts, new phenomena are predicted, and unexplored 


Chemistry and Physics. 501 


fields of investigation are suggested. When the fluorescent vapor 
is placed in a uniform magnetic field and is excited by plane 
polarized light there can be no ordinary Zeeman effect. The 
. fluorescent light will be elliptically polarized in the magnetic field 
and plane polarized in the absence of this field. The eccentricity 
and the orientation of the major-axis of the ellipses will vary 
from line to line of the resonance spectrum. In particular, the 
fundamental line will remain plane polarized while the plane of 
polarization will be rotated around the magnetic field through a 
formulated angle. The theory shows very clearly that the inten- 
sity of the fundamental fluorescent light will decrease and tend 
toward zero as the strength of the magnetic field is augmented. 
This phenomenon has been observed and studied by Wood and 
Ribaud. In these experiments the angle of rotation is predicted 
to be 71°°565 for a field of 30,000 gauss. The possibility of rota- 
tion was not suspected at the time of the experimental research 
and hence numerical data for testing this deduction from the 
general theory are wanting. For further details reference must 
be made to the original article.—PA7il. Mag., xxxii, p. 265, Sept., 
1916. H. S. U. 

8. Problems in Physics for Technical Schools, Colleges, and 
Universities ; by Witr1am D. Henperson. Pp. viii, 205, with 
167 figures. New York, 1916 (McGraw-Hill Book Co.).—These 
exercises are intended to supplement the usual one year’s course 
in general physics and they have been thoroughly tested by the 
author who causes his students to devote one class-hour a week 
wholly to the solution of practical problems bearing upon the 
fundamental principles treated in the lecture room and labora- 
tory. The problems are numerous (1025), they cover the entire 
field of elementary physics, and most of them are original. Each 
set of questions is preceded by a brief statement of the defini- 
tions and fundamental principles involved and a comparatively 
large number of illustrative examples are worked out in the text. 
‘The data involved are modern and conform to the recommenda- 
tions and practice of the United States Bureau of Standards. 
The index is preceded by an appendix containing thirty tables of 
formule and physical constants. Answers to the unsolved prob- 
lems are not given, 

It is difficult for a reviewer, who has not tested the book in 
the class room, to form a just opinion of the merits of the text. 
The following impressions, however, acquired by the present 
writer after having looked over the pages very thoughtfully, may 
merit recording. With few exceptions the remarks introductory 
to each group of problems seem very Incid, concise, and accurate. 
The general plan of the text also seems excellent. With regard 
to minor details, on the other hand, there is room for revision. 
For example, the distinction between the scientific meaning of the 
terms “fluid” and “liquid” is not made clear. In the tables no 
attention has been paid to percentage accuracy. Thus we find 
(on page 193): ‘¢ Pressure of one atmosphere = 76 cm. mercury = 
SO) tmapmercuryi— - . 0 1,012,634) dynes per ‘em* = .) 2” 


502 Scientific Intelligence. 


Table LX, on coefficients of linear expansion, contains no explicit 
indication of the temperature degree involved. The term bougie 
décimale is consistently written “Bourgie decimale.” Finally, 
the number of typographical errors is quite appreciable. 
H,.8. 0. 

9. General Physics. Third Edition ; by Henry Crew. Pp. 
xiv, 617 ; 441 figures. New York, 1916 (The Macmillan Co.).— 
A careful comparison of the latest edition of this work with the 
first (see vol. xxvi, page 241) shows that the text has been very 
carefully revised. The principal changes are: (i) a more con- 
crete and historical presentation of dynamics with greater promi- 
nence to statics; (ii) a simpler and more unified treatment of 
magnetism and electricity, secured by use of the electron theory; 
(iii) a new chapter on electromagnetism, in which the entire dis- 
cussion is based upon the two great discoveries of Oersted and 
Faraday. The usefulness of the book is enhanced by numerous 
minor additions such as sections on liquid air, diamagnetism, 
atmospheric electricity, photometry, Gaede’s rotary pump, the 
Gnome gasoline engine, etc. We also note that many new refer- 
ences to text-books have been incorporated at the ends of the 
chapters and that the problems are now numbered consecutively 
from 1 to 456. As usual, the author’s style is clear and interest- 
ing, and the text as a whole is polished and elegant. 4H. 8. U. 


II. Grorogy Anp Minerawoey. 


1. Zhe Coal Measures Amphibia of North America; by 
Roy Ler Moopir. Carnegie Institution of Washington, Publi- 
cation No. 238, 1916, x + 222 pp., 26 pls, 43 text figs.—This 
excellent monograph does great credit to its author and to the 
Carnegie Institution. It brings together all that is known of 
Paleozoic amphibians, and describes in detail 88 species in 49 
genera found in the Coal Measures of North America. Linton, 
Ohio, has yielded 50 species ; Mazon Creek, Illinois, 10 ; and the 
Jogeins coal field of Nova Scotia, 18. The author informs us 
that these stegocephalians of the Coal Measures are highly differ- 
entiated and specialized animals of aquatic, terrestrial, and 
arboreal habitats. Specialization is seen in loss of limbs, ribs, 
and ventral armature, and in the acquirement of claws, running 
legs, and a long, expanded propelling tail. In size they range 
from an inch to several feet. ‘“‘No known characters of these 
animals tend to ally them directly with any known group of 
fishes . . . indicating a long antecedent history for the 
amphibian group.” Their origin is probably even pre-Devonian, 
On the other hand, even the modern tailless forms seem to be 
related to Pelion lyelli, which may have been a jumping animal. 
Most of the forms belong to the order Microsauria, “ lizard-like 
animals with a well-developed ventral scutellation” ; they are 


Geology and Mineralogy. 503 


all small forms and the stock died out early in the Permian. Far 
more rare are the branchiosaurians, also small animals, which are 
essentially naked, and are water inhabitants ; they are “ without 
doubt, ancestral to the modern Caudata.” The relatively large 
Femnospondylia are very rare in America, and of the Stereo- 
spondylia, common in the Triassic, there appear to be none 
present. Cc. Ss. 

2. Papers from the Geological Department, Glasgow Univer- 
sity, Volume II, 1915.—There are here fifteen papers reprinted 
from various scientific journals appearing during 1915, The fol- 
lowing three papers by Professor Gregory are of general interest 
and should be read by American geologists: (1) Suess’s Classi- 
fication of Eurasian Mountains, (2) Deserts, and (3) The Relative 
Distribution of Fiords and Volcanoes. 6.8: 

3. West Virginia Geological Survey, I. C. Wuuitrr, State 
Geologist. Raleigh County and the Western Portions of Mercer 
and Summers Counties ; by Cuarves E. Kress, aided by D. D. 
Trxnts, Jr. Pp. xx, 778; 31 pls., 10 figs., and a separate case of 
geologic and topographic maps of the entire area in two sheets.— 
This is another of the important detailed County reports issued 
by the West Virginia Survey. Raleigh County is very rich in 
coal and is believed to contain the greatest thickness of coal beds 
in one mountain (1750 ft. in height, near Dorothy) in the Appa- 
lachian field. The area described embraces the great New River 
and Pocahontas smokeless coal districts, while western Raleigh 
holds immense deposits of Kanawha Splint and gas coals. 

Part IV of the volume contains a paper (pp. 663 to 734 and 
plate xxxi) by Wm. ArmstronG Pricx on the paleontology of 
Raleigh, Wyoming, McDowell and adjacent counties. The 
price of the Report with case of maps, including soil report and 
map, is $2.50. Extra copies of geologic maps, 75 cents each, and 
of topographic maps, 50 cents each. 

Included with this Report is a folded plate, 40x6 inches, show- 
ing the names, number and intervals separating the Coal Beds of 
West Virginia, and extending from the top of the Dunkard 
Series to the base of the Pottsville Series, on the scale of 1 inch 
to 200 feet. This has been compiled and revised to June 2, 1916, 
by Ray V. Hennen, Assistant Geologist. Price, 25 cents. 

4. Papers on Coal and the Coal Industry.—Illinois Geological 
Survey. Engineering Experiment Station University of Illinois. 
U.S. Bureau of Mines. Bulletin 3. Chemical Study of Illinois 
Coals; by 8S. W. Parr. Pp. 86; 1 pl., 10 figs., 28 tables. Bulle- 
tin 15. Coal Resources of District VI; by Girpert H. Cany: 
Field work by R. D. Wurrxr, Frxep. H. Kay, and others. Pp. 
94; 7 pls., 25 figs., 13 tables. 

Virginia Geological Survey. THomas L. Watson, ‘Director. 
Bulletin No. XII. The Coal Resources of the Clintwood and 
Bucu Quadrangles, Virginia; by Henry Hryps. Pp. vii, 206; 
11 pls., 21 figs. 

Canada, Department of Mines, Mines Branch; Eucrne 


504 Scientific Intelligence. 


Haanet, Director. An investigation of the Coals of Canada, 
with reference to their Economic Qualities. Extra Volume. 
Weathering of Coal; by J. B. Porrer, assisted by 8. L. Brunton, 
and others. Pp. xii, 194, 6 pls., 65 figs. Ottawa, 1915. 

The Coal Industry of Colorado; by Ratpo W. Saumway. 
Colorado School of Mines Quarterly, vol. ii, No. 2, pp. 26-32. 

“The Cost of Coal” is the title of an important paper of 
especial interest at the present time by George Otis Smith and 
C. E. Lesher of the U. 8. Geological Survey, read before the 
faa oe Mining Congress at Chicago on November 14. 

Notes on Radiolarian Cherts in Oregon: a Correction ; 
tye Warren D. Sura (communicated).—In the recent notes on 
“Radiolarian Cherts,” published on pp. 299, 300 of the October 
number, Cretaceous in the first paragraph should read Jura 
Trias (2) Dr. Diller submitted his specimens to Dr. Hinde in 
the british Museum, who recognized imperfect casts of radiolaria, 
and, as I understand, it was he who assigned these rocks to that 
age. I believe that I found some more determinable specimens, 
and my information merely confirms and amplifies that published 
by Dr. Diller. 

New Mineral names ; by W. E. Forp (communicated— 
continued from pp. 566-570, June, 1916).— 

Creedite. E. S. Larsen and R. C. Wells, Nat. Ac. Se., ii 
360, 1916.—In grains and poorly developed prismatic crystals. 
Probably monoclinic. Nearly colorless. H.= 3:5. G. = 2°73. 
Perfect cleavage parallel to the elongation of the crystals and 
bisecting the obtuse angle of the prism. Cleavage fragments 
show parallel extinction with the emergence of an optical axis 
nearly normal to the cleavage plane. Sections cut in the pris- 
matic zone at right angles to the cleayage show extinction angles 
of 41° and the emergence of the bisectrix Y, with irregular twin- 
ning. Refractive indices, a = 1461,, B=1478, y= 1°485 ; 
2Vx,(meas.)=64° 22’. Comp.—CaSO,.2CaF,.2A1(F.0OH),.2H,0. 
Fusible with intumescence to a white enamel, giving the calcium 
flame. Slowly but completely soluble in acids. Found at a flu- 
orite-barite vein near Wagon Wheel Gap, Colorado. Intimately 
associated with a dull white kaolinite and barite. Named from 
the Creed Quadrangle in which it is found. 

Hibbenite. A. H. Phillips, this oes xlii, 276, 1916.— 
Orthorhombic. Tabular parallel to a(100). @:6:¢=0°589 :1 
0-488. Forms present, a(100), 6(010), (120), pill), d(i01). 
Cleavage parallel to the three pinacoids. G.= 3°21. H. = 3°75. 
Birefringence weak. Optically —. Comp.—2Zn,(PO,),.Zn(OH),. 
61/2 H,O. Easily fusible. Decrepitates in the closed tube, 
yielding water. Found with spencerite at Hudson Bay Mine at 
Salmo, B. C. Named after Pres. Hibben of Princeton. 

Leifite. O. B. Béggild, (Medd. om Gronland, li, 429, 1915). 
A silicate from Greenland with the composition Na, Al,Si,O,,.2NaF. 
. A complete description of this mineral has not as yet been ayail- 
able. 


—= 


Miscellaneous Intelligence. 505 


Margarosanite. W. E. Ford and W. M. Bradley, this Jour- 
nal, xlii, 159, 1916.—Probably triclinic. In rhombic-shaped 
cleavage plates, with angles of 102° and 78°. Extinction angles 
on cleavage plates of 44°, and 54° with the outlines of plates 
(secondary cleavage directions). Colorless and transparent with 
a pearly luster. H. = 2°5-3. G, = 3:99. Comp.—Pb(Ca, Mn), 
(SiO,),. Fuses easily and quietly in the reducing flame to an 
opaque glass. Found at Franklin, N. J. Named from Greek 
words meaning, pearly and tabular. 

Spencerite. A. H. Phillips, this Journal, xlii, 275, 1916.— 
In radiating and reticulated crystals. Color white with pearly 
luster on a good cleavage. G.=3:12. H.=2°7. Comp.— 
Zu,(PO,), Zn(OH), .8H,O. Decrepitates in the closed tube, yield- 
ing water. Found at the Hudson Bay Mine, Salmo, B. C. 

Sulphatice Cancrinite. E. 8. Larsen and George Steiger, 
this Journal, xlii, 332, 1916.—A cancerinite with nearly one-half 
the CO, replaced by SO,. Differs from cancrinite by having 
lower refractive indices and birefringence. w = 1°509, «= 1500. 
Found in an altered rock (uncompahgrite) on Beaver Creek, a 
branch of Cebolla Creek, Gunnison Co., Col. 


III Muscetuanrous Sorentiric INTELLIGENCE. 


1. Centennial Celebration of the United States Coast and 
Geodetic Survey; E. Lester Jones. Superintendent. April 5 
and 6, 1916. Washington, D. C. Pp. 196; 45 figs.—The one 
hundredth anniversary of the United States Coast Survey was 
celebrated in Washington on April 5th and 6th. The event was 
a memorable one and it is well that the occasion should be per- 
manently commemorated in the present volume. It is remarkable 
that, so early in the history of this country, those in charge of 
the Government should have had the foresight to lay the founda- 
tions for an organization so essential to the welfare of the nation, 
so useful in its different lines of work, and so broad and thorough 
in scope. 

There were three public sessions on the days noted, presided 
over by the Superintendent, also a banquet at which some two 
hundred and fifty gentlemen were present. The addresses are 
given in this volume in full, and in addition to those from the 
President and the Secretary of Commerce, others also of general 
interest were delivered, notably by members of allied scientific 
institutions connected with the Government, which have profited 
by the work of the Survey. An interesting series of portraits of 
the gentlemen who have served as superintendents, from the time 
of Dr. Ferdinand Rudolf Hassler in 1816, is likewise included. 

The work which has been and is being accomplished was 
presented to the eye by the extensive exhibit in the National 
Museum. This displayed “the various types of instruments used 


506 Scientific Intelligence. 


in the operations of the Survey, ranging from historic examples 
of apparatus designed and used by Hassler and Bache to the 
latest forms employed at the present day. Notable features were 
astronomical, geodetic, tidal, topographic, and hydrographic 
apparatus which owe their origin to the Survey and were con- 
structed in its workshops. The manifold experiences of the field 
parties of the Bureau under the various conditions encountered in 
the field of operations, extending from the Arctic Ocean to the 
southern limits of the Philippine Archipelago, were illustrated by 
prints from photographs made in the field. The progress of the 
developments that has marked the improvements in . surveying 
results between 1816 and 1916 was graphically shown by com- 
parison of field sheets and by published charts from various 
periods.” : 

2. National Academy of Sciences.—The autumn meeting of 
the Academy was held on November 13, 14, and 15, in the new 
buildings of the Massachusetts Institute of Technology in Cam- 
bridge. The meeting was presided over by the President, Dr. 
William H. Welch, and was largely attended. Besides the many 
papers presented (in part by title only} there were some sixty inter- 
esting exhibits open on Monday afternoon and evening, each per- 
sonally explained by the exhibitor. The members of the Academy 
were entertained on Monday evening by President and Mrs. Mac- 
laurin of the Massachusetts Institute of Technology and Presi- 
dent and Mrs. Lowell of Harvard University. The general Acad- 
emy dinner was held on Tuesday evening, and on Wednesday 
evening the American Academy of Arts and Sciences held a 
special meeting, when the Rumford medal was presented to 
Charles G. Abbot, for his researches on Solar Radiation. 

The titles of papers presented are as follows: 


Raymond PEARL: Some effects of the continued administration of alcohol 
to the domestic fowl, with special reference to the progeny. 

Epwarp S. Morse: Protoconch of Solemya. 

ALFRED G. Mayer: Further studies of nerve conduction. 

E, G. Conxuin: The share of egg and sperm in heredity. 

JACQUES Lors: Diffusion and secretion. 

L. B. Menpet and S. E. Jorpan: Some interrelations between diet, growth, 
and the chemical composition of the body. 

ALESSANDRO FapsrRi: Micro-cinematographs of marine and freshwater 
organisms. 

Henry L. Appot: Hydrology of the Isthmus of Panama. 

JOHN M. Cuarke: The strand and the undertow. 

W. LinpeGren: Notes on the deposition of quartz, chalcedony, and opal. 

W. M. Davis: Sublacustrine glacial erosion in Montana. 

Epwin H. Hatt: Electric conduction in metals. 

Epwarp B. Rosa: The silver voltameter as an international standard. 

R. W. Woop: One-dimensional gases and the reflection of molecules. 
Series in resonance spectra. 

Exrav Txomson: Inferences concerning auroras. 

A. A. Micuetson: Report of progress in experiments for measuring the 
rigidity of the earth. The laws of elastico-viscous flow. 

C. G. Apgor: On the preservation of knowledge. 


Miscellaneous Intelligence. 507 


Frawz Boas: Further evidence regarding the instability of human types. 

Ross G. Harrison: Transplantation of limbs. 

Cuas. B. Davenport: Heredity of stature. 

F¥. R. Mouzton: On analytic functions of infinitely many variables. 

Henry S. Ware, F. N. Cour and Lovuisn D. Cummines : Enumeration of 
all triad systems on fifteen elements. 

Wixziam BE, Story: Some variable 3-term scales of relation. 

CHartes P. OLtvinr: The meteor system of Pons-Winnecke’s comet. 139 
parabolic orbits of meteor streams. 

A. G. Wesster: Practical tests of a new phonotrope. 

Hpw. L. Nicnous: New data on the phosphorescence of certain sulphides. 

G. P. Baxter and H. W. STARKWeEATHER: A revision of the atomic 
weight of tin. 

T. W. Ricwarps and H. 8. Davis: Improvements in calorimetric combus- 
tion. 

T. W. Ricwarps and C. Wapsworts, 3d: Further study of the atomic 
weight of lead of radioactive origin. 

GiLBert N. Lewis: Chemical Affinity. 

Wm. TRELEASE: The American oaks. 

H. 8. Jennines: The numerical results of diverse systems of breeding, 
with relation to two pairs of factors. linked or independent. 

W. R. Mites: Some psycho-physiological processes as affected by alcohol. 

WA.terR B, Cannon: Oscillatory variations in the contraction of rhythmi- 
cally stimulated muscles. 

Wm. H. Datu: On some anomalies in the distribution of Pacific coast 
mollusca. 

G. H. Parker: The responses of hydroids to gravity. 

W. M. Wuereter: The phylogenetic development of subapterous and 
apterous castes in the Formicide. 

W. J. Croztmr: On cell penetration by acids: the chloracetic acids. On 
the immunity coloration of some nudibranches. 

HovreL JoRDAN: The rheotropism of the marine fish known as ‘‘ hamlet” 
or ‘‘ grouper” (Hpenephalus striatus). 

A. C. Watton: The occurrence of Ascaris triquetra, Schrank, in dogs. 


The sessions of Monday evening and Tuesday afternoon were 
devoted to a meeting of the National Research Council with the 
National Academy. The following addresses were made: 

W. H. Wetcu: The formation of the National Research Council at the 
request of the President of the United States. 

S. W. Srratton: Target practice in the Navy and some of the research 
problems involved; illustrated with moving pictures. 

GxrorGe Hh, Hae, Chairman of the National Research Council. The work 


of the National Research Council; Recent observations of organized science 
in England and France. 


Lirur. Cou. GrorcE O. Seurer: Scientific research for national defense, 
as illustrated by the problems of aviation. 


Artuur A. Noyrs: The nitrogen problem in war and in agriculture. 


3. Lhe American Association for the Advancement of Science. 
—The American Association for the Advancement of Science, 
and more than thirty national scientific societies affiliated with it, 
will meet in New York City during the last week of December, 
1916, under the auspices of Columbia University, New York 
University, the College of the City of New York, the American 
Museum of Natural History and the other scientific and educa- 
tional institutions of the city. Dr. Charles R. Van Hise, presi- 
dent of the University of Wisconsin, will preside; the address of 
the retiring president will be given by Dr. W. W. Campbell, 

Am. Jour. Soe CUTE SERIES, Vou. XLII, No. 252.—Dxrcrempmr, 1916. 


508 Scientific Intelligence. 


director of the Lick Observatory. The executive committee of the 
general local committee consists of Henry F.Osborn, chairman, J.J. 
Stevenson, M. I. Papin, Charles Baskerville, N. L. Britton, Simon 
Flexner, EK. B. Wilson and J. McKeen Cattell, secretary. Dr. R. 
S. Woodward, president of the Carnegie Institution of Washing- 
ton, is treasurer of the Association, and Dr. L. O. Howard, of the 
Smithsonian Institution, is the permanent secretary. This is the 
sixty-ninth meeting of the American Association, which was 
established in 1848; it is, further, the first of the greater con- 
vocation week meetings, to be held hereafter once in four years, 
successively in New York, Chicago and Washington. When the 
association last met in New York ten years ago, there were about 
5,000 members, the attendance was over 2,000 and there were 
nearly 1,000 papers on the programs; the membership of the 
association at present numbers over 10,000; the coming meeting 
may, therefore, be expected to be large and interesting. 

4, Publications of the Carnegie Institution of Washington.— 
Recent publications of the Carnegie Institution are noted in the 
following list (continued from p. 305, March, and p. 378, April, 
1916): 

Ne. 34, American Fossil Cycads. Volume II. Taxonomy; 
by G. R. Wietanp. 4to. Pp. vil, 277; 58 pls. 96 figs. A 
notice of this important work will appear in a later number. 

No. 74. The Vulgate Version of the Arthurian Romances ; 
edited from manuscripts in the British Museum by H. Oskar 
Sommer. Index of names and places to volumes I-VII. 4to. 
press 

No. 151. A Sylow Factor Table of the First Twelve Thou- 
sand Numbers giving the possible number of Sylow sub-groups 
of a group of given order between the limits of 0 and 12000; by 
Henry W. Sracer. Pp. xii, 120. 

No. 202. A Concordance to the Works of Horace ; compiled 
and edited by Lanz Coorrer. Pp. ix, 593. 

No. 215 B. History of Manufactures in the United States 
1607-1860; by Victor 8. CrarK. With an Introductory Note 
by Henry W. Farnam. Pp. xii, 675, 7 pls. 

No. 220. Guide to the Materials for American History in 
Swiss and Austrian Archives ; by Atpert B. Faust. Pp. x, 299. 

No. 237. Six-linked Inheritance in Drosophila; by T. H. 
Morean and C. B. Briners. Pp. 87, 2 pls., tables and tigures. 

No. 238. The Coal Measures Amphibia of North America, by 
Roy L. Moopiz. Pp. x, 222, 26 pls., 43 text-figs. See p. 502. 

No. 240. The Jukes in1915; by Arruur H. EstaBroox. 4to. 
Pp., vil, 85. 

No. 241. Studies of Inheritance in Guinea-Pigs and Rats; by 
W. E. Caste and Srewatt Wricur. Pp. iv, 192; 7 pls. 

No. 242. Plant Succession: An Analysis of the Development 
of Vegetation ; by Freprric EK. CLements. Pp. xiii, 512. 

No. 243. Gonadectomy in relation to the secondary sexual 
characters of some domestic Birds; by H. D. Goopaue. Pp. 52 ; 
7 pis. 


Miscellaneous Intelligence. 509 


The Carnegie Institution has also undertaken the republication 
of the leading Classics of International Law, under the editorship 
of Dr. James Brown Scott. Sufficient reason for this undertak- 
ing is found in the difficulty of obtaining texts in convenient 
form for scientific study; of the earlier works, for example, few 
are to be found in the libraries of this country. Further than 
this, some of the most important works have never been translated 
into English, being only accessible in the Latin texts. 

The following works have been recently issued: 

Le Droit des Gens ou Principes de la Loi Naturelle. Appliqués 
A la conduite et aux affaires des Nations et des Souverains; par M. 
DE VatrEeL. With an Introduction by ALBERT DE LAPRADELLE. 

Volume I. Reproduction of Books I and II of Edition of 
1758. Pp. lv, XXVI, 541; with a portrait of Vattell. 

Volume II. Reproduction of Books III and IV of Edition of 
WBye Ppssia: 

Volume III. Translation of the Edition of 1758 ; by Cuartus 
G. Fenwick. With an Introduction by ALBERT DE LaPRADELLE. 
Pp. lix, 398. 

De Jure Naturae et Gentium Dissertationes; by SamurL 
Racnet. Volume I. A reproduction of the text of 1676, with 
Introduction by Lupwie von Bar, and list of errata. Pp. 335. 
Volume IJ. A Translation of the text ; by Joan Pawrny Bate; 
with index of authors cited. Pp. 233. 


OBITUARY. 


PROFESSOR CLEVELAND ABBE, the distinguished meteorologist, 
died at his home in Chevy Chase, near Washington, on October 
28, in his seventy-eighth year. His early work was largely in 
astronomy and it was when Director of the Observatory at Oin- 
cinnati in 1870 that he was invited by Chief Signal Officer Gen. 
A. J. Myer to come to Washington and undertake the work of 
weather prediction in this country. The system of weather fore- 
casting then established through his efforts not only grew to have 
a broad, scientific basis in this country but was adopted from 
here by many other civilized countries. He was also an active 
student of problems relating to meteorological subjects, and his 
contributions to this department of science were many and 
important. 

Dr. Percitvart Lowe 1, Director of the Lowell Observatory at 
Flagstaff, Arizona, died on November 12 in his sixty-first year. 
Born in Boston, of a distinguished family, he brought to his life’s 
work as an astronomer rare intellectual gifts, keenness of observa- 
tion, a vivid imagination and great industry. His investigations 
of Mars, as also of some of the other planets, led to conclusions 
which excited great interest and won him recognition by many 
astronomical and learned societies, but sober science has generally 
held that some of these conclusions were based more upon imagi- 
nation than upon actual fact. 

Proressor Pizrrre Dunem, the eminent French writer on 
mathematical physics, died at Cabrespine on September 14. 


INDEX TO VOLUME XLII.* 


A 


Academy, National, meeting at Bos- 


ton, 506. 
Accumulator, lead, Féry, 366. 
Amber, Burmese, insectsin,Cockerell, 
135. 


Andrews, E. C., geological history | 


of Australian flowering plants, 171. 
Arctowski, H., pleionian cycle of 
climatic fluctuations, 27. 
Arnold, J. L., Physics, 4386. 
Association, American, meeting at 
New York, 507. 
Auditory sense, Marage, 435. 
Australian plants, geological history, 
Andrews, 171. 


B 
Baltic Provinces, geology of, 437. 


Barus, C., rotation of interference | =. 


fringes, 63; spectrum interferom- 
etry. 403. 

Bassler, H., Cycadophyte from North 
American Coal Measures, 21. 

Berry, E. W., Upper Cretaceous 
floras, 81; fossil nutmeg from Texas, 
241. 

Birds of North America, Ridgway, 
86. 

Blackwelder, E., geologic réle of 
phosphorus, 285. 

Blake, J. M., plotting crystal zones 
on paper, 486. 

Blaney, D., Pleistocene lecality on 
Mt. Desert Island, 399. 


BOTANY. 


Plant Anatomy, Stevens, 284. 
— Culture, Goff, 284. 
See also GEOLOGY. 


Bradley, W. M., hydrozincite, 59; 


margarosanite, 159. 

British Museum catalogues, 87. 

Brooklyn Institute, bulletin, 87, 509. 

Brown, G. V., selensulphur from 
Hawaii, 132. 

Browning, P. E., detection and sep- 
aration of tellurium, arsenic, etc., 
106; separation of cesium, etc., 
279 ; electrolysis, etc., of gallium, 


389. 


| Burling, L. D., Albertella fauna, 469 


| Burton, E. F., Physical Properties 
of Colloidal Solutions, 79. 
Cc 
| California, Tejon Eocene, Dickerson, 
80. 
Canada, Department of Mines, 84., 
| — geol. survey, 84. 
| Carnegie Foundation, annual report, 
88; bulletin IX, 169. 
— Institution, publications, 508. 
Chamberlain, J. S., Organic Agri- 
cultural Chemistry, 165. 
|Chamberlin, T. C., Origin of the 
| Earth, 167, 371. 
Chemistry, Analytical, Treadwell and 
| Hall, 74. 
— Industrial, Thorp and Lewis, 165. 
of Metabolism, Problems, von 
Firth and Smith, 442. 
— Organic Agricultural, Chamberlain, 
| niGo: 
| — Physical. Lewis, 75. 


| 


| — Physiological, Hawk, 76. 


|— Progress for 1915, Annual Report, 
166. 


CHEMISTRY. 


Aluminium, determination, Blum, 
432. 

Ammonia, new method for estimat- 
ing, Foxwell, 74. 

Arsenate, lead-chlor, McDonnell and 
Smith, 139. 

Cesium, ete., separation, Browning 
and Spencer, 279. 

Calcium tartrate, crystallization, 
Chattaway, 497. 

Chlorides in presence of thiocya- 
nates, 498. 

Cobalt, new volumetric method, 
Engle and Gustavson, 481. 

Copper sulphate, basic, Young and 
Stearn, 497. 

Fluorine, Gautier and Clausmann, 
364. 

— in soluble fiuorvides, Dinwiddie, 
464. 

Gallium, electrolysis, ete., Brown- 
ing and Uhler, 389. 


* This Index contains the general heads, BoTANY, CHEMISTRY, GEOLOGY, MINERALS, 
OBITUARY; under each the titles of Articles referring thereto are included. 


INDEX. 


CHEMISTRY—cont. 


Germanium in zine materials, Bu- 
chanan, 430. 

Hydrofiuoric and fluosilicie acids, 
Dinwiddie, 421. 

Hydrogen, ionization, 
76. 

Iodine, action of light upon, Bor- 
dier, 496. 

Lithium, separation from 
sium, ete., Palkin, 496. 

Metals, common, qualitative separa- 
tion, Clarens, 364. 

—solution in ferric 
Name and Hill, 301. 

Nitrogen, modification, Strutt, 368. 

Silicon, thermo-chemistry, Mixter, 
125. 

Sulphur, sulphide, estimation, Dru- 
shel and Elston, 155. 

Tellurium, arsenic, etc., detection 
and separation, Browning, ef al., 
106. 

Thorium, separation from 
Thornton, 151. 

Tin, arsenic and antimony, separa- 
tion, Welch and Weber, 74. 

Vanadie acid, estimation, Edgar, 
360. 

Vanadium, separation of, Turner, 
109 

Cleland, H. F., Geology, 282. 

Climatic fluctuations, pleionian cy- 
cle of, Arvctowski, 27. 

Coal and Coal Industry, 508. 

Coast Survey, United States, centen- 

nial celebration, 505. 

Cockerell, T. D. A., insects in Bur- 

mese amber, 135. 

Colloidal Solutions, Burton, 79. 

Color Vision, theory, Houstoun, 433. 

Continental fracturing, Oceanica, 
Schuchert, 91. 

Crew, H., Physics, 50. 

Crystal optics, use of graduated 

sphere, Warren, 493. 

— zones, plotting, Blake, 486. 


Dempster, 


potas- 


salts, Van 


iron, 


D 


Dale, T. N., Algonkian Cambrian 
boundary in Vermont. 120. 

Dall, W. H., Bivaive Mollusks of the 
west coast of America, 439. 

Darton, N. H., geology of Luna 
County, New Mexico, 82. 

Dinwiddie, J. G., hydrofluoric and 
fluosilicie acids, 421; fluorine in 
soluble fluorides, 464. 

Drushel, W. A., sulphide sulphur, 
155. 

Duff, A. W., Physics, 487. 


511 


E 


Earth, Origin, Chamberlin, 167, 371. 

Earthquake Investigation Commit- 
tee, Japanese, 84, 

Eaton, G. F., Osteological Material 
from Machu Picchu, 86, 281. 

Bacar ion Board, General, report, 
8S . 

— Public, in Maryland, 88. 

Electricity, Pidduck, 79. 

— Hmission from Hot Bodies, Rich- 
ardson, 369. 

Elston, C. M., sulphide sulphur, 
155. 

Emerald deposits of Muzo, Colombia, 
Pogue, 85. 

Emerson, B. K., Mineralogical 
notes, 233. 

Emery, W. B., igneous geology of 
Carrizo Mountain, Arizona, 349. 


F 


Florida, discovery of fossil human 
remains, Sellards, 1. 

Florissant beds, Coleoptera from, 81. 

Ford, W. E., hydrozincite, 59; mar- 
garosanite, 159; new mineral names, 
504. 

Fringes, interference, rotation, 

Barus, 63. ; 


G 


Gaskell, W. H., Involuntary Nervy- 
ous System, 87. 

Geodes of the Keokuk beds, 
Tuyl, 34. 


Van 


GEOLOGICAL REPORTS. 
Canada, 84. 
Mllinois, 503. 
United States, 440. 
Virginia, 82. 
West Virginia, 503. 
Wisconsin, 83. ; 
Geology, Cleland, 282. 


GEOLOGY. 


Albertella fauna, Burling, 469. 

Algonkian Cambrian boundary in 
Vermont, Dale, 120. 

Amphibia, Coal Measures of North 
America, Moodie, 502. 

Berea formation of Ohio, ete., Ver- 
wiebe, 48. : 

Brachiopoda, Permian, of Armenia, 
Stoyanow, 439. 

Cambrian geology, Walcott, 439. 

—and Pvye-Cambrian formations 
Montana, Walcott, 572. 


512 


GEOLOGY—cont. 


Carrizo Mountain, Arizona, igneous 
geology, Emery, 349. 

Chapman sandstone of Maine, 
fauna, Williams, 169. 

Cherts, radiolarian, in Oregon, 
Smith, 299, 504. 

Chilopods and trilobites, ancestry, 
Tothill, 373. 

Coleoptera, new, from the Florissant 
beds, Wickham, 81. 

Continental fracturing in Oceanica, 
Schuchert, 91. 

Cretaceous, Upper, floras of the 
world, Berry, 81. ; 

Cycadophyte from North American 
Coal Measures, Bassler, 21. 

Cyprinid fish, British Columbia, 
Hussakof, 18. 

Devonian faunas of MacKenzie 
River Valley, Kindle, 246. 

Dolomite, origin, Van Tuyl, 249. 

Kehinoidea of the Buda limestone, 
Whitney, 440. 
Eocene, Lower, floras of southeast- 
ern North America, Berry, 438. 
Fauna of Chapman sandstone of 
Maine, Williams, 169. 

Flora, Liassic, of the Mixteca Alta, 
Wieland, 370. 

Floras, Upper Cretaceous, of the 
World, Berry, 81. 

Fossil fuels, interrelations, Steven- 
son, 439. 

—human remains, discovery in 
Florida, Sellards, 1. 

Insects in Burmese amber, Cockerell, 
135. 


Keokuk beds, geodes of, Van Tuy], | 


34. 

Lava eruption of Stromboli, 1915, 
Perret, 443. 

Mollusks, Bivalve, of the Nortuest 
Coast of America, Dall, 439. 

Nutmeg, fossil, from Texas, Berry, 
241, 

Ordovician strata of the Baltic 
basin, Raymond, 437. 

— Upper, formations in Canada, 
Foerste, 438. 


Osteological material from Machu | 


Picchu, Eaton, 86. 


Plants, Australian flowering, geo- | 


logical history, Andrews, 171. 


Pleistocene locality, Mt. Desert | 


Island, Blaney and Loomis, 399. 
Pliohippus lullianus, Troxell, 335. 
Pre-Cambrian nomenclature, 

Schuchert, 475. 
Pseudorthoceras knoxense, Girty, 

387. 


INDEX. 


Silurian strata of Esthonia, Russia, 
Twenhofel, 437. 
Tejon Hocene of California, Dicker- 
son, 80. 
Tertiary faunal horizons of Wash- 
ington, Weaver, 81. 
Totem americana, Sellards, 
30 
Tortoise, new, Sellards, 285. 
Trilobites, Cambrian, Walcett, 439. 
Tumularia, Paleozoic alcyonarian, 
Robinson, 162. 
Voleanie domes in the Pacific, 
Powers, 261. 
Giltner, W., microbiology, 87. 
Girty, G. H. ., apical end of Pseud- 
orthoceras knoxense, 387. 
Glasgow University, geological pub- 
lications, 503. 
Goff, E. S., Plant Culture, 284. 


H 


Hall, W. T., Chemistry, 74. 

Hawaii, selensulphur, Brown, 132. 

Hawk, P. B., Physiological Chem- 
istry, 7 

Henao ton W. D., Physics, 500. 

Hill, D. W., solution of metals in 
ferric salts, 301. 

Horse, early Pliocene one-toed, 
Troxell, 335. 

Houstoun, R. A., Theory of Color. 
Vision, 433. 

Human remains, fossil, discovery in 
Florida, Sellards, 1. 

Hussakof, L., new Cyprinid fish 
from British Columbia, 18. 


I 


Ichikawa, S., Japanese minerals, 111. 

India, Board of Scientific Advice, 284. 

Indices, refractive, new method of 
determining, 498. 

Insects, ancestry of, Tothill, 373. 


| Insurance and Annuities for Teach- 


ers, Pritchett, 169. 

Ions, recombination by X-rays, Jaun- 
cey, 146. 

Isostasy and the planetesimal theory, 
Chamberlin, 371. 


J 
Japan, minerals from, Ichikawa, 111. 
Japanese Earthquake Commission, 


Jauncey, G. E. M., effect of mag- 
netic field on recombination of ions 
by X rays, 146. 

Jointing, a factor in degradation of 
lithosphere, Ehrenfeld, 168. 


INDEX. 


K 


Kindle, E. M., Devonian faunas of 
the MacKenzie River Valley, 246. 


L 


Larsen, E. S., sulphatic cancrinite 
from Colorado, 3382. 

Lewis, W. C. McC., Physical Chem- 
istry, 70. 

Lewis, W. K., Industrial Chemistry, 
165. 

Loomis, F. B., Pleistocene locality 
on Mt. Desert Island, 399. 


M 


Magnesium, single-line radiation, 
McLennan, ‘78. 

Magnetic field, effect on recombina- 
tion of ions produced by X-rays, 
Jauncey, 146. 

Maryland Educational Survey Com- 
mission, report, 88. 

McDonnell, C. C., lead-chlor arsen- 
ate, 139. 

Merrill, G. P., catalogue of meteor- 
ites in U. S. Nat. Museum, 2838. 

Meteorites, Catalogue of, in U. S. 
National Museum, 283. 

Mexico, Liassic Flora, Wieland, 370. 

Microbiology, Giltner, 87. 

Mineralogic Notes, Schaller, 85. 

Minerals, opaque, determination, 
Murdoch, 85. 


MINERALS 


Anhydrite, 233. 
Japan, 117. 
Calcite, Japan, 113. Czancrinite, sul- 
phatic, Colorado, 332, 505. Cle- 
veite, Norway, 365. Cordierite, 
Japan, 115. Creedite, Colorado, 

504. 

Diabantite, 233. 

Emeralds, Colombia, 85. 

Galena, Japan, 111. 

Hibbenite, British Columbia, 275, 
004. Hydrozincite, 59. 

Leifite, Greenland, 504. Limonite 
pseudomorph, 233. 

Margarosanite, New Jersey, 159, 
505. Mimetite, artificial, 139. 

Natrolite, British Columbia, 472. 

Pinite, Japan, 115. 

Selensulphur from Hawaii, com- 
position, Brown, 132. Spencer- 
ite, British Columbia, 275, 505. 

Mines, Canada, Department of, 84. 
— United States, Bureau of, publica- 
cations, 83. 


Arsenic, native, 


5138 


Mining World Index, Vol. VIII, 90. 

Mixter, W. G., thermochemistry of 
silicon, 120. 

Moodie, R. L., Coal Measures am- 
phibia of North America, 502. 

Mt. Desert Island, Pleistocene local- 
ity, Blaney and Loomis, 399. 

Mulliken, S. P., Identification of 
Organic Compounds, 166, 

Murdoch, J., determination of opaque 
minerals, 85. 


N 


Napier Tercentenary Volume, Knott, 
89. 

Nervous System, Involuntary, Gas- 
kell, 87. 

New Mexico, Luna County, Geol- 
ogy, Darton, 82. 

Nomenclature, pre-Cambrian, Schu- 
chert, 475. 


OBITUARY 


Abbe, Cleveland, 509. 
Duhem, P., 509. 
Galitzin, Prince B., 372. 
Jungfleisch, E., 90. 
Lignier, O., 90. 
Lowell, P., 509. 
Metehnikoff, E., 170. 
Prosser, C. S., 372. 
Ramsay, Sir W., 170. 
Royce, J., 372. 
Schwalbe, G., 372. 
Schwarzschild, K., 372, 
Thompson, S. P., 90. 
Oceanica, continental] fracturing and 
diastrophism, Schuchert, 91. 
Ohio, Berea formation, Verwiebe, 43. 
Oregon, radiolarian cherts, Smith, 
299, 504. 
Organic Compounds, Identification, 
Mulliken, 166. 
Osteological Material from Machu 
Picchu, Eaton, 86, 281. 
Ozone, Vosmaer, 482. 


P 


Pacific, volcanic domes in, Powers, 
261. 

Pennsylvania, oil and gas map, 1915, 
84. 

Perret, F. A., lava eruption of Strom- 
boli, 1915, 443. 

Peru, osteological material 
Machu Picchu, Haton, 86, 281. 

Phillips, A. H:, new zinc phosphates 
from British Columbia, 275; new 
forms of natrolite, 472. 

Phosphorus, geologic role, Black- 
welder, 285. 


from 


514 


Physics, General, Crew, 501. 

— Problems in, Henderson, 500. 

— Technical, Arnold, 487. 

— Textbook, Duff, 436. 

Pidduck, F. B., Electricity, 79. 

Pogue, J. E., emerald deposits of 
Muzo, Colombia, 85. 

Porter, L., detection and separation 
of tellurium, arsenic, etc., 106. 

Powers, S., volcanic domes in the 
Pacific, 261. 


R 


Radio-lead, density, from cleveite, 
Richards and Wadsworth, 365. 

Richardson, O. W., Emission of 
Electricity from Hot Bodies, 369. 

pee ile R., Birds of No. America, 
8 


Robinson, W. I., Paleozoic Aleyona- 
rian Tumularia, 162. 

Rocks, Igneous, of Carrizo Mountain, 
Arizona, Emery, 349. 

Russell, E. J., Soils and Manures, 
283. 


S) 


Schaller, W. T., mineralogic notes, 
85. 

Schuchert, C., continental fracturing 
and diastrophism in Oceanica, 91 ; 
pre-Cambrian nomenclature, 475. 

Sellards, E. H., fossil human re- 
mains, discovery in Florida, 1 ; new 
tortoise from Florida, 235. 


Simpson, G. S., detection and 
separation of tellurium, arsenic, 
etc., 106. 


Smith, A. J., Chemistry of Metabol- 
ism, translation, 442. 

Smith, C. M., lead-chlor arsenate, 
139. 

Smith, W. D., radiolarian cherts in 
Oregon, 299, 504. 
Soils and Manures, Russell, 283. 
Spectra, rotation of 
fringes, Barus, 63. 
Spectrum interferometry, Barus, 
403. 

— lines, structure of broadened, Mer- 
ton, 77. 

Spencer, S. R., separation of cesium, 
ete., 279. 

Steiger, G., sulphatic 
from Colorado, 352. 
Stevens, W. C., Plant Anatomy, 

284. 
Stromboli, lava eruption, 1915, Per- 
ret, 443. 


cancrinite 


interference 


INDEX, 


T 


Bap acd Py of silicon, Mixter, 

25. 

Thornton, W. M. Jr., separation of 
thorium from iron, 151. 

Thorp, F. H., Industrial Chemistry, 
165. 

Too, J. D., ancestry of insects, 

Treadwell, F. P., Analytical Chem- 
istry, 74. 

Trilobites, ancestry, Tothill, 373. 

Troxell, E. L., early Pliocene one- 
toed horse, 335. 

Turner, W. A., separation of vana- 
dium, 109. 


U 


Uhler, H. S., electrolysis etc., of 

gallium, 389, : 

United States Bureau of Mines, 83. 

— Coast Survey, Centennial celebra- 
tion, 505. 

— Geol. Survey, 440. 


V 


Van Name, R.G., solution of metals 
in ferric salts, 301. 

Van Tuyl, F. M., geodes of the 
Keokuk beds, 34; origin of dolo- 
mite, 249. 

Vapors, fluorescent. Silberstein, 499. 

Verwiebe, W. A., Berea formation 
of Ohio, ete., 43. 

Virginia, geol. survey, 82. 

Volcanoes, domes in the Pacific, Pow- 
ers, 261; lava eruption of Strom- 
boli, 1915, Perret, 443. 

Von Fiirth, O., Chemistry of Metab- 
olism, 442, 

Vosmaer, A., Ozone, 432. 


w 


Walcott, C. D., Cambrian forma- 
tions of Montana, 372; Cambrian 
Trilobites, 459. 

Walker Museum, Contributions, 82. 

Warren, C. H., sphere for crystal 
optics problems, 493. 

Washington, Eocene and _ post- 
EKocene formutions, Weaver, 81. 

West Virginia Geol. Survey, 508. 

Wieland, G. R., Flora Liasica de la 
Mixteca Alta, 370. 

Williams, H. S., fauna of Chapman 
Sandstone of Maine, 169. 

Wisconsin, physical geography, 83. 


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GONTENTS, 


Sia 
& * 
Page 
Arr. XLIV.—The Lava Eruption of Stromboli, Summer-— 
Autumn, 1915); by, As PRRBET Os eae. Se ee 
XLV.—Determination of Fluorine in Soluble Fluorides; by 
JG; Din wiopiny 26: ° * staat Sie So eee 464, 


XLVI.—The Albertella Fauna Located in the Middle 
Cambrian of British Columbia and Alberta; by L. D. 
BURLING 2 2 oo Sh CaP ee eke A 


XLVII.—Some New Forms of Natrolite; by A. H. Puirurrs 472 
XLVIIJ.—On Pre-Cambrian Nomenclature; by C. Scaucunrr 475 
XLIX.—Plotting Crystal Zones on Paper; by J. M. Braker. 486 


L.—A Graduated Sphere for the Solution of Problems in 
Crystal Optics; ‘by C. H. WARREN. <-22_ 2355. -2 aes 493 


SCIENTIFIC INTELLIGENCE, 


Chemistry and Physics—Separation of Lithium from Potassium and Sodium, 
S. Parkin: Action of Light upon Iodine and Iodide of Starch, M. H. 
Borvier, 496.—Crystallization of Calcium Tartrate, F. D, Coatraway: 
Basic Copper Sulphates, S$. W. Youne and A, E. Strarn, 497.—Determi- 
nation of Chlorides in Presence of Thiocyanates, F. W. BRucKMILLER: 
New Method of Determining Refractive Indices, R. W. Cumsnire, 498.— 
Fluorescent Vapors and their Magneto-optic Properties, 499.—Problems in 
Physics for Technical Schools, Colleges, and Universities, W. D, HrenpER- 
son, 501.—General Physics, Third Edition, H. Crew, 502. 


Geology and Mineralogy—Coal Measures Amphibia of North.America, R. L. 
Moonie, 502.—Papers from the Geological Department, Glasgow Univer- 
sity: West Virginia Geological Survey, I. C. Wuite: Papers on Coal and 
the Coal Industry, 503.—Notes on Radiolarian Cherts in Oregon: a Correc- 
tion: New Mineral names, W. E. Forp, 504. 


Miscellaneous Scientific Intelligence—Centennial Celebration of the United 
States Coast and Geodetic Survey, H. L. Jonzs, 505.—National Academy 
of Sciences, 506.—American Association for the Advancement of Science, 
507.—Publications of the Carnegie Institution of Washington, 508. 


Obituary—C. ABBE: P, LowEuu: P. Dugem, 509. 


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